[v5,5/5] firmware: imx: adds miscdev

Commit Message

Pankaj Gupta July 12, 2024, 6:20 a.m. UTC

Adds the driver for communication interface to secure-enclave,
for exchanging messages with NXP secure enclave HW IP(s) like
EdgeLock Enclave from:
- User-Space Applications via character driver.

ABI documentation for the NXP secure-enclave driver.

User-space library using this driver:
- i.MX Secure Enclave library:
  -- URL: https://github.com/nxp-imx/imx-secure-enclave.git,
- i.MX Secure Middle-Ware:
  -- URL: https://github.com/nxp-imx/imx-smw.git

Signed-off-by: Pankaj Gupta <[e-mail]>
---
 Documentation/ABI/testing/se-cdev |  43 +++
 drivers/firmware/imx/ele_common.c | 192 ++++++++++-
 drivers/firmware/imx/ele_common.h |   4 +
 drivers/firmware/imx/se_ctrl.c    | 697 ++++++++++++++++++++++++++++++++++++++
 drivers/firmware/imx/se_ctrl.h    |  49 +++
 include/uapi/linux/se_ioctl.h     |  94 +++++
 6 files changed, 1076 insertions(+), 3 deletions(-)

Comments

Frank Li July 12, 2024, 10:19 p.m. UTC | #1

On Fri, Jul 12, 2024 at 11:50:00AM +0530, Pankaj Gupta wrote:
> Adds the driver for communication interface to secure-enclave,
> for exchanging messages with NXP secure enclave HW IP(s) like
> EdgeLock Enclave from:
> - User-Space Applications via character driver.
> 
> ABI documentation for the NXP secure-enclave driver.
> 
> User-space library using this driver:
> - i.MX Secure Enclave library:
>   -- URL: https://github.com/nxp-imx/imx-secure-enclave.git,
> - i.MX Secure Middle-Ware:
>   -- URL: https://github.com/nxp-imx/imx-smw.git
> 
> Signed-off-by: Pankaj Gupta <[e-mail]>
> ---
>  Documentation/ABI/testing/se-cdev |  43 +++
>  drivers/firmware/imx/ele_common.c | 192 ++++++++++-
>  drivers/firmware/imx/ele_common.h |   4 +
>  drivers/firmware/imx/se_ctrl.c    | 697 ++++++++++++++++++++++++++++++++++++++
>  drivers/firmware/imx/se_ctrl.h    |  49 +++
>  include/uapi/linux/se_ioctl.h     |  94 +++++
>  6 files changed, 1076 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/se-cdev b/Documentation/ABI/testing/se-cdev
> new file mode 100644
> index 000000000000..3451c909ccc4
> --- /dev/null
> +++ b/Documentation/ABI/testing/se-cdev
> @@ -0,0 +1,43 @@
> +What:		/dev/<se>_mu[0-9]+_ch[0-9]+
> +Date:		May 2024
> +KernelVersion:	6.8
> +Contact:	[e-mail], [e-mail]
> +Description:
> +		NXP offers multiple hardware IP(s) for secure enclaves like EdgeLock-
> +		Enclave(ELE), SECO. The character device file descriptors
> +		/dev/<se>_mu*_ch* are the interface between userspace NXP's secure-
> +		enclave shared library and the kernel driver.
> +
> +		The ioctl(2)-based ABI is defined and documented in
> +		[include]<linux/firmware/imx/ele_mu_ioctl.h>.
> +		ioctl(s) are used primarily for:
> +			- shared memory management
> +			- allocation of I/O buffers
> +			- getting mu info
> +			- setting a dev-ctx as receiver to receive all the commands from FW
> +			- getting SoC info
> +			- send command and receive command response
> +
> +		The following file operations are supported:
> +
> +		open(2)
> +		  Currently the only useful flags are O_RDWR.
> +
> +		read(2)
> +		  Every read() from the opened character device context is waiting on
> +		  wait_event_interruptible, that gets set by the registered mailbox callback
> +		  function, indicating a message received from the firmware on message-
> +		  unit.
> +
> +		write(2)
> +		  Every write() to the opened character device context needs to acquire
> +		  mailbox_lock before sending message on to the message unit.
> +
> +		close(2)
> +		  Stops and frees up the I/O contexts that were associated
> +		  with the file descriptor.
> +
> +Users:		https://github.com/nxp-imx/imx-secure-enclave.git,
> +		https://github.com/nxp-imx/imx-smw.git
> +		crypto/skcipher,
> +		drivers/nvmem/imx-ocotp-ele.c
> diff --git a/drivers/firmware/imx/ele_common.c b/drivers/firmware/imx/ele_common.c
> index b2be32550e9b..88169cd8f369 100644
> --- a/drivers/firmware/imx/ele_common.c
> +++ b/drivers/firmware/imx/ele_common.c
> @@ -78,6 +78,149 @@ int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg)
>  	return err;
>  }
>  
> +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> +			void *rx_buf,
> +			int rx_buf_sz)
> +{
> +	struct se_msg_hdr *header;
> +	int err;
> +
> +	err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
> +	if (err) {
> +		dev_err(dev_ctx->dev,
> +			"%s: Err[0x%x]:Interrupted by signal.\n",
> +			dev_ctx->miscdev.name, err);
> +		goto exit;
> +	}
> +
> +	header = (struct se_msg_hdr *) dev_ctx->temp_resp;
> +
> +	if (header->tag == dev_ctx->priv->rsp_tag) {
> +		if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv->waiting_rsp_dev != dev_ctx) {
> +			dev_warn(dev_ctx->dev,
> +			"Dev-ctx waiting for response mismatch (%s != %s).\n",
> +			dev_ctx->miscdev.name, dev_ctx->priv->waiting_rsp_dev->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +	}
> +
> +	dev_dbg(dev_ctx->dev,
> +		"%s: %s %s\n",
> +		dev_ctx->miscdev.name,
> +		__func__,
> +		"message received, start transmit to user");
> +
> +	/*
> +	 * Check that the size passed as argument is larger than
> +	 * the one carried in the message.
> +	 *
> +	 * In case of US-command/response, the dev_ctx->temp_resp_size
> +	 * is set before sending the command.
> +	 *
> +	 * In case of NVM Slave-command/response, the dev_ctx->temp_resp_size
> +	 * is set after receing the message from mailbox.
> +	 */
> +	if (dev_ctx->temp_resp_size > rx_buf_sz) {
> +		dev_err(dev_ctx->dev,
> +			"%s: User buffer too small (%d < %d)\n",
> +			dev_ctx->miscdev.name,
> +			rx_buf_sz, dev_ctx->temp_resp_size);
> +		 dev_ctx->temp_resp_size = rx_buf_sz;
> +	}
> +
> +	/* We may need to copy the output data to user before
> +	 * delivering the completion message.
> +	 */
> +	err = se_dev_ctx_cpy_out_data(dev_ctx, true);
> +	if (err < 0)
> +		goto exit;
> +
> +	/* Copy data from the buffer */
> +	print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
> +			     dev_ctx->temp_resp, dev_ctx->temp_resp_size, false);
> +	if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx->temp_resp_size)) {
> +		dev_err(dev_ctx->dev,
> +			"%s: Failed to copy to user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	err = dev_ctx->temp_resp_size;
> +exit:
> +	if (err < 0)
> +		se_dev_ctx_cpy_out_data(dev_ctx, false);
> +
> +	/* free memory allocated on the shared buffers. */
> +	dev_ctx->secure_mem.pos = 0;
> +	dev_ctx->non_secure_mem.pos = 0;
> +
> +	dev_ctx->pending_hdr = 0;
> +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> +
> +	return err;
> +}
> +
> +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> +			 void *tx_msg, int tx_msg_sz)
> +{
> +	struct se_if_priv *priv = dev_ctx->priv;
> +	struct se_msg_hdr *header;
> +	u32 size_to_send;
> +	int err;
> +
> +	header = (struct se_msg_hdr *) tx_msg;
> +
> +	/*
> +	 * Check that the size passed as argument matches the size
> +	 * carried in the message.
> +	 */
> +	size_to_send = header->size << 2;
> +
> +	if (size_to_send != tx_msg_sz) {
> +		err = -EINVAL;
> +		dev_err(priv->dev,
> +			"%s: User buf hdr(0x%x) sz mismatced with input-sz (%d != %d).\n",
> +			dev_ctx->miscdev.name, *(u32 *)header, size_to_send, tx_msg_sz);
> +		goto exit;
> +	}
> +
> +	/* Check the message is valid according to tags */
> +	if (header->tag == priv->rsp_tag) {
> +		/* Check the device context can send the command */
> +		if (dev_ctx != priv->cmd_receiver_dev) {
> +			dev_err(priv->dev,
> +				"%s: Channel not configured to send resp to FW.",
> +				dev_ctx->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +	} else if (header->tag == priv->cmd_tag) {
> +		if (priv->waiting_rsp_dev != dev_ctx) {
> +			dev_err(priv->dev,
> +				"%s: Channel not configured to send cmd to FW.",
> +				dev_ctx->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +		lockdep_assert_held(&priv->se_if_cmd_lock);
> +	} else {
> +		dev_err(priv->dev,
> +			"%s: The message does not have a valid TAG\n",
> +			dev_ctx->miscdev.name);
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +	err = ele_msg_send(priv, tx_msg);
> +	if (err < 0)
> +		goto exit;
> +
> +	err = size_to_send;
> +exit:
> +	return err;
> +}
> +
>  static bool exception_for_size(struct se_if_priv *priv,
>  				struct se_msg_hdr *header)
>  {
> @@ -99,6 +242,7 @@ static bool exception_for_size(struct se_if_priv *priv,
>  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>  {
>  	struct device *dev = mbox_cl->dev;
> +	struct se_if_device_ctx *dev_ctx;
>  	struct se_if_priv *priv;
>  	struct se_msg_hdr *header;
>  	u32 rx_msg_sz;
> @@ -114,8 +258,50 @@ void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>  	header = msg;
>  	rx_msg_sz = header->size << 2;
>  
> -	if (header->tag == priv->rsp_tag) {
> -		if (!priv->waiting_rsp_dev) {
> +	/* Incoming command: wake up the receiver if any. */
> +	if (header->tag == priv->cmd_tag) {
> +		dev_dbg(dev, "Selecting cmd receiver\n");
> +		dev_ctx = priv->cmd_receiver_dev;
> +		/* Pre-allocated buffer of MAX_NVM_MSG_LEN
> +		 * as the NVM command are initiated by FW.
> +		 * Size is revealed as part of this call function.
> +		 */
> +		if (rx_msg_sz > MAX_NVM_MSG_LEN) {
> +			dev_err(dev,
> +				"%s: Msg recvd hdr(0x%x) with greater[%d] than allocated buf-sz.\n",
> +				dev_ctx->miscdev.name,
> +				*(u32 *) header,
> +				rx_msg_sz);
> +		} else
> +			memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> +
> +		/* NVM buffer size are not known prior receiving it from FW.
> +		 */
> +		dev_ctx->temp_resp_size = rx_msg_sz;
> +
> +		/* Allow user to read */
> +		dev_ctx->pending_hdr = 1;
> +		wake_up_interruptible(&dev_ctx->wq);
> +
> +		return;
> +	} else if (header->tag == priv->rsp_tag) {
> +		if (priv->waiting_rsp_dev) {
> +			dev_dbg(dev, "Selecting rsp waiter\n");
> +			dev_ctx = priv->waiting_rsp_dev;
> +			if (rx_msg_sz != dev_ctx->temp_resp_size
> +				&& !exception_for_size(priv, header))
> +				dev_err(dev,
> +					"%s: Msg RSP hdr(0x%x) with different sz(%d != %d).\n",
> +					dev_ctx->miscdev.name,
> +					*(u32 *) header,
> +					rx_msg_sz, dev_ctx->temp_resp_size);
> +			else
> +				memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> +
> +			/* Allow user to read */
> +			dev_ctx->pending_hdr = 1;
> +			wake_up_interruptible(&dev_ctx->wq);
> +		} else {
>  			/*
>  			 * Reading the EdgeLock Enclave response
>  			 * to the command, sent by other
> @@ -132,8 +318,8 @@ void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>  
>  			complete(&priv->done);
>  			spin_unlock(&priv->lock);
> -			return;
>  		}
> +		return;
>  	}
>  
>  	dev_err(dev, "Failed to select a device for message: %.8x\n",
> diff --git a/drivers/firmware/imx/ele_common.h b/drivers/firmware/imx/ele_common.h
> index 5ef775a42ab3..7b1c6bfc138b 100644
> --- a/drivers/firmware/imx/ele_common.h
> +++ b/drivers/firmware/imx/ele_common.h
> @@ -17,6 +17,10 @@ uint32_t se_add_msg_crc(uint32_t *msg, uint32_t msg_len);
>  int ele_msg_rcv(struct se_if_priv *priv);
>  int ele_msg_send(struct se_if_priv *priv, void *tx_msg);
>  int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
> +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> +			void *rx_msg, int rx_msg_sz);
> +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> +			 void *tx_msg, int tx_msg_sz);
>  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);
>  int se_val_rsp_hdr_n_status(struct se_if_priv *priv,
>  			    struct se_msg_hdr *header,
> diff --git a/drivers/firmware/imx/se_ctrl.c b/drivers/firmware/imx/se_ctrl.c
> index a844794d2b39..8fb2af0f0dd3 100644
> --- a/drivers/firmware/imx/se_ctrl.c
> +++ b/drivers/firmware/imx/se_ctrl.c
> @@ -23,6 +23,7 @@
>  #include <linux/slab.h>
>  #include <linux/string.h>
>  #include <linux/sys_soc.h>
> +#include <uapi/linux/se_ioctl.h>
>  
>  #include "ele_base_msg.h"
>  #include "ele_common.h"
> @@ -196,6 +197,608 @@ static int se_soc_info(struct se_if_priv *priv,
>  	return 0;
>  }
>  
> +static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx *dev_ctx,
> +					    u64 arg)
> +{
> +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> +	struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
> +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> +	struct se_api_msg *rx_msg __free(kfree) = NULL;
> +	int err = 0;
> +
> +	if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
> +			   sizeof(cmd_snd_rcv_rsp_info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: User buffer too small(%d < %d)\n",
> +			dev_ctx->miscdev.name,
> +			cmd_snd_rcv_rsp_info.tx_buf_sz,
> +			SE_MU_HDR_SZ);
> +		err = -ENOSPC;
> +		goto exit;
> +	}
> +
> +	rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
> +	if (!rx_msg) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
> +			     cmd_snd_rcv_rsp_info.tx_buf_sz);
> +	if (IS_ERR(tx_msg)) {
> +		err = PTR_ERR(tx_msg);
> +		goto exit;
> +	}
> +
> +	if (tx_msg->header.tag != priv->cmd_tag) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	scoped_guard(mutex, &priv->se_if_cmd_lock);

You totally wrong use scoped_guard in whole patch.

fun()
{
     guard(); //which means lock here
     ...
     return; // unlock here
}

scoped_guard()
{     // lock here
      ...
      //unlock here
}

your code scoped_guard(mutex, &priv->se_if_cmd_lock);
is equal to
 
      mutex_lock();
      mutex_unlock();

Nothing protected by mutex lock at all.

Frank Li
 

> +	priv->waiting_rsp_dev = dev_ctx;
> +	dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
> +
> +	/* Device Context that is assigned to be a
> +	 * FW's command receiver, has pre-allocated buffer.
> +	 */
> +	if (dev_ctx != priv->cmd_receiver_dev)
> +		dev_ctx->temp_resp = rx_msg;
> +
> +	err = ele_miscdev_msg_send(dev_ctx,
> +				   tx_msg,
> +				   cmd_snd_rcv_rsp_info.tx_buf_sz);
> +	if (err < 0)
> +		goto exit;
> +
> +	cmd_snd_rcv_rsp_info.tx_buf_sz = err;
> +
> +	err = ele_miscdev_msg_rcv(dev_ctx,
> +				  cmd_snd_rcv_rsp_info.rx_buf,
> +				  cmd_snd_rcv_rsp_info.rx_buf_sz);
> +
> +	if (err < 0)
> +		goto exit;
> +
> +	cmd_snd_rcv_rsp_info.rx_buf_sz = err;
> +
> +exit:
> +	dev_ctx->temp_resp_size = 0;
> +	priv->waiting_rsp_dev = NULL;
> +	if (dev_ctx != priv->cmd_receiver_dev)
> +		dev_ctx->temp_resp = NULL;
> +
> +	if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
> +			 sizeof(cmd_snd_rcv_rsp_info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +	}
> +	return err;
> +}
> +
> +/*
> + * File operations for user-space
> + */
> +
> +/* Write a message to the MU. */
> +static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
> +				size_t size, loff_t *ppos)
> +{
> +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> +	struct se_if_device_ctx *dev_ctx;
> +	struct se_if_priv *priv;
> +	int err;
> +
> +	dev_ctx = container_of(fp->private_data,
> +			       struct se_if_device_ctx,
> +			       miscdev);
> +	priv = dev_ctx->priv;
> +	dev_dbg(priv->dev,
> +		"%s: write from buf (%p)%zu, ppos=%lld\n",
> +			dev_ctx->miscdev.name,
> +			buf, size, ((ppos) ? *ppos : 0));
> +
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	if (size < SE_MU_HDR_SZ) {
> +		dev_err(priv->dev,
> +			"%s: User buffer too small(%zu < %d)\n",
> +				dev_ctx->miscdev.name,
> +				size, SE_MU_HDR_SZ);
> +		err = -ENOSPC;
> +		goto exit;
> +	}
> +	tx_msg = memdup_user(buf, size);
> +	if (IS_ERR(tx_msg)) {
> +		err = PTR_ERR(tx_msg);
> +		goto exit;
> +	}
> +
> +	print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
> +			     tx_msg, size, false);
> +
> +	err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +/*
> + * Read a message from the MU.
> + * Blocking until a message is available.
> + */
> +static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
> +			       size_t size, loff_t *ppos)
> +{
> +	struct se_if_device_ctx *dev_ctx;
> +	struct se_if_priv *priv;
> +	int err;
> +
> +	dev_ctx = container_of(fp->private_data,
> +			       struct se_if_device_ctx,
> +			       miscdev);
> +	priv = dev_ctx->priv;
> +	dev_dbg(priv->dev,
> +		"%s: read to buf %p(%zu), ppos=%lld\n",
> +			dev_ctx->miscdev.name,
> +			buf, size, ((ppos) ? *ppos : 0));
> +
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
> +				u64 arg)
> +{
> +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> +	struct se_if_node_info *if_node_info;
> +	struct se_ioctl_get_if_info info;
> +	int err = 0;
> +
> +	if_node_info = (struct se_if_node_info *)priv->info;
> +
> +	info.se_if_id = if_node_info->se_if_id;
> +	info.interrupt_idx = 0;
> +	info.tz = 0;
> +	info.did = if_node_info->se_if_did;
> +	info.cmd_tag = if_node_info->cmd_tag;
> +	info.rsp_tag = if_node_info->rsp_tag;
> +	info.success_tag = if_node_info->success_tag;
> +	info.base_api_ver = if_node_info->base_api_ver;
> +	info.fw_api_ver = if_node_info->fw_api_ver;
> +
> +	dev_dbg(priv->dev,
> +		"%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
> +			dev_ctx->miscdev.name,
> +			info.se_if_id, info.interrupt_idx, info.tz, info.did);
> +
> +	if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy mu info to user\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* Need to copy the output data to user-device context.
> + */
> +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy)
> +{
> +	struct se_buf_desc *b_desc, *temp;
> +
> +	list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link) {
> +		if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr && do_cpy) {
> +
> +			dev_dbg(dev_ctx->dev,
> +				"%s: Copy output data to user\n",
> +				dev_ctx->miscdev.name);
> +			if (copy_to_user(b_desc->usr_buf_ptr,
> +					 b_desc->shared_buf_ptr,
> +					 b_desc->size)) {
> +				dev_err(dev_ctx->dev,
> +					"%s: Failure copying output data to user.",
> +					dev_ctx->miscdev.name);
> +				return -EFAULT;
> +			}
> +		}
> +
> +		if (b_desc->shared_buf_ptr)
> +			memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> +
> +		list_del(&b_desc->link);
> +		kfree(b_desc);
> +	}
> +	return 0;
> +}
> +
> +/*
> + * Clean the used Shared Memory space,
> + * whether its Input Data copied from user buffers, or
> + * Data received from FW.
> + */
> +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
> +{
> +	struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
> +						 &dev_ctx->pending_out};
> +	struct se_buf_desc *b_desc, *temp;
> +	int i;
> +
> +	for (i = 0; i < 2; i++) {
> +		list_for_each_entry_safe(b_desc, temp,
> +					 dev_ctx_lists[i], link) {
> +
> +			if (b_desc->shared_buf_ptr)
> +				memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> +
> +			list_del(&b_desc->link);
> +			kfree(b_desc);
> +		}
> +	}
> +}
> +
> +/*
> + * Copy a buffer of data to/from the user and return the address to use in
> + * messages
> + */
> +static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
> +					    u64 arg)
> +{
> +	struct se_shared_mem *shared_mem = NULL;
> +	struct se_ioctl_setup_iobuf io = {0};
> +	struct se_buf_desc *b_desc = NULL;
> +	int err = 0;
> +	u32 pos;
> +
> +	if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed copy iobuf config from user\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	dev_dbg(dev_ctx->priv->dev,
> +			"%s: io [buf: %p(%d) flag: %x]\n",
> +			dev_ctx->miscdev.name,
> +			io.user_buf, io.length, io.flags);
> +
> +	if (io.length == 0 || !io.user_buf) {
> +		/*
> +		 * Accept NULL pointers since some buffers are optional
> +		 * in FW commands. In this case we should return 0 as
> +		 * pointer to be embedded into the message.
> +		 * Skip all data copy part of code below.
> +		 */
> +		io.ele_addr = 0;
> +		goto copy;
> +	}
> +
> +	/* Select the shared memory to be used for this buffer. */
> +	if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
> +		/* App requires to use secure memory for this buffer.*/
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed allocate SEC MEM memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	} else {
> +		/* No specific requirement for this buffer. */
> +		shared_mem = &dev_ctx->non_secure_mem;
> +	}
> +
> +	/* Check there is enough space in the shared memory. */
> +	if (shared_mem->size < shared_mem->pos ||
> +		round_up(io.length, 8u) >= (shared_mem->size - shared_mem->pos)) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Not enough space in shared memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	/* Allocate space in shared memory. 8 bytes aligned. */
> +	pos = shared_mem->pos;
> +	shared_mem->pos += round_up(io.length, 8u);
> +	io.ele_addr = (u64)shared_mem->dma_addr + pos;
> +
> +	if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
> +	    !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
> +		/*Add base address to get full address.*/
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed allocate SEC MEM memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	memset(shared_mem->ptr + pos, 0, io.length);
> +	if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
> +	    (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
> +		/*
> +		 * buffer is input:
> +		 * copy data from user space to this allocated buffer.
> +		 */
> +		if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
> +				   io.length)) {
> +			dev_err(dev_ctx->priv->dev,
> +				"%s: Failed copy data to shared memory\n",
> +				dev_ctx->miscdev.name);
> +			err = -EFAULT;
> +			goto exit;
> +		}
> +	}
> +
> +	b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
> +	if (!b_desc) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +copy:
> +	/* Provide the EdgeLock Enclave address to user space only if success.*/
> +	if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy iobuff setup to user\n",
> +				dev_ctx->miscdev.name);
> +		kfree(b_desc);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	if (b_desc) {
> +		b_desc->shared_buf_ptr = shared_mem->ptr + pos;
> +		b_desc->usr_buf_ptr = io.user_buf;
> +		b_desc->size = io.length;
> +
> +		if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
> +			/*
> +			 * buffer is input:
> +			 * add an entry in the "pending input buffers" list so
> +			 * that copied data can be cleaned from shared memory
> +			 * later.
> +			 */
> +			list_add_tail(&b_desc->link, &dev_ctx->pending_in);
> +		} else {
> +			/*
> +			 * buffer is output:
> +			 * add an entry in the "pending out buffers" list so data
> +			 * can be copied to user space when receiving Secure-Enclave
> +			 * response.
> +			 */
> +			list_add_tail(&b_desc->link, &dev_ctx->pending_out);
> +		}
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* IOCTL to provide SoC information */
> +static int se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx *dev_ctx,
> +					     u64 arg)
> +{
> +	const struct se_if_node_info_list *info_list;
> +	struct se_ioctl_get_soc_info soc_info;
> +	int err = -EINVAL;
> +
> +	info_list = device_get_match_data(dev_ctx->priv->dev);
> +	if (!info_list)
> +		goto exit;
> +
> +	soc_info.soc_id = info_list->soc_id;
> +	soc_info.soc_rev = dev_ctx->priv->soc_rev;
> +
> +	err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
> +	if (err) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy soc info to user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* Open a character device. */
> +static int se_if_fops_open(struct inode *nd, struct file *fp)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	int err = 0;
> +
> +	/* Avoid race if opened at the same time */
> +	if (down_trylock(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	/* Authorize only 1 instance. */
> +	if (dev_ctx->status != SE_IF_CTX_FREE) {
> +		err = -EBUSY;
> +		goto exit;
> +	}
> +
> +	/*
> +	 * Allocate some memory for data exchanges with S40x.
> +	 * This will be used for data not requiring secure memory.
> +	 */
> +	dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
> +					MAX_DATA_SIZE_PER_USER,
> +					&dev_ctx->non_secure_mem.dma_addr,
> +					GFP_KERNEL);
> +	if (!dev_ctx->non_secure_mem.ptr) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
> +	dev_ctx->non_secure_mem.pos = 0;
> +	dev_ctx->status = SE_IF_CTX_OPENED;
> +
> +	dev_ctx->pending_hdr = 0;
> +
> +	goto exit;
> +
> +	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> +			   dev_ctx->non_secure_mem.ptr,
> +			   dev_ctx->non_secure_mem.dma_addr);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +/* Close a character device. */
> +static int se_if_fops_close(struct inode *nd, struct file *fp)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	struct se_if_priv *priv = dev_ctx->priv;
> +
> +	/* Avoid race if closed at the same time */
> +	if (down_trylock(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	/* The device context has not been opened */
> +	if (dev_ctx->status != SE_IF_CTX_OPENED)
> +		goto exit;
> +
> +	/* check if this device was registered as command receiver. */
> +	if (priv->cmd_receiver_dev == dev_ctx) {
> +		priv->cmd_receiver_dev = NULL;
> +		kfree(dev_ctx->temp_resp);
> +	}
> +
> +	/* check if this device was registered as waiting response. */
> +	if (priv->waiting_rsp_dev == dev_ctx) {
> +		priv->waiting_rsp_dev = NULL;
> +		mutex_unlock(&priv->se_if_cmd_lock);
> +	}
> +
> +	/* Unmap secure memory shared buffer. */
> +	if (dev_ctx->secure_mem.ptr)
> +		devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
> +
> +	dev_ctx->secure_mem.ptr = NULL;
> +	dev_ctx->secure_mem.dma_addr = 0;
> +	dev_ctx->secure_mem.size = 0;
> +	dev_ctx->secure_mem.pos = 0;
> +
> +	/* Free non-secure shared buffer. */
> +	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> +			   dev_ctx->non_secure_mem.ptr,
> +			   dev_ctx->non_secure_mem.dma_addr);
> +
> +	dev_ctx->non_secure_mem.ptr = NULL;
> +	dev_ctx->non_secure_mem.dma_addr = 0;
> +	dev_ctx->non_secure_mem.size = 0;
> +	dev_ctx->non_secure_mem.pos = 0;
> +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> +	dev_ctx->status = SE_IF_CTX_FREE;
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return 0;
> +}
> +
> +/* IOCTL entry point of a character device */
> +static long se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	struct se_if_priv *se_if_priv = dev_ctx->priv;
> +	int err = -EINVAL;
> +
> +	/* Prevent race during change of device context */
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	switch (cmd) {
> +	case SE_IOCTL_ENABLE_CMD_RCV:
> +		if (!se_if_priv->cmd_receiver_dev) {
> +			err = 0;
> +			se_if_priv->cmd_receiver_dev = dev_ctx;
> +			dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN, GFP_KERNEL);
> +			if (!dev_ctx->temp_resp)
> +				err = -ENOMEM;
> +		}
> +		break;
> +	case SE_IOCTL_GET_MU_INFO:
> +		err = se_ioctl_get_mu_info(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_SETUP_IOBUF:
> +		err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_GET_SOC_INFO:
> +		err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_CMD_SEND_RCV_RSP:
> +		err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
> +		break;
> +
> +	default:
> +		err = -EINVAL;
> +		dev_dbg(se_if_priv->dev,
> +			"%s: IOCTL %.8x not supported\n",
> +				dev_ctx->miscdev.name,
> +				cmd);
> +	}
> +
> +	up(&dev_ctx->fops_lock);
> +	return (long)err;
> +}
> +
> +/* Char driver setup */
> +static const struct file_operations se_if_fops = {
> +	.open		= se_if_fops_open,
> +	.owner		= THIS_MODULE,
> +	.release	= se_if_fops_close,
> +	.unlocked_ioctl = se_ioctl,
> +	.read		= se_if_fops_read,
> +	.write		= se_if_fops_write,
> +};
> +
> +/* interface for managed res to unregister a character device */
> +static void if_misc_deregister(void *miscdevice)
> +{
> +	misc_deregister(miscdevice);
> +}
> +
>  /* interface for managed res to free a mailbox channel */
>  static void if_mbox_free_channel(void *mbox_chan)
>  {
> @@ -233,6 +836,7 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct se_if_priv *priv;
> +	int i;
>  
>  	priv = dev_get_drvdata(dev);
>  
> @@ -252,6 +856,17 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>  		priv->imem.buf = NULL;
>  	}
>  
> +	if (priv->ctxs) {
> +		for (i = 0; i < priv->max_dev_ctx; i++) {
> +			if (priv->ctxs[i]) {
> +				devm_remove_action(dev,
> +						   if_misc_deregister,
> +						   &priv->ctxs[i]->miscdev);
> +				misc_deregister(&priv->ctxs[i]->miscdev);
> +			}
> +		}
> +	}
> +
>  	/* No need to check, if reserved memory is allocated
>  	 * before calling for its release. Or clearing the
>  	 * un-set bit.
> @@ -259,6 +874,74 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>  	of_reserved_mem_device_release(dev);
>  }
>  
> +static int init_device_context(struct se_if_priv *priv)
> +{
> +	const struct se_if_node_info *info = priv->info;
> +	struct se_if_device_ctx *dev_ctx;
> +	u8 *devname;
> +	int ret = 0;
> +	int i;
> +
> +	priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv->max_dev_ctx,
> +				  GFP_KERNEL);
> +
> +	if (!priv->ctxs) {
> +		ret = -ENOMEM;
> +		return ret;
> +	}
> +
> +	/* Create users */
> +	for (i = 0; i < priv->max_dev_ctx; i++) {
> +		dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx), GFP_KERNEL);
> +		if (!dev_ctx) {
> +			ret = -ENOMEM;
> +			return ret;
> +		}
> +
> +		dev_ctx->dev = priv->dev;
> +		dev_ctx->status = SE_IF_CTX_FREE;
> +		dev_ctx->priv = priv;
> +
> +		priv->ctxs[i] = dev_ctx;
> +
> +		/* Default value invalid for an header. */
> +		init_waitqueue_head(&dev_ctx->wq);
> +
> +		INIT_LIST_HEAD(&dev_ctx->pending_out);
> +		INIT_LIST_HEAD(&dev_ctx->pending_in);
> +		sema_init(&dev_ctx->fops_lock, 1);
> +
> +		devname = devm_kasprintf(priv->dev, GFP_KERNEL, "%s_ch%d",
> +					 info->se_name, i);
> +		if (!devname) {
> +			ret = -ENOMEM;
> +			return ret;
> +		}
> +
> +		dev_ctx->miscdev.name = devname;
> +		dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
> +		dev_ctx->miscdev.fops = &se_if_fops;
> +		dev_ctx->miscdev.parent = priv->dev;
> +		ret = misc_register(&dev_ctx->miscdev);
> +		if (ret) {
> +			dev_err(priv->dev, "failed to register misc device %d\n",
> +				ret);
> +			return ret;
> +		}
> +
> +		ret = devm_add_action(priv->dev, if_misc_deregister,
> +				      &dev_ctx->miscdev);
> +		if (ret) {
> +			dev_err(priv->dev,
> +				"failed[%d] to add action to the misc-dev\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
>  static void se_load_firmware(const struct firmware *fw, void *context)
>  {
>  	struct se_if_priv *priv = (struct se_if_priv *) context;
> @@ -427,6 +1110,16 @@ static int se_if_probe(struct platform_device *pdev)
>  		ret = 0;
>  	}
>  
> +	if (info->max_dev_ctx) {
> +		ret = init_device_context(priv);
> +		if (ret) {
> +			dev_err(dev,
> +				"Failed[0x%x] to create device contexts.\n",
> +				ret);
> +			goto exit;
> +		}
> +	}
> +
>  	dev_info(dev, "i.MX secure-enclave: %s interface to firmware, configured.\n",
>  		 info->se_name);
>  	return ret;
> @@ -467,6 +1160,10 @@ static int se_resume(struct device *dev)
>  {
>  	struct se_if_priv *priv = dev_get_drvdata(dev);
>  	const struct se_if_node_info *info = priv->info;
> +	int i;
> +
> +	for (i = 0; i < priv->max_dev_ctx; i++)
> +		wake_up_interruptible(&priv->ctxs[i]->wq);
>  
>  	if (info && info->imem_mgmt)
>  		se_restore_imem_state(priv);
> diff --git a/drivers/firmware/imx/se_ctrl.h b/drivers/firmware/imx/se_ctrl.h
> index 4be2235d2170..b49346372746 100644
> --- a/drivers/firmware/imx/se_ctrl.h
> +++ b/drivers/firmware/imx/se_ctrl.h
> @@ -13,15 +13,62 @@
>  #define MAX_FW_LOAD_RETRIES		50
>  
>  #define RES_STATUS(x)			FIELD_GET(0x000000ff, x)
> +#define MAX_DATA_SIZE_PER_USER		(65 * 1024)
> +#define MAX_NVM_MSG_LEN			(256)
>  #define MESSAGING_VERSION_6		0x6
>  #define MESSAGING_VERSION_7		0x7
>  
> +#define SE_MU_IO_FLAGS_USE_SEC_MEM	(0x02u)
> +#define SE_MU_IO_FLAGS_USE_SHORT_ADDR	(0x04u)
> +
>  struct se_imem_buf {
>  	u8 *buf;
>  	phys_addr_t phyaddr;
>  	u32 size;
>  };
>  
> +struct se_buf_desc {
> +	u8 *shared_buf_ptr;
> +	u8 *usr_buf_ptr;
> +	u32 size;
> +	struct list_head link;
> +};
> +
> +/* Status of a char device */
> +enum se_if_dev_ctx_status_t {
> +	SE_IF_CTX_FREE,
> +	SE_IF_CTX_OPENED
> +};
> +
> +struct se_shared_mem {
> +	dma_addr_t dma_addr;
> +	u32 size;
> +	u32 pos;
> +	u8 *ptr;
> +};
> +
> +/* Private struct for each char device instance. */
> +struct se_if_device_ctx {
> +	struct device *dev;
> +	struct se_if_priv *priv;
> +	struct miscdevice miscdev;
> +
> +	enum se_if_dev_ctx_status_t status;
> +	wait_queue_head_t wq;
> +	struct semaphore fops_lock;
> +
> +	u32 pending_hdr;
> +	struct list_head pending_in;
> +	struct list_head pending_out;
> +
> +	struct se_shared_mem secure_mem;
> +	struct se_shared_mem non_secure_mem;
> +
> +	struct se_api_msg *temp_resp;
> +	u32 temp_resp_size;
> +	struct notifier_block se_notify;
> +};
> +
>  /* Header of the messages exchange with the EdgeLock Enclave */
>  struct se_msg_hdr {
>  	u8 ver;
> @@ -80,4 +127,6 @@ struct se_if_priv {
>  	struct se_imem_buf imem;
>  };
>  
> +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy);
> +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx);
>  #endif
> diff --git a/include/uapi/linux/se_ioctl.h b/include/uapi/linux/se_ioctl.h
> new file mode 100644
> index 000000000000..c2d0a92ef626
> --- /dev/null
> +++ b/include/uapi/linux/se_ioctl.h
> @@ -0,0 +1,94 @@
> +/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause*/
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#ifndef SE_IOCTL_H
> +#define SE_IOCTL_H
> +
> +/* IOCTL definitions. */
> +
> +struct se_ioctl_setup_iobuf {
> +	u8 *user_buf;
> +	u32 length;
> +	u32 flags;
> +	u64 ele_addr;
> +};
> +
> +struct se_ioctl_shared_mem_cfg {
> +	u32 base_offset;
> +	u32 size;
> +};
> +
> +struct se_ioctl_get_if_info {
> +	u8 se_if_id;
> +	u8 interrupt_idx;
> +	u8 tz;
> +	u8 did;
> +	u8 cmd_tag;
> +	u8 rsp_tag;
> +	u8 success_tag;
> +	u8 base_api_ver;
> +	u8 fw_api_ver;
> +};
> +
> +struct se_ioctl_cmd_snd_rcv_rsp_info {
> +	u32 *tx_buf;
> +	int tx_buf_sz;
> +	u32 *rx_buf;
> +	int rx_buf_sz;
> +};
> +
> +struct se_ioctl_get_soc_info {
> +	u16 soc_id;
> +	u16 soc_rev;
> +};
> +
> +/* IO Buffer Flags */
> +#define SE_IO_BUF_FLAGS_IS_OUTPUT	(0x00u)
> +#define SE_IO_BUF_FLAGS_IS_INPUT	(0x01u)
> +#define SE_IO_BUF_FLAGS_USE_SEC_MEM	(0x02u)
> +#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR	(0x04u)
> +#define SE_IO_BUF_FLAGS_IS_IN_OUT	(0x10u)
> +
> +/* IOCTLS */
> +#define SE_IOCTL			0x0A /* like MISC_MAJOR. */
> +
> +/*
> + * ioctl to designated the current fd as logical-reciever.
> + * This is ioctl is send when the nvm-daemon, a slave to the
> + * firmware is started by the user.
> + */
> +#define SE_IOCTL_ENABLE_CMD_RCV	_IO(SE_IOCTL, 0x01)
> +
> +/*
> + * ioctl to get the buffer allocated from the memory, which is shared
> + * between kernel and FW.
> + * Post allocation, the kernel tagged the allocated memory with:
> + *  Output
> + *  Input
> + *  Input-Output
> + *  Short address
> + *  Secure-memory
> + */
> +#define SE_IOCTL_SETUP_IOBUF	_IOWR(SE_IOCTL, 0x03, \
> +					struct se_ioctl_setup_iobuf)
> +
> +/*
> + * ioctl to get the mu information, that is used to exchange message
> + * with FW, from user-spaced.
> + */
> +#define SE_IOCTL_GET_MU_INFO	_IOR(SE_IOCTL, 0x04, \
> +					struct se_ioctl_get_if_info)
> +/*
> + * ioctl to get SoC Info from user-space.
> + */
> +#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
> +					struct se_ioctl_get_soc_info)
> +
> +/*
> + * ioctl to send command and receive response from user-space.
> + */
> +#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
> +					struct se_ioctl_cmd_snd_rcv_rsp_info)
> +#endif
> 
> -- 
> 2.34.1
>

Amit Singh Tomar July 15, 2024, 7:24 a.m. UTC | #2

On 7/12/2024 11:50 AM, Pankaj Gupta wrote:
> 
> Adds the driver for communication interface to secure-enclave,
> for exchanging messages with NXP secure enclave HW IP(s) like
> EdgeLock Enclave from:
> - User-Space Applications via character driver.
> 
> ABI documentation for the NXP secure-enclave driver.
> 
> User-space library using this driver:
> - i.MX Secure Enclave library:
>     -- URL:https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsecure-2Denclave.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=A4zE7ce-kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsecure-2Denclave.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=A4zE7ce-kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k&e=>,
> - i.MX Secure Middle-Ware:
>     -- URL:https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsmw.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=T2WGFwKVpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsmw.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=T2WGFwKVpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw&e=>
> 
> Signed-off-by: Pankaj Gupta <[e-mail]>
> ---
>    Documentation/ABI/testing/se-cdev |  43 +++
>    drivers/firmware/imx/ele_common.c | 192 ++++++++++-
>    drivers/firmware/imx/ele_common.h |   4 +
>    drivers/firmware/imx/se_ctrl.c    | 697 ++++++++++++++++++++++++++++++++++++++
>    drivers/firmware/imx/se_ctrl.h    |  49 +++
>    include/uapi/linux/se_ioctl.h     |  94 +++++
>    6 files changed, 1076 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/se-cdev b/Documentation/ABI/testing/se-cdev
> new file mode 100644
> index 000000000000..3451c909ccc4
> --- /dev/null
> +++ b/Documentation/ABI/testing/se-cdev
> @@ -0,0 +1,43 @@
> +What:		/dev/<se>_mu[0-9]+_ch[0-9]+
> +Date:		May 2024
> +KernelVersion:	6.8
> +Contact:	[e-mail], [e-mail]
> +Description:
> +		NXP offers multiple hardware IP(s) for secure enclaves like EdgeLock-
> +		Enclave(ELE), SECO. The character device file descriptors
> +		/dev/<se>_mu*_ch* are the interface between userspace NXP's secure-
> +		enclave shared library and the kernel driver.
> +
> +		The ioctl(2)-based ABI is defined and documented in
> +		[include]<linux/firmware/imx/ele_mu_ioctl.h>.
> +		ioctl(s) are used primarily for:
> +			- shared memory management
> +			- allocation of I/O buffers
> +			- getting mu info
> +			- setting a dev-ctx as receiver to receive all the commands from FW
> +			- getting SoC info
> +			- send command and receive command response
> +
> +		The following file operations are supported:
> +
> +		open(2)
> +		  Currently the only useful flags are O_RDWR.
> +
> +		read(2)
> +		  Every read() from the opened character device context is waiting on
> +		  wait_event_interruptible, that gets set by the registered mailbox callback
> +		  function, indicating a message received from the firmware on message-
> +		  unit.
> +
> +		write(2)
> +		  Every write() to the opened character device context needs to acquire
> +		  mailbox_lock before sending message on to the message unit.
> +
> +		close(2)
> +		  Stops and frees up the I/O contexts that were associated
> +		  with the file descriptor.
> +
> +Users:		https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsecure-2Denclave.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=A4zE7ce-kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsecure-2Denclave.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=A4zE7ce-kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k&e=>,
> +		https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsmw.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=T2WGFwKVpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_nxp-2Dimx_imx-2Dsmw.git&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=3B5Yr-4HUlH7ooyxfcf-aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm&s=T2WGFwKVpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw&e=>
> +		crypto/skcipher,
> +		drivers/nvmem/imx-ocotp-ele.c
> diff --git a/drivers/firmware/imx/ele_common.c b/drivers/firmware/imx/ele_common.c
> index b2be32550e9b..88169cd8f369 100644
> --- a/drivers/firmware/imx/ele_common.c
> +++ b/drivers/firmware/imx/ele_common.c
> @@ -78,6 +78,149 @@ int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg)
>    	return err;
>    }
>    
> +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> +			void *rx_buf,
> +			int rx_buf_sz)
> +{
> +	struct se_msg_hdr *header;
> +	int err;
> +
> +	err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
> +	if (err) {
> +		dev_err(dev_ctx->dev,
> +			"%s: Err[0x%x]:Interrupted by signal.\n",
> +			dev_ctx->miscdev.name, err);
> +		goto exit;
> +	}
> +
> +	header = (struct se_msg_hdr *) dev_ctx->temp_resp;
> +
> +	if (header->tag == dev_ctx->priv->rsp_tag) {
> +		if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv->waiting_rsp_dev != dev_ctx) {
> +			dev_warn(dev_ctx->dev,
> +			"Dev-ctx waiting for response mismatch (%s != %s).\n",
> +			dev_ctx->miscdev.name, dev_ctx->priv->waiting_rsp_dev->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +	}
> +
> +	dev_dbg(dev_ctx->dev,
> +		"%s: %s %s\n",
> +		dev_ctx->miscdev.name,
> +		__func__,
> +		"message received, start transmit to user");
> +
> +	/*
> +	 * Check that the size passed as argument is larger than
> +	 * the one carried in the message.
> +	 *
> +	 * In case of US-command/response, the dev_ctx->temp_resp_size
> +	 * is set before sending the command.
> +	 *
> +	 * In case of NVM Slave-command/response, the dev_ctx->temp_resp_size
> +	 * is set after receing the message from mailbox.
> +	 */
> +	if (dev_ctx->temp_resp_size > rx_buf_sz) {
> +		dev_err(dev_ctx->dev,
> +			"%s: User buffer too small (%d < %d)\n",
> +			dev_ctx->miscdev.name,
> +			rx_buf_sz, dev_ctx->temp_resp_size);
> +		 dev_ctx->temp_resp_size = rx_buf_sz;
> +	}
> +
> +	/* We may need to copy the output data to user before
> +	 * delivering the completion message.
> +	 */
> +	err = se_dev_ctx_cpy_out_data(dev_ctx, true);
> +	if (err < 0)
> +		goto exit;
> +
> +	/* Copy data from the buffer */
> +	print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
> +			     dev_ctx->temp_resp, dev_ctx->temp_resp_size, false);
> +	if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx->temp_resp_size)) {
> +		dev_err(dev_ctx->dev,
> +			"%s: Failed to copy to user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	err = dev_ctx->temp_resp_size;
> +exit:
> +	if (err < 0)
> +		se_dev_ctx_cpy_out_data(dev_ctx, false);
> +
> +	/* free memory allocated on the shared buffers. */
> +	dev_ctx->secure_mem.pos = 0;
> +	dev_ctx->non_secure_mem.pos = 0;
> +
> +	dev_ctx->pending_hdr = 0;
> +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> +
> +	return err;
> +}
> +
> +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> +			 void *tx_msg, int tx_msg_sz)
> +{
> +	struct se_if_priv *priv = dev_ctx->priv;
> +	struct se_msg_hdr *header;
> +	u32 size_to_send;
> +	int err;
> +
> +	header = (struct se_msg_hdr *) tx_msg;
> +
> +	/*
> +	 * Check that the size passed as argument matches the size
> +	 * carried in the message.
> +	 */
> +	size_to_send = header->size << 2;
> +
> +	if (size_to_send != tx_msg_sz) {
> +		err = -EINVAL;
> +		dev_err(priv->dev,
> +			"%s: User buf hdr(0x%x) sz mismatced with input-sz (%d != %d).\n",
> +			dev_ctx->miscdev.name, *(u32 *)header, size_to_send, tx_msg_sz);
> +		goto exit;
> +	}
> +
> +	/* Check the message is valid according to tags */
> +	if (header->tag == priv->rsp_tag) {
> +		/* Check the device context can send the command */
> +		if (dev_ctx != priv->cmd_receiver_dev) {
> +			dev_err(priv->dev,
> +				"%s: Channel not configured to send resp to FW.",
> +				dev_ctx->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +	} else if (header->tag == priv->cmd_tag) {
> +		if (priv->waiting_rsp_dev != dev_ctx) {
> +			dev_err(priv->dev,
> +				"%s: Channel not configured to send cmd to FW.",
> +				dev_ctx->miscdev.name);
> +			err = -EPERM;
> +			goto exit;
> +		}
> +		lockdep_assert_held(&priv->se_if_cmd_lock);

nit: Placement of this call is bit unusual (or do have some reason to 
it), it might be better to place it at the beginning of the function.

> +	} else {
> +		dev_err(priv->dev,
> +			"%s: The message does not have a valid TAG\n",
> +			dev_ctx->miscdev.name);
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +	err = ele_msg_send(priv, tx_msg);
> +	if (err < 0)
> +		goto exit;
> +
> +	err = size_to_send;
> +exit:
> +	return err;
> +}
> +
>    static bool exception_for_size(struct se_if_priv *priv,
>    				struct se_msg_hdr *header)
>    {
> @@ -99,6 +242,7 @@ static bool exception_for_size(struct se_if_priv *priv,
>    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>    {
>    	struct device *dev = mbox_cl->dev;
> +	struct se_if_device_ctx *dev_ctx;
>    	struct se_if_priv *priv;
>    	struct se_msg_hdr *header;
>    	u32 rx_msg_sz;
> @@ -114,8 +258,50 @@ void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>    	header = msg;
>    	rx_msg_sz = header->size << 2;
>    
> -	if (header->tag == priv->rsp_tag) {
> -		if (!priv->waiting_rsp_dev) {
> +	/* Incoming command: wake up the receiver if any. */
> +	if (header->tag == priv->cmd_tag) {
> +		dev_dbg(dev, "Selecting cmd receiver\n");
> +		dev_ctx = priv->cmd_receiver_dev;
> +		/* Pre-allocated buffer of MAX_NVM_MSG_LEN
> +		 * as the NVM command are initiated by FW.
> +		 * Size is revealed as part of this call function.
> +		 */
> +		if (rx_msg_sz > MAX_NVM_MSG_LEN) {
> +			dev_err(dev,
> +				"%s: Msg recvd hdr(0x%x) with greater[%d] than allocated buf-sz.\n",
> +				dev_ctx->miscdev.name,
> +				*(u32 *) header,
> +				rx_msg_sz);
> +		} else
> +			memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> +
> +		/* NVM buffer size are not known prior receiving it from FW.
> +		 */
> +		dev_ctx->temp_resp_size = rx_msg_sz;
> +
> +		/* Allow user to read */
> +		dev_ctx->pending_hdr = 1;
> +		wake_up_interruptible(&dev_ctx->wq);
> +
> +		return;
> +	} else if (header->tag == priv->rsp_tag) {
> +		if (priv->waiting_rsp_dev) {
> +			dev_dbg(dev, "Selecting rsp waiter\n");
> +			dev_ctx = priv->waiting_rsp_dev;
> +			if (rx_msg_sz != dev_ctx->temp_resp_size
> +				&& !exception_for_size(priv, header))
> +				dev_err(dev,
> +					"%s: Msg RSP hdr(0x%x) with different sz(%d != %d).\n",
> +					dev_ctx->miscdev.name,
> +					*(u32 *) header,
> +					rx_msg_sz, dev_ctx->temp_resp_size);
> +			else
> +				memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> +
> +			/* Allow user to read */
> +			dev_ctx->pending_hdr = 1;
> +			wake_up_interruptible(&dev_ctx->wq);
> +		} else {
>    			/*
>    			 * Reading the EdgeLock Enclave response
>    			 * to the command, sent by other
> @@ -132,8 +318,8 @@ void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>    
>    			complete(&priv->done);
>    			spin_unlock(&priv->lock);
> -			return;
>    		}
> +		return;
>    	}
>    
>    	dev_err(dev, "Failed to select a device for message: %.8x\n",
> diff --git a/drivers/firmware/imx/ele_common.h b/drivers/firmware/imx/ele_common.h
> index 5ef775a42ab3..7b1c6bfc138b 100644
> --- a/drivers/firmware/imx/ele_common.h
> +++ b/drivers/firmware/imx/ele_common.h
> @@ -17,6 +17,10 @@ uint32_t se_add_msg_crc(uint32_t *msg, uint32_t msg_len);
>    int ele_msg_rcv(struct se_if_priv *priv);
>    int ele_msg_send(struct se_if_priv *priv, void *tx_msg);
>    int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
> +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> +			void *rx_msg, int rx_msg_sz);
> +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> +			 void *tx_msg, int tx_msg_sz);
>    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);
>    int se_val_rsp_hdr_n_status(struct se_if_priv *priv,
>    			    struct se_msg_hdr *header,
> diff --git a/drivers/firmware/imx/se_ctrl.c b/drivers/firmware/imx/se_ctrl.c
> index a844794d2b39..8fb2af0f0dd3 100644
> --- a/drivers/firmware/imx/se_ctrl.c
> +++ b/drivers/firmware/imx/se_ctrl.c
> @@ -23,6 +23,7 @@
>    #include <linux/slab.h>
>    #include <linux/string.h>
>    #include <linux/sys_soc.h>
> +#include <uapi/linux/se_ioctl.h>
>    
>    #include "ele_base_msg.h"
>    #include "ele_common.h"
> @@ -196,6 +197,608 @@ static int se_soc_info(struct se_if_priv *priv,
>    	return 0;
>    }
>    
> +static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx *dev_ctx,
> +					    u64 arg)
> +{
> +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> +	struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
> +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> +	struct se_api_msg *rx_msg __free(kfree) = NULL;
> +	int err = 0;
> +
> +	if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
> +			   sizeof(cmd_snd_rcv_rsp_info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: User buffer too small(%d < %d)\n",
> +			dev_ctx->miscdev.name,
> +			cmd_snd_rcv_rsp_info.tx_buf_sz,
> +			SE_MU_HDR_SZ);
> +		err = -ENOSPC;
> +		goto exit;
> +	}
> +
> +	rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
> +	if (!rx_msg) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
> +			     cmd_snd_rcv_rsp_info.tx_buf_sz);
> +	if (IS_ERR(tx_msg)) {
> +		err = PTR_ERR(tx_msg);
> +		goto exit;
> +	}
> +
> +	if (tx_msg->header.tag != priv->cmd_tag) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	scoped_guard(mutex, &priv->se_if_cmd_lock);
> +	priv->waiting_rsp_dev = dev_ctx;
> +	dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
> +
> +	/* Device Context that is assigned to be a
> +	 * FW's command receiver, has pre-allocated buffer.
> +	 */
> +	if (dev_ctx != priv->cmd_receiver_dev)
> +		dev_ctx->temp_resp = rx_msg;
> +
> +	err = ele_miscdev_msg_send(dev_ctx,
> +				   tx_msg,
> +				   cmd_snd_rcv_rsp_info.tx_buf_sz);
> +	if (err < 0)
> +		goto exit;
> +
> +	cmd_snd_rcv_rsp_info.tx_buf_sz = err;
> +
> +	err = ele_miscdev_msg_rcv(dev_ctx,
> +				  cmd_snd_rcv_rsp_info.rx_buf,
> +				  cmd_snd_rcv_rsp_info.rx_buf_sz);
> +
> +	if (err < 0)
> +		goto exit;
> +
> +	cmd_snd_rcv_rsp_info.rx_buf_sz = err;
> +
> +exit:
> +	dev_ctx->temp_resp_size = 0;
> +	priv->waiting_rsp_dev = NULL;
> +	if (dev_ctx != priv->cmd_receiver_dev)
> +		dev_ctx->temp_resp = NULL;
> +
> +	if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
> +			 sizeof(cmd_snd_rcv_rsp_info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +	}
> +	return err;
> +}
> +
> +/*
> + * File operations for user-space
> + */
> +
> +/* Write a message to the MU. */
> +static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
> +				size_t size, loff_t *ppos)
> +{
> +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> +	struct se_if_device_ctx *dev_ctx;
> +	struct se_if_priv *priv;
> +	int err;
> +
> +	dev_ctx = container_of(fp->private_data,
> +			       struct se_if_device_ctx,
> +			       miscdev);
> +	priv = dev_ctx->priv;
> +	dev_dbg(priv->dev,
> +		"%s: write from buf (%p)%zu, ppos=%lld\n",
> +			dev_ctx->miscdev.name,
> +			buf, size, ((ppos) ? *ppos : 0));
> +
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	if (size < SE_MU_HDR_SZ) {
> +		dev_err(priv->dev,
> +			"%s: User buffer too small(%zu < %d)\n",
> +				dev_ctx->miscdev.name,
> +				size, SE_MU_HDR_SZ);
> +		err = -ENOSPC;
> +		goto exit;
> +	}
> +	tx_msg = memdup_user(buf, size);
> +	if (IS_ERR(tx_msg)) {
> +		err = PTR_ERR(tx_msg);
> +		goto exit;
> +	}
> +
> +	print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
> +			     tx_msg, size, false);
> +
> +	err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +/*
> + * Read a message from the MU.
> + * Blocking until a message is available.
> + */
> +static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
> +			       size_t size, loff_t *ppos)
> +{
> +	struct se_if_device_ctx *dev_ctx;
> +	struct se_if_priv *priv;
> +	int err;
> +
> +	dev_ctx = container_of(fp->private_data,
> +			       struct se_if_device_ctx,
> +			       miscdev);
> +	priv = dev_ctx->priv;
> +	dev_dbg(priv->dev,
> +		"%s: read to buf %p(%zu), ppos=%lld\n",
> +			dev_ctx->miscdev.name,
> +			buf, size, ((ppos) ? *ppos : 0));
> +
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> +		err = -EINVAL;
> +		goto exit;
> +	}
> +
> +	err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
> +				u64 arg)
> +{
> +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> +	struct se_if_node_info *if_node_info;
> +	struct se_ioctl_get_if_info info;
> +	int err = 0;
> +
> +	if_node_info = (struct se_if_node_info *)priv->info;
> +
> +	info.se_if_id = if_node_info->se_if_id;
> +	info.interrupt_idx = 0;
> +	info.tz = 0;
> +	info.did = if_node_info->se_if_did;
> +	info.cmd_tag = if_node_info->cmd_tag;
> +	info.rsp_tag = if_node_info->rsp_tag;
> +	info.success_tag = if_node_info->success_tag;
> +	info.base_api_ver = if_node_info->base_api_ver;
> +	info.fw_api_ver = if_node_info->fw_api_ver;
> +
> +	dev_dbg(priv->dev,
> +		"%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
> +			dev_ctx->miscdev.name,
> +			info.se_if_id, info.interrupt_idx, info.tz, info.did);
> +
> +	if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy mu info to user\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* Need to copy the output data to user-device context.
> + */
> +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy)
> +{
> +	struct se_buf_desc *b_desc, *temp;
> +
> +	list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link) {
> +		if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr && do_cpy) {
> +
> +			dev_dbg(dev_ctx->dev,
> +				"%s: Copy output data to user\n",
> +				dev_ctx->miscdev.name);
> +			if (copy_to_user(b_desc->usr_buf_ptr,
> +					 b_desc->shared_buf_ptr,
> +					 b_desc->size)) {
> +				dev_err(dev_ctx->dev,
> +					"%s: Failure copying output data to user.",
> +					dev_ctx->miscdev.name);
> +				return -EFAULT;
> +			}
> +		}
> +
> +		if (b_desc->shared_buf_ptr)
> +			memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> +
> +		list_del(&b_desc->link);
> +		kfree(b_desc);
> +	}
> +	return 0;
> +}
> +
> +/*
> + * Clean the used Shared Memory space,
> + * whether its Input Data copied from user buffers, or
> + * Data received from FW.
> + */
> +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
> +{
> +	struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
> +						 &dev_ctx->pending_out};
> +	struct se_buf_desc *b_desc, *temp;
> +	int i;
> +
> +	for (i = 0; i < 2; i++) {
> +		list_for_each_entry_safe(b_desc, temp,
> +					 dev_ctx_lists[i], link) {
> +
> +			if (b_desc->shared_buf_ptr)
> +				memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> +
> +			list_del(&b_desc->link);
> +			kfree(b_desc);
> +		}
> +	}
> +}
> +
> +/*
> + * Copy a buffer of data to/from the user and return the address to use in
> + * messages
> + */
> +static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
> +					    u64 arg)
> +{
> +	struct se_shared_mem *shared_mem = NULL;
> +	struct se_ioctl_setup_iobuf io = {0};
> +	struct se_buf_desc *b_desc = NULL;
> +	int err = 0;
> +	u32 pos;
> +
> +	if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed copy iobuf config from user\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	dev_dbg(dev_ctx->priv->dev,
> +			"%s: io [buf: %p(%d) flag: %x]\n",
> +			dev_ctx->miscdev.name,
> +			io.user_buf, io.length, io.flags);
> +
> +	if (io.length == 0 || !io.user_buf) {
> +		/*
> +		 * Accept NULL pointers since some buffers are optional
> +		 * in FW commands. In this case we should return 0 as
> +		 * pointer to be embedded into the message.
> +		 * Skip all data copy part of code below.
> +		 */
> +		io.ele_addr = 0;
> +		goto copy;
> +	}
> +
> +	/* Select the shared memory to be used for this buffer. */
> +	if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
> +		/* App requires to use secure memory for this buffer.*/
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed allocate SEC MEM memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	} else {
> +		/* No specific requirement for this buffer. */
> +		shared_mem = &dev_ctx->non_secure_mem;
> +	}
> +
> +	/* Check there is enough space in the shared memory. */
> +	if (shared_mem->size < shared_mem->pos ||
> +		round_up(io.length, 8u) >= (shared_mem->size - shared_mem->pos)) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Not enough space in shared memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	/* Allocate space in shared memory. 8 bytes aligned. */
> +	pos = shared_mem->pos;
> +	shared_mem->pos += round_up(io.length, 8u);
> +	io.ele_addr = (u64)shared_mem->dma_addr + pos;
> +
> +	if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
> +	    !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
> +		/*Add base address to get full address.*/
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed allocate SEC MEM memory\n",
> +				dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	memset(shared_mem->ptr + pos, 0, io.length);
> +	if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
> +	    (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
> +		/*
> +		 * buffer is input:
> +		 * copy data from user space to this allocated buffer.
> +		 */
> +		if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
> +				   io.length)) {
> +			dev_err(dev_ctx->priv->dev,
> +				"%s: Failed copy data to shared memory\n",
> +				dev_ctx->miscdev.name);
> +			err = -EFAULT;
> +			goto exit;
> +		}
> +	}
> +
> +	b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
> +	if (!b_desc) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +copy:
> +	/* Provide the EdgeLock Enclave address to user space only if success.*/
> +	if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy iobuff setup to user\n",
> +				dev_ctx->miscdev.name);
> +		kfree(b_desc);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +	if (b_desc) {
> +		b_desc->shared_buf_ptr = shared_mem->ptr + pos;
> +		b_desc->usr_buf_ptr = io.user_buf;
> +		b_desc->size = io.length;
> +
> +		if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
> +			/*
> +			 * buffer is input:
> +			 * add an entry in the "pending input buffers" list so
> +			 * that copied data can be cleaned from shared memory
> +			 * later.
> +			 */
> +			list_add_tail(&b_desc->link, &dev_ctx->pending_in);
> +		} else {
> +			/*
> +			 * buffer is output:
> +			 * add an entry in the "pending out buffers" list so data
> +			 * can be copied to user space when receiving Secure-Enclave
> +			 * response.
> +			 */
> +			list_add_tail(&b_desc->link, &dev_ctx->pending_out);
> +		}
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* IOCTL to provide SoC information */
> +static int se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx *dev_ctx,
> +					     u64 arg)
> +{
> +	const struct se_if_node_info_list *info_list;
> +	struct se_ioctl_get_soc_info soc_info;
> +	int err = -EINVAL;
> +
> +	info_list = device_get_match_data(dev_ctx->priv->dev);
> +	if (!info_list)
> +		goto exit;
> +
> +	soc_info.soc_id = info_list->soc_id;
> +	soc_info.soc_rev = dev_ctx->priv->soc_rev;
> +
> +	err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
> +	if (err) {
> +		dev_err(dev_ctx->priv->dev,
> +			"%s: Failed to copy soc info to user\n",
> +			dev_ctx->miscdev.name);
> +		err = -EFAULT;
> +		goto exit;
> +	}
> +
> +exit:
> +	return err;
> +}
> +
> +/* Open a character device. */
> +static int se_if_fops_open(struct inode *nd, struct file *fp)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	int err = 0;
> +
> +	/* Avoid race if opened at the same time */
> +	if (down_trylock(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	/* Authorize only 1 instance. */
> +	if (dev_ctx->status != SE_IF_CTX_FREE) {
> +		err = -EBUSY;
> +		goto exit;
> +	}
> +
> +	/*
> +	 * Allocate some memory for data exchanges with S40x.
> +	 * This will be used for data not requiring secure memory.
> +	 */
> +	dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
> +					MAX_DATA_SIZE_PER_USER,
> +					&dev_ctx->non_secure_mem.dma_addr,
> +					GFP_KERNEL);
> +	if (!dev_ctx->non_secure_mem.ptr) {
> +		err = -ENOMEM;
> +		goto exit;
> +	}
> +
> +	dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
> +	dev_ctx->non_secure_mem.pos = 0;
> +	dev_ctx->status = SE_IF_CTX_OPENED;
> +
> +	dev_ctx->pending_hdr = 0;
> +
> +	goto exit;
> +
> +	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> +			   dev_ctx->non_secure_mem.ptr,
> +			   dev_ctx->non_secure_mem.dma_addr);
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return err;
> +}
> +
> +/* Close a character device. */
> +static int se_if_fops_close(struct inode *nd, struct file *fp)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	struct se_if_priv *priv = dev_ctx->priv;
> +
> +	/* Avoid race if closed at the same time */
> +	if (down_trylock(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	/* The device context has not been opened */
> +	if (dev_ctx->status != SE_IF_CTX_OPENED)
> +		goto exit;
> +
> +	/* check if this device was registered as command receiver. */
> +	if (priv->cmd_receiver_dev == dev_ctx) {
> +		priv->cmd_receiver_dev = NULL;
> +		kfree(dev_ctx->temp_resp);
> +	}
> +
> +	/* check if this device was registered as waiting response. */
> +	if (priv->waiting_rsp_dev == dev_ctx) {
> +		priv->waiting_rsp_dev = NULL;
> +		mutex_unlock(&priv->se_if_cmd_lock);
> +	}
> +
> +	/* Unmap secure memory shared buffer. */
> +	if (dev_ctx->secure_mem.ptr)
> +		devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
> +
> +	dev_ctx->secure_mem.ptr = NULL;
> +	dev_ctx->secure_mem.dma_addr = 0;
> +	dev_ctx->secure_mem.size = 0;
> +	dev_ctx->secure_mem.pos = 0;
> +
> +	/* Free non-secure shared buffer. */
> +	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> +			   dev_ctx->non_secure_mem.ptr,
> +			   dev_ctx->non_secure_mem.dma_addr);
> +
> +	dev_ctx->non_secure_mem.ptr = NULL;
> +	dev_ctx->non_secure_mem.dma_addr = 0;
> +	dev_ctx->non_secure_mem.size = 0;
> +	dev_ctx->non_secure_mem.pos = 0;
> +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> +	dev_ctx->status = SE_IF_CTX_FREE;
> +
> +exit:
> +	up(&dev_ctx->fops_lock);
> +	return 0;
> +}
> +
> +/* IOCTL entry point of a character device */
> +static long se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> +{
> +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> +							struct se_if_device_ctx,
> +							miscdev);
> +	struct se_if_priv *se_if_priv = dev_ctx->priv;
> +	int err = -EINVAL;
> +
> +	/* Prevent race during change of device context */
> +	if (down_interruptible(&dev_ctx->fops_lock))
> +		return -EBUSY;
> +
> +	switch (cmd) {
> +	case SE_IOCTL_ENABLE_CMD_RCV:
> +		if (!se_if_priv->cmd_receiver_dev) {
> +			err = 0;
> +			se_if_priv->cmd_receiver_dev = dev_ctx;
> +			dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN, GFP_KERNEL);
> +			if (!dev_ctx->temp_resp)
> +				err = -ENOMEM;
> +		}
> +		break;
> +	case SE_IOCTL_GET_MU_INFO:
> +		err = se_ioctl_get_mu_info(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_SETUP_IOBUF:
> +		err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_GET_SOC_INFO:
> +		err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
> +		break;
> +	case SE_IOCTL_CMD_SEND_RCV_RSP:
> +		err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
> +		break;
> +
> +	default:
> +		err = -EINVAL;
> +		dev_dbg(se_if_priv->dev,
> +			"%s: IOCTL %.8x not supported\n",
> +				dev_ctx->miscdev.name,
> +				cmd);
> +	}
> +
> +	up(&dev_ctx->fops_lock);
> +	return (long)err;
> +}
> +
> +/* Char driver setup */
> +static const struct file_operations se_if_fops = {
> +	.open		= se_if_fops_open,
> +	.owner		= THIS_MODULE,
> +	.release	= se_if_fops_close,
> +	.unlocked_ioctl = se_ioctl,
> +	.read		= se_if_fops_read,
> +	.write		= se_if_fops_write,
> +};
> +
> +/* interface for managed res to unregister a character device */
> +static void if_misc_deregister(void *miscdevice)
> +{
> +	misc_deregister(miscdevice);
> +}
> +
>    /* interface for managed res to free a mailbox channel */
>    static void if_mbox_free_channel(void *mbox_chan)
>    {
> @@ -233,6 +836,7 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>    {
>    	struct device *dev = &pdev->dev;
>    	struct se_if_priv *priv;
> +	int i;
>    
>    	priv = dev_get_drvdata(dev);
>    
> @@ -252,6 +856,17 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>    		priv->imem.buf = NULL;
>    	}
>    
> +	if (priv->ctxs) {
> +		for (i = 0; i < priv->max_dev_ctx; i++) {
> +			if (priv->ctxs[i]) {
> +				devm_remove_action(dev,
> +						   if_misc_deregister,
> +						   &priv->ctxs[i]->miscdev);
> +				misc_deregister(&priv->ctxs[i]->miscdev);
> +			}
> +		}
> +	}
> +
>    	/* No need to check, if reserved memory is allocated
>    	 * before calling for its release. Or clearing the
>    	 * un-set bit.
> @@ -259,6 +874,74 @@ static void se_if_probe_cleanup(struct platform_device *pdev)
>    	of_reserved_mem_device_release(dev);
>    }
>    
> +static int init_device_context(struct se_if_priv *priv)
> +{
> +	const struct se_if_node_info *info = priv->info;
> +	struct se_if_device_ctx *dev_ctx;
> +	u8 *devname;
> +	int ret = 0;
> +	int i;
> +
> +	priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv->max_dev_ctx,
> +				  GFP_KERNEL);
> +
> +	if (!priv->ctxs) {
> +		ret = -ENOMEM;
> +		return ret;
> +	}
> +
> +	/* Create users */
> +	for (i = 0; i < priv->max_dev_ctx; i++) {
> +		dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx), GFP_KERNEL);
> +		if (!dev_ctx) {
> +			ret = -ENOMEM;
> +			return ret;
> +		}
> +
> +		dev_ctx->dev = priv->dev;
> +		dev_ctx->status = SE_IF_CTX_FREE;
> +		dev_ctx->priv = priv;
> +
> +		priv->ctxs[i] = dev_ctx;
> +
> +		/* Default value invalid for an header. */
> +		init_waitqueue_head(&dev_ctx->wq);
> +
> +		INIT_LIST_HEAD(&dev_ctx->pending_out);
> +		INIT_LIST_HEAD(&dev_ctx->pending_in);
> +		sema_init(&dev_ctx->fops_lock, 1);
> +
> +		devname = devm_kasprintf(priv->dev, GFP_KERNEL, "%s_ch%d",
> +					 info->se_name, i);
> +		if (!devname) {
> +			ret = -ENOMEM;
> +			return ret;
> +		}
> +
> +		dev_ctx->miscdev.name = devname;
> +		dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
> +		dev_ctx->miscdev.fops = &se_if_fops;
> +		dev_ctx->miscdev.parent = priv->dev;
> +		ret = misc_register(&dev_ctx->miscdev);
> +		if (ret) {
> +			dev_err(priv->dev, "failed to register misc device %d\n",
> +				ret);
> +			return ret;
> +		}
> +
> +		ret = devm_add_action(priv->dev, if_misc_deregister,
> +				      &dev_ctx->miscdev);
> +		if (ret) {
> +			dev_err(priv->dev,
> +				"failed[%d] to add action to the misc-dev\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
>    static void se_load_firmware(const struct firmware *fw, void *context)
>    {
>    	struct se_if_priv *priv = (struct se_if_priv *) context;
> @@ -427,6 +1110,16 @@ static int se_if_probe(struct platform_device *pdev)
>    		ret = 0;
>    	}
>    
> +	if (info->max_dev_ctx) {
> +		ret = init_device_context(priv);
> +		if (ret) {
> +			dev_err(dev,
> +				"Failed[0x%x] to create device contexts.\n",
> +				ret);
> +			goto exit;
> +		}
> +	}
> +
>    	dev_info(dev, "i.MX secure-enclave: %s interface to firmware, configured.\n",
>    		 info->se_name);
>    	return ret;
> @@ -467,6 +1160,10 @@ static int se_resume(struct device *dev)
>    {
>    	struct se_if_priv *priv = dev_get_drvdata(dev);
>    	const struct se_if_node_info *info = priv->info;
> +	int i;
> +
> +	for (i = 0; i < priv->max_dev_ctx; i++)
> +		wake_up_interruptible(&priv->ctxs[i]->wq);
>    
>    	if (info && info->imem_mgmt)
>    		se_restore_imem_state(priv);
> diff --git a/drivers/firmware/imx/se_ctrl.h b/drivers/firmware/imx/se_ctrl.h
> index 4be2235d2170..b49346372746 100644
> --- a/drivers/firmware/imx/se_ctrl.h
> +++ b/drivers/firmware/imx/se_ctrl.h
> @@ -13,15 +13,62 @@
>    #define MAX_FW_LOAD_RETRIES		50
>    
>    #define RES_STATUS(x)			FIELD_GET(0x000000ff, x)
> +#define MAX_DATA_SIZE_PER_USER		(65 * 1024)
> +#define MAX_NVM_MSG_LEN			(256)
>    #define MESSAGING_VERSION_6		0x6
>    #define MESSAGING_VERSION_7		0x7
>    
> +#define SE_MU_IO_FLAGS_USE_SEC_MEM	(0x02u)
> +#define SE_MU_IO_FLAGS_USE_SHORT_ADDR	(0x04u)
> +
>    struct se_imem_buf {
>    	u8 *buf;
>    	phys_addr_t phyaddr;
>    	u32 size;
>    };
>    
> +struct se_buf_desc {
> +	u8 *shared_buf_ptr;
> +	u8 *usr_buf_ptr;
> +	u32 size;
> +	struct list_head link;
> +};
> +
> +/* Status of a char device */
> +enum se_if_dev_ctx_status_t {
> +	SE_IF_CTX_FREE,
> +	SE_IF_CTX_OPENED
> +};
> +
> +struct se_shared_mem {
> +	dma_addr_t dma_addr;
> +	u32 size;
> +	u32 pos;
> +	u8 *ptr;
> +};
> +
> +/* Private struct for each char device instance. */
> +struct se_if_device_ctx {
> +	struct device *dev;
> +	struct se_if_priv *priv;
> +	struct miscdevice miscdev;
> +
> +	enum se_if_dev_ctx_status_t status;
> +	wait_queue_head_t wq;
> +	struct semaphore fops_lock;
> +
> +	u32 pending_hdr;
> +	struct list_head pending_in;
> +	struct list_head pending_out;
> +
> +	struct se_shared_mem secure_mem;
> +	struct se_shared_mem non_secure_mem;
> +
> +	struct se_api_msg *temp_resp;
> +	u32 temp_resp_size;
> +	struct notifier_block se_notify;
> +};
> +
>    /* Header of the messages exchange with the EdgeLock Enclave */
>    struct se_msg_hdr {
>    	u8 ver;
> @@ -80,4 +127,6 @@ struct se_if_priv {
>    	struct se_imem_buf imem;
>    };
>    
> +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy);
> +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx);
>    #endif
> diff --git a/include/uapi/linux/se_ioctl.h b/include/uapi/linux/se_ioctl.h
> new file mode 100644
> index 000000000000..c2d0a92ef626
> --- /dev/null
> +++ b/include/uapi/linux/se_ioctl.h
> @@ -0,0 +1,94 @@
> +/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause*/
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#ifndef SE_IOCTL_H
> +#define SE_IOCTL_H
> +
> +/* IOCTL definitions. */
> +
> +struct se_ioctl_setup_iobuf {
> +	u8 *user_buf;
> +	u32 length;
> +	u32 flags;
> +	u64 ele_addr;
> +};
> +
> +struct se_ioctl_shared_mem_cfg {
> +	u32 base_offset;
> +	u32 size;
> +};
> +
> +struct se_ioctl_get_if_info {
> +	u8 se_if_id;
> +	u8 interrupt_idx;
> +	u8 tz;
> +	u8 did;
> +	u8 cmd_tag;
> +	u8 rsp_tag;
> +	u8 success_tag;
> +	u8 base_api_ver;
> +	u8 fw_api_ver;
> +};
> +
> +struct se_ioctl_cmd_snd_rcv_rsp_info {
> +	u32 *tx_buf;
> +	int tx_buf_sz;
> +	u32 *rx_buf;
> +	int rx_buf_sz;
> +};
> +
> +struct se_ioctl_get_soc_info {
> +	u16 soc_id;
> +	u16 soc_rev;
> +};
> +
> +/* IO Buffer Flags */
> +#define SE_IO_BUF_FLAGS_IS_OUTPUT	(0x00u)
> +#define SE_IO_BUF_FLAGS_IS_INPUT	(0x01u)
> +#define SE_IO_BUF_FLAGS_USE_SEC_MEM	(0x02u)
> +#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR	(0x04u)
> +#define SE_IO_BUF_FLAGS_IS_IN_OUT	(0x10u)
> +
> +/* IOCTLS */
> +#define SE_IOCTL			0x0A /* like MISC_MAJOR. */
> +
> +/*
> + * ioctl to designated the current fd as logical-reciever.
> + * This is ioctl is send when the nvm-daemon, a slave to the
> + * firmware is started by the user.
> + */
> +#define SE_IOCTL_ENABLE_CMD_RCV	_IO(SE_IOCTL, 0x01)
> +
> +/*
> + * ioctl to get the buffer allocated from the memory, which is shared
> + * between kernel and FW.
> + * Post allocation, the kernel tagged the allocated memory with:
> + *  Output
> + *  Input
> + *  Input-Output
> + *  Short address
> + *  Secure-memory
> + */
> +#define SE_IOCTL_SETUP_IOBUF	_IOWR(SE_IOCTL, 0x03, \
> +					struct se_ioctl_setup_iobuf)
> +
> +/*
> + * ioctl to get the mu information, that is used to exchange message
> + * with FW, from user-spaced.
> + */
> +#define SE_IOCTL_GET_MU_INFO	_IOR(SE_IOCTL, 0x04, \
> +					struct se_ioctl_get_if_info)
> +/*
> + * ioctl to get SoC Info from user-space.
> + */
> +#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
> +					struct se_ioctl_get_soc_info)
> +
> +/*
> + * ioctl to send command and receive response from user-space.
> + */
> +#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
> +					struct se_ioctl_cmd_snd_rcv_rsp_info)
> +#endif
> 
> -- 
> 2.34.1
> 
>

Pankaj Gupta July 15, 2024, 9:03 a.m. UTC | #3

> -----Original Message-----
> From: Amit Singh Tomar <[e-mail]>
> Sent: Monday, July 15, 2024 12:55 PM
> To: Pankaj Gupta <[e-mail]>; Jonathan Corbet
> <[e-mail]>; Rob Herring <[e-mail]>; Krzysztof Kozlowski
> <[e-mail]>; Conor Dooley <[e-mail]>; Shawn Guo
> <[e-mail]>; Sascha Hauer <[e-mail]>;
> Pengutronix Kernel Team <[e-mail]>; Fabio Estevam
> <[e-mail]>; Rob Herring <[e-mail]>
> Cc: [e-mail]; [e-mail];
> [e-mail]; [e-mail]; linux-arm-
> [e-mail]
> Subject: [EXT] [PATCH v5 5/5] firmware: imx: adds miscdev
> 
> Caution: This is an external email. Please take care when clicking links or
> opening attachments. When in doubt, report the message using the 'Report
> this email' button
> 
> 
> On 7/12/2024 11:50 AM, Pankaj Gupta wrote:
> >
> > Adds the driver for communication interface to secure-enclave,
> > for exchanging messages with NXP secure enclave HW IP(s) like
> > EdgeLock Enclave from:
> > - User-Space Applications via character driver.
> >
> > ABI documentation for the NXP secure-enclave driver.
> >
> > User-space library using this driver:
> > - i.MX Secure Enclave library:
> >     --
> URL:https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2F
> urldefense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-
> 3A__github.com_nxp-2Dimx_imx-2Dsecure-
> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120880069
> 5%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=LfnzkhZGIK
> nWy2KlRXAYT8AAx8xg3T6D0aJUAYQVpS4%3D&reserved=0
> <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld
> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-2Dsecure-
> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120880997
> 2%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=HAxt3R3eat
> RNAtv6A04gbIES3HQ2InunUvxXNM7JZ9c%3D&reserved=0>,
> > - i.MX Secure Middle-Ware:
> >     --
> URL:https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2F
> urldefense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-
> 3A__github.com_nxp-2Dimx_imx-
> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120881627
> 8%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=eoJowSH32
> RObqIYVRSjNSRXsDZYRHEo8EgTuWGuqcLw%3D&reserved=0
> <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld
> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-
> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120882083
> 7%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=VQfW4JiTw
> MyPtpCvkN7jz91OAmjNQbwoqcT6xoTW%2BjQ%3D&reserved=0>
> >
> > Signed-off-by: Pankaj Gupta <[e-mail]>
> > ---
> >    Documentation/ABI/testing/se-cdev |  43 +++
> >    drivers/firmware/imx/ele_common.c | 192 ++++++++++-
> >    drivers/firmware/imx/ele_common.h |   4 +
> >    drivers/firmware/imx/se_ctrl.c    | 697
> ++++++++++++++++++++++++++++++++++++++
> >    drivers/firmware/imx/se_ctrl.h    |  49 +++
> >    include/uapi/linux/se_ioctl.h     |  94 +++++
> >    6 files changed, 1076 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/se-cdev
> b/Documentation/ABI/testing/se-cdev
> > new file mode 100644
> > index 000000000000..3451c909ccc4
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/se-cdev
> > @@ -0,0 +1,43 @@
> > +What:                /dev/<se>_mu[0-9]+_ch[0-9]+
> > +Date:                May 2024
> > +KernelVersion:       6.8
> > +Contact:     [e-mail], [e-mail]
> > +Description:
> > +             NXP offers multiple hardware IP(s) for secure enclaves like EdgeLock-
> > +             Enclave(ELE), SECO. The character device file descriptors
> > +             /dev/<se>_mu*_ch* are the interface between userspace NXP's
> secure-
> > +             enclave shared library and the kernel driver.
> > +
> > +             The ioctl(2)-based ABI is defined and documented in
> > +             [include]<linux/firmware/imx/ele_mu_ioctl.h>.
> > +             ioctl(s) are used primarily for:
> > +                     - shared memory management
> > +                     - allocation of I/O buffers
> > +                     - getting mu info
> > +                     - setting a dev-ctx as receiver to receive all the commands from
> FW
> > +                     - getting SoC info
> > +                     - send command and receive command response
> > +
> > +             The following file operations are supported:
> > +
> > +             open(2)
> > +               Currently the only useful flags are O_RDWR.
> > +
> > +             read(2)
> > +               Every read() from the opened character device context is waiting on
> > +               wait_event_interruptible, that gets set by the registered mailbox
> callback
> > +               function, indicating a message received from the firmware on
> message-
> > +               unit.
> > +
> > +             write(2)
> > +               Every write() to the opened character device context needs to
> acquire
> > +               mailbox_lock before sending message on to the message unit.
> > +
> > +             close(2)
> > +               Stops and frees up the I/O contexts that were associated
> > +               with the file descriptor.
> > +
> > +Users:
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldef
> ense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-2Dsecure-
> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120882519
> 7%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=%2F%2FHN
> V%2F%2FlYkPyoKDXFYvd47oIeKHTR7rnwtgz%2FYm4Szg%3D&reserved=0
> <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld
> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-2Dsecure-
> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120882963
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> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=Qyd5KBGqb
> 78IHjvFQmAyJlq5YSbbViboRTLl0IyGxzg%3D&reserved=0>,
> > +
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldef
> ense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-
> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120883392
> 8%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=%2FzaGw%
> 2BcCV%2F%2FMUA1tdxVNhwE0avSM18wIriqH1%2FMoohQ%3D&reserved=
> 0
> <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld
> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
> 2Dimx_imx-
> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
> 4HUlH7ooyxfcf-
> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120883820
> 8%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=7EHPHbB5Y
> XpDKVGIjHAyj8X1Kr1Gjba%2FcrwQPYgvP2k%3D&reserved=0>
> > +             crypto/skcipher,
> > +             drivers/nvmem/imx-ocotp-ele.c
> > diff --git a/drivers/firmware/imx/ele_common.c
> b/drivers/firmware/imx/ele_common.c
> > index b2be32550e9b..88169cd8f369 100644
> > --- a/drivers/firmware/imx/ele_common.c
> > +++ b/drivers/firmware/imx/ele_common.c
> > @@ -78,6 +78,149 @@ int ele_msg_send_rcv(struct se_if_priv *priv, void
> *tx_msg, void *rx_msg)
> >       return err;
> >    }
> >
> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> > +                     void *rx_buf,
> > +                     int rx_buf_sz)
> > +{
> > +     struct se_msg_hdr *header;
> > +     int err;
> > +
> > +     err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
> > +     if (err) {
> > +             dev_err(dev_ctx->dev,
> > +                     "%s: Err[0x%x]:Interrupted by signal.\n",
> > +                     dev_ctx->miscdev.name, err);
> > +             goto exit;
> > +     }
> > +
> > +     header = (struct se_msg_hdr *) dev_ctx->temp_resp;
> > +
> > +     if (header->tag == dev_ctx->priv->rsp_tag) {
> > +             if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv-
> >waiting_rsp_dev != dev_ctx) {
> > +                     dev_warn(dev_ctx->dev,
> > +                     "Dev-ctx waiting for response mismatch (%s != %s).\n",
> > +                     dev_ctx->miscdev.name, dev_ctx->priv->waiting_rsp_dev-
> >miscdev.name);
> > +                     err = -EPERM;
> > +                     goto exit;
> > +             }
> > +     }
> > +
> > +     dev_dbg(dev_ctx->dev,
> > +             "%s: %s %s\n",
> > +             dev_ctx->miscdev.name,
> > +             __func__,
> > +             "message received, start transmit to user");
> > +
> > +     /*
> > +      * Check that the size passed as argument is larger than
> > +      * the one carried in the message.
> > +      *
> > +      * In case of US-command/response, the dev_ctx->temp_resp_size
> > +      * is set before sending the command.
> > +      *
> > +      * In case of NVM Slave-command/response, the dev_ctx-
> >temp_resp_size
> > +      * is set after receing the message from mailbox.
> > +      */
> > +     if (dev_ctx->temp_resp_size > rx_buf_sz) {
> > +             dev_err(dev_ctx->dev,
> > +                     "%s: User buffer too small (%d < %d)\n",
> > +                     dev_ctx->miscdev.name,
> > +                     rx_buf_sz, dev_ctx->temp_resp_size);
> > +              dev_ctx->temp_resp_size = rx_buf_sz;
> > +     }
> > +
> > +     /* We may need to copy the output data to user before
> > +      * delivering the completion message.
> > +      */
> > +     err = se_dev_ctx_cpy_out_data(dev_ctx, true);
> > +     if (err < 0)
> > +             goto exit;
> > +
> > +     /* Copy data from the buffer */
> > +     print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
> > +                          dev_ctx->temp_resp, dev_ctx->temp_resp_size, false);
> > +     if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx-
> >temp_resp_size)) {
> > +             dev_err(dev_ctx->dev,
> > +                     "%s: Failed to copy to user\n",
> > +                     dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +     err = dev_ctx->temp_resp_size;
> > +exit:
> > +     if (err < 0)
> > +             se_dev_ctx_cpy_out_data(dev_ctx, false);
> > +
> > +     /* free memory allocated on the shared buffers. */
> > +     dev_ctx->secure_mem.pos = 0;
> > +     dev_ctx->non_secure_mem.pos = 0;
> > +
> > +     dev_ctx->pending_hdr = 0;
> > +     se_dev_ctx_shared_mem_cleanup(dev_ctx);
> > +
> > +     return err;
> > +}
> > +
> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> > +                      void *tx_msg, int tx_msg_sz)
> > +{
> > +     struct se_if_priv *priv = dev_ctx->priv;
> > +     struct se_msg_hdr *header;
> > +     u32 size_to_send;
> > +     int err;
> > +
> > +     header = (struct se_msg_hdr *) tx_msg;
> > +
> > +     /*
> > +      * Check that the size passed as argument matches the size
> > +      * carried in the message.
> > +      */
> > +     size_to_send = header->size << 2;
> > +
> > +     if (size_to_send != tx_msg_sz) {
> > +             err = -EINVAL;
> > +             dev_err(priv->dev,
> > +                     "%s: User buf hdr(0x%x) sz mismatced with input-sz
> (%d != %d).\n",
> > +                     dev_ctx->miscdev.name, *(u32 *)header, size_to_send,
> tx_msg_sz);
> > +             goto exit;
> > +     }
> > +
> > +     /* Check the message is valid according to tags */
> > +     if (header->tag == priv->rsp_tag) {
> > +             /* Check the device context can send the command */
> > +             if (dev_ctx != priv->cmd_receiver_dev) {
> > +                     dev_err(priv->dev,
> > +                             "%s: Channel not configured to send resp to FW.",
> > +                             dev_ctx->miscdev.name);
> > +                     err = -EPERM;
> > +                     goto exit;
> > +             }
> > +     } else if (header->tag == priv->cmd_tag) {
> > +             if (priv->waiting_rsp_dev != dev_ctx) {
> > +                     dev_err(priv->dev,
> > +                             "%s: Channel not configured to send cmd to FW.",
> > +                             dev_ctx->miscdev.name);
> > +                     err = -EPERM;
> > +                     goto exit;
> > +             }
> > +             lockdep_assert_held(&priv->se_if_cmd_lock);
> 
> nit: Placement of this call is bit unusual (or do have some reason to
> it), it might be better to place it at the beginning of the function.

The command lock is taken only in the case of command-message. Hence it placed under check for command message.

> 
> > +     } else {
> > +             dev_err(priv->dev,
> > +                     "%s: The message does not have a valid TAG\n",
> > +                     dev_ctx->miscdev.name);
> > +             err = -EINVAL;
> > +             goto exit;
> > +     }
> > +     err = ele_msg_send(priv, tx_msg);
> > +     if (err < 0)
> > +             goto exit;
> > +
> > +     err = size_to_send;
> > +exit:
> > +     return err;
> > +}
> > +
> >    static bool exception_for_size(struct se_if_priv *priv,
> >                               struct se_msg_hdr *header)
> >    {
> > @@ -99,6 +242,7 @@ static bool exception_for_size(struct se_if_priv *priv,
> >    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
> >    {
> >       struct device *dev = mbox_cl->dev;
> > +     struct se_if_device_ctx *dev_ctx;
> >       struct se_if_priv *priv;
> >       struct se_msg_hdr *header;
> >       u32 rx_msg_sz;
> > @@ -114,8 +258,50 @@ void se_if_rx_callback(struct mbox_client
> *mbox_cl, void *msg)
> >       header = msg;
> >       rx_msg_sz = header->size << 2;
> >
> > -     if (header->tag == priv->rsp_tag) {
> > -             if (!priv->waiting_rsp_dev) {
> > +     /* Incoming command: wake up the receiver if any. */
> > +     if (header->tag == priv->cmd_tag) {
> > +             dev_dbg(dev, "Selecting cmd receiver\n");
> > +             dev_ctx = priv->cmd_receiver_dev;
> > +             /* Pre-allocated buffer of MAX_NVM_MSG_LEN
> > +              * as the NVM command are initiated by FW.
> > +              * Size is revealed as part of this call function.
> > +              */
> > +             if (rx_msg_sz > MAX_NVM_MSG_LEN) {
> > +                     dev_err(dev,
> > +                             "%s: Msg recvd hdr(0x%x) with greater[%d] than allocated
> buf-sz.\n",
> > +                             dev_ctx->miscdev.name,
> > +                             *(u32 *) header,
> > +                             rx_msg_sz);
> > +             } else
> > +                     memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> > +
> > +             /* NVM buffer size are not known prior receiving it from FW.
> > +              */
> > +             dev_ctx->temp_resp_size = rx_msg_sz;
> > +
> > +             /* Allow user to read */
> > +             dev_ctx->pending_hdr = 1;
> > +             wake_up_interruptible(&dev_ctx->wq);
> > +
> > +             return;
> > +     } else if (header->tag == priv->rsp_tag) {
> > +             if (priv->waiting_rsp_dev) {
> > +                     dev_dbg(dev, "Selecting rsp waiter\n");
> > +                     dev_ctx = priv->waiting_rsp_dev;
> > +                     if (rx_msg_sz != dev_ctx->temp_resp_size
> > +                             && !exception_for_size(priv, header))
> > +                             dev_err(dev,
> > +                                     "%s: Msg RSP hdr(0x%x) with different sz(%d != %d).\n",
> > +                                     dev_ctx->miscdev.name,
> > +                                     *(u32 *) header,
> > +                                     rx_msg_sz, dev_ctx->temp_resp_size);
> > +                     else
> > +                             memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> > +
> > +                     /* Allow user to read */
> > +                     dev_ctx->pending_hdr = 1;
> > +                     wake_up_interruptible(&dev_ctx->wq);
> > +             } else {
> >                       /*
> >                        * Reading the EdgeLock Enclave response
> >                        * to the command, sent by other
> > @@ -132,8 +318,8 @@ void se_if_rx_callback(struct mbox_client *mbox_cl,
> void *msg)
> >
> >                       complete(&priv->done);
> >                       spin_unlock(&priv->lock);
> > -                     return;
> >               }
> > +             return;
> >       }
> >
> >       dev_err(dev, "Failed to select a device for message: %.8x\n",
> > diff --git a/drivers/firmware/imx/ele_common.h
> b/drivers/firmware/imx/ele_common.h
> > index 5ef775a42ab3..7b1c6bfc138b 100644
> > --- a/drivers/firmware/imx/ele_common.h
> > +++ b/drivers/firmware/imx/ele_common.h
> > @@ -17,6 +17,10 @@ uint32_t se_add_msg_crc(uint32_t *msg, uint32_t
> msg_len);
> >    int ele_msg_rcv(struct se_if_priv *priv);
> >    int ele_msg_send(struct se_if_priv *priv, void *tx_msg);
> >    int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> > +                     void *rx_msg, int rx_msg_sz);
> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> > +                      void *tx_msg, int tx_msg_sz);
> >    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);
> >    int se_val_rsp_hdr_n_status(struct se_if_priv *priv,
> >                           struct se_msg_hdr *header,
> > diff --git a/drivers/firmware/imx/se_ctrl.c b/drivers/firmware/imx/se_ctrl.c
> > index a844794d2b39..8fb2af0f0dd3 100644
> > --- a/drivers/firmware/imx/se_ctrl.c
> > +++ b/drivers/firmware/imx/se_ctrl.c
> > @@ -23,6 +23,7 @@
> >    #include <linux/slab.h>
> >    #include <linux/string.h>
> >    #include <linux/sys_soc.h>
> > +#include <uapi/linux/se_ioctl.h>
> >
> >    #include "ele_base_msg.h"
> >    #include "ele_common.h"
> > @@ -196,6 +197,608 @@ static int se_soc_info(struct se_if_priv *priv,
> >       return 0;
> >    }
> >
> > +static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx
> *dev_ctx,
> > +                                         u64 arg)
> > +{
> > +     struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> > +     struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
> > +     struct se_api_msg *tx_msg __free(kfree) = NULL;
> > +     struct se_api_msg *rx_msg __free(kfree) = NULL;
> > +     int err = 0;
> > +
> > +     if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
> > +                        sizeof(cmd_snd_rcv_rsp_info))) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> > +                     dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +     if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: User buffer too small(%d < %d)\n",
> > +                     dev_ctx->miscdev.name,
> > +                     cmd_snd_rcv_rsp_info.tx_buf_sz,
> > +                     SE_MU_HDR_SZ);
> > +             err = -ENOSPC;
> > +             goto exit;
> > +     }
> > +
> > +     rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
> > +     if (!rx_msg) {
> > +             err = -ENOMEM;
> > +             goto exit;
> > +     }
> > +
> > +     tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
> > +                          cmd_snd_rcv_rsp_info.tx_buf_sz);
> > +     if (IS_ERR(tx_msg)) {
> > +             err = PTR_ERR(tx_msg);
> > +             goto exit;
> > +     }
> > +
> > +     if (tx_msg->header.tag != priv->cmd_tag) {
> > +             err = -EINVAL;
> > +             goto exit;
> > +     }
> > +
> > +     scoped_guard(mutex, &priv->se_if_cmd_lock);
> > +     priv->waiting_rsp_dev = dev_ctx;
> > +     dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
> > +
> > +     /* Device Context that is assigned to be a
> > +      * FW's command receiver, has pre-allocated buffer.
> > +      */
> > +     if (dev_ctx != priv->cmd_receiver_dev)
> > +             dev_ctx->temp_resp = rx_msg;
> > +
> > +     err = ele_miscdev_msg_send(dev_ctx,
> > +                                tx_msg,
> > +                                cmd_snd_rcv_rsp_info.tx_buf_sz);
> > +     if (err < 0)
> > +             goto exit;
> > +
> > +     cmd_snd_rcv_rsp_info.tx_buf_sz = err;
> > +
> > +     err = ele_miscdev_msg_rcv(dev_ctx,
> > +                               cmd_snd_rcv_rsp_info.rx_buf,
> > +                               cmd_snd_rcv_rsp_info.rx_buf_sz);
> > +
> > +     if (err < 0)
> > +             goto exit;
> > +
> > +     cmd_snd_rcv_rsp_info.rx_buf_sz = err;
> > +
> > +exit:
> > +     dev_ctx->temp_resp_size = 0;
> > +     priv->waiting_rsp_dev = NULL;
> > +     if (dev_ctx != priv->cmd_receiver_dev)
> > +             dev_ctx->temp_resp = NULL;
> > +
> > +     if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
> > +                      sizeof(cmd_snd_rcv_rsp_info))) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
> > +                     dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +     }
> > +     return err;
> > +}
> > +
> > +/*
> > + * File operations for user-space
> > + */
> > +
> > +/* Write a message to the MU. */
> > +static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
> > +                             size_t size, loff_t *ppos)
> > +{
> > +     struct se_api_msg *tx_msg __free(kfree) = NULL;
> > +     struct se_if_device_ctx *dev_ctx;
> > +     struct se_if_priv *priv;
> > +     int err;
> > +
> > +     dev_ctx = container_of(fp->private_data,
> > +                            struct se_if_device_ctx,
> > +                            miscdev);
> > +     priv = dev_ctx->priv;
> > +     dev_dbg(priv->dev,
> > +             "%s: write from buf (%p)%zu, ppos=%lld\n",
> > +                     dev_ctx->miscdev.name,
> > +                     buf, size, ((ppos) ? *ppos : 0));
> > +
> > +     if (down_interruptible(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     if (dev_ctx->status != SE_IF_CTX_OPENED) {
> > +             err = -EINVAL;
> > +             goto exit;
> > +     }
> > +
> > +     if (size < SE_MU_HDR_SZ) {
> > +             dev_err(priv->dev,
> > +                     "%s: User buffer too small(%zu < %d)\n",
> > +                             dev_ctx->miscdev.name,
> > +                             size, SE_MU_HDR_SZ);
> > +             err = -ENOSPC;
> > +             goto exit;
> > +     }
> > +     tx_msg = memdup_user(buf, size);
> > +     if (IS_ERR(tx_msg)) {
> > +             err = PTR_ERR(tx_msg);
> > +             goto exit;
> > +     }
> > +
> > +     print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
> > +                          tx_msg, size, false);
> > +
> > +     err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return err;
> > +}
> > +
> > +/*
> > + * Read a message from the MU.
> > + * Blocking until a message is available.
> > + */
> > +static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
> > +                            size_t size, loff_t *ppos)
> > +{
> > +     struct se_if_device_ctx *dev_ctx;
> > +     struct se_if_priv *priv;
> > +     int err;
> > +
> > +     dev_ctx = container_of(fp->private_data,
> > +                            struct se_if_device_ctx,
> > +                            miscdev);
> > +     priv = dev_ctx->priv;
> > +     dev_dbg(priv->dev,
> > +             "%s: read to buf %p(%zu), ppos=%lld\n",
> > +                     dev_ctx->miscdev.name,
> > +                     buf, size, ((ppos) ? *ppos : 0));
> > +
> > +     if (down_interruptible(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     if (dev_ctx->status != SE_IF_CTX_OPENED) {
> > +             err = -EINVAL;
> > +             goto exit;
> > +     }
> > +
> > +     err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return err;
> > +}
> > +
> > +static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
> > +                             u64 arg)
> > +{
> > +     struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> > +     struct se_if_node_info *if_node_info;
> > +     struct se_ioctl_get_if_info info;
> > +     int err = 0;
> > +
> > +     if_node_info = (struct se_if_node_info *)priv->info;
> > +
> > +     info.se_if_id = if_node_info->se_if_id;
> > +     info.interrupt_idx = 0;
> > +     info.tz = 0;
> > +     info.did = if_node_info->se_if_did;
> > +     info.cmd_tag = if_node_info->cmd_tag;
> > +     info.rsp_tag = if_node_info->rsp_tag;
> > +     info.success_tag = if_node_info->success_tag;
> > +     info.base_api_ver = if_node_info->base_api_ver;
> > +     info.fw_api_ver = if_node_info->fw_api_ver;
> > +
> > +     dev_dbg(priv->dev,
> > +             "%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
> > +                     dev_ctx->miscdev.name,
> > +                     info.se_if_id, info.interrupt_idx, info.tz, info.did);
> > +
> > +     if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed to copy mu info to user\n",
> > +                             dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +exit:
> > +     return err;
> > +}
> > +
> > +/* Need to copy the output data to user-device context.
> > + */
> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
> do_cpy)
> > +{
> > +     struct se_buf_desc *b_desc, *temp;
> > +
> > +     list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link) {
> > +             if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr && do_cpy) {
> > +
> > +                     dev_dbg(dev_ctx->dev,
> > +                             "%s: Copy output data to user\n",
> > +                             dev_ctx->miscdev.name);
> > +                     if (copy_to_user(b_desc->usr_buf_ptr,
> > +                                      b_desc->shared_buf_ptr,
> > +                                      b_desc->size)) {
> > +                             dev_err(dev_ctx->dev,
> > +                                     "%s: Failure copying output data to user.",
> > +                                     dev_ctx->miscdev.name);
> > +                             return -EFAULT;
> > +                     }
> > +             }
> > +
> > +             if (b_desc->shared_buf_ptr)
> > +                     memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> > +
> > +             list_del(&b_desc->link);
> > +             kfree(b_desc);
> > +     }
> > +     return 0;
> > +}
> > +
> > +/*
> > + * Clean the used Shared Memory space,
> > + * whether its Input Data copied from user buffers, or
> > + * Data received from FW.
> > + */
> > +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
> > +{
> > +     struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
> > +                                              &dev_ctx->pending_out};
> > +     struct se_buf_desc *b_desc, *temp;
> > +     int i;
> > +
> > +     for (i = 0; i < 2; i++) {
> > +             list_for_each_entry_safe(b_desc, temp,
> > +                                      dev_ctx_lists[i], link) {
> > +
> > +                     if (b_desc->shared_buf_ptr)
> > +                             memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> > +
> > +                     list_del(&b_desc->link);
> > +                     kfree(b_desc);
> > +             }
> > +     }
> > +}
> > +
> > +/*
> > + * Copy a buffer of data to/from the user and return the address to use in
> > + * messages
> > + */
> > +static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
> > +                                         u64 arg)
> > +{
> > +     struct se_shared_mem *shared_mem = NULL;
> > +     struct se_ioctl_setup_iobuf io = {0};
> > +     struct se_buf_desc *b_desc = NULL;
> > +     int err = 0;
> > +     u32 pos;
> > +
> > +     if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed copy iobuf config from user\n",
> > +                             dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +     dev_dbg(dev_ctx->priv->dev,
> > +                     "%s: io [buf: %p(%d) flag: %x]\n",
> > +                     dev_ctx->miscdev.name,
> > +                     io.user_buf, io.length, io.flags);
> > +
> > +     if (io.length == 0 || !io.user_buf) {
> > +             /*
> > +              * Accept NULL pointers since some buffers are optional
> > +              * in FW commands. In this case we should return 0 as
> > +              * pointer to be embedded into the message.
> > +              * Skip all data copy part of code below.
> > +              */
> > +             io.ele_addr = 0;
> > +             goto copy;
> > +     }
> > +
> > +     /* Select the shared memory to be used for this buffer. */
> > +     if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
> > +             /* App requires to use secure memory for this buffer.*/
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed allocate SEC MEM memory\n",
> > +                             dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     } else {
> > +             /* No specific requirement for this buffer. */
> > +             shared_mem = &dev_ctx->non_secure_mem;
> > +     }
> > +
> > +     /* Check there is enough space in the shared memory. */
> > +     if (shared_mem->size < shared_mem->pos ||
> > +             round_up(io.length, 8u) >= (shared_mem->size - shared_mem-
> >pos)) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Not enough space in shared memory\n",
> > +                             dev_ctx->miscdev.name);
> > +             err = -ENOMEM;
> > +             goto exit;
> > +     }
> > +
> > +     /* Allocate space in shared memory. 8 bytes aligned. */
> > +     pos = shared_mem->pos;
> > +     shared_mem->pos += round_up(io.length, 8u);
> > +     io.ele_addr = (u64)shared_mem->dma_addr + pos;
> > +
> > +     if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
> > +         !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
> > +             /*Add base address to get full address.*/
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed allocate SEC MEM memory\n",
> > +                             dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +     memset(shared_mem->ptr + pos, 0, io.length);
> > +     if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
> > +         (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
> > +             /*
> > +              * buffer is input:
> > +              * copy data from user space to this allocated buffer.
> > +              */
> > +             if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
> > +                                io.length)) {
> > +                     dev_err(dev_ctx->priv->dev,
> > +                             "%s: Failed copy data to shared memory\n",
> > +                             dev_ctx->miscdev.name);
> > +                     err = -EFAULT;
> > +                     goto exit;
> > +             }
> > +     }
> > +
> > +     b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
> > +     if (!b_desc) {
> > +             err = -ENOMEM;
> > +             goto exit;
> > +     }
> > +
> > +copy:
> > +     /* Provide the EdgeLock Enclave address to user space only if success.*/
> > +     if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed to copy iobuff setup to user\n",
> > +                             dev_ctx->miscdev.name);
> > +             kfree(b_desc);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +     if (b_desc) {
> > +             b_desc->shared_buf_ptr = shared_mem->ptr + pos;
> > +             b_desc->usr_buf_ptr = io.user_buf;
> > +             b_desc->size = io.length;
> > +
> > +             if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
> > +                     /*
> > +                      * buffer is input:
> > +                      * add an entry in the "pending input buffers" list so
> > +                      * that copied data can be cleaned from shared memory
> > +                      * later.
> > +                      */
> > +                     list_add_tail(&b_desc->link, &dev_ctx->pending_in);
> > +             } else {
> > +                     /*
> > +                      * buffer is output:
> > +                      * add an entry in the "pending out buffers" list so data
> > +                      * can be copied to user space when receiving Secure-Enclave
> > +                      * response.
> > +                      */
> > +                     list_add_tail(&b_desc->link, &dev_ctx->pending_out);
> > +             }
> > +     }
> > +
> > +exit:
> > +     return err;
> > +}
> > +
> > +/* IOCTL to provide SoC information */
> > +static int se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx
> *dev_ctx,
> > +                                          u64 arg)
> > +{
> > +     const struct se_if_node_info_list *info_list;
> > +     struct se_ioctl_get_soc_info soc_info;
> > +     int err = -EINVAL;
> > +
> > +     info_list = device_get_match_data(dev_ctx->priv->dev);
> > +     if (!info_list)
> > +             goto exit;
> > +
> > +     soc_info.soc_id = info_list->soc_id;
> > +     soc_info.soc_rev = dev_ctx->priv->soc_rev;
> > +
> > +     err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
> > +     if (err) {
> > +             dev_err(dev_ctx->priv->dev,
> > +                     "%s: Failed to copy soc info to user\n",
> > +                     dev_ctx->miscdev.name);
> > +             err = -EFAULT;
> > +             goto exit;
> > +     }
> > +
> > +exit:
> > +     return err;
> > +}
> > +
> > +/* Open a character device. */
> > +static int se_if_fops_open(struct inode *nd, struct file *fp)
> > +{
> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +                                                     struct se_if_device_ctx,
> > +                                                     miscdev);
> > +     int err = 0;
> > +
> > +     /* Avoid race if opened at the same time */
> > +     if (down_trylock(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     /* Authorize only 1 instance. */
> > +     if (dev_ctx->status != SE_IF_CTX_FREE) {
> > +             err = -EBUSY;
> > +             goto exit;
> > +     }
> > +
> > +     /*
> > +      * Allocate some memory for data exchanges with S40x.
> > +      * This will be used for data not requiring secure memory.
> > +      */
> > +     dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
> > +                                     MAX_DATA_SIZE_PER_USER,
> > +                                     &dev_ctx->non_secure_mem.dma_addr,
> > +                                     GFP_KERNEL);
> > +     if (!dev_ctx->non_secure_mem.ptr) {
> > +             err = -ENOMEM;
> > +             goto exit;
> > +     }
> > +
> > +     dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
> > +     dev_ctx->non_secure_mem.pos = 0;
> > +     dev_ctx->status = SE_IF_CTX_OPENED;
> > +
> > +     dev_ctx->pending_hdr = 0;
> > +
> > +     goto exit;
> > +
> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> > +                        dev_ctx->non_secure_mem.ptr,
> > +                        dev_ctx->non_secure_mem.dma_addr);
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return err;
> > +}
> > +
> > +/* Close a character device. */
> > +static int se_if_fops_close(struct inode *nd, struct file *fp)
> > +{
> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +                                                     struct se_if_device_ctx,
> > +                                                     miscdev);
> > +     struct se_if_priv *priv = dev_ctx->priv;
> > +
> > +     /* Avoid race if closed at the same time */
> > +     if (down_trylock(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     /* The device context has not been opened */
> > +     if (dev_ctx->status != SE_IF_CTX_OPENED)
> > +             goto exit;
> > +
> > +     /* check if this device was registered as command receiver. */
> > +     if (priv->cmd_receiver_dev == dev_ctx) {
> > +             priv->cmd_receiver_dev = NULL;
> > +             kfree(dev_ctx->temp_resp);
> > +     }
> > +
> > +     /* check if this device was registered as waiting response. */
> > +     if (priv->waiting_rsp_dev == dev_ctx) {
> > +             priv->waiting_rsp_dev = NULL;
> > +             mutex_unlock(&priv->se_if_cmd_lock);
> > +     }
> > +
> > +     /* Unmap secure memory shared buffer. */
> > +     if (dev_ctx->secure_mem.ptr)
> > +             devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
> > +
> > +     dev_ctx->secure_mem.ptr = NULL;
> > +     dev_ctx->secure_mem.dma_addr = 0;
> > +     dev_ctx->secure_mem.size = 0;
> > +     dev_ctx->secure_mem.pos = 0;
> > +
> > +     /* Free non-secure shared buffer. */
> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> > +                        dev_ctx->non_secure_mem.ptr,
> > +                        dev_ctx->non_secure_mem.dma_addr);
> > +
> > +     dev_ctx->non_secure_mem.ptr = NULL;
> > +     dev_ctx->non_secure_mem.dma_addr = 0;
> > +     dev_ctx->non_secure_mem.size = 0;
> > +     dev_ctx->non_secure_mem.pos = 0;
> > +     se_dev_ctx_shared_mem_cleanup(dev_ctx);
> > +     dev_ctx->status = SE_IF_CTX_FREE;
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return 0;
> > +}
> > +
> > +/* IOCTL entry point of a character device */
> > +static long se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
> > +{
> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +                                                     struct se_if_device_ctx,
> > +                                                     miscdev);
> > +     struct se_if_priv *se_if_priv = dev_ctx->priv;
> > +     int err = -EINVAL;
> > +
> > +     /* Prevent race during change of device context */
> > +     if (down_interruptible(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     switch (cmd) {
> > +     case SE_IOCTL_ENABLE_CMD_RCV:
> > +             if (!se_if_priv->cmd_receiver_dev) {
> > +                     err = 0;
> > +                     se_if_priv->cmd_receiver_dev = dev_ctx;
> > +                     dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN,
> GFP_KERNEL);
> > +                     if (!dev_ctx->temp_resp)
> > +                             err = -ENOMEM;
> > +             }
> > +             break;
> > +     case SE_IOCTL_GET_MU_INFO:
> > +             err = se_ioctl_get_mu_info(dev_ctx, arg);
> > +             break;
> > +     case SE_IOCTL_SETUP_IOBUF:
> > +             err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
> > +             break;
> > +     case SE_IOCTL_GET_SOC_INFO:
> > +             err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
> > +             break;
> > +     case SE_IOCTL_CMD_SEND_RCV_RSP:
> > +             err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
> > +             break;
> > +
> > +     default:
> > +             err = -EINVAL;
> > +             dev_dbg(se_if_priv->dev,
> > +                     "%s: IOCTL %.8x not supported\n",
> > +                             dev_ctx->miscdev.name,
> > +                             cmd);
> > +     }
> > +
> > +     up(&dev_ctx->fops_lock);
> > +     return (long)err;
> > +}
> > +
> > +/* Char driver setup */
> > +static const struct file_operations se_if_fops = {
> > +     .open           = se_if_fops_open,
> > +     .owner          = THIS_MODULE,
> > +     .release        = se_if_fops_close,
> > +     .unlocked_ioctl = se_ioctl,
> > +     .read           = se_if_fops_read,
> > +     .write          = se_if_fops_write,
> > +};
> > +
> > +/* interface for managed res to unregister a character device */
> > +static void if_misc_deregister(void *miscdevice)
> > +{
> > +     misc_deregister(miscdevice);
> > +}
> > +
> >    /* interface for managed res to free a mailbox channel */
> >    static void if_mbox_free_channel(void *mbox_chan)
> >    {
> > @@ -233,6 +836,7 @@ static void se_if_probe_cleanup(struct
> platform_device *pdev)
> >    {
> >       struct device *dev = &pdev->dev;
> >       struct se_if_priv *priv;
> > +     int i;
> >
> >       priv = dev_get_drvdata(dev);
> >
> > @@ -252,6 +856,17 @@ static void se_if_probe_cleanup(struct
> platform_device *pdev)
> >               priv->imem.buf = NULL;
> >       }
> >
> > +     if (priv->ctxs) {
> > +             for (i = 0; i < priv->max_dev_ctx; i++) {
> > +                     if (priv->ctxs[i]) {
> > +                             devm_remove_action(dev,
> > +                                                if_misc_deregister,
> > +                                                &priv->ctxs[i]->miscdev);
> > +                             misc_deregister(&priv->ctxs[i]->miscdev);
> > +                     }
> > +             }
> > +     }
> > +
> >       /* No need to check, if reserved memory is allocated
> >        * before calling for its release. Or clearing the
> >        * un-set bit.
> > @@ -259,6 +874,74 @@ static void se_if_probe_cleanup(struct
> platform_device *pdev)
> >       of_reserved_mem_device_release(dev);
> >    }
> >
> > +static int init_device_context(struct se_if_priv *priv)
> > +{
> > +     const struct se_if_node_info *info = priv->info;
> > +     struct se_if_device_ctx *dev_ctx;
> > +     u8 *devname;
> > +     int ret = 0;
> > +     int i;
> > +
> > +     priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv-
> >max_dev_ctx,
> > +                               GFP_KERNEL);
> > +
> > +     if (!priv->ctxs) {
> > +             ret = -ENOMEM;
> > +             return ret;
> > +     }
> > +
> > +     /* Create users */
> > +     for (i = 0; i < priv->max_dev_ctx; i++) {
> > +             dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx), GFP_KERNEL);
> > +             if (!dev_ctx) {
> > +                     ret = -ENOMEM;
> > +                     return ret;
> > +             }
> > +
> > +             dev_ctx->dev = priv->dev;
> > +             dev_ctx->status = SE_IF_CTX_FREE;
> > +             dev_ctx->priv = priv;
> > +
> > +             priv->ctxs[i] = dev_ctx;
> > +
> > +             /* Default value invalid for an header. */
> > +             init_waitqueue_head(&dev_ctx->wq);
> > +
> > +             INIT_LIST_HEAD(&dev_ctx->pending_out);
> > +             INIT_LIST_HEAD(&dev_ctx->pending_in);
> > +             sema_init(&dev_ctx->fops_lock, 1);
> > +
> > +             devname = devm_kasprintf(priv->dev, GFP_KERNEL, "%s_ch%d",
> > +                                      info->se_name, i);
> > +             if (!devname) {
> > +                     ret = -ENOMEM;
> > +                     return ret;
> > +             }
> > +
> > +             dev_ctx->miscdev.name = devname;
> > +             dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
> > +             dev_ctx->miscdev.fops = &se_if_fops;
> > +             dev_ctx->miscdev.parent = priv->dev;
> > +             ret = misc_register(&dev_ctx->miscdev);
> > +             if (ret) {
> > +                     dev_err(priv->dev, "failed to register misc device %d\n",
> > +                             ret);
> > +                     return ret;
> > +             }
> > +
> > +             ret = devm_add_action(priv->dev, if_misc_deregister,
> > +                                   &dev_ctx->miscdev);
> > +             if (ret) {
> > +                     dev_err(priv->dev,
> > +                             "failed[%d] to add action to the misc-dev\n",
> > +                             ret);
> > +                     return ret;
> > +             }
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> >    static void se_load_firmware(const struct firmware *fw, void *context)
> >    {
> >       struct se_if_priv *priv = (struct se_if_priv *) context;
> > @@ -427,6 +1110,16 @@ static int se_if_probe(struct platform_device
> *pdev)
> >               ret = 0;
> >       }
> >
> > +     if (info->max_dev_ctx) {
> > +             ret = init_device_context(priv);
> > +             if (ret) {
> > +                     dev_err(dev,
> > +                             "Failed[0x%x] to create device contexts.\n",
> > +                             ret);
> > +                     goto exit;
> > +             }
> > +     }
> > +
> >       dev_info(dev, "i.MX secure-enclave: %s interface to firmware,
> configured.\n",
> >                info->se_name);
> >       return ret;
> > @@ -467,6 +1160,10 @@ static int se_resume(struct device *dev)
> >    {
> >       struct se_if_priv *priv = dev_get_drvdata(dev);
> >       const struct se_if_node_info *info = priv->info;
> > +     int i;
> > +
> > +     for (i = 0; i < priv->max_dev_ctx; i++)
> > +             wake_up_interruptible(&priv->ctxs[i]->wq);
> >
> >       if (info && info->imem_mgmt)
> >               se_restore_imem_state(priv);
> > diff --git a/drivers/firmware/imx/se_ctrl.h b/drivers/firmware/imx/se_ctrl.h
> > index 4be2235d2170..b49346372746 100644
> > --- a/drivers/firmware/imx/se_ctrl.h
> > +++ b/drivers/firmware/imx/se_ctrl.h
> > @@ -13,15 +13,62 @@
> >    #define MAX_FW_LOAD_RETRIES                50
> >
> >    #define RES_STATUS(x)                      FIELD_GET(0x000000ff, x)
> > +#define MAX_DATA_SIZE_PER_USER               (65 * 1024)
> > +#define MAX_NVM_MSG_LEN                      (256)
> >    #define MESSAGING_VERSION_6                0x6
> >    #define MESSAGING_VERSION_7                0x7
> >
> > +#define SE_MU_IO_FLAGS_USE_SEC_MEM   (0x02u)
> > +#define SE_MU_IO_FLAGS_USE_SHORT_ADDR        (0x04u)
> > +
> >    struct se_imem_buf {
> >       u8 *buf;
> >       phys_addr_t phyaddr;
> >       u32 size;
> >    };
> >
> > +struct se_buf_desc {
> > +     u8 *shared_buf_ptr;
> > +     u8 *usr_buf_ptr;
> > +     u32 size;
> > +     struct list_head link;
> > +};
> > +
> > +/* Status of a char device */
> > +enum se_if_dev_ctx_status_t {
> > +     SE_IF_CTX_FREE,
> > +     SE_IF_CTX_OPENED
> > +};
> > +
> > +struct se_shared_mem {
> > +     dma_addr_t dma_addr;
> > +     u32 size;
> > +     u32 pos;
> > +     u8 *ptr;
> > +};
> > +
> > +/* Private struct for each char device instance. */
> > +struct se_if_device_ctx {
> > +     struct device *dev;
> > +     struct se_if_priv *priv;
> > +     struct miscdevice miscdev;
> > +
> > +     enum se_if_dev_ctx_status_t status;
> > +     wait_queue_head_t wq;
> > +     struct semaphore fops_lock;
> > +
> > +     u32 pending_hdr;
> > +     struct list_head pending_in;
> > +     struct list_head pending_out;
> > +
> > +     struct se_shared_mem secure_mem;
> > +     struct se_shared_mem non_secure_mem;
> > +
> > +     struct se_api_msg *temp_resp;
> > +     u32 temp_resp_size;
> > +     struct notifier_block se_notify;
> > +};
> > +
> >    /* Header of the messages exchange with the EdgeLock Enclave */
> >    struct se_msg_hdr {
> >       u8 ver;
> > @@ -80,4 +127,6 @@ struct se_if_priv {
> >       struct se_imem_buf imem;
> >    };
> >
> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
> do_cpy);
> > +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx);
> >    #endif
> > diff --git a/include/uapi/linux/se_ioctl.h b/include/uapi/linux/se_ioctl.h
> > new file mode 100644
> > index 000000000000..c2d0a92ef626
> > --- /dev/null
> > +++ b/include/uapi/linux/se_ioctl.h
> > @@ -0,0 +1,94 @@
> > +/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-
> Clause*/
> > +/*
> > + * Copyright 2024 NXP
> > + */
> > +
> > +#ifndef SE_IOCTL_H
> > +#define SE_IOCTL_H
> > +
> > +/* IOCTL definitions. */
> > +
> > +struct se_ioctl_setup_iobuf {
> > +     u8 *user_buf;
> > +     u32 length;
> > +     u32 flags;
> > +     u64 ele_addr;
> > +};
> > +
> > +struct se_ioctl_shared_mem_cfg {
> > +     u32 base_offset;
> > +     u32 size;
> > +};
> > +
> > +struct se_ioctl_get_if_info {
> > +     u8 se_if_id;
> > +     u8 interrupt_idx;
> > +     u8 tz;
> > +     u8 did;
> > +     u8 cmd_tag;
> > +     u8 rsp_tag;
> > +     u8 success_tag;
> > +     u8 base_api_ver;
> > +     u8 fw_api_ver;
> > +};
> > +
> > +struct se_ioctl_cmd_snd_rcv_rsp_info {
> > +     u32 *tx_buf;
> > +     int tx_buf_sz;
> > +     u32 *rx_buf;
> > +     int rx_buf_sz;
> > +};
> > +
> > +struct se_ioctl_get_soc_info {
> > +     u16 soc_id;
> > +     u16 soc_rev;
> > +};
> > +
> > +/* IO Buffer Flags */
> > +#define SE_IO_BUF_FLAGS_IS_OUTPUT    (0x00u)
> > +#define SE_IO_BUF_FLAGS_IS_INPUT     (0x01u)
> > +#define SE_IO_BUF_FLAGS_USE_SEC_MEM  (0x02u)
> > +#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR       (0x04u)
> > +#define SE_IO_BUF_FLAGS_IS_IN_OUT    (0x10u)
> > +
> > +/* IOCTLS */
> > +#define SE_IOCTL                     0x0A /* like MISC_MAJOR. */
> > +
> > +/*
> > + * ioctl to designated the current fd as logical-reciever.
> > + * This is ioctl is send when the nvm-daemon, a slave to the
> > + * firmware is started by the user.
> > + */
> > +#define SE_IOCTL_ENABLE_CMD_RCV      _IO(SE_IOCTL, 0x01)
> > +
> > +/*
> > + * ioctl to get the buffer allocated from the memory, which is shared
> > + * between kernel and FW.
> > + * Post allocation, the kernel tagged the allocated memory with:
> > + *  Output
> > + *  Input
> > + *  Input-Output
> > + *  Short address
> > + *  Secure-memory
> > + */
> > +#define SE_IOCTL_SETUP_IOBUF _IOWR(SE_IOCTL, 0x03, \
> > +                                     struct se_ioctl_setup_iobuf)
> > +
> > +/*
> > + * ioctl to get the mu information, that is used to exchange message
> > + * with FW, from user-spaced.
> > + */
> > +#define SE_IOCTL_GET_MU_INFO _IOR(SE_IOCTL, 0x04, \
> > +                                     struct se_ioctl_get_if_info)
> > +/*
> > + * ioctl to get SoC Info from user-space.
> > + */
> > +#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
> > +                                     struct se_ioctl_get_soc_info)
> > +
> > +/*
> > + * ioctl to send command and receive response from user-space.
> > + */
> > +#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
> > +                                     struct se_ioctl_cmd_snd_rcv_rsp_info)
> > +#endif
> >
> > --
> > 2.34.1
> >
> >

Sascha Hauer July 15, 2024, 10:56 a.m. UTC | #4

Hi Frank,

On Fri, Jul 12, 2024 at 06:19:22PM -0400, Frank Li wrote:
> > +	rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
> > +	if (!rx_msg) {
> > +		err = -ENOMEM;
> > +		goto exit;
> > +	}
> > +
> > +	tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
> > +			     cmd_snd_rcv_rsp_info.tx_buf_sz);
> > +	if (IS_ERR(tx_msg)) {
> > +		err = PTR_ERR(tx_msg);
> > +		goto exit;
> > +	}
> > +
> > +	if (tx_msg->header.tag != priv->cmd_tag) {
> > +		err = -EINVAL;
> > +		goto exit;
> > +	}
> > +
> > +	scoped_guard(mutex, &priv->se_if_cmd_lock);
> 
> You totally wrong use scoped_guard in whole patch.
> 
> fun()
> {
>      guard(); //which means lock here
>      ...
>      return; // unlock here
> }
> 
> scoped_guard()
> {     // lock here
>       ...
>       //unlock here
> }
> 
> your code scoped_guard(mutex, &priv->se_if_cmd_lock);
> is equal to
>  
>       mutex_lock();
>       mutex_unlock();
> 
> Nothing protected by mutex lock at all.

Thanks for bringing this on the table again. I already mourned about
this in v2 of this series, but didn't notice the issue wasn't fixed
then.

Sascha

Amit Singh Tomar July 16, 2024, 3:30 a.m. UTC | #5

On 7/15/2024 2:33 PM, Pankaj Gupta wrote:
>> >
>> > Signed-off-by: Pankaj Gupta <[e-mail]>
>> > ---
>> >    Documentation/ABI/testing/se-cdev |  43 +++
>> >    drivers/firmware/imx/ele_common.c | 192 ++++++++++-
>> >    drivers/firmware/imx/ele_common.h |   4 +
>> >    drivers/firmware/imx/se_ctrl.c    | 697
>> ++++++++++++++++++++++++++++++++++++++
>> >    drivers/firmware/imx/se_ctrl.h    |  49 +++
>> >    include/uapi/linux/se_ioctl.h     |  94 +++++
>> >    6 files changed, 1076 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/Documentation/ABI/testing/se-cdev
>> b/Documentation/ABI/testing/se-cdev
>> > new file mode 100644
>> > index 000000000000..3451c909ccc4
>> > --- /dev/null
>> > +++ b/Documentation/ABI/testing/se-cdev
>> > @@ -0,0 +1,43 @@
>> > +What:                /dev/<se>_mu[0-9]+_ch[0-9]+
>> > +Date:                May 2024
>> > +KernelVersion:       6.8
>> > +Contact:     [e-mail], [e-mail]
>> > +Description:
>> > +             NXP offers multiple hardware IP(s) for secure enclaves like EdgeLock-
>> > +             Enclave(ELE), SECO. The character device file descriptors
>> > +             /dev/<se>_mu*_ch* are the interface between userspace NXP's
>> secure-
>> > +             enclave shared library and the kernel driver.
>> > +
>> > +             The ioctl(2)-based ABI is defined and documented in
>> > +             [include]<linux/firmware/imx/ele_mu_ioctl.h>.
>> > +             ioctl(s) are used primarily for:
>> > +                     - shared memory management
>> > +                     - allocation of I/O buffers
>> > +                     - getting mu info
>> > +                     - setting a dev-ctx as receiver to receive all the commands from
>> FW
>> > +                     - getting SoC info
>> > +                     - send command and receive command response
>> > +
>> > +             The following file operations are supported:
>> > +
>> > +             open(2)
>> > +               Currently the only useful flags are O_RDWR.
>> > +
>> > +             read(2)
>> > +               Every read() from the opened character device context is waiting on
>> > +               wait_event_interruptible, that gets set by the registered mailbox
>> callback
>> > +               function, indicating a message received from the firmware on
>> message-
>> > +               unit.
>> > +
>> > +             write(2)
>> > +               Every write() to the opened character device context needs to
>> acquire
>> > +               mailbox_lock before sending message on to the message unit.
>> > +
>> > +             close(2)
>> > +               Stops and frees up the I/O contexts that were associated
>> > +               with the file descriptor.
>> > +
>> > +Users:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldef&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=tlWEfCGEI9rQKPNa6Hqtp12aeU3xAt52L_W8G0a_gns&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldef&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=tlWEfCGEI9rQKPNa6Hqtp12aeU3xAt52L_W8G0a_gns&e=>
>> ense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
>> 2Dimx_imx-2Dsecure-
>> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
>> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
>> 4HUlH7ooyxfcf-
>> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
>> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
>> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
>> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120882519
>> 7%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
>> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=%2F%2FHN
>> V%2F%2FlYkPyoKDXFYvd47oIeKHTR7rnwtgz%2FYm4Szg%3D&reserved=0
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furld&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=5yRhH69PhbqhbDOL5Ob4suOtQm4EnfbilespsbVU0cU&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furld&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=5yRhH69PhbqhbDOL5Ob4suOtQm4EnfbilespsbVU0cU&e=>
>> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
>> 2Dimx_imx-2Dsecure-
>> 2Denclave.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%
>> 3DV_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
>> 4HUlH7ooyxfcf-
>> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DA4zE7ce-
>> kjpGZKtsRrqZiqW7asUowcGapT0QWWzWW3k%26e%3D&data=05%7C02%7
>> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
>> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120882963
>> 1%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
>> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=Qyd5KBGqb
>> 78IHjvFQmAyJlq5YSbbViboRTLl0IyGxzg%3D&reserved=0>,
>> > +
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldef&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=tlWEfCGEI9rQKPNa6Hqtp12aeU3xAt52L_W8G0a_gns&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldef&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=tlWEfCGEI9rQKPNa6Hqtp12aeU3xAt52L_W8G0a_gns&e=>
>> ense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
>> 2Dimx_imx-
>> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
>> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
>> 4HUlH7ooyxfcf-
>> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
>> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
>> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
>> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120883392
>> 8%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
>> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=%2FzaGw%
>> 2BcCV%2F%2FMUA1tdxVNhwE0avSM18wIriqH1%2FMoohQ%3D&reserved=
>> 0
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furld&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=5yRhH69PhbqhbDOL5Ob4suOtQm4EnfbilespsbVU0cU&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furld&d=DwIFAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU&m=irs9uaMkZhrBGwocSQHnF3oPtWbcHMxKGUrMqKRCEPlpxSwXEjtvRG6tSZIgZpdP&s=5yRhH69PhbqhbDOL5Ob4suOtQm4EnfbilespsbVU0cU&e=>
>> efense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__github.com_nxp-
>> 2Dimx_imx-
>> 2Dsmw.git%26d%3DDwICaQ%26c%3DnKjWec2b6R0mOyPaz7xtfQ%26r%3D
>> V_GK7jRuCHDErm6txmgDK1-MbUihtnSQ3gPgB-A-JKU%26m%3D3B5Yr-
>> 4HUlH7ooyxfcf-
>> aduiDYoo4kM4RS1h04NEzdn8QxoJjMviHugQtMh04YXm%26s%3DT2WGFwK
>> VpY19AaCUWWaSX7SllYLFZ6bFKZspKqc2Nuw%26e%3D&data=05%7C02%7
>> Cpankaj.gupta%40nxp.com%7C209a9f8fa717476622e308dca49f4664%7C6
>> 86ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63856625120883820
>> 8%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
>> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=7EHPHbB5Y
>> XpDKVGIjHAyj8X1Kr1Gjba%2FcrwQPYgvP2k%3D&reserved=0>
>> > +             crypto/skcipher,
>> > +             drivers/nvmem/imx-ocotp-ele.c
>> > diff --git a/drivers/firmware/imx/ele_common.c
>> b/drivers/firmware/imx/ele_common.c
>> > index b2be32550e9b..88169cd8f369 100644
>> > --- a/drivers/firmware/imx/ele_common.c
>> > +++ b/drivers/firmware/imx/ele_common.c
>> > @@ -78,6 +78,149 @@ int ele_msg_send_rcv(struct se_if_priv *priv, void
>> *tx_msg, void *rx_msg)
>> >       return err;
>> >    }
>> >
>> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
>> > +                     void *rx_buf,
>> > +                     int rx_buf_sz)
>> > +{
>> > +     struct se_msg_hdr *header;
>> > +     int err;
>> > +
>> > +     err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
>> > +     if (err) {
>> > +             dev_err(dev_ctx->dev,
>> > +                     "%s: Err[0x%x]:Interrupted by signal.\n",
>> > +                     dev_ctx->miscdev.name, err);
>> > +             goto exit;
>> > +     }
>> > +
>> > +     header = (struct se_msg_hdr *) dev_ctx->temp_resp;
>> > +
>> > +     if (header->tag == dev_ctx->priv->rsp_tag) {
>> > +             if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv-
>> >waiting_rsp_dev != dev_ctx) {
>> > +                     dev_warn(dev_ctx->dev,
>> > +                     "Dev-ctx waiting for response mismatch (%s != %s).\n",
>> > +                     dev_ctx->miscdev.name, dev_ctx->priv->waiting_rsp_dev-
>> >miscdev.name);
>> > +                     err = -EPERM;
>> > +                     goto exit;
>> > +             }
>> > +     }
>> > +
>> > +     dev_dbg(dev_ctx->dev,
>> > +             "%s: %s %s\n",
>> > +             dev_ctx->miscdev.name,
>> > +             __func__,
>> > +             "message received, start transmit to user");
>> > +
>> > +     /*
>> > +      * Check that the size passed as argument is larger than
>> > +      * the one carried in the message.
>> > +      *
>> > +      * In case of US-command/response, the dev_ctx->temp_resp_size
>> > +      * is set before sending the command.
>> > +      *
>> > +      * In case of NVM Slave-command/response, the dev_ctx-
>> >temp_resp_size
>> > +      * is set after receing the message from mailbox.
>> > +      */
>> > +     if (dev_ctx->temp_resp_size > rx_buf_sz) {
>> > +             dev_err(dev_ctx->dev,
>> > +                     "%s: User buffer too small (%d < %d)\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     rx_buf_sz, dev_ctx->temp_resp_size);
>> > +              dev_ctx->temp_resp_size = rx_buf_sz;
>> > +     }
>> > +
>> > +     /* We may need to copy the output data to user before
>> > +      * delivering the completion message.
>> > +      */
>> > +     err = se_dev_ctx_cpy_out_data(dev_ctx, true);
>> > +     if (err < 0)
>> > +             goto exit;
>> > +
>> > +     /* Copy data from the buffer */
>> > +     print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
>> > +                          dev_ctx->temp_resp, dev_ctx->temp_resp_size, false);
>> > +     if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx-
>> >temp_resp_size)) {
>> > +             dev_err(dev_ctx->dev,
>> > +                     "%s: Failed to copy to user\n",
>> > +                     dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     err = dev_ctx->temp_resp_size;
>> > +exit:
>> > +     if (err < 0)
>> > +             se_dev_ctx_cpy_out_data(dev_ctx, false);
>> > +
>> > +     /* free memory allocated on the shared buffers. */
>> > +     dev_ctx->secure_mem.pos = 0;
>> > +     dev_ctx->non_secure_mem.pos = 0;
>> > +
>> > +     dev_ctx->pending_hdr = 0;
>> > +     se_dev_ctx_shared_mem_cleanup(dev_ctx);
>> > +
>> > +     return err;
>> > +}
>> > +
>> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
>> > +                      void *tx_msg, int tx_msg_sz)
>> > +{
>> > +     struct se_if_priv *priv = dev_ctx->priv;
>> > +     struct se_msg_hdr *header;
>> > +     u32 size_to_send;
>> > +     int err;
>> > +
>> > +     header = (struct se_msg_hdr *) tx_msg;
>> > +
>> > +     /*
>> > +      * Check that the size passed as argument matches the size
>> > +      * carried in the message.
>> > +      */
>> > +     size_to_send = header->size << 2;
>> > +
>> > +     if (size_to_send != tx_msg_sz) {
>> > +             err = -EINVAL;
>> > +             dev_err(priv->dev,
>> > +                     "%s: User buf hdr(0x%x) sz mismatced with input-sz
>> (%d != %d).\n",
>> > +                     dev_ctx->miscdev.name, *(u32 *)header, size_to_send,
>> tx_msg_sz);
>> > +             goto exit;
>> > +     }
>> > +
>> > +     /* Check the message is valid according to tags */
>> > +     if (header->tag == priv->rsp_tag) {
>> > +             /* Check the device context can send the command */
>> > +             if (dev_ctx != priv->cmd_receiver_dev) {
>> > +                     dev_err(priv->dev,
>> > +                             "%s: Channel not configured to send resp to FW.",
>> > +                             dev_ctx->miscdev.name);
>> > +                     err = -EPERM;
>> > +                     goto exit;
>> > +             }
>> > +     } else if (header->tag == priv->cmd_tag) {
>> > +             if (priv->waiting_rsp_dev != dev_ctx) {
>> > +                     dev_err(priv->dev,
>> > +                             "%s: Channel not configured to send cmd to FW.",
>> > +                             dev_ctx->miscdev.name);
>> > +                     err = -EPERM;
>> > +                     goto exit;
>> > +             }
>> > +             lockdep_assert_held(&priv->se_if_cmd_lock);
>> 
>> nit: Placement of this call is bit unusual (or do have some reason to
>> it), it might be better to place it at the beginning of the function.
> 
> The command lock is taken only in the case of command-message. Hence it placed under check for command message.
I thought lockdep_assert_held was used to ensure that 
ele_miscdev_msg_send is called while holding a lock, but I'm still not 
clear on why it's placed here.
> 
>> 
>> > +     } else {
>> > +             dev_err(priv->dev,
>> > +                     "%s: The message does not have a valid TAG\n",
>> > +                     dev_ctx->miscdev.name);
>> > +             err = -EINVAL;
>> > +             goto exit;
>> > +     }
>> > +     err = ele_msg_send(priv, tx_msg);
>> > +     if (err < 0)
>> > +             goto exit;
>> > +
>> > +     err = size_to_send;
>> > +exit:
>> > +     return err;
>> > +}
>> > +
>> >    static bool exception_for_size(struct se_if_priv *priv,
>> >                               struct se_msg_hdr *header)
>> >    {
>> > @@ -99,6 +242,7 @@ static bool exception_for_size(struct se_if_priv *priv,
>> >    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
>> >    {
>> >       struct device *dev = mbox_cl->dev;
>> > +     struct se_if_device_ctx *dev_ctx;
>> >       struct se_if_priv *priv;
>> >       struct se_msg_hdr *header;
>> >       u32 rx_msg_sz;
>> > @@ -114,8 +258,50 @@ void se_if_rx_callback(struct mbox_client
>> *mbox_cl, void *msg)
>> >       header = msg;
>> >       rx_msg_sz = header->size << 2;
>> >
>> > -     if (header->tag == priv->rsp_tag) {
>> > -             if (!priv->waiting_rsp_dev) {
>> > +     /* Incoming command: wake up the receiver if any. */
>> > +     if (header->tag == priv->cmd_tag) {
>> > +             dev_dbg(dev, "Selecting cmd receiver\n");
>> > +             dev_ctx = priv->cmd_receiver_dev;
>> > +             /* Pre-allocated buffer of MAX_NVM_MSG_LEN
>> > +              * as the NVM command are initiated by FW.
>> > +              * Size is revealed as part of this call function.
>> > +              */
>> > +             if (rx_msg_sz > MAX_NVM_MSG_LEN) {
>> > +                     dev_err(dev,
>> > +                             "%s: Msg recvd hdr(0x%x) with greater[%d] than allocated
>> buf-sz.\n",
>> > +                             dev_ctx->miscdev.name,
>> > +                             *(u32 *) header,
>> > +                             rx_msg_sz);
>> > +             } else
>> > +                     memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
>> > +
>> > +             /* NVM buffer size are not known prior receiving it from FW.
>> > +              */
>> > +             dev_ctx->temp_resp_size = rx_msg_sz;
>> > +
>> > +             /* Allow user to read */
>> > +             dev_ctx->pending_hdr = 1;
>> > +             wake_up_interruptible(&dev_ctx->wq);
>> > +
>> > +             return;
>> > +     } else if (header->tag == priv->rsp_tag) {
>> > +             if (priv->waiting_rsp_dev) {
>> > +                     dev_dbg(dev, "Selecting rsp waiter\n");
>> > +                     dev_ctx = priv->waiting_rsp_dev;
>> > +                     if (rx_msg_sz != dev_ctx->temp_resp_size
>> > +                             && !exception_for_size(priv, header))
>> > +                             dev_err(dev,
>> > +                                     "%s: Msg RSP hdr(0x%x) with different sz(%d != %d).\n",
>> > +                                     dev_ctx->miscdev.name,
>> > +                                     *(u32 *) header,
>> > +                                     rx_msg_sz, dev_ctx->temp_resp_size);
>> > +                     else
>> > +                             memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
>> > +
>> > +                     /* Allow user to read */
>> > +                     dev_ctx->pending_hdr = 1;
>> > +                     wake_up_interruptible(&dev_ctx->wq);
>> > +             } else {
>> >                       /*
>> >                        * Reading the EdgeLock Enclave response
>> >                        * to the command, sent by other
>> > @@ -132,8 +318,8 @@ void se_if_rx_callback(struct mbox_client *mbox_cl,
>> void *msg)
>> >
>> >                       complete(&priv->done);
>> >                       spin_unlock(&priv->lock);
>> > -                     return;
>> >               }
>> > +             return;
>> >       }
>> >
>> >       dev_err(dev, "Failed to select a device for message: %.8x\n",
>> > diff --git a/drivers/firmware/imx/ele_common.h
>> b/drivers/firmware/imx/ele_common.h
>> > index 5ef775a42ab3..7b1c6bfc138b 100644
>> > --- a/drivers/firmware/imx/ele_common.h
>> > +++ b/drivers/firmware/imx/ele_common.h
>> > @@ -17,6 +17,10 @@ uint32_t se_add_msg_crc(uint32_t *msg, uint32_t
>> msg_len);
>> >    int ele_msg_rcv(struct se_if_priv *priv);
>> >    int ele_msg_send(struct se_if_priv *priv, void *tx_msg);
>> >    int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
>> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
>> > +                     void *rx_msg, int rx_msg_sz);
>> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
>> > +                      void *tx_msg, int tx_msg_sz);
>> >    void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);
>> >    int se_val_rsp_hdr_n_status(struct se_if_priv *priv,
>> >                           struct se_msg_hdr *header,
>> > diff --git a/drivers/firmware/imx/se_ctrl.c b/drivers/firmware/imx/se_ctrl.c
>> > index a844794d2b39..8fb2af0f0dd3 100644
>> > --- a/drivers/firmware/imx/se_ctrl.c
>> > +++ b/drivers/firmware/imx/se_ctrl.c
>> > @@ -23,6 +23,7 @@
>> >    #include <linux/slab.h>
>> >    #include <linux/string.h>
>> >    #include <linux/sys_soc.h>
>> > +#include <uapi/linux/se_ioctl.h>
>> >
>> >    #include "ele_base_msg.h"
>> >    #include "ele_common.h"
>> > @@ -196,6 +197,608 @@ static int se_soc_info(struct se_if_priv *priv,
>> >       return 0;
>> >    }
>> >
>> > +static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx
>> *dev_ctx,
>> > +                                         u64 arg)
>> > +{
>> > +     struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
>> > +     struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
>> > +     struct se_api_msg *tx_msg __free(kfree) = NULL;
>> > +     struct se_api_msg *rx_msg __free(kfree) = NULL;
>> > +     int err = 0;
>> > +
>> > +     if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
>> > +                        sizeof(cmd_snd_rcv_rsp_info))) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
>> > +                     dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: User buffer too small(%d < %d)\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     cmd_snd_rcv_rsp_info.tx_buf_sz,
>> > +                     SE_MU_HDR_SZ);
>> > +             err = -ENOSPC;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
>> > +     if (!rx_msg) {
>> > +             err = -ENOMEM;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
>> > +                          cmd_snd_rcv_rsp_info.tx_buf_sz);
>> > +     if (IS_ERR(tx_msg)) {
>> > +             err = PTR_ERR(tx_msg);
>> > +             goto exit;
>> > +     }
>> > +
>> > +     if (tx_msg->header.tag != priv->cmd_tag) {
>> > +             err = -EINVAL;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     scoped_guard(mutex, &priv->se_if_cmd_lock);
>> > +     priv->waiting_rsp_dev = dev_ctx;
>> > +     dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
>> > +
>> > +     /* Device Context that is assigned to be a
>> > +      * FW's command receiver, has pre-allocated buffer.
>> > +      */
>> > +     if (dev_ctx != priv->cmd_receiver_dev)
>> > +             dev_ctx->temp_resp = rx_msg;
>> > +
>> > +     err = ele_miscdev_msg_send(dev_ctx,
>> > +                                tx_msg,
>> > +                                cmd_snd_rcv_rsp_info.tx_buf_sz);
>> > +     if (err < 0)
>> > +             goto exit;
>> > +
>> > +     cmd_snd_rcv_rsp_info.tx_buf_sz = err;
>> > +
>> > +     err = ele_miscdev_msg_rcv(dev_ctx,
>> > +                               cmd_snd_rcv_rsp_info.rx_buf,
>> > +                               cmd_snd_rcv_rsp_info.rx_buf_sz);
>> > +
>> > +     if (err < 0)
>> > +             goto exit;
>> > +
>> > +     cmd_snd_rcv_rsp_info.rx_buf_sz = err;
>> > +
>> > +exit:
>> > +     dev_ctx->temp_resp_size = 0;
>> > +     priv->waiting_rsp_dev = NULL;
>> > +     if (dev_ctx != priv->cmd_receiver_dev)
>> > +             dev_ctx->temp_resp = NULL;
>> > +
>> > +     if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
>> > +                      sizeof(cmd_snd_rcv_rsp_info))) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
>> > +                     dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +     }
>> > +     return err;
>> > +}
>> > +
>> > +/*
>> > + * File operations for user-space
>> > + */
>> > +
>> > +/* Write a message to the MU. */
>> > +static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
>> > +                             size_t size, loff_t *ppos)
>> > +{
>> > +     struct se_api_msg *tx_msg __free(kfree) = NULL;
>> > +     struct se_if_device_ctx *dev_ctx;
>> > +     struct se_if_priv *priv;
>> > +     int err;
>> > +
>> > +     dev_ctx = container_of(fp->private_data,
>> > +                            struct se_if_device_ctx,
>> > +                            miscdev);
>> > +     priv = dev_ctx->priv;
>> > +     dev_dbg(priv->dev,
>> > +             "%s: write from buf (%p)%zu, ppos=%lld\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     buf, size, ((ppos) ? *ppos : 0));
>> > +
>> > +     if (down_interruptible(&dev_ctx->fops_lock))
>> > +             return -EBUSY;
>> > +
>> > +     if (dev_ctx->status != SE_IF_CTX_OPENED) {
>> > +             err = -EINVAL;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     if (size < SE_MU_HDR_SZ) {
>> > +             dev_err(priv->dev,
>> > +                     "%s: User buffer too small(%zu < %d)\n",
>> > +                             dev_ctx->miscdev.name,
>> > +                             size, SE_MU_HDR_SZ);
>> > +             err = -ENOSPC;
>> > +             goto exit;
>> > +     }
>> > +     tx_msg = memdup_user(buf, size);
>> > +     if (IS_ERR(tx_msg)) {
>> > +             err = PTR_ERR(tx_msg);
>> > +             goto exit;
>> > +     }
>> > +
>> > +     print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
>> > +                          tx_msg, size, false);
>> > +
>> > +     err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
>> > +
>> > +exit:
>> > +     up(&dev_ctx->fops_lock);
>> > +     return err;
>> > +}
>> > +
>> > +/*
>> > + * Read a message from the MU.
>> > + * Blocking until a message is available.
>> > + */
>> > +static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
>> > +                            size_t size, loff_t *ppos)
>> > +{
>> > +     struct se_if_device_ctx *dev_ctx;
>> > +     struct se_if_priv *priv;
>> > +     int err;
>> > +
>> > +     dev_ctx = container_of(fp->private_data,
>> > +                            struct se_if_device_ctx,
>> > +                            miscdev);
>> > +     priv = dev_ctx->priv;
>> > +     dev_dbg(priv->dev,
>> > +             "%s: read to buf %p(%zu), ppos=%lld\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     buf, size, ((ppos) ? *ppos : 0));
>> > +
>> > +     if (down_interruptible(&dev_ctx->fops_lock))
>> > +             return -EBUSY;
>> > +
>> > +     if (dev_ctx->status != SE_IF_CTX_OPENED) {
>> > +             err = -EINVAL;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
>> > +
>> > +exit:
>> > +     up(&dev_ctx->fops_lock);
>> > +     return err;
>> > +}
>> > +
>> > +static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
>> > +                             u64 arg)
>> > +{
>> > +     struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
>> > +     struct se_if_node_info *if_node_info;
>> > +     struct se_ioctl_get_if_info info;
>> > +     int err = 0;
>> > +
>> > +     if_node_info = (struct se_if_node_info *)priv->info;
>> > +
>> > +     info.se_if_id = if_node_info->se_if_id;
>> > +     info.interrupt_idx = 0;
>> > +     info.tz = 0;
>> > +     info.did = if_node_info->se_if_did;
>> > +     info.cmd_tag = if_node_info->cmd_tag;
>> > +     info.rsp_tag = if_node_info->rsp_tag;
>> > +     info.success_tag = if_node_info->success_tag;
>> > +     info.base_api_ver = if_node_info->base_api_ver;
>> > +     info.fw_api_ver = if_node_info->fw_api_ver;
>> > +
>> > +     dev_dbg(priv->dev,
>> > +             "%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     info.se_if_id, info.interrupt_idx, info.tz, info.did);
>> > +
>> > +     if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed to copy mu info to user\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +exit:
>> > +     return err;
>> > +}
>> > +
>> > +/* Need to copy the output data to user-device context.
>> > + */
>> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
>> do_cpy)
>> > +{
>> > +     struct se_buf_desc *b_desc, *temp;
>> > +
>> > +     list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link) {
>> > +             if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr && do_cpy) {
>> > +
>> > +                     dev_dbg(dev_ctx->dev,
>> > +                             "%s: Copy output data to user\n",
>> > +                             dev_ctx->miscdev.name);
>> > +                     if (copy_to_user(b_desc->usr_buf_ptr,
>> > +                                      b_desc->shared_buf_ptr,
>> > +                                      b_desc->size)) {
>> > +                             dev_err(dev_ctx->dev,
>> > +                                     "%s: Failure copying output data to user.",
>> > +                                     dev_ctx->miscdev.name);
>> > +                             return -EFAULT;
>> > +                     }
>> > +             }
>> > +
>> > +             if (b_desc->shared_buf_ptr)
>> > +                     memset(b_desc->shared_buf_ptr, 0, b_desc->size);
>> > +
>> > +             list_del(&b_desc->link);
>> > +             kfree(b_desc);
>> > +     }
>> > +     return 0;
>> > +}
>> > +
>> > +/*
>> > + * Clean the used Shared Memory space,
>> > + * whether its Input Data copied from user buffers, or
>> > + * Data received from FW.
>> > + */
>> > +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
>> > +{
>> > +     struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
>> > +                                              &dev_ctx->pending_out};
>> > +     struct se_buf_desc *b_desc, *temp;
>> > +     int i;
>> > +
>> > +     for (i = 0; i < 2; i++) {
>> > +             list_for_each_entry_safe(b_desc, temp,
>> > +                                      dev_ctx_lists[i], link) {
>> > +
>> > +                     if (b_desc->shared_buf_ptr)
>> > +                             memset(b_desc->shared_buf_ptr, 0, b_desc->size);
>> > +
>> > +                     list_del(&b_desc->link);
>> > +                     kfree(b_desc);
>> > +             }
>> > +     }
>> > +}
>> > +
>> > +/*
>> > + * Copy a buffer of data to/from the user and return the address to use in
>> > + * messages
>> > + */
>> > +static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
>> > +                                         u64 arg)
>> > +{
>> > +     struct se_shared_mem *shared_mem = NULL;
>> > +     struct se_ioctl_setup_iobuf io = {0};
>> > +     struct se_buf_desc *b_desc = NULL;
>> > +     int err = 0;
>> > +     u32 pos;
>> > +
>> > +     if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed copy iobuf config from user\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     dev_dbg(dev_ctx->priv->dev,
>> > +                     "%s: io [buf: %p(%d) flag: %x]\n",
>> > +                     dev_ctx->miscdev.name,
>> > +                     io.user_buf, io.length, io.flags);
>> > +
>> > +     if (io.length == 0 || !io.user_buf) {
>> > +             /*
>> > +              * Accept NULL pointers since some buffers are optional
>> > +              * in FW commands. In this case we should return 0 as
>> > +              * pointer to be embedded into the message.
>> > +              * Skip all data copy part of code below.
>> > +              */
>> > +             io.ele_addr = 0;
>> > +             goto copy;
>> > +     }
>> > +
>> > +     /* Select the shared memory to be used for this buffer. */
>> > +     if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
>> > +             /* App requires to use secure memory for this buffer.*/
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed allocate SEC MEM memory\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     } else {
>> > +             /* No specific requirement for this buffer. */
>> > +             shared_mem = &dev_ctx->non_secure_mem;
>> > +     }
>> > +
>> > +     /* Check there is enough space in the shared memory. */
>> > +     if (shared_mem->size < shared_mem->pos ||
>> > +             round_up(io.length, 8u) >= (shared_mem->size - shared_mem-
>> >pos)) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Not enough space in shared memory\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             err = -ENOMEM;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     /* Allocate space in shared memory. 8 bytes aligned. */
>> > +     pos = shared_mem->pos;
>> > +     shared_mem->pos += round_up(io.length, 8u);
>> > +     io.ele_addr = (u64)shared_mem->dma_addr + pos;
>> > +
>> > +     if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
>> > +         !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
>> > +             /*Add base address to get full address.*/
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed allocate SEC MEM memory\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     memset(shared_mem->ptr + pos, 0, io.length);
>> > +     if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
>> > +         (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
>> > +             /*
>> > +              * buffer is input:
>> > +              * copy data from user space to this allocated buffer.
>> > +              */
>> > +             if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
>> > +                                io.length)) {
>> > +                     dev_err(dev_ctx->priv->dev,
>> > +                             "%s: Failed copy data to shared memory\n",
>> > +                             dev_ctx->miscdev.name);
>> > +                     err = -EFAULT;
>> > +                     goto exit;
>> > +             }
>> > +     }
>> > +
>> > +     b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
>> > +     if (!b_desc) {
>> > +             err = -ENOMEM;
>> > +             goto exit;
>> > +     }
>> > +
>> > +copy:
>> > +     /* Provide the EdgeLock Enclave address to user space only if success.*/
>> > +     if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed to copy iobuff setup to user\n",
>> > +                             dev_ctx->miscdev.name);
>> > +             kfree(b_desc);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     if (b_desc) {
>> > +             b_desc->shared_buf_ptr = shared_mem->ptr + pos;
>> > +             b_desc->usr_buf_ptr = io.user_buf;
>> > +             b_desc->size = io.length;
>> > +
>> > +             if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
>> > +                     /*
>> > +                      * buffer is input:
>> > +                      * add an entry in the "pending input buffers" list so
>> > +                      * that copied data can be cleaned from shared memory
>> > +                      * later.
>> > +                      */
>> > +                     list_add_tail(&b_desc->link, &dev_ctx->pending_in);
>> > +             } else {
>> > +                     /*
>> > +                      * buffer is output:
>> > +                      * add an entry in the "pending out buffers" list so data
>> > +                      * can be copied to user space when receiving Secure-Enclave
>> > +                      * response.
>> > +                      */
>> > +                     list_add_tail(&b_desc->link, &dev_ctx->pending_out);
>> > +             }
>> > +     }
>> > +
>> > +exit:
>> > +     return err;
>> > +}
>> > +
>> > +/* IOCTL to provide SoC information */
>> > +static int se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx
>> *dev_ctx,
>> > +                                          u64 arg)
>> > +{
>> > +     const struct se_if_node_info_list *info_list;
>> > +     struct se_ioctl_get_soc_info soc_info;
>> > +     int err = -EINVAL;
>> > +
>> > +     info_list = device_get_match_data(dev_ctx->priv->dev);
>> > +     if (!info_list)
>> > +             goto exit;
>> > +
>> > +     soc_info.soc_id = info_list->soc_id;
>> > +     soc_info.soc_rev = dev_ctx->priv->soc_rev;
>> > +
>> > +     err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
>> > +     if (err) {
>> > +             dev_err(dev_ctx->priv->dev,
>> > +                     "%s: Failed to copy soc info to user\n",
>> > +                     dev_ctx->miscdev.name);
>> > +             err = -EFAULT;
>> > +             goto exit;
>> > +     }
>> > +
>> > +exit:
>> > +     return err;
>> > +}
>> > +
>> > +/* Open a character device. */
>> > +static int se_if_fops_open(struct inode *nd, struct file *fp)
>> > +{
>> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
>> > +                                                     struct se_if_device_ctx,
>> > +                                                     miscdev);
>> > +     int err = 0;
>> > +
>> > +     /* Avoid race if opened at the same time */
>> > +     if (down_trylock(&dev_ctx->fops_lock))
>> > +             return -EBUSY;
>> > +
>> > +     /* Authorize only 1 instance. */
>> > +     if (dev_ctx->status != SE_IF_CTX_FREE) {
>> > +             err = -EBUSY;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     /*
>> > +      * Allocate some memory for data exchanges with S40x.
>> > +      * This will be used for data not requiring secure memory.
>> > +      */
>> > +     dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
>> > +                                     MAX_DATA_SIZE_PER_USER,
>> > +                                     &dev_ctx->non_secure_mem.dma_addr,
>> > +                                     GFP_KERNEL);
>> > +     if (!dev_ctx->non_secure_mem.ptr) {
>> > +             err = -ENOMEM;
>> > +             goto exit;
>> > +     }
>> > +
>> > +     dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
>> > +     dev_ctx->non_secure_mem.pos = 0;
>> > +     dev_ctx->status = SE_IF_CTX_OPENED;
>> > +
>> > +     dev_ctx->pending_hdr = 0;
>> > +
>> > +     goto exit;
>> > +
>> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
>> > +                        dev_ctx->non_secure_mem.ptr,
>> > +                        dev_ctx->non_secure_mem.dma_addr);
>> > +
>> > +exit:
>> > +     up(&dev_ctx->fops_lock);
>> > +     return err;
>> > +}
>> > +
>> > +/* Close a character device. */
>> > +static int se_if_fops_close(struct inode *nd, struct file *fp)
>> > +{
>> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
>> > +                                                     struct se_if_device_ctx,
>> > +                                                     miscdev);
>> > +     struct se_if_priv *priv = dev_ctx->priv;
>> > +
>> > +     /* Avoid race if closed at the same time */
>> > +     if (down_trylock(&dev_ctx->fops_lock))
>> > +             return -EBUSY;
>> > +
>> > +     /* The device context has not been opened */
>> > +     if (dev_ctx->status != SE_IF_CTX_OPENED)
>> > +             goto exit;
>> > +
>> > +     /* check if this device was registered as command receiver. */
>> > +     if (priv->cmd_receiver_dev == dev_ctx) {
>> > +             priv->cmd_receiver_dev = NULL;
>> > +             kfree(dev_ctx->temp_resp);
>> > +     }
>> > +
>> > +     /* check if this device was registered as waiting response. */
>> > +     if (priv->waiting_rsp_dev == dev_ctx) {
>> > +             priv->waiting_rsp_dev = NULL;
>> > +             mutex_unlock(&priv->se_if_cmd_lock);
>> > +     }
>> > +
>> > +     /* Unmap secure memory shared buffer. */
>> > +     if (dev_ctx->secure_mem.ptr)
>> > +             devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
>> > +
>> > +     dev_ctx->secure_mem.ptr = NULL;
>> > +     dev_ctx->secure_mem.dma_addr = 0;
>> > +     dev_ctx->secure_mem.size = 0;
>> > +     dev_ctx->secure_mem.pos = 0;
>> > +
>> > +     /* Free non-secure shared buffer. */
>> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
>> > +                        dev_ctx->non_secure_mem.ptr,
>> > +                        dev_ctx->non_secure_mem.dma_addr);
>> > +
>> > +     dev_ctx->non_secure_mem.ptr = NULL;
>> > +     dev_ctx->non_secure_mem.dma_addr = 0;
>> > +     dev_ctx->non_secure_mem.size = 0;
>> > +     dev_ctx->non_secure_mem.pos = 0;
>> > +     se_dev_ctx_shared_mem_cleanup(dev_ctx);
>> > +     dev_ctx->status = SE_IF_CTX_FREE;
>> > +
>> > +exit:
>> > +     up(&dev_ctx->fops_lock);
>> > +     return 0;
>> > +}
>> > +
>> > +/* IOCTL entry point of a character device */
>> > +static long se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
>> > +{
>> > +     struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
>> > +                                                     struct se_if_device_ctx,
>> > +                                                     miscdev);
>> > +     struct se_if_priv *se_if_priv = dev_ctx->priv;
>> > +     int err = -EINVAL;
>> > +
>> > +     /* Prevent race during change of device context */
>> > +     if (down_interruptible(&dev_ctx->fops_lock))
>> > +             return -EBUSY;
>> > +
>> > +     switch (cmd) {
>> > +     case SE_IOCTL_ENABLE_CMD_RCV:
>> > +             if (!se_if_priv->cmd_receiver_dev) {
>> > +                     err = 0;
>> > +                     se_if_priv->cmd_receiver_dev = dev_ctx;
>> > +                     dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN,
>> GFP_KERNEL);
>> > +                     if (!dev_ctx->temp_resp)
>> > +                             err = -ENOMEM;
>> > +             }
>> > +             break;
>> > +     case SE_IOCTL_GET_MU_INFO:
>> > +             err = se_ioctl_get_mu_info(dev_ctx, arg);
>> > +             break;
>> > +     case SE_IOCTL_SETUP_IOBUF:
>> > +             err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
>> > +             break;
>> > +     case SE_IOCTL_GET_SOC_INFO:
>> > +             err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
>> > +             break;
>> > +     case SE_IOCTL_CMD_SEND_RCV_RSP:
>> > +             err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
>> > +             break;
>> > +
>> > +     default:
>> > +             err = -EINVAL;
>> > +             dev_dbg(se_if_priv->dev,
>> > +                     "%s: IOCTL %.8x not supported\n",
>> > +                             dev_ctx->miscdev.name,
>> > +                             cmd);
>> > +     }
>> > +
>> > +     up(&dev_ctx->fops_lock);
>> > +     return (long)err;
>> > +}
>> > +
>> > +/* Char driver setup */
>> > +static const struct file_operations se_if_fops = {
>> > +     .open           = se_if_fops_open,
>> > +     .owner          = THIS_MODULE,
>> > +     .release        = se_if_fops_close,
>> > +     .unlocked_ioctl = se_ioctl,
>> > +     .read           = se_if_fops_read,
>> > +     .write          = se_if_fops_write,
>> > +};
>> > +
>> > +/* interface for managed res to unregister a character device */
>> > +static void if_misc_deregister(void *miscdevice)
>> > +{
>> > +     misc_deregister(miscdevice);
>> > +}
>> > +
>> >    /* interface for managed res to free a mailbox channel */
>> >    static void if_mbox_free_channel(void *mbox_chan)
>> >    {
>> > @@ -233,6 +836,7 @@ static void se_if_probe_cleanup(struct
>> platform_device *pdev)
>> >    {
>> >       struct device *dev = &pdev->dev;
>> >       struct se_if_priv *priv;
>> > +     int i;
>> >
>> >       priv = dev_get_drvdata(dev);
>> >
>> > @@ -252,6 +856,17 @@ static void se_if_probe_cleanup(struct
>> platform_device *pdev)
>> >               priv->imem.buf = NULL;
>> >       }
>> >
>> > +     if (priv->ctxs) {
>> > +             for (i = 0; i < priv->max_dev_ctx; i++) {
>> > +                     if (priv->ctxs[i]) {
>> > +                             devm_remove_action(dev,
>> > +                                                if_misc_deregister,
>> > +                                                &priv->ctxs[i]->miscdev);
>> > +                             misc_deregister(&priv->ctxs[i]->miscdev);
>> > +                     }
>> > +             }
>> > +     }
>> > +
>> >       /* No need to check, if reserved memory is allocated
>> >        * before calling for its release. Or clearing the
>> >        * un-set bit.
>> > @@ -259,6 +874,74 @@ static void se_if_probe_cleanup(struct
>> platform_device *pdev)
>> >       of_reserved_mem_device_release(dev);
>> >    }
>> >
>> > +static int init_device_context(struct se_if_priv *priv)
>> > +{
>> > +     const struct se_if_node_info *info = priv->info;
>> > +     struct se_if_device_ctx *dev_ctx;
>> > +     u8 *devname;
>> > +     int ret = 0;
>> > +     int i;
>> > +
>> > +     priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv-
>> >max_dev_ctx,
>> > +                               GFP_KERNEL);
>> > +
>> > +     if (!priv->ctxs) {
>> > +             ret = -ENOMEM;
>> > +             return ret;
>> > +     }
>> > +
>> > +     /* Create users */
>> > +     for (i = 0; i < priv->max_dev_ctx; i++) {
>> > +             dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx), GFP_KERNEL);
>> > +             if (!dev_ctx) {
>> > +                     ret = -ENOMEM;
>> > +                     return ret;
>> > +             }
>> > +
>> > +             dev_ctx->dev = priv->dev;
>> > +             dev_ctx->status = SE_IF_CTX_FREE;
>> > +             dev_ctx->priv = priv;
>> > +
>> > +             priv->ctxs[i] = dev_ctx;
>> > +
>> > +             /* Default value invalid for an header. */
>> > +             init_waitqueue_head(&dev_ctx->wq);
>> > +
>> > +             INIT_LIST_HEAD(&dev_ctx->pending_out);
>> > +             INIT_LIST_HEAD(&dev_ctx->pending_in);
>> > +             sema_init(&dev_ctx->fops_lock, 1);
>> > +
>> > +             devname = devm_kasprintf(priv->dev, GFP_KERNEL, "%s_ch%d",
>> > +                                      info->se_name, i);
>> > +             if (!devname) {
>> > +                     ret = -ENOMEM;
>> > +                     return ret;
>> > +             }
>> > +
>> > +             dev_ctx->miscdev.name = devname;
>> > +             dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
>> > +             dev_ctx->miscdev.fops = &se_if_fops;
>> > +             dev_ctx->miscdev.parent = priv->dev;
>> > +             ret = misc_register(&dev_ctx->miscdev);
>> > +             if (ret) {
>> > +                     dev_err(priv->dev, "failed to register misc device %d\n",
>> > +                             ret);
>> > +                     return ret;
>> > +             }
>> > +
>> > +             ret = devm_add_action(priv->dev, if_misc_deregister,
>> > +                                   &dev_ctx->miscdev);
>> > +             if (ret) {
>> > +                     dev_err(priv->dev,
>> > +                             "failed[%d] to add action to the misc-dev\n",
>> > +                             ret);
>> > +                     return ret;
>> > +             }
>> > +     }
>> > +
>> > +     return ret;
>> > +}
>> > +
>> >    static void se_load_firmware(const struct firmware *fw, void *context)
>> >    {
>> >       struct se_if_priv *priv = (struct se_if_priv *) context;
>> > @@ -427,6 +1110,16 @@ static int se_if_probe(struct platform_device
>> *pdev)
>> >               ret = 0;
>> >       }
>> >
>> > +     if (info->max_dev_ctx) {
>> > +             ret = init_device_context(priv);
>> > +             if (ret) {
>> > +                     dev_err(dev,
>> > +                             "Failed[0x%x] to create device contexts.\n",
>> > +                             ret);
>> > +                     goto exit;
>> > +             }
>> > +     }
>> > +
>> >       dev_info(dev, "i.MX secure-enclave: %s interface to firmware,
>> configured.\n",
>> >                info->se_name);
>> >       return ret;
>> > @@ -467,6 +1160,10 @@ static int se_resume(struct device *dev)
>> >    {
>> >       struct se_if_priv *priv = dev_get_drvdata(dev);
>> >       const struct se_if_node_info *info = priv->info;
>> > +     int i;
>> > +
>> > +     for (i = 0; i < priv->max_dev_ctx; i++)
>> > +             wake_up_interruptible(&priv->ctxs[i]->wq);
>> >
>> >       if (info && info->imem_mgmt)
>> >               se_restore_imem_state(priv);
>> > diff --git a/drivers/firmware/imx/se_ctrl.h b/drivers/firmware/imx/se_ctrl.h
>> > index 4be2235d2170..b49346372746 100644
>> > --- a/drivers/firmware/imx/se_ctrl.h
>> > +++ b/drivers/firmware/imx/se_ctrl.h
>> > @@ -13,15 +13,62 @@
>> >    #define MAX_FW_LOAD_RETRIES                50
>> >
>> >    #define RES_STATUS(x)                      FIELD_GET(0x000000ff, x)
>> > +#define MAX_DATA_SIZE_PER_USER               (65 * 1024)
>> > +#define MAX_NVM_MSG_LEN                      (256)
>> >    #define MESSAGING_VERSION_6                0x6
>> >    #define MESSAGING_VERSION_7                0x7
>> >
>> > +#define SE_MU_IO_FLAGS_USE_SEC_MEM   (0x02u)
>> > +#define SE_MU_IO_FLAGS_USE_SHORT_ADDR        (0x04u)
>> > +
>> >    struct se_imem_buf {
>> >       u8 *buf;
>> >       phys_addr_t phyaddr;
>> >       u32 size;
>> >    };
>> >
>> > +struct se_buf_desc {
>> > +     u8 *shared_buf_ptr;
>> > +     u8 *usr_buf_ptr;
>> > +     u32 size;
>> > +     struct list_head link;
>> > +};
>> > +
>> > +/* Status of a char device */
>> > +enum se_if_dev_ctx_status_t {
>> > +     SE_IF_CTX_FREE,
>> > +     SE_IF_CTX_OPENED
>> > +};
>> > +
>> > +struct se_shared_mem {
>> > +     dma_addr_t dma_addr;
>> > +     u32 size;
>> > +     u32 pos;
>> > +     u8 *ptr;
>> > +};
>> > +
>> > +/* Private struct for each char device instance. */
>> > +struct se_if_device_ctx {
>> > +     struct device *dev;
>> > +     struct se_if_priv *priv;
>> > +     struct miscdevice miscdev;
>> > +
>> > +     enum se_if_dev_ctx_status_t status;
>> > +     wait_queue_head_t wq;
>> > +     struct semaphore fops_lock;
>> > +
>> > +     u32 pending_hdr;
>> > +     struct list_head pending_in;
>> > +     struct list_head pending_out;
>> > +
>> > +     struct se_shared_mem secure_mem;
>> > +     struct se_shared_mem non_secure_mem;
>> > +
>> > +     struct se_api_msg *temp_resp;
>> > +     u32 temp_resp_size;
>> > +     struct notifier_block se_notify;
>> > +};
>> > +
>> >    /* Header of the messages exchange with the EdgeLock Enclave */
>> >    struct se_msg_hdr {
>> >       u8 ver;
>> > @@ -80,4 +127,6 @@ struct se_if_priv {
>> >       struct se_imem_buf imem;
>> >    };
>> >
>> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
>> do_cpy);
>> > +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx);
>> >    #endif
>> > diff --git a/include/uapi/linux/se_ioctl.h b/include/uapi/linux/se_ioctl.h
>> > new file mode 100644
>> > index 000000000000..c2d0a92ef626
>> > --- /dev/null
>> > +++ b/include/uapi/linux/se_ioctl.h
>> > @@ -0,0 +1,94 @@
>> > +/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-
>> Clause*/
>> > +/*
>> > + * Copyright 2024 NXP
>> > + */
>> > +
>> > +#ifndef SE_IOCTL_H
>> > +#define SE_IOCTL_H
>> > +
>> > +/* IOCTL definitions. */
>> > +
>> > +struct se_ioctl_setup_iobuf {
>> > +     u8 *user_buf;
>> > +     u32 length;
>> > +     u32 flags;
>> > +     u64 ele_addr;
>> > +};
>> > +
>> > +struct se_ioctl_shared_mem_cfg {
>> > +     u32 base_offset;
>> > +     u32 size;
>> > +};
>> > +
>> > +struct se_ioctl_get_if_info {
>> > +     u8 se_if_id;
>> > +     u8 interrupt_idx;
>> > +     u8 tz;
>> > +     u8 did;
>> > +     u8 cmd_tag;
>> > +     u8 rsp_tag;
>> > +     u8 success_tag;
>> > +     u8 base_api_ver;
>> > +     u8 fw_api_ver;
>> > +};
>> > +
>> > +struct se_ioctl_cmd_snd_rcv_rsp_info {
>> > +     u32 *tx_buf;
>> > +     int tx_buf_sz;
>> > +     u32 *rx_buf;
>> > +     int rx_buf_sz;
>> > +};
>> > +
>> > +struct se_ioctl_get_soc_info {
>> > +     u16 soc_id;
>> > +     u16 soc_rev;
>> > +};
>> > +
>> > +/* IO Buffer Flags */
>> > +#define SE_IO_BUF_FLAGS_IS_OUTPUT    (0x00u)
>> > +#define SE_IO_BUF_FLAGS_IS_INPUT     (0x01u)
>> > +#define SE_IO_BUF_FLAGS_USE_SEC_MEM  (0x02u)
>> > +#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR       (0x04u)
>> > +#define SE_IO_BUF_FLAGS_IS_IN_OUT    (0x10u)
>> > +
>> > +/* IOCTLS */
>> > +#define SE_IOCTL                     0x0A /* like MISC_MAJOR. */
>> > +
>> > +/*
>> > + * ioctl to designated the current fd as logical-reciever.
>> > + * This is ioctl is send when the nvm-daemon, a slave to the
>> > + * firmware is started by the user.
>> > + */
>> > +#define SE_IOCTL_ENABLE_CMD_RCV      _IO(SE_IOCTL, 0x01)
>> > +
>> > +/*
>> > + * ioctl to get the buffer allocated from the memory, which is shared
>> > + * between kernel and FW.
>> > + * Post allocation, the kernel tagged the allocated memory with:
>> > + *  Output
>> > + *  Input
>> > + *  Input-Output
>> > + *  Short address
>> > + *  Secure-memory
>> > + */
>> > +#define SE_IOCTL_SETUP_IOBUF _IOWR(SE_IOCTL, 0x03, \
>> > +                                     struct se_ioctl_setup_iobuf)
>> > +
>> > +/*
>> > + * ioctl to get the mu information, that is used to exchange message
>> > + * with FW, from user-spaced.
>> > + */
>> > +#define SE_IOCTL_GET_MU_INFO _IOR(SE_IOCTL, 0x04, \
>> > +                                     struct se_ioctl_get_if_info)
>> > +/*
>> > + * ioctl to get SoC Info from user-space.
>> > + */
>> > +#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
>> > +                                     struct se_ioctl_get_soc_info)
>> > +
>> > +/*
>> > + * ioctl to send command and receive response from user-space.
>> > + */
>> > +#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
>> > +                                     struct se_ioctl_cmd_snd_rcv_rsp_info)
>> > +#endif
>> >
>> > --
>> > 2.34.1
>> >
>> >
>

Pankaj Gupta July 16, 2024, 4:50 a.m. UTC | #6

> -----Original Message-----
> From: Frank Li <[e-mail]>
> Sent: Saturday, July 13, 2024 3:49 AM
> To: Pankaj Gupta <[e-mail]>
> Cc: Jonathan Corbet <[e-mail]>; Rob Herring <[e-mail]>;
> Krzysztof Kozlowski <[e-mail]>; Conor Dooley
> <[e-mail]>; Shawn Guo <[e-mail]>; Sascha Hauer
> <[e-mail]>; Pengutronix Kernel Team
> <[e-mail]>; Fabio Estevam <[e-mail]>; Rob
> Herring <[e-mail]>; [e-mail]; linux-
> [e-mail]; [e-mail]; [e-mail];
> [e-mail]
> Subject: Re: [PATCH v5 5/5] firmware: imx: adds miscdev
> 
> On Fri, Jul 12, 2024 at 11:50:00AM +0530, Pankaj Gupta wrote:
> > Adds the driver for communication interface to secure-enclave, for
> > exchanging messages with NXP secure enclave HW IP(s) like EdgeLock
> > Enclave from:
> > - User-Space Applications via character driver.
> >
> > ABI documentation for the NXP secure-enclave driver.
> >
> > User-space library using this driver:
> > - i.MX Secure Enclave library:
> >   -- URL: https://github.com/nxp-imx/imx-secure-enclave.git,
> > - i.MX Secure Middle-Ware:
> >   -- URL: https://github.com/nxp-imx/imx-smw.git
> >
> > Signed-off-by: Pankaj Gupta <[e-mail]>
> > ---
> >  Documentation/ABI/testing/se-cdev |  43 +++
> > drivers/firmware/imx/ele_common.c | 192 ++++++++++-
> >  drivers/firmware/imx/ele_common.h |   4 +
> >  drivers/firmware/imx/se_ctrl.c    | 697
> ++++++++++++++++++++++++++++++++++++++
> >  drivers/firmware/imx/se_ctrl.h    |  49 +++
> >  include/uapi/linux/se_ioctl.h     |  94 +++++
> >  6 files changed, 1076 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/se-cdev
> > b/Documentation/ABI/testing/se-cdev
> > new file mode 100644
> > index 000000000000..3451c909ccc4
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/se-cdev
> > @@ -0,0 +1,43 @@
> > +What:		/dev/<se>_mu[0-9]+_ch[0-9]+
> > +Date:		May 2024
> > +KernelVersion:	6.8
> > +Contact:	[e-mail], [e-mail]
> > +Description:
> > +		NXP offers multiple hardware IP(s) for secure enclaves like
> EdgeLock-
> > +		Enclave(ELE), SECO. The character device file descriptors
> > +		/dev/<se>_mu*_ch* are the interface between userspace
> NXP's secure-
> > +		enclave shared library and the kernel driver.
> > +
> > +		The ioctl(2)-based ABI is defined and documented in
> > +		[include]<linux/firmware/imx/ele_mu_ioctl.h>.
> > +		ioctl(s) are used primarily for:
> > +			- shared memory management
> > +			- allocation of I/O buffers
> > +			- getting mu info
> > +			- setting a dev-ctx as receiver to receive all the
> commands from FW
> > +			- getting SoC info
> > +			- send command and receive command response
> > +
> > +		The following file operations are supported:
> > +
> > +		open(2)
> > +		  Currently the only useful flags are O_RDWR.
> > +
> > +		read(2)
> > +		  Every read() from the opened character device context is
> waiting on
> > +		  wait_event_interruptible, that gets set by the registered
> mailbox callback
> > +		  function, indicating a message received from the firmware on
> message-
> > +		  unit.
> > +
> > +		write(2)
> > +		  Every write() to the opened character device context needs
> to acquire
> > +		  mailbox_lock before sending message on to the message
> unit.
> > +
> > +		close(2)
> > +		  Stops and frees up the I/O contexts that were associated
> > +		  with the file descriptor.
> > +
> > +Users:		https://github.com/nxp-imx/imx-secure-enclave.git,
> > +		https://github.com/nxp-imx/imx-smw.git
> > +		crypto/skcipher,
> > +		drivers/nvmem/imx-ocotp-ele.c
> > diff --git a/drivers/firmware/imx/ele_common.c
> > b/drivers/firmware/imx/ele_common.c
> > index b2be32550e9b..88169cd8f369 100644
> > --- a/drivers/firmware/imx/ele_common.c
> > +++ b/drivers/firmware/imx/ele_common.c
> > @@ -78,6 +78,149 @@ int ele_msg_send_rcv(struct se_if_priv *priv, void
> *tx_msg, void *rx_msg)
> >  	return err;
> >  }
> >
> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> > +			void *rx_buf,
> > +			int rx_buf_sz)
> > +{
> > +	struct se_msg_hdr *header;
> > +	int err;
> > +
> > +	err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr !=
> 0);
> > +	if (err) {
> > +		dev_err(dev_ctx->dev,
> > +			"%s: Err[0x%x]:Interrupted by signal.\n",
> > +			dev_ctx->miscdev.name, err);
> > +		goto exit;
> > +	}
> > +
> > +	header = (struct se_msg_hdr *) dev_ctx->temp_resp;
> > +
> > +	if (header->tag == dev_ctx->priv->rsp_tag) {
> > +		if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv-
> >waiting_rsp_dev != dev_ctx) {
> > +			dev_warn(dev_ctx->dev,
> > +			"Dev-ctx waiting for response mismatch
> (%s != %s).\n",
> > +			dev_ctx->miscdev.name, dev_ctx->priv-
> >waiting_rsp_dev->miscdev.name);
> > +			err = -EPERM;
> > +			goto exit;
> > +		}
> > +	}
> > +
> > +	dev_dbg(dev_ctx->dev,
> > +		"%s: %s %s\n",
> > +		dev_ctx->miscdev.name,
> > +		__func__,
> > +		"message received, start transmit to user");
> > +
> > +	/*
> > +	 * Check that the size passed as argument is larger than
> > +	 * the one carried in the message.
> > +	 *
> > +	 * In case of US-command/response, the dev_ctx->temp_resp_size
> > +	 * is set before sending the command.
> > +	 *
> > +	 * In case of NVM Slave-command/response, the dev_ctx-
> >temp_resp_size
> > +	 * is set after receing the message from mailbox.
> > +	 */
> > +	if (dev_ctx->temp_resp_size > rx_buf_sz) {
> > +		dev_err(dev_ctx->dev,
> > +			"%s: User buffer too small (%d < %d)\n",
> > +			dev_ctx->miscdev.name,
> > +			rx_buf_sz, dev_ctx->temp_resp_size);
> > +		 dev_ctx->temp_resp_size = rx_buf_sz;
> > +	}
> > +
> > +	/* We may need to copy the output data to user before
> > +	 * delivering the completion message.
> > +	 */
> > +	err = se_dev_ctx_cpy_out_data(dev_ctx, true);
> > +	if (err < 0)
> > +		goto exit;
> > +
> > +	/* Copy data from the buffer */
> > +	print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
> > +			     dev_ctx->temp_resp, dev_ctx->temp_resp_size,
> false);
> > +	if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx-
> >temp_resp_size)) {
> > +		dev_err(dev_ctx->dev,
> > +			"%s: Failed to copy to user\n",
> > +			dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +	err = dev_ctx->temp_resp_size;
> > +exit:
> > +	if (err < 0)
> > +		se_dev_ctx_cpy_out_data(dev_ctx, false);
> > +
> > +	/* free memory allocated on the shared buffers. */
> > +	dev_ctx->secure_mem.pos = 0;
> > +	dev_ctx->non_secure_mem.pos = 0;
> > +
> > +	dev_ctx->pending_hdr = 0;
> > +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> > +
> > +	return err;
> > +}
> > +
> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> > +			 void *tx_msg, int tx_msg_sz)
> > +{
> > +	struct se_if_priv *priv = dev_ctx->priv;
> > +	struct se_msg_hdr *header;
> > +	u32 size_to_send;
> > +	int err;
> > +
> > +	header = (struct se_msg_hdr *) tx_msg;
> > +
> > +	/*
> > +	 * Check that the size passed as argument matches the size
> > +	 * carried in the message.
> > +	 */
> > +	size_to_send = header->size << 2;
> > +
> > +	if (size_to_send != tx_msg_sz) {
> > +		err = -EINVAL;
> > +		dev_err(priv->dev,
> > +			"%s: User buf hdr(0x%x) sz mismatced with input-sz
> (%d != %d).\n",
> > +			dev_ctx->miscdev.name, *(u32 *)header,
> size_to_send, tx_msg_sz);
> > +		goto exit;
> > +	}
> > +
> > +	/* Check the message is valid according to tags */
> > +	if (header->tag == priv->rsp_tag) {
> > +		/* Check the device context can send the command */
> > +		if (dev_ctx != priv->cmd_receiver_dev) {
> > +			dev_err(priv->dev,
> > +				"%s: Channel not configured to send resp to
> FW.",
> > +				dev_ctx->miscdev.name);
> > +			err = -EPERM;
> > +			goto exit;
> > +		}
> > +	} else if (header->tag == priv->cmd_tag) {
> > +		if (priv->waiting_rsp_dev != dev_ctx) {
> > +			dev_err(priv->dev,
> > +				"%s: Channel not configured to send cmd to
> FW.",
> > +				dev_ctx->miscdev.name);
> > +			err = -EPERM;
> > +			goto exit;
> > +		}
> > +		lockdep_assert_held(&priv->se_if_cmd_lock);
> > +	} else {
> > +		dev_err(priv->dev,
> > +			"%s: The message does not have a valid TAG\n",
> > +			dev_ctx->miscdev.name);
> > +		err = -EINVAL;
> > +		goto exit;
> > +	}
> > +	err = ele_msg_send(priv, tx_msg);
> > +	if (err < 0)
> > +		goto exit;
> > +
> > +	err = size_to_send;
> > +exit:
> > +	return err;
> > +}
> > +
> >  static bool exception_for_size(struct se_if_priv *priv,
> >  				struct se_msg_hdr *header)
> >  {
> > @@ -99,6 +242,7 @@ static bool exception_for_size(struct se_if_priv
> > *priv,  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
> > {
> >  	struct device *dev = mbox_cl->dev;
> > +	struct se_if_device_ctx *dev_ctx;
> >  	struct se_if_priv *priv;
> >  	struct se_msg_hdr *header;
> >  	u32 rx_msg_sz;
> > @@ -114,8 +258,50 @@ void se_if_rx_callback(struct mbox_client
> *mbox_cl, void *msg)
> >  	header = msg;
> >  	rx_msg_sz = header->size << 2;
> >
> > -	if (header->tag == priv->rsp_tag) {
> > -		if (!priv->waiting_rsp_dev) {
> > +	/* Incoming command: wake up the receiver if any. */
> > +	if (header->tag == priv->cmd_tag) {
> > +		dev_dbg(dev, "Selecting cmd receiver\n");
> > +		dev_ctx = priv->cmd_receiver_dev;
> > +		/* Pre-allocated buffer of MAX_NVM_MSG_LEN
> > +		 * as the NVM command are initiated by FW.
> > +		 * Size is revealed as part of this call function.
> > +		 */
> > +		if (rx_msg_sz > MAX_NVM_MSG_LEN) {
> > +			dev_err(dev,
> > +				"%s: Msg recvd hdr(0x%x) with greater[%d]
> than allocated buf-sz.\n",
> > +				dev_ctx->miscdev.name,
> > +				*(u32 *) header,
> > +				rx_msg_sz);
> > +		} else
> > +			memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
> > +
> > +		/* NVM buffer size are not known prior receiving it from FW.
> > +		 */
> > +		dev_ctx->temp_resp_size = rx_msg_sz;
> > +
> > +		/* Allow user to read */
> > +		dev_ctx->pending_hdr = 1;
> > +		wake_up_interruptible(&dev_ctx->wq);
> > +
> > +		return;
> > +	} else if (header->tag == priv->rsp_tag) {
> > +		if (priv->waiting_rsp_dev) {
> > +			dev_dbg(dev, "Selecting rsp waiter\n");
> > +			dev_ctx = priv->waiting_rsp_dev;
> > +			if (rx_msg_sz != dev_ctx->temp_resp_size
> > +				&& !exception_for_size(priv, header))
> > +				dev_err(dev,
> > +					"%s: Msg RSP hdr(0x%x) with
> different sz(%d != %d).\n",
> > +					dev_ctx->miscdev.name,
> > +					*(u32 *) header,
> > +					rx_msg_sz, dev_ctx->temp_resp_size);
> > +			else
> > +				memcpy(dev_ctx->temp_resp, msg,
> rx_msg_sz);
> > +
> > +			/* Allow user to read */
> > +			dev_ctx->pending_hdr = 1;
> > +			wake_up_interruptible(&dev_ctx->wq);
> > +		} else {
> >  			/*
> >  			 * Reading the EdgeLock Enclave response
> >  			 * to the command, sent by other
> > @@ -132,8 +318,8 @@ void se_if_rx_callback(struct mbox_client
> > *mbox_cl, void *msg)
> >
> >  			complete(&priv->done);
> >  			spin_unlock(&priv->lock);
> > -			return;
> >  		}
> > +		return;
> >  	}
> >
> >  	dev_err(dev, "Failed to select a device for message: %.8x\n", diff
> > --git a/drivers/firmware/imx/ele_common.h
> > b/drivers/firmware/imx/ele_common.h
> > index 5ef775a42ab3..7b1c6bfc138b 100644
> > --- a/drivers/firmware/imx/ele_common.h
> > +++ b/drivers/firmware/imx/ele_common.h
> > @@ -17,6 +17,10 @@ uint32_t se_add_msg_crc(uint32_t *msg, uint32_t
> > msg_len);  int ele_msg_rcv(struct se_if_priv *priv);  int
> > ele_msg_send(struct se_if_priv *priv, void *tx_msg);  int
> > ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
> > +int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
> > +			void *rx_msg, int rx_msg_sz);
> > +int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
> > +			 void *tx_msg, int tx_msg_sz);
> >  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);  int
> > se_val_rsp_hdr_n_status(struct se_if_priv *priv,
> >  			    struct se_msg_hdr *header,
> > diff --git a/drivers/firmware/imx/se_ctrl.c
> > b/drivers/firmware/imx/se_ctrl.c index a844794d2b39..8fb2af0f0dd3
> > 100644
> > --- a/drivers/firmware/imx/se_ctrl.c
> > +++ b/drivers/firmware/imx/se_ctrl.c
> > @@ -23,6 +23,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/string.h>
> >  #include <linux/sys_soc.h>
> > +#include <uapi/linux/se_ioctl.h>
> >
> >  #include "ele_base_msg.h"
> >  #include "ele_common.h"
> > @@ -196,6 +197,608 @@ static int se_soc_info(struct se_if_priv *priv,
> >  	return 0;
> >  }
> >
> > +static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx
> *dev_ctx,
> > +					    u64 arg)
> > +{
> > +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> > +	struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
> > +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> > +	struct se_api_msg *rx_msg __free(kfree) = NULL;
> > +	int err = 0;
> > +
> > +	if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
> > +			   sizeof(cmd_snd_rcv_rsp_info))) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed to copy cmd_snd_rcv_rsp_info from
> user\n",
> > +			dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +	if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: User buffer too small(%d < %d)\n",
> > +			dev_ctx->miscdev.name,
> > +			cmd_snd_rcv_rsp_info.tx_buf_sz,
> > +			SE_MU_HDR_SZ);
> > +		err = -ENOSPC;
> > +		goto exit;
> > +	}
> > +
> > +	rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
> > +	if (!rx_msg) {
> > +		err = -ENOMEM;
> > +		goto exit;
> > +	}
> > +
> > +	tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
> > +			     cmd_snd_rcv_rsp_info.tx_buf_sz);
> > +	if (IS_ERR(tx_msg)) {
> > +		err = PTR_ERR(tx_msg);
> > +		goto exit;
> > +	}
> > +
> > +	if (tx_msg->header.tag != priv->cmd_tag) {
> > +		err = -EINVAL;
> > +		goto exit;
> > +	}
> > +
> > +	scoped_guard(mutex, &priv->se_if_cmd_lock);
> 
> You totally wrong use scoped_guard in whole patch.
> 
> fun()
> {
>      guard(); //which means lock here
>      ...
>      return; // unlock here
> }
> 
> scoped_guard()
> {     // lock here
>       ...
>       //unlock here
> }
> 
> your code scoped_guard(mutex, &priv->se_if_cmd_lock); is equal to
> 
>       mutex_lock();
>       mutex_unlock();
> 
> Nothing protected by mutex lock at all.
> 
> Frank Li

Thanks for the explanation, Frank.
Will replace scope_guard with guard().

> 
> 
> > +	priv->waiting_rsp_dev = dev_ctx;
> > +	dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
> > +
> > +	/* Device Context that is assigned to be a
> > +	 * FW's command receiver, has pre-allocated buffer.
> > +	 */
> > +	if (dev_ctx != priv->cmd_receiver_dev)
> > +		dev_ctx->temp_resp = rx_msg;
> > +
> > +	err = ele_miscdev_msg_send(dev_ctx,
> > +				   tx_msg,
> > +				   cmd_snd_rcv_rsp_info.tx_buf_sz);
> > +	if (err < 0)
> > +		goto exit;
> > +
> > +	cmd_snd_rcv_rsp_info.tx_buf_sz = err;
> > +
> > +	err = ele_miscdev_msg_rcv(dev_ctx,
> > +				  cmd_snd_rcv_rsp_info.rx_buf,
> > +				  cmd_snd_rcv_rsp_info.rx_buf_sz);
> > +
> > +	if (err < 0)
> > +		goto exit;
> > +
> > +	cmd_snd_rcv_rsp_info.rx_buf_sz = err;
> > +
> > +exit:
> > +	dev_ctx->temp_resp_size = 0;
> > +	priv->waiting_rsp_dev = NULL;
> > +	if (dev_ctx != priv->cmd_receiver_dev)
> > +		dev_ctx->temp_resp = NULL;
> > +
> > +	if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
> > +			 sizeof(cmd_snd_rcv_rsp_info))) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed to copy cmd_snd_rcv_rsp_info from
> user\n",
> > +			dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +	}
> > +	return err;
> > +}
> > +
> > +/*
> > + * File operations for user-space
> > + */
> > +
> > +/* Write a message to the MU. */
> > +static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
> > +				size_t size, loff_t *ppos)
> > +{
> > +	struct se_api_msg *tx_msg __free(kfree) = NULL;
> > +	struct se_if_device_ctx *dev_ctx;
> > +	struct se_if_priv *priv;
> > +	int err;
> > +
> > +	dev_ctx = container_of(fp->private_data,
> > +			       struct se_if_device_ctx,
> > +			       miscdev);
> > +	priv = dev_ctx->priv;
> > +	dev_dbg(priv->dev,
> > +		"%s: write from buf (%p)%zu, ppos=%lld\n",
> > +			dev_ctx->miscdev.name,
> > +			buf, size, ((ppos) ? *ppos : 0));
> > +
> > +	if (down_interruptible(&dev_ctx->fops_lock))
> > +		return -EBUSY;
> > +
> > +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> > +		err = -EINVAL;
> > +		goto exit;
> > +	}
> > +
> > +	if (size < SE_MU_HDR_SZ) {
> > +		dev_err(priv->dev,
> > +			"%s: User buffer too small(%zu < %d)\n",
> > +				dev_ctx->miscdev.name,
> > +				size, SE_MU_HDR_SZ);
> > +		err = -ENOSPC;
> > +		goto exit;
> > +	}
> > +	tx_msg = memdup_user(buf, size);
> > +	if (IS_ERR(tx_msg)) {
> > +		err = PTR_ERR(tx_msg);
> > +		goto exit;
> > +	}
> > +
> > +	print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
> > +			     tx_msg, size, false);
> > +
> > +	err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
> > +
> > +exit:
> > +	up(&dev_ctx->fops_lock);
> > +	return err;
> > +}
> > +
> > +/*
> > + * Read a message from the MU.
> > + * Blocking until a message is available.
> > + */
> > +static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
> > +			       size_t size, loff_t *ppos)
> > +{
> > +	struct se_if_device_ctx *dev_ctx;
> > +	struct se_if_priv *priv;
> > +	int err;
> > +
> > +	dev_ctx = container_of(fp->private_data,
> > +			       struct se_if_device_ctx,
> > +			       miscdev);
> > +	priv = dev_ctx->priv;
> > +	dev_dbg(priv->dev,
> > +		"%s: read to buf %p(%zu), ppos=%lld\n",
> > +			dev_ctx->miscdev.name,
> > +			buf, size, ((ppos) ? *ppos : 0));
> > +
> > +	if (down_interruptible(&dev_ctx->fops_lock))
> > +		return -EBUSY;
> > +
> > +	if (dev_ctx->status != SE_IF_CTX_OPENED) {
> > +		err = -EINVAL;
> > +		goto exit;
> > +	}
> > +
> > +	err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
> > +
> > +exit:
> > +	up(&dev_ctx->fops_lock);
> > +	return err;
> > +}
> > +
> > +static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
> > +				u64 arg)
> > +{
> > +	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
> > +	struct se_if_node_info *if_node_info;
> > +	struct se_ioctl_get_if_info info;
> > +	int err = 0;
> > +
> > +	if_node_info = (struct se_if_node_info *)priv->info;
> > +
> > +	info.se_if_id = if_node_info->se_if_id;
> > +	info.interrupt_idx = 0;
> > +	info.tz = 0;
> > +	info.did = if_node_info->se_if_did;
> > +	info.cmd_tag = if_node_info->cmd_tag;
> > +	info.rsp_tag = if_node_info->rsp_tag;
> > +	info.success_tag = if_node_info->success_tag;
> > +	info.base_api_ver = if_node_info->base_api_ver;
> > +	info.fw_api_ver = if_node_info->fw_api_ver;
> > +
> > +	dev_dbg(priv->dev,
> > +		"%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
> > +			dev_ctx->miscdev.name,
> > +			info.se_if_id, info.interrupt_idx, info.tz, info.did);
> > +
> > +	if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed to copy mu info to user\n",
> > +				dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +exit:
> > +	return err;
> > +}
> > +
> > +/* Need to copy the output data to user-device context.
> > + */
> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
> > +do_cpy) {
> > +	struct se_buf_desc *b_desc, *temp;
> > +
> > +	list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link)
> {
> > +		if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr &&
> do_cpy) {
> > +
> > +			dev_dbg(dev_ctx->dev,
> > +				"%s: Copy output data to user\n",
> > +				dev_ctx->miscdev.name);
> > +			if (copy_to_user(b_desc->usr_buf_ptr,
> > +					 b_desc->shared_buf_ptr,
> > +					 b_desc->size)) {
> > +				dev_err(dev_ctx->dev,
> > +					"%s: Failure copying output data to
> user.",
> > +					dev_ctx->miscdev.name);
> > +				return -EFAULT;
> > +			}
> > +		}
> > +
> > +		if (b_desc->shared_buf_ptr)
> > +			memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> > +
> > +		list_del(&b_desc->link);
> > +		kfree(b_desc);
> > +	}
> > +	return 0;
> > +}
> > +
> > +/*
> > + * Clean the used Shared Memory space,
> > + * whether its Input Data copied from user buffers, or
> > + * Data received from FW.
> > + */
> > +void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
> > +{
> > +	struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
> > +						 &dev_ctx->pending_out};
> > +	struct se_buf_desc *b_desc, *temp;
> > +	int i;
> > +
> > +	for (i = 0; i < 2; i++) {
> > +		list_for_each_entry_safe(b_desc, temp,
> > +					 dev_ctx_lists[i], link) {
> > +
> > +			if (b_desc->shared_buf_ptr)
> > +				memset(b_desc->shared_buf_ptr, 0, b_desc-
> >size);
> > +
> > +			list_del(&b_desc->link);
> > +			kfree(b_desc);
> > +		}
> > +	}
> > +}
> > +
> > +/*
> > + * Copy a buffer of data to/from the user and return the address to
> > +use in
> > + * messages
> > + */
> > +static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
> > +					    u64 arg)
> > +{
> > +	struct se_shared_mem *shared_mem = NULL;
> > +	struct se_ioctl_setup_iobuf io = {0};
> > +	struct se_buf_desc *b_desc = NULL;
> > +	int err = 0;
> > +	u32 pos;
> > +
> > +	if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed copy iobuf config from user\n",
> > +				dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +	dev_dbg(dev_ctx->priv->dev,
> > +			"%s: io [buf: %p(%d) flag: %x]\n",
> > +			dev_ctx->miscdev.name,
> > +			io.user_buf, io.length, io.flags);
> > +
> > +	if (io.length == 0 || !io.user_buf) {
> > +		/*
> > +		 * Accept NULL pointers since some buffers are optional
> > +		 * in FW commands. In this case we should return 0 as
> > +		 * pointer to be embedded into the message.
> > +		 * Skip all data copy part of code below.
> > +		 */
> > +		io.ele_addr = 0;
> > +		goto copy;
> > +	}
> > +
> > +	/* Select the shared memory to be used for this buffer. */
> > +	if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
> > +		/* App requires to use secure memory for this buffer.*/
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed allocate SEC MEM memory\n",
> > +				dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	} else {
> > +		/* No specific requirement for this buffer. */
> > +		shared_mem = &dev_ctx->non_secure_mem;
> > +	}
> > +
> > +	/* Check there is enough space in the shared memory. */
> > +	if (shared_mem->size < shared_mem->pos ||
> > +		round_up(io.length, 8u) >= (shared_mem->size -
> shared_mem->pos)) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Not enough space in shared memory\n",
> > +				dev_ctx->miscdev.name);
> > +		err = -ENOMEM;
> > +		goto exit;
> > +	}
> > +
> > +	/* Allocate space in shared memory. 8 bytes aligned. */
> > +	pos = shared_mem->pos;
> > +	shared_mem->pos += round_up(io.length, 8u);
> > +	io.ele_addr = (u64)shared_mem->dma_addr + pos;
> > +
> > +	if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
> > +	    !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
> > +		/*Add base address to get full address.*/
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed allocate SEC MEM memory\n",
> > +				dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +	memset(shared_mem->ptr + pos, 0, io.length);
> > +	if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
> > +	    (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
> > +		/*
> > +		 * buffer is input:
> > +		 * copy data from user space to this allocated buffer.
> > +		 */
> > +		if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
> > +				   io.length)) {
> > +			dev_err(dev_ctx->priv->dev,
> > +				"%s: Failed copy data to shared memory\n",
> > +				dev_ctx->miscdev.name);
> > +			err = -EFAULT;
> > +			goto exit;
> > +		}
> > +	}
> > +
> > +	b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
> > +	if (!b_desc) {
> > +		err = -ENOMEM;
> > +		goto exit;
> > +	}
> > +
> > +copy:
> > +	/* Provide the EdgeLock Enclave address to user space only if
> success.*/
> > +	if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed to copy iobuff setup to user\n",
> > +				dev_ctx->miscdev.name);
> > +		kfree(b_desc);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +	if (b_desc) {
> > +		b_desc->shared_buf_ptr = shared_mem->ptr + pos;
> > +		b_desc->usr_buf_ptr = io.user_buf;
> > +		b_desc->size = io.length;
> > +
> > +		if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
> > +			/*
> > +			 * buffer is input:
> > +			 * add an entry in the "pending input buffers" list so
> > +			 * that copied data can be cleaned from shared
> memory
> > +			 * later.
> > +			 */
> > +			list_add_tail(&b_desc->link, &dev_ctx->pending_in);
> > +		} else {
> > +			/*
> > +			 * buffer is output:
> > +			 * add an entry in the "pending out buffers" list so data
> > +			 * can be copied to user space when receiving Secure-
> Enclave
> > +			 * response.
> > +			 */
> > +			list_add_tail(&b_desc->link, &dev_ctx->pending_out);
> > +		}
> > +	}
> > +
> > +exit:
> > +	return err;
> > +}
> > +
> > +/* IOCTL to provide SoC information */ static int
> > +se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx *dev_ctx,
> > +					     u64 arg)
> > +{
> > +	const struct se_if_node_info_list *info_list;
> > +	struct se_ioctl_get_soc_info soc_info;
> > +	int err = -EINVAL;
> > +
> > +	info_list = device_get_match_data(dev_ctx->priv->dev);
> > +	if (!info_list)
> > +		goto exit;
> > +
> > +	soc_info.soc_id = info_list->soc_id;
> > +	soc_info.soc_rev = dev_ctx->priv->soc_rev;
> > +
> > +	err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
> > +	if (err) {
> > +		dev_err(dev_ctx->priv->dev,
> > +			"%s: Failed to copy soc info to user\n",
> > +			dev_ctx->miscdev.name);
> > +		err = -EFAULT;
> > +		goto exit;
> > +	}
> > +
> > +exit:
> > +	return err;
> > +}
> > +
> > +/* Open a character device. */
> > +static int se_if_fops_open(struct inode *nd, struct file *fp) {
> > +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +							struct
> se_if_device_ctx,
> > +							miscdev);
> > +	int err = 0;
> > +
> > +	/* Avoid race if opened at the same time */
> > +	if (down_trylock(&dev_ctx->fops_lock))
> > +		return -EBUSY;
> > +
> > +	/* Authorize only 1 instance. */
> > +	if (dev_ctx->status != SE_IF_CTX_FREE) {
> > +		err = -EBUSY;
> > +		goto exit;
> > +	}
> > +
> > +	/*
> > +	 * Allocate some memory for data exchanges with S40x.
> > +	 * This will be used for data not requiring secure memory.
> > +	 */
> > +	dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx-
> >dev,
> > +					MAX_DATA_SIZE_PER_USER,
> > +					&dev_ctx-
> >non_secure_mem.dma_addr,
> > +					GFP_KERNEL);
> > +	if (!dev_ctx->non_secure_mem.ptr) {
> > +		err = -ENOMEM;
> > +		goto exit;
> > +	}
> > +
> > +	dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
> > +	dev_ctx->non_secure_mem.pos = 0;
> > +	dev_ctx->status = SE_IF_CTX_OPENED;
> > +
> > +	dev_ctx->pending_hdr = 0;
> > +
> > +	goto exit;
> > +
> > +	dmam_free_coherent(dev_ctx->priv->dev,
> MAX_DATA_SIZE_PER_USER,
> > +			   dev_ctx->non_secure_mem.ptr,
> > +			   dev_ctx->non_secure_mem.dma_addr);
> > +
> > +exit:
> > +	up(&dev_ctx->fops_lock);
> > +	return err;
> > +}
> > +
> > +/* Close a character device. */
> > +static int se_if_fops_close(struct inode *nd, struct file *fp) {
> > +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +							struct
> se_if_device_ctx,
> > +							miscdev);
> > +	struct se_if_priv *priv = dev_ctx->priv;
> > +
> > +	/* Avoid race if closed at the same time */
> > +	if (down_trylock(&dev_ctx->fops_lock))
> > +		return -EBUSY;
> > +
> > +	/* The device context has not been opened */
> > +	if (dev_ctx->status != SE_IF_CTX_OPENED)
> > +		goto exit;
> > +
> > +	/* check if this device was registered as command receiver. */
> > +	if (priv->cmd_receiver_dev == dev_ctx) {
> > +		priv->cmd_receiver_dev = NULL;
> > +		kfree(dev_ctx->temp_resp);
> > +	}
> > +
> > +	/* check if this device was registered as waiting response. */
> > +	if (priv->waiting_rsp_dev == dev_ctx) {
> > +		priv->waiting_rsp_dev = NULL;
> > +		mutex_unlock(&priv->se_if_cmd_lock);
> > +	}
> > +
> > +	/* Unmap secure memory shared buffer. */
> > +	if (dev_ctx->secure_mem.ptr)
> > +		devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
> > +
> > +	dev_ctx->secure_mem.ptr = NULL;
> > +	dev_ctx->secure_mem.dma_addr = 0;
> > +	dev_ctx->secure_mem.size = 0;
> > +	dev_ctx->secure_mem.pos = 0;
> > +
> > +	/* Free non-secure shared buffer. */
> > +	dmam_free_coherent(dev_ctx->priv->dev,
> MAX_DATA_SIZE_PER_USER,
> > +			   dev_ctx->non_secure_mem.ptr,
> > +			   dev_ctx->non_secure_mem.dma_addr);
> > +
> > +	dev_ctx->non_secure_mem.ptr = NULL;
> > +	dev_ctx->non_secure_mem.dma_addr = 0;
> > +	dev_ctx->non_secure_mem.size = 0;
> > +	dev_ctx->non_secure_mem.pos = 0;
> > +	se_dev_ctx_shared_mem_cleanup(dev_ctx);
> > +	dev_ctx->status = SE_IF_CTX_FREE;
> > +
> > +exit:
> > +	up(&dev_ctx->fops_lock);
> > +	return 0;
> > +}
> > +
> > +/* IOCTL entry point of a character device */ static long
> > +se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) {
> > +	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
> > +							struct
> se_if_device_ctx,
> > +							miscdev);
> > +	struct se_if_priv *se_if_priv = dev_ctx->priv;
> > +	int err = -EINVAL;
> > +
> > +	/* Prevent race during change of device context */
> > +	if (down_interruptible(&dev_ctx->fops_lock))
> > +		return -EBUSY;
> > +
> > +	switch (cmd) {
> > +	case SE_IOCTL_ENABLE_CMD_RCV:
> > +		if (!se_if_priv->cmd_receiver_dev) {
> > +			err = 0;
> > +			se_if_priv->cmd_receiver_dev = dev_ctx;
> > +			dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN,
> GFP_KERNEL);
> > +			if (!dev_ctx->temp_resp)
> > +				err = -ENOMEM;
> > +		}
> > +		break;
> > +	case SE_IOCTL_GET_MU_INFO:
> > +		err = se_ioctl_get_mu_info(dev_ctx, arg);
> > +		break;
> > +	case SE_IOCTL_SETUP_IOBUF:
> > +		err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
> > +		break;
> > +	case SE_IOCTL_GET_SOC_INFO:
> > +		err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
> > +		break;
> > +	case SE_IOCTL_CMD_SEND_RCV_RSP:
> > +		err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
> > +		break;
> > +
> > +	default:
> > +		err = -EINVAL;
> > +		dev_dbg(se_if_priv->dev,
> > +			"%s: IOCTL %.8x not supported\n",
> > +				dev_ctx->miscdev.name,
> > +				cmd);
> > +	}
> > +
> > +	up(&dev_ctx->fops_lock);
> > +	return (long)err;
> > +}
> > +
> > +/* Char driver setup */
> > +static const struct file_operations se_if_fops = {
> > +	.open		= se_if_fops_open,
> > +	.owner		= THIS_MODULE,
> > +	.release	= se_if_fops_close,
> > +	.unlocked_ioctl = se_ioctl,
> > +	.read		= se_if_fops_read,
> > +	.write		= se_if_fops_write,
> > +};
> > +
> > +/* interface for managed res to unregister a character device */
> > +static void if_misc_deregister(void *miscdevice) {
> > +	misc_deregister(miscdevice);
> > +}
> > +
> >  /* interface for managed res to free a mailbox channel */  static
> > void if_mbox_free_channel(void *mbox_chan)  { @@ -233,6 +836,7 @@
> > static void se_if_probe_cleanup(struct platform_device *pdev)  {
> >  	struct device *dev = &pdev->dev;
> >  	struct se_if_priv *priv;
> > +	int i;
> >
> >  	priv = dev_get_drvdata(dev);
> >
> > @@ -252,6 +856,17 @@ static void se_if_probe_cleanup(struct
> platform_device *pdev)
> >  		priv->imem.buf = NULL;
> >  	}
> >
> > +	if (priv->ctxs) {
> > +		for (i = 0; i < priv->max_dev_ctx; i++) {
> > +			if (priv->ctxs[i]) {
> > +				devm_remove_action(dev,
> > +						   if_misc_deregister,
> > +						   &priv->ctxs[i]->miscdev);
> > +				misc_deregister(&priv->ctxs[i]->miscdev);
> > +			}
> > +		}
> > +	}
> > +
> >  	/* No need to check, if reserved memory is allocated
> >  	 * before calling for its release. Or clearing the
> >  	 * un-set bit.
> > @@ -259,6 +874,74 @@ static void se_if_probe_cleanup(struct
> platform_device *pdev)
> >  	of_reserved_mem_device_release(dev);
> >  }
> >
> > +static int init_device_context(struct se_if_priv *priv) {
> > +	const struct se_if_node_info *info = priv->info;
> > +	struct se_if_device_ctx *dev_ctx;
> > +	u8 *devname;
> > +	int ret = 0;
> > +	int i;
> > +
> > +	priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv-
> >max_dev_ctx,
> > +				  GFP_KERNEL);
> > +
> > +	if (!priv->ctxs) {
> > +		ret = -ENOMEM;
> > +		return ret;
> > +	}
> > +
> > +	/* Create users */
> > +	for (i = 0; i < priv->max_dev_ctx; i++) {
> > +		dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx),
> GFP_KERNEL);
> > +		if (!dev_ctx) {
> > +			ret = -ENOMEM;
> > +			return ret;
> > +		}
> > +
> > +		dev_ctx->dev = priv->dev;
> > +		dev_ctx->status = SE_IF_CTX_FREE;
> > +		dev_ctx->priv = priv;
> > +
> > +		priv->ctxs[i] = dev_ctx;
> > +
> > +		/* Default value invalid for an header. */
> > +		init_waitqueue_head(&dev_ctx->wq);
> > +
> > +		INIT_LIST_HEAD(&dev_ctx->pending_out);
> > +		INIT_LIST_HEAD(&dev_ctx->pending_in);
> > +		sema_init(&dev_ctx->fops_lock, 1);
> > +
> > +		devname = devm_kasprintf(priv->dev, GFP_KERNEL,
> "%s_ch%d",
> > +					 info->se_name, i);
> > +		if (!devname) {
> > +			ret = -ENOMEM;
> > +			return ret;
> > +		}
> > +
> > +		dev_ctx->miscdev.name = devname;
> > +		dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
> > +		dev_ctx->miscdev.fops = &se_if_fops;
> > +		dev_ctx->miscdev.parent = priv->dev;
> > +		ret = misc_register(&dev_ctx->miscdev);
> > +		if (ret) {
> > +			dev_err(priv->dev, "failed to register misc
> device %d\n",
> > +				ret);
> > +			return ret;
> > +		}
> > +
> > +		ret = devm_add_action(priv->dev, if_misc_deregister,
> > +				      &dev_ctx->miscdev);
> > +		if (ret) {
> > +			dev_err(priv->dev,
> > +				"failed[%d] to add action to the misc-dev\n",
> > +				ret);
> > +			return ret;
> > +		}
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >  static void se_load_firmware(const struct firmware *fw, void
> > *context)  {
> >  	struct se_if_priv *priv = (struct se_if_priv *) context; @@ -427,6
> > +1110,16 @@ static int se_if_probe(struct platform_device *pdev)
> >  		ret = 0;
> >  	}
> >
> > +	if (info->max_dev_ctx) {
> > +		ret = init_device_context(priv);
> > +		if (ret) {
> > +			dev_err(dev,
> > +				"Failed[0x%x] to create device contexts.\n",
> > +				ret);
> > +			goto exit;
> > +		}
> > +	}
> > +
> >  	dev_info(dev, "i.MX secure-enclave: %s interface to firmware,
> configured.\n",
> >  		 info->se_name);
> >  	return ret;
> > @@ -467,6 +1160,10 @@ static int se_resume(struct device *dev)  {
> >  	struct se_if_priv *priv = dev_get_drvdata(dev);
> >  	const struct se_if_node_info *info = priv->info;
> > +	int i;
> > +
> > +	for (i = 0; i < priv->max_dev_ctx; i++)
> > +		wake_up_interruptible(&priv->ctxs[i]->wq);
> >
> >  	if (info && info->imem_mgmt)
> >  		se_restore_imem_state(priv);
> > diff --git a/drivers/firmware/imx/se_ctrl.h
> > b/drivers/firmware/imx/se_ctrl.h index 4be2235d2170..b49346372746
> > 100644
> > --- a/drivers/firmware/imx/se_ctrl.h
> > +++ b/drivers/firmware/imx/se_ctrl.h
> > @@ -13,15 +13,62 @@
> >  #define MAX_FW_LOAD_RETRIES		50
> >
> >  #define RES_STATUS(x)			FIELD_GET(0x000000ff, x)
> > +#define MAX_DATA_SIZE_PER_USER		(65 * 1024)
> > +#define MAX_NVM_MSG_LEN			(256)
> >  #define MESSAGING_VERSION_6		0x6
> >  #define MESSAGING_VERSION_7		0x7
> >
> > +#define SE_MU_IO_FLAGS_USE_SEC_MEM	(0x02u)
> > +#define SE_MU_IO_FLAGS_USE_SHORT_ADDR	(0x04u)
> > +
> >  struct se_imem_buf {
> >  	u8 *buf;
> >  	phys_addr_t phyaddr;
> >  	u32 size;
> >  };
> >
> > +struct se_buf_desc {
> > +	u8 *shared_buf_ptr;
> > +	u8 *usr_buf_ptr;
> > +	u32 size;
> > +	struct list_head link;
> > +};
> > +
> > +/* Status of a char device */
> > +enum se_if_dev_ctx_status_t {
> > +	SE_IF_CTX_FREE,
> > +	SE_IF_CTX_OPENED
> > +};
> > +
> > +struct se_shared_mem {
> > +	dma_addr_t dma_addr;
> > +	u32 size;
> > +	u32 pos;
> > +	u8 *ptr;
> > +};
> > +
> > +/* Private struct for each char device instance. */ struct
> > +se_if_device_ctx {
> > +	struct device *dev;
> > +	struct se_if_priv *priv;
> > +	struct miscdevice miscdev;
> > +
> > +	enum se_if_dev_ctx_status_t status;
> > +	wait_queue_head_t wq;
> > +	struct semaphore fops_lock;
> > +
> > +	u32 pending_hdr;
> > +	struct list_head pending_in;
> > +	struct list_head pending_out;
> > +
> > +	struct se_shared_mem secure_mem;
> > +	struct se_shared_mem non_secure_mem;
> > +
> > +	struct se_api_msg *temp_resp;
> > +	u32 temp_resp_size;
> > +	struct notifier_block se_notify;
> > +};
> > +
> >  /* Header of the messages exchange with the EdgeLock Enclave */
> > struct se_msg_hdr {
> >  	u8 ver;
> > @@ -80,4 +127,6 @@ struct se_if_priv {
> >  	struct se_imem_buf imem;
> >  };
> >
> > +int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool
> > +do_cpy); void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx
> > +*dev_ctx);
> >  #endif
> > diff --git a/include/uapi/linux/se_ioctl.h
> > b/include/uapi/linux/se_ioctl.h new file mode 100644 index
> > 000000000000..c2d0a92ef626
> > --- /dev/null
> > +++ b/include/uapi/linux/se_ioctl.h
> > @@ -0,0 +1,94 @@
> > +/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR
> > +BSD-3-Clause*/
> > +/*
> > + * Copyright 2024 NXP
> > + */
> > +
> > +#ifndef SE_IOCTL_H
> > +#define SE_IOCTL_H
> > +
> > +/* IOCTL definitions. */
> > +
> > +struct se_ioctl_setup_iobuf {
> > +	u8 *user_buf;
> > +	u32 length;
> > +	u32 flags;
> > +	u64 ele_addr;
> > +};
> > +
> > +struct se_ioctl_shared_mem_cfg {
> > +	u32 base_offset;
> > +	u32 size;
> > +};
> > +
> > +struct se_ioctl_get_if_info {
> > +	u8 se_if_id;
> > +	u8 interrupt_idx;
> > +	u8 tz;
> > +	u8 did;
> > +	u8 cmd_tag;
> > +	u8 rsp_tag;
> > +	u8 success_tag;
> > +	u8 base_api_ver;
> > +	u8 fw_api_ver;
> > +};
> > +
> > +struct se_ioctl_cmd_snd_rcv_rsp_info {
> > +	u32 *tx_buf;
> > +	int tx_buf_sz;
> > +	u32 *rx_buf;
> > +	int rx_buf_sz;
> > +};
> > +
> > +struct se_ioctl_get_soc_info {
> > +	u16 soc_id;
> > +	u16 soc_rev;
> > +};
> > +
> > +/* IO Buffer Flags */
> > +#define SE_IO_BUF_FLAGS_IS_OUTPUT	(0x00u)
> > +#define SE_IO_BUF_FLAGS_IS_INPUT	(0x01u)
> > +#define SE_IO_BUF_FLAGS_USE_SEC_MEM	(0x02u)
> > +#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR	(0x04u)
> > +#define SE_IO_BUF_FLAGS_IS_IN_OUT	(0x10u)
> > +
> > +/* IOCTLS */
> > +#define SE_IOCTL			0x0A /* like MISC_MAJOR. */
> > +
> > +/*
> > + * ioctl to designated the current fd as logical-reciever.
> > + * This is ioctl is send when the nvm-daemon, a slave to the
> > + * firmware is started by the user.
> > + */
> > +#define SE_IOCTL_ENABLE_CMD_RCV	_IO(SE_IOCTL, 0x01)
> > +
> > +/*
> > + * ioctl to get the buffer allocated from the memory, which is shared
> > + * between kernel and FW.
> > + * Post allocation, the kernel tagged the allocated memory with:
> > + *  Output
> > + *  Input
> > + *  Input-Output
> > + *  Short address
> > + *  Secure-memory
> > + */
> > +#define SE_IOCTL_SETUP_IOBUF	_IOWR(SE_IOCTL, 0x03, \
> > +					struct se_ioctl_setup_iobuf)
> > +
> > +/*
> > + * ioctl to get the mu information, that is used to exchange message
> > + * with FW, from user-spaced.
> > + */
> > +#define SE_IOCTL_GET_MU_INFO	_IOR(SE_IOCTL, 0x04, \
> > +					struct se_ioctl_get_if_info)
> > +/*
> > + * ioctl to get SoC Info from user-space.
> > + */
> > +#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
> > +					struct se_ioctl_get_soc_info)
> > +
> > +/*
> > + * ioctl to send command and receive response from user-space.
> > + */
> > +#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
> > +					struct
> se_ioctl_cmd_snd_rcv_rsp_info) #endif
> >
> > --
> > 2.34.1
> >

Fabio Estevam July 16, 2024, 12:54 p.m. UTC | #7

On Tue, Jul 16, 2024 at 1:50 AM Pankaj Gupta <[e-mail]> wrote:

> Thanks for the explanation, Frank.
> Will replace scope_guard with guard().

Please properly trim your replies to only the relevant context.

Keeping the full message makes it too hard to locate your reply within
such a big thread.

Patch

diff --git a/Documentation/ABI/testing/se-cdev b/Documentation/ABI/testing/se-cdev
new file mode 100644
index 000000000000..3451c909ccc4
--- /dev/null
+++ b/Documentation/ABI/testing/se-cdev
@@ -0,0 +1,43 @@ 
+What:		/dev/<se>_mu[0-9]+_ch[0-9]+
+Date:		May 2024
+KernelVersion:	6.8
+Contact:	[e-mail], [e-mail]
+Description:
+		NXP offers multiple hardware IP(s) for secure enclaves like EdgeLock-
+		Enclave(ELE), SECO. The character device file descriptors
+		/dev/<se>_mu*_ch* are the interface between userspace NXP's secure-
+		enclave shared library and the kernel driver.
+
+		The ioctl(2)-based ABI is defined and documented in
+		[include]<linux/firmware/imx/ele_mu_ioctl.h>.
+		ioctl(s) are used primarily for:
+			- shared memory management
+			- allocation of I/O buffers
+			- getting mu info
+			- setting a dev-ctx as receiver to receive all the commands from FW
+			- getting SoC info
+			- send command and receive command response
+
+		The following file operations are supported:
+
+		open(2)
+		  Currently the only useful flags are O_RDWR.
+
+		read(2)
+		  Every read() from the opened character device context is waiting on
+		  wait_event_interruptible, that gets set by the registered mailbox callback
+		  function, indicating a message received from the firmware on message-
+		  unit.
+
+		write(2)
+		  Every write() to the opened character device context needs to acquire
+		  mailbox_lock before sending message on to the message unit.
+
+		close(2)
+		  Stops and frees up the I/O contexts that were associated
+		  with the file descriptor.
+
+Users:		https://github.com/nxp-imx/imx-secure-enclave.git,
+		https://github.com/nxp-imx/imx-smw.git
+		crypto/skcipher,
+		drivers/nvmem/imx-ocotp-ele.c
diff --git a/drivers/firmware/imx/ele_common.c b/drivers/firmware/imx/ele_common.c
index b2be32550e9b..88169cd8f369 100644
--- a/drivers/firmware/imx/ele_common.c
+++ b/drivers/firmware/imx/ele_common.c
@@ -78,6 +78,149 @@  int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg)
 	return err;
 }
 
+int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
+			void *rx_buf,
+			int rx_buf_sz)
+{
+	struct se_msg_hdr *header;
+	int err;
+
+	err = wait_event_interruptible(dev_ctx->wq, dev_ctx->pending_hdr != 0);
+	if (err) {
+		dev_err(dev_ctx->dev,
+			"%s: Err[0x%x]:Interrupted by signal.\n",
+			dev_ctx->miscdev.name, err);
+		goto exit;
+	}
+
+	header = (struct se_msg_hdr *) dev_ctx->temp_resp;
+
+	if (header->tag == dev_ctx->priv->rsp_tag) {
+		if (dev_ctx->priv->waiting_rsp_dev && dev_ctx->priv->waiting_rsp_dev != dev_ctx) {
+			dev_warn(dev_ctx->dev,
+			"Dev-ctx waiting for response mismatch (%s != %s).\n",
+			dev_ctx->miscdev.name, dev_ctx->priv->waiting_rsp_dev->miscdev.name);
+			err = -EPERM;
+			goto exit;
+		}
+	}
+
+	dev_dbg(dev_ctx->dev,
+		"%s: %s %s\n",
+		dev_ctx->miscdev.name,
+		__func__,
+		"message received, start transmit to user");
+
+	/*
+	 * Check that the size passed as argument is larger than
+	 * the one carried in the message.
+	 *
+	 * In case of US-command/response, the dev_ctx->temp_resp_size
+	 * is set before sending the command.
+	 *
+	 * In case of NVM Slave-command/response, the dev_ctx->temp_resp_size
+	 * is set after receing the message from mailbox.
+	 */
+	if (dev_ctx->temp_resp_size > rx_buf_sz) {
+		dev_err(dev_ctx->dev,
+			"%s: User buffer too small (%d < %d)\n",
+			dev_ctx->miscdev.name,
+			rx_buf_sz, dev_ctx->temp_resp_size);
+		 dev_ctx->temp_resp_size = rx_buf_sz;
+	}
+
+	/* We may need to copy the output data to user before
+	 * delivering the completion message.
+	 */
+	err = se_dev_ctx_cpy_out_data(dev_ctx, true);
+	if (err < 0)
+		goto exit;
+
+	/* Copy data from the buffer */
+	print_hex_dump_debug("to user ", DUMP_PREFIX_OFFSET, 4, 4,
+			     dev_ctx->temp_resp, dev_ctx->temp_resp_size, false);
+	if (copy_to_user(rx_buf, dev_ctx->temp_resp, dev_ctx->temp_resp_size)) {
+		dev_err(dev_ctx->dev,
+			"%s: Failed to copy to user\n",
+			dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+	err = dev_ctx->temp_resp_size;
+exit:
+	if (err < 0)
+		se_dev_ctx_cpy_out_data(dev_ctx, false);
+
+	/* free memory allocated on the shared buffers. */
+	dev_ctx->secure_mem.pos = 0;
+	dev_ctx->non_secure_mem.pos = 0;
+
+	dev_ctx->pending_hdr = 0;
+	se_dev_ctx_shared_mem_cleanup(dev_ctx);
+
+	return err;
+}
+
+int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
+			 void *tx_msg, int tx_msg_sz)
+{
+	struct se_if_priv *priv = dev_ctx->priv;
+	struct se_msg_hdr *header;
+	u32 size_to_send;
+	int err;
+
+	header = (struct se_msg_hdr *) tx_msg;
+
+	/*
+	 * Check that the size passed as argument matches the size
+	 * carried in the message.
+	 */
+	size_to_send = header->size << 2;
+
+	if (size_to_send != tx_msg_sz) {
+		err = -EINVAL;
+		dev_err(priv->dev,
+			"%s: User buf hdr(0x%x) sz mismatced with input-sz (%d != %d).\n",
+			dev_ctx->miscdev.name, *(u32 *)header, size_to_send, tx_msg_sz);
+		goto exit;
+	}
+
+	/* Check the message is valid according to tags */
+	if (header->tag == priv->rsp_tag) {
+		/* Check the device context can send the command */
+		if (dev_ctx != priv->cmd_receiver_dev) {
+			dev_err(priv->dev,
+				"%s: Channel not configured to send resp to FW.",
+				dev_ctx->miscdev.name);
+			err = -EPERM;
+			goto exit;
+		}
+	} else if (header->tag == priv->cmd_tag) {
+		if (priv->waiting_rsp_dev != dev_ctx) {
+			dev_err(priv->dev,
+				"%s: Channel not configured to send cmd to FW.",
+				dev_ctx->miscdev.name);
+			err = -EPERM;
+			goto exit;
+		}
+		lockdep_assert_held(&priv->se_if_cmd_lock);
+	} else {
+		dev_err(priv->dev,
+			"%s: The message does not have a valid TAG\n",
+			dev_ctx->miscdev.name);
+		err = -EINVAL;
+		goto exit;
+	}
+	err = ele_msg_send(priv, tx_msg);
+	if (err < 0)
+		goto exit;
+
+	err = size_to_send;
+exit:
+	return err;
+}
+
 static bool exception_for_size(struct se_if_priv *priv,
 				struct se_msg_hdr *header)
 {
@@ -99,6 +242,7 @@  static bool exception_for_size(struct se_if_priv *priv,
 void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
 {
 	struct device *dev = mbox_cl->dev;
+	struct se_if_device_ctx *dev_ctx;
 	struct se_if_priv *priv;
 	struct se_msg_hdr *header;
 	u32 rx_msg_sz;
@@ -114,8 +258,50 @@  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
 	header = msg;
 	rx_msg_sz = header->size << 2;
 
-	if (header->tag == priv->rsp_tag) {
-		if (!priv->waiting_rsp_dev) {
+	/* Incoming command: wake up the receiver if any. */
+	if (header->tag == priv->cmd_tag) {
+		dev_dbg(dev, "Selecting cmd receiver\n");
+		dev_ctx = priv->cmd_receiver_dev;
+		/* Pre-allocated buffer of MAX_NVM_MSG_LEN
+		 * as the NVM command are initiated by FW.
+		 * Size is revealed as part of this call function.
+		 */
+		if (rx_msg_sz > MAX_NVM_MSG_LEN) {
+			dev_err(dev,
+				"%s: Msg recvd hdr(0x%x) with greater[%d] than allocated buf-sz.\n",
+				dev_ctx->miscdev.name,
+				*(u32 *) header,
+				rx_msg_sz);
+		} else
+			memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
+
+		/* NVM buffer size are not known prior receiving it from FW.
+		 */
+		dev_ctx->temp_resp_size = rx_msg_sz;
+
+		/* Allow user to read */
+		dev_ctx->pending_hdr = 1;
+		wake_up_interruptible(&dev_ctx->wq);
+
+		return;
+	} else if (header->tag == priv->rsp_tag) {
+		if (priv->waiting_rsp_dev) {
+			dev_dbg(dev, "Selecting rsp waiter\n");
+			dev_ctx = priv->waiting_rsp_dev;
+			if (rx_msg_sz != dev_ctx->temp_resp_size
+				&& !exception_for_size(priv, header))
+				dev_err(dev,
+					"%s: Msg RSP hdr(0x%x) with different sz(%d != %d).\n",
+					dev_ctx->miscdev.name,
+					*(u32 *) header,
+					rx_msg_sz, dev_ctx->temp_resp_size);
+			else
+				memcpy(dev_ctx->temp_resp, msg, rx_msg_sz);
+
+			/* Allow user to read */
+			dev_ctx->pending_hdr = 1;
+			wake_up_interruptible(&dev_ctx->wq);
+		} else {
 			/*
 			 * Reading the EdgeLock Enclave response
 			 * to the command, sent by other
@@ -132,8 +318,8 @@  void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg)
 
 			complete(&priv->done);
 			spin_unlock(&priv->lock);
-			return;
 		}
+		return;
 	}
 
 	dev_err(dev, "Failed to select a device for message: %.8x\n",
diff --git a/drivers/firmware/imx/ele_common.h b/drivers/firmware/imx/ele_common.h
index 5ef775a42ab3..7b1c6bfc138b 100644
--- a/drivers/firmware/imx/ele_common.h
+++ b/drivers/firmware/imx/ele_common.h
@@ -17,6 +17,10 @@  uint32_t se_add_msg_crc(uint32_t *msg, uint32_t msg_len);
 int ele_msg_rcv(struct se_if_priv *priv);
 int ele_msg_send(struct se_if_priv *priv, void *tx_msg);
 int ele_msg_send_rcv(struct se_if_priv *priv, void *tx_msg, void *rx_msg);
+int ele_miscdev_msg_rcv(struct se_if_device_ctx *dev_ctx,
+			void *rx_msg, int rx_msg_sz);
+int ele_miscdev_msg_send(struct se_if_device_ctx *dev_ctx,
+			 void *tx_msg, int tx_msg_sz);
 void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg);
 int se_val_rsp_hdr_n_status(struct se_if_priv *priv,
 			    struct se_msg_hdr *header,
diff --git a/drivers/firmware/imx/se_ctrl.c b/drivers/firmware/imx/se_ctrl.c
index a844794d2b39..8fb2af0f0dd3 100644
--- a/drivers/firmware/imx/se_ctrl.c
+++ b/drivers/firmware/imx/se_ctrl.c
@@ -23,6 +23,7 @@ 
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/sys_soc.h>
+#include <uapi/linux/se_ioctl.h>
 
 #include "ele_base_msg.h"
 #include "ele_common.h"
@@ -196,6 +197,608 @@  static int se_soc_info(struct se_if_priv *priv,
 	return 0;
 }
 
+static int se_ioctl_cmd_snd_rcv_rsp_handler(struct se_if_device_ctx *dev_ctx,
+					    u64 arg)
+{
+	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
+	struct se_ioctl_cmd_snd_rcv_rsp_info cmd_snd_rcv_rsp_info;
+	struct se_api_msg *tx_msg __free(kfree) = NULL;
+	struct se_api_msg *rx_msg __free(kfree) = NULL;
+	int err = 0;
+
+	if (copy_from_user(&cmd_snd_rcv_rsp_info, (u8 *)arg,
+			   sizeof(cmd_snd_rcv_rsp_info))) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
+			dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+	if (cmd_snd_rcv_rsp_info.tx_buf_sz < SE_MU_HDR_SZ) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: User buffer too small(%d < %d)\n",
+			dev_ctx->miscdev.name,
+			cmd_snd_rcv_rsp_info.tx_buf_sz,
+			SE_MU_HDR_SZ);
+		err = -ENOSPC;
+		goto exit;
+	}
+
+	rx_msg = kzalloc(cmd_snd_rcv_rsp_info.rx_buf_sz, GFP_KERNEL);
+	if (!rx_msg) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	tx_msg = memdup_user(cmd_snd_rcv_rsp_info.tx_buf,
+			     cmd_snd_rcv_rsp_info.tx_buf_sz);
+	if (IS_ERR(tx_msg)) {
+		err = PTR_ERR(tx_msg);
+		goto exit;
+	}
+
+	if (tx_msg->header.tag != priv->cmd_tag) {
+		err = -EINVAL;
+		goto exit;
+	}
+
+	scoped_guard(mutex, &priv->se_if_cmd_lock);
+	priv->waiting_rsp_dev = dev_ctx;
+	dev_ctx->temp_resp_size = cmd_snd_rcv_rsp_info.rx_buf_sz;
+
+	/* Device Context that is assigned to be a
+	 * FW's command receiver, has pre-allocated buffer.
+	 */
+	if (dev_ctx != priv->cmd_receiver_dev)
+		dev_ctx->temp_resp = rx_msg;
+
+	err = ele_miscdev_msg_send(dev_ctx,
+				   tx_msg,
+				   cmd_snd_rcv_rsp_info.tx_buf_sz);
+	if (err < 0)
+		goto exit;
+
+	cmd_snd_rcv_rsp_info.tx_buf_sz = err;
+
+	err = ele_miscdev_msg_rcv(dev_ctx,
+				  cmd_snd_rcv_rsp_info.rx_buf,
+				  cmd_snd_rcv_rsp_info.rx_buf_sz);
+
+	if (err < 0)
+		goto exit;
+
+	cmd_snd_rcv_rsp_info.rx_buf_sz = err;
+
+exit:
+	dev_ctx->temp_resp_size = 0;
+	priv->waiting_rsp_dev = NULL;
+	if (dev_ctx != priv->cmd_receiver_dev)
+		dev_ctx->temp_resp = NULL;
+
+	if (copy_to_user((void *)arg, &cmd_snd_rcv_rsp_info,
+			 sizeof(cmd_snd_rcv_rsp_info))) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed to copy cmd_snd_rcv_rsp_info from user\n",
+			dev_ctx->miscdev.name);
+		err = -EFAULT;
+	}
+	return err;
+}
+
+/*
+ * File operations for user-space
+ */
+
+/* Write a message to the MU. */
+static ssize_t se_if_fops_write(struct file *fp, const char __user *buf,
+				size_t size, loff_t *ppos)
+{
+	struct se_api_msg *tx_msg __free(kfree) = NULL;
+	struct se_if_device_ctx *dev_ctx;
+	struct se_if_priv *priv;
+	int err;
+
+	dev_ctx = container_of(fp->private_data,
+			       struct se_if_device_ctx,
+			       miscdev);
+	priv = dev_ctx->priv;
+	dev_dbg(priv->dev,
+		"%s: write from buf (%p)%zu, ppos=%lld\n",
+			dev_ctx->miscdev.name,
+			buf, size, ((ppos) ? *ppos : 0));
+
+	if (down_interruptible(&dev_ctx->fops_lock))
+		return -EBUSY;
+
+	if (dev_ctx->status != SE_IF_CTX_OPENED) {
+		err = -EINVAL;
+		goto exit;
+	}
+
+	if (size < SE_MU_HDR_SZ) {
+		dev_err(priv->dev,
+			"%s: User buffer too small(%zu < %d)\n",
+				dev_ctx->miscdev.name,
+				size, SE_MU_HDR_SZ);
+		err = -ENOSPC;
+		goto exit;
+	}
+	tx_msg = memdup_user(buf, size);
+	if (IS_ERR(tx_msg)) {
+		err = PTR_ERR(tx_msg);
+		goto exit;
+	}
+
+	print_hex_dump_debug("from user ", DUMP_PREFIX_OFFSET, 4, 4,
+			     tx_msg, size, false);
+
+	err = ele_miscdev_msg_send(dev_ctx, tx_msg, size);
+
+exit:
+	up(&dev_ctx->fops_lock);
+	return err;
+}
+
+/*
+ * Read a message from the MU.
+ * Blocking until a message is available.
+ */
+static ssize_t se_if_fops_read(struct file *fp, char __user *buf,
+			       size_t size, loff_t *ppos)
+{
+	struct se_if_device_ctx *dev_ctx;
+	struct se_if_priv *priv;
+	int err;
+
+	dev_ctx = container_of(fp->private_data,
+			       struct se_if_device_ctx,
+			       miscdev);
+	priv = dev_ctx->priv;
+	dev_dbg(priv->dev,
+		"%s: read to buf %p(%zu), ppos=%lld\n",
+			dev_ctx->miscdev.name,
+			buf, size, ((ppos) ? *ppos : 0));
+
+	if (down_interruptible(&dev_ctx->fops_lock))
+		return -EBUSY;
+
+	if (dev_ctx->status != SE_IF_CTX_OPENED) {
+		err = -EINVAL;
+		goto exit;
+	}
+
+	err = ele_miscdev_msg_rcv(dev_ctx, buf, size);
+
+exit:
+	up(&dev_ctx->fops_lock);
+	return err;
+}
+
+static int se_ioctl_get_mu_info(struct se_if_device_ctx *dev_ctx,
+				u64 arg)
+{
+	struct se_if_priv *priv = dev_get_drvdata(dev_ctx->dev);
+	struct se_if_node_info *if_node_info;
+	struct se_ioctl_get_if_info info;
+	int err = 0;
+
+	if_node_info = (struct se_if_node_info *)priv->info;
+
+	info.se_if_id = if_node_info->se_if_id;
+	info.interrupt_idx = 0;
+	info.tz = 0;
+	info.did = if_node_info->se_if_did;
+	info.cmd_tag = if_node_info->cmd_tag;
+	info.rsp_tag = if_node_info->rsp_tag;
+	info.success_tag = if_node_info->success_tag;
+	info.base_api_ver = if_node_info->base_api_ver;
+	info.fw_api_ver = if_node_info->fw_api_ver;
+
+	dev_dbg(priv->dev,
+		"%s: info [se_if_id: %d, irq_idx: %d, tz: 0x%x, did: 0x%x]\n",
+			dev_ctx->miscdev.name,
+			info.se_if_id, info.interrupt_idx, info.tz, info.did);
+
+	if (copy_to_user((u8 *)arg, &info, sizeof(info))) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed to copy mu info to user\n",
+				dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+exit:
+	return err;
+}
+
+/* Need to copy the output data to user-device context.
+ */
+int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy)
+{
+	struct se_buf_desc *b_desc, *temp;
+
+	list_for_each_entry_safe(b_desc, temp, &dev_ctx->pending_out, link) {
+		if (b_desc->usr_buf_ptr && b_desc->shared_buf_ptr && do_cpy) {
+
+			dev_dbg(dev_ctx->dev,
+				"%s: Copy output data to user\n",
+				dev_ctx->miscdev.name);
+			if (copy_to_user(b_desc->usr_buf_ptr,
+					 b_desc->shared_buf_ptr,
+					 b_desc->size)) {
+				dev_err(dev_ctx->dev,
+					"%s: Failure copying output data to user.",
+					dev_ctx->miscdev.name);
+				return -EFAULT;
+			}
+		}
+
+		if (b_desc->shared_buf_ptr)
+			memset(b_desc->shared_buf_ptr, 0, b_desc->size);
+
+		list_del(&b_desc->link);
+		kfree(b_desc);
+	}
+	return 0;
+}
+
+/*
+ * Clean the used Shared Memory space,
+ * whether its Input Data copied from user buffers, or
+ * Data received from FW.
+ */
+void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx)
+{
+	struct list_head *dev_ctx_lists[] = {&dev_ctx->pending_in,
+						 &dev_ctx->pending_out};
+	struct se_buf_desc *b_desc, *temp;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		list_for_each_entry_safe(b_desc, temp,
+					 dev_ctx_lists[i], link) {
+
+			if (b_desc->shared_buf_ptr)
+				memset(b_desc->shared_buf_ptr, 0, b_desc->size);
+
+			list_del(&b_desc->link);
+			kfree(b_desc);
+		}
+	}
+}
+
+/*
+ * Copy a buffer of data to/from the user and return the address to use in
+ * messages
+ */
+static int se_ioctl_setup_iobuf_handler(struct se_if_device_ctx *dev_ctx,
+					    u64 arg)
+{
+	struct se_shared_mem *shared_mem = NULL;
+	struct se_ioctl_setup_iobuf io = {0};
+	struct se_buf_desc *b_desc = NULL;
+	int err = 0;
+	u32 pos;
+
+	if (copy_from_user(&io, (u8 *)arg, sizeof(io))) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed copy iobuf config from user\n",
+				dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+	dev_dbg(dev_ctx->priv->dev,
+			"%s: io [buf: %p(%d) flag: %x]\n",
+			dev_ctx->miscdev.name,
+			io.user_buf, io.length, io.flags);
+
+	if (io.length == 0 || !io.user_buf) {
+		/*
+		 * Accept NULL pointers since some buffers are optional
+		 * in FW commands. In this case we should return 0 as
+		 * pointer to be embedded into the message.
+		 * Skip all data copy part of code below.
+		 */
+		io.ele_addr = 0;
+		goto copy;
+	}
+
+	/* Select the shared memory to be used for this buffer. */
+	if (io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) {
+		/* App requires to use secure memory for this buffer.*/
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed allocate SEC MEM memory\n",
+				dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	} else {
+		/* No specific requirement for this buffer. */
+		shared_mem = &dev_ctx->non_secure_mem;
+	}
+
+	/* Check there is enough space in the shared memory. */
+	if (shared_mem->size < shared_mem->pos ||
+		round_up(io.length, 8u) >= (shared_mem->size - shared_mem->pos)) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Not enough space in shared memory\n",
+				dev_ctx->miscdev.name);
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	/* Allocate space in shared memory. 8 bytes aligned. */
+	pos = shared_mem->pos;
+	shared_mem->pos += round_up(io.length, 8u);
+	io.ele_addr = (u64)shared_mem->dma_addr + pos;
+
+	if ((io.flags & SE_MU_IO_FLAGS_USE_SEC_MEM) &&
+	    !(io.flags & SE_MU_IO_FLAGS_USE_SHORT_ADDR)) {
+		/*Add base address to get full address.*/
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed allocate SEC MEM memory\n",
+				dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+	memset(shared_mem->ptr + pos, 0, io.length);
+	if ((io.flags & SE_IO_BUF_FLAGS_IS_INPUT) ||
+	    (io.flags & SE_IO_BUF_FLAGS_IS_IN_OUT)) {
+		/*
+		 * buffer is input:
+		 * copy data from user space to this allocated buffer.
+		 */
+		if (copy_from_user(shared_mem->ptr + pos, io.user_buf,
+				   io.length)) {
+			dev_err(dev_ctx->priv->dev,
+				"%s: Failed copy data to shared memory\n",
+				dev_ctx->miscdev.name);
+			err = -EFAULT;
+			goto exit;
+		}
+	}
+
+	b_desc = kzalloc(sizeof(*b_desc), GFP_KERNEL);
+	if (!b_desc) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+copy:
+	/* Provide the EdgeLock Enclave address to user space only if success.*/
+	if (copy_to_user((u8 *)arg, &io, sizeof(io))) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed to copy iobuff setup to user\n",
+				dev_ctx->miscdev.name);
+		kfree(b_desc);
+		err = -EFAULT;
+		goto exit;
+	}
+
+	if (b_desc) {
+		b_desc->shared_buf_ptr = shared_mem->ptr + pos;
+		b_desc->usr_buf_ptr = io.user_buf;
+		b_desc->size = io.length;
+
+		if (io.flags & SE_IO_BUF_FLAGS_IS_INPUT) {
+			/*
+			 * buffer is input:
+			 * add an entry in the "pending input buffers" list so
+			 * that copied data can be cleaned from shared memory
+			 * later.
+			 */
+			list_add_tail(&b_desc->link, &dev_ctx->pending_in);
+		} else {
+			/*
+			 * buffer is output:
+			 * add an entry in the "pending out buffers" list so data
+			 * can be copied to user space when receiving Secure-Enclave
+			 * response.
+			 */
+			list_add_tail(&b_desc->link, &dev_ctx->pending_out);
+		}
+	}
+
+exit:
+	return err;
+}
+
+/* IOCTL to provide SoC information */
+static int se_ioctl_get_se_soc_info_handler(struct se_if_device_ctx *dev_ctx,
+					     u64 arg)
+{
+	const struct se_if_node_info_list *info_list;
+	struct se_ioctl_get_soc_info soc_info;
+	int err = -EINVAL;
+
+	info_list = device_get_match_data(dev_ctx->priv->dev);
+	if (!info_list)
+		goto exit;
+
+	soc_info.soc_id = info_list->soc_id;
+	soc_info.soc_rev = dev_ctx->priv->soc_rev;
+
+	err = (int)copy_to_user((u8 *)arg, (u8 *)(&soc_info), sizeof(soc_info));
+	if (err) {
+		dev_err(dev_ctx->priv->dev,
+			"%s: Failed to copy soc info to user\n",
+			dev_ctx->miscdev.name);
+		err = -EFAULT;
+		goto exit;
+	}
+
+exit:
+	return err;
+}
+
+/* Open a character device. */
+static int se_if_fops_open(struct inode *nd, struct file *fp)
+{
+	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
+							struct se_if_device_ctx,
+							miscdev);
+	int err = 0;
+
+	/* Avoid race if opened at the same time */
+	if (down_trylock(&dev_ctx->fops_lock))
+		return -EBUSY;
+
+	/* Authorize only 1 instance. */
+	if (dev_ctx->status != SE_IF_CTX_FREE) {
+		err = -EBUSY;
+		goto exit;
+	}
+
+	/*
+	 * Allocate some memory for data exchanges with S40x.
+	 * This will be used for data not requiring secure memory.
+	 */
+	dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
+					MAX_DATA_SIZE_PER_USER,
+					&dev_ctx->non_secure_mem.dma_addr,
+					GFP_KERNEL);
+	if (!dev_ctx->non_secure_mem.ptr) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
+	dev_ctx->non_secure_mem.pos = 0;
+	dev_ctx->status = SE_IF_CTX_OPENED;
+
+	dev_ctx->pending_hdr = 0;
+
+	goto exit;
+
+	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
+			   dev_ctx->non_secure_mem.ptr,
+			   dev_ctx->non_secure_mem.dma_addr);
+
+exit:
+	up(&dev_ctx->fops_lock);
+	return err;
+}
+
+/* Close a character device. */
+static int se_if_fops_close(struct inode *nd, struct file *fp)
+{
+	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
+							struct se_if_device_ctx,
+							miscdev);
+	struct se_if_priv *priv = dev_ctx->priv;
+
+	/* Avoid race if closed at the same time */
+	if (down_trylock(&dev_ctx->fops_lock))
+		return -EBUSY;
+
+	/* The device context has not been opened */
+	if (dev_ctx->status != SE_IF_CTX_OPENED)
+		goto exit;
+
+	/* check if this device was registered as command receiver. */
+	if (priv->cmd_receiver_dev == dev_ctx) {
+		priv->cmd_receiver_dev = NULL;
+		kfree(dev_ctx->temp_resp);
+	}
+
+	/* check if this device was registered as waiting response. */
+	if (priv->waiting_rsp_dev == dev_ctx) {
+		priv->waiting_rsp_dev = NULL;
+		mutex_unlock(&priv->se_if_cmd_lock);
+	}
+
+	/* Unmap secure memory shared buffer. */
+	if (dev_ctx->secure_mem.ptr)
+		devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
+
+	dev_ctx->secure_mem.ptr = NULL;
+	dev_ctx->secure_mem.dma_addr = 0;
+	dev_ctx->secure_mem.size = 0;
+	dev_ctx->secure_mem.pos = 0;
+
+	/* Free non-secure shared buffer. */
+	dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
+			   dev_ctx->non_secure_mem.ptr,
+			   dev_ctx->non_secure_mem.dma_addr);
+
+	dev_ctx->non_secure_mem.ptr = NULL;
+	dev_ctx->non_secure_mem.dma_addr = 0;
+	dev_ctx->non_secure_mem.size = 0;
+	dev_ctx->non_secure_mem.pos = 0;
+	se_dev_ctx_shared_mem_cleanup(dev_ctx);
+	dev_ctx->status = SE_IF_CTX_FREE;
+
+exit:
+	up(&dev_ctx->fops_lock);
+	return 0;
+}
+
+/* IOCTL entry point of a character device */
+static long se_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+	struct se_if_device_ctx *dev_ctx = container_of(fp->private_data,
+							struct se_if_device_ctx,
+							miscdev);
+	struct se_if_priv *se_if_priv = dev_ctx->priv;
+	int err = -EINVAL;
+
+	/* Prevent race during change of device context */
+	if (down_interruptible(&dev_ctx->fops_lock))
+		return -EBUSY;
+
+	switch (cmd) {
+	case SE_IOCTL_ENABLE_CMD_RCV:
+		if (!se_if_priv->cmd_receiver_dev) {
+			err = 0;
+			se_if_priv->cmd_receiver_dev = dev_ctx;
+			dev_ctx->temp_resp = kzalloc(MAX_NVM_MSG_LEN, GFP_KERNEL);
+			if (!dev_ctx->temp_resp)
+				err = -ENOMEM;
+		}
+		break;
+	case SE_IOCTL_GET_MU_INFO:
+		err = se_ioctl_get_mu_info(dev_ctx, arg);
+		break;
+	case SE_IOCTL_SETUP_IOBUF:
+		err = se_ioctl_setup_iobuf_handler(dev_ctx, arg);
+		break;
+	case SE_IOCTL_GET_SOC_INFO:
+		err = se_ioctl_get_se_soc_info_handler(dev_ctx, arg);
+		break;
+	case SE_IOCTL_CMD_SEND_RCV_RSP:
+		err = se_ioctl_cmd_snd_rcv_rsp_handler(dev_ctx, arg);
+		break;
+
+	default:
+		err = -EINVAL;
+		dev_dbg(se_if_priv->dev,
+			"%s: IOCTL %.8x not supported\n",
+				dev_ctx->miscdev.name,
+				cmd);
+	}
+
+	up(&dev_ctx->fops_lock);
+	return (long)err;
+}
+
+/* Char driver setup */
+static const struct file_operations se_if_fops = {
+	.open		= se_if_fops_open,
+	.owner		= THIS_MODULE,
+	.release	= se_if_fops_close,
+	.unlocked_ioctl = se_ioctl,
+	.read		= se_if_fops_read,
+	.write		= se_if_fops_write,
+};
+
+/* interface for managed res to unregister a character device */
+static void if_misc_deregister(void *miscdevice)
+{
+	misc_deregister(miscdevice);
+}
+
 /* interface for managed res to free a mailbox channel */
 static void if_mbox_free_channel(void *mbox_chan)
 {
@@ -233,6 +836,7 @@  static void se_if_probe_cleanup(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct se_if_priv *priv;
+	int i;
 
 	priv = dev_get_drvdata(dev);
 
@@ -252,6 +856,17 @@  static void se_if_probe_cleanup(struct platform_device *pdev)
 		priv->imem.buf = NULL;
 	}
 
+	if (priv->ctxs) {
+		for (i = 0; i < priv->max_dev_ctx; i++) {
+			if (priv->ctxs[i]) {
+				devm_remove_action(dev,
+						   if_misc_deregister,
+						   &priv->ctxs[i]->miscdev);
+				misc_deregister(&priv->ctxs[i]->miscdev);
+			}
+		}
+	}
+
 	/* No need to check, if reserved memory is allocated
 	 * before calling for its release. Or clearing the
 	 * un-set bit.
@@ -259,6 +874,74 @@  static void se_if_probe_cleanup(struct platform_device *pdev)
 	of_reserved_mem_device_release(dev);
 }
 
+static int init_device_context(struct se_if_priv *priv)
+{
+	const struct se_if_node_info *info = priv->info;
+	struct se_if_device_ctx *dev_ctx;
+	u8 *devname;
+	int ret = 0;
+	int i;
+
+	priv->ctxs = devm_kzalloc(priv->dev, sizeof(dev_ctx) * priv->max_dev_ctx,
+				  GFP_KERNEL);
+
+	if (!priv->ctxs) {
+		ret = -ENOMEM;
+		return ret;
+	}
+
+	/* Create users */
+	for (i = 0; i < priv->max_dev_ctx; i++) {
+		dev_ctx = devm_kzalloc(priv->dev, sizeof(*dev_ctx), GFP_KERNEL);
+		if (!dev_ctx) {
+			ret = -ENOMEM;
+			return ret;
+		}
+
+		dev_ctx->dev = priv->dev;
+		dev_ctx->status = SE_IF_CTX_FREE;
+		dev_ctx->priv = priv;
+
+		priv->ctxs[i] = dev_ctx;
+
+		/* Default value invalid for an header. */
+		init_waitqueue_head(&dev_ctx->wq);
+
+		INIT_LIST_HEAD(&dev_ctx->pending_out);
+		INIT_LIST_HEAD(&dev_ctx->pending_in);
+		sema_init(&dev_ctx->fops_lock, 1);
+
+		devname = devm_kasprintf(priv->dev, GFP_KERNEL, "%s_ch%d",
+					 info->se_name, i);
+		if (!devname) {
+			ret = -ENOMEM;
+			return ret;
+		}
+
+		dev_ctx->miscdev.name = devname;
+		dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
+		dev_ctx->miscdev.fops = &se_if_fops;
+		dev_ctx->miscdev.parent = priv->dev;
+		ret = misc_register(&dev_ctx->miscdev);
+		if (ret) {
+			dev_err(priv->dev, "failed to register misc device %d\n",
+				ret);
+			return ret;
+		}
+
+		ret = devm_add_action(priv->dev, if_misc_deregister,
+				      &dev_ctx->miscdev);
+		if (ret) {
+			dev_err(priv->dev,
+				"failed[%d] to add action to the misc-dev\n",
+				ret);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
 static void se_load_firmware(const struct firmware *fw, void *context)
 {
 	struct se_if_priv *priv = (struct se_if_priv *) context;
@@ -427,6 +1110,16 @@  static int se_if_probe(struct platform_device *pdev)
 		ret = 0;
 	}
 
+	if (info->max_dev_ctx) {
+		ret = init_device_context(priv);
+		if (ret) {
+			dev_err(dev,
+				"Failed[0x%x] to create device contexts.\n",
+				ret);
+			goto exit;
+		}
+	}
+
 	dev_info(dev, "i.MX secure-enclave: %s interface to firmware, configured.\n",
 		 info->se_name);
 	return ret;
@@ -467,6 +1160,10 @@  static int se_resume(struct device *dev)
 {
 	struct se_if_priv *priv = dev_get_drvdata(dev);
 	const struct se_if_node_info *info = priv->info;
+	int i;
+
+	for (i = 0; i < priv->max_dev_ctx; i++)
+		wake_up_interruptible(&priv->ctxs[i]->wq);
 
 	if (info && info->imem_mgmt)
 		se_restore_imem_state(priv);
diff --git a/drivers/firmware/imx/se_ctrl.h b/drivers/firmware/imx/se_ctrl.h
index 4be2235d2170..b49346372746 100644
--- a/drivers/firmware/imx/se_ctrl.h
+++ b/drivers/firmware/imx/se_ctrl.h
@@ -13,15 +13,62 @@ 
 #define MAX_FW_LOAD_RETRIES		50
 
 #define RES_STATUS(x)			FIELD_GET(0x000000ff, x)
+#define MAX_DATA_SIZE_PER_USER		(65 * 1024)
+#define MAX_NVM_MSG_LEN			(256)
 #define MESSAGING_VERSION_6		0x6
 #define MESSAGING_VERSION_7		0x7
 
+#define SE_MU_IO_FLAGS_USE_SEC_MEM	(0x02u)
+#define SE_MU_IO_FLAGS_USE_SHORT_ADDR	(0x04u)
+
 struct se_imem_buf {
 	u8 *buf;
 	phys_addr_t phyaddr;
 	u32 size;
 };
 
+struct se_buf_desc {
+	u8 *shared_buf_ptr;
+	u8 *usr_buf_ptr;
+	u32 size;
+	struct list_head link;
+};
+
+/* Status of a char device */
+enum se_if_dev_ctx_status_t {
+	SE_IF_CTX_FREE,
+	SE_IF_CTX_OPENED
+};
+
+struct se_shared_mem {
+	dma_addr_t dma_addr;
+	u32 size;
+	u32 pos;
+	u8 *ptr;
+};
+
+/* Private struct for each char device instance. */
+struct se_if_device_ctx {
+	struct device *dev;
+	struct se_if_priv *priv;
+	struct miscdevice miscdev;
+
+	enum se_if_dev_ctx_status_t status;
+	wait_queue_head_t wq;
+	struct semaphore fops_lock;
+
+	u32 pending_hdr;
+	struct list_head pending_in;
+	struct list_head pending_out;
+
+	struct se_shared_mem secure_mem;
+	struct se_shared_mem non_secure_mem;
+
+	struct se_api_msg *temp_resp;
+	u32 temp_resp_size;
+	struct notifier_block se_notify;
+};
+
 /* Header of the messages exchange with the EdgeLock Enclave */
 struct se_msg_hdr {
 	u8 ver;
@@ -80,4 +127,6 @@  struct se_if_priv {
 	struct se_imem_buf imem;
 };
 
+int se_dev_ctx_cpy_out_data(struct se_if_device_ctx *dev_ctx, bool do_cpy);
+void se_dev_ctx_shared_mem_cleanup(struct se_if_device_ctx *dev_ctx);
 #endif
diff --git a/include/uapi/linux/se_ioctl.h b/include/uapi/linux/se_ioctl.h
new file mode 100644
index 000000000000..c2d0a92ef626
--- /dev/null
+++ b/include/uapi/linux/se_ioctl.h
@@ -0,0 +1,94 @@ 
+/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause*/
+/*
+ * Copyright 2024 NXP
+ */
+
+#ifndef SE_IOCTL_H
+#define SE_IOCTL_H
+
+/* IOCTL definitions. */
+
+struct se_ioctl_setup_iobuf {
+	u8 *user_buf;
+	u32 length;
+	u32 flags;
+	u64 ele_addr;
+};
+
+struct se_ioctl_shared_mem_cfg {
+	u32 base_offset;
+	u32 size;
+};
+
+struct se_ioctl_get_if_info {
+	u8 se_if_id;
+	u8 interrupt_idx;
+	u8 tz;
+	u8 did;
+	u8 cmd_tag;
+	u8 rsp_tag;
+	u8 success_tag;
+	u8 base_api_ver;
+	u8 fw_api_ver;
+};
+
+struct se_ioctl_cmd_snd_rcv_rsp_info {
+	u32 *tx_buf;
+	int tx_buf_sz;
+	u32 *rx_buf;
+	int rx_buf_sz;
+};
+
+struct se_ioctl_get_soc_info {
+	u16 soc_id;
+	u16 soc_rev;
+};
+
+/* IO Buffer Flags */
+#define SE_IO_BUF_FLAGS_IS_OUTPUT	(0x00u)
+#define SE_IO_BUF_FLAGS_IS_INPUT	(0x01u)
+#define SE_IO_BUF_FLAGS_USE_SEC_MEM	(0x02u)
+#define SE_IO_BUF_FLAGS_USE_SHORT_ADDR	(0x04u)
+#define SE_IO_BUF_FLAGS_IS_IN_OUT	(0x10u)
+
+/* IOCTLS */
+#define SE_IOCTL			0x0A /* like MISC_MAJOR. */
+
+/*
+ * ioctl to designated the current fd as logical-reciever.
+ * This is ioctl is send when the nvm-daemon, a slave to the
+ * firmware is started by the user.
+ */
+#define SE_IOCTL_ENABLE_CMD_RCV	_IO(SE_IOCTL, 0x01)
+
+/*
+ * ioctl to get the buffer allocated from the memory, which is shared
+ * between kernel and FW.
+ * Post allocation, the kernel tagged the allocated memory with:
+ *  Output
+ *  Input
+ *  Input-Output
+ *  Short address
+ *  Secure-memory
+ */
+#define SE_IOCTL_SETUP_IOBUF	_IOWR(SE_IOCTL, 0x03, \
+					struct se_ioctl_setup_iobuf)
+
+/*
+ * ioctl to get the mu information, that is used to exchange message
+ * with FW, from user-spaced.
+ */
+#define SE_IOCTL_GET_MU_INFO	_IOR(SE_IOCTL, 0x04, \
+					struct se_ioctl_get_if_info)
+/*
+ * ioctl to get SoC Info from user-space.
+ */
+#define SE_IOCTL_GET_SOC_INFO      _IOR(SE_IOCTL, 0x06, \
+					struct se_ioctl_get_soc_info)
+
+/*
+ * ioctl to send command and receive response from user-space.
+ */
+#define SE_IOCTL_CMD_SEND_RCV_RSP _IOWR(SE_IOCTL, 0x07, \
+					struct se_ioctl_cmd_snd_rcv_rsp_info)
+#endif