@@ -9,7 +9,7 @@ menu "Firmware Drivers"
config ARM_SCMI_PROTOCOL
tristate "ARM System Control and Management Interface (SCMI) Message Protocol"
depends on ARM || ARM64 || COMPILE_TEST
- depends on MAILBOX || HAVE_ARM_SMCCC_DISCOVERY
+ depends on MAILBOX || HAVE_ARM_SMCCC_DISCOVERY || OPTEE
help
ARM System Control and Management Interface (SCMI) protocol is a
set of operating system-independent software interfaces that are
@@ -4,6 +4,7 @@ scmi-driver-y = driver.o notify.o
scmi-transport-y = shmem.o
scmi-transport-$(CONFIG_MAILBOX) += mailbox.o
scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o
+scmi-transport-$(CONFIG_OPTEE) += optee_service.o
scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o
scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \
$(scmi-transport-y)
@@ -334,6 +334,9 @@ extern const struct scmi_desc scmi_mailbox_desc;
#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
extern const struct scmi_desc scmi_smc_desc;
#endif
+#ifdef CONFIG_OPTEE
+extern const struct scmi_desc scmi_optee_desc;
+#endif
void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
@@ -1570,6 +1570,9 @@ static const struct of_device_id scmi_of_match[] = {
{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
+#endif
+#ifdef CONFIG_OPTEE
+ { .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc },
#endif
{ /* Sentinel */ },
};
new file mode 100644
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019-2021 Linaro Limited
+ */
+
+#include <uapi/linux/tee.h>
+#include <linux/freezer.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+#include <linux/uuid.h>
+
+#include "common.h"
+
+#define DRIVER_NAME "optee-scmi-agent"
+
+/*
+ * PTA_SCMI_CMD_CAPABILITIES - Get channel capabilities
+ *
+ * [out] value[0].a: Capability bit mask (PTA_SCMI_CAPS_*)
+ * [out] value[0].b: Extended capabilities or 0
+ */
+#define PTA_SCMI_CMD_CAPABILITIES 0
+
+/*
+ * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL - Process SCMI message in SMT buffer
+ *
+ * [in] value[0].a: Channel handle
+ *
+ * Shared memory used for SCMI message/response exhange is expected
+ * already identified and bound to channel handle in both SCMI agent
+ * and SCMI server (OP-TEE) parts.
+ * The memory uses SMT header to carry SCMI meta-data (protocol ID and
+ * protocol message ID).
+ */
+#define PTA_SCMI_CMD_PROCESS_SMT_CHANNEL 1
+
+/*
+ * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE - Process SMT/SCMI message
+ *
+ * [in] value[0].a: Channel handle
+ * [in/out] memref[1]: Message/response buffer (SMT and SCMI payload)
+ *
+ * Shared memory used for SCMI message/response is a SMT buffer
+ * referenced by param[1]. It shall be 128 bytes large to fit response
+ * payload whatever message playload size.
+ * The memory uses SMT header to carry SCMI meta-data (protocol ID and
+ * protocol message ID).
+ */
+#define PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE 2
+
+/*
+ * PTA_SCMI_CMD_GET_CHANNEL_HANDLE - Get handle for an SCMI channel
+ *
+ * Get a handle for the SCMI channel. This handle value is to be passed
+ * as argument to some commands as PTA_SCMI_CMD_PROCESS_*.
+ *
+ * [in] value[0].a: Channel identifier or 0 if no assigned ID
+ * [in] value[0].b: Requested capabilities mask (PTA_SCMI_CAPS_*)
+ * [out] value[0].a: Returned channel handle
+ */
+#define PTA_SCMI_CMD_GET_CHANNEL_HANDLE 3
+
+/*
+ * Channel capabilities
+ */
+
+/* Channel supports shared memory using the SMT header protocol */
+#define PTA_SCMI_CAPS_SMT_HEADER BIT(0)
+
+struct optee_scmi_channel {
+ /* Channel handle retrieved from OP-TEE */
+ u32 channel_hdl;
+ /* Channel entry protection */
+ struct mutex mu;
+ /* Channel private data */
+ u32 tee_session;
+ struct optee_scmi_agent *agent;
+ struct scmi_chan_info *cinfo;
+ struct scmi_shared_mem __iomem *shmem;
+ /* Channel capabilities */
+ u32 caps;
+ /* Reference in agent's channel list */
+ struct list_head link;
+};
+
+/**
+ * struct optee_scmi_agent - OP-TEE transport private data
+ */
+struct optee_scmi_agent {
+ /* TEE context the agent operates with */
+ struct device *dev;
+ struct tee_context *tee_ctx;
+ /* Supported channel capabilities (PTA_SCMI_CAPS_*) */
+ u32 caps;
+ /* List all created channels */
+ struct list_head channel_list;
+};
+
+/* There is only 1 SCMI PTA to connect to */
+static struct optee_scmi_agent *agent_private;
+
+static struct list_head optee_agent_list = LIST_HEAD_INIT(optee_agent_list);
+static DEFINE_MUTEX(list_mutex);
+
+static int open_session(struct optee_scmi_agent *agent, u32 *tee_session)
+{
+ struct device *dev = agent->dev;
+ struct tee_client_device *scmi_pta = to_tee_client_device(dev);
+ struct tee_ioctl_open_session_arg sess_arg;
+ int ret;
+
+ memset(&sess_arg, 0, sizeof(sess_arg));
+
+ /* Open a session toward SCMI PTA with REE_KERNEL identity */
+ memcpy(sess_arg.uuid, scmi_pta->id.uuid.b, TEE_IOCTL_UUID_LEN);
+ sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+ ret = tee_client_open_session(agent->tee_ctx, &sess_arg, NULL);
+ if ((ret < 0) || (sess_arg.ret != 0)) {
+ dev_err(dev, "tee_client_open_session failed, err: %x\n",
+ sess_arg.ret);
+ return -EINVAL;
+ }
+
+ *tee_session = sess_arg.session;
+
+ return 0;
+}
+
+static void close_session(struct optee_scmi_agent *agent, u32 tee_session)
+{
+ tee_client_close_session(agent->tee_ctx, tee_session);
+}
+
+static int get_capabilities(struct optee_scmi_agent *agent)
+{
+ int ret;
+ struct tee_ioctl_invoke_arg inv_arg;
+ struct tee_param param[1];
+ u32 tee_session;
+
+ ret = open_session(agent, &tee_session);
+ if (ret)
+ return ret;
+
+ memset(&inv_arg, 0, sizeof(inv_arg));
+ memset(¶m, 0, sizeof(param));
+
+ inv_arg.func = PTA_SCMI_CMD_CAPABILITIES;
+ inv_arg.session = tee_session;
+ inv_arg.num_params = 1;
+
+ param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+ ret = tee_client_invoke_func(agent->tee_ctx, &inv_arg, param);
+
+ close_session(agent, tee_session);
+
+ if ((ret < 0) || (inv_arg.ret != 0)) {
+ dev_err(agent->dev, "Can't get capabilities: %d / %#x\n",
+ ret, inv_arg.ret);
+
+ return -EOPNOTSUPP;
+ }
+
+ agent->caps = param[0].u.value.a;
+
+ if (!(agent->caps & PTA_SCMI_CAPS_SMT_HEADER)) {
+ dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT\n");
+
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int get_channel(struct optee_scmi_channel *channel)
+{
+ struct device *dev = channel->agent->dev;
+ int ret;
+ struct tee_ioctl_invoke_arg inv_arg;
+ struct tee_param param[1];
+ unsigned int caps;
+
+ caps = PTA_SCMI_CAPS_SMT_HEADER;
+
+ memset(&inv_arg, 0, sizeof(inv_arg));
+ memset(¶m, 0, sizeof(param));
+
+ inv_arg.func = PTA_SCMI_CMD_GET_CHANNEL_HANDLE;
+ inv_arg.session = channel->tee_session;
+ inv_arg.num_params = 1;
+
+ param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
+ param[0].u.value.a = 0;
+ param[0].u.value.b = caps;
+
+ ret = tee_client_invoke_func(channel->agent->tee_ctx, &inv_arg, param);
+
+ if (ret || inv_arg.ret) {
+ dev_err(dev, "Can't get channel with caps %#x: ret=%d, tee-res=%#x\n",
+ caps, ret, inv_arg.ret);
+
+ return -EOPNOTSUPP;
+ }
+
+ /* Only channel handler is used, can discard old channel ID value */
+ channel->channel_hdl = param[0].u.value.a;
+ channel->caps = caps;
+
+ return 0;
+}
+
+/* Invocation of the PTA through a regular command invoke */
+static int invoke_process_smt_channel(struct optee_scmi_channel *channel)
+{
+ int ret;
+ struct tee_ioctl_invoke_arg inv_arg;
+ struct tee_param param[1];
+
+ if (!(channel->caps & PTA_SCMI_CAPS_SMT_HEADER))
+ return -EINVAL;
+
+ memset(&inv_arg, 0, sizeof(inv_arg));
+ memset(¶m, 0, sizeof(param));
+
+ inv_arg.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL;
+ inv_arg.session = channel->tee_session;
+ inv_arg.num_params = 1;
+
+ param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+ param[0].u.value.a = channel->channel_hdl;
+
+ ret = tee_client_invoke_func(channel->agent->tee_ctx, &inv_arg, param);
+ if (ret < 0 || inv_arg.ret) {
+ dev_err(channel->agent->dev, "Failed on channel handle %u: 0x%x\n",
+ channel->channel_hdl, inv_arg.ret);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static bool optee_chan_available(struct device *dev, int idx)
+{
+ struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
+
+ if (!np)
+ return false;
+
+ of_node_put(np);
+
+ return true;
+}
+
+static int optee_chan_setup_shmem(struct scmi_chan_info *cinfo, bool tx,
+ struct optee_scmi_channel *channel)
+{
+ struct device *cdev = cinfo->dev;
+ struct device_node *np;
+ resource_size_t size;
+ struct resource res;
+ int ret;
+
+ np = of_parse_phandle(cdev->of_node, "shmem", 0);
+ ret = of_address_to_resource(np, 0, &res);
+ of_node_put(np);
+ if (ret) {
+ dev_err(cdev, "failed to get SCMI Tx shared memory\n");
+ return ret;
+ }
+
+ size = resource_size(&res);
+
+ channel->shmem = devm_ioremap(cdev, res.start, size);
+ if (!channel->shmem) {
+ dev_err(cdev, "failed to ioremap SCMI Tx shared memory\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ return 0;
+}
+
+static void optee_clear_channel(struct scmi_chan_info *cinfo)
+{
+ struct optee_scmi_channel *channel = cinfo->transport_info;
+
+ shmem_clear_channel(channel->shmem);
+}
+
+static int optee_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+ bool tx)
+{
+ struct device *cdev = cinfo->dev;
+ struct optee_scmi_channel *channel;
+ int ret, idx = tx ? 0 : 1;
+
+ /* Shall wait for OP-TEE driver to be up and ready */
+ if (!agent_private || !agent_private->tee_ctx)
+ return -EPROBE_DEFER;
+
+ channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
+ if (!channel)
+ return -ENOMEM;
+
+ ret = optee_chan_setup_shmem(cinfo, tx, channel);
+ if (ret)
+ return ret;
+
+ cinfo->transport_info = channel;
+ channel->cinfo = cinfo;
+ channel->agent = agent_private;
+
+ ret = open_session(channel->agent, &channel->tee_session);
+ if (ret)
+ return ret;
+
+ ret = get_channel(channel);
+ if (ret)
+ goto err;
+
+ mutex_init(&channel->mu);
+
+ mutex_lock(&list_mutex);
+ list_add(&channel->link, &channel->agent->channel_list);
+ mutex_unlock(&list_mutex);
+
+ return 0;
+
+err:
+ close_session(channel->agent, channel->tee_session);
+ channel->tee_session = 0;
+
+ return ret;
+}
+
+static int optee_chan_free(int id, void *p, void *data)
+{
+ struct scmi_chan_info *cinfo = p;
+ struct optee_scmi_channel *channel = cinfo->transport_info;
+
+ mutex_lock(&list_mutex);
+ list_del(&channel->link);
+ mutex_unlock(&list_mutex);
+
+ cinfo->transport_info = NULL;
+ channel->cinfo = NULL;
+
+ scmi_free_channel(cinfo, data, id);
+
+ return 0;
+}
+
+static struct scmi_shared_mem *get_channel_shm(struct optee_scmi_channel *chan,
+ struct scmi_xfer *xfer)
+{
+ if (!chan)
+ return NULL;
+
+ return chan->shmem;
+}
+
+static int optee_send_message(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct optee_scmi_channel *channel = cinfo->transport_info;
+ struct scmi_shared_mem *shmem;
+ int ret = 0;
+
+ if (!channel && !channel->agent && !channel->agent->tee_ctx)
+ return -ENODEV;
+
+ shmem = get_channel_shm(channel, xfer);
+
+ mutex_lock(&channel->mu);
+ shmem_tx_prepare(shmem, xfer);
+
+ ret = invoke_process_smt_channel(channel);
+
+ scmi_rx_callback(cinfo, shmem_read_header(shmem));
+ mutex_unlock(&channel->mu);
+
+ return ret;
+}
+
+static void optee_fetch_response(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct optee_scmi_channel *channel = cinfo->transport_info;
+ struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer);
+
+ shmem_fetch_response(shmem, xfer);
+}
+
+static bool optee_poll_done(struct scmi_chan_info *cinfo,
+ struct scmi_xfer *xfer)
+{
+ struct optee_scmi_channel *channel = cinfo->transport_info;
+ struct scmi_shared_mem *shmem = get_channel_shm(channel, xfer);
+
+ return shmem_poll_done(shmem, xfer);
+}
+
+static struct scmi_transport_ops scmi_optee_ops = {
+ .chan_available = optee_chan_available,
+ .chan_setup = optee_chan_setup,
+ .chan_free = optee_chan_free,
+ .send_message = optee_send_message,
+ .fetch_response = optee_fetch_response,
+ .clear_channel = optee_clear_channel,
+ .poll_done = optee_poll_done,
+};
+
+const struct scmi_desc scmi_optee_desc = {
+ .ops = &scmi_optee_ops,
+ .max_rx_timeout_ms = 30, /* We may increase this if required */
+ .max_msg = 8,
+ .max_msg_size = 128,
+};
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+ return ver->impl_id == TEE_IMPL_ID_OPTEE;
+}
+
+static int optee_scmi_probe(struct device *dev)
+{
+ struct optee_scmi_agent *agent;
+ struct tee_context *tee_ctx;
+ int ret;
+
+ tee_ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
+ if (IS_ERR(tee_ctx))
+ return -ENODEV;
+
+ agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
+ if (!agent) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ agent->dev = dev;
+ agent->tee_ctx = tee_ctx;
+
+ ret = get_capabilities(agent);
+ if (ret)
+ goto err;
+
+ /* We currently support only 1 OP-TEE device */
+ if (WARN_ON(agent_private)) {
+ ret = -EINVAL;
+ goto err;
+ }
+ agent_private = agent;
+
+ INIT_LIST_HEAD(&agent->channel_list);
+
+ dev_dbg(dev, "OP-TEE SCMI channel probed\n");
+
+ return 0;
+
+err:
+ tee_client_close_context(tee_ctx);
+ return ret;
+}
+
+static int optee_scmi_remove(struct device *dev)
+{
+ struct optee_scmi_channel *channel;
+ struct list_head *elt, *n;
+
+ mutex_lock(&list_mutex);
+ list_for_each_safe(elt, n, &agent_private->channel_list) {
+ channel = list_entry(elt, struct optee_scmi_channel, link);
+ list_del(&channel->link);
+ }
+ mutex_unlock(&list_mutex);
+
+ tee_client_close_context(agent_private->tee_ctx);
+
+ agent_private = NULL;
+
+ return 0;
+}
+
+static const struct tee_client_device_id optee_scmi_id_table[] = {
+ {
+ UUID_INIT(0xa8cfe406, 0xd4f5, 0x4a2e,
+ 0x9f, 0x8d, 0xa2, 0x5d, 0xc7, 0x54, 0xc0, 0x99)
+ },
+ { }
+};
+
+MODULE_DEVICE_TABLE(tee, optee_scmi_id_table);
+
+static struct tee_client_driver optee_scmi_driver = {
+ .id_table = optee_scmi_id_table,
+ .driver = {
+ .name = DRIVER_NAME,
+ .bus = &tee_bus_type,
+ .probe = optee_scmi_probe,
+ .remove = optee_scmi_remove,
+ },
+};
+
+static int __init optee_scmi_init(void)
+{
+ return driver_register(&optee_scmi_driver.driver);
+}
+
+static void __exit optee_scmi_exit(void)
+{
+ driver_unregister(&optee_scmi_driver.driver);
+}
+
+module_init(optee_scmi_init);
+module_exit(optee_scmi_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Etienne Carriere <etienne.carriere@linaro.org>");
+MODULE_DESCRIPTION("OP-TEE SCMI transport driver");
Add a new transport channel to the SCMI firmware interface driver for SCMI message exchange based on OP-TEE transport channel that leverage OP-TEE secure threaded context for processing of SCMI messages. The current proposal uses a statically defined physical memory area to be used as shared memory SCMI endpoints. The location is extracted from the FDT upon property "shmem". Entry in OP-TEE threaded context is realized by invoking a service PTA (Pseudo TA) in OP-TEE OS. Each invocation carries a agent numerical identifier for which a message is pending in the shared memory. The OP-TEE service provides means to get the agent identifier value for a given shared memory location. OPTEE transport driver depends on CONFIG_OPTEE and probes from SCMI compatible identifier "linaro,scmi-optee". Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org> --- drivers/firmware/Kconfig | 2 +- drivers/firmware/arm_scmi/Makefile | 1 + drivers/firmware/arm_scmi/common.h | 3 + drivers/firmware/arm_scmi/driver.c | 3 + drivers/firmware/arm_scmi/optee_service.c | 529 ++++++++++++++++++++++ 5 files changed, 537 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/arm_scmi/optee_service.c