[RFC,6/6] spi: Get rid of the spi_flash_read() API

Commit Message

Boris Brezillon Feb. 5, 2018, 11:21 p.m. UTC

From: Boris Brezillon <[e-mail]>

This API has been replaced by the spi_mem_xx() one, its only user
(spi-nor) has been converted to spi_mem_xx() and all SPI controller
drivers that were implementing the ->spi_flash_xxx() hooks are also
implementing the spi_mem ones. So we can safely get rid of this API.

Signed-off-by: Boris Brezillon <[e-mail]>
---
 drivers/spi/spi-bcm-qspi.c | 38 +++----------------------------
 drivers/spi/spi-bcm53xx.c  | 20 +---------------
 drivers/spi/spi-ti-qspi.c  | 41 ---------------------------------
 drivers/spi/spi.c          | 57 ----------------------------------------------
 include/linux/spi/spi.h    | 53 ------------------------------------------
 5 files changed, 4 insertions(+), 205 deletions(-)

Comments

Vignesh Raghavendra Feb. 16, 2018, 10:21 a.m. UTC | #1

Hi Boris,

On Tuesday 06 February 2018 04:51 AM, Boris Brezillon wrote:
> From: Boris Brezillon <[e-mail]>
> 
> This API has been replaced by the spi_mem_xx() one, its only user
> (spi-nor) has been converted to spi_mem_xx() and all SPI controller
> drivers that were implementing the ->spi_flash_xxx() hooks are also
> implementing the spi_mem ones. So we can safely get rid of this API.
> 
> Signed-off-by: Boris Brezillon <[e-mail]>
> ---

>  drivers/spi/spi-ti-qspi.c  | 41 ---------------------------------

> -static bool ti_qspi_spi_flash_can_dma(struct spi_device *spi,
> -				      struct spi_flash_read_message *msg)
> -{
> -	return virt_addr_valid(msg->buf);
> -}
> -


This causes kernel crash because spi_map_buf() now tries to map
vmalloc'd buffers in LPAE backed memory not accessible by 32bit DMA:

ubiattach -p /dev/mtd9
[  114.482439] Unable to handle kernel paging request at virtual address
bf867000
[  114.489689] pgd = 045b2870
[  114.492403] [bf867000] *pgd=ad22c003, *pmd=00000000
[  114.497309] Internal error: Oops: 2a06 [#1] PREEMPT SMP ARM
[  114.502903] Modules linked in: ecdh_generic extcon_usb_gpio
omap_aes_driver omap_sham omap_des des_generic crypto_engine omap_crypto
[  114.514894] CPU: 1 PID: 1862 Comm: ubiattach Not tainted
4.16.0-rc1-next-20180212-00009-gbaa4bd31694e-dirty #16
[  114.525023] Hardware name: Generic DRA74X (Flattened Device Tree)
[  114.531145] PC is at v7_dma_inv_range+0x30/0x48
[  114.535693] LR is at dma_cache_maint_page+0x110/0x124
[  114.540763] pc : [<c0218fdc>]    lr : [<c02149e0>]    p


We need ->can_dma like interface in spi_controller_mem_ops to prevent
such buffers being mapped for certain SoCs. Or SPI NOR framework needs
to use bounce buffers.

Boris Brezillon Feb. 16, 2018, 10:24 a.m. UTC | #2

On Fri, 16 Feb 2018 15:51:00 +0530
Vignesh R <[e-mail]> wrote:

> Hi Boris,
> 
> On Tuesday 06 February 2018 04:51 AM, Boris Brezillon wrote:
> > From: Boris Brezillon <[e-mail]>
> > 
> > This API has been replaced by the spi_mem_xx() one, its only user
> > (spi-nor) has been converted to spi_mem_xx() and all SPI controller
> > drivers that were implementing the ->spi_flash_xxx() hooks are also
> > implementing the spi_mem ones. So we can safely get rid of this API.
> > 
> > Signed-off-by: Boris Brezillon <[e-mail]>
> > ---  
> 
> >  drivers/spi/spi-ti-qspi.c  | 41 ---------------------------------  
> 
> > -static bool ti_qspi_spi_flash_can_dma(struct spi_device *spi,
> > -				      struct spi_flash_read_message *msg)
> > -{
> > -	return virt_addr_valid(msg->buf);
> > -}
> > -  
> 
> 
> This causes kernel crash because spi_map_buf() now tries to map
> vmalloc'd buffers in LPAE backed memory not accessible by 32bit DMA:
> 
> ubiattach -p /dev/mtd9
> [  114.482439] Unable to handle kernel paging request at virtual address
> bf867000
> [  114.489689] pgd = 045b2870
> [  114.492403] [bf867000] *pgd=ad22c003, *pmd=00000000
> [  114.497309] Internal error: Oops: 2a06 [#1] PREEMPT SMP ARM
> [  114.502903] Modules linked in: ecdh_generic extcon_usb_gpio
> omap_aes_driver omap_sham omap_des des_generic crypto_engine omap_crypto
> [  114.514894] CPU: 1 PID: 1862 Comm: ubiattach Not tainted
> 4.16.0-rc1-next-20180212-00009-gbaa4bd31694e-dirty #16
> [  114.525023] Hardware name: Generic DRA74X (Flattened Device Tree)
> [  114.531145] PC is at v7_dma_inv_range+0x30/0x48
> [  114.535693] LR is at dma_cache_maint_page+0x110/0x124
> [  114.540763] pc : [<c0218fdc>]    lr : [<c02149e0>]    p
> 
> 
> We need ->can_dma like interface in spi_controller_mem_ops to prevent
> such buffers being mapped for certain SoCs. Or SPI NOR framework needs
> to use bounce buffers.
> 
> 

Actually, I'm doing the test directly in ti_qspi_exec_mem_op(), it's
just that my test is wrong :-):

		if (!virt_addr_valid(op->data.buf.in) &&
		    !spi_controller_dma_map_mem_op_data(mem->spi->master,
							op, &sgt)) {

should be

		if (virt_addr_valid(op->data.buf.in) &&
		    !spi_controller_dma_map_mem_op_data(mem->spi->master,
							op, &sgt)) {

Patch

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index f47a13453ef6..4670fe5d83f8 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -946,9 +946,10 @@  static int bcm_qspi_mspi_exec_mem_op(struct spi_device *spi,
 	return ret;
 }
 
-static int bcm_qspi_exec_mem_op(struct spi_device *spi,
+static int bcm_qspi_exec_mem_op(struct spi_mem *mem,
 				const struct spi_mem_op *op)
 {
+	struct spi_device *spi = mem->spi;
 	struct bcm_qspi *qspi = spi_master_get_devdata(spi->master);
 	int ret = 0, i;
 	bool mspi_read = false;
@@ -998,38 +999,6 @@  static int bcm_qspi_exec_mem_op(struct spi_device *spi,
 	return ret;
 }
 
-static int bcm_qspi_exec_mem_op_wrapper(struct spi_mem *mem,
-					const struct spi_mem_op *op)
-{
-	return bcm_qspi_exec_mem_op(mem->spi, op);
-}
-
-static int bcm_qspi_flash_read_wrapper(struct spi_device *spi,
-				       struct spi_flash_read_message *msg)
-{
-	int i, ret;
-	u8 addrs[4];
-	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(msg->read_opcode, 1),
-					  SPI_MEM_OP_ADDRS(msg->addr_width,
-							   addrs,
-							   msg->addr_nbits),
-					  SPI_MEM_OP_DUMMY(msg->dummy_bytes,
-							   msg->addr_nbits),
-					  SPI_MEM_OP_DATA_IN(msg->len,
-							     msg->buf,
-							     msg->data_nbits));
-
-	for (i = msg->addr_width - 1; i >= 0; i--)
-		addrs[i] = msg->from >> (i * 8);
-
-	msg->retlen = 0;
-	ret = bcm_qspi_exec_mem_op(spi, &op);
-	if (!ret)
-		msg->retlen = msg->len;
-
-	return ret;
-}
-
 static void bcm_qspi_cleanup(struct spi_device *spi)
 {
 	struct bcm_qspi_parms *xp = spi_get_ctldata(spi);
@@ -1225,7 +1194,7 @@  static void bcm_qspi_hw_uninit(struct bcm_qspi *qspi)
 }
 
 static const struct spi_controller_mem_ops bcm_qspi_mem_ops = {
-	.exec_op = bcm_qspi_exec_mem_op_wrapper,
+	.exec_op = bcm_qspi_exec_mem_op,
 };
 
 static const struct of_device_id bcm_qspi_of_match[] = {
@@ -1270,7 +1239,6 @@  int bcm_qspi_probe(struct platform_device *pdev,
 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_RX_DUAL | SPI_RX_QUAD;
 	master->setup = bcm_qspi_setup;
 	master->transfer_one = bcm_qspi_transfer_one;
-	master->spi_flash_read = bcm_qspi_flash_read_wrapper;
 	master->mem_ops = &bcm_qspi_mem_ops;
 	master->cleanup = bcm_qspi_cleanup;
 	master->dev.of_node = dev->of_node;
diff --git a/drivers/spi/spi-bcm53xx.c b/drivers/spi/spi-bcm53xx.c
index c681d432e26c..707213418bb3 100644
--- a/drivers/spi/spi-bcm53xx.c
+++ b/drivers/spi/spi-bcm53xx.c
@@ -297,22 +297,6 @@  static const struct spi_controller_mem_ops bcm53xxspi_mem_ops = {
 	.exec_op = bcm53xxspi_exec_mem_op,
 };
 
-static int bcm53xxspi_flash_read(struct spi_device *spi,
-				 struct spi_flash_read_message *msg)
-{
-	struct bcm53xxspi *b53spi = spi_master_get_devdata(spi->master);
-	int ret = 0;
-
-	if (msg->from + msg->len > BCM53XXSPI_FLASH_WINDOW)
-		return -EINVAL;
-
-	bcm53xxspi_enable_bspi(b53spi);
-	memcpy_fromio(msg->buf, b53spi->mmio_base + msg->from, msg->len);
-	msg->retlen = msg->len;
-
-	return ret;
-}
-
 /**************************************************
  * BCMA
  **************************************************/
@@ -351,10 +335,8 @@  static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 
 	master->dev.of_node = dev->of_node;
 	master->transfer_one = bcm53xxspi_transfer_one;
-	if (b53spi->mmio_base) {
+	if (b53spi->mmio_base)
 		master->mem_ops = &bcm53xxspi_mem_ops;
-		master->spi_flash_read = bcm53xxspi_flash_read;
-	}
 
 	bcma_set_drvdata(core, b53spi);
 
diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index 40cac3ef6cc9..50237e2753b2 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -529,44 +529,6 @@  static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8 opcode,
 		      QSPI_SPI_SETUP_REG(spi->chip_select));
 }
 
-static bool ti_qspi_spi_flash_can_dma(struct spi_device *spi,
-				      struct spi_flash_read_message *msg)
-{
-	return virt_addr_valid(msg->buf);
-}
-
-static int ti_qspi_spi_flash_read(struct spi_device *spi,
-				  struct spi_flash_read_message *msg)
-{
-	struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
-	int ret = 0;
-
-	mutex_lock(&qspi->list_lock);
-
-	if (!qspi->mmap_enabled)
-		ti_qspi_enable_memory_map(spi);
-	ti_qspi_setup_mmap_read(spi, msg->read_opcode, msg->data_nbits,
-				msg->addr_width, msg->dummy_bytes);
-
-	if (qspi->rx_chan) {
-		if (msg->cur_msg_mapped)
-			ret = ti_qspi_dma_xfer_sg(qspi, msg->rx_sg, msg->from);
-		else
-			ret = ti_qspi_dma_bounce_buffer(qspi, msg->from,
-							msg->buf, msg->len);
-		if (ret)
-			goto err_unlock;
-	} else {
-		memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len);
-	}
-	msg->retlen = msg->len;
-
-err_unlock:
-	mutex_unlock(&qspi->list_lock);
-
-	return ret;
-}
-
 static int ti_qspi_exec_mem_op(struct spi_mem *mem,
 			       const struct spi_mem_op *op)
 {
@@ -729,7 +691,6 @@  static int ti_qspi_probe(struct platform_device *pdev)
 	master->dev.of_node = pdev->dev.of_node;
 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
 				     SPI_BPW_MASK(8);
-	master->spi_flash_read = ti_qspi_spi_flash_read;
 	master->mem_ops = &ti_qspi_mem_ops;
 
 	if (!of_property_read_u32(np, "num-cs", &num_cs))
@@ -828,7 +789,6 @@  static int ti_qspi_probe(struct platform_device *pdev)
 		dma_release_channel(qspi->rx_chan);
 		goto no_dma;
 	}
-	master->spi_flash_can_dma = ti_qspi_spi_flash_can_dma;
 	master->dma_rx = qspi->rx_chan;
 	init_completion(&qspi->transfer_complete);
 	if (res_mmap)
@@ -842,7 +802,6 @@  static int ti_qspi_probe(struct platform_device *pdev)
 				 "mmap failed with error %ld using PIO mode\n",
 				 PTR_ERR(qspi->mmap_base));
 			qspi->mmap_base = NULL;
-			master->spi_flash_read = NULL;
 			master->mem_ops = NULL;
 		}
 	}
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 57bc540a0521..0491ef8c321f 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3046,63 +3046,6 @@  int spi_async_locked(struct spi_device *spi, struct spi_message *message)
 }
 EXPORT_SYMBOL_GPL(spi_async_locked);
 
-
-int spi_flash_read(struct spi_device *spi,
-		   struct spi_flash_read_message *msg)
-
-{
-	struct spi_controller *master = spi->controller;
-	struct device *rx_dev = NULL;
-	int ret;
-
-	if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
-	     msg->addr_nbits == SPI_NBITS_DUAL) &&
-	    !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
-		return -EINVAL;
-	if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
-	     msg->addr_nbits == SPI_NBITS_QUAD) &&
-	    !(spi->mode & SPI_TX_QUAD))
-		return -EINVAL;
-	if (msg->data_nbits == SPI_NBITS_DUAL &&
-	    !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
-		return -EINVAL;
-	if (msg->data_nbits == SPI_NBITS_QUAD &&
-	    !(spi->mode &  SPI_RX_QUAD))
-		return -EINVAL;
-
-	if (master->auto_runtime_pm) {
-		ret = pm_runtime_get_sync(master->dev.parent);
-		if (ret < 0) {
-			dev_err(&master->dev, "Failed to power device: %d\n",
-				ret);
-			return ret;
-		}
-	}
-
-	mutex_lock(&master->bus_lock_mutex);
-	mutex_lock(&master->io_mutex);
-	if (master->dma_rx && master->spi_flash_can_dma(spi, msg)) {
-		rx_dev = master->dma_rx->device->dev;
-		ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
-				  msg->buf, msg->len,
-				  DMA_FROM_DEVICE);
-		if (!ret)
-			msg->cur_msg_mapped = true;
-	}
-	ret = master->spi_flash_read(spi, msg);
-	if (msg->cur_msg_mapped)
-		spi_unmap_buf(master, rx_dev, &msg->rx_sg,
-			      DMA_FROM_DEVICE);
-	mutex_unlock(&master->io_mutex);
-	mutex_unlock(&master->bus_lock_mutex);
-
-	if (master->auto_runtime_pm)
-		pm_runtime_put(master->dev.parent);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(spi_flash_read);
-
 /*-------------------------------------------------------------------------*/
 
 /* Utility methods for SPI protocol drivers, layered on
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index af3c4ac62b55..0921d2c82b35 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -26,7 +26,6 @@  struct dma_chan;
 struct property_entry;
 struct spi_controller;
 struct spi_transfer;
-struct spi_flash_read_message;
 struct spi_controller_mem_ops;
 
 /*
@@ -382,11 +381,6 @@  static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *	     controller has native support for memory like operations.
  * @unprepare_message: undo any work done by prepare_message().
  * @slave_abort: abort the ongoing transfer request on an SPI slave controller
- * @spi_flash_read: to support spi-controller hardwares that provide
- *                  accelerated interface to read from flash devices.
- * @spi_flash_can_dma: analogous to can_dma() interface, but for
- *		       controllers implementing spi_flash_read.
- * @flash_read_supported: spi device supports flash read
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *	number. Any individual value may be -ENOENT for CS lines that
  *	are not GPIOs (driven by the SPI controller itself).
@@ -552,11 +546,6 @@  struct spi_controller {
 	int (*unprepare_message)(struct spi_controller *ctlr,
 				 struct spi_message *message);
 	int (*slave_abort)(struct spi_controller *ctlr);
-	int (*spi_flash_read)(struct  spi_device *spi,
-			      struct spi_flash_read_message *msg);
-	bool (*spi_flash_can_dma)(struct spi_device *spi,
-				  struct spi_flash_read_message *msg);
-	bool (*flash_read_supported)(struct spi_device *spi);
 
 	/*
 	 * These hooks are for drivers that use a generic implementation
@@ -1190,48 +1179,6 @@  static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
 	return be16_to_cpu(result);
 }
 
-/**
- * struct spi_flash_read_message - flash specific information for
- * spi-masters that provide accelerated flash read interfaces
- * @buf: buffer to read data
- * @from: offset within the flash from where data is to be read
- * @len: length of data to be read
- * @retlen: actual length of data read
- * @read_opcode: read_opcode to be used to communicate with flash
- * @addr_width: number of address bytes
- * @dummy_bytes: number of dummy bytes
- * @opcode_nbits: number of lines to send opcode
- * @addr_nbits: number of lines to send address
- * @data_nbits: number of lines for data
- * @rx_sg: Scatterlist for receive data read from flash
- * @cur_msg_mapped: message has been mapped for DMA
- */
-struct spi_flash_read_message {
-	void *buf;
-	loff_t from;
-	size_t len;
-	size_t retlen;
-	u8 read_opcode;
-	u8 addr_width;
-	u8 dummy_bytes;
-	u8 opcode_nbits;
-	u8 addr_nbits;
-	u8 data_nbits;
-	struct sg_table rx_sg;
-	bool cur_msg_mapped;
-};
-
-/* SPI core interface for flash read support */
-static inline bool spi_flash_read_supported(struct spi_device *spi)
-{
-	return spi->controller->spi_flash_read &&
-	       (!spi->controller->flash_read_supported ||
-	       spi->controller->flash_read_supported(spi));
-}
-
-int spi_flash_read(struct spi_device *spi,
-		   struct spi_flash_read_message *msg);
-
 /*---------------------------------------------------------------------------*/
 
 /* SPI memory related definitions. */