[PATCH v2] spi: remove struct spi_message::is_dma_mapped

[David Lechner <dlechner@xxxxxxxxxxxx>]

There are no more users of the deprecated is_dma_mapped in struct
spi_message so it can be removed.

References in documentation and comments are also removed.

A few similar checks if xfer->tx_dma or xfer->rx_dma are not NULL are
also removed since these are now guaranteed to be NULL because they
were previously set only if is_dma_mapped was true.

Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
---
Changes in v2:
- Fix spi-pxa2xx.c:947:29: error: unused variable ‘message’
- Link to v1: https://lore.kernel.org/r/20240315-spi-remove-is_dma_mapped-v1-1-ca876f9de1c5@xxxxxxxxxxxx
---
 Documentation/spi/pxa2xx.rst      |  3 ---
 Documentation/spi/spi-summary.rst |  4 ----
 drivers/spi/spi-atmel.c           |  8 ++------
 drivers/spi/spi-pxa2xx.c          | 11 -----------
 drivers/spi/spi.c                 |  7 -------
 include/linux/spi/spi.h           | 11 +++--------
 6 files changed, 5 insertions(+), 39 deletions(-)

diff --git a/Documentation/spi/pxa2xx.rst b/Documentation/spi/pxa2xx.rst
index 19479b801826..43e0b758803a 100644
--- a/Documentation/spi/pxa2xx.rst
+++ b/Documentation/spi/pxa2xx.rst
@@ -194,9 +194,6 @@ The following logic is used to determine the type of I/O to be used on
 a per "spi_transfer" basis::
 
   if spi_message.len > 65536 then
-	if spi_message.is_dma_mapped or rx_dma_buf != 0 or tx_dma_buf != 0 then
-		reject premapped transfers
-
 	print "rate limited" warning
 	use PIO transfers
 
diff --git a/Documentation/spi/spi-summary.rst b/Documentation/spi/spi-summary.rst
index 546de37d6caf..f7f8b1573f25 100644
--- a/Documentation/spi/spi-summary.rst
+++ b/Documentation/spi/spi-summary.rst
@@ -419,10 +419,6 @@ any more such messages.
     to make extra copies unless the hardware requires it (e.g. working
     around hardware errata that force the use of bounce buffering).
 
-    If standard dma_map_single() handling of these buffers is inappropriate,
-    you can use spi_message.is_dma_mapped to tell the controller driver
-    that you've already provided the relevant DMA addresses.
-
   - The basic I/O primitive is spi_async().  Async requests may be
     issued in any context (irq handler, task, etc) and completion
     is reported using a callback provided with the message.
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index bad34998454a..b62f57390d8f 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -987,8 +987,6 @@ static void atmel_spi_pdc_next_xfer(struct spi_controller *host,
  * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
  *  - The buffer is either valid for CPU access, else NULL
  *  - If the buffer is valid, so is its DMA address
- *
- * This driver manages the dma address unless message->is_dma_mapped.
  */
 static int
 atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
@@ -1374,8 +1372,7 @@ static int atmel_spi_one_transfer(struct spi_controller *host,
 	 * DMA map early, for performance (empties dcache ASAP) and
 	 * better fault reporting.
 	 */
-	if ((!host->cur_msg->is_dma_mapped)
-		&& as->use_pdc) {
+	if (as->use_pdc) {
 		if (atmel_spi_dma_map_xfer(as, xfer) < 0)
 			return -ENOMEM;
 	}
@@ -1454,8 +1451,7 @@ static int atmel_spi_one_transfer(struct spi_controller *host,
 		}
 	}
 
-	if (!host->cur_msg->is_dma_mapped
-		&& as->use_pdc)
+	if (as->use_pdc)
 		atmel_spi_dma_unmap_xfer(host, xfer);
 
 	if (as->use_pdc)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index f2a856f6a99e..6c2a14418972 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -944,7 +944,6 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller,
 				   struct spi_transfer *transfer)
 {
 	struct driver_data *drv_data = spi_controller_get_devdata(controller);
-	struct spi_message *message = controller->cur_msg;
 	struct chip_data *chip = spi_get_ctldata(spi);
 	u32 dma_thresh = chip->dma_threshold;
 	u32 dma_burst = chip->dma_burst_size;
@@ -959,16 +958,6 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller,
 
 	/* Check if we can DMA this transfer */
 	if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
-
-		/* Reject already-mapped transfers; PIO won't always work */
-		if (message->is_dma_mapped
-				|| transfer->rx_dma || transfer->tx_dma) {
-			dev_err(&spi->dev,
-				"Mapped transfer length of %u is greater than %d\n",
-				transfer->len, MAX_DMA_LEN);
-			return -EINVAL;
-		}
-
 		/* Warn ... we force this to PIO mode */
 		dev_warn_ratelimited(&spi->dev,
 				     "DMA disabled for transfer length %u greater than %d\n",
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ff75838c1b5d..a2f01116ba09 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3709,9 +3709,6 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
 	 * to the same values as *xferp, so tx_buf, rx_buf and len
 	 * are all identical (as well as most others)
 	 * so we just have to fix up len and the pointers.
-	 *
-	 * This also includes support for the depreciated
-	 * spi_message.is_dma_mapped interface.
 	 */
 
 	/*
@@ -3725,12 +3722,8 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
 		/* Update rx_buf, tx_buf and DMA */
 		if (xfers[i].rx_buf)
 			xfers[i].rx_buf += offset;
-		if (xfers[i].rx_dma)
-			xfers[i].rx_dma += offset;
 		if (xfers[i].tx_buf)
 			xfers[i].tx_buf += offset;
-		if (xfers[i].tx_dma)
-			xfers[i].tx_dma += offset;
 
 		/* Update length */
 		xfers[i].len = min(maxsize, xfers[i].len - offset);
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index c459809efee4..b589e2547439 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -955,8 +955,8 @@ struct spi_res {
  * struct spi_transfer - a read/write buffer pair
  * @tx_buf: data to be written (DMA-safe memory), or NULL
  * @rx_buf: data to be read (DMA-safe memory), or NULL
- * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
- * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
+ * @tx_dma: DMA address of tx_buf, currently not for client use
+ * @rx_dma: DMA address of rx_buf, currently not for client use
  * @tx_nbits: number of bits used for writing. If 0 the default
  *      (SPI_NBITS_SINGLE) is used.
  * @rx_nbits: number of bits used for reading. If 0 the default
@@ -1066,8 +1066,7 @@ struct spi_transfer {
 	/*
 	 * It's okay if tx_buf == rx_buf (right?).
 	 * For MicroWire, one buffer must be NULL.
-	 * Buffers must work with dma_*map_single() calls, unless
-	 * spi_message.is_dma_mapped reports a pre-existing mapping.
+	 * Buffers must work with dma_*map_single() calls.
 	 */
 	const void	*tx_buf;
 	void		*rx_buf;
@@ -1111,8 +1110,6 @@ struct spi_transfer {
  * struct spi_message - one multi-segment SPI transaction
  * @transfers: list of transfer segments in this transaction
  * @spi: SPI device to which the transaction is queued
- * @is_dma_mapped: if true, the caller provided both DMA and CPU virtual
- *	addresses for each transfer buffer
  * @pre_optimized: peripheral driver pre-optimized the message
  * @optimized: the message is in the optimized state
  * @prepared: spi_prepare_message was called for the this message
@@ -1146,8 +1143,6 @@ struct spi_message {
 
 	struct spi_device	*spi;
 
-	unsigned		is_dma_mapped:1;
-
 	/* spi_optimize_message() was called for this message */
 	bool			pre_optimized;
 	/* __spi_optimize_message() was called for this message */

---
base-commit: 10402419f2d60890525f590b54d0eaec3de0d87a
change-id: 20240315-spi-remove-is_dma_mapped-ac067635662e