[v5,2/7] dmaengine: Add DMA_MEMCPY_SG transaction op

Commit Message

Dave Jiang Aug. 21, 2017, 9:10 p.m. UTC

Adding a dmaengine transaction operation that allows copy to/from a
scatterlist and a flat buffer.

Signed-off-by: Dave Jiang <[e-mail]>
---
 Documentation/dmaengine/provider.txt |    3 +++
 drivers/dma/dmaengine.c              |    2 ++
 include/linux/dmaengine.h            |   19 +++++++++++++++++++
 3 files changed, 24 insertions(+)

Patch

diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index a75f52f..6241e36 100644
--- a/Documentation/dmaengine/provider.txt
+++ b/Documentation/dmaengine/provider.txt
@@ -181,6 +181,9 @@  Currently, the types available are:
     - Used by the client drivers to register a callback that will be
       called on a regular basis through the DMA controller interrupt
 
+  * DMA_MEMCPY_SG
+    - The device supports scatterlist to/from memory.
+
   * DMA_PRIVATE
     - The devices only supports slave transfers, and as such isn't
       available for async transfers.
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 428b141..4d2c4e1 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -937,6 +937,8 @@  int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_memset);
 	BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
 		!device->device_prep_dma_interrupt);
+	BUG_ON(dma_has_cap(DMA_MEMCPY_SG, device->cap_mask) &&
+		!device->device_prep_dma_memcpy_sg);
 	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
 		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 64fbd38..0c91411 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -67,6 +67,7 @@  enum dma_transaction_type {
 	DMA_PQ_VAL,
 	DMA_MEMSET,
 	DMA_MEMSET_SG,
+	DMA_MEMCPY_SG,
 	DMA_INTERRUPT,
 	DMA_PRIVATE,
 	DMA_ASYNC_TX,
@@ -692,6 +693,7 @@  struct dma_filter {
  * @device_prep_dma_pq_val: prepares a pqzero_sum operation
  * @device_prep_dma_memset: prepares a memset operation
  * @device_prep_dma_memset_sg: prepares a memset operation over a scatter list
+ * @device_prep_dma_memcpy_sg: prepares memcpy between scatterlist and buffer
  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
  * @device_prep_slave_sg: prepares a slave dma operation
  * @device_prep_dma_cyclic: prepare a cyclic dma operation suitable for audio.
@@ -768,6 +770,10 @@  struct dma_device {
 	struct dma_async_tx_descriptor *(*device_prep_dma_memset_sg)(
 		struct dma_chan *chan, struct scatterlist *sg,
 		unsigned int nents, int value, unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_dma_memcpy_sg)(
+		struct dma_chan *chan,
+		struct scatterlist *sg, unsigned int sg_nents,
+		dma_addr_t buf, bool to_sg, unsigned long flags);
 	struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
 		struct dma_chan *chan, unsigned long flags);
 
@@ -899,6 +905,19 @@  static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memcpy(
 						    len, flags);
 }
 
+static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memcpy_sg(
+		struct dma_chan *chan, struct scatterlist *sg,
+		unsigned int sg_nents, dma_addr_t buf, bool to_sg,
+		unsigned long flags)
+{
+	if (!chan || !chan->device ||
+			!chan->device->device_prep_dma_memcpy_sg)
+		return NULL;
+
+	return chan->device->device_prep_dma_memcpy_sg(chan, sg, sg_nents,
+						       buf, to_sg, flags);
+}
+
 /**
  * dmaengine_terminate_all() - Terminate all active DMA transfers
  * @chan: The channel for which to terminate the transfers