The current API allows the driver to accelerate memset by using the DMA
controller.
However, it does so over a contiguous memory area, which might proves
inefficient when you have to do it over a non-contiguous yet repititive
pattern, since you have to create a number of descriptors and then submit
each other.
Add a memset operation going over a scatter list to handle such cases in a
single call.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
---
include/linux/dmaengine.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index e2f5eb419976..8da299cc7361 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -66,6 +66,7 @@ enum dma_transaction_type {
DMA_XOR_VAL,
DMA_PQ_VAL,
DMA_MEMSET,
+ DMA_MEMSET_SG,
DMA_INTERRUPT,
DMA_SG,
DMA_PRIVATE,
@@ -616,6 +617,7 @@ struct dma_tx_state {
* @device_prep_dma_pq: prepares a pq operation
* @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_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.
@@ -682,6 +684,9 @@ struct dma_device {
struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
unsigned long flags);
+ 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_interrupt)(
struct dma_chan *chan, unsigned long flags);
struct dma_async_tx_descriptor *(*device_prep_dma_sg)(
--
2.4.5
--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
