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 <[email protected]> --- 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 linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
