diff options
| author | Ben Walker <benjamin.walker@intel.com> | 2022-03-01 11:25:48 -0700 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2022-04-20 17:28:12 +0530 |
| commit | fc44ff0ae9f2aa20b64c4e63ab4614156df80240 (patch) | |
| tree | 0b27142d92dd94e768a4d075b43df4628be831ea | |
| parent | 439b5e765a00a546e8f6b6eedac69889d0b5a869 (diff) | |
dmaengine: Document dmaengine_prep_dma_memset
Document this function to make clear the expected behavior of the
'value' parameter. It was intended to match the behavior of POSIX memset
as laid out here:
https://lore.kernel.org/dmaengine/YejrA5ZWZ3lTRO%2F1@matsya/
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Link: https://lore.kernel.org/r/20220301182551.883474-2-benjamin.walker@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | Documentation/driver-api/dmaengine/provider.rst | 6 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 8 |
2 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst index d3fa80e333b1..1e0f1f85d10e 100644 --- a/Documentation/driver-api/dmaengine/provider.rst +++ b/Documentation/driver-api/dmaengine/provider.rst @@ -206,6 +206,12 @@ Currently, the types available are: - The device is able to perform parity check using RAID6 P+Q algorithm against a memory buffer. +- DMA_MEMSET + + - The device is able to fill memory with the provided pattern + + - The pattern is treated as a single byte signed value. + - DMA_INTERRUPT - The device is able to trigger a dummy transfer that will diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 6db9e03afd0b..b46b88e6aa0d 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1030,6 +1030,14 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma( return chan->device->device_prep_interleaved_dma(chan, xt, flags); } +/** + * dmaengine_prep_dma_memset() - Prepare a DMA memset descriptor. + * @chan: The channel to be used for this descriptor + * @dest: Address of buffer to be set + * @value: Treated as a single byte value that fills the destination buffer + * @len: The total size of dest + * @flags: DMA engine flags + */ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memset( struct dma_chan *chan, dma_addr_t dest, int value, size_t len, unsigned long flags) |