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| author |   Russell King - ARM Linux <linux@arm.linux.org.uk> | 2012-03-06 22:34:46 +0000 |
|---|---|---|
| committer |   Vinod Koul <vinod.koul@linux.intel.com> | 2012-03-13 11:36:52 +0530 |
| commit | 884485e1f12dcd39390f042e772cdbefc9ebb750 (patch) | |
| tree | a35fccb601c48ae1ea839aa6d62e4f102f7b66c3 /drivers/dma/dmaengine.h | |
| parent | dmaengine: add private header file (diff) | |
| download | linux-dev-884485e1f12dcd39390f042e772cdbefc9ebb750.tar.xz linux-dev-884485e1f12dcd39390f042e772cdbefc9ebb750.zip | |
dmaengine: consolidate assignment of DMA cookies
Everyone deals with assigning DMA cookies in the same way (it's part of
the API so they should be), so lets consolidate the common code into a
helper function to avoid this duplication.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma/dmaengine.h')
| -rw-r--r-- | drivers/dma/dmaengine.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h index 968570dde2eb..7692c8644045 100644 --- a/drivers/dma/dmaengine.h +++ b/drivers/dma/dmaengine.h @@ -7,4 +7,24 @@ #include <linux/dmaengine.h> +/** + * dma_cookie_assign - assign a DMA engine cookie to the descriptor + * @tx: descriptor needing cookie + * + * Assign a unique non-zero per-channel cookie to the descriptor. + * Note: caller is expected to hold a lock to prevent concurrency. + */ +static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx) +{ + struct dma_chan *chan = tx->chan; + dma_cookie_t cookie; + + cookie = chan->cookie + 1; + if (cookie < DMA_MIN_COOKIE) + cookie = DMA_MIN_COOKIE; + tx->cookie = chan->cookie = cookie; + + return cookie; +} + #endif |