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authorRussell King - ARM Linux <linux@arm.linux.org.uk>2012-03-06 23:35:07 +0100
committerVinod Koul <vinod.koul@linux.intel.com>2012-03-13 07:07:01 +0100
commitf7fbce07c6ce26a25b4e0cb5f241c361fde87901 (patch)
tree66e6321b5ef49e18479ffeb1ed4fd5169e120f97 /drivers/dma/dmaengine.h
parentdmaengine: consolidate assignment of DMA cookies (diff)
downloadlinux-f7fbce07c6ce26a25b4e0cb5f241c361fde87901.tar.xz
linux-f7fbce07c6ce26a25b4e0cb5f241c361fde87901.zip
dmaengine: provide a common function for completing a dma descriptor
Provide a common function to do the cookie mechanics for completing a DMA descriptor. 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.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
index 7692c8644045..47e099772b8e 100644
--- a/drivers/dma/dmaengine.h
+++ b/drivers/dma/dmaengine.h
@@ -5,6 +5,7 @@
#ifndef DMAENGINE_H
#define DMAENGINE_H
+#include <linux/bug.h>
#include <linux/dmaengine.h>
/**
@@ -27,4 +28,21 @@ static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
return cookie;
}
+/**
+ * dma_cookie_complete - complete a descriptor
+ * @tx: descriptor to complete
+ *
+ * Mark this descriptor complete by updating the channels completed
+ * cookie marker. Zero the descriptors cookie to prevent accidental
+ * repeated completions.
+ *
+ * Note: caller is expected to hold a lock to prevent concurrency.
+ */
+static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
+{
+ BUG_ON(tx->cookie < DMA_MIN_COOKIE);
+ tx->chan->completed_cookie = tx->cookie;
+ tx->cookie = 0;
+}
+
#endif