diff options
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 |