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/*
* The contents of this file are private to DMA engine drivers, and is not
* part of the API to be used by DMA engine users.
*/
#ifndef DMAENGINE_H
#define DMAENGINE_H
#include <linux/bug.h>
#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;
}
/**
* 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
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