[linux-2.6-block.git] / drivers / dma / dmaengine.h

/*
 * 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_init - initialize the cookies for a DMA channel
 * @chan: dma channel to initialize
 */
static inline void dma_cookie_init(struct dma_chan *chan)
{
	chan->cookie = DMA_MIN_COOKIE;
	chan->completed_cookie = DMA_MIN_COOKIE;
}

/**
 * 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;
}

/**
 * dma_cookie_status - report cookie status
 * @chan: dma channel
 * @cookie: cookie we are interested in
 * @state: dma_tx_state structure to return last/used cookies
 *
 * Report the status of the cookie, filling in the state structure if
 * non-NULL.  No locking is required.
 */
static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
	dma_cookie_t cookie, struct dma_tx_state *state)
{
	dma_cookie_t used, complete;

	used = chan->cookie;
	complete = chan->completed_cookie;
	barrier();
	if (state) {
		state->last = complete;
		state->used = used;
		state->residue = 0;
	}
	return dma_async_is_complete(cookie, complete, used);
}

static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
{
	if (state)
		state->residue = residue;
}

#endif
Commit	Line	Data
d2ebfb33 RKAL	1	/*
	2	* The contents of this file are private to DMA engine drivers, and is not
	3	* part of the API to be used by DMA engine users.
	4	*/
	5	#ifndef DMAENGINE_H
	6	#define DMAENGINE_H
	7
f7fbce07	8	#include <linux/bug.h>
d2ebfb33 RKAL	9	#include <linux/dmaengine.h>
d2ebfb33 RKAL	10
d3ee98cd RKAL	11	/**
	12	* dma_cookie_init - initialize the cookies for a DMA channel
	13	* @chan: dma channel to initialize
	14	*/
	15	static inline void dma_cookie_init(struct dma_chan *chan)
	16	{
	17	chan->cookie = DMA_MIN_COOKIE;
	18	chan->completed_cookie = DMA_MIN_COOKIE;
	19	}
	20
884485e1 RKAL	21	/**
	22	* dma_cookie_assign - assign a DMA engine cookie to the descriptor
	23	* @tx: descriptor needing cookie
	24	*
	25	* Assign a unique non-zero per-channel cookie to the descriptor.
	26	* Note: caller is expected to hold a lock to prevent concurrency.
	27	*/
	28	static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
	29	{
	30	struct dma_chan *chan = tx->chan;
	31	dma_cookie_t cookie;
	32
	33	cookie = chan->cookie + 1;
	34	if (cookie < DMA_MIN_COOKIE)
	35	cookie = DMA_MIN_COOKIE;
	36	tx->cookie = chan->cookie = cookie;
	37
	38	return cookie;
	39	}
	40
f7fbce07 RKAL	41	/**
	42	* dma_cookie_complete - complete a descriptor
	43	* @tx: descriptor to complete
	44	*
	45	* Mark this descriptor complete by updating the channels completed
	46	* cookie marker. Zero the descriptors cookie to prevent accidental
	47	* repeated completions.
	48	*
	49	* Note: caller is expected to hold a lock to prevent concurrency.
	50	*/
	51	static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
	52	{
	53	BUG_ON(tx->cookie < DMA_MIN_COOKIE);
	54	tx->chan->completed_cookie = tx->cookie;
	55	tx->cookie = 0;
	56	}
	57
96a2af41 RKAL	58	/**
	59	* dma_cookie_status - report cookie status
	60	* @chan: dma channel
	61	* @cookie: cookie we are interested in
	62	* @state: dma_tx_state structure to return last/used cookies
	63	*
	64	* Report the status of the cookie, filling in the state structure if
	65	* non-NULL. No locking is required.
	66	*/
	67	static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
	68	dma_cookie_t cookie, struct dma_tx_state *state)
	69	{
	70	dma_cookie_t used, complete;
	71
	72	used = chan->cookie;
	73	complete = chan->completed_cookie;
	74	barrier();
	75	if (state) {
	76	state->last = complete;
	77	state->used = used;
	78	state->residue = 0;
	79	}
	80	return dma_async_is_complete(cookie, complete, used);
	81	}
	82
	83	static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
	84	{
	85	if (state)
	86	state->residue = residue;
	87	}
	88
d2ebfb33	89	#endif