[mirror_ubuntu-bionic-kernel.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_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
884485e1 RKAL	11	/**
	12	* dma_cookie_assign - assign a DMA engine cookie to the descriptor
	13	* @tx: descriptor needing cookie
	14	*
	15	* Assign a unique non-zero per-channel cookie to the descriptor.
	16	* Note: caller is expected to hold a lock to prevent concurrency.
	17	*/
	18	static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descriptor *tx)
	19	{
	20	struct dma_chan *chan = tx->chan;
	21	dma_cookie_t cookie;
	22
	23	cookie = chan->cookie + 1;
	24	if (cookie < DMA_MIN_COOKIE)
	25	cookie = DMA_MIN_COOKIE;
	26	tx->cookie = chan->cookie = cookie;
	27
	28	return cookie;
	29	}
	30
f7fbce07 RKAL	31	/**
	32	* dma_cookie_complete - complete a descriptor
	33	* @tx: descriptor to complete
	34	*
	35	* Mark this descriptor complete by updating the channels completed
	36	* cookie marker. Zero the descriptors cookie to prevent accidental
	37	* repeated completions.
	38	*
	39	* Note: caller is expected to hold a lock to prevent concurrency.
	40	*/
	41	static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
	42	{
	43	BUG_ON(tx->cookie < DMA_MIN_COOKIE);
	44	tx->chan->completed_cookie = tx->cookie;
	45	tx->cookie = 0;
	46	}
	47
96a2af41 RKAL	48	/**
	49	* dma_cookie_status - report cookie status
	50	* @chan: dma channel
	51	* @cookie: cookie we are interested in
	52	* @state: dma_tx_state structure to return last/used cookies
	53	*
	54	* Report the status of the cookie, filling in the state structure if
	55	* non-NULL. No locking is required.
	56	*/
	57	static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
	58	dma_cookie_t cookie, struct dma_tx_state *state)
	59	{
	60	dma_cookie_t used, complete;
	61
	62	used = chan->cookie;
	63	complete = chan->completed_cookie;
	64	barrier();
	65	if (state) {
	66	state->last = complete;
	67	state->used = used;
	68	state->residue = 0;
	69	}
	70	return dma_async_is_complete(cookie, complete, used);
	71	}
	72
	73	static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
	74	{
	75	if (state)
	76	state->residue = residue;
	77	}
	78
d2ebfb33	79	#endif