90 lines
2.2 KiB
C
Executable File
90 lines
2.2 KiB
C
Executable File
/*
|
|
* 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
|