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/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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;
}
struct dmaengine_desc_callback {
dma_async_tx_callback callback;
dma_async_tx_callback_result callback_result;
void *callback_param;
};
/**
* dmaengine_desc_get_callback - get the passed in callback function
* @tx: tx descriptor
* @cb: temp struct to hold the callback info
*
* Fill the passed in cb struct with what's available in the passed in
* tx descriptor struct
* No locking is required.
*/
static inline void
dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
struct dmaengine_desc_callback *cb)
{
cb->callback = tx->callback;
cb->callback_result = tx->callback_result;
cb->callback_param = tx->callback_param;
}
/**
* dmaengine_desc_callback_invoke - call the callback function in cb struct
* @cb: temp struct that is holding the callback info
* @result: transaction result
*
* Call the callback function provided in the cb struct with the parameter
* in the cb struct.
* Locking is dependent on the driver.
*/
static inline void
dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
const struct dmaengine_result *result)
{
struct dmaengine_result dummy_result = {
.result = DMA_TRANS_NOERROR,
.residue = 0
};
if (cb->callback_result) {
if (!result)
result = &dummy_result;
cb->callback_result(cb->callback_param, result);
} else if (cb->callback) {
cb->callback(cb->callback_param);
}
}
/**
* dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
* then immediately call the callback.
* @tx: dma async tx descriptor
* @result: transaction result
*
* Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
* in a single function since no work is necessary in between for the driver.
* Locking is dependent on the driver.
*/
static inline void
dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
const struct dmaengine_result *result)
{
struct dmaengine_desc_callback cb;
dmaengine_desc_get_callback(tx, &cb);
dmaengine_desc_callback_invoke(&cb, result);
}
/**
* dmaengine_desc_callback_valid - verify the callback is valid in cb
* @cb: callback info struct
*
* Return a bool that verifies whether callback in cb is valid or not.
* No locking is required.
*/
static inline bool
dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
{
return cb->callback || cb->callback_result;
}
#endif
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