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Diffstat (limited to 'drivers/dma/dmaengine.h')
| -rw-r--r-- | drivers/dma/dmaengine.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h new file mode 100644 index 000000000..302f13efd --- /dev/null +++ b/drivers/dma/dmaengine.h @@ -0,0 +1,174 @@ +/* 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 |