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author | Vinod Koul <vinod.koul@intel.com> | 2016-01-06 15:17:47 +0530 |
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committer | Vinod Koul <vinod.koul@intel.com> | 2016-01-06 15:17:47 +0530 |
commit | d3f1e93ce8e00be19711c35f0c67c54a58aea559 (patch) | |
tree | 58010cdfa4fc473fc0693410b4a444755c4438c9 /include/linux/dmaengine.h | |
parent | 7c7b680fa6b0866af2c4876da261bbfe710315d6 (diff) | |
parent | b1d6ab1aa8cdc23b89bcd578ea8d5e3c501a13d9 (diff) | |
download | linux-stable-d3f1e93ce8e00be19711c35f0c67c54a58aea559.tar.gz linux-stable-d3f1e93ce8e00be19711c35f0c67c54a58aea559.tar.bz2 linux-stable-d3f1e93ce8e00be19711c35f0c67c54a58aea559.zip |
Merge branch 'topic/async' into for-linus
Diffstat (limited to 'include/linux/dmaengine.h')
-rw-r--r-- | include/linux/dmaengine.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 8ab3bafc2332..16a1cad30c33 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -681,6 +681,8 @@ struct dma_filter { * paused. Returns 0 or an error code * @device_terminate_all: Aborts all transfers on a channel. Returns 0 * or an error code + * @device_synchronize: Synchronizes the termination of a transfers to the + * current context. * @device_tx_status: poll for transaction completion, the optional * txstate parameter can be supplied with a pointer to get a * struct with auxiliary transfer status information, otherwise the call @@ -767,6 +769,7 @@ struct dma_device { int (*device_pause)(struct dma_chan *chan); int (*device_resume)(struct dma_chan *chan); int (*device_terminate_all)(struct dma_chan *chan); + void (*device_synchronize)(struct dma_chan *chan); enum dma_status (*device_tx_status)(struct dma_chan *chan, dma_cookie_t cookie, @@ -858,6 +861,13 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg( src_sg, src_nents, flags); } +/** + * dmaengine_terminate_all() - Terminate all active DMA transfers + * @chan: The channel for which to terminate the transfers + * + * This function is DEPRECATED use either dmaengine_terminate_sync() or + * dmaengine_terminate_async() instead. + */ static inline int dmaengine_terminate_all(struct dma_chan *chan) { if (chan->device->device_terminate_all) @@ -866,6 +876,88 @@ static inline int dmaengine_terminate_all(struct dma_chan *chan) return -ENOSYS; } +/** + * dmaengine_terminate_async() - Terminate all active DMA transfers + * @chan: The channel for which to terminate the transfers + * + * Calling this function will terminate all active and pending descriptors + * that have previously been submitted to the channel. It is not guaranteed + * though that the transfer for the active descriptor has stopped when the + * function returns. Furthermore it is possible the complete callback of a + * submitted transfer is still running when this function returns. + * + * dmaengine_synchronize() needs to be called before it is safe to free + * any memory that is accessed by previously submitted descriptors or before + * freeing any resources accessed from within the completion callback of any + * perviously submitted descriptors. + * + * This function can be called from atomic context as well as from within a + * complete callback of a descriptor submitted on the same channel. + * + * If none of the two conditions above apply consider using + * dmaengine_terminate_sync() instead. + */ +static inline int dmaengine_terminate_async(struct dma_chan *chan) +{ + if (chan->device->device_terminate_all) + return chan->device->device_terminate_all(chan); + + return -EINVAL; +} + +/** + * dmaengine_synchronize() - Synchronize DMA channel termination + * @chan: The channel to synchronize + * + * Synchronizes to the DMA channel termination to the current context. When this + * function returns it is guaranteed that all transfers for previously issued + * descriptors have stopped and and it is safe to free the memory assoicated + * with them. Furthermore it is guaranteed that all complete callback functions + * for a previously submitted descriptor have finished running and it is safe to + * free resources accessed from within the complete callbacks. + * + * The behavior of this function is undefined if dma_async_issue_pending() has + * been called between dmaengine_terminate_async() and this function. + * + * This function must only be called from non-atomic context and must not be + * called from within a complete callback of a descriptor submitted on the same + * channel. + */ +static inline void dmaengine_synchronize(struct dma_chan *chan) +{ + might_sleep(); + + if (chan->device->device_synchronize) + chan->device->device_synchronize(chan); +} + +/** + * dmaengine_terminate_sync() - Terminate all active DMA transfers + * @chan: The channel for which to terminate the transfers + * + * Calling this function will terminate all active and pending transfers + * that have previously been submitted to the channel. It is similar to + * dmaengine_terminate_async() but guarantees that the DMA transfer has actually + * stopped and that all complete callbacks have finished running when the + * function returns. + * + * This function must only be called from non-atomic context and must not be + * called from within a complete callback of a descriptor submitted on the same + * channel. + */ +static inline int dmaengine_terminate_sync(struct dma_chan *chan) +{ + int ret; + + ret = dmaengine_terminate_async(chan); + if (ret) + return ret; + + dmaengine_synchronize(chan); + + return 0; +} + static inline int dmaengine_pause(struct dma_chan *chan) { if (chan->device->device_pause) |