From f083f557186d77de5f14bf90aec1bfe2503cf513 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Wed, 20 Jul 2016 13:10:31 -0700 Subject: dmaengine: Add helper function to prep for error reporting Dmaengine does not provide a way to pass back the result from a DMA transaction through the callback function. We are adding dmaengine helper function in order to prep for a mechanism that allow result status and other information through the callback. The initial conversion will make the existing driver use these new helper functions but retain the original behavior of the code. However, the helper functions paves a way towards adding the result parameter through callback. Signed-off-by: Dave Jiang Reviewed-by: Lars-Peter Clausen Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.h | 72 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) (limited to 'drivers/dma/dmaengine.h') diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h index 17f983a4e9ba..94a4379c7639 100644 --- a/drivers/dma/dmaengine.h +++ b/drivers/dma/dmaengine.h @@ -86,4 +86,76 @@ static inline void dma_set_residue(struct dma_tx_state *state, u32 residue) state->residue = residue; } +struct dmaengine_desc_callback { + dma_async_tx_callback callback; + 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_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: dummy pointer for now + * + * 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 void *result) +{ + 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: dummy pointer for now + * + * 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 void *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) ? true : false; +} + #endif -- cgit v1.2.1 From f067025bc676ba8d18fba5f959598339e39b86db Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Wed, 20 Jul 2016 13:13:50 -0700 Subject: dmaengine: add support to provide error result from a DMA transation Adding a new callback that will provide the error result for a transaction. The result is allocated on the stack and the callback should create a copy if it wishes to retain the information after exiting. The result parameter is now defined and takes over the dummy void pointer we placed in the helper functions previously. dmaengine drivers should start converting to the new "callback_result" callback in order to receive transaction results. Signed-off-by: Dave Jiang Reviewed-by: Lars-Peter Clausen Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.h | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) (limited to 'drivers/dma/dmaengine.h') diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h index 94a4379c7639..882ff9448c3b 100644 --- a/drivers/dma/dmaengine.h +++ b/drivers/dma/dmaengine.h @@ -88,6 +88,7 @@ static inline void dma_set_residue(struct dma_tx_state *state, u32 residue) struct dmaengine_desc_callback { dma_async_tx_callback callback; + dma_async_tx_callback_result callback_result; void *callback_param; }; @@ -105,13 +106,14 @@ 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: dummy pointer for now + * @result: transaction result * * Call the callback function provided in the cb struct with the parameter * in the cb struct. @@ -119,17 +121,27 @@ dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx, */ static inline void dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb, - const void *result) + const struct dmaengine_result *result) { - if (cb->callback) + 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: dummy pointer for now + * @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. @@ -137,7 +149,7 @@ dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb, */ static inline void dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx, - const void *result) + const struct dmaengine_result *result) { struct dmaengine_desc_callback cb; -- cgit v1.2.1