diff options
| -rw-r--r-- | include/linux/dmaengine.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 8ad9a4e839f6..1b866e9a6ed1 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -184,6 +184,8 @@ struct dma_interleaved_template { * operation it continues the calculation with new sources * @DMA_PREP_FENCE - tell the driver that subsequent operations depend * on the result of this operation + * @DMA_CTRL_REUSE: client can reuse the descriptor and submit again till + * cleared or freed */ enum dma_ctrl_flags { DMA_PREP_INTERRUPT = (1 << 0), @@ -192,6 +194,7 @@ enum dma_ctrl_flags { DMA_PREP_PQ_DISABLE_Q = (1 << 3), DMA_PREP_CONTINUE = (1 << 4), DMA_PREP_FENCE = (1 << 5), + DMA_CTRL_REUSE = (1 << 6), }; /** @@ -401,6 +404,8 @@ enum dma_residue_granularity { * @cmd_pause: true, if pause and thereby resume is supported * @cmd_terminate: true, if terminate cmd is supported * @residue_granularity: granularity of the reported transfer residue + * @descriptor_reuse: if a descriptor can be reused by client and + * resubmitted multiple times */ struct dma_slave_caps { u32 src_addr_widths; @@ -409,6 +414,7 @@ struct dma_slave_caps { bool cmd_pause; bool cmd_terminate; enum dma_residue_granularity residue_granularity; + bool descriptor_reuse; }; static inline const char *dma_chan_name(struct dma_chan *chan) @@ -468,6 +474,7 @@ struct dma_async_tx_descriptor { dma_addr_t phys; struct dma_chan *chan; dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx); + int (*desc_free)(struct dma_async_tx_descriptor *tx); dma_async_tx_callback callback; void *callback_param; struct dmaengine_unmap_data *unmap; @@ -1175,6 +1182,39 @@ static inline int dma_get_slave_caps(struct dma_chan *chan, } #endif +static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx) +{ + struct dma_slave_caps caps; + + dma_get_slave_caps(tx->chan, &caps); + + if (caps.descriptor_reuse) { + tx->flags |= DMA_CTRL_REUSE; + return 0; + } else { + return -EPERM; + } +} + +static inline void dmaengine_desc_clear_reuse(struct dma_async_tx_descriptor *tx) +{ + tx->flags &= ~DMA_CTRL_REUSE; +} + +static inline bool dmaengine_desc_test_reuse(struct dma_async_tx_descriptor *tx) +{ + return (tx->flags & DMA_CTRL_REUSE) == DMA_CTRL_REUSE; +} + +static inline int dmaengine_desc_free(struct dma_async_tx_descriptor *desc) +{ + /* this is supported for reusable desc, so check that */ + if (dmaengine_desc_test_reuse(desc)) + return desc->desc_free(desc); + else + return -EPERM; +} + /* --- DMA device --- */ int dma_async_device_register(struct dma_device *device); |