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Commit 27242021 authored by Vinod Koul's avatar Vinod Koul
Browse files

dmaengine: Add DMA_CTRL_REUSE 



This adds new descriptor flag for reusing a descriptor by submitting
multiple times by a client, for example video buffer.
Add helper APIs for this as well

Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Acked-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
parent 60884dde

include/linux/dmaengine.h

+40 −0
Original line number Diff line number Diff line
@@ -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);