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Commit 9324fdf5 authored by Vinod Koul's avatar Vinod Koul
Browse files

Merge branch 'topic/core' into for-linus

parents 4983a501 5f88d970

Documentation/dmaengine/provider.txt

+6 −5
Original line number Diff line number Diff line
@@ -345,11 +345,12 @@ where to put them) 
      that abstracts it away.



  * DMA_CTRL_ACK

    - Undocumented feature

    - No one really has an idea of what it's about, besides being

      related to reusing the DMA transaction descriptors or having

      additional transactions added to it in the async-tx API

    - Useless in the case of the slave API

    - If set, the transfer can be reused after being completed.

    - There is a guarantee the transfer won't be freed until it is acked

      by async_tx_ack().

    - As a consequence, if a device driver wants to skip the dma_map_sg() and

      dma_unmap_sg() in between 2 transfers, because the DMA'd data wasn't used,

      it can resubmit the transfer right after its completion.



General Design Notes

--------------------

drivers/dma/virt-dma.c

+13 −6
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx) 
	spin_lock_irqsave(&vc->lock, flags);

	cookie = dma_cookie_assign(tx);



	list_add_tail(&vd->node, &vc->desc_submitted);

	list_move_tail(&vd->node, &vc->desc_submitted);

	spin_unlock_irqrestore(&vc->lock, flags);



	dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: submitted\n",
@@ -83,7 +83,9 @@ static void vchan_complete(unsigned long arg) 
		cb_data = vd->tx.callback_param;



		list_del(&vd->node);



		if (async_tx_test_ack(&vd->tx))

			list_add(&vd->node, &vc->desc_allocated);

		else

			vc->desc_free(vd);



		if (cb)
@@ -96,11 +98,15 @@ void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head) 
	while (!list_empty(head)) {

		struct virt_dma_desc *vd = list_first_entry(head,

			struct virt_dma_desc, node);

		list_del(&vd->node);

		if (async_tx_test_ack(&vd->tx)) {

			list_move_tail(&vd->node, &vc->desc_allocated);

		} else {

			dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd);

			list_del(&vd->node);

			vc->desc_free(vd);

		}

	}

}

EXPORT_SYMBOL_GPL(vchan_dma_desc_free_list);



void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
@@ -108,6 +114,7 @@ void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev) 
	dma_cookie_init(&vc->chan);



	spin_lock_init(&vc->lock);

	INIT_LIST_HEAD(&vc->desc_allocated);

	INIT_LIST_HEAD(&vc->desc_submitted);

	INIT_LIST_HEAD(&vc->desc_issued);

	INIT_LIST_HEAD(&vc->desc_completed);

drivers/dma/virt-dma.h

+12 −1
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ struct virt_dma_chan { 
	spinlock_t lock;



	/* protected by vc.lock */

	struct list_head desc_allocated;

	struct list_head desc_submitted;

	struct list_head desc_issued;

	struct list_head desc_completed;
@@ -55,11 +56,16 @@ static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan 
	struct virt_dma_desc *vd, unsigned long tx_flags)

{

	extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);

	unsigned long flags;



	dma_async_tx_descriptor_init(&vd->tx, &vc->chan);

	vd->tx.flags = tx_flags;

	vd->tx.tx_submit = vchan_tx_submit;



	spin_lock_irqsave(&vc->lock, flags);

	list_add_tail(&vd->node, &vc->desc_allocated);

	spin_unlock_irqrestore(&vc->lock, flags);



	return &vd->tx;

}
@@ -122,7 +128,8 @@ static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc) 
}



/**

 * vchan_get_all_descriptors - obtain all submitted and issued descriptors

 * vchan_get_all_descriptors - obtain all allocated, submitted and issued

 *                             descriptors

 * vc: virtual channel to get descriptors from

 * head: list of descriptors found

 *
@@ -134,6 +141,7 @@ static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc) 
static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,

	struct list_head *head)

{

	list_splice_tail_init(&vc->desc_allocated, head);

	list_splice_tail_init(&vc->desc_submitted, head);

	list_splice_tail_init(&vc->desc_issued, head);

	list_splice_tail_init(&vc->desc_completed, head);
@@ -141,11 +149,14 @@ static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc, 


static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)

{

	struct virt_dma_desc *vd;

	unsigned long flags;

	LIST_HEAD(head);



	spin_lock_irqsave(&vc->lock, flags);

	vchan_get_all_descriptors(vc, &head);

	list_for_each_entry(vd, &head, node)

		async_tx_clear_ack(&vd->tx);

	spin_unlock_irqrestore(&vc->lock, flags);



	vchan_dma_desc_free_list(vc, &head);

include/linux/dmaengine.h

+8 −0
Original line number Diff line number Diff line
@@ -123,10 +123,18 @@ enum dma_transfer_direction { 
 *	 chunk and before first src/dst address for next chunk.

 *	 Ignored for dst(assumed 0), if dst_inc is true and dst_sgl is false.

 *	 Ignored for src(assumed 0), if src_inc is true and src_sgl is false.

 * @dst_icg: Number of bytes to jump after last dst address of this

 *	 chunk and before the first dst address for next chunk.

 *	 Ignored if dst_inc is true and dst_sgl is false.

 * @src_icg: Number of bytes to jump after last src address of this

 *	 chunk and before the first src address for next chunk.

 *	 Ignored if src_inc is true and src_sgl is false.

 */

struct data_chunk {

	size_t size;

	size_t icg;

	size_t dst_icg;

	size_t src_icg;

};



/**