Commit 9c4d1e7b authored by Ira Snyder's avatar Ira Snyder Committed by Dan Williams
Browse files

fsldma: support async_tx dependencies and automatic unmapping 



Previous to this patch, the dma_run_dependencies() function has been
called while holding desc_lock. This function can call tx_submit() for
other descriptors, which may try to re-grab the lock. Avoid this by
moving the descriptors to be cleaned up to a temporary list, and
dropping the lock before cleanup.

At the same time, add support for automatic unmapping of src and dst
buffers, as offered by the DMAEngine API.

Signed-off-by: default avatarIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent f04cd407

drivers/dma/fsldma.c

+95 −36
Original line number Diff line number Diff line
@@ -83,6 +83,11 @@ static void set_desc_cnt(struct fsldma_chan *chan, 
	hw->count = CPU_TO_DMA(chan, count, 32);

}



static u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc)

{

	return DMA_TO_CPU(chan, desc->hw.count, 32);

}



static void set_desc_src(struct fsldma_chan *chan,

			 struct fsl_dma_ld_hw *hw, dma_addr_t src)

{
@@ -93,6 +98,16 @@ static void set_desc_src(struct fsldma_chan *chan, 
	hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);

}



static dma_addr_t get_desc_src(struct fsldma_chan *chan,

			       struct fsl_desc_sw *desc)

{

	u64 snoop_bits;



	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)

		? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;

	return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits;

}



static void set_desc_dst(struct fsldma_chan *chan,

			 struct fsl_dma_ld_hw *hw, dma_addr_t dst)

{
@@ -103,6 +118,16 @@ static void set_desc_dst(struct fsldma_chan *chan, 
	hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);

}



static dma_addr_t get_desc_dst(struct fsldma_chan *chan,

			       struct fsl_desc_sw *desc)

{

	u64 snoop_bits;



	snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)

		? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;

	return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits;

}



static void set_desc_next(struct fsldma_chan *chan,

			  struct fsl_dma_ld_hw *hw, dma_addr_t next)

{
@@ -805,6 +830,57 @@ static int fsl_dma_device_control(struct dma_chan *dchan, 
	return 0;

}



/**

 * fsldma_cleanup_descriptor - cleanup and free a single link descriptor

 * @chan: Freescale DMA channel

 * @desc: descriptor to cleanup and free

 *

 * This function is used on a descriptor which has been executed by the DMA

 * controller. It will run any callbacks, submit any dependencies, and then

 * free the descriptor.

 */

static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,

				      struct fsl_desc_sw *desc)

{

	struct dma_async_tx_descriptor *txd = &desc->async_tx;

	struct device *dev = chan->common.device->dev;

	dma_addr_t src = get_desc_src(chan, desc);

	dma_addr_t dst = get_desc_dst(chan, desc);

	u32 len = get_desc_cnt(chan, desc);



	/* Run the link descriptor callback function */

	if (txd->callback) {

#ifdef FSL_DMA_LD_DEBUG

		chan_dbg(chan, "LD %p callback\n", desc);

#endif

		txd->callback(txd->callback_param);

	}



	/* Run any dependencies */

	dma_run_dependencies(txd);



	/* Unmap the dst buffer, if requested */

	if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {

		if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)

			dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE);

		else

			dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE);

	}



	/* Unmap the src buffer, if requested */

	if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {

		if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)

			dma_unmap_single(dev, src, len, DMA_TO_DEVICE);

		else

			dma_unmap_page(dev, src, len, DMA_TO_DEVICE);

	}



#ifdef FSL_DMA_LD_DEBUG

	chan_dbg(chan, "LD %p free\n", desc);

#endif

	dma_pool_free(chan->desc_pool, desc, txd->phys);

}



/**

 * fsl_chan_ld_cleanup - Clean up link descriptors

 * @chan : Freescale DMA channel
@@ -818,56 +894,39 @@ static int fsl_dma_device_control(struct dma_chan *dchan, 
static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)

{

	struct fsl_desc_sw *desc, *_desc;

	LIST_HEAD(ld_cleanup);

	unsigned long flags;



	spin_lock_irqsave(&chan->desc_lock, flags);



	/* if the ld_running list is empty, there is nothing to do */

	if (list_empty(&chan->ld_running)) {

		chan_dbg(chan, "no descriptors to cleanup\n");

		goto out_unlock;

	/* update the cookie if we have some descriptors to cleanup */

	if (!list_empty(&chan->ld_running)) {

		dma_cookie_t cookie;



		desc = to_fsl_desc(chan->ld_running.prev);

		cookie = desc->async_tx.cookie;



		chan->completed_cookie = cookie;

		chan_dbg(chan, "completed cookie=%d\n", cookie);

	}



	/*

	 * Get the last descriptor, update the cookie to it

	 *

	 * This is done before callbacks run so that clients can check the

	 * status of their DMA transfer inside the callback.

	 * move the descriptors to a temporary list so we can drop the lock

	 * during the entire cleanup operation

	 */

	desc = to_fsl_desc(chan->ld_running.prev);

	chan->completed_cookie = desc->async_tx.cookie;

	chan_dbg(chan, "completed_cookie = %d\n", chan->completed_cookie);

	list_splice_tail_init(&chan->ld_running, &ld_cleanup);



	spin_unlock_irqrestore(&chan->desc_lock, flags);



	/* Run the callback for each descriptor, in order */

	list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {

		dma_async_tx_callback callback;

		void *callback_param;

	list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {



		/* Remove from the list of running transactions */

		/* Remove from the list of transactions */

		list_del(&desc->node);



		/* Run the link descriptor callback function */

		callback = desc->async_tx.callback;

		callback_param = desc->async_tx.callback_param;

		if (callback) {

			spin_unlock_irqrestore(&chan->desc_lock, flags);

#ifdef FSL_DMA_LD_DEBUG

			chan_dbg(chan, "LD %p callback\n", desc);

#endif

			callback(callback_param);

			spin_lock_irqsave(&chan->desc_lock, flags);

		}



		/* Run any dependencies, then free the descriptor */

		dma_run_dependencies(&desc->async_tx);

#ifdef FSL_DMA_LD_DEBUG

		chan_dbg(chan, "LD %p free\n", desc);

#endif

		dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);

		/* Run all cleanup for this descriptor */

		fsldma_cleanup_descriptor(chan, desc);

	}



out_unlock:

	spin_unlock_irqrestore(&chan->desc_lock, flags);

}



/**

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