Commit 41d5e59c authored by Dan Williams's avatar Dan Williams
Browse files

dmaengine: add a release for dma class devices and dependent infrastructure 



Resolves:
WARNING: at drivers/base/core.c:122 device_release+0x4d/0x52()
Device 'dma0chan0' does not have a release() function, it is broken and must be fixed.

The dma_chan_dev object is introduced to gear-match sysfs kobject and
dmaengine channel lifetimes.  When a channel is removed access to the
sysfs entries return -ENODEV until the kobject can be released.

The bulk of the change is updates to existing code to handle the extra
layer of indirection between a dma_chan and its struct device.

Reported-by: default avatarAlexander Beregalov <a.beregalov@gmail.com>
Acked-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 4fac7fa5

drivers/dma/dmaengine.c

+83 −23
Original line number Diff line number Diff line
@@ -64,36 +64,75 @@ static long dmaengine_ref_count; 


/* --- sysfs implementation --- */



/**

 * dev_to_dma_chan - convert a device pointer to the its sysfs container object

 * @dev - device node

 *

 * Must be called under dma_list_mutex

 */

static struct dma_chan *dev_to_dma_chan(struct device *dev)

{

	struct dma_chan_dev *chan_dev;



	chan_dev = container_of(dev, typeof(*chan_dev), device);

	return chan_dev->chan;

}



static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct dma_chan *chan = to_dma_chan(dev);

	struct dma_chan *chan;

	unsigned long count = 0;

	int i;

	int err;



	mutex_lock(&dma_list_mutex);

	chan = dev_to_dma_chan(dev);

	if (chan) {

		for_each_possible_cpu(i)

			count += per_cpu_ptr(chan->local, i)->memcpy_count;

		err = sprintf(buf, "%lu\n", count);

	} else

		err = -ENODEV;

	mutex_unlock(&dma_list_mutex);



	return sprintf(buf, "%lu\n", count);

	return err;

}



static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr,

				      char *buf)

{

	struct dma_chan *chan = to_dma_chan(dev);

	struct dma_chan *chan;

	unsigned long count = 0;

	int i;

	int err;



	mutex_lock(&dma_list_mutex);

	chan = dev_to_dma_chan(dev);

	if (chan) {

		for_each_possible_cpu(i)

			count += per_cpu_ptr(chan->local, i)->bytes_transferred;

		err = sprintf(buf, "%lu\n", count);

	} else

		err = -ENODEV;

	mutex_unlock(&dma_list_mutex);



	return sprintf(buf, "%lu\n", count);

	return err;

}



static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct dma_chan *chan = to_dma_chan(dev);

	struct dma_chan *chan;

	int err;



	mutex_lock(&dma_list_mutex);

	chan = dev_to_dma_chan(dev);

	if (chan)

		err = sprintf(buf, "%d\n", chan->client_count);

	else

		err = -ENODEV;

	mutex_unlock(&dma_list_mutex);



	return sprintf(buf, "%d\n", chan->client_count);

	return err;

}



static struct device_attribute dma_attrs[] = {
@@ -103,9 +142,18 @@ static struct device_attribute dma_attrs[] = { 
	__ATTR_NULL

};



static void chan_dev_release(struct device *dev)

{

	struct dma_chan_dev *chan_dev;



	chan_dev = container_of(dev, typeof(*chan_dev), device);

	kfree(chan_dev);

}



static struct class dma_devclass = {

	.name		= "dma",

	.dev_attrs	= dma_attrs,

	.dev_release	= chan_dev_release,

};



/* --- client and device registration --- */
@@ -420,7 +468,7 @@ static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_devic 
	list_for_each_entry(chan, &dev->channels, device_node) {

		if (chan->client_count) {

			pr_debug("%s: %s busy\n",

				 __func__, dev_name(&chan->dev));

				 __func__, dma_chan_name(chan));

			continue;

		}

		ret = chan;
@@ -466,22 +514,22 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v 


			if (err == -ENODEV) {

				pr_debug("%s: %s module removed\n", __func__,

					 dev_name(&chan->dev));

					 dma_chan_name(chan));

				list_del_rcu(&device->global_node);

			} else if (err)

				pr_err("dmaengine: failed to get %s: (%d)\n",

				       dev_name(&chan->dev), err);

				       dma_chan_name(chan), err);

			else

				break;

		} else

			pr_debug("%s: %s filter said false\n",

				 __func__, dev_name(&chan->dev));

				 __func__, dma_chan_name(chan));

		chan = NULL;

	}

	mutex_unlock(&dma_list_mutex);



	pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail",

		 chan ? dev_name(&chan->dev) : NULL);

		 chan ? dma_chan_name(chan) : NULL);



	return chan;

}
@@ -521,7 +569,7 @@ void dmaengine_get(void) 
				break;

			} else if (err)

				pr_err("dmaengine: failed to get %s: (%d)\n",

				       dev_name(&chan->dev), err);

				       dma_chan_name(chan), err);

		}

	}
@@ -601,14 +649,20 @@ int dma_async_device_register(struct dma_device *device) 
		chan->local = alloc_percpu(typeof(*chan->local));

		if (chan->local == NULL)

			continue;

		chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);

		if (chan->dev == NULL) {

			free_percpu(chan->local);

			continue;

		}



		chan->chan_id = chancnt++;

		chan->dev.class = &dma_devclass;

		chan->dev.parent = device->dev;

		dev_set_name(&chan->dev, "dma%dchan%d",

		chan->dev->device.class = &dma_devclass;

		chan->dev->device.parent = device->dev;

		chan->dev->chan = chan;

		dev_set_name(&chan->dev->device, "dma%dchan%d",

			     device->dev_id, chan->chan_id);



		rc = device_register(&chan->dev);

		rc = device_register(&chan->dev->device);

		if (rc) {

			free_percpu(chan->local);

			chan->local = NULL;
@@ -645,7 +699,10 @@ err_out: 
	list_for_each_entry(chan, &device->channels, device_node) {

		if (chan->local == NULL)

			continue;

		device_unregister(&chan->dev);

		mutex_lock(&dma_list_mutex);

		chan->dev->chan = NULL;

		mutex_unlock(&dma_list_mutex);

		device_unregister(&chan->dev->device);

		free_percpu(chan->local);

	}

	return rc;
@@ -672,7 +729,10 @@ void dma_async_device_unregister(struct dma_device *device) 
		WARN_ONCE(chan->client_count,

			  "%s called while %d clients hold a reference\n",

			  __func__, chan->client_count);

		device_unregister(&chan->dev);

		mutex_lock(&dma_list_mutex);

		chan->dev->chan = NULL;

		mutex_unlock(&dma_list_mutex);

		device_unregister(&chan->dev->device);

	}

}

EXPORT_SYMBOL(dma_async_device_unregister);
@@ -845,7 +905,7 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) 
		return DMA_SUCCESS;



	WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for"

		  " %s\n", __func__, dev_name(&tx->chan->dev));

		  " %s\n", __func__, dma_chan_name(tx->chan));



	/* poll through the dependency chain, return when tx is complete */

	do {

drivers/dma/dmatest.c

+7 −7
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ static bool dmatest_match_channel(struct dma_chan *chan) 
{

	if (test_channel[0] == '\0')

		return true;

	return strcmp(dev_name(&chan->dev), test_channel) == 0;

	return strcmp(dma_chan_name(chan), test_channel) == 0;

}



static bool dmatest_match_device(struct dma_device *device)
@@ -325,7 +325,7 @@ static int dmatest_add_channel(struct dma_chan *chan) 


	dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);

	if (!dtc) {

		pr_warning("dmatest: No memory for %s\n", dev_name(&chan->dev));

		pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));

		return -ENOMEM;

	}
@@ -336,16 +336,16 @@ static int dmatest_add_channel(struct dma_chan *chan) 
		thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);

		if (!thread) {

			pr_warning("dmatest: No memory for %s-test%u\n",

				   dev_name(&chan->dev), i);

				   dma_chan_name(chan), i);

			break;

		}

		thread->chan = dtc->chan;

		smp_wmb();

		thread->task = kthread_run(dmatest_func, thread, "%s-test%u",

				dev_name(&chan->dev), i);

				dma_chan_name(chan), i);

		if (IS_ERR(thread->task)) {

			pr_warning("dmatest: Failed to run thread %s-test%u\n",

					dev_name(&chan->dev), i);

					dma_chan_name(chan), i);

			kfree(thread);

			break;

		}
@@ -355,7 +355,7 @@ static int dmatest_add_channel(struct dma_chan *chan) 
		list_add_tail(&thread->node, &dtc->threads);

	}



	pr_info("dmatest: Started %u threads using %s\n", i, dev_name(&chan->dev));

	pr_info("dmatest: Started %u threads using %s\n", i, dma_chan_name(chan));



	list_add_tail(&dtc->node, &dmatest_channels);

	nr_channels++;
@@ -408,7 +408,7 @@ static void __exit dmatest_exit(void) 
		list_del(&dtc->node);

		dmatest_cleanup_channel(dtc);

		pr_debug("dmatest: dropped channel %s\n",

			 dev_name(&dtc->chan->dev));

			 dma_chan_name(dtc->chan));

		dma_release_channel(dtc->chan);

	}

}

drivers/dma/dw_dmac.c

+50 −41
Original line number Diff line number Diff line
@@ -70,6 +70,15 @@ 
 * the controller, though.

 */



static struct device *chan2dev(struct dma_chan *chan)

{

	return &chan->dev->device;

}

static struct device *chan2parent(struct dma_chan *chan)

{

	return chan->dev->device.parent;

}



static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)

{

	return list_entry(dwc->active_list.next, struct dw_desc, desc_node);
@@ -93,12 +102,12 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) 
			ret = desc;

			break;

		}

		dev_dbg(&dwc->chan.dev, "desc %p not ACKed\n", desc);

		dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);

		i++;

	}

	spin_unlock_bh(&dwc->lock);



	dev_vdbg(&dwc->chan.dev, "scanned %u descriptors on freelist\n", i);

	dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);



	return ret;

}
@@ -108,10 +117,10 @@ static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc) 
	struct dw_desc	*child;



	list_for_each_entry(child, &desc->txd.tx_list, desc_node)

		dma_sync_single_for_cpu(dwc->chan.dev.parent,

		dma_sync_single_for_cpu(chan2parent(&dwc->chan),

				child->txd.phys, sizeof(child->lli),

				DMA_TO_DEVICE);

	dma_sync_single_for_cpu(dwc->chan.dev.parent,

	dma_sync_single_for_cpu(chan2parent(&dwc->chan),

			desc->txd.phys, sizeof(desc->lli),

			DMA_TO_DEVICE);

}
@@ -129,11 +138,11 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) 


		spin_lock_bh(&dwc->lock);

		list_for_each_entry(child, &desc->txd.tx_list, desc_node)

			dev_vdbg(&dwc->chan.dev,

			dev_vdbg(chan2dev(&dwc->chan),

					"moving child desc %p to freelist\n",

					child);

		list_splice_init(&desc->txd.tx_list, &dwc->free_list);

		dev_vdbg(&dwc->chan.dev, "moving desc %p to freelist\n", desc);

		dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);

		list_add(&desc->desc_node, &dwc->free_list);

		spin_unlock_bh(&dwc->lock);

	}
@@ -163,9 +172,9 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first) 


	/* ASSERT:  channel is idle */

	if (dma_readl(dw, CH_EN) & dwc->mask) {

		dev_err(&dwc->chan.dev,

		dev_err(chan2dev(&dwc->chan),

			"BUG: Attempted to start non-idle channel\n");

		dev_err(&dwc->chan.dev,

		dev_err(chan2dev(&dwc->chan),

			"  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",

			channel_readl(dwc, SAR),

			channel_readl(dwc, DAR),
@@ -193,7 +202,7 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc) 
	void				*param;

	struct dma_async_tx_descriptor	*txd = &desc->txd;



	dev_vdbg(&dwc->chan.dev, "descriptor %u complete\n", txd->cookie);

	dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);



	dwc->completed = txd->cookie;

	callback = txd->callback;
@@ -208,11 +217,11 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc) 
	 * mapped before they were submitted...

	 */

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

		dma_unmap_page(dwc->chan.dev.parent, desc->lli.dar, desc->len,

				DMA_FROM_DEVICE);

		dma_unmap_page(chan2parent(&dwc->chan), desc->lli.dar,

			       desc->len, DMA_FROM_DEVICE);

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

		dma_unmap_page(dwc->chan.dev.parent, desc->lli.sar, desc->len,

				DMA_TO_DEVICE);

		dma_unmap_page(chan2parent(&dwc->chan), desc->lli.sar,

			       desc->len, DMA_TO_DEVICE);



	/*

	 * The API requires that no submissions are done from a
@@ -228,7 +237,7 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc) 
	LIST_HEAD(list);



	if (dma_readl(dw, CH_EN) & dwc->mask) {

		dev_err(&dwc->chan.dev,

		dev_err(chan2dev(&dwc->chan),

			"BUG: XFER bit set, but channel not idle!\n");



		/* Try to continue after resetting the channel... */
@@ -273,7 +282,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) 
		return;

	}



	dev_vdbg(&dwc->chan.dev, "scan_descriptors: llp=0x%x\n", llp);

	dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);



	list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {

		if (desc->lli.llp == llp)
@@ -292,7 +301,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) 
		dwc_descriptor_complete(dwc, desc);

	}



	dev_err(&dwc->chan.dev,

	dev_err(chan2dev(&dwc->chan),

		"BUG: All descriptors done, but channel not idle!\n");



	/* Try to continue after resetting the channel... */
@@ -308,7 +317,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) 


static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)

{

	dev_printk(KERN_CRIT, &dwc->chan.dev,

	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),

			"  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",

			lli->sar, lli->dar, lli->llp,

			lli->ctlhi, lli->ctllo);
@@ -342,9 +351,9 @@ static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc) 
	 * controller flagged an error instead of scribbling over

	 * random memory locations.

	 */

	dev_printk(KERN_CRIT, &dwc->chan.dev,

	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),

			"Bad descriptor submitted for DMA!\n");

	dev_printk(KERN_CRIT, &dwc->chan.dev,

	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),

			"  cookie: %d\n", bad_desc->txd.cookie);

	dwc_dump_lli(dwc, &bad_desc->lli);

	list_for_each_entry(child, &bad_desc->txd.tx_list, desc_node)
@@ -442,12 +451,12 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx) 
	 * for DMA. But this is hard to do in a race-free manner.

	 */

	if (list_empty(&dwc->active_list)) {

		dev_vdbg(&tx->chan->dev, "tx_submit: started %u\n",

		dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",

				desc->txd.cookie);

		dwc_dostart(dwc, desc);

		list_add_tail(&desc->desc_node, &dwc->active_list);

	} else {

		dev_vdbg(&tx->chan->dev, "tx_submit: queued %u\n",

		dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",

				desc->txd.cookie);



		list_add_tail(&desc->desc_node, &dwc->queue);
@@ -472,11 +481,11 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
	unsigned int		dst_width;

	u32			ctllo;



	dev_vdbg(&chan->dev, "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",

	dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",

			dest, src, len, flags);



	if (unlikely(!len)) {

		dev_dbg(&chan->dev, "prep_dma_memcpy: length is zero!\n");

		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");

		return NULL;

	}
@@ -516,7 +525,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
			first = desc;

		} else {

			prev->lli.llp = desc->txd.phys;

			dma_sync_single_for_device(chan->dev.parent,

			dma_sync_single_for_device(chan2parent(chan),

					prev->txd.phys, sizeof(prev->lli),

					DMA_TO_DEVICE);

			list_add_tail(&desc->desc_node,
@@ -531,7 +540,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
		prev->lli.ctllo |= DWC_CTLL_INT_EN;



	prev->lli.llp = 0;

	dma_sync_single_for_device(chan->dev.parent,

	dma_sync_single_for_device(chan2parent(chan),

			prev->txd.phys, sizeof(prev->lli),

			DMA_TO_DEVICE);
@@ -562,7 +571,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
	struct scatterlist	*sg;

	size_t			total_len = 0;



	dev_vdbg(&chan->dev, "prep_dma_slave\n");

	dev_vdbg(chan2dev(chan), "prep_dma_slave\n");



	if (unlikely(!dws || !sg_len))

		return NULL;
@@ -570,7 +579,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
	reg_width = dws->reg_width;

	prev = first = NULL;



	sg_len = dma_map_sg(chan->dev.parent, sgl, sg_len, direction);

	sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);



	switch (direction) {

	case DMA_TO_DEVICE:
@@ -587,7 +596,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 


			desc = dwc_desc_get(dwc);

			if (!desc) {

				dev_err(&chan->dev,

				dev_err(chan2dev(chan),

					"not enough descriptors available\n");

				goto err_desc_get;

			}
@@ -607,7 +616,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
				first = desc;

			} else {

				prev->lli.llp = desc->txd.phys;

				dma_sync_single_for_device(chan->dev.parent,

				dma_sync_single_for_device(chan2parent(chan),

						prev->txd.phys,

						sizeof(prev->lli),

						DMA_TO_DEVICE);
@@ -633,7 +642,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 


			desc = dwc_desc_get(dwc);

			if (!desc) {

				dev_err(&chan->dev,

				dev_err(chan2dev(chan),

					"not enough descriptors available\n");

				goto err_desc_get;

			}
@@ -653,7 +662,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
				first = desc;

			} else {

				prev->lli.llp = desc->txd.phys;

				dma_sync_single_for_device(chan->dev.parent,

				dma_sync_single_for_device(chan2parent(chan),

						prev->txd.phys,

						sizeof(prev->lli),

						DMA_TO_DEVICE);
@@ -673,7 +682,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
		prev->lli.ctllo |= DWC_CTLL_INT_EN;



	prev->lli.llp = 0;

	dma_sync_single_for_device(chan->dev.parent,

	dma_sync_single_for_device(chan2parent(chan),

			prev->txd.phys, sizeof(prev->lli),

			DMA_TO_DEVICE);
@@ -768,11 +777,11 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) 
	u32			cfghi;

	u32			cfglo;



	dev_vdbg(&chan->dev, "alloc_chan_resources\n");

	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");



	/* ASSERT:  channel is idle */

	if (dma_readl(dw, CH_EN) & dwc->mask) {

		dev_dbg(&chan->dev, "DMA channel not idle?\n");

		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");

		return -EIO;

	}
@@ -808,7 +817,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) 


		desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);

		if (!desc) {

			dev_info(&chan->dev,

			dev_info(chan2dev(chan),

				"only allocated %d descriptors\n", i);

			spin_lock_bh(&dwc->lock);

			break;
@@ -818,7 +827,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) 
		desc->txd.tx_submit = dwc_tx_submit;

		desc->txd.flags = DMA_CTRL_ACK;

		INIT_LIST_HEAD(&desc->txd.tx_list);

		desc->txd.phys = dma_map_single(chan->dev.parent, &desc->lli,

		desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,

				sizeof(desc->lli), DMA_TO_DEVICE);

		dwc_desc_put(dwc, desc);
@@ -833,7 +842,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) 


	spin_unlock_bh(&dwc->lock);



	dev_dbg(&chan->dev,

	dev_dbg(chan2dev(chan),

		"alloc_chan_resources allocated %d descriptors\n", i);



	return i;
@@ -846,7 +855,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan) 
	struct dw_desc		*desc, *_desc;

	LIST_HEAD(list);



	dev_dbg(&chan->dev, "free_chan_resources (descs allocated=%u)\n",

	dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",

			dwc->descs_allocated);



	/* ASSERT:  channel is idle */
@@ -867,13 +876,13 @@ static void dwc_free_chan_resources(struct dma_chan *chan) 
	spin_unlock_bh(&dwc->lock);



	list_for_each_entry_safe(desc, _desc, &list, desc_node) {

		dev_vdbg(&chan->dev, "  freeing descriptor %p\n", desc);

		dma_unmap_single(chan->dev.parent, desc->txd.phys,

		dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);

		dma_unmap_single(chan2parent(chan), desc->txd.phys,

				sizeof(desc->lli), DMA_TO_DEVICE);

		kfree(desc);

	}



	dev_vdbg(&chan->dev, "free_chan_resources done\n");

	dev_vdbg(chan2dev(chan), "free_chan_resources done\n");

}



/*----------------------------------------------------------------------*/

drivers/dma/fsldma.c

+1 −1
Original line number Diff line number Diff line
@@ -822,7 +822,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev, 
	 */

	WARN_ON(fdev->feature != new_fsl_chan->feature);



	new_fsl_chan->dev = &new_fsl_chan->common.dev;

	new_fsl_chan->dev = &new_fsl_chan->common.dev->device;

	new_fsl_chan->reg_base = ioremap(new_fsl_chan->reg.start,

			new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);

include/linux/dmaengine.h

+16 −3
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ struct dma_chan_percpu { 
 * @device: ptr to the dma device who supplies this channel, always !%NULL

 * @cookie: last cookie value returned to client

 * @chan_id: channel ID for sysfs

 * @class_dev: class device for sysfs

 * @dev: class device for sysfs

 * @refcount: kref, used in "bigref" slow-mode

 * @slow_ref: indicates that the DMA channel is free

 * @rcu: the DMA channel's RCU head
@@ -128,7 +128,7 @@ struct dma_chan { 


	/* sysfs */

	int chan_id;

	struct device dev;

	struct dma_chan_dev *dev;



	struct list_head device_node;

	struct dma_chan_percpu *local;
@@ -136,7 +136,20 @@ struct dma_chan { 
	int table_count;

};



#define to_dma_chan(p) container_of(p, struct dma_chan, dev)

/**

 * struct dma_chan_dev - relate sysfs device node to backing channel device

 * @chan - driver channel device

 * @device - sysfs device

 */

struct dma_chan_dev {

	struct dma_chan *chan;

	struct device device;

};



static inline const char *dma_chan_name(struct dma_chan *chan)

{

	return dev_name(&chan->dev->device);

}



void dma_chan_cleanup(struct kref *kref);

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