Commit 498e8631 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'stable/for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 

Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "Cleanups in the swiotlb code and extra debugfs knobs to help with the
  field diagnostics"

* 'stable/for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb-xen: ensure we have a single callsite for xen_dma_map_page
  swiotlb-xen: simplify the DMA sync method implementations
  swiotlb-xen: use ->map_page to implement ->map_sg
  swiotlb-xen: make instances match their method names
  swiotlb: save io_tlb_used to local variable before leaving critical section
  swiotlb: dump used and total slots when swiotlb buffer is full
parents e4eaa9ef 063b8271

drivers/xen/swiotlb-xen.c

+59 −137
Original line number Diff line number Diff line
@@ -391,13 +391,8 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, 
	if (dma_capable(dev, dev_addr, size) &&

	    !range_straddles_page_boundary(phys, size) &&

		!xen_arch_need_swiotlb(dev, phys, dev_addr) &&

		(swiotlb_force != SWIOTLB_FORCE)) {

		/* we are not interested in the dma_addr returned by

		 * xen_dma_map_page, only in the potential cache flushes executed

		 * by the function. */

		xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);

		return dev_addr;

	}

		swiotlb_force != SWIOTLB_FORCE)

		goto done;



	/*

	 * Oh well, have to allocate and map a bounce buffer.
@@ -410,21 +405,27 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, 
		return DMA_MAPPING_ERROR;



	dev_addr = xen_phys_to_bus(map);

	xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),

					dev_addr, map & ~PAGE_MASK, size, dir, attrs);



	/*

	 * Ensure that the address returned is DMA'ble

	 */

	if (dma_capable(dev, dev_addr, size))

		return dev_addr;



	attrs |= DMA_ATTR_SKIP_CPU_SYNC;

	swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);



	if (unlikely(!dma_capable(dev, dev_addr, size))) {

		swiotlb_tbl_unmap_single(dev, map, size, dir,

				attrs | DMA_ATTR_SKIP_CPU_SYNC);

		return DMA_MAPPING_ERROR;

	}



	page = pfn_to_page(map >> PAGE_SHIFT);

	offset = map & ~PAGE_MASK;

done:

	/*

	 * we are not interested in the dma_addr returned by xen_dma_map_page,

	 * only in the potential cache flushes executed by the function.

	 */

	xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);

	return dev_addr;

}



/*

 * Unmap a single streaming mode DMA translation.  The dma_addr and size must

 * match what was provided for in a previous xen_swiotlb_map_page call.  All
@@ -455,48 +456,28 @@ static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 
	xen_unmap_single(hwdev, dev_addr, size, dir, attrs);

}



/*

 * Make physical memory consistent for a single streaming mode DMA translation

 * after a transfer.

 *

 * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer

 * using the cpu, yet do not wish to teardown the dma mapping, you must

 * call this function before doing so.  At the next point you give the dma

 * address back to the card, you must first perform a

 * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer

 */

static void

xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,

			size_t size, enum dma_data_direction dir,

			enum dma_sync_target target)

xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,

		size_t size, enum dma_data_direction dir)

{

	phys_addr_t paddr = xen_bus_to_phys(dev_addr);



	BUG_ON(dir == DMA_NONE);

	phys_addr_t paddr = xen_bus_to_phys(dma_addr);



	if (target == SYNC_FOR_CPU)

		xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);

	xen_dma_sync_single_for_cpu(dev, dma_addr, size, dir);



	/* NOTE: We use dev_addr here, not paddr! */

	if (is_xen_swiotlb_buffer(dev_addr))

		swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);



	if (target == SYNC_FOR_DEVICE)

		xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);

	if (is_xen_swiotlb_buffer(dma_addr))

		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);

}



void

xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,

static void

xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,

		size_t size, enum dma_data_direction dir)

{

	xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);

}

	phys_addr_t paddr = xen_bus_to_phys(dma_addr);



void

xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,

				   size_t size, enum dma_data_direction dir)

{

	xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);

	if (is_xen_swiotlb_buffer(dma_addr))

		swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);



	xen_dma_sync_single_for_device(dev, dma_addr, size, dir);

}



/*
@@ -504,9 +485,8 @@ xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, 
 * concerning calls here are the same as for swiotlb_unmap_page() above.

 */

static void

xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,

			   int nelems, enum dma_data_direction dir,

			   unsigned long attrs)

xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,

		enum dma_data_direction dir, unsigned long attrs)

{

	struct scatterlist *sg;

	int i;
@@ -518,26 +498,9 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, 


}



/*

 * Map a set of buffers described by scatterlist in streaming mode for DMA.

 * This is the scatter-gather version of the above xen_swiotlb_map_page

 * interface.  Here the scatter gather list elements are each tagged with the

 * appropriate dma address and length.  They are obtained via

 * sg_dma_{address,length}(SG).

 *

 * NOTE: An implementation may be able to use a smaller number of

 *       DMA address/length pairs than there are SG table elements.

 *       (for example via virtual mapping capabilities)

 *       The routine returns the number of addr/length pairs actually

 *       used, at most nents.

 *

 * Device ownership issues as mentioned above for xen_swiotlb_map_page are the

 * same here.

 */

static int

xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,

			 int nelems, enum dma_data_direction dir,

			 unsigned long attrs)

xen_swiotlb_map_sg(struct device *dev, struct scatterlist *sgl, int nelems,

		enum dma_data_direction dir, unsigned long attrs)

{

	struct scatterlist *sg;

	int i;
@@ -545,85 +508,44 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, 
	BUG_ON(dir == DMA_NONE);



	for_each_sg(sgl, sg, nelems, i) {

		phys_addr_t paddr = sg_phys(sg);

		dma_addr_t dev_addr = xen_phys_to_bus(paddr);



		if (swiotlb_force == SWIOTLB_FORCE ||

		    xen_arch_need_swiotlb(hwdev, paddr, dev_addr) ||

		    !dma_capable(hwdev, dev_addr, sg->length) ||

		    range_straddles_page_boundary(paddr, sg->length)) {

			phys_addr_t map = swiotlb_tbl_map_single(hwdev,

								 start_dma_addr,

								 sg_phys(sg),

								 sg->length,

								 dir, attrs);

			if (map == DMA_MAPPING_ERROR) {

				dev_warn(hwdev, "swiotlb buffer is full\n");

				/* Don't panic here, we expect map_sg users

				   to do proper error handling. */

				attrs |= DMA_ATTR_SKIP_CPU_SYNC;

				xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,

							   attrs);

				sg_dma_len(sgl) = 0;

				return 0;

			}

			dev_addr = xen_phys_to_bus(map);

			xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),

						dev_addr,

						map & ~PAGE_MASK,

						sg->length,

						dir,

						attrs);

			sg->dma_address = dev_addr;

		} else {

			/* we are not interested in the dma_addr returned by

			 * xen_dma_map_page, only in the potential cache flushes executed

			 * by the function. */

			xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),

						dev_addr,

						paddr & ~PAGE_MASK,

						sg->length,

						dir,

						attrs);

			sg->dma_address = dev_addr;

		}

		sg->dma_address = xen_swiotlb_map_page(dev, sg_page(sg),

				sg->offset, sg->length, dir, attrs);

		if (sg->dma_address == DMA_MAPPING_ERROR)

			goto out_unmap;

		sg_dma_len(sg) = sg->length;

	}



	return nelems;

out_unmap:

	xen_swiotlb_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);

	sg_dma_len(sgl) = 0;

	return 0;

}



/*

 * Make physical memory consistent for a set of streaming mode DMA translations

 * after a transfer.

 *

 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules

 * and usage.

 */

static void

xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,

		    int nelems, enum dma_data_direction dir,

		    enum dma_sync_target target)

xen_swiotlb_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,

			    int nelems, enum dma_data_direction dir)

{

	struct scatterlist *sg;

	int i;



	for_each_sg(sgl, sg, nelems, i)

		xen_swiotlb_sync_single(hwdev, sg->dma_address,

					sg_dma_len(sg), dir, target);

	for_each_sg(sgl, sg, nelems, i) {

		xen_swiotlb_sync_single_for_cpu(dev, sg->dma_address,

				sg->length, dir);

	}



static void

xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,

			    int nelems, enum dma_data_direction dir)

{

	xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);

}



static void

xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,

xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,

			       int nelems, enum dma_data_direction dir)

{

	xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);

	struct scatterlist *sg;

	int i;



	for_each_sg(sgl, sg, nelems, i) {

		xen_swiotlb_sync_single_for_device(dev, sg->dma_address,

				sg->length, dir);

	}

}



/*
@@ -690,8 +612,8 @@ const struct dma_map_ops xen_swiotlb_dma_ops = { 
	.sync_single_for_device = xen_swiotlb_sync_single_for_device,

	.sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,

	.sync_sg_for_device = xen_swiotlb_sync_sg_for_device,

	.map_sg = xen_swiotlb_map_sg_attrs,

	.unmap_sg = xen_swiotlb_unmap_sg_attrs,

	.map_sg = xen_swiotlb_map_sg,

	.unmap_sg = xen_swiotlb_unmap_sg,

	.map_page = xen_swiotlb_map_page,

	.unmap_page = xen_swiotlb_unmap_page,

	.dma_supported = xen_swiotlb_dma_supported,

kernel/dma/swiotlb.c

+5 −1
Original line number Diff line number Diff line
@@ -452,6 +452,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, 
	unsigned long mask;

	unsigned long offset_slots;

	unsigned long max_slots;

	unsigned long tmp_io_tlb_used;



	if (no_iotlb_memory)

		panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
@@ -538,9 +539,12 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, 
	} while (index != wrap);



not_found:

	tmp_io_tlb_used = io_tlb_used;



	spin_unlock_irqrestore(&io_tlb_lock, flags);

	if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())

		dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);

		dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",

			 size, io_tlb_nslabs, tmp_io_tlb_used);

	return DMA_MAPPING_ERROR;

found:

	io_tlb_used += nslots;

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