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Commit 0443fa00 authored by Alexander Duyck's avatar Alexander Duyck Committed by Konrad Rzeszutek Wilk
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swiotlb: Add support for DMA_ATTR_SKIP_CPU_SYNC 



As a first step to making DMA_ATTR_SKIP_CPU_SYNC apply to architectures
beyond just ARM I need to make it so that the swiotlb will respect the
flag.  In order to do that I also need to update the swiotlb-xen since it
heavily makes use of the functionality.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad@kernel.org>
parent 76418421

drivers/xen/swiotlb-xen.c

+7 −4
Original line number Diff line number Diff line
@@ -405,7 +405,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, 
	 */

	trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);



	map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir);

	map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,

				     attrs);

	if (map == SWIOTLB_MAP_ERROR)

		return DMA_ERROR_CODE;
@@ -419,7 +420,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, 
	if (dma_capable(dev, dev_addr, size))

		return dev_addr;



	swiotlb_tbl_unmap_single(dev, map, size, dir);

	swiotlb_tbl_unmap_single(dev, map, size, dir,

				 attrs | DMA_ATTR_SKIP_CPU_SYNC);



	return DMA_ERROR_CODE;

}
@@ -445,7 +447,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, 


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

	if (is_xen_swiotlb_buffer(dev_addr)) {

		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);

		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);

		return;

	}
@@ -558,11 +560,12 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, 
								 start_dma_addr,

								 sg_phys(sg),

								 sg->length,

								 dir);

								 dir, attrs);

			if (map == SWIOTLB_MAP_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;

include/linux/swiotlb.h

+4 −2
Original line number Diff line number Diff line
@@ -44,11 +44,13 @@ enum dma_sync_target { 
extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,

					  dma_addr_t tbl_dma_addr,

					  phys_addr_t phys, size_t size,

					  enum dma_data_direction dir);

					  enum dma_data_direction dir,

					  unsigned long attrs);



extern void swiotlb_tbl_unmap_single(struct device *hwdev,

				     phys_addr_t tlb_addr,

				     size_t size, enum dma_data_direction dir);

				     size_t size, enum dma_data_direction dir,

				     unsigned long attrs);



extern void swiotlb_tbl_sync_single(struct device *hwdev,

				    phys_addr_t tlb_addr,

lib/swiotlb.c

+38 −21
Original line number Diff line number Diff line
@@ -425,7 +425,8 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, 
phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,

				   dma_addr_t tbl_dma_addr,

				   phys_addr_t orig_addr, size_t size,

				   enum dma_data_direction dir)

				   enum dma_data_direction dir,

				   unsigned long attrs)

{

	unsigned long flags;

	phys_addr_t tlb_addr;
@@ -526,7 +527,8 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, 
	 */

	for (i = 0; i < nslots; i++)

		io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT);

	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)

	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&

	    (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))

		swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE);



	return tlb_addr;
@@ -539,18 +541,20 @@ EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single); 


static phys_addr_t

map_single(struct device *hwdev, phys_addr_t phys, size_t size,

	   enum dma_data_direction dir)

	   enum dma_data_direction dir, unsigned long attrs)

{

	dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start);



	return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);

	return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size,

				      dir, attrs);

}



/*

 * dma_addr is the kernel virtual address of the bounce buffer to unmap.

 */

void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,

			      size_t size, enum dma_data_direction dir)

			      size_t size, enum dma_data_direction dir,

			      unsigned long attrs)

{

	unsigned long flags;

	int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
@@ -561,6 +565,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, 
	 * First, sync the memory before unmapping the entry

	 */

	if (orig_addr != INVALID_PHYS_ADDR &&

	    !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&

	    ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))

		swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE);
@@ -654,7 +659,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
		 * GFP_DMA memory; fall back on map_single(), which

		 * will grab memory from the lowest available address range.

		 */

		phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE);

		phys_addr_t paddr = map_single(hwdev, 0, size,

					       DMA_FROM_DEVICE, 0);

		if (paddr == SWIOTLB_MAP_ERROR)

			goto err_warn;
@@ -667,9 +673,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, 
			       (unsigned long long)dma_mask,

			       (unsigned long long)dev_addr);



			/* DMA_TO_DEVICE to avoid memcpy in unmap_single */

			/*

			 * DMA_TO_DEVICE to avoid memcpy in unmap_single.

			 * The DMA_ATTR_SKIP_CPU_SYNC is optional.

			 */

			swiotlb_tbl_unmap_single(hwdev, paddr,

						 size, DMA_TO_DEVICE);

						 size, DMA_TO_DEVICE,

						 DMA_ATTR_SKIP_CPU_SYNC);

			goto err_warn;

		}

	}
@@ -698,8 +708,12 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, 
	if (!is_swiotlb_buffer(paddr))

		free_pages((unsigned long)vaddr, get_order(size));

	else

		/* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */

		swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE);

		/*

		 * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single.

		 * DMA_ATTR_SKIP_CPU_SYNC is optional.

		 */

		swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE,

					 DMA_ATTR_SKIP_CPU_SYNC);

}

EXPORT_SYMBOL(swiotlb_free_coherent);
@@ -755,7 +769,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, 
	trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);



	/* Oh well, have to allocate and map a bounce buffer. */

	map = map_single(dev, phys, size, dir);

	map = map_single(dev, phys, size, dir, attrs);

	if (map == SWIOTLB_MAP_ERROR) {

		swiotlb_full(dev, size, dir, 1);

		return phys_to_dma(dev, io_tlb_overflow_buffer);
@@ -764,12 +778,13 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, 
	dev_addr = phys_to_dma(dev, map);



	/* Ensure that the address returned is DMA'ble */

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

		swiotlb_tbl_unmap_single(dev, map, size, dir);

		return phys_to_dma(dev, io_tlb_overflow_buffer);

	}



	if (dma_capable(dev, dev_addr, size))

		return dev_addr;



	swiotlb_tbl_unmap_single(dev, map, size, dir,

				 attrs | DMA_ATTR_SKIP_CPU_SYNC);



	return phys_to_dma(dev, io_tlb_overflow_buffer);

}

EXPORT_SYMBOL_GPL(swiotlb_map_page);
@@ -782,14 +797,15 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page); 
 * whatever the device wrote there.

 */

static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,

			 size_t size, enum dma_data_direction dir)

			 size_t size, enum dma_data_direction dir,

			 unsigned long attrs)

{

	phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);



	BUG_ON(dir == DMA_NONE);



	if (is_swiotlb_buffer(paddr)) {

		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);

		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);

		return;

	}
@@ -809,7 +825,7 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 
			size_t size, enum dma_data_direction dir,

			unsigned long attrs)

{

	unmap_single(hwdev, dev_addr, size, dir);

	unmap_single(hwdev, dev_addr, size, dir, attrs);

}

EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
@@ -891,7 +907,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, 
		if (swiotlb_force ||

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

			phys_addr_t map = map_single(hwdev, sg_phys(sg),

						     sg->length, dir);

						     sg->length, dir, attrs);

			if (map == SWIOTLB_MAP_ERROR) {

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

				   to do proper error handling. */
@@ -925,7 +941,8 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, 
	BUG_ON(dir == DMA_NONE);



	for_each_sg(sgl, sg, nelems, i)

		unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir);

		unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir,

			     attrs);



}

EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);