Commit 063b8271 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Konrad Rzeszutek Wilk
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swiotlb-xen: ensure we have a single callsite for xen_dma_map_page 



Refactor the code a bit to make further changes easier.

Reviewed-by: default avatarStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 2e12dcee

drivers/xen/swiotlb-xen.c

+16 −15
Original line number Diff line number Diff line
@@ -388,13 +388,8 @@ 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.
@@ -407,21 +402,27 @@ 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