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swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/…
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…device

Call xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu,
xen_dma_sync_single_for_device from swiotlb-xen to ensure cpu/device
coherency of the pages used for DMA, including the ones belonging to the
swiotlb buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Stefano Stabellini committed Oct 25, 2013
1 parent 7100b07 commit 6cf0546
Showing 1 changed file with 31 additions and 8 deletions.
39 changes: 31 additions & 8 deletions drivers/xen/swiotlb-xen.c
Original file line number Diff line number Diff line change
Expand Up @@ -378,8 +378,13 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
* buffering it.
*/
if (dma_capable(dev, dev_addr, size) &&
!range_straddles_page_boundary(phys, size) && !swiotlb_force)
!range_straddles_page_boundary(phys, size) && !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, offset, size, dir, attrs);
return dev_addr;
}

/*
* Oh well, have to allocate and map a bounce buffer.
Expand All @@ -388,6 +393,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
if (map == SWIOTLB_MAP_ERROR)
return DMA_ERROR_CODE;

xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
map & ~PAGE_MASK, size, dir, attrs);
dev_addr = xen_phys_to_bus(map);

/*
Expand All @@ -410,12 +417,15 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
* whatever the device wrote there.
*/
static void xen_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,
struct dma_attrs *attrs)
{
phys_addr_t paddr = xen_bus_to_phys(dev_addr);

BUG_ON(dir == DMA_NONE);

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

/* NOTE: We use dev_addr here, not paddr! */
if (is_xen_swiotlb_buffer(dev_addr)) {
swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
Expand All @@ -438,7 +448,7 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
xen_unmap_single(hwdev, dev_addr, size, dir);
xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
}
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page);

Expand All @@ -461,11 +471,15 @@ xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,

BUG_ON(dir == DMA_NONE);

if (target == SYNC_FOR_CPU)
xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);

/* NOTE: We use dev_addr here, not paddr! */
if (is_xen_swiotlb_buffer(dev_addr)) {
if (is_xen_swiotlb_buffer(dev_addr))
swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
return;
}

if (target == SYNC_FOR_DEVICE)
xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir);

if (dir != DMA_FROM_DEVICE)
return;
Expand Down Expand Up @@ -536,8 +550,17 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
return DMA_ERROR_CODE;
}
sg->dma_address = xen_phys_to_bus(map);
} else
} 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),
paddr & ~PAGE_MASK,
sg->length,
dir,
attrs);
sg->dma_address = dev_addr;
}
sg_dma_len(sg) = sg->length;
}
return nelems;
Expand All @@ -559,7 +582,7 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
BUG_ON(dir == DMA_NONE);

for_each_sg(sgl, sg, nelems, i)
xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir);
xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);

}
EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs);
Expand Down

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