Refactor the code a bit to make further changes easier.
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
drivers/xen/swiotlb-xen.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 9a951504dc12..5dcb06fe9667 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -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.
@@ -410,19 +405,25 @@ 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;
+ }
- 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;
}
/*
--
2.20.1
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