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: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Christoph Hellwig 2019-04-11 09:20:00 +02:00 committed by Konrad Rzeszutek Wilk
parent 2e12dceef3
commit 063b8271ec

View File

@ -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