[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 18/19] swiotlb-xen: no need to do execute two bus_to_phys translations in a row
xen_unmap_single calls xen_bus_to_phys, then passes dev_addr to is_xen_swiotlb_buffer that calls xen_bus_to_phys again. xen_bus_to_phys is potentially a slow operation that might involve walking a tree. We can avoid calling xen_bus_to_phys twice by removing the is_xen_swiotlb_buffer call and doing the check directly in xen_unmap_single using the physical address. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> --- drivers/xen/swiotlb-xen.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4d50058..6d9ca61 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -426,8 +426,8 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, xen_dma_unmap_page(hwdev, paddr, size, dir, attrs); - /* NOTE: We use dev_addr here, not paddr! */ - if (is_xen_swiotlb_buffer(dev_addr)) { + if (paddr >= virt_to_phys(xen_io_tlb_start) && + paddr < virt_to_phys(xen_io_tlb_end)) { swiotlb_tbl_unmap_single(hwdev, paddr, size, dir); return; } -- 1.7.2.5 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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