From c884227eaae9936f8ecbde6e1387bccdab5f4e90 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Date: Fri, 21 Nov 2014 11:10:39 +0000 Subject: [PATCH] swiotlb-xen: remove BUG_ON in xen_bus_to_phys On x86 truncation cannot occur because config XEN depends on X86_64 || (X86_32 && X86_PAE). On ARM truncation can occur without CONFIG_ARM_LPAE, when the dma operation involves foreign grants. However in that case the physical address returned by xen_bus_to_phys is actually invalid (there is no mfn to pfn tracking for foreign grants on ARM) and it is not used. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: stable@vger.kernel.org --- drivers/xen/swiotlb-xen.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 498b6544fd62..153cf1482125 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -96,8 +96,6 @@ static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr) dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT; phys_addr_t paddr = dma; - BUG_ON(paddr != dma); /* truncation has occurred, should never happen */ - paddr |= baddr & ~PAGE_MASK; return paddr; -- 2.34.1