Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.18 012/150] swiotlb-xen: remove BUG_ON in xen_bus_to_phys | Date | Tue, 13 Jan 2015 23:21:23 -0800 |
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3.18-stable review patch. If anyone has any objections, please let me know.
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From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
commit c884227eaae9936f8ecbde6e1387bccdab5f4e90 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/xen/swiotlb-xen.c | 2 -- 1 file changed, 2 deletions(-)
--- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -96,8 +96,6 @@ static inline phys_addr_t xen_bus_to_phy 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;
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