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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-11-21 11:10:39 +0000 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-12-04 12:41:56 +0000 |
| commit | c884227eaae9936f8ecbde6e1387bccdab5f4e90 (patch) | |
| tree | a12fd8f936773ef95c601f9f1049c350c126a491 /drivers/xen | |
| parent | d6883e6f32e07ef2cc974753ba00927de099e6d7 (diff) | |
| download | lwn-c884227eaae9936f8ecbde6e1387bccdab5f4e90.tar.gz lwn-c884227eaae9936f8ecbde6e1387bccdab5f4e90.zip | |
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
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 2 |
1 files changed, 0 insertions, 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; |