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authorMike Rapoport <rppt@linux.ibm.com>2021-09-30 04:30:38 +0300
committerWill Deacon <will@kernel.org>2021-10-01 14:54:45 +0100
commita9c38c5d267cb94871dfa2de5539c92025c855d7 (patch)
tree012387d007ec90b73ed0546f34b0d20b1acccdc5 /kernel/dma/mapping.c
parent5816b3e6577eaa676ceb00a848f0fd65fe2adc29 (diff)
dma-mapping: remove bogus test for pfn_valid from dma_map_resource
dma_map_resource() uses pfn_valid() to ensure the range is not RAM. However, pfn_valid() only checks for availability of the memory map for a PFN but it does not ensure that the PFN is actually backed by RAM. As dma_map_resource() is the only method in DMA mapping APIs that has this check, simply drop the pfn_valid() test from dma_map_resource(). Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/ Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20210930013039.11260-2-rppt@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'kernel/dma/mapping.c')
-rw-r--r--kernel/dma/mapping.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 06fec5547e7c..dda8d8b84a55 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -296,10 +296,6 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
if (WARN_ON_ONCE(!dev->dma_mask))
return DMA_MAPPING_ERROR;
- /* Don't allow RAM to be mapped */
- if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr))))
- return DMA_MAPPING_ERROR;
-
if (dma_map_direct(dev, ops))
addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
else if (ops->map_resource)