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| author | Mike Rapoport <rppt@linux.ibm.com> | 2021-09-30 04:30:38 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-27 15:38:50 +0300 |
| commit | c01430cf5b8769d98f476c9516f22306f0323415 (patch) | |
| tree | d0fb8c3a2240d67ecad72cdfd2009a2168ce1ffc /kernel | |
| parent | 155ae0547cb8c8b7b5fa96891dbaba0c664b023b (diff) | |
| download | linux-c01430cf5b8769d98f476c9516f22306f0323415.tar.xz | |
dma-mapping: remove bogus test for pfn_valid from dma_map_resource
commit a9c38c5d267cb94871dfa2de5539c92025c855d7 upstream.
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>
Fixes: 859a85ddf90e ("mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE")
Link: https://lore.kernel.org/r/Yl0IZWT2nsiYtqBT@linux.ibm.com
Signed-off-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/dma/mapping.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 8349a9f2c345..9478eccd1c8e 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) |