Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-17 10:26:09 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

dma-mapping: remove bogus test for pfn_valid from dma_map_resource

Browse Source 
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>
This commit is contained in:
Mike Rapoport 2021-09-30 04:30:38 +03:00 committed by Will Deacon
parent 5816b3e657
commit a9c38c5d26
1 changed files with 0 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
kernel/dma/mapping.c
View File

@ -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)