From a9c38c5d267cb94871dfa2de5539c92025c855d7 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 30 Sep 2021 04:30:38 +0300 Subject: 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 Reviewed-by: Christoph Hellwig Acked-by: David Hildenbrand Link: https://lore.kernel.org/r/20210930013039.11260-2-rppt@kernel.org Signed-off-by: Will Deacon --- kernel/dma/mapping.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'kernel/dma') 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) -- cgit