From a9c38c5d267cb94871dfa2de5539c92025c855d7 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 30 Sep 2021 04:30:38 +0300 Subject: [PATCH 1/2] 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(-) 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) From 3de360c3fdb34fbdbaf6da3af94367d3fded95d3 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 30 Sep 2021 04:30:39 +0300 Subject: [PATCH 2/2] arm64/mm: drop HAVE_ARCH_PFN_VALID CONFIG_SPARSEMEM_VMEMMAP is now the only available memory model on arm64 platforms and free_unused_memmap() would just return without creating any holes in the memmap mapping. There is no need for any special handling in pfn_valid() and HAVE_ARCH_PFN_VALID can just be dropped. This also moves the pfn upper bits sanity check into generic pfn_valid(). [rppt: rebased on v5.15-rc3] Link: https://lkml.kernel.org/r/1621947349-25421-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Acked-by: David Hildenbrand Acked-by: Mike Rapoport Cc: Catalin Marinas Cc: Will Deacon Cc: David Hildenbrand Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mike Rapoport Link: https://lore.kernel.org/r/20210930013039.11260-3-rppt@kernel.org Signed-off-by: Will Deacon --- arch/arm64/Kconfig | 1 - arch/arm64/include/asm/page.h | 1 - arch/arm64/mm/init.c | 37 ----------------------------------- 3 files changed, 39 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5c7ae4c3954b..53dd23f305be 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -154,7 +154,6 @@ config ARM64 select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT - select HAVE_ARCH_PFN_VALID select HAVE_ARCH_PREL32_RELOCATIONS select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_SECCOMP_FILTER diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index f98c91bbd7c1..993a27ea6f54 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -41,7 +41,6 @@ void tag_clear_highpage(struct page *to); typedef struct page *pgtable_t; -int pfn_valid(unsigned long pfn); int pfn_is_map_memory(unsigned long pfn); #include diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 37a81754d9b6..e60c6eb813b7 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -160,43 +160,6 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) free_area_init(max_zone_pfns); } -int pfn_valid(unsigned long pfn) -{ - phys_addr_t addr = PFN_PHYS(pfn); - struct mem_section *ms; - - /* - * Ensure the upper PAGE_SHIFT bits are clear in the - * pfn. Else it might lead to false positives when - * some of the upper bits are set, but the lower bits - * match a valid pfn. - */ - if (PHYS_PFN(addr) != pfn) - return 0; - - if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) - return 0; - - ms = __pfn_to_section(pfn); - if (!valid_section(ms)) - return 0; - - /* - * ZONE_DEVICE memory does not have the memblock entries. - * memblock_is_map_memory() check for ZONE_DEVICE based - * addresses will always fail. Even the normal hotplugged - * memory will never have MEMBLOCK_NOMAP flag set in their - * memblock entries. Skip memblock search for all non early - * memory sections covering all of hotplug memory including - * both normal and ZONE_DEVICE based. - */ - if (!early_section(ms)) - return pfn_section_valid(ms, pfn); - - return memblock_is_memory(addr); -} -EXPORT_SYMBOL(pfn_valid); - int pfn_is_map_memory(unsigned long pfn) { phys_addr_t addr = PFN_PHYS(pfn);