From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: arm64: drop pfn_valid_within() and simplify pfn_valid() The arm64's version of pfn_valid() differs from the generic because of two reasons: * Parts of the memory map are freed during boot. This makes it necessary to verify that there is actual physical memory that corresponds to a pfn which is done by querying memblock. * There are NOMAP memory regions. These regions are not mapped in the linear map and until the previous commit the struct pages representing these areas had default values. As the consequence of absence of the special treatment of NOMAP regions in the memory map it was necessary to use memblock_is_map_memory() in pfn_valid() and to have pfn_valid_within() aliased to pfn_valid() so that generic mm functionality would not treat a NOMAP page as a normal page. Since the NOMAP regions are now marked as PageReserved(), pfn walkers and the rest of core mm will treat them as unusable memory and thus pfn_valid_within() is no longer required at all and can be disabled on arm64. pfn_valid() can be slightly simplified by replacing memblock_is_map_memory() with memblock_is_memory(). [rppt@xxxxxxxxxx: fix merge fix] Link: https://lkml.kernel.org/r/YJtoQhidtIJOhYsV@xxxxxxxxxx Link: https://lkml.kernel.org/r/20210511100550.28178-5-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/Kconfig | 1 - arch/arm64/mm/init.c | 2 +- 2 files changed, 1 insertion(+), 2 deletions(-) --- a/arch/arm64/Kconfig~arm64-drop-pfn_valid_within-and-simplify-pfn_valid +++ a/arch/arm64/Kconfig @@ -201,7 +201,6 @@ config ARM64 select HAVE_KPROBES select HAVE_KRETPROBES select HAVE_GENERIC_VDSO - select HOLES_IN_ZONE select IOMMU_DMA if IOMMU_SUPPORT select IRQ_DOMAIN select IRQ_FORCED_THREADING --- a/arch/arm64/mm/init.c~arm64-drop-pfn_valid_within-and-simplify-pfn_valid +++ a/arch/arm64/mm/init.c @@ -252,7 +252,7 @@ int pfn_valid(unsigned long pfn) if (!early_section(ms)) return pfn_section_valid(ms, pfn); - return memblock_is_map_memory(addr); + return memblock_is_memory(addr); } EXPORT_SYMBOL(pfn_valid); _
