From 093bbe211ea566fa828536275e09ee9d75df1f25 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Fri, 5 Mar 2021 10:54:58 +0530 Subject: [PATCH] arm64/mm: Reorganize pfn_valid() There are multiple instances of pfn_to_section_nr() and __pfn_to_section() when CONFIG_SPARSEMEM is enabled. This can be optimized if memory section is fetched earlier. This replaces the open coded PFN and ADDR conversion with PFN_PHYS() and PHYS_PFN() helpers. While there, also add a comment. This does not cause any functional change. Cc: Catalin Marinas Cc: Will Deacon Cc: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: David Hildenbrand Signed-off-by: Anshuman Khandual Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/1614921898-4099-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/mm/init.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 5920c527845a..3685e12aba9b 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -219,16 +219,26 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) int pfn_valid(unsigned long pfn) { - phys_addr_t addr = pfn << PAGE_SHIFT; + phys_addr_t addr = PFN_PHYS(pfn); - if ((addr >> PAGE_SHIFT) != pfn) + /* + * 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; #ifdef CONFIG_SPARSEMEM +{ + struct mem_section *ms; + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; - if (!valid_section(__pfn_to_section(pfn))) + ms = __pfn_to_section(pfn); + if (!valid_section(ms)) return 0; /* @@ -240,8 +250,9 @@ int pfn_valid(unsigned long pfn) * memory sections covering all of hotplug memory including * both normal and ZONE_DEVICE based. */ - if (!early_section(__pfn_to_section(pfn))) - return pfn_section_valid(__pfn_to_section(pfn), pfn); + if (!early_section(ms)) + return pfn_section_valid(ms, pfn); +} #endif return memblock_is_map_memory(addr); } -- 2.20.1