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authorAnshuman Khandual2021-03-05 10:54:58 +0530
committerWill Deacon2021-03-08 18:04:00 +0000
commit093bbe211ea566fa828536275e09ee9d75df1f25 (patch)
treead12eaa0be08543ab665ed369facd53cceebbe90 /arch
parenteeb0753ba27b26f609e61f9950b14f1b934fe429 (diff)
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 <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/1614921898-4099-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/mm/init.c21
1 files 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);
}