From 16c9afc776608324ca71c0bc354987bab532f51d Mon Sep 17 00:00:00 2001
From: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Wed, 30 Jun 2021 18:51:26 -0700
Subject: 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().
Link: https://lkml.kernel.org/r/1621947349-25421-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/mmzone.h | 9 +++++++++
1 file changed, 9 insertions(+)
(limited to 'include')
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7da43337ad23..7bc7e41b6c31 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1460,6 +1460,15 @@ static inline int pfn_valid(unsigned long 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(PFN_PHYS(pfn)) != pfn)
+ return 0;
+
if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
return 0;
ms = __nr_to_section(pfn_to_section_nr(pfn));
--
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