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authorAnshuman Khandual <anshuman.khandual@arm.com>2020-06-04 01:00:56 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-04 05:09:46 +0200
commitbe51e3fde5c10f269c065fdca2caf28e4708e21e (patch)
tree6c7eb90cbbdd6502462a69a45cc7af604a755c56
parentmm/hugetlb: avoid unnecessary check on pud and pmd entry in huge_pte_offset (diff)
downloadlinux-be51e3fde5c10f269c065fdca2caf28e4708e21e.tar.xz
linux-be51e3fde5c10f269c065fdca2caf28e4708e21e.zip
arm64/mm: drop __HAVE_ARCH_HUGE_PTEP_GET
Patch series "mm/hugetlb: Add some new generic fallbacks", v3. This series adds the following new generic fallbacks. Before that it drops __HAVE_ARCH_HUGE_PTEP_GET from arm64 platform. 1. is_hugepage_only_range() 2. arch_clear_hugepage_flags() After this arm (32 bit) remains the sole platform defining it's own huge_ptep_get() via __HAVE_ARCH_HUGE_PTEP_GET. This patch (of 3): Platform specific huge_ptep_get() is required only when fetching the huge PTE involves more than just dereferencing the page table pointer. This is not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along with it's __HAVE_ARCH_HUGE_PTEP_GET subscription. Before that, it updates the generic huge_ptep_get() with READ_ONCE() which will prevent known page table issues with THP on arm64. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1588907271-11920-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r//1506527369-19535-1-git-send-email-will.deacon@arm.com/ Link: http://lkml.kernel.org/r/1588907271-11920-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm64/include/asm/hugetlb.h6
-rw-r--r--include/asm-generic/hugetlb.h2
2 files changed, 1 insertions, 7 deletions
diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 2eb6c234d594..b88878ddc88b 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -17,12 +17,6 @@
extern bool arch_hugetlb_migration_supported(struct hstate *h);
#endif
-#define __HAVE_ARCH_HUGE_PTEP_GET
-static inline pte_t huge_ptep_get(pte_t *ptep)
-{
- return READ_ONCE(*ptep);
-}
-
static inline int is_hugepage_only_range(struct mm_struct *mm,
unsigned long addr, unsigned long len)
{
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 822f433ac95c..40f85decc2ee 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -122,7 +122,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
#ifndef __HAVE_ARCH_HUGE_PTEP_GET
static inline pte_t huge_ptep_get(pte_t *ptep)
{
- return *ptep;
+ return READ_ONCE(*ptep);
}
#endif