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| author | Dan Williams <dan.j.williams@intel.com> | 2018-05-03 17:06:11 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-05-15 08:32:41 +0200 |
| commit | da7bc9c57eb0e91e048d05f7dbe5014a8b81ccfa (patch) | |
| tree | a9f7f781dc1e2b803ffed73e16f8860ff1d086f9 /arch/x86/include/asm/string_64.h | |
| parent | 67b8d5c7081221efa252e111cd52532ec6d4266f (diff) | |
| download | linux-0-day-da7bc9c57eb0e91e048d05f7dbe5014a8b81ccfa.tar.gz linux-0-day-da7bc9c57eb0e91e048d05f7dbe5014a8b81ccfa.tar.xz | |
x86/asm/memcpy_mcsafe: Remove loop unrolling
In preparation for teaching memcpy_mcsafe() to return 'bytes remaining'
rather than pass / fail, simplify the implementation to remove loop
unrolling. The unrolling complicates the fault handling for negligible
benefit given modern CPUs perform loop stream detection.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: hch@lst.de
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/152539237092.31796.9115692316555638048.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/string_64.h')
| -rw-r--r-- | arch/x86/include/asm/string_64.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 533f74c300c25..4752f8984923c 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -116,7 +116,7 @@ int strcmp(const char *cs, const char *ct); #endif #define __HAVE_ARCH_MEMCPY_MCSAFE 1 -__must_check int memcpy_mcsafe_unrolled(void *dst, const void *src, size_t cnt); +__must_check int __memcpy_mcsafe(void *dst, const void *src, size_t cnt); DECLARE_STATIC_KEY_FALSE(mcsafe_key); /** @@ -138,7 +138,7 @@ memcpy_mcsafe(void *dst, const void *src, size_t cnt) { #ifdef CONFIG_X86_MCE if (static_branch_unlikely(&mcsafe_key)) - return memcpy_mcsafe_unrolled(dst, src, cnt); + return __memcpy_mcsafe(dst, src, cnt); else #endif memcpy(dst, src, cnt); |