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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2015-04-15 12:51:26 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-04-16 13:08:21 +0300 |
| commit | 6a907738ab9840ca3d71c22cd28fba4cbae7f7ce (patch) | |
| tree | 1398ad6eb538beffbdb0db9b2a648d7d7ae0905c /arch/x86 | |
| parent | c0f6feba784e1087b905ad097d2d9ac0aaf744a5 (diff) | |
| download | linux-6a907738ab9840ca3d71c22cd28fba4cbae7f7ce.tar.xz | |
x86/asm: Enable fast 32-bit put_user_64() for copy_to_user()
For fixed sized copies, copy_to_user() will utilize
__put_user_size() fastpaths. However, it is missing the
translation for 64-bit copies on x86/32.
Testing on a Pinetrail Atom, the 64 bit put_user() fastpath
is substantially faster than the generic copy_to_user()
fallback.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1429091486-11443-1-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 3c03a5de64d3..0ed5504c6060 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -59,6 +59,10 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); return ret; + case 8: + __put_user_size(*(u64 *)from, (u64 __user *)to, + 8, ret, 8); + return ret; } } return __copy_to_user_ll(to, from, n); |