x86/asm: Enable fast 32-bit put_user_64() for copy_to_user()

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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>

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Chris Wilson 2015-04-15 10:51:26 +01:00 • committed by Ingo Molnar

parent c0f6feba78

commit 6a907738ab

1 changed files with 4 additions and 0 deletions

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arch/x86/include/asm/uaccess_32.h

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