From 6a907738ab9840ca3d71c22cd28fba4cbae7f7ce Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 15 Apr 2015 10:51:26 +0100 Subject: [PATCH] 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 Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner 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 --- arch/x86/include/asm/uaccess_32.h | 4 ++++ 1 file changed, 4 insertions(+) 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); -- 2.39.2