Commit-ID: 6a907738ab9840ca3d71c22cd28fba4cbae7f7ce Gitweb: http://git.kernel.org/tip/6a907738ab9840ca3d71c22cd28fba4cbae7f7ce Author: Chris Wilson <[email protected]> AuthorDate: Wed, 15 Apr 2015 10:51:26 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 16 Apr 2015 12:08:21 +0200
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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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 3c03a5d..0ed5504 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
