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authorChris Wilson <chris@chris-wilson.co.uk>2015-04-15 12:51:26 +0300
committerIngo Molnar <mingo@kernel.org>2015-04-16 13:08:21 +0300
commit6a907738ab9840ca3d71c22cd28fba4cbae7f7ce (patch)
tree1398ad6eb538beffbdb0db9b2a648d7d7ae0905c /arch/x86/include/asm/uaccess_32.h
parentc0f6feba784e1087b905ad097d2d9ac0aaf744a5 (diff)
downloadlinux-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/include/asm/uaccess_32.h')
-rw-r--r--arch/x86/include/asm/uaccess_32.h4
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);