Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a2d236b3 authored by Jan Beulich's avatar Jan Beulich Committed by Linus Torvalds
Browse files

[PATCH] x86-64: Lose constraints on cmpxchg 



While only cosmetic for x86-64, this adjusts the cmpxchg code appearantly
inherited from i386 to use more generic constraints.

Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 1a426cb7

include/asm-x86_64/system.h

+3 −3
Original line number Diff line number Diff line
@@ -253,19 +253,19 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, 
	case 2:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "r"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	case 4:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "r"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	case 8:

		__asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"

				     : "=a"(prev)

				     : "q"(new), "m"(*__xg(ptr)), "0"(old)

				     : "r"(new), "m"(*__xg(ptr)), "0"(old)

				     : "memory");

		return prev;

	}