From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753840AbYHPHji (ORCPT ); Sat, 16 Aug 2008 03:39:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751708AbYHPHj3 (ORCPT ); Sat, 16 Aug 2008 03:39:29 -0400 Received: from tomts36-srv.bellnexxia.net ([209.226.175.93]:40745 "EHLO tomts36-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751592AbYHPHj2 (ORCPT ); Sat, 16 Aug 2008 03:39:28 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArcEANsapkhMRKxB/2dsb2JhbACBYrEggVg Date: Sat, 16 Aug 2008 03:39:26 -0400 From: Mathieu Desnoyers To: "H. Peter Anvin" Cc: Jeremy Fitzhardinge , Andrew Morton , Ingo Molnar , Linus Torvalds , Joe Perches , linux-kernel@vger.kernel.org Subject: [PATCH] x86_64 : support atomic ops with 64 bits integer values Message-ID: <20080816073926.GA19546@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 03:33:59 up 72 days, 12:14, 5 users, load average: 0.60, 0.43, 0.28 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org x86_64 add/sub atomic ops does not seems to accept integer values bigger than 32 bits as immediates. Intel's add/sub documentation specifies they have to be passed as registers. http://gcc.gnu.org/onlinedocs/gcc-4.3.0/gcc/Machine-Constraints.html#Machine-Constraints states : e 32-bit signed integer constant, or a symbolic reference known to fit that range (for immediate operands in sign-extending x86-64 instructions). Z 32-bit unsigned integer constant, or a symbolic reference known to fit that range (for immediate operands in zero-extending x86-64 instructions). Since add/sub does sign extension, using the "e" constraint seems appropriate. It applies to 2.6.27-rc, 2.6.26, 2.6.25... Signed-off-by: Mathieu Desnoyers CC: Jeremy Fitzhardinge CC: "H. Peter Anvin" CC: Andrew Morton CC: Ingo Molnar CC: Linus Torvalds CC: Joe Perches --- include/asm-x86/atomic_64.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: linux-2.6-lttng/include/asm-x86/atomic_64.h =================================================================== --- linux-2.6-lttng.orig/include/asm-x86/atomic_64.h 2008-08-16 03:19:35.000000000 -0400 +++ linux-2.6-lttng/include/asm-x86/atomic_64.h 2008-08-16 03:21:18.000000000 -0400 @@ -228,7 +228,7 @@ static inline void atomic64_add(long i, { asm volatile(LOCK_PREFIX "addq %1,%0" : "=m" (v->counter) - : "ir" (i), "m" (v->counter)); + : "er" (i), "m" (v->counter)); } /** @@ -242,7 +242,7 @@ static inline void atomic64_sub(long i, { asm volatile(LOCK_PREFIX "subq %1,%0" : "=m" (v->counter) - : "ir" (i), "m" (v->counter)); + : "er" (i), "m" (v->counter)); } /** @@ -260,7 +260,7 @@ static inline int atomic64_sub_and_test( asm volatile(LOCK_PREFIX "subq %2,%0; sete %1" : "=m" (v->counter), "=qm" (c) - : "ir" (i), "m" (v->counter) : "memory"); + : "er" (i), "m" (v->counter) : "memory"); return c; } @@ -341,7 +341,7 @@ static inline int atomic64_add_negative( asm volatile(LOCK_PREFIX "addq %2,%0; sets %1" : "=m" (v->counter), "=qm" (c) - : "ir" (i), "m" (v->counter) : "memory"); + : "er" (i), "m" (v->counter) : "memory"); return c; } -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68