From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761230AbYG3XhW (ORCPT ); Wed, 30 Jul 2008 19:37:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761138AbYG3Xg6 (ORCPT ); Wed, 30 Jul 2008 19:36:58 -0400 Received: from mail.suse.de ([195.135.220.2]:35755 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761123AbYG3Xg4 (ORCPT ); Wed, 30 Jul 2008 19:36:56 -0400 Date: Wed, 30 Jul 2008 16:27:10 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, jejb@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Nickolay Vinogradov , Russell King Subject: [patch 13/29] ARM: fix fls() for 64-bit arguments Message-ID: <20080730232710.GN30670@suse.de> References: <20080730231003.655833364@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="arm-fix-fls-for-64-bit-arguments.patch" In-Reply-To: <20080730232451.GA30670@suse.de> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Andrew Morton commit 0c65f459ce6c8bd873a61b3ae1e57858ab1debf3 upstream arm's fls() is implemented as a macro, causing it to misbehave when passed 64-bit arguments. Fix. Cc: Nickolay Vinogradov Tested-by: Krzysztof Halasa Signed-off-by: Andrew Morton Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- include/asm-arm/bitops.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/include/asm-arm/bitops.h +++ b/include/asm-arm/bitops.h @@ -277,9 +277,16 @@ static inline int constant_fls(int x) * the clz instruction for much better code efficiency. */ -#define fls(x) \ +#define __fls(x) \ ( __builtin_constant_p(x) ? constant_fls(x) : \ ({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) ) + +/* Implement fls() in C so that 64-bit args are suitably truncated */ +static inline int fls(int x) +{ + return __fls(x); +} + #define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) #define __ffs(x) (ffs(x) - 1) #define ffz(x) __ffs( ~(x) ) --