Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751191AbWBCKZc (ORCPT ); Fri, 3 Feb 2006 05:25:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751168AbWBCKZc (ORCPT ); Fri, 3 Feb 2006 05:25:32 -0500 Received: from witte.sonytel.be ([80.88.33.193]:12683 "EHLO witte.sonytel.be") by vger.kernel.org with ESMTP id S1751156AbWBCKZb (ORCPT ); Fri, 3 Feb 2006 05:25:31 -0500 Date: Fri, 3 Feb 2006 11:24:30 +0100 (CET) From: Geert Uytterhoeven To: Russell King cc: "Chen, Kenneth W" , "'Christoph Hellwig'" , "'Akinobu Mita'" , Grant Grundler , Linux Kernel Development , linux-ia64@vger.kernel.org Subject: Re: [PATCH 1/12] generic *_bit() In-Reply-To: <20060201191957.GG3072@flint.arm.linux.org.uk> Message-ID: References: <20060201180237.GA18464@infradead.org> <200602011807.k11I7ag15563@unix-os.sc.intel.com> <20060201191957.GG3072@flint.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1970 Lines: 45 On Wed, 1 Feb 2006, Russell King wrote: > On Wed, Feb 01, 2006 at 10:07:28AM -0800, Chen, Kenneth W wrote: > > Christoph Hellwig wrote on Wednesday, February 01, 2006 10:03 AM > > > > Akinobu Mita wrote on Wednesday, January 25, 2006 7:29 PM > > > > > This patch introduces the C-language equivalents of the functions below: > > > > > > > > > > - atomic operation: > > > > > void set_bit(int nr, volatile unsigned long *addr); > > > > > void clear_bit(int nr, volatile unsigned long *addr); > > > > > void change_bit(int nr, volatile unsigned long *addr); > > > > > int test_and_set_bit(int nr, volatile unsigned long *addr); > > > > > int test_and_clear_bit(int nr, volatile unsigned long *addr); > > > > > int test_and_change_bit(int nr, volatile unsigned long *addr); > > > > > > > > I wonder why you did not make these functions take volatile > > > > unsigned int * address argument? > > > > > > Because they are defined to operate on arrays of unsigned long > > > > I think these should be defined to operate on arrays of unsigned int. > > Bit is a bit, no matter how many byte you load (8/16/32/64), you can > > only operate on just one bit. > > Invalid assumption, from the point of view of endianness across different > architectures. Consider where bit 0 is for a LE and BE unsigned long * > vs a LE and BE unsigned char *. Intel doesn't care about big endian (cfr. your lkml back issues of January 2006). Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/