Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752531AbaJ2DGT (ORCPT ); Tue, 28 Oct 2014 23:06:19 -0400 Received: from smtprelay0164.hostedemail.com ([216.40.44.164]:59975 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750707AbaJ2DGS (ORCPT ); Tue, 28 Oct 2014 23:06:18 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::::::::::::,RULES_HIT:41:355:379:541:599:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1540:1593:1594:1711:1730:1747:1777:1792:2194:2199:2393:2559:2562:2828:2901:3138:3139:3140:3141:3142:3352:3622:3865:3866:3867:3871:3872:3873:3874:4321:5007:6261:6691:7808:10004:10400:10848:11026:11232:11473:11658:11914:12438:12517:12519:12740:13019:13069:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: room48_8e06b969d8738 X-Filterd-Recvd-Size: 2268 Message-ID: <1414551974.10912.16.camel@perches.com> Subject: Re: [PATCH] 6fire: Convert byte_rev_table uses to bitrev8 From: Joe Perches To: "Wang, Yalin" Cc: Jaroslav Kysela , Takashi Iwai , Russell King , "linux-mm@kvack.org" , Will Deacon , Akinobu Mita , "linux-arm-kernel@lists.infradead.org" , alsa-devel , LKML Date: Tue, 28 Oct 2014 20:06:14 -0700 In-Reply-To: <35FD53F367049845BC99AC72306C23D103E010D1825C@CNBJMBX05.corpusers.net> References: <35FD53F367049845BC99AC72306C23D103E010D18254@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18257@CNBJMBX05.corpusers.net> <1414392371.8884.2.camel@perches.com> <1414531369.10912.14.camel@perches.com> <35FD53F367049845BC99AC72306C23D103E010D1825C@CNBJMBX05.corpusers.net> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.7-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-10-29 at 10:42 +0800, Wang, Yalin wrote: > > Use the inline function instead of directly indexing the array. > > This allows some architectures with hardware instructions for bit reversals > > to eliminate the array. [] > > On Sun, 2014-10-26 at 23:46 -0700, Joe Perches wrote: > > > On Mon, 2014-10-27 at 14:37 +0800, Wang, Yalin wrote: > > > > this change add CONFIG_HAVE_ARCH_BITREVERSE config option, so that > > > > we can use arm/arm64 rbit instruction to do bitrev operation by > > > > hardware. [] > I think the most safe way is change byte_rev_table[] to be satic, > So that no driver can access it directly, > The build error can remind the developer if they use byte_rev_table[] > Directly . You can do that with your later patch, but the existing uses _must_ be converted first so you don't break the build. -- 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/