From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753518AbbAICQm (ORCPT ); Thu, 8 Jan 2015 21:16:42 -0500 Received: from cnbjrel01.sonyericsson.com ([219.141.167.165]:5177 "EHLO cnbjrel01.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751890AbbAICQl convert rfc822-to-8bit (ORCPT ); Thu, 8 Jan 2015 21:16:41 -0500 From: "Wang, Yalin" To: "'Russell King - ARM Linux'" CC: "'Will Deacon'" , "'Ard Biesheuvel'" , "'linux-kernel@vger.kernel.org'" , "'akinobu.mita@gmail.com'" , "'linux-mm@kvack.org'" , "'Joe Perches'" , "'linux-arm-kernel@lists.infradead.org'" Date: Fri, 9 Jan 2015 10:16:32 +0800 Subject: RE: [RFC V6 2/3] arm:add bitrev.h file to support rbit instruction Thread-Topic: [RFC V6 2/3] arm:add bitrev.h file to support rbit instruction Thread-Index: AdArcq8uzjbeRP0XTp2yrVmbjjbdhgAPqq6A Message-ID: <35FD53F367049845BC99AC72306C23D103EDAF89E195@CNBJMBX05.corpusers.net> References: <20141030120127.GC32589@arm.com> <20141030135749.GE32589@arm.com> <35FD53F367049845BC99AC72306C23D103E010D18272@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18273@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18275@CNBJMBX05.corpusers.net> <20141113235322.GC4042@n2100.arm.linux.org.uk> <35FD53F367049845BC99AC72306C23D103E010D1829B@CNBJMBX05.corpusers.net> <20141114095812.GG4042@n2100.arm.linux.org.uk> <35FD53F367049845BC99AC72306C23D103E688B313C6@CNBJMBX05.corpusers.net> <20150108184059.GZ12302@n2100.arm.linux.org.uk> In-Reply-To: <20150108184059.GZ12302@n2100.arm.linux.org.uk> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Russell King - ARM Linux [mailto:linux@arm.linux.org.uk] > Sent: Friday, January 09, 2015 2:41 AM > To: Wang, Yalin > Cc: 'Will Deacon'; 'Ard Biesheuvel'; 'linux-kernel@vger.kernel.org'; > 'akinobu.mita@gmail.com'; 'linux-mm@kvack.org'; 'Joe Perches'; 'linux-arm- > kernel@lists.infradead.org' > Subject: Re: [RFC V6 2/3] arm:add bitrev.h file to support rbit instruction > > On Mon, Nov 17, 2014 at 10:38:58AM +0800, Wang, Yalin wrote: > > Joe has submitted patches to maintainers, So we need wait for them to > > be accepted . > > I ran these patches through my autobuilder, and while most builds didn't > seem to be a problem, the randconfigs found errors: > > /tmp/ccbiuDjS.s:137: Error: selected processor does not support ARM mode > `rbit r3,r2' > /tmp/ccbiuDjS.s:145: Error: selected processor does not support ARM mode > `rbit r0,r1' > make[4]: *** [drivers/iio/amplifiers/ad8366.o] Error 1 > > /tmp/ccFhnoO3.s:6789: Error: selected processor does not support ARM mode > `rbit r2,r2' > make[4]: *** [drivers/mtd/devices/docg3.o] Error 1 > > /tmp/cckMf2pp.s:239: Error: selected processor does not support ARM mode > `rbit ip,ip' > /tmp/cckMf2pp.s:241: Error: selected processor does not support ARM mode > `rbit r2,r2' > /tmp/cckMf2pp.s:248: Error: selected processor does not support ARM mode > `rbit lr,lr' > /tmp/cckMf2pp.s:250: Error: selected processor does not support ARM mode > `rbit r3,r3' > make[5]: *** [drivers/video/fbdev/nvidia/nvidia.o] Error 1 > > /tmp/ccTgULsO.s:1151: Error: selected processor does not support ARM mode > `rbit r1,r1' > /tmp/ccTgULsO.s:1158: Error: selected processor does not support ARM mode > `rbit r0,r0' > /tmp/ccTgULsO.s:1164: Error: selected processor does not support ARM mode > `rbit ip,ip' > /tmp/ccTgULsO.s:1166: Error: selected processor does not support ARM mode > `rbit r3,r3' > /tmp/ccTgULsO.s:1227: Error: selected processor does not support ARM mode > `rbit r5,r5' > /tmp/ccTgULsO.s:1229: Error: selected processor does not support ARM mode > `rbit lr,lr' > /tmp/ccTgULsO.s:1236: Error: selected processor does not support ARM mode > `rbit r0,r0' > /tmp/ccTgULsO.s:1238: Error: selected processor does not support ARM mode > `rbit r3,r3' > make[5]: *** [drivers/video/fbdev/nvidia/nv_accel.o] Error 1 > > The root cause is that the kernel being built is supposed to support both > ARMv7 and ARMv6K CPUs. However, "rbit" is only available on > ARMv6T2 (thumb2) and ARMv7, and not plain ARMv6 or ARMv6K CPUs. > In the patch that you applied: 8205/1 add bitrev.h file to support rbit instruction I have add : + select HAVE_ARCH_BITREVERSE if ((CPU_V7M || CPU_V7) && !CPU_V6) If you build kernel support ARMv6K, should CONFIG_CPU_V6=y, isn't it ? Then will not build hardware rbit instruction, isn't it ? Thanks