From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755728AbaJaHyY (ORCPT ); Fri, 31 Oct 2014 03:54:24 -0400 Received: from cnbjrel01.sonyericsson.com ([219.141.167.165]:18270 "EHLO cnbjrel01.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751212AbaJaHyX convert rfc822-to-8bit (ORCPT ); Fri, 31 Oct 2014 03:54:23 -0400 From: "Wang, Yalin" To: "'Will Deacon'" , "'Ard Biesheuvel'" CC: "'Russell King - ARM Linux'" , "'linux-kernel@vger.kernel.org'" , "'akinobu.mita@gmail.com'" , "'linux-mm@kvack.org'" , "'Joe Perches'" , "'linux-arm-kernel@lists.infradead.org'" Date: Fri, 31 Oct 2014 15:54:16 +0800 Subject: RE: [RFC V6 2/3] add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction Thread-Topic: [RFC V6 2/3] add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction Thread-Index: Ac/0SYsLYyTdMNPAS1SmHcF7f8oZ+gAcg3/QAARlW3AABKQ3AA== Message-ID: <35FD53F367049845BC99AC72306C23D103E010D1827D@CNBJMBX05.corpusers.net> References: <1414392371.8884.2.camel@perches.com> <35FD53F367049845BC99AC72306C23D103E010D1825F@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18260@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18261@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18264@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18265@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18266@CNBJMBX05.corpusers.net> <20141030120127.GC32589@arm.com> <20141030135749.GE32589@arm.com> <35FD53F367049845BC99AC72306C23D103E010D18272@CNBJMBX05.corpusers.net> <35FD53F367049845BC99AC72306C23D103E010D18273@CNBJMBX05.corpusers.net> In-Reply-To: <35FD53F367049845BC99AC72306C23D103E010D18273@CNBJMBX05.corpusers.net> 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 > From: Wang, Yalin > Subject: [RFC V6 2/3] add CONFIG_HAVE_ARCH_BITREVERSE to support rbit > instruction > > This patch add bitrev.h file to support rbit instruction, so that we can do > bitrev operation by hardware. > Signed-off-by: Yalin Wang > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/bitrev.h | 21 +++++++++++++++++++++ > 2 files changed, 22 insertions(+) > create mode 100644 arch/arm/include/asm/bitrev.h > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 89c4b5c..be92b3b > 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -28,6 +28,7 @@ config ARM > select HANDLE_DOMAIN_IRQ > select HARDIRQS_SW_RESEND > select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) > + select HAVE_ARCH_BITREVERSE if (CPU_V7M || CPU_V7) > select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL > select HAVE_ARCH_KGDB > select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) diff --git > a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h new file > mode 100644 index 0000000..e9b2571 > --- /dev/null > +++ b/arch/arm/include/asm/bitrev.h > @@ -0,0 +1,21 @@ > +#ifndef __ASM_ARM_BITREV_H > +#define __ASM_ARM_BITREV_H > + > +static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x) { > + __asm__ ("rbit %0, %1" : "=r" (x) : "r" (x)); > + return x; > +} > + > +static __always_inline __attribute_const__ u16 __arch_bitrev16(u16 x) { > + return __arch_bitrev32((u32)x) >> 16; > +} > + > +static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) { > + return __arch_bitrev32((u32)x) >> 24; > +} > + > +#endif > + > -- > 2.1.1 Wrong title, please ignore this one , I have resend another [RFC V6 2/3] . Thanks