From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id E27DA280022 for ; Fri, 31 Oct 2014 01:41:02 -0400 (EDT) Received: by mail-pd0-f169.google.com with SMTP id y10so6599023pdj.14 for ; Thu, 30 Oct 2014 22:41:02 -0700 (PDT) Received: from cnbjrel01.sonyericsson.com (cnbjrel01.sonyericsson.com. [219.141.167.165]) by mx.google.com with ESMTPS id hp10si8401910pad.114.2014.10.30.22.41.00 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 30 Oct 2014 22:41:02 -0700 (PDT) From: "Wang, Yalin" Date: Fri, 31 Oct 2014 13:40:55 +0800 Subject: [RFC V6 2/3] add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction Message-ID: <35FD53F367049845BC99AC72306C23D103E010D18273@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> In-Reply-To: <35FD53F367049845BC99AC72306C23D103E010D18272@CNBJMBX05.corpusers.net> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "Wang, Yalin" , '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'" 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" : "=3Dr" (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 + --=20 2.1.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org