From patchwork Tue Jan 29 01:30:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kim Phillips X-Patchwork-Id: 2058721 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 1517FDF2EC for ; Tue, 29 Jan 2013 01:35:40 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U004e-0007xh-IA; Tue, 29 Jan 2013 01:33:20 +0000 Received: from co1ehsobe002.messaging.microsoft.com ([216.32.180.185] helo=co1outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U004b-0007wz-TN for linux-arm-kernel@lists.infradead.org; Tue, 29 Jan 2013 01:33:18 +0000 Received: from mail19-co1-R.bigfish.com (10.243.78.202) by CO1EHSOBE020.bigfish.com (10.243.66.83) with Microsoft SMTP Server id 14.1.225.23; Tue, 29 Jan 2013 01:33:15 +0000 Received: from mail19-co1 (localhost [127.0.0.1]) by mail19-co1-R.bigfish.com (Postfix) with ESMTP id B79517C0126; Tue, 29 Jan 2013 01:33:15 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzzz1ee6h1de0h1202h1e76h1d1ah1d2ahzz17326ah8275dh8275bhz2dh2a8h668h839h944hd24he5bhf0ah1220h1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1155h) Received: from mail19-co1 (localhost.localdomain [127.0.0.1]) by mail19-co1 (MessageSwitch) id 135942319412245_21622; Tue, 29 Jan 2013 01:33:14 +0000 (UTC) Received: from CO1EHSMHS029.bigfish.com (unknown [10.243.78.204]) by mail19-co1.bigfish.com (Postfix) with ESMTP id F25C3680048; Tue, 29 Jan 2013 01:33:13 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CO1EHSMHS029.bigfish.com (10.243.66.39) with Microsoft SMTP Server (TLS) id 14.1.225.23; Tue, 29 Jan 2013 01:33:13 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-004.039d.mgd.msft.net (10.84.1.14) with Microsoft SMTP Server (TLS) id 14.2.318.3; Tue, 29 Jan 2013 01:33:12 +0000 Received: from x9.am.freescale.net (x9.am.freescale.net [10.82.120.9]) by az84smr01.freescale.net (8.14.3/8.14.0) with SMTP id r0T1XAt7020192; Mon, 28 Jan 2013 18:33:11 -0700 Date: Mon, 28 Jan 2013 19:30:33 -0600 From: Kim Phillips To: Russell King , Andrew Morton Subject: [RFC] arm: use built-in byte swap function Message-ID: <20130128193033.8a0b0a871150c99247f05a95@freescale.com> Organization: Freescale Semiconductor, Inc. X-Mailer: Sylpheed 3.2.0 (GTK+ 2.24.13; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130128_203318_103161_1B3A80D1 X-CRM114-Status: GOOD ( 11.59 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [216.32.180.185 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: David Woodhouse , Rusty Russell , linux-kernel@vger.kernel.org, Daniel Santos , Borislav Petkov , David Rientjes , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Enable the compiler intrinsic for byte swapping on arch ARM. This allows the compiler to detect and be able to optimize out byte swappings, e.g. in big endian to big endian moves. AFAICT, arm gcc got __builtin_bswap{32,64} support in 4.6, and for the 16-bit version in 4.8. Signed-off-by: Kim Phillips --- akin to: http://comments.gmane.org/gmane.linux.kernel.cross-arch/16016 based on linux-next. Depends on commit "compiler-gcc{3,4}.h: Use GCC_VERSION macro" by Daniel Santos , currently in the akpm branch. RFC because of unfamiliarity with arch ARM, and that at91sam9rl, at91rm9200, and lpd270 (so far, at least) builds fail with: include/uapi/linux/swab.h:60: undefined reference to `__bswapsi2' I'm using eldk-5.2.1/armv7a's arm-linux-gnueabi-gcc (GCC) 4.6.4 20120303 (prerelease) arch/arm/Kconfig | 1 + include/linux/compiler-gcc4.h | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index eda8711..437d11a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -3,6 +3,7 @@ config ARM default y select ARCH_BINFMT_ELF_RANDOMIZE_PIE select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select ARCH_USE_BUILTIN_BSWAP select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT if MMU diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 68b162d..da5f728 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -67,7 +67,8 @@ #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP -#if GCC_VERSION >= 40400 +#if (!defined(__arm__) && GCC_VERSION >= 40400) || \ + (defined(__arm__) && GCC_VERSION >= 40600) #define __HAVE_BUILTIN_BSWAP32__ #define __HAVE_BUILTIN_BSWAP64__ #endif