From patchwork Fri Nov 4 18:17:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 80911 Delivered-To: patch@linaro.org Received: by 10.140.97.165 with SMTP id m34csp111627qge; Fri, 4 Nov 2016 11:19:24 -0700 (PDT) X-Received: by 10.98.208.131 with SMTP id p125mr2183851pfg.168.1478283564184; Fri, 04 Nov 2016 11:19:24 -0700 (PDT) Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id nw5si14967836pab.314.2016.11.04.11.19.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 04 Nov 2016 11:19:24 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c2j3i-0000SQ-WD; Fri, 04 Nov 2016 18:17:47 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c2j3e-0000Rd-K6 for linux-arm-kernel@lists.infradead.org; Fri, 04 Nov 2016 18:17:43 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8786528; Fri, 4 Nov 2016 11:17:21 -0700 (PDT) Received: from localhost.localdomain (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E7E223F220; Fri, 4 Nov 2016 11:17:20 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] arm64: percpu: kill off final ACCESS_ONCE() uses Date: Fri, 4 Nov 2016 18:17:06 +0000 Message-Id: <1478283426-6649-1-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 2.7.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161104_111742_677490_1D2A3279 X-CRM114-Status: UNSURE ( 8.64 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -8.3 (--------) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-8.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , Will Deacon , Dmitry Vyukov MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org For several reasons it is preferable to use {READ,WRITE}_ONCE() rather than ACCESS_ONCE(). For example, these handle aggregate types, result in shorter source code, and better document the intended access (which may be useful for instrumentation features such as the upcoming KTSAN). Over a number of patches, most uses of ACCESS_ONCE() in arch/arm64 have been migrated to {READ,WRITE}_ONCE(). For consistency, and the above reasons, this patch migrates the final remaining uses. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Will Deacon --- arch/arm64/include/asm/percpu.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel Acked-by: Dmitry Vyukov diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h index 5394c84..4afb6fc 100644 --- a/arch/arm64/include/asm/percpu.h +++ b/arch/arm64/include/asm/percpu.h @@ -101,16 +101,16 @@ static inline unsigned long __percpu_read(void *ptr, int size) switch (size) { case 1: - ret = ACCESS_ONCE(*(u8 *)ptr); + ret = READ_ONCE(*(u8 *)ptr); break; case 2: - ret = ACCESS_ONCE(*(u16 *)ptr); + ret = READ_ONCE(*(u16 *)ptr); break; case 4: - ret = ACCESS_ONCE(*(u32 *)ptr); + ret = READ_ONCE(*(u32 *)ptr); break; case 8: - ret = ACCESS_ONCE(*(u64 *)ptr); + ret = READ_ONCE(*(u64 *)ptr); break; default: BUILD_BUG(); @@ -123,16 +123,16 @@ static inline void __percpu_write(void *ptr, unsigned long val, int size) { switch (size) { case 1: - ACCESS_ONCE(*(u8 *)ptr) = (u8)val; + WRITE_ONCE(*(u8 *)ptr, (u8)val); break; case 2: - ACCESS_ONCE(*(u16 *)ptr) = (u16)val; + WRITE_ONCE(*(u16 *)ptr, (u16)val); break; case 4: - ACCESS_ONCE(*(u32 *)ptr) = (u32)val; + WRITE_ONCE(*(u32 *)ptr, (u32)val); break; case 8: - ACCESS_ONCE(*(u64 *)ptr) = (u64)val; + WRITE_ONCE(*(u64 *)ptr, (u64)val); break; default: BUILD_BUG();