From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751874AbeDENKF (ORCPT ); Thu, 5 Apr 2018 09:10:05 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38356 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751418AbeDENJW (ORCPT ); Thu, 5 Apr 2018 09:09:22 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org BEE746076C Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: arnd@arndb.de, timur@codeaurora.org, sulrich@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 3/5] io: define stronger ordering for the default writeX() implementation Date: Thu, 5 Apr 2018 09:09:11 -0400 Message-Id: <1522933753-19589-3-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1522933753-19589-1-git-send-email-okaya@codeaurora.org> References: <1522933753-19589-1-git-send-email-okaya@codeaurora.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The default implementation of mapping writeX() to __raw_writeX() is wrong. writeX() has stronger ordering semantics. Compiler is allowed to reorder memory writes against __raw_writeX(). Use the previously defined __io_aw() and __io_bw() macros to harden code generation according to architecture support. Signed-off-by: Sinan Kaya --- include/asm-generic/io.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index d27e8af..964725e 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -208,7 +208,9 @@ static inline u64 readq(const volatile void __iomem *addr) #define writeb writeb static inline void writeb(u8 value, volatile void __iomem *addr) { + __io_bw(); __raw_writeb(value, addr); + __io_aw(); } #endif @@ -216,7 +218,9 @@ static inline void writeb(u8 value, volatile void __iomem *addr) #define writew writew static inline void writew(u16 value, volatile void __iomem *addr) { + __io_bw(); __raw_writew(cpu_to_le16(value), addr); + __io_aw(); } #endif @@ -224,7 +228,9 @@ static inline void writew(u16 value, volatile void __iomem *addr) #define writel writel static inline void writel(u32 value, volatile void __iomem *addr) { + __io_bw(); __raw_writel(__cpu_to_le32(value), addr); + __io_aw(); } #endif @@ -233,7 +239,9 @@ static inline void writel(u32 value, volatile void __iomem *addr) #define writeq writeq static inline void writeq(u64 value, volatile void __iomem *addr) { + __io_bw(); __raw_writeq(__cpu_to_le64(value), addr); + __io_aw(); } #endif #endif /* CONFIG_64BIT */ -- 2.7.4