From patchwork Fri Apr 7 19:06:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 9670267 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7AF4160364 for ; Fri, 7 Apr 2017 19:06:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 68202285B6 for ; Fri, 7 Apr 2017 19:06:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5BEA72860E; Fri, 7 Apr 2017 19:06:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0806F285B6 for ; Fri, 7 Apr 2017 19:06:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=dAnGIDrJmaqiR8tjj4jXwnrW3AxLHIc7mykIzsJsyto=; b=Zuy dYCSK2rBA1yayOpbKO1R7HPINrAE3nPFy3zffdBudaUFZmat55u182gBYDlv506FJ53HAGpr/D66/ ZbbASpfTYW+DlO+LoNFsCShO1hYbNBguxivs5gPFPezIuGiMd2YQflh+bqSQGQgbfuy2fpNOE6dqX Tp7o1Fefo+ZrThBZ2cZR7vYaLHLWJqGv7ci3W5mQz+56WHGjPVKifw6dt2yHzbgZ1guLlmcsjtRXW EhUMkVXk/smZcVihceFWTr4WSrpLftVCVCBZPIY/F5juQbGafpXhLjG8YkjgLPD/ltDrbY/0TkyID anCMRr4kzcSLqWa+C9fJPU6F6iJGmdg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cwZDg-0003pO-3f; Fri, 07 Apr 2017 19:06:52 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cwZDc-0003nR-Ex for linux-arm-kernel@lists.infradead.org; Fri, 07 Apr 2017 19:06:49 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 782AD60A0A; Fri, 7 Apr 2017 19:06:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1491591987; bh=zMcWWlKDXf+JB6NL/IAhZv1TR8WXRE4wsOcW3roN51k=; h=From:To:Cc:Subject:Date:From; b=gnNvyjazCaAiP2NzT1fpOQBD0w6/mTrbWsQs6I3+FjytoXKxO1Q0NEOVzmBhHd5Z6 u9tfMBYXXx4TdpBtbAUWP1MRLzBuhy0tiYqI9X4zx/+gN/el+3MWl5HSJFqMZxCSuH Mas4V8QiGf7rAg1whyDQJ1LO+2znSVPF2WvhRIOU= Received: from drakthul.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 9C7A760A0A; Fri, 7 Apr 2017 19:06:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1491591986; bh=zMcWWlKDXf+JB6NL/IAhZv1TR8WXRE4wsOcW3roN51k=; h=From:To:Cc:Subject:Date:From; b=cJTRuOqoWNlsoLVX1qUpeTq79Is37Aa8t/DcuM4tlUDevFKh3uI1zwyqxuTMN6YWu hMtuBqAdp3CzdcUmFdhrCPWDhQiWExe4zB7x66Rpf125peHcxFQsz1Bqm7s30473cT 9A/1817mW4Hew1O0XecNTijUsu6SnO1yorxzb5PI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 9C7A760A0A 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: linux-scsi@vger.kernel.org, timur@codeaurora.org Subject: [PATCH V2] scsi: mpt3sas: remove redundant wmb Date: Fri, 7 Apr 2017 15:06:18 -0400 Message-Id: <1491591978-17880-1-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.9.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170407_120648_535966_7B1A2252 X-CRM114-Status: UNSURE ( 9.57 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "James E.J. Bottomley" , "Martin K. Petersen" , Chaitra P B , linux-arm-msm@vger.kernel.org, Sathya Prakash , open list , Sinan Kaya , Suganath Prabu Subramani , "open list:LSILOGIC MPT FUSION DRIVERS FC/SAS/SPI" , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Due to relaxed ordering requirements on multiple architectures, drivers are required to use wmb/rmb/mb combinations when they need to guarantee observability between the memory and the HW. The mpt3sas driver is already using wmb() for this purpose. However, it issues a writel following wmb(). writel() function on arm/arm64 arhictectures have an embedded wmb() call inside. This results in unnecessary performance loss and code duplication. writel already guarantees ordering for both cpu and bus. we don't need additional wmb() Signed-off-by: Sinan Kaya Reviewed-by: Brian King --- drivers/scsi/mpt3sas/mpt3sas_base.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 5b7aec5..18039bb 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1025,7 +1025,6 @@ static int mpt3sas_remove_dead_ioc_func(void *arg) 0 : ioc->reply_free_host_index + 1; ioc->reply_free[ioc->reply_free_host_index] = cpu_to_le32(reply); - wmb(); writel(ioc->reply_free_host_index, &ioc->chip->ReplyFreeHostIndex); } @@ -1074,7 +1073,6 @@ static int mpt3sas_remove_dead_ioc_func(void *arg) return IRQ_NONE; } - wmb(); if (ioc->is_warpdrive) { writel(reply_q->reply_post_host_index, ioc->reply_post_host_index[msix_index]);