From patchwork Wed Aug 18 08:04:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12443571 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E73CDC432BE for ; Wed, 18 Aug 2021 08:08:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B41206108B for ; Wed, 18 Aug 2021 08:08:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B41206108B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gYB1zFdb2bFvaJtPFeroQon7oTwtvXRabf9/RK8BHMs=; b=x7lPP4At6fkTsP B6SNrZDPxKakq5fLrDsTYs1NQr1QSK8Ua4WHdBndEhibr4lTcEqhcsJih/MwZY8seOrwmXHLzX9kx pm/jmkx3HDfy/I32RCqXGsiLwwVmtos4kmL9gTjGaDte8s+JxnlmR128L7HwOrA8x/MPvDv4vj9Ye GzjMhYjWM0zs6fTTxkYaEovCBV0h9tYGuwYlE2A6MWXPTEiPMhVcFDrZTXJ23pIxHnGLjUJ/H4H3/ ODaDLMGmGANC735VtBKW/iGJYY5qTuz6C/2I8q89O4ws5MEZyIjAw2KJEbmmnUhiANUu0gAUzoW1r yRIL7+xrFBk9w7NPqCMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mGGaL-004ZWn-5G; Wed, 18 Aug 2021 08:06:05 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mGGa7-004ZSY-HT for linux-arm-kernel@lists.infradead.org; Wed, 18 Aug 2021 08:05:53 +0000 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GqL2d4sM0z8sZm; Wed, 18 Aug 2021 16:01:45 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 18 Aug 2021 16:05:48 +0800 Received: from thunder-town.china.huawei.com (10.174.178.242) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 18 Aug 2021 16:05:48 +0800 From: Zhen Lei To: Will Deacon , Robin Murphy , "Joerg Roedel" , linux-arm-kernel , iommu , CC: Zhen Lei , John Garry Subject: [PATCH v2 1/2] iommu/arm-smmu-v3: Properly handle the return value of arm_smmu_cmdq_build_cmd() Date: Wed, 18 Aug 2021 16:04:51 +0800 Message-ID: <20210818080452.2079-2-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20210818080452.2079-1-thunder.leizhen@huawei.com> References: <20210818080452.2079-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.242] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210818_010551_829718_ABC2A306 X-CRM114-Status: GOOD ( 12.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 1. Build command CMD_SYNC cannot fail. So the return value can be ignored. 2. The arm_smmu_cmdq_build_cmd() almost never fails, the addition of "unlikely()" can optimize the instruction pipeline. 3. Check the return value in arm_smmu_cmdq_batch_add(). Signed-off-by: Zhen Lei --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 3646bf8f021cd4c..01e95b56ffa07d1 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -409,10 +409,7 @@ static void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu, dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]); /* Convert the erroneous command into a CMD_SYNC */ - if (arm_smmu_cmdq_build_cmd(cmd, &cmd_sync)) { - dev_err(smmu->dev, "failed to convert to CMD_SYNC\n"); - return; - } + arm_smmu_cmdq_build_cmd(cmd, &cmd_sync); queue_write(Q_ENT(q, cons), cmd, q->ent_dwords); } @@ -860,7 +857,7 @@ static int __arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, { u64 cmd[CMDQ_ENT_DWORDS]; - if (arm_smmu_cmdq_build_cmd(cmd, ent)) { + if (unlikely(arm_smmu_cmdq_build_cmd(cmd, ent))) { dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", ent->opcode); return -EINVAL; @@ -885,11 +882,20 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu, struct arm_smmu_cmdq_batch *cmds, struct arm_smmu_cmdq_ent *cmd) { + int index; + if (cmds->num == CMDQ_BATCH_ENTRIES) { arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, false); cmds->num = 0; } - arm_smmu_cmdq_build_cmd(&cmds->cmds[cmds->num * CMDQ_ENT_DWORDS], cmd); + + index = cmds->num * CMDQ_ENT_DWORDS; + if (unlikely(arm_smmu_cmdq_build_cmd(&cmds->cmds[index], cmd))) { + dev_warn(smmu->dev, "ignoring unknown CMDQ opcode 0x%x\n", + cmd->opcode); + return; + } + cmds->num++; }