From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 13695C432BE for ; Wed, 18 Aug 2021 08:05:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E182F60F39 for ; Wed, 18 Aug 2021 08:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239849AbhHRIGb (ORCPT ); Wed, 18 Aug 2021 04:06:31 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:8875 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239589AbhHRIGZ (ORCPT ); Wed, 18 Aug 2021 04:06:25 -0400 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 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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++; } -- 2.26.0.106.g9fadedd