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=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 43115C4338F for ; Wed, 11 Aug 2021 15:55:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F37A60FDA for ; Wed, 11 Aug 2021 15:55:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233330AbhHKP4G (ORCPT ); Wed, 11 Aug 2021 11:56:06 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3628 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233678AbhHKPym (ORCPT ); Wed, 11 Aug 2021 11:54:42 -0400 Received: from fraeml705-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GlDrP41YTz6G9PZ; Wed, 11 Aug 2021 23:53:41 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml705-chm.china.huawei.com (10.206.15.54) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Wed, 11 Aug 2021 17:54:16 +0200 Received: from localhost.localdomain (10.69.192.58) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 11 Aug 2021 16:54:14 +0100 From: John Garry To: , CC: , , , , , , "John Garry" Subject: [PATCH] iommu/arm-smmu-v3: Stop pre-zeroing batch commands Date: Wed, 11 Aug 2021 23:49:26 +0800 Message-ID: <1628696966-88386-1-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.58] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pre-zeroing the batched commands structure is inefficient, as individual commands are zeroed later in arm_smmu_cmdq_build_cmd(). The size is quite large and commonly most commands won't even be used: struct arm_smmu_cmdq_batch cmds = {}; 345c: 52800001 mov w1, #0x0 // #0 3460: d2808102 mov x2, #0x408 // #1032 3464: 910143a0 add x0, x29, #0x50 3468: 94000000 bl 0 Stop pre-zeroing the complete structure and only zero the num member. Signed-off-by: John Garry 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 cbc57edfa4e2..2a4f3fb938f6 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1082,7 +1082,7 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain, size_t i; unsigned long flags; struct arm_smmu_master *master; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; struct arm_smmu_device *smmu = smmu_domain->smmu; struct arm_smmu_cmdq_ent cmd = { .opcode = CMDQ_OP_CFGI_CD, @@ -1092,6 +1092,8 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain, }, }; + cmds.num = 0; + spin_lock_irqsave(&smmu_domain->devices_lock, flags); list_for_each_entry(master, &smmu_domain->devices, domain_head) { for (i = 0; i < master->num_streams; i++) { @@ -1908,7 +1910,7 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid, unsigned long flags; struct arm_smmu_cmdq_ent cmd; struct arm_smmu_master *master; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS)) return 0; @@ -1932,6 +1934,8 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid, arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd); + cmds.num = 0; + spin_lock_irqsave(&smmu_domain->devices_lock, flags); list_for_each_entry(master, &smmu_domain->devices, domain_head) { if (!master->ats_enabled) @@ -1980,7 +1984,7 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, struct arm_smmu_device *smmu = smmu_domain->smmu; unsigned long end = iova + size, num_pages = 0, tg = 0; size_t inv_range = granule; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; if (!size) return; @@ -1998,6 +2002,8 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, num_pages = size >> tg; } + cmds.num = 0; + while (iova < end) { if (smmu->features & ARM_SMMU_FEAT_RANGE_INV) { /* -- 2.26.2