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=-10.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 30888C3A59E for ; Wed, 21 Aug 2019 15:19:47 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 0D523216F4 for ; Wed, 21 Aug 2019 15:19:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D523216F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 2830AEC6; Wed, 21 Aug 2019 15:19:28 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 2C37FEC4 for ; Wed, 21 Aug 2019 15:19:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id E10ABE6 for ; Wed, 21 Aug 2019 15:19:24 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9226C337; Wed, 21 Aug 2019 08:19:24 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A1D573F718; Wed, 21 Aug 2019 08:19:23 -0700 (PDT) From: Will Deacon To: iommu@lists.linux-foundation.org Subject: [PATCH v2 4/8] iommu/arm-smmu-v3: Don't issue CMD_SYNC for zero-length invalidations Date: Wed, 21 Aug 2019 16:17:45 +0100 Message-Id: <20190821151749.23743-5-will@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190821151749.23743-1-will@kernel.org> References: <20190821151749.23743-1-will@kernel.org> Cc: Jean-Philippe Brucker , Will Deacon , Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Calling arm_smmu_tlb_inv_range() with a size of zero, perhaps due to an empty 'iommu_iotlb_gather' structure, should be a NOP. Elide the CMD_SYNC when there is no invalidation to be performed. Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 2be11a11bb8b..b7b3b0ff8ed6 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1977,6 +1977,9 @@ static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, }, }; + if (!size) + return; + if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) { cmd.opcode = CMDQ_OP_TLBI_NH_VA; cmd.tlbi.asid = smmu_domain->s1_cfg.cd.asid; -- 2.11.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu