From patchwork Thu Feb 13 10:14:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 1237394 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=LxfZfpNC; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48JC701y86z9s29 for ; Thu, 13 Feb 2020 21:14:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729666AbgBMKOv (ORCPT ); Thu, 13 Feb 2020 05:14:51 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:33102 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729494AbgBMKOv (ORCPT ); Thu, 13 Feb 2020 05:14:51 -0500 Received: by mail-wr1-f65.google.com with SMTP id u6so5948157wrt.0 for ; Thu, 13 Feb 2020 02:14:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=x5dk7qiKtWru6EN2nFzBqe4Wug6V5GV2jfq/LzU0wiw=; b=LxfZfpNC9g2Kao3Ca86IBRs1BVelmn8AvrmBdYYcvu/Ke2cjSOzIyL4tYo+CSK06ir w3b22BZqfdo7gA4OGIO7IPlmKXPutox8+BQRijvmJOLUFg76kRhQNt87DPJR4X9qAiMM +A7sCzIh/nwBLfWMREpCrSBlAqcRv1kBTi7+wkAkOLYjSyYzxvIfzyWCPOhfF2PIoZMr 68xchnfm0tHysAcpb+CfWLgd+nrsjJ/carvqlZNvfgjhupYg/vPbGHa8oLMduRWowQxN SEyTmYq+kC8yFTfIDpTSzTGunUntmDOwNm/FB/pRONEy4RDWQgjDrBAGU67PZ2o+JbRW 6vGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=x5dk7qiKtWru6EN2nFzBqe4Wug6V5GV2jfq/LzU0wiw=; b=BuZ4I9FkAHHk3aDNBgjWP5/7YvKwUDRnT4+Ve+51IJF4CKWA9LtYhsIa1e2X3kgcxz whSctkGfEGDfF5yycjfv8V4iEr5JK+k1ZVWAwdEHsyVjjh3huhHgbzku4N6ColfcR1Q+ v0/uzS7wXZNjCZFrJhomifVm/TEOgsbTzORR/vvXgr0LFeiVoR2f1CayqocVvyFUum9D c3ViOryfbMYE1DhFYyed9XGNoiOsHJqpTs+d3koHYaKwBYVE+lFnnGS1IQGsOybjQPt8 Vd53mNo1VnLaaeVWfi8otRmp2oLQjddfoRjBZPAm7T5LkAlgH9mGpMM2+Eau1rIrLcnR PXEA== X-Gm-Message-State: APjAAAUaMHaA71WHzdmn7xuRHWF7nZiUquyLuOCrbwSxbKcsmit1aj7i oohhsN9InBwrLB9sIiWOsljv2PgDfdg= X-Google-Smtp-Source: APXvYqw6o99I0CZZyiTcqdl7ceH4XsBTkQw3w/87dL8LUwOg4DxhwdracytpcV7NsxduI66j7hSHCQ== X-Received: by 2002:adf:f787:: with SMTP id q7mr20817905wrp.297.1581588887619; Thu, 13 Feb 2020 02:14:47 -0800 (PST) Received: from localhost.localdomain ([2001:171b:2276:930:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id y131sm2428059wmc.13.2020.02.13.02.14.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Feb 2020 02:14:47 -0800 (PST) From: Jean-Philippe Brucker To: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, will@kernel.org, bhelgaas@google.com Cc: joro@8bytes.org, robin.murphy@arm.com, jonathan.cameron@huawei.com, zhangfei.gao@linaro.org Subject: [PATCH 4/4] iommu/arm-smmu-v3: Write level-1 descriptors atomically Date: Thu, 13 Feb 2020 11:14:35 +0100 Message-Id: <20200213101435.229932-5-jean-philippe@linaro.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213101435.229932-1-jean-philippe@linaro.org> References: <20200213101435.229932-1-jean-philippe@linaro.org> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Use WRITE_ONCE() to make sure that the SMMU doesn't read incomplete stream table descriptors. Refer to the comment about 64-bit accesses, and add the comment to the equivalent context descriptor code. Signed-off-by: Jean-Philippe Brucker --- drivers/iommu/arm-smmu-v3.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 11123fbf22a5..034ad9671b83 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1539,6 +1539,7 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst, u64 val = (l1_desc->l2ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) | CTXDESC_L1_DESC_V; + /* See comment in arm_smmu_write_ctx_desc() */ WRITE_ONCE(*dst, cpu_to_le64(val)); } @@ -1734,7 +1735,8 @@ arm_smmu_write_strtab_l1_desc(__le64 *dst, struct arm_smmu_strtab_l1_desc *desc) val |= FIELD_PREP(STRTAB_L1_DESC_SPAN, desc->span); val |= desc->l2ptr_dma & STRTAB_L1_DESC_L2PTR_MASK; - *dst = cpu_to_le64(val); + /* See comment in arm_smmu_write_ctx_desc() */ + WRITE_ONCE(*dst, cpu_to_le64(val)); } static void arm_smmu_sync_ste_for_sid(struct arm_smmu_device *smmu, u32 sid)