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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 A593DC432BE for ; Tue, 17 Aug 2021 01:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8838D60EAF for ; Tue, 17 Aug 2021 01:39:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236434AbhHQBkD (ORCPT ); Mon, 16 Aug 2021 21:40:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236111AbhHQBj6 (ORCPT ); Mon, 16 Aug 2021 21:39:58 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F92EC0613C1 for ; Mon, 16 Aug 2021 18:39:26 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id m24-20020a17090a7f98b0290178b1a81700so3437430pjl.4 for ; Mon, 16 Aug 2021 18:39:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rTpdRIu7FpzvBFJwAANhpBrL0QFcTu4ptjq1LAtftzQ=; b=ezZ42GIRfs9eXpeKCSPeUfZMHb1oY8KWX1Zmv/qEJMLBhMLRgHr4ZHj2Iyx5HQ3MmP Z3PYeWqP7NNkbRmfxJEvAHQaFiGbsIfNDRy7t/gkJPLdNtYfYZu8fZwd6DiaBo5hQSE2 I2c4PNhFo9A9maeFjR1CnjRPPIzbjxogbUd/U= 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=rTpdRIu7FpzvBFJwAANhpBrL0QFcTu4ptjq1LAtftzQ=; b=X6eXF4NH3wcCy6Axxbapg+oTwdGBOsJPKRXRGPvn9mGjkssXV15mDiuleyLA95livi auhfmLJ+NqVpCl4edjUcnREkytbd2FLX150oSulWH6ASb6rFd3UqAvaHQbOmjwzFmyRb hbqd7iTT8a1znqLTzbBiHbp9C3kTP18Ypt9NI+0yir+LTtOCxhePG/zW2nFRvUcIzzLG CybAPMLnDlgEaxvFoKC9IAhLS+Q0xkxz3P1gLGkfibWk7BTBynrweUDAbhmqNcv3VuHf vU44dmunGe7NeGWA8eE6R2IZe+k6xyR60US0kv08B4OMfFjwsA9wjHT+kZ84kaEXsWlY qi6Q== X-Gm-Message-State: AOAM532R3PPtX0c6zAhyHY1WClkoSDE5MjyitDlOUNvCL4MmpZCpD06J rssGBHaE4+UwXdnPZjjTQueNUg== X-Google-Smtp-Source: ABdhPJzHt0Q3iODtQezPrYHRIiO+4+NDCtHq9DghJp3azP1e9Y6fx29b/XrikZInLJlJdBmZNNDH2A== X-Received: by 2002:a17:90a:d181:: with SMTP id fu1mr838875pjb.137.1629164365817; Mon, 16 Aug 2021 18:39:25 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:6864:767c:2ff8:749d]) by smtp.gmail.com with UTF8SMTPSA id n185sm409593pfn.171.2021.08.16.18.39.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 16 Aug 2021 18:39:25 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Robin Murphy , Christoph Hellwig Cc: Joerg Roedel , Will Deacon , Lu Baolu , Tom Murphy , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, David Stevens Subject: [PATCH v6 3/7] dma-iommu: skip extra sync during unmap w/swiotlb Date: Tue, 17 Aug 2021 10:38:48 +0900 Message-Id: <20210817013852.3222824-4-stevensd@google.com> X-Mailer: git-send-email 2.33.0.rc1.237.g0d66db33f3-goog In-Reply-To: <20210817013852.3222824-1-stevensd@google.com> References: <20210817013852.3222824-1-stevensd@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Stevens Calling the iommu_dma_sync_*_for_cpu functions during unmap can cause two copies out of the swiotlb buffer. Do the arch sync directly in __iommu_dma_unmap_swiotlb instead to avoid this. This makes the call to iommu_dma_sync_sg_for_cpu for untrusted devices in iommu_dma_unmap_sg no longer necessary, so move that invocation later in the function. Signed-off-by: David Stevens Reviewed-by: Christoph Hellwig --- drivers/iommu/dma-iommu.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 8098ce593640..5dd2c517dbf5 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -504,6 +504,9 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr, if (WARN_ON(!phys)) return; + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && !dev_is_dma_coherent(dev)) + arch_sync_dma_for_cpu(phys, size, dir); + __iommu_dma_unmap(dev, dma_addr, size); if (unlikely(is_swiotlb_buffer(phys))) @@ -853,8 +856,6 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir, unsigned long attrs) { - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_single_for_cpu(dev, dma_handle, size, dir); __iommu_dma_unmap_swiotlb(dev, dma_handle, size, dir, attrs); } @@ -1062,14 +1063,14 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, struct scatterlist *tmp; int i; - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir); - if (dev_is_untrusted(dev)) { iommu_dma_unmap_sg_swiotlb(dev, sg, nents, dir, attrs); return; } + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir); + /* * The scatterlist segments are mapped into a single * contiguous IOVA allocation, so this is incredibly easy. -- 2.33.0.rc1.237.g0d66db33f3-goog