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=-19.1 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, 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 AB883C433B4 for ; Tue, 18 May 2021 06:44:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D5F960240 for ; Tue, 18 May 2021 06:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346833AbhERGpx (ORCPT ); Tue, 18 May 2021 02:45:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346847AbhERGpn (ORCPT ); Tue, 18 May 2021 02:45:43 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E102C061763 for ; Mon, 17 May 2021 23:44:25 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id h20-20020a17090aa894b029015db8f3969eso370256pjq.3 for ; Mon, 17 May 2021 23:44:25 -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=5ME8xbVrLT1BUR1nn0WZNGLiSd7pBJOleL70nFokS5s=; b=OF5AjuorPUcDKWCIY2cI21H2QqMOy56tOlb0bZaIuHy41Pwxx9aMTnun5rob6gYmNy tgGRoEPhDR55PbYrhqOPK0hpUqcTAR/MhBXnq/aiEU0qq5WmIFoKlkSikiQ9Em1vIBZa h3DKJVKEpqlEZnw8ltIXGcqxM6Zc9DKkgDW2s= 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=5ME8xbVrLT1BUR1nn0WZNGLiSd7pBJOleL70nFokS5s=; b=Nnaw2mUZxATJQJ725NE+nKmvT/IRIOpriwG9vwvpa7suXlqIrW4VUHOqeOdzU6LSeI gNr2SkM1UAhB7rDqsySLwrMj6kycu2sVlogNcgvxFdKMuHhZZRSwe3USqXX415/9xyU4 pcynQqjL7SfVy0ZBIps7BagDG2vf8szuKkrWJFskLzHz2m2n6qjOzrpFwaAhkzKGfbMI MKamdZ3PzPC7dkPdOPz5BOT0lOT4spWfEeVljbgo7FXH0SSmvwYOR31nlKx+JpFG3s/Y 1bHbsauyTJUvP7aUeyl5vtx2bOZu1/24gBCvb0yKJhfYUcMoFZX2bcu9U1mTh+3y3g6A ky6g== X-Gm-Message-State: AOAM531P/myG0oRjoMhP5rdtepi/kfD7nTWkGgRAylSfuSzehMp0Toon Qbf5MBJQaLF1Djx8H1h8RrqQoA== X-Google-Smtp-Source: ABdhPJwvGub0AH2WlfaqVuMPJjLs6kJJo5gDHdTcQu2VZaWHgS/8ilwSFIpGismzEgDCho/YgbEpcg== X-Received: by 2002:a17:902:c24c:b029:ee:f427:9808 with SMTP id 12-20020a170902c24cb02900eef4279808mr2892227plg.58.1621320265144; Mon, 17 May 2021 23:44:25 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:f284:b819:54ca:c198]) by smtp.gmail.com with UTF8SMTPSA id l15sm3725121pjj.23.2021.05.17.23.44.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 May 2021 23:44:24 -0700 (PDT) From: Claire Chang To: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Cc: benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, Robin Murphy , grant.likely@arm.com, xypron.glpk@gmx.de, Thierry Reding , mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, Greg KH , Saravana Kannan , "Rafael J . Wysocki" , heikki.krogerus@linux.intel.com, Andy Shevchenko , Randy Dunlap , Dan Williams , Bartosz Golaszewski , linux-devicetree , lkml , linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org, Nicolas Boichat , Jim Quinlan , tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com, chris@chris-wilson.co.uk, tientzu@chromium.org, daniel@ffwll.ch, airlied@linux.ie, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, jxgao@google.com, joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com, matthew.auld@intel.com, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com Subject: [PATCH v7 13/15] dma-direct: Allocate memory from restricted DMA pool if available Date: Tue, 18 May 2021 14:42:13 +0800 Message-Id: <20210518064215.2856977-14-tientzu@chromium.org> X-Mailer: git-send-email 2.31.1.751.gd2f1c929bd-goog In-Reply-To: <20210518064215.2856977-1-tientzu@chromium.org> References: <20210518064215.2856977-1-tientzu@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Note that since coherent allocation needs remapping, one must set up another device coherent pool by shared-dma-pool and use dma_alloc_from_dev_coherent instead for atomic coherent allocation. Signed-off-by: Claire Chang --- kernel/dma/direct.c | 38 +++++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index eb4098323bbc..0d521f78c7b9 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -78,6 +78,10 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) static void __dma_direct_free_pages(struct device *dev, struct page *page, size_t size) { +#ifdef CONFIG_DMA_RESTRICTED_POOL + if (swiotlb_free(dev, page, size)) + return; +#endif dma_free_contiguous(dev, page, size); } @@ -92,7 +96,17 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, &phys_limit); - page = dma_alloc_contiguous(dev, size, gfp); + +#ifdef CONFIG_DMA_RESTRICTED_POOL + page = swiotlb_alloc(dev, size); + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + __dma_direct_free_pages(dev, page, size); + page = NULL; + } +#endif + + if (!page) + page = dma_alloc_contiguous(dev, size, gfp); if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { dma_free_contiguous(dev, page, size); page = NULL; @@ -148,7 +162,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, gfp |= __GFP_NOWARN; if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev)) { + !force_dma_unencrypted(dev) && !is_dev_swiotlb_force(dev)) { page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); if (!page) return NULL; @@ -161,18 +175,23 @@ void *dma_direct_alloc(struct device *dev, size_t size, } if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && - !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev)) + !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev) && + !is_dev_swiotlb_force(dev)) return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); /* * Remapping or decrypting memory may block. If either is required and * we can't block, allocate the memory from the atomic pools. + * If restricted DMA (i.e., is_dev_swiotlb_force) is required, one must + * set up another device coherent pool by shared-dma-pool and use + * dma_alloc_from_dev_coherent instead. */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && !gfpflags_allow_blocking(gfp) && (force_dma_unencrypted(dev) || - (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev)))) + (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !dev_is_dma_coherent(dev))) && + !is_dev_swiotlb_force(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); /* we always manually zero the memory once we are done */ @@ -253,15 +272,15 @@ void dma_direct_free(struct device *dev, size_t size, unsigned int page_order = get_order(size); if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev)) { + !force_dma_unencrypted(dev) && !is_dev_swiotlb_force(dev)) { /* cpu_addr is a struct page cookie, not a kernel address */ dma_free_contiguous(dev, cpu_addr, size); return; } if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && - !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev)) { + !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev) && + !is_dev_swiotlb_force(dev)) { arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); return; } @@ -289,7 +308,8 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, void *ret; if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp)) + force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && + !is_dev_swiotlb_force(dev)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); page = __dma_direct_alloc_pages(dev, size, gfp); -- 2.31.1.751.gd2f1c929bd-goog