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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 28F59ECE58E for ; Mon, 14 Oct 2019 15:16:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A08C20854 for ; Mon, 14 Oct 2019 15:16:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387435AbfJNPQ0 (ORCPT ); Mon, 14 Oct 2019 11:16:26 -0400 Received: from foss.arm.com ([217.140.110.172]:46702 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732397AbfJNPQ0 (ORCPT ); Mon, 14 Oct 2019 11:16:26 -0400 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 E731A28; Mon, 14 Oct 2019 08:16:25 -0700 (PDT) Received: from e112269-lin.cambridge.arm.com (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C8FEF3F68E; Mon, 14 Oct 2019 08:16:24 -0700 (PDT) From: Steven Price To: Daniel Vetter , David Airlie , Rob Herring , Tomeu Vizoso Cc: Alyssa Rosenzweig , Steven Price , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/panfrost: DMA map all pages shared with the GPU Date: Mon, 14 Oct 2019 16:16:16 +0100 Message-Id: <20191014151616.14099-1-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pages shared with the GPU are (often) not cache coherent with the CPU so cache maintenance is required to flush the CPU's caches. This was already done when mapping pages on fault, but wasn't previously done when mapping a freshly allocated page. Fix this by moving the call to dma_map_sg() into mmu_map_sg() ensuring that it is always called when pages are mapped onto the GPU. Since mmu_map_sg() can now fail the code also now has to handle an error return. Not performing this cache maintenance can cause errors in the GPU output (CPU caches are later flushed and overwrite the GPU output). In theory it also allows the GPU (and by extension user space) to observe the memory contents prior to sanitization. Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver") Signed-off-by: Steven Price --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index bdd990568476..0495e48c238d 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -248,6 +248,9 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu, struct io_pgtable_ops *ops = mmu->pgtbl_ops; u64 start_iova = iova; + if (!dma_map_sg(pfdev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL)) + return -EINVAL; + for_each_sg(sgt->sgl, sgl, sgt->nents, count) { unsigned long paddr = sg_dma_address(sgl); size_t len = sg_dma_len(sgl); @@ -275,6 +278,7 @@ int panfrost_mmu_map(struct panfrost_gem_object *bo) struct panfrost_device *pfdev = to_panfrost_device(obj->dev); struct sg_table *sgt; int prot = IOMMU_READ | IOMMU_WRITE; + int ret; if (WARN_ON(bo->is_mapped)) return 0; @@ -286,10 +290,12 @@ int panfrost_mmu_map(struct panfrost_gem_object *bo) if (WARN_ON(IS_ERR(sgt))) return PTR_ERR(sgt); - mmu_map_sg(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT, prot, sgt); - bo->is_mapped = true; + ret = mmu_map_sg(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT, + prot, sgt); + if (ret == 0) + bo->is_mapped = true; - return 0; + return ret; } void panfrost_mmu_unmap(struct panfrost_gem_object *bo) @@ -503,12 +509,10 @@ int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as, u64 addr) if (ret) goto err_pages; - if (!dma_map_sg(pfdev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL)) { - ret = -EINVAL; + ret = mmu_map_sg(pfdev, bo->mmu, addr, + IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt); + if (ret) goto err_map; - } - - mmu_map_sg(pfdev, bo->mmu, addr, IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt); bo->is_mapped = true; -- 2.20.1