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Tue, 12 May 2020 09:01:21 +0000 (GMT) From: Marek Szyprowski To: dri-devel@lists.freedesktop.org, iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Cc: Marek Szyprowski , Christoph Hellwig , Robin Murphy , Bartlomiej Zolnierkiewicz , linux-arm-kernel@lists.infradead.org, David Airlie , Daniel Vetter , Gerd Hoffmann , virtualization@lists.linux-foundation.org Subject: [PATCH v4 25/38] drm: virtio: fix common struct sg_table related issues Date: Tue, 12 May 2020 11:00:45 +0200 Message-Id: <20200512090058.14910-25-m.szyprowski@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200512090058.14910-1-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA0WSa0hTYRzGfXe2szPb4jQlX0wSB0kGzUtSB5RRUXG+FNGXwMhaepqSN3ac pRJ5KS9LwxtkmkcLwdR5m6ZppKnpvM7bMrVyXkotMiWnoZm1eWZ9+73P/3ne5//CiyHi5zxH LDgsklKGyUMkqC23vnN94PAM1eTvMdcOiXR9N4eoya3iEX/qMxHCsLqEEqXlHRyiqMWHmJvo RgiTYZpDaGdHecRI02OUqHjzkU+0Ln/iESX9DHpcRGoYDSBfrRVxyYa1KR5pvK/jkLXFd8j3 W7MImT1WAsiX43EoudT8FiUf1JUBckW7//wuP1vfQCokOIpSusuu2gY1D5nQiNWDt2rXc/hx QO+iBgIM4t5wueoJamEx/gzA/IIoNbA1swnAnjaTdbACYNngnp1AYn4WhzWVAKgxGPisyZxI rj5pYRT3hOpF9XbYHr8HYFe60BJA8AUOTPpdCywDO/wCNPblbpu4+AHIZCVsswiXwWJdOsq2 OcPy6teIhQVm3Vi4ybVcBPFOPpxM/sZhTafgVrwGYdkOftXV8Vl2gr3ZadZAIoDT+go+e0gD cCQhF7AuH/hBv2Guw8z7ucGqJndWPgHbmWzEIkN8Nxxb3H4+Ysas+odWWQRTksSs2xXm6Sr/ 1bYODlvXIWHfJLuzGO8AsDAxg58BnPP+lxUBUAYcKBUdqqBozzDqppSWh9KqMIU0IDxUC8yf qXdL9+MFWB2+1gZwDEiEohSvRn8xTx5FR4e2AYghEnvR3WCzJAqUR8dQyvArSlUIRbeBfRhX 4iA68vTLZTGukEdSNygqglLuTDmYwDEOnOkaH5OBjQJ55sRSqkfsaGz4u6MTgphUFaZo6vAK 0M/o7U/b+F20q8zxdTu39/t8YUHSYL/Do1LmtnF5sPRSv7/3dW2LuOXX5grjyjS7KxlBfE98 lnJmYb5B4kFHTmdWnG2Q0kNbvk7CKReeUDaQ9rPRhSedsjEdq8Q+1yASLh0k9zyEKGn5X9XI 7FVIAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJIsWRmVeSWpSXmKPExsVy+t/xu7oPU3fFGdzZaW7Re+4kk8XGGetZ Lf5vm8hsceXrezaLlauPMlks2G9t8ezWSWaLL1ceMllsenyN1eLyrjlsFmuP3GW3OPjhCavF 8rPz2Bx4PdbMW8PosffbAhaP7d8esHrc7z7O5LF5Sb3H7X+PmT0m31jO6LH7ZgObx/t9V9k8 +rasYvT4vEkugDtKz6Yov7QkVSEjv7jEVina0MJIz9DSQs/IxFLP0Ng81srIVEnfziYlNSez LLVI3y5BL2PfxS9sBV81Kjb/nMLewHhOsYuRk0NCwESiefYkpi5GLg4hgaWMEr/evWeCSMhI nJzWwAphC0v8udbFBlH0iVFi0aWlYEVsAoYSXW8hEiICnYwS07o/soM4zAIfmCT+/f3HBlIl LBAgsWvzErAOFgFViXmTmsDivAJ2EkuO97JBrJCXWL3hADOIzQkUvz//DwuILSRQKPHo6luW CYx8CxgZVjGKpJYW56bnFhvpFSfmFpfmpesl5+duYgRGy7ZjP7fsYOx6F3yIUYCDUYmHt8No Z5wQa2JZcWXuIUYJDmYlEd6WTKAQb0piZVVqUX58UWlOavEhRlOgoyYyS4km5wMjOa8k3tDU 0NzC0tDc2NzYzEJJnLdD4GCMkEB6YklqdmpqQWoRTB8TB6dUA2PuvOfei10T+12/er9qf/6k XFNou0rr6U1MC11sAjNcDG9dezvtN6tOyd9rwjlHrn+cyKOYseYed2/zzwuFu5mbonZEXNr7 Q1KnN7Zk5YMfBnf299y/Eh3VlcDytTEojX1J1N+926+Zl7Ud2l38/tNj38NSDlYOdsfVrwid sRPdfMbzQBKHmboSS3FGoqEWc1FxIgCn5n02rAIAAA== X-CMS-MailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a References: <20200512085710.14688-1-m.szyprowski@samsung.com> <20200512090058.14910-1-m.szyprowski@samsung.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski@samsung.com/T/ --- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++++++++++++++++-------------- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +++++------ 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..399556f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo) if (shmem->pages) { if (shmem->mapped) { - dma_unmap_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->mapped, - DMA_TO_DEVICE); + dma_unmap_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); shmem->mapped = 0; } @@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, } if (use_dma_api) { - shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, - shmem->pages->nents, - DMA_TO_DEVICE); - *nents = shmem->mapped; + ret = dma_map_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); + if (ret) + return ret; + *nents = shmem->mapped = shmem->pages->nents; } else { - *nents = shmem->pages->nents; + *nents = shmem->pages->orig_nents; } *ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry), @@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, return -ENOMEM; } - for_each_sg(shmem->pages->sgl, sg, *nents, si) { - (*ents)[si].addr = cpu_to_le64(use_dma_api - ? sg_dma_address(sg) - : sg_phys(sg)); - (*ents)[si].length = cpu_to_le32(sg->length); - (*ents)[si].padding = 0; + if (use_dma_api) { + for_each_sgtable_dma_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg)); + (*ents)[si].length = cpu_to_le32(sg_dma_len(sg)); + (*ents)[si].padding = 0; + } + } else { + for_each_sgtable_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_phys(sg)); + (*ents)[si].length = cpu_to_le32(sg->length); + (*ents)[si].padding = 0; + } } + return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..e5765db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents) return NULL; } - for_each_sg(sgt->sgl, sg, *sg_ents, i) { + for_each_sgtable_sg(sgt, sg, i) { pg = vmalloc_to_page(data); if (!pg) { sg_free_table(sgt); @@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); @@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); -- 1.9.1 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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,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 13345C8184A for ; Tue, 12 May 2020 09:01:39 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 D5E7920714 for ; 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Tue, 12 May 2020 09:01:22 +0000 (GMT) Received: from eusmgms2.samsung.com (unknown [182.198.249.180]) by eusmtrp1.samsung.com (KnoxPortal) with ESMTP id 20200512090122eusmtrp1a0a85054f72ecc8fb8808473db1f0a0d~OPFt0YFlK0188101881eusmtrp1T; Tue, 12 May 2020 09:01:21 +0000 (GMT) X-AuditID: cbfec7f2-f0bff7000001ef66-97-5eba65e299dd Received: from eusmtip1.samsung.com ( [203.254.199.221]) by eusmgms2.samsung.com (EUCPMTA) with SMTP id E0.03.07950.1E56ABE5; Tue, 12 May 2020 10:01:21 +0100 (BST) Received: from AMDC2765.digital.local (unknown [106.120.51.73]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20200512090121eusmtip1816550070391c915aab8c82555df8d5c~OPFtNMLkh0919809198eusmtip15; Tue, 12 May 2020 09:01:21 +0000 (GMT) From: Marek Szyprowski To: dri-devel@lists.freedesktop.org, iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 25/38] drm: virtio: fix common struct sg_table related issues Date: Tue, 12 May 2020 11:00:45 +0200 Message-Id: <20200512090058.14910-25-m.szyprowski@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200512090058.14910-1-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA0WSa0hTYRzGfXe2szPb4jQlX0wSB0kGzUtSB5RRUXG+FNGXwMhaepqSN3ac pRJ5KS9LwxtkmkcLwdR5m6ZppKnpvM7bMrVyXkotMiWnoZm1eWZ9+73P/3ne5//CiyHi5zxH LDgsklKGyUMkqC23vnN94PAM1eTvMdcOiXR9N4eoya3iEX/qMxHCsLqEEqXlHRyiqMWHmJvo RgiTYZpDaGdHecRI02OUqHjzkU+0Ln/iESX9DHpcRGoYDSBfrRVxyYa1KR5pvK/jkLXFd8j3 W7MImT1WAsiX43EoudT8FiUf1JUBckW7//wuP1vfQCokOIpSusuu2gY1D5nQiNWDt2rXc/hx QO+iBgIM4t5wueoJamEx/gzA/IIoNbA1swnAnjaTdbACYNngnp1AYn4WhzWVAKgxGPisyZxI rj5pYRT3hOpF9XbYHr8HYFe60BJA8AUOTPpdCywDO/wCNPblbpu4+AHIZCVsswiXwWJdOsq2 OcPy6teIhQVm3Vi4ybVcBPFOPpxM/sZhTafgVrwGYdkOftXV8Vl2gr3ZadZAIoDT+go+e0gD cCQhF7AuH/hBv2Guw8z7ucGqJndWPgHbmWzEIkN8Nxxb3H4+Ysas+odWWQRTksSs2xXm6Sr/ 1bYODlvXIWHfJLuzGO8AsDAxg58BnPP+lxUBUAYcKBUdqqBozzDqppSWh9KqMIU0IDxUC8yf qXdL9+MFWB2+1gZwDEiEohSvRn8xTx5FR4e2AYghEnvR3WCzJAqUR8dQyvArSlUIRbeBfRhX 4iA68vTLZTGukEdSNygqglLuTDmYwDEOnOkaH5OBjQJ55sRSqkfsaGz4u6MTgphUFaZo6vAK 0M/o7U/b+F20q8zxdTu39/t8YUHSYL/Do1LmtnF5sPRSv7/3dW2LuOXX5grjyjS7KxlBfE98 lnJmYb5B4kFHTmdWnG2Q0kNbvk7CKReeUDaQ9rPRhSedsjEdq8Q+1yASLh0k9zyEKGn5X9XI 7FVIAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJIsWRmVeSWpSXmKPExsVy+t/xu7oPU3fFGdzZaW7Re+4kk8XGGetZ Lf5vm8hsceXrezaLlauPMlks2G9t8ezWSWaLL1ceMllsenyN1eLyrjlsFmuP3GW3OPjhCavF 8rPz2Bx4PdbMW8PosffbAhaP7d8esHrc7z7O5LF5Sb3H7X+PmT0m31jO6LH7ZgObx/t9V9k8 +rasYvT4vEkugDtKz6Yov7QkVSEjv7jEVina0MJIz9DSQs/IxFLP0Ng81srIVEnfziYlNSez LLVI3y5BL2PfxS9sBV81Kjb/nMLewHhOsYuRk0NCwESiefYkpi5GLg4hgaWMEr/evWeCSMhI nJzWwAphC0v8udbFBlH0iVFi0aWlYEVsAoYSXW8hEiICnYwS07o/soM4zAIfmCT+/f3HBlIl LBAgsWvzErAOFgFViXmTmsDivAJ2EkuO97JBrJCXWL3hADOIzQkUvz//DwuILSRQKPHo6luW CYx8CxgZVjGKpJYW56bnFhvpFSfmFpfmpesl5+duYgRGy7ZjP7fsYOx6F3yIUYCDUYmHt8No Z5wQa2JZcWXuIUYJDmYlEd6WTKAQb0piZVVqUX58UWlOavEhRlOgoyYyS4km5wMjOa8k3tDU 0NzC0tDc2NzYzEJJnLdD4GCMkEB6YklqdmpqQWoRTB8TB6dUA2PuvOfei10T+12/er9qf/6k XFNou0rr6U1MC11sAjNcDG9dezvtN6tOyd9rwjlHrn+cyKOYseYed2/zzwuFu5mbonZEXNr7 Q1KnN7Zk5YMfBnf299y/Eh3VlcDytTEojX1J1N+926+Zl7Ud2l38/tNj38NSDlYOdsfVrwid sRPdfMbzQBKHmboSS3FGoqEWc1FxIgCn5n02rAIAAA== X-CMS-MailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-Msg-Generator: CA X-RootMTR: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a References: <20200512085710.14688-1-m.szyprowski@samsung.com> <20200512090058.14910-1-m.szyprowski@samsung.com> Cc: Bartlomiej Zolnierkiewicz , David Airlie , virtualization@lists.linux-foundation.org, Gerd Hoffmann , Daniel Vetter , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 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 Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski@samsung.com/T/ --- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++++++++++++++++-------------- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +++++------ 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..399556f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo) if (shmem->pages) { if (shmem->mapped) { - dma_unmap_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->mapped, - DMA_TO_DEVICE); + dma_unmap_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); shmem->mapped = 0; } @@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, } if (use_dma_api) { - shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, - shmem->pages->nents, - DMA_TO_DEVICE); - *nents = shmem->mapped; + ret = dma_map_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); + if (ret) + return ret; + *nents = shmem->mapped = shmem->pages->nents; } else { - *nents = shmem->pages->nents; + *nents = shmem->pages->orig_nents; } *ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry), @@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, return -ENOMEM; } - for_each_sg(shmem->pages->sgl, sg, *nents, si) { - (*ents)[si].addr = cpu_to_le64(use_dma_api - ? sg_dma_address(sg) - : sg_phys(sg)); - (*ents)[si].length = cpu_to_le32(sg->length); - (*ents)[si].padding = 0; + if (use_dma_api) { + for_each_sgtable_dma_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg)); + (*ents)[si].length = cpu_to_le32(sg_dma_len(sg)); + (*ents)[si].padding = 0; + } + } else { + for_each_sgtable_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_phys(sg)); + (*ents)[si].length = cpu_to_le32(sg->length); + (*ents)[si].padding = 0; + } } + return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..e5765db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents) return NULL; } - for_each_sg(sgt->sgl, sg, *sg_ents, i) { + for_each_sgtable_sg(sgt, sg, i) { pg = vmalloc_to_page(data); if (!pg) { sg_free_table(sgt); @@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); @@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); -- 1.9.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: [PATCH v4 25/38] drm: virtio: fix common struct sg_table related issues Date: Tue, 12 May 2020 11:00:45 +0200 Message-ID: <20200512090058.14910-25-m.szyprowski@samsung.com> References: <20200512085710.14688-1-m.szyprowski@samsung.com> <20200512090058.14910-1-m.szyprowski@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200512090058.14910-1-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Sender: "iommu" To: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Bartlomiej Zolnierkiewicz , David Airlie , virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Gerd Hoffmann , Daniel Vetter , Robin Murphy , Christoph Hellwig , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: virtualization@lists.linuxfoundation.org The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org/T/ --- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++++++++++++++++-------------- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +++++------ 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..399556f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo) if (shmem->pages) { if (shmem->mapped) { - dma_unmap_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->mapped, - DMA_TO_DEVICE); + dma_unmap_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); shmem->mapped = 0; } @@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, } if (use_dma_api) { - shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, - shmem->pages->nents, - DMA_TO_DEVICE); - *nents = shmem->mapped; + ret = dma_map_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); + if (ret) + return ret; + *nents = shmem->mapped = shmem->pages->nents; } else { - *nents = shmem->pages->nents; + *nents = shmem->pages->orig_nents; } *ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry), @@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, return -ENOMEM; } - for_each_sg(shmem->pages->sgl, sg, *nents, si) { - (*ents)[si].addr = cpu_to_le64(use_dma_api - ? sg_dma_address(sg) - : sg_phys(sg)); - (*ents)[si].length = cpu_to_le32(sg->length); - (*ents)[si].padding = 0; + if (use_dma_api) { + for_each_sgtable_dma_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg)); + (*ents)[si].length = cpu_to_le32(sg_dma_len(sg)); + (*ents)[si].padding = 0; + } + } else { + for_each_sgtable_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_phys(sg)); + (*ents)[si].length = cpu_to_le32(sg->length); + (*ents)[si].padding = 0; + } } + return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..e5765db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents) return NULL; } - for_each_sg(sgt->sgl, sg, *sg_ents, i) { + for_each_sgtable_sg(sgt, sg, i) { pg = vmalloc_to_page(data); if (!pg) { sg_free_table(sgt); @@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); @@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); -- 1.9.1 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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 95BC1C54E4A for ; Tue, 12 May 2020 09:08:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 50BF420575 for ; 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Tue, 12 May 2020 09:01:22 +0000 (GMT) Received: from eusmgms2.samsung.com (unknown [182.198.249.180]) by eusmtrp1.samsung.com (KnoxPortal) with ESMTP id 20200512090122eusmtrp1a0a85054f72ecc8fb8808473db1f0a0d~OPFt0YFlK0188101881eusmtrp1T; Tue, 12 May 2020 09:01:21 +0000 (GMT) X-AuditID: cbfec7f2-f0bff7000001ef66-97-5eba65e299dd Received: from eusmtip1.samsung.com ( [203.254.199.221]) by eusmgms2.samsung.com (EUCPMTA) with SMTP id E0.03.07950.1E56ABE5; Tue, 12 May 2020 10:01:21 +0100 (BST) Received: from AMDC2765.digital.local (unknown [106.120.51.73]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20200512090121eusmtip1816550070391c915aab8c82555df8d5c~OPFtNMLkh0919809198eusmtip15; Tue, 12 May 2020 09:01:21 +0000 (GMT) From: Marek Szyprowski To: dri-devel@lists.freedesktop.org, iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 25/38] drm: virtio: fix common struct sg_table related issues Date: Tue, 12 May 2020 11:00:45 +0200 Message-Id: <20200512090058.14910-25-m.szyprowski@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200512090058.14910-1-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA0WSa0hTYRzGfXe2szPb4jQlX0wSB0kGzUtSB5RRUXG+FNGXwMhaepqSN3ac pRJ5KS9LwxtkmkcLwdR5m6ZppKnpvM7bMrVyXkotMiWnoZm1eWZ9+73P/3ne5//CiyHi5zxH LDgsklKGyUMkqC23vnN94PAM1eTvMdcOiXR9N4eoya3iEX/qMxHCsLqEEqXlHRyiqMWHmJvo RgiTYZpDaGdHecRI02OUqHjzkU+0Ln/iESX9DHpcRGoYDSBfrRVxyYa1KR5pvK/jkLXFd8j3 W7MImT1WAsiX43EoudT8FiUf1JUBckW7//wuP1vfQCokOIpSusuu2gY1D5nQiNWDt2rXc/hx QO+iBgIM4t5wueoJamEx/gzA/IIoNbA1swnAnjaTdbACYNngnp1AYn4WhzWVAKgxGPisyZxI rj5pYRT3hOpF9XbYHr8HYFe60BJA8AUOTPpdCywDO/wCNPblbpu4+AHIZCVsswiXwWJdOsq2 OcPy6teIhQVm3Vi4ybVcBPFOPpxM/sZhTafgVrwGYdkOftXV8Vl2gr3ZadZAIoDT+go+e0gD cCQhF7AuH/hBv2Guw8z7ucGqJndWPgHbmWzEIkN8Nxxb3H4+Ysas+odWWQRTksSs2xXm6Sr/ 1bYODlvXIWHfJLuzGO8AsDAxg58BnPP+lxUBUAYcKBUdqqBozzDqppSWh9KqMIU0IDxUC8yf qXdL9+MFWB2+1gZwDEiEohSvRn8xTx5FR4e2AYghEnvR3WCzJAqUR8dQyvArSlUIRbeBfRhX 4iA68vTLZTGukEdSNygqglLuTDmYwDEOnOkaH5OBjQJ55sRSqkfsaGz4u6MTgphUFaZo6vAK 0M/o7U/b+F20q8zxdTu39/t8YUHSYL/Do1LmtnF5sPRSv7/3dW2LuOXX5grjyjS7KxlBfE98 lnJmYb5B4kFHTmdWnG2Q0kNbvk7CKReeUDaQ9rPRhSedsjEdq8Q+1yASLh0k9zyEKGn5X9XI 7FVIAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJIsWRmVeSWpSXmKPExsVy+t/xu7oPU3fFGdzZaW7Re+4kk8XGGetZ Lf5vm8hsceXrezaLlauPMlks2G9t8ezWSWaLL1ceMllsenyN1eLyrjlsFmuP3GW3OPjhCavF 8rPz2Bx4PdbMW8PosffbAhaP7d8esHrc7z7O5LF5Sb3H7X+PmT0m31jO6LH7ZgObx/t9V9k8 +rasYvT4vEkugDtKz6Yov7QkVSEjv7jEVina0MJIz9DSQs/IxFLP0Ng81srIVEnfziYlNSez LLVI3y5BL2PfxS9sBV81Kjb/nMLewHhOsYuRk0NCwESiefYkpi5GLg4hgaWMEr/evWeCSMhI nJzWwAphC0v8udbFBlH0iVFi0aWlYEVsAoYSXW8hEiICnYwS07o/soM4zAIfmCT+/f3HBlIl LBAgsWvzErAOFgFViXmTmsDivAJ2EkuO97JBrJCXWL3hADOIzQkUvz//DwuILSRQKPHo6luW CYx8CxgZVjGKpJYW56bnFhvpFSfmFpfmpesl5+duYgRGy7ZjP7fsYOx6F3yIUYCDUYmHt8No Z5wQa2JZcWXuIUYJDmYlEd6WTKAQb0piZVVqUX58UWlOavEhRlOgoyYyS4km5wMjOa8k3tDU 0NzC0tDc2NzYzEJJnLdD4GCMkEB6YklqdmpqQWoRTB8TB6dUA2PuvOfei10T+12/er9qf/6k XFNou0rr6U1MC11sAjNcDG9dezvtN6tOyd9rwjlHrn+cyKOYseYed2/zzwuFu5mbonZEXNr7 Q1KnN7Zk5YMfBnf299y/Eh3VlcDytTEojX1J1N+926+Zl7Ud2l38/tNj38NSDlYOdsfVrwid sRPdfMbzQBKHmboSS3FGoqEWc1FxIgCn5n02rAIAAA== X-CMS-MailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-Msg-Generator: CA X-RootMTR: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a References: <20200512085710.14688-1-m.szyprowski@samsung.com> <20200512090058.14910-1-m.szyprowski@samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200512_020124_654332_ED298628 X-CRM114-Status: GOOD ( 16.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bartlomiej Zolnierkiewicz , David Airlie , virtualization@lists.linux-foundation.org, Gerd Hoffmann , Daniel Vetter , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Marek Szyprowski MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski@samsung.com/T/ --- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++++++++++++++++-------------- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +++++------ 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..399556f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo) if (shmem->pages) { if (shmem->mapped) { - dma_unmap_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->mapped, - DMA_TO_DEVICE); + dma_unmap_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); shmem->mapped = 0; } @@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, } if (use_dma_api) { - shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, - shmem->pages->nents, - DMA_TO_DEVICE); - *nents = shmem->mapped; + ret = dma_map_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); + if (ret) + return ret; + *nents = shmem->mapped = shmem->pages->nents; } else { - *nents = shmem->pages->nents; + *nents = shmem->pages->orig_nents; } *ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry), @@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, return -ENOMEM; } - for_each_sg(shmem->pages->sgl, sg, *nents, si) { - (*ents)[si].addr = cpu_to_le64(use_dma_api - ? sg_dma_address(sg) - : sg_phys(sg)); - (*ents)[si].length = cpu_to_le32(sg->length); - (*ents)[si].padding = 0; + if (use_dma_api) { + for_each_sgtable_dma_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg)); + (*ents)[si].length = cpu_to_le32(sg_dma_len(sg)); + (*ents)[si].padding = 0; + } + } else { + for_each_sgtable_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_phys(sg)); + (*ents)[si].length = cpu_to_le32(sg->length); + (*ents)[si].padding = 0; + } } + return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..e5765db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents) return NULL; } - for_each_sg(sgt->sgl, sg, *sg_ents, i) { + for_each_sgtable_sg(sgt, sg, i) { pg = vmalloc_to_page(data); if (!pg) { sg_free_table(sgt); @@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); @@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 E10B5C81856 for ; 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Tue, 12 May 2020 09:01:21 +0000 (GMT) From: Marek Szyprowski To: dri-devel@lists.freedesktop.org, iommu@lists.linux-foundation.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 25/38] drm: virtio: fix common struct sg_table related issues Date: Tue, 12 May 2020 11:00:45 +0200 Message-Id: <20200512090058.14910-25-m.szyprowski@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200512090058.14910-1-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA0WSa0hTYRzGfXe2szPb4jQlX0wSB0kGzUtSB5RRUXG+FNGXwMhaepqSN3ac pRJ5KS9LwxtkmkcLwdR5m6ZppKnpvM7bMrVyXkotMiWnoZm1eWZ9+73P/3ne5//CiyHi5zxH LDgsklKGyUMkqC23vnN94PAM1eTvMdcOiXR9N4eoya3iEX/qMxHCsLqEEqXlHRyiqMWHmJvo RgiTYZpDaGdHecRI02OUqHjzkU+0Ln/iESX9DHpcRGoYDSBfrRVxyYa1KR5pvK/jkLXFd8j3 W7MImT1WAsiX43EoudT8FiUf1JUBckW7//wuP1vfQCokOIpSusuu2gY1D5nQiNWDt2rXc/hx QO+iBgIM4t5wueoJamEx/gzA/IIoNbA1swnAnjaTdbACYNngnp1AYn4WhzWVAKgxGPisyZxI rj5pYRT3hOpF9XbYHr8HYFe60BJA8AUOTPpdCywDO/wCNPblbpu4+AHIZCVsswiXwWJdOsq2 OcPy6teIhQVm3Vi4ybVcBPFOPpxM/sZhTafgVrwGYdkOftXV8Vl2gr3ZadZAIoDT+go+e0gD cCQhF7AuH/hBv2Guw8z7ucGqJndWPgHbmWzEIkN8Nxxb3H4+Ysas+odWWQRTksSs2xXm6Sr/ 1bYODlvXIWHfJLuzGO8AsDAxg58BnPP+lxUBUAYcKBUdqqBozzDqppSWh9KqMIU0IDxUC8yf qXdL9+MFWB2+1gZwDEiEohSvRn8xTx5FR4e2AYghEnvR3WCzJAqUR8dQyvArSlUIRbeBfRhX 4iA68vTLZTGukEdSNygqglLuTDmYwDEOnOkaH5OBjQJ55sRSqkfsaGz4u6MTgphUFaZo6vAK 0M/o7U/b+F20q8zxdTu39/t8YUHSYL/Do1LmtnF5sPRSv7/3dW2LuOXX5grjyjS7KxlBfE98 lnJmYb5B4kFHTmdWnG2Q0kNbvk7CKReeUDaQ9rPRhSedsjEdq8Q+1yASLh0k9zyEKGn5X9XI 7FVIAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprJIsWRmVeSWpSXmKPExsVy+t/xu7oPU3fFGdzZaW7Re+4kk8XGGetZ Lf5vm8hsceXrezaLlauPMlks2G9t8ezWSWaLL1ceMllsenyN1eLyrjlsFmuP3GW3OPjhCavF 8rPz2Bx4PdbMW8PosffbAhaP7d8esHrc7z7O5LF5Sb3H7X+PmT0m31jO6LH7ZgObx/t9V9k8 +rasYvT4vEkugDtKz6Yov7QkVSEjv7jEVina0MJIz9DSQs/IxFLP0Ng81srIVEnfziYlNSez LLVI3y5BL2PfxS9sBV81Kjb/nMLewHhOsYuRk0NCwESiefYkpi5GLg4hgaWMEr/evWeCSMhI nJzWwAphC0v8udbFBlH0iVFi0aWlYEVsAoYSXW8hEiICnYwS07o/soM4zAIfmCT+/f3HBlIl LBAgsWvzErAOFgFViXmTmsDivAJ2EkuO97JBrJCXWL3hADOIzQkUvz//DwuILSRQKPHo6luW CYx8CxgZVjGKpJYW56bnFhvpFSfmFpfmpesl5+duYgRGy7ZjP7fsYOx6F3yIUYCDUYmHt8No Z5wQa2JZcWXuIUYJDmYlEd6WTKAQb0piZVVqUX58UWlOavEhRlOgoyYyS4km5wMjOa8k3tDU 0NzC0tDc2NzYzEJJnLdD4GCMkEB6YklqdmpqQWoRTB8TB6dUA2PuvOfei10T+12/er9qf/6k XFNou0rr6U1MC11sAjNcDG9dezvtN6tOyd9rwjlHrn+cyKOYseYed2/zzwuFu5mbonZEXNr7 Q1KnN7Zk5YMfBnf299y/Eh3VlcDytTEojX1J1N+926+Zl7Ud2l38/tNj38NSDlYOdsfVrwid sRPdfMbzQBKHmboSS3FGoqEWc1FxIgCn5n02rAIAAA== X-CMS-MailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-Msg-Generator: CA X-RootMTR: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a X-EPHeader: CA CMS-TYPE: 201P X-CMS-RootMailID: 20200512090122eucas1p10cc3f42cb0452a8a279fcc8702e50a7a References: <20200512085710.14688-1-m.szyprowski@samsung.com> <20200512090058.14910-1-m.szyprowski@samsung.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bartlomiej Zolnierkiewicz , David Airlie , virtualization@lists.linux-foundation.org, Gerd Hoffmann , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Marek Szyprowski MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function returns the number of the created entries in the DMA address space. However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with the original number of the entries passed to the dma_map_sg(). struct sg_table is a common structure used for describing a non-contiguous memory buffer, used commonly in the DRM and graphics subsystems. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling DMA-mapping functions with a wrong number of entries or ignoring the number of mapped entries returned by the dma_map_sg() function. To avoid such issues, lets use a common dma-mapping wrappers operating directly on the struct sg_table objects and use scatterlist page iterators where possible. This, almost always, hides references to the nents and orig_nents entries, making the code robust, easier to follow and copy/paste safe. Signed-off-by: Marek Szyprowski --- For more information, see '[PATCH v4 00/38] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lore.kernel.org/dri-devel/20200512085710.14688-1-m.szyprowski@samsung.com/T/ --- drivers/gpu/drm/virtio/virtgpu_object.c | 36 +++++++++++++++++++-------------- drivers/gpu/drm/virtio/virtgpu_vq.c | 12 +++++------ 2 files changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..399556f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo) if (shmem->pages) { if (shmem->mapped) { - dma_unmap_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->mapped, - DMA_TO_DEVICE); + dma_unmap_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); shmem->mapped = 0; } @@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, } if (use_dma_api) { - shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent, - shmem->pages->sgl, - shmem->pages->nents, - DMA_TO_DEVICE); - *nents = shmem->mapped; + ret = dma_map_sgtable(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE, 0); + if (ret) + return ret; + *nents = shmem->mapped = shmem->pages->nents; } else { - *nents = shmem->pages->nents; + *nents = shmem->pages->orig_nents; } *ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry), @@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev, return -ENOMEM; } - for_each_sg(shmem->pages->sgl, sg, *nents, si) { - (*ents)[si].addr = cpu_to_le64(use_dma_api - ? sg_dma_address(sg) - : sg_phys(sg)); - (*ents)[si].length = cpu_to_le32(sg->length); - (*ents)[si].padding = 0; + if (use_dma_api) { + for_each_sgtable_dma_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg)); + (*ents)[si].length = cpu_to_le32(sg_dma_len(sg)); + (*ents)[si].padding = 0; + } + } else { + for_each_sgtable_sg(shmem->pages, sg, si) { + (*ents)[si].addr = cpu_to_le64(sg_phys(sg)); + (*ents)[si].length = cpu_to_le32(sg->length); + (*ents)[si].padding = 0; + } } + return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..e5765db 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents) return NULL; } - for_each_sg(sgt->sgl, sg, *sg_ents, i) { + for_each_sgtable_sg(sgt, sg, i) { pg = vmalloc_to_page(data); if (!pg) { sg_free_table(sgt); @@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); @@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev, struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo); if (use_dma_api) - dma_sync_sg_for_device(vgdev->vdev->dev.parent, - shmem->pages->sgl, shmem->pages->nents, - DMA_TO_DEVICE); + dma_sync_sgtable_for_device(vgdev->vdev->dev.parent, + shmem->pages, DMA_TO_DEVICE); cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p)); memset(cmd_p, 0, sizeof(*cmd_p)); -- 1.9.1 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel