tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
drm/virtio: support mapping exported vram
Implement virtgpu specific map_dma_buf callback to support mapping
exported vram object dma-bufs. The dma-buf callback is used directly, as
vram objects don't have backing pages and thus can't implement the
drm_gem_object_funcs.get_sg_table callback.
Signed-off-by: David Stevens <stevensd@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20210813005441.608293-1-stevensd@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
authored by
David Stevens
and committed by
Gerd Hoffmann
ea5ea3d8
f492283b
+99
-2
+8
drivers/gpu/drm/virtio/virtgpu_drv.h
+8
drivers/gpu/drm/virtio/virtgpu_drv.h
···
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#ifndef VIRTIO_DRV_H
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#define VIRTIO_DRV_H
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#include <linux/dma-direction.h>
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#include <linux/virtio.h>
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#include <linux/virtio_ids.h>
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#include <linux/virtio_config.h>
···
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int virtio_gpu_vram_create(struct virtio_gpu_device *vgdev,
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struct virtio_gpu_object_params *params,
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struct virtio_gpu_object **bo_ptr);
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struct sg_table *virtio_gpu_vram_map_dma_buf(struct virtio_gpu_object *bo,
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struct device *dev,
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enum dma_data_direction dir);
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void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
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struct sg_table *sgt,
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enum dma_data_direction dir);
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#endif
+30
-2
drivers/gpu/drm/virtio/virtgpu_prime.c
+30
-2
drivers/gpu/drm/virtio/virtgpu_prime.c
···
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return 0;
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}
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static struct sg_table *
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virtgpu_gem_map_dma_buf(struct dma_buf_attachment *attach,
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enum dma_data_direction dir)
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{
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struct drm_gem_object *obj = attach->dmabuf->priv;
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struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
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if (virtio_gpu_is_vram(bo))
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return virtio_gpu_vram_map_dma_buf(bo, attach->dev, dir);
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return drm_gem_map_dma_buf(attach, dir);
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}
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static void virtgpu_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
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struct sg_table *sgt,
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enum dma_data_direction dir)
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{
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struct drm_gem_object *obj = attach->dmabuf->priv;
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struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
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if (virtio_gpu_is_vram(bo)) {
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virtio_gpu_vram_unmap_dma_buf(attach->dev, sgt, dir);
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return;
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}
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drm_gem_unmap_dma_buf(attach, sgt, dir);
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}
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static const struct virtio_dma_buf_ops virtgpu_dmabuf_ops = {
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.ops = {
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.cache_sgt_mapping = true,
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.attach = virtio_dma_buf_attach,
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.detach = drm_gem_map_detach,
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-
.map_dma_buf = drm_gem_map_dma_buf,
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.unmap_dma_buf = drm_gem_unmap_dma_buf,
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.map_dma_buf = virtgpu_gem_map_dma_buf,
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.unmap_dma_buf = virtgpu_gem_unmap_dma_buf,
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.release = drm_gem_dmabuf_release,
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.mmap = drm_gem_dmabuf_mmap,
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.vmap = drm_gem_dmabuf_vmap,
+61
drivers/gpu/drm/virtio/virtgpu_vram.c
+61
drivers/gpu/drm/virtio/virtgpu_vram.c
···
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// SPDX-License-Identifier: GPL-2.0
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#include "virtgpu_drv.h"
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#include <linux/dma-mapping.h>
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static void virtio_gpu_vram_free(struct drm_gem_object *obj)
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{
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struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
···
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vram->vram_node.start >> PAGE_SHIFT,
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vm_size, vma->vm_page_prot);
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return ret;
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}
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struct sg_table *virtio_gpu_vram_map_dma_buf(struct virtio_gpu_object *bo,
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struct device *dev,
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enum dma_data_direction dir)
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{
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struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
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struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
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struct sg_table *sgt;
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dma_addr_t addr;
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int ret;
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sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
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if (!sgt)
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return ERR_PTR(-ENOMEM);
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if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) {
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// Virtio devices can access the dma-buf via its UUID. Return a stub
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// sg_table so the dma-buf API still works.
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if (!is_virtio_device(dev) || !vgdev->has_resource_assign_uuid) {
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ret = -EIO;
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goto out;
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}
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return sgt;
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}
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ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
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if (ret)
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goto out;
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addr = dma_map_resource(dev, vram->vram_node.start,
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vram->vram_node.size, dir,
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DMA_ATTR_SKIP_CPU_SYNC);
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ret = dma_mapping_error(dev, addr);
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if (ret)
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goto out;
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sg_set_page(sgt->sgl, NULL, vram->vram_node.size, 0);
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sg_dma_address(sgt->sgl) = addr;
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sg_dma_len(sgt->sgl) = vram->vram_node.size;
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return sgt;
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out:
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sg_free_table(sgt);
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kfree(sgt);
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return ERR_PTR(ret);
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}
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void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
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struct sg_table *sgt,
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enum dma_data_direction dir)
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{
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if (sgt->nents) {
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dma_unmap_resource(dev, sg_dma_address(sgt->sgl),
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sg_dma_len(sgt->sgl), dir,
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DMA_ATTR_SKIP_CPU_SYNC);
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}
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sg_free_table(sgt);
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kfree(sgt);
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}
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static const struct drm_gem_object_funcs virtio_gpu_vram_funcs = {