1// SPDX-License-Identifier: GPL-2.0
  2#include "virtgpu_drv.h"
  3
  4#include <linux/dma-mapping.h>
  5
  6static void virtio_gpu_vram_free(struct drm_gem_object *obj)
  7{
  8	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
  9	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
 10	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
 11	bool unmap;
 12
 13	if (bo->created) {
 14		spin_lock(&vgdev->host_visible_lock);
 15		unmap = drm_mm_node_allocated(&vram->vram_node);
 16		spin_unlock(&vgdev->host_visible_lock);
 17
 18		if (unmap)
 19			virtio_gpu_cmd_unmap(vgdev, bo);
 20
 21		virtio_gpu_cmd_unref_resource(vgdev, bo);
 22		virtio_gpu_notify(vgdev);
 23		return;
 24	}
 25}
 26
 27static const struct vm_operations_struct virtio_gpu_vram_vm_ops = {
 28	.open = drm_gem_vm_open,
 29	.close = drm_gem_vm_close,
 30};
 31
 32static int virtio_gpu_vram_mmap(struct drm_gem_object *obj,
 33				struct vm_area_struct *vma)
 34{
 35	int ret;
 36	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
 37	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
 38	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
 39	unsigned long vm_size = vma->vm_end - vma->vm_start;
 40
 41	if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE))
 42		return -EINVAL;
 43
 44	wait_event(vgdev->resp_wq, vram->map_state != STATE_INITIALIZING);
 45	if (vram->map_state != STATE_OK)
 46		return -EINVAL;
 47
 48	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
 49	vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND;
 50	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 51	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
 52	vma->vm_ops = &virtio_gpu_vram_vm_ops;
 53
 54	if (vram->map_info == VIRTIO_GPU_MAP_CACHE_WC)
 55		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 56	else if (vram->map_info == VIRTIO_GPU_MAP_CACHE_UNCACHED)
 57		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 58
 59	/* Partial mappings of GEM buffers don't happen much in practice. */
 60	if (vm_size != vram->vram_node.size)
 61		return -EINVAL;
 62
 63	ret = io_remap_pfn_range(vma, vma->vm_start,
 64				 vram->vram_node.start >> PAGE_SHIFT,
 65				 vm_size, vma->vm_page_prot);
 66	return ret;
 67}
 68
 69struct sg_table *virtio_gpu_vram_map_dma_buf(struct virtio_gpu_object *bo,
 70					     struct device *dev,
 71					     enum dma_data_direction dir)
 72{
 73	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
 74	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
 75	struct sg_table *sgt;
 76	dma_addr_t addr;
 77	int ret;
 78
 79	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 80	if (!sgt)
 81		return ERR_PTR(-ENOMEM);
 82
 83	if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) {
 84		// Virtio devices can access the dma-buf via its UUID. Return a stub
 85		// sg_table so the dma-buf API still works.
 86		if (!is_virtio_device(dev) || !vgdev->has_resource_assign_uuid) {
 87			ret = -EIO;
 88			goto out;
 89		}
 90		return sgt;
 91	}
 92
 93	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 94	if (ret)
 95		goto out;
 96
 97	addr = dma_map_resource(dev, vram->vram_node.start,
 98				vram->vram_node.size, dir,
 99				DMA_ATTR_SKIP_CPU_SYNC);
100	ret = dma_mapping_error(dev, addr);
101	if (ret)
102		goto out;
103
104	sg_set_page(sgt->sgl, NULL, vram->vram_node.size, 0);
105	sg_dma_address(sgt->sgl) = addr;
106	sg_dma_len(sgt->sgl) = vram->vram_node.size;
107
108	return sgt;
109out:
110	sg_free_table(sgt);
111	kfree(sgt);
112	return ERR_PTR(ret);
113}
114
115void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
116				   struct sg_table *sgt,
117				   enum dma_data_direction dir)
118{
119	if (sgt->nents) {
120		dma_unmap_resource(dev, sg_dma_address(sgt->sgl),
121				   sg_dma_len(sgt->sgl), dir,
122				   DMA_ATTR_SKIP_CPU_SYNC);
123	}
124	sg_free_table(sgt);
125	kfree(sgt);
126}
127
128static const struct drm_gem_object_funcs virtio_gpu_vram_funcs = {
129	.open = virtio_gpu_gem_object_open,
130	.close = virtio_gpu_gem_object_close,
131	.free = virtio_gpu_vram_free,
132	.mmap = virtio_gpu_vram_mmap,
133	.export = virtgpu_gem_prime_export,
134};
135
136bool virtio_gpu_is_vram(struct virtio_gpu_object *bo)
137{
138	return bo->base.base.funcs == &virtio_gpu_vram_funcs;
139}
140
141static int virtio_gpu_vram_map(struct virtio_gpu_object *bo)
142{
143	int ret;
144	uint64_t offset;
145	struct virtio_gpu_object_array *objs;
146	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
147	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
148
149	if (!vgdev->has_host_visible)
150		return -EINVAL;
151
152	spin_lock(&vgdev->host_visible_lock);
153	ret = drm_mm_insert_node(&vgdev->host_visible_mm, &vram->vram_node,
154				 bo->base.base.size);
155	spin_unlock(&vgdev->host_visible_lock);
156
157	if (ret)
158		return ret;
159
160	objs = virtio_gpu_array_alloc(1);
161	if (!objs) {
162		ret = -ENOMEM;
163		goto err_remove_node;
164	}
165
166	virtio_gpu_array_add_obj(objs, &bo->base.base);
167	/*TODO: Add an error checking helper function in drm_mm.h */
168	offset = vram->vram_node.start - vgdev->host_visible_region.addr;
169
170	ret = virtio_gpu_cmd_map(vgdev, objs, offset);
171	if (ret) {
172		virtio_gpu_array_put_free(objs);
173		goto err_remove_node;
174	}
175
176	return 0;
177
178err_remove_node:
179	spin_lock(&vgdev->host_visible_lock);
180	drm_mm_remove_node(&vram->vram_node);
181	spin_unlock(&vgdev->host_visible_lock);
182	return ret;
183}
184
185int virtio_gpu_vram_create(struct virtio_gpu_device *vgdev,
186			   struct virtio_gpu_object_params *params,
187			   struct virtio_gpu_object **bo_ptr)
188{
189	struct drm_gem_object *obj;
190	struct virtio_gpu_object_vram *vram;
191	int ret;
192
193	vram = kzalloc(sizeof(*vram), GFP_KERNEL);
194	if (!vram)
195		return -ENOMEM;
196
197	obj = &vram->base.base.base;
198	obj->funcs = &virtio_gpu_vram_funcs;
199
200	params->size = PAGE_ALIGN(params->size);
201	drm_gem_private_object_init(vgdev->ddev, obj, params->size);
202
203	/* Create fake offset */
204	ret = drm_gem_create_mmap_offset(obj);
205	if (ret) {
206		kfree(vram);
207		return ret;
208	}
209
210	ret = virtio_gpu_resource_id_get(vgdev, &vram->base.hw_res_handle);
211	if (ret) {
212		kfree(vram);
213		return ret;
214	}
215
216	virtio_gpu_cmd_resource_create_blob(vgdev, &vram->base, params, NULL,
217					    0);
218	if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) {
219		ret = virtio_gpu_vram_map(&vram->base);
220		if (ret) {
221			virtio_gpu_vram_free(obj);
222			return ret;
223		}
224	}
225
226	*bo_ptr = &vram->base;
227	return 0;
228}