xref: /linux/drivers/gpu/drm/virtio/virtgpu_vram.c (revision 570f7e331f5febb30f1384817463c7e42b65ca7d)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "virtgpu_drv.h"
3 
4 #include <linux/dma-mapping.h>
5 
6 static DEFINE_MUTEX(map_lock);
7 
8 static void virtio_gpu_vram_free(struct drm_gem_object *obj)
9 {
10 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
11 	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
12 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
13 	bool unmap;
14 
15 	if (bo->created) {
16 		spin_lock(&vgdev->host_visible_lock);
17 		unmap = drm_mm_node_allocated(&vram->vram_node);
18 		spin_unlock(&vgdev->host_visible_lock);
19 
20 		if (unmap)
21 			virtio_gpu_cmd_unmap(vgdev, bo);
22 
23 		virtio_gpu_remove_from_restore_list(bo);
24 		virtio_gpu_cmd_unref_resource(vgdev, bo, false);
25 		virtio_gpu_notify(vgdev);
26 		return;
27 	}
28 }
29 
30 static const struct vm_operations_struct virtio_gpu_vram_vm_ops = {
31 	.open = drm_gem_vm_open,
32 	.close = drm_gem_vm_close,
33 };
34 
35 static int virtio_gpu_vram_mmap(struct drm_gem_object *obj,
36 				struct vm_area_struct *vma)
37 {
38 	int ret;
39 	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
40 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
41 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
42 	unsigned long vm_size = vma->vm_end - vma->vm_start;
43 	unsigned long vm_end;
44 
45 	if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE))
46 		return -EINVAL;
47 
48 	virtio_gpu_vram_map_deferred(vram);
49 
50 	if (vram->map_state == STATE_INITIALIZING)
51 		virtio_gpu_notify(vgdev);
52 
53 	wait_event(vgdev->resp_wq, vram->map_state != STATE_INITIALIZING);
54 	if (vram->map_state != STATE_OK)
55 		return -EINVAL;
56 
57 	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
58 	vm_flags_set(vma, VM_MIXEDMAP | VM_DONTEXPAND);
59 	vma->vm_page_prot = vma_get_page_prot(vma);
60 	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
61 	vma->vm_ops = &virtio_gpu_vram_vm_ops;
62 
63 	if (vram->map_info == VIRTIO_GPU_MAP_CACHE_WC)
64 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
65 	else if (vram->map_info == VIRTIO_GPU_MAP_CACHE_UNCACHED)
66 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
67 
68 	if (check_add_overflow(vma->vm_pgoff << PAGE_SHIFT, vm_size, &vm_end))
69 		return -EINVAL;
70 
71 	if (vm_end > vram->vram_node.size)
72 		return -EINVAL;
73 
74 	ret = io_remap_pfn_range(vma, vma->vm_start,
75 				 (vram->vram_node.start >> PAGE_SHIFT) + vma->vm_pgoff,
76 				 vm_size, vma->vm_page_prot);
77 	return ret;
78 }
79 
80 struct sg_table *virtio_gpu_vram_map_dma_buf(struct virtio_gpu_object *bo,
81 					     struct device *dev,
82 					     enum dma_data_direction dir)
83 {
84 	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
85 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
86 	struct sg_table *sgt;
87 	dma_addr_t addr;
88 	int ret;
89 
90 	sgt = kzalloc_obj(*sgt);
91 	if (!sgt)
92 		return ERR_PTR(-ENOMEM);
93 
94 	if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) {
95 		// Virtio devices can access the dma-buf via its UUID. Return a stub
96 		// sg_table so the dma-buf API still works.
97 		if (!is_virtio_device(dev) || !vgdev->has_resource_assign_uuid) {
98 			ret = -EIO;
99 			goto out;
100 		}
101 		return sgt;
102 	}
103 
104 	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
105 	if (ret)
106 		goto out;
107 
108 	addr = dma_map_resource(dev, vram->vram_node.start,
109 				vram->vram_node.size, dir,
110 				DMA_ATTR_SKIP_CPU_SYNC);
111 	ret = dma_mapping_error(dev, addr);
112 	if (ret)
113 		goto out;
114 
115 	sg_set_page(sgt->sgl, NULL, vram->vram_node.size, 0);
116 	sg_dma_address(sgt->sgl) = addr;
117 	sg_dma_len(sgt->sgl) = vram->vram_node.size;
118 
119 	return sgt;
120 out:
121 	sg_free_table(sgt);
122 	kfree(sgt);
123 	return ERR_PTR(ret);
124 }
125 
126 void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
127 				   struct sg_table *sgt,
128 				   enum dma_data_direction dir)
129 {
130 	if (sgt->nents) {
131 		dma_unmap_resource(dev, sg_dma_address(sgt->sgl),
132 				   sg_dma_len(sgt->sgl), dir,
133 				   DMA_ATTR_SKIP_CPU_SYNC);
134 	}
135 	sg_free_table(sgt);
136 	kfree(sgt);
137 }
138 
139 static const struct drm_gem_object_funcs virtio_gpu_vram_funcs = {
140 	.open = virtio_gpu_gem_object_open,
141 	.close = virtio_gpu_gem_object_close,
142 	.free = virtio_gpu_vram_free,
143 	.mmap = virtio_gpu_vram_mmap,
144 	.export = virtgpu_gem_prime_export,
145 };
146 
147 bool virtio_gpu_is_vram(struct virtio_gpu_object *bo)
148 {
149 	return bo->base.base.funcs == &virtio_gpu_vram_funcs;
150 }
151 
152 static int virtio_gpu_vram_map(struct virtio_gpu_object *bo)
153 {
154 	int ret;
155 	uint64_t offset;
156 	struct virtio_gpu_object_array *objs;
157 	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
158 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
159 
160 	if (!vgdev->has_host_visible)
161 		return -EINVAL;
162 
163 	spin_lock(&vgdev->host_visible_lock);
164 	ret = drm_mm_insert_node(&vgdev->host_visible_mm, &vram->vram_node,
165 				 bo->base.base.size);
166 	spin_unlock(&vgdev->host_visible_lock);
167 
168 	if (ret)
169 		return ret;
170 
171 	objs = virtio_gpu_array_alloc(1);
172 	if (!objs) {
173 		ret = -ENOMEM;
174 		goto err_remove_node;
175 	}
176 
177 	virtio_gpu_array_add_obj(objs, &bo->base.base);
178 	/*TODO: Add an error checking helper function in drm_mm.h */
179 	offset = vram->vram_node.start - vgdev->host_visible_region.addr;
180 
181 	ret = virtio_gpu_cmd_map(vgdev, objs, offset);
182 	if (ret) {
183 		virtio_gpu_array_put_free(objs);
184 		goto err_remove_node;
185 	}
186 
187 	return 0;
188 
189 err_remove_node:
190 	spin_lock(&vgdev->host_visible_lock);
191 	drm_mm_remove_node(&vram->vram_node);
192 	spin_unlock(&vgdev->host_visible_lock);
193 	return ret;
194 }
195 
196 int virtio_gpu_vram_create(struct virtio_gpu_device *vgdev,
197 			   struct virtio_gpu_object_params *params,
198 			   struct virtio_gpu_object **bo_ptr)
199 {
200 	struct drm_gem_object *obj;
201 	struct virtio_gpu_object_vram *vram;
202 	int ret;
203 
204 	vram = kzalloc_obj(*vram);
205 	if (!vram)
206 		return -ENOMEM;
207 
208 	obj = &vram->base.base.base;
209 	obj->funcs = &virtio_gpu_vram_funcs;
210 
211 	INIT_LIST_HEAD(&vram->base.restore_node);
212 
213 	params->size = PAGE_ALIGN(params->size);
214 	drm_gem_private_object_init(vgdev->ddev, obj, params->size);
215 
216 	/* Create fake offset */
217 	ret = drm_gem_create_mmap_offset(obj);
218 	if (ret) {
219 		kfree(vram);
220 		return ret;
221 	}
222 
223 	ret = virtio_gpu_resource_id_get(vgdev, &vram->base.hw_res_handle);
224 	if (ret) {
225 		kfree(vram);
226 		return ret;
227 	}
228 
229 	virtio_gpu_cmd_resource_create_blob(vgdev, &vram->base, params, NULL,
230 					    0);
231 	if (!(params->blob_hints & DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING)) {
232 		if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) {
233 			ret = virtio_gpu_vram_map(&vram->base);
234 			if (ret) {
235 				virtio_gpu_vram_free(obj);
236 				return ret;
237 			}
238 		}
239 	}
240 
241 	*bo_ptr = &vram->base;
242 	return 0;
243 }
244 
245 void virtio_gpu_vram_map_deferred(struct virtio_gpu_object_vram *vram)
246 {
247 	if (!(vram->base.blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE))
248 		return;
249 
250 	mutex_lock(&map_lock);
251 	if (!drm_mm_node_allocated(&vram->vram_node))
252 		virtio_gpu_vram_map(&vram->base);
253 	mutex_unlock(&map_lock);
254 }
255