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(lock: &vgdev->host_visible_lock);
15 unmap = drm_mm_node_allocated(node: &vram->vram_node);
16 spin_unlock(lock: &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(node: &obj->vma_node);
49 vm_flags_set(vma, VM_MIXEDMAP | VM_DONTEXPAND);
50 vma->vm_page_prot = vm_get_page_prot(vm_flags: 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(prot: 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, addr: vma->vm_start,
64 pfn: vram->vram_node.start >> PAGE_SHIFT,
65 size: vm_size, prot: 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(size: sizeof(*sgt), GFP_KERNEL);
80 if (!sgt)
81 return ERR_PTR(error: -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, phys_addr: vram->vram_node.start,
98 size: vram->vram_node.size, dir,
99 DMA_ATTR_SKIP_CPU_SYNC);
100 ret = dma_mapping_error(dev, dma_addr: addr);
101 if (ret)
102 goto out;
103
104 sg_set_page(sg: sgt->sgl, NULL, len: vram->vram_node.size, offset: 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(objp: sgt);
112 return ERR_PTR(error: 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(objp: 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(lock: &vgdev->host_visible_lock);
153 ret = drm_mm_insert_node(mm: &vgdev->host_visible_mm, node: &vram->vram_node,
154 size: bo->base.base.size);
155 spin_unlock(lock: &vgdev->host_visible_lock);
156
157 if (ret)
158 return ret;
159
160 objs = virtio_gpu_array_alloc(nents: 1);
161 if (!objs) {
162 ret = -ENOMEM;
163 goto err_remove_node;
164 }
165
166 virtio_gpu_array_add_obj(objs, obj: &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(lock: &vgdev->host_visible_lock);
180 drm_mm_remove_node(node: &vram->vram_node);
181 spin_unlock(lock: &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(size: 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(dev: vgdev->ddev, obj, size: params->size);
202
203 /* Create fake offset */
204 ret = drm_gem_create_mmap_offset(obj);
205 if (ret) {
206 kfree(objp: vram);
207 return ret;
208 }
209
210 ret = virtio_gpu_resource_id_get(vgdev, resid: &vram->base.hw_res_handle);
211 if (ret) {
212 kfree(objp: vram);
213 return ret;
214 }
215
216 virtio_gpu_cmd_resource_create_blob(vgdev, bo: &vram->base, params, NULL,
217 nents: 0);
218 if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) {
219 ret = virtio_gpu_vram_map(bo: &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}
229

source code of linux/drivers/gpu/drm/virtio/virtgpu_vram.c