1 // SPDX-License-Identifier: GPL-2.0
2 #include "virtgpu_drv.h"
3 
4 static void virtio_gpu_vram_free(struct drm_gem_object *obj)
5 {
6 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
7 	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
8 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
9 	bool unmap;
10 
11 	if (bo->created) {
12 		spin_lock(&vgdev->host_visible_lock);
13 		unmap = drm_mm_node_allocated(&vram->vram_node);
14 		spin_unlock(&vgdev->host_visible_lock);
15 
16 		if (unmap)
17 			virtio_gpu_cmd_unmap(vgdev, bo);
18 
19 		virtio_gpu_cmd_unref_resource(vgdev, bo);
20 		virtio_gpu_notify(vgdev);
21 		return;
22 	}
23 }
24 
25 static const struct vm_operations_struct virtio_gpu_vram_vm_ops = {
26 	.open = drm_gem_vm_open,
27 	.close = drm_gem_vm_close,
28 };
29 
30 static int virtio_gpu_vram_mmap(struct drm_gem_object *obj,
31 				struct vm_area_struct *vma)
32 {
33 	int ret;
34 	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
35 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
36 	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
37 	unsigned long vm_size = vma->vm_end - vma->vm_start;
38 
39 	if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE))
40 		return -EINVAL;
41 
42 	wait_event(vgdev->resp_wq, vram->map_state != STATE_INITIALIZING);
43 	if (vram->map_state != STATE_OK)
44 		return -EINVAL;
45 
46 	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
47 	vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND;
48 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
49 	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
50 	vma->vm_ops = &virtio_gpu_vram_vm_ops;
51 
52 	if (vram->map_info == VIRTIO_GPU_MAP_CACHE_WC)
53 		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
54 	else if (vram->map_info == VIRTIO_GPU_MAP_CACHE_UNCACHED)
55 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
56 
57 	/* Partial mappings of GEM buffers don't happen much in practice. */
58 	if (vm_size != vram->vram_node.size)
59 		return -EINVAL;
60 
61 	ret = io_remap_pfn_range(vma, vma->vm_start,
62 				 vram->vram_node.start >> PAGE_SHIFT,
63 				 vm_size, vma->vm_page_prot);
64 	return ret;
65 }
66 
67 static const struct drm_gem_object_funcs virtio_gpu_vram_funcs = {
68 	.open = virtio_gpu_gem_object_open,
69 	.close = virtio_gpu_gem_object_close,
70 	.free = virtio_gpu_vram_free,
71 	.mmap = virtio_gpu_vram_mmap,
72 };
73 
74 bool virtio_gpu_is_vram(struct virtio_gpu_object *bo)
75 {
76 	return bo->base.base.funcs == &virtio_gpu_vram_funcs;
77 }
78 
79 static int virtio_gpu_vram_map(struct virtio_gpu_object *bo)
80 {
81 	int ret;
82 	uint64_t offset;
83 	struct virtio_gpu_object_array *objs;
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 
87 	if (!vgdev->has_host_visible)
88 		return -EINVAL;
89 
90 	spin_lock(&vgdev->host_visible_lock);
91 	ret = drm_mm_insert_node(&vgdev->host_visible_mm, &vram->vram_node,
92 				 bo->base.base.size);
93 	spin_unlock(&vgdev->host_visible_lock);
94 
95 	if (ret)
96 		return ret;
97 
98 	objs = virtio_gpu_array_alloc(1);
99 	if (!objs) {
100 		ret = -ENOMEM;
101 		goto err_remove_node;
102 	}
103 
104 	virtio_gpu_array_add_obj(objs, &bo->base.base);
105 	/*TODO: Add an error checking helper function in drm_mm.h */
106 	offset = vram->vram_node.start - vgdev->host_visible_region.addr;
107 
108 	ret = virtio_gpu_cmd_map(vgdev, objs, offset);
109 	if (ret) {
110 		virtio_gpu_array_put_free(objs);
111 		goto err_remove_node;
112 	}
113 
114 	return 0;
115 
116 err_remove_node:
117 	spin_lock(&vgdev->host_visible_lock);
118 	drm_mm_remove_node(&vram->vram_node);
119 	spin_unlock(&vgdev->host_visible_lock);
120 	return ret;
121 }
122 
123 int virtio_gpu_vram_create(struct virtio_gpu_device *vgdev,
124 			   struct virtio_gpu_object_params *params,
125 			   struct virtio_gpu_object **bo_ptr)
126 {
127 	struct drm_gem_object *obj;
128 	struct virtio_gpu_object_vram *vram;
129 	int ret;
130 
131 	vram = kzalloc(sizeof(*vram), GFP_KERNEL);
132 	if (!vram)
133 		return -ENOMEM;
134 
135 	obj = &vram->base.base.base;
136 	obj->funcs = &virtio_gpu_vram_funcs;
137 	drm_gem_private_object_init(vgdev->ddev, obj, params->size);
138 
139 	/* Create fake offset */
140 	ret = drm_gem_create_mmap_offset(obj);
141 	if (ret) {
142 		kfree(vram);
143 		return ret;
144 	}
145 
146 	ret = virtio_gpu_resource_id_get(vgdev, &vram->base.hw_res_handle);
147 	if (ret) {
148 		kfree(vram);
149 		return ret;
150 	}
151 
152 	virtio_gpu_cmd_resource_create_blob(vgdev, &vram->base, params, NULL,
153 					    0);
154 	if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) {
155 		ret = virtio_gpu_vram_map(&vram->base);
156 		if (ret) {
157 			virtio_gpu_vram_free(obj);
158 			return ret;
159 		}
160 	}
161 
162 	*bo_ptr = &vram->base;
163 	return 0;
164 }
165