1 /*
2  * Copyright (C) 2015 Red Hat, Inc.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial
15  * portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  */
25 
26 #include <linux/dma-mapping.h>
27 #include <linux/moduleparam.h>
28 
29 #include "virtgpu_drv.h"
30 
31 static int virtio_gpu_virglrenderer_workaround = 1;
32 module_param_named(virglhack, virtio_gpu_virglrenderer_workaround, int, 0400);
33 
34 static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
35 				       uint32_t *resid)
36 {
37 	if (virtio_gpu_virglrenderer_workaround) {
38 		/*
39 		 * Hack to avoid re-using resource IDs.
40 		 *
41 		 * virglrenderer versions up to (and including) 0.7.0
42 		 * can't deal with that.  virglrenderer commit
43 		 * "f91a9dd35715 Fix unlinking resources from hash
44 		 * table." (Feb 2019) fixes the bug.
45 		 */
46 		static atomic_t seqno = ATOMIC_INIT(0);
47 		int handle = atomic_inc_return(&seqno);
48 		*resid = handle + 1;
49 	} else {
50 		int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL);
51 		if (handle < 0)
52 			return handle;
53 		*resid = handle + 1;
54 	}
55 	return 0;
56 }
57 
58 static void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id)
59 {
60 	if (!virtio_gpu_virglrenderer_workaround) {
61 		ida_free(&vgdev->resource_ida, id - 1);
62 	}
63 }
64 
65 void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
66 {
67 	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
68 
69 	virtio_gpu_resource_id_put(vgdev, bo->hw_res_handle);
70 	if (virtio_gpu_is_shmem(bo)) {
71 		struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
72 
73 		if (shmem->pages) {
74 			if (shmem->mapped) {
75 				dma_unmap_sg(vgdev->vdev->dev.parent,
76 					     shmem->pages->sgl, shmem->mapped,
77 					     DMA_TO_DEVICE);
78 				shmem->mapped = 0;
79 			}
80 
81 			sg_free_table(shmem->pages);
82 			kfree(shmem->pages);
83 			shmem->pages = NULL;
84 			drm_gem_shmem_unpin(&bo->base.base);
85 		}
86 
87 		drm_gem_shmem_free_object(&bo->base.base);
88 	}
89 }
90 
91 static void virtio_gpu_free_object(struct drm_gem_object *obj)
92 {
93 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
94 	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
95 
96 	if (bo->created) {
97 		virtio_gpu_cmd_unref_resource(vgdev, bo);
98 		virtio_gpu_notify(vgdev);
99 		/* completion handler calls virtio_gpu_cleanup_object() */
100 		return;
101 	}
102 	virtio_gpu_cleanup_object(bo);
103 }
104 
105 static const struct drm_gem_object_funcs virtio_gpu_shmem_funcs = {
106 	.free = virtio_gpu_free_object,
107 	.open = virtio_gpu_gem_object_open,
108 	.close = virtio_gpu_gem_object_close,
109 
110 	.print_info = drm_gem_shmem_print_info,
111 	.pin = drm_gem_shmem_pin,
112 	.unpin = drm_gem_shmem_unpin,
113 	.get_sg_table = drm_gem_shmem_get_sg_table,
114 	.vmap = drm_gem_shmem_vmap,
115 	.vunmap = drm_gem_shmem_vunmap,
116 	.mmap = drm_gem_shmem_mmap,
117 };
118 
119 bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo)
120 {
121 	return bo->base.base.funcs == &virtio_gpu_shmem_funcs;
122 }
123 
124 struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev,
125 						size_t size)
126 {
127 	struct virtio_gpu_object_shmem *shmem;
128 	struct drm_gem_shmem_object *dshmem;
129 
130 	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
131 	if (!shmem)
132 		return NULL;
133 
134 	dshmem = &shmem->base.base;
135 	dshmem->base.funcs = &virtio_gpu_shmem_funcs;
136 	dshmem->map_cached = true;
137 	return &dshmem->base;
138 }
139 
140 static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
141 					struct virtio_gpu_object *bo,
142 					struct virtio_gpu_mem_entry **ents,
143 					unsigned int *nents)
144 {
145 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
146 	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
147 	struct scatterlist *sg;
148 	int si, ret;
149 
150 	ret = drm_gem_shmem_pin(&bo->base.base);
151 	if (ret < 0)
152 		return -EINVAL;
153 
154 	/*
155 	 * virtio_gpu uses drm_gem_shmem_get_sg_table instead of
156 	 * drm_gem_shmem_get_pages_sgt because virtio has it's own set of
157 	 * dma-ops. This is discouraged for other drivers, but should be fine
158 	 * since virtio_gpu doesn't support dma-buf import from other devices.
159 	 */
160 	shmem->pages = drm_gem_shmem_get_sg_table(&bo->base.base);
161 	if (!shmem->pages) {
162 		drm_gem_shmem_unpin(&bo->base.base);
163 		return -EINVAL;
164 	}
165 
166 	if (use_dma_api) {
167 		shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent,
168 					   shmem->pages->sgl,
169 					   shmem->pages->nents,
170 					   DMA_TO_DEVICE);
171 		*nents = shmem->mapped;
172 	} else {
173 		*nents = shmem->pages->nents;
174 	}
175 
176 	*ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry),
177 			      GFP_KERNEL);
178 	if (!(*ents)) {
179 		DRM_ERROR("failed to allocate ent list\n");
180 		return -ENOMEM;
181 	}
182 
183 	for_each_sg(shmem->pages->sgl, sg, *nents, si) {
184 		(*ents)[si].addr = cpu_to_le64(use_dma_api
185 					       ? sg_dma_address(sg)
186 					       : sg_phys(sg));
187 		(*ents)[si].length = cpu_to_le32(sg->length);
188 		(*ents)[si].padding = 0;
189 	}
190 	return 0;
191 }
192 
193 int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
194 			     struct virtio_gpu_object_params *params,
195 			     struct virtio_gpu_object **bo_ptr,
196 			     struct virtio_gpu_fence *fence)
197 {
198 	struct virtio_gpu_object_array *objs = NULL;
199 	struct drm_gem_shmem_object *shmem_obj;
200 	struct virtio_gpu_object *bo;
201 	struct virtio_gpu_mem_entry *ents;
202 	unsigned int nents;
203 	int ret;
204 
205 	*bo_ptr = NULL;
206 
207 	params->size = roundup(params->size, PAGE_SIZE);
208 	shmem_obj = drm_gem_shmem_create(vgdev->ddev, params->size);
209 	if (IS_ERR(shmem_obj))
210 		return PTR_ERR(shmem_obj);
211 	bo = gem_to_virtio_gpu_obj(&shmem_obj->base);
212 
213 	ret = virtio_gpu_resource_id_get(vgdev, &bo->hw_res_handle);
214 	if (ret < 0)
215 		goto err_free_gem;
216 
217 	bo->dumb = params->dumb;
218 
219 	if (fence) {
220 		ret = -ENOMEM;
221 		objs = virtio_gpu_array_alloc(1);
222 		if (!objs)
223 			goto err_put_id;
224 		virtio_gpu_array_add_obj(objs, &bo->base.base);
225 
226 		ret = virtio_gpu_array_lock_resv(objs);
227 		if (ret != 0)
228 			goto err_put_objs;
229 	}
230 
231 	if (params->virgl) {
232 		virtio_gpu_cmd_resource_create_3d(vgdev, bo, params,
233 						  objs, fence);
234 	} else {
235 		virtio_gpu_cmd_create_resource(vgdev, bo, params,
236 					       objs, fence);
237 	}
238 
239 	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
240 	if (ret != 0) {
241 		virtio_gpu_free_object(&shmem_obj->base);
242 		return ret;
243 	}
244 
245 	virtio_gpu_object_attach(vgdev, bo, ents, nents);
246 
247 	*bo_ptr = bo;
248 	return 0;
249 
250 err_put_objs:
251 	virtio_gpu_array_put_free(objs);
252 err_put_id:
253 	virtio_gpu_resource_id_put(vgdev, bo->hw_res_handle);
254 err_free_gem:
255 	drm_gem_shmem_free_object(&shmem_obj->base);
256 	return ret;
257 }
258