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3248877e DA |
1 | /* |
2 | * Copyright © 2012 Red Hat | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice (including the next | |
12 | * paragraph) shall be included in all copies or substantial portions of the | |
13 | * Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
21 | * IN THE SOFTWARE. | |
22 | * | |
23 | * Authors: | |
24 | * Dave Airlie <airlied@redhat.com> | |
25 | * Rob Clark <rob.clark@linaro.org> | |
26 | * | |
27 | */ | |
28 | ||
29 | #include <linux/export.h> | |
30 | #include <linux/dma-buf.h> | |
760285e7 | 31 | #include <drm/drmP.h> |
3248877e DA |
32 | |
33 | /* | |
34 | * DMA-BUF/GEM Object references and lifetime overview: | |
35 | * | |
36 | * On the export the dma_buf holds a reference to the exporting GEM | |
37 | * object. It takes this reference in handle_to_fd_ioctl, when it | |
38 | * first calls .prime_export and stores the exporting GEM object in | |
39 | * the dma_buf priv. This reference is released when the dma_buf | |
40 | * object goes away in the driver .release function. | |
41 | * | |
42 | * On the import the importing GEM object holds a reference to the | |
43 | * dma_buf (which in turn holds a ref to the exporting GEM object). | |
44 | * It takes that reference in the fd_to_handle ioctl. | |
45 | * It calls dma_buf_get, creates an attachment to it and stores the | |
46 | * attachment in the GEM object. When this attachment is destroyed | |
47 | * when the imported object is destroyed, we remove the attachment | |
48 | * and drop the reference to the dma_buf. | |
49 | * | |
50 | * Thus the chain of references always flows in one direction | |
51 | * (avoiding loops): importing_gem -> dmabuf -> exporting_gem | |
52 | * | |
53 | * Self-importing: if userspace is using PRIME as a replacement for flink | |
54 | * then it will get a fd->handle request for a GEM object that it created. | |
55 | * Drivers should detect this situation and return back the gem object | |
56 | * from the dma-buf private. | |
57 | */ | |
58 | ||
59 | struct drm_prime_member { | |
60 | struct list_head entry; | |
61 | struct dma_buf *dma_buf; | |
62 | uint32_t handle; | |
63 | }; | |
64 | ||
65 | int drm_gem_prime_handle_to_fd(struct drm_device *dev, | |
66 | struct drm_file *file_priv, uint32_t handle, uint32_t flags, | |
67 | int *prime_fd) | |
68 | { | |
69 | struct drm_gem_object *obj; | |
70 | void *buf; | |
0ff926c7 | 71 | int ret; |
3248877e DA |
72 | |
73 | obj = drm_gem_object_lookup(dev, file_priv, handle); | |
74 | if (!obj) | |
75 | return -ENOENT; | |
76 | ||
77 | mutex_lock(&file_priv->prime.lock); | |
78 | /* re-export the original imported object */ | |
79 | if (obj->import_attach) { | |
80 | get_dma_buf(obj->import_attach->dmabuf); | |
81 | *prime_fd = dma_buf_fd(obj->import_attach->dmabuf, flags); | |
82 | drm_gem_object_unreference_unlocked(obj); | |
83 | mutex_unlock(&file_priv->prime.lock); | |
84 | return 0; | |
85 | } | |
86 | ||
87 | if (obj->export_dma_buf) { | |
88 | get_dma_buf(obj->export_dma_buf); | |
89 | *prime_fd = dma_buf_fd(obj->export_dma_buf, flags); | |
90 | drm_gem_object_unreference_unlocked(obj); | |
91 | } else { | |
92 | buf = dev->driver->gem_prime_export(dev, obj, flags); | |
93 | if (IS_ERR(buf)) { | |
94 | /* normally the created dma-buf takes ownership of the ref, | |
95 | * but if that fails then drop the ref | |
96 | */ | |
97 | drm_gem_object_unreference_unlocked(obj); | |
98 | mutex_unlock(&file_priv->prime.lock); | |
99 | return PTR_ERR(buf); | |
100 | } | |
101 | obj->export_dma_buf = buf; | |
102 | *prime_fd = dma_buf_fd(buf, flags); | |
103 | } | |
0ff926c7 DA |
104 | /* if we've exported this buffer the cheat and add it to the import list |
105 | * so we get the correct handle back | |
106 | */ | |
107 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, | |
108 | obj->export_dma_buf, handle); | |
109 | if (ret) { | |
110 | drm_gem_object_unreference_unlocked(obj); | |
111 | mutex_unlock(&file_priv->prime.lock); | |
112 | return ret; | |
113 | } | |
114 | ||
3248877e DA |
115 | mutex_unlock(&file_priv->prime.lock); |
116 | return 0; | |
117 | } | |
118 | EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); | |
119 | ||
120 | int drm_gem_prime_fd_to_handle(struct drm_device *dev, | |
121 | struct drm_file *file_priv, int prime_fd, uint32_t *handle) | |
122 | { | |
123 | struct dma_buf *dma_buf; | |
124 | struct drm_gem_object *obj; | |
125 | int ret; | |
126 | ||
127 | dma_buf = dma_buf_get(prime_fd); | |
128 | if (IS_ERR(dma_buf)) | |
129 | return PTR_ERR(dma_buf); | |
130 | ||
131 | mutex_lock(&file_priv->prime.lock); | |
132 | ||
133 | ret = drm_prime_lookup_imported_buf_handle(&file_priv->prime, | |
134 | dma_buf, handle); | |
135 | if (!ret) { | |
136 | ret = 0; | |
137 | goto out_put; | |
138 | } | |
139 | ||
140 | /* never seen this one, need to import */ | |
141 | obj = dev->driver->gem_prime_import(dev, dma_buf); | |
142 | if (IS_ERR(obj)) { | |
143 | ret = PTR_ERR(obj); | |
144 | goto out_put; | |
145 | } | |
146 | ||
147 | ret = drm_gem_handle_create(file_priv, obj, handle); | |
148 | drm_gem_object_unreference_unlocked(obj); | |
149 | if (ret) | |
150 | goto out_put; | |
151 | ||
152 | ret = drm_prime_add_imported_buf_handle(&file_priv->prime, | |
153 | dma_buf, *handle); | |
154 | if (ret) | |
155 | goto fail; | |
156 | ||
157 | mutex_unlock(&file_priv->prime.lock); | |
158 | return 0; | |
159 | ||
160 | fail: | |
161 | /* hmm, if driver attached, we are relying on the free-object path | |
162 | * to detach.. which seems ok.. | |
163 | */ | |
164 | drm_gem_object_handle_unreference_unlocked(obj); | |
165 | out_put: | |
166 | dma_buf_put(dma_buf); | |
167 | mutex_unlock(&file_priv->prime.lock); | |
168 | return ret; | |
169 | } | |
170 | EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); | |
171 | ||
172 | int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, | |
173 | struct drm_file *file_priv) | |
174 | { | |
175 | struct drm_prime_handle *args = data; | |
176 | uint32_t flags; | |
177 | ||
178 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) | |
179 | return -EINVAL; | |
180 | ||
181 | if (!dev->driver->prime_handle_to_fd) | |
182 | return -ENOSYS; | |
183 | ||
184 | /* check flags are valid */ | |
185 | if (args->flags & ~DRM_CLOEXEC) | |
186 | return -EINVAL; | |
187 | ||
188 | /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ | |
189 | flags = args->flags & DRM_CLOEXEC; | |
190 | ||
191 | return dev->driver->prime_handle_to_fd(dev, file_priv, | |
192 | args->handle, flags, &args->fd); | |
193 | } | |
194 | ||
195 | int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, | |
196 | struct drm_file *file_priv) | |
197 | { | |
198 | struct drm_prime_handle *args = data; | |
199 | ||
200 | if (!drm_core_check_feature(dev, DRIVER_PRIME)) | |
201 | return -EINVAL; | |
202 | ||
203 | if (!dev->driver->prime_fd_to_handle) | |
204 | return -ENOSYS; | |
205 | ||
206 | return dev->driver->prime_fd_to_handle(dev, file_priv, | |
207 | args->fd, &args->handle); | |
208 | } | |
209 | ||
210 | /* | |
211 | * drm_prime_pages_to_sg | |
212 | * | |
213 | * this helper creates an sg table object from a set of pages | |
214 | * the driver is responsible for mapping the pages into the | |
215 | * importers address space | |
216 | */ | |
217 | struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) | |
218 | { | |
219 | struct sg_table *sg = NULL; | |
220 | struct scatterlist *iter; | |
221 | int i; | |
222 | int ret; | |
223 | ||
224 | sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); | |
225 | if (!sg) | |
226 | goto out; | |
227 | ||
228 | ret = sg_alloc_table(sg, nr_pages, GFP_KERNEL); | |
229 | if (ret) | |
230 | goto out; | |
231 | ||
232 | for_each_sg(sg->sgl, iter, nr_pages, i) | |
233 | sg_set_page(iter, pages[i], PAGE_SIZE, 0); | |
234 | ||
235 | return sg; | |
236 | out: | |
237 | kfree(sg); | |
238 | return NULL; | |
239 | } | |
240 | EXPORT_SYMBOL(drm_prime_pages_to_sg); | |
241 | ||
51ab7ba2 DA |
242 | /* export an sg table into an array of pages and addresses |
243 | this is currently required by the TTM driver in order to do correct fault | |
244 | handling */ | |
245 | int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, | |
246 | dma_addr_t *addrs, int max_pages) | |
247 | { | |
248 | unsigned count; | |
249 | struct scatterlist *sg; | |
250 | struct page *page; | |
251 | u32 len, offset; | |
252 | int pg_index; | |
253 | dma_addr_t addr; | |
254 | ||
255 | pg_index = 0; | |
256 | for_each_sg(sgt->sgl, sg, sgt->nents, count) { | |
257 | len = sg->length; | |
258 | offset = sg->offset; | |
259 | page = sg_page(sg); | |
260 | addr = sg_dma_address(sg); | |
261 | ||
262 | while (len > 0) { | |
263 | if (WARN_ON(pg_index >= max_pages)) | |
264 | return -1; | |
265 | pages[pg_index] = page; | |
266 | if (addrs) | |
267 | addrs[pg_index] = addr; | |
268 | ||
269 | page++; | |
270 | addr += PAGE_SIZE; | |
271 | len -= PAGE_SIZE; | |
272 | pg_index++; | |
273 | } | |
274 | } | |
275 | return 0; | |
276 | } | |
277 | EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); | |
3248877e DA |
278 | /* helper function to cleanup a GEM/prime object */ |
279 | void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) | |
280 | { | |
281 | struct dma_buf_attachment *attach; | |
282 | struct dma_buf *dma_buf; | |
283 | attach = obj->import_attach; | |
284 | if (sg) | |
285 | dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); | |
286 | dma_buf = attach->dmabuf; | |
287 | dma_buf_detach(attach->dmabuf, attach); | |
288 | /* remove the reference */ | |
289 | dma_buf_put(dma_buf); | |
290 | } | |
291 | EXPORT_SYMBOL(drm_prime_gem_destroy); | |
292 | ||
293 | void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) | |
294 | { | |
295 | INIT_LIST_HEAD(&prime_fpriv->head); | |
296 | mutex_init(&prime_fpriv->lock); | |
297 | } | |
298 | EXPORT_SYMBOL(drm_prime_init_file_private); | |
299 | ||
300 | void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) | |
301 | { | |
302 | struct drm_prime_member *member, *safe; | |
303 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { | |
304 | list_del(&member->entry); | |
305 | kfree(member); | |
306 | } | |
307 | } | |
308 | EXPORT_SYMBOL(drm_prime_destroy_file_private); | |
309 | ||
310 | int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle) | |
311 | { | |
312 | struct drm_prime_member *member; | |
313 | ||
314 | member = kmalloc(sizeof(*member), GFP_KERNEL); | |
315 | if (!member) | |
316 | return -ENOMEM; | |
317 | ||
318 | member->dma_buf = dma_buf; | |
319 | member->handle = handle; | |
320 | list_add(&member->entry, &prime_fpriv->head); | |
321 | return 0; | |
322 | } | |
323 | EXPORT_SYMBOL(drm_prime_add_imported_buf_handle); | |
324 | ||
325 | int drm_prime_lookup_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle) | |
326 | { | |
327 | struct drm_prime_member *member; | |
328 | ||
329 | list_for_each_entry(member, &prime_fpriv->head, entry) { | |
330 | if (member->dma_buf == dma_buf) { | |
331 | *handle = member->handle; | |
332 | return 0; | |
333 | } | |
334 | } | |
335 | return -ENOENT; | |
336 | } | |
337 | EXPORT_SYMBOL(drm_prime_lookup_imported_buf_handle); | |
338 | ||
339 | void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) | |
340 | { | |
341 | struct drm_prime_member *member, *safe; | |
342 | ||
343 | mutex_lock(&prime_fpriv->lock); | |
344 | list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { | |
345 | if (member->dma_buf == dma_buf) { | |
346 | list_del(&member->entry); | |
347 | kfree(member); | |
348 | } | |
349 | } | |
350 | mutex_unlock(&prime_fpriv->lock); | |
351 | } | |
352 | EXPORT_SYMBOL(drm_prime_remove_imported_buf_handle); |