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9c92ab61 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d4cab38e GP |
2 | /* |
3 | * drivers/dma-buf/sync_file.c | |
4 | * | |
5 | * Copyright (C) 2012 Google, Inc. | |
d4cab38e GP |
6 | */ |
7 | ||
519f490d | 8 | #include <linux/dma-fence-unwrap.h> |
d4cab38e GP |
9 | #include <linux/export.h> |
10 | #include <linux/file.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/poll.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/uaccess.h> | |
17 | #include <linux/anon_inodes.h> | |
460bfc41 GP |
18 | #include <linux/sync_file.h> |
19 | #include <uapi/linux/sync_file.h> | |
d4cab38e GP |
20 | |
21 | static const struct file_operations sync_file_fops; | |
22 | ||
a02b9dc9 | 23 | static struct sync_file *sync_file_alloc(void) |
d4cab38e GP |
24 | { |
25 | struct sync_file *sync_file; | |
26 | ||
a02b9dc9 | 27 | sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL); |
d4cab38e GP |
28 | if (!sync_file) |
29 | return NULL; | |
30 | ||
31 | sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops, | |
32 | sync_file, 0); | |
33 | if (IS_ERR(sync_file->file)) | |
34 | goto err; | |
35 | ||
d4cab38e GP |
36 | init_waitqueue_head(&sync_file->wq); |
37 | ||
a02b9dc9 GP |
38 | INIT_LIST_HEAD(&sync_file->cb.node); |
39 | ||
d4cab38e GP |
40 | return sync_file; |
41 | ||
42 | err: | |
43 | kfree(sync_file); | |
44 | return NULL; | |
45 | } | |
46 | ||
f54d1867 | 47 | static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb) |
d4cab38e | 48 | { |
d4cab38e GP |
49 | struct sync_file *sync_file; |
50 | ||
a02b9dc9 | 51 | sync_file = container_of(cb, struct sync_file, cb); |
d4cab38e | 52 | |
a02b9dc9 | 53 | wake_up_all(&sync_file->wq); |
d4cab38e GP |
54 | } |
55 | ||
56 | /** | |
c240a714 | 57 | * sync_file_create() - creates a sync file |
d4cab38e GP |
58 | * @fence: fence to add to the sync_fence |
59 | * | |
24a36734 DV |
60 | * Creates a sync_file containg @fence. This function acquires and additional |
61 | * reference of @fence for the newly-created &sync_file, if it succeeds. The | |
62 | * sync_file can be released with fput(sync_file->file). Returns the | |
63 | * sync_file or NULL in case of error. | |
d4cab38e | 64 | */ |
f54d1867 | 65 | struct sync_file *sync_file_create(struct dma_fence *fence) |
d4cab38e GP |
66 | { |
67 | struct sync_file *sync_file; | |
68 | ||
a02b9dc9 | 69 | sync_file = sync_file_alloc(); |
d4cab38e GP |
70 | if (!sync_file) |
71 | return NULL; | |
72 | ||
f54d1867 | 73 | sync_file->fence = dma_fence_get(fence); |
a02b9dc9 | 74 | |
d4cab38e GP |
75 | return sync_file; |
76 | } | |
77 | EXPORT_SYMBOL(sync_file_create); | |
78 | ||
d4cab38e GP |
79 | static struct sync_file *sync_file_fdget(int fd) |
80 | { | |
81 | struct file *file = fget(fd); | |
82 | ||
83 | if (!file) | |
84 | return NULL; | |
85 | ||
86 | if (file->f_op != &sync_file_fops) | |
87 | goto err; | |
88 | ||
89 | return file->private_data; | |
90 | ||
91 | err: | |
92 | fput(file); | |
93 | return NULL; | |
94 | } | |
95 | ||
972526a4 GP |
96 | /** |
97 | * sync_file_get_fence - get the fence related to the sync_file fd | |
98 | * @fd: sync_file fd to get the fence from | |
99 | * | |
100 | * Ensures @fd references a valid sync_file and returns a fence that | |
101 | * represents all fence in the sync_file. On error NULL is returned. | |
102 | */ | |
f54d1867 | 103 | struct dma_fence *sync_file_get_fence(int fd) |
972526a4 GP |
104 | { |
105 | struct sync_file *sync_file; | |
f54d1867 | 106 | struct dma_fence *fence; |
972526a4 GP |
107 | |
108 | sync_file = sync_file_fdget(fd); | |
109 | if (!sync_file) | |
110 | return NULL; | |
111 | ||
f54d1867 | 112 | fence = dma_fence_get(sync_file->fence); |
972526a4 GP |
113 | fput(sync_file->file); |
114 | ||
115 | return fence; | |
116 | } | |
117 | EXPORT_SYMBOL(sync_file_get_fence); | |
118 | ||
71ebc9a3 CW |
119 | /** |
120 | * sync_file_get_name - get the name of the sync_file | |
121 | * @sync_file: sync_file to get the fence from | |
122 | * @buf: destination buffer to copy sync_file name into | |
123 | * @len: available size of destination buffer. | |
124 | * | |
125 | * Each sync_file may have a name assigned either by the user (when merging | |
126 | * sync_files together) or created from the fence it contains. In the latter | |
127 | * case construction of the name is deferred until use, and so requires | |
128 | * sync_file_get_name(). | |
129 | * | |
130 | * Returns: a string representing the name. | |
131 | */ | |
132 | char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len) | |
133 | { | |
134 | if (sync_file->user_name[0]) { | |
bcfa6be2 | 135 | strscpy(buf, sync_file->user_name, len); |
71ebc9a3 CW |
136 | } else { |
137 | struct dma_fence *fence = sync_file->fence; | |
138 | ||
b312d8ca | 139 | snprintf(buf, len, "%s-%s%llu-%lld", |
71ebc9a3 CW |
140 | fence->ops->get_driver_name(fence), |
141 | fence->ops->get_timeline_name(fence), | |
142 | fence->context, | |
143 | fence->seqno); | |
144 | } | |
145 | ||
146 | return buf; | |
147 | } | |
148 | ||
d4cab38e GP |
149 | /** |
150 | * sync_file_merge() - merge two sync_files | |
151 | * @name: name of new fence | |
152 | * @a: sync_file a | |
153 | * @b: sync_file b | |
154 | * | |
155 | * Creates a new sync_file which contains copies of all the fences in both | |
156 | * @a and @b. @a and @b remain valid, independent sync_file. Returns the | |
157 | * new merged sync_file or NULL in case of error. | |
158 | */ | |
159 | static struct sync_file *sync_file_merge(const char *name, struct sync_file *a, | |
160 | struct sync_file *b) | |
161 | { | |
d4cab38e | 162 | struct sync_file *sync_file; |
245a4a7b | 163 | struct dma_fence *fence; |
d4cab38e | 164 | |
a02b9dc9 | 165 | sync_file = sync_file_alloc(); |
d4cab38e GP |
166 | if (!sync_file) |
167 | return NULL; | |
168 | ||
245a4a7b CK |
169 | fence = dma_fence_unwrap_merge(a->fence, b->fence); |
170 | if (!fence) { | |
171 | fput(sync_file->file); | |
172 | return NULL; | |
d4cab38e | 173 | } |
245a4a7b | 174 | sync_file->fence = fence; |
bcfa6be2 | 175 | strscpy(sync_file->user_name, name, sizeof(sync_file->user_name)); |
d4cab38e GP |
176 | return sync_file; |
177 | } | |
178 | ||
d8f2ebaa | 179 | static int sync_file_release(struct inode *inode, struct file *file) |
d4cab38e | 180 | { |
d8f2ebaa | 181 | struct sync_file *sync_file = file->private_data; |
d4cab38e | 182 | |
99f82843 | 183 | if (test_bit(POLL_ENABLED, &sync_file->flags)) |
f54d1867 CW |
184 | dma_fence_remove_callback(sync_file->fence, &sync_file->cb); |
185 | dma_fence_put(sync_file->fence); | |
d4cab38e | 186 | kfree(sync_file); |
d4cab38e | 187 | |
d4cab38e GP |
188 | return 0; |
189 | } | |
190 | ||
afc9a42b | 191 | static __poll_t sync_file_poll(struct file *file, poll_table *wait) |
d4cab38e GP |
192 | { |
193 | struct sync_file *sync_file = file->private_data; | |
d4cab38e GP |
194 | |
195 | poll_wait(file, &sync_file->wq, wait); | |
196 | ||
99f82843 CW |
197 | if (list_empty(&sync_file->cb.node) && |
198 | !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) { | |
f54d1867 CW |
199 | if (dma_fence_add_callback(sync_file->fence, &sync_file->cb, |
200 | fence_check_cb_func) < 0) | |
e2416553 GP |
201 | wake_up_all(&sync_file->wq); |
202 | } | |
d4cab38e | 203 | |
a9a08845 | 204 | return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0; |
d4cab38e GP |
205 | } |
206 | ||
207 | static long sync_file_ioctl_merge(struct sync_file *sync_file, | |
92e06213 | 208 | unsigned long arg) |
d4cab38e GP |
209 | { |
210 | int fd = get_unused_fd_flags(O_CLOEXEC); | |
211 | int err; | |
212 | struct sync_file *fence2, *fence3; | |
213 | struct sync_merge_data data; | |
214 | ||
215 | if (fd < 0) | |
216 | return fd; | |
217 | ||
218 | if (copy_from_user(&data, (void __user *)arg, sizeof(data))) { | |
219 | err = -EFAULT; | |
220 | goto err_put_fd; | |
221 | } | |
222 | ||
223 | if (data.flags || data.pad) { | |
224 | err = -EINVAL; | |
225 | goto err_put_fd; | |
226 | } | |
227 | ||
228 | fence2 = sync_file_fdget(data.fd2); | |
229 | if (!fence2) { | |
230 | err = -ENOENT; | |
231 | goto err_put_fd; | |
232 | } | |
233 | ||
234 | data.name[sizeof(data.name) - 1] = '\0'; | |
235 | fence3 = sync_file_merge(data.name, sync_file, fence2); | |
236 | if (!fence3) { | |
237 | err = -ENOMEM; | |
238 | goto err_put_fence2; | |
239 | } | |
240 | ||
241 | data.fence = fd; | |
242 | if (copy_to_user((void __user *)arg, &data, sizeof(data))) { | |
243 | err = -EFAULT; | |
244 | goto err_put_fence3; | |
245 | } | |
246 | ||
247 | fd_install(fd, fence3->file); | |
248 | fput(fence2->file); | |
249 | return 0; | |
250 | ||
251 | err_put_fence3: | |
252 | fput(fence3->file); | |
253 | ||
254 | err_put_fence2: | |
255 | fput(fence2->file); | |
256 | ||
257 | err_put_fd: | |
258 | put_unused_fd(fd); | |
259 | return err; | |
260 | } | |
261 | ||
f7974880 | 262 | static int sync_fill_fence_info(struct dma_fence *fence, |
92e06213 | 263 | struct sync_fence_info *info) |
d4cab38e | 264 | { |
bcfa6be2 | 265 | strscpy(info->obj_name, fence->ops->get_timeline_name(fence), |
d4cab38e | 266 | sizeof(info->obj_name)); |
bcfa6be2 | 267 | strscpy(info->driver_name, fence->ops->get_driver_name(fence), |
d4cab38e | 268 | sizeof(info->driver_name)); |
d6c99f4b CW |
269 | |
270 | info->status = dma_fence_get_status(fence); | |
76250f2b CW |
271 | while (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) && |
272 | !test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) | |
273 | cpu_relax(); | |
274 | info->timestamp_ns = | |
275 | test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags) ? | |
276 | ktime_to_ns(fence->timestamp) : | |
277 | ktime_set(0, 0); | |
f7974880 JER |
278 | |
279 | return info->status; | |
d4cab38e GP |
280 | } |
281 | ||
282 | static long sync_file_ioctl_fence_info(struct sync_file *sync_file, | |
92e06213 | 283 | unsigned long arg) |
d4cab38e | 284 | { |
d4cab38e | 285 | struct sync_fence_info *fence_info = NULL; |
519f490d CK |
286 | struct dma_fence_unwrap iter; |
287 | struct sync_file_info info; | |
288 | unsigned int num_fences; | |
289 | struct dma_fence *fence; | |
290 | int ret; | |
d4cab38e | 291 | __u32 size; |
d4cab38e GP |
292 | |
293 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
294 | return -EFAULT; | |
295 | ||
296 | if (info.flags || info.pad) | |
297 | return -EINVAL; | |
298 | ||
519f490d CK |
299 | num_fences = 0; |
300 | dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) | |
301 | ++num_fences; | |
a02b9dc9 | 302 | |
d4cab38e GP |
303 | /* |
304 | * Passing num_fences = 0 means that userspace doesn't want to | |
305 | * retrieve any sync_fence_info. If num_fences = 0 we skip filling | |
306 | * sync_fence_info and return the actual number of fences on | |
307 | * info->num_fences. | |
308 | */ | |
f7974880 | 309 | if (!info.num_fences) { |
7891c30a | 310 | info.status = dma_fence_get_status(sync_file->fence); |
d4cab38e | 311 | goto no_fences; |
f7974880 JER |
312 | } else { |
313 | info.status = 1; | |
314 | } | |
d4cab38e | 315 | |
a02b9dc9 | 316 | if (info.num_fences < num_fences) |
d4cab38e GP |
317 | return -EINVAL; |
318 | ||
a02b9dc9 | 319 | size = num_fences * sizeof(*fence_info); |
d4cab38e GP |
320 | fence_info = kzalloc(size, GFP_KERNEL); |
321 | if (!fence_info) | |
322 | return -ENOMEM; | |
323 | ||
519f490d CK |
324 | num_fences = 0; |
325 | dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) { | |
326 | int status; | |
327 | ||
328 | status = sync_fill_fence_info(fence, &fence_info[num_fences++]); | |
f7974880 JER |
329 | info.status = info.status <= 0 ? info.status : status; |
330 | } | |
d4cab38e GP |
331 | |
332 | if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info, | |
333 | size)) { | |
334 | ret = -EFAULT; | |
335 | goto out; | |
336 | } | |
337 | ||
338 | no_fences: | |
71ebc9a3 | 339 | sync_file_get_name(sync_file, info.name, sizeof(info.name)); |
a02b9dc9 | 340 | info.num_fences = num_fences; |
d4cab38e GP |
341 | |
342 | if (copy_to_user((void __user *)arg, &info, sizeof(info))) | |
343 | ret = -EFAULT; | |
344 | else | |
345 | ret = 0; | |
346 | ||
347 | out: | |
348 | kfree(fence_info); | |
349 | ||
350 | return ret; | |
351 | } | |
352 | ||
353 | static long sync_file_ioctl(struct file *file, unsigned int cmd, | |
92e06213 | 354 | unsigned long arg) |
d4cab38e GP |
355 | { |
356 | struct sync_file *sync_file = file->private_data; | |
357 | ||
358 | switch (cmd) { | |
359 | case SYNC_IOC_MERGE: | |
360 | return sync_file_ioctl_merge(sync_file, arg); | |
361 | ||
362 | case SYNC_IOC_FILE_INFO: | |
363 | return sync_file_ioctl_fence_info(sync_file, arg); | |
364 | ||
365 | default: | |
366 | return -ENOTTY; | |
367 | } | |
368 | } | |
369 | ||
370 | static const struct file_operations sync_file_fops = { | |
371 | .release = sync_file_release, | |
372 | .poll = sync_file_poll, | |
373 | .unlocked_ioctl = sync_file_ioctl, | |
1832f2d8 | 374 | .compat_ioctl = compat_ptr_ioctl, |
d4cab38e | 375 | }; |