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v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * drivers/dma-buf/sync_file.c
  4 *
  5 * Copyright (C) 2012 Google, Inc.
 
 
 
 
 
 
 
 
 
 
  6 */
  7
  8#include <linux/dma-fence-unwrap.h>
  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>
 18#include <linux/sync_file.h>
 19#include <uapi/linux/sync_file.h>
 20
 21static const struct file_operations sync_file_fops;
 22
 23static struct sync_file *sync_file_alloc(void)
 24{
 25	struct sync_file *sync_file;
 26
 27	sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
 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
 
 
 36	init_waitqueue_head(&sync_file->wq);
 37
 38	INIT_LIST_HEAD(&sync_file->cb.node);
 39
 40	return sync_file;
 41
 42err:
 43	kfree(sync_file);
 44	return NULL;
 45}
 46
 47static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb)
 48{
 49	struct sync_file *sync_file;
 50
 51	sync_file = container_of(cb, struct sync_file, cb);
 52
 53	wake_up_all(&sync_file->wq);
 54}
 55
 56/**
 57 * sync_file_create() - creates a sync file
 58 * @fence:	fence to add to the sync_fence
 59 *
 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.
 64 */
 65struct sync_file *sync_file_create(struct dma_fence *fence)
 66{
 67	struct sync_file *sync_file;
 68
 69	sync_file = sync_file_alloc();
 70	if (!sync_file)
 71		return NULL;
 72
 73	sync_file->fence = dma_fence_get(fence);
 74
 
 
 
 
 
 75	return sync_file;
 76}
 77EXPORT_SYMBOL(sync_file_create);
 78
 
 
 
 
 
 
 
 79static 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
 91err:
 92	fput(file);
 93	return NULL;
 94}
 95
 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 */
103struct dma_fence *sync_file_get_fence(int fd)
104{
105	struct sync_file *sync_file;
106	struct dma_fence *fence;
107
108	sync_file = sync_file_fdget(fd);
109	if (!sync_file)
110		return NULL;
111
112	fence = dma_fence_get(sync_file->fence);
113	fput(sync_file->file);
114
115	return fence;
116}
117EXPORT_SYMBOL(sync_file_get_fence);
118
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 */
132char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len)
133{
134	if (sync_file->user_name[0]) {
135		strscpy(buf, sync_file->user_name, len);
 
 
 
 
 
 
 
 
 
136	} else {
137		struct dma_fence *fence = sync_file->fence;
 
 
 
 
138
139		snprintf(buf, len, "%s-%s%llu-%lld",
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
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 */
159static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
160					 struct sync_file *b)
161{
162	struct sync_file *sync_file;
163	struct dma_fence *fence;
 
164
165	sync_file = sync_file_alloc();
166	if (!sync_file)
167		return NULL;
168
169	fence = dma_fence_unwrap_merge(a->fence, b->fence);
170	if (!fence) {
171		fput(sync_file->file);
172		return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
173	}
174	sync_file->fence = fence;
175	strscpy(sync_file->user_name, name, sizeof(sync_file->user_name));
176	return sync_file;
 
 
 
 
 
177}
178
179static int sync_file_release(struct inode *inode, struct file *file)
180{
181	struct sync_file *sync_file = file->private_data;
 
182
183	if (test_bit(POLL_ENABLED, &sync_file->flags))
184		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
185	dma_fence_put(sync_file->fence);
186	kfree(sync_file);
 
 
 
 
 
187
 
188	return 0;
189}
190
191static __poll_t sync_file_poll(struct file *file, poll_table *wait)
192{
193	struct sync_file *sync_file = file->private_data;
194
195	poll_wait(file, &sync_file->wq, wait);
196
197	if (list_empty(&sync_file->cb.node) &&
198	    !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {
199		if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
200					   fence_check_cb_func) < 0)
201			wake_up_all(&sync_file->wq);
202	}
203
204	return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0;
205}
206
207static long sync_file_ioctl_merge(struct sync_file *sync_file,
208				  unsigned long arg)
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
251err_put_fence3:
252	fput(fence3->file);
253
254err_put_fence2:
255	fput(fence2->file);
256
257err_put_fd:
258	put_unused_fd(fd);
259	return err;
260}
261
262static int sync_fill_fence_info(struct dma_fence *fence,
263				 struct sync_fence_info *info)
264{
265	strscpy(info->obj_name, fence->ops->get_timeline_name(fence),
266		sizeof(info->obj_name));
267	strscpy(info->driver_name, fence->ops->get_driver_name(fence),
268		sizeof(info->driver_name));
269
270	info->status = dma_fence_get_status(fence);
271	info->timestamp_ns =
272		dma_fence_is_signaled(fence) ?
273			ktime_to_ns(dma_fence_timestamp(fence)) :
274			ktime_set(0, 0);
275
276	return info->status;
277}
278
279static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
280				       unsigned long arg)
281{
282	struct sync_fence_info *fence_info = NULL;
283	struct dma_fence_unwrap iter;
284	struct sync_file_info info;
285	unsigned int num_fences;
286	struct dma_fence *fence;
287	int ret;
288	__u32 size;
 
289
290	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
291		return -EFAULT;
292
293	if (info.flags || info.pad)
294		return -EINVAL;
295
296	num_fences = 0;
297	dma_fence_unwrap_for_each(fence, &iter, sync_file->fence)
298		++num_fences;
299
300	/*
301	 * Passing num_fences = 0 means that userspace doesn't want to
302	 * retrieve any sync_fence_info. If num_fences = 0 we skip filling
303	 * sync_fence_info and return the actual number of fences on
304	 * info->num_fences.
305	 */
306	if (!info.num_fences) {
307		info.status = dma_fence_get_status(sync_file->fence);
308		goto no_fences;
309	} else {
310		info.status = 1;
311	}
312
313	if (info.num_fences < num_fences)
314		return -EINVAL;
315
316	size = num_fences * sizeof(*fence_info);
317	fence_info = kzalloc(size, GFP_KERNEL);
318	if (!fence_info)
319		return -ENOMEM;
320
321	num_fences = 0;
322	dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) {
323		int status;
324
325		status = sync_fill_fence_info(fence, &fence_info[num_fences++]);
326		info.status = info.status <= 0 ? info.status : status;
327	}
328
329	if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
330			 size)) {
331		ret = -EFAULT;
332		goto out;
333	}
334
335no_fences:
336	sync_file_get_name(sync_file, info.name, sizeof(info.name));
 
337	info.num_fences = num_fences;
338
339	if (copy_to_user((void __user *)arg, &info, sizeof(info)))
340		ret = -EFAULT;
341	else
342		ret = 0;
343
344out:
345	kfree(fence_info);
346
347	return ret;
348}
349
350static int sync_file_ioctl_set_deadline(struct sync_file *sync_file,
351					unsigned long arg)
352{
353	struct sync_set_deadline ts;
354
355	if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))
356		return -EFAULT;
357
358	if (ts.pad)
359		return -EINVAL;
360
361	dma_fence_set_deadline(sync_file->fence, ns_to_ktime(ts.deadline_ns));
362
363	return 0;
364}
365
366static long sync_file_ioctl(struct file *file, unsigned int cmd,
367			    unsigned long arg)
368{
369	struct sync_file *sync_file = file->private_data;
370
371	switch (cmd) {
372	case SYNC_IOC_MERGE:
373		return sync_file_ioctl_merge(sync_file, arg);
374
375	case SYNC_IOC_FILE_INFO:
376		return sync_file_ioctl_fence_info(sync_file, arg);
377
378	case SYNC_IOC_SET_DEADLINE:
379		return sync_file_ioctl_set_deadline(sync_file, arg);
380
381	default:
382		return -ENOTTY;
383	}
384}
385
386static const struct file_operations sync_file_fops = {
387	.release = sync_file_release,
388	.poll = sync_file_poll,
389	.unlocked_ioctl = sync_file_ioctl,
390	.compat_ioctl = compat_ptr_ioctl,
391};
v4.10.11
 
  1/*
  2 * drivers/dma-buf/sync_file.c
  3 *
  4 * Copyright (C) 2012 Google, Inc.
  5 *
  6 * This software is licensed under the terms of the GNU General Public
  7 * License version 2, as published by the Free Software Foundation, and
  8 * may be copied, distributed, and modified under those terms.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 */
 16
 
 17#include <linux/export.h>
 18#include <linux/file.h>
 19#include <linux/fs.h>
 20#include <linux/kernel.h>
 21#include <linux/poll.h>
 22#include <linux/sched.h>
 23#include <linux/slab.h>
 24#include <linux/uaccess.h>
 25#include <linux/anon_inodes.h>
 26#include <linux/sync_file.h>
 27#include <uapi/linux/sync_file.h>
 28
 29static const struct file_operations sync_file_fops;
 30
 31static struct sync_file *sync_file_alloc(void)
 32{
 33	struct sync_file *sync_file;
 34
 35	sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
 36	if (!sync_file)
 37		return NULL;
 38
 39	sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,
 40					     sync_file, 0);
 41	if (IS_ERR(sync_file->file))
 42		goto err;
 43
 44	kref_init(&sync_file->kref);
 45
 46	init_waitqueue_head(&sync_file->wq);
 47
 48	INIT_LIST_HEAD(&sync_file->cb.node);
 49
 50	return sync_file;
 51
 52err:
 53	kfree(sync_file);
 54	return NULL;
 55}
 56
 57static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb)
 58{
 59	struct sync_file *sync_file;
 60
 61	sync_file = container_of(cb, struct sync_file, cb);
 62
 63	wake_up_all(&sync_file->wq);
 64}
 65
 66/**
 67 * sync_file_create() - creates a sync file
 68 * @fence:	fence to add to the sync_fence
 69 *
 70 * Creates a sync_file containg @fence. Once this is called, the sync_file
 71 * takes ownership of @fence. The sync_file can be released with
 72 * fput(sync_file->file). Returns the sync_file or NULL in case of error.
 
 73 */
 74struct sync_file *sync_file_create(struct dma_fence *fence)
 75{
 76	struct sync_file *sync_file;
 77
 78	sync_file = sync_file_alloc();
 79	if (!sync_file)
 80		return NULL;
 81
 82	sync_file->fence = dma_fence_get(fence);
 83
 84	snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%llu-%d",
 85		 fence->ops->get_driver_name(fence),
 86		 fence->ops->get_timeline_name(fence), fence->context,
 87		 fence->seqno);
 88
 89	return sync_file;
 90}
 91EXPORT_SYMBOL(sync_file_create);
 92
 93/**
 94 * sync_file_fdget() - get a sync_file from an fd
 95 * @fd:		fd referencing a fence
 96 *
 97 * Ensures @fd references a valid sync_file, increments the refcount of the
 98 * backing file. Returns the sync_file or NULL in case of error.
 99 */
100static struct sync_file *sync_file_fdget(int fd)
101{
102	struct file *file = fget(fd);
103
104	if (!file)
105		return NULL;
106
107	if (file->f_op != &sync_file_fops)
108		goto err;
109
110	return file->private_data;
111
112err:
113	fput(file);
114	return NULL;
115}
116
117/**
118 * sync_file_get_fence - get the fence related to the sync_file fd
119 * @fd:		sync_file fd to get the fence from
120 *
121 * Ensures @fd references a valid sync_file and returns a fence that
122 * represents all fence in the sync_file. On error NULL is returned.
123 */
124struct dma_fence *sync_file_get_fence(int fd)
125{
126	struct sync_file *sync_file;
127	struct dma_fence *fence;
128
129	sync_file = sync_file_fdget(fd);
130	if (!sync_file)
131		return NULL;
132
133	fence = dma_fence_get(sync_file->fence);
134	fput(sync_file->file);
135
136	return fence;
137}
138EXPORT_SYMBOL(sync_file_get_fence);
139
140static int sync_file_set_fence(struct sync_file *sync_file,
141			       struct dma_fence **fences, int num_fences)
 
 
 
 
 
 
 
 
 
 
 
 
142{
143	struct dma_fence_array *array;
144
145	/*
146	 * The reference for the fences in the new sync_file and held
147	 * in add_fence() during the merge procedure, so for num_fences == 1
148	 * we already own a new reference to the fence. For num_fence > 1
149	 * we own the reference of the dma_fence_array creation.
150	 */
151	if (num_fences == 1) {
152		sync_file->fence = fences[0];
153		kfree(fences);
154	} else {
155		array = dma_fence_array_create(num_fences, fences,
156					       dma_fence_context_alloc(1),
157					       1, false);
158		if (!array)
159			return -ENOMEM;
160
161		sync_file->fence = &array->base;
 
 
 
 
162	}
163
164	return 0;
165}
166
167static struct dma_fence **get_fences(struct sync_file *sync_file,
168				     int *num_fences)
169{
170	if (dma_fence_is_array(sync_file->fence)) {
171		struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
172
173		*num_fences = array->num_fences;
174		return array->fences;
175	}
176
177	*num_fences = 1;
178	return &sync_file->fence;
179}
180
181static void add_fence(struct dma_fence **fences,
182		      int *i, struct dma_fence *fence)
183{
184	fences[*i] = fence;
185
186	if (!dma_fence_is_signaled(fence)) {
187		dma_fence_get(fence);
188		(*i)++;
189	}
190}
191
192/**
193 * sync_file_merge() - merge two sync_files
194 * @name:	name of new fence
195 * @a:		sync_file a
196 * @b:		sync_file b
197 *
198 * Creates a new sync_file which contains copies of all the fences in both
199 * @a and @b.  @a and @b remain valid, independent sync_file. Returns the
200 * new merged sync_file or NULL in case of error.
201 */
202static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
203					 struct sync_file *b)
204{
205	struct sync_file *sync_file;
206	struct dma_fence **fences, **nfences, **a_fences, **b_fences;
207	int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
208
209	sync_file = sync_file_alloc();
210	if (!sync_file)
211		return NULL;
212
213	a_fences = get_fences(a, &a_num_fences);
214	b_fences = get_fences(b, &b_num_fences);
215	if (a_num_fences > INT_MAX - b_num_fences)
216		return NULL;
217
218	num_fences = a_num_fences + b_num_fences;
219
220	fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
221	if (!fences)
222		goto err;
223
224	/*
225	 * Assume sync_file a and b are both ordered and have no
226	 * duplicates with the same context.
227	 *
228	 * If a sync_file can only be created with sync_file_merge
229	 * and sync_file_create, this is a reasonable assumption.
230	 */
231	for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
232		struct dma_fence *pt_a = a_fences[i_a];
233		struct dma_fence *pt_b = b_fences[i_b];
234
235		if (pt_a->context < pt_b->context) {
236			add_fence(fences, &i, pt_a);
237
238			i_a++;
239		} else if (pt_a->context > pt_b->context) {
240			add_fence(fences, &i, pt_b);
241
242			i_b++;
243		} else {
244			if (pt_a->seqno - pt_b->seqno <= INT_MAX)
245				add_fence(fences, &i, pt_a);
246			else
247				add_fence(fences, &i, pt_b);
248
249			i_a++;
250			i_b++;
251		}
252	}
253
254	for (; i_a < a_num_fences; i_a++)
255		add_fence(fences, &i, a_fences[i_a]);
256
257	for (; i_b < b_num_fences; i_b++)
258		add_fence(fences, &i, b_fences[i_b]);
259
260	if (i == 0)
261		fences[i++] = dma_fence_get(a_fences[0]);
262
263	if (num_fences > i) {
264		nfences = krealloc(fences, i * sizeof(*fences),
265				  GFP_KERNEL);
266		if (!nfences)
267			goto err;
268
269		fences = nfences;
270	}
271
272	if (sync_file_set_fence(sync_file, fences, i) < 0) {
273		kfree(fences);
274		goto err;
275	}
276
277	strlcpy(sync_file->name, name, sizeof(sync_file->name));
278	return sync_file;
279
280err:
281	fput(sync_file->file);
282	return NULL;
283
284}
285
286static void sync_file_free(struct kref *kref)
287{
288	struct sync_file *sync_file = container_of(kref, struct sync_file,
289						     kref);
290
291	if (test_bit(POLL_ENABLED, &sync_file->fence->flags))
292		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
293	dma_fence_put(sync_file->fence);
294	kfree(sync_file);
295}
296
297static int sync_file_release(struct inode *inode, struct file *file)
298{
299	struct sync_file *sync_file = file->private_data;
300
301	kref_put(&sync_file->kref, sync_file_free);
302	return 0;
303}
304
305static unsigned int sync_file_poll(struct file *file, poll_table *wait)
306{
307	struct sync_file *sync_file = file->private_data;
308
309	poll_wait(file, &sync_file->wq, wait);
310
311	if (!test_and_set_bit(POLL_ENABLED, &sync_file->fence->flags)) {
 
312		if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
313					   fence_check_cb_func) < 0)
314			wake_up_all(&sync_file->wq);
315	}
316
317	return dma_fence_is_signaled(sync_file->fence) ? POLLIN : 0;
318}
319
320static long sync_file_ioctl_merge(struct sync_file *sync_file,
321				  unsigned long arg)
322{
323	int fd = get_unused_fd_flags(O_CLOEXEC);
324	int err;
325	struct sync_file *fence2, *fence3;
326	struct sync_merge_data data;
327
328	if (fd < 0)
329		return fd;
330
331	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
332		err = -EFAULT;
333		goto err_put_fd;
334	}
335
336	if (data.flags || data.pad) {
337		err = -EINVAL;
338		goto err_put_fd;
339	}
340
341	fence2 = sync_file_fdget(data.fd2);
342	if (!fence2) {
343		err = -ENOENT;
344		goto err_put_fd;
345	}
346
347	data.name[sizeof(data.name) - 1] = '\0';
348	fence3 = sync_file_merge(data.name, sync_file, fence2);
349	if (!fence3) {
350		err = -ENOMEM;
351		goto err_put_fence2;
352	}
353
354	data.fence = fd;
355	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
356		err = -EFAULT;
357		goto err_put_fence3;
358	}
359
360	fd_install(fd, fence3->file);
361	fput(fence2->file);
362	return 0;
363
364err_put_fence3:
365	fput(fence3->file);
366
367err_put_fence2:
368	fput(fence2->file);
369
370err_put_fd:
371	put_unused_fd(fd);
372	return err;
373}
374
375static void sync_fill_fence_info(struct dma_fence *fence,
376				 struct sync_fence_info *info)
377{
378	strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
379		sizeof(info->obj_name));
380	strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
381		sizeof(info->driver_name));
382	if (dma_fence_is_signaled(fence))
383		info->status = fence->status >= 0 ? 1 : fence->status;
384	else
385		info->status = 0;
386	info->timestamp_ns = ktime_to_ns(fence->timestamp);
 
 
 
387}
388
389static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
390				       unsigned long arg)
391{
 
 
392	struct sync_file_info info;
393	struct sync_fence_info *fence_info = NULL;
394	struct dma_fence **fences;
 
395	__u32 size;
396	int num_fences, ret, i;
397
398	if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
399		return -EFAULT;
400
401	if (info.flags || info.pad)
402		return -EINVAL;
403
404	fences = get_fences(sync_file, &num_fences);
 
 
405
406	/*
407	 * Passing num_fences = 0 means that userspace doesn't want to
408	 * retrieve any sync_fence_info. If num_fences = 0 we skip filling
409	 * sync_fence_info and return the actual number of fences on
410	 * info->num_fences.
411	 */
412	if (!info.num_fences)
 
413		goto no_fences;
 
 
 
414
415	if (info.num_fences < num_fences)
416		return -EINVAL;
417
418	size = num_fences * sizeof(*fence_info);
419	fence_info = kzalloc(size, GFP_KERNEL);
420	if (!fence_info)
421		return -ENOMEM;
422
423	for (i = 0; i < num_fences; i++)
424		sync_fill_fence_info(fences[i], &fence_info[i]);
 
 
 
 
 
425
426	if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
427			 size)) {
428		ret = -EFAULT;
429		goto out;
430	}
431
432no_fences:
433	strlcpy(info.name, sync_file->name, sizeof(info.name));
434	info.status = dma_fence_is_signaled(sync_file->fence);
435	info.num_fences = num_fences;
436
437	if (copy_to_user((void __user *)arg, &info, sizeof(info)))
438		ret = -EFAULT;
439	else
440		ret = 0;
441
442out:
443	kfree(fence_info);
444
445	return ret;
446}
447
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
448static long sync_file_ioctl(struct file *file, unsigned int cmd,
449			    unsigned long arg)
450{
451	struct sync_file *sync_file = file->private_data;
452
453	switch (cmd) {
454	case SYNC_IOC_MERGE:
455		return sync_file_ioctl_merge(sync_file, arg);
456
457	case SYNC_IOC_FILE_INFO:
458		return sync_file_ioctl_fence_info(sync_file, arg);
459
 
 
 
460	default:
461		return -ENOTTY;
462	}
463}
464
465static const struct file_operations sync_file_fops = {
466	.release = sync_file_release,
467	.poll = sync_file_poll,
468	.unlocked_ioctl = sync_file_ioctl,
469	.compat_ioctl = sync_file_ioctl,
470};
471