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1/*
2 * posix-clock.c - support for dynamic clock devices
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20#include <linux/device.h>
21#include <linux/export.h>
22#include <linux/file.h>
23#include <linux/posix-clock.h>
24#include <linux/slab.h>
25#include <linux/syscalls.h>
26#include <linux/uaccess.h>
27
28static void delete_clock(struct kref *kref);
29
30/*
31 * Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
32 */
33static struct posix_clock *get_posix_clock(struct file *fp)
34{
35 struct posix_clock *clk = fp->private_data;
36
37 down_read(&clk->rwsem);
38
39 if (!clk->zombie)
40 return clk;
41
42 up_read(&clk->rwsem);
43
44 return NULL;
45}
46
47static void put_posix_clock(struct posix_clock *clk)
48{
49 up_read(&clk->rwsem);
50}
51
52static ssize_t posix_clock_read(struct file *fp, char __user *buf,
53 size_t count, loff_t *ppos)
54{
55 struct posix_clock *clk = get_posix_clock(fp);
56 int err = -EINVAL;
57
58 if (!clk)
59 return -ENODEV;
60
61 if (clk->ops.read)
62 err = clk->ops.read(clk, fp->f_flags, buf, count);
63
64 put_posix_clock(clk);
65
66 return err;
67}
68
69static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
70{
71 struct posix_clock *clk = get_posix_clock(fp);
72 unsigned int result = 0;
73
74 if (!clk)
75 return POLLERR;
76
77 if (clk->ops.poll)
78 result = clk->ops.poll(clk, fp, wait);
79
80 put_posix_clock(clk);
81
82 return result;
83}
84
85static int posix_clock_fasync(int fd, struct file *fp, int on)
86{
87 struct posix_clock *clk = get_posix_clock(fp);
88 int err = 0;
89
90 if (!clk)
91 return -ENODEV;
92
93 if (clk->ops.fasync)
94 err = clk->ops.fasync(clk, fd, fp, on);
95
96 put_posix_clock(clk);
97
98 return err;
99}
100
101static int posix_clock_mmap(struct file *fp, struct vm_area_struct *vma)
102{
103 struct posix_clock *clk = get_posix_clock(fp);
104 int err = -ENODEV;
105
106 if (!clk)
107 return -ENODEV;
108
109 if (clk->ops.mmap)
110 err = clk->ops.mmap(clk, vma);
111
112 put_posix_clock(clk);
113
114 return err;
115}
116
117static long posix_clock_ioctl(struct file *fp,
118 unsigned int cmd, unsigned long arg)
119{
120 struct posix_clock *clk = get_posix_clock(fp);
121 int err = -ENOTTY;
122
123 if (!clk)
124 return -ENODEV;
125
126 if (clk->ops.ioctl)
127 err = clk->ops.ioctl(clk, cmd, arg);
128
129 put_posix_clock(clk);
130
131 return err;
132}
133
134#ifdef CONFIG_COMPAT
135static long posix_clock_compat_ioctl(struct file *fp,
136 unsigned int cmd, unsigned long arg)
137{
138 struct posix_clock *clk = get_posix_clock(fp);
139 int err = -ENOTTY;
140
141 if (!clk)
142 return -ENODEV;
143
144 if (clk->ops.ioctl)
145 err = clk->ops.ioctl(clk, cmd, arg);
146
147 put_posix_clock(clk);
148
149 return err;
150}
151#endif
152
153static int posix_clock_open(struct inode *inode, struct file *fp)
154{
155 int err;
156 struct posix_clock *clk =
157 container_of(inode->i_cdev, struct posix_clock, cdev);
158
159 down_read(&clk->rwsem);
160
161 if (clk->zombie) {
162 err = -ENODEV;
163 goto out;
164 }
165 if (clk->ops.open)
166 err = clk->ops.open(clk, fp->f_mode);
167 else
168 err = 0;
169
170 if (!err) {
171 kref_get(&clk->kref);
172 fp->private_data = clk;
173 }
174out:
175 up_read(&clk->rwsem);
176 return err;
177}
178
179static int posix_clock_release(struct inode *inode, struct file *fp)
180{
181 struct posix_clock *clk = fp->private_data;
182 int err = 0;
183
184 if (clk->ops.release)
185 err = clk->ops.release(clk);
186
187 kref_put(&clk->kref, delete_clock);
188
189 fp->private_data = NULL;
190
191 return err;
192}
193
194static const struct file_operations posix_clock_file_operations = {
195 .owner = THIS_MODULE,
196 .llseek = no_llseek,
197 .read = posix_clock_read,
198 .poll = posix_clock_poll,
199 .unlocked_ioctl = posix_clock_ioctl,
200 .open = posix_clock_open,
201 .release = posix_clock_release,
202 .fasync = posix_clock_fasync,
203 .mmap = posix_clock_mmap,
204#ifdef CONFIG_COMPAT
205 .compat_ioctl = posix_clock_compat_ioctl,
206#endif
207};
208
209int posix_clock_register(struct posix_clock *clk, dev_t devid)
210{
211 int err;
212
213 kref_init(&clk->kref);
214 init_rwsem(&clk->rwsem);
215
216 cdev_init(&clk->cdev, &posix_clock_file_operations);
217 clk->cdev.owner = clk->ops.owner;
218 err = cdev_add(&clk->cdev, devid, 1);
219
220 return err;
221}
222EXPORT_SYMBOL_GPL(posix_clock_register);
223
224static void delete_clock(struct kref *kref)
225{
226 struct posix_clock *clk = container_of(kref, struct posix_clock, kref);
227
228 if (clk->release)
229 clk->release(clk);
230}
231
232void posix_clock_unregister(struct posix_clock *clk)
233{
234 cdev_del(&clk->cdev);
235
236 down_write(&clk->rwsem);
237 clk->zombie = true;
238 up_write(&clk->rwsem);
239
240 kref_put(&clk->kref, delete_clock);
241}
242EXPORT_SYMBOL_GPL(posix_clock_unregister);
243
244struct posix_clock_desc {
245 struct file *fp;
246 struct posix_clock *clk;
247};
248
249static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
250{
251 struct file *fp = fget(CLOCKID_TO_FD(id));
252 int err = -EINVAL;
253
254 if (!fp)
255 return err;
256
257 if (fp->f_op->open != posix_clock_open || !fp->private_data)
258 goto out;
259
260 cd->fp = fp;
261 cd->clk = get_posix_clock(fp);
262
263 err = cd->clk ? 0 : -ENODEV;
264out:
265 if (err)
266 fput(fp);
267 return err;
268}
269
270static void put_clock_desc(struct posix_clock_desc *cd)
271{
272 put_posix_clock(cd->clk);
273 fput(cd->fp);
274}
275
276static int pc_clock_adjtime(clockid_t id, struct timex *tx)
277{
278 struct posix_clock_desc cd;
279 int err;
280
281 err = get_clock_desc(id, &cd);
282 if (err)
283 return err;
284
285 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
286 err = -EACCES;
287 goto out;
288 }
289
290 if (cd.clk->ops.clock_adjtime)
291 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
292 else
293 err = -EOPNOTSUPP;
294out:
295 put_clock_desc(&cd);
296
297 return err;
298}
299
300static int pc_clock_gettime(clockid_t id, struct timespec *ts)
301{
302 struct posix_clock_desc cd;
303 int err;
304
305 err = get_clock_desc(id, &cd);
306 if (err)
307 return err;
308
309 if (cd.clk->ops.clock_gettime)
310 err = cd.clk->ops.clock_gettime(cd.clk, ts);
311 else
312 err = -EOPNOTSUPP;
313
314 put_clock_desc(&cd);
315
316 return err;
317}
318
319static int pc_clock_getres(clockid_t id, struct timespec *ts)
320{
321 struct posix_clock_desc cd;
322 int err;
323
324 err = get_clock_desc(id, &cd);
325 if (err)
326 return err;
327
328 if (cd.clk->ops.clock_getres)
329 err = cd.clk->ops.clock_getres(cd.clk, ts);
330 else
331 err = -EOPNOTSUPP;
332
333 put_clock_desc(&cd);
334
335 return err;
336}
337
338static int pc_clock_settime(clockid_t id, const struct timespec *ts)
339{
340 struct posix_clock_desc cd;
341 int err;
342
343 err = get_clock_desc(id, &cd);
344 if (err)
345 return err;
346
347 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
348 err = -EACCES;
349 goto out;
350 }
351
352 if (cd.clk->ops.clock_settime)
353 err = cd.clk->ops.clock_settime(cd.clk, ts);
354 else
355 err = -EOPNOTSUPP;
356out:
357 put_clock_desc(&cd);
358
359 return err;
360}
361
362static int pc_timer_create(struct k_itimer *kit)
363{
364 clockid_t id = kit->it_clock;
365 struct posix_clock_desc cd;
366 int err;
367
368 err = get_clock_desc(id, &cd);
369 if (err)
370 return err;
371
372 if (cd.clk->ops.timer_create)
373 err = cd.clk->ops.timer_create(cd.clk, kit);
374 else
375 err = -EOPNOTSUPP;
376
377 put_clock_desc(&cd);
378
379 return err;
380}
381
382static int pc_timer_delete(struct k_itimer *kit)
383{
384 clockid_t id = kit->it_clock;
385 struct posix_clock_desc cd;
386 int err;
387
388 err = get_clock_desc(id, &cd);
389 if (err)
390 return err;
391
392 if (cd.clk->ops.timer_delete)
393 err = cd.clk->ops.timer_delete(cd.clk, kit);
394 else
395 err = -EOPNOTSUPP;
396
397 put_clock_desc(&cd);
398
399 return err;
400}
401
402static void pc_timer_gettime(struct k_itimer *kit, struct itimerspec *ts)
403{
404 clockid_t id = kit->it_clock;
405 struct posix_clock_desc cd;
406
407 if (get_clock_desc(id, &cd))
408 return;
409
410 if (cd.clk->ops.timer_gettime)
411 cd.clk->ops.timer_gettime(cd.clk, kit, ts);
412
413 put_clock_desc(&cd);
414}
415
416static int pc_timer_settime(struct k_itimer *kit, int flags,
417 struct itimerspec *ts, struct itimerspec *old)
418{
419 clockid_t id = kit->it_clock;
420 struct posix_clock_desc cd;
421 int err;
422
423 err = get_clock_desc(id, &cd);
424 if (err)
425 return err;
426
427 if (cd.clk->ops.timer_settime)
428 err = cd.clk->ops.timer_settime(cd.clk, kit, flags, ts, old);
429 else
430 err = -EOPNOTSUPP;
431
432 put_clock_desc(&cd);
433
434 return err;
435}
436
437struct k_clock clock_posix_dynamic = {
438 .clock_getres = pc_clock_getres,
439 .clock_set = pc_clock_settime,
440 .clock_get = pc_clock_gettime,
441 .clock_adj = pc_clock_adjtime,
442 .timer_create = pc_timer_create,
443 .timer_set = pc_timer_settime,
444 .timer_del = pc_timer_delete,
445 .timer_get = pc_timer_gettime,
446};
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Support for dynamic clock devices
4 *
5 * Copyright (C) 2010 OMICRON electronics GmbH
6 */
7#include <linux/device.h>
8#include <linux/export.h>
9#include <linux/file.h>
10#include <linux/posix-clock.h>
11#include <linux/slab.h>
12#include <linux/syscalls.h>
13#include <linux/uaccess.h>
14
15#include "posix-timers.h"
16
17/*
18 * Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
19 */
20static struct posix_clock *get_posix_clock(struct file *fp)
21{
22 struct posix_clock_context *pccontext = fp->private_data;
23 struct posix_clock *clk = pccontext->clk;
24
25 down_read(&clk->rwsem);
26
27 if (!clk->zombie)
28 return clk;
29
30 up_read(&clk->rwsem);
31
32 return NULL;
33}
34
35static void put_posix_clock(struct posix_clock *clk)
36{
37 up_read(&clk->rwsem);
38}
39
40static ssize_t posix_clock_read(struct file *fp, char __user *buf,
41 size_t count, loff_t *ppos)
42{
43 struct posix_clock_context *pccontext = fp->private_data;
44 struct posix_clock *clk = get_posix_clock(fp);
45 int err = -EINVAL;
46
47 if (!clk)
48 return -ENODEV;
49
50 if (clk->ops.read)
51 err = clk->ops.read(pccontext, fp->f_flags, buf, count);
52
53 put_posix_clock(clk);
54
55 return err;
56}
57
58static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
59{
60 struct posix_clock_context *pccontext = fp->private_data;
61 struct posix_clock *clk = get_posix_clock(fp);
62 __poll_t result = 0;
63
64 if (!clk)
65 return EPOLLERR;
66
67 if (clk->ops.poll)
68 result = clk->ops.poll(pccontext, fp, wait);
69
70 put_posix_clock(clk);
71
72 return result;
73}
74
75static long posix_clock_ioctl(struct file *fp,
76 unsigned int cmd, unsigned long arg)
77{
78 struct posix_clock_context *pccontext = fp->private_data;
79 struct posix_clock *clk = get_posix_clock(fp);
80 int err = -ENOTTY;
81
82 if (!clk)
83 return -ENODEV;
84
85 if (clk->ops.ioctl)
86 err = clk->ops.ioctl(pccontext, cmd, arg);
87
88 put_posix_clock(clk);
89
90 return err;
91}
92
93#ifdef CONFIG_COMPAT
94static long posix_clock_compat_ioctl(struct file *fp,
95 unsigned int cmd, unsigned long arg)
96{
97 struct posix_clock_context *pccontext = fp->private_data;
98 struct posix_clock *clk = get_posix_clock(fp);
99 int err = -ENOTTY;
100
101 if (!clk)
102 return -ENODEV;
103
104 if (clk->ops.ioctl)
105 err = clk->ops.ioctl(pccontext, cmd, arg);
106
107 put_posix_clock(clk);
108
109 return err;
110}
111#endif
112
113static int posix_clock_open(struct inode *inode, struct file *fp)
114{
115 int err;
116 struct posix_clock *clk =
117 container_of(inode->i_cdev, struct posix_clock, cdev);
118 struct posix_clock_context *pccontext;
119
120 down_read(&clk->rwsem);
121
122 if (clk->zombie) {
123 err = -ENODEV;
124 goto out;
125 }
126 pccontext = kzalloc(sizeof(*pccontext), GFP_KERNEL);
127 if (!pccontext) {
128 err = -ENOMEM;
129 goto out;
130 }
131 pccontext->clk = clk;
132 fp->private_data = pccontext;
133 if (clk->ops.open)
134 err = clk->ops.open(pccontext, fp->f_mode);
135 else
136 err = 0;
137
138 if (!err) {
139 get_device(clk->dev);
140 }
141out:
142 up_read(&clk->rwsem);
143 return err;
144}
145
146static int posix_clock_release(struct inode *inode, struct file *fp)
147{
148 struct posix_clock_context *pccontext = fp->private_data;
149 struct posix_clock *clk;
150 int err = 0;
151
152 if (!pccontext)
153 return -ENODEV;
154 clk = pccontext->clk;
155
156 if (clk->ops.release)
157 err = clk->ops.release(pccontext);
158
159 put_device(clk->dev);
160
161 kfree(pccontext);
162 fp->private_data = NULL;
163
164 return err;
165}
166
167static const struct file_operations posix_clock_file_operations = {
168 .owner = THIS_MODULE,
169 .llseek = no_llseek,
170 .read = posix_clock_read,
171 .poll = posix_clock_poll,
172 .unlocked_ioctl = posix_clock_ioctl,
173 .open = posix_clock_open,
174 .release = posix_clock_release,
175#ifdef CONFIG_COMPAT
176 .compat_ioctl = posix_clock_compat_ioctl,
177#endif
178};
179
180int posix_clock_register(struct posix_clock *clk, struct device *dev)
181{
182 int err;
183
184 init_rwsem(&clk->rwsem);
185
186 cdev_init(&clk->cdev, &posix_clock_file_operations);
187 err = cdev_device_add(&clk->cdev, dev);
188 if (err) {
189 pr_err("%s unable to add device %d:%d\n",
190 dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
191 return err;
192 }
193 clk->cdev.owner = clk->ops.owner;
194 clk->dev = dev;
195
196 return 0;
197}
198EXPORT_SYMBOL_GPL(posix_clock_register);
199
200void posix_clock_unregister(struct posix_clock *clk)
201{
202 cdev_device_del(&clk->cdev, clk->dev);
203
204 down_write(&clk->rwsem);
205 clk->zombie = true;
206 up_write(&clk->rwsem);
207
208 put_device(clk->dev);
209}
210EXPORT_SYMBOL_GPL(posix_clock_unregister);
211
212struct posix_clock_desc {
213 struct file *fp;
214 struct posix_clock *clk;
215};
216
217static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
218{
219 struct file *fp = fget(clockid_to_fd(id));
220 int err = -EINVAL;
221
222 if (!fp)
223 return err;
224
225 if (fp->f_op->open != posix_clock_open || !fp->private_data)
226 goto out;
227
228 cd->fp = fp;
229 cd->clk = get_posix_clock(fp);
230
231 err = cd->clk ? 0 : -ENODEV;
232out:
233 if (err)
234 fput(fp);
235 return err;
236}
237
238static void put_clock_desc(struct posix_clock_desc *cd)
239{
240 put_posix_clock(cd->clk);
241 fput(cd->fp);
242}
243
244static int pc_clock_adjtime(clockid_t id, struct __kernel_timex *tx)
245{
246 struct posix_clock_desc cd;
247 int err;
248
249 err = get_clock_desc(id, &cd);
250 if (err)
251 return err;
252
253 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
254 err = -EACCES;
255 goto out;
256 }
257
258 if (cd.clk->ops.clock_adjtime)
259 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
260 else
261 err = -EOPNOTSUPP;
262out:
263 put_clock_desc(&cd);
264
265 return err;
266}
267
268static int pc_clock_gettime(clockid_t id, struct timespec64 *ts)
269{
270 struct posix_clock_desc cd;
271 int err;
272
273 err = get_clock_desc(id, &cd);
274 if (err)
275 return err;
276
277 if (cd.clk->ops.clock_gettime)
278 err = cd.clk->ops.clock_gettime(cd.clk, ts);
279 else
280 err = -EOPNOTSUPP;
281
282 put_clock_desc(&cd);
283
284 return err;
285}
286
287static int pc_clock_getres(clockid_t id, struct timespec64 *ts)
288{
289 struct posix_clock_desc cd;
290 int err;
291
292 err = get_clock_desc(id, &cd);
293 if (err)
294 return err;
295
296 if (cd.clk->ops.clock_getres)
297 err = cd.clk->ops.clock_getres(cd.clk, ts);
298 else
299 err = -EOPNOTSUPP;
300
301 put_clock_desc(&cd);
302
303 return err;
304}
305
306static int pc_clock_settime(clockid_t id, const struct timespec64 *ts)
307{
308 struct posix_clock_desc cd;
309 int err;
310
311 err = get_clock_desc(id, &cd);
312 if (err)
313 return err;
314
315 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
316 err = -EACCES;
317 goto out;
318 }
319
320 if (cd.clk->ops.clock_settime)
321 err = cd.clk->ops.clock_settime(cd.clk, ts);
322 else
323 err = -EOPNOTSUPP;
324out:
325 put_clock_desc(&cd);
326
327 return err;
328}
329
330const struct k_clock clock_posix_dynamic = {
331 .clock_getres = pc_clock_getres,
332 .clock_set = pc_clock_settime,
333 .clock_get_timespec = pc_clock_gettime,
334 .clock_adj = pc_clock_adjtime,
335};