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-rw-r--r--kernel/time/posix-clock.c451
1 files changed, 451 insertions, 0 deletions
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
new file mode 100644
index 000000000000..25028dd4fa18
--- /dev/null
+++ b/kernel/time/posix-clock.c
@@ -0,0 +1,451 @@
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/file.h>
22#include <linux/mutex.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 mutex_lock(&clk->mutex);
38
39 if (!clk->zombie)
40 return clk;
41
42 mutex_unlock(&clk->mutex);
43
44 return NULL;
45}
46
47static void put_posix_clock(struct posix_clock *clk)
48{
49 mutex_unlock(&clk->mutex);
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 int result = 0;
73
74 if (!clk)
75 return -ENODEV;
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 mutex_lock(&clk->mutex);
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 mutex_unlock(&clk->mutex);
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 mutex_init(&clk->mutex);
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 if (err)
220 goto no_cdev;
221
222 return err;
223no_cdev:
224 mutex_destroy(&clk->mutex);
225 return err;
226}
227EXPORT_SYMBOL_GPL(posix_clock_register);
228
229static void delete_clock(struct kref *kref)
230{
231 struct posix_clock *clk = container_of(kref, struct posix_clock, kref);
232 mutex_destroy(&clk->mutex);
233 if (clk->release)
234 clk->release(clk);
235}
236
237void posix_clock_unregister(struct posix_clock *clk)
238{
239 cdev_del(&clk->cdev);
240
241 mutex_lock(&clk->mutex);
242 clk->zombie = true;
243 mutex_unlock(&clk->mutex);
244
245 kref_put(&clk->kref, delete_clock);
246}
247EXPORT_SYMBOL_GPL(posix_clock_unregister);
248
249struct posix_clock_desc {
250 struct file *fp;
251 struct posix_clock *clk;
252};
253
254static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
255{
256 struct file *fp = fget(CLOCKID_TO_FD(id));
257 int err = -EINVAL;
258
259 if (!fp)
260 return err;
261
262 if (fp->f_op->open != posix_clock_open || !fp->private_data)
263 goto out;
264
265 cd->fp = fp;
266 cd->clk = get_posix_clock(fp);
267
268 err = cd->clk ? 0 : -ENODEV;
269out:
270 if (err)
271 fput(fp);
272 return err;
273}
274
275static void put_clock_desc(struct posix_clock_desc *cd)
276{
277 put_posix_clock(cd->clk);
278 fput(cd->fp);
279}
280
281static int pc_clock_adjtime(clockid_t id, struct timex *tx)
282{
283 struct posix_clock_desc cd;
284 int err;
285
286 err = get_clock_desc(id, &cd);
287 if (err)
288 return err;
289
290 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
291 err = -EACCES;
292 goto out;
293 }
294
295 if (cd.clk->ops.clock_adjtime)
296 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
297 else
298 err = -EOPNOTSUPP;
299out:
300 put_clock_desc(&cd);
301
302 return err;
303}
304
305static int pc_clock_gettime(clockid_t id, struct timespec *ts)
306{
307 struct posix_clock_desc cd;
308 int err;
309
310 err = get_clock_desc(id, &cd);
311 if (err)
312 return err;
313
314 if (cd.clk->ops.clock_gettime)
315 err = cd.clk->ops.clock_gettime(cd.clk, ts);
316 else
317 err = -EOPNOTSUPP;
318
319 put_clock_desc(&cd);
320
321 return err;
322}
323
324static int pc_clock_getres(clockid_t id, struct timespec *ts)
325{
326 struct posix_clock_desc cd;
327 int err;
328
329 err = get_clock_desc(id, &cd);
330 if (err)
331 return err;
332
333 if (cd.clk->ops.clock_getres)
334 err = cd.clk->ops.clock_getres(cd.clk, ts);
335 else
336 err = -EOPNOTSUPP;
337
338 put_clock_desc(&cd);
339
340 return err;
341}
342
343static int pc_clock_settime(clockid_t id, const struct timespec *ts)
344{
345 struct posix_clock_desc cd;
346 int err;
347
348 err = get_clock_desc(id, &cd);
349 if (err)
350 return err;
351
352 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
353 err = -EACCES;
354 goto out;
355 }
356
357 if (cd.clk->ops.clock_settime)
358 err = cd.clk->ops.clock_settime(cd.clk, ts);
359 else
360 err = -EOPNOTSUPP;
361out:
362 put_clock_desc(&cd);
363
364 return err;
365}
366
367static int pc_timer_create(struct k_itimer *kit)
368{
369 clockid_t id = kit->it_clock;
370 struct posix_clock_desc cd;
371 int err;
372
373 err = get_clock_desc(id, &cd);
374 if (err)
375 return err;
376
377 if (cd.clk->ops.timer_create)
378 err = cd.clk->ops.timer_create(cd.clk, kit);
379 else
380 err = -EOPNOTSUPP;
381
382 put_clock_desc(&cd);
383
384 return err;
385}
386
387static int pc_timer_delete(struct k_itimer *kit)
388{
389 clockid_t id = kit->it_clock;
390 struct posix_clock_desc cd;
391 int err;
392
393 err = get_clock_desc(id, &cd);
394 if (err)
395 return err;
396
397 if (cd.clk->ops.timer_delete)
398 err = cd.clk->ops.timer_delete(cd.clk, kit);
399 else
400 err = -EOPNOTSUPP;
401
402 put_clock_desc(&cd);
403
404 return err;
405}
406
407static void pc_timer_gettime(struct k_itimer *kit, struct itimerspec *ts)
408{
409 clockid_t id = kit->it_clock;
410 struct posix_clock_desc cd;
411
412 if (get_clock_desc(id, &cd))
413 return;
414
415 if (cd.clk->ops.timer_gettime)
416 cd.clk->ops.timer_gettime(cd.clk, kit, ts);
417
418 put_clock_desc(&cd);
419}
420
421static int pc_timer_settime(struct k_itimer *kit, int flags,
422 struct itimerspec *ts, struct itimerspec *old)
423{
424 clockid_t id = kit->it_clock;
425 struct posix_clock_desc cd;
426 int err;
427
428 err = get_clock_desc(id, &cd);
429 if (err)
430 return err;
431
432 if (cd.clk->ops.timer_settime)
433 err = cd.clk->ops.timer_settime(cd.clk, kit, flags, ts, old);
434 else
435 err = -EOPNOTSUPP;
436
437 put_clock_desc(&cd);
438
439 return err;
440}
441
442struct k_clock clock_posix_dynamic = {
443 .clock_getres = pc_clock_getres,
444 .clock_set = pc_clock_settime,
445 .clock_get = pc_clock_gettime,
446 .clock_adj = pc_clock_adjtime,
447 .timer_create = pc_timer_create,
448 .timer_set = pc_timer_settime,
449 .timer_del = pc_timer_delete,
450 .timer_get = pc_timer_gettime,
451};
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-26 12:18:48 -0500