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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 *clk = fp->private_data;
23
24 down_read(&clk->rwsem);
25
26 if (!clk->zombie)
27 return clk;
28
29 up_read(&clk->rwsem);
30
31 return NULL;
32}
33
34static void put_posix_clock(struct posix_clock *clk)
35{
36 up_read(&clk->rwsem);
37}
38
39static ssize_t posix_clock_read(struct file *fp, char __user *buf,
40 size_t count, loff_t *ppos)
41{
42 struct posix_clock *clk = get_posix_clock(fp);
43 int err = -EINVAL;
44
45 if (!clk)
46 return -ENODEV;
47
48 if (clk->ops.read)
49 err = clk->ops.read(clk, fp->f_flags, buf, count);
50
51 put_posix_clock(clk);
52
53 return err;
54}
55
56static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
57{
58 struct posix_clock *clk = get_posix_clock(fp);
59 __poll_t result = 0;
60
61 if (!clk)
62 return EPOLLERR;
63
64 if (clk->ops.poll)
65 result = clk->ops.poll(clk, fp, wait);
66
67 put_posix_clock(clk);
68
69 return result;
70}
71
72static long posix_clock_ioctl(struct file *fp,
73 unsigned int cmd, unsigned long arg)
74{
75 struct posix_clock *clk = get_posix_clock(fp);
76 int err = -ENOTTY;
77
78 if (!clk)
79 return -ENODEV;
80
81 if (clk->ops.ioctl)
82 err = clk->ops.ioctl(clk, cmd, arg);
83
84 put_posix_clock(clk);
85
86 return err;
87}
88
89#ifdef CONFIG_COMPAT
90static long posix_clock_compat_ioctl(struct file *fp,
91 unsigned int cmd, unsigned long arg)
92{
93 struct posix_clock *clk = get_posix_clock(fp);
94 int err = -ENOTTY;
95
96 if (!clk)
97 return -ENODEV;
98
99 if (clk->ops.ioctl)
100 err = clk->ops.ioctl(clk, cmd, arg);
101
102 put_posix_clock(clk);
103
104 return err;
105}
106#endif
107
108static int posix_clock_open(struct inode *inode, struct file *fp)
109{
110 int err;
111 struct posix_clock *clk =
112 container_of(inode->i_cdev, struct posix_clock, cdev);
113
114 down_read(&clk->rwsem);
115
116 if (clk->zombie) {
117 err = -ENODEV;
118 goto out;
119 }
120 if (clk->ops.open)
121 err = clk->ops.open(clk, fp->f_mode);
122 else
123 err = 0;
124
125 if (!err) {
126 get_device(clk->dev);
127 fp->private_data = clk;
128 }
129out:
130 up_read(&clk->rwsem);
131 return err;
132}
133
134static int posix_clock_release(struct inode *inode, struct file *fp)
135{
136 struct posix_clock *clk = fp->private_data;
137 int err = 0;
138
139 if (clk->ops.release)
140 err = clk->ops.release(clk);
141
142 put_device(clk->dev);
143
144 fp->private_data = NULL;
145
146 return err;
147}
148
149static const struct file_operations posix_clock_file_operations = {
150 .owner = THIS_MODULE,
151 .llseek = no_llseek,
152 .read = posix_clock_read,
153 .poll = posix_clock_poll,
154 .unlocked_ioctl = posix_clock_ioctl,
155 .open = posix_clock_open,
156 .release = posix_clock_release,
157#ifdef CONFIG_COMPAT
158 .compat_ioctl = posix_clock_compat_ioctl,
159#endif
160};
161
162int posix_clock_register(struct posix_clock *clk, struct device *dev)
163{
164 int err;
165
166 init_rwsem(&clk->rwsem);
167
168 cdev_init(&clk->cdev, &posix_clock_file_operations);
169 err = cdev_device_add(&clk->cdev, dev);
170 if (err) {
171 pr_err("%s unable to add device %d:%d\n",
172 dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
173 return err;
174 }
175 clk->cdev.owner = clk->ops.owner;
176 clk->dev = dev;
177
178 return 0;
179}
180EXPORT_SYMBOL_GPL(posix_clock_register);
181
182void posix_clock_unregister(struct posix_clock *clk)
183{
184 cdev_device_del(&clk->cdev, clk->dev);
185
186 down_write(&clk->rwsem);
187 clk->zombie = true;
188 up_write(&clk->rwsem);
189
190 put_device(clk->dev);
191}
192EXPORT_SYMBOL_GPL(posix_clock_unregister);
193
194struct posix_clock_desc {
195 struct file *fp;
196 struct posix_clock *clk;
197};
198
199static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
200{
201 struct file *fp = fget(clockid_to_fd(id));
202 int err = -EINVAL;
203
204 if (!fp)
205 return err;
206
207 if (fp->f_op->open != posix_clock_open || !fp->private_data)
208 goto out;
209
210 cd->fp = fp;
211 cd->clk = get_posix_clock(fp);
212
213 err = cd->clk ? 0 : -ENODEV;
214out:
215 if (err)
216 fput(fp);
217 return err;
218}
219
220static void put_clock_desc(struct posix_clock_desc *cd)
221{
222 put_posix_clock(cd->clk);
223 fput(cd->fp);
224}
225
226static int pc_clock_adjtime(clockid_t id, struct __kernel_timex *tx)
227{
228 struct posix_clock_desc cd;
229 int err;
230
231 err = get_clock_desc(id, &cd);
232 if (err)
233 return err;
234
235 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
236 err = -EACCES;
237 goto out;
238 }
239
240 if (cd.clk->ops.clock_adjtime)
241 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
242 else
243 err = -EOPNOTSUPP;
244out:
245 put_clock_desc(&cd);
246
247 return err;
248}
249
250static int pc_clock_gettime(clockid_t id, struct timespec64 *ts)
251{
252 struct posix_clock_desc cd;
253 int err;
254
255 err = get_clock_desc(id, &cd);
256 if (err)
257 return err;
258
259 if (cd.clk->ops.clock_gettime)
260 err = cd.clk->ops.clock_gettime(cd.clk, ts);
261 else
262 err = -EOPNOTSUPP;
263
264 put_clock_desc(&cd);
265
266 return err;
267}
268
269static int pc_clock_getres(clockid_t id, struct timespec64 *ts)
270{
271 struct posix_clock_desc cd;
272 int err;
273
274 err = get_clock_desc(id, &cd);
275 if (err)
276 return err;
277
278 if (cd.clk->ops.clock_getres)
279 err = cd.clk->ops.clock_getres(cd.clk, ts);
280 else
281 err = -EOPNOTSUPP;
282
283 put_clock_desc(&cd);
284
285 return err;
286}
287
288static int pc_clock_settime(clockid_t id, const struct timespec64 *ts)
289{
290 struct posix_clock_desc cd;
291 int err;
292
293 err = get_clock_desc(id, &cd);
294 if (err)
295 return err;
296
297 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
298 err = -EACCES;
299 goto out;
300 }
301
302 if (cd.clk->ops.clock_settime)
303 err = cd.clk->ops.clock_settime(cd.clk, ts);
304 else
305 err = -EOPNOTSUPP;
306out:
307 put_clock_desc(&cd);
308
309 return err;
310}
311
312const struct k_clock clock_posix_dynamic = {
313 .clock_getres = pc_clock_getres,
314 .clock_set = pc_clock_settime,
315 .clock_get_timespec = pc_clock_gettime,
316 .clock_adj = pc_clock_adjtime,
317};
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 *clk = fp->private_data;
23
24 down_read(&clk->rwsem);
25
26 if (!clk->zombie)
27 return clk;
28
29 up_read(&clk->rwsem);
30
31 return NULL;
32}
33
34static void put_posix_clock(struct posix_clock *clk)
35{
36 up_read(&clk->rwsem);
37}
38
39static ssize_t posix_clock_read(struct file *fp, char __user *buf,
40 size_t count, loff_t *ppos)
41{
42 struct posix_clock *clk = get_posix_clock(fp);
43 int err = -EINVAL;
44
45 if (!clk)
46 return -ENODEV;
47
48 if (clk->ops.read)
49 err = clk->ops.read(clk, fp->f_flags, buf, count);
50
51 put_posix_clock(clk);
52
53 return err;
54}
55
56static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
57{
58 struct posix_clock *clk = get_posix_clock(fp);
59 __poll_t result = 0;
60
61 if (!clk)
62 return EPOLLERR;
63
64 if (clk->ops.poll)
65 result = clk->ops.poll(clk, fp, wait);
66
67 put_posix_clock(clk);
68
69 return result;
70}
71
72static long posix_clock_ioctl(struct file *fp,
73 unsigned int cmd, unsigned long arg)
74{
75 struct posix_clock *clk = get_posix_clock(fp);
76 int err = -ENOTTY;
77
78 if (!clk)
79 return -ENODEV;
80
81 if (clk->ops.ioctl)
82 err = clk->ops.ioctl(clk, cmd, arg);
83
84 put_posix_clock(clk);
85
86 return err;
87}
88
89#ifdef CONFIG_COMPAT
90static long posix_clock_compat_ioctl(struct file *fp,
91 unsigned int cmd, unsigned long arg)
92{
93 struct posix_clock *clk = get_posix_clock(fp);
94 int err = -ENOTTY;
95
96 if (!clk)
97 return -ENODEV;
98
99 if (clk->ops.ioctl)
100 err = clk->ops.ioctl(clk, cmd, arg);
101
102 put_posix_clock(clk);
103
104 return err;
105}
106#endif
107
108static int posix_clock_open(struct inode *inode, struct file *fp)
109{
110 int err;
111 struct posix_clock *clk =
112 container_of(inode->i_cdev, struct posix_clock, cdev);
113
114 down_read(&clk->rwsem);
115
116 if (clk->zombie) {
117 err = -ENODEV;
118 goto out;
119 }
120 if (clk->ops.open)
121 err = clk->ops.open(clk, fp->f_mode);
122 else
123 err = 0;
124
125 if (!err) {
126 get_device(clk->dev);
127 fp->private_data = clk;
128 }
129out:
130 up_read(&clk->rwsem);
131 return err;
132}
133
134static int posix_clock_release(struct inode *inode, struct file *fp)
135{
136 struct posix_clock *clk = fp->private_data;
137 int err = 0;
138
139 if (clk->ops.release)
140 err = clk->ops.release(clk);
141
142 put_device(clk->dev);
143
144 fp->private_data = NULL;
145
146 return err;
147}
148
149static const struct file_operations posix_clock_file_operations = {
150 .owner = THIS_MODULE,
151 .llseek = no_llseek,
152 .read = posix_clock_read,
153 .poll = posix_clock_poll,
154 .unlocked_ioctl = posix_clock_ioctl,
155 .open = posix_clock_open,
156 .release = posix_clock_release,
157#ifdef CONFIG_COMPAT
158 .compat_ioctl = posix_clock_compat_ioctl,
159#endif
160};
161
162int posix_clock_register(struct posix_clock *clk, struct device *dev)
163{
164 int err;
165
166 init_rwsem(&clk->rwsem);
167
168 cdev_init(&clk->cdev, &posix_clock_file_operations);
169 err = cdev_device_add(&clk->cdev, dev);
170 if (err) {
171 pr_err("%s unable to add device %d:%d\n",
172 dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
173 return err;
174 }
175 clk->cdev.owner = clk->ops.owner;
176 clk->dev = dev;
177
178 return 0;
179}
180EXPORT_SYMBOL_GPL(posix_clock_register);
181
182void posix_clock_unregister(struct posix_clock *clk)
183{
184 cdev_device_del(&clk->cdev, clk->dev);
185
186 down_write(&clk->rwsem);
187 clk->zombie = true;
188 up_write(&clk->rwsem);
189
190 put_device(clk->dev);
191}
192EXPORT_SYMBOL_GPL(posix_clock_unregister);
193
194struct posix_clock_desc {
195 struct file *fp;
196 struct posix_clock *clk;
197};
198
199static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
200{
201 struct file *fp = fget(clockid_to_fd(id));
202 int err = -EINVAL;
203
204 if (!fp)
205 return err;
206
207 if (fp->f_op->open != posix_clock_open || !fp->private_data)
208 goto out;
209
210 cd->fp = fp;
211 cd->clk = get_posix_clock(fp);
212
213 err = cd->clk ? 0 : -ENODEV;
214out:
215 if (err)
216 fput(fp);
217 return err;
218}
219
220static void put_clock_desc(struct posix_clock_desc *cd)
221{
222 put_posix_clock(cd->clk);
223 fput(cd->fp);
224}
225
226static int pc_clock_adjtime(clockid_t id, struct __kernel_timex *tx)
227{
228 struct posix_clock_desc cd;
229 int err;
230
231 err = get_clock_desc(id, &cd);
232 if (err)
233 return err;
234
235 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
236 err = -EACCES;
237 goto out;
238 }
239
240 if (cd.clk->ops.clock_adjtime)
241 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
242 else
243 err = -EOPNOTSUPP;
244out:
245 put_clock_desc(&cd);
246
247 return err;
248}
249
250static int pc_clock_gettime(clockid_t id, struct timespec64 *ts)
251{
252 struct posix_clock_desc cd;
253 int err;
254
255 err = get_clock_desc(id, &cd);
256 if (err)
257 return err;
258
259 if (cd.clk->ops.clock_gettime)
260 err = cd.clk->ops.clock_gettime(cd.clk, ts);
261 else
262 err = -EOPNOTSUPP;
263
264 put_clock_desc(&cd);
265
266 return err;
267}
268
269static int pc_clock_getres(clockid_t id, struct timespec64 *ts)
270{
271 struct posix_clock_desc cd;
272 int err;
273
274 err = get_clock_desc(id, &cd);
275 if (err)
276 return err;
277
278 if (cd.clk->ops.clock_getres)
279 err = cd.clk->ops.clock_getres(cd.clk, ts);
280 else
281 err = -EOPNOTSUPP;
282
283 put_clock_desc(&cd);
284
285 return err;
286}
287
288static int pc_clock_settime(clockid_t id, const struct timespec64 *ts)
289{
290 struct posix_clock_desc cd;
291 int err;
292
293 err = get_clock_desc(id, &cd);
294 if (err)
295 return err;
296
297 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
298 err = -EACCES;
299 goto out;
300 }
301
302 if (cd.clk->ops.clock_settime)
303 err = cd.clk->ops.clock_settime(cd.clk, ts);
304 else
305 err = -EOPNOTSUPP;
306out:
307 put_clock_desc(&cd);
308
309 return err;
310}
311
312const struct k_clock clock_posix_dynamic = {
313 .clock_getres = pc_clock_getres,
314 .clock_set = pc_clock_settime,
315 .clock_get_timespec = pc_clock_gettime,
316 .clock_adj = pc_clock_adjtime,
317};