[linux-2.6-block.git] / kernel / time / posix-clock.c

/*
 * posix-clock.c - support for dynamic clock devices
 *
 * Copyright (C) 2010 OMICRON electronics GmbH
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/device.h>
#include <linux/file.h>
#include <linux/mutex.h>
#include <linux/posix-clock.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>

static void delete_clock(struct kref *kref);

/*
 * Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
 */
static struct posix_clock *get_posix_clock(struct file *fp)
{
	struct posix_clock *clk = fp->private_data;

	mutex_lock(&clk->mutex);

	if (!clk->zombie)
		return clk;

	mutex_unlock(&clk->mutex);

	return NULL;
}

static void put_posix_clock(struct posix_clock *clk)
{
	mutex_unlock(&clk->mutex);
}

static ssize_t posix_clock_read(struct file *fp, char __user *buf,
				size_t count, loff_t *ppos)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int err = -EINVAL;

	if (!clk)
		return -ENODEV;

	if (clk->ops.read)
		err = clk->ops.read(clk, fp->f_flags, buf, count);

	put_posix_clock(clk);

	return err;
}

static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int result = 0;

	if (!clk)
		return -ENODEV;

	if (clk->ops.poll)
		result = clk->ops.poll(clk, fp, wait);

	put_posix_clock(clk);

	return result;
}

static int posix_clock_fasync(int fd, struct file *fp, int on)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int err = 0;

	if (!clk)
		return -ENODEV;

	if (clk->ops.fasync)
		err = clk->ops.fasync(clk, fd, fp, on);

	put_posix_clock(clk);

	return err;
}

static int posix_clock_mmap(struct file *fp, struct vm_area_struct *vma)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int err = -ENODEV;

	if (!clk)
		return -ENODEV;

	if (clk->ops.mmap)
		err = clk->ops.mmap(clk, vma);

	put_posix_clock(clk);

	return err;
}

static long posix_clock_ioctl(struct file *fp,
			      unsigned int cmd, unsigned long arg)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int err = -ENOTTY;

	if (!clk)
		return -ENODEV;

	if (clk->ops.ioctl)
		err = clk->ops.ioctl(clk, cmd, arg);

	put_posix_clock(clk);

	return err;
}

#ifdef CONFIG_COMPAT
static long posix_clock_compat_ioctl(struct file *fp,
				     unsigned int cmd, unsigned long arg)
{
	struct posix_clock *clk = get_posix_clock(fp);
	int err = -ENOTTY;

	if (!clk)
		return -ENODEV;

	if (clk->ops.ioctl)
		err = clk->ops.ioctl(clk, cmd, arg);

	put_posix_clock(clk);

	return err;
}
#endif

static int posix_clock_open(struct inode *inode, struct file *fp)
{
	int err;
	struct posix_clock *clk =
		container_of(inode->i_cdev, struct posix_clock, cdev);

	mutex_lock(&clk->mutex);

	if (clk->zombie) {
		err = -ENODEV;
		goto out;
	}
	if (clk->ops.open)
		err = clk->ops.open(clk, fp->f_mode);
	else
		err = 0;

	if (!err) {
		kref_get(&clk->kref);
		fp->private_data = clk;
	}
out:
	mutex_unlock(&clk->mutex);
	return err;
}

static int posix_clock_release(struct inode *inode, struct file *fp)
{
	struct posix_clock *clk = fp->private_data;
	int err = 0;

	if (clk->ops.release)
		err = clk->ops.release(clk);

	kref_put(&clk->kref, delete_clock);

	fp->private_data = NULL;

	return err;
}

static const struct file_operations posix_clock_file_operations = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= posix_clock_read,
	.poll		= posix_clock_poll,
	.unlocked_ioctl	= posix_clock_ioctl,
	.open		= posix_clock_open,
	.release	= posix_clock_release,
	.fasync		= posix_clock_fasync,
	.mmap		= posix_clock_mmap,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= posix_clock_compat_ioctl,
#endif
};

int posix_clock_register(struct posix_clock *clk, dev_t devid)
{
	int err;

	kref_init(&clk->kref);
	mutex_init(&clk->mutex);

	cdev_init(&clk->cdev, &posix_clock_file_operations);
	clk->cdev.owner = clk->ops.owner;
	err = cdev_add(&clk->cdev, devid, 1);
	if (err)
		goto no_cdev;

	return err;
no_cdev:
	mutex_destroy(&clk->mutex);
	return err;
}
EXPORT_SYMBOL_GPL(posix_clock_register);

static void delete_clock(struct kref *kref)
{
	struct posix_clock *clk = container_of(kref, struct posix_clock, kref);
	mutex_destroy(&clk->mutex);
	if (clk->release)
		clk->release(clk);
}

void posix_clock_unregister(struct posix_clock *clk)
{
	cdev_del(&clk->cdev);

	mutex_lock(&clk->mutex);
	clk->zombie = true;
	mutex_unlock(&clk->mutex);

	kref_put(&clk->kref, delete_clock);
}
EXPORT_SYMBOL_GPL(posix_clock_unregister);

struct posix_clock_desc {
	struct file *fp;
	struct posix_clock *clk;
};

static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
{
	struct file *fp = fget(CLOCKID_TO_FD(id));
	int err = -EINVAL;

	if (!fp)
		return err;

	if (fp->f_op->open != posix_clock_open || !fp->private_data)
		goto out;

	cd->fp = fp;
	cd->clk = get_posix_clock(fp);

	err = cd->clk ? 0 : -ENODEV;
out:
	if (err)
		fput(fp);
	return err;
}

static void put_clock_desc(struct posix_clock_desc *cd)
{
	put_posix_clock(cd->clk);
	fput(cd->fp);
}

static int pc_clock_adjtime(clockid_t id, struct timex *tx)
{
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
		err = -EACCES;
		goto out;
	}

	if (cd.clk->ops.clock_adjtime)
		err = cd.clk->ops.clock_adjtime(cd.clk, tx);
	else
		err = -EOPNOTSUPP;
out:
	put_clock_desc(&cd);

	return err;
}

static int pc_clock_gettime(clockid_t id, struct timespec *ts)
{
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if (cd.clk->ops.clock_gettime)
		err = cd.clk->ops.clock_gettime(cd.clk, ts);
	else
		err = -EOPNOTSUPP;

	put_clock_desc(&cd);

	return err;
}

static int pc_clock_getres(clockid_t id, struct timespec *ts)
{
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if (cd.clk->ops.clock_getres)
		err = cd.clk->ops.clock_getres(cd.clk, ts);
	else
		err = -EOPNOTSUPP;

	put_clock_desc(&cd);

	return err;
}

static int pc_clock_settime(clockid_t id, const struct timespec *ts)
{
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
		err = -EACCES;
		goto out;
	}

	if (cd.clk->ops.clock_settime)
		err = cd.clk->ops.clock_settime(cd.clk, ts);
	else
		err = -EOPNOTSUPP;
out:
	put_clock_desc(&cd);

	return err;
}

static int pc_timer_create(struct k_itimer *kit)
{
	clockid_t id = kit->it_clock;
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if (cd.clk->ops.timer_create)
		err = cd.clk->ops.timer_create(cd.clk, kit);
	else
		err = -EOPNOTSUPP;

	put_clock_desc(&cd);

	return err;
}

static int pc_timer_delete(struct k_itimer *kit)
{
	clockid_t id = kit->it_clock;
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if (cd.clk->ops.timer_delete)
		err = cd.clk->ops.timer_delete(cd.clk, kit);
	else
		err = -EOPNOTSUPP;

	put_clock_desc(&cd);

	return err;
}

static void pc_timer_gettime(struct k_itimer *kit, struct itimerspec *ts)
{
	clockid_t id = kit->it_clock;
	struct posix_clock_desc cd;

	if (get_clock_desc(id, &cd))
		return;

	if (cd.clk->ops.timer_gettime)
		cd.clk->ops.timer_gettime(cd.clk, kit, ts);

	put_clock_desc(&cd);
}

static int pc_timer_settime(struct k_itimer *kit, int flags,
			    struct itimerspec *ts, struct itimerspec *old)
{
	clockid_t id = kit->it_clock;
	struct posix_clock_desc cd;
	int err;

	err = get_clock_desc(id, &cd);
	if (err)
		return err;

	if (cd.clk->ops.timer_settime)
		err = cd.clk->ops.timer_settime(cd.clk, kit, flags, ts, old);
	else
		err = -EOPNOTSUPP;

	put_clock_desc(&cd);

	return err;
}

struct k_clock clock_posix_dynamic = {
	.clock_getres	= pc_clock_getres,
	.clock_set	= pc_clock_settime,
	.clock_get	= pc_clock_gettime,
	.clock_adj	= pc_clock_adjtime,
	.timer_create	= pc_timer_create,
	.timer_set	= pc_timer_settime,
	.timer_del	= pc_timer_delete,
	.timer_get	= pc_timer_gettime,
};
Commit	Line	Data
0606f422 RC	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
	28	static void delete_clock(struct kref *kref);
	29
	30	/*
	31	* Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
	32	*/
	33	static 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
	47	static void put_posix_clock(struct posix_clock *clk)
	48	{
	49	mutex_unlock(&clk->mutex);
	50	}
	51
	52	static 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
69	static 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
85	static 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
101	static 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
117	static 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
135	static 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
153	static 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	}
174	out:
175	mutex_unlock(&clk->mutex);
176	return err;
177	}
178
179	static 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
194	static 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
209	int 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;
223	no_cdev:
224	mutex_destroy(&clk->mutex);
225	return err;
226	}
227	EXPORT_SYMBOL_GPL(posix_clock_register);
228
229	static 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
237	void 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	}
247	EXPORT_SYMBOL_GPL(posix_clock_unregister);
248
249	struct posix_clock_desc {
250	struct file *fp;
251	struct posix_clock *clk;
252	};
253
254	static 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;
269	out:
270	if (err)
271	fput(fp);
272	return err;
273	}
274
275	static void put_clock_desc(struct posix_clock_desc *cd)
276	{
277	put_posix_clock(cd->clk);
278	fput(cd->fp);
279	}
280
281	static 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
6e6823d1 TH	290	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
	291	err = -EACCES;
	292	goto out;
	293	}
	294
0606f422 RC	295	if (cd.clk->ops.clock_adjtime)
	296	err = cd.clk->ops.clock_adjtime(cd.clk, tx);
	297	else
	298	err = -EOPNOTSUPP;
6e6823d1	299	out:
0606f422 RC	300	put_clock_desc(&cd);
	301
	302	return err;
	303	}
	304
	305	static 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
	324	static 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
	343	static 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
6e6823d1 TH	352	if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
	353	err = -EACCES;
	354	goto out;
	355	}
	356
0606f422 RC	357	if (cd.clk->ops.clock_settime)
	358	err = cd.clk->ops.clock_settime(cd.clk, ts);
	359	else
	360	err = -EOPNOTSUPP;
6e6823d1	361	out:
0606f422 RC	362	put_clock_desc(&cd);
	363
	364	return err;
	365	}
	366
	367	static 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
	387	static 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
	407	static 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
	421	static 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
442	struct 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	};