1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PTP 1588 clock support - character device implementation.
4  *
5  * Copyright (C) 2010 OMICRON electronics GmbH
6  */
7 #include <linux/compat.h>
8 #include <linux/module.h>
9 #include <linux/posix-clock.h>
10 #include <linux/poll.h>
11 #include <linux/sched.h>
12 #include <linux/slab.h>
13 #include <linux/timekeeping.h>
14 #include <linux/debugfs.h>
15 
16 #include <linux/nospec.h>
17 
18 #include "ptp_private.h"
19 
ptp_disable_pinfunc(struct ptp_clock_info * ops,enum ptp_pin_function func,unsigned int chan)20 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
21 			       enum ptp_pin_function func, unsigned int chan)
22 {
23 	struct ptp_clock_request rq;
24 	int err = 0;
25 
26 	memset(&rq, 0, sizeof(rq));
27 
28 	switch (func) {
29 	case PTP_PF_NONE:
30 		break;
31 	case PTP_PF_EXTTS:
32 		rq.type = PTP_CLK_REQ_EXTTS;
33 		rq.extts.index = chan;
34 		err = ops->enable(ops, &rq, 0);
35 		break;
36 	case PTP_PF_PEROUT:
37 		rq.type = PTP_CLK_REQ_PEROUT;
38 		rq.perout.index = chan;
39 		err = ops->enable(ops, &rq, 0);
40 		break;
41 	case PTP_PF_PHYSYNC:
42 		break;
43 	default:
44 		return -EINVAL;
45 	}
46 
47 	return err;
48 }
49 
ptp_set_pinfunc(struct ptp_clock * ptp,unsigned int pin,enum ptp_pin_function func,unsigned int chan)50 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
51 		    enum ptp_pin_function func, unsigned int chan)
52 {
53 	struct ptp_clock_info *info = ptp->info;
54 	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
55 	unsigned int i;
56 
57 	/* Check to see if any other pin previously had this function. */
58 	for (i = 0; i < info->n_pins; i++) {
59 		if (info->pin_config[i].func == func &&
60 		    info->pin_config[i].chan == chan) {
61 			pin1 = &info->pin_config[i];
62 			break;
63 		}
64 	}
65 	if (pin1 && i == pin)
66 		return 0;
67 
68 	/* Check the desired function and channel. */
69 	switch (func) {
70 	case PTP_PF_NONE:
71 		break;
72 	case PTP_PF_EXTTS:
73 		if (chan >= info->n_ext_ts)
74 			return -EINVAL;
75 		break;
76 	case PTP_PF_PEROUT:
77 		if (chan >= info->n_per_out)
78 			return -EINVAL;
79 		break;
80 	case PTP_PF_PHYSYNC:
81 		if (chan != 0)
82 			return -EINVAL;
83 		break;
84 	default:
85 		return -EINVAL;
86 	}
87 
88 	if (info->verify(info, pin, func, chan)) {
89 		pr_err("driver cannot use function %u and channel %u on pin %u\n",
90 		       func, chan, pin);
91 		return -EOPNOTSUPP;
92 	}
93 
94 	/* Disable whatever function was previously assigned. */
95 	if (pin1) {
96 		ptp_disable_pinfunc(info, func, chan);
97 		pin1->func = PTP_PF_NONE;
98 		pin1->chan = 0;
99 	}
100 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
101 	pin2->func = func;
102 	pin2->chan = chan;
103 
104 	return 0;
105 }
106 
ptp_open(struct posix_clock_context * pccontext,fmode_t fmode)107 int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
108 {
109 	struct ptp_clock *ptp =
110 		container_of(pccontext->clk, struct ptp_clock, clock);
111 	struct timestamp_event_queue *queue;
112 	char debugfsname[32];
113 	unsigned long flags;
114 
115 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
116 	if (!queue)
117 		return -EINVAL;
118 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
119 	if (!queue->mask) {
120 		kfree(queue);
121 		return -EINVAL;
122 	}
123 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
124 	spin_lock_init(&queue->lock);
125 	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
126 	list_add_tail(&queue->qlist, &ptp->tsevqs);
127 	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
128 	pccontext->private_clkdata = queue;
129 
130 	/* Debugfs contents */
131 	sprintf(debugfsname, "0x%p", queue);
132 	queue->debugfs_instance =
133 		debugfs_create_dir(debugfsname, ptp->debugfs_root);
134 	queue->dfs_bitmap.array = (u32 *)queue->mask;
135 	queue->dfs_bitmap.n_elements =
136 		DIV_ROUND_UP(PTP_MAX_CHANNELS, BITS_PER_BYTE * sizeof(u32));
137 	debugfs_create_u32_array("mask", 0444, queue->debugfs_instance,
138 				 &queue->dfs_bitmap);
139 
140 	return 0;
141 }
142 
ptp_release(struct posix_clock_context * pccontext)143 int ptp_release(struct posix_clock_context *pccontext)
144 {
145 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
146 	unsigned long flags;
147 	struct ptp_clock *ptp =
148 		container_of(pccontext->clk, struct ptp_clock, clock);
149 
150 	debugfs_remove(queue->debugfs_instance);
151 	pccontext->private_clkdata = NULL;
152 	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
153 	list_del(&queue->qlist);
154 	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
155 	bitmap_free(queue->mask);
156 	kfree(queue);
157 	return 0;
158 }
159 
ptp_ioctl(struct posix_clock_context * pccontext,unsigned int cmd,unsigned long arg)160 long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
161 	       unsigned long arg)
162 {
163 	struct ptp_clock *ptp =
164 		container_of(pccontext->clk, struct ptp_clock, clock);
165 	struct ptp_sys_offset_extended *extoff = NULL;
166 	struct ptp_sys_offset_precise precise_offset;
167 	struct system_device_crosststamp xtstamp;
168 	struct ptp_clock_info *ops = ptp->info;
169 	struct ptp_sys_offset *sysoff = NULL;
170 	struct timestamp_event_queue *tsevq;
171 	struct ptp_system_timestamp sts;
172 	struct ptp_clock_request req;
173 	struct ptp_clock_caps caps;
174 	struct ptp_clock_time *pct;
175 	unsigned int i, pin_index;
176 	struct ptp_pin_desc pd;
177 	struct timespec64 ts;
178 	int enable, err = 0;
179 
180 	if (in_compat_syscall() && cmd != PTP_ENABLE_PPS && cmd != PTP_ENABLE_PPS2)
181 		arg = (unsigned long)compat_ptr(arg);
182 
183 	tsevq = pccontext->private_clkdata;
184 
185 	switch (cmd) {
186 
187 	case PTP_CLOCK_GETCAPS:
188 	case PTP_CLOCK_GETCAPS2:
189 		memset(&caps, 0, sizeof(caps));
190 
191 		caps.max_adj = ptp->info->max_adj;
192 		caps.n_alarm = ptp->info->n_alarm;
193 		caps.n_ext_ts = ptp->info->n_ext_ts;
194 		caps.n_per_out = ptp->info->n_per_out;
195 		caps.pps = ptp->info->pps;
196 		caps.n_pins = ptp->info->n_pins;
197 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
198 		caps.adjust_phase = ptp->info->adjphase != NULL &&
199 				    ptp->info->getmaxphase != NULL;
200 		if (caps.adjust_phase)
201 			caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
202 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
203 			err = -EFAULT;
204 		break;
205 
206 	case PTP_EXTTS_REQUEST:
207 	case PTP_EXTTS_REQUEST2:
208 		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0) {
209 			err = -EACCES;
210 			break;
211 		}
212 		memset(&req, 0, sizeof(req));
213 
214 		if (copy_from_user(&req.extts, (void __user *)arg,
215 				   sizeof(req.extts))) {
216 			err = -EFAULT;
217 			break;
218 		}
219 		if (cmd == PTP_EXTTS_REQUEST2) {
220 			/* Tell the drivers to check the flags carefully. */
221 			req.extts.flags |= PTP_STRICT_FLAGS;
222 			/* Make sure no reserved bit is set. */
223 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
224 			    req.extts.rsv[0] || req.extts.rsv[1]) {
225 				err = -EINVAL;
226 				break;
227 			}
228 			/* Ensure one of the rising/falling edge bits is set. */
229 			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
230 			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
231 				err = -EINVAL;
232 				break;
233 			}
234 		} else if (cmd == PTP_EXTTS_REQUEST) {
235 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
236 			req.extts.rsv[0] = 0;
237 			req.extts.rsv[1] = 0;
238 		}
239 		if (req.extts.index >= ops->n_ext_ts) {
240 			err = -EINVAL;
241 			break;
242 		}
243 		req.type = PTP_CLK_REQ_EXTTS;
244 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
245 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
246 			return -ERESTARTSYS;
247 		err = ops->enable(ops, &req, enable);
248 		mutex_unlock(&ptp->pincfg_mux);
249 		break;
250 
251 	case PTP_PEROUT_REQUEST:
252 	case PTP_PEROUT_REQUEST2:
253 		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0) {
254 			err = -EACCES;
255 			break;
256 		}
257 		memset(&req, 0, sizeof(req));
258 
259 		if (copy_from_user(&req.perout, (void __user *)arg,
260 				   sizeof(req.perout))) {
261 			err = -EFAULT;
262 			break;
263 		}
264 		if (cmd == PTP_PEROUT_REQUEST2) {
265 			struct ptp_perout_request *perout = &req.perout;
266 
267 			if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
268 				err = -EINVAL;
269 				break;
270 			}
271 			/*
272 			 * The "on" field has undefined meaning if
273 			 * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
274 			 * it as reserved, which must be set to zero.
275 			 */
276 			if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
277 			    (perout->rsv[0] || perout->rsv[1] ||
278 			     perout->rsv[2] || perout->rsv[3])) {
279 				err = -EINVAL;
280 				break;
281 			}
282 			if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
283 				/* The duty cycle must be subunitary. */
284 				if (perout->on.sec > perout->period.sec ||
285 				    (perout->on.sec == perout->period.sec &&
286 				     perout->on.nsec > perout->period.nsec)) {
287 					err = -ERANGE;
288 					break;
289 				}
290 			}
291 			if (perout->flags & PTP_PEROUT_PHASE) {
292 				/*
293 				 * The phase should be specified modulo the
294 				 * period, therefore anything equal or larger
295 				 * than 1 period is invalid.
296 				 */
297 				if (perout->phase.sec > perout->period.sec ||
298 				    (perout->phase.sec == perout->period.sec &&
299 				     perout->phase.nsec >= perout->period.nsec)) {
300 					err = -ERANGE;
301 					break;
302 				}
303 			}
304 		} else if (cmd == PTP_PEROUT_REQUEST) {
305 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
306 			req.perout.rsv[0] = 0;
307 			req.perout.rsv[1] = 0;
308 			req.perout.rsv[2] = 0;
309 			req.perout.rsv[3] = 0;
310 		}
311 		if (req.perout.index >= ops->n_per_out) {
312 			err = -EINVAL;
313 			break;
314 		}
315 		req.type = PTP_CLK_REQ_PEROUT;
316 		enable = req.perout.period.sec || req.perout.period.nsec;
317 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
318 			return -ERESTARTSYS;
319 		err = ops->enable(ops, &req, enable);
320 		mutex_unlock(&ptp->pincfg_mux);
321 		break;
322 
323 	case PTP_ENABLE_PPS:
324 	case PTP_ENABLE_PPS2:
325 		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0) {
326 			err = -EACCES;
327 			break;
328 		}
329 		memset(&req, 0, sizeof(req));
330 
331 		if (!capable(CAP_SYS_TIME))
332 			return -EPERM;
333 		req.type = PTP_CLK_REQ_PPS;
334 		enable = arg ? 1 : 0;
335 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
336 			return -ERESTARTSYS;
337 		err = ops->enable(ops, &req, enable);
338 		mutex_unlock(&ptp->pincfg_mux);
339 		break;
340 
341 	case PTP_SYS_OFFSET_PRECISE:
342 	case PTP_SYS_OFFSET_PRECISE2:
343 		if (!ptp->info->getcrosststamp) {
344 			err = -EOPNOTSUPP;
345 			break;
346 		}
347 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
348 		if (err)
349 			break;
350 
351 		memset(&precise_offset, 0, sizeof(precise_offset));
352 		ts = ktime_to_timespec64(xtstamp.device);
353 		precise_offset.device.sec = ts.tv_sec;
354 		precise_offset.device.nsec = ts.tv_nsec;
355 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
356 		precise_offset.sys_realtime.sec = ts.tv_sec;
357 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
358 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
359 		precise_offset.sys_monoraw.sec = ts.tv_sec;
360 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
361 		if (copy_to_user((void __user *)arg, &precise_offset,
362 				 sizeof(precise_offset)))
363 			err = -EFAULT;
364 		break;
365 
366 	case PTP_SYS_OFFSET_EXTENDED:
367 	case PTP_SYS_OFFSET_EXTENDED2:
368 		if (!ptp->info->gettimex64) {
369 			err = -EOPNOTSUPP;
370 			break;
371 		}
372 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
373 		if (IS_ERR(extoff)) {
374 			err = PTR_ERR(extoff);
375 			extoff = NULL;
376 			break;
377 		}
378 		if (extoff->n_samples > PTP_MAX_SAMPLES ||
379 		    extoff->rsv[0] || extoff->rsv[1] ||
380 		    (extoff->clockid != CLOCK_REALTIME &&
381 		     extoff->clockid != CLOCK_MONOTONIC &&
382 		     extoff->clockid != CLOCK_MONOTONIC_RAW)) {
383 			err = -EINVAL;
384 			break;
385 		}
386 		sts.clockid = extoff->clockid;
387 		for (i = 0; i < extoff->n_samples; i++) {
388 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
389 			if (err)
390 				goto out;
391 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
392 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
393 			extoff->ts[i][1].sec = ts.tv_sec;
394 			extoff->ts[i][1].nsec = ts.tv_nsec;
395 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
396 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
397 		}
398 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
399 			err = -EFAULT;
400 		break;
401 
402 	case PTP_SYS_OFFSET:
403 	case PTP_SYS_OFFSET2:
404 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
405 		if (IS_ERR(sysoff)) {
406 			err = PTR_ERR(sysoff);
407 			sysoff = NULL;
408 			break;
409 		}
410 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
411 			err = -EINVAL;
412 			break;
413 		}
414 		pct = &sysoff->ts[0];
415 		for (i = 0; i < sysoff->n_samples; i++) {
416 			ktime_get_real_ts64(&ts);
417 			pct->sec = ts.tv_sec;
418 			pct->nsec = ts.tv_nsec;
419 			pct++;
420 			if (ops->gettimex64)
421 				err = ops->gettimex64(ops, &ts, NULL);
422 			else
423 				err = ops->gettime64(ops, &ts);
424 			if (err)
425 				goto out;
426 			pct->sec = ts.tv_sec;
427 			pct->nsec = ts.tv_nsec;
428 			pct++;
429 		}
430 		ktime_get_real_ts64(&ts);
431 		pct->sec = ts.tv_sec;
432 		pct->nsec = ts.tv_nsec;
433 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
434 			err = -EFAULT;
435 		break;
436 
437 	case PTP_PIN_GETFUNC:
438 	case PTP_PIN_GETFUNC2:
439 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
440 			err = -EFAULT;
441 			break;
442 		}
443 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
444 				|| pd.rsv[3] || pd.rsv[4])
445 			&& cmd == PTP_PIN_GETFUNC2) {
446 			err = -EINVAL;
447 			break;
448 		} else if (cmd == PTP_PIN_GETFUNC) {
449 			pd.rsv[0] = 0;
450 			pd.rsv[1] = 0;
451 			pd.rsv[2] = 0;
452 			pd.rsv[3] = 0;
453 			pd.rsv[4] = 0;
454 		}
455 		pin_index = pd.index;
456 		if (pin_index >= ops->n_pins) {
457 			err = -EINVAL;
458 			break;
459 		}
460 		pin_index = array_index_nospec(pin_index, ops->n_pins);
461 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
462 			return -ERESTARTSYS;
463 		pd = ops->pin_config[pin_index];
464 		mutex_unlock(&ptp->pincfg_mux);
465 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
466 			err = -EFAULT;
467 		break;
468 
469 	case PTP_PIN_SETFUNC:
470 	case PTP_PIN_SETFUNC2:
471 		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0) {
472 			err = -EACCES;
473 			break;
474 		}
475 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
476 			err = -EFAULT;
477 			break;
478 		}
479 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
480 				|| pd.rsv[3] || pd.rsv[4])
481 			&& cmd == PTP_PIN_SETFUNC2) {
482 			err = -EINVAL;
483 			break;
484 		} else if (cmd == PTP_PIN_SETFUNC) {
485 			pd.rsv[0] = 0;
486 			pd.rsv[1] = 0;
487 			pd.rsv[2] = 0;
488 			pd.rsv[3] = 0;
489 			pd.rsv[4] = 0;
490 		}
491 		pin_index = pd.index;
492 		if (pin_index >= ops->n_pins) {
493 			err = -EINVAL;
494 			break;
495 		}
496 		pin_index = array_index_nospec(pin_index, ops->n_pins);
497 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
498 			return -ERESTARTSYS;
499 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
500 		mutex_unlock(&ptp->pincfg_mux);
501 		break;
502 
503 	case PTP_MASK_CLEAR_ALL:
504 		bitmap_clear(tsevq->mask, 0, PTP_MAX_CHANNELS);
505 		break;
506 
507 	case PTP_MASK_EN_SINGLE:
508 		if (copy_from_user(&i, (void __user *)arg, sizeof(i))) {
509 			err = -EFAULT;
510 			break;
511 		}
512 		if (i >= PTP_MAX_CHANNELS) {
513 			err = -EFAULT;
514 			break;
515 		}
516 		set_bit(i, tsevq->mask);
517 		break;
518 
519 	default:
520 		err = -ENOTTY;
521 		break;
522 	}
523 
524 out:
525 	kfree(extoff);
526 	kfree(sysoff);
527 	return err;
528 }
529 
ptp_poll(struct posix_clock_context * pccontext,struct file * fp,poll_table * wait)530 __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
531 		  poll_table *wait)
532 {
533 	struct ptp_clock *ptp =
534 		container_of(pccontext->clk, struct ptp_clock, clock);
535 	struct timestamp_event_queue *queue;
536 
537 	queue = pccontext->private_clkdata;
538 	if (!queue)
539 		return EPOLLERR;
540 
541 	poll_wait(fp, &ptp->tsev_wq, wait);
542 
543 	return queue_cnt(queue) ? EPOLLIN : 0;
544 }
545 
546 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
547 
ptp_read(struct posix_clock_context * pccontext,uint rdflags,char __user * buf,size_t cnt)548 ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
549 		 char __user *buf, size_t cnt)
550 {
551 	struct ptp_clock *ptp =
552 		container_of(pccontext->clk, struct ptp_clock, clock);
553 	struct timestamp_event_queue *queue;
554 	struct ptp_extts_event *event;
555 	unsigned long flags;
556 	size_t qcnt, i;
557 	int result;
558 
559 	queue = pccontext->private_clkdata;
560 	if (!queue) {
561 		result = -EINVAL;
562 		goto exit;
563 	}
564 
565 	if (cnt % sizeof(struct ptp_extts_event) != 0) {
566 		result = -EINVAL;
567 		goto exit;
568 	}
569 
570 	if (cnt > EXTTS_BUFSIZE)
571 		cnt = EXTTS_BUFSIZE;
572 
573 	cnt = cnt / sizeof(struct ptp_extts_event);
574 
575 	if (wait_event_interruptible(ptp->tsev_wq,
576 				     ptp->defunct || queue_cnt(queue))) {
577 		return -ERESTARTSYS;
578 	}
579 
580 	if (ptp->defunct) {
581 		result = -ENODEV;
582 		goto exit;
583 	}
584 
585 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
586 	if (!event) {
587 		result = -ENOMEM;
588 		goto exit;
589 	}
590 
591 	spin_lock_irqsave(&queue->lock, flags);
592 
593 	qcnt = queue_cnt(queue);
594 
595 	if (cnt > qcnt)
596 		cnt = qcnt;
597 
598 	for (i = 0; i < cnt; i++) {
599 		event[i] = queue->buf[queue->head];
600 		/* Paired with READ_ONCE() in queue_cnt() */
601 		WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
602 	}
603 
604 	spin_unlock_irqrestore(&queue->lock, flags);
605 
606 	cnt = cnt * sizeof(struct ptp_extts_event);
607 
608 	result = cnt;
609 	if (copy_to_user(buf, event, cnt)) {
610 		result = -EFAULT;
611 		goto free_event;
612 	}
613 
614 free_event:
615 	kfree(event);
616 exit:
617 	return result;
618 }
619