xref: /dragonfly/sys/dev/misc/evdev/cdev.c (revision ed183f8c)
1 /*-
2  * Copyright (c) 2014 Jakub Wojciech Klama <jceel@FreeBSD.org>
3  * Copyright (c) 2015-2016 Vladimir Kondratyev <wulf@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include "opt_evdev.h"
31 
32 #include <sys/types.h>
33 #include <sys/module.h>
34 #include <sys/devfs.h>
35 
36 #include <sys/param.h>
37 #include <sys/conf.h>
38 #include <sys/filio.h>
39 #include <sys/fcntl.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/poll.h>
43 #include <sys/proc.h>
44 #include <sys/systm.h>
45 #include <sys/time.h>
46 #include <sys/vnode.h> /* IO_NDELAY in read() */
47 #include <sys/uio.h>
48 
49 #include <sys/errno.h>
50 
51 #include <sys/device.h>
52 #include <sys/bus.h>
53 
54 /* Use FreeBSD bitstring locally. */
55 #include "freebsd-bitstring.h"
56 
57 #include <dev/misc/evdev/evdev.h>
58 #include <dev/misc/evdev/evdev_private.h>
59 #include <dev/misc/evdev/input.h>
60 
61 #ifdef EVDEV_DEBUG
62 #define	debugf(client, fmt, args...)	kprintf("evdev cdev: "fmt"\n", ##args)
63 #else
64 #define	debugf(client, fmt, args...)
65 #endif
66 
67 #define	DEF_RING_REPORTS	8
68 
69 static d_open_t		evdev_open;
70 static d_read_t		evdev_read;
71 static d_write_t	evdev_write;
72 static d_ioctl_t	evdev_ioctl;
73 static d_kqfilter_t	evdev_kqfilter;
74 
75 static int evdev_kqread(struct knote *kn, long hint);
76 static void evdev_kqdetach(struct knote *kn);
77 static void evdev_dtor(void *);
78 static int evdev_ioctl_eviocgbit(struct evdev_dev *, int, int, caddr_t);
79 static void evdev_client_filter_queue(struct evdev_client *, uint16_t);
80 
81 static struct dev_ops evdev_cdevsw = {
82 	{ "evdev", 0, 0 },
83 	.d_open = evdev_open,
84 	.d_read = evdev_read,
85 	.d_write = evdev_write,
86 	.d_ioctl = evdev_ioctl,
87 	.d_kqfilter = evdev_kqfilter,
88 };
89 
90 static struct filterops evdev_cdev_filterops = {
91 	.f_flags = FILTEROP_ISFD,
92 	.f_attach = NULL,
93 	.f_detach = evdev_kqdetach,
94 	.f_event = evdev_kqread,
95 };
96 
97 static int
98 evdev_open(struct dev_open_args *ap)
99 {
100 	cdev_t dev = ap->a_head.a_dev;
101 	struct evdev_dev *evdev = dev->si_drv1;
102 	struct evdev_client *client;
103 	size_t buffer_size;
104 	int ret;
105 
106 	if (evdev == NULL)
107 		return (ENODEV);
108 
109 	/* Initialize client structure */
110 	buffer_size = evdev->ev_report_size * DEF_RING_REPORTS;
111 	client = kmalloc(offsetof(struct evdev_client, ec_buffer) +
112 	    sizeof(struct input_event) * buffer_size,
113 	    M_EVDEV, M_WAITOK | M_ZERO);
114 
115 	/* Initialize ring buffer */
116 	client->ec_buffer_size = buffer_size;
117 	client->ec_buffer_head = 0;
118 	client->ec_buffer_tail = 0;
119 	client->ec_buffer_ready = 0;
120 
121 	client->ec_evdev = evdev;
122 	lockinit(&client->ec_buffer_mtx, "evclient", 0, LK_CANRECURSE);
123 
124 	/* Avoid race with evdev_unregister */
125 	EVDEV_LOCK(evdev);
126 	if (dev->si_drv1 == NULL)
127 		ret = ENODEV;
128 	else
129 		ret = evdev_register_client(evdev, client);
130 
131 	if (ret != 0)
132 		evdev_revoke_client(client);
133 	/*
134 	 * Unlock evdev here because non-sleepable lock held
135 	 * while calling devfs_set_cdevpriv upsets WITNESS
136 	 */
137 	EVDEV_UNLOCK(evdev);
138 
139 	if (!ret)
140 		ret = devfs_set_cdevpriv(ap->a_fp, client, &evdev_dtor);
141 
142 	if (ret != 0) {
143 		debugf(client, "cannot register evdev client");
144 	}
145 
146 	return (ret);
147 }
148 
149 static void
150 evdev_dtor(void *data)
151 {
152 	struct evdev_client *client = (struct evdev_client *)data;
153 
154 	EVDEV_LOCK(client->ec_evdev);
155 	if (!client->ec_revoked)
156 		evdev_dispose_client(client->ec_evdev, client);
157 	EVDEV_UNLOCK(client->ec_evdev);
158 
159 	funsetown(&client->ec_sigio);
160 	lockuninit(&client->ec_buffer_mtx);
161 	kfree(client, M_EVDEV);
162 }
163 
164 static int
165 evdev_read(struct dev_read_args *ap)
166 {
167 	struct uio *uio = ap->a_uio;
168 	int ioflag = ap->a_ioflag;
169 	struct evdev_client *client;
170 	struct input_event event;
171 	int ret = 0;
172 	int remaining;
173 
174 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
175 	if (ret != 0)
176 		return (ret);
177 
178 	debugf(client, "read %zd bytes by thread %d", uio->uio_resid, 0);
179 
180 	if (client->ec_revoked)
181 		return (ENODEV);
182 
183 	/* Zero-sized reads are allowed for error checking */
184 	if (uio->uio_resid != 0 && uio->uio_resid < sizeof(struct input_event))
185 		return (EINVAL);
186 
187 	remaining = uio->uio_resid / sizeof(struct input_event);
188 
189 	EVDEV_CLIENT_LOCKQ(client);
190 
191 	if (EVDEV_CLIENT_EMPTYQ(client)) {
192 		if (ioflag & IO_NDELAY) {
193 			ret = EWOULDBLOCK;
194 		} else {
195 			if (remaining != 0) {
196 				client->ec_blocked = true;
197 				ret = lksleep(client, &client->ec_buffer_mtx,
198 				    PCATCH, "evread", 0);
199 			}
200 		}
201 	}
202 
203 	while (ret == 0 && !EVDEV_CLIENT_EMPTYQ(client) && remaining > 0) {
204 		memcpy(&event, &client->ec_buffer[client->ec_buffer_head],
205 		    sizeof(struct input_event));
206 		client->ec_buffer_head =
207 		    (client->ec_buffer_head + 1) % client->ec_buffer_size;
208 		remaining--;
209 
210 		EVDEV_CLIENT_UNLOCKQ(client);
211 		ret = uiomove((void *)&event, sizeof(struct input_event), uio);
212 		EVDEV_CLIENT_LOCKQ(client);
213 	}
214 
215 	EVDEV_CLIENT_UNLOCKQ(client);
216 
217 	return (ret);
218 }
219 
220 static int
221 evdev_write(struct dev_write_args *ap)
222 {
223 	cdev_t dev = ap->a_head.a_dev;
224 	struct uio *uio = ap->a_uio;
225 	struct evdev_dev *evdev = dev->si_drv1;
226 	struct evdev_client *client;
227 	struct input_event event;
228 	int ret = 0;
229 
230 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
231 	if (ret != 0)
232 		return (ret);
233 
234 	debugf(client, "write %zd bytes by thread %d", uio->uio_resid, 0);
235 
236 	if (client->ec_revoked || evdev == NULL)
237 		return (ENODEV);
238 
239 	if (uio->uio_resid % sizeof(struct input_event) != 0) {
240 		debugf(client, "write size not multiple of input_event size");
241 		return (EINVAL);
242 	}
243 
244 	while (uio->uio_resid > 0 && ret == 0) {
245 		ret = uiomove((void *)&event, sizeof(struct input_event), uio);
246 		if (ret == 0)
247 			ret = evdev_inject_event(evdev, event.type, event.code,
248 			    event.value);
249 	}
250 
251 	return (ret);
252 }
253 
254 static int
255 evdev_kqfilter(struct dev_kqfilter_args *ap)
256 {
257 	struct knote *kn = ap->a_kn;
258 	struct klist *klist;
259 	struct evdev_client *client;
260 	int ret;
261 
262 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
263 	if (ret != 0)
264 		return (ret);
265 
266 	if (client->ec_revoked)
267 		return (ENODEV);
268 
269 	switch(kn->kn_filter) {
270 	case EVFILT_READ:
271 		kn->kn_fop = &evdev_cdev_filterops;
272 		break;
273 	default:
274 		return(EINVAL);
275 	}
276 	kn->kn_hook = (caddr_t)client;
277 
278 	klist = &client->kqinfo.ki_note;
279 	knote_insert(klist, kn);
280 	return (0);
281 }
282 
283 static int
284 evdev_kqread(struct knote *kn, long hint)
285 {
286 	struct evdev_client *client;
287 	int ret;
288 	int locked = 0;
289 
290 	client = (struct evdev_client *)kn->kn_hook;
291 
292 	/* NOTE on DragonFly v FreeBSD.
293 	 * FreeBSD locks the klist when calling f_event, i.e. evdev_kqread().
294 	 * That's why the plain assertion EVDEV_CLIENT_LOCKQ_ASSERT(client)
295 	 * fails on DragonFly: DragonFly does not ensure the lock associated
296 	 * with the klist is locked.
297 	 * To mimic FreeBSD's behavior, we will lock ec_buffer_mtx if
298 	 * it was not locked, and unlock when leaving.
299 	 */
300 	locked = lockowned(&(client)->ec_buffer_mtx);
301 	if (!locked)
302 		EVDEV_CLIENT_LOCKQ(client);
303 
304 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
305 
306 	if (client->ec_revoked) {
307 		kn->kn_flags |= EV_EOF;
308 		ret = 1;
309 	} else {
310 		kn->kn_data = EVDEV_CLIENT_SIZEQ(client) *
311 		    sizeof(struct input_event);
312 		ret = !EVDEV_CLIENT_EMPTYQ(client);
313 	}
314 
315 	/* Unlock if ec_buffer_mtx was not locked. */
316 	if (!locked) {
317 		EVDEV_CLIENT_UNLOCKQ(client);
318 	}
319 
320 	return (ret);
321 }
322 
323 static void
324 evdev_kqdetach(struct knote *kn)
325 {
326 	struct evdev_client *client;
327 
328 	client = (struct evdev_client *)kn->kn_hook;
329 	knote_remove(&client->kqinfo.ki_note, kn);
330 }
331 
332 static int
333 evdev_ioctl(struct dev_ioctl_args *ap)
334 {
335 	cdev_t dev = ap->a_head.a_dev;
336 	u_long cmd = ap->a_cmd;
337 	caddr_t data = ap->a_data;
338 	struct evdev_dev *evdev = dev->si_drv1;
339 	struct evdev_client *client;
340 	struct input_keymap_entry *ke;
341 	int ret, len, limit, type_num;
342 	uint32_t code;
343 	size_t nvalues;
344 
345 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
346 	if (ret != 0)
347 		return (ret);
348 
349 	if (client->ec_revoked || evdev == NULL)
350 		return (ENODEV);
351 
352 	/* file I/O ioctl handling */
353 	switch (cmd) {
354 	case FIOSETOWN:
355 		return (fsetown(*(int *)data, &client->ec_sigio));
356 
357 	case FIOGETOWN:
358 		*(int *)data = fgetown(&client->ec_sigio);
359 		return (0);
360 
361 	case FIONBIO:
362 		return (0);
363 
364 	case FIOASYNC:
365 		if (*(int *)data)
366 			client->ec_async = true;
367 		else
368 			client->ec_async = false;
369 
370 		return (0);
371 
372 	case FIONREAD:
373 		EVDEV_CLIENT_LOCKQ(client);
374 		*(int *)data =
375 		    EVDEV_CLIENT_SIZEQ(client) * sizeof(struct input_event);
376 		EVDEV_CLIENT_UNLOCKQ(client);
377 		return (0);
378 	}
379 
380 	len = IOCPARM_LEN(cmd);
381 	debugf(client, "ioctl called: cmd=0x%08lx, data=%p", cmd, data);
382 
383 	/* evdev fixed-length ioctls handling */
384 	switch (cmd) {
385 	case EVIOCGVERSION:
386 		*(int *)data = EV_VERSION;
387 		return (0);
388 
389 	case EVIOCGID:
390 		debugf(client, "EVIOCGID: bus=%d vendor=0x%04x product=0x%04x",
391 		    evdev->ev_id.bustype, evdev->ev_id.vendor,
392 		    evdev->ev_id.product);
393 		memcpy(data, &evdev->ev_id, sizeof(struct input_id));
394 		return (0);
395 
396 	case EVIOCGREP:
397 		if (!evdev_event_supported(evdev, EV_REP))
398 			return (ENOTSUP);
399 
400 		memcpy(data, evdev->ev_rep, sizeof(evdev->ev_rep));
401 		return (0);
402 
403 	case EVIOCSREP:
404 		if (!evdev_event_supported(evdev, EV_REP))
405 			return (ENOTSUP);
406 
407 		evdev_inject_event(evdev, EV_REP, REP_DELAY, ((int *)data)[0]);
408 		evdev_inject_event(evdev, EV_REP, REP_PERIOD,
409 		    ((int *)data)[1]);
410 		return (0);
411 
412 	case EVIOCGKEYCODE:
413 		/* Fake unsupported ioctl */
414 		return (0);
415 
416 	case EVIOCGKEYCODE_V2:
417 		if (evdev->ev_methods == NULL ||
418 		    evdev->ev_methods->ev_get_keycode == NULL)
419 			return (ENOTSUP);
420 
421 		ke = (struct input_keymap_entry *)data;
422 		evdev->ev_methods->ev_get_keycode(evdev, evdev->ev_softc, ke);
423 		return (0);
424 
425 	case EVIOCSKEYCODE:
426 		/* Fake unsupported ioctl */
427 		return (0);
428 
429 	case EVIOCSKEYCODE_V2:
430 		if (evdev->ev_methods == NULL ||
431 		    evdev->ev_methods->ev_set_keycode == NULL)
432 			return (ENOTSUP);
433 
434 		ke = (struct input_keymap_entry *)data;
435 		evdev->ev_methods->ev_set_keycode(evdev, evdev->ev_softc, ke);
436 		return (0);
437 
438 	case EVIOCGABS(0) ... EVIOCGABS(ABS_MAX):
439 		if (evdev->ev_absinfo == NULL)
440 			return (EINVAL);
441 
442 		memcpy(data, &evdev->ev_absinfo[cmd - EVIOCGABS(0)],
443 		    sizeof(struct input_absinfo));
444 		return (0);
445 
446 	case EVIOCSABS(0) ... EVIOCSABS(ABS_MAX):
447 		if (evdev->ev_absinfo == NULL)
448 			return (EINVAL);
449 
450 		code = cmd - EVIOCSABS(0);
451 		/* mt-slot number can not be changed */
452 		if (code == ABS_MT_SLOT)
453 			return (EINVAL);
454 
455 		EVDEV_LOCK(evdev);
456 		evdev_set_absinfo(evdev, code, (struct input_absinfo *)data);
457 		EVDEV_UNLOCK(evdev);
458 		return (0);
459 
460 	case EVIOCSFF:
461 	case EVIOCRMFF:
462 	case EVIOCGEFFECTS:
463 		/* Fake unsupported ioctls */
464 		return (0);
465 
466 	case EVIOCGRAB:
467 		EVDEV_LOCK(evdev);
468 		if (*(int *)data)
469 			ret = evdev_grab_client(evdev, client);
470 		else
471 			ret = evdev_release_client(evdev, client);
472 		EVDEV_UNLOCK(evdev);
473 		return (ret);
474 
475 	case EVIOCREVOKE:
476 		if (*(int *)data != 0)
477 			return (EINVAL);
478 
479 		EVDEV_LOCK(evdev);
480 		if (dev->si_drv1 != NULL && !client->ec_revoked) {
481 			evdev_dispose_client(evdev, client);
482 			evdev_revoke_client(client);
483 		}
484 		EVDEV_UNLOCK(evdev);
485 		return (0);
486 
487 	case EVIOCSCLOCKID:
488 		switch (*(int *)data) {
489 		case CLOCK_REALTIME:
490 			client->ec_clock_id = EV_CLOCK_REALTIME;
491 			return (0);
492 		case CLOCK_MONOTONIC:
493 			client->ec_clock_id = EV_CLOCK_MONOTONIC;
494 			return (0);
495 		default:
496 			return (EINVAL);
497 		}
498 	}
499 
500 	/* evdev variable-length ioctls handling */
501 	switch (IOCBASECMD(cmd)) {
502 	case EVIOCGNAME(0):
503 		strlcpy(data, evdev->ev_name, len);
504 		return (0);
505 
506 	case EVIOCGPHYS(0):
507 		if (evdev->ev_shortname[0] == 0)
508 			return (ENOENT);
509 
510 		strlcpy(data, evdev->ev_shortname, len);
511 		return (0);
512 
513 	case EVIOCGUNIQ(0):
514 		if (evdev->ev_serial[0] == 0)
515 			return (ENOENT);
516 
517 		strlcpy(data, evdev->ev_serial, len);
518 		return (0);
519 
520 	case EVIOCGPROP(0):
521 		limit = MIN(len, bitstr_size(INPUT_PROP_CNT));
522 		memcpy(data, evdev->ev_prop_flags, limit);
523 		return (0);
524 
525 	case EVIOCGMTSLOTS(0):
526 		if (evdev->ev_mt == NULL)
527 			return (EINVAL);
528 		if (len < sizeof(uint32_t))
529 			return (EINVAL);
530 		code = *(uint32_t *)data;
531 		if (!ABS_IS_MT(code))
532 			return (EINVAL);
533 
534 		nvalues =
535 		    MIN(len / sizeof(int32_t) - 1, MAXIMAL_MT_SLOT(evdev) + 1);
536 		for (int i = 0; i < nvalues; i++)
537 			((int32_t *)data)[i + 1] =
538 			    evdev_get_mt_value(evdev, i, code);
539 		return (0);
540 
541 	case EVIOCGKEY(0):
542 		limit = MIN(len, bitstr_size(KEY_CNT));
543 		EVDEV_LOCK(evdev);
544 		evdev_client_filter_queue(client, EV_KEY);
545 		memcpy(data, evdev->ev_key_states, limit);
546 		EVDEV_UNLOCK(evdev);
547 		return (0);
548 
549 	case EVIOCGLED(0):
550 		limit = MIN(len, bitstr_size(LED_CNT));
551 		EVDEV_LOCK(evdev);
552 		evdev_client_filter_queue(client, EV_LED);
553 		memcpy(data, evdev->ev_led_states, limit);
554 		EVDEV_UNLOCK(evdev);
555 		return (0);
556 
557 	case EVIOCGSND(0):
558 		limit = MIN(len, bitstr_size(SND_CNT));
559 		EVDEV_LOCK(evdev);
560 		evdev_client_filter_queue(client, EV_SND);
561 		memcpy(data, evdev->ev_snd_states, limit);
562 		EVDEV_UNLOCK(evdev);
563 		return (0);
564 
565 	case EVIOCGSW(0):
566 		limit = MIN(len, bitstr_size(SW_CNT));
567 		EVDEV_LOCK(evdev);
568 		evdev_client_filter_queue(client, EV_SW);
569 		memcpy(data, evdev->ev_sw_states, limit);
570 		EVDEV_UNLOCK(evdev);
571 		return (0);
572 
573 	case EVIOCGBIT(0, 0) ... EVIOCGBIT(EV_MAX, 0):
574 		type_num = IOCBASECMD(cmd) - EVIOCGBIT(0, 0);
575 		debugf(client, "EVIOCGBIT(%d): data=%p, len=%d", type_num,
576 		    data, len);
577 		return (evdev_ioctl_eviocgbit(evdev, type_num, len, data));
578 	}
579 
580 	return (EINVAL);
581 }
582 
583 static int
584 evdev_ioctl_eviocgbit(struct evdev_dev *evdev, int type, int len, caddr_t data)
585 {
586 	/*
587 	 * We will use freebsd-bitstring.h locally. This ensures bitmap
588 	 * is of type (unsigned long *). DragonFly's original bitmap
589 	 * is (unsigned char *).
590 	 */
591 	unsigned long *bitmap;
592 	int limit;
593 
594 	switch (type) {
595 	case 0:
596 		bitmap = evdev->ev_type_flags;
597 		limit = EV_CNT;
598 		break;
599 	case EV_KEY:
600 		bitmap = evdev->ev_key_flags;
601 		limit = KEY_CNT;
602 		break;
603 	case EV_REL:
604 		bitmap = evdev->ev_rel_flags;
605 		limit = REL_CNT;
606 		break;
607 	case EV_ABS:
608 		bitmap = evdev->ev_abs_flags;
609 		limit = ABS_CNT;
610 		break;
611 	case EV_MSC:
612 		bitmap = evdev->ev_msc_flags;
613 		limit = MSC_CNT;
614 		break;
615 	case EV_LED:
616 		bitmap = evdev->ev_led_flags;
617 		limit = LED_CNT;
618 		break;
619 	case EV_SND:
620 		bitmap = evdev->ev_snd_flags;
621 		limit = SND_CNT;
622 		break;
623 	case EV_SW:
624 		bitmap = evdev->ev_sw_flags;
625 		limit = SW_CNT;
626 		break;
627 	case EV_FF:
628 		/*
629 		 * We don't support EV_FF now, so let's
630 		 * just fake it returning only zeros.
631 		 */
632 		bzero(data, len);
633 		return (0);
634 	default:
635 		return (ENOTTY);
636 	}
637 
638 	/*
639 	 * Clear ioctl data buffer in case it's bigger than
640 	 * bitmap size
641 	 */
642 	bzero(data, len);
643 
644 	limit = bitstr_size(limit);
645 	len = MIN(limit, len);
646 	memcpy(data, bitmap, len);
647 	return (0);
648 }
649 
650 void
651 evdev_revoke_client(struct evdev_client *client)
652 {
653 
654 	EVDEV_LOCK_ASSERT(client->ec_evdev);
655 
656 	client->ec_revoked = true;
657 }
658 
659 void
660 evdev_notify_event(struct evdev_client *client)
661 {
662 
663 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
664 
665 	if (client->ec_blocked) {
666 		client->ec_blocked = false;
667 		wakeup(client);
668 	}
669 	if (client->ec_selected) {
670 		client->ec_selected = false;
671 		wakeup(&client->kqinfo);
672 	}
673 
674 	KNOTE(&client->kqinfo.ki_note, 0);
675 
676 	if (client->ec_async && client->ec_sigio != NULL)
677 		pgsigio(client->ec_sigio, SIGIO, 0);
678 }
679 
680 int
681 evdev_cdev_create(struct evdev_dev *evdev)
682 {
683 	cdev_t dev;
684 	int ret, unit;
685 
686 	/*
687 	 * Iterate over devices input/eventX until we find a non-existing
688 	 * one and record its number in unit.
689 	 */
690 	unit = 0;
691 	while (devfs_find_device_by_name("input/event%d", unit) != NULL) {
692 	    unit++;
693 	}
694 
695 	/*
696 	 * Put unit as minor. Minor and major will determine st_rdev of
697 	 * eventX. Ensuring that all eventX have different major and minor
698 	 * will make st_rdev unique. This is needed by libinput, which
699 	 * determines eventX from st_rdev.
700 	 */
701 	dev = make_dev(&evdev_cdevsw, unit, UID_ROOT, GID_WHEEL, 0600,
702 	    "input/event%d", unit);
703 
704 	if (dev != NULL) {
705 		dev->si_drv1 = evdev;
706 		evdev->ev_cdev = dev;
707 		evdev->ev_unit = unit;
708 		ret = 0;
709 	} else {
710 		ret = ENODEV;
711 		goto err;
712 	}
713 
714 	reference_dev(evdev->ev_cdev);
715 
716 err:
717 	return (ret);
718 }
719 
720 int
721 evdev_cdev_destroy(struct evdev_dev *evdev)
722 {
723 
724 	if (evdev->ev_cdev) {
725 		dev_ops_remove_minor(&evdev_cdevsw, evdev->ev_unit);
726 	}
727 
728 	return (0);
729 }
730 
731 static void
732 evdev_client_gettime(struct evdev_client *client, struct timeval *tv)
733 {
734 
735 	switch (client->ec_clock_id) {
736 	case EV_CLOCK_BOOTTIME:
737 		/*
738 		 * XXX: FreeBSD does not support true POSIX monotonic clock.
739 		 *      So aliase EV_CLOCK_BOOTTIME to EV_CLOCK_MONOTONIC.
740 		 */
741 	case EV_CLOCK_MONOTONIC:
742 		microuptime(tv);
743 		break;
744 
745 	case EV_CLOCK_REALTIME:
746 	default:
747 		microtime(tv);
748 		break;
749 	}
750 }
751 
752 void
753 evdev_client_push(struct evdev_client *client, uint16_t type, uint16_t code,
754     int32_t value)
755 {
756 	struct timeval time;
757 	size_t count, head, tail, ready;
758 
759 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
760 	head = client->ec_buffer_head;
761 	tail = client->ec_buffer_tail;
762 	ready = client->ec_buffer_ready;
763 	count = client->ec_buffer_size;
764 
765 	/* If queue is full drop its content and place SYN_DROPPED event */
766 	if ((tail + 1) % count == head) {
767 		debugf(client, "client %p: buffer overflow", client);
768 
769 		head = (tail + count - 1) % count;
770 		client->ec_buffer[head] = (struct input_event) {
771 			.type = EV_SYN,
772 			.code = SYN_DROPPED,
773 			.value = 0
774 		};
775 		/*
776 		 * XXX: Here is a small race window from now till the end of
777 		 *      report. The queue is empty but client has been already
778 		 *      notified of data readyness. Can be fixed in two ways:
779 		 * 1. Implement bulk insert so queue lock would not be dropped
780 		 *    till the SYN_REPORT event.
781 		 * 2. Insert SYN_REPORT just now and skip remaining events
782 		 */
783 		client->ec_buffer_head = head;
784 		client->ec_buffer_ready = head;
785 	}
786 
787 	client->ec_buffer[tail].type = type;
788 	client->ec_buffer[tail].code = code;
789 	client->ec_buffer[tail].value = value;
790 	client->ec_buffer_tail = (tail + 1) % count;
791 
792 	/* Allow users to read events only after report has been completed */
793 	if (type == EV_SYN && code == SYN_REPORT) {
794 		evdev_client_gettime(client, &time);
795 		for (; ready != client->ec_buffer_tail;
796 		    ready = (ready + 1) % count)
797 			client->ec_buffer[ready].time = time;
798 		client->ec_buffer_ready = client->ec_buffer_tail;
799 	}
800 }
801 
802 void
803 evdev_client_dumpqueue(struct evdev_client *client)
804 {
805 	struct input_event *event;
806 	size_t i, head, tail, ready, size;
807 
808 	head = client->ec_buffer_head;
809 	tail = client->ec_buffer_tail;
810 	ready = client->ec_buffer_ready;
811 	size = client->ec_buffer_size;
812 
813 	kprintf("evdev client: %p\n", client);
814 	kprintf("event queue: head=%zu ready=%zu tail=%zu size=%zu\n",
815 	    head, ready, tail, size);
816 
817 	kprintf("queue contents:\n");
818 
819 	for (i = 0; i < size; i++) {
820 		event = &client->ec_buffer[i];
821 		kprintf("%zu: ", i);
822 
823 		if (i < head || i > tail)
824 			kprintf("unused\n");
825 		else
826 			kprintf("type=%d code=%d value=%d ", event->type,
827 			    event->code, event->value);
828 
829 		if (i == head)
830 			kprintf("<- head\n");
831 		else if (i == tail)
832 			kprintf("<- tail\n");
833 		else if (i == ready)
834 			kprintf("<- ready\n");
835 		else
836 			kprintf("\n");
837 	}
838 }
839 
840 static void
841 evdev_client_filter_queue(struct evdev_client *client, uint16_t type)
842 {
843 	struct input_event *event;
844 	size_t head, tail, count, i;
845 	bool last_was_syn = false;
846 
847 	EVDEV_CLIENT_LOCKQ(client);
848 
849 	i = head = client->ec_buffer_head;
850 	tail = client->ec_buffer_tail;
851 	count = client->ec_buffer_size;
852 	client->ec_buffer_ready = client->ec_buffer_tail;
853 
854 	while (i != client->ec_buffer_tail) {
855 		event = &client->ec_buffer[i];
856 		i = (i + 1) % count;
857 
858 		/* Skip event of given type */
859 		if (event->type == type)
860 			continue;
861 
862 		/* Remove empty SYN_REPORT events */
863 		if (event->type == EV_SYN && event->code == SYN_REPORT) {
864 			if (last_was_syn)
865 				continue;
866 			else
867 				client->ec_buffer_ready = (tail + 1) % count;
868 		}
869 
870 		/* Rewrite entry */
871 		memcpy(&client->ec_buffer[tail], event,
872 		    sizeof(struct input_event));
873 
874 		last_was_syn = (event->type == EV_SYN &&
875 		    event->code == SYN_REPORT);
876 
877 		tail = (tail + 1) % count;
878 	}
879 
880 	client->ec_buffer_head = i;
881 	client->ec_buffer_tail = tail;
882 
883 	EVDEV_CLIENT_UNLOCKQ(client);
884 }
885