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wsevent.c revision 1.34.12.1
      1 /* $NetBSD: wsevent.c,v 1.34.12.1 2012/10/30 17:22:12 yamt Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2006, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Julio M. Merino Vidal.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
     34  *
     35  * Redistribution and use in source and binary forms, with or without
     36  * modification, are permitted provided that the following conditions
     37  * are met:
     38  * 1. Redistributions of source code must retain the above copyright
     39  *    notice, this list of conditions and the following disclaimer.
     40  * 2. Redistributions in binary form must reproduce the above copyright
     41  *    notice, this list of conditions and the following disclaimer in the
     42  *    documentation and/or other materials provided with the distribution.
     43  * 3. All advertising materials mentioning features or use of this software
     44  *    must display the following acknowledgement:
     45  *      This product includes software developed by Christopher G. Demetriou
     46  *	for the NetBSD Project.
     47  * 4. The name of the author may not be used to endorse or promote products
     48  *    derived from this software without specific prior written permission
     49  *
     50  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     53  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     56  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     57  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     58  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     59  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     60  */
     61 
     62 /*
     63  * Copyright (c) 1992, 1993
     64  *	The Regents of the University of California.  All rights reserved.
     65  *
     66  * This software was developed by the Computer Systems Engineering group
     67  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     68  * contributed to Berkeley.
     69  *
     70  * All advertising materials mentioning features or use of this software
     71  * must display the following acknowledgement:
     72  *	This product includes software developed by the University of
     73  *	California, Lawrence Berkeley Laboratory.
     74  *
     75  * Redistribution and use in source and binary forms, with or without
     76  * modification, are permitted provided that the following conditions
     77  * are met:
     78  * 1. Redistributions of source code must retain the above copyright
     79  *    notice, this list of conditions and the following disclaimer.
     80  * 2. Redistributions in binary form must reproduce the above copyright
     81  *    notice, this list of conditions and the following disclaimer in the
     82  *    documentation and/or other materials provided with the distribution.
     83  * 3. Neither the name of the University nor the names of its contributors
     84  *    may be used to endorse or promote products derived from this software
     85  *    without specific prior written permission.
     86  *
     87  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     88  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     89  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     90  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     91  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     92  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     93  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     94  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     95  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     96  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     97  * SUCH DAMAGE.
     98  *
     99  *	@(#)event.c	8.1 (Berkeley) 6/11/93
    100  */
    101 
    102 /*
    103  * Internal "wscons_event" queue interface for the keyboard and mouse drivers.
    104  */
    105 
    106 #include <sys/cdefs.h>
    107 __KERNEL_RCSID(0, "$NetBSD: wsevent.c,v 1.34.12.1 2012/10/30 17:22:12 yamt Exp $");
    108 
    109 #include "opt_compat_netbsd.h"
    110 #include "opt_modular.h"
    111 
    112 #include <sys/param.h>
    113 #include <sys/kernel.h>
    114 #include <sys/fcntl.h>
    115 #include <sys/kmem.h>
    116 #include <sys/proc.h>
    117 #include <sys/systm.h>
    118 #include <sys/vnode.h>
    119 #include <sys/select.h>
    120 #include <sys/poll.h>
    121 
    122 #include <dev/wscons/wsconsio.h>
    123 #include <dev/wscons/wseventvar.h>
    124 
    125 /*
    126  * Size of a wsevent queue (measured in number of events).
    127  * Should be a power of two so that `%' is fast.
    128  * At the moment, the value below makes the queues use 2 Kbytes each; this
    129  * value may need tuning.
    130  */
    131 #define	WSEVENT_QSIZE	256
    132 
    133 #define EVSIZE(ver)	((ver) == WSEVENT_VERSION ? \
    134     sizeof(struct wscons_event) : \
    135     sizeof(struct owscons_event))
    136 #define EVARRAY(ev, idx) (&(ev)->q[(idx)])
    137 
    138 /*
    139  * Priority of code managing wsevent queues.  PWSEVENT is set just above
    140  * PSOCK, which is just above TTIPRI, on the theory that mouse and keyboard
    141  * `user' input should be quick.
    142  */
    143 #define	PWSEVENT	23
    144 #define	splwsevent()	spltty()
    145 
    146 static void	wsevent_intr(void *);
    147 
    148 /*
    149  * Initialize a wscons_event queue.
    150  */
    151 void
    152 wsevent_init(struct wseventvar *ev, struct proc *p)
    153 {
    154 
    155 	if (ev->q != NULL) {
    156 #ifdef DIAGNOSTIC
    157 		printf("wsevent_init: already init\n");
    158 #endif
    159 		return;
    160 	}
    161 	/* For binary compat. New code must call WSxxxIO_SETVERSION */
    162 	ev->version = 0;
    163 	ev->get = ev->put = 0;
    164 	ev->q = kmem_alloc(WSEVENT_QSIZE * sizeof(*ev->q), KM_SLEEP);
    165 	selinit(&ev->sel);
    166 	ev->io = p;
    167 	ev->sih = softint_establish(SOFTINT_MPSAFE | SOFTINT_CLOCK,
    168 	    wsevent_intr, ev);
    169 }
    170 
    171 /*
    172  * Tear down a wscons_event queue.
    173  */
    174 void
    175 wsevent_fini(struct wseventvar *ev)
    176 {
    177 	if (ev->q == NULL) {
    178 #ifdef DIAGNOSTIC
    179 		printf("wsevent_fini: already fini\n");
    180 #endif
    181 		return;
    182 	}
    183 	seldestroy(&ev->sel);
    184 	kmem_free(ev->q, WSEVENT_QSIZE * sizeof(*ev->q));
    185 	ev->q = NULL;
    186 	softint_disestablish(ev->sih);
    187 }
    188 
    189 #if defined(COMPAT_50) || defined(MODULAR)
    190 static int
    191 wsevent_copyout_events50(const struct wscons_event *events, int cnt,
    192     struct uio *uio)
    193 {
    194 	int i;
    195 
    196 	for (i = 0; i < cnt; i++) {
    197 		const struct wscons_event *ev = &events[i];
    198 		struct owscons_event ev50;
    199 		int error;
    200 
    201 		ev50.type = ev->type;
    202 		ev50.value = ev->value;
    203 		timespec_to_timespec50(&ev->time, &ev50.time);
    204 
    205 		error = uiomove(&ev50, sizeof(ev50), uio);
    206 		if (error) {
    207 			return error;
    208 		}
    209 	}
    210 	return 0;
    211 }
    212 #else /* defined(COMPAT_50) || defined(MODULAR) */
    213 static int
    214 wsevent_copyout_events50(const struct wscons_event *events, int cnt,
    215     struct uio *uio)
    216 {
    217 
    218 	return EINVAL;
    219 }
    220 #endif /* defined(COMPAT_50) || defined(MODULAR) */
    221 
    222 static int
    223 wsevent_copyout_events(const struct wscons_event *events, int cnt,
    224     struct uio *uio, int ver)
    225 {
    226 
    227 	switch (ver) {
    228 	case 0:
    229 		return wsevent_copyout_events50(events, cnt, uio);
    230 	case WSEVENT_VERSION:
    231 		return uiomove(__UNCONST(events), cnt * sizeof(*events), uio);
    232 	default:
    233 		panic("%s: unknown version %d", __func__, ver);
    234 	}
    235 }
    236 
    237 /*
    238  * User-level interface: read, poll.
    239  * (User cannot write an event queue.)
    240  */
    241 int
    242 wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
    243 {
    244 	int s, n, cnt, error;
    245 	const int ver = ev->version;
    246 	const size_t evsize = EVSIZE(ver);
    247 
    248 	/*
    249 	 * Make sure we can return at least 1.
    250 	 */
    251 	if (uio->uio_resid < evsize)
    252 		return (EMSGSIZE);	/* ??? */
    253 	s = splwsevent();
    254 	while (ev->get == ev->put) {
    255 		if (flags & IO_NDELAY) {
    256 			splx(s);
    257 			return (EWOULDBLOCK);
    258 		}
    259 		ev->wanted = 1;
    260 		error = tsleep(ev, PWSEVENT | PCATCH, "wsevent_read", 0);
    261 		if (error) {
    262 			splx(s);
    263 			return (error);
    264 		}
    265 	}
    266 	/*
    267 	 * Move wscons_event from tail end of queue (there is at least one
    268 	 * there).
    269 	 */
    270 	if (ev->put < ev->get)
    271 		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
    272 	else
    273 		cnt = ev->put - ev->get;	/* events in [get..put) */
    274 	splx(s);
    275 	n = howmany(uio->uio_resid, evsize);
    276 	if (cnt > n)
    277 		cnt = n;
    278 	error = wsevent_copyout_events(EVARRAY(ev, ev->get), cnt, uio, ver);
    279 	n -= cnt;
    280 	/*
    281 	 * If we do not wrap to 0, used up all our space, or had an error,
    282 	 * stop.  Otherwise move from front of queue to put index, if there
    283 	 * is anything there to move.
    284 	 */
    285 	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
    286 	    n == 0 || error || (cnt = ev->put) == 0)
    287 		return (error);
    288 	if (cnt > n)
    289 		cnt = n;
    290 	error = wsevent_copyout_events(EVARRAY(ev, 0), cnt, uio, ver);
    291 	ev->get = cnt;
    292 	return (error);
    293 }
    294 
    295 int
    296 wsevent_poll(struct wseventvar *ev, int events, struct lwp *l)
    297 {
    298 	int revents = 0;
    299 	int s = splwsevent();
    300 
    301         if (events & (POLLIN | POLLRDNORM)) {
    302 		if (ev->get != ev->put)
    303 			revents |= events & (POLLIN | POLLRDNORM);
    304 		else
    305 			selrecord(l, &ev->sel);
    306 	}
    307 
    308 	splx(s);
    309 	return (revents);
    310 }
    311 
    312 static void
    313 filt_wseventrdetach(struct knote *kn)
    314 {
    315 	struct wseventvar *ev = kn->kn_hook;
    316 	int s;
    317 
    318 	s = splwsevent();
    319 	SLIST_REMOVE(&ev->sel.sel_klist, kn, knote, kn_selnext);
    320 	splx(s);
    321 }
    322 
    323 static int
    324 filt_wseventread(struct knote *kn, long hint)
    325 {
    326 	struct wseventvar *ev = kn->kn_hook;
    327 
    328 	if (ev->get == ev->put)
    329 		return (0);
    330 
    331 	if (ev->get < ev->put)
    332 		kn->kn_data = ev->put - ev->get;
    333 	else
    334 		kn->kn_data = (WSEVENT_QSIZE - ev->get) + ev->put;
    335 
    336 	kn->kn_data *= EVSIZE(ev->version);
    337 
    338 	return (1);
    339 }
    340 
    341 static const struct filterops wsevent_filtops =
    342 	{ 1, NULL, filt_wseventrdetach, filt_wseventread };
    343 
    344 int
    345 wsevent_kqfilter(struct wseventvar *ev, struct knote *kn)
    346 {
    347 	struct klist *klist;
    348 	int s;
    349 
    350 	switch (kn->kn_filter) {
    351 	case EVFILT_READ:
    352 		klist = &ev->sel.sel_klist;
    353 		kn->kn_fop = &wsevent_filtops;
    354 		break;
    355 
    356 	default:
    357 		return (EINVAL);
    358 	}
    359 
    360 	kn->kn_hook = ev;
    361 
    362 	s = splwsevent();
    363 	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
    364 	splx(s);
    365 
    366 	return (0);
    367 }
    368 
    369 /*
    370  * Wakes up all listener of the 'ev' queue.
    371  */
    372 void
    373 wsevent_wakeup(struct wseventvar *ev)
    374 {
    375 
    376 	selnotify(&ev->sel, 0, 0);
    377 
    378 	if (ev->wanted) {
    379 		ev->wanted = 0;
    380 		wakeup(ev);
    381 	}
    382 
    383 	if (ev->async) {
    384 		softint_schedule(ev->sih);
    385 	}
    386 }
    387 
    388 /*
    389  * Soft interrupt handler: sends signal to async proc.
    390  */
    391 static void
    392 wsevent_intr(void *cookie)
    393 {
    394 	struct wseventvar *ev;
    395 
    396 	ev = cookie;
    397 
    398 	if (ev->async) {
    399 		mutex_enter(proc_lock);
    400 		psignal(ev->io, SIGIO);
    401 		mutex_exit(proc_lock);
    402 	}
    403 }
    404 
    405 /*
    406  * Injects the set of events given in 'events', whose size is 'nevents',
    407  * into the 'ev' queue.  If there is not enough free space to inject them
    408  * all, returns ENOSPC and the queue is left intact; otherwise returns 0
    409  * and wakes up all listeners.
    410  */
    411 int
    412 wsevent_inject(struct wseventvar *ev, struct wscons_event *events,
    413     size_t nevents)
    414 {
    415 	size_t avail, i;
    416 	struct timespec t;
    417 
    418 	/* Calculate number of free slots in the queue. */
    419 	if (ev->put < ev->get)
    420 		avail = ev->get - ev->put;
    421 	else
    422 		avail = WSEVENT_QSIZE - (ev->put - ev->get);
    423 	KASSERT(avail <= WSEVENT_QSIZE);
    424 
    425 	/* Fail if there is all events will not fit in the queue. */
    426 	if (avail < nevents)
    427 		return ENOSPC;
    428 
    429 	/* Use the current time for all events. */
    430 	getnanotime(&t);
    431 
    432 	/* Inject the events. */
    433 	for (i = 0; i < nevents; i++) {
    434 		struct wscons_event *we;
    435 
    436 		we = EVARRAY(ev, ev->put);
    437 		we->type = events[i].type;
    438 		we->value = events[i].value;
    439 		we->time = t;
    440 
    441 		ev->put = (ev->put + 1) % WSEVENT_QSIZE;
    442 	}
    443 	wsevent_wakeup(ev);
    444 
    445 	return 0;
    446 }
    447 
    448 int
    449 wsevent_setversion(struct wseventvar *ev, int vers)
    450 {
    451 	if (ev == NULL)
    452 		return EINVAL;
    453 
    454 	switch (vers) {
    455 	case 0:
    456 	case WSEVENT_VERSION:
    457 		break;
    458 	default:
    459 		return EINVAL;
    460 	}
    461 
    462 	if (vers == ev->version)
    463 		return 0;
    464 
    465 	ev->get = ev->put = 0;
    466 	ev->version = vers;
    467 	return 0;
    468 }
    469