xref: /netbsd/sys/dev/wscons/wsevent.c (revision d4c0b446)
1 /* $NetBSD: wsevent.c,v 1.46 2020/12/18 01:41:23 thorpej 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 1.46 2020/12/18 01:41:23 thorpej Exp $");
108 
109 #ifdef _KERNEL_OPT
110 #include "opt_compat_netbsd.h"
111 #include "opt_modular.h"
112 #endif
113 
114 #include <sys/param.h>
115 #include <sys/kernel.h>
116 #include <sys/fcntl.h>
117 #include <sys/kmem.h>
118 #include <sys/proc.h>
119 #include <sys/systm.h>
120 #include <sys/vnode.h>
121 #include <sys/select.h>
122 #include <sys/poll.h>
123 #include <sys/compat_stub.h>
124 #include <sys/sysctl.h>
125 
126 #include <dev/wscons/wsconsio.h>
127 #include <dev/wscons/wseventvar.h>
128 
129 /*
130  * Size of a wsevent queue (measured in number of events).
131  * Should be a power of two so that `%' is fast.
132  * At the moment, the value below makes the queues use 2 Kbytes each; this
133  * value may need tuning.
134  */
135 #define	WSEVENT_QSIZE	256
136 
137 #define EVSIZE(ver)	((ver) == WSEVENT_VERSION ? \
138     sizeof(struct wscons_event) : \
139     sizeof(struct owscons_event))
140 #define EVARRAY(ev, idx) (&(ev)->q[(idx)])
141 
142 static int wsevent_default_version = WSEVENT_VERSION;
143 
144 /*
145  * Priority of code managing wsevent queues.  PWSEVENT is set just above
146  * PSOCK, which is just above TTIPRI, on the theory that mouse and keyboard
147  * `user' input should be quick.
148  */
149 #define	PWSEVENT	23
150 #define	splwsevent()	spltty()
151 
152 static void	wsevent_intr(void *);
153 
154 /*
155  * Initialize a wscons_event queue.
156  */
157 void
158 wsevent_init(struct wseventvar *ev, struct proc *p)
159 {
160 
161 	if (ev->q != NULL) {
162 #ifdef DIAGNOSTIC
163 		printf("wsevent_init: already init\n");
164 #endif
165 		return;
166 	}
167 	/*
168 	 * For binary compat set default version and either build with
169 	 * COMPAT_50 or load COMPAT_50 module to include the compatibility
170 	 * code.
171 	 */
172 	if (wsevent_default_version >= 0 &&
173 	    wsevent_default_version < WSEVENT_VERSION)
174 		ev->version = wsevent_default_version;
175 	else
176 		ev->version = WSEVENT_VERSION;
177 
178 	ev->get = ev->put = 0;
179 	ev->q = kmem_alloc(WSEVENT_QSIZE * sizeof(*ev->q), KM_SLEEP);
180 	selinit(&ev->sel);
181 	ev->io = p;
182 	ev->sih = softint_establish(SOFTINT_MPSAFE | SOFTINT_CLOCK,
183 	    wsevent_intr, ev);
184 }
185 
186 /*
187  * Tear down a wscons_event queue.
188  */
189 void
190 wsevent_fini(struct wseventvar *ev)
191 {
192 	if (ev->q == NULL) {
193 #ifdef DIAGNOSTIC
194 		printf("wsevent_fini: already fini\n");
195 #endif
196 		return;
197 	}
198 	seldestroy(&ev->sel);
199 	kmem_free(ev->q, WSEVENT_QSIZE * sizeof(*ev->q));
200 	ev->q = NULL;
201 	softint_disestablish(ev->sih);
202 }
203 
204 static int
205 wsevent_copyout_events(const struct wscons_event *events, int cnt,
206     struct uio *uio, int ver)
207 {
208 	int error;
209 
210 	switch (ver) {
211 	case 0:
212 		MODULE_HOOK_CALL(wscons_copyout_events_50_hook,
213 		    (events, cnt, uio), enosys(), error);
214 		if (error == ENOSYS)
215 			error = EINVAL;
216 		return error;
217 	case WSEVENT_VERSION:
218 		return uiomove(__UNCONST(events), cnt * sizeof(*events), uio);
219 	default:
220 		panic("%s: unknown version %d", __func__, ver);
221 	}
222 }
223 
224 /*
225  * User-level interface: read, poll.
226  * (User cannot write an event queue.)
227  */
228 int
229 wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
230 {
231 	int s, n, cnt, error;
232 	const int ver = ev->version;
233 	const size_t evsize = EVSIZE(ver);
234 
235 	/*
236 	 * Make sure we can return at least 1.
237 	 */
238 	if (uio->uio_resid < evsize)
239 		return (EMSGSIZE);	/* ??? */
240 	s = splwsevent();
241 	while (ev->get == ev->put) {
242 		if (flags & IO_NDELAY) {
243 			splx(s);
244 			return (EWOULDBLOCK);
245 		}
246 		ev->wanted = 1;
247 		error = tsleep(ev, PWSEVENT | PCATCH, "wsevent_read", 0);
248 		if (error) {
249 			splx(s);
250 			return (error);
251 		}
252 	}
253 	/*
254 	 * Move wscons_event from tail end of queue (there is at least one
255 	 * there).
256 	 */
257 	if (ev->put < ev->get)
258 		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
259 	else
260 		cnt = ev->put - ev->get;	/* events in [get..put) */
261 	splx(s);
262 	n = howmany(uio->uio_resid, evsize);
263 	if (cnt > n)
264 		cnt = n;
265 	error = wsevent_copyout_events(EVARRAY(ev, ev->get), cnt, uio, ver);
266 	n -= cnt;
267 	/*
268 	 * If we do not wrap to 0, used up all our space, or had an error,
269 	 * stop.  Otherwise move from front of queue to put index, if there
270 	 * is anything there to move.
271 	 */
272 	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
273 	    n == 0 || error || (cnt = ev->put) == 0)
274 		return (error);
275 	if (cnt > n)
276 		cnt = n;
277 	error = wsevent_copyout_events(EVARRAY(ev, 0), cnt, uio, ver);
278 	ev->get = cnt;
279 	return (error);
280 }
281 
282 int
283 wsevent_poll(struct wseventvar *ev, int events, struct lwp *l)
284 {
285 	int revents = 0;
286 	int s = splwsevent();
287 
288         if (events & (POLLIN | POLLRDNORM)) {
289 		if (ev->get != ev->put)
290 			revents |= events & (POLLIN | POLLRDNORM);
291 		else
292 			selrecord(l, &ev->sel);
293 	}
294 
295 	splx(s);
296 	return (revents);
297 }
298 
299 static void
300 filt_wseventrdetach(struct knote *kn)
301 {
302 	struct wseventvar *ev = kn->kn_hook;
303 	int s;
304 
305 	s = splwsevent();
306 	selremove_knote(&ev->sel, kn);
307 	splx(s);
308 }
309 
310 static int
311 filt_wseventread(struct knote *kn, long hint)
312 {
313 	struct wseventvar *ev = kn->kn_hook;
314 
315 	if (ev->get == ev->put)
316 		return (0);
317 
318 	if (ev->get < ev->put)
319 		kn->kn_data = ev->put - ev->get;
320 	else
321 		kn->kn_data = (WSEVENT_QSIZE - ev->get) + ev->put;
322 
323 	kn->kn_data *= EVSIZE(ev->version);
324 
325 	return (1);
326 }
327 
328 static const struct filterops wsevent_filtops = {
329 	.f_isfd = 1,
330 	.f_attach = NULL,
331 	.f_detach = filt_wseventrdetach,
332 	.f_event = filt_wseventread,
333 };
334 
335 int
336 wsevent_kqfilter(struct wseventvar *ev, struct knote *kn)
337 {
338 	int s;
339 
340 	switch (kn->kn_filter) {
341 	case EVFILT_READ:
342 		kn->kn_fop = &wsevent_filtops;
343 		break;
344 
345 	default:
346 		return (EINVAL);
347 	}
348 
349 	kn->kn_hook = ev;
350 
351 	s = splwsevent();
352 	selrecord_knote(&ev->sel, kn);
353 	splx(s);
354 
355 	return (0);
356 }
357 
358 /*
359  * Wakes up all listener of the 'ev' queue.
360  */
361 void
362 wsevent_wakeup(struct wseventvar *ev)
363 {
364 
365 	selnotify(&ev->sel, 0, 0);
366 
367 	if (ev->wanted) {
368 		ev->wanted = 0;
369 		wakeup(ev);
370 	}
371 
372 	if (ev->async) {
373 		softint_schedule(ev->sih);
374 	}
375 }
376 
377 /*
378  * Soft interrupt handler: sends signal to async proc.
379  */
380 static void
381 wsevent_intr(void *cookie)
382 {
383 	struct wseventvar *ev;
384 
385 	ev = cookie;
386 
387 	if (ev->async) {
388 		mutex_enter(&proc_lock);
389 		psignal(ev->io, SIGIO);
390 		mutex_exit(&proc_lock);
391 	}
392 }
393 
394 /*
395  * Injects the set of events given in 'events', whose size is 'nevents',
396  * into the 'ev' queue.  If there is not enough free space to inject them
397  * all, returns ENOSPC and the queue is left intact; otherwise returns 0
398  * and wakes up all listeners.
399  */
400 int
401 wsevent_inject(struct wseventvar *ev, struct wscons_event *events,
402     size_t nevents)
403 {
404 	size_t avail, i;
405 	struct timespec t;
406 
407 	/* Calculate number of free slots in the queue. */
408 	if (ev->put < ev->get)
409 		avail = ev->get - ev->put;
410 	else
411 		avail = WSEVENT_QSIZE - (ev->put - ev->get);
412 	KASSERT(avail <= WSEVENT_QSIZE);
413 
414 	/* Fail if there is all events will not fit in the queue. */
415 	if (avail < nevents)
416 		return ENOSPC;
417 
418 	/* Use the current time for all events. */
419 	getnanotime(&t);
420 
421 	/* Inject the events. */
422 	for (i = 0; i < nevents; i++) {
423 		struct wscons_event *we;
424 
425 		we = EVARRAY(ev, ev->put);
426 		we->type = events[i].type;
427 		we->value = events[i].value;
428 		we->time = t;
429 
430 		ev->put = (ev->put + 1) % WSEVENT_QSIZE;
431 	}
432 	wsevent_wakeup(ev);
433 
434 	return 0;
435 }
436 
437 int
438 wsevent_setversion(struct wseventvar *ev, int vers)
439 {
440 	if (ev == NULL)
441 		return EINVAL;
442 
443 	switch (vers) {
444 	case 0:
445 	case WSEVENT_VERSION:
446 		break;
447 	default:
448 		return EINVAL;
449 	}
450 
451 	if (vers == ev->version)
452 		return 0;
453 
454 	ev->get = ev->put = 0;
455 	ev->version = vers;
456 	return 0;
457 }
458 
459 SYSCTL_SETUP(sysctl_wsevent_setup, "sysctl hw.wsevent subtree setup")
460 {
461         const struct sysctlnode *node = NULL;
462 
463         if (sysctl_createv(clog, 0, NULL, &node,
464             CTLFLAG_PERMANENT,
465             CTLTYPE_NODE, "wsevent", NULL,
466             NULL, 0, NULL, 0,
467             CTL_HW, CTL_CREATE, CTL_EOL) != 0)
468                 return;
469 
470         sysctl_createv(clog, 0, &node, NULL,
471             CTLFLAG_READWRITE,
472             CTLTYPE_INT, "default_version",
473             SYSCTL_DESCR("Set default event version for compatibility"),
474             NULL, 0, &wsevent_default_version, 0,
475             CTL_CREATE, CTL_EOL);
476 }
477