wsevent.c revision 1.3
1/* $OpenBSD: wsevent.c,v 1.3 2003/06/02 23:28:04 millert Exp $ */
2/* $NetBSD: wsevent.c,v 1.5 2000/03/30 12:45:44 augustss Exp $ */
3
4/*
5 * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *      This product includes software developed by Christopher G. Demetriou
18 *	for the NetBSD Project.
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36/*
37 * Copyright (c) 1992, 1993
38 *	The Regents of the University of California.  All rights reserved.
39 *
40 * This software was developed by the Computer Systems Engineering group
41 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
42 * contributed to Berkeley.
43 *
44 * All advertising materials mentioning features or use of this software
45 * must display the following acknowledgement:
46 *	This product includes software developed by the University of
47 *	California, Lawrence Berkeley Laboratory.
48 *
49 * Redistribution and use in source and binary forms, with or without
50 * modification, are permitted provided that the following conditions
51 * are met:
52 * 1. Redistributions of source code must retain the above copyright
53 *    notice, this list of conditions and the following disclaimer.
54 * 2. Redistributions in binary form must reproduce the above copyright
55 *    notice, this list of conditions and the following disclaimer in the
56 *    documentation and/or other materials provided with the distribution.
57 * 3. Neither the name of the University nor the names of its contributors
58 *    may be used to endorse or promote products derived from this software
59 *    without specific prior written permission.
60 *
61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71 * SUCH DAMAGE.
72 *
73 *	@(#)event.c	8.1 (Berkeley) 6/11/93
74 */
75
76/*
77 * Internal "wscons_event" queue interface for the keyboard and mouse drivers.
78 */
79
80#include <sys/param.h>
81#include <sys/fcntl.h>
82#include <sys/malloc.h>
83#include <sys/proc.h>
84#include <sys/systm.h>
85#include <sys/vnode.h>
86#include <sys/select.h>
87#include <sys/poll.h>
88
89#include <dev/wscons/wsconsio.h>
90#include <dev/wscons/wseventvar.h>
91
92/*
93 * Initialize a wscons_event queue.
94 */
95void
96wsevent_init(ev)
97	struct wseventvar *ev;
98{
99
100	ev->get = ev->put = 0;
101	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
102	    M_DEVBUF, M_WAITOK);
103	memset((caddr_t)ev->q, 0, WSEVENT_QSIZE * sizeof(struct wscons_event));
104}
105
106/*
107 * Tear down a wscons_event queue.
108 */
109void
110wsevent_fini(ev)
111	struct wseventvar *ev;
112{
113
114	free(ev->q, M_DEVBUF);
115}
116
117/*
118 * User-level interface: read, poll.
119 * (User cannot write an event queue.)
120 */
121int
122wsevent_read(ev, uio, flags)
123	struct wseventvar *ev;
124	struct uio *uio;
125	int flags;
126{
127	int s, n, cnt, error;
128
129	/*
130	 * Make sure we can return at least 1.
131	 */
132	if (uio->uio_resid < sizeof(struct wscons_event))
133		return (EMSGSIZE);	/* ??? */
134	s = splwsevent();
135	while (ev->get == ev->put) {
136		if (flags & IO_NDELAY) {
137			splx(s);
138			return (EWOULDBLOCK);
139		}
140		ev->wanted = 1;
141		error = tsleep((caddr_t)ev, PWSEVENT | PCATCH,
142		    "wsevent_read", 0);
143		if (error) {
144			splx(s);
145			return (error);
146		}
147	}
148	/*
149	 * Move wscons_event from tail end of queue (there is at least one
150	 * there).
151	 */
152	if (ev->put < ev->get)
153		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
154	else
155		cnt = ev->put - ev->get;	/* events in [get..put) */
156	splx(s);
157	n = howmany(uio->uio_resid, sizeof(struct wscons_event));
158	if (cnt > n)
159		cnt = n;
160	error = uiomove((caddr_t)&ev->q[ev->get],
161	    cnt * sizeof(struct wscons_event), uio);
162	n -= cnt;
163	/*
164	 * If we do not wrap to 0, used up all our space, or had an error,
165	 * stop.  Otherwise move from front of queue to put index, if there
166	 * is anything there to move.
167	 */
168	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
169	    n == 0 || error || (cnt = ev->put) == 0)
170		return (error);
171	if (cnt > n)
172		cnt = n;
173	error = uiomove((caddr_t)&ev->q[0],
174	    cnt * sizeof(struct wscons_event), uio);
175	ev->get = cnt;
176	return (error);
177}
178
179int
180wsevent_poll(ev, events, p)
181	struct wseventvar *ev;
182	int events;
183	struct proc *p;
184{
185	int revents = 0;
186	int s = splwsevent();
187
188        if (events & (POLLIN | POLLRDNORM)) {
189		if (ev->get != ev->put)
190			revents |= events & (POLLIN | POLLRDNORM);
191		else
192			selrecord(p, &ev->sel);
193	}
194
195	splx(s);
196	return (revents);
197}
198