wsevent.c revision 1.2 
1/* $OpenBSD: wsevent.c,v 1.2 2000/08/01 13:51:18 mickey 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. All advertising materials mentioning features or use of this software
58 *    must display the following acknowledgement:
59 *	This product includes software developed by the University of
60 *	California, Berkeley and its contributors.
61 * 4. Neither the name of the University nor the names of its contributors
62 *    may be used to endorse or promote products derived from this software
63 *    without specific prior written permission.
64 *
65 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
66 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
69 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
70 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
71 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
72 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
73 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
74 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
75 * SUCH DAMAGE.
76 *
77 *	@(#)event.c	8.1 (Berkeley) 6/11/93
78 */
79
80/*
81 * Internal "wscons_event" queue interface for the keyboard and mouse drivers.
82 */
83
84#include <sys/param.h>
85#include <sys/fcntl.h>
86#include <sys/malloc.h>
87#include <sys/proc.h>
88#include <sys/systm.h>
89#include <sys/vnode.h>
90#include <sys/select.h>
91#include <sys/poll.h>
92
93#include <dev/wscons/wsconsio.h>
94#include <dev/wscons/wseventvar.h>
95
96/*
97 * Initialize a wscons_event queue.
98 */
99void
100wsevent_init(ev)
101	struct wseventvar *ev;
102{
103
104	ev->get = ev->put = 0;
105	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
106	    M_DEVBUF, M_WAITOK);
107	memset((caddr_t)ev->q, 0, WSEVENT_QSIZE * sizeof(struct wscons_event));
108}
109
110/*
111 * Tear down a wscons_event queue.
112 */
113void
114wsevent_fini(ev)
115	struct wseventvar *ev;
116{
117
118	free(ev->q, M_DEVBUF);
119}
120
121/*
122 * User-level interface: read, poll.
123 * (User cannot write an event queue.)
124 */
125int
126wsevent_read(ev, uio, flags)
127	struct wseventvar *ev;
128	struct uio *uio;
129	int flags;
130{
131	int s, n, cnt, error;
132
133	/*
134	 * Make sure we can return at least 1.
135	 */
136	if (uio->uio_resid < sizeof(struct wscons_event))
137		return (EMSGSIZE);	/* ??? */
138	s = splwsevent();
139	while (ev->get == ev->put) {
140		if (flags & IO_NDELAY) {
141			splx(s);
142			return (EWOULDBLOCK);
143		}
144		ev->wanted = 1;
145		error = tsleep((caddr_t)ev, PWSEVENT | PCATCH,
146		    "wsevent_read", 0);
147		if (error) {
148			splx(s);
149			return (error);
150		}
151	}
152	/*
153	 * Move wscons_event from tail end of queue (there is at least one
154	 * there).
155	 */
156	if (ev->put < ev->get)
157		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
158	else
159		cnt = ev->put - ev->get;	/* events in [get..put) */
160	splx(s);
161	n = howmany(uio->uio_resid, sizeof(struct wscons_event));
162	if (cnt > n)
163		cnt = n;
164	error = uiomove((caddr_t)&ev->q[ev->get],
165	    cnt * sizeof(struct wscons_event), uio);
166	n -= cnt;
167	/*
168	 * If we do not wrap to 0, used up all our space, or had an error,
169	 * stop.  Otherwise move from front of queue to put index, if there
170	 * is anything there to move.
171	 */
172	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
173	    n == 0 || error || (cnt = ev->put) == 0)
174		return (error);
175	if (cnt > n)
176		cnt = n;
177	error = uiomove((caddr_t)&ev->q[0],
178	    cnt * sizeof(struct wscons_event), uio);
179	ev->get = cnt;
180	return (error);
181}
182
183int
184wsevent_poll(ev, events, p)
185	struct wseventvar *ev;
186	int events;
187	struct proc *p;
188{
189	int revents = 0;
190	int s = splwsevent();
191
192        if (events & (POLLIN | POLLRDNORM)) {
193		if (ev->get != ev->put)
194			revents |= events & (POLLIN | POLLRDNORM);
195		else
196			selrecord(p, &ev->sel);
197	}
198
199	splx(s);
200	return (revents);
201}
202