xref: /openbsd/sys/dev/wscons/wsevent.c (revision a6445c1d)
1 /* $OpenBSD: wsevent.c,v 1.10 2014/09/14 14:17:25 jsg Exp $ */
2 /* $NetBSD: wsevent.c,v 1.16 2003/08/07 16:31:29 agc 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 /*
35  * Copyright (c) 1992, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * This software was developed by the Computer Systems Engineering group
39  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
40  * contributed to Berkeley.
41  *
42  * All advertising materials mentioning features or use of this software
43  * must display the following acknowledgement:
44  *	This product includes software developed by the University of
45  *	California, Lawrence Berkeley Laboratory.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  * 2. Redistributions in binary form must reproduce the above copyright
53  *    notice, this list of conditions and the following disclaimer in the
54  *    documentation and/or other materials provided with the distribution.
55  * 3. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	@(#)event.c	8.1 (Berkeley) 6/11/93
72  */
73 
74 /*
75  * Internal "wscons_event" queue interface for the keyboard and mouse drivers.
76  */
77 
78 #include <sys/param.h>
79 #include <sys/fcntl.h>
80 #include <sys/malloc.h>
81 #include <sys/systm.h>
82 #include <sys/vnode.h>
83 #include <sys/selinfo.h>
84 #include <sys/poll.h>
85 
86 #include <dev/wscons/wsconsio.h>
87 #include <dev/wscons/wseventvar.h>
88 
89 /*
90  * Initialize a wscons_event queue.
91  */
92 void
93 wsevent_init(struct wseventvar *ev)
94 {
95 
96 	if (ev->q != NULL) {
97 #ifdef DIAGNOSTIC
98 		printf("wsevent_init: already initialized\n");
99 #endif
100 		return;
101 	}
102 	ev->get = ev->put = 0;
103 	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
104 	    M_DEVBUF, M_WAITOK | M_ZERO);
105 }
106 
107 /*
108  * Tear down a wscons_event queue.
109  */
110 void
111 wsevent_fini(struct wseventvar *ev)
112 {
113 	if (ev->q == NULL) {
114 #ifdef DIAGNOSTIC
115 		printf("wsevent_fini: already invoked\n");
116 #endif
117 		return;
118 	}
119 	free(ev->q, M_DEVBUF, 0);
120 	ev->q = NULL;
121 }
122 
123 /*
124  * User-level interface: read, poll.
125  * (User cannot write an event queue.)
126  */
127 int
128 wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
129 {
130 	int s, n, cnt, error;
131 
132 	/*
133 	 * Make sure we can return at least 1.
134 	 */
135 	if (uio->uio_resid < sizeof(struct wscons_event))
136 		return (EMSGSIZE);	/* ??? */
137 	s = splwsevent();
138 	while (ev->get == ev->put) {
139 		if (flags & IO_NDELAY) {
140 			splx(s);
141 			return (EWOULDBLOCK);
142 		}
143 		ev->wanted = 1;
144 		error = tsleep(ev, PWSEVENT | PCATCH,
145 		    "wsevent_read", 0);
146 		if (error) {
147 			splx(s);
148 			return (error);
149 		}
150 	}
151 	/*
152 	 * Move wscons_event from tail end of queue (there is at least one
153 	 * there).
154 	 */
155 	if (ev->put < ev->get)
156 		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
157 	else
158 		cnt = ev->put - ev->get;	/* events in [get..put) */
159 	splx(s);
160 	n = howmany(uio->uio_resid, sizeof(struct wscons_event));
161 	if (cnt > n)
162 		cnt = n;
163 	error = uiomove((caddr_t)&ev->q[ev->get],
164 	    cnt * sizeof(struct wscons_event), uio);
165 	n -= cnt;
166 	/*
167 	 * If we do not wrap to 0, used up all our space, or had an error,
168 	 * stop.  Otherwise move from front of queue to put index, if there
169 	 * is anything there to move.
170 	 */
171 	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
172 	    n == 0 || error || (cnt = ev->put) == 0)
173 		return (error);
174 	if (cnt > n)
175 		cnt = n;
176 	error = uiomove((caddr_t)&ev->q[0],
177 	    cnt * sizeof(struct wscons_event), uio);
178 	ev->get = cnt;
179 	return (error);
180 }
181 
182 int
183 wsevent_poll(struct wseventvar *ev, int events, 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