xref: /openbsd-src/sys/dev/wscons/wsevent.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /* $OpenBSD: wsevent.c,v 1.9 2014/07/12 18:48:53 tedu 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/proc.h>
82 #include <sys/systm.h>
83 #include <sys/vnode.h>
84 #include <sys/selinfo.h>
85 #include <sys/poll.h>
86 
87 #include <dev/wscons/wsconsio.h>
88 #include <dev/wscons/wseventvar.h>
89 
90 /*
91  * Initialize a wscons_event queue.
92  */
93 void
94 wsevent_init(struct wseventvar *ev)
95 {
96 
97 	if (ev->q != NULL) {
98 #ifdef DIAGNOSTIC
99 		printf("wsevent_init: already initialized\n");
100 #endif
101 		return;
102 	}
103 	ev->get = ev->put = 0;
104 	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
105 	    M_DEVBUF, M_WAITOK | M_ZERO);
106 }
107 
108 /*
109  * Tear down a wscons_event queue.
110  */
111 void
112 wsevent_fini(struct wseventvar *ev)
113 {
114 	if (ev->q == NULL) {
115 #ifdef DIAGNOSTIC
116 		printf("wsevent_fini: already invoked\n");
117 #endif
118 		return;
119 	}
120 	free(ev->q, M_DEVBUF, 0);
121 	ev->q = NULL;
122 }
123 
124 /*
125  * User-level interface: read, poll.
126  * (User cannot write an event queue.)
127  */
128 int
129 wsevent_read(struct wseventvar *ev, struct uio *uio, 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(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 
183 int
184 wsevent_poll(struct wseventvar *ev, int events, struct proc *p)
185 {
186 	int revents = 0;
187 	int s = splwsevent();
188 
189 	if (events & (POLLIN | POLLRDNORM)) {
190 		if (ev->get != ev->put)
191 			revents |= events & (POLLIN | POLLRDNORM);
192 		else
193 			selrecord(p, &ev->sel);
194 	}
195 
196 	splx(s);
197 	return (revents);
198 }
199