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wsevent.c revision 1.6
      1 /* $NetBSD: wsevent.c,v 1.6 2001/10/13 15:56:16 augustss Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *      This product includes software developed by Christopher G. Demetriou
     17  *	for the NetBSD Project.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: wsevent.c,v 1.6 2001/10/13 15:56:16 augustss Exp $");
     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  */
     99 void
    100 wsevent_init(struct wseventvar *ev)
    101 {
    102 
    103 	ev->get = ev->put = 0;
    104 	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
    105 	    M_DEVBUF, M_WAITOK);
    106 	memset((caddr_t)ev->q, 0, WSEVENT_QSIZE * sizeof(struct wscons_event));
    107 }
    108 
    109 /*
    110  * Tear down a wscons_event queue.
    111  */
    112 void
    113 wsevent_fini(struct wseventvar *ev)
    114 {
    115 
    116 	free(ev->q, M_DEVBUF);
    117 }
    118 
    119 /*
    120  * User-level interface: read, poll.
    121  * (User cannot write an event queue.)
    122  */
    123 int
    124 wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
    125 {
    126 	int s, n, cnt, error;
    127 
    128 	/*
    129 	 * Make sure we can return at least 1.
    130 	 */
    131 	if (uio->uio_resid < sizeof(struct wscons_event))
    132 		return (EMSGSIZE);	/* ??? */
    133 	s = splwsevent();
    134 	while (ev->get == ev->put) {
    135 		if (flags & IO_NDELAY) {
    136 			splx(s);
    137 			return (EWOULDBLOCK);
    138 		}
    139 		ev->wanted = 1;
    140 		error = tsleep((caddr_t)ev, PWSEVENT | PCATCH,
    141 		    "wsevent_read", 0);
    142 		if (error) {
    143 			splx(s);
    144 			return (error);
    145 		}
    146 	}
    147 	/*
    148 	 * Move wscons_event from tail end of queue (there is at least one
    149 	 * there).
    150 	 */
    151 	if (ev->put < ev->get)
    152 		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
    153 	else
    154 		cnt = ev->put - ev->get;	/* events in [get..put) */
    155 	splx(s);
    156 	n = howmany(uio->uio_resid, sizeof(struct wscons_event));
    157 	if (cnt > n)
    158 		cnt = n;
    159 	error = uiomove((caddr_t)&ev->q[ev->get],
    160 	    cnt * sizeof(struct wscons_event), uio);
    161 	n -= cnt;
    162 	/*
    163 	 * If we do not wrap to 0, used up all our space, or had an error,
    164 	 * stop.  Otherwise move from front of queue to put index, if there
    165 	 * is anything there to move.
    166 	 */
    167 	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
    168 	    n == 0 || error || (cnt = ev->put) == 0)
    169 		return (error);
    170 	if (cnt > n)
    171 		cnt = n;
    172 	error = uiomove((caddr_t)&ev->q[0],
    173 	    cnt * sizeof(struct wscons_event), uio);
    174 	ev->get = cnt;
    175 	return (error);
    176 }
    177 
    178 int
    179 wsevent_poll(struct wseventvar *ev, int events, struct proc *p)
    180 {
    181 	int revents = 0;
    182 	int s = splwsevent();
    183 
    184         if (events & (POLLIN | POLLRDNORM)) {
    185 		if (ev->get != ev->put)
    186 			revents |= events & (POLLIN | POLLRDNORM);
    187 		else
    188 			selrecord(p, &ev->sel);
    189 	}
    190 
    191 	splx(s);
    192 	return (revents);
    193 }
    194