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event.c revision 1.4 
      1 /*	$NetBSD: event.c,v 1.4 2000/03/30 12:45:42 augustss Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * All advertising materials mentioning features or use of this software
     12  * must display the following acknowledgement:
     13  *	This product includes software developed by the University of
     14  *	California, Lawrence Berkeley Laboratory.
     15  *
     16  * Redistribution and use in source and binary forms, with or without
     17  * modification, are permitted provided that the following conditions
     18  * are met:
     19  * 1. Redistributions of source code must retain the above copyright
     20  *    notice, this list of conditions and the following disclaimer.
     21  * 2. Redistributions in binary form must reproduce the above copyright
     22  *    notice, this list of conditions and the following disclaimer in the
     23  *    documentation and/or other materials provided with the distribution.
     24  * 3. All advertising materials mentioning features or use of this software
     25  *    must display the following acknowledgement:
     26  *	This product includes software developed by the University of
     27  *	California, Berkeley and its contributors.
     28  * 4. Neither the name of the University nor the names of its contributors
     29  *    may be used to endorse or promote products derived from this software
     30  *    without specific prior written permission.
     31  *
     32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     42  * SUCH DAMAGE.
     43  *
     44  *	@(#)event.c	8.1 (Berkeley) 6/11/93
     45  */
     46 
     47 /*
     48  * Internal `Firm_event' interface for the keyboard and mouse drivers.
     49  */
     50 
     51 #include <sys/param.h>
     52 #include <sys/fcntl.h>
     53 #include <sys/malloc.h>
     54 #include <sys/proc.h>
     55 #include <sys/systm.h>
     56 #include <sys/vnode.h>
     57 #include <sys/select.h>
     58 #include <sys/poll.h>
     59 
     60 #include <machine/vuid_event.h>
     61 #include <dev/sun/event_var.h>
     62 
     63 /*
     64  * Initialize a firm_event queue.
     65  */
     66 void
     67 ev_init(ev)
     68 	struct evvar *ev;
     69 {
     70 
     71 	ev->ev_get = ev->ev_put = 0;
     72 	ev->ev_q = malloc((u_long)EV_QSIZE * sizeof(struct firm_event),
     73 	    M_DEVBUF, M_WAITOK);
     74 	bzero((caddr_t)ev->ev_q, EV_QSIZE * sizeof(struct firm_event));
     75 }
     76 
     77 /*
     78  * Tear down a firm_event queue.
     79  */
     80 void
     81 ev_fini(ev)
     82 	struct evvar *ev;
     83 {
     84 
     85 	free(ev->ev_q, M_DEVBUF);
     86 }
     87 
     88 /*
     89  * User-level interface: read, select.
     90  * (User cannot write an event queue.)
     91  */
     92 int
     93 ev_read(ev, uio, flags)
     94 	struct evvar *ev;
     95 	struct uio *uio;
     96 	int flags;
     97 {
     98 	int s, n, cnt, error;
     99 
    100 	/*
    101 	 * Make sure we can return at least 1.
    102 	 */
    103 	if (uio->uio_resid < sizeof(struct firm_event))
    104 		return (EMSGSIZE);	/* ??? */
    105 	s = splev();
    106 	while (ev->ev_get == ev->ev_put) {
    107 		if (flags & IO_NDELAY) {
    108 			splx(s);
    109 			return (EWOULDBLOCK);
    110 		}
    111 		ev->ev_wanted = 1;
    112 		error = tsleep((caddr_t)ev, PEVENT | PCATCH, "firm_event", 0);
    113 		if (error) {
    114 			splx(s);
    115 			return (error);
    116 		}
    117 	}
    118 	/*
    119 	 * Move firm_events from tail end of queue (there is at least one
    120 	 * there).
    121 	 */
    122 	if (ev->ev_put < ev->ev_get)
    123 		cnt = EV_QSIZE - ev->ev_get;	/* events in [get..QSIZE) */
    124 	else
    125 		cnt = ev->ev_put - ev->ev_get;	/* events in [get..put) */
    126 	splx(s);
    127 	n = howmany(uio->uio_resid, sizeof(struct firm_event));
    128 	if (cnt > n)
    129 		cnt = n;
    130 	error = uiomove((caddr_t)&ev->ev_q[ev->ev_get],
    131 	    cnt * sizeof(struct firm_event), uio);
    132 	n -= cnt;
    133 	/*
    134 	 * If we do not wrap to 0, used up all our space, or had an error,
    135 	 * stop.  Otherwise move from front of queue to put index, if there
    136 	 * is anything there to move.
    137 	 */
    138 	if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 ||
    139 	    n == 0 || error || (cnt = ev->ev_put) == 0)
    140 		return (error);
    141 	if (cnt > n)
    142 		cnt = n;
    143 	error = uiomove((caddr_t)&ev->ev_q[0],
    144 	    cnt * sizeof(struct firm_event), uio);
    145 	ev->ev_get = cnt;
    146 	return (error);
    147 }
    148 
    149 int
    150 ev_poll(ev, events, p)
    151 	struct evvar *ev;
    152 	int events;
    153 	struct proc *p;
    154 {
    155 	int s = splev(), revents = 0;
    156 
    157 	if (events & (POLLIN | POLLRDNORM)) {
    158 		if (ev->ev_get == ev->ev_put)
    159 			selrecord(p, &ev->ev_sel);
    160 		else
    161 			revents |= events & (POLLIN | POLLRDNORM);
    162 	}
    163 	revents |= events & (POLLOUT | POLLWRNORM);
    164 
    165 	splx(s);
    166 	return (revents);
    167 }
    168