1 /* $NetBSD: event.c,v 1.2 1996/05/29 17:03:41 oki 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 58 #include <machine/vuid_event.h> 59 #include <x68k/dev/event_var.h> 60 61 /* 62 * Initialize a firm_event queue. 63 */ 64 void 65 ev_init(ev) 66 register struct evvar *ev; 67 { 68 69 ev->ev_get = ev->ev_put = 0; 70 ev->ev_q = malloc((u_long)EV_QSIZE * sizeof(struct firm_event), 71 M_DEVBUF, M_WAITOK); 72 bzero((caddr_t)ev->ev_q, EV_QSIZE * sizeof(struct firm_event)); 73 } 74 75 /* 76 * Tear down a firm_event queue. 77 */ 78 void 79 ev_fini(ev) 80 register struct evvar *ev; 81 { 82 83 free(ev->ev_q, M_DEVBUF); 84 } 85 86 /* 87 * User-level interface: read, select. 88 * (User cannot write an event queue.) 89 */ 90 int 91 ev_read(ev, uio, flags) 92 register struct evvar *ev; 93 struct uio *uio; 94 int flags; 95 { 96 int s, n, cnt, error; 97 98 /* 99 * Make sure we can return at least 1. 100 */ 101 if (uio->uio_resid < sizeof(struct firm_event)) 102 return (EMSGSIZE); /* ??? */ 103 s = splev(); 104 while (ev->ev_get == ev->ev_put) { 105 if (flags & IO_NDELAY) { 106 splx(s); 107 return (EWOULDBLOCK); 108 } 109 ev->ev_wanted = 1; 110 error = tsleep((caddr_t)ev, PEVENT | PCATCH, "firm_event", 0); 111 if (error) { 112 splx(s); 113 return (error); 114 } 115 } 116 /* 117 * Move firm_events from tail end of queue (there is at least one 118 * there). 119 */ 120 if (ev->ev_put < ev->ev_get) 121 cnt = EV_QSIZE - ev->ev_get; /* events in [get..QSIZE) */ 122 else 123 cnt = ev->ev_put - ev->ev_get; /* events in [get..put) */ 124 splx(s); 125 n = howmany(uio->uio_resid, sizeof(struct firm_event)); 126 if (cnt > n) 127 cnt = n; 128 error = uiomove((caddr_t)&ev->ev_q[ev->ev_get], 129 cnt * sizeof(struct firm_event), uio); 130 n -= cnt; 131 /* 132 * If we do not wrap to 0, used up all our space, or had an error, 133 * stop. Otherwise move from front of queue to put index, if there 134 * is anything there to move. 135 */ 136 if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 || 137 n == 0 || error || (cnt = ev->ev_put) == 0) 138 return (error); 139 if (cnt > n) 140 cnt = n; 141 error = uiomove((caddr_t)&ev->ev_q[0], 142 cnt * sizeof(struct firm_event), uio); 143 ev->ev_get = cnt; 144 return (error); 145 } 146 147 int 148 ev_select(ev, rw, p) 149 register struct evvar *ev; 150 int rw; 151 struct proc *p; 152 { 153 int s = splev(); 154 155 switch (rw) { 156 157 case FREAD: 158 /* succeed if there is something to read */ 159 if (ev->ev_get != ev->ev_put) { 160 splx(s); 161 return (1); 162 } 163 selrecord(p, &ev->ev_sel); 164 break; 165 166 case FWRITE: 167 splx(s); 168 return (1); /* always fails => never blocks */ 169 } 170 splx(s); 171 return (0); 172 } 173