1 /* $NetBSD: event.c,v 1.13 2008/03/01 14:16:50 rmind 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. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)event.c 8.1 (Berkeley) 6/11/93 41 */ 42 43 /* 44 * Internal `Firm_event' interface for the keyboard and mouse drivers. 45 */ 46 47 #include <sys/cdefs.h> 48 __KERNEL_RCSID(0, "$NetBSD: event.c,v 1.13 2008/03/01 14:16:50 rmind Exp $"); 49 50 #include <sys/param.h> 51 #include <sys/fcntl.h> 52 #include <sys/malloc.h> 53 #include <sys/proc.h> 54 #include <sys/systm.h> 55 #include <sys/vnode.h> 56 #include <sys/select.h> 57 #include <sys/poll.h> 58 59 #include <machine/vuid_event.h> 60 #include <x68k/dev/event_var.h> 61 62 /* 63 * Initialize a firm_event queue. 64 */ 65 void 66 ev_init(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|M_ZERO); 72 selinit(&ev->ev_sel); 73 } 74 75 /* 76 * Tear down a firm_event queue. 77 */ 78 void 79 ev_fini(struct evvar *ev) 80 { 81 82 seldestroy(&ev->ev_sel); 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(struct evvar *ev, struct uio *uio, int flags) 92 { 93 int s, n, cnt, error; 94 95 /* 96 * Make sure we can return at least 1. 97 */ 98 if (uio->uio_resid < sizeof(struct firm_event)) 99 return (EMSGSIZE); /* ??? */ 100 s = splev(); 101 while (ev->ev_get == ev->ev_put) { 102 if (flags & IO_NDELAY) { 103 splx(s); 104 return (EWOULDBLOCK); 105 } 106 ev->ev_wanted = 1; 107 error = tsleep((void *)ev, PEVENT | PCATCH, "firm_event", 0); 108 if (error) { 109 splx(s); 110 return (error); 111 } 112 } 113 /* 114 * Move firm_events from tail end of queue (there is at least one 115 * there). 116 */ 117 if (ev->ev_put < ev->ev_get) 118 cnt = EV_QSIZE - ev->ev_get; /* events in [get..QSIZE) */ 119 else 120 cnt = ev->ev_put - ev->ev_get; /* events in [get..put) */ 121 splx(s); 122 n = howmany(uio->uio_resid, sizeof(struct firm_event)); 123 if (cnt > n) 124 cnt = n; 125 error = uiomove((void *)&ev->ev_q[ev->ev_get], 126 cnt * sizeof(struct firm_event), uio); 127 n -= cnt; 128 /* 129 * If we do not wrap to 0, used up all our space, or had an error, 130 * stop. Otherwise move from front of queue to put index, if there 131 * is anything there to move. 132 */ 133 if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 || 134 n == 0 || error || (cnt = ev->ev_put) == 0) 135 return (error); 136 if (cnt > n) 137 cnt = n; 138 error = uiomove((void *)&ev->ev_q[0], 139 cnt * sizeof(struct firm_event), uio); 140 ev->ev_get = cnt; 141 return (error); 142 } 143 144 int 145 ev_poll(struct evvar *ev, int events, struct lwp *l) 146 { 147 int s, revents = 0; 148 149 s = splev(); 150 if (events & (POLLIN | POLLRDNORM)) { 151 if (ev->ev_get == ev->ev_put) 152 selrecord(l, &ev->ev_sel); 153 else 154 revents |= events & (POLLIN | POLLRDNORM); 155 } 156 revents |= events & (POLLOUT | POLLWRNORM); 157 splx(s); 158 return (revents); 159 } 160 161 static void 162 filt_evrdetach(struct knote *kn) 163 { 164 struct evvar *ev = kn->kn_hook; 165 int s; 166 167 s = splev(); 168 SLIST_REMOVE(&ev->ev_sel.sel_klist, kn, knote, kn_selnext); 169 splx(s); 170 } 171 172 static int 173 filt_evread(struct knote *kn, long hint) 174 { 175 struct evvar *ev = kn->kn_hook; 176 177 if (ev->ev_get == ev->ev_put) 178 return (0); 179 180 if (ev->ev_get < ev->ev_put) 181 kn->kn_data = ev->ev_put - ev->ev_get; 182 else 183 kn->kn_data = (EV_QSIZE - ev->ev_get) + 184 ev->ev_put; 185 186 kn->kn_data *= sizeof(struct firm_event); 187 188 return (1); 189 } 190 191 static const struct filterops ev_filtops = 192 { 1, NULL, filt_evrdetach, filt_evread }; 193 194 int 195 ev_kqfilter(struct evvar *ev, struct knote *kn) 196 { 197 struct klist *klist; 198 int s; 199 200 switch (kn->kn_filter) { 201 case EVFILT_READ: 202 klist = &ev->ev_sel.sel_klist; 203 kn->kn_fop = &ev_filtops; 204 break; 205 206 default: 207 return (1); 208 } 209 210 kn->kn_hook = ev; 211 212 s = splev(); 213 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 214 splx(s); 215 216 return (0); 217 } 218