1 /* $NetBSD: event.c,v 1.20 2022/05/26 14:30:36 tsutsui 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 1.20 2022/05/26 14:30:36 tsutsui Exp $"); 49 50 #include <sys/param.h> 51 #include <sys/fcntl.h> 52 #include <sys/kmem.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 #include <sys/mutex.h> 59 #include <sys/condvar.h> 60 61 #include <machine/vuid_event.h> 62 #include <x68k/dev/event_var.h> 63 64 /* 65 * Initialize a firm_event queue. 66 */ 67 void 68 ev_init(struct evvar *ev, const char *name, kmutex_t *mtx) 69 { 70 71 ev->ev_get = ev->ev_put = 0; 72 ev->ev_q = kmem_zalloc((size_t)EV_QSIZE * sizeof(struct firm_event), 73 KM_SLEEP); 74 selinit(&ev->ev_sel); 75 ev->ev_lock = mtx; 76 cv_init(&ev->ev_cv, name); 77 } 78 79 /* 80 * Tear down a firm_event queue. 81 */ 82 void 83 ev_fini(struct evvar *ev) 84 { 85 86 cv_destroy(&ev->ev_cv); 87 seldestroy(&ev->ev_sel); 88 kmem_free(ev->ev_q, (size_t)EV_QSIZE * sizeof(struct firm_event)); 89 } 90 91 /* 92 * User-level interface: read, select. 93 * (User cannot write an event queue.) 94 */ 95 int 96 ev_read(struct evvar *ev, struct uio *uio, int flags) 97 { 98 int n, cnt, put, 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 mutex_enter(ev->ev_lock); 106 while (ev->ev_get == ev->ev_put) { 107 if (flags & IO_NDELAY) { 108 mutex_exit(ev->ev_lock); 109 return EWOULDBLOCK; 110 } 111 ev->ev_wanted = true; 112 error = cv_wait_sig(&ev->ev_cv, ev->ev_lock); 113 if (error != 0) { 114 mutex_exit(ev->ev_lock); 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 put = ev->ev_put; 127 mutex_exit(ev->ev_lock); 128 n = howmany(uio->uio_resid, sizeof(struct firm_event)); 129 if (cnt > n) 130 cnt = n; 131 error = uiomove((void *)&ev->ev_q[ev->ev_get], 132 cnt * sizeof(struct firm_event), uio); 133 n -= cnt; 134 /* 135 * If we do not wrap to 0, used up all our space, or had an error, 136 * stop. Otherwise move from front of queue to put index, if there 137 * is anything there to move. 138 */ 139 if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 || 140 n == 0 || error || (cnt = put) == 0) 141 return error; 142 if (cnt > n) 143 cnt = n; 144 error = uiomove((void *)&ev->ev_q[0], 145 cnt * sizeof(struct firm_event), uio); 146 ev->ev_get = cnt; 147 return error; 148 } 149 150 int 151 ev_poll(struct evvar *ev, int events, struct lwp *l) 152 { 153 int revents = 0; 154 155 mutex_enter(ev->ev_lock); 156 if (events & (POLLIN | POLLRDNORM)) { 157 if (ev->ev_get == ev->ev_put) 158 selrecord(l, &ev->ev_sel); 159 else 160 revents |= events & (POLLIN | POLLRDNORM); 161 } 162 revents |= events & (POLLOUT | POLLWRNORM); 163 mutex_exit(ev->ev_lock); 164 return revents; 165 } 166 167 void 168 ev_wakeup(struct evvar *ev) 169 { 170 171 mutex_enter(ev->ev_lock); 172 selnotify(&ev->ev_sel, 0, 0); 173 if (ev->ev_wanted) { 174 ev->ev_wanted = false; 175 cv_signal(&ev->ev_cv); 176 } 177 mutex_exit(ev->ev_lock); 178 179 if (ev->ev_async) { 180 mutex_enter(&proc_lock); 181 psignal(ev->ev_io, SIGIO); 182 mutex_exit(&proc_lock); 183 } 184 } 185 186 static void 187 filt_evrdetach(struct knote *kn) 188 { 189 struct evvar *ev = kn->kn_hook; 190 191 mutex_enter(ev->ev_lock); 192 selremove_knote(&ev->ev_sel, kn); 193 mutex_exit(ev->ev_lock); 194 } 195 196 static int 197 filt_evread(struct knote *kn, long hint) 198 { 199 struct evvar *ev = kn->kn_hook; 200 int rv = 1; 201 202 mutex_enter(ev->ev_lock); 203 if (ev->ev_get == ev->ev_put) { 204 rv = 0; 205 } else { 206 if (ev->ev_get < ev->ev_put) 207 kn->kn_data = ev->ev_put - ev->ev_get; 208 else 209 kn->kn_data = (EV_QSIZE - ev->ev_get) + 210 ev->ev_put; 211 212 kn->kn_data *= sizeof(struct firm_event); 213 } 214 mutex_exit(ev->ev_lock); 215 216 return rv; 217 } 218 219 static const struct filterops ev_filtops = { 220 .f_flags = FILTEROP_ISFD, 221 .f_attach = NULL, 222 .f_detach = filt_evrdetach, 223 .f_event = filt_evread, 224 }; 225 226 int 227 ev_kqfilter(struct evvar *ev, struct knote *kn) 228 { 229 230 switch (kn->kn_filter) { 231 case EVFILT_READ: 232 kn->kn_fop = &ev_filtops; 233 break; 234 235 default: 236 return EINVAL; 237 } 238 239 kn->kn_hook = ev; 240 241 mutex_enter(ev->ev_lock); 242 selrecord_knote(&ev->ev_sel, kn); 243 mutex_exit(ev->ev_lock); 244 245 return 0; 246 } 247
Indexes created Mon Sep 22 10:09:38 GMT 2025