wsevent.c revision 1.17
1/* $OpenBSD: wsevent.c,v 1.17 2017/04/11 14:43:49 dhill Exp $ */ 2/* $NetBSD: wsevent.c,v 1.16 2003/08/07 16:31:29 agc Exp $ */ 3 4/* 5 * Copyright (c) 1996, 1997 Christopher G. Demetriou. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christopher G. Demetriou 18 * for the NetBSD Project. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34/* 35 * Copyright (c) 1992, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * This software was developed by the Computer Systems Engineering group 39 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 40 * contributed to Berkeley. 41 * 42 * All advertising materials mentioning features or use of this software 43 * must display the following acknowledgement: 44 * This product includes software developed by the University of 45 * California, Lawrence Berkeley Laboratory. 46 * 47 * Redistribution and use in source and binary forms, with or without 48 * modification, are permitted provided that the following conditions 49 * are met: 50 * 1. Redistributions of source code must retain the above copyright 51 * notice, this list of conditions and the following disclaimer. 52 * 2. Redistributions in binary form must reproduce the above copyright 53 * notice, this list of conditions and the following disclaimer in the 54 * documentation and/or other materials provided with the distribution. 55 * 3. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)event.c 8.1 (Berkeley) 6/11/93 72 */ 73 74/* 75 * Internal "wscons_event" queue interface for the keyboard and mouse drivers. 76 */ 77 78#include <sys/param.h> 79#include <sys/malloc.h> 80#include <sys/systm.h> 81#include <sys/vnode.h> 82#include <sys/selinfo.h> 83#include <sys/poll.h> 84 85#include <dev/wscons/wsconsio.h> 86#include <dev/wscons/wseventvar.h> 87 88void filt_wseventdetach(struct knote *); 89int filt_wseventread(struct knote *, long); 90 91const struct filterops wsevent_filtops = { 92 1, 93 NULL, 94 filt_wseventdetach, 95 filt_wseventread 96}; 97 98/* 99 * Initialize a wscons_event queue. 100 */ 101void 102wsevent_init(struct wseventvar *ev) 103{ 104 105 if (ev->q != NULL) { 106#ifdef DIAGNOSTIC 107 printf("wsevent_init: already initialized\n"); 108#endif 109 return; 110 } 111 ev->get = ev->put = 0; 112 ev->q = malloc(WSEVENT_QSIZE * sizeof(struct wscons_event), 113 M_DEVBUF, M_WAITOK | M_ZERO); 114} 115 116/* 117 * Tear down a wscons_event queue. 118 */ 119void 120wsevent_fini(struct wseventvar *ev) 121{ 122 if (ev->q == NULL) { 123#ifdef DIAGNOSTIC 124 printf("wsevent_fini: already invoked\n"); 125#endif 126 return; 127 } 128 free(ev->q, M_DEVBUF, 0); 129 ev->q = NULL; 130} 131 132/* 133 * User-level interface: read, poll. 134 * (User cannot write an event queue.) 135 */ 136int 137wsevent_read(struct wseventvar *ev, struct uio *uio, int flags) 138{ 139 int s, error; 140 u_int cnt; 141 size_t n; 142 143 /* 144 * Make sure we can return at least 1. 145 */ 146 if (uio->uio_resid < sizeof(struct wscons_event)) 147 return (EMSGSIZE); /* ??? */ 148 s = splwsevent(); 149 while (ev->get == ev->put) { 150 if (flags & IO_NDELAY) { 151 splx(s); 152 return (EWOULDBLOCK); 153 } 154 ev->wanted = 1; 155 error = tsleep(ev, PWSEVENT | PCATCH, 156 "wsevent_read", 0); 157 if (error) { 158 splx(s); 159 return (error); 160 } 161 } 162 /* 163 * Move wscons_event from tail end of queue (there is at least one 164 * there). 165 */ 166 if (ev->put < ev->get) 167 cnt = WSEVENT_QSIZE - ev->get; /* events in [get..QSIZE) */ 168 else 169 cnt = ev->put - ev->get; /* events in [get..put) */ 170 splx(s); 171 n = howmany(uio->uio_resid, sizeof(struct wscons_event)); 172 if (cnt > n) 173 cnt = n; 174 error = uiomove((caddr_t)&ev->q[ev->get], 175 cnt * sizeof(struct wscons_event), uio); 176 n -= cnt; 177 /* 178 * If we do not wrap to 0, used up all our space, or had an error, 179 * stop. Otherwise move from front of queue to put index, if there 180 * is anything there to move. 181 */ 182 if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 || 183 n == 0 || error || (cnt = ev->put) == 0) 184 return (error); 185 if (cnt > n) 186 cnt = n; 187 error = uiomove((caddr_t)&ev->q[0], 188 cnt * sizeof(struct wscons_event), uio); 189 ev->get = cnt; 190 return (error); 191} 192 193int 194wsevent_poll(struct wseventvar *ev, int events, struct proc *p) 195{ 196 int revents = 0; 197 int s = splwsevent(); 198 199 if (events & (POLLIN | POLLRDNORM)) { 200 if (ev->get != ev->put) 201 revents |= events & (POLLIN | POLLRDNORM); 202 else 203 selrecord(p, &ev->sel); 204 } 205 206 splx(s); 207 return (revents); 208} 209 210int 211wsevent_kqfilter(struct wseventvar *ev, struct knote *kn) 212{ 213 struct klist *klist; 214 int s; 215 216 klist = &ev->sel.si_note; 217 218 switch (kn->kn_filter) { 219 case EVFILT_READ: 220 kn->kn_fop = &wsevent_filtops; 221 break; 222 default: 223 return (EINVAL); 224 } 225 226 kn->kn_hook = ev; 227 228 s = splwsevent(); 229 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 230 splx(s); 231 232 return (0); 233} 234 235void 236filt_wseventdetach(struct knote *kn) 237{ 238 struct wseventvar *ev = kn->kn_hook; 239 struct klist *klist = &ev->sel.si_note; 240 int s; 241 242 s = splwsevent(); 243 SLIST_REMOVE(klist, kn, knote, kn_selnext); 244 splx(s); 245} 246 247int 248filt_wseventread(struct knote *kn, long hint) 249{ 250 struct wseventvar *ev = kn->kn_hook; 251 252 if (ev->get == ev->put) 253 return (0); 254 255 if (ev->get < ev->put) 256 kn->kn_data = ev->put - ev->get; 257 else 258 kn->kn_data = (WSEVENT_QSIZE - ev->get) + ev->put; 259 260 return (1); 261} 262