/* $NetBSD: event.c,v 1.20 2022/05/26 14:30:36 tsutsui Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)event.c 8.1 (Berkeley) 6/11/93 */ /* * Internal `Firm_event' interface for the keyboard and mouse drivers. */ #include __KERNEL_RCSID(0, "$NetBSD: event.c,v 1.20 2022/05/26 14:30:36 tsutsui Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include /* * Initialize a firm_event queue. */ void ev_init(struct evvar *ev, const char *name, kmutex_t *mtx) { ev->ev_get = ev->ev_put = 0; ev->ev_q = kmem_zalloc((size_t)EV_QSIZE * sizeof(struct firm_event), KM_SLEEP); selinit(&ev->ev_sel); ev->ev_lock = mtx; cv_init(&ev->ev_cv, name); } /* * Tear down a firm_event queue. */ void ev_fini(struct evvar *ev) { cv_destroy(&ev->ev_cv); seldestroy(&ev->ev_sel); kmem_free(ev->ev_q, (size_t)EV_QSIZE * sizeof(struct firm_event)); } /* * User-level interface: read, select. * (User cannot write an event queue.) */ int ev_read(struct evvar *ev, struct uio *uio, int flags) { int n, cnt, put, error; /* * Make sure we can return at least 1. */ if (uio->uio_resid < sizeof(struct firm_event)) return EMSGSIZE; /* ??? */ mutex_enter(ev->ev_lock); while (ev->ev_get == ev->ev_put) { if (flags & IO_NDELAY) { mutex_exit(ev->ev_lock); return EWOULDBLOCK; } ev->ev_wanted = true; error = cv_wait_sig(&ev->ev_cv, ev->ev_lock); if (error != 0) { mutex_exit(ev->ev_lock); return error; } } /* * Move firm_events from tail end of queue (there is at least one * there). */ if (ev->ev_put < ev->ev_get) cnt = EV_QSIZE - ev->ev_get; /* events in [get..QSIZE) */ else cnt = ev->ev_put - ev->ev_get; /* events in [get..put) */ put = ev->ev_put; mutex_exit(ev->ev_lock); n = howmany(uio->uio_resid, sizeof(struct firm_event)); if (cnt > n) cnt = n; error = uiomove((void *)&ev->ev_q[ev->ev_get], cnt * sizeof(struct firm_event), uio); n -= cnt; /* * If we do not wrap to 0, used up all our space, or had an error, * stop. Otherwise move from front of queue to put index, if there * is anything there to move. */ if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 || n == 0 || error || (cnt = put) == 0) return error; if (cnt > n) cnt = n; error = uiomove((void *)&ev->ev_q[0], cnt * sizeof(struct firm_event), uio); ev->ev_get = cnt; return error; } int ev_poll(struct evvar *ev, int events, struct lwp *l) { int revents = 0; mutex_enter(ev->ev_lock); if (events & (POLLIN | POLLRDNORM)) { if (ev->ev_get == ev->ev_put) selrecord(l, &ev->ev_sel); else revents |= events & (POLLIN | POLLRDNORM); } revents |= events & (POLLOUT | POLLWRNORM); mutex_exit(ev->ev_lock); return revents; } void ev_wakeup(struct evvar *ev) { mutex_enter(ev->ev_lock); selnotify(&ev->ev_sel, 0, 0); if (ev->ev_wanted) { ev->ev_wanted = false; cv_signal(&ev->ev_cv); } mutex_exit(ev->ev_lock); if (ev->ev_async) { mutex_enter(&proc_lock); psignal(ev->ev_io, SIGIO); mutex_exit(&proc_lock); } } static void filt_evrdetach(struct knote *kn) { struct evvar *ev = kn->kn_hook; mutex_enter(ev->ev_lock); selremove_knote(&ev->ev_sel, kn); mutex_exit(ev->ev_lock); } static int filt_evread(struct knote *kn, long hint) { struct evvar *ev = kn->kn_hook; int rv = 1; mutex_enter(ev->ev_lock); if (ev->ev_get == ev->ev_put) { rv = 0; } else { if (ev->ev_get < ev->ev_put) kn->kn_data = ev->ev_put - ev->ev_get; else kn->kn_data = (EV_QSIZE - ev->ev_get) + ev->ev_put; kn->kn_data *= sizeof(struct firm_event); } mutex_exit(ev->ev_lock); return rv; } static const struct filterops ev_filtops = { .f_flags = FILTEROP_ISFD, .f_attach = NULL, .f_detach = filt_evrdetach, .f_event = filt_evread, }; int ev_kqfilter(struct evvar *ev, struct knote *kn) { switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &ev_filtops; break; default: return EINVAL; } kn->kn_hook = ev; mutex_enter(ev->ev_lock); selrecord_knote(&ev->ev_sel, kn); mutex_exit(ev->ev_lock); return 0; }