FreeBSD/Linux Kernel Cross Reference
sys/dev/wscons/wsevent.c

     /* $NetBSD: wsevent.c,v 1.16 2003/08/07 16:31:29 agc Exp $ */
     
     /*
      * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
      *
      * 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Christopher G. Demetriou
     *      for the NetBSD Project.
     * 4. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
     */
    
    /*
     * 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 "wscons_event" queue interface for the keyboard and mouse drivers.
     */
    
    #include <sys/cdefs.h>
    __KERNEL_RCSID(0, "$NetBSD: wsevent.c,v 1.16 2003/08/07 16:31:29 agc Exp $");
    
    #include <sys/param.h>
    #include <sys/fcntl.h>
    #include <sys/malloc.h>
    #include <sys/proc.h>
    #include <sys/systm.h>
    #include <sys/vnode.h>
    #include <sys/select.h>
    #include <sys/poll.h>
    
    #include <dev/wscons/wsconsio.h>
    #include <dev/wscons/wseventvar.h>
    
    /*
     * Initialize a wscons_event queue.
     */
    void
    wsevent_init(struct wseventvar *ev)
    {
    
            if (ev->q != NULL) {
   #ifdef DIAGNOSTIC
                   printf("wsevent_init: already init\n");
   #endif
                   return;
           }
           ev->get = ev->put = 0;
           ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
                          M_DEVBUF, M_WAITOK|M_ZERO);
   }
   
   /*
    * Tear down a wscons_event queue.
    */
   void
   wsevent_fini(struct wseventvar *ev)
   {
           if (ev->q == NULL) {
   #ifdef DIAGNOSTIC
                   printf("wsevent_fini: already fini\n");
   #endif
                   return;
           }
           free(ev->q, M_DEVBUF);
           ev->q = NULL;
   }
   
   /*
    * User-level interface: read, poll.
    * (User cannot write an event queue.)
    */
   int
   wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
   {
           int s, n, cnt, error;
   
           /*
            * Make sure we can return at least 1.
            */
           if (uio->uio_resid < sizeof(struct wscons_event))
                   return (EMSGSIZE);      /* ??? */
           s = splwsevent();
           while (ev->get == ev->put) {
                   if (flags & IO_NDELAY) {
                           splx(s);
                           return (EWOULDBLOCK);
                   }
                   ev->wanted = 1;
                   error = tsleep(ev, PWSEVENT | PCATCH,
                       "wsevent_read", 0);
                   if (error) {
                           splx(s);
                           return (error);
                   }
           }
           /*
            * Move wscons_event from tail end of queue (there is at least one
            * there).
            */
           if (ev->put < ev->get)
                   cnt = WSEVENT_QSIZE - ev->get;  /* events in [get..QSIZE) */
           else
                   cnt = ev->put - ev->get;        /* events in [get..put) */
           splx(s);
           n = howmany(uio->uio_resid, sizeof(struct wscons_event));
           if (cnt > n)
                   cnt = n;
           error = uiomove(&ev->q[ev->get],
               cnt * sizeof(struct wscons_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->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
               n == 0 || error || (cnt = ev->put) == 0)
                   return (error);
           if (cnt > n)
                   cnt = n;
           error = uiomove(&ev->q[0],
               cnt * sizeof(struct wscons_event), uio);
           ev->get = cnt;
           return (error);
   }
   
   int
   wsevent_poll(struct wseventvar *ev, int events, struct proc *p)
   {
           int revents = 0;
           int s = splwsevent();
   
           if (events & (POLLIN | POLLRDNORM)) {
                   if (ev->get != ev->put)
                           revents |= events & (POLLIN | POLLRDNORM);
                   else
                           selrecord(p, &ev->sel);
           }
   
           splx(s);
           return (revents);
   }
   
   static void
   filt_wseventrdetach(struct knote *kn)
   {
           struct wseventvar *ev = kn->kn_hook;
           int s;
   
           s = splwsevent();
           SLIST_REMOVE(&ev->sel.sel_klist, kn, knote, kn_selnext);
           splx(s);
   }
   
   static int
   filt_wseventread(struct knote *kn, long hint)
   {
           struct wseventvar *ev = kn->kn_hook;
   
           if (ev->get == ev->put)
                   return (0);
   
           if (ev->get < ev->put)
                   kn->kn_data = ev->put - ev->get;
           else
                   kn->kn_data = (WSEVENT_QSIZE - ev->get) +
                       ev->put;
   
           kn->kn_data *= sizeof(struct wscons_event);
   
           return (1);
   }
   
   static const struct filterops wsevent_filtops =
           { 1, NULL, filt_wseventrdetach, filt_wseventread };
   
   int
   wsevent_kqfilter(struct wseventvar *ev, struct knote *kn)
   {
           struct klist *klist;
           int s;
   
           switch (kn->kn_filter) {
           case EVFILT_READ:
                   klist = &ev->sel.sel_klist;
                   kn->kn_fop = &wsevent_filtops;
                   break;
   
           default:
                   return (1);
           }
   
           kn->kn_hook = ev;
   
           s = splwsevent();
           SLIST_INSERT_HEAD(klist, kn, kn_selnext);
           splx(s);
   
           return (0);
   }

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