sys/dev/drm/linux_async.c

   1 /*-
   2  * Copyright (c) 2015 François Tigeot
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include <sys/spinlock2.h>
  28 #include <linux/async.h>
  29
  30 static async_cookie_t cookie_counter = 1;
  31
  32 /* Protects cookie_counter */
  33 static struct lock linux_async_lock;
  34 LOCK_SYSINIT(linux_async_lock, &linux_async_lock, "lasync", LK_CANRECURSE);
  35
  36 /* async_schedule: schedule a function for asynchronous execution */
  37 async_cookie_t async_schedule(async_func_t func, void *data)
  38 {
  39         async_cookie_t cookie;
  40
  41         lockmgr(&linux_async_lock, LK_EXCLUSIVE);
  42         cookie_counter++;
  43         cookie = cookie_counter;
  44         lockmgr(&linux_async_lock, LK_RELEASE);
  45
  46         /* XXX: Just run the function synchronously for now */
  47         func(data, cookie);
  48
  49         return cookie;
  50 }