root/sys/dev/drm/linux_async.c
/*-
 * Copyright (c) 2015-2019 François Tigeot <ftigeot@wolfpond.org>
 * 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 unmodified, 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.
 *
 * 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.
 */

#include <sys/spinlock2.h>
#include <linux/async.h>

#include <sys/kernel.h>

static async_cookie_t cookie_counter = 1;

/* Protects cookie_counter */
static struct lock linux_async_lock;
LOCK_SYSINIT(linux_async_lock, &linux_async_lock, "lasync", LK_CANRECURSE);

/* async_schedule: schedule a function for asynchronous execution */
async_cookie_t async_schedule(async_func_t func, void *data)
{
        async_cookie_t cookie;

        lockmgr(&linux_async_lock, LK_EXCLUSIVE);
        cookie_counter++;
        cookie = cookie_counter;
        lockmgr(&linux_async_lock, LK_RELEASE);

        /* XXX: Just run the function synchronously for now */
        func(data, cookie);

        return cookie;
}