/*
 * Copyright (c) 2011 The FreeBSD Foundation
 * All rights reserved.
 *
 * This software was developed by Konstantin Belousov under sponsorship from
 * the FreeBSD Foundation.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/dev/drm2/drm_linux_list_sort.c,v 1.1 2012/05/22 11:07:44 kib Exp $
 */

#include <drm/drmP.h>

struct drm_list_sort_thunk {
	int (*cmp)(void *, struct list_head *, struct list_head *);
	void *priv;
};

static int
drm_le_cmp(void *priv, const void *d1, const void *d2)
{
	struct list_head *le1, *le2;
	struct drm_list_sort_thunk *thunk;

	thunk = priv;
	le1 = __DECONST(struct list_head *, d1);
	le2 = __DECONST(struct list_head *, d2);
	return ((thunk->cmp)(thunk->priv, le1, le2));
}

/*
 * Punt and use array sort.
 */
void
drm_list_sort(void *priv, struct list_head *head, int (*cmp)(void *priv,
    struct list_head *a, struct list_head *b))
{
	struct drm_list_sort_thunk thunk;
	struct list_head **ar, *le;
	int count, i;

	count = 0;
	list_for_each(le, head)
		count++;
	ar = kmalloc(sizeof(struct list_head *) * count, M_TEMP, M_WAITOK);
	i = 0;
	list_for_each(le, head)
		ar[i++] = le;
	thunk.cmp = cmp;
	thunk.priv = priv;
	kqsort_r(ar, count, sizeof(struct list_head *), &thunk, drm_le_cmp);
	INIT_LIST_HEAD(head);
	for (i = 0; i < count; i++)
		list_add_tail(ar[i], head);
	drm_free(ar, M_TEMP);
}