/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 *
 * NAME: gen_util.c
 *
 * DESC: Generic kernel utility functions
 *
 */

#include <sys/types.h>
#include <sys/debug.h>
#include <sys/kmem.h>
#include <sys/ib/clients/of/sol_ofs/sol_ofs_common.h>

/*
 * Doubly linked per user context IB resource list definitions
 * Protection must occur * outside of the list.
 */

/*
 * add_genlist()
 *
 * Adds the entry to the tail of the list.
 */
genlist_entry_t *
add_genlist(genlist_t *list, uintptr_t data, void *data_context)
{

        genlist_entry_t *new_entry;

        new_entry = (genlist_entry_t *)(kmem_zalloc(sizeof (genlist_entry_t),
            KM_SLEEP));

        if (new_entry != NULL) {
                new_entry->data_context = data_context;
                new_entry->data = data;
                new_entry->next = NULL;
                new_entry->prev = list->tail;

                if (!list->count) {
                        list->tail = new_entry;
                        list->head = new_entry;
                } else {
                        list->tail->next = new_entry;
                        list->tail = new_entry;
                }
                list->count++;
        }
        return (new_entry);
}

/*
 * delete_genlist() - delete the specified entry from the list.
 */
void delete_genlist(genlist_t *list, genlist_entry_t *entry) {

        ASSERT(entry);

        if (entry->prev) {
                entry->prev->next = entry->next;
        } else {
                list->head = entry->next;
        }

        if (entry->next) {
                entry->next->prev = entry->prev;
        } else {
                list->tail = entry->prev;
        }

        list->count--;
        entry->prev = entry->next = NULL;
        kmem_free((void *)entry, sizeof (genlist_entry_t));
}

/*
 * remove_genlist_head() - remove the entry from the list head, but
 *                          don't delete it.
 */
genlist_entry_t *remove_genlist_head(genlist_t *list) {

        genlist_entry_t *entry = list->head;

        if (list->head) {
                list->head = list->head->next;
                list->count--;

                if (!list->head)
                        list->tail = list->head;
        }

        return (entry);
}

/*
 * flush_genlist
 */
void flush_genlist(genlist_t *list) {

        genlist_entry_t *entry;

        entry = remove_genlist_head(list);

        while (entry) {
                kmem_free((void *)entry, sizeof (genlist_entry_t));
                entry = remove_genlist_head(list);
        }
        init_genlist(list);
}

bool genlist_empty(genlist_t *list) {

        if (list->head != NULL)
                return (FALSE);
        else
                return (TRUE);
}

/*
 * FUNCTION: insert_genlist_tail()
 */
void insert_genlist_tail(genlist_t *list, genlist_entry_t *entry) {

        entry->next = NULL;
        entry->prev = list->tail;

        if (!list->count) {
                list->tail = entry;
                list->head = entry;
        } else {
                list->tail->next = entry;
                list->tail = entry;
        }
        list->count++;
}