source: mainline/generic/include/mm/buddy.h@ bb68433

/*
 * Copyright (C) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - 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.
 */

#ifndef __BUDDY_H__
#define __BUDDY_H__

#include <arch/types.h>
#include <typedefs.h>

#define BUDDY_SYSTEM_INNER_BLOCK        0xff

/** Buddy system operations to be implemented by each implementations. */
struct buddy_system_operations {
        link_t *(* find_buddy)(buddy_system_t *, link_t *);             /**< Return pointer to left-side or right-side buddy for block passed as argument. */
        link_t *(* bisect)(buddy_system_t *, link_t *);                 /**< Bisect the block passed as argument and return pointer to the new right-side buddy. */
        link_t *(* coalesce)(buddy_system_t *, link_t *, link_t *);     /**< Coalesce two buddies into a bigger block. */
        void (*set_order)(buddy_system_t *, link_t *, __u8);            /**< Set order of block passed as argument. */
        __u8 (*get_order)(buddy_system_t *, link_t *);                  /**< Return order of block passed as argument. */
        void (*mark_busy)(buddy_system_t *, link_t *);                  /**< Mark block as busy */
        void (*mark_available)(buddy_system_t *, link_t *);                     /**< Mark block as busy */
        /** Find parent of block that has given order  */
        link_t *(* find_block)(buddy_system_t *, link_t *, __u8);
        void (* print_id)(buddy_system_t *, link_t *);
};

struct buddy_system {
        __u8 max_order;                         /**< Maximal order of block which can be stored by buddy system. */
        link_t *order;
        buddy_system_operations_t *op;
        void *data;                             /**< Pointer to be used by the implementation. */
};

extern void buddy_system_create(buddy_system_t *b,
                                __u8 max_order, 
                                buddy_system_operations_t *op, void *data);
extern link_t *buddy_system_alloc(buddy_system_t *b, __u8 i);
extern bool buddy_system_can_alloc(buddy_system_t *b, __u8 order);
extern void buddy_system_free(buddy_system_t *b, link_t *block);
extern void buddy_system_structure_print(buddy_system_t *b, size_t elem_size);
extern size_t buddy_conf_size(int max_order);
extern link_t *buddy_system_alloc_block(buddy_system_t *b, link_t *block);

#endif