kernel/generic/include/mm/buddy.h

   1 /*
   2  * Copyright (C) 2005 Jakub Jermar
   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  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - 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  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup genericmm
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #ifndef KERN_BUDDY_H_
  36 #define KERN_BUDDY_H_
  37
  38 #include <arch/types.h>
  39 #include <typedefs.h>
  40
  41 #define BUDDY_SYSTEM_INNER_BLOCK        0xff
  42
  43 /** Buddy system operations to be implemented by each implementation. */
  44 struct buddy_system_operations {
  45         /** Return pointer to left-side or right-side buddy for block passed as
  46           * argument. */
  47         link_t *(* find_buddy)(buddy_system_t *, link_t *);
  48         /** Bisect the block passed as argument and return pointer to the new
  49           * right-side buddy. */
  50         link_t *(* bisect)(buddy_system_t *, link_t *);
  51         /** Coalesce two buddies into a bigger block. */
  52         link_t *(* coalesce)(buddy_system_t *, link_t *, link_t *);
  53         /** Set order of block passed as argument. */
  54         void (*set_order)(buddy_system_t *, link_t *, uint8_t);
  55         /** Return order of block passed as argument. */
  56         uint8_t (*get_order)(buddy_system_t *, link_t *);
  57         /** Mark block as busy. */
  58         void (*mark_busy)(buddy_system_t *, link_t *);
  59         /** Mark block as available. */
  60         void (*mark_available)(buddy_system_t *, link_t *);
  61         /** Find parent of block that has given order  */
  62         link_t *(* find_block)(buddy_system_t *, link_t *, uint8_t);
  63         void (* print_id)(buddy_system_t *, link_t *);
  64 };
  65
  66 struct buddy_system {
  67         /** Maximal order of block which can be stored by buddy system. */
  68         uint8_t max_order;
  69         link_t *order;
  70         buddy_system_operations_t *op;
  71         /** Pointer to be used by the implementation. */
  72         void *data;
  73 };
  74
  75 extern void buddy_system_create(buddy_system_t *b, uint8_t max_order,
  76         buddy_system_operations_t *op, void *data);
  77 extern link_t *buddy_system_alloc(buddy_system_t *b, uint8_t i);
  78 extern bool buddy_system_can_alloc(buddy_system_t *b, uint8_t order);
  79 extern void buddy_system_free(buddy_system_t *b, link_t *block);
  80 extern void buddy_system_structure_print(buddy_system_t *b, size_t elem_size);
  81 extern size_t buddy_conf_size(int max_order);
  82 extern link_t *buddy_system_alloc_block(buddy_system_t *b, link_t *block);
  83
  84 #endif
  85
  86 /** @}
  87  */