source: trunk/kernel/mm/khm.h @ 1

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1/*
2 * khm.h - kernel heap manager used for variable size memory allocation.
3 *
4 * Authors  Ghassan Almaless (2008,2009,2010,2011,2012)
5 *          Mohamed Lamine Karaoui (2015)
6 *          Alain Greiner (2016)
7 *
8 * Copyright (c) UPMC Sorbonne Universites
9 *
10 * This file is part of ALMOS-MKH.
11 *
12 * ALMOS-MKH is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; version 2.0 of the License.
15 *
16 * ALMOS-MKH is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
23 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26#ifndef _HEAP_MANAGER_H_
27#define _HEAP_MANAGER_H_
28
29#include <almos_config.h>
30#include <hal_types.h>
31#include <spinlock.h>
32
33/*******************************************************************************************
34 * This structure defines a Kernel Heap Manager (KHM) in a given cluster.
35 * It is used to allocate memory objects, that are not
36 * enough replicated to justify a dedicated KCM allocator.
37 ******************************************************************************************/
38
39typedef struct khm_s
40{
41        spinlock_t lock;           /*! lock protecting exclusive access to heap               */
42        intptr_t   base;           /*! heap base address                                      */
43        uint32_t   size;           /*! heap size (bytes)                                      */
44        intptr_t   next;           /*! next free block address                                */
45}
46khm_t;
47
48/*******************************************************************************************
49 * This structure defines an allocated block descriptor for the KHM.
50 * This block descriptor is stored at the beginning of the allocated block.
51 * The returned pointer is the allocated memory block base + block descriptor size.
52 ******************************************************************************************/
53
54typedef struct khm_block_s
55{
56        uint32_t   busy:1;         /*! free block if zero                                     */
57        uint32_t   size:31;        /*! size coded on 31 bits                                  */
58} 
59khm_block_t;
60
61
62/*******************************************************************************************
63 * This function initializes a KHM heap manager in a given cluster.
64 * It is used to allocate variable size memory objects, that are not
65 * enough replicated to justify a dedicated KCM allocator.
66 *******************************************************************************************
67 * @ khm        : pointer on KHM to initialize.
68 * @ heap_base  : heap base address.
69 * @ heap_size  : heap size in bytes.
70 ******************************************************************************************/
71void khm_init( khm_t    * khm );
72
73/*******************************************************************************************
74 * This function allocates a memory block from the local KHM.
75 * The actual size of the allocated block is the requested size, plus the block descriptor
76 * size, rounded to a cache line size.
77 *******************************************************************************************
78 * @ khm    : pointer on local kernel heap manager.
79 * @ size   : number of requested bytes (must be smaller than 2G bytes).
80 * @ returns a pointer on memory block if success / returns NULL if failure.
81 ******************************************************************************************/
82void * khm_alloc( khm_t    * khm,
83                  uint32_t   size );
84
85/*******************************************************************************************
86 * This function releases a previoully allocated memory block to the local KHM.
87 *******************************************************************************************
88 * @ ptr    : pointer on released block.
89 ******************************************************************************************/
90void  khm_free( void * ptr );
91
92#endif  /* _HEAP_MANAGER_H_ */
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