source: trunk/kernel/mm/khm.c @ 551

Last change on this file since 551 was 551, checked in by nicolas.van.phan@…, 3 years ago

Make locks before IDLE Init busy

File size: 4.4 KB
Line 
1/*
2 * khm.c - kernel heap manager implementation.
3 *
4 * Authors  Ghassan Almaless (2008,2009,2010,2011,2012)
5 *          Alain Greiner (2016)
6 *
7 * Copyright (c)  UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#include <kernel_config.h>
26#include <hal_kernel_types.h>
27#include <hal_special.h>
28#include <spinlock.h>
29#include <bits.h>
30#include <printk.h>
31#include <thread.h>
32#include <cluster.h>
33#include <page.h>
34#include <ppm.h>
35#include <khm.h>
36
37
38////////////////////////////
39void khm_init( khm_t * khm )
40{
41        // check config parameters
42        assert( ((CONFIG_PPM_PAGE_SHIFT + CONFIG_PPM_HEAP_ORDER) < 32 ) ,
43                 "CONFIG_PPM_HEAP_ORDER too large" );
44
45        // initialize lock
46        spinlock_init( &khm->lock );
47
48        // compute kernel heap size
49        intptr_t heap_size = (1 << CONFIG_PPM_HEAP_ORDER) << CONFIG_PPM_PAGE_SHIFT;
50
51        // get kernel heap base from PPM
52        page_t * page      = ppm_alloc_pages( CONFIG_PPM_HEAP_ORDER );
53        xptr_t   base_xp   = ppm_page2base( XPTR( local_cxy, page ) );
54        void   * heap_base = GET_PTR( base_xp );
55
56        // initialize first block (complete heap)
57        khm_block_t * block = (khm_block_t *)heap_base;
58        block->size = heap_size;
59        block->busy = 0;
60
61        // initialize KHM fields
62        khm->base    = (intptr_t)heap_base;
63        khm->size    = heap_size;
64        khm->next    = (intptr_t)heap_base;
65}
66
67/////////////////////////////////
68void * khm_alloc( khm_t    * khm,
69                  uint32_t   size )
70{
71        khm_block_t  * current;
72        khm_block_t  * next;
73        uint32_t       effective_size;
74
75        // compute actual block size
76        effective_size = size + sizeof(khm_block_t);
77        effective_size = ARROUND_UP( effective_size, CONFIG_CACHE_LINE_SIZE );
78
79        // get lock protecting heap
80        uint32_t       irq_state;
81        spinlock_lock_busy( &khm->lock, &irq_state );
82
83        // define a starting block to scan existing blocks
84        if( ((khm_block_t*)khm->next)->size < effective_size ) current = (khm_block_t*)khm->base;
85        else                                                   current = (khm_block_t*)khm->next;
86
87        // scan all existing blocks to find a free block large enough
88        while( current->busy || (current->size < effective_size))
89        {
90                // get next block pointer
91                current = (khm_block_t*)((char*)current + current->size);
92
93                if( (intptr_t)current >= (khm->base + khm->size) )  // heap full
94                {
95                        spinlock_unlock_busy(&khm->lock, irq_state );
96
97                        printk("\n[ERROR] in %s : failed to allocate block of size %d\n",
98                               __FUNCTION__ , effective_size );
99                        return NULL;
100                }
101        }
102
103        // split the current block if it is too large
104        if( (current->size - effective_size) >= CONFIG_CACHE_LINE_SIZE )
105        {
106                // update new free block features
107                next           = (khm_block_t *)((char*)current + effective_size);
108                next->size     = current->size - effective_size;
109                next->busy     = 0;
110
111                // register new free block
112                khm->next = (intptr_t)next;
113
114                // update allocated block features
115                current->size  = effective_size;
116                current->busy  = 1;
117        }
118        else
119        {
120                // change block state
121                current->busy  = 1;
122        }
123
124        // release lock protecting heap
125        spinlock_unlock_busy( &khm->lock, irq_state );
126
127        return (char*)current + sizeof(khm_block_t);
128}
129
130///////////////////////////
131void khm_free( void * ptr )
132{
133        khm_t * khm = &LOCAL_CLUSTER->khm;
134
135        khm_block_t * current;
136        khm_block_t * next;
137
138        if(ptr == NULL) return;
139
140        current = (khm_block_t *)((char*)ptr - sizeof(khm_block_t));
141
142        // get lock protecting heap
143        spinlock_lock(&khm->lock);
144
145        assert( (current->busy == 1) , "page already freed" );
146
147        // release block
148        current->busy = 0;
149
150        // try to merge released block with the next
151        while ( 1 )
152        {
153                next = (khm_block_t*)((char*)current + current->size);
154                if ( ((intptr_t)next >= (khm->base + khm->size)) || (next->busy == 1) ) break;
155                current->size += next->size;
156        }
157
158        if( (intptr_t)current < khm->next ) khm->next = (intptr_t)current;
159
160        // release lock protecting heap
161        spinlock_unlock( &khm->lock );
162}
163
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