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1 /**************************************************************************
2  *
3  * Copyright (C) 1999 Wittawat Yamwong
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included
13  * in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * WITTAWAT YAMWONG, OR ANY OTHER CONTRIBUTORS BE LIABLE FOR ANY CLAIM,
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
21  * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22  *
23  **************************************************************************/
24 
25 
26 #include "util/u_debug.h"
27 
28 #include "util/u_memory.h"
29 #include "util/u_mm.h"
30 #include "util/macros.h"
31 
32 
33 void
u_mmDumpMemInfo(const struct mem_block * heap)34 u_mmDumpMemInfo(const struct mem_block *heap)
35 {
36    debug_printf("Memory heap %p:\n", (void *) heap);
37    if (heap == NULL) {
38       debug_printf("  heap == 0\n");
39    }
40    else {
41       const struct mem_block *p;
42       int total_used = 0, total_free = 0;
43 
44       for (p = heap->next; p != heap; p = p->next) {
45 	 debug_printf("  Offset:%08x, Size:%08x, %c%c\n", p->ofs, p->size,
46                       p->free ? 'F':'.',
47                       p->reserved ? 'R':'.');
48          if (p->free)
49             total_free += p->size;
50          else
51             total_used += p->size;
52       }
53 
54       debug_printf("'\nMemory stats: total = %d, used = %d, free = %d\n",
55                    total_used + total_free, total_used, total_free);
56       debug_printf("\nFree list:\n");
57 
58       for (p = heap->next_free; p != heap; p = p->next_free) {
59 	 debug_printf(" FREE Offset:%08x, Size:%08x, %c%c\n", p->ofs, p->size,
60                       p->free ? 'F':'.',
61                       p->reserved ? 'R':'.');
62       }
63 
64    }
65    debug_printf("End of memory blocks\n");
66 }
67 
68 
69 struct mem_block *
u_mmInit(int ofs,int size)70 u_mmInit(int ofs, int size)
71 {
72    struct mem_block *heap, *block;
73 
74    if (size <= 0)
75       return NULL;
76 
77    heap = CALLOC_STRUCT(mem_block);
78    if (!heap)
79       return NULL;
80 
81    block = CALLOC_STRUCT(mem_block);
82    if (!block) {
83       FREE(heap);
84       return NULL;
85    }
86 
87    heap->next = block;
88    heap->prev = block;
89    heap->next_free = block;
90    heap->prev_free = block;
91 
92    block->heap = heap;
93    block->next = heap;
94    block->prev = heap;
95    block->next_free = heap;
96    block->prev_free = heap;
97 
98    block->ofs = ofs;
99    block->size = size;
100    block->free = 1;
101 
102    return heap;
103 }
104 
105 
106 static struct mem_block *
SliceBlock(struct mem_block * p,int startofs,int size,int reserved,UNUSED int alignment)107 SliceBlock(struct mem_block *p,
108            int startofs, int size,
109            int reserved, UNUSED int alignment)
110 {
111    struct mem_block *newblock;
112 
113    /* break left  [p, newblock, p->next], then p = newblock */
114    if (startofs > p->ofs) {
115       newblock = CALLOC_STRUCT(mem_block);
116       if (!newblock)
117 	 return NULL;
118       newblock->ofs = startofs;
119       newblock->size = p->size - (startofs - p->ofs);
120       newblock->free = 1;
121       newblock->heap = p->heap;
122 
123       newblock->next = p->next;
124       newblock->prev = p;
125       p->next->prev = newblock;
126       p->next = newblock;
127 
128       newblock->next_free = p->next_free;
129       newblock->prev_free = p;
130       p->next_free->prev_free = newblock;
131       p->next_free = newblock;
132 
133       p->size -= newblock->size;
134       p = newblock;
135    }
136 
137    /* break right, also [p, newblock, p->next] */
138    if (size < p->size) {
139       newblock = CALLOC_STRUCT(mem_block);
140       if (!newblock)
141 	 return NULL;
142       newblock->ofs = startofs + size;
143       newblock->size = p->size - size;
144       newblock->free = 1;
145       newblock->heap = p->heap;
146 
147       newblock->next = p->next;
148       newblock->prev = p;
149       p->next->prev = newblock;
150       p->next = newblock;
151 
152       newblock->next_free = p->next_free;
153       newblock->prev_free = p;
154       p->next_free->prev_free = newblock;
155       p->next_free = newblock;
156 
157       p->size = size;
158    }
159 
160    /* p = middle block */
161    p->free = 0;
162 
163    /* Remove p from the free list:
164     */
165    p->next_free->prev_free = p->prev_free;
166    p->prev_free->next_free = p->next_free;
167 
168    p->next_free = 0;
169    p->prev_free = 0;
170 
171    p->reserved = reserved;
172    return p;
173 }
174 
175 
176 struct mem_block *
u_mmAllocMem(struct mem_block * heap,int size,int align2,int startSearch)177 u_mmAllocMem(struct mem_block *heap, int size, int align2, int startSearch)
178 {
179    struct mem_block *p;
180    const int mask = (1 << align2)-1;
181    int startofs = 0;
182    int endofs;
183 
184    assert(size >= 0);
185    assert(align2 >= 0);
186    /* Make sure that a byte alignment isn't getting passed for our
187     * power-of-two alignment arg.
188     */
189    assert(align2 < 32);
190 
191    if (!heap || align2 < 0 || size <= 0)
192       return NULL;
193 
194    for (p = heap->next_free; p != heap; p = p->next_free) {
195       assert(p->free);
196 
197       startofs = (p->ofs + mask) & ~mask;
198       if ( startofs < startSearch ) {
199 	 startofs = startSearch;
200       }
201       endofs = startofs+size;
202       if (endofs <= (p->ofs+p->size))
203 	 break;
204    }
205 
206    if (p == heap)
207       return NULL;
208 
209    assert(p->free);
210    p = SliceBlock(p,startofs,size,0,mask+1);
211 
212    return p;
213 }
214 
215 
216 struct mem_block *
u_mmFindBlock(struct mem_block * heap,int start)217 u_mmFindBlock(struct mem_block *heap, int start)
218 {
219    struct mem_block *p;
220 
221    for (p = heap->next; p != heap; p = p->next) {
222       if (p->ofs == start)
223 	 return p;
224    }
225 
226    return NULL;
227 }
228 
229 
230 static inline int
Join2Blocks(struct mem_block * p)231 Join2Blocks(struct mem_block *p)
232 {
233    /* XXX there should be some assertions here */
234 
235    /* NOTE: heap->free == 0 */
236 
237    if (p->free && p->next->free) {
238       struct mem_block *q = p->next;
239 
240       assert(p->ofs + p->size == q->ofs);
241       p->size += q->size;
242 
243       p->next = q->next;
244       q->next->prev = p;
245 
246       q->next_free->prev_free = q->prev_free;
247       q->prev_free->next_free = q->next_free;
248 
249       FREE(q);
250       return 1;
251    }
252    return 0;
253 }
254 
255 int
u_mmFreeMem(struct mem_block * b)256 u_mmFreeMem(struct mem_block *b)
257 {
258    if (!b)
259       return 0;
260 
261    if (b->free) {
262       debug_printf("block already free\n");
263       return -1;
264    }
265    if (b->reserved) {
266       debug_printf("block is reserved\n");
267       return -1;
268    }
269 
270    b->free = 1;
271    b->next_free = b->heap->next_free;
272    b->prev_free = b->heap;
273    b->next_free->prev_free = b;
274    b->prev_free->next_free = b;
275 
276    Join2Blocks(b);
277    if (b->prev != b->heap)
278       Join2Blocks(b->prev);
279 
280    return 0;
281 }
282 
283 
284 void
u_mmDestroy(struct mem_block * heap)285 u_mmDestroy(struct mem_block *heap)
286 {
287    struct mem_block *p;
288 
289    if (!heap)
290       return;
291 
292    for (p = heap->next; p != heap; ) {
293       struct mem_block *next = p->next;
294       FREE(p);
295       p = next;
296    }
297 
298    FREE(heap);
299 }
300