1 /*
2  * GLX Hardware Device Driver common code
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 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 
29 #include <stdlib.h>
30 #include <assert.h>
31 
32 #include "xf86drm.h"
33 #include "libdrm_macros.h"
34 #include "mm.h"
35 
mmDumpMemInfo(const struct mem_block * heap)36 drm_private void mmDumpMemInfo(const struct mem_block *heap)
37 {
38 	drmMsg("Memory heap %p:\n", (void *)heap);
39 	if (heap == 0) {
40 		drmMsg("  heap == 0\n");
41 	} else {
42 		const struct mem_block *p;
43 
44 		for (p = heap->next; p != heap; p = p->next) {
45 			drmMsg("  Offset:%08x, Size:%08x, %c%c\n", p->ofs,
46 			       p->size, p->free ? 'F' : '.',
47 			       p->reserved ? 'R' : '.');
48 		}
49 
50 		drmMsg("\nFree list:\n");
51 
52 		for (p = heap->next_free; p != heap; p = p->next_free) {
53 			drmMsg(" FREE Offset:%08x, Size:%08x, %c%c\n", p->ofs,
54 			       p->size, p->free ? 'F' : '.',
55 			       p->reserved ? 'R' : '.');
56 		}
57 
58 	}
59 	drmMsg("End of memory blocks\n");
60 }
61 
mmInit(int ofs,int size)62 drm_private struct mem_block *mmInit(int ofs, int size)
63 {
64 	struct mem_block *heap, *block;
65 
66 	if (size <= 0)
67 		return NULL;
68 
69 	heap = (struct mem_block *)calloc(1, sizeof(struct mem_block));
70 	if (!heap)
71 		return NULL;
72 
73 	block = (struct mem_block *)calloc(1, sizeof(struct mem_block));
74 	if (!block) {
75 		free(heap);
76 		return NULL;
77 	}
78 
79 	heap->next = block;
80 	heap->prev = block;
81 	heap->next_free = block;
82 	heap->prev_free = block;
83 
84 	block->heap = heap;
85 	block->next = heap;
86 	block->prev = heap;
87 	block->next_free = heap;
88 	block->prev_free = heap;
89 
90 	block->ofs = ofs;
91 	block->size = size;
92 	block->free = 1;
93 
94 	return heap;
95 }
96 
SliceBlock(struct mem_block * p,int startofs,int size,int reserved,int alignment)97 static struct mem_block *SliceBlock(struct mem_block *p,
98 				    int startofs, int size,
99 				    int reserved, int alignment)
100 {
101 	struct mem_block *newblock;
102 
103 	/* break left  [p, newblock, p->next], then p = newblock */
104 	if (startofs > p->ofs) {
105 		newblock =
106 		    (struct mem_block *)calloc(1, sizeof(struct mem_block));
107 		if (!newblock)
108 			return NULL;
109 		newblock->ofs = startofs;
110 		newblock->size = p->size - (startofs - p->ofs);
111 		newblock->free = 1;
112 		newblock->heap = p->heap;
113 
114 		newblock->next = p->next;
115 		newblock->prev = p;
116 		p->next->prev = newblock;
117 		p->next = newblock;
118 
119 		newblock->next_free = p->next_free;
120 		newblock->prev_free = p;
121 		p->next_free->prev_free = newblock;
122 		p->next_free = newblock;
123 
124 		p->size -= newblock->size;
125 		p = newblock;
126 	}
127 
128 	/* break right, also [p, newblock, p->next] */
129 	if (size < p->size) {
130 		newblock =
131 		    (struct mem_block *)calloc(1, sizeof(struct mem_block));
132 		if (!newblock)
133 			return NULL;
134 		newblock->ofs = startofs + size;
135 		newblock->size = p->size - size;
136 		newblock->free = 1;
137 		newblock->heap = p->heap;
138 
139 		newblock->next = p->next;
140 		newblock->prev = p;
141 		p->next->prev = newblock;
142 		p->next = newblock;
143 
144 		newblock->next_free = p->next_free;
145 		newblock->prev_free = p;
146 		p->next_free->prev_free = newblock;
147 		p->next_free = newblock;
148 
149 		p->size = size;
150 	}
151 
152 	/* p = middle block */
153 	p->free = 0;
154 
155 	/* Remove p from the free list:
156 	 */
157 	p->next_free->prev_free = p->prev_free;
158 	p->prev_free->next_free = p->next_free;
159 
160 	p->next_free = 0;
161 	p->prev_free = 0;
162 
163 	p->reserved = reserved;
164 	return p;
165 }
166 
mmAllocMem(struct mem_block * heap,int size,int align2,int startSearch)167 drm_private struct mem_block *mmAllocMem(struct mem_block *heap, int size,
168 					 int align2, int startSearch)
169 {
170 	struct mem_block *p;
171 	const int mask = (1 << align2) - 1;
172 	int startofs = 0;
173 	int endofs;
174 
175 	if (!heap || align2 < 0 || size <= 0)
176 		return NULL;
177 
178 	for (p = heap->next_free; p != heap; p = p->next_free) {
179 		assert(p->free);
180 
181 		startofs = (p->ofs + mask) & ~mask;
182 		if (startofs < startSearch) {
183 			startofs = startSearch;
184 		}
185 		endofs = startofs + size;
186 		if (endofs <= (p->ofs + p->size))
187 			break;
188 	}
189 
190 	if (p == heap)
191 		return NULL;
192 
193 	assert(p->free);
194 	p = SliceBlock(p, startofs, size, 0, mask + 1);
195 
196 	return p;
197 }
198 
Join2Blocks(struct mem_block * p)199 static int Join2Blocks(struct mem_block *p)
200 {
201 	/* XXX there should be some assertions here */
202 
203 	/* NOTE: heap->free == 0 */
204 
205 	if (p->free && p->next->free) {
206 		struct mem_block *q = p->next;
207 
208 		assert(p->ofs + p->size == q->ofs);
209 		p->size += q->size;
210 
211 		p->next = q->next;
212 		q->next->prev = p;
213 
214 		q->next_free->prev_free = q->prev_free;
215 		q->prev_free->next_free = q->next_free;
216 
217 		free(q);
218 		return 1;
219 	}
220 	return 0;
221 }
222 
mmFreeMem(struct mem_block * b)223 drm_private int mmFreeMem(struct mem_block *b)
224 {
225 	if (!b)
226 		return 0;
227 
228 	if (b->free) {
229 		drmMsg("block already free\n");
230 		return -1;
231 	}
232 	if (b->reserved) {
233 		drmMsg("block is reserved\n");
234 		return -1;
235 	}
236 
237 	b->free = 1;
238 	b->next_free = b->heap->next_free;
239 	b->prev_free = b->heap;
240 	b->next_free->prev_free = b;
241 	b->prev_free->next_free = b;
242 
243 	Join2Blocks(b);
244 	if (b->prev != b->heap)
245 		Join2Blocks(b->prev);
246 
247 	return 0;
248 }
249 
mmDestroy(struct mem_block * heap)250 drm_private void mmDestroy(struct mem_block *heap)
251 {
252 	struct mem_block *p;
253 
254 	if (!heap)
255 		return;
256 
257 	for (p = heap->next; p != heap;) {
258 		struct mem_block *next = p->next;
259 		free(p);
260 		p = next;
261 	}
262 
263 	free(heap);
264 }
265