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Diffstat (limited to 'drivers/gpu/drm/drm_mm.c')
-rw-r--r--drivers/gpu/drm/drm_mm.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
new file mode 100644
index 000000000000..dcff9e9b52e3
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+++ b/drivers/gpu/drm/drm_mm.c
@@ -0,0 +1,295 @@
1/**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 *
27 **************************************************************************/
28
29/*
30 * Generic simple memory manager implementation. Intended to be used as a base
31 * class implementation for more advanced memory managers.
32 *
33 * Note that the algorithm used is quite simple and there might be substantial
34 * performance gains if a smarter free list is implemented. Currently it is just an
35 * unordered stack of free regions. This could easily be improved if an RB-tree
36 * is used instead. At least if we expect heavy fragmentation.
37 *
38 * Aligned allocations can also see improvement.
39 *
40 * Authors:
41 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
42 */
43
44#include "drmP.h"
45#include <linux/slab.h>
46
47unsigned long drm_mm_tail_space(struct drm_mm *mm)
48{
49 struct list_head *tail_node;
50 struct drm_mm_node *entry;
51
52 tail_node = mm->ml_entry.prev;
53 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
54 if (!entry->free)
55 return 0;
56
57 return entry->size;
58}
59
60int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
61{
62 struct list_head *tail_node;
63 struct drm_mm_node *entry;
64
65 tail_node = mm->ml_entry.prev;
66 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
67 if (!entry->free)
68 return -ENOMEM;
69
70 if (entry->size <= size)
71 return -ENOMEM;
72
73 entry->size -= size;
74 return 0;
75}
76
77
78static int drm_mm_create_tail_node(struct drm_mm *mm,
79 unsigned long start,
80 unsigned long size)
81{
82 struct drm_mm_node *child;
83
84 child = (struct drm_mm_node *)
85 drm_alloc(sizeof(*child), DRM_MEM_MM);
86 if (!child)
87 return -ENOMEM;
88
89 child->free = 1;
90 child->size = size;
91 child->start = start;
92 child->mm = mm;
93
94 list_add_tail(&child->ml_entry, &mm->ml_entry);
95 list_add_tail(&child->fl_entry, &mm->fl_entry);
96
97 return 0;
98}
99
100
101int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size)
102{
103 struct list_head *tail_node;
104 struct drm_mm_node *entry;
105
106 tail_node = mm->ml_entry.prev;
107 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
108 if (!entry->free) {
109 return drm_mm_create_tail_node(mm, entry->start + entry->size, size);
110 }
111 entry->size += size;
112 return 0;
113}
114
115static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
116 unsigned long size)
117{
118 struct drm_mm_node *child;
119
120 child = (struct drm_mm_node *)
121 drm_alloc(sizeof(*child), DRM_MEM_MM);
122 if (!child)
123 return NULL;
124
125 INIT_LIST_HEAD(&child->fl_entry);
126
127 child->free = 0;
128 child->size = size;
129 child->start = parent->start;
130 child->mm = parent->mm;
131
132 list_add_tail(&child->ml_entry, &parent->ml_entry);
133 INIT_LIST_HEAD(&child->fl_entry);
134
135 parent->size -= size;
136 parent->start += size;
137 return child;
138}
139
140
141
142struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent,
143 unsigned long size, unsigned alignment)
144{
145
146 struct drm_mm_node *align_splitoff = NULL;
147 struct drm_mm_node *child;
148 unsigned tmp = 0;
149
150 if (alignment)
151 tmp = parent->start % alignment;
152
153 if (tmp) {
154 align_splitoff = drm_mm_split_at_start(parent, alignment - tmp);
155 if (!align_splitoff)
156 return NULL;
157 }
158
159 if (parent->size == size) {
160 list_del_init(&parent->fl_entry);
161 parent->free = 0;
162 return parent;
163 } else {
164 child = drm_mm_split_at_start(parent, size);
165 }
166
167 if (align_splitoff)
168 drm_mm_put_block(align_splitoff);
169
170 return child;
171}
172
173/*
174 * Put a block. Merge with the previous and / or next block if they are free.
175 * Otherwise add to the free stack.
176 */
177
178void drm_mm_put_block(struct drm_mm_node * cur)
179{
180
181 struct drm_mm *mm = cur->mm;
182 struct list_head *cur_head = &cur->ml_entry;
183 struct list_head *root_head = &mm->ml_entry;
184 struct drm_mm_node *prev_node = NULL;
185 struct drm_mm_node *next_node;
186
187 int merged = 0;
188
189 if (cur_head->prev != root_head) {
190 prev_node = list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
191 if (prev_node->free) {
192 prev_node->size += cur->size;
193 merged = 1;
194 }
195 }
196 if (cur_head->next != root_head) {
197 next_node = list_entry(cur_head->next, struct drm_mm_node, ml_entry);
198 if (next_node->free) {
199 if (merged) {
200 prev_node->size += next_node->size;
201 list_del(&next_node->ml_entry);
202 list_del(&next_node->fl_entry);
203 drm_free(next_node, sizeof(*next_node),
204 DRM_MEM_MM);
205 } else {
206 next_node->size += cur->size;
207 next_node->start = cur->start;
208 merged = 1;
209 }
210 }
211 }
212 if (!merged) {
213 cur->free = 1;
214 list_add(&cur->fl_entry, &mm->fl_entry);
215 } else {
216 list_del(&cur->ml_entry);
217 drm_free(cur, sizeof(*cur), DRM_MEM_MM);
218 }
219}
220
221struct drm_mm_node *drm_mm_search_free(const struct drm_mm * mm,
222 unsigned long size,
223 unsigned alignment, int best_match)
224{
225 struct list_head *list;
226 const struct list_head *free_stack = &mm->fl_entry;
227 struct drm_mm_node *entry;
228 struct drm_mm_node *best;
229 unsigned long best_size;
230 unsigned wasted;
231
232 best = NULL;
233 best_size = ~0UL;
234
235 list_for_each(list, free_stack) {
236 entry = list_entry(list, struct drm_mm_node, fl_entry);
237 wasted = 0;
238
239 if (entry->size < size)
240 continue;
241
242 if (alignment) {
243 register unsigned tmp = entry->start % alignment;
244 if (tmp)
245 wasted += alignment - tmp;
246 }
247
248
249 if (entry->size >= size + wasted) {
250 if (!best_match)
251 return entry;
252 if (size < best_size) {
253 best = entry;
254 best_size = entry->size;
255 }
256 }
257 }
258
259 return best;
260}
261
262int drm_mm_clean(struct drm_mm * mm)
263{
264 struct list_head *head = &mm->ml_entry;
265
266 return (head->next->next == head);
267}
268
269int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
270{
271 INIT_LIST_HEAD(&mm->ml_entry);
272 INIT_LIST_HEAD(&mm->fl_entry);
273
274 return drm_mm_create_tail_node(mm, start, size);
275}
276
277
278void drm_mm_takedown(struct drm_mm * mm)
279{
280 struct list_head *bnode = mm->fl_entry.next;
281 struct drm_mm_node *entry;
282
283 entry = list_entry(bnode, struct drm_mm_node, fl_entry);
284
285 if (entry->ml_entry.next != &mm->ml_entry ||
286 entry->fl_entry.next != &mm->fl_entry) {
287 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
288 return;
289 }
290
291 list_del(&entry->fl_entry);
292 list_del(&entry->ml_entry);
293
294 drm_free(entry, sizeof(*entry), DRM_MEM_MM);
295}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-24 02:32:24 -0500