1 /**************************************************************************
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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.
27 **************************************************************************/
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
33 * Generic simple memory manager implementation. Intended to be used as a base
34 * class implementation for more advanced memory managers.
36 * Note that the algorithm used is quite simple and there might be substantial
37 * performance gains if a smarter free list is implemented. Currently it is just an
38 * unordered stack of free regions. This could easily be improved if an RB-tree
39 * is used instead. At least if we expect heavy fragmentation.
41 * Aligned allocations can also see improvement.
44 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
47 #include "dev/drm/drmP.h"
48 #include "dev/drm/drm_mm.h"
50 #define MM_UNUSED_TARGET 4
52 unsigned long drm_mm_tail_space(struct drm_mm *mm)
54 struct list_head *tail_node;
55 struct drm_mm_node *entry;
57 tail_node = mm->ml_entry.prev;
58 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
65 int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
67 struct list_head *tail_node;
68 struct drm_mm_node *entry;
70 tail_node = mm->ml_entry.prev;
71 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
75 if (entry->size <= size)
82 static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
84 struct drm_mm_node *child;
87 child = malloc(sizeof(*child), DRM_MEM_MM, M_NOWAIT);
89 child = malloc(sizeof(*child), DRM_MEM_MM, M_WAITOK);
91 if (unlikely(child == NULL)) {
92 mtx_lock(&mm->unused_lock);
93 if (list_empty(&mm->unused_nodes))
97 list_entry(mm->unused_nodes.next,
98 struct drm_mm_node, fl_entry);
99 list_del(&child->fl_entry);
102 mtx_unlock(&mm->unused_lock);
107 int drm_mm_pre_get(struct drm_mm *mm)
109 struct drm_mm_node *node;
111 mtx_lock(&mm->unused_lock);
112 while (mm->num_unused < MM_UNUSED_TARGET) {
113 mtx_unlock(&mm->unused_lock);
114 node = malloc(sizeof(*node), DRM_MEM_MM, M_WAITOK);
115 mtx_lock(&mm->unused_lock);
117 if (unlikely(node == NULL)) {
118 int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
119 mtx_unlock(&mm->unused_lock);
123 list_add_tail(&node->fl_entry, &mm->unused_nodes);
125 mtx_unlock(&mm->unused_lock);
129 static int drm_mm_create_tail_node(struct drm_mm *mm,
131 unsigned long size, int atomic)
133 struct drm_mm_node *child;
135 child = drm_mm_kmalloc(mm, atomic);
136 if (unlikely(child == NULL))
141 child->start = start;
144 list_add_tail(&child->ml_entry, &mm->ml_entry);
145 list_add_tail(&child->fl_entry, &mm->fl_entry);
150 int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic)
152 struct list_head *tail_node;
153 struct drm_mm_node *entry;
155 tail_node = mm->ml_entry.prev;
156 entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
158 return drm_mm_create_tail_node(mm, entry->start + entry->size,
165 static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
169 struct drm_mm_node *child;
171 child = drm_mm_kmalloc(parent->mm, atomic);
172 if (unlikely(child == NULL))
175 INIT_LIST_HEAD(&child->fl_entry);
179 child->start = parent->start;
180 child->mm = parent->mm;
182 list_add_tail(&child->ml_entry, &parent->ml_entry);
183 INIT_LIST_HEAD(&child->fl_entry);
185 parent->size -= size;
186 parent->start += size;
191 struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
197 struct drm_mm_node *align_splitoff = NULL;
201 tmp = node->start % alignment;
205 drm_mm_split_at_start(node, alignment - tmp, atomic);
206 if (unlikely(align_splitoff == NULL))
210 if (node->size == size) {
211 list_del_init(&node->fl_entry);
214 node = drm_mm_split_at_start(node, size, atomic);
218 drm_mm_put_block(align_splitoff);
224 * Put a block. Merge with the previous and / or next block if they are free.
225 * Otherwise add to the free stack.
228 void drm_mm_put_block(struct drm_mm_node *cur)
231 struct drm_mm *mm = cur->mm;
232 struct list_head *cur_head = &cur->ml_entry;
233 struct list_head *root_head = &mm->ml_entry;
234 struct drm_mm_node *prev_node = NULL;
235 struct drm_mm_node *next_node;
239 if (cur_head->prev != root_head) {
241 list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
242 if (prev_node->free) {
243 prev_node->size += cur->size;
247 if (cur_head->next != root_head) {
249 list_entry(cur_head->next, struct drm_mm_node, ml_entry);
250 if (next_node->free) {
252 prev_node->size += next_node->size;
253 list_del(&next_node->ml_entry);
254 list_del(&next_node->fl_entry);
255 if (mm->num_unused < MM_UNUSED_TARGET) {
256 list_add(&next_node->fl_entry,
260 free(next_node, DRM_MEM_MM);
262 next_node->size += cur->size;
263 next_node->start = cur->start;
270 list_add(&cur->fl_entry, &mm->fl_entry);
272 list_del(&cur->ml_entry);
273 if (mm->num_unused < MM_UNUSED_TARGET) {
274 list_add(&cur->fl_entry, &mm->unused_nodes);
277 free(cur, DRM_MEM_MM);
281 struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
283 unsigned alignment, int best_match)
285 struct list_head *list;
286 const struct list_head *free_stack = &mm->fl_entry;
287 struct drm_mm_node *entry;
288 struct drm_mm_node *best;
289 unsigned long best_size;
295 list_for_each(list, free_stack) {
296 entry = list_entry(list, struct drm_mm_node, fl_entry);
299 if (entry->size < size)
303 register unsigned tmp = entry->start % alignment;
305 wasted += alignment - tmp;
308 if (entry->size >= size + wasted) {
311 if (size < best_size) {
313 best_size = entry->size;
321 int drm_mm_clean(struct drm_mm * mm)
323 struct list_head *head = &mm->ml_entry;
325 return (head->next->next == head);
328 int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
330 INIT_LIST_HEAD(&mm->ml_entry);
331 INIT_LIST_HEAD(&mm->fl_entry);
332 INIT_LIST_HEAD(&mm->unused_nodes);
334 mtx_init(&mm->unused_lock, "drm_unused", NULL, MTX_DEF);
336 /* XXX This could be non-atomic but gets called from a locked path */
337 return drm_mm_create_tail_node(mm, start, size, 1);
340 void drm_mm_takedown(struct drm_mm * mm)
342 struct list_head *bnode = mm->fl_entry.next;
343 struct drm_mm_node *entry;
344 struct drm_mm_node *next;
346 entry = list_entry(bnode, struct drm_mm_node, fl_entry);
348 if (entry->ml_entry.next != &mm->ml_entry ||
349 entry->fl_entry.next != &mm->fl_entry) {
350 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
354 list_del(&entry->fl_entry);
355 list_del(&entry->ml_entry);
356 free(entry, DRM_MEM_MM);
358 mtx_lock(&mm->unused_lock);
359 list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) {
360 list_del(&entry->fl_entry);
361 free(entry, DRM_MEM_MM);
364 mtx_unlock(&mm->unused_lock);
366 mtx_destroy(&mm->unused_lock);
368 KASSERT(mm->num_unused == 0, ("num_unused != 0"));