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path: root/drivers/gpu/drm/drm_hashtab.c
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Diffstat (limited to 'drivers/gpu/drm/drm_hashtab.c')
-rw-r--r--drivers/gpu/drm/drm_hashtab.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c
new file mode 100644
index 000000000000..33160673a7b7
--- /dev/null
+++ b/drivers/gpu/drm/drm_hashtab.c
@@ -0,0 +1,202 @@
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 * Simple open hash tab implementation.
30 *
31 * Authors:
32 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
33 */
34
35#include "drmP.h"
36#include "drm_hashtab.h"
37#include <linux/hash.h>
38
39int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
40{
41 unsigned int i;
42
43 ht->size = 1 << order;
44 ht->order = order;
45 ht->fill = 0;
46 ht->table = NULL;
47 ht->use_vmalloc = ((ht->size * sizeof(*ht->table)) > PAGE_SIZE);
48 if (!ht->use_vmalloc) {
49 ht->table = drm_calloc(ht->size, sizeof(*ht->table),
50 DRM_MEM_HASHTAB);
51 }
52 if (!ht->table) {
53 ht->use_vmalloc = 1;
54 ht->table = vmalloc(ht->size*sizeof(*ht->table));
55 }
56 if (!ht->table) {
57 DRM_ERROR("Out of memory for hash table\n");
58 return -ENOMEM;
59 }
60 for (i=0; i< ht->size; ++i) {
61 INIT_HLIST_HEAD(&ht->table[i]);
62 }
63 return 0;
64}
65
66void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
67{
68 struct drm_hash_item *entry;
69 struct hlist_head *h_list;
70 struct hlist_node *list;
71 unsigned int hashed_key;
72 int count = 0;
73
74 hashed_key = hash_long(key, ht->order);
75 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
76 h_list = &ht->table[hashed_key];
77 hlist_for_each(list, h_list) {
78 entry = hlist_entry(list, struct drm_hash_item, head);
79 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
80 }
81}
82
83static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht,
84 unsigned long key)
85{
86 struct drm_hash_item *entry;
87 struct hlist_head *h_list;
88 struct hlist_node *list;
89 unsigned int hashed_key;
90
91 hashed_key = hash_long(key, ht->order);
92 h_list = &ht->table[hashed_key];
93 hlist_for_each(list, h_list) {
94 entry = hlist_entry(list, struct drm_hash_item, head);
95 if (entry->key == key)
96 return list;
97 if (entry->key > key)
98 break;
99 }
100 return NULL;
101}
102
103
104int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
105{
106 struct drm_hash_item *entry;
107 struct hlist_head *h_list;
108 struct hlist_node *list, *parent;
109 unsigned int hashed_key;
110 unsigned long key = item->key;
111
112 hashed_key = hash_long(key, ht->order);
113 h_list = &ht->table[hashed_key];
114 parent = NULL;
115 hlist_for_each(list, h_list) {
116 entry = hlist_entry(list, struct drm_hash_item, head);
117 if (entry->key == key)
118 return -EINVAL;
119 if (entry->key > key)
120 break;
121 parent = list;
122 }
123 if (parent) {
124 hlist_add_after(parent, &item->head);
125 } else {
126 hlist_add_head(&item->head, h_list);
127 }
128 return 0;
129}
130
131/*
132 * Just insert an item and return any "bits" bit key that hasn't been
133 * used before.
134 */
135int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
136 unsigned long seed, int bits, int shift,
137 unsigned long add)
138{
139 int ret;
140 unsigned long mask = (1 << bits) - 1;
141 unsigned long first, unshifted_key;
142
143 unshifted_key = hash_long(seed, bits);
144 first = unshifted_key;
145 do {
146 item->key = (unshifted_key << shift) + add;
147 ret = drm_ht_insert_item(ht, item);
148 if (ret)
149 unshifted_key = (unshifted_key + 1) & mask;
150 } while(ret && (unshifted_key != first));
151
152 if (ret) {
153 DRM_ERROR("Available key bit space exhausted\n");
154 return -EINVAL;
155 }
156 return 0;
157}
158
159int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
160 struct drm_hash_item **item)
161{
162 struct hlist_node *list;
163
164 list = drm_ht_find_key(ht, key);
165 if (!list)
166 return -EINVAL;
167
168 *item = hlist_entry(list, struct drm_hash_item, head);
169 return 0;
170}
171
172int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
173{
174 struct hlist_node *list;
175
176 list = drm_ht_find_key(ht, key);
177 if (list) {
178 hlist_del_init(list);
179 ht->fill--;
180 return 0;
181 }
182 return -EINVAL;
183}
184
185int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
186{
187 hlist_del_init(&item->head);
188 ht->fill--;
189 return 0;
190}
191
192void drm_ht_remove(struct drm_open_hash *ht)
193{
194 if (ht->table) {
195 if (ht->use_vmalloc)
196 vfree(ht->table);
197 else
198 drm_free(ht->table, ht->size * sizeof(*ht->table),
199 DRM_MEM_HASHTAB);
200 ht->table = NULL;
201 }
202}
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