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 #include <sys/cdefs.h>
30 /*
31 * Simple open hash tab implementation.
32 *
33 * Authors:
34 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
35 */
36
37 #include <dev/drm2/drmP.h>
38 #include <dev/drm2/drm_hashtab.h>
39
40 #include <sys/hash.h>
41
drm_ht_create(struct drm_open_hash * ht,unsigned int order)42 int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
43 {
44 ht->size = 1 << order;
45 ht->order = order;
46 ht->table = NULL;
47 ht->table = hashinit_flags(ht->size, DRM_MEM_HASHTAB, &ht->mask,
48 HASH_NOWAIT);
49 if (!ht->table) {
50 DRM_ERROR("Out of memory for hash table\n");
51 return -ENOMEM;
52 }
53 return 0;
54 }
55 EXPORT_SYMBOL(drm_ht_create);
56
drm_ht_verbose_list(struct drm_open_hash * ht,unsigned long key)57 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
58 {
59 struct drm_hash_item *entry;
60 struct drm_hash_item_list *h_list;
61 unsigned int hashed_key;
62 int count = 0;
63
64 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
65 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
66 h_list = &ht->table[hashed_key & ht->mask];
67 LIST_FOREACH(entry, h_list, head)
68 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
69 }
70
drm_ht_find_key(struct drm_open_hash * ht,unsigned long key)71 static struct drm_hash_item *drm_ht_find_key(struct drm_open_hash *ht,
72 unsigned long key)
73 {
74 struct drm_hash_item *entry;
75 struct drm_hash_item_list *h_list;
76 unsigned int hashed_key;
77
78 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
79 h_list = &ht->table[hashed_key & ht->mask];
80 LIST_FOREACH(entry, h_list, head) {
81 if (entry->key == key)
82 return entry;
83 if (entry->key > key)
84 break;
85 }
86 return NULL;
87 }
88
89
drm_ht_insert_item(struct drm_open_hash * ht,struct drm_hash_item * item)90 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
91 {
92 struct drm_hash_item *entry, *parent;
93 struct drm_hash_item_list *h_list;
94 unsigned int hashed_key;
95 unsigned long key = item->key;
96
97 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
98 h_list = &ht->table[hashed_key & ht->mask];
99 parent = NULL;
100 LIST_FOREACH(entry, h_list, head) {
101 if (entry->key == key)
102 return -EINVAL;
103 if (entry->key > key)
104 break;
105 parent = entry;
106 }
107 if (parent) {
108 LIST_INSERT_AFTER(parent, item, head);
109 } else {
110 LIST_INSERT_HEAD(h_list, item, head);
111 }
112 return 0;
113 }
114 EXPORT_SYMBOL(drm_ht_insert_item);
115
116 /*
117 * Just insert an item and return any "bits" bit key that hasn't been
118 * used before.
119 */
drm_ht_just_insert_please(struct drm_open_hash * ht,struct drm_hash_item * item,unsigned long seed,int bits,int shift,unsigned long add)120 int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
121 unsigned long seed, int bits, int shift,
122 unsigned long add)
123 {
124 int ret;
125 unsigned long mask = (1 << bits) - 1;
126 unsigned long first, unshifted_key = 0;
127
128 unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key);
129 first = unshifted_key;
130 do {
131 item->key = (unshifted_key << shift) + add;
132 ret = drm_ht_insert_item(ht, item);
133 if (ret)
134 unshifted_key = (unshifted_key + 1) & mask;
135 } while(ret && (unshifted_key != first));
136
137 if (ret) {
138 DRM_ERROR("Available key bit space exhausted\n");
139 return -EINVAL;
140 }
141 return 0;
142 }
143 EXPORT_SYMBOL(drm_ht_just_insert_please);
144
drm_ht_find_item(struct drm_open_hash * ht,unsigned long key,struct drm_hash_item ** item)145 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
146 struct drm_hash_item **item)
147 {
148 struct drm_hash_item *entry;
149
150 entry = drm_ht_find_key(ht, key);
151 if (!entry)
152 return -EINVAL;
153
154 *item = entry;
155 return 0;
156 }
157 EXPORT_SYMBOL(drm_ht_find_item);
158
drm_ht_remove_key(struct drm_open_hash * ht,unsigned long key)159 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
160 {
161 struct drm_hash_item *entry;
162
163 entry = drm_ht_find_key(ht, key);
164 if (entry) {
165 LIST_REMOVE(entry, head);
166 return 0;
167 }
168 return -EINVAL;
169 }
170
drm_ht_remove_item(struct drm_open_hash * ht,struct drm_hash_item * item)171 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
172 {
173 LIST_REMOVE(item, head);
174 return 0;
175 }
176 EXPORT_SYMBOL(drm_ht_remove_item);
177
drm_ht_remove(struct drm_open_hash * ht)178 void drm_ht_remove(struct drm_open_hash *ht)
179 {
180 if (ht->table) {
181 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask);
182 ht->table = NULL;
183 }
184 }
185 EXPORT_SYMBOL(drm_ht_remove);
186