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3a1bd924 TH |
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: | |
96de0e25 | 32 | * Thomas Hellström <thomas-at-tungstengraphics-dot-com> |
3a1bd924 TH |
33 | */ |
34 | ||
760285e7 DH |
35 | #include <drm/drmP.h> |
36 | #include <drm/drm_hashtab.h> | |
3a1bd924 | 37 | #include <linux/hash.h> |
5a0e3ad6 | 38 | #include <linux/slab.h> |
2d1a8a48 | 39 | #include <linux/export.h> |
3a1bd924 | 40 | |
e0be428e | 41 | int drm_ht_create(struct drm_open_hash *ht, unsigned int order) |
3a1bd924 | 42 | { |
7811bddb | 43 | unsigned int size = 1 << order; |
3a1bd924 | 44 | |
3a1bd924 | 45 | ht->order = order; |
c1185ccd | 46 | ht->table = NULL; |
7811bddb CW |
47 | if (size <= PAGE_SIZE / sizeof(*ht->table)) |
48 | ht->table = kcalloc(size, sizeof(*ht->table), GFP_KERNEL); | |
49 | else | |
50 | ht->table = vzalloc(size*sizeof(*ht->table)); | |
3a1bd924 TH |
51 | if (!ht->table) { |
52 | DRM_ERROR("Out of memory for hash table\n"); | |
53 | return -ENOMEM; | |
54 | } | |
3a1bd924 TH |
55 | return 0; |
56 | } | |
f2cb5d86 | 57 | EXPORT_SYMBOL(drm_ht_create); |
3a1bd924 | 58 | |
e0be428e | 59 | void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key) |
3a1bd924 | 60 | { |
e0be428e | 61 | struct drm_hash_item *entry; |
3a1bd924 | 62 | struct hlist_head *h_list; |
3a1bd924 TH |
63 | unsigned int hashed_key; |
64 | int count = 0; | |
65 | ||
66 | hashed_key = hash_long(key, ht->order); | |
67 | DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); | |
68 | h_list = &ht->table[hashed_key]; | |
b67bfe0d | 69 | hlist_for_each_entry(entry, h_list, head) |
3a1bd924 | 70 | DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); |
3a1bd924 TH |
71 | } |
72 | ||
bc5f4523 | 73 | static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht, |
3a1bd924 TH |
74 | unsigned long key) |
75 | { | |
e0be428e | 76 | struct drm_hash_item *entry; |
3a1bd924 | 77 | struct hlist_head *h_list; |
3a1bd924 TH |
78 | unsigned int hashed_key; |
79 | ||
80 | hashed_key = hash_long(key, ht->order); | |
81 | h_list = &ht->table[hashed_key]; | |
b67bfe0d | 82 | hlist_for_each_entry(entry, h_list, head) { |
3a1bd924 | 83 | if (entry->key == key) |
b67bfe0d | 84 | return &entry->head; |
3a1bd924 TH |
85 | if (entry->key > key) |
86 | break; | |
87 | } | |
88 | return NULL; | |
89 | } | |
90 | ||
384cc2f9 TH |
91 | static struct hlist_node *drm_ht_find_key_rcu(struct drm_open_hash *ht, |
92 | unsigned long key) | |
93 | { | |
94 | struct drm_hash_item *entry; | |
95 | struct hlist_head *h_list; | |
384cc2f9 TH |
96 | unsigned int hashed_key; |
97 | ||
98 | hashed_key = hash_long(key, ht->order); | |
99 | h_list = &ht->table[hashed_key]; | |
b67bfe0d | 100 | hlist_for_each_entry_rcu(entry, h_list, head) { |
384cc2f9 | 101 | if (entry->key == key) |
b67bfe0d | 102 | return &entry->head; |
384cc2f9 TH |
103 | if (entry->key > key) |
104 | break; | |
105 | } | |
106 | return NULL; | |
107 | } | |
3a1bd924 | 108 | |
e0be428e | 109 | int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) |
3a1bd924 | 110 | { |
e0be428e | 111 | struct drm_hash_item *entry; |
3a1bd924 | 112 | struct hlist_head *h_list; |
b67bfe0d | 113 | struct hlist_node *parent; |
3a1bd924 TH |
114 | unsigned int hashed_key; |
115 | unsigned long key = item->key; | |
116 | ||
117 | hashed_key = hash_long(key, ht->order); | |
118 | h_list = &ht->table[hashed_key]; | |
119 | parent = NULL; | |
b67bfe0d | 120 | hlist_for_each_entry(entry, h_list, head) { |
3a1bd924 | 121 | if (entry->key == key) |
47cc1409 | 122 | return -EINVAL; |
3a1bd924 TH |
123 | if (entry->key > key) |
124 | break; | |
b67bfe0d | 125 | parent = &entry->head; |
3a1bd924 TH |
126 | } |
127 | if (parent) { | |
1d023284 | 128 | hlist_add_behind_rcu(&item->head, parent); |
3a1bd924 | 129 | } else { |
d7144556 | 130 | hlist_add_head_rcu(&item->head, h_list); |
3a1bd924 TH |
131 | } |
132 | return 0; | |
133 | } | |
a2c0a97b | 134 | EXPORT_SYMBOL(drm_ht_insert_item); |
3a1bd924 TH |
135 | |
136 | /* | |
bc5f4523 | 137 | * Just insert an item and return any "bits" bit key that hasn't been |
3a1bd924 TH |
138 | * used before. |
139 | */ | |
e0be428e | 140 | int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item, |
3a1bd924 TH |
141 | unsigned long seed, int bits, int shift, |
142 | unsigned long add) | |
143 | { | |
144 | int ret; | |
145 | unsigned long mask = (1 << bits) - 1; | |
146 | unsigned long first, unshifted_key; | |
147 | ||
148 | unshifted_key = hash_long(seed, bits); | |
149 | first = unshifted_key; | |
150 | do { | |
151 | item->key = (unshifted_key << shift) + add; | |
152 | ret = drm_ht_insert_item(ht, item); | |
153 | if (ret) | |
154 | unshifted_key = (unshifted_key + 1) & mask; | |
155 | } while(ret && (unshifted_key != first)); | |
156 | ||
157 | if (ret) { | |
158 | DRM_ERROR("Available key bit space exhausted\n"); | |
159 | return -EINVAL; | |
160 | } | |
161 | return 0; | |
162 | } | |
f2cb5d86 | 163 | EXPORT_SYMBOL(drm_ht_just_insert_please); |
3a1bd924 | 164 | |
e0be428e DA |
165 | int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, |
166 | struct drm_hash_item **item) | |
3a1bd924 TH |
167 | { |
168 | struct hlist_node *list; | |
169 | ||
384cc2f9 | 170 | list = drm_ht_find_key_rcu(ht, key); |
3a1bd924 | 171 | if (!list) |
47cc1409 | 172 | return -EINVAL; |
3a1bd924 | 173 | |
e0be428e | 174 | *item = hlist_entry(list, struct drm_hash_item, head); |
3a1bd924 TH |
175 | return 0; |
176 | } | |
f2cb5d86 | 177 | EXPORT_SYMBOL(drm_ht_find_item); |
3a1bd924 | 178 | |
e0be428e | 179 | int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key) |
3a1bd924 TH |
180 | { |
181 | struct hlist_node *list; | |
182 | ||
183 | list = drm_ht_find_key(ht, key); | |
184 | if (list) { | |
d7144556 | 185 | hlist_del_init_rcu(list); |
3a1bd924 TH |
186 | return 0; |
187 | } | |
47cc1409 | 188 | return -EINVAL; |
3a1bd924 TH |
189 | } |
190 | ||
e0be428e | 191 | int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) |
3a1bd924 | 192 | { |
d7144556 | 193 | hlist_del_init_rcu(&item->head); |
3a1bd924 TH |
194 | return 0; |
195 | } | |
a2c0a97b | 196 | EXPORT_SYMBOL(drm_ht_remove_item); |
3a1bd924 | 197 | |
e0be428e | 198 | void drm_ht_remove(struct drm_open_hash *ht) |
3a1bd924 TH |
199 | { |
200 | if (ht->table) { | |
1d5cfdb0 | 201 | kvfree(ht->table); |
3a1bd924 TH |
202 | ht->table = NULL; |
203 | } | |
204 | } | |
f2cb5d86 | 205 | EXPORT_SYMBOL(drm_ht_remove); |