Rev 5060 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4075 | Serge | 1 | /************************************************************************** |
| 2 | * |
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| 3 | * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA. |
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| 4 | * All Rights Reserved. |
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| 5 | * |
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| 6 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 7 | * copy of this software and associated documentation files (the |
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| 8 | * "Software"), to deal in the Software without restriction, including |
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| 9 | * without limitation the rights to use, copy, modify, merge, publish, |
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| 10 | * distribute, sub license, and/or sell copies of the Software, and to |
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| 11 | * permit persons to whom the Software is furnished to do so, subject to |
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| 12 | * the following conditions: |
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| 13 | * |
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| 14 | * The above copyright notice and this permission notice (including the |
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| 15 | * next paragraph) shall be included in all copies or substantial portions |
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| 16 | * of the Software. |
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| 17 | * |
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| 18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 20 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
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| 21 | * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
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| 22 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
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| 23 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
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| 24 | * USE OR OTHER DEALINGS IN THE SOFTWARE. |
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| 25 | * |
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| 26 | * |
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| 27 | **************************************************************************/ |
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| 28 | /* |
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| 29 | * Simple open hash tab implementation. |
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| 30 | * |
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| 31 | * Authors: |
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| 32 | * Thomas Hellström |
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| 33 | */ |
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| 34 | |||
| 35 | #include |
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| 36 | #include |
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| 37 | #include |
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| 38 | #include |
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| 39 | #include |
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| 40 | |||
| 41 | int drm_ht_create(struct drm_open_hash *ht, unsigned int order) |
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| 42 | { |
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| 43 | unsigned int size = 1 << order; |
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| 44 | |||
| 45 | ht->order = order; |
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| 46 | ht->table = NULL; |
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| 47 | ht->table = kcalloc(size, sizeof(*ht->table), GFP_KERNEL); |
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| 48 | if (!ht->table) { |
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| 49 | DRM_ERROR("Out of memory for hash table\n"); |
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| 50 | return -ENOMEM; |
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| 51 | } |
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| 52 | return 0; |
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| 53 | } |
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| 54 | EXPORT_SYMBOL(drm_ht_create); |
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| 55 | |||
| 56 | void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key) |
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| 57 | { |
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| 58 | struct drm_hash_item *entry; |
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| 59 | struct hlist_head *h_list; |
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| 60 | unsigned int hashed_key; |
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| 61 | int count = 0; |
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| 62 | |||
| 63 | hashed_key = hash_long(key, ht->order); |
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| 64 | DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); |
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| 65 | h_list = &ht->table[hashed_key]; |
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| 66 | hlist_for_each_entry(entry, h_list, head) |
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| 67 | DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); |
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| 68 | } |
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| 69 | |||
| 70 | static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht, |
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| 71 | unsigned long key) |
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| 72 | { |
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| 73 | struct drm_hash_item *entry; |
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| 74 | struct hlist_head *h_list; |
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| 75 | unsigned int hashed_key; |
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| 76 | |||
| 77 | hashed_key = hash_long(key, ht->order); |
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| 78 | h_list = &ht->table[hashed_key]; |
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| 79 | hlist_for_each_entry(entry, h_list, head) { |
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| 80 | if (entry->key == key) |
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| 81 | return &entry->head; |
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| 82 | if (entry->key > key) |
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| 83 | break; |
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| 84 | } |
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| 85 | return NULL; |
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| 86 | } |
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| 87 | |||
| 88 | static struct hlist_node *drm_ht_find_key_rcu(struct drm_open_hash *ht, |
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| 89 | unsigned long key) |
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| 90 | { |
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| 91 | struct drm_hash_item *entry; |
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| 92 | struct hlist_head *h_list; |
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| 93 | unsigned int hashed_key; |
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| 94 | |||
| 95 | hashed_key = hash_long(key, ht->order); |
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| 96 | h_list = &ht->table[hashed_key]; |
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| 97 | hlist_for_each_entry_rcu(entry, h_list, head) { |
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| 98 | if (entry->key == key) |
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| 99 | return &entry->head; |
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| 100 | if (entry->key > key) |
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| 101 | break; |
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| 102 | } |
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| 103 | return NULL; |
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| 104 | } |
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| 105 | |||
| 106 | int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) |
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| 107 | { |
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| 108 | struct drm_hash_item *entry; |
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| 109 | struct hlist_head *h_list; |
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| 110 | struct hlist_node *parent; |
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| 111 | unsigned int hashed_key; |
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| 112 | unsigned long key = item->key; |
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| 113 | |||
| 114 | hashed_key = hash_long(key, ht->order); |
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| 115 | h_list = &ht->table[hashed_key]; |
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| 116 | parent = NULL; |
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| 117 | hlist_for_each_entry(entry, h_list, head) { |
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| 118 | if (entry->key == key) |
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| 119 | return -EINVAL; |
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| 120 | if (entry->key > key) |
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| 121 | break; |
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| 122 | parent = &entry->head; |
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| 123 | } |
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| 124 | if (parent) { |
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| 5060 | serge | 125 | hlist_add_behind_rcu(&item->head, parent); |
| 4075 | Serge | 126 | } else { |
| 127 | hlist_add_head_rcu(&item->head, h_list); |
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| 128 | } |
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| 129 | return 0; |
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| 130 | } |
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| 131 | EXPORT_SYMBOL(drm_ht_insert_item); |
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| 132 | |||
| 133 | /* |
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| 134 | * Just insert an item and return any "bits" bit key that hasn't been |
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| 135 | * used before. |
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| 136 | */ |
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| 137 | int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item, |
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| 138 | unsigned long seed, int bits, int shift, |
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| 139 | unsigned long add) |
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| 140 | { |
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| 141 | int ret; |
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| 142 | unsigned long mask = (1 << bits) - 1; |
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| 143 | unsigned long first, unshifted_key; |
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| 144 | |||
| 145 | unshifted_key = hash_long(seed, bits); |
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| 146 | first = unshifted_key; |
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| 147 | do { |
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| 148 | item->key = (unshifted_key << shift) + add; |
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| 149 | ret = drm_ht_insert_item(ht, item); |
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| 150 | if (ret) |
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| 151 | unshifted_key = (unshifted_key + 1) & mask; |
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| 152 | } while(ret && (unshifted_key != first)); |
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| 153 | |||
| 154 | if (ret) { |
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| 155 | DRM_ERROR("Available key bit space exhausted\n"); |
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| 156 | return -EINVAL; |
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| 157 | } |
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| 158 | return 0; |
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| 159 | } |
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| 160 | EXPORT_SYMBOL(drm_ht_just_insert_please); |
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| 161 | |||
| 162 | int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, |
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| 163 | struct drm_hash_item **item) |
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| 164 | { |
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| 165 | struct hlist_node *list; |
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| 166 | |||
| 167 | list = drm_ht_find_key_rcu(ht, key); |
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| 168 | if (!list) |
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| 169 | return -EINVAL; |
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| 170 | |||
| 171 | *item = hlist_entry(list, struct drm_hash_item, head); |
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| 172 | return 0; |
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| 173 | } |
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| 174 | EXPORT_SYMBOL(drm_ht_find_item); |
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| 175 | |||
| 176 | int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key) |
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| 177 | { |
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| 178 | struct hlist_node *list; |
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| 179 | |||
| 180 | list = drm_ht_find_key(ht, key); |
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| 181 | if (list) { |
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| 182 | hlist_del_init_rcu(list); |
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| 183 | return 0; |
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| 184 | } |
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| 185 | return -EINVAL; |
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| 186 | } |
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| 187 | |||
| 188 | int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) |
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| 189 | { |
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| 190 | hlist_del_init_rcu(&item->head); |
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| 191 | return 0; |
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| 192 | } |
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| 193 | EXPORT_SYMBOL(drm_ht_remove_item); |
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| 194 | |||
| 195 | void drm_ht_remove(struct drm_open_hash *ht) |
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| 196 | { |
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| 197 | if (ht->table) { |
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| 198 | kfree(ht->table); |
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| 199 | ht->table = NULL; |
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| 200 | } |
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| 201 | } |
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| 202 | EXPORT_SYMBOL(drm_ht_remove); |