2 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial portions
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
20 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
23 * USE OR OTHER DEALINGS IN THE SOFTWARE.
27 * Simple open hash tab implementation.
30 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
33 #include <linux/export.h>
34 #include <linux/hash.h>
36 #include <linux/rculist.h>
37 #include <linux/slab.h>
38 #include <linux/vmalloc.h>
40 #include <drm/drm_print.h>
42 #include "vmwgfx_hashtab.h"
44 int vmwgfx_ht_create(struct vmwgfx_open_hash *ht, unsigned int order)
46 unsigned int size = 1 << order;
50 if (size <= PAGE_SIZE / sizeof(*ht->table))
51 ht->table = kcalloc(size, sizeof(*ht->table), GFP_KERNEL);
53 ht->table = vzalloc(array_size(size, sizeof(*ht->table)));
55 DRM_ERROR("Out of memory for hash table\n");
61 void vmwgfx_ht_verbose_list(struct vmwgfx_open_hash *ht, unsigned long key)
63 struct vmwgfx_hash_item *entry;
64 struct hlist_head *h_list;
65 unsigned int hashed_key;
68 hashed_key = hash_long(key, ht->order);
69 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
70 h_list = &ht->table[hashed_key];
71 hlist_for_each_entry(entry, h_list, head)
72 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
75 static struct hlist_node *vmwgfx_ht_find_key(struct vmwgfx_open_hash *ht, unsigned long key)
77 struct vmwgfx_hash_item *entry;
78 struct hlist_head *h_list;
79 unsigned int hashed_key;
81 hashed_key = hash_long(key, ht->order);
82 h_list = &ht->table[hashed_key];
83 hlist_for_each_entry(entry, h_list, head) {
84 if (entry->key == key)
92 static struct hlist_node *vmwgfx_ht_find_key_rcu(struct vmwgfx_open_hash *ht, unsigned long key)
94 struct vmwgfx_hash_item *entry;
95 struct hlist_head *h_list;
96 unsigned int hashed_key;
98 hashed_key = hash_long(key, ht->order);
99 h_list = &ht->table[hashed_key];
100 hlist_for_each_entry_rcu(entry, h_list, head) {
101 if (entry->key == key)
103 if (entry->key > key)
109 int vmwgfx_ht_insert_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item)
111 struct vmwgfx_hash_item *entry;
112 struct hlist_head *h_list;
113 struct hlist_node *parent;
114 unsigned int hashed_key;
115 unsigned long key = item->key;
117 hashed_key = hash_long(key, ht->order);
118 h_list = &ht->table[hashed_key];
120 hlist_for_each_entry(entry, h_list, head) {
121 if (entry->key == key)
123 if (entry->key > key)
125 parent = &entry->head;
128 hlist_add_behind_rcu(&item->head, parent);
130 hlist_add_head_rcu(&item->head, h_list);
135 * Just insert an item and return any "bits" bit key that hasn't been
138 int vmwgfx_ht_just_insert_please(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item,
139 unsigned long seed, int bits, int shift,
143 unsigned long mask = (1UL << bits) - 1;
144 unsigned long first, unshifted_key;
146 unshifted_key = hash_long(seed, bits);
147 first = unshifted_key;
149 item->key = (unshifted_key << shift) + add;
150 ret = vmwgfx_ht_insert_item(ht, item);
152 unshifted_key = (unshifted_key + 1) & mask;
153 } while (ret && (unshifted_key != first));
156 DRM_ERROR("Available key bit space exhausted\n");
162 int vmwgfx_ht_find_item(struct vmwgfx_open_hash *ht, unsigned long key,
163 struct vmwgfx_hash_item **item)
165 struct hlist_node *list;
167 list = vmwgfx_ht_find_key_rcu(ht, key);
171 *item = hlist_entry(list, struct vmwgfx_hash_item, head);
175 int vmwgfx_ht_remove_key(struct vmwgfx_open_hash *ht, unsigned long key)
177 struct hlist_node *list;
179 list = vmwgfx_ht_find_key(ht, key);
181 hlist_del_init_rcu(list);
187 int vmwgfx_ht_remove_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item)
189 hlist_del_init_rcu(&item->head);
193 void vmwgfx_ht_remove(struct vmwgfx_open_hash *ht)