1 /**************************************************************************
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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.
27 * $FreeBSD: src/sys/dev/drm/drm_hashtab.c,v 1.1 2010/01/31 14:25:29 rnoland Exp $
28 **************************************************************************/
31 * Simple open hash tab implementation.
34 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
40 #include "drm_hashtab.h"
42 int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
44 ht->size = 1 << order;
47 ht->table = hashinit(ht->size, DRM_MEM_HASHTAB, &ht->mask);
49 DRM_ERROR("Out of memory for hash table\n");
55 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
57 struct drm_hash_item *entry;
58 struct drm_hash_item_list *h_list;
59 unsigned int hashed_key;
62 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
63 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
64 h_list = &ht->table[hashed_key & ht->mask];
65 LIST_FOREACH(entry, h_list, head)
66 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
69 static struct drm_hash_item *
70 drm_ht_find_key(struct drm_open_hash *ht, unsigned long key)
72 struct drm_hash_item *entry;
73 struct drm_hash_item_list *h_list;
74 unsigned int hashed_key;
76 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
77 h_list = &ht->table[hashed_key & ht->mask];
78 LIST_FOREACH(entry, h_list, head) {
79 if (entry->key == key)
88 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
90 struct drm_hash_item *entry, *parent;
91 struct drm_hash_item_list *h_list;
92 unsigned int hashed_key;
93 unsigned long key = item->key;
95 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
96 h_list = &ht->table[hashed_key & ht->mask];
98 LIST_FOREACH(entry, h_list, head) {
99 if (entry->key == key)
101 if (entry->key > key)
106 LIST_INSERT_AFTER(parent, item, head);
108 LIST_INSERT_HEAD(h_list, item, head);
114 * Just insert an item and return any "bits" bit key that hasn't been
117 int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
118 unsigned long seed, int bits, int shift,
122 unsigned long mask = (1 << bits) - 1;
123 unsigned long first, unshifted_key = 0;
125 unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key);
126 first = unshifted_key;
128 item->key = (unshifted_key << shift) + add;
129 ret = drm_ht_insert_item(ht, item);
131 unshifted_key = (unshifted_key + 1) & mask;
132 } while(ret && (unshifted_key != first));
135 DRM_ERROR("Available key bit space exhausted\n");
141 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
142 struct drm_hash_item **item)
144 struct drm_hash_item *entry;
146 entry = drm_ht_find_key(ht, key);
154 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
156 struct drm_hash_item *entry;
158 entry = drm_ht_find_key(ht, key);
160 LIST_REMOVE(entry, head);
166 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
168 LIST_REMOVE(item, head);
172 void drm_ht_remove(struct drm_open_hash *ht)
175 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask);