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 __FBSDID("$FreeBSD: releng/9.0/sys/dev/drm/drm_hashtab.c 207118 2010-04-23 14:48:30Z rnoland $");
31
32 /*
33 * Simple open hash tab implementation.
34 *
35 * Authors:
36 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
37 */
38
39 #include "dev/drm/drmP.h"
40 #include "dev/drm/drm_hashtab.h"
41
42 #include <sys/hash.h>
43
44 int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
45 {
46 ht->size = 1 << order;
47 ht->order = order;
48 ht->table = NULL;
49 ht->table = hashinit_flags(ht->size, DRM_MEM_HASHTAB, &ht->mask,
50 HASH_NOWAIT);
51 if (!ht->table) {
52 DRM_ERROR("Out of memory for hash table\n");
53 return -ENOMEM;
54 }
55 return 0;
56 }
57
58 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
59 {
60 struct drm_hash_item *entry;
61 struct drm_hash_item_list *h_list;
62 unsigned int hashed_key;
63 int count = 0;
64
65 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
66 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
67 h_list = &ht->table[hashed_key & ht->mask];
68 LIST_FOREACH(entry, h_list, head)
69 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
70 }
71
72 static struct drm_hash_item *
73 drm_ht_find_key(struct drm_open_hash *ht, unsigned long key)
74 {
75 struct drm_hash_item *entry;
76 struct drm_hash_item_list *h_list;
77 unsigned int hashed_key;
78
79 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
80 h_list = &ht->table[hashed_key & ht->mask];
81 LIST_FOREACH(entry, h_list, head) {
82 if (entry->key == key)
83 return entry;
84 if (entry->key > key)
85 break;
86 }
87 return NULL;
88 }
89
90
91 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
92 {
93 struct drm_hash_item *entry, *parent;
94 struct drm_hash_item_list *h_list;
95 unsigned int hashed_key;
96 unsigned long key = item->key;
97
98 hashed_key = hash32_buf(&key, sizeof(key), ht->order);
99 h_list = &ht->table[hashed_key & ht->mask];
100 parent = NULL;
101 LIST_FOREACH(entry, h_list, head) {
102 if (entry->key == key)
103 return -EINVAL;
104 if (entry->key > key)
105 break;
106 parent = entry;
107 }
108 if (parent) {
109 LIST_INSERT_AFTER(parent, item, head);
110 } else {
111 LIST_INSERT_HEAD(h_list, item, head);
112 }
113 return 0;
114 }
115
116 /*
117 * Just insert an item and return any "bits" bit key that hasn't been
118 * used before.
119 */
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
144 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
145 struct drm_hash_item **item)
146 {
147 struct drm_hash_item *entry;
148
149 entry = drm_ht_find_key(ht, key);
150 if (!entry)
151 return -EINVAL;
152
153 *item = entry;
154 return 0;
155 }
156
157 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
158 {
159 struct drm_hash_item *entry;
160
161 entry = drm_ht_find_key(ht, key);
162 if (entry) {
163 LIST_REMOVE(entry, head);
164 return 0;
165 }
166 return -EINVAL;
167 }
168
169 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
170 {
171 LIST_REMOVE(item, head);
172 return 0;
173 }
174
175 void drm_ht_remove(struct drm_open_hash *ht)
176 {
177 if (ht->table) {
178 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask);
179 ht->table = NULL;
180 }
181 }
Cache object: dfee312d8ae78d0cde6be6ce387145ee
|