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Thomas Hellstrom3a1bd922006-08-07 21:30:28 +10001/**************************************************************************
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:
Jan Engelhardt96de0e22007-10-19 23:21:04 +020032 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100033 */
34
35#include "drmP.h"
36#include "drm_hashtab.h"
37#include <linux/hash.h>
38
Dave Airliee0be4282007-07-12 10:26:44 +100039int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100040{
41 unsigned int i;
42
43 ht->size = 1 << order;
44 ht->order = order;
45 ht->fill = 0;
Dave Airliec1185cc2007-02-18 18:23:11 +110046 ht->table = NULL;
Dave Airliecd839d02007-02-18 17:14:09 +110047 ht->use_vmalloc = ((ht->size * sizeof(*ht->table)) > PAGE_SIZE);
48 if (!ht->use_vmalloc) {
Eric Anholt9a298b22009-03-24 12:23:04 -070049 ht->table = kcalloc(ht->size, sizeof(*ht->table), GFP_KERNEL);
Dave Airliecd839d02007-02-18 17:14:09 +110050 }
51 if (!ht->table) {
52 ht->use_vmalloc = 1;
53 ht->table = vmalloc(ht->size*sizeof(*ht->table));
54 }
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100055 if (!ht->table) {
56 DRM_ERROR("Out of memory for hash table\n");
57 return -ENOMEM;
58 }
59 for (i=0; i< ht->size; ++i) {
60 INIT_HLIST_HEAD(&ht->table[i]);
61 }
62 return 0;
63}
Jerome Glissef2cb5d82009-04-08 17:16:24 +020064EXPORT_SYMBOL(drm_ht_create);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100065
Dave Airliee0be4282007-07-12 10:26:44 +100066void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100067{
Dave Airliee0be4282007-07-12 10:26:44 +100068 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100069 struct hlist_head *h_list;
70 struct hlist_node *list;
71 unsigned int hashed_key;
72 int count = 0;
73
74 hashed_key = hash_long(key, ht->order);
75 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
76 h_list = &ht->table[hashed_key];
77 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +100078 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100079 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
80 }
81}
82
Dave Airliebc5f4522007-11-05 12:50:58 +100083static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100084 unsigned long key)
85{
Dave Airliee0be4282007-07-12 10:26:44 +100086 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100087 struct hlist_head *h_list;
88 struct hlist_node *list;
89 unsigned int hashed_key;
90
91 hashed_key = hash_long(key, ht->order);
92 h_list = &ht->table[hashed_key];
93 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +100094 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100095 if (entry->key == key)
96 return list;
97 if (entry->key > key)
98 break;
99 }
100 return NULL;
101}
102
103
Dave Airliee0be4282007-07-12 10:26:44 +1000104int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000105{
Dave Airliee0be4282007-07-12 10:26:44 +1000106 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000107 struct hlist_head *h_list;
108 struct hlist_node *list, *parent;
109 unsigned int hashed_key;
110 unsigned long key = item->key;
111
112 hashed_key = hash_long(key, ht->order);
113 h_list = &ht->table[hashed_key];
114 parent = NULL;
115 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +1000116 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000117 if (entry->key == key)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000118 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000119 if (entry->key > key)
120 break;
121 parent = list;
122 }
123 if (parent) {
124 hlist_add_after(parent, &item->head);
125 } else {
126 hlist_add_head(&item->head, h_list);
127 }
128 return 0;
129}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800130EXPORT_SYMBOL(drm_ht_insert_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000131
132/*
Dave Airliebc5f4522007-11-05 12:50:58 +1000133 * Just insert an item and return any "bits" bit key that hasn't been
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000134 * used before.
135 */
Dave Airliee0be4282007-07-12 10:26:44 +1000136int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000137 unsigned long seed, int bits, int shift,
138 unsigned long add)
139{
140 int ret;
141 unsigned long mask = (1 << bits) - 1;
142 unsigned long first, unshifted_key;
143
144 unshifted_key = hash_long(seed, bits);
145 first = unshifted_key;
146 do {
147 item->key = (unshifted_key << shift) + add;
148 ret = drm_ht_insert_item(ht, item);
149 if (ret)
150 unshifted_key = (unshifted_key + 1) & mask;
151 } while(ret && (unshifted_key != first));
152
153 if (ret) {
154 DRM_ERROR("Available key bit space exhausted\n");
155 return -EINVAL;
156 }
157 return 0;
158}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200159EXPORT_SYMBOL(drm_ht_just_insert_please);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000160
Dave Airliee0be4282007-07-12 10:26:44 +1000161int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
162 struct drm_hash_item **item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000163{
164 struct hlist_node *list;
165
166 list = drm_ht_find_key(ht, key);
167 if (!list)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000168 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000169
Dave Airliee0be4282007-07-12 10:26:44 +1000170 *item = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000171 return 0;
172}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200173EXPORT_SYMBOL(drm_ht_find_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000174
Dave Airliee0be4282007-07-12 10:26:44 +1000175int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000176{
177 struct hlist_node *list;
178
179 list = drm_ht_find_key(ht, key);
180 if (list) {
181 hlist_del_init(list);
182 ht->fill--;
183 return 0;
184 }
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000185 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000186}
187
Dave Airliee0be4282007-07-12 10:26:44 +1000188int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000189{
190 hlist_del_init(&item->head);
191 ht->fill--;
192 return 0;
193}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800194EXPORT_SYMBOL(drm_ht_remove_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000195
Dave Airliee0be4282007-07-12 10:26:44 +1000196void drm_ht_remove(struct drm_open_hash *ht)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000197{
198 if (ht->table) {
Dave Airliecd839d02007-02-18 17:14:09 +1100199 if (ht->use_vmalloc)
200 vfree(ht->table);
201 else
Eric Anholt9a298b22009-03-24 12:23:04 -0700202 kfree(ht->table);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000203 ht->table = NULL;
204 }
205}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200206EXPORT_SYMBOL(drm_ht_remove);