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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
David Howells760285e2012-10-02 18:01:07 +010035#include <drm/drmP.h>
36#include <drm/drm_hashtab.h>
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100037#include <linux/hash.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090038#include <linux/slab.h>
Paul Gortmaker2d1a8a42011-08-30 18:16:33 -040039#include <linux/export.h>
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100040
Dave Airliee0be4282007-07-12 10:26:44 +100041int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100042{
Chris Wilson7811bdd2011-01-26 18:33:25 +000043 unsigned int size = 1 << order;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100044
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100045 ht->order = order;
Dave Airliec1185cc2007-02-18 18:23:11 +110046 ht->table = NULL;
Chris Wilson7811bdd2011-01-26 18:33:25 +000047 if (size <= PAGE_SIZE / sizeof(*ht->table))
48 ht->table = kcalloc(size, sizeof(*ht->table), GFP_KERNEL);
49 else
50 ht->table = vzalloc(size*sizeof(*ht->table));
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100051 if (!ht->table) {
52 DRM_ERROR("Out of memory for hash table\n");
53 return -ENOMEM;
54 }
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100055 return 0;
56}
Jerome Glissef2cb5d82009-04-08 17:16:24 +020057EXPORT_SYMBOL(drm_ht_create);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100058
Dave Airliee0be4282007-07-12 10:26:44 +100059void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100060{
Dave Airliee0be4282007-07-12 10:26:44 +100061 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100062 struct hlist_head *h_list;
63 struct hlist_node *list;
64 unsigned int hashed_key;
65 int count = 0;
66
67 hashed_key = hash_long(key, ht->order);
68 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
69 h_list = &ht->table[hashed_key];
70 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +100071 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100072 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
73 }
74}
75
Dave Airliebc5f4522007-11-05 12:50:58 +100076static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100077 unsigned long key)
78{
Dave Airliee0be4282007-07-12 10:26:44 +100079 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100080 struct hlist_head *h_list;
81 struct hlist_node *list;
82 unsigned int hashed_key;
83
84 hashed_key = hash_long(key, ht->order);
85 h_list = &ht->table[hashed_key];
86 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +100087 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100088 if (entry->key == key)
89 return list;
90 if (entry->key > key)
91 break;
92 }
93 return NULL;
94}
95
96
Dave Airliee0be4282007-07-12 10:26:44 +100097int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100098{
Dave Airliee0be4282007-07-12 10:26:44 +100099 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000100 struct hlist_head *h_list;
101 struct hlist_node *list, *parent;
102 unsigned int hashed_key;
103 unsigned long key = item->key;
104
105 hashed_key = hash_long(key, ht->order);
106 h_list = &ht->table[hashed_key];
107 parent = NULL;
108 hlist_for_each(list, h_list) {
Dave Airliee0be4282007-07-12 10:26:44 +1000109 entry = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000110 if (entry->key == key)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000111 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000112 if (entry->key > key)
113 break;
114 parent = list;
115 }
116 if (parent) {
117 hlist_add_after(parent, &item->head);
118 } else {
119 hlist_add_head(&item->head, h_list);
120 }
121 return 0;
122}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800123EXPORT_SYMBOL(drm_ht_insert_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000124
125/*
Dave Airliebc5f4522007-11-05 12:50:58 +1000126 * Just insert an item and return any "bits" bit key that hasn't been
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000127 * used before.
128 */
Dave Airliee0be4282007-07-12 10:26:44 +1000129int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000130 unsigned long seed, int bits, int shift,
131 unsigned long add)
132{
133 int ret;
134 unsigned long mask = (1 << bits) - 1;
135 unsigned long first, unshifted_key;
136
137 unshifted_key = hash_long(seed, bits);
138 first = unshifted_key;
139 do {
140 item->key = (unshifted_key << shift) + add;
141 ret = drm_ht_insert_item(ht, item);
142 if (ret)
143 unshifted_key = (unshifted_key + 1) & mask;
144 } while(ret && (unshifted_key != first));
145
146 if (ret) {
147 DRM_ERROR("Available key bit space exhausted\n");
148 return -EINVAL;
149 }
150 return 0;
151}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200152EXPORT_SYMBOL(drm_ht_just_insert_please);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000153
Dave Airliee0be4282007-07-12 10:26:44 +1000154int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
155 struct drm_hash_item **item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000156{
157 struct hlist_node *list;
158
159 list = drm_ht_find_key(ht, key);
160 if (!list)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000161 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000162
Dave Airliee0be4282007-07-12 10:26:44 +1000163 *item = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000164 return 0;
165}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200166EXPORT_SYMBOL(drm_ht_find_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000167
Dave Airliee0be4282007-07-12 10:26:44 +1000168int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000169{
170 struct hlist_node *list;
171
172 list = drm_ht_find_key(ht, key);
173 if (list) {
174 hlist_del_init(list);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000175 return 0;
176 }
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000177 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000178}
179
Dave Airliee0be4282007-07-12 10:26:44 +1000180int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000181{
182 hlist_del_init(&item->head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000183 return 0;
184}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800185EXPORT_SYMBOL(drm_ht_remove_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000186
Dave Airliee0be4282007-07-12 10:26:44 +1000187void drm_ht_remove(struct drm_open_hash *ht)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000188{
189 if (ht->table) {
Chris Wilson7811bdd2011-01-26 18:33:25 +0000190 if ((PAGE_SIZE / sizeof(*ht->table)) >> ht->order)
Eric Anholt9a298b22009-03-24 12:23:04 -0700191 kfree(ht->table);
Chris Wilson7811bdd2011-01-26 18:33:25 +0000192 else
193 vfree(ht->table);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000194 ht->table = NULL;
195 }
196}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200197EXPORT_SYMBOL(drm_ht_remove);