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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;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100063 unsigned int hashed_key;
64 int count = 0;
65
66 hashed_key = hash_long(key, ht->order);
67 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
68 h_list = &ht->table[hashed_key];
Sasha Levinb67bfe02013-02-27 17:06:00 -080069 hlist_for_each_entry(entry, h_list, head)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100070 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100071}
72
Dave Airliebc5f4522007-11-05 12:50:58 +100073static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100074 unsigned long key)
75{
Dave Airliee0be4282007-07-12 10:26:44 +100076 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100077 struct hlist_head *h_list;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +100078 unsigned int hashed_key;
79
80 hashed_key = hash_long(key, ht->order);
81 h_list = &ht->table[hashed_key];
Sasha Levinb67bfe02013-02-27 17:06:00 -080082 hlist_for_each_entry(entry, h_list, head) {
Thomas Hellstrom384cc2f2012-11-20 12:16:47 +000083 if (entry->key == key)
Sasha Levinb67bfe02013-02-27 17:06:00 -080084 return &entry->head;
Thomas Hellstrom384cc2f2012-11-20 12:16:47 +000085 if (entry->key > key)
86 break;
87 }
88 return NULL;
89}
90
91static struct hlist_node *drm_ht_find_key_rcu(struct drm_open_hash *ht,
92 unsigned long key)
93{
94 struct drm_hash_item *entry;
95 struct hlist_head *h_list;
Thomas Hellstrom384cc2f2012-11-20 12:16:47 +000096 unsigned int hashed_key;
97
98 hashed_key = hash_long(key, ht->order);
99 h_list = &ht->table[hashed_key];
Sasha Levinb67bfe02013-02-27 17:06:00 -0800100 hlist_for_each_entry_rcu(entry, h_list, head) {
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000101 if (entry->key == key)
Sasha Levinb67bfe02013-02-27 17:06:00 -0800102 return &entry->head;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000103 if (entry->key > key)
104 break;
105 }
106 return NULL;
107}
108
Dave Airliee0be4282007-07-12 10:26:44 +1000109int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000110{
Dave Airliee0be4282007-07-12 10:26:44 +1000111 struct drm_hash_item *entry;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000112 struct hlist_head *h_list;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800113 struct hlist_node *parent;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000114 unsigned int hashed_key;
115 unsigned long key = item->key;
116
117 hashed_key = hash_long(key, ht->order);
118 h_list = &ht->table[hashed_key];
119 parent = NULL;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800120 hlist_for_each_entry(entry, h_list, head) {
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000121 if (entry->key == key)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000122 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000123 if (entry->key > key)
124 break;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800125 parent = &entry->head;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000126 }
127 if (parent) {
Thomas Hellstromd7144552012-11-06 11:31:48 +0000128 hlist_add_after_rcu(parent, &item->head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000129 } else {
Thomas Hellstromd7144552012-11-06 11:31:48 +0000130 hlist_add_head_rcu(&item->head, h_list);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000131 }
132 return 0;
133}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800134EXPORT_SYMBOL(drm_ht_insert_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000135
136/*
Dave Airliebc5f4522007-11-05 12:50:58 +1000137 * Just insert an item and return any "bits" bit key that hasn't been
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000138 * used before.
139 */
Dave Airliee0be4282007-07-12 10:26:44 +1000140int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000141 unsigned long seed, int bits, int shift,
142 unsigned long add)
143{
144 int ret;
145 unsigned long mask = (1 << bits) - 1;
146 unsigned long first, unshifted_key;
147
148 unshifted_key = hash_long(seed, bits);
149 first = unshifted_key;
150 do {
151 item->key = (unshifted_key << shift) + add;
152 ret = drm_ht_insert_item(ht, item);
153 if (ret)
154 unshifted_key = (unshifted_key + 1) & mask;
155 } while(ret && (unshifted_key != first));
156
157 if (ret) {
158 DRM_ERROR("Available key bit space exhausted\n");
159 return -EINVAL;
160 }
161 return 0;
162}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200163EXPORT_SYMBOL(drm_ht_just_insert_please);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000164
Dave Airliee0be4282007-07-12 10:26:44 +1000165int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
166 struct drm_hash_item **item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000167{
168 struct hlist_node *list;
169
Thomas Hellstrom384cc2f2012-11-20 12:16:47 +0000170 list = drm_ht_find_key_rcu(ht, key);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000171 if (!list)
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000172 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000173
Dave Airliee0be4282007-07-12 10:26:44 +1000174 *item = hlist_entry(list, struct drm_hash_item, head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000175 return 0;
176}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200177EXPORT_SYMBOL(drm_ht_find_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000178
Dave Airliee0be4282007-07-12 10:26:44 +1000179int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000180{
181 struct hlist_node *list;
182
183 list = drm_ht_find_key(ht, key);
184 if (list) {
Thomas Hellstromd7144552012-11-06 11:31:48 +0000185 hlist_del_init_rcu(list);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000186 return 0;
187 }
Thomas Hellstrom47cc1402006-09-22 04:04:18 +1000188 return -EINVAL;
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000189}
190
Dave Airliee0be4282007-07-12 10:26:44 +1000191int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000192{
Thomas Hellstromd7144552012-11-06 11:31:48 +0000193 hlist_del_init_rcu(&item->head);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000194 return 0;
195}
Jesse Barnesa2c0a972008-11-05 10:31:53 -0800196EXPORT_SYMBOL(drm_ht_remove_item);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000197
Dave Airliee0be4282007-07-12 10:26:44 +1000198void drm_ht_remove(struct drm_open_hash *ht)
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000199{
200 if (ht->table) {
Chris Wilson7811bdd2011-01-26 18:33:25 +0000201 if ((PAGE_SIZE / sizeof(*ht->table)) >> ht->order)
Eric Anholt9a298b22009-03-24 12:23:04 -0700202 kfree(ht->table);
Chris Wilson7811bdd2011-01-26 18:33:25 +0000203 else
204 vfree(ht->table);
Thomas Hellstrom3a1bd922006-08-07 21:30:28 +1000205 ht->table = NULL;
206 }
207}
Jerome Glissef2cb5d82009-04-08 17:16:24 +0200208EXPORT_SYMBOL(drm_ht_remove);