1 /**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismack, 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:
32 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
33 */
34
35 #ifndef DRM_HASHTAB_H
36 #define DRM_HASHTAB_H
37
38 #include <linux/list.h>
39
40 #define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
41
42 struct drm_hash_item {
43 struct hlist_node head;
44 unsigned long key;
45 };
46
47 struct drm_open_hash {
48 struct hlist_head *table;
49 u8 order;
50 };
51
52 int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
53 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
54 int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
55 unsigned long seed, int bits, int shift,
56 unsigned long add);
57 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);
58
59 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
60 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
61 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
62 void drm_ht_remove(struct drm_open_hash *ht);
63
64 /*
65 * RCU-safe interface
66 *
67 * The user of this API needs to make sure that two or more instances of the
68 * hash table manipulation functions are never run simultaneously.
69 * The lookup function drm_ht_find_item_rcu may, however, run simultaneously
70 * with any of the manipulation functions as long as it's called from within
71 * an RCU read-locked section.
72 */
73 #define drm_ht_insert_item_rcu drm_ht_insert_item
74 #define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
75 #define drm_ht_remove_key_rcu drm_ht_remove_key
76 #define drm_ht_remove_item_rcu drm_ht_remove_item
77 #define drm_ht_find_item_rcu drm_ht_find_item
78
79 #endif