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("$FreeBSD$");
31
32/*
33 * Simple open hash tab implementation.
34 *
35 * Authors:
36 * Thomas Hellstr��m <thomas-at-tungstengraphics-dot-com>
37 */
38
39#include <dev/drm2/drmP.h>
40#include <dev/drm2/drm_hashtab.h>
41
42#include <sys/hash.h>
43
44int 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}
57EXPORT_SYMBOL(drm_ht_create);
58
59void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
60{
61	struct drm_hash_item *entry;
62	struct drm_hash_item_list *h_list;
63	unsigned int hashed_key;
64	int count = 0;
65
66	hashed_key = hash32_buf(&key, sizeof(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 & ht->mask];
69	LIST_FOREACH(entry, h_list, head)
70		DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
71}
72
73static struct drm_hash_item *drm_ht_find_key(struct drm_open_hash *ht,
74					  unsigned long key)
75{
76	struct drm_hash_item *entry;
77	struct drm_hash_item_list *h_list;
78	unsigned int hashed_key;
79
80	hashed_key = hash32_buf(&key, sizeof(key), ht->order);
81	h_list = &ht->table[hashed_key & ht->mask];
82	LIST_FOREACH(entry, h_list, head) {
83		if (entry->key == key)
84			return entry;
85		if (entry->key > key)
86			break;
87	}
88	return NULL;
89}
90
91
92int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
93{
94	struct drm_hash_item *entry, *parent;
95	struct drm_hash_item_list *h_list;
96	unsigned int hashed_key;
97	unsigned long key = item->key;
98
99	hashed_key = hash32_buf(&key, sizeof(key), ht->order);
100	h_list = &ht->table[hashed_key & ht->mask];
101	parent = NULL;
102	LIST_FOREACH(entry, h_list, head) {
103		if (entry->key == key)
104			return -EINVAL;
105		if (entry->key > key)
106			break;
107		parent = entry;
108	}
109	if (parent) {
110		LIST_INSERT_AFTER(parent, item, head);
111	} else {
112		LIST_INSERT_HEAD(h_list, item, head);
113	}
114	return 0;
115}
116EXPORT_SYMBOL(drm_ht_insert_item);
117
118/*
119 * Just insert an item and return any "bits" bit key that hasn't been
120 * used before.
121 */
122int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
123			      unsigned long seed, int bits, int shift,
124			      unsigned long add)
125{
126	int ret;
127	unsigned long mask = (1 << bits) - 1;
128	unsigned long first, unshifted_key = 0;
129
130	unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key);
131	first = unshifted_key;
132	do {
133		item->key = (unshifted_key << shift) + add;
134		ret = drm_ht_insert_item(ht, item);
135		if (ret)
136			unshifted_key = (unshifted_key + 1) & mask;
137	} while(ret && (unshifted_key != first));
138
139	if (ret) {
140		DRM_ERROR("Available key bit space exhausted\n");
141		return -EINVAL;
142	}
143	return 0;
144}
145EXPORT_SYMBOL(drm_ht_just_insert_please);
146
147int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
148		     struct drm_hash_item **item)
149{
150	struct drm_hash_item *entry;
151
152	entry = drm_ht_find_key(ht, key);
153	if (!entry)
154		return -EINVAL;
155
156	*item = entry;
157	return 0;
158}
159EXPORT_SYMBOL(drm_ht_find_item);
160
161int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
162{
163	struct drm_hash_item *entry;
164
165	entry = drm_ht_find_key(ht, key);
166	if (entry) {
167		LIST_REMOVE(entry, head);
168		return 0;
169	}
170	return -EINVAL;
171}
172
173int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
174{
175	LIST_REMOVE(item, head);
176	return 0;
177}
178EXPORT_SYMBOL(drm_ht_remove_item);
179
180void drm_ht_remove(struct drm_open_hash *ht)
181{
182	if (ht->table) {
183		hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask);
184		ht->table = NULL;
185	}
186}
187EXPORT_SYMBOL(drm_ht_remove);
188