1272343Sngie/**************************************************************************
2272343Sngie *
3272343Sngie * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
4272343Sngie * All Rights Reserved.
5272343Sngie *
6272343Sngie * Permission is hereby granted, free of charge, to any person obtaining a
7272343Sngie * copy of this software and associated documentation files (the
8272343Sngie * "Software"), to deal in the Software without restriction, including
9272343Sngie * without limitation the rights to use, copy, modify, merge, publish,
10272343Sngie * distribute, sub license, and/or sell copies of the Software, and to
11272343Sngie * permit persons to whom the Software is furnished to do so, subject to
12272343Sngie * the following conditions:
13272343Sngie *
14272343Sngie * The above copyright notice and this permission notice (including the
15272343Sngie * next paragraph) shall be included in all copies or substantial portions
16272343Sngie * of the Software.
17272343Sngie *
18272343Sngie * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19272343Sngie * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20272343Sngie * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21272343Sngie * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22272343Sngie * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23272343Sngie * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24272343Sngie * USE OR OTHER DEALINGS IN THE SOFTWARE.
25272343Sngie *
26272343Sngie *
27272343Sngie **************************************************************************/
28272343Sngie
29272343Sngie#include <sys/cdefs.h>
30272343Sngie__KERNEL_RCSID(0, "$NetBSD$");
31272343Sngie
32272343Sngie/*
33272343Sngie * Simple open hash tab implementation.
34272343Sngie *
35272343Sngie * Authors:
36272343Sngie * Thomas Hellstr��m <thomas-at-tungstengraphics-dot-com>
37272343Sngie */
38272343Sngie
39272343Sngie#include "drmP.h"
40272343Sngie#include "drm_hashtab.h"
41272343Sngie
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(ht->size, HASH_LIST, false, &ht->mask);
50	if (!ht->table) {
51		DRM_ERROR("Out of memory for hash table\n");
52		return -ENOMEM;
53	}
54	return 0;
55}
56
57void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
58{
59	struct drm_hash_item *entry;
60	struct drm_hash_item_list *h_list;
61	unsigned int hashed_key;
62	int count = 0;
63
64	hashed_key = hash32_buf(&key, sizeof(key), ht->order);
65	DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
66	h_list = &ht->table[hashed_key & ht->mask];
67	LIST_FOREACH(entry, h_list, head)
68		DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
69}
70
71static struct drm_hash_item *
72drm_ht_find_key(struct drm_open_hash *ht, unsigned long key)
73{
74	struct drm_hash_item *entry;
75	struct drm_hash_item_list *h_list;
76	unsigned int hashed_key;
77
78	hashed_key = hash32_buf(&key, sizeof(key), ht->order);
79	h_list = &ht->table[hashed_key & ht->mask];
80	LIST_FOREACH(entry, h_list, head) {
81		if (entry->key == key)
82			return entry;
83		if (entry->key > key)
84			break;
85	}
86	return NULL;
87}
88
89
90int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
91{
92	struct drm_hash_item *entry, *parent;
93	struct drm_hash_item_list *h_list;
94	unsigned int hashed_key;
95	unsigned long key = item->key;
96
97	hashed_key = hash32_buf(&key, sizeof(key), ht->order);
98	h_list = &ht->table[hashed_key & ht->mask];
99	parent = NULL;
100	LIST_FOREACH(entry, h_list, head) {
101		if (entry->key == key)
102			return -EINVAL;
103		if (entry->key > key)
104			break;
105		parent = entry;
106	}
107	if (parent) {
108		LIST_INSERT_AFTER(parent, item, head);
109	} else {
110		LIST_INSERT_HEAD(h_list, item, head);
111	}
112	return 0;
113}
114
115/*
116 * Just insert an item and return any "bits" bit key that hasn't been
117 * used before.
118 */
119int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
120			      unsigned long seed, int bits, int shift,
121			      unsigned long add)
122{
123	int ret;
124	unsigned long mask = (1 << bits) - 1;
125	unsigned long first, unshifted_key = 0;
126
127	unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key);
128	first = unshifted_key;
129	do {
130		item->key = (unshifted_key << shift) + add;
131		ret = drm_ht_insert_item(ht, item);
132		if (ret)
133			unshifted_key = (unshifted_key + 1) & mask;
134	} while(ret && (unshifted_key != first));
135
136	if (ret) {
137		DRM_ERROR("Available key bit space exhausted\n");
138		return -EINVAL;
139	}
140	return 0;
141}
142
143int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
144		     struct drm_hash_item **item)
145{
146	struct drm_hash_item *entry;
147
148	entry = drm_ht_find_key(ht, key);
149	if (!entry)
150		return -EINVAL;
151
152	*item = entry;
153	return 0;
154}
155
156int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
157{
158	struct drm_hash_item *entry;
159
160	entry = drm_ht_find_key(ht, key);
161	if (entry) {
162		LIST_REMOVE(entry, head);
163		return 0;
164	}
165	return -EINVAL;
166}
167
168int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
169{
170	LIST_REMOVE(item, head);
171	return 0;
172}
173
174void drm_ht_remove(struct drm_open_hash *ht)
175{
176	if (ht->table) {
177		hashdone(ht->table, HASH_LIST, ht->mask);
178		ht->table = NULL;
179	}
180}
181