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 * $FreeBSD: src/sys/dev/drm/drm_hashtab.c,v 1.1 2010/01/31 14:25:29 rnoland Exp $ 28 **************************************************************************/ 29 30 /* 31 * Simple open hash tab implementation. 32 * 33 * Authors: 34 * Thomas Hellström <thomas-at-tungstengraphics-dot-com> 35 */ 36 37 #include <sys/hash.h> 38 39 #include "drmP.h" 40 #include "drm_hashtab.h" 41 42 int drm_ht_create(struct drm_open_hash *ht, unsigned int order) 43 { 44 ht->size = 1 << order; 45 ht->order = order; 46 ht->table = NULL; 47 ht->table = hashinit(ht->size, DRM_MEM_HASHTAB, &ht->mask); 48 if (!ht->table) { 49 DRM_ERROR("Out of memory for hash table\n"); 50 return -ENOMEM; 51 } 52 return 0; 53 } 54 55 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key) 56 { 57 struct drm_hash_item *entry; 58 struct drm_hash_item_list *h_list; 59 unsigned int hashed_key; 60 int count = 0; 61 62 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 63 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); 64 h_list = &ht->table[hashed_key & ht->mask]; 65 LIST_FOREACH(entry, h_list, head) 66 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); 67 } 68 69 static struct drm_hash_item * 70 drm_ht_find_key(struct drm_open_hash *ht, unsigned long key) 71 { 72 struct drm_hash_item *entry; 73 struct drm_hash_item_list *h_list; 74 unsigned int hashed_key; 75 76 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 77 h_list = &ht->table[hashed_key & ht->mask]; 78 LIST_FOREACH(entry, h_list, head) { 79 if (entry->key == key) 80 return entry; 81 if (entry->key > key) 82 break; 83 } 84 return NULL; 85 } 86 87 88 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) 89 { 90 struct drm_hash_item *entry, *parent; 91 struct drm_hash_item_list *h_list; 92 unsigned int hashed_key; 93 unsigned long key = item->key; 94 95 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 96 h_list = &ht->table[hashed_key & ht->mask]; 97 parent = NULL; 98 LIST_FOREACH(entry, h_list, head) { 99 if (entry->key == key) 100 return -EINVAL; 101 if (entry->key > key) 102 break; 103 parent = entry; 104 } 105 if (parent) { 106 LIST_INSERT_AFTER(parent, item, head); 107 } else { 108 LIST_INSERT_HEAD(h_list, item, head); 109 } 110 return 0; 111 } 112 113 /* 114 * Just insert an item and return any "bits" bit key that hasn't been 115 * used before. 116 */ 117 int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item, 118 unsigned long seed, int bits, int shift, 119 unsigned long add) 120 { 121 int ret; 122 unsigned long mask = (1 << bits) - 1; 123 unsigned long first, unshifted_key = 0; 124 125 unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key); 126 first = unshifted_key; 127 do { 128 item->key = (unshifted_key << shift) + add; 129 ret = drm_ht_insert_item(ht, item); 130 if (ret) 131 unshifted_key = (unshifted_key + 1) & mask; 132 } while(ret && (unshifted_key != first)); 133 134 if (ret) { 135 DRM_ERROR("Available key bit space exhausted\n"); 136 return -EINVAL; 137 } 138 return 0; 139 } 140 141 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, 142 struct drm_hash_item **item) 143 { 144 struct drm_hash_item *entry; 145 146 entry = drm_ht_find_key(ht, key); 147 if (!entry) 148 return -EINVAL; 149 150 *item = entry; 151 return 0; 152 } 153 154 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key) 155 { 156 struct drm_hash_item *entry; 157 158 entry = drm_ht_find_key(ht, key); 159 if (entry) { 160 LIST_REMOVE(entry, head); 161 return 0; 162 } 163 return -EINVAL; 164 } 165 166 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) 167 { 168 LIST_REMOVE(item, head); 169 return 0; 170 } 171 172 void drm_ht_remove(struct drm_open_hash *ht) 173 { 174 if (ht->table) { 175 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask); 176 ht->table = NULL; 177 } 178 } 179