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 Hellström <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 44 int 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 } 57 EXPORT_SYMBOL(drm_ht_create); 58 59 void 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 73 static 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 92 int 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 } 116 EXPORT_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 */ 122 int 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 } 145 EXPORT_SYMBOL(drm_ht_just_insert_please); 146 147 int 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 } 159 EXPORT_SYMBOL(drm_ht_find_item); 160 161 int 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 } 172 173 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) 174 { 175 LIST_REMOVE(item, head); 176 return 0; 177 } 178 EXPORT_SYMBOL(drm_ht_remove_item); 179 180 void 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 } 187 EXPORT_SYMBOL(drm_ht_remove); 188