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 /* 31 * Simple open hash tab implementation. 32 * 33 * Authors: 34 * Thomas Hellström <thomas-at-tungstengraphics-dot-com> 35 */ 36 37 #include <dev/drm2/drmP.h> 38 #include <dev/drm2/drm_hashtab.h> 39 40 #include <sys/hash.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_flags(ht->size, DRM_MEM_HASHTAB, &ht->mask, 48 HASH_NOWAIT); 49 if (!ht->table) { 50 DRM_ERROR("Out of memory for hash table\n"); 51 return -ENOMEM; 52 } 53 return 0; 54 } 55 EXPORT_SYMBOL(drm_ht_create); 56 57 void 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 71 static struct drm_hash_item *drm_ht_find_key(struct drm_open_hash *ht, 72 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 90 int 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 EXPORT_SYMBOL(drm_ht_insert_item); 115 116 /* 117 * Just insert an item and return any "bits" bit key that hasn't been 118 * used before. 119 */ 120 int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item, 121 unsigned long seed, int bits, int shift, 122 unsigned long add) 123 { 124 int ret; 125 unsigned long mask = (1 << bits) - 1; 126 unsigned long first, unshifted_key = 0; 127 128 unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key); 129 first = unshifted_key; 130 do { 131 item->key = (unshifted_key << shift) + add; 132 ret = drm_ht_insert_item(ht, item); 133 if (ret) 134 unshifted_key = (unshifted_key + 1) & mask; 135 } while(ret && (unshifted_key != first)); 136 137 if (ret) { 138 DRM_ERROR("Available key bit space exhausted\n"); 139 return -EINVAL; 140 } 141 return 0; 142 } 143 EXPORT_SYMBOL(drm_ht_just_insert_please); 144 145 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, 146 struct drm_hash_item **item) 147 { 148 struct drm_hash_item *entry; 149 150 entry = drm_ht_find_key(ht, key); 151 if (!entry) 152 return -EINVAL; 153 154 *item = entry; 155 return 0; 156 } 157 EXPORT_SYMBOL(drm_ht_find_item); 158 159 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key) 160 { 161 struct drm_hash_item *entry; 162 163 entry = drm_ht_find_key(ht, key); 164 if (entry) { 165 LIST_REMOVE(entry, head); 166 return 0; 167 } 168 return -EINVAL; 169 } 170 171 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) 172 { 173 LIST_REMOVE(item, head); 174 return 0; 175 } 176 EXPORT_SYMBOL(drm_ht_remove_item); 177 178 void drm_ht_remove(struct drm_open_hash *ht) 179 { 180 if (ht->table) { 181 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask); 182 ht->table = NULL; 183 } 184 } 185 EXPORT_SYMBOL(drm_ht_remove); 186