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 58 void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key) 59 { 60 struct drm_hash_item *entry; 61 struct drm_hash_item_list *h_list; 62 unsigned int hashed_key; 63 int count = 0; 64 65 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 66 DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); 67 h_list = &ht->table[hashed_key & ht->mask]; 68 LIST_FOREACH(entry, h_list, head) 69 DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); 70 } 71 72 static struct drm_hash_item * 73 drm_ht_find_key(struct drm_open_hash *ht, unsigned long key) 74 { 75 struct drm_hash_item *entry; 76 struct drm_hash_item_list *h_list; 77 unsigned int hashed_key; 78 79 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 80 h_list = &ht->table[hashed_key & ht->mask]; 81 LIST_FOREACH(entry, h_list, head) { 82 if (entry->key == key) 83 return entry; 84 if (entry->key > key) 85 break; 86 } 87 return NULL; 88 } 89 90 91 int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) 92 { 93 struct drm_hash_item *entry, *parent; 94 struct drm_hash_item_list *h_list; 95 unsigned int hashed_key; 96 unsigned long key = item->key; 97 98 hashed_key = hash32_buf(&key, sizeof(key), ht->order); 99 h_list = &ht->table[hashed_key & ht->mask]; 100 parent = NULL; 101 LIST_FOREACH(entry, h_list, head) { 102 if (entry->key == key) 103 return -EINVAL; 104 if (entry->key > key) 105 break; 106 parent = entry; 107 } 108 if (parent) { 109 LIST_INSERT_AFTER(parent, item, head); 110 } else { 111 LIST_INSERT_HEAD(h_list, item, head); 112 } 113 return 0; 114 } 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 } 143 144 int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, 145 struct drm_hash_item **item) 146 { 147 struct drm_hash_item *entry; 148 149 entry = drm_ht_find_key(ht, key); 150 if (!entry) 151 return -EINVAL; 152 153 *item = entry; 154 return 0; 155 } 156 157 int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key) 158 { 159 struct drm_hash_item *entry; 160 161 entry = drm_ht_find_key(ht, key); 162 if (entry) { 163 LIST_REMOVE(entry, head); 164 return 0; 165 } 166 return -EINVAL; 167 } 168 169 int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item) 170 { 171 LIST_REMOVE(item, head); 172 return 0; 173 } 174 175 void drm_ht_remove(struct drm_open_hash *ht) 176 { 177 if (ht->table) { 178 hashdestroy(ht->table, DRM_MEM_HASHTAB, ht->mask); 179 ht->table = NULL; 180 } 181 } 182