/************************************************************************** * * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * * **************************************************************************/ /* * Simple open hash tab implementation. * * Authors: * Thomas Hellstr�m <thomas-at-tungstengraphics-dot-com> */ #include "drmP.h" #include "drm_hashtab.h" #include <linux/hash.h> int drm_ht_create(drm_open_hash_t *ht, unsigned int order) { unsigned int i; ht->size = 1 << order; ht->order = order; ht->fill = 0; ht->table = NULL; ht->use_vmalloc = ((ht->size * sizeof(*ht->table)) > PAGE_SIZE); if (!ht->use_vmalloc) { ht->table = drm_calloc(ht->size, sizeof(*ht->table), DRM_MEM_HASHTAB); } if (!ht->table) { ht->use_vmalloc = 1; ht->table = vmalloc(ht->size*sizeof(*ht->table)); } if (!ht->table) { DRM_ERROR("Out of memory for hash table\n"); return -ENOMEM; } for (i=0; i< ht->size; ++i) { INIT_HLIST_HEAD(&ht->table[i]); } return 0; } void drm_ht_verbose_list(drm_open_hash_t *ht, unsigned long key) { drm_hash_item_t *entry; struct hlist_head *h_list; struct hlist_node *list; unsigned int hashed_key; int count = 0; hashed_key = hash_long(key, ht->order); DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); h_list = &ht->table[hashed_key]; hlist_for_each(list, h_list) { entry = hlist_entry(list, drm_hash_item_t, head); DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); } } static struct hlist_node *drm_ht_find_key(drm_open_hash_t *ht, unsigned long key) { drm_hash_item_t *entry; struct hlist_head *h_list; struct hlist_node *list; unsigned int hashed_key; hashed_key = hash_long(key, ht->order); h_list = &ht->table[hashed_key]; hlist_for_each(list, h_list) { entry = hlist_entry(list, drm_hash_item_t, head); if (entry->key == key) return list; if (entry->key > key) break; } return NULL; } int drm_ht_insert_item(drm_open_hash_t *ht, drm_hash_item_t *item) { drm_hash_item_t *entry; struct hlist_head *h_list; struct hlist_node *list, *parent; unsigned int hashed_key; unsigned long key = item->key; hashed_key = hash_long(key, ht->order); h_list = &ht->table[hashed_key]; parent = NULL; hlist_for_each(list, h_list) { entry = hlist_entry(list, drm_hash_item_t, head); if (entry->key == key) return -EINVAL; if (entry->key > key) break; parent = list; } if (parent) { hlist_add_after(parent, &item->head); } else { hlist_add_head(&item->head, h_list); } return 0; } /* * Just insert an item and return any "bits" bit key that hasn't been * used before. */ int drm_ht_just_insert_please(drm_open_hash_t *ht, drm_hash_item_t *item, unsigned long seed, int bits, int shift, unsigned long add) { int ret; unsigned long mask = (1 << bits) - 1; unsigned long first, unshifted_key; unshifted_key = hash_long(seed, bits); first = unshifted_key; do { item->key = (unshifted_key << shift) + add; ret = drm_ht_insert_item(ht, item); if (ret) unshifted_key = (unshifted_key + 1) & mask; } while(ret && (unshifted_key != first)); if (ret) { DRM_ERROR("Available key bit space exhausted\n"); return -EINVAL; } return 0; } int drm_ht_find_item(drm_open_hash_t *ht, unsigned long key, drm_hash_item_t **item) { struct hlist_node *list; list = drm_ht_find_key(ht, key); if (!list) return -EINVAL; *item = hlist_entry(list, drm_hash_item_t, head); return 0; } int drm_ht_remove_key(drm_open_hash_t *ht, unsigned long key) { struct hlist_node *list; list = drm_ht_find_key(ht, key); if (list) { hlist_del_init(list); ht->fill--; return 0; } return -EINVAL; } int drm_ht_remove_item(drm_open_hash_t *ht, drm_hash_item_t *item) { hlist_del_init(&item->head); ht->fill--; return 0; } void drm_ht_remove(drm_open_hash_t *ht) { if (ht->table) { if (ht->use_vmalloc) vfree(ht->table); else drm_free(ht->table, ht->size * sizeof(*ht->table), DRM_MEM_HASHTAB); ht->table = NULL; } }