linux/include/drm/drm_hashtab.h
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   1/**************************************************************************
   2 *
   3 * Copyright 2006 Tungsten Graphics, Inc., Bismack, 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 * Simple open hash tab implementation.
  30 *
  31 * Authors:
  32 * Thomas Hellstr\xC3\xB6m <thomas-at-tungstengraphics-dot-com>
  33 */
  34
  35#ifndef DRM_HASHTAB_H
  36#define DRM_HASHTAB_H
  37
  38#include <linux/list.h>
  39
  40#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
  41
  42struct drm_hash_item {
  43        struct hlist_node head;
  44        unsigned long key;
  45};
  46
  47struct drm_open_hash {
  48        struct hlist_head *table;
  49        u8 order;
  50};
  51
  52extern int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
  53extern int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
  54extern int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
  55                                     unsigned long seed, int bits, int shift,
  56                                     unsigned long add);
  57extern int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);
  58
  59extern void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
  60extern int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
  61extern int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
  62extern void drm_ht_remove(struct drm_open_hash *ht);
  63
  64/*
  65 * RCU-safe interface
  66 *
  67 * The user of this API needs to make sure that two or more instances of the
  68 * hash table manipulation functions are never run simultaneously.
  69 * The lookup function drm_ht_find_item_rcu may, however, run simultaneously
  70 * with any of the manipulation functions as long as it's called from within
  71 * an RCU read-locked section.
  72 */
  73#define drm_ht_insert_item_rcu drm_ht_insert_item
  74#define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
  75#define drm_ht_remove_key_rcu drm_ht_remove_key
  76#define drm_ht_remove_item_rcu drm_ht_remove_item
  77#define drm_ht_find_item_rcu drm_ht_find_item
  78
  79#endif
  80