mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
384cc2f968
While hashtab should now be RCU-safe, Add a drm_ht_xxx_api for consumers to use to make it obvious what locking mechanism is used. Document the way the rcu-safe interface should be used. Don't use rcu-safe list traversal in modify operations where we should use a spinlock / mutex anyway. Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
80 lines
3.1 KiB
C
80 lines
3.1 KiB
C
/**************************************************************************
|
|
*
|
|
* Copyright 2006 Tungsten Graphics, Inc., Bismack, 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 Hellström <thomas-at-tungstengraphics-dot-com>
|
|
*/
|
|
|
|
#ifndef DRM_HASHTAB_H
|
|
#define DRM_HASHTAB_H
|
|
|
|
#include <linux/list.h>
|
|
|
|
#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
|
|
|
|
struct drm_hash_item {
|
|
struct hlist_node head;
|
|
unsigned long key;
|
|
};
|
|
|
|
struct drm_open_hash {
|
|
struct hlist_head *table;
|
|
u8 order;
|
|
};
|
|
|
|
extern int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
|
|
extern int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
|
|
extern int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
|
|
unsigned long seed, int bits, int shift,
|
|
unsigned long add);
|
|
extern int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);
|
|
|
|
extern void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
|
|
extern int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
|
|
extern int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
|
|
extern void drm_ht_remove(struct drm_open_hash *ht);
|
|
|
|
/*
|
|
* RCU-safe interface
|
|
*
|
|
* The user of this API needs to make sure that two or more instances of the
|
|
* hash table manipulation functions are never run simultaneously.
|
|
* The lookup function drm_ht_find_item_rcu may, however, run simultaneously
|
|
* with any of the manipulation functions as long as it's called from within
|
|
* an RCU read-locked section.
|
|
*/
|
|
#define drm_ht_insert_item_rcu drm_ht_insert_item
|
|
#define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
|
|
#define drm_ht_remove_key_rcu drm_ht_remove_key
|
|
#define drm_ht_remove_item_rcu drm_ht_remove_item
|
|
#define drm_ht_find_item_rcu drm_ht_find_item
|
|
|
|
#endif
|