LXR linux/include/linux/mbcache.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_MBCACHE_H
   3#define _LINUX_MBCACHE_H
   4
   5#include <linux/hash.h>
   6#include <linux/list_bl.h>
   7#include <linux/list.h>
   8#include <linux/atomic.h>
   9#include <linux/fs.h>
  10
  11struct mb_cache;
  12
  13struct mb_cache_entry {
  14        /* List of entries in cache - protected by cache->c_list_lock */
  15        struct list_head        e_list;
  16        /* Hash table list - protected by hash chain bitlock */
  17        struct hlist_bl_node    e_hash_list;
  18        atomic_t                e_refcnt;
  19        /* Key in hash - stable during lifetime of the entry */
  20        u32                     e_key;
  21        u32                     e_referenced:1;
  22        u32                     e_reusable:1;
  23        /* User provided value - stable during lifetime of the entry */
  24        u64                     e_value;
  25};
  26
  27struct mb_cache *mb_cache_create(int bucket_bits);
  28void mb_cache_destroy(struct mb_cache *cache);
  29
  30int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
  31                          u64 value, bool reusable);
  32void __mb_cache_entry_free(struct mb_cache_entry *entry);
  33static inline int mb_cache_entry_put(struct mb_cache *cache,
  34                                     struct mb_cache_entry *entry)
  35{
  36        if (!atomic_dec_and_test(&entry->e_refcnt))
  37                return 0;
  38        __mb_cache_entry_free(entry);
  39        return 1;
  40}
  41
  42void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value);
  43struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
  44                                          u64 value);
  45struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
  46                                                 u32 key);
  47struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
  48                                                struct mb_cache_entry *entry);
  49void mb_cache_entry_touch(struct mb_cache *cache,
  50                          struct mb_cache_entry *entry);
  51
  52#endif  /* _LINUX_MBCACHE_H */
  53