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
11 struct mb_cache;
12
13 struct 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
27 struct mb_cache *mb_cache_create(int bucket_bits);
28 void mb_cache_destroy(struct mb_cache *cache);
29
30 int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
31 u64 value, bool reusable);
32 void __mb_cache_entry_free(struct mb_cache_entry *entry);
mb_cache_entry_put(struct mb_cache * cache,struct mb_cache_entry * entry)33 static 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
42 void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value);
43 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
44 u64 value);
45 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
46 u32 key);
47 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
48 struct mb_cache_entry *entry);
49 void mb_cache_entry_touch(struct mb_cache *cache,
50 struct mb_cache_entry *entry);
51
52 #endif /* _LINUX_MBCACHE_H */
53