xref: /linux-6.15/include/linux/mbcache.h (revision bbb03029)
1 #ifndef _LINUX_MBCACHE_H
2 #define _LINUX_MBCACHE_H
3 
4 #include <linux/hash.h>
5 #include <linux/list_bl.h>
6 #include <linux/list.h>
7 #include <linux/atomic.h>
8 #include <linux/fs.h>
9 
10 struct mb_cache;
11 
12 struct mb_cache_entry {
13 	/* List of entries in cache - protected by cache->c_list_lock */
14 	struct list_head	e_list;
15 	/* Hash table list - protected by hash chain bitlock */
16 	struct hlist_bl_node	e_hash_list;
17 	atomic_t		e_refcnt;
18 	/* Key in hash - stable during lifetime of the entry */
19 	u32			e_key;
20 	u32			e_referenced:1;
21 	u32			e_reusable:1;
22 	/* User provided value - stable during lifetime of the entry */
23 	u64			e_value;
24 };
25 
26 struct mb_cache *mb_cache_create(int bucket_bits);
27 void mb_cache_destroy(struct mb_cache *cache);
28 
29 int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
30 			  u64 value, bool reusable);
31 void __mb_cache_entry_free(struct mb_cache_entry *entry);
32 static inline int mb_cache_entry_put(struct mb_cache *cache,
33 				     struct mb_cache_entry *entry)
34 {
35 	if (!atomic_dec_and_test(&entry->e_refcnt))
36 		return 0;
37 	__mb_cache_entry_free(entry);
38 	return 1;
39 }
40 
41 void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value);
42 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
43 					  u64 value);
44 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
45 						 u32 key);
46 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
47 						struct mb_cache_entry *entry);
48 void mb_cache_entry_touch(struct mb_cache *cache,
49 			  struct mb_cache_entry *entry);
50 
51 #endif	/* _LINUX_MBCACHE_H */
52