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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
7a2508e1 JK |
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 | ||
a44e84a9 JK |
13 | /* Cache entry flags */ |
14 | enum { | |
15 | MBE_REFERENCED_B = 0, | |
16 | MBE_REUSABLE_B | |
17 | }; | |
18 | ||
7a2508e1 JK |
19 | struct mb_cache_entry { |
20 | /* List of entries in cache - protected by cache->c_list_lock */ | |
21 | struct list_head e_list; | |
307af6c8 JK |
22 | /* |
23 | * Hash table list - protected by hash chain bitlock. The entry is | |
24 | * guaranteed to be hashed while e_refcnt > 0. | |
25 | */ | |
7a2508e1 | 26 | struct hlist_bl_node e_hash_list; |
307af6c8 JK |
27 | /* |
28 | * Entry refcount. Once it reaches zero, entry is unhashed and freed. | |
29 | * While refcount > 0, the entry is guaranteed to stay in the hash and | |
30 | * e.g. mb_cache_entry_try_delete() will fail. | |
31 | */ | |
7a2508e1 JK |
32 | atomic_t e_refcnt; |
33 | /* Key in hash - stable during lifetime of the entry */ | |
34 | u32 e_key; | |
a44e84a9 | 35 | unsigned long e_flags; |
c07dfcb4 TE |
36 | /* User provided value - stable during lifetime of the entry */ |
37 | u64 e_value; | |
7a2508e1 JK |
38 | }; |
39 | ||
40 | struct mb_cache *mb_cache_create(int bucket_bits); | |
41 | void mb_cache_destroy(struct mb_cache *cache); | |
42 | ||
43 | int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, | |
c07dfcb4 | 44 | u64 value, bool reusable); |
307af6c8 JK |
45 | void __mb_cache_entry_free(struct mb_cache *cache, |
46 | struct mb_cache_entry *entry); | |
3dc96bba | 47 | void mb_cache_entry_wait_unused(struct mb_cache_entry *entry); |
307af6c8 JK |
48 | static inline void mb_cache_entry_put(struct mb_cache *cache, |
49 | struct mb_cache_entry *entry) | |
7a2508e1 | 50 | { |
3dc96bba JK |
51 | unsigned int cnt = atomic_dec_return(&entry->e_refcnt); |
52 | ||
53 | if (cnt > 0) { | |
307af6c8 | 54 | if (cnt <= 2) |
3dc96bba | 55 | wake_up_var(&entry->e_refcnt); |
307af6c8 | 56 | return; |
3dc96bba | 57 | } |
307af6c8 | 58 | __mb_cache_entry_free(cache, entry); |
7a2508e1 JK |
59 | } |
60 | ||
3dc96bba JK |
61 | struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache, |
62 | u32 key, u64 value); | |
6048c64b | 63 | struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, |
c07dfcb4 | 64 | u64 value); |
7a2508e1 JK |
65 | struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, |
66 | u32 key); | |
67 | struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, | |
68 | struct mb_cache_entry *entry); | |
69 | void mb_cache_entry_touch(struct mb_cache *cache, | |
70 | struct mb_cache_entry *entry); | |
71 | ||
72 | #endif /* _LINUX_MBCACHE_H */ |