1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
27a2508e1SJan Kara #ifndef _LINUX_MBCACHE_H
37a2508e1SJan Kara #define _LINUX_MBCACHE_H
47a2508e1SJan Kara
57a2508e1SJan Kara #include <linux/hash.h>
67a2508e1SJan Kara #include <linux/list_bl.h>
77a2508e1SJan Kara #include <linux/list.h>
87a2508e1SJan Kara #include <linux/atomic.h>
97a2508e1SJan Kara #include <linux/fs.h>
107a2508e1SJan Kara
117a2508e1SJan Kara struct mb_cache;
127a2508e1SJan Kara
13*a44e84a9SJan Kara /* Cache entry flags */
14*a44e84a9SJan Kara enum {
15*a44e84a9SJan Kara MBE_REFERENCED_B = 0,
16*a44e84a9SJan Kara MBE_REUSABLE_B
17*a44e84a9SJan Kara };
18*a44e84a9SJan Kara
197a2508e1SJan Kara struct mb_cache_entry {
207a2508e1SJan Kara /* List of entries in cache - protected by cache->c_list_lock */
217a2508e1SJan Kara struct list_head e_list;
22307af6c8SJan Kara /*
23307af6c8SJan Kara * Hash table list - protected by hash chain bitlock. The entry is
24307af6c8SJan Kara * guaranteed to be hashed while e_refcnt > 0.
25307af6c8SJan Kara */
267a2508e1SJan Kara struct hlist_bl_node e_hash_list;
27307af6c8SJan Kara /*
28307af6c8SJan Kara * Entry refcount. Once it reaches zero, entry is unhashed and freed.
29307af6c8SJan Kara * While refcount > 0, the entry is guaranteed to stay in the hash and
30307af6c8SJan Kara * e.g. mb_cache_entry_try_delete() will fail.
31307af6c8SJan Kara */
327a2508e1SJan Kara atomic_t e_refcnt;
337a2508e1SJan Kara /* Key in hash - stable during lifetime of the entry */
347a2508e1SJan Kara u32 e_key;
35*a44e84a9SJan Kara unsigned long e_flags;
36c07dfcb4STahsin Erdogan /* User provided value - stable during lifetime of the entry */
37c07dfcb4STahsin Erdogan u64 e_value;
387a2508e1SJan Kara };
397a2508e1SJan Kara
407a2508e1SJan Kara struct mb_cache *mb_cache_create(int bucket_bits);
417a2508e1SJan Kara void mb_cache_destroy(struct mb_cache *cache);
427a2508e1SJan Kara
437a2508e1SJan Kara int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
44c07dfcb4STahsin Erdogan u64 value, bool reusable);
45307af6c8SJan Kara void __mb_cache_entry_free(struct mb_cache *cache,
46307af6c8SJan Kara struct mb_cache_entry *entry);
473dc96bbaSJan Kara void mb_cache_entry_wait_unused(struct mb_cache_entry *entry);
mb_cache_entry_put(struct mb_cache * cache,struct mb_cache_entry * entry)48307af6c8SJan Kara static inline void mb_cache_entry_put(struct mb_cache *cache,
497a2508e1SJan Kara struct mb_cache_entry *entry)
507a2508e1SJan Kara {
513dc96bbaSJan Kara unsigned int cnt = atomic_dec_return(&entry->e_refcnt);
523dc96bbaSJan Kara
533dc96bbaSJan Kara if (cnt > 0) {
54307af6c8SJan Kara if (cnt <= 2)
553dc96bbaSJan Kara wake_up_var(&entry->e_refcnt);
56307af6c8SJan Kara return;
573dc96bbaSJan Kara }
58307af6c8SJan Kara __mb_cache_entry_free(cache, entry);
597a2508e1SJan Kara }
607a2508e1SJan Kara
613dc96bbaSJan Kara struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache,
623dc96bbaSJan Kara u32 key, u64 value);
636048c64bSAndreas Gruenbacher struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
64c07dfcb4STahsin Erdogan u64 value);
657a2508e1SJan Kara struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
667a2508e1SJan Kara u32 key);
677a2508e1SJan Kara struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
687a2508e1SJan Kara struct mb_cache_entry *entry);
697a2508e1SJan Kara void mb_cache_entry_touch(struct mb_cache *cache,
707a2508e1SJan Kara struct mb_cache_entry *entry);
717a2508e1SJan Kara
727a2508e1SJan Kara #endif /* _LINUX_MBCACHE_H */
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