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); 33 void mb_cache_entry_wait_unused(struct mb_cache_entry *entry); 34 static inline int mb_cache_entry_put(struct mb_cache *cache, 35 struct mb_cache_entry *entry) 36 { 37 unsigned int cnt = atomic_dec_return(&entry->e_refcnt); 38 39 if (cnt > 0) { 40 if (cnt <= 3) 41 wake_up_var(&entry->e_refcnt); 42 return 0; 43 } 44 __mb_cache_entry_free(entry); 45 return 1; 46 } 47 48 struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache, 49 u32 key, u64 value); 50 void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value); 51 struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, 52 u64 value); 53 struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache, 54 u32 key); 55 struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache, 56 struct mb_cache_entry *entry); 57 void mb_cache_entry_touch(struct mb_cache *cache, 58 struct mb_cache_entry *entry); 59 60 #endif /* _LINUX_MBCACHE_H */ 61