73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||
|
|
#ifndef _LINUX_MBCACHE_H
|
||
|
|
#define _LINUX_MBCACHE_H
|
||
|
|
|
||
|
|
#include <linux/hash.h>
|
||
|
|
#include <linux/list_bl.h>
|
||
|
|
#include <linux/list.h>
|
||
|
|
#include <linux/atomic.h>
|
||
|
|
#include <linux/fs.h>
|
||
|
|
|
||
|
|
struct mb_cache;
|
||
|
|
|
||
|
|
/* Cache entry flags */
|
||
|
|
enum {
|
||
|
|
MBE_REFERENCED_B = 0,
|
||
|
|
MBE_REUSABLE_B
|
||
|
|
};
|
||
|
|
|
||
|
|
struct mb_cache_entry {
|
||
|
|
/* List of entries in cache - protected by cache->c_list_lock */
|
||
|
|
struct list_head e_list;
|
||
|
|
/*
|
||
|
|
* Hash table list - protected by hash chain bitlock. The entry is
|
||
|
|
* guaranteed to be hashed while e_refcnt > 0.
|
||
|
|
*/
|
||
|
|
struct hlist_bl_node e_hash_list;
|
||
|
|
/*
|
||
|
|
* Entry refcount. Once it reaches zero, entry is unhashed and freed.
|
||
|
|
* While refcount > 0, the entry is guaranteed to stay in the hash and
|
||
|
|
* e.g. mb_cache_entry_try_delete() will fail.
|
||
|
|
*/
|
||
|
|
atomic_t e_refcnt;
|
||
|
|
/* Key in hash - stable during lifetime of the entry */
|
||
|
|
u32 e_key;
|
||
|
|
unsigned long e_flags;
|
||
|
|
/* User provided value - stable during lifetime of the entry */
|
||
|
|
u64 e_value;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct mb_cache *mb_cache_create(int bucket_bits);
|
||
|
|
void mb_cache_destroy(struct mb_cache *cache);
|
||
|
|
|
||
|
|
int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
|
||
|
|
u64 value, bool reusable);
|
||
|
|
void __mb_cache_entry_free(struct mb_cache *cache,
|
||
|
|
struct mb_cache_entry *entry);
|
||
|
|
void mb_cache_entry_wait_unused(struct mb_cache_entry *entry);
|
||
|
|
static inline void mb_cache_entry_put(struct mb_cache *cache,
|
||
|
|
struct mb_cache_entry *entry)
|
||
|
|
{
|
||
|
|
unsigned int cnt = atomic_dec_return(&entry->e_refcnt);
|
||
|
|
|
||
|
|
if (cnt > 0) {
|
||
|
|
if (cnt <= 2)
|
||
|
|
wake_up_var(&entry->e_refcnt);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
__mb_cache_entry_free(cache, entry);
|
||
|
|
}
|
||
|
|
|
||
|
|
struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache,
|
||
|
|
u32 key, u64 value);
|
||
|
|
struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
|
||
|
|
u64 value);
|
||
|
|
struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
|
||
|
|
u32 key);
|
||
|
|
struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
|
||
|
|
struct mb_cache_entry *entry);
|
||
|
|
void mb_cache_entry_touch(struct mb_cache *cache,
|
||
|
|
struct mb_cache_entry *entry);
|
||
|
|
|
||
|
|
#endif /* _LINUX_MBCACHE_H */
|