open-cas-linux/modules/cas_cache/ocf_env_refcnt.h
Jan Musial 27eed48976 Per-cpu reference counters
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Signed-off-by: Jan Musial <jan.musial@huawei.com>
Signed-off-by: Robert Baldyga <robert.baldyga@huawei.com>
Signed-off-by: Ian Levine <ian.levine@huawei.com>
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>
2025-02-25 16:21:02 +01:00

105 lines
2.4 KiB
C

/*
* Copyright(c) 2019-2021 Intel Corporation
* Copyright(c) 2023-2025 Huawei Technologies Co., Ltd.
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef __OCF_ENV_REFCNT_H__
#define __OCF_ENV_REFCNT_H__
#include "ocf_env.h"
typedef void (*env_refcnt_cb_t)(void *priv);
struct env_refcnt_pcpu {
env_atomic64 counter;
bool freeze;
};
typedef void (*env_refcnt_do_on_cpu_cb_t)(void *priv);
struct notify_cpu_work {
struct work_struct work;
/* function to call on each cpu */
env_refcnt_do_on_cpu_cb_t cb;
/* priv passed to cb */
void *priv;
/* refcnt instance */
struct env_refcnt *rc;
};
struct env_refcnt {
struct env_refcnt_pcpu __percpu *pcpu __aligned(64);
struct {
/* freeze counter */
int counter;
/* global counter used instead of per-CPU ones after
* freeze
*/
env_atomic64 countdown;
/* freeze initializing - freeze was requested but not all
* CPUs were notified.
*/
bool initializing;
env_spinlock lock;
} freeze;
struct {
struct notify_cpu_work **notify_work_items;
env_atomic to_notify;
wait_queue_head_t notify_wait_queue;
struct workqueue_struct *notify_work_queue;
} notify;
struct {
env_atomic armed;
env_refcnt_cb_t pfn;
void *priv;
} callback;
char name[32];
};
/* Initialize reference counter */
int env_refcnt_init(struct env_refcnt *rc, const char *name, size_t name_len);
void env_refcnt_deinit(struct env_refcnt *rc);
/* Try to increment counter. Returns counter value (> 0) if successful, 0
* if counter is frozen
*/
bool env_refcnt_inc(struct env_refcnt *rc);
/* Decrement reference counter */
void env_refcnt_dec(struct env_refcnt *rc);
/* Disallow incrementing of underlying counter - attempts to increment counter
* will be failing until env_refcnt_unfreeze is called.
* It's ok to call freeze multiple times, in which case counter is frozen
* until all freeze calls are offset by a corresponding unfreeze.
*/
void env_refcnt_freeze(struct env_refcnt *rc);
/* Cancel the effect of single env_refcnt_freeze call */
void env_refcnt_unfreeze(struct env_refcnt *rc);
bool env_refcnt_frozen(struct env_refcnt *rc);
bool env_refcnt_zeroed(struct env_refcnt *rc);
/* Register callback to be called when reference counter drops to 0.
* Must be called after counter is frozen.
* Cannot be called until previously regsitered callback had fired.
*/
void env_refcnt_register_zero_cb(struct env_refcnt *rc, env_refcnt_cb_t cb,
void *priv);
#endif // __OCF_ENV_REFCNT_H__