OpenCloudOS-Kernel/kernel/rcu/rcu_segcblist.h

126 lines
4.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* RCU segmented callback lists, internal-to-rcu header file
*
* Copyright IBM Corporation, 2017
*
* Authors: Paul E. McKenney <paulmck@linux.ibm.com>
*/
#include <linux/rcu_segcblist.h>
/*
* Account for the fact that a previously dequeued callback turned out
* to be marked as lazy.
*/
static inline void rcu_cblist_dequeued_lazy(struct rcu_cblist *rclp)
{
rclp->len_lazy--;
}
void rcu_cblist_init(struct rcu_cblist *rclp);
struct rcu_head *rcu_cblist_dequeue(struct rcu_cblist *rclp);
/*
* Is the specified rcu_segcblist structure empty?
*
* But careful! The fact that the ->head field is NULL does not
* necessarily imply that there are no callbacks associated with
* this structure. When callbacks are being invoked, they are
* removed as a group. If callback invocation must be preempted,
* the remaining callbacks will be added back to the list. Either
* way, the counts are updated later.
*
* So it is often the case that rcu_segcblist_n_cbs() should be used
* instead.
*/
static inline bool rcu_segcblist_empty(struct rcu_segcblist *rsclp)
{
return !rsclp->head;
}
/* Return number of callbacks in segmented callback list. */
static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
{
return READ_ONCE(rsclp->len);
}
/* Return number of lazy callbacks in segmented callback list. */
static inline long rcu_segcblist_n_lazy_cbs(struct rcu_segcblist *rsclp)
{
return rsclp->len_lazy;
}
/* Return number of lazy callbacks in segmented callback list. */
static inline long rcu_segcblist_n_nonlazy_cbs(struct rcu_segcblist *rsclp)
{
return rsclp->len - rsclp->len_lazy;
}
/*
* Is the specified rcu_segcblist enabled, for example, not corresponding
* to an offline or callback-offloaded CPU?
*/
static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
{
return !!rsclp->tails[RCU_NEXT_TAIL];
}
/*
* Are all segments following the specified segment of the specified
* rcu_segcblist structure empty of callbacks? (The specified
* segment might well contain callbacks.)
*/
static inline bool rcu_segcblist_restempty(struct rcu_segcblist *rsclp, int seg)
{
return !*rsclp->tails[seg];
}
/*
* Interim function to return rcu_segcblist head pointer. Longer term, the
* rcu_segcblist will be used more pervasively, removing the need for this
* function.
*/
static inline struct rcu_head *rcu_segcblist_head(struct rcu_segcblist *rsclp)
{
return rsclp->head;
}
/*
* Interim function to return rcu_segcblist head pointer. Longer term, the
* rcu_segcblist will be used more pervasively, removing the need for this
* function.
*/
static inline struct rcu_head **rcu_segcblist_tail(struct rcu_segcblist *rsclp)
{
WARN_ON_ONCE(rcu_segcblist_empty(rsclp));
return rsclp->tails[RCU_NEXT_TAIL];
}
void rcu_segcblist_init(struct rcu_segcblist *rsclp);
void rcu_segcblist_disable(struct rcu_segcblist *rsclp);
bool rcu_segcblist_ready_cbs(struct rcu_segcblist *rsclp);
bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp);
struct rcu_head *rcu_segcblist_first_cb(struct rcu_segcblist *rsclp);
struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp);
void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
struct rcu_head *rhp, bool lazy);
bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
struct rcu_head *rhp, bool lazy);
void rcu_segcblist_extract_count(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_extract_done_cbs(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_extract_pend_cbs(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_insert_count(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_insert_done_cbs(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_insert_pend_cbs(struct rcu_segcblist *rsclp,
struct rcu_cblist *rclp);
void rcu_segcblist_advance(struct rcu_segcblist *rsclp, unsigned long seq);
bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq);
void rcu_segcblist_merge(struct rcu_segcblist *dst_rsclp,
struct rcu_segcblist *src_rsclp);