swh:1:snp:3c665ee4f67729f27f2e40193ab88e7298cf0fef
Tip revision: 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 authored by Linus Torvalds on 25 April 2021, 20:49:08 UTC
Linux 5.12
Linux 5.12
Tip revision: 9f4ad9e
rcu_segcblist.h
/* 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>
/* Return number of callbacks in the specified callback list. */
static inline long rcu_cblist_n_cbs(struct rcu_cblist *rclp)
{
return READ_ONCE(rclp->len);
}
/* Return number of callbacks in segmented callback list by summing seglen. */
long rcu_segcblist_n_segment_cbs(struct rcu_segcblist *rsclp);
void rcu_cblist_init(struct rcu_cblist *rclp);
void rcu_cblist_enqueue(struct rcu_cblist *rclp, struct rcu_head *rhp);
void rcu_cblist_flush_enqueue(struct rcu_cblist *drclp,
struct rcu_cblist *srclp,
struct rcu_head *rhp);
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 !READ_ONCE(rsclp->head);
}
/* Return number of callbacks in segmented callback list. */
static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
{
#ifdef CONFIG_RCU_NOCB_CPU
return atomic_long_read(&rsclp->len);
#else
return READ_ONCE(rsclp->len);
#endif
}
static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp,
int flags)
{
rsclp->flags |= flags;
}
static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
int flags)
{
rsclp->flags &= ~flags;
}
static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
int flags)
{
return READ_ONCE(rsclp->flags) & flags;
}
/*
* Is the specified rcu_segcblist enabled, for example, not corresponding
* to an offline CPU?
*/
static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
{
return rcu_segcblist_test_flags(rsclp, SEGCBLIST_ENABLED);
}
/* Is the specified rcu_segcblist offloaded, or is SEGCBLIST_SOFTIRQ_ONLY set? */
static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
{
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
!rcu_segcblist_test_flags(rsclp, SEGCBLIST_SOFTIRQ_ONLY))
return true;
return false;
}
static inline bool rcu_segcblist_completely_offloaded(struct rcu_segcblist *rsclp)
{
int flags = SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP | SEGCBLIST_OFFLOADED;
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) && (rsclp->flags & flags) == flags)
return true;
return false;
}
/*
* 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 !READ_ONCE(*READ_ONCE(rsclp->tails[seg]));
}
/*
* Is the specified segment of the specified rcu_segcblist structure
* empty of callbacks?
*/
static inline bool rcu_segcblist_segempty(struct rcu_segcblist *rsclp, int seg)
{
if (seg == RCU_DONE_TAIL)
return &rsclp->head == rsclp->tails[RCU_DONE_TAIL];
return rsclp->tails[seg - 1] == rsclp->tails[seg];
}
void rcu_segcblist_inc_len(struct rcu_segcblist *rsclp);
void rcu_segcblist_add_len(struct rcu_segcblist *rsclp, long v);
void rcu_segcblist_init(struct rcu_segcblist *rsclp);
void rcu_segcblist_disable(struct rcu_segcblist *rsclp);
void rcu_segcblist_offload(struct rcu_segcblist *rsclp, bool offload);
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);
bool rcu_segcblist_nextgp(struct rcu_segcblist *rsclp, unsigned long *lp);
void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
struct rcu_head *rhp);
bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
struct rcu_head *rhp);
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);