diff options
Diffstat (limited to '')
-rw-r--r-- | kernel/rcu/rcu_segcblist.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h new file mode 100644 index 000000000..5c293afc0 --- /dev/null +++ b/kernel/rcu/rcu_segcblist.h @@ -0,0 +1,106 @@ +/* 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); +} + +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 +} + +/* + * 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 rsclp->enabled; +} + +/* Is the specified rcu_segcblist offloaded? */ +static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp) +{ + return rsclp->offloaded; +} + +/* + * 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])); +} + +void rcu_segcblist_inc_len(struct rcu_segcblist *rsclp); +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 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_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); |