/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU segmented callback lists, internal-to-rcu header file * * Copyright IBM Corporation, 2017 * * Authors: Paul E. McKenney */ #include /* 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 } /* * 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 IS_ENABLED(CONFIG_RCU_NOCB_CPU) && 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_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 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);