1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * RCU segmented callback lists, internal-to-rcu header file
5 * Copyright IBM Corporation, 2017
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
10 #include <linux/rcu_segcblist.h>
13 * Account for the fact that a previously dequeued callback turned out
14 * to be marked as lazy.
16 static inline void rcu_cblist_dequeued_lazy(struct rcu_cblist *rclp)
21 void rcu_cblist_init(struct rcu_cblist *rclp);
22 struct rcu_head *rcu_cblist_dequeue(struct rcu_cblist *rclp);
25 * Is the specified rcu_segcblist structure empty?
27 * But careful! The fact that the ->head field is NULL does not
28 * necessarily imply that there are no callbacks associated with
29 * this structure. When callbacks are being invoked, they are
30 * removed as a group. If callback invocation must be preempted,
31 * the remaining callbacks will be added back to the list. Either
32 * way, the counts are updated later.
34 * So it is often the case that rcu_segcblist_n_cbs() should be used
37 static inline bool rcu_segcblist_empty(struct rcu_segcblist *rsclp)
39 return !READ_ONCE(rsclp->head);
42 /* Return number of callbacks in segmented callback list. */
43 static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
45 return READ_ONCE(rsclp->len);
48 /* Return number of lazy callbacks in segmented callback list. */
49 static inline long rcu_segcblist_n_lazy_cbs(struct rcu_segcblist *rsclp)
51 return rsclp->len_lazy;
54 /* Return number of lazy callbacks in segmented callback list. */
55 static inline long rcu_segcblist_n_nonlazy_cbs(struct rcu_segcblist *rsclp)
57 return rsclp->len - rsclp->len_lazy;
61 * Is the specified rcu_segcblist enabled, for example, not corresponding
64 static inline bool rcu_segcblist_is_enabled(struct rcu_segcblist *rsclp)
66 return rsclp->enabled;
69 /* Is the specified rcu_segcblist offloaded? */
70 static inline bool rcu_segcblist_is_offloaded(struct rcu_segcblist *rsclp)
72 return rsclp->offloaded;
76 * Are all segments following the specified segment of the specified
77 * rcu_segcblist structure empty of callbacks? (The specified
78 * segment might well contain callbacks.)
80 static inline bool rcu_segcblist_restempty(struct rcu_segcblist *rsclp, int seg)
82 return !READ_ONCE(*READ_ONCE(rsclp->tails[seg]));
85 void rcu_segcblist_init(struct rcu_segcblist *rsclp);
86 void rcu_segcblist_disable(struct rcu_segcblist *rsclp);
87 void rcu_segcblist_offload(struct rcu_segcblist *rsclp);
88 bool rcu_segcblist_ready_cbs(struct rcu_segcblist *rsclp);
89 bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp);
90 struct rcu_head *rcu_segcblist_first_cb(struct rcu_segcblist *rsclp);
91 struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp);
92 void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,
93 struct rcu_head *rhp, bool lazy);
94 bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,
95 struct rcu_head *rhp, bool lazy);
96 void rcu_segcblist_extract_count(struct rcu_segcblist *rsclp,
97 struct rcu_cblist *rclp);
98 void rcu_segcblist_extract_done_cbs(struct rcu_segcblist *rsclp,
99 struct rcu_cblist *rclp);
100 void rcu_segcblist_extract_pend_cbs(struct rcu_segcblist *rsclp,
101 struct rcu_cblist *rclp);
102 void rcu_segcblist_insert_count(struct rcu_segcblist *rsclp,
103 struct rcu_cblist *rclp);
104 void rcu_segcblist_insert_done_cbs(struct rcu_segcblist *rsclp,
105 struct rcu_cblist *rclp);
106 void rcu_segcblist_insert_pend_cbs(struct rcu_segcblist *rsclp,
107 struct rcu_cblist *rclp);
108 void rcu_segcblist_advance(struct rcu_segcblist *rsclp, unsigned long seq);
109 bool rcu_segcblist_accelerate(struct rcu_segcblist *rsclp, unsigned long seq);
110 void rcu_segcblist_merge(struct rcu_segcblist *dst_rsclp,
111 struct rcu_segcblist *src_rsclp);