LXR linux/include/linux/rcupdate

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_SCHED_RCUPDATE_WAIT_H
   3#define _LINUX_SCHED_RCUPDATE_WAIT_H
   4
   5/*
   6 * RCU synchronization types and methods:
   7 */
   8
   9#include <linux/rcupdate.h>
  10#include <linux/completion.h>
  11
  12/*
  13 * Structure allowing asynchronous waiting on RCU.
  14 */
  15struct rcu_synchronize {
  16        struct rcu_head head;
  17        struct completion completion;
  18};
  19void wakeme_after_rcu(struct rcu_head *head);
  20
  21void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
  22                   struct rcu_synchronize *rs_array);
  23
  24#define _wait_rcu_gp(checktiny, ...) \
  25do {                                                                    \
  26        call_rcu_func_t __crcu_array[] = { __VA_ARGS__ };               \
  27        struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)];    \
  28        __wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array),              \
  29                        __crcu_array, __rs_array);                      \
  30} while (0)
  31
  32#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)
  33
  34/**
  35 * synchronize_rcu_mult - Wait concurrently for multiple grace periods
  36 * @...: List of call_rcu() functions for different grace periods to wait on
  37 *
  38 * This macro waits concurrently for multiple types of RCU grace periods.
  39 * For example, synchronize_rcu_mult(call_rcu, call_rcu_tasks) would wait
  40 * on concurrent RCU and RCU-tasks grace periods.  Waiting on a given SRCU
  41 * domain requires you to write a wrapper function for that SRCU domain's
  42 * call_srcu() function, with this wrapper supplying the pointer to the
  43 * corresponding srcu_struct.
  44 *
  45 * The first argument tells Tiny RCU's _wait_rcu_gp() not to
  46 * bother waiting for RCU.  The reason for this is because anywhere
  47 * synchronize_rcu_mult() can be called is automatically already a full
  48 * grace period.
  49 */
  50#define synchronize_rcu_mult(...) \
  51        _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
  52
  53#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */
  54