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 the flavors to wait on.
  37 *
  38 * This macro waits concurrently for multiple flavors of RCU grace periods.
  39 * For example, synchronize_rcu_mult(call_rcu, call_rcu_bh) would wait
  40 * on concurrent RCU and RCU-bh grace periods.  Waiting on a give SRCU
  41 * domain requires you to write a wrapper function for that SRCU domain's
  42 * call_srcu() function, supplying the corresponding srcu_struct.
  43 *
  44 * If Tiny RCU, tell _wait_rcu_gp() not to bother waiting for RCU
  45 * or RCU-bh, given that anywhere synchronize_rcu_mult() can be called
  46 * is automatically a grace period.
  47 */
  48#define synchronize_rcu_mult(...) \
  49        _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
  50
  51#endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */
  52