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 | */ |
15 | struct rcu_synchronize { |
16 | struct rcu_head head; |
17 | struct completion completion; |
18 | }; |
19 | void wakeme_after_rcu(struct rcu_head *head); |
20 | |
21 | void __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, ...) \ |
25 | do { \ |
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 | * Note that call_rcu_hurry() should be used instead of call_rcu() |
46 | * because in kernels built with CONFIG_RCU_LAZY=y the delay between the |
47 | * invocation of call_rcu() and that of the corresponding RCU callback |
48 | * can be multiple seconds. |
49 | * |
50 | * The first argument tells Tiny RCU's _wait_rcu_gp() not to |
51 | * bother waiting for RCU. The reason for this is because anywhere |
52 | * synchronize_rcu_mult() can be called is automatically already a full |
53 | * grace period. |
54 | */ |
55 | #define synchronize_rcu_mult(...) \ |
56 | _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) |
57 | |
58 | #endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */ |
59 | |