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 | #include <linux/sched.h> |
12 | |
13 | /* |
14 | * Structure allowing asynchronous waiting on RCU. |
15 | */ |
16 | struct rcu_synchronize { |
17 | struct rcu_head head; |
18 | struct completion completion; |
19 | }; |
20 | void wakeme_after_rcu(struct rcu_head *head); |
21 | |
22 | void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, |
23 | struct rcu_synchronize *rs_array); |
24 | |
25 | #define _wait_rcu_gp(checktiny, ...) \ |
26 | do { \ |
27 | call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \ |
28 | struct rcu_synchronize __rs_array[ARRAY_SIZE(__crcu_array)]; \ |
29 | __wait_rcu_gp(checktiny, ARRAY_SIZE(__crcu_array), \ |
30 | __crcu_array, __rs_array); \ |
31 | } while (0) |
32 | |
33 | #define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__) |
34 | |
35 | /** |
36 | * synchronize_rcu_mult - Wait concurrently for multiple grace periods |
37 | * @...: List of call_rcu() functions for different grace periods to wait on |
38 | * |
39 | * This macro waits concurrently for multiple types of RCU grace periods. |
40 | * For example, synchronize_rcu_mult(call_rcu, call_rcu_tasks) would wait |
41 | * on concurrent RCU and RCU-tasks grace periods. Waiting on a given SRCU |
42 | * domain requires you to write a wrapper function for that SRCU domain's |
43 | * call_srcu() function, with this wrapper supplying the pointer to the |
44 | * corresponding srcu_struct. |
45 | * |
46 | * Note that call_rcu_hurry() should be used instead of call_rcu() |
47 | * because in kernels built with CONFIG_RCU_LAZY=y the delay between the |
48 | * invocation of call_rcu() and that of the corresponding RCU callback |
49 | * can be multiple seconds. |
50 | * |
51 | * The first argument tells Tiny RCU's _wait_rcu_gp() not to |
52 | * bother waiting for RCU. The reason for this is because anywhere |
53 | * synchronize_rcu_mult() can be called is automatically already a full |
54 | * grace period. |
55 | */ |
56 | #define synchronize_rcu_mult(...) \ |
57 | _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__) |
58 | |
59 | static inline void cond_resched_rcu(void) |
60 | { |
61 | #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) |
62 | rcu_read_unlock(); |
63 | cond_resched(); |
64 | rcu_read_lock(); |
65 | #endif |
66 | } |
67 | |
68 | #endif /* _LINUX_SCHED_RCUPDATE_WAIT_H */ |
69 | |