rcupdate.h revision 345934 
1/*-
2 * Copyright (c) 2016-2017 Mellanox Technologies, Ltd.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/11/sys/compat/linuxkpi/common/include/linux/rcupdate.h 345934 2019-04-05 11:29:05Z hselasky $
27 */
28#ifndef	_LINUX_RCUPDATE_H_
29#define	_LINUX_RCUPDATE_H_
30
31#include <linux/compiler.h>
32#include <linux/types.h>
33
34#include <machine/atomic.h>
35
36#define	LINUX_KFREE_RCU_OFFSET_MAX	4096	/* exclusive */
37
38#define	RCU_INITIALIZER(v)			\
39	((__typeof(*(v)) *)(v))
40
41#define	RCU_INIT_POINTER(p, v) do {		\
42	(p) = (v);				\
43} while (0)
44
45#define	call_rcu(ptr, func) do {		\
46	linux_call_rcu(ptr, func);		\
47} while (0)
48
49#define	rcu_barrier(void) do {			\
50	linux_rcu_barrier();			\
51} while (0)
52
53#define	rcu_read_lock(void) do {		\
54	linux_rcu_read_lock();			\
55} while (0)
56
57#define	rcu_read_unlock(void) do {		\
58	linux_rcu_read_unlock();		\
59} while (0)
60
61#define	synchronize_rcu(void) do {	\
62	linux_synchronize_rcu();	\
63} while (0)
64
65#define	synchronize_rcu_expedited(void) do {	\
66	linux_synchronize_rcu();		\
67} while (0)
68
69#define	kfree_rcu(ptr, rcu_head) do {				\
70	CTASSERT(offsetof(__typeof(*(ptr)), rcu_head) <		\
71	    LINUX_KFREE_RCU_OFFSET_MAX);			\
72	call_rcu(&(ptr)->rcu_head, (rcu_callback_t)(uintptr_t)	\
73	    offsetof(__typeof(*(ptr)), rcu_head));		\
74} while (0)
75
76#define	rcu_access_pointer(p)			\
77	((__typeof(*p) *)READ_ONCE(p))
78
79#define	rcu_dereference_protected(p, c)		\
80	((__typeof(*p) *)READ_ONCE(p))
81
82#define	rcu_dereference(p)			\
83	rcu_dereference_protected(p, 0)
84
85#define	rcu_dereference_raw(p)			\
86	((__typeof(*p) *)READ_ONCE(p))
87
88#define	rcu_pointer_handoff(p) (p)
89
90#define	rcu_assign_pointer(p, v) do {				\
91	atomic_store_rel_ptr((volatile uintptr_t *)&(p),	\
92	    (uintptr_t)(v));					\
93} while (0)
94
95/* prototypes */
96
97extern void linux_call_rcu(struct rcu_head *ptr, rcu_callback_t func);
98extern void linux_rcu_barrier(void);
99extern void linux_rcu_read_lock(void);
100extern void linux_rcu_read_unlock(void);
101extern void linux_synchronize_rcu(void);
102
103/* Empty implementation for !DEBUG */
104#define	init_rcu_head(...)
105#define	destroy_rcu_head(...)
106#define	init_rcu_head_on_stack(...)
107#define	destroy_rcu_head_on_stack(...)
108
109#endif					/* _LINUX_RCUPDATE_H_ */
110