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 359958 2020-04-15 05:02:49Z 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/* BSD specific defines */
39#define	RCU_TYPE_REGULAR 0
40#define	RCU_TYPE_SLEEPABLE 1
41#define	RCU_TYPE_MAX 2
42
43#define	RCU_INITIALIZER(v)			\
44	((__typeof(*(v)) *)(v))
45
46#define	RCU_INIT_POINTER(p, v) do {		\
47	(p) = (v);				\
48} while (0)
49
50#define	call_rcu(ptr, func) do {		\
51	linux_call_rcu(RCU_TYPE_REGULAR, ptr, func);	\
52} while (0)
53
54#define	rcu_barrier(void) do {			\
55	linux_rcu_barrier(RCU_TYPE_REGULAR);	\
56} while (0)
57
58#define	rcu_read_lock(void) do {		\
59	linux_rcu_read_lock(RCU_TYPE_REGULAR);	\
60} while (0)
61
62#define	rcu_read_unlock(void) do {		\
63	linux_rcu_read_unlock(RCU_TYPE_REGULAR);\
64} while (0)
65
66#define	synchronize_rcu(void) do {	\
67	linux_synchronize_rcu(RCU_TYPE_REGULAR);	\
68} while (0)
69
70#define	synchronize_rcu_expedited(void) do {	\
71	linux_synchronize_rcu(RCU_TYPE_REGULAR);	\
72} while (0)
73
74#define	kfree_rcu(ptr, rcu_head) do {				\
75	CTASSERT(offsetof(__typeof(*(ptr)), rcu_head) <		\
76	    LINUX_KFREE_RCU_OFFSET_MAX);			\
77	call_rcu(&(ptr)->rcu_head, (rcu_callback_t)(uintptr_t)	\
78	    offsetof(__typeof(*(ptr)), rcu_head));		\
79} while (0)
80
81#define	rcu_access_pointer(p)			\
82	((__typeof(*p) *)READ_ONCE(p))
83
84#define	rcu_dereference_protected(p, c)		\
85	((__typeof(*p) *)READ_ONCE(p))
86
87#define	rcu_dereference(p)			\
88	rcu_dereference_protected(p, 0)
89
90#define	rcu_dereference_raw(p)			\
91	((__typeof(*p) *)READ_ONCE(p))
92
93#define	rcu_pointer_handoff(p) (p)
94
95#define	rcu_assign_pointer(p, v) do {				\
96	atomic_store_rel_ptr((volatile uintptr_t *)&(p),	\
97	    (uintptr_t)(v));					\
98} while (0)
99
100/* prototypes */
101
102extern void linux_call_rcu(unsigned type, struct rcu_head *ptr, rcu_callback_t func);
103extern void linux_rcu_barrier(unsigned type);
104extern void linux_rcu_read_lock(unsigned type);
105extern void linux_rcu_read_unlock(unsigned type);
106extern void linux_synchronize_rcu(unsigned type);
107
108/* Empty implementation for !DEBUG */
109#define	init_rcu_head(...)
110#define	destroy_rcu_head(...)
111#define	init_rcu_head_on_stack(...)
112#define	destroy_rcu_head_on_stack(...)
113
114#endif					/* _LINUX_RCUPDATE_H_ */
115