2 * Copyright (c) 2016-2017 Mellanox Technologies, Ltd.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
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.
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.
28 #ifndef _LINUX_RCUPDATE_H_
29 #define _LINUX_RCUPDATE_H_
31 #include <linux/compiler.h>
32 #include <linux/types.h>
34 #include <machine/atomic.h>
36 #define LINUX_KFREE_RCU_OFFSET_MAX 4096 /* exclusive */
38 /* BSD specific defines */
39 #define RCU_TYPE_REGULAR 0
40 #define RCU_TYPE_SLEEPABLE 1
41 #define RCU_TYPE_MAX 2
43 #define RCU_INITIALIZER(v) \
44 ((__typeof(*(v)) *)(v))
46 #define RCU_INIT_POINTER(p, v) do { \
50 #define call_rcu(ptr, func) do { \
51 linux_call_rcu(RCU_TYPE_REGULAR, ptr, func); \
54 #define rcu_barrier(void) do { \
55 linux_rcu_barrier(RCU_TYPE_REGULAR); \
58 #define rcu_read_lock(void) do { \
59 linux_rcu_read_lock(RCU_TYPE_REGULAR); \
62 #define rcu_read_unlock(void) do { \
63 linux_rcu_read_unlock(RCU_TYPE_REGULAR);\
66 #define synchronize_rcu(void) do { \
67 linux_synchronize_rcu(RCU_TYPE_REGULAR); \
70 #define synchronize_rcu_expedited(void) do { \
71 linux_synchronize_rcu(RCU_TYPE_REGULAR); \
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)); \
81 #define rcu_access_pointer(p) \
82 ((__typeof(*p) *)READ_ONCE(p))
84 #define rcu_dereference_protected(p, c) \
85 ((__typeof(*p) *)READ_ONCE(p))
87 #define rcu_dereference(p) \
88 rcu_dereference_protected(p, 0)
90 #define rcu_dereference_raw(p) \
91 ((__typeof(*p) *)READ_ONCE(p))
93 #define rcu_pointer_handoff(p) (p)
95 #define rcu_assign_pointer(p, v) do { \
96 atomic_store_rel_ptr((volatile uintptr_t *)&(p), \
100 #define rcu_swap_protected(rcu, ptr, c) do { \
101 typeof(ptr) p = rcu_dereference_protected(rcu, c); \
102 rcu_assign_pointer(rcu, ptr); \
108 extern void linux_call_rcu(unsigned type, struct rcu_head *ptr, rcu_callback_t func);
109 extern void linux_rcu_barrier(unsigned type);
110 extern void linux_rcu_read_lock(unsigned type);
111 extern void linux_rcu_read_unlock(unsigned type);
112 extern void linux_synchronize_rcu(unsigned type);
114 /* Empty implementation for !DEBUG */
115 #define init_rcu_head(...)
116 #define destroy_rcu_head(...)
117 #define init_rcu_head_on_stack(...)
118 #define destroy_rcu_head_on_stack(...)
120 #endif /* _LINUX_RCUPDATE_H_ */