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 * $FreeBSD$ 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 97 extern void linux_call_rcu(struct rcu_head *ptr, rcu_callback_t func); 98 extern void linux_rcu_barrier(void); 99 extern void linux_rcu_read_lock(void); 100 extern void linux_rcu_read_unlock(void); 101 extern 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