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 /* 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_check(p, c) \ 91 rcu_dereference_protected(p, c) 92 93 #define rcu_dereference_raw(p) \ 94 ((__typeof(*p) *)READ_ONCE(p)) 95 96 #define rcu_pointer_handoff(p) (p) 97 98 #define rcu_assign_pointer(p, v) do { \ 99 atomic_store_rel_ptr((volatile uintptr_t *)&(p), \ 100 (uintptr_t)(v)); \ 101 } while (0) 102 103 #define rcu_replace_pointer(rcu, ptr, c) \ 104 ({ \ 105 typeof(ptr) __tmp = rcu_dereference_protected(rcu, c); \ 106 rcu_assign_pointer(rcu, ptr); \ 107 __tmp; \ 108 }) 109 110 #define rcu_swap_protected(rcu, ptr, c) do { \ 111 typeof(ptr) p = rcu_dereference_protected(rcu, c); \ 112 rcu_assign_pointer(rcu, ptr); \ 113 (ptr) = p; \ 114 } while (0) 115 116 /* prototypes */ 117 118 extern void linux_call_rcu(unsigned type, struct rcu_head *ptr, rcu_callback_t func); 119 extern void linux_rcu_barrier(unsigned type); 120 extern void linux_rcu_read_lock(unsigned type); 121 extern void linux_rcu_read_unlock(unsigned type); 122 extern void linux_synchronize_rcu(unsigned type); 123 124 /* Empty implementation for !DEBUG */ 125 #define init_rcu_head(...) 126 #define destroy_rcu_head(...) 127 #define init_rcu_head_on_stack(...) 128 #define destroy_rcu_head_on_stack(...) 129 130 #endif /* _LINUX_RCUPDATE_H_ */ 131