1 /* $NetBSD: rcupdate.h,v 1.8 2021/12/19 11:49:11 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _LINUX_RCUPDATE_H_ 33 #define _LINUX_RCUPDATE_H_ 34 35 #include <sys/atomic.h> 36 #include <sys/cdefs.h> 37 #include <sys/systm.h> 38 39 #include <linux/bug.h> 40 41 #define __rcu 42 43 #define RCU_INIT_POINTER(P, V) ((P) = (V)) 44 45 #define rcu_assign_pointer(P,V) atomic_store_release(&(P), (V)) 46 #define rcu_dereference(P) atomic_load_consume(&(P)) 47 #define rcu_access_pointer(P) atomic_load_relaxed(&(P)) 48 49 #define rcu_dereference_raw rcu_dereference 50 51 #define rcu_dereference_protected(P, C) ({ \ 52 WARN_ON(!(C)); \ 53 (P); \ 54 }) 55 56 #define rcu_replace_pointer(PTRP, NEWPTR, C) ({ \ 57 __typeof__(PTRP) __rrp_ptrp = (PTRP); \ 58 __typeof__(PTRP) __rrp_oldptr = \ 59 rcu_dereference_protected(__rrp_ptrp, C); \ 60 rcu_assign_pointer(__rrp_ptrp, NEWPTR); \ 61 __rrp_oldptr; \ 62 }) 63 64 65 /* kill_dependency */ 66 #define rcu_pointer_handoff(P) (P) 67 68 struct rcu_head { 69 union { 70 void (*callback)(struct rcu_head *); 71 void *obj; 72 } rcuh_u; 73 struct rcu_head *rcuh_next; 74 }; 75 76 #define _kfree_rcu linux__kfree_rcu 77 #define call_rcu linux_call_rcu 78 #define cond_synchronize_rcu linux_cond_synchronize_rcu 79 #define destroy_rcu_head linux_destroy_rcu_head 80 #define init_rcu_head linux_init_rcu_head 81 #define get_state_synchronize_rcu linux_get_state_synchronize_rcu 82 #define rcu_barrier linux_rcu_barrier 83 #define synchronize_rcu linux_synchronize_rcu 84 #define synchronize_rcu_expedited linux_synchronize_rcu_expedited 85 86 int linux_rcu_gc_init(void); 87 void linux_rcu_gc_fini(void); 88 89 void init_rcu_head(struct rcu_head *); 90 void destroy_rcu_head(struct rcu_head *); 91 92 void call_rcu(struct rcu_head *, void (*)(struct rcu_head *)); 93 void rcu_barrier(void); 94 void synchronize_rcu(void); 95 void synchronize_rcu_expedited(void); 96 97 unsigned long get_state_synchronize_rcu(void); 98 void cond_synchronize_rcu(unsigned long); 99 100 void _kfree_rcu(struct rcu_head *, void *); 101 102 static inline void 103 rcu_read_lock(void) 104 { 105 106 kpreempt_disable(); /* implies __insn_barrier */ 107 } 108 109 static inline void 110 rcu_read_unlock(void) 111 { 112 113 kpreempt_enable(); /* implies __insn_barrier */ 114 } 115 116 #define kfree_rcu(P, F) \ 117 _kfree_rcu(&(P)->F, (P)) 118 119 #endif /* _LINUX_RCUPDATE_H_ */ 120