1 /* 2 * Copyright (c) 2017-2020 François Tigeot <ftigeot@wolfpond.org> 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 27 #ifndef _LINUX_RCUPDATE_H_ 28 #define _LINUX_RCUPDATE_H_ 29 30 #include <linux/types.h> 31 #include <linux/cache.h> 32 #include <linux/spinlock.h> 33 #include <linux/threads.h> 34 #include <linux/cpumask.h> 35 #include <linux/seqlock.h> 36 #include <linux/lockdep.h> 37 #include <linux/completion.h> 38 #include <linux/bug.h> 39 #include <linux/compiler.h> 40 #include <linux/ktime.h> 41 42 #include <asm/barrier.h> 43 44 #include <linux/rcutree.h> 45 46 static inline void 47 call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *)) 48 { 49 func(head); 50 } 51 52 static inline void 53 rcu_read_lock(void) 54 { 55 preempt_disable(); 56 } 57 58 static inline void 59 rcu_read_unlock(void) 60 { 61 preempt_enable(); 62 } 63 64 #define rcu_dereference_protected(p, condition) \ 65 ((typeof(*p) *)(p)) 66 67 #define rcu_dereference(p) \ 68 ({ \ 69 typeof(*(p)) *__rcu_dereference_tmp = READ_ONCE(p); \ 70 __rcu_dereference_tmp; \ 71 }) 72 73 #define rcu_assign_pointer(p, v) \ 74 do { \ 75 cpu_mfence(); \ 76 WRITE_ONCE((p), (v)); \ 77 } while (0) 78 79 #define RCU_INIT_POINTER(p, v) \ 80 do { \ 81 p = v; \ 82 } while (0) 83 84 #define kfree_rcu(ptr, rcu_head) \ 85 do { \ 86 kfree(ptr); \ 87 } while (0) 88 89 #define rcu_access_pointer(p) ((typeof(*p) *)READ_ONCE(p)) 90 91 #define rcu_pointer_handoff(p) (p) 92 93 #endif /* _LINUX_RCUPDATE_H_ */ 94