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 #ifndef _LINUXKPI_LINUX_RCUPDATE_H_ 27 #define _LINUXKPI_LINUX_RCUPDATE_H_ 28 29 #include <linux/compiler.h> 30 #include <linux/types.h> 31 32 #include <machine/atomic.h> 33 34 #define LINUX_KFREE_RCU_OFFSET_MAX 4096 /* exclusive */ 35 36 /* BSD specific defines */ 37 #define RCU_TYPE_REGULAR 0 38 #define RCU_TYPE_SLEEPABLE 1 39 #define RCU_TYPE_MAX 2 40 41 #define RCU_INITIALIZER(v) \ 42 ((__typeof(*(v)) *)(v)) 43 44 #define RCU_INIT_POINTER(p, v) do { \ 45 (p) = (v); \ 46 } while (0) 47 48 #define call_rcu(ptr, func) do { \ 49 linux_call_rcu(RCU_TYPE_REGULAR, ptr, func); \ 50 } while (0) 51 52 #define rcu_barrier(void) do { \ 53 linux_rcu_barrier(RCU_TYPE_REGULAR); \ 54 } while (0) 55 56 #define rcu_read_lock(void) do { \ 57 linux_rcu_read_lock(RCU_TYPE_REGULAR); \ 58 } while (0) 59 60 #define rcu_read_unlock(void) do { \ 61 linux_rcu_read_unlock(RCU_TYPE_REGULAR);\ 62 } while (0) 63 64 #define synchronize_rcu(void) do { \ 65 linux_synchronize_rcu(RCU_TYPE_REGULAR); \ 66 } while (0) 67 68 #define synchronize_rcu_expedited(void) do { \ 69 linux_synchronize_rcu(RCU_TYPE_REGULAR); \ 70 } while (0) 71 72 #define kfree_rcu(ptr, rcu_head) do { \ 73 CTASSERT(offsetof(__typeof(*(ptr)), rcu_head) < \ 74 LINUX_KFREE_RCU_OFFSET_MAX); \ 75 call_rcu(&(ptr)->rcu_head, (rcu_callback_t)(uintptr_t) \ 76 offsetof(__typeof(*(ptr)), rcu_head)); \ 77 } while (0) 78 79 #define rcu_access_pointer(p) \ 80 ((__typeof(*p) *)READ_ONCE(p)) 81 82 #define rcu_dereference_protected(p, c) \ 83 ((__typeof(*p) *)READ_ONCE(p)) 84 85 #define rcu_dereference(p) \ 86 rcu_dereference_protected(p, 0) 87 88 #define rcu_dereference_check(p, c) \ 89 rcu_dereference_protected(p, c) 90 91 #define rcu_dereference_raw(p) \ 92 ((__typeof(*p) *)READ_ONCE(p)) 93 94 #define rcu_pointer_handoff(p) (p) 95 96 #define rcu_assign_pointer(p, v) do { \ 97 atomic_store_rel_ptr((volatile uintptr_t *)&(p), \ 98 (uintptr_t)(v)); \ 99 } while (0) 100 101 #define rcu_replace_pointer(rcu, ptr, c) \ 102 ({ \ 103 typeof(ptr) __tmp = rcu_dereference_protected(rcu, c); \ 104 rcu_assign_pointer(rcu, ptr); \ 105 __tmp; \ 106 }) 107 108 #define rcu_swap_protected(rcu, ptr, c) do { \ 109 typeof(ptr) p = rcu_dereference_protected(rcu, c); \ 110 rcu_assign_pointer(rcu, ptr); \ 111 (ptr) = p; \ 112 } while (0) 113 114 /* prototypes */ 115 116 extern void linux_call_rcu(unsigned type, struct rcu_head *ptr, rcu_callback_t func); 117 extern void linux_rcu_barrier(unsigned type); 118 extern void linux_rcu_read_lock(unsigned type); 119 extern void linux_rcu_read_unlock(unsigned type); 120 extern void linux_synchronize_rcu(unsigned type); 121 122 /* Empty implementation for !DEBUG */ 123 #define init_rcu_head(...) 124 #define destroy_rcu_head(...) 125 #define init_rcu_head_on_stack(...) 126 #define destroy_rcu_head_on_stack(...) 127 128 #endif /* _LINUXKPI_LINUX_RCUPDATE_H_ */ 129