1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2017 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 #ifndef _LINUX_SPINLOCK_H_ 32 #define _LINUX_SPINLOCK_H_ 33 34 #include <sys/param.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/kdb.h> 39 40 #include <linux/compiler.h> 41 #include <linux/rwlock.h> 42 #include <linux/bottom_half.h> 43 44 typedef struct { 45 struct mtx m; 46 } spinlock_t; 47 48 /* 49 * By defining CONFIG_SPIN_SKIP LinuxKPI spinlocks and asserts will be 50 * skipped during panic(). By default it is disabled due to 51 * performance reasons. 52 */ 53 #ifdef CONFIG_SPIN_SKIP 54 #define SPIN_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active) 55 #else 56 #define SPIN_SKIP(void) 0 57 #endif 58 59 #define spin_lock(_l) do { \ 60 if (SPIN_SKIP()) \ 61 break; \ 62 mtx_lock(&(_l)->m); \ 63 local_bh_disable(); \ 64 } while (0) 65 66 #define spin_lock_bh(_l) do { \ 67 spin_lock(_l); \ 68 } while (0) 69 70 #define spin_lock_irq(_l) do { \ 71 spin_lock(_l); \ 72 } while (0) 73 74 #define spin_unlock(_l) do { \ 75 if (SPIN_SKIP()) \ 76 break; \ 77 local_bh_enable(); \ 78 mtx_unlock(&(_l)->m); \ 79 } while (0) 80 81 #define spin_unlock_bh(_l) do { \ 82 spin_unlock(_l); \ 83 } while (0) 84 85 #define spin_unlock_irq(_l) do { \ 86 spin_unlock(_l); \ 87 } while (0) 88 89 #define spin_trylock(_l) ({ \ 90 int __ret; \ 91 if (SPIN_SKIP()) { \ 92 __ret = 1; \ 93 } else { \ 94 __ret = mtx_trylock(&(_l)->m); \ 95 if (likely(__ret != 0)) \ 96 local_bh_disable(); \ 97 } \ 98 __ret; \ 99 }) 100 101 #define spin_lock_nested(_l, _n) do { \ 102 if (SPIN_SKIP()) \ 103 break; \ 104 mtx_lock_flags(&(_l)->m, MTX_DUPOK); \ 105 local_bh_disable(); \ 106 } while (0) 107 108 #define spin_lock_irqsave(_l, flags) do { \ 109 (flags) = 0; \ 110 spin_lock(_l); \ 111 } while (0) 112 113 #define spin_lock_irqsave_nested(_l, flags, _n) do { \ 114 (flags) = 0; \ 115 spin_lock_nested(_l, _n); \ 116 } while (0) 117 118 #define spin_unlock_irqrestore(_l, flags) do { \ 119 spin_unlock(_l); \ 120 } while (0) 121 122 #ifdef WITNESS_ALL 123 /* NOTE: the maximum WITNESS name is 64 chars */ 124 #define __spin_lock_name(name, file, line) \ 125 (((const char *){file ":" #line "-" name}) + \ 126 (sizeof(file) > 16 ? sizeof(file) - 16 : 0)) 127 #else 128 #define __spin_lock_name(name, file, line) name 129 #endif 130 #define _spin_lock_name(...) __spin_lock_name(__VA_ARGS__) 131 #define spin_lock_name(name) _spin_lock_name(name, __FILE__, __LINE__) 132 133 #define spin_lock_init(lock) linux_spin_lock_init(lock, spin_lock_name("lnxspin")) 134 135 static inline void 136 linux_spin_lock_init(spinlock_t *lock, const char *name) 137 { 138 139 memset(lock, 0, sizeof(*lock)); 140 mtx_init(&lock->m, name, NULL, MTX_DEF | MTX_NOWITNESS); 141 } 142 143 static inline void 144 spin_lock_destroy(spinlock_t *lock) 145 { 146 147 mtx_destroy(&lock->m); 148 } 149 150 #define DEFINE_SPINLOCK(lock) \ 151 spinlock_t lock; \ 152 MTX_SYSINIT(lock, &(lock).m, spin_lock_name("lnxspin"), MTX_DEF) 153 154 #define assert_spin_locked(_l) do { \ 155 if (SPIN_SKIP()) \ 156 break; \ 157 mtx_assert(&(_l)->m, MA_OWNED); \ 158 } while (0) 159 160 #endif /* _LINUX_SPINLOCK_H_ */ 161