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 <asm/atomic.h> 35 #include <sys/param.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/kdb.h> 40 41 #include <linux/compiler.h> 42 #include <linux/rwlock.h> 43 #include <linux/bottom_half.h> 44 45 typedef struct { 46 struct mtx m; 47 } spinlock_t; 48 49 /* 50 * By defining CONFIG_SPIN_SKIP LinuxKPI spinlocks and asserts will be 51 * skipped during panic(). By default it is disabled due to 52 * performance reasons. 53 */ 54 #ifdef CONFIG_SPIN_SKIP 55 #define SPIN_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active) 56 #else 57 #define SPIN_SKIP(void) 0 58 #endif 59 60 #define spin_lock(_l) do { \ 61 if (SPIN_SKIP()) \ 62 break; \ 63 mtx_lock(&(_l)->m); \ 64 local_bh_disable(); \ 65 } while (0) 66 67 #define spin_lock_bh(_l) do { \ 68 spin_lock(_l); \ 69 local_bh_disable(); \ 70 } while (0) 71 72 #define spin_lock_irq(_l) do { \ 73 spin_lock(_l); \ 74 } while (0) 75 76 #define spin_unlock(_l) do { \ 77 if (SPIN_SKIP()) \ 78 break; \ 79 local_bh_enable(); \ 80 mtx_unlock(&(_l)->m); \ 81 } while (0) 82 83 #define spin_unlock_bh(_l) do { \ 84 local_bh_enable(); \ 85 spin_unlock(_l); \ 86 } while (0) 87 88 #define spin_unlock_irq(_l) do { \ 89 spin_unlock(_l); \ 90 } while (0) 91 92 #define spin_trylock(_l) ({ \ 93 int __ret; \ 94 if (SPIN_SKIP()) { \ 95 __ret = 1; \ 96 } else { \ 97 __ret = mtx_trylock(&(_l)->m); \ 98 if (likely(__ret != 0)) \ 99 local_bh_disable(); \ 100 } \ 101 __ret; \ 102 }) 103 104 #define spin_trylock_irq(_l) \ 105 spin_trylock(_l) 106 107 #define spin_lock_nested(_l, _n) do { \ 108 if (SPIN_SKIP()) \ 109 break; \ 110 mtx_lock_flags(&(_l)->m, MTX_DUPOK); \ 111 local_bh_disable(); \ 112 } while (0) 113 114 #define spin_lock_irqsave(_l, flags) do { \ 115 (flags) = 0; \ 116 spin_lock(_l); \ 117 } while (0) 118 119 #define spin_lock_irqsave_nested(_l, flags, _n) do { \ 120 (flags) = 0; \ 121 spin_lock_nested(_l, _n); \ 122 } while (0) 123 124 #define spin_unlock_irqrestore(_l, flags) do { \ 125 spin_unlock(_l); \ 126 } while (0) 127 128 #ifdef WITNESS_ALL 129 /* NOTE: the maximum WITNESS name is 64 chars */ 130 #define __spin_lock_name(name, file, line) \ 131 (((const char *){file ":" #line "-" name}) + \ 132 (sizeof(file) > 16 ? sizeof(file) - 16 : 0)) 133 #else 134 #define __spin_lock_name(name, file, line) name 135 #endif 136 #define _spin_lock_name(...) __spin_lock_name(__VA_ARGS__) 137 #define spin_lock_name(name) _spin_lock_name(name, __FILE__, __LINE__) 138 139 #define spin_lock_init(lock) linux_spin_lock_init(lock, spin_lock_name("lnxspin")) 140 141 static inline void 142 linux_spin_lock_init(spinlock_t *lock, const char *name) 143 { 144 145 memset(lock, 0, sizeof(*lock)); 146 mtx_init(&lock->m, name, NULL, MTX_DEF | MTX_NOWITNESS); 147 } 148 149 static inline void 150 spin_lock_destroy(spinlock_t *lock) 151 { 152 153 mtx_destroy(&lock->m); 154 } 155 156 #define DEFINE_SPINLOCK(lock) \ 157 spinlock_t lock; \ 158 MTX_SYSINIT(lock, &(lock).m, spin_lock_name("lnxspin"), MTX_DEF) 159 160 #define assert_spin_locked(_l) do { \ 161 if (SPIN_SKIP()) \ 162 break; \ 163 mtx_assert(&(_l)->m, MA_OWNED); \ 164 } while (0) 165 166 static inline int 167 atomic_dec_and_lock_irqsave(atomic_t *cnt, spinlock_t *lock, 168 unsigned long flags) 169 { 170 spin_lock_irqsave(lock, flags); 171 if (atomic_dec_and_test(cnt)) 172 return 1; 173 spin_unlock_irqrestore(lock, flags); 174 return 0; 175 } 176 177 #endif /* _LINUX_SPINLOCK_H_ */ 178