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 #ifndef _LINUXKPI_LINUX_SPINLOCK_H_ 30 #define _LINUXKPI_LINUX_SPINLOCK_H_ 31 32 #include <asm/atomic.h> 33 #include <sys/param.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/mutex.h> 37 #include <sys/kdb.h> 38 39 #include <linux/cleanup.h> 40 #include <linux/compiler.h> 41 #include <linux/rwlock.h> 42 #include <linux/bottom_half.h> 43 #include <linux/lockdep.h> 44 #include <linux/preempt.h> 45 46 typedef struct mtx 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); \ 63 local_bh_disable(); \ 64 } while (0) 65 66 #define spin_lock_bh(_l) do { \ 67 spin_lock(_l); \ 68 local_bh_disable(); \ 69 } while (0) 70 71 #define spin_lock_irq(_l) do { \ 72 spin_lock(_l); \ 73 } while (0) 74 75 #define spin_unlock(_l) do { \ 76 if (SPIN_SKIP()) \ 77 break; \ 78 local_bh_enable(); \ 79 mtx_unlock(_l); \ 80 } while (0) 81 82 #define spin_unlock_bh(_l) do { \ 83 local_bh_enable(); \ 84 spin_unlock(_l); \ 85 } while (0) 86 87 #define spin_unlock_irq(_l) do { \ 88 spin_unlock(_l); \ 89 } while (0) 90 91 #define spin_trylock(_l) ({ \ 92 int __ret; \ 93 if (SPIN_SKIP()) { \ 94 __ret = 1; \ 95 } else { \ 96 __ret = mtx_trylock(_l); \ 97 if (likely(__ret != 0)) \ 98 local_bh_disable(); \ 99 } \ 100 __ret; \ 101 }) 102 103 #define spin_trylock_irq(_l) \ 104 spin_trylock(_l) 105 106 #define spin_trylock_irqsave(_l, flags) ({ \ 107 (flags) = 0; \ 108 spin_trylock(_l); \ 109 }) 110 111 #define spin_lock_nested(_l, _n) do { \ 112 if (SPIN_SKIP()) \ 113 break; \ 114 mtx_lock_flags(_l, MTX_DUPOK); \ 115 local_bh_disable(); \ 116 } while (0) 117 118 #define spin_lock_irqsave(_l, flags) do { \ 119 (flags) = 0; \ 120 spin_lock(_l); \ 121 } while (0) 122 123 #define spin_lock_irqsave_nested(_l, flags, _n) do { \ 124 (flags) = 0; \ 125 spin_lock_nested(_l, _n); \ 126 } while (0) 127 128 #define spin_unlock_irqrestore(_l, flags) do { \ 129 (void)(flags); \ 130 spin_unlock(_l); \ 131 } while (0) 132 133 #ifdef WITNESS_ALL 134 /* NOTE: the maximum WITNESS name is 64 chars */ 135 #define __spin_lock_name(name, file, line) \ 136 (((const char *){file ":" #line "-" name}) + \ 137 (sizeof(file) > 16 ? sizeof(file) - 16 : 0)) 138 #else 139 #define __spin_lock_name(name, file, line) name 140 #endif 141 #define _spin_lock_name(...) __spin_lock_name(__VA_ARGS__) 142 #define spin_lock_name(name) _spin_lock_name(name, __FILE__, __LINE__) 143 144 #define spin_lock_init(lock) mtx_init(lock, spin_lock_name("lnxspin"), \ 145 NULL, MTX_DEF | MTX_NOWITNESS | MTX_NEW) 146 147 #define spin_lock_destroy(_l) mtx_destroy(_l) 148 149 #define DEFINE_SPINLOCK(lock) \ 150 spinlock_t lock; \ 151 MTX_SYSINIT(lock, &lock, spin_lock_name("lnxspin"), MTX_DEF) 152 153 #define assert_spin_locked(_l) do { \ 154 if (SPIN_SKIP()) \ 155 break; \ 156 mtx_assert(_l, MA_OWNED); \ 157 } while (0) 158 159 #define local_irq_save(flags) do { \ 160 (flags) = 0; \ 161 } while (0) 162 163 #define local_irq_restore(flags) do { \ 164 (void)(flags); \ 165 } while (0) 166 167 #define atomic_dec_and_lock_irqsave(cnt, lock, flags) \ 168 _atomic_dec_and_lock_irqsave(cnt, lock, &(flags)) 169 static inline int 170 _atomic_dec_and_lock_irqsave(atomic_t *cnt, spinlock_t *lock, 171 unsigned long *flags) 172 { 173 if (atomic_add_unless(cnt, -1, 1)) 174 return (0); 175 176 spin_lock_irqsave(lock, *flags); 177 if (atomic_dec_and_test(cnt)) 178 return (1); 179 spin_unlock_irqrestore(lock, *flags); 180 return (0); 181 } 182 183 /* 184 * struct raw_spinlock 185 */ 186 187 typedef struct raw_spinlock { 188 struct mtx lock; 189 } raw_spinlock_t; 190 191 #define raw_spin_lock_init(rlock) \ 192 mtx_init(&(rlock)->lock, spin_lock_name("lnxspin_raw"), \ 193 NULL, MTX_DEF | MTX_NOWITNESS | MTX_NEW) 194 195 #define raw_spin_lock(rl) spin_lock(&(rl)->lock) 196 #define raw_spin_trylock(rl) spin_trylock(&(rl)->lock) 197 #define raw_spin_unlock(rl) spin_unlock(&(rl)->lock) 198 199 #define raw_spin_lock_irqsave(rl, f) spin_lock_irqsave(&(rl)->lock, (f)) 200 #define raw_spin_trylock_irqsave(rl, f) spin_trylock_irqsave(&(rl)->lock, (f)) 201 #define raw_spin_unlock_irqrestore(rl, f) spin_unlock_irqrestore(&(rl)->lock, (f)) 202 203 /* 204 * cleanup.h related pre-defined cases. 205 */ 206 DEFINE_LOCK_GUARD_1(spinlock_irqsave, 207 spinlock_t, 208 spin_lock_irqsave(_T->lock, _T->flags), 209 spin_unlock_irqrestore(_T->lock, _T->flags), 210 unsigned long flags) 211 212 #endif /* _LINUXKPI_LINUX_SPINLOCK_H_ */ 213