1 #ifndef __LINUX_SPINLOCK_H 2 #define __LINUX_SPINLOCK_H 3 4 /* 5 * include/linux/spinlock.h - generic spinlock/rwlock declarations 6 * 7 * here's the role of the various spinlock/rwlock related include files: 8 * 9 * on SMP builds: 10 * 11 * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the 12 * initializers 13 * 14 * linux/spinlock_types.h: 15 * defines the generic type and initializers 16 * 17 * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel 18 * implementations, mostly inline assembly code 19 * 20 * (also included on UP-debug builds:) 21 * 22 * linux/spinlock_api_smp.h: 23 * contains the prototypes for the _spin_*() APIs. 24 * 25 * linux/spinlock.h: builds the final spin_*() APIs. 26 * 27 * on UP builds: 28 * 29 * linux/spinlock_type_up.h: 30 * contains the generic, simplified UP spinlock type. 31 * (which is an empty structure on non-debug builds) 32 * 33 * linux/spinlock_types.h: 34 * defines the generic type and initializers 35 * 36 * linux/spinlock_up.h: 37 * contains the __raw_spin_*()/etc. version of UP 38 * builds. (which are NOPs on non-debug, non-preempt 39 * builds) 40 * 41 * (included on UP-non-debug builds:) 42 * 43 * linux/spinlock_api_up.h: 44 * builds the _spin_*() APIs. 45 * 46 * linux/spinlock.h: builds the final spin_*() APIs. 47 */ 48 49 #include <linux/preempt.h> 50 #include <linux/linkage.h> 51 #include <linux/compiler.h> 52 #include <linux/thread_info.h> 53 #include <linux/kernel.h> 54 #include <linux/stringify.h> 55 56 #include <asm/system.h> 57 58 /* 59 * Must define these before including other files, inline functions need them 60 */ 61 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME 62 63 #define LOCK_SECTION_START(extra) \ 64 ".subsection 1\n\t" \ 65 extra \ 66 ".ifndef " LOCK_SECTION_NAME "\n\t" \ 67 LOCK_SECTION_NAME ":\n\t" \ 68 ".endif\n" 69 70 #define LOCK_SECTION_END \ 71 ".previous\n\t" 72 73 #define __lockfunc fastcall __attribute__((section(".spinlock.text"))) 74 75 /* 76 * Pull the raw_spinlock_t and raw_rwlock_t definitions: 77 */ 78 #include <linux/spinlock_types.h> 79 80 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock); 81 82 /* 83 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them): 84 */ 85 #ifdef CONFIG_SMP 86 # include <asm/spinlock.h> 87 #else 88 # include <linux/spinlock_up.h> 89 #endif 90 91 #ifdef CONFIG_DEBUG_SPINLOCK 92 extern void __spin_lock_init(spinlock_t *lock, const char *name, 93 struct lock_class_key *key); 94 # define spin_lock_init(lock) \ 95 do { \ 96 static struct lock_class_key __key; \ 97 \ 98 __spin_lock_init((lock), #lock, &__key); \ 99 } while (0) 100 101 #else 102 # define spin_lock_init(lock) \ 103 do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0) 104 #endif 105 106 #ifdef CONFIG_DEBUG_SPINLOCK 107 extern void __rwlock_init(rwlock_t *lock, const char *name, 108 struct lock_class_key *key); 109 # define rwlock_init(lock) \ 110 do { \ 111 static struct lock_class_key __key; \ 112 \ 113 __rwlock_init((lock), #lock, &__key); \ 114 } while (0) 115 #else 116 # define rwlock_init(lock) \ 117 do { *(lock) = RW_LOCK_UNLOCKED; } while (0) 118 #endif 119 120 #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock) 121 122 /** 123 * spin_unlock_wait - wait until the spinlock gets unlocked 124 * @lock: the spinlock in question. 125 */ 126 #define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock) 127 128 /* 129 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: 130 */ 131 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) 132 # include <linux/spinlock_api_smp.h> 133 #else 134 # include <linux/spinlock_api_up.h> 135 #endif 136 137 #ifdef CONFIG_DEBUG_SPINLOCK 138 extern void _raw_spin_lock(spinlock_t *lock); 139 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) 140 extern int _raw_spin_trylock(spinlock_t *lock); 141 extern void _raw_spin_unlock(spinlock_t *lock); 142 extern void _raw_read_lock(rwlock_t *lock); 143 extern int _raw_read_trylock(rwlock_t *lock); 144 extern void _raw_read_unlock(rwlock_t *lock); 145 extern void _raw_write_lock(rwlock_t *lock); 146 extern int _raw_write_trylock(rwlock_t *lock); 147 extern void _raw_write_unlock(rwlock_t *lock); 148 #else 149 # define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock) 150 # define _raw_spin_lock_flags(lock, flags) \ 151 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags)) 152 # define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock) 153 # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) 154 # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock) 155 # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock) 156 # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock) 157 # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock) 158 # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock) 159 # define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock) 160 #endif 161 162 #define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock) 163 #define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock) 164 165 /* 166 * Define the various spin_lock and rw_lock methods. Note we define these 167 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various 168 * methods are defined as nops in the case they are not required. 169 */ 170 #define spin_trylock(lock) __cond_lock(_spin_trylock(lock)) 171 #define read_trylock(lock) __cond_lock(_read_trylock(lock)) 172 #define write_trylock(lock) __cond_lock(_write_trylock(lock)) 173 174 #define spin_lock(lock) _spin_lock(lock) 175 176 #ifdef CONFIG_DEBUG_LOCK_ALLOC 177 # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass) 178 #else 179 # define spin_lock_nested(lock, subclass) _spin_lock(lock) 180 #endif 181 182 #define write_lock(lock) _write_lock(lock) 183 #define read_lock(lock) _read_lock(lock) 184 185 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) 186 #define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock) 187 #define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock) 188 #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock) 189 #else 190 #define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags) 191 #define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags) 192 #define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags) 193 #endif 194 195 #define spin_lock_irq(lock) _spin_lock_irq(lock) 196 #define spin_lock_bh(lock) _spin_lock_bh(lock) 197 198 #define read_lock_irq(lock) _read_lock_irq(lock) 199 #define read_lock_bh(lock) _read_lock_bh(lock) 200 201 #define write_lock_irq(lock) _write_lock_irq(lock) 202 #define write_lock_bh(lock) _write_lock_bh(lock) 203 204 /* 205 * We inline the unlock functions in the nondebug case: 206 */ 207 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \ 208 !defined(CONFIG_SMP) 209 # define spin_unlock(lock) _spin_unlock(lock) 210 # define read_unlock(lock) _read_unlock(lock) 211 # define write_unlock(lock) _write_unlock(lock) 212 # define spin_unlock_irq(lock) _spin_unlock_irq(lock) 213 # define read_unlock_irq(lock) _read_unlock_irq(lock) 214 # define write_unlock_irq(lock) _write_unlock_irq(lock) 215 #else 216 # define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) 217 # define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock) 218 # define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock) 219 # define spin_unlock_irq(lock) \ 220 do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) 221 # define read_unlock_irq(lock) \ 222 do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) 223 # define write_unlock_irq(lock) \ 224 do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) 225 #endif 226 227 #define spin_unlock_irqrestore(lock, flags) \ 228 _spin_unlock_irqrestore(lock, flags) 229 #define spin_unlock_bh(lock) _spin_unlock_bh(lock) 230 231 #define read_unlock_irqrestore(lock, flags) \ 232 _read_unlock_irqrestore(lock, flags) 233 #define read_unlock_bh(lock) _read_unlock_bh(lock) 234 235 #define write_unlock_irqrestore(lock, flags) \ 236 _write_unlock_irqrestore(lock, flags) 237 #define write_unlock_bh(lock) _write_unlock_bh(lock) 238 239 #define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock)) 240 241 #define spin_trylock_irq(lock) \ 242 ({ \ 243 local_irq_disable(); \ 244 _spin_trylock(lock) ? \ 245 1 : ({ local_irq_enable(); 0; }); \ 246 }) 247 248 #define spin_trylock_irqsave(lock, flags) \ 249 ({ \ 250 local_irq_save(flags); \ 251 _spin_trylock(lock) ? \ 252 1 : ({ local_irq_restore(flags); 0; }); \ 253 }) 254 255 /* 256 * Pull the atomic_t declaration: 257 * (asm-mips/atomic.h needs above definitions) 258 */ 259 #include <asm/atomic.h> 260 /** 261 * atomic_dec_and_lock - lock on reaching reference count zero 262 * @atomic: the atomic counter 263 * @lock: the spinlock in question 264 */ 265 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); 266 #define atomic_dec_and_lock(atomic, lock) \ 267 __cond_lock(_atomic_dec_and_lock(atomic, lock)) 268 269 /** 270 * spin_can_lock - would spin_trylock() succeed? 271 * @lock: the spinlock in question. 272 */ 273 #define spin_can_lock(lock) (!spin_is_locked(lock)) 274 275 #endif /* __LINUX_SPINLOCK_H */ 276
