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Rev | Author | Line No. | Line |
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1408 | serge | 1 | #ifndef __LINUX_SPINLOCK_H |
2 | #define __LINUX_SPINLOCK_H |
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3 | |||
4 | /* |
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5 | * include/linux/spinlock.h - generic spinlock/rwlock declarations |
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6 | * |
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7 | * here's the role of the various spinlock/rwlock related include files: |
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8 | * |
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9 | * on SMP builds: |
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10 | * |
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1970 | serge | 11 | * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the |
1408 | serge | 12 | * initializers |
13 | * |
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14 | * linux/spinlock_types.h: |
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15 | * defines the generic type and initializers |
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16 | * |
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1970 | serge | 17 | * asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel |
1408 | serge | 18 | * implementations, mostly inline assembly code |
19 | * |
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20 | * (also included on UP-debug builds:) |
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21 | * |
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22 | * linux/spinlock_api_smp.h: |
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23 | * contains the prototypes for the _spin_*() APIs. |
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24 | * |
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25 | * linux/spinlock.h: builds the final spin_*() APIs. |
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26 | * |
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27 | * on UP builds: |
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28 | * |
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29 | * linux/spinlock_type_up.h: |
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30 | * contains the generic, simplified UP spinlock type. |
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31 | * (which is an empty structure on non-debug builds) |
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32 | * |
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33 | * linux/spinlock_types.h: |
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34 | * defines the generic type and initializers |
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35 | * |
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36 | * linux/spinlock_up.h: |
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1970 | serge | 37 | * contains the arch_spin_*()/etc. version of UP |
1408 | serge | 38 | * builds. (which are NOPs on non-debug, non-preempt |
39 | * builds) |
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40 | * |
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41 | * (included on UP-non-debug builds:) |
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42 | * |
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43 | * linux/spinlock_api_up.h: |
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44 | * builds the _spin_*() APIs. |
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45 | * |
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46 | * linux/spinlock.h: builds the final spin_*() APIs. |
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47 | */ |
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48 | |||
49 | #include |
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5272 | serge | 50 | #include |
5270 | serge | 51 | #include |
1408 | serge | 52 | #include |
5272 | serge | 53 | #include |
1408 | serge | 54 | #include |
55 | #include |
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5272 | serge | 56 | #include |
5270 | serge | 57 | #include |
1408 | serge | 58 | |
59 | |||
60 | /* |
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61 | * Must define these before including other files, inline functions need them |
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62 | */ |
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1970 | serge | 63 | #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME |
1408 | serge | 64 | |
65 | #define LOCK_SECTION_START(extra) \ |
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66 | ".subsection 1\n\t" \ |
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67 | extra \ |
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68 | ".ifndef " LOCK_SECTION_NAME "\n\t" \ |
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69 | LOCK_SECTION_NAME ":\n\t" \ |
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70 | ".endif\n" |
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71 | |||
72 | #define LOCK_SECTION_END \ |
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73 | ".previous\n\t" |
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74 | |||
75 | #define __lockfunc __attribute__((section(".spinlock.text"))) |
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76 | |||
77 | /* |
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1970 | serge | 78 | * Pull the arch_spinlock_t and arch_rwlock_t definitions: |
1408 | serge | 79 | */ |
80 | #include |
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81 | |||
82 | /* |
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1970 | serge | 83 | * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them): |
1408 | serge | 84 | */ |
85 | #ifdef CONFIG_SMP |
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86 | # include |
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87 | #else |
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88 | # include |
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89 | #endif |
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90 | |||
91 | #ifdef CONFIG_DEBUG_SPINLOCK |
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5272 | serge | 92 | extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, |
6082 | serge | 93 | struct lock_class_key *key); |
5272 | serge | 94 | # define raw_spin_lock_init(lock) \ |
1408 | serge | 95 | do { \ |
96 | static struct lock_class_key __key; \ |
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97 | \ |
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5272 | serge | 98 | __raw_spin_lock_init((lock), #lock, &__key); \ |
1408 | serge | 99 | } while (0) |
100 | |||
101 | #else |
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5272 | serge | 102 | # define raw_spin_lock_init(lock) \ |
103 | do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) |
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1408 | serge | 104 | #endif |
105 | |||
5272 | serge | 106 | #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) |
1408 | serge | 107 | |
108 | #ifdef CONFIG_GENERIC_LOCKBREAK |
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5272 | serge | 109 | #define raw_spin_is_contended(lock) ((lock)->break_lock) |
1408 | serge | 110 | #else |
111 | |||
5272 | serge | 112 | #ifdef arch_spin_is_contended |
113 | #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) |
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1408 | serge | 114 | #else |
5272 | serge | 115 | #define raw_spin_is_contended(lock) (((void)(lock), 0)) |
116 | #endif /*arch_spin_is_contended*/ |
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1408 | serge | 117 | #endif |
118 | |||
5272 | serge | 119 | /* |
120 | * Despite its name it doesn't necessarily has to be a full barrier. |
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121 | * It should only guarantee that a STORE before the critical section |
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6082 | serge | 122 | * can not be reordered with LOADs and STOREs inside this section. |
5272 | serge | 123 | * spin_lock() is the one-way barrier, this LOAD can not escape out |
124 | * of the region. So the default implementation simply ensures that |
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125 | * a STORE can not move into the critical section, smp_wmb() should |
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126 | * serialize it with another STORE done by spin_lock(). |
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127 | */ |
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128 | #ifndef smp_mb__before_spinlock |
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129 | #define smp_mb__before_spinlock() smp_wmb() |
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1408 | serge | 130 | #endif |
131 | |||
132 | /** |
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5272 | serge | 133 | * raw_spin_unlock_wait - wait until the spinlock gets unlocked |
1408 | serge | 134 | * @lock: the spinlock in question. |
135 | */ |
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5272 | serge | 136 | #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) |
1408 | serge | 137 | |
138 | #ifdef CONFIG_DEBUG_SPINLOCK |
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5272 | serge | 139 | extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); |
140 | #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) |
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141 | extern int do_raw_spin_trylock(raw_spinlock_t *lock); |
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142 | extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); |
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1408 | serge | 143 | #else |
5272 | serge | 144 | static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) |
145 | { |
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146 | __acquire(lock); |
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147 | arch_spin_lock(&lock->raw_lock); |
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148 | } |
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149 | |||
150 | static inline void |
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151 | do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) |
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152 | { |
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153 | __acquire(lock); |
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154 | arch_spin_lock_flags(&lock->raw_lock, *flags); |
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155 | } |
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156 | |||
157 | static inline int do_raw_spin_trylock(raw_spinlock_t *lock) |
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158 | { |
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159 | return arch_spin_trylock(&(lock)->raw_lock); |
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160 | } |
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161 | |||
162 | static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) |
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163 | { |
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164 | arch_spin_unlock(&lock->raw_lock); |
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165 | __release(lock); |
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166 | } |
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1408 | serge | 167 | #endif |
168 | |||
169 | /* |
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5272 | serge | 170 | * Define the various spin_lock methods. Note we define these |
171 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The |
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172 | * various methods are defined as nops in the case they are not |
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173 | * required. |
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1408 | serge | 174 | */ |
5272 | serge | 175 | #define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) |
1408 | serge | 176 | |
5272 | serge | 177 | #define raw_spin_lock(lock) _raw_spin_lock(lock) |
1408 | serge | 178 | |
179 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
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5272 | serge | 180 | # define raw_spin_lock_nested(lock, subclass) \ |
181 | _raw_spin_lock_nested(lock, subclass) |
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6082 | serge | 182 | # define raw_spin_lock_bh_nested(lock, subclass) \ |
183 | _raw_spin_lock_bh_nested(lock, subclass) |
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5272 | serge | 184 | |
185 | # define raw_spin_lock_nest_lock(lock, nest_lock) \ |
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1408 | serge | 186 | do { \ |
187 | typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ |
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5272 | serge | 188 | _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ |
1408 | serge | 189 | } while (0) |
190 | #else |
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5272 | serge | 191 | /* |
192 | * Always evaluate the 'subclass' argument to avoid that the compiler |
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193 | * warns about set-but-not-used variables when building with |
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194 | * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. |
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195 | */ |
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196 | # define raw_spin_lock_nested(lock, subclass) \ |
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197 | _raw_spin_lock(((void)(subclass), (lock))) |
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198 | # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) |
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6082 | serge | 199 | # define raw_spin_lock_bh_nested(lock, subclass) _raw_spin_lock_bh(lock) |
1408 | serge | 200 | #endif |
201 | |||
202 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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203 | |||
5272 | serge | 204 | #define raw_spin_lock_irqsave(lock, flags) \ |
1408 | serge | 205 | do { \ |
206 | typecheck(unsigned long, flags); \ |
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5272 | serge | 207 | flags = _raw_spin_lock_irqsave(lock); \ |
1408 | serge | 208 | } while (0) |
209 | |||
210 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
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5272 | serge | 211 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
1408 | serge | 212 | do { \ |
213 | typecheck(unsigned long, flags); \ |
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5272 | serge | 214 | flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ |
1408 | serge | 215 | } while (0) |
216 | #else |
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5272 | serge | 217 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
1408 | serge | 218 | do { \ |
219 | typecheck(unsigned long, flags); \ |
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5272 | serge | 220 | flags = _raw_spin_lock_irqsave(lock); \ |
1408 | serge | 221 | } while (0) |
222 | #endif |
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223 | |||
224 | #else |
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225 | |||
5272 | serge | 226 | #define raw_spin_lock_irqsave(lock, flags) \ |
1408 | serge | 227 | do { \ |
228 | typecheck(unsigned long, flags); \ |
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5272 | serge | 229 | _raw_spin_lock_irqsave(lock, flags); \ |
1408 | serge | 230 | } while (0) |
231 | |||
5272 | serge | 232 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
233 | raw_spin_lock_irqsave(lock, flags) |
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234 | |||
1408 | serge | 235 | #endif |
236 | |||
5272 | serge | 237 | #define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) |
238 | #define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) |
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239 | #define raw_spin_unlock(lock) _raw_spin_unlock(lock) |
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240 | #define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) |
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1408 | serge | 241 | |
5272 | serge | 242 | #define raw_spin_unlock_irqrestore(lock, flags) \ |
6082 | serge | 243 | do { \ |
244 | typecheck(unsigned long, flags); \ |
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5272 | serge | 245 | _raw_spin_unlock_irqrestore(lock, flags); \ |
1408 | serge | 246 | } while (0) |
5272 | serge | 247 | #define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) |
1408 | serge | 248 | |
5272 | serge | 249 | #define raw_spin_trylock_bh(lock) \ |
250 | __cond_lock(lock, _raw_spin_trylock_bh(lock)) |
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1408 | serge | 251 | |
5272 | serge | 252 | #define raw_spin_trylock_irq(lock) \ |
1408 | serge | 253 | ({ \ |
254 | local_irq_disable(); \ |
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5272 | serge | 255 | raw_spin_trylock(lock) ? \ |
1408 | serge | 256 | 1 : ({ local_irq_enable(); 0; }); \ |
257 | }) |
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258 | |||
5272 | serge | 259 | #define raw_spin_trylock_irqsave(lock, flags) \ |
1408 | serge | 260 | ({ \ |
261 | local_irq_save(flags); \ |
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5272 | serge | 262 | raw_spin_trylock(lock) ? \ |
1408 | serge | 263 | 1 : ({ local_irq_restore(flags); 0; }); \ |
264 | }) |
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265 | |||
5272 | serge | 266 | /** |
267 | * raw_spin_can_lock - would raw_spin_trylock() succeed? |
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268 | * @lock: the spinlock in question. |
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269 | */ |
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270 | #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) |
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271 | |||
272 | /* Include rwlock functions */ |
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273 | #include |
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274 | |||
275 | /* |
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276 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: |
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277 | */ |
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278 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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279 | # include |
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280 | #else |
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281 | # include |
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282 | #endif |
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283 | |||
284 | /* |
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285 | * Map the spin_lock functions to the raw variants for PREEMPT_RT=n |
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286 | */ |
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287 | |||
6082 | serge | 288 | static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock) |
5272 | serge | 289 | { |
290 | return &lock->rlock; |
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291 | } |
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292 | |||
293 | #define spin_lock_init(_lock) \ |
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294 | do { \ |
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295 | spinlock_check(_lock); \ |
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296 | raw_spin_lock_init(&(_lock)->rlock); \ |
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297 | } while (0) |
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298 | |||
6082 | serge | 299 | static __always_inline void spin_lock(spinlock_t *lock) |
5272 | serge | 300 | { |
301 | raw_spin_lock(&lock->rlock); |
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302 | } |
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303 | |||
6082 | serge | 304 | static __always_inline void spin_lock_bh(spinlock_t *lock) |
5272 | serge | 305 | { |
306 | raw_spin_lock_bh(&lock->rlock); |
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307 | } |
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308 | |||
6082 | serge | 309 | static __always_inline int spin_trylock(spinlock_t *lock) |
5272 | serge | 310 | { |
311 | return raw_spin_trylock(&lock->rlock); |
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312 | } |
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313 | |||
314 | #define spin_lock_nested(lock, subclass) \ |
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315 | do { \ |
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316 | raw_spin_lock_nested(spinlock_check(lock), subclass); \ |
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317 | } while (0) |
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318 | |||
6082 | serge | 319 | #define spin_lock_bh_nested(lock, subclass) \ |
320 | do { \ |
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321 | raw_spin_lock_bh_nested(spinlock_check(lock), subclass);\ |
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322 | } while (0) |
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323 | |||
5272 | serge | 324 | #define spin_lock_nest_lock(lock, nest_lock) \ |
325 | do { \ |
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326 | raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ |
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327 | } while (0) |
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328 | |||
6082 | serge | 329 | static __always_inline void spin_lock_irq(spinlock_t *lock) |
5272 | serge | 330 | { |
331 | raw_spin_lock_irq(&lock->rlock); |
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332 | } |
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333 | |||
334 | #define spin_lock_irqsave(lock, flags) \ |
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335 | do { \ |
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336 | raw_spin_lock_irqsave(spinlock_check(lock), flags); \ |
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337 | } while (0) |
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338 | |||
339 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
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340 | do { \ |
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341 | raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ |
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342 | } while (0) |
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343 | |||
6082 | serge | 344 | static __always_inline void spin_unlock(spinlock_t *lock) |
5272 | serge | 345 | { |
346 | raw_spin_unlock(&lock->rlock); |
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347 | } |
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348 | |||
6082 | serge | 349 | static __always_inline void spin_unlock_bh(spinlock_t *lock) |
5272 | serge | 350 | { |
351 | raw_spin_unlock_bh(&lock->rlock); |
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352 | } |
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353 | |||
6082 | serge | 354 | static __always_inline void spin_unlock_irq(spinlock_t *lock) |
5272 | serge | 355 | { |
356 | raw_spin_unlock_irq(&lock->rlock); |
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357 | } |
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358 | |||
6082 | serge | 359 | static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) |
5272 | serge | 360 | { |
361 | raw_spin_unlock_irqrestore(&lock->rlock, flags); |
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362 | } |
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363 | |||
6082 | serge | 364 | static __always_inline int spin_trylock_bh(spinlock_t *lock) |
5272 | serge | 365 | { |
366 | return raw_spin_trylock_bh(&lock->rlock); |
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367 | } |
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368 | |||
6082 | serge | 369 | static __always_inline int spin_trylock_irq(spinlock_t *lock) |
5272 | serge | 370 | { |
371 | return raw_spin_trylock_irq(&lock->rlock); |
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372 | } |
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373 | |||
374 | #define spin_trylock_irqsave(lock, flags) \ |
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6082 | serge | 375 | ({ \ |
5272 | serge | 376 | raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ |
1408 | serge | 377 | }) |
378 | |||
6082 | serge | 379 | static __always_inline void spin_unlock_wait(spinlock_t *lock) |
5272 | serge | 380 | { |
381 | raw_spin_unlock_wait(&lock->rlock); |
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382 | } |
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383 | |||
6082 | serge | 384 | static __always_inline int spin_is_locked(spinlock_t *lock) |
5272 | serge | 385 | { |
386 | return raw_spin_is_locked(&lock->rlock); |
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387 | } |
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388 | |||
6082 | serge | 389 | static __always_inline int spin_is_contended(spinlock_t *lock) |
5272 | serge | 390 | { |
391 | return raw_spin_is_contended(&lock->rlock); |
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392 | } |
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393 | |||
6082 | serge | 394 | static __always_inline int spin_can_lock(spinlock_t *lock) |
5272 | serge | 395 | { |
396 | return raw_spin_can_lock(&lock->rlock); |
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397 | } |
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398 | |||
399 | #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) |
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400 | |||
1408 | serge | 401 | /* |
402 | * Pull the atomic_t declaration: |
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403 | * (asm-mips/atomic.h needs above definitions) |
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404 | */ |
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5272 | serge | 405 | #include |
1408 | serge | 406 | /** |
407 | * atomic_dec_and_lock - lock on reaching reference count zero |
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408 | * @atomic: the atomic counter |
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409 | * @lock: the spinlock in question |
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410 | * |
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411 | * Decrements @atomic by 1. If the result is 0, returns true and locks |
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412 | * @lock. Returns false for all other cases. |
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413 | */ |
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414 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
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415 | #define atomic_dec_and_lock(atomic, lock) \ |
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416 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
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417 | |||
418 | #endif /* __LINUX_SPINLOCK_H */ |