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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 |
7143 | serge | 54 | #include |
1408 | serge | 55 | #include |
56 | #include |
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5272 | serge | 57 | #include |
5270 | serge | 58 | #include |
1408 | serge | 59 | |
60 | |||
61 | /* |
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62 | * Must define these before including other files, inline functions need them |
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63 | */ |
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1970 | serge | 64 | #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME |
1408 | serge | 65 | |
66 | #define LOCK_SECTION_START(extra) \ |
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67 | ".subsection 1\n\t" \ |
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68 | extra \ |
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69 | ".ifndef " LOCK_SECTION_NAME "\n\t" \ |
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70 | LOCK_SECTION_NAME ":\n\t" \ |
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71 | ".endif\n" |
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72 | |||
73 | #define LOCK_SECTION_END \ |
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74 | ".previous\n\t" |
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75 | |||
76 | #define __lockfunc __attribute__((section(".spinlock.text"))) |
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77 | |||
78 | /* |
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1970 | serge | 79 | * Pull the arch_spinlock_t and arch_rwlock_t definitions: |
1408 | serge | 80 | */ |
81 | #include |
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82 | |||
83 | /* |
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1970 | serge | 84 | * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them): |
1408 | serge | 85 | */ |
86 | #ifdef CONFIG_SMP |
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87 | # include |
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88 | #else |
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89 | # include |
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90 | #endif |
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91 | |||
92 | #ifdef CONFIG_DEBUG_SPINLOCK |
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5272 | serge | 93 | extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, |
6082 | serge | 94 | struct lock_class_key *key); |
5272 | serge | 95 | # define raw_spin_lock_init(lock) \ |
1408 | serge | 96 | do { \ |
97 | static struct lock_class_key __key; \ |
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98 | \ |
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5272 | serge | 99 | __raw_spin_lock_init((lock), #lock, &__key); \ |
1408 | serge | 100 | } while (0) |
101 | |||
102 | #else |
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5272 | serge | 103 | # define raw_spin_lock_init(lock) \ |
104 | do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) |
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1408 | serge | 105 | #endif |
106 | |||
5272 | serge | 107 | #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) |
1408 | serge | 108 | |
109 | #ifdef CONFIG_GENERIC_LOCKBREAK |
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5272 | serge | 110 | #define raw_spin_is_contended(lock) ((lock)->break_lock) |
1408 | serge | 111 | #else |
112 | |||
5272 | serge | 113 | #ifdef arch_spin_is_contended |
114 | #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) |
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1408 | serge | 115 | #else |
5272 | serge | 116 | #define raw_spin_is_contended(lock) (((void)(lock), 0)) |
117 | #endif /*arch_spin_is_contended*/ |
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1408 | serge | 118 | #endif |
119 | |||
5272 | serge | 120 | /* |
121 | * Despite its name it doesn't necessarily has to be a full barrier. |
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122 | * It should only guarantee that a STORE before the critical section |
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6082 | serge | 123 | * can not be reordered with LOADs and STOREs inside this section. |
5272 | serge | 124 | * spin_lock() is the one-way barrier, this LOAD can not escape out |
125 | * of the region. So the default implementation simply ensures that |
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126 | * a STORE can not move into the critical section, smp_wmb() should |
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127 | * serialize it with another STORE done by spin_lock(). |
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128 | */ |
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129 | #ifndef smp_mb__before_spinlock |
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130 | #define smp_mb__before_spinlock() smp_wmb() |
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1408 | serge | 131 | #endif |
132 | |||
133 | /** |
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5272 | serge | 134 | * raw_spin_unlock_wait - wait until the spinlock gets unlocked |
1408 | serge | 135 | * @lock: the spinlock in question. |
136 | */ |
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5272 | serge | 137 | #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) |
1408 | serge | 138 | |
139 | #ifdef CONFIG_DEBUG_SPINLOCK |
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5272 | serge | 140 | extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); |
141 | #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) |
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142 | extern int do_raw_spin_trylock(raw_spinlock_t *lock); |
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143 | extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); |
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1408 | serge | 144 | #else |
5272 | serge | 145 | static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) |
146 | { |
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147 | __acquire(lock); |
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148 | arch_spin_lock(&lock->raw_lock); |
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149 | } |
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150 | |||
151 | static inline void |
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152 | do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) |
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153 | { |
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154 | __acquire(lock); |
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155 | arch_spin_lock_flags(&lock->raw_lock, *flags); |
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156 | } |
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157 | |||
158 | static inline int do_raw_spin_trylock(raw_spinlock_t *lock) |
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159 | { |
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160 | return arch_spin_trylock(&(lock)->raw_lock); |
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161 | } |
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162 | |||
163 | static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) |
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164 | { |
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165 | arch_spin_unlock(&lock->raw_lock); |
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166 | __release(lock); |
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167 | } |
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1408 | serge | 168 | #endif |
169 | |||
170 | /* |
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5272 | serge | 171 | * Define the various spin_lock methods. Note we define these |
172 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The |
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173 | * various methods are defined as nops in the case they are not |
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174 | * required. |
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1408 | serge | 175 | */ |
5272 | serge | 176 | #define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) |
1408 | serge | 177 | |
5272 | serge | 178 | #define raw_spin_lock(lock) _raw_spin_lock(lock) |
1408 | serge | 179 | |
180 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
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5272 | serge | 181 | # define raw_spin_lock_nested(lock, subclass) \ |
182 | _raw_spin_lock_nested(lock, subclass) |
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6082 | serge | 183 | # define raw_spin_lock_bh_nested(lock, subclass) \ |
184 | _raw_spin_lock_bh_nested(lock, subclass) |
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5272 | serge | 185 | |
186 | # define raw_spin_lock_nest_lock(lock, nest_lock) \ |
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1408 | serge | 187 | do { \ |
188 | typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ |
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5272 | serge | 189 | _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ |
1408 | serge | 190 | } while (0) |
191 | #else |
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5272 | serge | 192 | /* |
193 | * Always evaluate the 'subclass' argument to avoid that the compiler |
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194 | * warns about set-but-not-used variables when building with |
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195 | * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. |
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196 | */ |
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197 | # define raw_spin_lock_nested(lock, subclass) \ |
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198 | _raw_spin_lock(((void)(subclass), (lock))) |
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199 | # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) |
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6082 | serge | 200 | # define raw_spin_lock_bh_nested(lock, subclass) _raw_spin_lock_bh(lock) |
1408 | serge | 201 | #endif |
202 | |||
203 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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204 | |||
5272 | serge | 205 | #define raw_spin_lock_irqsave(lock, flags) \ |
1408 | serge | 206 | do { \ |
207 | typecheck(unsigned long, flags); \ |
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5272 | serge | 208 | flags = _raw_spin_lock_irqsave(lock); \ |
1408 | serge | 209 | } while (0) |
210 | |||
211 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
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5272 | serge | 212 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
1408 | serge | 213 | do { \ |
214 | typecheck(unsigned long, flags); \ |
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5272 | serge | 215 | flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ |
1408 | serge | 216 | } while (0) |
217 | #else |
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5272 | serge | 218 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
1408 | serge | 219 | do { \ |
220 | typecheck(unsigned long, flags); \ |
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5272 | serge | 221 | flags = _raw_spin_lock_irqsave(lock); \ |
1408 | serge | 222 | } while (0) |
223 | #endif |
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224 | |||
225 | #else |
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226 | |||
5272 | serge | 227 | #define raw_spin_lock_irqsave(lock, flags) \ |
1408 | serge | 228 | do { \ |
229 | typecheck(unsigned long, flags); \ |
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5272 | serge | 230 | _raw_spin_lock_irqsave(lock, flags); \ |
1408 | serge | 231 | } while (0) |
232 | |||
5272 | serge | 233 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
234 | raw_spin_lock_irqsave(lock, flags) |
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235 | |||
1408 | serge | 236 | #endif |
237 | |||
5272 | serge | 238 | #define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) |
239 | #define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) |
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240 | #define raw_spin_unlock(lock) _raw_spin_unlock(lock) |
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241 | #define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) |
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1408 | serge | 242 | |
5272 | serge | 243 | #define raw_spin_unlock_irqrestore(lock, flags) \ |
6082 | serge | 244 | do { \ |
245 | typecheck(unsigned long, flags); \ |
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5272 | serge | 246 | _raw_spin_unlock_irqrestore(lock, flags); \ |
1408 | serge | 247 | } while (0) |
5272 | serge | 248 | #define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) |
1408 | serge | 249 | |
5272 | serge | 250 | #define raw_spin_trylock_bh(lock) \ |
251 | __cond_lock(lock, _raw_spin_trylock_bh(lock)) |
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1408 | serge | 252 | |
5272 | serge | 253 | #define raw_spin_trylock_irq(lock) \ |
1408 | serge | 254 | ({ \ |
255 | local_irq_disable(); \ |
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5272 | serge | 256 | raw_spin_trylock(lock) ? \ |
1408 | serge | 257 | 1 : ({ local_irq_enable(); 0; }); \ |
258 | }) |
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259 | |||
5272 | serge | 260 | #define raw_spin_trylock_irqsave(lock, flags) \ |
1408 | serge | 261 | ({ \ |
262 | local_irq_save(flags); \ |
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5272 | serge | 263 | raw_spin_trylock(lock) ? \ |
1408 | serge | 264 | 1 : ({ local_irq_restore(flags); 0; }); \ |
265 | }) |
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266 | |||
5272 | serge | 267 | /** |
268 | * raw_spin_can_lock - would raw_spin_trylock() succeed? |
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269 | * @lock: the spinlock in question. |
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270 | */ |
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271 | #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) |
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272 | |||
273 | /* Include rwlock functions */ |
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274 | #include |
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275 | |||
276 | /* |
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277 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: |
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278 | */ |
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279 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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280 | # include |
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281 | #else |
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282 | # include |
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283 | #endif |
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284 | |||
285 | /* |
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286 | * Map the spin_lock functions to the raw variants for PREEMPT_RT=n |
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287 | */ |
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288 | |||
6082 | serge | 289 | static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock) |
5272 | serge | 290 | { |
291 | return &lock->rlock; |
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292 | } |
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293 | |||
294 | #define spin_lock_init(_lock) \ |
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295 | do { \ |
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296 | spinlock_check(_lock); \ |
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297 | raw_spin_lock_init(&(_lock)->rlock); \ |
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298 | } while (0) |
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299 | |||
6082 | serge | 300 | static __always_inline void spin_lock(spinlock_t *lock) |
5272 | serge | 301 | { |
302 | raw_spin_lock(&lock->rlock); |
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303 | } |
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304 | |||
6082 | serge | 305 | static __always_inline void spin_lock_bh(spinlock_t *lock) |
5272 | serge | 306 | { |
307 | raw_spin_lock_bh(&lock->rlock); |
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308 | } |
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309 | |||
6082 | serge | 310 | static __always_inline int spin_trylock(spinlock_t *lock) |
5272 | serge | 311 | { |
312 | return raw_spin_trylock(&lock->rlock); |
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313 | } |
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314 | |||
315 | #define spin_lock_nested(lock, subclass) \ |
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316 | do { \ |
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317 | raw_spin_lock_nested(spinlock_check(lock), subclass); \ |
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318 | } while (0) |
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319 | |||
6082 | serge | 320 | #define spin_lock_bh_nested(lock, subclass) \ |
321 | do { \ |
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322 | raw_spin_lock_bh_nested(spinlock_check(lock), subclass);\ |
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323 | } while (0) |
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324 | |||
5272 | serge | 325 | #define spin_lock_nest_lock(lock, nest_lock) \ |
326 | do { \ |
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327 | raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ |
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328 | } while (0) |
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329 | |||
6082 | serge | 330 | static __always_inline void spin_lock_irq(spinlock_t *lock) |
5272 | serge | 331 | { |
332 | raw_spin_lock_irq(&lock->rlock); |
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333 | } |
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334 | |||
335 | #define spin_lock_irqsave(lock, flags) \ |
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336 | do { \ |
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337 | raw_spin_lock_irqsave(spinlock_check(lock), flags); \ |
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338 | } while (0) |
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339 | |||
340 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
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341 | do { \ |
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342 | raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ |
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343 | } while (0) |
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344 | |||
6082 | serge | 345 | static __always_inline void spin_unlock(spinlock_t *lock) |
5272 | serge | 346 | { |
347 | raw_spin_unlock(&lock->rlock); |
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348 | } |
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349 | |||
6082 | serge | 350 | static __always_inline void spin_unlock_bh(spinlock_t *lock) |
5272 | serge | 351 | { |
352 | raw_spin_unlock_bh(&lock->rlock); |
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353 | } |
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354 | |||
6082 | serge | 355 | static __always_inline void spin_unlock_irq(spinlock_t *lock) |
5272 | serge | 356 | { |
357 | raw_spin_unlock_irq(&lock->rlock); |
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358 | } |
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359 | |||
6082 | serge | 360 | static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) |
5272 | serge | 361 | { |
362 | raw_spin_unlock_irqrestore(&lock->rlock, flags); |
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363 | } |
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364 | |||
6082 | serge | 365 | static __always_inline int spin_trylock_bh(spinlock_t *lock) |
5272 | serge | 366 | { |
367 | return raw_spin_trylock_bh(&lock->rlock); |
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368 | } |
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369 | |||
6082 | serge | 370 | static __always_inline int spin_trylock_irq(spinlock_t *lock) |
5272 | serge | 371 | { |
372 | return raw_spin_trylock_irq(&lock->rlock); |
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373 | } |
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374 | |||
375 | #define spin_trylock_irqsave(lock, flags) \ |
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6082 | serge | 376 | ({ \ |
5272 | serge | 377 | raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ |
1408 | serge | 378 | }) |
379 | |||
6082 | serge | 380 | static __always_inline void spin_unlock_wait(spinlock_t *lock) |
5272 | serge | 381 | { |
382 | raw_spin_unlock_wait(&lock->rlock); |
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383 | } |
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384 | |||
6082 | serge | 385 | static __always_inline int spin_is_locked(spinlock_t *lock) |
5272 | serge | 386 | { |
387 | return raw_spin_is_locked(&lock->rlock); |
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388 | } |
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389 | |||
6082 | serge | 390 | static __always_inline int spin_is_contended(spinlock_t *lock) |
5272 | serge | 391 | { |
392 | return raw_spin_is_contended(&lock->rlock); |
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393 | } |
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394 | |||
6082 | serge | 395 | static __always_inline int spin_can_lock(spinlock_t *lock) |
5272 | serge | 396 | { |
397 | return raw_spin_can_lock(&lock->rlock); |
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398 | } |
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399 | |||
400 | #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) |
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401 | |||
1408 | serge | 402 | /* |
403 | * Pull the atomic_t declaration: |
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404 | * (asm-mips/atomic.h needs above definitions) |
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405 | */ |
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5272 | serge | 406 | #include |
1408 | serge | 407 | /** |
408 | * atomic_dec_and_lock - lock on reaching reference count zero |
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409 | * @atomic: the atomic counter |
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410 | * @lock: the spinlock in question |
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411 | * |
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412 | * Decrements @atomic by 1. If the result is 0, returns true and locks |
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413 | * @lock. Returns false for all other cases. |
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414 | */ |
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415 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
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416 | #define atomic_dec_and_lock(atomic, lock) \ |
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417 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
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418 | |||
419 | #endif /* __LINUX_SPINLOCK_H */ |