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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 arch_spinlock_t/arch_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 arch_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 arch_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/typecheck.h>
50#include <linux/preempt.h>
51#include <linux/linkage.h>
52#include <linux/compiler.h>
53#include <linux/irqflags.h>
54#include <linux/thread_info.h>
55#include <linux/kernel.h>
56#include <linux/stringify.h>
57#include <linux/bottom_half.h>
58#include <asm/barrier.h>
59
60
61/*
62 * Must define these before including other files, inline functions need them
63 */
64#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME
65
66#define LOCK_SECTION_START(extra) \
67 ".subsection 1\n\t" \
68 extra \
69 ".ifndef " LOCK_SECTION_NAME "\n\t" \
70 LOCK_SECTION_NAME ":\n\t" \
71 ".endif\n"
72
73#define LOCK_SECTION_END \
74 ".previous\n\t"
75
76#define __lockfunc __attribute__((section(".spinlock.text")))
77
78/*
79 * Pull the arch_spinlock_t and arch_rwlock_t definitions:
80 */
81#include <linux/spinlock_types.h>
82
83/*
84 * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
85 */
86#ifdef CONFIG_SMP
87# include <asm/spinlock.h>
88#else
89# include <linux/spinlock_up.h>
90#endif
91
92#ifdef CONFIG_DEBUG_SPINLOCK
93 extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
94 struct lock_class_key *key);
95# define raw_spin_lock_init(lock) \
96do { \
97 static struct lock_class_key __key; \
98 \
99 __raw_spin_lock_init((lock), #lock, &__key); \
100} while (0)
101
102#else
103# define raw_spin_lock_init(lock) \
104 do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
105#endif
106
107#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
108
109#ifdef CONFIG_GENERIC_LOCKBREAK
110#define raw_spin_is_contended(lock) ((lock)->break_lock)
111#else
112
113#ifdef arch_spin_is_contended
114#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
115#else
116#define raw_spin_is_contended(lock) (((void)(lock), 0))
117#endif /*arch_spin_is_contended*/
118#endif
119
120/*
121 * Despite its name it doesn't necessarily has to be a full barrier.
122 * It should only guarantee that a STORE before the critical section
123 * can not be reordered with LOADs and STOREs inside this section.
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
126 * a STORE can not move into the critical section, smp_wmb() should
127 * serialize it with another STORE done by spin_lock().
128 */
129#ifndef smp_mb__before_spinlock
130#define smp_mb__before_spinlock() smp_wmb()
131#endif
132
133/**
134 * raw_spin_unlock_wait - wait until the spinlock gets unlocked
135 * @lock: the spinlock in question.
136 */
137#define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock)
138
139#ifdef CONFIG_DEBUG_SPINLOCK
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)
142 extern int do_raw_spin_trylock(raw_spinlock_t *lock);
143 extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
144#else
145static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
146{
147 __acquire(lock);
148 arch_spin_lock(&lock->raw_lock);
149}
150
151static inline void
152do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock)
153{
154 __acquire(lock);
155 arch_spin_lock_flags(&lock->raw_lock, *flags);
156}
157
158static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
159{
160 return arch_spin_trylock(&(lock)->raw_lock);
161}
162
163static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
164{
165 arch_spin_unlock(&lock->raw_lock);
166 __release(lock);
167}
168#endif
169
170/*
171 * Define the various spin_lock methods. Note we define these
172 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
173 * various methods are defined as nops in the case they are not
174 * required.
175 */
176#define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock))
177
178#define raw_spin_lock(lock) _raw_spin_lock(lock)
179
180#ifdef CONFIG_DEBUG_LOCK_ALLOC
181# define raw_spin_lock_nested(lock, subclass) \
182 _raw_spin_lock_nested(lock, subclass)
183# define raw_spin_lock_bh_nested(lock, subclass) \
184 _raw_spin_lock_bh_nested(lock, subclass)
185
186# define raw_spin_lock_nest_lock(lock, nest_lock) \
187 do { \
188 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
189 _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
190 } while (0)
191#else
192/*
193 * Always evaluate the 'subclass' argument to avoid that the compiler
194 * warns about set-but-not-used variables when building with
195 * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1.
196 */
197# define raw_spin_lock_nested(lock, subclass) \
198 _raw_spin_lock(((void)(subclass), (lock)))
199# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock)
200# define raw_spin_lock_bh_nested(lock, subclass) _raw_spin_lock_bh(lock)
201#endif
202
203#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
204
205#define raw_spin_lock_irqsave(lock, flags) \
206 do { \
207 typecheck(unsigned long, flags); \
208 flags = _raw_spin_lock_irqsave(lock); \
209 } while (0)
210
211#ifdef CONFIG_DEBUG_LOCK_ALLOC
212#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
213 do { \
214 typecheck(unsigned long, flags); \
215 flags = _raw_spin_lock_irqsave_nested(lock, subclass); \
216 } while (0)
217#else
218#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
219 do { \
220 typecheck(unsigned long, flags); \
221 flags = _raw_spin_lock_irqsave(lock); \
222 } while (0)
223#endif
224
225#else
226
227#define raw_spin_lock_irqsave(lock, flags) \
228 do { \
229 typecheck(unsigned long, flags); \
230 _raw_spin_lock_irqsave(lock, flags); \
231 } while (0)
232
233#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
234 raw_spin_lock_irqsave(lock, flags)
235
236#endif
237
238#define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock)
239#define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock)
240#define raw_spin_unlock(lock) _raw_spin_unlock(lock)
241#define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock)
242
243#define raw_spin_unlock_irqrestore(lock, flags) \
244 do { \
245 typecheck(unsigned long, flags); \
246 _raw_spin_unlock_irqrestore(lock, flags); \
247 } while (0)
248#define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock)
249
250#define raw_spin_trylock_bh(lock) \
251 __cond_lock(lock, _raw_spin_trylock_bh(lock))
252
253#define raw_spin_trylock_irq(lock) \
254({ \
255 local_irq_disable(); \
256 raw_spin_trylock(lock) ? \
257 1 : ({ local_irq_enable(); 0; }); \
258})
259
260#define raw_spin_trylock_irqsave(lock, flags) \
261({ \
262 local_irq_save(flags); \
263 raw_spin_trylock(lock) ? \
264 1 : ({ local_irq_restore(flags); 0; }); \
265})
266
267/**
268 * raw_spin_can_lock - would raw_spin_trylock() succeed?
269 * @lock: the spinlock in question.
270 */
271#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
272
273/* Include rwlock functions */
274#include <linux/rwlock.h>
275
276/*
277 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
278 */
279#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
280# include <linux/spinlock_api_smp.h>
281#else
282# include <linux/spinlock_api_up.h>
283#endif
284
285/*
286 * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
287 */
288
289static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
290{
291 return &lock->rlock;
292}
293
294#define spin_lock_init(_lock) \
295do { \
296 spinlock_check(_lock); \
297 raw_spin_lock_init(&(_lock)->rlock); \
298} while (0)
299
300static __always_inline void spin_lock(spinlock_t *lock)
301{
302 raw_spin_lock(&lock->rlock);
303}
304
305static __always_inline void spin_lock_bh(spinlock_t *lock)
306{
307 raw_spin_lock_bh(&lock->rlock);
308}
309
310static __always_inline int spin_trylock(spinlock_t *lock)
311{
312 return raw_spin_trylock(&lock->rlock);
313}
314
315#define spin_lock_nested(lock, subclass) \
316do { \
317 raw_spin_lock_nested(spinlock_check(lock), subclass); \
318} while (0)
319
320#define spin_lock_bh_nested(lock, subclass) \
321do { \
322 raw_spin_lock_bh_nested(spinlock_check(lock), subclass);\
323} while (0)
324
325#define spin_lock_nest_lock(lock, nest_lock) \
326do { \
327 raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
328} while (0)
329
330static __always_inline void spin_lock_irq(spinlock_t *lock)
331{
332 raw_spin_lock_irq(&lock->rlock);
333}
334
335#define spin_lock_irqsave(lock, flags) \
336do { \
337 raw_spin_lock_irqsave(spinlock_check(lock), flags); \
338} while (0)
339
340#define spin_lock_irqsave_nested(lock, flags, subclass) \
341do { \
342 raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
343} while (0)
344
345static __always_inline void spin_unlock(spinlock_t *lock)
346{
347 raw_spin_unlock(&lock->rlock);
348}
349
350static __always_inline void spin_unlock_bh(spinlock_t *lock)
351{
352 raw_spin_unlock_bh(&lock->rlock);
353}
354
355static __always_inline void spin_unlock_irq(spinlock_t *lock)
356{
357 raw_spin_unlock_irq(&lock->rlock);
358}
359
360static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
361{
362 raw_spin_unlock_irqrestore(&lock->rlock, flags);
363}
364
365static __always_inline int spin_trylock_bh(spinlock_t *lock)
366{
367 return raw_spin_trylock_bh(&lock->rlock);
368}
369
370static __always_inline int spin_trylock_irq(spinlock_t *lock)
371{
372 return raw_spin_trylock_irq(&lock->rlock);
373}
374
375#define spin_trylock_irqsave(lock, flags) \
376({ \
377 raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
378})
379
380static __always_inline void spin_unlock_wait(spinlock_t *lock)
381{
382 raw_spin_unlock_wait(&lock->rlock);
383}
384
385static __always_inline int spin_is_locked(spinlock_t *lock)
386{
387 return raw_spin_is_locked(&lock->rlock);
388}
389
390static __always_inline int spin_is_contended(spinlock_t *lock)
391{
392 return raw_spin_is_contended(&lock->rlock);
393}
394
395static __always_inline int spin_can_lock(spinlock_t *lock)
396{
397 return raw_spin_can_lock(&lock->rlock);
398}
399
400#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
401
402/*
403 * Pull the atomic_t declaration:
404 * (asm-mips/atomic.h needs above definitions)
405 */
406#include <linux/atomic.h>
407/**
408 * atomic_dec_and_lock - lock on reaching reference count zero
409 * @atomic: the atomic counter
410 * @lock: the spinlock in question
411 *
412 * Decrements @atomic by 1. If the result is 0, returns true and locks
413 * @lock. Returns false for all other cases.
414 */
415extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
416#define atomic_dec_and_lock(atomic, lock) \
417 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
418
419#endif /* __LINUX_SPINLOCK_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_SPINLOCK_H
3#define __LINUX_SPINLOCK_H
4#define __LINUX_INSIDE_SPINLOCK_H
5
6/*
7 * include/linux/spinlock.h - generic spinlock/rwlock declarations
8 *
9 * here's the role of the various spinlock/rwlock related include files:
10 *
11 * on SMP builds:
12 *
13 * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the
14 * initializers
15 *
16 * linux/spinlock_types_raw:
17 * The raw types and initializers
18 * linux/spinlock_types.h:
19 * defines the generic type and initializers
20 *
21 * asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel
22 * implementations, mostly inline assembly code
23 *
24 * (also included on UP-debug builds:)
25 *
26 * linux/spinlock_api_smp.h:
27 * contains the prototypes for the _spin_*() APIs.
28 *
29 * linux/spinlock.h: builds the final spin_*() APIs.
30 *
31 * on UP builds:
32 *
33 * linux/spinlock_type_up.h:
34 * contains the generic, simplified UP spinlock type.
35 * (which is an empty structure on non-debug builds)
36 *
37 * linux/spinlock_types_raw:
38 * The raw RT types and initializers
39 * linux/spinlock_types.h:
40 * defines the generic type and initializers
41 *
42 * linux/spinlock_up.h:
43 * contains the arch_spin_*()/etc. version of UP
44 * builds. (which are NOPs on non-debug, non-preempt
45 * builds)
46 *
47 * (included on UP-non-debug builds:)
48 *
49 * linux/spinlock_api_up.h:
50 * builds the _spin_*() APIs.
51 *
52 * linux/spinlock.h: builds the final spin_*() APIs.
53 */
54
55#include <linux/typecheck.h>
56#include <linux/preempt.h>
57#include <linux/linkage.h>
58#include <linux/compiler.h>
59#include <linux/irqflags.h>
60#include <linux/thread_info.h>
61#include <linux/stringify.h>
62#include <linux/bottom_half.h>
63#include <linux/lockdep.h>
64#include <asm/barrier.h>
65#include <asm/mmiowb.h>
66
67
68/*
69 * Must define these before including other files, inline functions need them
70 */
71#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME
72
73#define LOCK_SECTION_START(extra) \
74 ".subsection 1\n\t" \
75 extra \
76 ".ifndef " LOCK_SECTION_NAME "\n\t" \
77 LOCK_SECTION_NAME ":\n\t" \
78 ".endif\n"
79
80#define LOCK_SECTION_END \
81 ".previous\n\t"
82
83#define __lockfunc __section(".spinlock.text")
84
85/*
86 * Pull the arch_spinlock_t and arch_rwlock_t definitions:
87 */
88#include <linux/spinlock_types.h>
89
90/*
91 * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
92 */
93#ifdef CONFIG_SMP
94# include <asm/spinlock.h>
95#else
96# include <linux/spinlock_up.h>
97#endif
98
99#ifdef CONFIG_DEBUG_SPINLOCK
100 extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
101 struct lock_class_key *key, short inner);
102
103# define raw_spin_lock_init(lock) \
104do { \
105 static struct lock_class_key __key; \
106 \
107 __raw_spin_lock_init((lock), #lock, &__key, LD_WAIT_SPIN); \
108} while (0)
109
110#else
111# define raw_spin_lock_init(lock) \
112 do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
113#endif
114
115#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
116
117#ifdef arch_spin_is_contended
118#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
119#else
120#define raw_spin_is_contended(lock) (((void)(lock), 0))
121#endif /*arch_spin_is_contended*/
122
123/*
124 * smp_mb__after_spinlock() provides the equivalent of a full memory barrier
125 * between program-order earlier lock acquisitions and program-order later
126 * memory accesses.
127 *
128 * This guarantees that the following two properties hold:
129 *
130 * 1) Given the snippet:
131 *
132 * { X = 0; Y = 0; }
133 *
134 * CPU0 CPU1
135 *
136 * WRITE_ONCE(X, 1); WRITE_ONCE(Y, 1);
137 * spin_lock(S); smp_mb();
138 * smp_mb__after_spinlock(); r1 = READ_ONCE(X);
139 * r0 = READ_ONCE(Y);
140 * spin_unlock(S);
141 *
142 * it is forbidden that CPU0 does not observe CPU1's store to Y (r0 = 0)
143 * and CPU1 does not observe CPU0's store to X (r1 = 0); see the comments
144 * preceding the call to smp_mb__after_spinlock() in __schedule() and in
145 * try_to_wake_up().
146 *
147 * 2) Given the snippet:
148 *
149 * { X = 0; Y = 0; }
150 *
151 * CPU0 CPU1 CPU2
152 *
153 * spin_lock(S); spin_lock(S); r1 = READ_ONCE(Y);
154 * WRITE_ONCE(X, 1); smp_mb__after_spinlock(); smp_rmb();
155 * spin_unlock(S); r0 = READ_ONCE(X); r2 = READ_ONCE(X);
156 * WRITE_ONCE(Y, 1);
157 * spin_unlock(S);
158 *
159 * it is forbidden that CPU0's critical section executes before CPU1's
160 * critical section (r0 = 1), CPU2 observes CPU1's store to Y (r1 = 1)
161 * and CPU2 does not observe CPU0's store to X (r2 = 0); see the comments
162 * preceding the calls to smp_rmb() in try_to_wake_up() for similar
163 * snippets but "projected" onto two CPUs.
164 *
165 * Property (2) upgrades the lock to an RCsc lock.
166 *
167 * Since most load-store architectures implement ACQUIRE with an smp_mb() after
168 * the LL/SC loop, they need no further barriers. Similarly all our TSO
169 * architectures imply an smp_mb() for each atomic instruction and equally don't
170 * need more.
171 *
172 * Architectures that can implement ACQUIRE better need to take care.
173 */
174#ifndef smp_mb__after_spinlock
175#define smp_mb__after_spinlock() kcsan_mb()
176#endif
177
178#ifdef CONFIG_DEBUG_SPINLOCK
179 extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
180 extern int do_raw_spin_trylock(raw_spinlock_t *lock);
181 extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
182#else
183static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
184{
185 __acquire(lock);
186 arch_spin_lock(&lock->raw_lock);
187 mmiowb_spin_lock();
188}
189
190static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
191{
192 int ret = arch_spin_trylock(&(lock)->raw_lock);
193
194 if (ret)
195 mmiowb_spin_lock();
196
197 return ret;
198}
199
200static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
201{
202 mmiowb_spin_unlock();
203 arch_spin_unlock(&lock->raw_lock);
204 __release(lock);
205}
206#endif
207
208/*
209 * Define the various spin_lock methods. Note we define these
210 * regardless of whether CONFIG_SMP or CONFIG_PREEMPTION are set. The
211 * various methods are defined as nops in the case they are not
212 * required.
213 */
214#define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock))
215
216#define raw_spin_lock(lock) _raw_spin_lock(lock)
217
218#ifdef CONFIG_DEBUG_LOCK_ALLOC
219# define raw_spin_lock_nested(lock, subclass) \
220 _raw_spin_lock_nested(lock, subclass)
221
222# define raw_spin_lock_nest_lock(lock, nest_lock) \
223 do { \
224 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
225 _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
226 } while (0)
227#else
228/*
229 * Always evaluate the 'subclass' argument to avoid that the compiler
230 * warns about set-but-not-used variables when building with
231 * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1.
232 */
233# define raw_spin_lock_nested(lock, subclass) \
234 _raw_spin_lock(((void)(subclass), (lock)))
235# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock)
236#endif
237
238#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
239
240#define raw_spin_lock_irqsave(lock, flags) \
241 do { \
242 typecheck(unsigned long, flags); \
243 flags = _raw_spin_lock_irqsave(lock); \
244 } while (0)
245
246#ifdef CONFIG_DEBUG_LOCK_ALLOC
247#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
248 do { \
249 typecheck(unsigned long, flags); \
250 flags = _raw_spin_lock_irqsave_nested(lock, subclass); \
251 } while (0)
252#else
253#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
254 do { \
255 typecheck(unsigned long, flags); \
256 flags = _raw_spin_lock_irqsave(lock); \
257 } while (0)
258#endif
259
260#else
261
262#define raw_spin_lock_irqsave(lock, flags) \
263 do { \
264 typecheck(unsigned long, flags); \
265 _raw_spin_lock_irqsave(lock, flags); \
266 } while (0)
267
268#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
269 raw_spin_lock_irqsave(lock, flags)
270
271#endif
272
273#define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock)
274#define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock)
275#define raw_spin_unlock(lock) _raw_spin_unlock(lock)
276#define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock)
277
278#define raw_spin_unlock_irqrestore(lock, flags) \
279 do { \
280 typecheck(unsigned long, flags); \
281 _raw_spin_unlock_irqrestore(lock, flags); \
282 } while (0)
283#define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock)
284
285#define raw_spin_trylock_bh(lock) \
286 __cond_lock(lock, _raw_spin_trylock_bh(lock))
287
288#define raw_spin_trylock_irq(lock) \
289({ \
290 local_irq_disable(); \
291 raw_spin_trylock(lock) ? \
292 1 : ({ local_irq_enable(); 0; }); \
293})
294
295#define raw_spin_trylock_irqsave(lock, flags) \
296({ \
297 local_irq_save(flags); \
298 raw_spin_trylock(lock) ? \
299 1 : ({ local_irq_restore(flags); 0; }); \
300})
301
302#ifndef CONFIG_PREEMPT_RT
303/* Include rwlock functions for !RT */
304#include <linux/rwlock.h>
305#endif
306
307/*
308 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
309 */
310#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
311# include <linux/spinlock_api_smp.h>
312#else
313# include <linux/spinlock_api_up.h>
314#endif
315
316/* Non PREEMPT_RT kernel, map to raw spinlocks: */
317#ifndef CONFIG_PREEMPT_RT
318
319/*
320 * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
321 */
322
323static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
324{
325 return &lock->rlock;
326}
327
328#ifdef CONFIG_DEBUG_SPINLOCK
329
330# define spin_lock_init(lock) \
331do { \
332 static struct lock_class_key __key; \
333 \
334 __raw_spin_lock_init(spinlock_check(lock), \
335 #lock, &__key, LD_WAIT_CONFIG); \
336} while (0)
337
338#else
339
340# define spin_lock_init(_lock) \
341do { \
342 spinlock_check(_lock); \
343 *(_lock) = __SPIN_LOCK_UNLOCKED(_lock); \
344} while (0)
345
346#endif
347
348static __always_inline void spin_lock(spinlock_t *lock)
349{
350 raw_spin_lock(&lock->rlock);
351}
352
353static __always_inline void spin_lock_bh(spinlock_t *lock)
354{
355 raw_spin_lock_bh(&lock->rlock);
356}
357
358static __always_inline int spin_trylock(spinlock_t *lock)
359{
360 return raw_spin_trylock(&lock->rlock);
361}
362
363#define spin_lock_nested(lock, subclass) \
364do { \
365 raw_spin_lock_nested(spinlock_check(lock), subclass); \
366} while (0)
367
368#define spin_lock_nest_lock(lock, nest_lock) \
369do { \
370 raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
371} while (0)
372
373static __always_inline void spin_lock_irq(spinlock_t *lock)
374{
375 raw_spin_lock_irq(&lock->rlock);
376}
377
378#define spin_lock_irqsave(lock, flags) \
379do { \
380 raw_spin_lock_irqsave(spinlock_check(lock), flags); \
381} while (0)
382
383#define spin_lock_irqsave_nested(lock, flags, subclass) \
384do { \
385 raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
386} while (0)
387
388static __always_inline void spin_unlock(spinlock_t *lock)
389{
390 raw_spin_unlock(&lock->rlock);
391}
392
393static __always_inline void spin_unlock_bh(spinlock_t *lock)
394{
395 raw_spin_unlock_bh(&lock->rlock);
396}
397
398static __always_inline void spin_unlock_irq(spinlock_t *lock)
399{
400 raw_spin_unlock_irq(&lock->rlock);
401}
402
403static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
404{
405 raw_spin_unlock_irqrestore(&lock->rlock, flags);
406}
407
408static __always_inline int spin_trylock_bh(spinlock_t *lock)
409{
410 return raw_spin_trylock_bh(&lock->rlock);
411}
412
413static __always_inline int spin_trylock_irq(spinlock_t *lock)
414{
415 return raw_spin_trylock_irq(&lock->rlock);
416}
417
418#define spin_trylock_irqsave(lock, flags) \
419({ \
420 raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
421})
422
423/**
424 * spin_is_locked() - Check whether a spinlock is locked.
425 * @lock: Pointer to the spinlock.
426 *
427 * This function is NOT required to provide any memory ordering
428 * guarantees; it could be used for debugging purposes or, when
429 * additional synchronization is needed, accompanied with other
430 * constructs (memory barriers) enforcing the synchronization.
431 *
432 * Returns: 1 if @lock is locked, 0 otherwise.
433 *
434 * Note that the function only tells you that the spinlock is
435 * seen to be locked, not that it is locked on your CPU.
436 *
437 * Further, on CONFIG_SMP=n builds with CONFIG_DEBUG_SPINLOCK=n,
438 * the return value is always 0 (see include/linux/spinlock_up.h).
439 * Therefore you should not rely heavily on the return value.
440 */
441static __always_inline int spin_is_locked(spinlock_t *lock)
442{
443 return raw_spin_is_locked(&lock->rlock);
444}
445
446static __always_inline int spin_is_contended(spinlock_t *lock)
447{
448 return raw_spin_is_contended(&lock->rlock);
449}
450
451#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock)
452
453#else /* !CONFIG_PREEMPT_RT */
454# include <linux/spinlock_rt.h>
455#endif /* CONFIG_PREEMPT_RT */
456
457/*
458 * Pull the atomic_t declaration:
459 * (asm-mips/atomic.h needs above definitions)
460 */
461#include <linux/atomic.h>
462/**
463 * atomic_dec_and_lock - lock on reaching reference count zero
464 * @atomic: the atomic counter
465 * @lock: the spinlock in question
466 *
467 * Decrements @atomic by 1. If the result is 0, returns true and locks
468 * @lock. Returns false for all other cases.
469 */
470extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
471#define atomic_dec_and_lock(atomic, lock) \
472 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
473
474extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
475 unsigned long *flags);
476#define atomic_dec_and_lock_irqsave(atomic, lock, flags) \
477 __cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags)))
478
479extern int _atomic_dec_and_raw_lock(atomic_t *atomic, raw_spinlock_t *lock);
480#define atomic_dec_and_raw_lock(atomic, lock) \
481 __cond_lock(lock, _atomic_dec_and_raw_lock(atomic, lock))
482
483extern int _atomic_dec_and_raw_lock_irqsave(atomic_t *atomic, raw_spinlock_t *lock,
484 unsigned long *flags);
485#define atomic_dec_and_raw_lock_irqsave(atomic, lock, flags) \
486 __cond_lock(lock, _atomic_dec_and_raw_lock_irqsave(atomic, lock, &(flags)))
487
488int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,
489 size_t max_size, unsigned int cpu_mult,
490 gfp_t gfp, const char *name,
491 struct lock_class_key *key);
492
493#define alloc_bucket_spinlocks(locks, lock_mask, max_size, cpu_mult, gfp) \
494 ({ \
495 static struct lock_class_key key; \
496 int ret; \
497 \
498 ret = __alloc_bucket_spinlocks(locks, lock_mask, max_size, \
499 cpu_mult, gfp, #locks, &key); \
500 ret; \
501 })
502
503void free_bucket_spinlocks(spinlock_t *locks);
504
505#undef __LINUX_INSIDE_SPINLOCK_H
506#endif /* __LINUX_SPINLOCK_H */