1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (2004) Linus Torvalds
4 *
5 * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
6 *
7 * Copyright (2004, 2005) Ingo Molnar
8 *
9 * This file contains the spinlock/rwlock implementations for the
10 * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
11 *
12 * Note that some architectures have special knowledge about the
13 * stack frames of these functions in their profile_pc. If you
14 * change anything significant here that could change the stack
15 * frame contact the architecture maintainers.
16 */
17
18 #include <linux/linkage.h>
19 #include <linux/preempt.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/debug_locks.h>
23 #include <linux/export.h>
24
25 #ifdef CONFIG_MMIOWB
26 #ifndef arch_mmiowb_state
27 DEFINE_PER_CPU(struct mmiowb_state, __mmiowb_state);
28 EXPORT_PER_CPU_SYMBOL(__mmiowb_state);
29 #endif
30 #endif
31
32 /*
33 * If lockdep is enabled then we use the non-preemption spin-ops
34 * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
35 * not re-enabled during lock-acquire (which the preempt-spin-ops do):
36 */
37 #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
38 /*
39 * The __lock_function inlines are taken from
40 * spinlock : include/linux/spinlock_api_smp.h
41 * rwlock : include/linux/rwlock_api_smp.h
42 */
43 #else
44
45 /*
46 * Some architectures can relax in favour of the CPU owning the lock.
47 */
48 #ifndef arch_read_relax
49 # define arch_read_relax(l) cpu_relax()
50 #endif
51 #ifndef arch_write_relax
52 # define arch_write_relax(l) cpu_relax()
53 #endif
54 #ifndef arch_spin_relax
55 # define arch_spin_relax(l) cpu_relax()
56 #endif
57
58 /*
59 * We build the __lock_function inlines here. They are too large for
60 * inlining all over the place, but here is only one user per function
61 * which embeds them into the calling _lock_function below.
62 *
63 * This could be a long-held lock. We both prepare to spin for a long
64 * time (making _this_ CPU preemptible if possible), and we also signal
65 * towards that other CPU that it should break the lock ASAP.
66 */
67 #define BUILD_LOCK_OPS(op, locktype) \
68 void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
69 { \
70 for (;;) { \
71 preempt_disable(); \
72 if (likely(do_raw_##op##_trylock(lock))) \
73 break; \
74 preempt_enable(); \
75 \
76 arch_##op##_relax(&lock->raw_lock); \
77 } \
78 } \
79 \
80 unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
81 { \
82 unsigned long flags; \
83 \
84 for (;;) { \
85 preempt_disable(); \
86 local_irq_save(flags); \
87 if (likely(do_raw_##op##_trylock(lock))) \
88 break; \
89 local_irq_restore(flags); \
90 preempt_enable(); \
91 \
92 arch_##op##_relax(&lock->raw_lock); \
93 } \
94 \
95 return flags; \
96 } \
97 \
98 void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
99 { \
100 _raw_##op##_lock_irqsave(lock); \
101 } \
102 \
103 void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
104 { \
105 unsigned long flags; \
106 \
107 /* */ \
108 /* Careful: we must exclude softirqs too, hence the */ \
109 /* irq-disabling. We use the generic preemption-aware */ \
110 /* function: */ \
111 /**/ \
112 flags = _raw_##op##_lock_irqsave(lock); \
113 local_bh_disable(); \
114 local_irq_restore(flags); \
115 } \
116
117 /*
118 * Build preemption-friendly versions of the following
119 * lock-spinning functions:
120 *
121 * __[spin|read|write]_lock()
122 * __[spin|read|write]_lock_irq()
123 * __[spin|read|write]_lock_irqsave()
124 * __[spin|read|write]_lock_bh()
125 */
126 BUILD_LOCK_OPS(spin, raw_spinlock);
127
128 #ifndef CONFIG_PREEMPT_RT
129 BUILD_LOCK_OPS(read, rwlock);
130 BUILD_LOCK_OPS(write, rwlock);
131 #endif
132
133 #endif
134
135 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
_raw_spin_trylock(raw_spinlock_t * lock)136 int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
137 {
138 return __raw_spin_trylock(lock);
139 }
140 EXPORT_SYMBOL(_raw_spin_trylock);
141 #endif
142
143 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
_raw_spin_trylock_bh(raw_spinlock_t * lock)144 int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)
145 {
146 return __raw_spin_trylock_bh(lock);
147 }
148 EXPORT_SYMBOL(_raw_spin_trylock_bh);
149 #endif
150
151 #ifndef CONFIG_INLINE_SPIN_LOCK
_raw_spin_lock(raw_spinlock_t * lock)152 void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)
153 {
154 __raw_spin_lock(lock);
155 }
156 EXPORT_SYMBOL(_raw_spin_lock);
157 #endif
158
159 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
_raw_spin_lock_irqsave(raw_spinlock_t * lock)160 unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)
161 {
162 return __raw_spin_lock_irqsave(lock);
163 }
164 EXPORT_SYMBOL(_raw_spin_lock_irqsave);
165 #endif
166
167 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
_raw_spin_lock_irq(raw_spinlock_t * lock)168 void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)
169 {
170 __raw_spin_lock_irq(lock);
171 }
172 EXPORT_SYMBOL(_raw_spin_lock_irq);
173 #endif
174
175 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
_raw_spin_lock_bh(raw_spinlock_t * lock)176 void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)
177 {
178 __raw_spin_lock_bh(lock);
179 }
180 EXPORT_SYMBOL(_raw_spin_lock_bh);
181 #endif
182
183 #ifdef CONFIG_UNINLINE_SPIN_UNLOCK
_raw_spin_unlock(raw_spinlock_t * lock)184 void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)
185 {
186 __raw_spin_unlock(lock);
187 }
188 EXPORT_SYMBOL(_raw_spin_unlock);
189 #endif
190
191 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
_raw_spin_unlock_irqrestore(raw_spinlock_t * lock,unsigned long flags)192 void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
193 {
194 __raw_spin_unlock_irqrestore(lock, flags);
195 }
196 EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);
197 #endif
198
199 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
_raw_spin_unlock_irq(raw_spinlock_t * lock)200 void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)
201 {
202 __raw_spin_unlock_irq(lock);
203 }
204 EXPORT_SYMBOL(_raw_spin_unlock_irq);
205 #endif
206
207 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
_raw_spin_unlock_bh(raw_spinlock_t * lock)208 void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
209 {
210 __raw_spin_unlock_bh(lock);
211 }
212 EXPORT_SYMBOL(_raw_spin_unlock_bh);
213 #endif
214
215 #ifndef CONFIG_PREEMPT_RT
216
217 #ifndef CONFIG_INLINE_READ_TRYLOCK
_raw_read_trylock(rwlock_t * lock)218 int __lockfunc _raw_read_trylock(rwlock_t *lock)
219 {
220 return __raw_read_trylock(lock);
221 }
222 EXPORT_SYMBOL(_raw_read_trylock);
223 #endif
224
225 #ifndef CONFIG_INLINE_READ_LOCK
_raw_read_lock(rwlock_t * lock)226 void __lockfunc _raw_read_lock(rwlock_t *lock)
227 {
228 __raw_read_lock(lock);
229 }
230 EXPORT_SYMBOL(_raw_read_lock);
231 #endif
232
233 #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
_raw_read_lock_irqsave(rwlock_t * lock)234 unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)
235 {
236 return __raw_read_lock_irqsave(lock);
237 }
238 EXPORT_SYMBOL(_raw_read_lock_irqsave);
239 #endif
240
241 #ifndef CONFIG_INLINE_READ_LOCK_IRQ
_raw_read_lock_irq(rwlock_t * lock)242 void __lockfunc _raw_read_lock_irq(rwlock_t *lock)
243 {
244 __raw_read_lock_irq(lock);
245 }
246 EXPORT_SYMBOL(_raw_read_lock_irq);
247 #endif
248
249 #ifndef CONFIG_INLINE_READ_LOCK_BH
_raw_read_lock_bh(rwlock_t * lock)250 void __lockfunc _raw_read_lock_bh(rwlock_t *lock)
251 {
252 __raw_read_lock_bh(lock);
253 }
254 EXPORT_SYMBOL(_raw_read_lock_bh);
255 #endif
256
257 #ifndef CONFIG_INLINE_READ_UNLOCK
_raw_read_unlock(rwlock_t * lock)258 void __lockfunc _raw_read_unlock(rwlock_t *lock)
259 {
260 __raw_read_unlock(lock);
261 }
262 EXPORT_SYMBOL(_raw_read_unlock);
263 #endif
264
265 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
_raw_read_unlock_irqrestore(rwlock_t * lock,unsigned long flags)266 void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
267 {
268 __raw_read_unlock_irqrestore(lock, flags);
269 }
270 EXPORT_SYMBOL(_raw_read_unlock_irqrestore);
271 #endif
272
273 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
_raw_read_unlock_irq(rwlock_t * lock)274 void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)
275 {
276 __raw_read_unlock_irq(lock);
277 }
278 EXPORT_SYMBOL(_raw_read_unlock_irq);
279 #endif
280
281 #ifndef CONFIG_INLINE_READ_UNLOCK_BH
_raw_read_unlock_bh(rwlock_t * lock)282 void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)
283 {
284 __raw_read_unlock_bh(lock);
285 }
286 EXPORT_SYMBOL(_raw_read_unlock_bh);
287 #endif
288
289 #ifndef CONFIG_INLINE_WRITE_TRYLOCK
_raw_write_trylock(rwlock_t * lock)290 int __lockfunc _raw_write_trylock(rwlock_t *lock)
291 {
292 return __raw_write_trylock(lock);
293 }
294 EXPORT_SYMBOL(_raw_write_trylock);
295 #endif
296
297 #ifndef CONFIG_INLINE_WRITE_LOCK
_raw_write_lock(rwlock_t * lock)298 void __lockfunc _raw_write_lock(rwlock_t *lock)
299 {
300 __raw_write_lock(lock);
301 }
302 EXPORT_SYMBOL(_raw_write_lock);
303 #endif
304
305 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
_raw_write_lock_irqsave(rwlock_t * lock)306 unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)
307 {
308 return __raw_write_lock_irqsave(lock);
309 }
310 EXPORT_SYMBOL(_raw_write_lock_irqsave);
311 #endif
312
313 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
_raw_write_lock_irq(rwlock_t * lock)314 void __lockfunc _raw_write_lock_irq(rwlock_t *lock)
315 {
316 __raw_write_lock_irq(lock);
317 }
318 EXPORT_SYMBOL(_raw_write_lock_irq);
319 #endif
320
321 #ifndef CONFIG_INLINE_WRITE_LOCK_BH
_raw_write_lock_bh(rwlock_t * lock)322 void __lockfunc _raw_write_lock_bh(rwlock_t *lock)
323 {
324 __raw_write_lock_bh(lock);
325 }
326 EXPORT_SYMBOL(_raw_write_lock_bh);
327 #endif
328
329 #ifndef CONFIG_INLINE_WRITE_UNLOCK
_raw_write_unlock(rwlock_t * lock)330 void __lockfunc _raw_write_unlock(rwlock_t *lock)
331 {
332 __raw_write_unlock(lock);
333 }
334 EXPORT_SYMBOL(_raw_write_unlock);
335 #endif
336
337 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
_raw_write_unlock_irqrestore(rwlock_t * lock,unsigned long flags)338 void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
339 {
340 __raw_write_unlock_irqrestore(lock, flags);
341 }
342 EXPORT_SYMBOL(_raw_write_unlock_irqrestore);
343 #endif
344
345 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
_raw_write_unlock_irq(rwlock_t * lock)346 void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)
347 {
348 __raw_write_unlock_irq(lock);
349 }
350 EXPORT_SYMBOL(_raw_write_unlock_irq);
351 #endif
352
353 #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
_raw_write_unlock_bh(rwlock_t * lock)354 void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
355 {
356 __raw_write_unlock_bh(lock);
357 }
358 EXPORT_SYMBOL(_raw_write_unlock_bh);
359 #endif
360
361 #endif /* !CONFIG_PREEMPT_RT */
362
363 #ifdef CONFIG_DEBUG_LOCK_ALLOC
364
_raw_spin_lock_nested(raw_spinlock_t * lock,int subclass)365 void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
366 {
367 preempt_disable();
368 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
369 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
370 }
371 EXPORT_SYMBOL(_raw_spin_lock_nested);
372
_raw_spin_lock_irqsave_nested(raw_spinlock_t * lock,int subclass)373 unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_spinlock_t *lock,
374 int subclass)
375 {
376 unsigned long flags;
377
378 local_irq_save(flags);
379 preempt_disable();
380 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
381 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
382 return flags;
383 }
384 EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);
385
_raw_spin_lock_nest_lock(raw_spinlock_t * lock,struct lockdep_map * nest_lock)386 void __lockfunc _raw_spin_lock_nest_lock(raw_spinlock_t *lock,
387 struct lockdep_map *nest_lock)
388 {
389 preempt_disable();
390 spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
391 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
392 }
393 EXPORT_SYMBOL(_raw_spin_lock_nest_lock);
394
395 #endif
396
in_lock_functions(unsigned long addr)397 notrace int in_lock_functions(unsigned long addr)
398 {
399 /* Linker adds these: start and end of __lockfunc functions */
400 extern char __lock_text_start[], __lock_text_end[];
401
402 return addr >= (unsigned long)__lock_text_start
403 && addr < (unsigned long)__lock_text_end;
404 }
405 EXPORT_SYMBOL(in_lock_functions);
406