Line data    Source code

       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 embedds 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 preemptable 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             : BUILD_LOCK_OPS(read, rwlock);
     128             : BUILD_LOCK_OPS(write, rwlock);
     129             : 
     130             : #endif
     131             : 
     132             : #ifndef CONFIG_INLINE_SPIN_TRYLOCK
     133       26610 : int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
     134             : {
     135       26610 :         return __raw_spin_trylock(lock);
     136             : }
     137             : EXPORT_SYMBOL(_raw_spin_trylock);
     138             : #endif
     139             : 
     140             : #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
     141           0 : int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)
     142             : {
     143           0 :         return __raw_spin_trylock_bh(lock);
     144             : }
     145             : EXPORT_SYMBOL(_raw_spin_trylock_bh);
     146             : #endif
     147             : 
     148             : #ifndef CONFIG_INLINE_SPIN_LOCK
     149     1565977 : void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)
     150             : {
     151     1565977 :         __raw_spin_lock(lock);
     152     1568539 : }
     153             : EXPORT_SYMBOL(_raw_spin_lock);
     154             : #endif
     155             : 
     156             : #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
     157     7244413 : unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)
     158             : {
     159     7244413 :         return __raw_spin_lock_irqsave(lock);
     160             : }
     161             : EXPORT_SYMBOL(_raw_spin_lock_irqsave);
     162             : #endif
     163             : 
     164             : #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
     165      141197 : void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)
     166             : {
     167      141197 :         __raw_spin_lock_irq(lock);
     168      141224 : }
     169             : EXPORT_SYMBOL(_raw_spin_lock_irq);
     170             : #endif
     171             : 
     172             : #ifndef CONFIG_INLINE_SPIN_LOCK_BH
     173        2497 : void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)
     174             : {
     175        2497 :         __raw_spin_lock_bh(lock);
     176        2497 : }
     177             : EXPORT_SYMBOL(_raw_spin_lock_bh);
     178             : #endif
     179             : 
     180             : #ifdef CONFIG_UNINLINE_SPIN_UNLOCK
     181     1615001 : void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)
     182             : {
     183     1615001 :         __raw_spin_unlock(lock);
     184     1616869 : }
     185             : EXPORT_SYMBOL(_raw_spin_unlock);
     186             : #endif
     187             : 
     188             : #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
     189     7246339 : void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
     190             : {
     191     7246339 :         __raw_spin_unlock_irqrestore(lock, flags);
     192     7241722 : }
     193             : EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);
     194             : #endif
     195             : 
     196             : #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
     197      171784 : void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)
     198             : {
     199      171784 :         __raw_spin_unlock_irq(lock);
     200      171771 : }
     201             : EXPORT_SYMBOL(_raw_spin_unlock_irq);
     202             : #endif
     203             : 
     204             : #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
     205        1416 : void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
     206             : {
     207        1416 :         __raw_spin_unlock_bh(lock);
     208        1416 : }
     209             : EXPORT_SYMBOL(_raw_spin_unlock_bh);
     210             : #endif
     211             : 
     212             : #ifndef CONFIG_INLINE_READ_TRYLOCK
     213           0 : int __lockfunc _raw_read_trylock(rwlock_t *lock)
     214             : {
     215           0 :         return __raw_read_trylock(lock);
     216             : }
     217             : EXPORT_SYMBOL(_raw_read_trylock);
     218             : #endif
     219             : 
     220             : #ifndef CONFIG_INLINE_READ_LOCK
     221       36691 : void __lockfunc _raw_read_lock(rwlock_t *lock)
     222             : {
     223       36691 :         __raw_read_lock(lock);
     224       36691 : }
     225             : EXPORT_SYMBOL(_raw_read_lock);
     226             : #endif
     227             : 
     228             : #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
     229        5028 : unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)
     230             : {
     231        5028 :         return __raw_read_lock_irqsave(lock);
     232             : }
     233             : EXPORT_SYMBOL(_raw_read_lock_irqsave);
     234             : #endif
     235             : 
     236             : #ifndef CONFIG_INLINE_READ_LOCK_IRQ
     237           0 : void __lockfunc _raw_read_lock_irq(rwlock_t *lock)
     238             : {
     239           0 :         __raw_read_lock_irq(lock);
     240           0 : }
     241             : EXPORT_SYMBOL(_raw_read_lock_irq);
     242             : #endif
     243             : 
     244             : #ifndef CONFIG_INLINE_READ_LOCK_BH
     245          41 : void __lockfunc _raw_read_lock_bh(rwlock_t *lock)
     246             : {
     247          41 :         __raw_read_lock_bh(lock);
     248          41 : }
     249             : EXPORT_SYMBOL(_raw_read_lock_bh);
     250             : #endif
     251             : 
     252             : #ifndef CONFIG_INLINE_READ_UNLOCK
     253       36691 : void __lockfunc _raw_read_unlock(rwlock_t *lock)
     254             : {
     255       36691 :         __raw_read_unlock(lock);
     256       36691 : }
     257             : EXPORT_SYMBOL(_raw_read_unlock);
     258             : #endif
     259             : 
     260             : #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
     261        5029 : void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
     262             : {
     263        5029 :         __raw_read_unlock_irqrestore(lock, flags);
     264        5028 : }
     265             : EXPORT_SYMBOL(_raw_read_unlock_irqrestore);
     266             : #endif
     267             : 
     268             : #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
     269           0 : void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)
     270             : {
     271           0 :         __raw_read_unlock_irq(lock);
     272           0 : }
     273             : EXPORT_SYMBOL(_raw_read_unlock_irq);
     274             : #endif
     275             : 
     276             : #ifndef CONFIG_INLINE_READ_UNLOCK_BH
     277          41 : void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)
     278             : {
     279          41 :         __raw_read_unlock_bh(lock);
     280          41 : }
     281             : EXPORT_SYMBOL(_raw_read_unlock_bh);
     282             : #endif
     283             : 
     284             : #ifndef CONFIG_INLINE_WRITE_TRYLOCK
     285           0 : int __lockfunc _raw_write_trylock(rwlock_t *lock)
     286             : {
     287           0 :         return __raw_write_trylock(lock);
     288             : }
     289             : EXPORT_SYMBOL(_raw_write_trylock);
     290             : #endif
     291             : 
     292             : #ifndef CONFIG_INLINE_WRITE_LOCK
     293        7479 : void __lockfunc _raw_write_lock(rwlock_t *lock)
     294             : {
     295        7479 :         __raw_write_lock(lock);
     296        7479 : }
     297             : EXPORT_SYMBOL(_raw_write_lock);
     298             : #endif
     299             : 
     300             : #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
     301           0 : unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)
     302             : {
     303           0 :         return __raw_write_lock_irqsave(lock);
     304             : }
     305             : EXPORT_SYMBOL(_raw_write_lock_irqsave);
     306             : #endif
     307             : 
     308             : #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
     309       14258 : void __lockfunc _raw_write_lock_irq(rwlock_t *lock)
     310             : {
     311       14258 :         __raw_write_lock_irq(lock);
     312       14261 : }
     313             : EXPORT_SYMBOL(_raw_write_lock_irq);
     314             : #endif
     315             : 
     316             : #ifndef CONFIG_INLINE_WRITE_LOCK_BH
     317         827 : void __lockfunc _raw_write_lock_bh(rwlock_t *lock)
     318             : {
     319         827 :         __raw_write_lock_bh(lock);
     320         827 : }
     321             : EXPORT_SYMBOL(_raw_write_lock_bh);
     322             : #endif
     323             : 
     324             : #ifndef CONFIG_INLINE_WRITE_UNLOCK
     325        7481 : void __lockfunc _raw_write_unlock(rwlock_t *lock)
     326             : {
     327        7481 :         __raw_write_unlock(lock);
     328        7481 : }
     329             : EXPORT_SYMBOL(_raw_write_unlock);
     330             : #endif
     331             : 
     332             : #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
     333           0 : void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
     334             : {
     335           0 :         __raw_write_unlock_irqrestore(lock, flags);
     336           0 : }
     337             : EXPORT_SYMBOL(_raw_write_unlock_irqrestore);
     338             : #endif
     339             : 
     340             : #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
     341       14259 : void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)
     342             : {
     343       14259 :         __raw_write_unlock_irq(lock);
     344       14260 : }
     345             : EXPORT_SYMBOL(_raw_write_unlock_irq);
     346             : #endif
     347             : 
     348             : #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
     349         825 : void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
     350             : {
     351         825 :         __raw_write_unlock_bh(lock);
     352         825 : }
     353             : EXPORT_SYMBOL(_raw_write_unlock_bh);
     354             : #endif
     355             : 
     356             : #ifdef CONFIG_DEBUG_LOCK_ALLOC
     357             : 
     358       31113 : void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
     359             : {
     360       31113 :         preempt_disable();
     361       31113 :         spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
     362       31113 :         LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
     363       31113 : }
     364             : EXPORT_SYMBOL(_raw_spin_lock_nested);
     365             : 
     366         193 : unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_spinlock_t *lock,
     367             :                                                    int subclass)
     368             : {
     369         193 :         unsigned long flags;
     370             : 
     371         386 :         local_irq_save(flags);
     372         193 :         preempt_disable();
     373         193 :         spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
     374         193 :         LOCK_CONTENDED_FLAGS(lock, do_raw_spin_trylock, do_raw_spin_lock,
     375             :                                 do_raw_spin_lock_flags, &flags);
     376         193 :         return flags;
     377             : }
     378             : EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);
     379             : 
     380           0 : void __lockfunc _raw_spin_lock_nest_lock(raw_spinlock_t *lock,
     381             :                                      struct lockdep_map *nest_lock)
     382             : {
     383           0 :         preempt_disable();
     384           0 :         spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
     385           0 :         LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
     386           0 : }
     387             : EXPORT_SYMBOL(_raw_spin_lock_nest_lock);
     388             : 
     389             : #endif
     390             : 
     391         117 : notrace int in_lock_functions(unsigned long addr)
     392             : {
     393             :         /* Linker adds these: start and end of __lockfunc functions */
     394         117 :         extern char __lock_text_start[], __lock_text_end[];
     395             : 
     396         117 :         return addr >= (unsigned long)__lock_text_start
     397         117 :         && addr < (unsigned long)__lock_text_end;
     398             : }
     399             : EXPORT_SYMBOL(in_lock_functions);