372 lines
7.7 KiB
C
372 lines
7.7 KiB
C
/*
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* Copyright (2004) Linus Torvalds
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*
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* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
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*
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* Copyright (2004) Ingo Molnar
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*/
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#include <linux/config.h>
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#include <linux/linkage.h>
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#include <linux/preempt.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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/*
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* Generic declaration of the raw read_trylock() function,
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* architectures are supposed to optimize this:
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*/
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int __lockfunc generic_raw_read_trylock(rwlock_t *lock)
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{
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_raw_read_lock(lock);
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return 1;
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}
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EXPORT_SYMBOL(generic_raw_read_trylock);
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int __lockfunc _spin_trylock(spinlock_t *lock)
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{
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preempt_disable();
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if (_raw_spin_trylock(lock))
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return 1;
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preempt_enable();
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return 0;
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}
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EXPORT_SYMBOL(_spin_trylock);
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int __lockfunc _read_trylock(rwlock_t *lock)
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{
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preempt_disable();
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if (_raw_read_trylock(lock))
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return 1;
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preempt_enable();
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return 0;
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}
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EXPORT_SYMBOL(_read_trylock);
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int __lockfunc _write_trylock(rwlock_t *lock)
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{
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preempt_disable();
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if (_raw_write_trylock(lock))
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return 1;
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preempt_enable();
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return 0;
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}
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EXPORT_SYMBOL(_write_trylock);
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#ifndef CONFIG_PREEMPT
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void __lockfunc _read_lock(rwlock_t *lock)
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{
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preempt_disable();
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_raw_read_lock(lock);
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}
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EXPORT_SYMBOL(_read_lock);
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unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
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{
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unsigned long flags;
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local_irq_save(flags);
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preempt_disable();
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_raw_spin_lock_flags(lock, flags);
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return flags;
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}
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EXPORT_SYMBOL(_spin_lock_irqsave);
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void __lockfunc _spin_lock_irq(spinlock_t *lock)
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{
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local_irq_disable();
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preempt_disable();
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_raw_spin_lock(lock);
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}
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EXPORT_SYMBOL(_spin_lock_irq);
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void __lockfunc _spin_lock_bh(spinlock_t *lock)
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{
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local_bh_disable();
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preempt_disable();
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_raw_spin_lock(lock);
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}
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EXPORT_SYMBOL(_spin_lock_bh);
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unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
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{
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unsigned long flags;
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local_irq_save(flags);
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preempt_disable();
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_raw_read_lock(lock);
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return flags;
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}
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EXPORT_SYMBOL(_read_lock_irqsave);
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void __lockfunc _read_lock_irq(rwlock_t *lock)
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{
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local_irq_disable();
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preempt_disable();
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_raw_read_lock(lock);
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}
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EXPORT_SYMBOL(_read_lock_irq);
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void __lockfunc _read_lock_bh(rwlock_t *lock)
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{
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local_bh_disable();
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preempt_disable();
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_raw_read_lock(lock);
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}
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EXPORT_SYMBOL(_read_lock_bh);
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unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
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{
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unsigned long flags;
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local_irq_save(flags);
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preempt_disable();
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_raw_write_lock(lock);
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return flags;
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}
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EXPORT_SYMBOL(_write_lock_irqsave);
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void __lockfunc _write_lock_irq(rwlock_t *lock)
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{
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local_irq_disable();
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preempt_disable();
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_raw_write_lock(lock);
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}
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EXPORT_SYMBOL(_write_lock_irq);
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void __lockfunc _write_lock_bh(rwlock_t *lock)
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{
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local_bh_disable();
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preempt_disable();
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_raw_write_lock(lock);
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}
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EXPORT_SYMBOL(_write_lock_bh);
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void __lockfunc _spin_lock(spinlock_t *lock)
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{
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preempt_disable();
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_raw_spin_lock(lock);
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}
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EXPORT_SYMBOL(_spin_lock);
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void __lockfunc _write_lock(rwlock_t *lock)
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{
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preempt_disable();
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_raw_write_lock(lock);
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}
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EXPORT_SYMBOL(_write_lock);
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#else /* CONFIG_PREEMPT: */
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/*
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* This could be a long-held lock. We both prepare to spin for a long
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* time (making _this_ CPU preemptable if possible), and we also signal
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* towards that other CPU that it should break the lock ASAP.
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*
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* (We do this in a function because inlining it would be excessive.)
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*/
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#define BUILD_LOCK_OPS(op, locktype) \
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void __lockfunc _##op##_lock(locktype##_t *lock) \
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{ \
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preempt_disable(); \
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for (;;) { \
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if (likely(_raw_##op##_trylock(lock))) \
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break; \
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preempt_enable(); \
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if (!(lock)->break_lock) \
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(lock)->break_lock = 1; \
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while (!op##_can_lock(lock) && (lock)->break_lock) \
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cpu_relax(); \
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preempt_disable(); \
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} \
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(lock)->break_lock = 0; \
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} \
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\
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EXPORT_SYMBOL(_##op##_lock); \
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\
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unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
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{ \
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unsigned long flags; \
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\
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preempt_disable(); \
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for (;;) { \
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local_irq_save(flags); \
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if (likely(_raw_##op##_trylock(lock))) \
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break; \
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local_irq_restore(flags); \
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\
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preempt_enable(); \
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if (!(lock)->break_lock) \
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(lock)->break_lock = 1; \
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while (!op##_can_lock(lock) && (lock)->break_lock) \
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cpu_relax(); \
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preempt_disable(); \
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} \
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(lock)->break_lock = 0; \
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return flags; \
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} \
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\
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EXPORT_SYMBOL(_##op##_lock_irqsave); \
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\
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void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
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{ \
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_##op##_lock_irqsave(lock); \
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} \
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\
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EXPORT_SYMBOL(_##op##_lock_irq); \
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\
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void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
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{ \
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unsigned long flags; \
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\
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/* */ \
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/* Careful: we must exclude softirqs too, hence the */ \
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/* irq-disabling. We use the generic preemption-aware */ \
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/* function: */ \
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/**/ \
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flags = _##op##_lock_irqsave(lock); \
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local_bh_disable(); \
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local_irq_restore(flags); \
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} \
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\
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EXPORT_SYMBOL(_##op##_lock_bh)
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/*
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* Build preemption-friendly versions of the following
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* lock-spinning functions:
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*
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* _[spin|read|write]_lock()
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* _[spin|read|write]_lock_irq()
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* _[spin|read|write]_lock_irqsave()
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* _[spin|read|write]_lock_bh()
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*/
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BUILD_LOCK_OPS(spin, spinlock);
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BUILD_LOCK_OPS(read, rwlock);
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BUILD_LOCK_OPS(write, rwlock);
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#endif /* CONFIG_PREEMPT */
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void __lockfunc _spin_unlock(spinlock_t *lock)
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{
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_raw_spin_unlock(lock);
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preempt_enable();
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}
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EXPORT_SYMBOL(_spin_unlock);
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void __lockfunc _write_unlock(rwlock_t *lock)
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{
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_raw_write_unlock(lock);
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preempt_enable();
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}
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EXPORT_SYMBOL(_write_unlock);
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void __lockfunc _read_unlock(rwlock_t *lock)
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{
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_raw_read_unlock(lock);
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preempt_enable();
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}
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EXPORT_SYMBOL(_read_unlock);
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void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
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{
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_raw_spin_unlock(lock);
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local_irq_restore(flags);
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preempt_enable();
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}
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EXPORT_SYMBOL(_spin_unlock_irqrestore);
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void __lockfunc _spin_unlock_irq(spinlock_t *lock)
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{
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_raw_spin_unlock(lock);
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local_irq_enable();
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preempt_enable();
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}
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EXPORT_SYMBOL(_spin_unlock_irq);
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void __lockfunc _spin_unlock_bh(spinlock_t *lock)
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{
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_raw_spin_unlock(lock);
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preempt_enable_no_resched();
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local_bh_enable();
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}
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EXPORT_SYMBOL(_spin_unlock_bh);
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void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
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{
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_raw_read_unlock(lock);
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local_irq_restore(flags);
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preempt_enable();
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}
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EXPORT_SYMBOL(_read_unlock_irqrestore);
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void __lockfunc _read_unlock_irq(rwlock_t *lock)
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{
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_raw_read_unlock(lock);
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local_irq_enable();
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preempt_enable();
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}
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EXPORT_SYMBOL(_read_unlock_irq);
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void __lockfunc _read_unlock_bh(rwlock_t *lock)
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{
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_raw_read_unlock(lock);
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preempt_enable_no_resched();
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local_bh_enable();
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}
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EXPORT_SYMBOL(_read_unlock_bh);
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void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
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{
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_raw_write_unlock(lock);
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local_irq_restore(flags);
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preempt_enable();
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}
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EXPORT_SYMBOL(_write_unlock_irqrestore);
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void __lockfunc _write_unlock_irq(rwlock_t *lock)
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{
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_raw_write_unlock(lock);
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local_irq_enable();
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preempt_enable();
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}
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EXPORT_SYMBOL(_write_unlock_irq);
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void __lockfunc _write_unlock_bh(rwlock_t *lock)
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{
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_raw_write_unlock(lock);
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preempt_enable_no_resched();
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local_bh_enable();
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}
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EXPORT_SYMBOL(_write_unlock_bh);
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int __lockfunc _spin_trylock_bh(spinlock_t *lock)
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{
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local_bh_disable();
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preempt_disable();
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if (_raw_spin_trylock(lock))
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return 1;
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preempt_enable_no_resched();
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local_bh_enable();
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return 0;
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}
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EXPORT_SYMBOL(_spin_trylock_bh);
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int in_lock_functions(unsigned long addr)
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{
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/* Linker adds these: start and end of __lockfunc functions */
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extern char __lock_text_start[], __lock_text_end[];
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return addr >= (unsigned long)__lock_text_start
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&& addr < (unsigned long)__lock_text_end;
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}
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EXPORT_SYMBOL(in_lock_functions);
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