/*
   * Copyright (2004) Linus Torvalds
   *
   * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
   *

   * Copyright (2004, 2005) Ingo Molnar
   *
   * This file contains the spinlock/rwlock implementations for the
   * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)

   *
   * Note that some architectures have special knowledge about the
   * stack frames of these functions in their profile_pc. If you
   * change anything significant here that could change the stack
   * frame contact the architecture maintainers.

   */

  #include <linux/linkage.h>
  #include <linux/preempt.h>
  #include <linux/spinlock.h>
  #include <linux/interrupt.h>

  #include <linux/debug_locks.h>

  #include <linux/export.h>

  /*
   * If lockdep is enabled then we use the non-preemption spin-ops
   * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
   * not re-enabled during lock-acquire (which the preempt-spin-ops do):
   */
  #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
  /*
   * The __lock_function inlines are taken from
   * include/linux/spinlock_api_smp.h
   */
  #else

  #define raw_read_can_lock(l)	read_can_lock(l)
  #define raw_write_can_lock(l)	write_can_lock(l)

  
  /*
   * Some architectures can relax in favour of the CPU owning the lock.
   */
  #ifndef arch_read_relax
  # define arch_read_relax(l)	cpu_relax()
  #endif
  #ifndef arch_write_relax
  # define arch_write_relax(l)	cpu_relax()
  #endif
  #ifndef arch_spin_relax
  # define arch_spin_relax(l)	cpu_relax()
  #endif

  /*
   * We build the __lock_function inlines here. They are too large for
   * inlining all over the place, but here is only one user per function
   * which embedds them into the calling _lock_function below.
   *
   * This could be a long-held lock. We both prepare to spin for a long
   * time (making _this_ CPU preemptable if possible), and we also signal
   * towards that other CPU that it should break the lock ASAP.
   */
  #define BUILD_LOCK_OPS(op, locktype)					\

  void __lockfunc __raw_##op##_lock(locktype##_t *lock)			\

  {									\
  	for (;;) {							\
  		preempt_disable();					\

  		if (likely(do_raw_##op##_trylock(lock)))		\

  			break;						\
  		preempt_enable();					\
  									\
  		if (!(lock)->break_lock)				\
  			(lock)->break_lock = 1;				\

  		while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\

  			arch_##op##_relax(&lock->raw_lock);		\

  	}								\
  	(lock)->break_lock = 0;						\
  }									\
  									\

  unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock)	\

  {									\
  	unsigned long flags;						\
  									\
  	for (;;) {							\
  		preempt_disable();					\
  		local_irq_save(flags);					\

  		if (likely(do_raw_##op##_trylock(lock)))		\

  			break;						\
  		local_irq_restore(flags);				\
  		preempt_enable();					\
  									\
  		if (!(lock)->break_lock)				\
  			(lock)->break_lock = 1;				\

  		while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\

  			arch_##op##_relax(&lock->raw_lock);		\

  	}								\
  	(lock)->break_lock = 0;						\
  	return flags;							\
  }									\
  									\

  void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock)		\

  {									\

  	_raw_##op##_lock_irqsave(lock);					\

  }									\
  									\

  void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock)		\

  {									\
  	unsigned long flags;						\
  									\
  	/*							*/	\
  	/* Careful: we must exclude softirqs too, hence the	*/	\
  	/* irq-disabling. We use the generic preemption-aware	*/	\
  	/* function:						*/	\
  	/**/								\

  	flags = _raw_##op##_lock_irqsave(lock);				\

  	local_bh_disable();						\
  	local_irq_restore(flags);					\
  }									\
  
  /*
   * Build preemption-friendly versions of the following
   * lock-spinning functions:
   *
   *         __[spin|read|write]_lock()
   *         __[spin|read|write]_lock_irq()
   *         __[spin|read|write]_lock_irqsave()
   *         __[spin|read|write]_lock_bh()
   */

  BUILD_LOCK_OPS(spin, raw_spinlock);

  BUILD_LOCK_OPS(read, rwlock);
  BUILD_LOCK_OPS(write, rwlock);
  
  #endif

  #ifndef CONFIG_INLINE_SPIN_TRYLOCK

  int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)

  {

  	return __raw_spin_trylock(lock);

  }

  EXPORT_SYMBOL(_raw_spin_trylock);

  #endif

  #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH

  int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)

  {

  	return __raw_spin_trylock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_spin_trylock_bh);

  #endif

  #ifndef CONFIG_INLINE_SPIN_LOCK

  void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)

  {

  	__raw_spin_lock(lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock);

  #endif

  #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE

  unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)

  {

  	return __raw_spin_lock_irqsave(lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock_irqsave);

  #endif

  #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ

  void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)

  {

  	__raw_spin_lock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock_irq);

  #endif

  #ifndef CONFIG_INLINE_SPIN_LOCK_BH

  void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)

  {

  	__raw_spin_lock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock_bh);

  #endif

  #ifdef CONFIG_UNINLINE_SPIN_UNLOCK

  void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)

  {

  	__raw_spin_unlock(lock);

  }

  EXPORT_SYMBOL(_raw_spin_unlock);

  #endif

  #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE

  void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)

  {

  	__raw_spin_unlock_irqrestore(lock, flags);

  }

  EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);

  #endif

  #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ

  void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)

  {

  	__raw_spin_unlock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_spin_unlock_irq);

  #endif

  #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH

  void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)

  {

  	__raw_spin_unlock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_spin_unlock_bh);

  #endif

  #ifndef CONFIG_INLINE_READ_TRYLOCK

  int __lockfunc _raw_read_trylock(rwlock_t *lock)

  {

  	return __raw_read_trylock(lock);

  }

  EXPORT_SYMBOL(_raw_read_trylock);

  #endif

  #ifndef CONFIG_INLINE_READ_LOCK

  void __lockfunc _raw_read_lock(rwlock_t *lock)

  {

  	__raw_read_lock(lock);

  }

  EXPORT_SYMBOL(_raw_read_lock);

  #endif

  #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE

  unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)

  {

  	return __raw_read_lock_irqsave(lock);

  }

  EXPORT_SYMBOL(_raw_read_lock_irqsave);

  #endif

  #ifndef CONFIG_INLINE_READ_LOCK_IRQ

  void __lockfunc _raw_read_lock_irq(rwlock_t *lock)

  {

  	__raw_read_lock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_read_lock_irq);

  #endif

  #ifndef CONFIG_INLINE_READ_LOCK_BH

  void __lockfunc _raw_read_lock_bh(rwlock_t *lock)

  {

  	__raw_read_lock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_read_lock_bh);

  #endif

  #ifndef CONFIG_INLINE_READ_UNLOCK

  void __lockfunc _raw_read_unlock(rwlock_t *lock)

  {

  	__raw_read_unlock(lock);

  }

  EXPORT_SYMBOL(_raw_read_unlock);

  #endif

  #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE

  void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)

  {

  	__raw_read_unlock_irqrestore(lock, flags);

  }

  EXPORT_SYMBOL(_raw_read_unlock_irqrestore);

  #endif

  #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ

  void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)

  {

  	__raw_read_unlock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_read_unlock_irq);

  #endif

  #ifndef CONFIG_INLINE_READ_UNLOCK_BH

  void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)

  {

  	__raw_read_unlock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_read_unlock_bh);

  #endif

  #ifndef CONFIG_INLINE_WRITE_TRYLOCK

  int __lockfunc _raw_write_trylock(rwlock_t *lock)

  {

  	return __raw_write_trylock(lock);

  }

  EXPORT_SYMBOL(_raw_write_trylock);

  #endif
  
  #ifndef CONFIG_INLINE_WRITE_LOCK

  void __lockfunc _raw_write_lock(rwlock_t *lock)

  {

  	__raw_write_lock(lock);

  }

  EXPORT_SYMBOL(_raw_write_lock);

  #endif
  
  #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE

  unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)

  {

  	return __raw_write_lock_irqsave(lock);

  }

  EXPORT_SYMBOL(_raw_write_lock_irqsave);

  #endif
  
  #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ

  void __lockfunc _raw_write_lock_irq(rwlock_t *lock)

  {

  	__raw_write_lock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_write_lock_irq);

  #endif
  
  #ifndef CONFIG_INLINE_WRITE_LOCK_BH

  void __lockfunc _raw_write_lock_bh(rwlock_t *lock)

  {

  	__raw_write_lock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_write_lock_bh);

  #endif
  
  #ifndef CONFIG_INLINE_WRITE_UNLOCK

  void __lockfunc _raw_write_unlock(rwlock_t *lock)

  {

  	__raw_write_unlock(lock);

  }

  EXPORT_SYMBOL(_raw_write_unlock);

  #endif

  #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE

  void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)

  {

  	__raw_write_unlock_irqrestore(lock, flags);

  }

  EXPORT_SYMBOL(_raw_write_unlock_irqrestore);

  #endif

  #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ

  void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)

  {

  	__raw_write_unlock_irq(lock);

  }

  EXPORT_SYMBOL(_raw_write_unlock_irq);

  #endif

  #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH

  void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)

  {

  	__raw_write_unlock_bh(lock);

  }

  EXPORT_SYMBOL(_raw_write_unlock_bh);

  #endif

  #ifdef CONFIG_DEBUG_LOCK_ALLOC

  void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)

  {

  	preempt_disable();
  	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);

  	LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock_nested);

  void __lockfunc _raw_spin_lock_bh_nested(raw_spinlock_t *lock, int subclass)
  {
  	__local_bh_disable_ip(_RET_IP_, SOFTIRQ_LOCK_OFFSET);
  	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
  	LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
  }
  EXPORT_SYMBOL(_raw_spin_lock_bh_nested);

  unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_spinlock_t *lock,

  						   int subclass)
  {
  	unsigned long flags;
  
  	local_irq_save(flags);
  	preempt_disable();
  	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);

  	LOCK_CONTENDED_FLAGS(lock, do_raw_spin_trylock, do_raw_spin_lock,
  				do_raw_spin_lock_flags, &flags);

  	return flags;
  }

  EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);

  void __lockfunc _raw_spin_lock_nest_lock(raw_spinlock_t *lock,

  				     struct lockdep_map *nest_lock)
  {
  	preempt_disable();
  	spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);

  	LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);

  }

  EXPORT_SYMBOL(_raw_spin_lock_nest_lock);

  #endif

  notrace int in_lock_functions(unsigned long addr)

  {
  	/* Linker adds these: start and end of __lockfunc functions */
  	extern char __lock_text_start[], __lock_text_end[];
  
  	return addr >= (unsigned long)__lock_text_start
  	&& addr < (unsigned long)__lock_text_end;
  }
  EXPORT_SYMBOL(in_lock_functions);