#ifndef __LINUX_SPINLOCK_H
  #define __LINUX_SPINLOCK_H
  
  /*
   * include/linux/spinlock.h - generic spinlock/rwlock declarations
   *
   * here's the role of the various spinlock/rwlock related include files:
   *
   * on SMP builds:
   *
   *  asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the
   *                        initializers
   *
   *  linux/spinlock_types.h:
   *                        defines the generic type and initializers
   *
   *  asm/spinlock.h:       contains the arch_spin_*()/etc. lowlevel
   *                        implementations, mostly inline assembly code
   *
   *   (also included on UP-debug builds:)
   *
   *  linux/spinlock_api_smp.h:
   *                        contains the prototypes for the _spin_*() APIs.
   *
   *  linux/spinlock.h:     builds the final spin_*() APIs.
   *
   * on UP builds:
   *
   *  linux/spinlock_type_up.h:
   *                        contains the generic, simplified UP spinlock type.
   *                        (which is an empty structure on non-debug builds)
   *
   *  linux/spinlock_types.h:
   *                        defines the generic type and initializers
   *
   *  linux/spinlock_up.h:
   *                        contains the arch_spin_*()/etc. version of UP
   *                        builds. (which are NOPs on non-debug, non-preempt
   *                        builds)
   *
   *   (included on UP-non-debug builds:)
   *
   *  linux/spinlock_api_up.h:
   *                        builds the _spin_*() APIs.
   *
   *  linux/spinlock.h:     builds the final spin_*() APIs.
   */
  
  #include <linux/typecheck.h>
  #include <linux/preempt.h>
  #include <linux/linkage.h>
  #include <linux/compiler.h>
  #include <linux/irqflags.h>
  #include <linux/thread_info.h>
  #include <linux/kernel.h>
  #include <linux/stringify.h>
  #include <linux/bottom_half.h>
  #include <asm/barrier.h>
  
  
  /*
   * Must define these before including other files, inline functions need them
   */
  #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME
  
  #define LOCK_SECTION_START(extra)               \
          ".subsection 1
  \t"                     \
          extra                                   \
          ".ifndef " LOCK_SECTION_NAME "
  \t"     \
          LOCK_SECTION_NAME ":
  \t"               \
          ".endif
  "
  
  #define LOCK_SECTION_END                        \
          ".previous
  \t"
  
  #define __lockfunc __attribute__((section(".spinlock.text")))
  
  /*
   * Pull the arch_spinlock_t and arch_rwlock_t definitions:
   */
  #include <linux/spinlock_types.h>
  
  /*
   * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
   */
  #ifdef CONFIG_SMP
  # include <asm/spinlock.h>
  #else
  # include <linux/spinlock_up.h>
  #endif
  
  #ifdef CONFIG_DEBUG_SPINLOCK
    extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
  				   struct lock_class_key *key);
  # define raw_spin_lock_init(lock)				\
  do {								\
  	static struct lock_class_key __key;			\
  								\
  	__raw_spin_lock_init((lock), #lock, &__key);		\
  } while (0)
  
  #else
  # define raw_spin_lock_init(lock)				\
  	do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
  #endif
  
  #define raw_spin_is_locked(lock)	arch_spin_is_locked(&(lock)->raw_lock)
  
  #ifdef CONFIG_GENERIC_LOCKBREAK
  #define raw_spin_is_contended(lock) ((lock)->break_lock)
  #else
  
  #ifdef arch_spin_is_contended
  #define raw_spin_is_contended(lock)	arch_spin_is_contended(&(lock)->raw_lock)
  #else
  #define raw_spin_is_contended(lock)	(((void)(lock), 0))
  #endif /*arch_spin_is_contended*/
  #endif
  
  /*
   * Despite its name it doesn't necessarily has to be a full barrier.
   * It should only guarantee that a STORE before the critical section
   * can not be reordered with a LOAD inside this section.
   * spin_lock() is the one-way barrier, this LOAD can not escape out
   * of the region. So the default implementation simply ensures that
   * a STORE can not move into the critical section, smp_wmb() should
   * serialize it with another STORE done by spin_lock().
   */
  #ifndef smp_mb__before_spinlock
  #define smp_mb__before_spinlock()	smp_wmb()
  #endif
  
  /*
   * Place this after a lock-acquisition primitive to guarantee that
   * an UNLOCK+LOCK pair act as a full barrier.  This guarantee applies
   * if the UNLOCK and LOCK are executed by the same CPU or if the
   * UNLOCK and LOCK operate on the same lock variable.
   */
  #ifndef smp_mb__after_unlock_lock
  #define smp_mb__after_unlock_lock()	do { } while (0)
  #endif
  
  /**
   * raw_spin_unlock_wait - wait until the spinlock gets unlocked
   * @lock: the spinlock in question.
   */
  #define raw_spin_unlock_wait(lock)	arch_spin_unlock_wait(&(lock)->raw_lock)
  
  #ifdef CONFIG_DEBUG_SPINLOCK
   extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
  #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock)
   extern int do_raw_spin_trylock(raw_spinlock_t *lock);
   extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
  #else
  static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
  {
  	__acquire(lock);
  	arch_spin_lock(&lock->raw_lock);
  }
  
  static inline void
  do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock)
  {
  	__acquire(lock);
  	arch_spin_lock_flags(&lock->raw_lock, *flags);
  }
  
  static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
  {
  	return arch_spin_trylock(&(lock)->raw_lock);
  }
  
  static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
  {
  	arch_spin_unlock(&lock->raw_lock);
  	__release(lock);
  }
  #endif
  
  /*
   * Define the various spin_lock methods.  Note we define these
   * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
   * various methods are defined as nops in the case they are not
   * required.
   */
  #define raw_spin_trylock(lock)	__cond_lock(lock, _raw_spin_trylock(lock))
  
  #define raw_spin_lock(lock)	_raw_spin_lock(lock)
  
  #ifdef CONFIG_DEBUG_LOCK_ALLOC
  # define raw_spin_lock_nested(lock, subclass) \
  	_raw_spin_lock_nested(lock, subclass)
  
  # define raw_spin_lock_nest_lock(lock, nest_lock)			\
  	 do {								\
  		 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
  		 _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
  	 } while (0)
  #else
  # define raw_spin_lock_nested(lock, subclass)		_raw_spin_lock(lock)
  # define raw_spin_lock_nest_lock(lock, nest_lock)	_raw_spin_lock(lock)
  #endif
  
  #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  
  #define raw_spin_lock_irqsave(lock, flags)			\
  	do {						\
  		typecheck(unsigned long, flags);	\
  		flags = _raw_spin_lock_irqsave(lock);	\
  	} while (0)
  
  #ifdef CONFIG_DEBUG_LOCK_ALLOC
  #define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\
  	do {								\
  		typecheck(unsigned long, flags);			\
  		flags = _raw_spin_lock_irqsave_nested(lock, subclass);	\
  	} while (0)
  #else
  #define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\
  	do {								\
  		typecheck(unsigned long, flags);			\
  		flags = _raw_spin_lock_irqsave(lock);			\
  	} while (0)
  #endif
  
  #else
  
  #define raw_spin_lock_irqsave(lock, flags)		\
  	do {						\
  		typecheck(unsigned long, flags);	\
  		_raw_spin_lock_irqsave(lock, flags);	\
  	} while (0)
  
  #define raw_spin_lock_irqsave_nested(lock, flags, subclass)	\
  	raw_spin_lock_irqsave(lock, flags)
  
  #endif
  
  #define raw_spin_lock_irq(lock)		_raw_spin_lock_irq(lock)
  #define raw_spin_lock_bh(lock)		_raw_spin_lock_bh(lock)
  #define raw_spin_unlock(lock)		_raw_spin_unlock(lock)
  #define raw_spin_unlock_irq(lock)	_raw_spin_unlock_irq(lock)
  
  #define raw_spin_unlock_irqrestore(lock, flags)		\
  	do {							\
  		typecheck(unsigned long, flags);		\
  		_raw_spin_unlock_irqrestore(lock, flags);	\
  	} while (0)
  #define raw_spin_unlock_bh(lock)	_raw_spin_unlock_bh(lock)
  
  #define raw_spin_trylock_bh(lock) \
  	__cond_lock(lock, _raw_spin_trylock_bh(lock))
  
  #define raw_spin_trylock_irq(lock) \
  ({ \
  	local_irq_disable(); \
  	raw_spin_trylock(lock) ? \
  	1 : ({ local_irq_enable(); 0;  }); \
  })
  
  #define raw_spin_trylock_irqsave(lock, flags) \
  ({ \
  	local_irq_save(flags); \
  	raw_spin_trylock(lock) ? \
  	1 : ({ local_irq_restore(flags); 0; }); \
  })
  
  /**
   * raw_spin_can_lock - would raw_spin_trylock() succeed?
   * @lock: the spinlock in question.
   */
  #define raw_spin_can_lock(lock)	(!raw_spin_is_locked(lock))
  
  /* Include rwlock functions */
  #include <linux/rwlock.h>
  
  /*
   * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
   */
  #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  # include <linux/spinlock_api_smp.h>
  #else
  # include <linux/spinlock_api_up.h>
  #endif
  
  /*
   * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
   */
  
  static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
  {
  	return &lock->rlock;
  }
  
  #define spin_lock_init(_lock)				\
  do {							\
  	spinlock_check(_lock);				\
  	raw_spin_lock_init(&(_lock)->rlock);		\
  } while (0)
  
  static inline void spin_lock(spinlock_t *lock)
  {
  	raw_spin_lock(&lock->rlock);
  }
  
  static inline void spin_lock_bh(spinlock_t *lock)
  {
  	raw_spin_lock_bh(&lock->rlock);
  }
  
  static inline int spin_trylock(spinlock_t *lock)
  {
  	return raw_spin_trylock(&lock->rlock);
  }
  
  #define spin_lock_nested(lock, subclass)			\
  do {								\
  	raw_spin_lock_nested(spinlock_check(lock), subclass);	\
  } while (0)
  
  #define spin_lock_nest_lock(lock, nest_lock)				\
  do {									\
  	raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);	\
  } while (0)
  
  static inline void spin_lock_irq(spinlock_t *lock)
  {
  	raw_spin_lock_irq(&lock->rlock);
  }
  
  #define spin_lock_irqsave(lock, flags)				\
  do {								\
  	raw_spin_lock_irqsave(spinlock_check(lock), flags);	\
  } while (0)
  
  #define spin_lock_irqsave_nested(lock, flags, subclass)			\
  do {									\
  	raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
  } while (0)
  
  static inline void spin_unlock(spinlock_t *lock)
  {
  	raw_spin_unlock(&lock->rlock);
  }
  
  static inline void spin_unlock_bh(spinlock_t *lock)
  {
  	raw_spin_unlock_bh(&lock->rlock);
  }
  
  static inline void spin_unlock_irq(spinlock_t *lock)
  {
  	raw_spin_unlock_irq(&lock->rlock);
  }
  
  static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
  {
  	raw_spin_unlock_irqrestore(&lock->rlock, flags);
  }
  
  static inline int spin_trylock_bh(spinlock_t *lock)
  {
  	return raw_spin_trylock_bh(&lock->rlock);
  }
  
  static inline int spin_trylock_irq(spinlock_t *lock)
  {
  	return raw_spin_trylock_irq(&lock->rlock);
  }
  
  #define spin_trylock_irqsave(lock, flags)			\
  ({								\
  	raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
  })
  
  static inline void spin_unlock_wait(spinlock_t *lock)
  {
  	raw_spin_unlock_wait(&lock->rlock);
  }
  
  static inline int spin_is_locked(spinlock_t *lock)
  {
  	return raw_spin_is_locked(&lock->rlock);
  }
  
  static inline int spin_is_contended(spinlock_t *lock)
  {
  	return raw_spin_is_contended(&lock->rlock);
  }
  
  static inline int spin_can_lock(spinlock_t *lock)
  {
  	return raw_spin_can_lock(&lock->rlock);
  }
  
  #define assert_spin_locked(lock)	assert_raw_spin_locked(&(lock)->rlock)
  
  /*
   * Pull the atomic_t declaration:
   * (asm-mips/atomic.h needs above definitions)
   */
  #include <linux/atomic.h>
  /**
   * atomic_dec_and_lock - lock on reaching reference count zero
   * @atomic: the atomic counter
   * @lock: the spinlock in question
   *
   * Decrements @atomic by 1.  If the result is 0, returns true and locks
   * @lock.  Returns false for all other cases.
   */
  extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
  #define atomic_dec_and_lock(atomic, lock) \
  		__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
  
  #endif /* __LINUX_SPINLOCK_H */