#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 LOADs and STOREs 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

  /**

   * 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_bh_nested(lock, subclass) \
  	_raw_spin_lock_bh_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

  /*
   * Always evaluate the 'subclass' argument to avoid that the compiler
   * warns about set-but-not-used variables when building with
   * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1.
   */
  # define raw_spin_lock_nested(lock, subclass)		\
  	_raw_spin_lock(((void)(subclass), (lock)))

  # define raw_spin_lock_nest_lock(lock, nest_lock)	_raw_spin_lock(lock)

  # define raw_spin_lock_bh_nested(lock, subclass)	_raw_spin_lock_bh(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 __always_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 __always_inline void spin_lock(spinlock_t *lock)

  {
  	raw_spin_lock(&lock->rlock);
  }

  static __always_inline void spin_lock_bh(spinlock_t *lock)

  {
  	raw_spin_lock_bh(&lock->rlock);
  }

  static __always_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_bh_nested(lock, subclass)			\
  do {								\
  	raw_spin_lock_bh_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 __always_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 __always_inline void spin_unlock(spinlock_t *lock)

  {
  	raw_spin_unlock(&lock->rlock);
  }

  static __always_inline void spin_unlock_bh(spinlock_t *lock)

  {
  	raw_spin_unlock_bh(&lock->rlock);
  }

  static __always_inline void spin_unlock_irq(spinlock_t *lock)

  {
  	raw_spin_unlock_irq(&lock->rlock);
  }

  static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)

  {
  	raw_spin_unlock_irqrestore(&lock->rlock, flags);
  }

  static __always_inline int spin_trylock_bh(spinlock_t *lock)

  {
  	return raw_spin_trylock_bh(&lock->rlock);
  }

  static __always_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 __always_inline void spin_unlock_wait(spinlock_t *lock)

  {
  	raw_spin_unlock_wait(&lock->rlock);
  }

  static __always_inline int spin_is_locked(spinlock_t *lock)

  {
  	return raw_spin_is_locked(&lock->rlock);
  }

  static __always_inline int spin_is_contended(spinlock_t *lock)

  {
  	return raw_spin_is_contended(&lock->rlock);
  }

  static __always_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 */