#ifndef _LINUX_IRQDESC_H
  #define _LINUX_IRQDESC_H
  
  /*
   * Core internal functions to deal with irq descriptors
   *
   * This include will move to kernel/irq once we cleaned up the tree.
   * For now it's included from <linux/irq.h>
   */
  
  struct irq_affinity_notify;
  struct proc_dir_entry;
  struct module;
  struct irq_desc;
  
  /**
   * struct irq_desc - interrupt descriptor
   * @irq_data:		per irq and chip data passed down to chip functions
   * @kstat_irqs:		irq stats per cpu
   * @handle_irq:		highlevel irq-events handler
   * @preflow_handler:	handler called before the flow handler (currently used by sparc)
   * @action:		the irq action chain
   * @status:		status information
   * @core_internal_state__do_not_mess_with_it: core internal status information
   * @depth:		disable-depth, for nested irq_disable() calls
   * @wake_depth:		enable depth, for multiple irq_set_irq_wake() callers
   * @irq_count:		stats field to detect stalled irqs
   * @last_unhandled:	aging timer for unhandled count
   * @irqs_unhandled:	stats field for spurious unhandled interrupts
   * @threads_handled:	stats field for deferred spurious detection of threaded handlers
   * @threads_handled_last: comparator field for deferred spurious detection of theraded handlers
   * @lock:		locking for SMP
   * @affinity_hint:	hint to user space for preferred irq affinity
   * @affinity_notify:	context for notification of affinity changes
   * @pending_mask:	pending rebalanced interrupts
   * @threads_oneshot:	bitfield to handle shared oneshot threads
   * @threads_active:	number of irqaction threads currently running
   * @wait_for_threads:	wait queue for sync_irq to wait for threaded handlers
   * @dir:		/proc/irq/ procfs entry
   * @name:		flow handler name for /proc/interrupts output
   */
  struct irq_desc {
  	struct irq_data		irq_data;
  	unsigned int __percpu	*kstat_irqs;
  	irq_flow_handler_t	handle_irq;
  #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
  	irq_preflow_handler_t	preflow_handler;
  #endif
  	struct irqaction	*action;	/* IRQ action list */
  	unsigned int		status_use_accessors;
  	unsigned int		core_internal_state__do_not_mess_with_it;
  	unsigned int		depth;		/* nested irq disables */
  	unsigned int		wake_depth;	/* nested wake enables */
  	unsigned int		irq_count;	/* For detecting broken IRQs */
  	unsigned long		last_unhandled;	/* Aging timer for unhandled count */
  	unsigned int		irqs_unhandled;
  	atomic_t		threads_handled;
  	int			threads_handled_last;
  	raw_spinlock_t		lock;
  	struct cpumask		*percpu_enabled;
  #ifdef CONFIG_SMP
  	const struct cpumask	*affinity_hint;
  	struct irq_affinity_notify *affinity_notify;
  #ifdef CONFIG_GENERIC_PENDING_IRQ
  	cpumask_var_t		pending_mask;
  #endif
  #endif
  	unsigned long		threads_oneshot;
  	atomic_t		threads_active;
  	wait_queue_head_t       wait_for_threads;
  #ifdef CONFIG_PROC_FS
  	struct proc_dir_entry	*dir;
  #endif
  	int			parent_irq;
  	struct module		*owner;
  	const char		*name;
  } ____cacheline_internodealigned_in_smp;
  
  #ifndef CONFIG_SPARSE_IRQ
  extern struct irq_desc irq_desc[NR_IRQS];
  #endif
  
  static inline struct irq_data *irq_desc_get_irq_data(struct irq_desc *desc)
  {
  	return &desc->irq_data;
  }
  
  static inline struct irq_chip *irq_desc_get_chip(struct irq_desc *desc)
  {
  	return desc->irq_data.chip;
  }
  
  static inline void *irq_desc_get_chip_data(struct irq_desc *desc)
  {
  	return desc->irq_data.chip_data;
  }
  
  static inline void *irq_desc_get_handler_data(struct irq_desc *desc)
  {
  	return desc->irq_data.handler_data;
  }
  
  static inline struct msi_desc *irq_desc_get_msi_desc(struct irq_desc *desc)
  {
  	return desc->irq_data.msi_desc;
  }
  
  /*
   * Architectures call this to let the generic IRQ layer
   * handle an interrupt. If the descriptor is attached to an
   * irqchip-style controller then we call the ->handle_irq() handler,
   * and it calls __do_IRQ() if it's attached to an irqtype-style controller.
   */
  static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *desc)
  {
  	desc->handle_irq(irq, desc);
  }
  
  int generic_handle_irq(unsigned int irq);
  
  /* Test to see if a driver has successfully requested an irq */
  static inline int irq_has_action(unsigned int irq)
  {
  	struct irq_desc *desc = irq_to_desc(irq);
  	return desc->action != NULL;
  }
  
  /* caller has locked the irq_desc and both params are valid */
  static inline void __irq_set_handler_locked(unsigned int irq,
  					    irq_flow_handler_t handler)
  {
  	struct irq_desc *desc;
  
  	desc = irq_to_desc(irq);
  	desc->handle_irq = handler;
  }
  
  /* caller has locked the irq_desc and both params are valid */
  static inline void
  __irq_set_chip_handler_name_locked(unsigned int irq, struct irq_chip *chip,
  				   irq_flow_handler_t handler, const char *name)
  {
  	struct irq_desc *desc;
  
  	desc = irq_to_desc(irq);
  	irq_desc_get_irq_data(desc)->chip = chip;
  	desc->handle_irq = handler;
  	desc->name = name;
  }
  
  static inline int irq_balancing_disabled(unsigned int irq)
  {
  	struct irq_desc *desc;
  
  	desc = irq_to_desc(irq);
  	return desc->status_use_accessors & IRQ_NO_BALANCING_MASK;
  }
  
  static inline int irq_is_percpu(unsigned int irq)
  {
  	struct irq_desc *desc;
  
  	desc = irq_to_desc(irq);
  	return desc->status_use_accessors & IRQ_PER_CPU;
  }
  
  static inline void
  irq_set_lockdep_class(unsigned int irq, struct lock_class_key *class)
  {
  	struct irq_desc *desc = irq_to_desc(irq);
  
  	if (desc)
  		lockdep_set_class(&desc->lock, class);
  }
  
  #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
  static inline void
  __irq_set_preflow_handler(unsigned int irq, irq_preflow_handler_t handler)
  {
  	struct irq_desc *desc;
  
  	desc = irq_to_desc(irq);
  	desc->preflow_handler = handler;
  }
  #endif
  
  #endif