text: #ifndef _LINUX_HW_BREAKPOINT_H
  #define _LINUX_HW_BREAKPOINT_H
  
  enum {
  	HW_BREAKPOINT_LEN_1 = 1,
  	HW_BREAKPOINT_LEN_2 = 2,
  	HW_BREAKPOINT_LEN_4 = 4,
  	HW_BREAKPOINT_LEN_8 = 8,
  };
  
  enum {
  	HW_BREAKPOINT_EMPTY	= 0,
  	HW_BREAKPOINT_R		= 1,
  	HW_BREAKPOINT_W		= 2,
  	HW_BREAKPOINT_RW	= HW_BREAKPOINT_R | HW_BREAKPOINT_W,
  	HW_BREAKPOINT_X		= 4,
  	HW_BREAKPOINT_INVALID   = HW_BREAKPOINT_RW | HW_BREAKPOINT_X,
  };
  
  enum bp_type_idx {
  	TYPE_INST 	= 0,
  #ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS
  	TYPE_DATA	= 0,
  #else
  	TYPE_DATA	= 1,
  #endif
  	TYPE_MAX
  };
  
  #ifdef __KERNEL__
  
  #include <linux/perf_event.h>
  
  #ifdef CONFIG_HAVE_HW_BREAKPOINT
  
  extern int __init init_hw_breakpoint(void);
  
  static inline void hw_breakpoint_init(struct perf_event_attr *attr)
  {
  	memset(attr, 0, sizeof(*attr));
  
  	attr->type = PERF_TYPE_BREAKPOINT;
  	attr->size = sizeof(*attr);
  	/*
  	 * As it's for in-kernel or ptrace use, we want it to be pinned
  	 * and to call its callback every hits.
  	 */
  	attr->pinned = 1;
  	attr->sample_period = 1;
  }
  
  static inline void ptrace_breakpoint_init(struct perf_event_attr *attr)
  {
  	hw_breakpoint_init(attr);
  	attr->exclude_kernel = 1;
  }
  
  static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
  {
  	return bp->attr.bp_addr;
  }
  
  static inline int hw_breakpoint_type(struct perf_event *bp)
  {
  	return bp->attr.bp_type;
  }
  
  static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
  {
  	return bp->attr.bp_len;
  }
  
  extern struct perf_event *
  register_user_hw_breakpoint(struct perf_event_attr *attr,
  			    perf_overflow_handler_t triggered,
  			    struct task_struct *tsk);
  
  /* FIXME: only change from the attr, and don't unregister */
  extern int
  modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
  
  /*
   * Kernel breakpoints are not associated with any particular thread.
   */
  extern struct perf_event *
  register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
  				perf_overflow_handler_t	triggered,
  				int cpu);
  
  extern struct perf_event * __percpu *
  register_wide_hw_breakpoint(struct perf_event_attr *attr,
  			    perf_overflow_handler_t triggered);
  
  extern int register_perf_hw_breakpoint(struct perf_event *bp);
  extern int __register_perf_hw_breakpoint(struct perf_event *bp);
  extern void unregister_hw_breakpoint(struct perf_event *bp);
  extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
  
  extern int dbg_reserve_bp_slot(struct perf_event *bp);
  extern int dbg_release_bp_slot(struct perf_event *bp);
  extern int reserve_bp_slot(struct perf_event *bp);
  extern void release_bp_slot(struct perf_event *bp);
  
  extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
  
  static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
  {
  	return &bp->hw.info;
  }
  
  #else /* !CONFIG_HAVE_HW_BREAKPOINT */
  
  static inline int __init init_hw_breakpoint(void) { return 0; }
  
  static inline struct perf_event *
  register_user_hw_breakpoint(struct perf_event_attr *attr,
  			    perf_overflow_handler_t triggered,
  			    struct task_struct *tsk)	{ return NULL; }
  static inline int
  modify_user_hw_breakpoint(struct perf_event *bp,
  			  struct perf_event_attr *attr)	{ return -ENOSYS; }
  static inline struct perf_event *
  register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
  				perf_overflow_handler_t	 triggered,
  				int cpu)		{ return NULL; }
  static inline struct perf_event * __percpu *
  register_wide_hw_breakpoint(struct perf_event_attr *attr,
  			    perf_overflow_handler_t triggered)	{ return NULL; }
  static inline int
  register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
  static inline int
  __register_perf_hw_breakpoint(struct perf_event *bp) 	{ return -ENOSYS; }
  static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
  static inline void
  unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }
  static inline int
  reserve_bp_slot(struct perf_event *bp)			{return -ENOSYS; }
  static inline void release_bp_slot(struct perf_event *bp) 		{ }
  
  static inline void flush_ptrace_hw_breakpoint(struct task_struct *tsk)	{ }
  
  static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
  {
  	return NULL;
  }
  
  #endif /* CONFIG_HAVE_HW_BREAKPOINT */
  #endif /* __KERNEL__ */
  
  #endif /* _LINUX_HW_BREAKPOINT_H */
  