/*
   * include/linux/cpu.h - generic cpu definition
   *
   * This is mainly for topological representation. We define the 
   * basic 'struct cpu' here, which can be embedded in per-arch 
   * definitions of processors.
   *
   * Basic handling of the devices is done in drivers/base/cpu.c
   * and system devices are handled in drivers/base/sys.c. 
   *

   * CPUs are exported via sysfs in the class/cpu/devices/

   * directory. 

   */
  #ifndef _LINUX_CPU_H_
  #define _LINUX_CPU_H_

  #include <linux/device.h>

  #include <linux/node.h>
  #include <linux/compiler.h>
  #include <linux/cpumask.h>

  
  struct cpu {
  	int node_id;		/* The node which contains the CPU */

  	int hotpluggable;	/* creates sysfs control file if hotpluggable */

  	struct device dev;

  };

  extern int register_cpu(struct cpu *cpu, int num);

  extern struct device *get_cpu_device(unsigned cpu);

  extern bool cpu_is_hotpluggable(unsigned cpu);

  extern int cpu_add_dev_attr(struct device_attribute *attr);
  extern void cpu_remove_dev_attr(struct device_attribute *attr);

  extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
  extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);

  extern int sched_create_sysfs_power_savings_entries(struct device *dev);

  #ifdef CONFIG_HOTPLUG_CPU

  extern void unregister_cpu(struct cpu *cpu);

  extern ssize_t arch_cpu_probe(const char *, size_t);
  extern ssize_t arch_cpu_release(const char *, size_t);

  #endif
  struct notifier_block;

  /*
   * CPU notifier priorities.
   */
  enum {

  	/*
  	 * SCHED_ACTIVE marks a cpu which is coming up active during
  	 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  	 * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  	 * cpu_active mask right after SCHED_ACTIVE.  During
  	 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  	 * ordered in the similar way.
  	 *
  	 * This ordering guarantees consistent cpu_active mask and
  	 * migration behavior to all cpu notifiers.
  	 */
  	CPU_PRI_SCHED_ACTIVE	= INT_MAX,
  	CPU_PRI_CPUSET_ACTIVE	= INT_MAX - 1,
  	CPU_PRI_SCHED_INACTIVE	= INT_MIN + 1,
  	CPU_PRI_CPUSET_INACTIVE	= INT_MIN,

  	/* migration should happen before other stuff but after perf */
  	CPU_PRI_PERF		= 20,
  	CPU_PRI_MIGRATION	= 10,

  	/* prepare workqueues for other notifiers */
  	CPU_PRI_WORKQUEUE	= 5,

  };

  #define CPU_ONLINE		0x0002 /* CPU (unsigned)v is up */
  #define CPU_UP_PREPARE		0x0003 /* CPU (unsigned)v coming up */
  #define CPU_UP_CANCELED		0x0004 /* CPU (unsigned)v NOT coming up */
  #define CPU_DOWN_PREPARE	0x0005 /* CPU (unsigned)v going down */
  #define CPU_DOWN_FAILED		0x0006 /* CPU (unsigned)v NOT going down */
  #define CPU_DEAD		0x0007 /* CPU (unsigned)v dead */
  #define CPU_DYING		0x0008 /* CPU (unsigned)v not running any task,
  					* not handling interrupts, soon dead.
  					* Called on the dying cpu, interrupts
  					* are already disabled. Must not
  					* sleep, must not fail */
  #define CPU_POST_DEAD		0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  					* lock is dropped */
  #define CPU_STARTING		0x000A /* CPU (unsigned)v soon running.
  					* Called on the new cpu, just before
  					* enabling interrupts. Must not sleep,
  					* must not fail */
  
  /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
   * operation in progress
   */
  #define CPU_TASKS_FROZEN	0x0010
  
  #define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
  #define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
  #define CPU_UP_CANCELED_FROZEN	(CPU_UP_CANCELED | CPU_TASKS_FROZEN)
  #define CPU_DOWN_PREPARE_FROZEN	(CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
  #define CPU_DOWN_FAILED_FROZEN	(CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
  #define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
  #define CPU_DYING_FROZEN	(CPU_DYING | CPU_TASKS_FROZEN)
  #define CPU_STARTING_FROZEN	(CPU_STARTING | CPU_TASKS_FROZEN)

  #ifdef CONFIG_SMP
  /* Need to know about CPUs going up/down? */

  #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  #define cpu_notifier(fn, pri) {					\
  	static struct notifier_block fn##_nb __cpuinitdata =	\
  		{ .notifier_call = fn, .priority = pri };	\
  	register_cpu_notifier(&fn##_nb);			\
  }
  #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
  #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */

  #ifdef CONFIG_HOTPLUG_CPU

  extern int register_cpu_notifier(struct notifier_block *nb);

  extern void unregister_cpu_notifier(struct notifier_block *nb);

  #else

  
  #ifndef MODULE
  extern int register_cpu_notifier(struct notifier_block *nb);
  #else
  static inline int register_cpu_notifier(struct notifier_block *nb)
  {
  	return 0;
  }
  #endif

  static inline void unregister_cpu_notifier(struct notifier_block *nb)
  {
  }
  #endif

  
  int cpu_up(unsigned int cpu);

  void notify_cpu_starting(unsigned int cpu);

  extern void cpu_maps_update_begin(void);
  extern void cpu_maps_update_done(void);

  #else	/* CONFIG_SMP */

  #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)

  static inline int register_cpu_notifier(struct notifier_block *nb)
  {
  	return 0;
  }

  static inline void unregister_cpu_notifier(struct notifier_block *nb)
  {
  }

  static inline void cpu_maps_update_begin(void)
  {
  }
  
  static inline void cpu_maps_update_done(void)
  {
  }

  #endif /* CONFIG_SMP */

  extern struct bus_type cpu_subsys;

  
  #ifdef CONFIG_HOTPLUG_CPU
  /* Stop CPUs going up and down. */

  extern void get_online_cpus(void);
  extern void put_online_cpus(void);

  #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)

  #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
  #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)

  int cpu_down(unsigned int cpu);

  #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
  extern void cpu_hotplug_driver_lock(void);
  extern void cpu_hotplug_driver_unlock(void);
  #else
  static inline void cpu_hotplug_driver_lock(void)
  {
  }
  
  static inline void cpu_hotplug_driver_unlock(void)
  {
  }
  #endif

  #else		/* CONFIG_HOTPLUG_CPU */

  #define get_online_cpus()	do { } while (0)
  #define put_online_cpus()	do { } while (0)

  #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)

  /* These aren't inline functions due to a GCC bug. */
  #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
  #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })

  #endif		/* CONFIG_HOTPLUG_CPU */

  #ifdef CONFIG_PM_SLEEP_SMP

  extern int disable_nonboot_cpus(void);
  extern void enable_nonboot_cpus(void);

  #else /* !CONFIG_PM_SLEEP_SMP */

  static inline int disable_nonboot_cpus(void) { return 0; }
  static inline void enable_nonboot_cpus(void) {}

  #endif /* !CONFIG_PM_SLEEP_SMP */

  #endif /* _LINUX_CPU_H_ */