1 /*

     2  * include/linux/cpu.h - generic cpu definition

     3  *

     4  * This is mainly for topological representation. We define the 

     5  * basic 'struct cpu' here, which can be embedded in per-arch 

     6  * definitions of processors.

     7  *

     8  * Basic handling of the devices is done in drivers/base/cpu.c

     9  * and system devices are handled in drivers/base/sys.c. 

    10  *

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

    12  * directory. 

    13  *

    14  * Per-cpu interfaces can be implemented using a struct device_interface. 

    15  * See the following for how to do this: 

    16  * - drivers/base/intf.c 

    17  * - Documentation/driver-model/interface.txt

    18  */

    19 #ifndef _LINUX_CPU_H_

    20 #define _LINUX_CPU_H_

    21 

    22 #include <linux/sysdev.h>

    23 #include <linux/node.h>

    24 #include <linux/compiler.h>

    25 #include <linux/cpumask.h>

    26 #include <linux/mutex.h>

    27 

    28 struct cpu {

    29 	int node_id;		/* The node which contains the CPU */

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

    31 	struct sys_device sysdev;

    32 };

    33 

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

    35 extern struct sys_device *get_cpu_sysdev(unsigned cpu);

    36 

    37 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);

    38 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);

    39 

    40 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);

    41 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);

    42 

    43 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);

    44 

    45 #ifdef CONFIG_HOTPLUG_CPU

    46 extern void unregister_cpu(struct cpu *cpu);

    47 #endif

    48 struct notifier_block;

    49 

    50 #ifdef CONFIG_SMP

    51 /* Need to know about CPUs going up/down? */

    52 #ifdef CONFIG_HOTPLUG_CPU

    53 extern int register_cpu_notifier(struct notifier_block *nb);

    54 extern void unregister_cpu_notifier(struct notifier_block *nb);

    55 #else

    56 

    57 #ifndef MODULE

    58 extern int register_cpu_notifier(struct notifier_block *nb);

    59 #else

    60 static inline int register_cpu_notifier(struct notifier_block *nb)

    61 {

    62 	return 0;

    63 }

    64 #endif

    65 

    66 static inline void unregister_cpu_notifier(struct notifier_block *nb)

    67 {

    68 }

    69 #endif

    70 

    71 int cpu_up(unsigned int cpu);

    72 void notify_cpu_starting(unsigned int cpu);

    73 extern void cpu_hotplug_init(void);

    74 extern void cpu_maps_update_begin(void);

    75 extern void cpu_maps_update_done(void);

    76 

    77 #else	/* CONFIG_SMP */

    78 

    79 static inline int register_cpu_notifier(struct notifier_block *nb)

    80 {

    81 	return 0;

    82 }

    83 

    84 static inline void unregister_cpu_notifier(struct notifier_block *nb)

    85 {

    86 }

    87 

    88 static inline void cpu_hotplug_init(void)

    89 {

    90 }

    91 

    92 static inline void cpu_maps_update_begin(void)

    93 {

    94 }

    95 

    96 static inline void cpu_maps_update_done(void)

    97 {

    98 }

    99 

   100 #endif /* CONFIG_SMP */

   101 extern struct sysdev_class cpu_sysdev_class;

   102 

   103 #ifdef CONFIG_HOTPLUG_CPU

   104 /* Stop CPUs going up and down. */

   105 

   106 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)

   107 {

   108 	mutex_lock(cpu_hp_mutex);

   109 }

   110 

   111 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)

   112 {

   113 	mutex_unlock(cpu_hp_mutex);

   114 }

   115 

   116 extern void get_online_cpus(void);

   117 extern void put_online_cpus(void);

   118 #define hotcpu_notifier(fn, pri) {				\

   119 	static struct notifier_block fn##_nb __cpuinitdata =	\

   120 		{ .notifier_call = fn, .priority = pri };	\

   121 	register_cpu_notifier(&fn##_nb);			\

   122 }

   123 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)

   124 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)

   125 int cpu_down(unsigned int cpu);

   126 

   127 #else		/* CONFIG_HOTPLUG_CPU */

   128 

   129 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)

   130 { }

   131 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)

   132 { }

   133 

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

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

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

   137 /* These aren't inline functions due to a GCC bug. */

   138 #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })

   139 #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })

   140 #endif		/* CONFIG_HOTPLUG_CPU */

   141 

   142 #ifdef CONFIG_PM_SLEEP_SMP

   143 extern int suspend_cpu_hotplug;

   144 

   145 extern int disable_nonboot_cpus(void);

   146 extern void enable_nonboot_cpus(void);

   147 #else /* !CONFIG_PM_SLEEP_SMP */

   148 #define suspend_cpu_hotplug	0

   149 

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

   151 static inline void enable_nonboot_cpus(void) {}

   152 #endif /* !CONFIG_PM_SLEEP_SMP */

   153 

   154 #endif /* _LINUX_CPU_H_ */