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 <asm/semaphore.h> 27 #include <linux/mutex.h> 28 29 struct cpu { 30 int node_id; /* The node which contains the CPU */ 31 int hotpluggable; /* creates sysfs control file if hotpluggable */ 32 struct sys_device sysdev; 33 }; 34 35 extern int register_cpu(struct cpu *cpu, int num); 36 extern struct sys_device *get_cpu_sysdev(unsigned cpu); 37 38 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr); 39 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr); 40 41 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs); 42 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs); 43 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 extern int register_cpu_notifier(struct notifier_block *nb); 53 #ifdef CONFIG_HOTPLUG_CPU 54 extern void unregister_cpu_notifier(struct notifier_block *nb); 55 #else 56 static inline void unregister_cpu_notifier(struct notifier_block *nb) 57 { 58 } 59 #endif 60 61 int cpu_up(unsigned int cpu); 62 63 #else 64 65 static inline int register_cpu_notifier(struct notifier_block *nb) 66 { 67 return 0; 68 } 69 static inline void unregister_cpu_notifier(struct notifier_block *nb) 70 { 71 } 72 73 #endif /* CONFIG_SMP */ 74 extern struct sysdev_class cpu_sysdev_class; 75 76 #ifdef CONFIG_HOTPLUG_CPU 77 /* Stop CPUs going up and down. */ 78 79 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 80 { 81 mutex_lock(cpu_hp_mutex); 82 } 83 84 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 85 { 86 mutex_unlock(cpu_hp_mutex); 87 } 88 89 extern void lock_cpu_hotplug(void); 90 extern void unlock_cpu_hotplug(void); 91 #define hotcpu_notifier(fn, pri) { \ 92 static struct notifier_block fn##_nb = \ 93 { .notifier_call = fn, .priority = pri }; \ 94 register_cpu_notifier(&fn##_nb); \ 95 } 96 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 97 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 98 int cpu_down(unsigned int cpu); 99 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 100 101 #else /* CONFIG_HOTPLUG_CPU */ 102 103 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 104 { } 105 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 106 { } 107 108 #define lock_cpu_hotplug() do { } while (0) 109 #define unlock_cpu_hotplug() do { } while (0) 110 #define lock_cpu_hotplug_interruptible() 0 111 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 112 #define register_hotcpu_notifier(nb) do { (void)(nb); } while (0) 113 #define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0) 114 115 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ 116 static inline int cpu_is_offline(int cpu) { return 0; } 117 #endif /* CONFIG_HOTPLUG_CPU */ 118 119 #ifdef CONFIG_SUSPEND_SMP 120 extern int disable_nonboot_cpus(void); 121 extern void enable_nonboot_cpus(void); 122 #else 123 static inline int disable_nonboot_cpus(void) { return 0; } 124 static inline void enable_nonboot_cpus(void) {} 125 #endif 126 127 #endif /* _LINUX_CPU_H_ */ 128