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 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls); 45 46 #ifdef CONFIG_HOTPLUG_CPU 47 extern void unregister_cpu(struct cpu *cpu); 48 #endif 49 struct notifier_block; 50 51 #ifdef CONFIG_SMP 52 /* Need to know about CPUs going up/down? */ 53 #ifdef CONFIG_HOTPLUG_CPU 54 extern int register_cpu_notifier(struct notifier_block *nb); 55 extern void unregister_cpu_notifier(struct notifier_block *nb); 56 #else 57 58 #ifndef MODULE 59 extern int register_cpu_notifier(struct notifier_block *nb); 60 #else 61 static inline int register_cpu_notifier(struct notifier_block *nb) 62 { 63 return 0; 64 } 65 #endif 66 67 static inline void unregister_cpu_notifier(struct notifier_block *nb) 68 { 69 } 70 #endif 71 72 int cpu_up(unsigned int cpu); 73 74 extern void cpu_hotplug_init(void); 75 76 #else 77 78 static inline int register_cpu_notifier(struct notifier_block *nb) 79 { 80 return 0; 81 } 82 83 static inline void unregister_cpu_notifier(struct notifier_block *nb) 84 { 85 } 86 87 static inline void cpu_hotplug_init(void) 88 { 89 } 90 91 #endif /* CONFIG_SMP */ 92 extern struct sysdev_class cpu_sysdev_class; 93 extern void cpu_maps_update_begin(void); 94 extern void cpu_maps_update_done(void); 95 96 #ifdef CONFIG_HOTPLUG_CPU 97 /* Stop CPUs going up and down. */ 98 99 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 100 { 101 mutex_lock(cpu_hp_mutex); 102 } 103 104 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 105 { 106 mutex_unlock(cpu_hp_mutex); 107 } 108 109 extern void get_online_cpus(void); 110 extern void put_online_cpus(void); 111 #define hotcpu_notifier(fn, pri) { \ 112 static struct notifier_block fn##_nb = \ 113 { .notifier_call = fn, .priority = pri }; \ 114 register_cpu_notifier(&fn##_nb); \ 115 } 116 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 117 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 118 int cpu_down(unsigned int cpu); 119 120 #else /* CONFIG_HOTPLUG_CPU */ 121 122 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 123 { } 124 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 125 { } 126 127 #define get_online_cpus() do { } while (0) 128 #define put_online_cpus() do { } while (0) 129 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 130 /* These aren't inline functions due to a GCC bug. */ 131 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 132 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 133 #endif /* CONFIG_HOTPLUG_CPU */ 134 135 #ifdef CONFIG_PM_SLEEP_SMP 136 extern int suspend_cpu_hotplug; 137 138 extern int disable_nonboot_cpus(void); 139 extern void enable_nonboot_cpus(void); 140 #else /* !CONFIG_PM_SLEEP_SMP */ 141 #define suspend_cpu_hotplug 0 142 143 static inline int disable_nonboot_cpus(void) { return 0; } 144 static inline void enable_nonboot_cpus(void) {} 145 #endif /* !CONFIG_PM_SLEEP_SMP */ 146 147 #endif /* _LINUX_CPU_H_ */ 148