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 extern void cpu_hotplug_init(void); 73 extern void cpu_maps_update_begin(void); 74 extern void cpu_maps_update_done(void); 75 76 #else /* CONFIG_SMP */ 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 static inline void cpu_maps_update_begin(void) 92 { 93 } 94 95 static inline void cpu_maps_update_done(void) 96 { 97 } 98 99 #endif /* CONFIG_SMP */ 100 extern struct sysdev_class cpu_sysdev_class; 101 102 #ifdef CONFIG_HOTPLUG_CPU 103 /* Stop CPUs going up and down. */ 104 105 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 106 { 107 mutex_lock(cpu_hp_mutex); 108 } 109 110 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 111 { 112 mutex_unlock(cpu_hp_mutex); 113 } 114 115 extern void get_online_cpus(void); 116 extern void put_online_cpus(void); 117 #define hotcpu_notifier(fn, pri) { \ 118 static struct notifier_block fn##_nb __cpuinitdata = \ 119 { .notifier_call = fn, .priority = pri }; \ 120 register_cpu_notifier(&fn##_nb); \ 121 } 122 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 123 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 124 int cpu_down(unsigned int cpu); 125 126 #else /* CONFIG_HOTPLUG_CPU */ 127 128 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 129 { } 130 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 131 { } 132 133 #define get_online_cpus() do { } while (0) 134 #define put_online_cpus() do { } while (0) 135 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 136 /* These aren't inline functions due to a GCC bug. */ 137 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; }) 138 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); }) 139 #endif /* CONFIG_HOTPLUG_CPU */ 140 141 #ifdef CONFIG_PM_SLEEP_SMP 142 extern int suspend_cpu_hotplug; 143 144 extern int disable_nonboot_cpus(void); 145 extern void enable_nonboot_cpus(void); 146 #else /* !CONFIG_PM_SLEEP_SMP */ 147 #define suspend_cpu_hotplug 0 148 149 static inline int disable_nonboot_cpus(void) { return 0; } 150 static inline void enable_nonboot_cpus(void) {} 151 #endif /* !CONFIG_PM_SLEEP_SMP */ 152 153 #endif /* _LINUX_CPU_H_ */ 154