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