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 28 struct cpu { 29 int node_id; /* The node which contains the CPU */ 30 int no_control; /* Should the sysfs control file be created? */ 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 #ifdef CONFIG_HOTPLUG_CPU 37 extern void unregister_cpu(struct cpu *cpu); 38 #endif 39 struct notifier_block; 40 41 #ifdef CONFIG_SMP 42 /* Need to know about CPUs going up/down? */ 43 extern int register_cpu_notifier(struct notifier_block *nb); 44 #ifdef CONFIG_HOTPLUG_CPU 45 extern void unregister_cpu_notifier(struct notifier_block *nb); 46 #else 47 static inline void unregister_cpu_notifier(struct notifier_block *nb) 48 { 49 } 50 #endif 51 52 int cpu_up(unsigned int cpu); 53 54 #else 55 56 static inline int register_cpu_notifier(struct notifier_block *nb) 57 { 58 return 0; 59 } 60 static inline void unregister_cpu_notifier(struct notifier_block *nb) 61 { 62 } 63 64 #endif /* CONFIG_SMP */ 65 extern struct sysdev_class cpu_sysdev_class; 66 67 #ifdef CONFIG_HOTPLUG_CPU 68 /* Stop CPUs going up and down. */ 69 extern void lock_cpu_hotplug(void); 70 extern void unlock_cpu_hotplug(void); 71 #define hotcpu_notifier(fn, pri) { \ 72 static struct notifier_block fn##_nb = \ 73 { .notifier_call = fn, .priority = pri }; \ 74 register_cpu_notifier(&fn##_nb); \ 75 } 76 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 77 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 78 int cpu_down(unsigned int cpu); 79 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 80 #else 81 #define lock_cpu_hotplug() do { } while (0) 82 #define unlock_cpu_hotplug() do { } while (0) 83 #define lock_cpu_hotplug_interruptible() 0 84 #define hotcpu_notifier(fn, pri) do { } while (0) 85 #define register_hotcpu_notifier(nb) do { } while (0) 86 #define unregister_hotcpu_notifier(nb) do { } while (0) 87 88 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ 89 static inline int cpu_is_offline(int cpu) { return 0; } 90 #endif 91 92 #endif /* _LINUX_CPU_H_ */ 93
