| 1 | /* |
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| 2 | * include/linux/cpu.h - generic cpu definition |
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| 3 | * |
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| 4 | * This is mainly for topological representation. We define the |
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| 5 | * basic 'struct cpu' here, which can be embedded in per-arch |
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| 6 | * definitions of processors. |
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| 7 | * |
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| 8 | * Basic handling of the devices is done in drivers/base/cpu.c |
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| 9 | * and system devices are handled in drivers/base/sys.c. |
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| 10 | * |
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| 11 | * CPUs are exported via driverfs in the class/cpu/devices/ |
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| 12 | * directory. |
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| 13 | * |
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| 14 | * Per-cpu interfaces can be implemented using a struct device_interface. |
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| 15 | * See the following for how to do this: |
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| 16 | * - drivers/base/intf.c |
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| 17 | * - Documentation/driver-model/interface.txt |
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| 18 | */ |
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| 19 | #ifndef _LINUX_CPU_H_ |
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| 20 | #define _LINUX_CPU_H_ |
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| 21 | |
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| 22 | #include <linux/sysdev.h> |
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| 23 | #include <linux/node.h> |
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| 24 | #include <asm/semaphore.h> |
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| 25 | |
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| 26 | struct cpu { |
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| 27 | int node_id; /* The node which contains the CPU */ |
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| 28 | int no_control; /* Should the sysfs control file be created? */ |
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| 29 | struct sys_device sysdev; |
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| 30 | }; |
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| 31 | |
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| 32 | extern int register_cpu(struct cpu *, int, struct node *); |
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| 33 | #ifdef CONFIG_HOTPLUG_CPU |
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| 34 | extern void unregister_cpu(struct cpu *, struct node *); |
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| 35 | #endif |
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| 36 | struct notifier_block; |
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| 37 | |
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| 38 | #ifdef CONFIG_SMP |
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| 39 | /* Need to know about CPUs going up/down? */ |
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| 40 | extern int register_cpu_notifier(struct notifier_block *nb); |
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| 41 | extern void unregister_cpu_notifier(struct notifier_block *nb); |
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| 42 | |
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| 43 | int cpu_up(unsigned int cpu); |
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| 44 | |
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| 45 | #else |
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| 46 | |
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| 47 | static inline int register_cpu_notifier(struct notifier_block *nb) |
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| 48 | { |
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| 49 | return 0; |
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| 50 | } |
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| 51 | static inline void unregister_cpu_notifier(struct notifier_block *nb) |
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| 52 | { |
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| 53 | } |
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| 54 | |
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| 55 | #endif /* CONFIG_SMP */ |
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| 56 | extern struct sysdev_class cpu_sysdev_class; |
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| 57 | |
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| 58 | #ifdef CONFIG_HOTPLUG_CPU |
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| 59 | /* Stop CPUs going up and down. */ |
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| 60 | extern struct semaphore cpucontrol; |
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| 61 | #define lock_cpu_hotplug() down(&cpucontrol) |
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| 62 | #define unlock_cpu_hotplug() up(&cpucontrol) |
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| 63 | #define lock_cpu_hotplug_interruptible() down_interruptible(&cpucontrol) |
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| 64 | #define hotcpu_notifier(fn, pri) { \ |
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| 65 | static struct notifier_block fn##_nb = \ |
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| 66 | { .notifier_call = fn, .priority = pri }; \ |
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| 67 | register_cpu_notifier(&fn##_nb); \ |
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| 68 | } |
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| 69 | int cpu_down(unsigned int cpu); |
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| 70 | #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) |
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| 71 | #else |
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| 72 | #define lock_cpu_hotplug() do { } while (0) |
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| 73 | #define unlock_cpu_hotplug() do { } while (0) |
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| 74 | #define lock_cpu_hotplug_interruptible() 0 |
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| 75 | #define hotcpu_notifier(fn, pri) |
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| 76 | |
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| 77 | /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ |
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| 78 | static inline int cpu_is_offline(int cpu) { return 0; } |
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| 79 | #endif |
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| 80 | |
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| 81 | #endif /* _LINUX_CPU_H_ */ |
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