include/linux/cpu.h

   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 driverfs 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/device.h>
  23 #include <linux/node.h>
  24 #include <asm/semaphore.h>
  25
  26 struct cpu {
  27         int node_id;            /* The node which contains the CPU */
  28         struct sys_device sysdev;
  29 };
  30
  31 extern int register_cpu(struct cpu *, int, struct node *);
  32 extern struct class cpu_class;
  33
  34 struct notifier_block;
  35
  36 #ifdef CONFIG_SMP
  37 /* Need to know about CPUs going up/down? */
  38 extern int register_cpu_notifier(struct notifier_block *nb);
  39 extern void unregister_cpu_notifier(struct notifier_block *nb);
  40
  41 int cpu_up(unsigned int cpu);
  42 #else
  43 static inline int register_cpu_notifier(struct notifier_block *nb)
  44 {
  45         return 0;
  46 }
  47 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  48 {
  49 }
  50 #endif /* CONFIG_SMP */
  51
  52 /* Stop CPUs going up and down. */
  53 extern struct semaphore cpucontrol;
  54 #endif /* _LINUX_CPU_H_ */