Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
28struct 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
34extern int register_cpu(struct cpu *, int, struct node *);
35extern struct sys_device *get_cpu_sysdev(int cpu);
36#ifdef CONFIG_HOTPLUG_CPU
37extern void unregister_cpu(struct cpu *, struct node *);
38#endif
39struct notifier_block;
40
41#ifdef CONFIG_SMP
42/* Need to know about CPUs going up/down? */
43extern int register_cpu_notifier(struct notifier_block *nb);
44extern void unregister_cpu_notifier(struct notifier_block *nb);
45extern int current_in_cpu_hotplug(void);
46
47int cpu_up(unsigned int cpu);
48
49#else
50
51static inline int register_cpu_notifier(struct notifier_block *nb)
52{
53 return 0;
54}
55static inline void unregister_cpu_notifier(struct notifier_block *nb)
56{
57}
58static inline int current_in_cpu_hotplug(void)
59{
60 return 0;
61}
62
63#endif /* CONFIG_SMP */
64extern struct sysdev_class cpu_sysdev_class;
65
66#ifdef CONFIG_HOTPLUG_CPU
67/* Stop CPUs going up and down. */
68extern void lock_cpu_hotplug(void);
69extern void unlock_cpu_hotplug(void);
70extern int lock_cpu_hotplug_interruptible(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}
76int cpu_down(unsigned int cpu);
77extern int __attribute__((weak)) smp_prepare_cpu(int cpu);
78#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
79#else
80#define lock_cpu_hotplug() do { } while (0)
81#define unlock_cpu_hotplug() do { } while (0)
82#define lock_cpu_hotplug_interruptible() 0
83#define hotcpu_notifier(fn, pri)
84
85/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
86static inline int cpu_is_offline(int cpu) { return 0; }
87#endif
88
89#endif /* _LINUX_CPU_H_ */