xref: /openbmc/linux/include/linux/cpu.h (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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 
27 struct cpu {
28 	int node_id;		/* The node which contains the CPU */
29 	int hotpluggable;	/* creates sysfs control file if hotpluggable */
30 	struct sys_device sysdev;
31 };
32 
33 extern int register_cpu(struct cpu *cpu, int num);
34 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
35 
36 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
37 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
38 
39 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
40 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
41 
42 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
43 
44 #ifdef CONFIG_HOTPLUG_CPU
45 extern void unregister_cpu(struct cpu *cpu);
46 extern ssize_t arch_cpu_probe(const char *, size_t);
47 extern ssize_t arch_cpu_release(const char *, size_t);
48 #endif
49 struct notifier_block;
50 
51 #ifdef CONFIG_SMP
52 /* Need to know about CPUs going up/down? */
53 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
54 #define cpu_notifier(fn, pri) {					\
55 	static struct notifier_block fn##_nb __cpuinitdata =	\
56 		{ .notifier_call = fn, .priority = pri };	\
57 	register_cpu_notifier(&fn##_nb);			\
58 }
59 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
60 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
61 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
62 #ifdef CONFIG_HOTPLUG_CPU
63 extern int register_cpu_notifier(struct notifier_block *nb);
64 extern void unregister_cpu_notifier(struct notifier_block *nb);
65 #else
66 
67 #ifndef MODULE
68 extern int register_cpu_notifier(struct notifier_block *nb);
69 #else
70 static inline int register_cpu_notifier(struct notifier_block *nb)
71 {
72 	return 0;
73 }
74 #endif
75 
76 static inline void unregister_cpu_notifier(struct notifier_block *nb)
77 {
78 }
79 #endif
80 
81 int cpu_up(unsigned int cpu);
82 void notify_cpu_starting(unsigned int cpu);
83 extern void cpu_maps_update_begin(void);
84 extern void cpu_maps_update_done(void);
85 
86 #else	/* CONFIG_SMP */
87 
88 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
89 
90 static inline int register_cpu_notifier(struct notifier_block *nb)
91 {
92 	return 0;
93 }
94 
95 static inline void unregister_cpu_notifier(struct notifier_block *nb)
96 {
97 }
98 
99 static inline void cpu_maps_update_begin(void)
100 {
101 }
102 
103 static inline void cpu_maps_update_done(void)
104 {
105 }
106 
107 #endif /* CONFIG_SMP */
108 extern struct sysdev_class cpu_sysdev_class;
109 
110 #ifdef CONFIG_HOTPLUG_CPU
111 /* Stop CPUs going up and down. */
112 
113 extern void get_online_cpus(void);
114 extern void put_online_cpus(void);
115 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
116 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
117 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
118 int cpu_down(unsigned int cpu);
119 
120 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
121 extern void cpu_hotplug_driver_lock(void);
122 extern void cpu_hotplug_driver_unlock(void);
123 #else
124 static inline void cpu_hotplug_driver_lock(void)
125 {
126 }
127 
128 static inline void cpu_hotplug_driver_unlock(void)
129 {
130 }
131 #endif
132 
133 #else		/* CONFIG_HOTPLUG_CPU */
134 
135 #define get_online_cpus()	do { } while (0)
136 #define put_online_cpus()	do { } while (0)
137 #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
138 /* These aren't inline functions due to a GCC bug. */
139 #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
140 #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
141 #endif		/* CONFIG_HOTPLUG_CPU */
142 
143 #ifdef CONFIG_PM_SLEEP_SMP
144 extern int suspend_cpu_hotplug;
145 
146 extern int disable_nonboot_cpus(void);
147 extern void enable_nonboot_cpus(void);
148 #else /* !CONFIG_PM_SLEEP_SMP */
149 #define suspend_cpu_hotplug	0
150 
151 static inline int disable_nonboot_cpus(void) { return 0; }
152 static inline void enable_nonboot_cpus(void) {}
153 #endif /* !CONFIG_PM_SLEEP_SMP */
154 
155 #endif /* _LINUX_CPU_H_ */
156