2 * include/linux/cpu.h - generic cpu definition
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.
8 * Basic handling of the devices is done in drivers/base/cpu.c
9 * and system devices are handled in drivers/base/sys.c.
11 * CPUs are exported via sysfs in the class/cpu/devices/
17 #include <linux/sysdev.h>
18 #include <linux/node.h>
19 #include <linux/compiler.h>
20 #include <linux/cpumask.h>
23 int node_id; /* The node which contains the CPU */
24 int hotpluggable; /* creates sysfs control file if hotpluggable */
25 struct sys_device sysdev;
28 extern int register_cpu(struct cpu *cpu, int num);
29 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
31 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
32 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
34 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
35 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
37 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
39 ssize_t cpu_show_meltdown(struct sysdev_class *class,
40 struct sysdev_class_attribute *attr, char *buf);
41 ssize_t cpu_show_spectre_v1(struct sysdev_class *class,
42 struct sysdev_class_attribute *attr, char *buf);
43 ssize_t cpu_show_spectre_v2(struct sysdev_class *class,
44 struct sysdev_class_attribute *attr, char *buf);
46 #ifdef CONFIG_HOTPLUG_CPU
47 extern void unregister_cpu(struct cpu *cpu);
48 extern ssize_t arch_cpu_probe(const char *, size_t);
49 extern ssize_t arch_cpu_release(const char *, size_t);
51 struct notifier_block;
54 * CPU notifier priorities.
58 * SCHED_ACTIVE marks a cpu which is coming up active during
59 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
60 * notifier. CPUSET_ACTIVE adjusts cpuset according to
61 * cpu_active mask right after SCHED_ACTIVE. During
62 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
63 * ordered in the similar way.
65 * This ordering guarantees consistent cpu_active mask and
66 * migration behavior to all cpu notifiers.
68 CPU_PRI_SCHED_ACTIVE = INT_MAX,
69 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
70 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
71 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
73 /* migration should happen before other stuff but after perf */
75 CPU_PRI_MIGRATION = 10,
76 /* bring up workqueues before normal notifiers and down after */
77 CPU_PRI_WORKQUEUE_UP = 5,
78 CPU_PRI_WORKQUEUE_DOWN = -5,
81 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
82 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
83 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
84 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
85 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
86 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
87 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
88 * not handling interrupts, soon dead.
89 * Called on the dying cpu, interrupts
90 * are already disabled. Must not
91 * sleep, must not fail */
92 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
94 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
95 * Called on the new cpu, just before
96 * enabling interrupts. Must not sleep,
99 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
100 * operation in progress
102 #define CPU_TASKS_FROZEN 0x0010
104 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
105 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
106 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
107 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
108 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
109 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
110 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
111 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
115 /* Need to know about CPUs going up/down? */
116 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
117 #define cpu_notifier(fn, pri) { \
118 static struct notifier_block fn##_nb __cpuinitdata = \
119 { .notifier_call = fn, .priority = pri }; \
120 register_cpu_notifier(&fn##_nb); \
122 extern int register_cpu_notifier(struct notifier_block *nb);
123 extern void unregister_cpu_notifier(struct notifier_block *nb);
125 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
126 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
128 static inline int register_cpu_notifier(struct notifier_block *nb)
133 static inline void unregister_cpu_notifier(struct notifier_block *nb)
138 int cpu_up(unsigned int cpu);
139 void notify_cpu_starting(unsigned int cpu);
140 extern void cpu_maps_update_begin(void);
141 extern void cpu_maps_update_done(void);
143 #else /* CONFIG_SMP */
145 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
147 static inline int register_cpu_notifier(struct notifier_block *nb)
152 static inline void unregister_cpu_notifier(struct notifier_block *nb)
156 static inline void cpu_maps_update_begin(void)
160 static inline void cpu_maps_update_done(void)
164 #endif /* CONFIG_SMP */
165 extern struct sysdev_class cpu_sysdev_class;
167 #ifdef CONFIG_HOTPLUG_CPU
168 /* Stop CPUs going up and down. */
170 extern void get_online_cpus(void);
171 extern void put_online_cpus(void);
172 extern void cpu_hotplug_disable(void);
173 extern void cpu_hotplug_enable(void);
174 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
175 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
176 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
177 int cpu_down(unsigned int cpu);
179 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
180 extern void cpu_hotplug_driver_lock(void);
181 extern void cpu_hotplug_driver_unlock(void);
183 static inline void cpu_hotplug_driver_lock(void)
187 static inline void cpu_hotplug_driver_unlock(void)
192 #else /* CONFIG_HOTPLUG_CPU */
194 #define get_online_cpus() do { } while (0)
195 #define put_online_cpus() do { } while (0)
196 #define cpu_hotplug_disable() do { } while (0)
197 #define cpu_hotplug_enable() do { } while (0)
198 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
199 /* These aren't inline functions due to a GCC bug. */
200 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
201 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
202 #endif /* CONFIG_HOTPLUG_CPU */
204 #ifdef CONFIG_PM_SLEEP_SMP
205 extern int disable_nonboot_cpus(void);
206 extern void enable_nonboot_cpus(void);
207 #else /* !CONFIG_PM_SLEEP_SMP */
208 static inline int disable_nonboot_cpus(void) { return 0; }
209 static inline void enable_nonboot_cpus(void) {}
210 #endif /* !CONFIG_PM_SLEEP_SMP */
212 #endif /* _LINUX_CPU_H_ */