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	 e545a6140b
			
		
	
	
		e545a6140b
		
	
	
	
	
		
			
			Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
		
			
				
	
	
		
			155 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			155 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * include/linux/cpu.h - generic cpu definition
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|  *
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|  * This is mainly for topological representation. We define the 
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|  * basic 'struct cpu' here, which can be embedded in per-arch 
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|  * definitions of processors.
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|  *
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|  * Basic handling of the devices is done in drivers/base/cpu.c
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|  * and system devices are handled in drivers/base/sys.c. 
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|  *
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|  * CPUs are exported via sysfs in the class/cpu/devices/
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|  * directory. 
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|  *
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|  * Per-cpu interfaces can be implemented using a struct device_interface. 
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|  * See the following for how to do this: 
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|  * - drivers/base/intf.c 
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|  * - Documentation/driver-model/interface.txt
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|  */
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| #ifndef _LINUX_CPU_H_
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| #define _LINUX_CPU_H_
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| 
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| #include <linux/sysdev.h>
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| #include <linux/node.h>
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| #include <linux/compiler.h>
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| #include <linux/cpumask.h>
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| #include <linux/mutex.h>
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| 
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| struct cpu {
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| 	int node_id;		/* The node which contains the CPU */
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| 	int hotpluggable;	/* creates sysfs control file if hotpluggable */
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| 	struct sys_device sysdev;
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| };
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| 
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| extern int register_cpu(struct cpu *cpu, int num);
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| extern struct sys_device *get_cpu_sysdev(unsigned cpu);
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| 
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| extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
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| extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
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| 
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| extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
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| extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
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| 
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| extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
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| 
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| #ifdef CONFIG_HOTPLUG_CPU
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| extern void unregister_cpu(struct cpu *cpu);
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| #endif
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| struct notifier_block;
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| 
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| #ifdef CONFIG_SMP
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| /* Need to know about CPUs going up/down? */
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| #ifdef CONFIG_HOTPLUG_CPU
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| extern int register_cpu_notifier(struct notifier_block *nb);
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| extern void unregister_cpu_notifier(struct notifier_block *nb);
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| #else
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| 
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| #ifndef MODULE
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| extern int register_cpu_notifier(struct notifier_block *nb);
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| #else
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| static inline int register_cpu_notifier(struct notifier_block *nb)
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| {
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| 	return 0;
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| }
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| #endif
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| 
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| static inline void unregister_cpu_notifier(struct notifier_block *nb)
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| {
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| }
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| #endif
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| 
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| int cpu_up(unsigned int cpu);
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| void notify_cpu_starting(unsigned int cpu);
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| extern void cpu_hotplug_init(void);
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| extern void cpu_maps_update_begin(void);
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| extern void cpu_maps_update_done(void);
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| 
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| #else	/* CONFIG_SMP */
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| 
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| static inline int register_cpu_notifier(struct notifier_block *nb)
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| {
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| 	return 0;
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| }
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| 
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| static inline void unregister_cpu_notifier(struct notifier_block *nb)
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| {
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| }
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| 
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| static inline void cpu_hotplug_init(void)
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| {
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| }
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| 
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| static inline void cpu_maps_update_begin(void)
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| {
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| }
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| 
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| static inline void cpu_maps_update_done(void)
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| {
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| }
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| 
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| #endif /* CONFIG_SMP */
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| extern struct sysdev_class cpu_sysdev_class;
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| 
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| #ifdef CONFIG_HOTPLUG_CPU
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| /* Stop CPUs going up and down. */
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| 
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| static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
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| {
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| 	mutex_lock(cpu_hp_mutex);
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| }
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| 
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| static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
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| {
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| 	mutex_unlock(cpu_hp_mutex);
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| }
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| 
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| extern void get_online_cpus(void);
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| extern void put_online_cpus(void);
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| #define hotcpu_notifier(fn, pri) {				\
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| 	static struct notifier_block fn##_nb __cpuinitdata =	\
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| 		{ .notifier_call = fn, .priority = pri };	\
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| 	register_cpu_notifier(&fn##_nb);			\
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| }
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| #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
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| #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
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| int cpu_down(unsigned int cpu);
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| 
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| #else		/* CONFIG_HOTPLUG_CPU */
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| 
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| static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
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| { }
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| static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
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| { }
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| 
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| #define get_online_cpus()	do { } while (0)
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| #define put_online_cpus()	do { } while (0)
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| #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
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| /* These aren't inline functions due to a GCC bug. */
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| #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
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| #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
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| #endif		/* CONFIG_HOTPLUG_CPU */
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| 
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| #ifdef CONFIG_PM_SLEEP_SMP
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| extern int suspend_cpu_hotplug;
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| 
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| extern int disable_nonboot_cpus(void);
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| extern void enable_nonboot_cpus(void);
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| #else /* !CONFIG_PM_SLEEP_SMP */
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| #define suspend_cpu_hotplug	0
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| 
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| static inline int disable_nonboot_cpus(void) { return 0; }
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| static inline void enable_nonboot_cpus(void) {}
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| #endif /* !CONFIG_PM_SLEEP_SMP */
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| 
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| #endif /* _LINUX_CPU_H_ */
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