86ef5c9a8e
Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use get_online_cpus and put_online_cpus instead as it highlights the refcount semantics in these operations. The new API guarantees protection against the cpu-hotplug operation, but it doesn't guarantee serialized access to any of the local data structures. Hence the changes needs to be reviewed. In case of pseries_add_processor/pseries_remove_processor, use cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the cpu_present_map there. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
142 lines
3.9 KiB
C
142 lines
3.9 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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#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 <asm/semaphore.h>
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#include <linux/mutex.h>
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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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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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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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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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extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
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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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#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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#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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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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int cpu_up(unsigned int cpu);
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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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static inline void unregister_cpu_notifier(struct notifier_block *nb)
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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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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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#ifdef CONFIG_HOTPLUG_CPU
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/* Stop CPUs going up and down. */
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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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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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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 = \
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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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#else /* CONFIG_HOTPLUG_CPU */
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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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#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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#ifdef CONFIG_PM_SLEEP_SMP
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extern int suspend_cpu_hotplug;
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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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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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#endif /* _LINUX_CPU_H_ */
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