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Commit 0902a904 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
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Driver core: Use generic offline/online for CPU offline/online 



Rework the CPU hotplug code in drivers/base/cpu.c to use the
generic offline/online support introduced previously instead of
its own CPU-specific code.

For this purpose, modify cpu_subsys to provide offline and online
callbacks for CONFIG_HOTPLUG_CPU set and remove the code handling
the CPU-specific 'online' sysfs attribute.

This modification is not supposed to change the user-observable
behavior of the kernel (i.e. the 'online' attribute will be present
in exactly the same place in sysfs and should trigger exactly the
same actions as before).

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarToshi Kani <toshi.kani@hp.com>
parent 4f3549d7

drivers/base/cpu.c

+32 −57
Original line number Original line Diff line number Diff line
@@ -16,12 +16,6 @@ 




#include "base.h"

#include "base.h"





struct bus_type cpu_subsys = {

	.name = "cpu",

	.dev_name = "cpu",

};

EXPORT_SYMBOL_GPL(cpu_subsys);



static DEFINE_PER_CPU(struct device *, cpu_sys_devices);

static DEFINE_PER_CPU(struct device *, cpu_sys_devices);





#ifdef CONFIG_HOTPLUG_CPU

#ifdef CONFIG_HOTPLUG_CPU
@@ -34,35 +28,17 @@ static void change_cpu_under_node(struct cpu *cpu, 
	cpu->node_id = to_nid;

	cpu->node_id = to_nid;

}

}





static ssize_t show_online(struct device *dev,

static int __ref cpu_subsys_online(struct device *dev)

			   struct device_attribute *attr,

			   char *buf)

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);



	return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id));

}



static ssize_t __ref store_online(struct device *dev,

				  struct device_attribute *attr,

				  const char *buf, size_t count)

{

{

	struct cpu *cpu = container_of(dev, struct cpu, dev);

	struct cpu *cpu = container_of(dev, struct cpu, dev);

	int cpuid = cpu->dev.id;

	int cpuid = dev->id;

	int from_nid, to_nid;

	int from_nid, to_nid;

	ssize_t ret;

	int ret;





	cpu_hotplug_driver_lock();

	cpu_hotplug_driver_lock();

	switch (buf[0]) {



	case '0':

		ret = cpu_down(cpuid);

		if (!ret)

			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);

		break;

	case '1':

	from_nid = cpu_to_node(cpuid);

	from_nid = cpu_to_node(cpuid);

	ret = cpu_up(cpuid);

	ret = cpu_up(cpuid);



	/*

	/*

	 * When hot adding memory to memoryless node and enabling a cpu

	 * When hot adding memory to memoryless node and enabling a cpu

	 * on the node, node number of the cpu may internally change.

	 * on the node, node number of the cpu may internally change.
@@ -71,32 +47,26 @@ static ssize_t __ref store_online(struct device *dev, 
	if (from_nid != to_nid)

	if (from_nid != to_nid)

		change_cpu_under_node(cpu, from_nid, to_nid);

		change_cpu_under_node(cpu, from_nid, to_nid);





		if (!ret)

			kobject_uevent(&dev->kobj, KOBJ_ONLINE);

		break;

	default:

		ret = -EINVAL;

	}

	cpu_hotplug_driver_unlock();

	cpu_hotplug_driver_unlock();



	if (ret >= 0)

		ret = count;

	return ret;

	return ret;

}

}

static DEVICE_ATTR(online, 0644, show_online, store_online);





static void __cpuinit register_cpu_control(struct cpu *cpu)

static int cpu_subsys_offline(struct device *dev)

{

{

	device_create_file(&cpu->dev, &dev_attr_online);

	int ret;



	cpu_hotplug_driver_lock();

	ret = cpu_down(dev->id);

	cpu_hotplug_driver_unlock();

	return ret;

}

}



void unregister_cpu(struct cpu *cpu)

void unregister_cpu(struct cpu *cpu)

{

{

	int logical_cpu = cpu->dev.id;

	int logical_cpu = cpu->dev.id;





	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));

	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));





	device_remove_file(&cpu->dev, &dev_attr_online);



	device_unregister(&cpu->dev);

	device_unregister(&cpu->dev);

	per_cpu(cpu_sys_devices, logical_cpu) = NULL;

	per_cpu(cpu_sys_devices, logical_cpu) = NULL;

	return;

	return;
@@ -123,12 +93,18 @@ static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); 
static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);

static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);

#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */

#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */





#else /* ... !CONFIG_HOTPLUG_CPU */

static inline void register_cpu_control(struct cpu *cpu)

{

}

#endif /* CONFIG_HOTPLUG_CPU */

#endif /* CONFIG_HOTPLUG_CPU */





struct bus_type cpu_subsys = {

	.name = "cpu",

	.dev_name = "cpu",

#ifdef CONFIG_HOTPLUG_CPU

	.online = cpu_subsys_online,

	.offline = cpu_subsys_offline,

#endif

};

EXPORT_SYMBOL_GPL(cpu_subsys);



#ifdef CONFIG_KEXEC

#ifdef CONFIG_KEXEC

#include <linux/kexec.h>

#include <linux/kexec.h>
@@ -277,12 +253,11 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) 
	cpu->dev.id = num;

	cpu->dev.id = num;

	cpu->dev.bus = &cpu_subsys;

	cpu->dev.bus = &cpu_subsys;

	cpu->dev.release = cpu_device_release;

	cpu->dev.release = cpu_device_release;

	cpu->dev.offline_disabled = !cpu->hotpluggable;

#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE

#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE

	cpu->dev.bus->uevent = arch_cpu_uevent;

	cpu->dev.bus->uevent = arch_cpu_uevent;

#endif

#endif

	error = device_register(&cpu->dev);

	error = device_register(&cpu->dev);

	if (!error && cpu->hotpluggable)

		register_cpu_control(cpu);

	if (!error)

	if (!error)

		per_cpu(cpu_sys_devices, num) = &cpu->dev;

		per_cpu(cpu_sys_devices, num) = &cpu->dev;

	if (!error)

	if (!error)