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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-05-03 00:25:49 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-05-12 14:14:17 +0200 |
commit | 0902a9044fa5b7a0456ea4daacec2c2b3189ba8c (patch) | |
tree | 7161c5cbf23ec6b8ef42f5655340be38e5f0e1a8 /drivers/base/cpu.c | |
parent | 4f3549d72d1b5c90ecc7e673402f38f4486d22c2 (diff) | |
download | lwn-0902a9044fa5b7a0456ea4daacec2c2b3189ba8c.tar.gz lwn-0902a9044fa5b7a0456ea4daacec2c2b3189ba8c.zip |
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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Diffstat (limited to 'drivers/base/cpu.c')
-rw-r--r-- | drivers/base/cpu.c | 89 |
1 files changed, 32 insertions, 57 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 3d48fc887ef4..25c8768172e9 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -16,12 +16,6 @@ #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); #ifdef CONFIG_HOTPLUG_CPU @@ -34,69 +28,45 @@ static void change_cpu_under_node(struct cpu *cpu, cpu->node_id = to_nid; } -static ssize_t show_online(struct device *dev, - struct device_attribute *attr, - char *buf) +static int __ref cpu_subsys_online(struct device *dev) { struct cpu *cpu = container_of(dev, struct cpu, dev); + int cpuid = dev->id; + int from_nid, to_nid; + int ret; + + cpu_hotplug_driver_lock(); + + from_nid = cpu_to_node(cpuid); + ret = cpu_up(cpuid); + /* + * When hot adding memory to memoryless node and enabling a cpu + * on the node, node number of the cpu may internally change. + */ + to_nid = cpu_to_node(cpuid); + if (from_nid != to_nid) + change_cpu_under_node(cpu, from_nid, to_nid); - return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id)); + cpu_hotplug_driver_unlock(); + return ret; } -static ssize_t __ref store_online(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) +static int cpu_subsys_offline(struct device *dev) { - struct cpu *cpu = container_of(dev, struct cpu, dev); - int cpuid = cpu->dev.id; - int from_nid, to_nid; - ssize_t ret; + int ret; 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); - ret = cpu_up(cpuid); - - /* - * When hot adding memory to memoryless node and enabling a cpu - * on the node, node number of the cpu may internally change. - */ - to_nid = cpu_to_node(cpuid); - if (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; - } + ret = cpu_down(dev->id); cpu_hotplug_driver_unlock(); - - if (ret >= 0) - ret = count; return ret; } -static DEVICE_ATTR(online, 0644, show_online, store_online); -static void __cpuinit register_cpu_control(struct cpu *cpu) -{ - device_create_file(&cpu->dev, &dev_attr_online); -} void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id; unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); - device_remove_file(&cpu->dev, &dev_attr_online); - device_unregister(&cpu->dev); per_cpu(cpu_sys_devices, logical_cpu) = NULL; 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); #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ -#else /* ... !CONFIG_HOTPLUG_CPU */ -static inline void register_cpu_control(struct cpu *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 #include <linux/kexec.h> @@ -277,12 +253,11 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.id = num; cpu->dev.bus = &cpu_subsys; cpu->dev.release = cpu_device_release; + cpu->dev.offline_disabled = !cpu->hotpluggable; #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE cpu->dev.bus->uevent = arch_cpu_uevent; #endif error = device_register(&cpu->dev); - if (!error && cpu->hotpluggable) - register_cpu_control(cpu); if (!error) per_cpu(cpu_sys_devices, num) = &cpu->dev; if (!error) |