From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH 2/3 RFC] Driver core: Use generic offline/online for CPU offline/online Date: Mon, 29 Apr 2013 14:28:02 +0200 Message-ID: <5608485.T3GFgtNYov@vostro.rjw.lan> References: <1576321.HU0tZ4cGWk@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1576321.HU0tZ4cGWk@vostro.rjw.lan> Sender: linux-kernel-owner@vger.kernel.org To: Greg Kroah-Hartman Cc: Toshi Kani , ACPI Devel Maling List , LKML , isimatu.yasuaki@jp.fujitsu.com, vasilis.liaskovitis@profitbricks.com List-Id: linux-acpi@vger.kernel.org From: Rafael J. Wysocki 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 --- drivers/base/cpu.c | 62 ++++++++++++----------------------------------------- 1 file changed, 15 insertions(+), 47 deletions(-) Index: linux-pm/drivers/base/cpu.c =================================================================== --- linux-pm.orig/drivers/base/cpu.c +++ linux-pm/drivers/base/cpu.c @@ -16,66 +16,25 @@ #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 -static ssize_t show_online(struct device *dev, - struct device_attribute *attr, - char *buf) +static int cpu_subsys_online(struct device *dev) { - struct cpu *cpu = container_of(dev, struct cpu, dev); - - return sprintf(buf, "%u\n", !!cpu_online(cpu->dev.id)); + return cpu_up(dev->id); } -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); - ssize_t ret; - - cpu_hotplug_driver_lock(); - switch (buf[0]) { - case '0': - ret = cpu_down(cpu->dev.id); - if (!ret) - kobject_uevent(&dev->kobj, KOBJ_OFFLINE); - break; - case '1': - ret = cpu_up(cpu->dev.id); - if (!ret) - kobject_uevent(&dev->kobj, KOBJ_ONLINE); - break; - default: - ret = -EINVAL; - } - cpu_hotplug_driver_unlock(); - - if (ret >= 0) - ret = count; - return ret; + return cpu_down(dev->id); } -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; @@ -108,6 +67,16 @@ static inline void register_cpu_control( } #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 @@ -245,12 +214,11 @@ int __cpuinit register_cpu(struct cpu *c 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)