Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * drivers/base/cpu.c - basic CPU class support
 */
 
#include <linux/sysdev.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/topology.h>
#include <linux/device.h>
#include <linux/node.h>
 
#include "base.h"
 
struct sysdev_class cpu_sysdev_class = {
	set_kset_name("cpu"),
};
EXPORT_SYMBOL(cpu_sysdev_class);
 
static struct sys_device *cpu_sys_devices[NR_CPUS];
 
#ifdef CONFIG_HOTPLUG_CPU
static ssize_t show_online(struct sys_device *dev, char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
 
	return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
}
 
static ssize_t store_online(struct sys_device *dev, const char *buf,
			    size_t count)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	ssize_t ret;
 
	switch (buf[0]) {
	case '0':
		ret = cpu_down(cpu->sysdev.id);
		if (!ret)
			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
		break;
	case '1':
		ret = cpu_up(cpu->sysdev.id);
		if (!ret)
			kobject_uevent(&dev->kobj, KOBJ_ONLINE);
		break;
	default:
		ret = -EINVAL;
	}
 
	if (ret >= 0)
		ret = count;
	return ret;
}
static SYSDEV_ATTR(online, 0644, show_online, store_online);
 
static void __devinit register_cpu_control(struct cpu *cpu)
{
	sysdev_create_file(&cpu->sysdev, &attr_online);
}
void unregister_cpu(struct cpu *cpu)
{
	int logical_cpu = cpu->sysdev.id;
 
	unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
 
	sysdev_remove_file(&cpu->sysdev, &attr_online);
 
	sysdev_unregister(&cpu->sysdev);
	cpu_sys_devices[logical_cpu] = NULL;
	return;
}
#else /* ... !CONFIG_HOTPLUG_CPU */
static inline void register_cpu_control(struct cpu *cpu)
{
}
#endif /* CONFIG_HOTPLUG_CPU */
 
#ifdef CONFIG_KEXEC
#include <linux/kexec.h>
 
static ssize_t show_crash_notes(struct sys_device *dev, char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
	ssize_t rc;
	unsigned long long addr;
	int cpunum;
 
	cpunum = cpu->sysdev.id;
 
	/*
	 * Might be reading other cpu's data based on which cpu read thread
	 * has been scheduled. But cpu data (memory) is allocated once during
	 * boot up and this data does not change there after. Hence this
	 * operation should be safe. No locking required.
	 */
	addr = __pa(per_cpu_ptr(crash_notes, cpunum));
	rc = sprintf(buf, "%Lx\n", addr);
	return rc;
}
static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
#endif
 
/*
 * register_cpu - Setup a sysfs device for a CPU.
 * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
 *	  sysfs for this CPU.
 * @num - CPU number to use when creating the device.
 *
 * Initialize and register the CPU device.
 */
int __devinit register_cpu(struct cpu *cpu, int num)
{
	int error;
	cpu->node_id = cpu_to_node(num);
	cpu->sysdev.id = num;
	cpu->sysdev.cls = &cpu_sysdev_class;
 
	error = sysdev_register(&cpu->sysdev);
 
	if (!error && cpu->hotpluggable)
		register_cpu_control(cpu);
	if (!error)
		cpu_sys_devices[num] = &cpu->sysdev;
	if (!error)
		register_cpu_under_node(num, cpu_to_node(num));
 
#ifdef CONFIG_KEXEC
	if (!error)
		error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
#endif
	return error;
}
 
struct sys_device *get_cpu_sysdev(unsigned cpu)
{
	if (cpu < NR_CPUS)
		return cpu_sys_devices[cpu];
	else
		return NULL;
}
EXPORT_SYMBOL_GPL(get_cpu_sysdev);
 
int __init cpu_dev_init(void)
{
	int err;
 
	err = sysdev_class_register(&cpu_sysdev_class);
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
	if (!err)
		err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
#endif
 
	return err;
}