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273 lines
6.6 KiB
273 lines
6.6 KiB
/*
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* drivers/base/cpu.c - basic CPU class support
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*/
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#include <linux/sysdev.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/cpu.h>
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#include <linux/topology.h>
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#include <linux/device.h>
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#include <linux/node.h>
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#include "base.h"
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static struct sysdev_class_attribute *cpu_sysdev_class_attrs[];
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struct sysdev_class cpu_sysdev_class = {
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.name = "cpu",
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.attrs = cpu_sysdev_class_attrs,
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};
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EXPORT_SYMBOL(cpu_sysdev_class);
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static DEFINE_PER_CPU(struct sys_device *, cpu_sys_devices);
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#ifdef CONFIG_HOTPLUG_CPU
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static ssize_t show_online(struct sys_device *dev, struct sysdev_attribute *attr,
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char *buf)
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{
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struct cpu *cpu = container_of(dev, struct cpu, sysdev);
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return sprintf(buf, "%u\n", !!cpu_online(cpu->sysdev.id));
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}
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static ssize_t __ref store_online(struct sys_device *dev, struct sysdev_attribute *attr,
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const char *buf, size_t count)
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{
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struct cpu *cpu = container_of(dev, struct cpu, sysdev);
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ssize_t ret;
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cpu_hotplug_driver_lock();
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switch (buf[0]) {
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case '0':
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ret = cpu_down(cpu->sysdev.id);
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if (!ret)
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kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
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break;
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case '1':
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ret = cpu_up(cpu->sysdev.id);
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if (!ret)
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kobject_uevent(&dev->kobj, KOBJ_ONLINE);
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break;
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default:
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ret = -EINVAL;
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}
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cpu_hotplug_driver_unlock();
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if (ret >= 0)
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ret = count;
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return ret;
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}
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static SYSDEV_ATTR(online, 0644, show_online, store_online);
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static void __cpuinit register_cpu_control(struct cpu *cpu)
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{
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sysdev_create_file(&cpu->sysdev, &attr_online);
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}
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void unregister_cpu(struct cpu *cpu)
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{
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int logical_cpu = cpu->sysdev.id;
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unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
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sysdev_remove_file(&cpu->sysdev, &attr_online);
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sysdev_unregister(&cpu->sysdev);
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per_cpu(cpu_sys_devices, logical_cpu) = NULL;
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return;
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}
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#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
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static ssize_t cpu_probe_store(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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const char *buf,
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size_t count)
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{
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return arch_cpu_probe(buf, count);
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}
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static ssize_t cpu_release_store(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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const char *buf,
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size_t count)
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{
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return arch_cpu_release(buf, count);
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}
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static SYSDEV_CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
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static SYSDEV_CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store);
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#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
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#else /* ... !CONFIG_HOTPLUG_CPU */
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static inline void register_cpu_control(struct cpu *cpu)
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{
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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#ifdef CONFIG_KEXEC
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#include <linux/kexec.h>
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static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute *attr,
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char *buf)
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{
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struct cpu *cpu = container_of(dev, struct cpu, sysdev);
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ssize_t rc;
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unsigned long long addr;
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int cpunum;
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cpunum = cpu->sysdev.id;
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/*
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* Might be reading other cpu's data based on which cpu read thread
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* has been scheduled. But cpu data (memory) is allocated once during
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* boot up and this data does not change there after. Hence this
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* operation should be safe. No locking required.
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*/
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addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
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rc = sprintf(buf, "%Lx\n", addr);
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return rc;
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}
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static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
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#endif
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/*
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* Print cpu online, possible, present, and system maps
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*/
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struct cpu_attr {
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struct sysdev_class_attribute attr;
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const struct cpumask *const * const map;
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};
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static ssize_t show_cpus_attr(struct sysdev_class *class,
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struct sysdev_class_attribute *attr,
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char *buf)
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{
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struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
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int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
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buf[n++] = '\n';
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buf[n] = '\0';
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return n;
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}
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#define _CPU_ATTR(name, map) \
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{ _SYSDEV_CLASS_ATTR(name, 0444, show_cpus_attr, NULL), map }
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/* Keep in sync with cpu_sysdev_class_attrs */
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static struct cpu_attr cpu_attrs[] = {
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_CPU_ATTR(online, &cpu_online_mask),
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_CPU_ATTR(possible, &cpu_possible_mask),
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_CPU_ATTR(present, &cpu_present_mask),
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};
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/*
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* Print values for NR_CPUS and offlined cpus
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*/
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static ssize_t print_cpus_kernel_max(struct sysdev_class *class,
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struct sysdev_class_attribute *attr, char *buf)
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{
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int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
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return n;
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}
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static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
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/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
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unsigned int total_cpus;
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static ssize_t print_cpus_offline(struct sysdev_class *class,
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struct sysdev_class_attribute *attr, char *buf)
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{
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int n = 0, len = PAGE_SIZE-2;
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cpumask_var_t offline;
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/* display offline cpus < nr_cpu_ids */
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if (!alloc_cpumask_var(&offline, GFP_KERNEL))
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return -ENOMEM;
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cpumask_complement(offline, cpu_online_mask);
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n = cpulist_scnprintf(buf, len, offline);
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free_cpumask_var(offline);
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/* display offline cpus >= nr_cpu_ids */
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if (total_cpus && nr_cpu_ids < total_cpus) {
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if (n && n < len)
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buf[n++] = ',';
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if (nr_cpu_ids == total_cpus-1)
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n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
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else
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n += snprintf(&buf[n], len - n, "%d-%d",
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nr_cpu_ids, total_cpus-1);
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}
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n += snprintf(&buf[n], len - n, "\n");
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return n;
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}
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static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL);
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/*
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* register_cpu - Setup a sysfs device for a CPU.
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* @cpu - cpu->hotpluggable field set to 1 will generate a control file in
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* sysfs for this CPU.
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* @num - CPU number to use when creating the device.
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*
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* Initialize and register the CPU device.
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*/
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int __cpuinit register_cpu(struct cpu *cpu, int num)
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{
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int error;
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cpu->node_id = cpu_to_node(num);
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cpu->sysdev.id = num;
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cpu->sysdev.cls = &cpu_sysdev_class;
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error = sysdev_register(&cpu->sysdev);
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if (!error && cpu->hotpluggable)
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register_cpu_control(cpu);
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if (!error)
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per_cpu(cpu_sys_devices, num) = &cpu->sysdev;
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if (!error)
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register_cpu_under_node(num, cpu_to_node(num));
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#ifdef CONFIG_KEXEC
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if (!error)
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error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
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#endif
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return error;
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}
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struct sys_device *get_cpu_sysdev(unsigned cpu)
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{
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if (cpu < nr_cpu_ids && cpu_possible(cpu))
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return per_cpu(cpu_sys_devices, cpu);
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else
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return NULL;
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}
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EXPORT_SYMBOL_GPL(get_cpu_sysdev);
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int __init cpu_dev_init(void)
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{
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int err;
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err = sysdev_class_register(&cpu_sysdev_class);
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#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
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if (!err)
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err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
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#endif
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return err;
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}
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static struct sysdev_class_attribute *cpu_sysdev_class_attrs[] = {
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#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
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&attr_probe,
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&attr_release,
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#endif
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&cpu_attrs[0].attr,
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&cpu_attrs[1].attr,
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&cpu_attrs[2].attr,
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&attr_kernel_max,
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&attr_offline,
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NULL
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};
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