static struct sys_device *cpu_sys_devices[NR_CPUS];
#ifdef CONFIG_HOTPLUG_CPU
-int __attribute__((weak)) smp_prepare_cpu (int cpu)
-{
- return 0;
-}
-
static ssize_t show_online(struct sys_device *dev, char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
case '0':
ret = cpu_down(cpu->sysdev.id);
if (!ret)
- kobject_hotplug(&dev->kobj, KOBJ_OFFLINE);
+ kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
break;
case '1':
- ret = smp_prepare_cpu(cpu->sysdev.id);
+ ret = cpu_up(cpu->sysdev.id);
if (!ret)
- ret = cpu_up(cpu->sysdev.id);
- if (!ret)
- kobject_hotplug(&dev->kobj, KOBJ_ONLINE);
+ kobject_uevent(&dev->kobj, KOBJ_ONLINE);
break;
default:
ret = -EINVAL;
}
#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 driverfs device for a CPU.
* @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
register_cpu_control(cpu);
if (!error)
cpu_sys_devices[num] = &cpu->sysdev;
+
+#ifdef CONFIG_KEXEC
+ if (!error)
+ error = sysdev_create_file(&cpu->sysdev, &attr_crash_notes);
+#endif
return error;
}
-struct sys_device *get_cpu_sysdev(int cpu)
+struct sys_device *get_cpu_sysdev(unsigned cpu)
{
if (cpu < NR_CPUS)
return cpu_sys_devices[cpu];