Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / drivers / base / cpu.c

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6ef3069..dd712b2 100644 (file)
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -9,12 +9,15 @@
 #include <linux/topology.h>
 #include <linux/device.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)
 {
@@ -33,10 +36,12 @@ static ssize_t store_online(struct sys_device *dev, const char *buf,
        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 = cpu_up(cpu->sysdev.id);
+               if (!ret)
+                       kobject_uevent(&dev->kobj, KOBJ_ONLINE);
                break;
        default:
                ret = -EINVAL;
@@ -54,6 +59,7 @@ static void __devinit register_cpu_control(struct cpu *cpu)
 }
 void unregister_cpu(struct cpu *cpu, struct node *root)
 {
+       int logical_cpu = cpu->sysdev.id;
 
        if (root)
                sysfs_remove_link(&root->sysdev.kobj,
@@ -61,7 +67,7 @@ void unregister_cpu(struct cpu *cpu, struct node *root)
        sysdev_remove_file(&cpu->sysdev, &attr_online);
 
        sysdev_unregister(&cpu->sysdev);
-
+       cpu_sys_devices[logical_cpu] = NULL;
        return;
 }
 #else /* ... !CONFIG_HOTPLUG_CPU */
@@ -70,6 +76,31 @@ 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 driverfs device for a CPU.
  * @cpu - Callers can set the cpu->no_control field to 1, to indicate not to
@@ -93,10 +124,24 @@ int __devinit register_cpu(struct cpu *cpu, int num, struct node *root)
                                          kobject_name(&cpu->sysdev.kobj));
        if (!error && !cpu->no_control)
                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(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)
 {