X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fbase%2Fcpu.c;h=dd712b24ec91900f3b75506af6ecf6467f7ba160;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=6ef3069b57107f2e12c5d2c7f238b77f5dacd97c;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6ef3069b5..dd712b24e 100644
--- 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)
 {