Subject: sysfs: add support for adding/removing sysfs attributes and attribute_group to cpus

This patch adds two functions to create and remove sysfs attributes and attribute_group to all cpus.
That allows to register sysfs attributes in a subdirectory like:
/sys/devices/system/cpu/cpuX/group_name/what_ever
This will be used by cbe_thermal to group all attributes dealing with
thermal support in one directory.

Signed-of-by: Christian Krafft <krafft@de.ibm.com>

Index: linux-2.6/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/sysfs.c
+++ linux-2.6/arch/powerpc/kernel/sysfs.c
@@ -299,6 +299,72 @@ static struct notifier_block __cpuinitda
 	.notifier_call	= sysfs_cpu_notify,
 };
 
+static DEFINE_MUTEX(cpu_mutex);
+
+int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
+{
+	int cpu;
+
+	mutex_lock(&cpu_mutex);
+
+	for_each_possible_cpu(cpu) {
+		sysdev_create_file(get_cpu_sysdev(cpu), attr);
+	}
+
+	mutex_unlock(&cpu_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
+
+int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
+{
+	int cpu;
+	struct sys_device *sysdev;
+
+	mutex_lock(&cpu_mutex);
+
+	for_each_possible_cpu(cpu) {
+		sysdev = get_cpu_sysdev(cpu);
+		sysfs_create_group(&sysdev->kobj, attrs);
+	}
+
+	mutex_unlock(&cpu_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
+
+
+void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
+{
+	int cpu;
+
+	mutex_lock(&cpu_mutex);
+
+	for_each_possible_cpu(cpu) {
+		sysdev_remove_file(get_cpu_sysdev(cpu), attr);
+	}
+
+	mutex_unlock(&cpu_mutex);
+}
+EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
+
+void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
+{
+	int cpu;
+	struct sys_device *sysdev;
+
+	mutex_lock(&cpu_mutex);
+
+	for_each_possible_cpu(cpu) {
+		sysdev = get_cpu_sysdev(cpu);
+		sysfs_remove_group(&sysdev->kobj, attrs);
+	}
+
+	mutex_unlock(&cpu_mutex);
+}
+EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
+
+
 /* NUMA stuff */
 
 #ifdef CONFIG_NUMA
Index: linux-2.6/include/linux/cpu.h
===================================================================
--- linux-2.6.orig/include/linux/cpu.h
+++ linux-2.6/include/linux/cpu.h
@@ -33,6 +33,14 @@ struct cpu {
 
 extern int register_cpu(struct cpu *cpu, int num);
 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
+
+extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
+extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
+
+extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
+extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
+
+
 #ifdef CONFIG_HOTPLUG_CPU
 extern void unregister_cpu(struct cpu *cpu);
 #endif