Add sysfs support for the i8259 PIC on x86_64

diff -uNr linux-2.6.8.1-i8259-shutdown.i386/arch/x86_64/kernel/i8259.c linux-2.6.8.1-i8259-sysfs.x86_64/arch/x86_64/kernel/i8259.c
@@ -342,6 +342,44 @@
 	}
 }
 
+static int i8259A_resume(struct sys_device *dev)
+{
+	init_8259A(0);
+	return 0;
+}
+
+static int i8259A_shutdown(struct sys_device *dev)
+{
+	/* Put the i8259A into a quiescent state that
+	 * the kernel initialization code can get it
+	 * out of.
+	 */
+	outb(0xff, 0x21);	/* mask all of 8259A-1 */
+	outb(0xff, 0xA1);	/* mask all of 8259A-1 */
+	return 0;
+}
+
+static struct sysdev_class i8259_sysdev_class = {
+	set_kset_name("i8259"),
+	.resume = i8259A_resume,
+	.shutdown = i8259A_shutdown,
+};
+
+static struct sys_device device_i8259A = {
+	.id	= 0,
+	.cls	= &i8259_sysdev_class,
+};
+
+static int __init i8259A_init_sysfs(void)
+{
+	int error = sysdev_class_register(&i8259_sysdev_class);
+	if (!error)
+		error = sysdev_register(&device_i8259A);
+	return error;
+}
+
+device_initcall(i8259A_init_sysfs);
+
 void __init init_8259A(int auto_eoi)
 {
 	unsigned long flags;