xen/stub: driver for memory hotplug

This patch create a file (xen-stub.c) for Xen stub drivers.
Xen stub drivers are used to reserve space for Xen drivers, i.e.
memory hotplug and cpu hotplug, and to block native drivers loaded,
so that real Xen drivers can be modular and loaded on demand.

This patch is specific for Xen memory hotplug (other Xen logic
can add stub drivers on their own). The xen stub driver will
occupied earlier via subsys_initcall (than native memory hotplug
driver via module_init and so blocking native). Later real Xen
memory hotplug logic will unregister the stub driver and register
itself to take effect on demand.

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/xen/acpi.h b/include/xen/acpi.h
index 48a9c0171b65..ce7e5264b320 100644
--- a/include/xen/acpi.h
+++ b/include/xen/acpi.h
@@ -40,6 +40,13 @@
 #include <xen/xen.h>
 #include <linux/acpi.h>
 
+#define ACPI_MEMORY_DEVICE_CLASS        "memory"
+#define ACPI_MEMORY_DEVICE_HID          "PNP0C80"
+#define ACPI_MEMORY_DEVICE_NAME         "Hotplug Mem Device"
+
+int xen_stub_memory_device_init(void);
+void xen_stub_memory_device_exit(void);
+
 int xen_acpi_notify_hypervisor_state(u8 sleep_state,
 				     u32 pm1a_cnt, u32 pm1b_cnd);