1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * xen-stub.c - stub drivers to reserve space for Xen
 4 *
 5 * Copyright (C) 2012 Intel Corporation
 6 *    Author: Liu Jinsong <jinsong.liu@intel.com>
 7 *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
 8 *
 9 * Copyright (C) 2012 Oracle Inc
10 *    Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
11 */
12
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/export.h>
16#include <linux/types.h>
17#include <linux/acpi.h>
18#include <xen/acpi.h>
19
20#ifdef CONFIG_ACPI
21
22/*--------------------------------------------
23	stub driver for Xen memory hotplug
24--------------------------------------------*/
25
26static const struct acpi_device_id memory_device_ids[] = {
27	{ACPI_MEMORY_DEVICE_HID, 0},
28	{"", 0},
29};
30
31static struct acpi_driver xen_stub_memory_device_driver = {
32	/* same name as native memory driver to block native loaded */
33	.name = "acpi_memhotplug",
34	.class = ACPI_MEMORY_DEVICE_CLASS,
35	.ids = memory_device_ids,
36};
37
38int xen_stub_memory_device_init(void)
39{
40	if (!xen_initial_domain())
41		return -ENODEV;
42
43	/* just reserve space for Xen, block native driver loaded */
44	return acpi_bus_register_driver(&xen_stub_memory_device_driver);
45}
46EXPORT_SYMBOL_GPL(xen_stub_memory_device_init);
47subsys_initcall(xen_stub_memory_device_init);
48
49void xen_stub_memory_device_exit(void)
50{
51	acpi_bus_unregister_driver(&xen_stub_memory_device_driver);
52}
53EXPORT_SYMBOL_GPL(xen_stub_memory_device_exit);
54
55
56/*--------------------------------------------
57	stub driver for Xen cpu hotplug
58--------------------------------------------*/
59
60static const struct acpi_device_id processor_device_ids[] = {
61	{ACPI_PROCESSOR_OBJECT_HID, 0},
62	{ACPI_PROCESSOR_DEVICE_HID, 0},
63	{"", 0},
64};
65
66static struct acpi_driver xen_stub_processor_driver = {
67	/* same name as native processor driver to block native loaded */
68	.name = "processor",
69	.class = ACPI_PROCESSOR_CLASS,
70	.ids = processor_device_ids,
71};
72
73int xen_stub_processor_init(void)
74{
75	if (!xen_initial_domain())
76		return -ENODEV;
77
78	/* just reserve space for Xen, block native driver loaded */
79	return acpi_bus_register_driver(&xen_stub_processor_driver);
80}
81EXPORT_SYMBOL_GPL(xen_stub_processor_init);
82subsys_initcall(xen_stub_processor_init);
83
84void xen_stub_processor_exit(void)
85{
86	acpi_bus_unregister_driver(&xen_stub_processor_driver);
87}
88EXPORT_SYMBOL_GPL(xen_stub_processor_exit);
89
90#endif