1 /*
2  * xen-stub.c - stub drivers to reserve space for Xen
3  *
4  * Copyright (C) 2012 Intel Corporation
5  *    Author: Liu Jinsong <jinsong.liu@intel.com>
6  *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
7  *
8  * Copyright (C) 2012 Oracle Inc
9  *    Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/export.h>
26 #include <linux/types.h>
27 #include <linux/acpi.h>
28 #include <xen/acpi.h>
29 
30 #ifdef CONFIG_ACPI
31 
32 /*--------------------------------------------
33 	stub driver for Xen memory hotplug
34 --------------------------------------------*/
35 
36 static const struct acpi_device_id memory_device_ids[] = {
37 	{ACPI_MEMORY_DEVICE_HID, 0},
38 	{"", 0},
39 };
40 
41 static struct acpi_driver xen_stub_memory_device_driver = {
42 	/* same name as native memory driver to block native loaded */
43 	.name = "acpi_memhotplug",
44 	.class = ACPI_MEMORY_DEVICE_CLASS,
45 	.ids = memory_device_ids,
46 };
47 
xen_stub_memory_device_init(void)48 int xen_stub_memory_device_init(void)
49 {
50 	if (!xen_initial_domain())
51 		return -ENODEV;
52 
53 	/* just reserve space for Xen, block native driver loaded */
54 	return acpi_bus_register_driver(&xen_stub_memory_device_driver);
55 }
56 EXPORT_SYMBOL_GPL(xen_stub_memory_device_init);
57 subsys_initcall(xen_stub_memory_device_init);
58 
xen_stub_memory_device_exit(void)59 void xen_stub_memory_device_exit(void)
60 {
61 	acpi_bus_unregister_driver(&xen_stub_memory_device_driver);
62 }
63 EXPORT_SYMBOL_GPL(xen_stub_memory_device_exit);
64 
65 
66 /*--------------------------------------------
67 	stub driver for Xen cpu hotplug
68 --------------------------------------------*/
69 
70 static const struct acpi_device_id processor_device_ids[] = {
71 	{ACPI_PROCESSOR_OBJECT_HID, 0},
72 	{ACPI_PROCESSOR_DEVICE_HID, 0},
73 	{"", 0},
74 };
75 
76 static struct acpi_driver xen_stub_processor_driver = {
77 	/* same name as native processor driver to block native loaded */
78 	.name = "processor",
79 	.class = ACPI_PROCESSOR_CLASS,
80 	.ids = processor_device_ids,
81 };
82 
xen_stub_processor_init(void)83 int xen_stub_processor_init(void)
84 {
85 	if (!xen_initial_domain())
86 		return -ENODEV;
87 
88 	/* just reserve space for Xen, block native driver loaded */
89 	return acpi_bus_register_driver(&xen_stub_processor_driver);
90 }
91 EXPORT_SYMBOL_GPL(xen_stub_processor_init);
92 subsys_initcall(xen_stub_processor_init);
93 
xen_stub_processor_exit(void)94 void xen_stub_processor_exit(void)
95 {
96 	acpi_bus_unregister_driver(&xen_stub_processor_driver);
97 }
98 EXPORT_SYMBOL_GPL(xen_stub_processor_exit);
99 
100 #endif
101