drivers/xen/xen-stub.c

   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
  26 static const struct acpi_device_id memory_device_ids[] = {
  27         {ACPI_MEMORY_DEVICE_HID, 0},
  28         {"", 0},
  29 };
  30
  31 static 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
  38 int 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 }
  46 EXPORT_SYMBOL_GPL(xen_stub_memory_device_init);
  47 subsys_initcall(xen_stub_memory_device_init);
  48
  49 void xen_stub_memory_device_exit(void)
  50 {
  51         acpi_bus_unregister_driver(&xen_stub_memory_device_driver);
  52 }
  53 EXPORT_SYMBOL_GPL(xen_stub_memory_device_exit);
  54
  55
  56 /*--------------------------------------------
  57         stub driver for Xen cpu hotplug
  58 --------------------------------------------*/
  59
  60 static const struct acpi_device_id processor_device_ids[] = {
  61         {ACPI_PROCESSOR_OBJECT_HID, 0},
  62         {ACPI_PROCESSOR_DEVICE_HID, 0},
  63         {"", 0},
  64 };
  65
  66 static 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
  73 int 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 }
  81 EXPORT_SYMBOL_GPL(xen_stub_processor_init);
  82 subsys_initcall(xen_stub_processor_init);
  83
  84 void xen_stub_processor_exit(void)
  85 {
  86         acpi_bus_unregister_driver(&xen_stub_processor_driver);
  87 }
  88 EXPORT_SYMBOL_GPL(xen_stub_processor_exit);
  89
  90 #endif