LXR linux/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
  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
  91