// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * xen-stub.c - stub drivers to reserve space for Xen
   *
   * Copyright (C) 2012 Intel Corporation
   *    Author: Liu Jinsong <jinsong.liu@intel.com>
   *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
   *
   * Copyright (C) 2012 Oracle Inc
   *    Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/export.h>
  #include <linux/types.h>
  #include <linux/acpi.h>

  #include <xen/acpi.h>

  #ifdef CONFIG_ACPI

  /*--------------------------------------------
  	stub driver for Xen memory hotplug
  --------------------------------------------*/

  static const struct acpi_device_id memory_device_ids[] = {
  	{ACPI_MEMORY_DEVICE_HID, 0},
  	{"", 0},
  };
  
  static struct acpi_driver xen_stub_memory_device_driver = {
  	/* same name as native memory driver to block native loaded */
  	.name = "acpi_memhotplug",
  	.class = ACPI_MEMORY_DEVICE_CLASS,
  	.ids = memory_device_ids,
  };
  
  int xen_stub_memory_device_init(void)
  {
  	if (!xen_initial_domain())
  		return -ENODEV;
  
  	/* just reserve space for Xen, block native driver loaded */
  	return acpi_bus_register_driver(&xen_stub_memory_device_driver);
  }
  EXPORT_SYMBOL_GPL(xen_stub_memory_device_init);
  subsys_initcall(xen_stub_memory_device_init);
  
  void xen_stub_memory_device_exit(void)
  {
  	acpi_bus_unregister_driver(&xen_stub_memory_device_driver);
  }
  EXPORT_SYMBOL_GPL(xen_stub_memory_device_exit);

  
  /*--------------------------------------------
  	stub driver for Xen cpu hotplug
  --------------------------------------------*/
  
  static const struct acpi_device_id processor_device_ids[] = {
  	{ACPI_PROCESSOR_OBJECT_HID, 0},
  	{ACPI_PROCESSOR_DEVICE_HID, 0},
  	{"", 0},
  };
  
  static struct acpi_driver xen_stub_processor_driver = {
  	/* same name as native processor driver to block native loaded */
  	.name = "processor",
  	.class = ACPI_PROCESSOR_CLASS,
  	.ids = processor_device_ids,
  };
  
  int xen_stub_processor_init(void)
  {
  	if (!xen_initial_domain())
  		return -ENODEV;
  
  	/* just reserve space for Xen, block native driver loaded */
  	return acpi_bus_register_driver(&xen_stub_processor_driver);
  }
  EXPORT_SYMBOL_GPL(xen_stub_processor_init);
  subsys_initcall(xen_stub_processor_init);
  
  void xen_stub_processor_exit(void)
  {
  	acpi_bus_unregister_driver(&xen_stub_processor_driver);
  }
  EXPORT_SYMBOL_GPL(xen_stub_processor_exit);

  #endif