text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
   *
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   */
  
  #define pr_fmt(fmt) "ACPI: " fmt
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/kernel.h>
  #include <linux/list.h>
  #include <linux/sched.h>
  #include <linux/pm.h>
  #include <linux/device.h>
  #include <linux/proc_fs.h>
  #include <linux/acpi.h>
  #include <linux/slab.h>
  #include <linux/regulator/machine.h>
  #include <linux/workqueue.h>
  #include <linux/reboot.h>
  #include <linux/delay.h>
  #ifdef CONFIG_X86
  #include <asm/mpspec.h>
  #include <linux/dmi.h>
  #endif
  #include <linux/acpi_iort.h>
  #include <linux/pci.h>
  #include <acpi/apei.h>
  #include <linux/suspend.h>
  
  #include "internal.h"
  
  struct acpi_device *acpi_root;
  struct proc_dir_entry *acpi_root_dir;
  EXPORT_SYMBOL(acpi_root_dir);
  
  #ifdef CONFIG_X86
  #ifdef CONFIG_ACPI_CUSTOM_DSDT
  static inline int set_copy_dsdt(const struct dmi_system_id *id)
  {
  	return 0;
  }
  #else
  static int set_copy_dsdt(const struct dmi_system_id *id)
  {
  	pr_notice("%s detected - force copy of DSDT to local memory\n", id->ident);
  	acpi_gbl_copy_dsdt_locally = 1;
  	return 0;
  }
  #endif
  
  static const struct dmi_system_id dsdt_dmi_table[] __initconst = {
  	/*
  	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
  	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
  	 */
  	{
  	 .callback = set_copy_dsdt,
  	 .ident = "TOSHIBA Satellite",
  	 .matches = {
  		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
  		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
  		},
  	},
  	{}
  };
  #endif
  
  /* --------------------------------------------------------------------------
                                  Device Management
     -------------------------------------------------------------------------- */
  
  acpi_status acpi_bus_get_status_handle(acpi_handle handle,
  				       unsigned long long *sta)
  {
  	acpi_status status;
  
  	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
  	if (ACPI_SUCCESS(status))
  		return AE_OK;
  
  	if (status == AE_NOT_FOUND) {
  		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
  		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
  		return AE_OK;
  	}
  	return status;
  }
  EXPORT_SYMBOL_GPL(acpi_bus_get_status_handle);
  
  int acpi_bus_get_status(struct acpi_device *device)
  {
  	acpi_status status;
  	unsigned long long sta;
  
  	if (acpi_device_always_present(device)) {
  		acpi_set_device_status(device, ACPI_STA_DEFAULT);
  		return 0;
  	}
  
  	/* Battery devices must have their deps met before calling _STA */
  	if (acpi_device_is_battery(device) && device->dep_unmet) {
  		acpi_set_device_status(device, 0);
  		return 0;
  	}
  
  	status = acpi_bus_get_status_handle(device->handle, &sta);
  	if (ACPI_FAILURE(status))
  		return -ENODEV;
  
  	acpi_set_device_status(device, sta);
  
  	if (device->status.functional && !device->status.present) {
  		pr_debug("Device [%s] status [%08x]: functional but not present\n",
  			 device->pnp.bus_id, (u32)sta);
  	}
  
  	pr_debug("Device [%s] status [%08x]\n", device->pnp.bus_id, (u32)sta);
  	return 0;
  }
  EXPORT_SYMBOL(acpi_bus_get_status);
  
  void acpi_bus_private_data_handler(acpi_handle handle,
  				   void *context)
  {
  	return;
  }
  EXPORT_SYMBOL(acpi_bus_private_data_handler);
  
  int acpi_bus_attach_private_data(acpi_handle handle, void *data)
  {
  	acpi_status status;
  
  	status = acpi_attach_data(handle,
  			acpi_bus_private_data_handler, data);
  	if (ACPI_FAILURE(status)) {
  		acpi_handle_debug(handle, "Error attaching device data\n");
  		return -ENODEV;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);
  
  int acpi_bus_get_private_data(acpi_handle handle, void **data)
  {
  	acpi_status status;
  
  	if (!data)
  		return -EINVAL;
  
  	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
  	if (ACPI_FAILURE(status)) {
  		acpi_handle_debug(handle, "No context for object\n");
  		return -ENODEV;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);
  
  void acpi_bus_detach_private_data(acpi_handle handle)
  {
  	acpi_detach_data(handle, acpi_bus_private_data_handler);
  }
  EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);
  
  static void acpi_print_osc_error(acpi_handle handle,
  				 struct acpi_osc_context *context, char *error)
  {
  	int i;
  
  	acpi_handle_debug(handle, "(%s): %s\n", context->uuid_str, error);
  
  	pr_debug("_OSC request data:");
  	for (i = 0; i < context->cap.length; i += sizeof(u32))
  		pr_debug(" %x", *((u32 *)(context->cap.pointer + i)));
  
  	pr_debug("\n");
  }
  
  acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
  {
  	acpi_status status;
  	struct acpi_object_list input;
  	union acpi_object in_params[4];
  	union acpi_object *out_obj;
  	guid_t guid;
  	u32 errors;
  	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
  
  	if (!context)
  		return AE_ERROR;
  	if (guid_parse(context->uuid_str, &guid))
  		return AE_ERROR;
  	context->ret.length = ACPI_ALLOCATE_BUFFER;
  	context->ret.pointer = NULL;
  
  	/* Setting up input parameters */
  	input.count = 4;
  	input.pointer = in_params;
  	in_params[0].type 		= ACPI_TYPE_BUFFER;
  	in_params[0].buffer.length 	= 16;
  	in_params[0].buffer.pointer	= (u8 *)&guid;
  	in_params[1].type 		= ACPI_TYPE_INTEGER;
  	in_params[1].integer.value 	= context->rev;
  	in_params[2].type 		= ACPI_TYPE_INTEGER;
  	in_params[2].integer.value	= context->cap.length/sizeof(u32);
  	in_params[3].type		= ACPI_TYPE_BUFFER;
  	in_params[3].buffer.length 	= context->cap.length;
  	in_params[3].buffer.pointer 	= context->cap.pointer;
  
  	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
  	if (ACPI_FAILURE(status))
  		return status;
  
  	if (!output.length)
  		return AE_NULL_OBJECT;
  
  	out_obj = output.pointer;
  	if (out_obj->type != ACPI_TYPE_BUFFER
  		|| out_obj->buffer.length != context->cap.length) {
  		acpi_print_osc_error(handle, context,
  			"_OSC evaluation returned wrong type");
  		status = AE_TYPE;
  		goto out_kfree;
  	}
  	/* Need to ignore the bit0 in result code */
  	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
  	if (errors) {
  		if (errors & OSC_REQUEST_ERROR)
  			acpi_print_osc_error(handle, context,
  				"_OSC request failed");
  		if (errors & OSC_INVALID_UUID_ERROR)
  			acpi_print_osc_error(handle, context,
  				"_OSC invalid UUID");
  		if (errors & OSC_INVALID_REVISION_ERROR)
  			acpi_print_osc_error(handle, context,
  				"_OSC invalid revision");
  		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
  			if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
  			    & OSC_QUERY_ENABLE)
  				goto out_success;
  			status = AE_SUPPORT;
  			goto out_kfree;
  		}
  		status = AE_ERROR;
  		goto out_kfree;
  	}
  out_success:
  	context->ret.length = out_obj->buffer.length;
  	context->ret.pointer = kmemdup(out_obj->buffer.pointer,
  				       context->ret.length, GFP_KERNEL);
  	if (!context->ret.pointer) {
  		status =  AE_NO_MEMORY;
  		goto out_kfree;
  	}
  	status =  AE_OK;
  
  out_kfree:
  	kfree(output.pointer);
  	if (status != AE_OK)
  		context->ret.pointer = NULL;
  	return status;
  }
  EXPORT_SYMBOL(acpi_run_osc);
  
  bool osc_sb_apei_support_acked;
  
  /*
   * ACPI 6.0 Section 8.4.4.2 Idle State Coordination
   * OSPM supports platform coordinated low power idle(LPI) states
   */
  bool osc_pc_lpi_support_confirmed;
  EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
  
  /*
   * ACPI 6.4 Operating System Capabilities for USB.
   */
  bool osc_sb_native_usb4_support_confirmed;
  EXPORT_SYMBOL_GPL(osc_sb_native_usb4_support_confirmed);
  
  static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
  static void acpi_bus_osc_negotiate_platform_control(void)
  {
  	u32 capbuf[2], *capbuf_ret;
  	struct acpi_osc_context context = {
  		.uuid_str = sb_uuid_str,
  		.rev = 1,
  		.cap.length = 8,
  		.cap.pointer = capbuf,
  	};
  	acpi_handle handle;
  
  	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
  	capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
  	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR_AGGREGATOR))
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
  	if (IS_ENABLED(CONFIG_ACPI_PROCESSOR))
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;
  
  	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
  	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
  
  #ifdef CONFIG_ARM64
  	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
  #endif
  #ifdef CONFIG_X86
  	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
  	if (boot_cpu_has(X86_FEATURE_HWP)) {
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
  	}
  #endif
  
  	if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;
  
  	if (IS_ENABLED(CONFIG_USB4))
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_NATIVE_USB4_SUPPORT;
  
  	if (!ghes_disable)
  		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
  	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
  		return;
  
  	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
  		return;
  
  	kfree(context.ret.pointer);
  
  	/* Now run _OSC again with query flag clear */
  	capbuf[OSC_QUERY_DWORD] = 0;
  
  	if (ACPI_FAILURE(acpi_run_osc(handle, &context)))
  		return;
  
  	capbuf_ret = context.ret.pointer;
  	osc_sb_apei_support_acked =
  		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
  	osc_pc_lpi_support_confirmed =
  		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
  	osc_sb_native_usb4_support_confirmed =
  		capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
  
  	kfree(context.ret.pointer);
  }
  
  /*
   * Native control of USB4 capabilities. If any of the tunneling bits is
   * set it means OS is in control and we use software based connection
   * manager.
   */
  u32 osc_sb_native_usb4_control;
  EXPORT_SYMBOL_GPL(osc_sb_native_usb4_control);
  
  static void acpi_bus_decode_usb_osc(const char *msg, u32 bits)
  {
  	printk(KERN_INFO PREFIX "%s USB3%c DisplayPort%c PCIe%c XDomain%c\n", msg,
  	       (bits & OSC_USB_USB3_TUNNELING) ? '+' : '-',
  	       (bits & OSC_USB_DP_TUNNELING) ? '+' : '-',
  	       (bits & OSC_USB_PCIE_TUNNELING) ? '+' : '-',
  	       (bits & OSC_USB_XDOMAIN) ? '+' : '-');
  }
  
  static u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
  static void acpi_bus_osc_negotiate_usb_control(void)
  {
  	u32 capbuf[3];
  	struct acpi_osc_context context = {
  		.uuid_str = sb_usb_uuid_str,
  		.rev = 1,
  		.cap.length = sizeof(capbuf),
  		.cap.pointer = capbuf,
  	};
  	acpi_handle handle;
  	acpi_status status;
  	u32 control;
  
  	if (!osc_sb_native_usb4_support_confirmed)
  		return;
  
  	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
  		return;
  
  	control = OSC_USB_USB3_TUNNELING | OSC_USB_DP_TUNNELING |
  		  OSC_USB_PCIE_TUNNELING | OSC_USB_XDOMAIN;
  
  	capbuf[OSC_QUERY_DWORD] = 0;
  	capbuf[OSC_SUPPORT_DWORD] = 0;
  	capbuf[OSC_CONTROL_DWORD] = control;
  
  	status = acpi_run_osc(handle, &context);
  	if (ACPI_FAILURE(status))
  		return;
  
  	if (context.ret.length != sizeof(capbuf)) {
  		printk(KERN_INFO PREFIX "USB4 _OSC: returned invalid length buffer\n");
  		goto out_free;
  	}
  
  	osc_sb_native_usb4_control =
  		control & ((u32 *)context.ret.pointer)[OSC_CONTROL_DWORD];
  
  	acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
  	acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",
  				osc_sb_native_usb4_control);
  
  out_free:
  	kfree(context.ret.pointer);
  }
  
  /* --------------------------------------------------------------------------
                               Notification Handling
     -------------------------------------------------------------------------- */
  
  /**
   * acpi_bus_notify
   * ---------------
   * Callback for all 'system-level' device notifications (values 0x00-0x7F).
   */
  static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
  {
  	struct acpi_device *adev;
  	struct acpi_driver *driver;
  	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
  	bool hotplug_event = false;
  
  	switch (type) {
  	case ACPI_NOTIFY_BUS_CHECK:
  		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
  		hotplug_event = true;
  		break;
  
  	case ACPI_NOTIFY_DEVICE_CHECK:
  		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
  		hotplug_event = true;
  		break;
  
  	case ACPI_NOTIFY_DEVICE_WAKE:
  		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
  		break;
  
  	case ACPI_NOTIFY_EJECT_REQUEST:
  		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
  		hotplug_event = true;
  		break;
  
  	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
  		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
  		/* TBD: Exactly what does 'light' mean? */
  		break;
  
  	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
  		acpi_handle_err(handle, "Device cannot be configured due "
  				"to a frequency mismatch\n");
  		break;
  
  	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
  		acpi_handle_err(handle, "Device cannot be configured due "
  				"to a bus mode mismatch\n");
  		break;
  
  	case ACPI_NOTIFY_POWER_FAULT:
  		acpi_handle_err(handle, "Device has suffered a power fault\n");
  		break;
  
  	default:
  		acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
  		break;
  	}
  
  	adev = acpi_bus_get_acpi_device(handle);
  	if (!adev)
  		goto err;
  
  	driver = adev->driver;
  	if (driver && driver->ops.notify &&
  	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
  		driver->ops.notify(adev, type);
  
  	if (!hotplug_event) {
  		acpi_bus_put_acpi_device(adev);
  		return;
  	}
  
  	if (ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
  		return;
  
  	acpi_bus_put_acpi_device(adev);
  
   err:
  	acpi_evaluate_ost(handle, type, ost_code, NULL);
  }
  
  static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
  {
  	struct acpi_device *device = data;
  
  	device->driver->ops.notify(device, event);
  }
  
  static void acpi_device_notify_fixed(void *data)
  {
  	struct acpi_device *device = data;
  
  	/* Fixed hardware devices have no handles */
  	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
  }
  
  static u32 acpi_device_fixed_event(void *data)
  {
  	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
  	return ACPI_INTERRUPT_HANDLED;
  }
  
  static int acpi_device_install_notify_handler(struct acpi_device *device)
  {
  	acpi_status status;
  
  	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
  		status =
  		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
  						     acpi_device_fixed_event,
  						     device);
  	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
  		status =
  		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
  						     acpi_device_fixed_event,
  						     device);
  	else
  		status = acpi_install_notify_handler(device->handle,
  						     ACPI_DEVICE_NOTIFY,
  						     acpi_device_notify,
  						     device);
  
  	if (ACPI_FAILURE(status))
  		return -EINVAL;
  	return 0;
  }
  
  static void acpi_device_remove_notify_handler(struct acpi_device *device)
  {
  	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
  		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
  						acpi_device_fixed_event);
  	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
  		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
  						acpi_device_fixed_event);
  	else
  		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
  					   acpi_device_notify);
  }
  
  /* Handle events targeting \_SB device (at present only graceful shutdown) */
  
  #define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
  #define ACPI_SB_INDICATE_INTERVAL	10000
  
  static void sb_notify_work(struct work_struct *dummy)
  {
  	acpi_handle sb_handle;
  
  	orderly_poweroff(true);
  
  	/*
  	 * After initiating graceful shutdown, the ACPI spec requires OSPM
  	 * to evaluate _OST method once every 10seconds to indicate that
  	 * the shutdown is in progress
  	 */
  	acpi_get_handle(NULL, "\\_SB", &sb_handle);
  	while (1) {
  		pr_info("Graceful shutdown in progress.\n");
  		acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
  				ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
  		msleep(ACPI_SB_INDICATE_INTERVAL);
  	}
  }
  
  static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
  {
  	static DECLARE_WORK(acpi_sb_work, sb_notify_work);
  
  	if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
  		if (!work_busy(&acpi_sb_work))
  			schedule_work(&acpi_sb_work);
  	} else
  		pr_warn("event %x is not supported by \\_SB device\n", event);
  }
  
  static int __init acpi_setup_sb_notify_handler(void)
  {
  	acpi_handle sb_handle;
  
  	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
  		return -ENXIO;
  
  	if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
  						acpi_sb_notify, NULL)))
  		return -EINVAL;
  
  	return 0;
  }
  
  /* --------------------------------------------------------------------------
                               Device Matching
     -------------------------------------------------------------------------- */
  
  /**
   * acpi_get_first_physical_node - Get first physical node of an ACPI device
   * @adev:	ACPI device in question
   *
   * Return: First physical node of ACPI device @adev
   */
  struct device *acpi_get_first_physical_node(struct acpi_device *adev)
  {
  	struct mutex *physical_node_lock = &adev->physical_node_lock;
  	struct device *phys_dev;
  
  	mutex_lock(physical_node_lock);
  	if (list_empty(&adev->physical_node_list)) {
  		phys_dev = NULL;
  	} else {
  		const struct acpi_device_physical_node *node;
  
  		node = list_first_entry(&adev->physical_node_list,
  					struct acpi_device_physical_node, node);
  
  		phys_dev = node->dev;
  	}
  	mutex_unlock(physical_node_lock);
  	return phys_dev;
  }
  EXPORT_SYMBOL_GPL(acpi_get_first_physical_node);
  
  static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
  						      const struct device *dev)
  {
  	const struct device *phys_dev = acpi_get_first_physical_node(adev);
  
  	return phys_dev && phys_dev == dev ? adev : NULL;
  }
  
  /**
   * acpi_device_is_first_physical_node - Is given dev first physical node
   * @adev: ACPI companion device
   * @dev: Physical device to check
   *
   * Function checks if given @dev is the first physical devices attached to
   * the ACPI companion device. This distinction is needed in some cases
   * where the same companion device is shared between many physical devices.
   *
   * Note that the caller have to provide valid @adev pointer.
   */
  bool acpi_device_is_first_physical_node(struct acpi_device *adev,
  					const struct device *dev)
  {
  	return !!acpi_primary_dev_companion(adev, dev);
  }
  
  /*
   * acpi_companion_match() - Can we match via ACPI companion device
   * @dev: Device in question
   *
   * Check if the given device has an ACPI companion and if that companion has
   * a valid list of PNP IDs, and if the device is the first (primary) physical
   * device associated with it.  Return the companion pointer if that's the case
   * or NULL otherwise.
   *
   * If multiple physical devices are attached to a single ACPI companion, we need
   * to be careful.  The usage scenario for this kind of relationship is that all
   * of the physical devices in question use resources provided by the ACPI
   * companion.  A typical case is an MFD device where all the sub-devices share
   * the parent's ACPI companion.  In such cases we can only allow the primary
   * (first) physical device to be matched with the help of the companion's PNP
   * IDs.
   *
   * Additional physical devices sharing the ACPI companion can still use
   * resources available from it but they will be matched normally using functions
   * provided by their bus types (and analogously for their modalias).
   */
  struct acpi_device *acpi_companion_match(const struct device *dev)
  {
  	struct acpi_device *adev;
  
  	adev = ACPI_COMPANION(dev);
  	if (!adev)
  		return NULL;
  
  	if (list_empty(&adev->pnp.ids))
  		return NULL;
  
  	return acpi_primary_dev_companion(adev, dev);
  }
  
  /**
   * acpi_of_match_device - Match device object using the "compatible" property.
   * @adev: ACPI device object to match.
   * @of_match_table: List of device IDs to match against.
   * @of_id: OF ID if matched
   *
   * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
   * identifiers and a _DSD object with the "compatible" property, use that
   * property to match against the given list of identifiers.
   */
  static bool acpi_of_match_device(struct acpi_device *adev,
  				 const struct of_device_id *of_match_table,
  				 const struct of_device_id **of_id)
  {
  	const union acpi_object *of_compatible, *obj;
  	int i, nval;
  
  	if (!adev)
  		return false;
  
  	of_compatible = adev->data.of_compatible;
  	if (!of_match_table || !of_compatible)
  		return false;
  
  	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
  		nval = of_compatible->package.count;
  		obj = of_compatible->package.elements;
  	} else { /* Must be ACPI_TYPE_STRING. */
  		nval = 1;
  		obj = of_compatible;
  	}
  	/* Now we can look for the driver DT compatible strings */
  	for (i = 0; i < nval; i++, obj++) {
  		const struct of_device_id *id;
  
  		for (id = of_match_table; id->compatible[0]; id++)
  			if (!strcasecmp(obj->string.pointer, id->compatible)) {
  				if (of_id)
  					*of_id = id;
  				return true;
  			}
  	}
  
  	return false;
  }
  
  static bool acpi_of_modalias(struct acpi_device *adev,
  			     char *modalias, size_t len)
  {
  	const union acpi_object *of_compatible;
  	const union acpi_object *obj;
  	const char *str, *chr;
  
  	of_compatible = adev->data.of_compatible;
  	if (!of_compatible)
  		return false;
  
  	if (of_compatible->type == ACPI_TYPE_PACKAGE)
  		obj = of_compatible->package.elements;
  	else /* Must be ACPI_TYPE_STRING. */
  		obj = of_compatible;
  
  	str = obj->string.pointer;
  	chr = strchr(str, ',');
  	strlcpy(modalias, chr ? chr + 1 : str, len);
  
  	return true;
  }
  
  /**
   * acpi_set_modalias - Set modalias using "compatible" property or supplied ID
   * @adev:	ACPI device object to match
   * @default_id:	ID string to use as default if no compatible string found
   * @modalias:   Pointer to buffer that modalias value will be copied into
   * @len:	Length of modalias buffer
   *
   * This is a counterpart of of_modalias_node() for struct acpi_device objects.
   * If there is a compatible string for @adev, it will be copied to @modalias
   * with the vendor prefix stripped; otherwise, @default_id will be used.
   */
  void acpi_set_modalias(struct acpi_device *adev, const char *default_id,
  		       char *modalias, size_t len)
  {
  	if (!acpi_of_modalias(adev, modalias, len))
  		strlcpy(modalias, default_id, len);
  }
  EXPORT_SYMBOL_GPL(acpi_set_modalias);
  
  static bool __acpi_match_device_cls(const struct acpi_device_id *id,
  				    struct acpi_hardware_id *hwid)
  {
  	int i, msk, byte_shift;
  	char buf[3];
  
  	if (!id->cls)
  		return false;
  
  	/* Apply class-code bitmask, before checking each class-code byte */
  	for (i = 1; i <= 3; i++) {
  		byte_shift = 8 * (3 - i);
  		msk = (id->cls_msk >> byte_shift) & 0xFF;
  		if (!msk)
  			continue;
  
  		sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
  		if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
  			return false;
  	}
  	return true;
  }
  
  static bool __acpi_match_device(struct acpi_device *device,
  				const struct acpi_device_id *acpi_ids,
  				const struct of_device_id *of_ids,
  				const struct acpi_device_id **acpi_id,
  				const struct of_device_id **of_id)
  {
  	const struct acpi_device_id *id;
  	struct acpi_hardware_id *hwid;
  
  	/*
  	 * If the device is not present, it is unnecessary to load device
  	 * driver for it.
  	 */
  	if (!device || !device->status.present)
  		return false;
  
  	list_for_each_entry(hwid, &device->pnp.ids, list) {
  		/* First, check the ACPI/PNP IDs provided by the caller. */
  		if (acpi_ids) {
  			for (id = acpi_ids; id->id[0] || id->cls; id++) {
  				if (id->id[0] && !strcmp((char *)id->id, hwid->id))
  					goto out_acpi_match;
  				if (id->cls && __acpi_match_device_cls(id, hwid))
  					goto out_acpi_match;
  			}
  		}
  
  		/*
  		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
  		 * "compatible" property if found.
  		 */
  		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id))
  			return acpi_of_match_device(device, of_ids, of_id);
  	}
  	return false;
  
  out_acpi_match:
  	if (acpi_id)
  		*acpi_id = id;
  	return true;
  }
  
  /**
   * acpi_match_device - Match a struct device against a given list of ACPI IDs
   * @ids: Array of struct acpi_device_id object to match against.
   * @dev: The device structure to match.
   *
   * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
   * object for that handle and use that object to match against a given list of
   * device IDs.
   *
   * Return a pointer to the first matching ID on success or %NULL on failure.
   */
  const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
  					       const struct device *dev)
  {
  	const struct acpi_device_id *id = NULL;
  
  	__acpi_match_device(acpi_companion_match(dev), ids, NULL, &id, NULL);
  	return id;
  }
  EXPORT_SYMBOL_GPL(acpi_match_device);
  
  static const void *acpi_of_device_get_match_data(const struct device *dev)
  {
  	struct acpi_device *adev = ACPI_COMPANION(dev);
  	const struct of_device_id *match = NULL;
  
  	if (!acpi_of_match_device(adev, dev->driver->of_match_table, &match))
  		return NULL;
  
  	return match->data;
  }
  
  const void *acpi_device_get_match_data(const struct device *dev)
  {
  	const struct acpi_device_id *match;
  
  	if (!dev->driver->acpi_match_table)
  		return acpi_of_device_get_match_data(dev);
  
  	match = acpi_match_device(dev->driver->acpi_match_table, dev);
  	if (!match)
  		return NULL;
  
  	return (const void *)match->driver_data;
  }
  EXPORT_SYMBOL_GPL(acpi_device_get_match_data);
  
  int acpi_match_device_ids(struct acpi_device *device,
  			  const struct acpi_device_id *ids)
  {
  	return __acpi_match_device(device, ids, NULL, NULL, NULL) ? 0 : -ENOENT;
  }
  EXPORT_SYMBOL(acpi_match_device_ids);
  
  bool acpi_driver_match_device(struct device *dev,
  			      const struct device_driver *drv)
  {
  	if (!drv->acpi_match_table)
  		return acpi_of_match_device(ACPI_COMPANION(dev),
  					    drv->of_match_table,
  					    NULL);
  
  	return __acpi_match_device(acpi_companion_match(dev),
  				   drv->acpi_match_table, drv->of_match_table,
  				   NULL, NULL);
  }
  EXPORT_SYMBOL_GPL(acpi_driver_match_device);
  
  /* --------------------------------------------------------------------------
                                ACPI Driver Management
     -------------------------------------------------------------------------- */
  
  /**
   * acpi_bus_register_driver - register a driver with the ACPI bus
   * @driver: driver being registered
   *
   * Registers a driver with the ACPI bus.  Searches the namespace for all
   * devices that match the driver's criteria and binds.  Returns zero for
   * success or a negative error status for failure.
   */
  int acpi_bus_register_driver(struct acpi_driver *driver)
  {
  	int ret;
  
  	if (acpi_disabled)
  		return -ENODEV;
  	driver->drv.name = driver->name;
  	driver->drv.bus = &acpi_bus_type;
  	driver->drv.owner = driver->owner;
  
  	ret = driver_register(&driver->drv);
  	return ret;
  }
  
  EXPORT_SYMBOL(acpi_bus_register_driver);
  
  /**
   * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
   * @driver: driver to unregister
   *
   * Unregisters a driver with the ACPI bus.  Searches the namespace for all
   * devices that match the driver's criteria and unbinds.
   */
  void acpi_bus_unregister_driver(struct acpi_driver *driver)
  {
  	driver_unregister(&driver->drv);
  }
  
  EXPORT_SYMBOL(acpi_bus_unregister_driver);
  
  /* --------------------------------------------------------------------------
                                ACPI Bus operations
     -------------------------------------------------------------------------- */
  
  static int acpi_bus_match(struct device *dev, struct device_driver *drv)
  {
  	struct acpi_device *acpi_dev = to_acpi_device(dev);
  	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
  
  	return acpi_dev->flags.match_driver
  		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
  }
  
  static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
  }
  
  static int acpi_device_probe(struct device *dev)
  {
  	struct acpi_device *acpi_dev = to_acpi_device(dev);
  	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
  	int ret;
  
  	if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
  		return -EINVAL;
  
  	if (!acpi_drv->ops.add)
  		return -ENOSYS;
  
  	ret = acpi_drv->ops.add(acpi_dev);
  	if (ret)
  		return ret;
  
  	acpi_dev->driver = acpi_drv;
  
  	pr_debug("Driver [%s] successfully bound to device [%s]\n",
  		 acpi_drv->name, acpi_dev->pnp.bus_id);
  
  	if (acpi_drv->ops.notify) {
  		ret = acpi_device_install_notify_handler(acpi_dev);
  		if (ret) {
  			if (acpi_drv->ops.remove)
  				acpi_drv->ops.remove(acpi_dev);
  
  			acpi_dev->driver = NULL;
  			acpi_dev->driver_data = NULL;
  			return ret;
  		}
  	}
  
  	pr_debug("Found driver [%s] for device [%s]\n", acpi_drv->name,
  		 acpi_dev->pnp.bus_id);
  
  	get_device(dev);
  	return 0;
  }
  
  static int acpi_device_remove(struct device *dev)
  {
  	struct acpi_device *acpi_dev = to_acpi_device(dev);
  	struct acpi_driver *acpi_drv = acpi_dev->driver;
  
  	if (acpi_drv) {
  		if (acpi_drv->ops.notify)
  			acpi_device_remove_notify_handler(acpi_dev);
  		if (acpi_drv->ops.remove)
  			acpi_drv->ops.remove(acpi_dev);
  	}
  	acpi_dev->driver = NULL;
  	acpi_dev->driver_data = NULL;
  
  	put_device(dev);
  	return 0;
  }
  
  struct bus_type acpi_bus_type = {
  	.name		= "acpi",
  	.match		= acpi_bus_match,
  	.probe		= acpi_device_probe,
  	.remove		= acpi_device_remove,
  	.uevent		= acpi_device_uevent,
  };
  
  /* --------------------------------------------------------------------------
                               Initialization/Cleanup
     -------------------------------------------------------------------------- */
  
  static int __init acpi_bus_init_irq(void)
  {
  	acpi_status status;
  	char *message = NULL;
  
  
  	/*
  	 * Let the system know what interrupt model we are using by
  	 * evaluating the \_PIC object, if exists.
  	 */
  
  	switch (acpi_irq_model) {
  	case ACPI_IRQ_MODEL_PIC:
  		message = "PIC";
  		break;
  	case ACPI_IRQ_MODEL_IOAPIC:
  		message = "IOAPIC";
  		break;
  	case ACPI_IRQ_MODEL_IOSAPIC:
  		message = "IOSAPIC";
  		break;
  	case ACPI_IRQ_MODEL_GIC:
  		message = "GIC";
  		break;
  	case ACPI_IRQ_MODEL_PLATFORM:
  		message = "platform specific model";
  		break;
  	default:
  		pr_info("Unknown interrupt routing model\n");
  		return -ENODEV;
  	}
  
  	pr_info("Using %s for interrupt routing\n", message);
  
  	status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
  	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
  		pr_info("_PIC evaluation failed: %s\n", acpi_format_exception(status));
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  /**
   * acpi_early_init - Initialize ACPICA and populate the ACPI namespace.
   *
   * The ACPI tables are accessible after this, but the handling of events has not
   * been initialized and the global lock is not available yet, so AML should not
   * be executed at this point.
   *
   * Doing this before switching the EFI runtime services to virtual mode allows
   * the EfiBootServices memory to be freed slightly earlier on boot.
   */
  void __init acpi_early_init(void)
  {
  	acpi_status status;
  
  	if (acpi_disabled)
  		return;
  
  	pr_info("Core revision %08x\n", ACPI_CA_VERSION);
  
  	/* enable workarounds, unless strict ACPI spec. compliance */
  	if (!acpi_strict)
  		acpi_gbl_enable_interpreter_slack = TRUE;
  
  	acpi_permanent_mmap = true;
  
  #ifdef CONFIG_X86
  	/*
  	 * If the machine falls into the DMI check table,
  	 * DSDT will be copied to memory.
  	 * Note that calling dmi_check_system() here on other architectures
  	 * would not be OK because only x86 initializes dmi early enough.
  	 * Thankfully only x86 systems need such quirks for now.
  	 */
  	dmi_check_system(dsdt_dmi_table);
  #endif
  
  	status = acpi_reallocate_root_table();
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to reallocate ACPI tables\n");
  		goto error0;
  	}
  
  	status = acpi_initialize_subsystem();
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to initialize the ACPI Interpreter\n");
  		goto error0;
  	}
  
  #ifdef CONFIG_X86
  	if (!acpi_ioapic) {
  		/* compatible (0) means level (3) */
  		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
  			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
  			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
  		}
  		/* Set PIC-mode SCI trigger type */
  		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
  					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
  	} else {
  		/*
  		 * now that acpi_gbl_FADT is initialized,
  		 * update it with result from INT_SRC_OVR parsing
  		 */
  		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
  	}
  #endif
  	return;
  
   error0:
  	disable_acpi();
  }
  
  /**
   * acpi_subsystem_init - Finalize the early initialization of ACPI.
   *
   * Switch over the platform to the ACPI mode (if possible).
   *
   * Doing this too early is generally unsafe, but at the same time it needs to be
   * done before all things that really depend on ACPI.  The right spot appears to
   * be before finalizing the EFI initialization.
   */
  void __init acpi_subsystem_init(void)
  {
  	acpi_status status;
  
  	if (acpi_disabled)
  		return;
  
  	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to enable ACPI\n");
  		disable_acpi();
  	} else {
  		/*
  		 * If the system is using ACPI then we can be reasonably
  		 * confident that any regulators are managed by the firmware
  		 * so tell the regulator core it has everything it needs to
  		 * know.
  		 */
  		regulator_has_full_constraints();
  	}
  }
  
  static acpi_status acpi_bus_table_handler(u32 event, void *table, void *context)
  {
  	acpi_scan_table_handler(event, table, context);
  
  	return acpi_sysfs_table_handler(event, table, context);
  }
  
  static int __init acpi_bus_init(void)
  {
  	int result;
  	acpi_status status;
  
  	acpi_os_initialize1();
  
  	status = acpi_load_tables();
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to load the System Description Tables\n");
  		goto error1;
  	}
  
  	/*
  	 * ACPI 2.0 requires the EC driver to be loaded and work before the EC
  	 * device is found in the namespace.
  	 *
  	 * This is accomplished by looking for the ECDT table and getting the EC
  	 * parameters out of that.
  	 *
  	 * Do that before calling acpi_initialize_objects() which may trigger EC
  	 * address space accesses.
  	 */
  	acpi_ec_ecdt_probe();
  
  	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to start the ACPI Interpreter\n");
  		goto error1;
  	}
  
  	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to initialize ACPI objects\n");
  		goto error1;
  	}
  
  	/* Set capability bits for _OSC under processor scope */
  	acpi_early_processor_osc();
  
  	/*
  	 * _OSC method may exist in module level code,
  	 * so it must be run after ACPI_FULL_INITIALIZATION
  	 */
  	acpi_bus_osc_negotiate_platform_control();
  	acpi_bus_osc_negotiate_usb_control();
  
  	/*
  	 * _PDC control method may load dynamic SSDT tables,
  	 * and we need to install the table handler before that.
  	 */
  	status = acpi_install_table_handler(acpi_bus_table_handler, NULL);
  
  	acpi_sysfs_init();
  
  	acpi_early_processor_set_pdc();
  
  	/*
  	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
  	 * is necessary to enable it as early as possible.
  	 */
  	acpi_ec_dsdt_probe();
  
  	pr_info("Interpreter enabled\n");
  
  	/* Initialize sleep structures */
  	acpi_sleep_init();
  
  	/*
  	 * Get the system interrupt model and evaluate \_PIC.
  	 */
  	result = acpi_bus_init_irq();
  	if (result)
  		goto error1;
  
  	/*
  	 * Register the for all standard device notifications.
  	 */
  	status =
  	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
  					&acpi_bus_notify, NULL);
  	if (ACPI_FAILURE(status)) {
  		pr_err("Unable to register for system notifications\n");
  		goto error1;
  	}
  
  	/*
  	 * Create the top ACPI proc directory
  	 */
  	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
  
  	result = bus_register(&acpi_bus_type);
  	if (!result)
  		return 0;
  
  	/* Mimic structured exception handling */
        error1:
  	acpi_terminate();
  	return -ENODEV;
  }
  
  struct kobject *acpi_kobj;
  EXPORT_SYMBOL_GPL(acpi_kobj);
  
  static int __init acpi_init(void)
  {
  	int result;
  
  	if (acpi_disabled) {
  		pr_info("Interpreter disabled.\n");
  		return -ENODEV;
  	}
  
  	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
  	if (!acpi_kobj) {
  		pr_debug("%s: kset create error\n", __func__);
  		acpi_kobj = NULL;
  	}
  
  	result = acpi_bus_init();
  	if (result) {
  		kobject_put(acpi_kobj);
  		disable_acpi();
  		return result;
  	}
  
  	pci_mmcfg_late_init();
  	acpi_iort_init();
  	acpi_scan_init();
  	acpi_ec_init();
  	acpi_debugfs_init();
  	acpi_sleep_proc_init();
  	acpi_wakeup_device_init();
  	acpi_debugger_init();
  	acpi_setup_sb_notify_handler();
  	return 0;
  }
  
  subsys_initcall(acpi_init);
  