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/*******************************************************************************

 *

 * Module Name: hwpci - Obtain PCI bus, device, and function numbers

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2015, Intel Corp.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions, and the following disclaimer,

 *    without modification.

 * 2. Redistributions in binary form must reproduce at minimum a disclaimer

 *    substantially similar to the "NO WARRANTY" disclaimer below

 *    ("Disclaimer") and any redistribution must be conditioned upon

 *    including a substantially similar Disclaimer requirement for further

 *    binary redistribution.

 * 3. Neither the names of the above-listed copyright holders nor the names

 *    of any contributors may be used to endorse or promote products derived

 *    from this software without specific prior written permission.

 *

 * Alternatively, this software may be distributed under the terms of the

 * GNU General Public License ("GPL") version 2 as published by the Free

 * Software Foundation.

 *

 * NO WARRANTY

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGES.

 */

#include 

#include "accommon.h"

#define _COMPONENT          ACPI_NAMESPACE

ACPI_MODULE_NAME("hwpci")

/* PCI configuration space values */

#define PCI_CFG_HEADER_TYPE_REG             0x0E

#define PCI_CFG_PRIMARY_BUS_NUMBER_REG      0x18

#define PCI_CFG_SECONDARY_BUS_NUMBER_REG    0x19

/* PCI header values */

#define PCI_HEADER_TYPE_MASK                0x7F

#define PCI_TYPE_BRIDGE                     0x01

#define PCI_TYPE_CARDBUS_BRIDGE             0x02

typedef struct acpi_pci_device {

	acpi_handle device;

	struct acpi_pci_device *next;

} acpi_pci_device;

/* Local prototypes */

static acpi_status

acpi_hw_build_pci_list(acpi_handle root_pci_device,

		       acpi_handle pci_region,

		       struct acpi_pci_device **return_list_head);

static acpi_status

acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,

			 struct acpi_pci_device *list_head);

static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head);

static acpi_status

acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,

			    acpi_handle pci_device,

			    u16 *bus_number, u8 *is_bridge);

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_derive_pci_id

 *

 * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be

 *                                    modified by this function.

 *              root_pci_device     - A handle to a PCI device object. This

 *                                    object must be a PCI Root Bridge having a

 *                                    _HID value of either PNP0A03 or PNP0A08

 *              pci_region          - A handle to a PCI configuration space

 *                                    Operation Region being initialized

 *

 * RETURN:      Status

 *

 * DESCRIPTION: This function derives a full PCI ID for a PCI device,

 *              consisting of a Segment number, Bus number, Device number,

 *              and function code.

 *

 *              The PCI hardware dynamically configures PCI bus numbers

 *              depending on the bus topology discovered during system

 *              initialization. This function is invoked during configuration

 *              of a PCI_Config Operation Region in order to (possibly) update

 *              the Bus/Device/Function numbers in the pci_id with the actual

 *              values as determined by the hardware and operating system

 *              configuration.

 *

 *              The pci_id parameter is initially populated during the Operation

 *              Region initialization. This function is then called, and is

 *              will make any necessary modifications to the Bus, Device, or

 *              Function number PCI ID subfields as appropriate for the

 *              current hardware and OS configuration.

 *

 * NOTE:        Created 08/2010. Replaces the previous OSL acpi_os_derive_pci_id

 *              interface since this feature is OS-independent. This module

 *              specifically avoids any use of recursion by building a local

 *              temporary device list.

 *

 ******************************************************************************/

acpi_status

acpi_hw_derive_pci_id(struct acpi_pci_id *pci_id,

		      acpi_handle root_pci_device, acpi_handle pci_region)

{

	acpi_status status;

	struct acpi_pci_device *list_head;

	ACPI_FUNCTION_TRACE(hw_derive_pci_id);

	if (!pci_id) {

		return_ACPI_STATUS(AE_BAD_PARAMETER);

	}

	/* Build a list of PCI devices, from pci_region up to root_pci_device */

	status =

	    acpi_hw_build_pci_list(root_pci_device, pci_region, &list_head);

	if (ACPI_SUCCESS(status)) {

		/* Walk the list, updating the PCI device/function/bus numbers */

		status = acpi_hw_process_pci_list(pci_id, list_head);

		/* Delete the list */

		acpi_hw_delete_pci_list(list_head);

	}

	return_ACPI_STATUS(status);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_build_pci_list

 *

 * PARAMETERS:  root_pci_device     - A handle to a PCI device object. This

 *                                    object is guaranteed to be a PCI Root

 *                                    Bridge having a _HID value of either

 *                                    PNP0A03 or PNP0A08

 *              pci_region          - A handle to the PCI configuration space

 *                                    Operation Region

 *              return_list_head    - Where the PCI device list is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Builds a list of devices from the input PCI region up to the

 *              Root PCI device for this namespace subtree.

 *

 ******************************************************************************/

static acpi_status

acpi_hw_build_pci_list(acpi_handle root_pci_device,

		       acpi_handle pci_region,

		       struct acpi_pci_device **return_list_head)

{

	acpi_handle current_device;

	acpi_handle parent_device;

	acpi_status status;

	struct acpi_pci_device *list_element;

	/*

	 * Ascend namespace branch until the root_pci_device is reached, building

	 * a list of device nodes. Loop will exit when either the PCI device is

	 * found, or the root of the namespace is reached.

	 */

	*return_list_head = NULL;

	current_device = pci_region;

	while (1) {

		status = acpi_get_parent(current_device, &parent_device);

		if (ACPI_FAILURE(status)) {

			/* Must delete the list before exit */

			acpi_hw_delete_pci_list(*return_list_head);

			return (status);

		}

		/* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */

		if (parent_device == root_pci_device) {

			return (AE_OK);

		}

		list_element = ACPI_ALLOCATE(sizeof(struct acpi_pci_device));

		if (!list_element) {

			/* Must delete the list before exit */

			acpi_hw_delete_pci_list(*return_list_head);

			return (AE_NO_MEMORY);

		}

		/* Put new element at the head of the list */

		list_element->next = *return_list_head;

		list_element->device = parent_device;

		*return_list_head = list_element;

		current_device = parent_device;

	}

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_process_pci_list

 *

 * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be

 *                                    modified by this function.

 *              list_head           - Device list created by

 *                                    acpi_hw_build_pci_list

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Walk downward through the PCI device list, getting the device

 *              info for each, via the PCI configuration space and updating

 *              the PCI ID as necessary. Deletes the list during traversal.

 *

 ******************************************************************************/

static acpi_status

acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,

			 struct acpi_pci_device *list_head)

{

	acpi_status status = AE_OK;

	struct acpi_pci_device *info;

	u16 bus_number;

	u8 is_bridge = TRUE;

	ACPI_FUNCTION_NAME(hw_process_pci_list);

	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,

			  "Input PciId:  Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n",

			  pci_id->segment, pci_id->bus, pci_id->device,

			  pci_id->function));

	bus_number = pci_id->bus;

	/*

	 * Descend down the namespace tree, collecting PCI device, function,

	 * and bus numbers. bus_number is only important for PCI bridges.

	 * Algorithm: As we descend the tree, use the last valid PCI device,

	 * function, and bus numbers that are discovered, and assign them

	 * to the PCI ID for the target device.

	 */

	info = list_head;

	while (info) {

		status = acpi_hw_get_pci_device_info(pci_id, info->device,

						     &bus_number, &is_bridge);

		if (ACPI_FAILURE(status)) {

			return (status);

		}

		info = info->next;

	}

	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,

			  "Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X "

			  "Status %X BusNumber %X IsBridge %X\n",

			  pci_id->segment, pci_id->bus, pci_id->device,

			  pci_id->function, status, bus_number, is_bridge));

	return (AE_OK);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_delete_pci_list

 *

 * PARAMETERS:  list_head           - Device list created by

 *                                    acpi_hw_build_pci_list

 *

 * RETURN:      None

 *

 * DESCRIPTION: Free the entire PCI list.

 *

 ******************************************************************************/

static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head)

{

	struct acpi_pci_device *next;

	struct acpi_pci_device *previous;

	next = list_head;

	while (next) {

		previous = next;

		next = previous->next;

		ACPI_FREE(previous);

	}

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_get_pci_device_info

 *

 * PARAMETERS:  pci_id              - Initial values for the PCI ID. May be

 *                                    modified by this function.

 *              pci_device          - Handle for the PCI device object

 *              bus_number          - Where a PCI bridge bus number is returned

 *              is_bridge           - Return value, indicates if this PCI

 *                                    device is a PCI bridge

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Get the device info for a single PCI device object. Get the

 *              _ADR (contains PCI device and function numbers), and for PCI

 *              bridge devices, get the bus number from PCI configuration

 *              space.

 *

 ******************************************************************************/

static acpi_status

acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,

			    acpi_handle pci_device,

			    u16 *bus_number, u8 *is_bridge)

{

	acpi_status status;

	acpi_object_type object_type;

	u64 return_value;

	u64 pci_value;

	/* We only care about objects of type Device */

	status = acpi_get_type(pci_device, &object_type);

	if (ACPI_FAILURE(status)) {

		return (status);

	}

	if (object_type != ACPI_TYPE_DEVICE) {

		return (AE_OK);

	}

	/* We need an _ADR. Ignore device if not present */

	status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR,

						 pci_device, &return_value);

	if (ACPI_FAILURE(status)) {

		return (AE_OK);

	}

	/*

	 * From _ADR, get the PCI Device and Function and

	 * update the PCI ID.

	 */

	pci_id->device = ACPI_HIWORD(ACPI_LODWORD(return_value));

	pci_id->function = ACPI_LOWORD(ACPI_LODWORD(return_value));

	/*

	 * If the previous device was a bridge, use the previous

	 * device bus number

	 */

	if (*is_bridge) {

		pci_id->bus = *bus_number;

	}

	/*

	 * Get the bus numbers from PCI Config space:

	 *

	 * First, get the PCI header_type

	 */

	*is_bridge = FALSE;

	status = acpi_os_read_pci_configuration(pci_id,

						PCI_CFG_HEADER_TYPE_REG,

						&pci_value, 8);

	if (ACPI_FAILURE(status)) {

		return (status);

	}

	/* We only care about bridges (1=pci_bridge, 2=card_bus_bridge) */

	pci_value &= PCI_HEADER_TYPE_MASK;

	if ((pci_value != PCI_TYPE_BRIDGE) &&

	    (pci_value != PCI_TYPE_CARDBUS_BRIDGE)) {

		return (AE_OK);

	}

	/* Bridge: Get the Primary bus_number */

	status = acpi_os_read_pci_configuration(pci_id,

						PCI_CFG_PRIMARY_BUS_NUMBER_REG,

						&pci_value, 8);

	if (ACPI_FAILURE(status)) {

		return (status);

	}

	*is_bridge = TRUE;

	pci_id->bus = (u16)pci_value;

	/* Bridge: Get the Secondary bus_number */

	status = acpi_os_read_pci_configuration(pci_id,

						PCI_CFG_SECONDARY_BUS_NUMBER_REG,

						&pci_value, 8);

	if (ACPI_FAILURE(status)) {

		return (status);

	}

	*bus_number = (u16)pci_value;

	return (AE_OK);

}