[mirror_ubuntu-artful-kernel.git] / drivers / acpi / acpica / hwpci.c

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

/*
 * Copyright (C) 2000 - 2017, 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 <acpi/acpi.h>
#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);
}
Commit	Line	Data
95abccb5 BM	1	/*******************************************************************************
	2	*
	3	* Module Name: hwpci - Obtain PCI bus, device, and function numbers
	4	*
	5	******************************************************************************/
	6
	7	/*
7735ca0e	8	* Copyright (C) 2000 - 2017, Intel Corp.
95abccb5 BM	9	* All rights reserved.
	10	*
	11	* Redistribution and use in source and binary forms, with or without
	12	* modification, are permitted provided that the following conditions
	13	* are met:
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions, and the following disclaimer,
	16	* without modification.
	17	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	18	* substantially similar to the "NO WARRANTY" disclaimer below
	19	* ("Disclaimer") and any redistribution must be conditioned upon
	20	* including a substantially similar Disclaimer requirement for further
	21	* binary redistribution.
	22	* 3. Neither the names of the above-listed copyright holders nor the names
	23	* of any contributors may be used to endorse or promote products derived
	24	* from this software without specific prior written permission.
	25	*
	26	* Alternatively, this software may be distributed under the terms of the
	27	* GNU General Public License ("GPL") version 2 as published by the Free
	28	* Software Foundation.
	29	*
	30	* NO WARRANTY
	31	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	32	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	33	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	34	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	35	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	36	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	37	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	38	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	39	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	40	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	41	* POSSIBILITY OF SUCH DAMAGES.
	42	*/
	43
	44	#include <acpi/acpi.h>
	45	#include "accommon.h"
	46
	47	#define _COMPONENT ACPI_NAMESPACE
	48	ACPI_MODULE_NAME("hwpci")
	49
	50	/* PCI configuration space values */
	51	#define PCI_CFG_HEADER_TYPE_REG 0x0E
	52	#define PCI_CFG_PRIMARY_BUS_NUMBER_REG 0x18
	53	#define PCI_CFG_SECONDARY_BUS_NUMBER_REG 0x19
	54	/* PCI header values */
	55	#define PCI_HEADER_TYPE_MASK 0x7F
	56	#define PCI_TYPE_BRIDGE 0x01
	57	#define PCI_TYPE_CARDBUS_BRIDGE 0x02
	58	typedef struct acpi_pci_device {
	59	acpi_handle device;
	60	struct acpi_pci_device *next;
	61
	62	} acpi_pci_device;
	63
	64	/* Local prototypes */
	65
	66	static acpi_status
	67	acpi_hw_build_pci_list(acpi_handle root_pci_device,
	68	acpi_handle pci_region,
	69	struct acpi_pci_device **return_list_head);
	70
	71	static acpi_status
	72	acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,
73	struct acpi_pci_device *list_head);
74
75	static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head);
76
77	static acpi_status
78	acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,
79	acpi_handle pci_device,
80	u16 bus_number, u8 is_bridge);
81
82	/*******************************************************************************
83	*
84	* FUNCTION: acpi_hw_derive_pci_id
85	*
86	* PARAMETERS: pci_id - Initial values for the PCI ID. May be
87	* modified by this function.
88	* root_pci_device - A handle to a PCI device object. This
89	* object must be a PCI Root Bridge having a
90	* _HID value of either PNP0A03 or PNP0A08
91	* pci_region - A handle to a PCI configuration space
92	* Operation Region being initialized
93	*
94	* RETURN: Status
95	*
96	* DESCRIPTION: This function derives a full PCI ID for a PCI device,
97	* consisting of a Segment number, Bus number, Device number,
98	* and function code.
99	*
100	* The PCI hardware dynamically configures PCI bus numbers
101	* depending on the bus topology discovered during system
102	* initialization. This function is invoked during configuration
103	* of a PCI_Config Operation Region in order to (possibly) update
104	* the Bus/Device/Function numbers in the pci_id with the actual
105	* values as determined by the hardware and operating system
106	* configuration.
107	*
108	* The pci_id parameter is initially populated during the Operation
109	* Region initialization. This function is then called, and is
110	* will make any necessary modifications to the Bus, Device, or
111	* Function number PCI ID subfields as appropriate for the
112	* current hardware and OS configuration.
113	*
114	* NOTE: Created 08/2010. Replaces the previous OSL acpi_os_derive_pci_id
115	* interface since this feature is OS-independent. This module
116	* specifically avoids any use of recursion by building a local
117	* temporary device list.
118	*
119	******************************************************************************/
120
121	acpi_status
122	acpi_hw_derive_pci_id(struct acpi_pci_id *pci_id,
123	acpi_handle root_pci_device, acpi_handle pci_region)
124	{
125	acpi_status status;
2900d56f	126	struct acpi_pci_device *list_head;
95abccb5 BM	127
	128	ACPI_FUNCTION_TRACE(hw_derive_pci_id);
	129
	130	if (!pci_id) {
	131	return_ACPI_STATUS(AE_BAD_PARAMETER);
	132	}
	133
	134	/* Build a list of PCI devices, from pci_region up to root_pci_device */
	135
	136	status =
	137	acpi_hw_build_pci_list(root_pci_device, pci_region, &list_head);
	138	if (ACPI_SUCCESS(status)) {
	139
	140	/* Walk the list, updating the PCI device/function/bus numbers */
	141
	142	status = acpi_hw_process_pci_list(pci_id, list_head);
95abccb5	143
c28fa24b DB	144	/* Delete the list */
	145
	146	acpi_hw_delete_pci_list(list_head);
	147	}
95abccb5	148
95abccb5 BM	149	return_ACPI_STATUS(status);
	150	}
	151
	152	/*******************************************************************************
	153	*
	154	* FUNCTION: acpi_hw_build_pci_list
	155	*
	156	* PARAMETERS: root_pci_device - A handle to a PCI device object. This
	157	* object is guaranteed to be a PCI Root
	158	* Bridge having a _HID value of either
	159	* PNP0A03 or PNP0A08
	160	* pci_region - A handle to the PCI configuration space
	161	* Operation Region
	162	* return_list_head - Where the PCI device list is returned
	163	*
	164	* RETURN: Status
	165	*
	166	* DESCRIPTION: Builds a list of devices from the input PCI region up to the
	167	* Root PCI device for this namespace subtree.
	168	*
	169	******************************************************************************/
	170
	171	static acpi_status
	172	acpi_hw_build_pci_list(acpi_handle root_pci_device,
	173	acpi_handle pci_region,
	174	struct acpi_pci_device **return_list_head)
	175	{
	176	acpi_handle current_device;
	177	acpi_handle parent_device;
	178	acpi_status status;
	179	struct acpi_pci_device *list_element;
95abccb5 BM	180
	181	/*
	182	* Ascend namespace branch until the root_pci_device is reached, building
	183	* a list of device nodes. Loop will exit when either the PCI device is
	184	* found, or the root of the namespace is reached.
	185	*/
2900d56f	186	*return_list_head = NULL;
95abccb5 BM	187	current_device = pci_region;
	188	while (1) {
	189	status = acpi_get_parent(current_device, &parent_device);
	190	if (ACPI_FAILURE(status)) {
c28fa24b DB	191
	192	/* Must delete the list before exit */
	193
	194	acpi_hw_delete_pci_list(*return_list_head);
95abccb5 BM	195	return (status);
	196	}
	197
	198	/* Finished when we reach the PCI root device (PNP0A03 or PNP0A08) */
	199
	200	if (parent_device == root_pci_device) {
95abccb5 BM	201	return (AE_OK);
	202	}
	203
	204	list_element = ACPI_ALLOCATE(sizeof(struct acpi_pci_device));
	205	if (!list_element) {
c28fa24b DB	206
	207	/* Must delete the list before exit */
	208
	209	acpi_hw_delete_pci_list(*return_list_head);
95abccb5 BM	210	return (AE_NO_MEMORY);
	211	}
	212
	213	/* Put new element at the head of the list */
	214
2900d56f	215	list_element->next = *return_list_head;
95abccb5	216	list_element->device = parent_device;
2900d56f	217	*return_list_head = list_element;
95abccb5 BM	218
	219	current_device = parent_device;
	220	}
	221	}
	222
	223	/*******************************************************************************
	224	*
	225	* FUNCTION: acpi_hw_process_pci_list
	226	*
	227	* PARAMETERS: pci_id - Initial values for the PCI ID. May be
	228	* modified by this function.
	229	* list_head - Device list created by
	230	* acpi_hw_build_pci_list
	231	*
	232	* RETURN: Status
	233	*
	234	* DESCRIPTION: Walk downward through the PCI device list, getting the device
	235	* info for each, via the PCI configuration space and updating
	236	* the PCI ID as necessary. Deletes the list during traversal.
	237	*
	238	******************************************************************************/
	239
	240	static acpi_status
	241	acpi_hw_process_pci_list(struct acpi_pci_id *pci_id,
	242	struct acpi_pci_device *list_head)
	243	{
	244	acpi_status status = AE_OK;
	245	struct acpi_pci_device *info;
	246	u16 bus_number;
	247	u8 is_bridge = TRUE;
	248
	249	ACPI_FUNCTION_NAME(hw_process_pci_list);
	250
	251	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
	252	"Input PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X\n",
	253	pci_id->segment, pci_id->bus, pci_id->device,
	254	pci_id->function));
	255
	256	bus_number = pci_id->bus;
	257
	258	/*
	259	* Descend down the namespace tree, collecting PCI device, function,
	260	* and bus numbers. bus_number is only important for PCI bridges.
	261	* Algorithm: As we descend the tree, use the last valid PCI device,
	262	* function, and bus numbers that are discovered, and assign them
	263	* to the PCI ID for the target device.
	264	*/
	265	info = list_head;
	266	while (info) {
	267	status = acpi_hw_get_pci_device_info(pci_id, info->device,
	268	&bus_number, &is_bridge);
	269	if (ACPI_FAILURE(status)) {
68aafc35	270	return (status);
95abccb5 BM	271	}
	272
	273	info = info->next;
	274	}
	275
	276	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
	277	"Output PciId: Seg %4.4X Bus %4.4X Dev %4.4X Func %4.4X "
	278	"Status %X BusNumber %X IsBridge %X\n",
	279	pci_id->segment, pci_id->bus, pci_id->device,
	280	pci_id->function, status, bus_number, is_bridge));
	281
68aafc35	282	return (AE_OK);
95abccb5 BM	283	}
	284
	285	/*******************************************************************************
	286	*
	287	* FUNCTION: acpi_hw_delete_pci_list
	288	*
	289	* PARAMETERS: list_head - Device list created by
	290	* acpi_hw_build_pci_list
	291	*
	292	* RETURN: None
	293	*
	294	* DESCRIPTION: Free the entire PCI list.
	295	*
	296	******************************************************************************/
	297
	298	static void acpi_hw_delete_pci_list(struct acpi_pci_device *list_head)
	299	{
	300	struct acpi_pci_device *next;
	301	struct acpi_pci_device *previous;
	302
	303	next = list_head;
	304	while (next) {
	305	previous = next;
	306	next = previous->next;
	307	ACPI_FREE(previous);
	308	}
	309	}
	310
	311	/*******************************************************************************
	312	*
	313	* FUNCTION: acpi_hw_get_pci_device_info
	314	*
	315	* PARAMETERS: pci_id - Initial values for the PCI ID. May be
	316	* modified by this function.
	317	* pci_device - Handle for the PCI device object
	318	* bus_number - Where a PCI bridge bus number is returned
	319	* is_bridge - Return value, indicates if this PCI
	320	* device is a PCI bridge
	321	*
	322	* RETURN: Status
	323	*
	324	* DESCRIPTION: Get the device info for a single PCI device object. Get the
	325	* _ADR (contains PCI device and function numbers), and for PCI
	326	* bridge devices, get the bus number from PCI configuration
	327	* space.
	328	*
	329	******************************************************************************/
	330
	331	static acpi_status
	332	acpi_hw_get_pci_device_info(struct acpi_pci_id *pci_id,
	333	acpi_handle pci_device,
	334	u16 bus_number, u8 is_bridge)
	335	{
	336	acpi_status status;
	337	acpi_object_type object_type;
	338	u64 return_value;
	339	u64 pci_value;
	340
	341	/* We only care about objects of type Device */
	342
	343	status = acpi_get_type(pci_device, &object_type);
	344	if (ACPI_FAILURE(status)) {
	345	return (status);
	346	}
347
348	if (object_type != ACPI_TYPE_DEVICE) {
349	return (AE_OK);
350	}
351
352	/* We need an _ADR. Ignore device if not present */
353
354	status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR,
355	pci_device, &return_value);
356	if (ACPI_FAILURE(status)) {
357	return (AE_OK);
358	}
359
360	/*
361	* From _ADR, get the PCI Device and Function and
362	* update the PCI ID.
363	*/
364	pci_id->device = ACPI_HIWORD(ACPI_LODWORD(return_value));
365	pci_id->function = ACPI_LOWORD(ACPI_LODWORD(return_value));
366
367	/*
368	* If the previous device was a bridge, use the previous
369	* device bus number
370	*/
371	if (*is_bridge) {
372	pci_id->bus = *bus_number;
373	}
374
375	/*
376	* Get the bus numbers from PCI Config space:
377	*
378	* First, get the PCI header_type
379	*/
380	*is_bridge = FALSE;
381	status = acpi_os_read_pci_configuration(pci_id,
382	PCI_CFG_HEADER_TYPE_REG,
383	&pci_value, 8);
384	if (ACPI_FAILURE(status)) {
385	return (status);
386	}
387
388	/* We only care about bridges (1=pci_bridge, 2=card_bus_bridge) */
389
390	pci_value &= PCI_HEADER_TYPE_MASK;
391
392	if ((pci_value != PCI_TYPE_BRIDGE) &&
393	(pci_value != PCI_TYPE_CARDBUS_BRIDGE)) {
394	return (AE_OK);
395	}
396
397	/* Bridge: Get the Primary bus_number */
398
399	status = acpi_os_read_pci_configuration(pci_id,
400	PCI_CFG_PRIMARY_BUS_NUMBER_REG,
401	&pci_value, 8);
402	if (ACPI_FAILURE(status)) {
403	return (status);
404	}
405
406	*is_bridge = TRUE;
407	pci_id->bus = (u16)pci_value;
408
409	/* Bridge: Get the Secondary bus_number */
410
411	status = acpi_os_read_pci_configuration(pci_id,
412	PCI_CFG_SECONDARY_BUS_NUMBER_REG,
413	&pci_value, 8);
414	if (ACPI_FAILURE(status)) {
415	return (status);
416	}
417
418	*bus_number = (u16)pci_value;
419	return (AE_OK);
420	}