linux-imx

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0

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

 *

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

 *

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

​

#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);