Intel Extensible Firmware Interface - Manual (Page 503)

Protocols — PCI Bus Support
Version 1.10 12/01/02 12-85
EFI_PCI_IO_PROTOCOL.GetLocation()
Summary
Retrieves this PCI controller’s current PCI bus number, device number, and function number.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_PCI_IO_PROTOCOL_GET_LOCATION) (
IN EFI_PCI_IO_PROTOCOL
*This,
OUT UINTN *SegmentNumber,
OUT UINTN *BusNumber,
OUT UINTN *DeviceNumber,
OUT UINTN *FunctionNumber
);
Parameters
This A pointer to the EFI_PCI_IO_PROTOCOL instance. Type
EFI_PCI_IO_PROTOCOL is defined in Section 12.4.
SegmentNumber The PCI controller’s current PCI segment number.
BusNumber The PCI controller’s current PCI bus number.
DeviceNumber The PCI controller’s current PCI device number.
FunctionNumber The PCI controller’s current PCI function number.
Description
The GetLocation() function retrieves a PCI controller’s current location on a PCI Host Bridge.
This is specified by a PCI segment number, PCI bus number, PCI device number, and PCI function
number. These values can be used with the PCI Root Bridge I/O Protocol to perform PCI
configuration cycles on the PCI controller, or any of its peer PCI controller’s on the same PCI Host
Bridge.
Status Codes Returned
EFI_SUCCESS The PCI controller location was returned.
EFI_INVALID_PARAMETER SegmentNumber is NULL .
EFI_INVALID_PARAMETER BusNumber is NULL .
EFI_INVALID_PARAMETER DeviceNumber is NULL .
EFI_INVALID_PARAMETER FunctionNumber is NULL .