audk/UefiPayloadPkg/Library/PciSegmentInfoLibAcpiBoardInfo/PciSegmentInfoLibAcpiBoardI...

60 lines
1.4 KiB
C

/** @file
PCI Segment Information Library that returns one segment whose
segment base address is retrieved from AcpiBoardInfo HOB.
Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiDxe.h>
#include <Guid/AcpiBoardInfoGuid.h>
#include <Library/HobLib.h>
#include <Library/PciSegmentInfoLib.h>
#include <Library/DebugLib.h>
STATIC PCI_SEGMENT_INFO mPciSegment0 = {
0, // Segment number
0, // To be fixed later
0, // Start bus number
255 // End bus number
};
/**
Return an array of PCI_SEGMENT_INFO holding the segment information.
Note: The returned array/buffer is owned by callee.
@param Count Return the count of segments.
@retval A callee owned array holding the segment information.
**/
PCI_SEGMENT_INFO *
EFIAPI
GetPciSegmentInfo (
UINTN *Count
)
{
EFI_HOB_GUID_TYPE *GuidHob;
ACPI_BOARD_INFO *AcpiBoardInfo;
ASSERT (Count != NULL);
if (Count == NULL) {
return NULL;
}
if (mPciSegment0.BaseAddress == 0) {
//
// Find the acpi board information guid hob
//
GuidHob = GetFirstGuidHob (&gUefiAcpiBoardInfoGuid);
ASSERT (GuidHob != NULL);
AcpiBoardInfo = (ACPI_BOARD_INFO *) GET_GUID_HOB_DATA (GuidHob);
mPciSegment0.BaseAddress = AcpiBoardInfo->PcieBaseAddress;
}
*Count = 1;
return &mPciSegment0;
}