OpenCorePkg/Library/OcPciIoLib/OcPciIoLib.c

/** @file
   PciIo overrides

   Copyright (c) 2023, xCuri0. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

#include "OcPciIoU.h"
#include <Library/OcPciIoLib.h>

EFI_CPU_IO2_PROTOCOL *
OcPciIoInstallProtocol (
  IN BOOLEAN  Reinstall
  )
{
  EFI_TPL                          Tpl;
  UINTN                            Index;
  EFI_STATUS                       Status;
  EFI_CPU_IO2_PROTOCOL             *CpuIo;
  UINTN                            HandleCount;
  EFI_HANDLE                       *HandleBuffer;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *PciRootBridgeIo;

  CpuIo = InitializeCpuIo2 ();
  if (CpuIo == NULL) {
    return NULL;
  }

  if (!Reinstall) {
    return CpuIo;
  }

  Tpl    = gBS->RaiseTPL (TPL_HIGH_LEVEL);
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiPciRootBridgeIoProtocolGuid,
                  NULL,
                  &HandleCount,
                  &HandleBuffer
                  );

  if (EFI_ERROR (Status)) {
    gBS->RestoreTPL (Tpl);
    return NULL;
  }

  DEBUG ((DEBUG_INFO, "OCPIO: Fixing CpuIo2\n"));
  // Override with 64-bit MMIO compatible functions
  CpuIo->Mem.Read  = CpuMemoryServiceRead;
  CpuIo->Mem.Write = CpuMemoryServiceWrite;

  for (Index = 0; Index < HandleCount; ++Index) {
    DEBUG ((DEBUG_INFO, "OCPIO: Fixing PciRootBridgeIo %d\n", Index));

    Status = gBS->HandleProtocol (
                    HandleBuffer[Index],
                    &gEfiPciRootBridgeIoProtocolGuid,
                    (VOID **)&PciRootBridgeIo
                    );
    if (EFI_ERROR (Status)) {
      break;
    }

    // Override with 64-bit MMIO compatible functions
    PciRootBridgeIo->Mem.Read  = RootBridgeIoMemRead;
    PciRootBridgeIo->Mem.Write = RootBridgeIoMemWrite;
  }

  gBS->RestoreTPL (Tpl);
  FreePool (HandleBuffer);
  return CpuIo;
}