OvmfPkg/XenAcpiPlatformDxe/EntryPoint.c

   1 /** @file
   2   Entry point of OVMF ACPI Platform Driver for Xen guests
   3
   4   Copyright (C) 2015-2021, Red Hat, Inc.
   5   Copyright (c) 2008 - 2015, Intel Corporation. All rights reserved.<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8 **/
   9
  10 #include <Guid/RootBridgesConnectedEventGroup.h> // gRootBridgesConnectedEve...
  11 #include <Library/DebugLib.h>                    // DEBUG()
  12 #include <Library/PcdLib.h>                      // PcdGetBool()
  13 #include <Library/UefiBootServicesTableLib.h>    // gBS
  14 #include <Protocol/AcpiTable.h>                  // EFI_ACPI_TABLE_PROTOCOL
  15
  16 #include "AcpiPlatform.h"
  17
  18 STATIC
  19 EFI_ACPI_TABLE_PROTOCOL *
  20 FindAcpiTableProtocol (
  21   VOID
  22   )
  23 {
  24   EFI_STATUS              Status;
  25   EFI_ACPI_TABLE_PROTOCOL *AcpiTable;
  26
  27   Status = gBS->LocateProtocol (
  28                   &gEfiAcpiTableProtocolGuid,
  29                   NULL,
  30                   (VOID**)&AcpiTable
  31                   );
  32   ASSERT_EFI_ERROR (Status);
  33   return AcpiTable;
  34 }
  35
  36
  37 STATIC
  38 VOID
  39 EFIAPI
  40 OnRootBridgesConnected (
  41   IN EFI_EVENT Event,
  42   IN VOID      *Context
  43   )
  44 {
  45   EFI_STATUS Status;
  46
  47   DEBUG ((DEBUG_INFO,
  48     "%a: root bridges have been connected, installing ACPI tables\n",
  49     __FUNCTION__));
  50   Status = InstallAcpiTables (FindAcpiTableProtocol ());
  51   if (EFI_ERROR (Status)) {
  52     DEBUG ((DEBUG_ERROR, "%a: InstallAcpiTables: %r\n", __FUNCTION__, Status));
  53   }
  54   gBS->CloseEvent (Event);
  55 }
  56
  57
  58 EFI_STATUS
  59 EFIAPI
  60 AcpiPlatformEntryPoint (
  61   IN EFI_HANDLE         ImageHandle,
  62   IN EFI_SYSTEM_TABLE   *SystemTable
  63   )
  64 {
  65   EFI_STATUS Status;
  66   EFI_EVENT  RootBridgesConnected;
  67
  68   //
  69   // If the platform doesn't support PCI, or PCI enumeration has been disabled,
  70   // install the tables at once, and let the entry point's return code reflect
  71   // the full functionality.
  72   //
  73   if (PcdGetBool (PcdPciDisableBusEnumeration)) {
  74     DEBUG ((DEBUG_INFO, "%a: PCI or its enumeration disabled, installing "
  75       "ACPI tables\n", __FUNCTION__));
  76     return InstallAcpiTables (FindAcpiTableProtocol ());
  77   }
  78
  79   //
  80   // Otherwise, delay installing the ACPI tables until root bridges are
  81   // connected. The entry point's return status will only reflect the callback
  82   // setup. (Note that we're a DXE_DRIVER; our entry point function is invoked
  83   // strictly before BDS is entered and can connect the root bridges.)
  84   //
  85   Status = gBS->CreateEventEx (EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
  86                   OnRootBridgesConnected, NULL /* Context */,
  87                   &gRootBridgesConnectedEventGroupGuid, &RootBridgesConnected);
  88   if (!EFI_ERROR (Status)) {
  89     DEBUG ((DEBUG_INFO,
  90       "%a: waiting for root bridges to be connected, registered callback\n",
  91       __FUNCTION__));
  92   }
  93
  94   return Status;
  95 }