]> git.proxmox.com Git - mirror_edk2.git/blobdiff - MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
MdeModulePkg/PciBus: Shadow option ROM after BARs are programmed
[mirror_edk2.git] / MdeModulePkg / Bus / Pci / PciBusDxe / PciLib.c
index 4717140255c1bce3970c4e71a9ca160d601d2b88..7255bcfbbcea2d06f95deaeafdc4817386b13ded 100644 (file)
@@ -1,7 +1,8 @@
 /** @file\r
   Internal library implementation for PCI Bus module.\r
 \r
-Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>\r
 This program and the accompanying materials\r
 are licensed and made available under the terms and conditions of the BSD License\r
 which accompanies this distribution.  The full text of the license may be found at\r
@@ -14,6 +15,57 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 \r
 #include "PciBus.h"\r
 \r
+GLOBAL_REMOVE_IF_UNREFERENCED\r
+CHAR16 *mBarTypeStr[] = {\r
+  L"Unknow",\r
+  L"  Io16",\r
+  L"  Io32",\r
+  L" Mem32",\r
+  L"PMem32",\r
+  L" Mem64",\r
+  L"PMem64",\r
+  L" OpRom",\r
+  L"    Io",\r
+  L"   Mem",\r
+  L"Unknow"\r
+  };\r
+\r
+/**\r
+  Retrieve the max bus number that is assigned to the Root Bridge hierarchy.\r
+  It can support the case that there are multiple bus ranges.\r
+\r
+  @param  Bridge           Bridge device instance.\r
+\r
+  @retval                  The max bus number that is assigned to this Root Bridge hierarchy.\r
+\r
+**/\r
+UINT16\r
+PciGetMaxBusNumber (\r
+  IN PCI_IO_DEVICE                      *Bridge\r
+  )\r
+{\r
+  PCI_IO_DEVICE                      *RootBridge;\r
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR  *BusNumberRanges;\r
+  UINT64                             MaxNumberInRange;\r
+\r
+  //\r
+  // Get PCI Root Bridge device\r
+  //\r
+  RootBridge = Bridge;\r
+  while (RootBridge->Parent != NULL) {\r
+    RootBridge = RootBridge->Parent;\r
+  }\r
+  MaxNumberInRange = 0;\r
+  //\r
+  // Iterate the bus number ranges to get max PCI bus number\r
+  //\r
+  BusNumberRanges = RootBridge->BusNumberRanges;\r
+  while (BusNumberRanges->Desc != ACPI_END_TAG_DESCRIPTOR) {\r
+    MaxNumberInRange = BusNumberRanges->AddrRangeMin + BusNumberRanges->AddrLen - 1;\r
+    BusNumberRanges++;\r
+  }\r
+  return (UINT16) MaxNumberInRange;\r
+}\r
 \r
 /**\r
   Retrieve the PCI Card device BAR information via PciIo interface.\r
@@ -153,6 +205,184 @@ RemoveRejectedPciDevices (
   }\r
 }\r
 \r
+/**\r
+  Dump the resourc map of the bridge device.\r
+\r
+  @param[in] BridgeResource   Resource descriptor of the bridge device.\r
+**/\r
+VOID\r
+DumpBridgeResource (\r
+  IN PCI_RESOURCE_NODE     *BridgeResource\r
+  )\r
+{\r
+  LIST_ENTRY               *Link;\r
+  PCI_RESOURCE_NODE        *Resource;\r
+  PCI_BAR                  *Bar;\r
+\r
+  if ((BridgeResource != NULL) && (BridgeResource->Length != 0)) {\r
+    DEBUG ((\r
+      EFI_D_INFO, "Type = %s; Base = 0x%lx;\tLength = 0x%lx;\tAlignment = 0x%lx\n",\r
+      mBarTypeStr[MIN (BridgeResource->ResType, PciBarTypeMaxType)],\r
+      BridgeResource->PciDev->PciBar[BridgeResource->Bar].BaseAddress,\r
+      BridgeResource->Length, BridgeResource->Alignment\r
+      ));\r
+    for ( Link = GetFirstNode (&BridgeResource->ChildList)\r
+        ; !IsNull (&BridgeResource->ChildList, Link)\r
+        ; Link = GetNextNode (&BridgeResource->ChildList, Link)\r
+        ) {\r
+      Resource = RESOURCE_NODE_FROM_LINK (Link);\r
+      if (Resource->ResourceUsage == PciResUsageTypical) {\r
+        Bar = Resource->Virtual ? Resource->PciDev->VfPciBar : Resource->PciDev->PciBar;\r
+        DEBUG ((\r
+          EFI_D_INFO, "   Base = 0x%lx;\tLength = 0x%lx;\tAlignment = 0x%lx;\tOwner = %s [%02x|%02x|%02x:",\r
+          Bar[Resource->Bar].BaseAddress, Resource->Length, Resource->Alignment,\r
+          IS_PCI_BRIDGE (&Resource->PciDev->Pci)     ? L"PPB" :\r
+          IS_CARDBUS_BRIDGE (&Resource->PciDev->Pci) ? L"P2C" :\r
+                                                       L"PCI",\r
+          Resource->PciDev->BusNumber, Resource->PciDev->DeviceNumber,\r
+          Resource->PciDev->FunctionNumber\r
+          ));\r
+\r
+        if ((!IS_PCI_BRIDGE (&Resource->PciDev->Pci) && !IS_CARDBUS_BRIDGE (&Resource->PciDev->Pci)) ||\r
+            (IS_PCI_BRIDGE (&Resource->PciDev->Pci) && (Resource->Bar < PPB_IO_RANGE)) ||\r
+            (IS_CARDBUS_BRIDGE (&Resource->PciDev->Pci) && (Resource->Bar < P2C_MEM_1))\r
+            ) {\r
+          //\r
+          // The resource requirement comes from the device itself.\r
+          //\r
+          DEBUG ((EFI_D_INFO, "%02x]", Bar[Resource->Bar].Offset));\r
+        } else {\r
+          //\r
+          // The resource requirement comes from the subordinate devices.\r
+          //\r
+          DEBUG ((EFI_D_INFO, "**]"));\r
+        }\r
+      } else {\r
+        DEBUG ((EFI_D_INFO, "   Base = Padding;\tLength = 0x%lx;\tAlignment = 0x%lx", Resource->Length, Resource->Alignment));\r
+      }\r
+      if (BridgeResource->ResType != Resource->ResType) {\r
+        DEBUG ((EFI_D_INFO, "; Type = %s", mBarTypeStr[MIN (Resource->ResType, PciBarTypeMaxType)]));\r
+      }\r
+      DEBUG ((EFI_D_INFO, "\n"));\r
+    }\r
+  }\r
+}\r
+\r
+/**\r
+  Find the corresponding resource node for the Device in child list of BridgeResource.\r
+\r
+  @param[in]  Device          Pointer to PCI_IO_DEVICE.\r
+  @param[in]  BridgeResource  Pointer to PCI_RESOURCE_NODE.\r
+  @param[out] DeviceResources Pointer to a buffer to receive resources for the Device.\r
+\r
+  @return Count of the resource descriptors returned.\r
+**/\r
+UINTN\r
+FindResourceNode (\r
+  IN  PCI_IO_DEVICE     *Device,\r
+  IN  PCI_RESOURCE_NODE *BridgeResource,\r
+  OUT PCI_RESOURCE_NODE **DeviceResources OPTIONAL\r
+  )\r
+{\r
+  LIST_ENTRY               *Link;\r
+  PCI_RESOURCE_NODE        *Resource;\r
+  UINTN                    Count;\r
+\r
+  Count = 0;\r
+  for ( Link = BridgeResource->ChildList.ForwardLink\r
+      ; Link != &BridgeResource->ChildList\r
+      ; Link = Link->ForwardLink\r
+      ) {\r
+    Resource = RESOURCE_NODE_FROM_LINK (Link);\r
+    if (Resource->PciDev == Device) {\r
+      if (DeviceResources != NULL) {\r
+        DeviceResources[Count] = Resource;\r
+      }\r
+      Count++;\r
+    }\r
+  }\r
+\r
+  return Count;\r
+}\r
+\r
+/**\r
+  Dump the resource map of all the devices under Bridge.\r
+\r
+  @param[in] Bridge        Bridge device instance.\r
+  @param[in] Resources     Resource descriptors for the bridge device.\r
+  @param[in] ResourceCount Count of resource descriptors.\r
+**/\r
+VOID\r
+DumpResourceMap (\r
+  IN PCI_IO_DEVICE     *Bridge,\r
+  IN PCI_RESOURCE_NODE **Resources,\r
+  IN UINTN             ResourceCount\r
+  )\r
+{\r
+  EFI_STATUS           Status;\r
+  LIST_ENTRY           *Link;\r
+  PCI_IO_DEVICE        *Device;\r
+  UINTN                Index;\r
+  CHAR16               *Str;\r
+  PCI_RESOURCE_NODE    **ChildResources;\r
+  UINTN                ChildResourceCount;\r
+\r
+  DEBUG ((EFI_D_INFO, "PciBus: Resource Map for "));\r
+\r
+  Status = gBS->OpenProtocol (\r
+                  Bridge->Handle,\r
+                  &gEfiPciRootBridgeIoProtocolGuid,\r
+                  NULL,\r
+                  NULL,\r
+                  NULL,\r
+                  EFI_OPEN_PROTOCOL_TEST_PROTOCOL\r
+                  );\r
+  if (EFI_ERROR (Status)) {\r
+    DEBUG ((\r
+      EFI_D_INFO, "Bridge [%02x|%02x|%02x]\n",\r
+      Bridge->BusNumber, Bridge->DeviceNumber, Bridge->FunctionNumber\r
+      ));\r
+  } else {\r
+    Str = ConvertDevicePathToText (\r
+            DevicePathFromHandle (Bridge->Handle),\r
+            FALSE,\r
+            FALSE\r
+            );\r
+    DEBUG ((EFI_D_INFO, "Root Bridge %s\n", Str != NULL ? Str : L""));\r
+    if (Str != NULL) {\r
+      FreePool (Str);\r
+    }\r
+  }\r
+\r
+  for (Index = 0; Index < ResourceCount; Index++) {\r
+    DumpBridgeResource (Resources[Index]);\r
+  }\r
+  DEBUG ((EFI_D_INFO, "\n"));\r
+\r
+  for ( Link = Bridge->ChildList.ForwardLink\r
+      ; Link != &Bridge->ChildList\r
+      ; Link = Link->ForwardLink\r
+      ) {\r
+    Device = PCI_IO_DEVICE_FROM_LINK (Link);\r
+    if (IS_PCI_BRIDGE (&Device->Pci)) {\r
+\r
+      ChildResourceCount = 0;\r
+      for (Index = 0; Index < ResourceCount; Index++) {\r
+        ChildResourceCount += FindResourceNode (Device, Resources[Index], NULL);\r
+      }\r
+      ChildResources = AllocatePool (sizeof (PCI_RESOURCE_NODE *) * ChildResourceCount);\r
+      ASSERT (ChildResources != NULL);\r
+      ChildResourceCount = 0;\r
+      for (Index = 0; Index < ResourceCount; Index++) {\r
+        ChildResourceCount += FindResourceNode (Device, Resources[Index], &ChildResources[ChildResourceCount]);\r
+      }\r
+\r
+      DumpResourceMap (Device, ChildResources, ChildResourceCount);\r
+      FreePool (ChildResources);\r
+    }\r
+  }\r
+}\r
+\r
 /**\r
   Submits the I/O and memory resource requirements for the specified PCI Host Bridge.\r
 \r
@@ -196,15 +426,9 @@ PciHostBridgeResourceAllocator (
   PCI_RESOURCE_NODE                              PMem32Pool;\r
   PCI_RESOURCE_NODE                              Mem64Pool;\r
   PCI_RESOURCE_NODE                              PMem64Pool;\r
-  BOOLEAN                                        ReAllocate;\r
   EFI_DEVICE_HANDLE_EXTENDED_DATA_PAYLOAD        HandleExtendedData;\r
   EFI_RESOURCE_ALLOC_FAILURE_ERROR_DATA_PAYLOAD  AllocFailExtendedData;\r
 \r
-  //\r
-  // Reallocate flag\r
-  //\r
-  ReAllocate = FALSE;\r
-\r
   //\r
   // It may try several times if the resource allocation fails\r
   //\r
@@ -237,14 +461,14 @@ PciHostBridgeResourceAllocator (
       //\r
 \r
       //\r
-      // If non-stardard PCI Bridge I/O window alignment is supported,\r
+      // If non-standard PCI Bridge I/O window alignment is supported,\r
       // set I/O aligment to minimum possible alignment for root bridge.\r
       //\r
       IoBridge = CreateResourceNode (\r
                    RootBridgeDev,\r
                    0,\r
                    FeaturePcdGet (PcdPciBridgeIoAlignmentProbe) ? 0x1FF: 0xFFF,\r
-                   0,\r
+                   RB_IO_RANGE,\r
                    PciBarTypeIo16,\r
                    PciResUsageTypical\r
                    );\r
@@ -253,7 +477,7 @@ PciHostBridgeResourceAllocator (
                       RootBridgeDev,\r
                       0,\r
                       0xFFFFF,\r
-                      0,\r
+                      RB_MEM32_RANGE,\r
                       PciBarTypeMem32,\r
                       PciResUsageTypical\r
                       );\r
@@ -262,7 +486,7 @@ PciHostBridgeResourceAllocator (
                        RootBridgeDev,\r
                        0,\r
                        0xFFFFF,\r
-                       0,\r
+                       RB_PMEM32_RANGE,\r
                        PciBarTypePMem32,\r
                        PciResUsageTypical\r
                        );\r
@@ -271,7 +495,7 @@ PciHostBridgeResourceAllocator (
                       RootBridgeDev,\r
                       0,\r
                       0xFFFFF,\r
-                      0,\r
+                      RB_MEM64_RANGE,\r
                       PciBarTypeMem64,\r
                       PciResUsageTypical\r
                       );\r
@@ -280,11 +504,22 @@ PciHostBridgeResourceAllocator (
                        RootBridgeDev,\r
                        0,\r
                        0xFFFFF,\r
-                       0,\r
+                       RB_PMEM64_RANGE,\r
                        PciBarTypePMem64,\r
                        PciResUsageTypical\r
                        );\r
 \r
+      //\r
+      // Get the max ROM size that the root bridge can process\r
+      // Insert to resource map so that there will be dedicate MEM32 resource range for Option ROM.\r
+      // All devices' Option ROM share the same MEM32 resource.\r
+      //\r
+      MaxOptionRomSize = GetMaxOptionRomSize (RootBridgeDev);\r
+      RootBridgeDev->PciBar[0].BarType   = PciBarTypeOpRom;\r
+      RootBridgeDev->PciBar[0].Length    = MaxOptionRomSize;\r
+      RootBridgeDev->PciBar[0].Alignment = MaxOptionRomSize - 1;\r
+      GetResourceFromDevice (RootBridgeDev, IoBridge, Mem32Bridge, PMem32Bridge, Mem64Bridge, PMem64Bridge);\r
+\r
       //\r
       // Create resourcemap by going through all the devices subject to this root bridge\r
       //\r
@@ -298,39 +533,7 @@ PciHostBridgeResourceAllocator (
         );\r
 \r
       //\r
-      // Get the max ROM size that the root bridge can process\r
-      //\r
-      RootBridgeDev->RomSize = Mem32Bridge->Length;\r
-\r
-      //\r
-      // Skip to enlarge the resource request during realloction\r
-      //\r
-      if (!ReAllocate) {\r
-        //\r
-        // Get Max Option Rom size for current root bridge\r
-        //\r
-        MaxOptionRomSize = GetMaxOptionRomSize (RootBridgeDev);\r
-\r
-        //\r
-        // Enlarger the mem32 resource to accomdate the option rom\r
-        // if the mem32 resource is not enough to hold the rom\r
-        //\r
-        if (MaxOptionRomSize > Mem32Bridge->Length) {\r
-\r
-          Mem32Bridge->Length     = MaxOptionRomSize;\r
-          RootBridgeDev->RomSize  = MaxOptionRomSize;\r
-\r
-          //\r
-          // Alignment should be adjusted as well\r
-          //\r
-          if (Mem32Bridge->Alignment < MaxOptionRomSize - 1) {\r
-            Mem32Bridge->Alignment = MaxOptionRomSize - 1;\r
-          }\r
-        }\r
-      }\r
-\r
-      //\r
-      // Based on the all the resource tree, contruct ACPI resource node to\r
+      // Based on the all the resource tree, construct ACPI resource node to\r
       // submit the resource aperture to pci host bridge protocol\r
       //\r
       Status = ConstructAcpiResourceRequestor (\r
@@ -361,6 +564,12 @@ PciHostBridgeResourceAllocator (
                                 RootBridgeDev->Handle,\r
                                 AcpiConfig\r
                                 );\r
+        //\r
+        // If SubmitResources returns error, PciBus isn't able to start.\r
+        // It's a fatal error so assertion is added.\r
+        //\r
+        DEBUG ((EFI_D_INFO, "PciBus: HostBridge->SubmitResources() - %r\n", Status));\r
+        ASSERT_EFI_ERROR (Status);\r
       }\r
 \r
       //\r
@@ -391,6 +600,7 @@ PciHostBridgeResourceAllocator (
     // Notify platform to start to program the resource\r
     //\r
     Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeAllocateResources);\r
+    DEBUG ((EFI_D_INFO, "PciBus: HostBridge->NotifyPhase(AllocateResources) - %r\n", Status));\r
     if (!FeaturePcdGet (PcdPciBusHotplugDeviceSupport)) {\r
       //\r
       // If Hot Plug is not supported\r
@@ -524,8 +734,6 @@ PciHostBridgeResourceAllocator (
       if (EFI_ERROR (Status)) {\r
         return Status;\r
       }\r
-\r
-      ReAllocate = TRUE;\r
     }\r
   }\r
   //\r
@@ -537,7 +745,7 @@ PciHostBridgeResourceAllocator (
   //\r
   REPORT_STATUS_CODE_WITH_EXTENDED_DATA (\r
         EFI_PROGRESS_CODE,\r
-        EFI_IO_BUS_PCI | EFI_IOB_PCI_PC_RES_ALLOC,\r
+        EFI_IO_BUS_PCI | EFI_IOB_PCI_RES_ALLOC,\r
         (VOID *) &HandleExtendedData,\r
         sizeof (HandleExtendedData)\r
         );\r
@@ -545,7 +753,11 @@ PciHostBridgeResourceAllocator (
   //\r
   // Notify pci bus driver starts to program the resource\r
   //\r
-  NotifyPhase (PciResAlloc, EfiPciHostBridgeSetResources);\r
+  Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeSetResources);\r
+\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
 \r
   RootBridgeDev     = NULL;\r
 \r
@@ -588,28 +800,21 @@ PciHostBridgeResourceAllocator (
       &PMem64Base\r
       );\r
 \r
-    //\r
-    // Process option rom for this root bridge\r
-    //\r
-    ProcessOptionRom (RootBridgeDev, Mem32Base, RootBridgeDev->RomSize);\r
-\r
     //\r
     // Create the entire system resource map from the information collected by\r
     // enumerator. Several resource tree was created\r
     //\r
-    GetResourceMap (\r
-      RootBridgeDev,\r
-      &IoBridge,\r
-      &Mem32Bridge,\r
-      &PMem32Bridge,\r
-      &Mem64Bridge,\r
-      &PMem64Bridge,\r
-      &IoPool,\r
-      &Mem32Pool,\r
-      &PMem32Pool,\r
-      &Mem64Pool,\r
-      &PMem64Pool\r
-      );\r
+    FindResourceNode (RootBridgeDev, &IoPool, &IoBridge);\r
+    FindResourceNode (RootBridgeDev, &Mem32Pool, &Mem32Bridge);\r
+    FindResourceNode (RootBridgeDev, &PMem32Pool, &PMem32Bridge);\r
+    FindResourceNode (RootBridgeDev, &Mem64Pool, &Mem64Bridge);\r
+    FindResourceNode (RootBridgeDev, &PMem64Pool, &PMem64Bridge);\r
+\r
+    ASSERT (IoBridge     != NULL);\r
+    ASSERT (Mem32Bridge  != NULL);\r
+    ASSERT (PMem32Bridge != NULL);\r
+    ASSERT (Mem64Bridge  != NULL);\r
+    ASSERT (PMem64Bridge != NULL);\r
 \r
     //\r
     // Program IO resources\r
@@ -651,6 +856,39 @@ PciHostBridgeResourceAllocator (
       PMem64Bridge\r
       );\r
 \r
+    //\r
+    // Process Option ROM for this root bridge after all BARs are programmed.\r
+    // The PPB's MEM32 RANGE BAR is re-programmed to the Option ROM BAR Base in order to\r
+    // shadow the Option ROM of the devices under the PPB.\r
+    // After the shadow, Option ROM BAR decoding is turned off and the PPB's MEM32 RANGE\r
+    // BAR is restored back to the original value.\r
+    // The original value is programmed by ProgramResource() above.\r
+    //\r
+    DEBUG ((\r
+      DEBUG_INFO, "Process Option ROM: BAR Base/Length = %lx/%lx\n",\r
+      RootBridgeDev->PciBar[0].BaseAddress, RootBridgeDev->PciBar[0].Length\r
+      ));\r
+    ProcessOptionRom (RootBridgeDev, RootBridgeDev->PciBar[0].BaseAddress, RootBridgeDev->PciBar[0].Length);\r
+\r
+    IoBridge    ->PciDev->PciBar[IoBridge    ->Bar].BaseAddress = IoBase;\r
+    Mem32Bridge ->PciDev->PciBar[Mem32Bridge ->Bar].BaseAddress = Mem32Base;\r
+    PMem32Bridge->PciDev->PciBar[PMem32Bridge->Bar].BaseAddress = PMem32Base;\r
+    Mem64Bridge ->PciDev->PciBar[Mem64Bridge ->Bar].BaseAddress = Mem64Base;\r
+    PMem64Bridge->PciDev->PciBar[PMem64Bridge->Bar].BaseAddress = PMem64Base;\r
+\r
+    //\r
+    // Dump the resource map for current root bridge\r
+    //\r
+    DEBUG_CODE (\r
+      PCI_RESOURCE_NODE *Resources[5];\r
+      Resources[0] = IoBridge;\r
+      Resources[1] = Mem32Bridge;\r
+      Resources[2] = PMem32Bridge;\r
+      Resources[3] = Mem64Bridge;\r
+      Resources[4] = PMem64Bridge;\r
+      DumpResourceMap (RootBridgeDev, Resources, ARRAY_SIZE (Resources));\r
+    );\r
+\r
     FreePool (AcpiConfig);\r
   }\r
 \r
@@ -666,9 +904,67 @@ PciHostBridgeResourceAllocator (
   //\r
   // Notify the resource allocation phase is to end\r
   //\r
-  NotifyPhase (PciResAlloc, EfiPciHostBridgeEndResourceAllocation);\r
+  Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeEndResourceAllocation);\r
 \r
-  return EFI_SUCCESS;\r
+  return Status;\r
+}\r
+\r
+/**\r
+  Allocate NumberOfBuses buses and return the next available PCI bus number.\r
+\r
+  @param  Bridge           Bridge device instance.\r
+  @param  StartBusNumber   Current available PCI bus number.\r
+  @param  NumberOfBuses    Number of buses enumerated below the StartBusNumber.\r
+  @param  NextBusNumber    Next available PCI bus number.\r
+\r
+  @retval EFI_SUCCESS           Available bus number resource is enough. Next available PCI bus number\r
+                                is returned in NextBusNumber.\r
+  @retval EFI_OUT_OF_RESOURCES  Available bus number resource is not enough for allocation.\r
+\r
+**/\r
+EFI_STATUS\r
+PciAllocateBusNumber (\r
+  IN PCI_IO_DEVICE                      *Bridge,\r
+  IN UINT8                              StartBusNumber,\r
+  IN UINT8                              NumberOfBuses,\r
+  OUT UINT8                             *NextBusNumber\r
+  )\r
+{\r
+  PCI_IO_DEVICE                      *RootBridge;\r
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR  *BusNumberRanges;\r
+  UINT8                              NextNumber;\r
+  UINT64                             MaxNumberInRange;\r
+\r
+  //\r
+  // Get PCI Root Bridge device\r
+  //\r
+  RootBridge = Bridge;\r
+  while (RootBridge->Parent != NULL) {\r
+    RootBridge = RootBridge->Parent;\r
+  }\r
+\r
+  //\r
+  // Get next available PCI bus number\r
+  //\r
+  BusNumberRanges = RootBridge->BusNumberRanges;\r
+  while (BusNumberRanges->Desc != ACPI_END_TAG_DESCRIPTOR) {\r
+    MaxNumberInRange = BusNumberRanges->AddrRangeMin + BusNumberRanges->AddrLen - 1;\r
+    if (StartBusNumber >= BusNumberRanges->AddrRangeMin && StartBusNumber <=  MaxNumberInRange) {\r
+      NextNumber = (UINT8)(StartBusNumber + NumberOfBuses);\r
+      while (NextNumber > MaxNumberInRange) {\r
+        ++BusNumberRanges;\r
+        if (BusNumberRanges->Desc == ACPI_END_TAG_DESCRIPTOR) {\r
+          return EFI_OUT_OF_RESOURCES;\r
+        }\r
+        NextNumber = (UINT8)(NextNumber + (BusNumberRanges->AddrRangeMin - (MaxNumberInRange + 1)));\r
+        MaxNumberInRange = BusNumberRanges->AddrRangeMin + BusNumberRanges->AddrLen - 1;\r
+      }\r
+      *NextBusNumber = NextNumber;\r
+      return EFI_SUCCESS;\r
+    }\r
+    BusNumberRanges++;\r
+  }\r
+  return EFI_OUT_OF_RESOURCES;\r
 }\r
 \r
 /**\r
@@ -698,7 +994,8 @@ PciScanBus (
   UINT8                             Device;\r
   UINT8                             Func;\r
   UINT64                            Address;\r
-  UINTN                             SecondBus;\r
+  UINT8                             SecondBus;\r
+  UINT8                             PaddedSubBus;\r
   UINT16                            Register;\r
   UINTN                             HpIndex;\r
   PCI_IO_DEVICE                     *PciDevice;\r
@@ -707,6 +1004,7 @@ PciScanBus (
   UINT64                            PciAddress;\r
   EFI_HPC_PADDING_ATTRIBUTES        Attributes;\r
   EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptors;\r
+  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *NextDescriptors;\r
   UINT16                            BusRange;\r
   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL   *PciRootBridgeIo;\r
   BOOLEAN                           BusPadding;\r
@@ -737,12 +1035,17 @@ PciScanBus (
                 Func\r
                 );\r
 \r
+      if (EFI_ERROR (Status) && Func == 0) {\r
+        //\r
+        // go to next device if there is no Function 0\r
+        //\r
+        break;\r
+      }\r
+\r
       if (EFI_ERROR (Status)) {\r
         continue;\r
       }\r
 \r
-      DEBUG((EFI_D_INFO, "Found DEV(%02d,%02d,%02d)\n", StartBusNumber, Device, Func ));\r
-\r
       //\r
       // Get the PCI device information\r
       //\r
@@ -783,6 +1086,7 @@ PciScanBus (
           // Check if it is a Hotplug PCI controller\r
           //\r
           if (IsRootPciHotPlugController (PciDevice->DevicePath, &HpIndex)) {\r
+            gPciRootHpcData[HpIndex].Found = TRUE;\r
 \r
             if (!gPciRootHpcData[HpIndex].Initialized) {\r
 \r
@@ -839,14 +1143,14 @@ PciScanBus (
           BusPadding = FALSE;\r
           if (gPciHotPlugInit != NULL) {\r
 \r
-            if (IsRootPciHotPlugBus (PciDevice->DevicePath, &HpIndex)) {\r
+            if (IsPciHotPlugBus (PciDevice)) {\r
 \r
               //\r
               // If it is initialized, get the padded bus range\r
               //\r
               Status = gPciHotPlugInit->GetResourcePadding (\r
                                           gPciHotPlugInit,\r
-                                          gPciRootHpcPool[HpIndex].HpbDevicePath,\r
+                                          PciDevice->DevicePath,\r
                                           PciAddress,\r
                                           &State,\r
                                           (VOID **) &Descriptors,\r
@@ -858,8 +1162,9 @@ PciScanBus (
               }\r
 \r
               BusRange = 0;\r
+              NextDescriptors = Descriptors;\r
               Status = PciGetBusRange (\r
-                        &Descriptors,\r
+                        &NextDescriptors,\r
                         NULL,\r
                         NULL,\r
                         &BusRange\r
@@ -867,24 +1172,22 @@ PciScanBus (
 \r
               FreePool (Descriptors);\r
 \r
-              if (EFI_ERROR (Status)) {\r
+              if (!EFI_ERROR (Status)) {\r
+                BusPadding = TRUE;\r
+              } else if (Status != EFI_NOT_FOUND) {\r
+                //\r
+                // EFI_NOT_FOUND is not a real error. It indicates no bus number padding requested.\r
+                //\r
                 return Status;\r
               }\r
-\r
-              BusPadding = TRUE;\r
             }\r
           }\r
         }\r
 \r
-        //\r
-        // Add feature to support customized secondary bus number\r
-        //\r
-        if (*SubBusNumber == 0) {\r
-          *SubBusNumber   = *PaddedBusRange;\r
-          *PaddedBusRange = 0;\r
+        Status = PciAllocateBusNumber (Bridge, *SubBusNumber, 1, SubBusNumber);\r
+        if (EFI_ERROR (Status)) {\r
+          return Status;\r
         }\r
-\r
-        (*SubBusNumber)++;\r
         SecondBus = *SubBusNumber;\r
 \r
         Register  = (UINT16) ((SecondBus << 8) | (UINT16) StartBusNumber);\r
@@ -908,7 +1211,7 @@ PciScanBus (
           // Temporarily initialize SubBusNumber to maximum bus number to ensure the\r
           // PCI configuration transaction to go through any PPB\r
           //\r
-          Register  = 0xFF;\r
+          Register  = PciGetMaxBusNumber (Bridge);\r
           Address   = EFI_PCI_ADDRESS (StartBusNumber, Device, Func, PCI_BRIDGE_SUBORDINATE_BUS_REGISTER_OFFSET);\r
           Status = PciRootBridgeIo->Pci.Write (\r
                                           PciRootBridgeIo,\r
@@ -929,10 +1232,9 @@ PciScanBus (
             EfiPciBeforeChildBusEnumeration\r
             );\r
 \r
-          DEBUG((EFI_D_INFO, "Scan  PPB(%02d,%02d,%02d)\n", PciDevice->BusNumber, PciDevice->DeviceNumber,PciDevice->FunctionNumber));\r
           Status = PciScanBus (\r
                     PciDevice,\r
-                    (UINT8) (SecondBus),\r
+                    SecondBus,\r
                     SubBusNumber,\r
                     PaddedBusRange\r
                     );\r
@@ -948,9 +1250,16 @@ PciScanBus (
           if ((Attributes == EfiPaddingPciRootBridge) &&\r
               (State & EFI_HPC_STATE_ENABLED) != 0    &&\r
               (State & EFI_HPC_STATE_INITIALIZED) != 0) {\r
-            *PaddedBusRange = (UINT8) ((UINT8) (BusRange) +*PaddedBusRange);\r
+            *PaddedBusRange = (UINT8) ((UINT8) (BusRange) + *PaddedBusRange);\r
           } else {\r
-            *SubBusNumber = (UINT8) ((UINT8) (BusRange) +*SubBusNumber);\r
+            //\r
+            // Reserve the larger one between the actual occupied bus number and padded bus number\r
+            //\r
+            Status = PciAllocateBusNumber (PciDevice, SecondBus, (UINT8) (BusRange), &PaddedSubBus);\r
+            if (EFI_ERROR (Status)) {\r
+              return Status;\r
+            }\r
+            *SubBusNumber = MAX (PaddedSubBus, *SubBusNumber);\r
           }\r
         }\r
 \r
@@ -974,7 +1283,10 @@ PciScanBus (
         if (PcdGetBool (PcdSrIovSupport) && PciDevice->SrIovCapabilityOffset != 0) {\r
           if (TempReservedBusNum < PciDevice->ReservedBusNum) {\r
 \r
-            (*SubBusNumber) = (UINT8)((*SubBusNumber) + PciDevice->ReservedBusNum - TempReservedBusNum);\r
+            Status = PciAllocateBusNumber (PciDevice, *SubBusNumber, (UINT8) (PciDevice->ReservedBusNum - TempReservedBusNum), SubBusNumber);\r
+            if (EFI_ERROR (Status)) {\r
+              return Status;\r
+            }\r
             TempReservedBusNum = PciDevice->ReservedBusNum;\r
 \r
             if (Func == 0) {\r
@@ -1035,7 +1347,7 @@ PciRootBridgeP2CProcess (
         //\r
         REPORT_STATUS_CODE_WITH_DEVICE_PATH (\r
           EFI_PROGRESS_CODE,\r
-          EFI_IO_BUS_PCI | EFI_IOB_PCI_PC_HPC_INIT,\r
+          EFI_IO_BUS_PCI | EFI_IOB_PCI_HPC_INIT,\r
           Temp->DevicePath\r
           );\r
 \r
@@ -1154,7 +1466,11 @@ PciHostBridgeEnumerator (
   //\r
   // Notify the bus allocation phase is about to start\r
   //\r
-  NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginBusAllocation);\r
+  Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginBusAllocation);\r
+\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
 \r
   DEBUG((EFI_D_INFO, "PCI Bus First Scanning\n"));\r
   RootBridgeHandle = NULL;\r
@@ -1235,13 +1551,18 @@ PciHostBridgeEnumerator (
     Status = AllRootHPCInitialized (STALL_1_SECOND * 15);\r
 \r
     if (EFI_ERROR (Status)) {\r
+      DEBUG ((EFI_D_ERROR, "Some root HPC failed to initialize\n"));\r
       return Status;\r
     }\r
 \r
     //\r
     // Notify the bus allocation phase is about to start for the 2nd time\r
     //\r
-    NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginBusAllocation);\r
+    Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginBusAllocation);\r
+\r
+    if (EFI_ERROR (Status)) {\r
+      return Status;\r
+    }\r
 \r
     DEBUG((EFI_D_INFO, "PCI Bus Second Scanning\n"));\r
     RootBridgeHandle = NULL;\r
@@ -1279,7 +1600,11 @@ PciHostBridgeEnumerator (
   //\r
   // Notify the resource allocation phase is to start\r
   //\r
-  NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginResourceAllocation);\r
+  Status = NotifyPhase (PciResAlloc, EfiPciHostBridgeBeginResourceAllocation);\r
+\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
 \r
   RootBridgeHandle = NULL;\r
   while (PciResAlloc->GetNextRootBridge (PciResAlloc, &RootBridgeHandle) == EFI_SUCCESS) {\r