OvmfPkg/Library/PciHostBridgeLib/PciHostBridgeLib.c

   1 /** @file
   2   OVMF's instance of the PCI Host Bridge Library.
   3
   4   Copyright (C) 2016, Red Hat, Inc.
   5   Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
   6
   7   This program and the accompanying materials are licensed and made available
   8   under the terms and conditions of the BSD License which accompanies this
   9   distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php.
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  13   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16 #include <PiDxe.h>
  17
  18 #include <IndustryStandard/Pci.h>
  19
  20 #include <Protocol/PciRootBridgeIo.h>
  21
  22 #include <Library/BaseMemoryLib.h>
  23 #include <Library/DebugLib.h>
  24 #include <Library/MemoryAllocationLib.h>
  25 #include <Library/PciHostBridgeLib.h>
  26 #include <Library/PciLib.h>
  27 #include <Library/QemuFwCfgLib.h>
  28
  29
  30 GLOBAL_REMOVE_IF_UNREFERENCED
  31 CHAR16 *mPciHostBridgeLibAcpiAddressSpaceTypeStr[] = {
  32   L"Mem", L"I/O", L"Bus"
  33 };
  34
  35
  36 /**
  37   Initialize a PCI_ROOT_BRIDGE structure.
  38
  39   param[in]  RootBusNumber     The bus number to store in RootBus.
  40
  41   param[in]  MaxSubBusNumber   The inclusive maximum bus number that can be
  42                                assigned to any subordinate bus found behind any
  43                                PCI bridge hanging off this root bus.
  44
  45                                The caller is repsonsible for ensuring that
  46                                RootBusNumber <= MaxSubBusNumber. If
  47                                RootBusNumber equals MaxSubBusNumber, then the
  48                                root bus has no room for subordinate buses.
  49
  50   param[out] RootBus           The PCI_ROOT_BRIDGE structure (allocated by the
  51                                caller) that should be filled in by this
  52                                function.
  53
  54   @retval EFI_SUCCESS           Initialization successful. A device path
  55                                 consisting of an ACPI device path node, with
  56                                 UID = RootBusNumber, has been allocated and
  57                                 linked into RootBus.
  58
  59   @retval EFI_OUT_OF_RESOURCES  Memory allocation failed.
  60 **/
  61 STATIC
  62 EFI_STATUS
  63 InitRootBridge (
  64   IN  UINT8           RootBusNumber,
  65   IN  UINT8           MaxSubBusNumber,
  66   OUT PCI_ROOT_BRIDGE *RootBus
  67   )
  68 {
  69   //
  70   // Be safe if other fields are added to PCI_ROOT_BRIDGE later.
  71   //
  72   ZeroMem (RootBus, sizeof *RootBus);
  73
  74   RootBus->Segment = 0;
  75
  76   RootBus->Supports   = EFI_PCI_ATTRIBUTE_IDE_PRIMARY_IO |
  77                         EFI_PCI_ATTRIBUTE_IDE_SECONDARY_IO |
  78                         EFI_PCI_ATTRIBUTE_ISA_IO_16 |
  79                         EFI_PCI_ATTRIBUTE_ISA_MOTHERBOARD_IO |
  80                         EFI_PCI_ATTRIBUTE_VGA_MEMORY |
  81                         EFI_PCI_ATTRIBUTE_VGA_IO_16  |
  82                         EFI_PCI_ATTRIBUTE_VGA_PALETTE_IO_16;
  83   RootBus->Attributes = RootBus->Supports;
  84
  85   return EFI_OUT_OF_RESOURCES;
  86 }
  87
  88
  89 /**
  90   Uninitialize a PCI_ROOT_BRIDGE structure set up with InitRootBridge().
  91
  92   param[in] RootBus  The PCI_ROOT_BRIDGE structure, allocated by the caller and
  93                      initialized with InitRootBridge(), that should be
  94                      uninitialized. This function doesn't free RootBus.
  95 **/
  96 STATIC
  97 VOID
  98 UninitRootBridge (
  99   IN PCI_ROOT_BRIDGE *RootBus
 100   )
 101 {
 102 }
 103
 104
 105 /**
 106   Return all the root bridge instances in an array.
 107
 108   @param Count  Return the count of root bridge instances.
 109
 110   @return All the root bridge instances in an array.
 111           The array should be passed into PciHostBridgeFreeRootBridges()
 112           when it's not used.
 113 **/
 114 PCI_ROOT_BRIDGE *
 115 EFIAPI
 116 PciHostBridgeGetRootBridges (
 117   UINTN *Count
 118   )
 119 {
 120   EFI_STATUS           Status;
 121   FIRMWARE_CONFIG_ITEM FwCfgItem;
 122   UINTN                FwCfgSize;
 123   UINT64               ExtraRootBridges;
 124   PCI_ROOT_BRIDGE      *Bridges;
 125   UINTN                Initialized;
 126   UINTN                LastRootBridgeNumber;
 127   UINTN                RootBridgeNumber;
 128
 129   *Count = 0;
 130
 131   //
 132   // QEMU provides the number of extra root buses, shortening the exhaustive
 133   // search below. If there is no hint, the feature is missing.
 134   //
 135   Status = QemuFwCfgFindFile ("etc/extra-pci-roots", &FwCfgItem, &FwCfgSize);
 136   if (EFI_ERROR (Status) || FwCfgSize != sizeof ExtraRootBridges) {
 137     ExtraRootBridges = 0;
 138   } else {
 139     QemuFwCfgSelectItem (FwCfgItem);
 140     QemuFwCfgReadBytes (FwCfgSize, &ExtraRootBridges);
 141
 142     if (ExtraRootBridges > PCI_MAX_BUS) {
 143       DEBUG ((EFI_D_ERROR, "%a: invalid count of extra root buses (%Lu) "
 144         "reported by QEMU\n", __FUNCTION__, ExtraRootBridges));
 145       return NULL;
 146     }
 147     DEBUG ((EFI_D_INFO, "%a: %Lu extra root buses reported by QEMU\n",
 148       __FUNCTION__, ExtraRootBridges));
 149   }
 150
 151   //
 152   // Allocate the "main" root bridge, and any extra root bridges.
 153   //
 154   Bridges = AllocatePool ((1 + (UINTN)ExtraRootBridges) * sizeof *Bridges);
 155   if (Bridges == NULL) {
 156     DEBUG ((EFI_D_ERROR, "%a: %r\n", __FUNCTION__, EFI_OUT_OF_RESOURCES));
 157     return NULL;
 158   }
 159   Initialized = 0;
 160
 161   //
 162   // The "main" root bus is always there.
 163   //
 164   LastRootBridgeNumber = 0;
 165
 166   //
 167   // Scan all other root buses. If function 0 of any device on a bus returns a
 168   // VendorId register value different from all-bits-one, then that bus is
 169   // alive.
 170   //
 171   for (RootBridgeNumber = 1;
 172        RootBridgeNumber <= PCI_MAX_BUS && Initialized < ExtraRootBridges;
 173        ++RootBridgeNumber) {
 174     UINTN Device;
 175
 176     for (Device = 0; Device <= PCI_MAX_DEVICE; ++Device) {
 177       if (PciRead16 (PCI_LIB_ADDRESS (RootBridgeNumber, Device, 0,
 178                        PCI_VENDOR_ID_OFFSET)) != MAX_UINT16) {
 179         break;
 180       }
 181     }
 182     if (Device <= PCI_MAX_DEVICE) {
 183       //
 184       // Found the next root bus. We can now install the *previous* one,
 185       // because now we know how big a bus number range *that* one has, for any
 186       // subordinate buses that might exist behind PCI bridges hanging off it.
 187       //
 188       Status = InitRootBridge ((UINT8)LastRootBridgeNumber,
 189                  (UINT8)(RootBridgeNumber - 1), &Bridges[Initialized]);
 190       if (EFI_ERROR (Status)) {
 191         goto FreeBridges;
 192       }
 193       ++Initialized;
 194       LastRootBridgeNumber = RootBridgeNumber;
 195     }
 196   }
 197
 198   //
 199   // Install the last root bus (which might be the only, ie. main, root bus, if
 200   // we've found no extra root buses).
 201   //
 202   Status = InitRootBridge ((UINT8)LastRootBridgeNumber, PCI_MAX_BUS,
 203              &Bridges[Initialized]);
 204   if (EFI_ERROR (Status)) {
 205     goto FreeBridges;
 206   }
 207   ++Initialized;
 208
 209   *Count = Initialized;
 210   return Bridges;
 211
 212 FreeBridges:
 213   while (Initialized > 0) {
 214     --Initialized;
 215     UninitRootBridge (&Bridges[Initialized]);
 216   }
 217
 218   FreePool (Bridges);
 219   return NULL;
 220 }
 221
 222
 223 /**
 224   Free the root bridge instances array returned from
 225   PciHostBridgeGetRootBridges().
 226
 227   @param  The root bridge instances array.
 228   @param  The count of the array.
 229 **/
 230 VOID
 231 EFIAPI
 232 PciHostBridgeFreeRootBridges (
 233   PCI_ROOT_BRIDGE *Bridges,
 234   UINTN           Count
 235   )
 236 {
 237   if (Bridges == NULL && Count == 0) {
 238     return;
 239   }
 240   ASSERT (Bridges != NULL && Count > 0);
 241
 242   do {
 243     --Count;
 244     UninitRootBridge (&Bridges[Count]);
 245   } while (Count > 0);
 246
 247   FreePool (Bridges);
 248 }
 249
 250
 251 /**
 252   Inform the platform that the resource conflict happens.
 253
 254   @param HostBridgeHandle Handle of the Host Bridge.
 255   @param Configuration    Pointer to PCI I/O and PCI memory resource
 256                           descriptors. The Configuration contains the resources
 257                           for all the root bridges. The resource for each root
 258                           bridge is terminated with END descriptor and an
 259                           additional END is appended indicating the end of the
 260                           entire resources. The resource descriptor field
 261                           values follow the description in
 262                           EFI_PCI_HOST_BRIDGE_RESOURCE_ALLOCATION_PROTOCOL
 263                           .SubmitResources().
 264 **/
 265 VOID
 266 EFIAPI
 267 PciHostBridgeResourceConflict (
 268   EFI_HANDLE                        HostBridgeHandle,
 269   VOID                              *Configuration
 270   )
 271 {
 272   EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Descriptor;
 273   UINTN                             RootBridgeIndex;
 274   DEBUG ((EFI_D_ERROR, "PciHostBridge: Resource conflict happens!\n"));
 275
 276   RootBridgeIndex = 0;
 277   Descriptor = (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *) Configuration;
 278   while (Descriptor->Desc == ACPI_ADDRESS_SPACE_DESCRIPTOR) {
 279     DEBUG ((EFI_D_ERROR, "RootBridge[%d]:\n", RootBridgeIndex++));
 280     for (; Descriptor->Desc == ACPI_ADDRESS_SPACE_DESCRIPTOR; Descriptor++) {
 281       ASSERT (Descriptor->ResType <
 282               (sizeof (mPciHostBridgeLibAcpiAddressSpaceTypeStr) /
 283                sizeof (mPciHostBridgeLibAcpiAddressSpaceTypeStr[0])
 284                )
 285               );
 286       DEBUG ((EFI_D_ERROR, " %s: Length/Alignment = 0x%lx / 0x%lx\n",
 287               mPciHostBridgeLibAcpiAddressSpaceTypeStr[Descriptor->ResType],
 288               Descriptor->AddrLen, Descriptor->AddrRangeMax
 289               ));
 290       if (Descriptor->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM) {
 291         DEBUG ((EFI_D_ERROR, "     Granularity/SpecificFlag = %ld / %02x%s\n",
 292                 Descriptor->AddrSpaceGranularity, Descriptor->SpecificFlag,
 293                 ((Descriptor->SpecificFlag &
 294                   EFI_ACPI_MEMORY_RESOURCE_SPECIFIC_FLAG_CACHEABLE_PREFETCHABLE
 295                   ) != 0) ? L" (Prefetchable)" : L""
 296                 ));
 297       }
 298     }
 299     //
 300     // Skip the END descriptor for root bridge
 301     //
 302     ASSERT (Descriptor->Desc == ACPI_END_TAG_DESCRIPTOR);
 303     Descriptor = (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *)(
 304                    (EFI_ACPI_END_TAG_DESCRIPTOR *)Descriptor + 1
 305                    );
 306   }
 307 }