OvmfPkg/Fdt/FdtPciPcdProducerLib/FdtPciPcdProducerLib.c

   1 /** @file
   2   FDT client library for consumers of PCI related dynamic PCDs
   3
   4   Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include <Uefi.h>
  11
  12 #include <Library/BaseLib.h>
  13 #include <Library/DebugLib.h>
  14 #include <Library/PcdLib.h>
  15 #include <Library/UefiBootServicesTableLib.h>
  16
  17 #include <Protocol/FdtClient.h>
  18
  19 //
  20 // We expect the "ranges" property of "pci-host-ecam-generic" to consist of
  21 // records like this.
  22 //
  23 #pragma pack (1)
  24 typedef struct {
  25   UINT32    Type;
  26   UINT64    ChildBase;
  27   UINT64    CpuBase;
  28   UINT64    Size;
  29 } DTB_PCI_HOST_RANGE_RECORD;
  30 #pragma pack ()
  31
  32 #define DTB_PCI_HOST_RANGE_RELOCATABLE   BIT31
  33 #define DTB_PCI_HOST_RANGE_PREFETCHABLE  BIT30
  34 #define DTB_PCI_HOST_RANGE_ALIASED       BIT29
  35 #define DTB_PCI_HOST_RANGE_MMIO32        BIT25
  36 #define DTB_PCI_HOST_RANGE_MMIO64        (BIT25 | BIT24)
  37 #define DTB_PCI_HOST_RANGE_IO            BIT24
  38 #define DTB_PCI_HOST_RANGE_TYPEMASK      (BIT31 | BIT30 | BIT29 | BIT25 | BIT24)
  39
  40 STATIC
  41 RETURN_STATUS
  42 GetPciIoTranslation (
  43   IN  FDT_CLIENT_PROTOCOL  *FdtClient,
  44   IN  INT32                Node,
  45   OUT UINT64               *IoTranslation
  46   )
  47 {
  48   UINT32      RecordIdx;
  49   CONST VOID  *Prop;
  50   UINT32      Len;
  51   EFI_STATUS  Status;
  52   UINT64      IoBase;
  53
  54   //
  55   // Iterate over "ranges".
  56   //
  57   Status = FdtClient->GetNodeProperty (FdtClient, Node, "ranges", &Prop, &Len);
  58   if (EFI_ERROR (Status) || (Len == 0) ||
  59       (Len % sizeof (DTB_PCI_HOST_RANGE_RECORD) != 0))
  60   {
  61     DEBUG ((DEBUG_ERROR, "%a: 'ranges' not found or invalid\n", __FUNCTION__));
  62     return RETURN_PROTOCOL_ERROR;
  63   }
  64
  65   for (RecordIdx = 0; RecordIdx < Len / sizeof (DTB_PCI_HOST_RANGE_RECORD);
  66        ++RecordIdx)
  67   {
  68     CONST DTB_PCI_HOST_RANGE_RECORD  *Record;
  69     UINT32                           Type;
  70
  71     Record = (CONST DTB_PCI_HOST_RANGE_RECORD *)Prop + RecordIdx;
  72     Type   = SwapBytes32 (Record->Type) & DTB_PCI_HOST_RANGE_TYPEMASK;
  73     if (Type == DTB_PCI_HOST_RANGE_IO) {
  74       IoBase         = SwapBytes64 (Record->ChildBase);
  75       *IoTranslation = SwapBytes64 (Record->CpuBase) - IoBase;
  76
  77       return RETURN_SUCCESS;
  78     }
  79   }
  80
  81   return RETURN_NOT_FOUND;
  82 }
  83
  84 RETURN_STATUS
  85 EFIAPI
  86 FdtPciPcdProducerLibConstructor (
  87   VOID
  88   )
  89 {
  90   UINT64               PciExpressBaseAddress;
  91   FDT_CLIENT_PROTOCOL  *FdtClient;
  92   CONST UINT64         *Reg;
  93   UINT32               RegSize;
  94   EFI_STATUS           Status;
  95   INT32                Node;
  96   RETURN_STATUS        RetStatus;
  97   UINT64               IoTranslation;
  98   RETURN_STATUS        PcdStatus;
  99
 100   PciExpressBaseAddress = PcdGet64 (PcdPciExpressBaseAddress);
 101   if (PciExpressBaseAddress != MAX_UINT64) {
 102     //
 103     // Assume that the fact that PciExpressBaseAddress has been changed from
 104     // its default value of MAX_UINT64 implies that this code has been
 105     // executed already, in the context of another module. That means we can
 106     // assume that PcdPciIoTranslation has been discovered from the DT node
 107     // as well.
 108     //
 109     return EFI_SUCCESS;
 110   }
 111
 112   Status = gBS->LocateProtocol (
 113                   &gFdtClientProtocolGuid,
 114                   NULL,
 115                   (VOID **)&FdtClient
 116                   );
 117   ASSERT_EFI_ERROR (Status);
 118
 119   PciExpressBaseAddress = 0;
 120   Status                = FdtClient->FindCompatibleNode (
 121                                        FdtClient,
 122                                        "pci-host-ecam-generic",
 123                                        &Node
 124                                        );
 125
 126   if (!EFI_ERROR (Status)) {
 127     Status = FdtClient->GetNodeProperty (
 128                           FdtClient,
 129                           Node,
 130                           "reg",
 131                           (CONST VOID **)&Reg,
 132                           &RegSize
 133                           );
 134
 135     if (!EFI_ERROR (Status) && (RegSize == 2 * sizeof (UINT64))) {
 136       PciExpressBaseAddress = SwapBytes64 (*Reg);
 137
 138       PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, FALSE);
 139       ASSERT_RETURN_ERROR (PcdStatus);
 140
 141       IoTranslation = 0;
 142       RetStatus     = GetPciIoTranslation (FdtClient, Node, &IoTranslation);
 143       if (!RETURN_ERROR (RetStatus)) {
 144         PcdStatus = PcdSet64S (PcdPciIoTranslation, IoTranslation);
 145         ASSERT_RETURN_ERROR (PcdStatus);
 146       } else {
 147         //
 148         // Support for I/O BARs is not mandatory, and so it does not make sense
 149         // to abort in the general case. So leave it up to the actual driver to
 150         // complain about this if it wants to, and just issue a warning here.
 151         //
 152         DEBUG ((
 153           DEBUG_WARN,
 154           "%a: 'pci-host-ecam-generic' device encountered with no I/O range\n",
 155           __FUNCTION__
 156           ));
 157       }
 158     }
 159   }
 160
 161   PcdStatus = PcdSet64S (PcdPciExpressBaseAddress, PciExpressBaseAddress);
 162   ASSERT_RETURN_ERROR (PcdStatus);
 163
 164   return RETURN_SUCCESS;
 165 }