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     DEBUG ((DEBUG_ERROR, "%a: 'ranges' not found or invalid\n", __FUNCTION__));
  61     return RETURN_PROTOCOL_ERROR;
  62   }
  63
  64   for (RecordIdx = 0; RecordIdx < Len / sizeof (DTB_PCI_HOST_RANGE_RECORD);
  65        ++RecordIdx) {
  66     CONST DTB_PCI_HOST_RANGE_RECORD *Record;
  67     UINT32                          Type;
  68
  69     Record = (CONST DTB_PCI_HOST_RANGE_RECORD *)Prop + RecordIdx;
  70     Type = SwapBytes32 (Record->Type) & DTB_PCI_HOST_RANGE_TYPEMASK;
  71     if (Type == DTB_PCI_HOST_RANGE_IO) {
  72       IoBase = SwapBytes64 (Record->ChildBase);
  73       *IoTranslation = SwapBytes64 (Record->CpuBase) - IoBase;
  74
  75       return RETURN_SUCCESS;
  76     }
  77   }
  78   return RETURN_NOT_FOUND;
  79 }
  80
  81 RETURN_STATUS
  82 EFIAPI
  83 FdtPciPcdProducerLibConstructor (
  84   VOID
  85   )
  86 {
  87   UINT64              PciExpressBaseAddress;
  88   FDT_CLIENT_PROTOCOL *FdtClient;
  89   CONST UINT64        *Reg;
  90   UINT32              RegSize;
  91   EFI_STATUS          Status;
  92   INT32               Node;
  93   RETURN_STATUS       RetStatus;
  94   UINT64              IoTranslation;
  95   RETURN_STATUS       PcdStatus;
  96
  97   PciExpressBaseAddress = PcdGet64 (PcdPciExpressBaseAddress);
  98   if (PciExpressBaseAddress != MAX_UINT64) {
  99     //
 100     // Assume that the fact that PciExpressBaseAddress has been changed from
 101     // its default value of MAX_UINT64 implies that this code has been
 102     // executed already, in the context of another module. That means we can
 103     // assume that PcdPciIoTranslation has been discovered from the DT node
 104     // as well.
 105     //
 106     return EFI_SUCCESS;
 107   }
 108
 109   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
 110                   (VOID **)&FdtClient);
 111   ASSERT_EFI_ERROR (Status);
 112
 113   PciExpressBaseAddress = 0;
 114   Status = FdtClient->FindCompatibleNode (FdtClient, "pci-host-ecam-generic",
 115                         &Node);
 116
 117   if (!EFI_ERROR (Status)) {
 118     Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg",
 119                           (CONST VOID **)&Reg, &RegSize);
 120
 121     if (!EFI_ERROR (Status) && RegSize == 2 * sizeof (UINT64)) {
 122       PciExpressBaseAddress = SwapBytes64 (*Reg);
 123
 124       PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, FALSE);
 125       ASSERT_RETURN_ERROR (PcdStatus);
 126
 127       IoTranslation = 0;
 128       RetStatus = GetPciIoTranslation (FdtClient, Node, &IoTranslation);
 129       if (!RETURN_ERROR (RetStatus)) {
 130           PcdStatus = PcdSet64S (PcdPciIoTranslation, IoTranslation);
 131           ASSERT_RETURN_ERROR (PcdStatus);
 132       } else {
 133         //
 134         // Support for I/O BARs is not mandatory, and so it does not make sense
 135         // to abort in the general case. So leave it up to the actual driver to
 136         // complain about this if it wants to, and just issue a warning here.
 137         //
 138         DEBUG ((DEBUG_WARN,
 139           "%a: 'pci-host-ecam-generic' device encountered with no I/O range\n",
 140           __FUNCTION__));
 141       }
 142     }
 143   }
 144
 145   PcdStatus = PcdSet64S (PcdPciExpressBaseAddress, PciExpressBaseAddress);
 146   ASSERT_RETURN_ERROR (PcdStatus);
 147
 148   return RETURN_SUCCESS;
 149 }