ArmVirtPkg/Library/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   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <Uefi.h>
  17
  18 #include <Library/BaseLib.h>
  19 #include <Library/DebugLib.h>
  20 #include <Library/PcdLib.h>
  21 #include <Library/UefiBootServicesTableLib.h>
  22
  23 #include <Protocol/FdtClient.h>
  24
  25 //
  26 // We expect the "ranges" property of "pci-host-ecam-generic" to consist of
  27 // records like this.
  28 //
  29 #pragma pack (1)
  30 typedef struct {
  31   UINT32 Type;
  32   UINT64 ChildBase;
  33   UINT64 CpuBase;
  34   UINT64 Size;
  35 } DTB_PCI_HOST_RANGE_RECORD;
  36 #pragma pack ()
  37
  38 #define DTB_PCI_HOST_RANGE_RELOCATABLE  BIT31
  39 #define DTB_PCI_HOST_RANGE_PREFETCHABLE BIT30
  40 #define DTB_PCI_HOST_RANGE_ALIASED      BIT29
  41 #define DTB_PCI_HOST_RANGE_MMIO32       BIT25
  42 #define DTB_PCI_HOST_RANGE_MMIO64       (BIT25 | BIT24)
  43 #define DTB_PCI_HOST_RANGE_IO           BIT24
  44 #define DTB_PCI_HOST_RANGE_TYPEMASK     (BIT31 | BIT30 | BIT29 | BIT25 | BIT24)
  45
  46 STATIC
  47 RETURN_STATUS
  48 GetPciIoTranslation (
  49   IN  FDT_CLIENT_PROTOCOL *FdtClient,
  50   IN  INT32               Node,
  51   OUT UINT64              *IoTranslation
  52   )
  53 {
  54   UINT32        RecordIdx;
  55   CONST VOID    *Prop;
  56   UINT32        Len;
  57   EFI_STATUS    Status;
  58   UINT64        IoBase;
  59
  60   //
  61   // Iterate over "ranges".
  62   //
  63   Status = FdtClient->GetNodeProperty (FdtClient, Node, "ranges", &Prop, &Len);
  64   if (EFI_ERROR (Status) || Len == 0 ||
  65       Len % sizeof (DTB_PCI_HOST_RANGE_RECORD) != 0) {
  66     DEBUG ((EFI_D_ERROR, "%a: 'ranges' not found or invalid\n", __FUNCTION__));
  67     return RETURN_PROTOCOL_ERROR;
  68   }
  69
  70   for (RecordIdx = 0; RecordIdx < Len / sizeof (DTB_PCI_HOST_RANGE_RECORD);
  71        ++RecordIdx) {
  72     CONST DTB_PCI_HOST_RANGE_RECORD *Record;
  73     UINT32                          Type;
  74
  75     Record = (CONST DTB_PCI_HOST_RANGE_RECORD *)Prop + RecordIdx;
  76     Type = SwapBytes32 (Record->Type) & DTB_PCI_HOST_RANGE_TYPEMASK;
  77     if (Type == DTB_PCI_HOST_RANGE_IO) {
  78       IoBase = SwapBytes64 (Record->ChildBase);
  79       *IoTranslation = SwapBytes64 (Record->CpuBase) - IoBase;
  80
  81       return RETURN_SUCCESS;
  82     }
  83   }
  84   return RETURN_NOT_FOUND;
  85 }
  86
  87 RETURN_STATUS
  88 EFIAPI
  89 FdtPciPcdProducerLibConstructor (
  90   VOID
  91   )
  92 {
  93   UINT64              PciExpressBaseAddress;
  94   FDT_CLIENT_PROTOCOL *FdtClient;
  95   CONST UINT64        *Reg;
  96   UINT32              RegSize;
  97   EFI_STATUS          Status;
  98   INT32               Node;
  99   RETURN_STATUS       RetStatus;
 100   UINT64              IoTranslation;
 101   RETURN_STATUS       PcdStatus;
 102
 103   PciExpressBaseAddress = PcdGet64 (PcdPciExpressBaseAddress);
 104   if (PciExpressBaseAddress != MAX_UINT64) {
 105     //
 106     // Assume that the fact that PciExpressBaseAddress has been changed from
 107     // its default value of MAX_UINT64 implies that this code has been
 108     // executed already, in the context of another module. That means we can
 109     // assume that PcdPciIoTranslation has been discovered from the DT node
 110     // as well.
 111     //
 112     return EFI_SUCCESS;
 113   }
 114
 115   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
 116                   (VOID **)&FdtClient);
 117   ASSERT_EFI_ERROR (Status);
 118
 119   PciExpressBaseAddress = 0;
 120   Status = FdtClient->FindCompatibleNode (FdtClient, "pci-host-ecam-generic",
 121                         &Node);
 122
 123   if (!EFI_ERROR (Status)) {
 124     Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg",
 125                           (CONST VOID **)&Reg, &RegSize);
 126
 127     if (!EFI_ERROR (Status) && RegSize == 2 * sizeof (UINT64)) {
 128       PciExpressBaseAddress = SwapBytes64 (*Reg);
 129
 130       PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, FALSE);
 131       ASSERT_RETURN_ERROR (PcdStatus);
 132
 133       IoTranslation = 0;
 134       RetStatus = GetPciIoTranslation (FdtClient, Node, &IoTranslation);
 135       if (!RETURN_ERROR (RetStatus)) {
 136           PcdStatus = PcdSet64S (PcdPciIoTranslation, IoTranslation);
 137           ASSERT_RETURN_ERROR (PcdStatus);
 138       } else {
 139         //
 140         // Support for I/O BARs is not mandatory, and so it does not make sense
 141         // to abort in the general case. So leave it up to the actual driver to
 142         // complain about this if it wants to, and just issue a warning here.
 143         //
 144         DEBUG ((EFI_D_WARN,
 145           "%a: 'pci-host-ecam-generic' device encountered with no I/O range\n",
 146           __FUNCTION__));
 147       }
 148     }
 149   }
 150
 151   PcdStatus = PcdSet64S (PcdPciExpressBaseAddress, PciExpressBaseAddress);
 152   ASSERT_RETURN_ERROR (PcdStatus);
 153
 154   return RETURN_SUCCESS;
 155 }