ArmVirtPkg/HighMemDxe/HighMemDxe.c

   1 /** @file
   2 *  High memory node enumeration DXE driver for ARM Virtual Machines
   3 *
   4 *  Copyright (c) 2015-2016, Linaro Ltd. All rights reserved.
   5 *
   6 *  SPDX-License-Identifier: BSD-2-Clause-Patent
   7 *
   8 **/
   9
  10 #include <Library/BaseLib.h>
  11 #include <Library/DebugLib.h>
  12 #include <Library/DxeServicesTableLib.h>
  13 #include <Library/PcdLib.h>
  14 #include <Library/UefiBootServicesTableLib.h>
  15
  16 #include <Protocol/Cpu.h>
  17 #include <Protocol/FdtClient.h>
  18
  19 EFI_STATUS
  20 EFIAPI
  21 InitializeHighMemDxe (
  22   IN EFI_HANDLE           ImageHandle,
  23   IN EFI_SYSTEM_TABLE     *SystemTable
  24   )
  25 {
  26   FDT_CLIENT_PROTOCOL               *FdtClient;
  27   EFI_CPU_ARCH_PROTOCOL             *Cpu;
  28   EFI_STATUS                        Status, FindNodeStatus;
  29   INT32                             Node;
  30   CONST UINT32                      *Reg;
  31   UINT32                            RegSize;
  32   UINTN                             AddressCells, SizeCells;
  33   UINT64                            CurBase;
  34   UINT64                            CurSize;
  35   UINT64                            Attributes;
  36   EFI_GCD_MEMORY_SPACE_DESCRIPTOR   GcdDescriptor;
  37
  38   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
  39                   (VOID **)&FdtClient);
  40   ASSERT_EFI_ERROR (Status);
  41
  42   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
  43                   (VOID **)&Cpu);
  44   ASSERT_EFI_ERROR (Status);
  45
  46   //
  47   // Check for memory node and add the memory spaces except the lowest one
  48   //
  49   for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,
  50                                      (CONST VOID **) &Reg, &AddressCells,
  51                                      &SizeCells, &RegSize);
  52        !EFI_ERROR (FindNodeStatus);
  53        FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,
  54                                      &Node, (CONST VOID **) &Reg, &AddressCells,
  55                                      &SizeCells, &RegSize)) {
  56     ASSERT (AddressCells <= 2);
  57     ASSERT (SizeCells <= 2);
  58
  59     while (RegSize > 0) {
  60       CurBase = SwapBytes32 (*Reg++);
  61       if (AddressCells > 1) {
  62         CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);
  63       }
  64       CurSize = SwapBytes32 (*Reg++);
  65       if (SizeCells > 1) {
  66         CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);
  67       }
  68       RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
  69
  70       Status = gDS->GetMemorySpaceDescriptor (CurBase, &GcdDescriptor);
  71       if (EFI_ERROR (Status)) {
  72         DEBUG ((DEBUG_WARN,
  73           "%a: Region 0x%lx - 0x%lx not found in the GCD memory space map\n",
  74           __FUNCTION__, CurBase, CurBase + CurSize - 1));
  75           continue;
  76       }
  77       if (GcdDescriptor.GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
  78         Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
  79                         CurSize, EFI_MEMORY_WB);
  80
  81         if (EFI_ERROR (Status)) {
  82           DEBUG ((EFI_D_ERROR,
  83             "%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",
  84             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
  85           continue;
  86         }
  87
  88         Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
  89                         EFI_MEMORY_WB);
  90         if (EFI_ERROR (Status)) {
  91           DEBUG ((DEBUG_WARN,
  92             "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
  93             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
  94         }
  95
  96         //
  97         // Due to the ambiguous nature of the RO/XP GCD memory space attributes,
  98         // it is impossible to add a memory space with the XP attribute in a way
  99         // that does not result in the XP attribute being set on *all* UEFI
 100         // memory map entries that are carved from it, including code regions
 101         // that require executable permissions.
 102         //
 103         // So instead, we never set the RO/XP attributes in the GCD memory space
 104         // capabilities or attribute fields, and apply any protections directly
 105         // on the page table mappings by going through the cpu arch protocol.
 106         //
 107         Attributes = EFI_MEMORY_WB;
 108         if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
 109              (1U << (UINT32)EfiConventionalMemory)) != 0) {
 110           Attributes |= EFI_MEMORY_XP;
 111         }
 112
 113         Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
 114
 115         if (EFI_ERROR (Status)) {
 116           DEBUG ((EFI_D_ERROR,
 117             "%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",
 118             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
 119         } else {
 120           DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",
 121             __FUNCTION__, CurBase, CurBase + CurSize - 1));
 122         }
 123       }
 124     }
 125   }
 126
 127   return EFI_SUCCESS;
 128 }