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 *  This program and the accompanying materials are licensed and made available
   7 *  under the terms and conditions of the BSD License which accompanies this
   8 *  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
  13 *  IMPLIED.
  14 *
  15 **/
  16
  17 #include <Library/BaseLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Library/DxeServicesTableLib.h>
  20 #include <Library/PcdLib.h>
  21 #include <Library/UefiBootServicesTableLib.h>
  22
  23 #include <Protocol/Cpu.h>
  24 #include <Protocol/FdtClient.h>
  25
  26 EFI_STATUS
  27 EFIAPI
  28 InitializeHighMemDxe (
  29   IN EFI_HANDLE           ImageHandle,
  30   IN EFI_SYSTEM_TABLE     *SystemTable
  31   )
  32 {
  33   FDT_CLIENT_PROTOCOL               *FdtClient;
  34   EFI_CPU_ARCH_PROTOCOL             *Cpu;
  35   EFI_STATUS                        Status, FindNodeStatus;
  36   INT32                             Node;
  37   CONST UINT32                      *Reg;
  38   UINT32                            RegSize;
  39   UINTN                             AddressCells, SizeCells;
  40   UINT64                            CurBase;
  41   UINT64                            CurSize;
  42   UINT64                            Attributes;
  43   EFI_GCD_MEMORY_SPACE_DESCRIPTOR   GcdDescriptor;
  44
  45   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
  46                   (VOID **)&FdtClient);
  47   ASSERT_EFI_ERROR (Status);
  48
  49   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
  50                   (VOID **)&Cpu);
  51   ASSERT_EFI_ERROR (Status);
  52
  53   //
  54   // Check for memory node and add the memory spaces except the lowest one
  55   //
  56   for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,
  57                                      (CONST VOID **) &Reg, &AddressCells,
  58                                      &SizeCells, &RegSize);
  59        !EFI_ERROR (FindNodeStatus);
  60        FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,
  61                                      &Node, (CONST VOID **) &Reg, &AddressCells,
  62                                      &SizeCells, &RegSize)) {
  63     ASSERT (AddressCells <= 2);
  64     ASSERT (SizeCells <= 2);
  65
  66     while (RegSize > 0) {
  67       CurBase = SwapBytes32 (*Reg++);
  68       if (AddressCells > 1) {
  69         CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);
  70       }
  71       CurSize = SwapBytes32 (*Reg++);
  72       if (SizeCells > 1) {
  73         CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);
  74       }
  75       RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
  76
  77       Status = gDS->GetMemorySpaceDescriptor (CurBase, &GcdDescriptor);
  78       if (EFI_ERROR (Status)) {
  79         DEBUG ((DEBUG_WARN,
  80           "%a: Region 0x%lx - 0x%lx not found in the GCD memory space map\n",
  81           __FUNCTION__, CurBase, CurBase + CurSize - 1));
  82           continue;
  83       }
  84       if (GcdDescriptor.GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
  85         Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
  86                         CurSize, EFI_MEMORY_WB);
  87
  88         if (EFI_ERROR (Status)) {
  89           DEBUG ((EFI_D_ERROR,
  90             "%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",
  91             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
  92           continue;
  93         }
  94
  95         Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
  96                         EFI_MEMORY_WB);
  97         if (EFI_ERROR (Status)) {
  98           DEBUG ((DEBUG_WARN,
  99             "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
 100             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
 101         }
 102
 103         //
 104         // Due to the ambiguous nature of the RO/XP GCD memory space attributes,
 105         // it is impossible to add a memory space with the XP attribute in a way
 106         // that does not result in the XP attribute being set on *all* UEFI
 107         // memory map entries that are carved from it, including code regions
 108         // that require executable permissions.
 109         //
 110         // So instead, we never set the RO/XP attributes in the GCD memory space
 111         // capabilities or attribute fields, and apply any protections directly
 112         // on the page table mappings by going through the cpu arch protocol.
 113         //
 114         Attributes = EFI_MEMORY_WB;
 115         if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
 116              (1U << (UINT32)EfiConventionalMemory)) != 0) {
 117           Attributes |= EFI_MEMORY_XP;
 118         }
 119
 120         Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
 121
 122         if (EFI_ERROR (Status)) {
 123           DEBUG ((EFI_D_ERROR,
 124             "%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",
 125             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
 126         } else {
 127           DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",
 128             __FUNCTION__, CurBase, CurBase + CurSize - 1));
 129         }
 130       }
 131     }
 132   }
 133
 134   return EFI_SUCCESS;
 135 }