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
  44   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
  45                   (VOID **)&FdtClient);
  46   ASSERT_EFI_ERROR (Status);
  47
  48   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
  49                   (VOID **)&Cpu);
  50   ASSERT_EFI_ERROR (Status);
  51
  52   //
  53   // Check for memory node and add the memory spaces except the lowest one
  54   //
  55   for (FindNodeStatus = FdtClient->FindMemoryNodeReg (FdtClient, &Node,
  56                                      (CONST VOID **) &Reg, &AddressCells,
  57                                      &SizeCells, &RegSize);
  58        !EFI_ERROR (FindNodeStatus);
  59        FindNodeStatus = FdtClient->FindNextMemoryNodeReg (FdtClient, Node,
  60                                      &Node, (CONST VOID **) &Reg, &AddressCells,
  61                                      &SizeCells, &RegSize)) {
  62     ASSERT (AddressCells <= 2);
  63     ASSERT (SizeCells <= 2);
  64
  65     while (RegSize > 0) {
  66       CurBase = SwapBytes32 (*Reg++);
  67       if (AddressCells > 1) {
  68         CurBase = (CurBase << 32) | SwapBytes32 (*Reg++);
  69       }
  70       CurSize = SwapBytes32 (*Reg++);
  71       if (SizeCells > 1) {
  72         CurSize = (CurSize << 32) | SwapBytes32 (*Reg++);
  73       }
  74       RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
  75
  76       if (PcdGet64 (PcdSystemMemoryBase) != CurBase) {
  77         Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
  78                         CurSize, EFI_MEMORY_WB);
  79
  80         if (EFI_ERROR (Status)) {
  81           DEBUG ((EFI_D_ERROR,
  82             "%a: Failed to add System RAM @ 0x%lx - 0x%lx (%r)\n",
  83             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
  84           continue;
  85         }
  86
  87         Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
  88                         EFI_MEMORY_WB);
  89         if (EFI_ERROR (Status)) {
  90           DEBUG ((DEBUG_WARN,
  91             "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
  92             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
  93         }
  94
  95         //
  96         // Due to the ambiguous nature of the RO/XP GCD memory space attributes,
  97         // it is impossible to add a memory space with the XP attribute in a way
  98         // that does not result in the XP attribute being set on *all* UEFI
  99         // memory map entries that are carved from it, including code regions
 100         // that require executable permissions.
 101         //
 102         // So instead, we never set the RO/XP attributes in the GCD memory space
 103         // capabilities or attribute fields, and apply any protections directly
 104         // on the page table mappings by going through the cpu arch protocol.
 105         //
 106         Attributes = EFI_MEMORY_WB;
 107         if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
 108              (1U << (UINT32)EfiConventionalMemory)) != 0) {
 109           Attributes |= EFI_MEMORY_XP;
 110         }
 111
 112         Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
 113
 114         if (EFI_ERROR (Status)) {
 115           DEBUG ((EFI_D_ERROR,
 116             "%a: Failed to set System RAM @ 0x%lx - 0x%lx attribute (%r)\n",
 117             __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
 118         } else {
 119           DEBUG ((EFI_D_INFO, "%a: Add System RAM @ 0x%lx - 0x%lx\n",
 120             __FUNCTION__, CurBase, CurBase + CurSize - 1));
 121         }
 122       }
 123     }
 124   }
 125
 126   return EFI_SUCCESS;
 127 }