ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c

   1 /*++
   2
   3 Copyright (c) 2009, Hewlett-Packard Company. All rights reserved.<BR>
   4 Portions copyright (c) 2010, Apple Inc. All rights reserved.<BR>
   5 Portions copyright (c) 2011-2013, ARM Ltd. All rights reserved.<BR>
   6
   7 This program and the accompanying materials
   8 are licensed and made available under the terms and conditions of the BSD License
   9 which accompanies this distribution.  The full text of the license may be found at
  10 http://opensource.org/licenses/bsd-license.php
  11
  12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15
  16 --*/
  17
  18 #include "CpuDxe.h"
  19
  20 #define TT_ATTR_INDX_INVALID    ((UINT32)~0)
  21
  22 STATIC
  23 UINT64
  24 GetFirstPageAttribute (
  25   IN UINT64  *FirstLevelTableAddress,
  26   IN UINTN    TableLevel
  27   )
  28 {
  29   UINT64 FirstEntry;
  30
  31   // Get the first entry of the table
  32   FirstEntry = *FirstLevelTableAddress;
  33
  34   if ((FirstEntry & TT_TYPE_MASK) == TT_TYPE_TABLE_ENTRY) {
  35     // Only valid for Levels 0, 1 and 2
  36     ASSERT (TableLevel < 3);
  37
  38     // Get the attribute of the subsequent table
  39     return GetFirstPageAttribute ((UINT64*)(FirstEntry & TT_ADDRESS_MASK_DESCRIPTION_TABLE), TableLevel + 1);
  40   } else if (((FirstEntry & TT_TYPE_MASK) == TT_TYPE_BLOCK_ENTRY) ||
  41              ((TableLevel == 3) && ((FirstEntry & TT_TYPE_MASK) == TT_TYPE_BLOCK_ENTRY_LEVEL3)))
  42   {
  43     return FirstEntry & TT_ATTR_INDX_MASK;
  44   } else {
  45     return TT_ATTR_INDX_INVALID;
  46   }
  47 }
  48
  49 STATIC
  50 UINT64
  51 GetNextEntryAttribute (
  52   IN     UINT64 *TableAddress,
  53   IN     UINTN   EntryCount,
  54   IN     UINTN   TableLevel,
  55   IN     UINT64  BaseAddress,
  56   IN OUT UINT32 *PrevEntryAttribute,
  57   IN OUT UINT64 *StartGcdRegion
  58   )
  59 {
  60   UINTN                             Index;
  61   UINT64                            Entry;
  62   UINT32                            EntryAttribute;
  63   UINT32                            EntryType;
  64   EFI_STATUS                        Status;
  65   UINTN                             NumberOfDescriptors;
  66   EFI_GCD_MEMORY_SPACE_DESCRIPTOR  *MemorySpaceMap;
  67
  68   // Get the memory space map from GCD
  69   MemorySpaceMap = NULL;
  70   Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
  71   ASSERT_EFI_ERROR (Status);
  72
  73   // We cannot get more than 3-level page table
  74   ASSERT (TableLevel <= 3);
  75
  76   // While the top level table might not contain TT_ENTRY_COUNT entries;
  77   // the subsequent ones should be filled up
  78   for (Index = 0; Index < EntryCount; Index++) {
  79     Entry = TableAddress[Index];
  80     EntryType = Entry & TT_TYPE_MASK;
  81     EntryAttribute = Entry  & TT_ATTR_INDX_MASK;
  82
  83     // If Entry is a Table Descriptor type entry then go through the sub-level table
  84     if ((EntryType == TT_TYPE_BLOCK_ENTRY) ||
  85         ((TableLevel == 3) && (EntryType == TT_TYPE_BLOCK_ENTRY_LEVEL3))) {
  86       if ((*PrevEntryAttribute == TT_ATTR_INDX_INVALID) || (EntryAttribute != *PrevEntryAttribute)) {
  87         if (*PrevEntryAttribute != TT_ATTR_INDX_INVALID) {
  88           // Update GCD with the last region
  89           SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
  90               *StartGcdRegion,
  91               (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel)) - 1) - *StartGcdRegion,
  92               PageAttributeToGcdAttribute (EntryAttribute));
  93         }
  94
  95         // Start of the new region
  96         *StartGcdRegion = BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel));
  97         *PrevEntryAttribute = EntryAttribute;
  98       } else {
  99         continue;
 100       }
 101     } else if (EntryType == TT_TYPE_TABLE_ENTRY) {
 102       // Table Entry type is only valid for Level 0, 1, 2
 103       ASSERT (TableLevel < 3);
 104
 105       // Increase the level number and scan the sub-level table
 106       GetNextEntryAttribute ((UINT64*)(Entry & TT_ADDRESS_MASK_DESCRIPTION_TABLE),
 107                              TT_ENTRY_COUNT, TableLevel + 1,
 108                              (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel))),
 109                              PrevEntryAttribute, StartGcdRegion);
 110     } else {
 111       if (*PrevEntryAttribute != TT_ATTR_INDX_INVALID) {
 112         // Update GCD with the last region
 113         SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
 114             *StartGcdRegion,
 115             (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel)) - 1) - *StartGcdRegion,
 116             PageAttributeToGcdAttribute (EntryAttribute));
 117
 118         // Start of the new region
 119         *StartGcdRegion = BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel));
 120         *PrevEntryAttribute = TT_ATTR_INDX_INVALID;
 121       }
 122     }
 123   }
 124
 125   return BaseAddress + (EntryCount * TT_ADDRESS_AT_LEVEL(TableLevel));
 126 }
 127
 128 EFI_STATUS
 129 SyncCacheConfig (
 130   IN  EFI_CPU_ARCH_PROTOCOL *CpuProtocol
 131   )
 132 {
 133   EFI_STATUS                          Status;
 134   UINT32                              PageAttribute = 0;
 135   UINT64                             *FirstLevelTableAddress;
 136   UINTN                               TableLevel;
 137   UINTN                               TableCount;
 138   UINTN                               NumberOfDescriptors;
 139   EFI_GCD_MEMORY_SPACE_DESCRIPTOR    *MemorySpaceMap;
 140   UINTN                               Tcr;
 141   UINTN                               T0SZ;
 142   UINT64                              BaseAddressGcdRegion;
 143   UINT64                              EndAddressGcdRegion;
 144
 145   // This code assumes MMU is enabled and filed with section translations
 146   ASSERT (ArmMmuEnabled ());
 147
 148   //
 149   // Get the memory space map from GCD
 150   //
 151   MemorySpaceMap = NULL;
 152   Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
 153   ASSERT_EFI_ERROR (Status);
 154
 155   // The GCD implementation maintains its own copy of the state of memory space attributes.  GCD needs
 156   // to know what the initial memory space attributes are.  The CPU Arch. Protocol does not provide a
 157   // GetMemoryAttributes function for GCD to get this so we must resort to calling GCD (as if we were
 158   // a client) to update its copy of the attributes.  This is bad architecture and should be replaced
 159   // with a way for GCD to query the CPU Arch. driver of the existing memory space attributes instead.
 160
 161   // Obtain page table base
 162   FirstLevelTableAddress = (UINT64*)(ArmGetTTBR0BaseAddress ());
 163
 164   // Get Translation Control Register value
 165   Tcr = ArmGetTCR ();
 166   // Get Address Region Size
 167   T0SZ = Tcr & TCR_T0SZ_MASK;
 168
 169   // Get the level of the first table for the indicated Address Region Size
 170   GetRootTranslationTableInfo (T0SZ, &TableLevel, &TableCount);
 171
 172   // First Attribute of the Page Tables
 173   PageAttribute = GetFirstPageAttribute (FirstLevelTableAddress, TableLevel);
 174
 175   // We scan from the start of the memory map (ie: at the address 0x0)
 176   BaseAddressGcdRegion = 0x0;
 177   EndAddressGcdRegion = GetNextEntryAttribute (FirstLevelTableAddress,
 178                                                TableCount, TableLevel,
 179                                                BaseAddressGcdRegion,
 180                                                &PageAttribute, &BaseAddressGcdRegion);
 181
 182   // Update GCD with the last region
 183   SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
 184       BaseAddressGcdRegion,
 185       EndAddressGcdRegion - BaseAddressGcdRegion,
 186       PageAttributeToGcdAttribute (PageAttribute));
 187
 188   return EFI_SUCCESS;
 189 }