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 <Library/MemoryAllocationLib.h>
  19 #include "CpuDxe.h"
  20
  21 #define TT_ATTR_INDX_INVALID    ((UINT32)~0)
  22
  23 STATIC
  24 UINT64
  25 GetFirstPageAttribute (
  26   IN UINT64  *FirstLevelTableAddress,
  27   IN UINTN    TableLevel
  28   )
  29 {
  30   UINT64 FirstEntry;
  31
  32   // Get the first entry of the table
  33   FirstEntry = *FirstLevelTableAddress;
  34
  35   if ((TableLevel != 3) && (FirstEntry & TT_TYPE_MASK) == TT_TYPE_TABLE_ENTRY) {
  36     // Only valid for Levels 0, 1 and 2
  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))) - *StartGcdRegion,
  92               PageAttributeToGcdAttribute (*PrevEntryAttribute));
  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))) - *StartGcdRegion,
 116             PageAttributeToGcdAttribute (*PrevEntryAttribute));
 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   FreePool (MemorySpaceMap);
 126
 127   return BaseAddress + (EntryCount * TT_ADDRESS_AT_LEVEL(TableLevel));
 128 }
 129
 130 EFI_STATUS
 131 SyncCacheConfig (
 132   IN  EFI_CPU_ARCH_PROTOCOL *CpuProtocol
 133   )
 134 {
 135   EFI_STATUS                          Status;
 136   UINT32                              PageAttribute = 0;
 137   UINT64                             *FirstLevelTableAddress;
 138   UINTN                               TableLevel;
 139   UINTN                               TableCount;
 140   UINTN                               NumberOfDescriptors;
 141   EFI_GCD_MEMORY_SPACE_DESCRIPTOR    *MemorySpaceMap;
 142   UINTN                               Tcr;
 143   UINTN                               T0SZ;
 144   UINT64                              BaseAddressGcdRegion;
 145   UINT64                              EndAddressGcdRegion;
 146
 147   // This code assumes MMU is enabled and filed with section translations
 148   ASSERT (ArmMmuEnabled ());
 149
 150   //
 151   // Get the memory space map from GCD
 152   //
 153   MemorySpaceMap = NULL;
 154   Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
 155   ASSERT_EFI_ERROR (Status);
 156
 157   // The GCD implementation maintains its own copy of the state of memory space attributes.  GCD needs
 158   // to know what the initial memory space attributes are.  The CPU Arch. Protocol does not provide a
 159   // GetMemoryAttributes function for GCD to get this so we must resort to calling GCD (as if we were
 160   // a client) to update its copy of the attributes.  This is bad architecture and should be replaced
 161   // with a way for GCD to query the CPU Arch. driver of the existing memory space attributes instead.
 162
 163   // Obtain page table base
 164   FirstLevelTableAddress = (UINT64*)(ArmGetTTBR0BaseAddress ());
 165
 166   // Get Translation Control Register value
 167   Tcr = ArmGetTCR ();
 168   // Get Address Region Size
 169   T0SZ = Tcr & TCR_T0SZ_MASK;
 170
 171   // Get the level of the first table for the indicated Address Region Size
 172   GetRootTranslationTableInfo (T0SZ, &TableLevel, &TableCount);
 173
 174   // First Attribute of the Page Tables
 175   PageAttribute = GetFirstPageAttribute (FirstLevelTableAddress, TableLevel);
 176
 177   // We scan from the start of the memory map (ie: at the address 0x0)
 178   BaseAddressGcdRegion = 0x0;
 179   EndAddressGcdRegion = GetNextEntryAttribute (FirstLevelTableAddress,
 180                                                TableCount, TableLevel,
 181                                                BaseAddressGcdRegion,
 182                                                &PageAttribute, &BaseAddressGcdRegion);
 183
 184   // Update GCD with the last region if valid
 185   if (PageAttribute != TT_ATTR_INDX_INVALID) {
 186     SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
 187         BaseAddressGcdRegion,
 188         EndAddressGcdRegion - BaseAddressGcdRegion,
 189         PageAttributeToGcdAttribute (PageAttribute));
 190   }
 191
 192   FreePool (MemorySpaceMap);
 193
 194   return EFI_SUCCESS;
 195 }
 196
 197 UINT64
 198 EfiAttributeToArmAttribute (
 199   IN UINT64                    EfiAttributes
 200   )
 201 {
 202   UINT64 ArmAttributes;
 203
 204   switch (EfiAttributes & EFI_MEMORY_CACHETYPE_MASK) {
 205   case EFI_MEMORY_UC:
 206     ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY;
 207     break;
 208   case EFI_MEMORY_WC:
 209     ArmAttributes = TT_ATTR_INDX_MEMORY_NON_CACHEABLE;
 210     break;
 211   case EFI_MEMORY_WT:
 212     ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_THROUGH;
 213     break;
 214   case EFI_MEMORY_WB:
 215     ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_BACK;
 216     break;
 217   default:
 218     DEBUG ((EFI_D_ERROR, "EfiAttributeToArmAttribute: 0x%lX attributes is not supported.\n", EfiAttributes));
 219     ASSERT (0);
 220     ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY;
 221   }
 222
 223   // Set the access flag to match the block attributes
 224   ArmAttributes |= TT_AF;
 225
 226   // Determine protection attributes
 227   if (EfiAttributes & EFI_MEMORY_WP) {
 228     ArmAttributes |= TT_AP_RO_RO;
 229   }
 230
 231   // Process eXecute Never attribute
 232   if (EfiAttributes & EFI_MEMORY_XP) {
 233     ArmAttributes |= TT_PXN_MASK;
 234   }
 235
 236   return ArmAttributes;
 237 }
 238
 239 // This function will recursively go down the page table to find the first block address linked to 'BaseAddress'.
 240 // And then the function will identify the size of the region that has the same page table attribute.
 241 EFI_STATUS
 242 GetMemoryRegionRec (
 243   IN     UINT64                  *TranslationTable,
 244   IN     UINTN                    TableLevel,
 245   IN     UINT64                  *LastBlockEntry,
 246   IN OUT UINTN                   *BaseAddress,
 247   OUT    UINTN                   *RegionLength,
 248   OUT    UINTN                   *RegionAttributes
 249   )
 250 {
 251   EFI_STATUS Status;
 252   UINT64    *NextTranslationTable;
 253   UINT64    *BlockEntry;
 254   UINT64     BlockEntryType;
 255   UINT64     EntryType;
 256
 257   if (TableLevel != 3) {
 258     BlockEntryType = TT_TYPE_BLOCK_ENTRY;
 259   } else {
 260     BlockEntryType = TT_TYPE_BLOCK_ENTRY_LEVEL3;
 261   }
 262
 263   // Find the block entry linked to the Base Address
 264   BlockEntry = (UINT64*)TT_GET_ENTRY_FOR_ADDRESS (TranslationTable, TableLevel, *BaseAddress);
 265   EntryType = *BlockEntry & TT_TYPE_MASK;
 266
 267   if ((TableLevel < 3) && (EntryType == TT_TYPE_TABLE_ENTRY)) {
 268     NextTranslationTable = (UINT64*)(*BlockEntry & TT_ADDRESS_MASK_DESCRIPTION_TABLE);
 269
 270     // The entry is a page table, so we go to the next level
 271     Status = GetMemoryRegionRec (
 272         NextTranslationTable, // Address of the next level page table
 273         TableLevel + 1, // Next Page Table level
 274         (UINTN*)TT_LAST_BLOCK_ADDRESS(NextTranslationTable, TT_ENTRY_COUNT),
 275         BaseAddress, RegionLength, RegionAttributes);
 276
 277     // In case of 'Success', it means the end of the block region has been found into the upper
 278     // level translation table
 279     if (!EFI_ERROR(Status)) {
 280       return EFI_SUCCESS;
 281     }
 282   } else if (EntryType == BlockEntryType) {
 283     // We have found the BlockEntry attached to the address. We save its start address (the start
 284     // address might be before the 'BaseAdress') and attributes
 285     *BaseAddress      = *BaseAddress & ~(TT_ADDRESS_AT_LEVEL(TableLevel) - 1);
 286     *RegionLength     = 0;
 287     *RegionAttributes = *BlockEntry & TT_ATTRIBUTES_MASK;
 288   } else {
 289     // We have an 'Invalid' entry
 290     return EFI_UNSUPPORTED;
 291   }
 292
 293   while (BlockEntry <= LastBlockEntry) {
 294     if ((*BlockEntry & TT_ATTRIBUTES_MASK) == *RegionAttributes) {
 295       *RegionLength = *RegionLength + TT_BLOCK_ENTRY_SIZE_AT_LEVEL(TableLevel);
 296     } else {
 297       // In case we have found the end of the region we return success
 298       return EFI_SUCCESS;
 299     }
 300     BlockEntry++;
 301   }
 302
 303   // If we have reached the end of the TranslationTable and we have not found the end of the region then
 304   // we return EFI_NOT_FOUND.
 305   // The caller will continue to look for the memory region at its level
 306   return EFI_NOT_FOUND;
 307 }
 308
 309 EFI_STATUS
 310 GetMemoryRegion (
 311   IN OUT UINTN                   *BaseAddress,
 312   OUT    UINTN                   *RegionLength,
 313   OUT    UINTN                   *RegionAttributes
 314   )
 315 {
 316   EFI_STATUS  Status;
 317   UINT64     *TranslationTable;
 318   UINTN       TableLevel;
 319   UINTN       EntryCount;
 320   UINTN       T0SZ;
 321
 322   ASSERT ((BaseAddress != NULL) && (RegionLength != NULL) && (RegionAttributes != NULL));
 323
 324   TranslationTable = ArmGetTTBR0BaseAddress ();
 325
 326   T0SZ = ArmGetTCR () & TCR_T0SZ_MASK;
 327   // Get the Table info from T0SZ
 328   GetRootTranslationTableInfo (T0SZ, &TableLevel, &EntryCount);
 329
 330   Status = GetMemoryRegionRec (TranslationTable, TableLevel,
 331       (UINTN*)TT_LAST_BLOCK_ADDRESS(TranslationTable, EntryCount),
 332       BaseAddress, RegionLength, RegionAttributes);
 333
 334   // If the region continues up to the end of the root table then GetMemoryRegionRec()
 335   // will return EFI_NOT_FOUND
 336   if (Status == EFI_NOT_FOUND) {
 337     return EFI_SUCCESS;
 338   } else {
 339     return Status;
 340   }
 341 }