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 Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
   7
   8 This program and the accompanying materials
   9 are licensed and made available under the terms and conditions of the BSD License
  10 which accompanies this distribution.  The full text of the license may be found at
  11 http://opensource.org/licenses/bsd-license.php
  12
  13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16
  17 --*/
  18
  19 #include <Library/MemoryAllocationLib.h>
  20 #include "CpuDxe.h"
  21
  22 #define TT_ATTR_INDX_INVALID    ((UINT32)~0)
  23
  24 STATIC
  25 UINT64
  26 GetFirstPageAttribute (
  27   IN UINT64  *FirstLevelTableAddress,
  28   IN UINTN    TableLevel
  29   )
  30 {
  31   UINT64 FirstEntry;
  32
  33   // Get the first entry of the table
  34   FirstEntry = *FirstLevelTableAddress;
  35
  36   if ((TableLevel != 3) && (FirstEntry & TT_TYPE_MASK) == TT_TYPE_TABLE_ENTRY) {
  37     // Only valid for Levels 0, 1 and 2
  38
  39     // Get the attribute of the subsequent table
  40     return GetFirstPageAttribute ((UINT64*)(FirstEntry & TT_ADDRESS_MASK_DESCRIPTION_TABLE), TableLevel + 1);
  41   } else if (((FirstEntry & TT_TYPE_MASK) == TT_TYPE_BLOCK_ENTRY) ||
  42              ((TableLevel == 3) && ((FirstEntry & TT_TYPE_MASK) == TT_TYPE_BLOCK_ENTRY_LEVEL3)))
  43   {
  44     return FirstEntry & TT_ATTR_INDX_MASK;
  45   } else {
  46     return TT_ATTR_INDX_INVALID;
  47   }
  48 }
  49
  50 STATIC
  51 UINT64
  52 GetNextEntryAttribute (
  53   IN     UINT64 *TableAddress,
  54   IN     UINTN   EntryCount,
  55   IN     UINTN   TableLevel,
  56   IN     UINT64  BaseAddress,
  57   IN OUT UINT32 *PrevEntryAttribute,
  58   IN OUT UINT64 *StartGcdRegion
  59   )
  60 {
  61   UINTN                             Index;
  62   UINT64                            Entry;
  63   UINT32                            EntryAttribute;
  64   UINT32                            EntryType;
  65   EFI_STATUS                        Status;
  66   UINTN                             NumberOfDescriptors;
  67   EFI_GCD_MEMORY_SPACE_DESCRIPTOR  *MemorySpaceMap;
  68
  69   // Get the memory space map from GCD
  70   MemorySpaceMap = NULL;
  71   Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
  72   ASSERT_EFI_ERROR (Status);
  73
  74   // We cannot get more than 3-level page table
  75   ASSERT (TableLevel <= 3);
  76
  77   // While the top level table might not contain TT_ENTRY_COUNT entries;
  78   // the subsequent ones should be filled up
  79   for (Index = 0; Index < EntryCount; Index++) {
  80     Entry = TableAddress[Index];
  81     EntryType = Entry & TT_TYPE_MASK;
  82     EntryAttribute = Entry  & TT_ATTR_INDX_MASK;
  83
  84     // If Entry is a Table Descriptor type entry then go through the sub-level table
  85     if ((EntryType == TT_TYPE_BLOCK_ENTRY) ||
  86         ((TableLevel == 3) && (EntryType == TT_TYPE_BLOCK_ENTRY_LEVEL3))) {
  87       if ((*PrevEntryAttribute == TT_ATTR_INDX_INVALID) || (EntryAttribute != *PrevEntryAttribute)) {
  88         if (*PrevEntryAttribute != TT_ATTR_INDX_INVALID) {
  89           // Update GCD with the last region
  90           SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
  91               *StartGcdRegion,
  92               (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel))) - *StartGcdRegion,
  93               PageAttributeToGcdAttribute (*PrevEntryAttribute));
  94         }
  95
  96         // Start of the new region
  97         *StartGcdRegion = BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel));
  98         *PrevEntryAttribute = EntryAttribute;
  99       } else {
 100         continue;
 101       }
 102     } else if (EntryType == TT_TYPE_TABLE_ENTRY) {
 103       // Table Entry type is only valid for Level 0, 1, 2
 104       ASSERT (TableLevel < 3);
 105
 106       // Increase the level number and scan the sub-level table
 107       GetNextEntryAttribute ((UINT64*)(Entry & TT_ADDRESS_MASK_DESCRIPTION_TABLE),
 108                              TT_ENTRY_COUNT, TableLevel + 1,
 109                              (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel))),
 110                              PrevEntryAttribute, StartGcdRegion);
 111     } else {
 112       if (*PrevEntryAttribute != TT_ATTR_INDX_INVALID) {
 113         // Update GCD with the last region
 114         SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
 115             *StartGcdRegion,
 116             (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel))) - *StartGcdRegion,
 117             PageAttributeToGcdAttribute (*PrevEntryAttribute));
 118
 119         // Start of the new region
 120         *StartGcdRegion = BaseAddress + (Index * TT_ADDRESS_AT_LEVEL(TableLevel));
 121         *PrevEntryAttribute = TT_ATTR_INDX_INVALID;
 122       }
 123     }
 124   }
 125
 126   FreePool (MemorySpaceMap);
 127
 128   return BaseAddress + (EntryCount * TT_ADDRESS_AT_LEVEL(TableLevel));
 129 }
 130
 131 EFI_STATUS
 132 SyncCacheConfig (
 133   IN  EFI_CPU_ARCH_PROTOCOL *CpuProtocol
 134   )
 135 {
 136   EFI_STATUS                          Status;
 137   UINT32                              PageAttribute = 0;
 138   UINT64                             *FirstLevelTableAddress;
 139   UINTN                               TableLevel;
 140   UINTN                               TableCount;
 141   UINTN                               NumberOfDescriptors;
 142   EFI_GCD_MEMORY_SPACE_DESCRIPTOR    *MemorySpaceMap;
 143   UINTN                               Tcr;
 144   UINTN                               T0SZ;
 145   UINT64                              BaseAddressGcdRegion;
 146   UINT64                              EndAddressGcdRegion;
 147
 148   // This code assumes MMU is enabled and filed with section translations
 149   ASSERT (ArmMmuEnabled ());
 150
 151   //
 152   // Get the memory space map from GCD
 153   //
 154   MemorySpaceMap = NULL;
 155   Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
 156   ASSERT_EFI_ERROR (Status);
 157
 158   // The GCD implementation maintains its own copy of the state of memory space attributes.  GCD needs
 159   // to know what the initial memory space attributes are.  The CPU Arch. Protocol does not provide a
 160   // GetMemoryAttributes function for GCD to get this so we must resort to calling GCD (as if we were
 161   // a client) to update its copy of the attributes.  This is bad architecture and should be replaced
 162   // with a way for GCD to query the CPU Arch. driver of the existing memory space attributes instead.
 163
 164   // Obtain page table base
 165   FirstLevelTableAddress = (UINT64*)(ArmGetTTBR0BaseAddress ());
 166
 167   // Get Translation Control Register value
 168   Tcr = ArmGetTCR ();
 169   // Get Address Region Size
 170   T0SZ = Tcr & TCR_T0SZ_MASK;
 171
 172   // Get the level of the first table for the indicated Address Region Size
 173   GetRootTranslationTableInfo (T0SZ, &TableLevel, &TableCount);
 174
 175   // First Attribute of the Page Tables
 176   PageAttribute = GetFirstPageAttribute (FirstLevelTableAddress, TableLevel);
 177
 178   // We scan from the start of the memory map (ie: at the address 0x0)
 179   BaseAddressGcdRegion = 0x0;
 180   EndAddressGcdRegion = GetNextEntryAttribute (FirstLevelTableAddress,
 181                                                TableCount, TableLevel,
 182                                                BaseAddressGcdRegion,
 183                                                &PageAttribute, &BaseAddressGcdRegion);
 184
 185   // Update GCD with the last region if valid
 186   if (PageAttribute != TT_ATTR_INDX_INVALID) {
 187     SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors,
 188         BaseAddressGcdRegion,
 189         EndAddressGcdRegion - BaseAddressGcdRegion,
 190         PageAttributeToGcdAttribute (PageAttribute));
 191   }
 192
 193   FreePool (MemorySpaceMap);
 194
 195   return EFI_SUCCESS;
 196 }
 197
 198 UINT64
 199 EfiAttributeToArmAttribute (
 200   IN UINT64                    EfiAttributes
 201   )
 202 {
 203   UINT64 ArmAttributes;
 204
 205   switch (EfiAttributes & EFI_MEMORY_CACHETYPE_MASK) {
 206   case EFI_MEMORY_UC:
 207     if (ArmReadCurrentEL () == AARCH64_EL2) {
 208       ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY | TT_XN_MASK;
 209     } else {
 210       ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY | TT_UXN_MASK | TT_PXN_MASK;
 211     }
 212     break;
 213   case EFI_MEMORY_WC:
 214     ArmAttributes = TT_ATTR_INDX_MEMORY_NON_CACHEABLE;
 215     break;
 216   case EFI_MEMORY_WT:
 217     ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_THROUGH | TT_SH_INNER_SHAREABLE;
 218     break;
 219   case EFI_MEMORY_WB:
 220     ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_BACK | TT_SH_INNER_SHAREABLE;
 221     break;
 222   default:
 223     ArmAttributes = TT_ATTR_INDX_MASK;
 224   }
 225
 226   // Set the access flag to match the block attributes
 227   ArmAttributes |= TT_AF;
 228
 229   // Determine protection attributes
 230   if (EfiAttributes & EFI_MEMORY_RO) {
 231     ArmAttributes |= TT_AP_RO_RO;
 232   }
 233
 234   // Process eXecute Never attribute
 235   if (EfiAttributes & EFI_MEMORY_XP) {
 236     ArmAttributes |= TT_PXN_MASK;
 237   }
 238
 239   return ArmAttributes;
 240 }
 241
 242 // This function will recursively go down the page table to find the first block address linked to 'BaseAddress'.
 243 // And then the function will identify the size of the region that has the same page table attribute.
 244 EFI_STATUS
 245 GetMemoryRegionRec (
 246   IN     UINT64                  *TranslationTable,
 247   IN     UINTN                    TableLevel,
 248   IN     UINT64                  *LastBlockEntry,
 249   IN OUT UINTN                   *BaseAddress,
 250   OUT    UINTN                   *RegionLength,
 251   OUT    UINTN                   *RegionAttributes
 252   )
 253 {
 254   EFI_STATUS Status;
 255   UINT64    *NextTranslationTable;
 256   UINT64    *BlockEntry;
 257   UINT64     BlockEntryType;
 258   UINT64     EntryType;
 259
 260   if (TableLevel != 3) {
 261     BlockEntryType = TT_TYPE_BLOCK_ENTRY;
 262   } else {
 263     BlockEntryType = TT_TYPE_BLOCK_ENTRY_LEVEL3;
 264   }
 265
 266   // Find the block entry linked to the Base Address
 267   BlockEntry = (UINT64*)TT_GET_ENTRY_FOR_ADDRESS (TranslationTable, TableLevel, *BaseAddress);
 268   EntryType = *BlockEntry & TT_TYPE_MASK;
 269
 270   if ((TableLevel < 3) && (EntryType == TT_TYPE_TABLE_ENTRY)) {
 271     NextTranslationTable = (UINT64*)(*BlockEntry & TT_ADDRESS_MASK_DESCRIPTION_TABLE);
 272
 273     // The entry is a page table, so we go to the next level
 274     Status = GetMemoryRegionRec (
 275         NextTranslationTable, // Address of the next level page table
 276         TableLevel + 1, // Next Page Table level
 277         (UINTN*)TT_LAST_BLOCK_ADDRESS(NextTranslationTable, TT_ENTRY_COUNT),
 278         BaseAddress, RegionLength, RegionAttributes);
 279
 280     // In case of 'Success', it means the end of the block region has been found into the upper
 281     // level translation table
 282     if (!EFI_ERROR(Status)) {
 283       return EFI_SUCCESS;
 284     }
 285
 286     // Now we processed the table move to the next entry
 287     BlockEntry++;
 288   } else if (EntryType == BlockEntryType) {
 289     // We have found the BlockEntry attached to the address. We save its start address (the start
 290     // address might be before the 'BaseAdress') and attributes
 291     *BaseAddress      = *BaseAddress & ~(TT_ADDRESS_AT_LEVEL(TableLevel) - 1);
 292     *RegionLength     = 0;
 293     *RegionAttributes = *BlockEntry & TT_ATTRIBUTES_MASK;
 294   } else {
 295     // We have an 'Invalid' entry
 296     return EFI_UNSUPPORTED;
 297   }
 298
 299   while (BlockEntry <= LastBlockEntry) {
 300     if ((*BlockEntry & TT_ATTRIBUTES_MASK) == *RegionAttributes) {
 301       *RegionLength = *RegionLength + TT_BLOCK_ENTRY_SIZE_AT_LEVEL(TableLevel);
 302     } else {
 303       // In case we have found the end of the region we return success
 304       return EFI_SUCCESS;
 305     }
 306     BlockEntry++;
 307   }
 308
 309   // If we have reached the end of the TranslationTable and we have not found the end of the region then
 310   // we return EFI_NOT_FOUND.
 311   // The caller will continue to look for the memory region at its level
 312   return EFI_NOT_FOUND;
 313 }
 314
 315 EFI_STATUS
 316 GetMemoryRegion (
 317   IN OUT UINTN                   *BaseAddress,
 318   OUT    UINTN                   *RegionLength,
 319   OUT    UINTN                   *RegionAttributes
 320   )
 321 {
 322   EFI_STATUS  Status;
 323   UINT64     *TranslationTable;
 324   UINTN       TableLevel;
 325   UINTN       EntryCount;
 326   UINTN       T0SZ;
 327
 328   ASSERT ((BaseAddress != NULL) && (RegionLength != NULL) && (RegionAttributes != NULL));
 329
 330   TranslationTable = ArmGetTTBR0BaseAddress ();
 331
 332   T0SZ = ArmGetTCR () & TCR_T0SZ_MASK;
 333   // Get the Table info from T0SZ
 334   GetRootTranslationTableInfo (T0SZ, &TableLevel, &EntryCount);
 335
 336   Status = GetMemoryRegionRec (TranslationTable, TableLevel,
 337       (UINTN*)TT_LAST_BLOCK_ADDRESS(TranslationTable, EntryCount),
 338       BaseAddress, RegionLength, RegionAttributes);
 339
 340   // If the region continues up to the end of the root table then GetMemoryRegionRec()
 341   // will return EFI_NOT_FOUND
 342   if (Status == EFI_NOT_FOUND) {
 343     return EFI_SUCCESS;
 344   } else {
 345     return Status;
 346   }
 347 }