[mirror_edk2.git] / MdeModulePkg / Core / DxeIplPeim / X64 / VirtualMemory.c

/** @file\r
  x64 Virtual Memory Management Services in the form of an IA-32 driver.  \r
  Used to establish a 1:1 Virtual to Physical Mapping that is required to\r
  enter Long Mode (x64 64-bit mode).\r
\r
  While we make a 1:1 mapping (identity mapping) for all physical pages \r
  we still need to use the MTRR's to ensure that the cachability attributes\r
  for all memory regions is correct.\r
\r
  The basic idea is to use 2MB page table entries where ever possible. If\r
  more granularity of cachability is required then 4K page tables are used.\r
\r
  References:\r
    1) IA-32 Intel(R) Architecture Software Developer's Manual Volume 1:Basic Architecture, Intel\r
    2) IA-32 Intel(R) Architecture Software Developer's Manual Volume 2:Instruction Set Reference, Intel\r
    3) IA-32 Intel(R) Architecture Software Developer's Manual Volume 3:System Programmer's Guide, Intel\r
\r
Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>\r
Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>\r
\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/  \r
\r
#include "DxeIpl.h"\r
#include "VirtualMemory.h"\r
\r
\r
/**\r
  Enable Execute Disable Bit.\r
\r
**/\r
VOID\r
EnableExecuteDisableBit (\r
  VOID\r
  )\r
{\r
  UINT64           MsrRegisters;\r
\r
  MsrRegisters = AsmReadMsr64 (0xC0000080);\r
  MsrRegisters |= BIT11;\r
  AsmWriteMsr64 (0xC0000080, MsrRegisters);\r
}\r
\r
/**\r
  Split 2M page to 4K.\r
\r
  @param[in]      PhysicalAddress       Start physical address the 2M page covered.\r
  @param[in, out] PageEntry2M           Pointer to 2M page entry.\r
  @param[in]      StackBase             Stack base address.\r
  @param[in]      StackSize             Stack size.\r
\r
**/\r
VOID\r
Split2MPageTo4K (\r
  IN EFI_PHYSICAL_ADDRESS               PhysicalAddress,\r
  IN OUT UINT64                         *PageEntry2M,\r
  IN EFI_PHYSICAL_ADDRESS               StackBase,\r
  IN UINTN                              StackSize\r
  )\r
{\r
  EFI_PHYSICAL_ADDRESS                  PhysicalAddress4K;\r
  UINTN                                 IndexOfPageTableEntries;\r
  PAGE_TABLE_4K_ENTRY                   *PageTableEntry;\r
  UINT64                                AddressEncMask;\r
\r
  //\r
  // Make sure AddressEncMask is contained to smallest supported address field\r
  //\r
  AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
\r
  PageTableEntry = AllocatePages (1);\r
  ASSERT (PageTableEntry != NULL);\r
\r
  //\r
  // Fill in 2M page entry.\r
  //\r
  *PageEntry2M = (UINT64) (UINTN) PageTableEntry | AddressEncMask | IA32_PG_P | IA32_PG_RW;\r
\r
  PhysicalAddress4K = PhysicalAddress;\r
  for (IndexOfPageTableEntries = 0; IndexOfPageTableEntries < 512; IndexOfPageTableEntries++, PageTableEntry++, PhysicalAddress4K += SIZE_4KB) {\r
    //\r
    // Fill in the Page Table entries\r
    //\r
    PageTableEntry->Uint64 = (UINT64) PhysicalAddress4K | AddressEncMask;\r
    PageTableEntry->Bits.ReadWrite = 1;\r
    PageTableEntry->Bits.Present = 1;\r
    if ((PhysicalAddress4K >= StackBase) && (PhysicalAddress4K < StackBase + StackSize)) {\r
      //\r
      // Set Nx bit for stack.\r
      //\r
      PageTableEntry->Bits.Nx = 1;\r
    }\r
  }\r
}\r
\r
/**\r
  Split 1G page to 2M.\r
\r
  @param[in]      PhysicalAddress       Start physical address the 1G page covered.\r
  @param[in, out] PageEntry1G           Pointer to 1G page entry.\r
  @param[in]      StackBase             Stack base address.\r
  @param[in]      StackSize             Stack size.\r
\r
**/\r
VOID\r
Split1GPageTo2M (\r
  IN EFI_PHYSICAL_ADDRESS               PhysicalAddress,\r
  IN OUT UINT64                         *PageEntry1G,\r
  IN EFI_PHYSICAL_ADDRESS               StackBase,\r
  IN UINTN                              StackSize\r
  )\r
{\r
  EFI_PHYSICAL_ADDRESS                  PhysicalAddress2M;\r
  UINTN                                 IndexOfPageDirectoryEntries;\r
  PAGE_TABLE_ENTRY                      *PageDirectoryEntry;\r
  UINT64                                AddressEncMask;\r
\r
  //\r
  // Make sure AddressEncMask is contained to smallest supported address field\r
  //\r
  AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
\r
  PageDirectoryEntry = AllocatePages (1);\r
  ASSERT (PageDirectoryEntry != NULL);\r
\r
  //\r
  // Fill in 1G page entry.\r
  //\r
  *PageEntry1G = (UINT64) (UINTN) PageDirectoryEntry | AddressEncMask | IA32_PG_P | IA32_PG_RW;\r
\r
  PhysicalAddress2M = PhysicalAddress;\r
  for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M += SIZE_2MB) {\r
    if ((PhysicalAddress2M < StackBase + StackSize) && ((PhysicalAddress2M + SIZE_2MB) > StackBase)) {\r
      //\r
      // Need to split this 2M page that covers stack range.\r
      //\r
      Split2MPageTo4K (PhysicalAddress2M, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);\r
    } else {\r
      //\r
      // Fill in the Page Directory entries\r
      //\r
      PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress2M | AddressEncMask;\r
      PageDirectoryEntry->Bits.ReadWrite = 1;\r
      PageDirectoryEntry->Bits.Present = 1;\r
      PageDirectoryEntry->Bits.MustBe1 = 1;\r
    }\r
  }\r
}\r
\r
/**\r
  Allocates and fills in the Page Directory and Page Table Entries to\r
  establish a 1:1 Virtual to Physical mapping.\r
\r
  @param[in] StackBase  Stack base address.\r
  @param[in] StackSize  Stack size.\r
\r
  @return The address of 4 level page map.\r
\r
**/\r
UINTN\r
CreateIdentityMappingPageTables (\r
  IN EFI_PHYSICAL_ADDRESS   StackBase,\r
  IN UINTN                  StackSize\r
  )\r
{  \r
  UINT32                                        RegEax;\r
  UINT32                                        RegEdx;\r
  UINT8                                         PhysicalAddressBits;\r
  EFI_PHYSICAL_ADDRESS                          PageAddress;\r
  UINTN                                         IndexOfPml4Entries;\r
  UINTN                                         IndexOfPdpEntries;\r
  UINTN                                         IndexOfPageDirectoryEntries;\r
  UINT32                                        NumberOfPml4EntriesNeeded;\r
  UINT32                                        NumberOfPdpEntriesNeeded;\r
  PAGE_MAP_AND_DIRECTORY_POINTER                *PageMapLevel4Entry;\r
  PAGE_MAP_AND_DIRECTORY_POINTER                *PageMap;\r
  PAGE_MAP_AND_DIRECTORY_POINTER                *PageDirectoryPointerEntry;\r
  PAGE_TABLE_ENTRY                              *PageDirectoryEntry;\r
  UINTN                                         TotalPagesNum;\r
  UINTN                                         BigPageAddress;\r
  VOID                                          *Hob;\r
  BOOLEAN                                       Page1GSupport;\r
  PAGE_TABLE_1G_ENTRY                           *PageDirectory1GEntry;\r
  UINT64                                        AddressEncMask;\r
\r
  //\r
  // Make sure AddressEncMask is contained to smallest supported address field\r
  //\r
  AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
\r
  Page1GSupport = FALSE;\r
  if (PcdGetBool(PcdUse1GPageTable)) {\r
    AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);\r
    if (RegEax >= 0x80000001) {\r
      AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);\r
      if ((RegEdx & BIT26) != 0) {\r
        Page1GSupport = TRUE;\r
      }\r
    }\r
  }\r
\r
  //\r
  // Get physical address bits supported.\r
  //\r
  Hob = GetFirstHob (EFI_HOB_TYPE_CPU);\r
  if (Hob != NULL) {\r
    PhysicalAddressBits = ((EFI_HOB_CPU *) Hob)->SizeOfMemorySpace;\r
  } else {\r
    AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);\r
    if (RegEax >= 0x80000008) {\r
      AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);\r
      PhysicalAddressBits = (UINT8) RegEax;\r
    } else {\r
      PhysicalAddressBits = 36;\r
    }\r
  }\r
\r
  //\r
  // IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses.\r
  //\r
  ASSERT (PhysicalAddressBits <= 52);\r
  if (PhysicalAddressBits > 48) {\r
    PhysicalAddressBits = 48;\r
  }\r
\r
  //\r
  // Calculate the table entries needed.\r
  //\r
  if (PhysicalAddressBits <= 39 ) {\r
    NumberOfPml4EntriesNeeded = 1;\r
    NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30));\r
  } else {\r
    NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 39));\r
    NumberOfPdpEntriesNeeded = 512;\r
  }\r
\r
  //\r
  // Pre-allocate big pages to avoid later allocations. \r
  //\r
  if (!Page1GSupport) {\r
    TotalPagesNum = (NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1;\r
  } else {\r
    TotalPagesNum = NumberOfPml4EntriesNeeded + 1;\r
  }\r
  BigPageAddress = (UINTN) AllocatePages (TotalPagesNum);\r
  ASSERT (BigPageAddress != 0);\r
\r
  //\r
  // By architecture only one PageMapLevel4 exists - so lets allocate storage for it.\r
  //\r
  PageMap         = (VOID *) BigPageAddress;\r
  BigPageAddress += SIZE_4KB;\r
\r
  PageMapLevel4Entry = PageMap;\r
  PageAddress        = 0;\r
  for (IndexOfPml4Entries = 0; IndexOfPml4Entries < NumberOfPml4EntriesNeeded; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
    //\r
    // Each PML4 entry points to a page of Page Directory Pointer entires.\r
    // So lets allocate space for them and fill them in in the IndexOfPdpEntries loop.\r
    //\r
    PageDirectoryPointerEntry = (VOID *) BigPageAddress;\r
    BigPageAddress += SIZE_4KB;\r
\r
    //\r
    // Make a PML4 Entry\r
    //\r
    PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry | AddressEncMask;\r
    PageMapLevel4Entry->Bits.ReadWrite = 1;\r
    PageMapLevel4Entry->Bits.Present = 1;\r
\r
    if (Page1GSupport) {\r
      PageDirectory1GEntry = (VOID *) PageDirectoryPointerEntry;\r
    \r
      for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectory1GEntry++, PageAddress += SIZE_1GB) {\r
        if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_1GB) > StackBase)) {\r
          Split1GPageTo2M (PageAddress, (UINT64 *) PageDirectory1GEntry, StackBase, StackSize);\r
        } else {\r
          //\r
          // Fill in the Page Directory entries\r
          //\r
          PageDirectory1GEntry->Uint64 = (UINT64)PageAddress | AddressEncMask;\r
          PageDirectory1GEntry->Bits.ReadWrite = 1;\r
          PageDirectory1GEntry->Bits.Present = 1;\r
          PageDirectory1GEntry->Bits.MustBe1 = 1;\r
        }\r
      }\r
    } else {\r
      for (IndexOfPdpEntries = 0; IndexOfPdpEntries < NumberOfPdpEntriesNeeded; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {\r
        //\r
        // Each Directory Pointer entries points to a page of Page Directory entires.\r
        // So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop.\r
        //       \r
        PageDirectoryEntry = (VOID *) BigPageAddress;\r
        BigPageAddress += SIZE_4KB;\r
\r
        //\r
        // Fill in a Page Directory Pointer Entries\r
        //\r
        PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry | AddressEncMask;\r
        PageDirectoryPointerEntry->Bits.ReadWrite = 1;\r
        PageDirectoryPointerEntry->Bits.Present = 1;\r
\r
        for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += SIZE_2MB) {\r
          if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_2MB) > StackBase)) {\r
            //\r
            // Need to split this 2M page that covers stack range.\r
            //\r
            Split2MPageTo4K (PageAddress, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);\r
          } else {\r
            //\r
            // Fill in the Page Directory entries\r
            //\r
            PageDirectoryEntry->Uint64 = (UINT64)PageAddress | AddressEncMask;\r
            PageDirectoryEntry->Bits.ReadWrite = 1;\r
            PageDirectoryEntry->Bits.Present = 1;\r
            PageDirectoryEntry->Bits.MustBe1 = 1;\r
          }\r
        }\r
      }\r
\r
      for (; IndexOfPdpEntries < 512; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {\r
        ZeroMem (\r
          PageDirectoryPointerEntry,\r
          sizeof(PAGE_MAP_AND_DIRECTORY_POINTER)\r
          );\r
      }\r
    }\r
  }\r
\r
  //\r
  // For the PML4 entries we are not using fill in a null entry.\r
  //\r
  for (; IndexOfPml4Entries < 512; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
    ZeroMem (\r
      PageMapLevel4Entry,\r
      sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)\r
      );\r
  }\r
\r
  if (PcdGetBool (PcdSetNxForStack)) {\r
    EnableExecuteDisableBit ();\r
  }\r
\r
  return (UINTN)PageMap;\r
}\r
\r
Commit	Line	Data
	1	/** @file\r
	2	x64 Virtual Memory Management Services in the form of an IA-32 driver. \r
	3	Used to establish a 1:1 Virtual to Physical Mapping that is required to\r
	4	enter Long Mode (x64 64-bit mode).\r
	5	\r
	6	While we make a 1:1 mapping (identity mapping) for all physical pages \r
	7	we still need to use the MTRR's to ensure that the cachability attributes\r
	8	for all memory regions is correct.\r
	9	\r
	10	The basic idea is to use 2MB page table entries where ever possible. If\r
	11	more granularity of cachability is required then 4K page tables are used.\r
	12	\r
	13	References:\r
	14	1) IA-32 Intel(R) Architecture Software Developer's Manual Volume 1:Basic Architecture, Intel\r
	15	2) IA-32 Intel(R) Architecture Software Developer's Manual Volume 2:Instruction Set Reference, Intel\r
	16	3) IA-32 Intel(R) Architecture Software Developer's Manual Volume 3:System Programmer's Guide, Intel\r
	17	\r
	18	Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>\r
	19	Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>\r
	20	\r
	21	This program and the accompanying materials\r
	22	are licensed and made available under the terms and conditions of the BSD License\r
	23	which accompanies this distribution. The full text of the license may be found at\r
	24	http://opensource.org/licenses/bsd-license.php\r
	25	\r
	26	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	27	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	28	\r
	29	**/ \r
	30	\r
	31	#include "DxeIpl.h"\r
	32	#include "VirtualMemory.h"\r
	33	\r
	34	\r
	35	/**\r
	36	Enable Execute Disable Bit.\r
	37	\r
	38	**/\r
	39	VOID\r
	40	EnableExecuteDisableBit (\r
	41	VOID\r
	42	)\r
	43	{\r
	44	UINT64 MsrRegisters;\r
	45	\r
	46	MsrRegisters = AsmReadMsr64 (0xC0000080);\r
	47	MsrRegisters \|= BIT11;\r
	48	AsmWriteMsr64 (0xC0000080, MsrRegisters);\r
	49	}\r
	50	\r
	51	/**\r
	52	Split 2M page to 4K.\r
	53	\r
	54	@param[in] PhysicalAddress Start physical address the 2M page covered.\r
	55	@param[in, out] PageEntry2M Pointer to 2M page entry.\r
	56	@param[in] StackBase Stack base address.\r
	57	@param[in] StackSize Stack size.\r
	58	\r
	59	**/\r
	60	VOID\r
	61	Split2MPageTo4K (\r
	62	IN EFI_PHYSICAL_ADDRESS PhysicalAddress,\r
	63	IN OUT UINT64 *PageEntry2M,\r
	64	IN EFI_PHYSICAL_ADDRESS StackBase,\r
	65	IN UINTN StackSize\r
	66	)\r
	67	{\r
	68	EFI_PHYSICAL_ADDRESS PhysicalAddress4K;\r
	69	UINTN IndexOfPageTableEntries;\r
	70	PAGE_TABLE_4K_ENTRY *PageTableEntry;\r
	71	UINT64 AddressEncMask;\r
	72	\r
	73	//\r
	74	// Make sure AddressEncMask is contained to smallest supported address field\r
	75	//\r
	76	AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
	77	\r
	78	PageTableEntry = AllocatePages (1);\r
	79	ASSERT (PageTableEntry != NULL);\r
	80	\r
	81	//\r
	82	// Fill in 2M page entry.\r
	83	//\r
	84	*PageEntry2M = (UINT64) (UINTN) PageTableEntry \| AddressEncMask \| IA32_PG_P \| IA32_PG_RW;\r
	85	\r
	86	PhysicalAddress4K = PhysicalAddress;\r
	87	for (IndexOfPageTableEntries = 0; IndexOfPageTableEntries < 512; IndexOfPageTableEntries++, PageTableEntry++, PhysicalAddress4K += SIZE_4KB) {\r
	88	//\r
	89	// Fill in the Page Table entries\r
	90	//\r
	91	PageTableEntry->Uint64 = (UINT64) PhysicalAddress4K \| AddressEncMask;\r
	92	PageTableEntry->Bits.ReadWrite = 1;\r
	93	PageTableEntry->Bits.Present = 1;\r
	94	if ((PhysicalAddress4K >= StackBase) && (PhysicalAddress4K < StackBase + StackSize)) {\r
	95	//\r
	96	// Set Nx bit for stack.\r
	97	//\r
	98	PageTableEntry->Bits.Nx = 1;\r
	99	}\r
	100	}\r
	101	}\r
	102	\r
	103	/**\r
	104	Split 1G page to 2M.\r
	105	\r
	106	@param[in] PhysicalAddress Start physical address the 1G page covered.\r
	107	@param[in, out] PageEntry1G Pointer to 1G page entry.\r
	108	@param[in] StackBase Stack base address.\r
	109	@param[in] StackSize Stack size.\r
	110	\r
	111	**/\r
	112	VOID\r
	113	Split1GPageTo2M (\r
	114	IN EFI_PHYSICAL_ADDRESS PhysicalAddress,\r
	115	IN OUT UINT64 *PageEntry1G,\r
	116	IN EFI_PHYSICAL_ADDRESS StackBase,\r
	117	IN UINTN StackSize\r
	118	)\r
	119	{\r
	120	EFI_PHYSICAL_ADDRESS PhysicalAddress2M;\r
	121	UINTN IndexOfPageDirectoryEntries;\r
	122	PAGE_TABLE_ENTRY *PageDirectoryEntry;\r
	123	UINT64 AddressEncMask;\r
	124	\r
	125	//\r
	126	// Make sure AddressEncMask is contained to smallest supported address field\r
	127	//\r
	128	AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
	129	\r
	130	PageDirectoryEntry = AllocatePages (1);\r
	131	ASSERT (PageDirectoryEntry != NULL);\r
	132	\r
	133	//\r
	134	// Fill in 1G page entry.\r
	135	//\r
	136	*PageEntry1G = (UINT64) (UINTN) PageDirectoryEntry \| AddressEncMask \| IA32_PG_P \| IA32_PG_RW;\r
	137	\r
	138	PhysicalAddress2M = PhysicalAddress;\r
	139	for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M += SIZE_2MB) {\r
	140	if ((PhysicalAddress2M < StackBase + StackSize) && ((PhysicalAddress2M + SIZE_2MB) > StackBase)) {\r
	141	//\r
	142	// Need to split this 2M page that covers stack range.\r
	143	//\r
	144	Split2MPageTo4K (PhysicalAddress2M, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);\r
	145	} else {\r
	146	//\r
	147	// Fill in the Page Directory entries\r
	148	//\r
	149	PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress2M \| AddressEncMask;\r
	150	PageDirectoryEntry->Bits.ReadWrite = 1;\r
	151	PageDirectoryEntry->Bits.Present = 1;\r
	152	PageDirectoryEntry->Bits.MustBe1 = 1;\r
	153	}\r
	154	}\r
	155	}\r
	156	\r
	157	/**\r
	158	Allocates and fills in the Page Directory and Page Table Entries to\r
	159	establish a 1:1 Virtual to Physical mapping.\r
	160	\r
	161	@param[in] StackBase Stack base address.\r
	162	@param[in] StackSize Stack size.\r
	163	\r
	164	@return The address of 4 level page map.\r
	165	\r
	166	**/\r
	167	UINTN\r
	168	CreateIdentityMappingPageTables (\r
	169	IN EFI_PHYSICAL_ADDRESS StackBase,\r
	170	IN UINTN StackSize\r
	171	)\r
	172	{ \r
	173	UINT32 RegEax;\r
	174	UINT32 RegEdx;\r
	175	UINT8 PhysicalAddressBits;\r
	176	EFI_PHYSICAL_ADDRESS PageAddress;\r
	177	UINTN IndexOfPml4Entries;\r
	178	UINTN IndexOfPdpEntries;\r
	179	UINTN IndexOfPageDirectoryEntries;\r
	180	UINT32 NumberOfPml4EntriesNeeded;\r
	181	UINT32 NumberOfPdpEntriesNeeded;\r
	182	PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry;\r
	183	PAGE_MAP_AND_DIRECTORY_POINTER *PageMap;\r
	184	PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;\r
	185	PAGE_TABLE_ENTRY *PageDirectoryEntry;\r
	186	UINTN TotalPagesNum;\r
	187	UINTN BigPageAddress;\r
	188	VOID *Hob;\r
	189	BOOLEAN Page1GSupport;\r
	190	PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry;\r
	191	UINT64 AddressEncMask;\r
	192	\r
	193	//\r
	194	// Make sure AddressEncMask is contained to smallest supported address field\r
	195	//\r
	196	AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;\r
	197	\r
	198	Page1GSupport = FALSE;\r
	199	if (PcdGetBool(PcdUse1GPageTable)) {\r
	200	AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);\r
	201	if (RegEax >= 0x80000001) {\r
	202	AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);\r
	203	if ((RegEdx & BIT26) != 0) {\r
	204	Page1GSupport = TRUE;\r
	205	}\r
	206	}\r
	207	}\r
	208	\r
	209	//\r
	210	// Get physical address bits supported.\r
	211	//\r
	212	Hob = GetFirstHob (EFI_HOB_TYPE_CPU);\r
	213	if (Hob != NULL) {\r
	214	PhysicalAddressBits = ((EFI_HOB_CPU *) Hob)->SizeOfMemorySpace;\r
	215	} else {\r
	216	AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);\r
	217	if (RegEax >= 0x80000008) {\r
	218	AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);\r
	219	PhysicalAddressBits = (UINT8) RegEax;\r
	220	} else {\r
	221	PhysicalAddressBits = 36;\r
	222	}\r
	223	}\r
	224	\r
	225	//\r
	226	// IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses.\r
	227	//\r
	228	ASSERT (PhysicalAddressBits <= 52);\r
	229	if (PhysicalAddressBits > 48) {\r
	230	PhysicalAddressBits = 48;\r
	231	}\r
	232	\r
	233	//\r
	234	// Calculate the table entries needed.\r
	235	//\r
	236	if (PhysicalAddressBits <= 39 ) {\r
	237	NumberOfPml4EntriesNeeded = 1;\r
	238	NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30));\r
	239	} else {\r
	240	NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 39));\r
	241	NumberOfPdpEntriesNeeded = 512;\r
	242	}\r
	243	\r
	244	//\r
	245	// Pre-allocate big pages to avoid later allocations. \r
	246	//\r
	247	if (!Page1GSupport) {\r
	248	TotalPagesNum = (NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1;\r
	249	} else {\r
	250	TotalPagesNum = NumberOfPml4EntriesNeeded + 1;\r
	251	}\r
	252	BigPageAddress = (UINTN) AllocatePages (TotalPagesNum);\r
	253	ASSERT (BigPageAddress != 0);\r
	254	\r
	255	//\r
	256	// By architecture only one PageMapLevel4 exists - so lets allocate storage for it.\r
	257	//\r
	258	PageMap = (VOID *) BigPageAddress;\r
	259	BigPageAddress += SIZE_4KB;\r
	260	\r
	261	PageMapLevel4Entry = PageMap;\r
	262	PageAddress = 0;\r
	263	for (IndexOfPml4Entries = 0; IndexOfPml4Entries < NumberOfPml4EntriesNeeded; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
	264	//\r
	265	// Each PML4 entry points to a page of Page Directory Pointer entires.\r
	266	// So lets allocate space for them and fill them in in the IndexOfPdpEntries loop.\r
	267	//\r
	268	PageDirectoryPointerEntry = (VOID *) BigPageAddress;\r
	269	BigPageAddress += SIZE_4KB;\r
	270	\r
	271	//\r
	272	// Make a PML4 Entry\r
	273	//\r
	274	PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry \| AddressEncMask;\r
	275	PageMapLevel4Entry->Bits.ReadWrite = 1;\r
	276	PageMapLevel4Entry->Bits.Present = 1;\r
	277	\r
	278	if (Page1GSupport) {\r
	279	PageDirectory1GEntry = (VOID *) PageDirectoryPointerEntry;\r
	280	\r
	281	for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectory1GEntry++, PageAddress += SIZE_1GB) {\r
	282	if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_1GB) > StackBase)) {\r
	283	Split1GPageTo2M (PageAddress, (UINT64 *) PageDirectory1GEntry, StackBase, StackSize);\r
	284	} else {\r
	285	//\r
	286	// Fill in the Page Directory entries\r
	287	//\r
	288	PageDirectory1GEntry->Uint64 = (UINT64)PageAddress \| AddressEncMask;\r
	289	PageDirectory1GEntry->Bits.ReadWrite = 1;\r
	290	PageDirectory1GEntry->Bits.Present = 1;\r
	291	PageDirectory1GEntry->Bits.MustBe1 = 1;\r
	292	}\r
	293	}\r
	294	} else {\r
	295	for (IndexOfPdpEntries = 0; IndexOfPdpEntries < NumberOfPdpEntriesNeeded; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {\r
	296	//\r
	297	// Each Directory Pointer entries points to a page of Page Directory entires.\r
	298	// So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop.\r
	299	// \r
	300	PageDirectoryEntry = (VOID *) BigPageAddress;\r
	301	BigPageAddress += SIZE_4KB;\r
	302	\r
	303	//\r
	304	// Fill in a Page Directory Pointer Entries\r
	305	//\r
	306	PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry \| AddressEncMask;\r
	307	PageDirectoryPointerEntry->Bits.ReadWrite = 1;\r
	308	PageDirectoryPointerEntry->Bits.Present = 1;\r
	309	\r
	310	for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += SIZE_2MB) {\r
	311	if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_2MB) > StackBase)) {\r
	312	//\r
	313	// Need to split this 2M page that covers stack range.\r
	314	//\r
	315	Split2MPageTo4K (PageAddress, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);\r
	316	} else {\r
	317	//\r
	318	// Fill in the Page Directory entries\r
	319	//\r
	320	PageDirectoryEntry->Uint64 = (UINT64)PageAddress \| AddressEncMask;\r
	321	PageDirectoryEntry->Bits.ReadWrite = 1;\r
	322	PageDirectoryEntry->Bits.Present = 1;\r
	323	PageDirectoryEntry->Bits.MustBe1 = 1;\r
	324	}\r
	325	}\r
	326	}\r
	327	\r
	328	for (; IndexOfPdpEntries < 512; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {\r
	329	ZeroMem (\r
	330	PageDirectoryPointerEntry,\r
	331	sizeof(PAGE_MAP_AND_DIRECTORY_POINTER)\r
	332	);\r
	333	}\r
	334	}\r
	335	}\r
	336	\r
	337	//\r
	338	// For the PML4 entries we are not using fill in a null entry.\r
	339	//\r
	340	for (; IndexOfPml4Entries < 512; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
	341	ZeroMem (\r
	342	PageMapLevel4Entry,\r
	343	sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)\r
	344	);\r
	345	}\r
	346	\r
	347	if (PcdGetBool (PcdSetNxForStack)) {\r
	348	EnableExecuteDisableBit ();\r
	349	}\r
	350	\r
	351	return (UINTN)PageMap;\r
	352	}\r
	353	\r