diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c')
| -rw-r--r-- | roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c | 511 |
1 files changed, 511 insertions, 0 deletions
diff --git a/roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c b/roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c new file mode 100644 index 000000000..6fb5112a1 --- /dev/null +++ b/roms/edk2/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c @@ -0,0 +1,511 @@ +/*++
+
+Copyright (c) 2009, Hewlett-Packard Company. All rights reserved.<BR>
+Portions copyright (c) 2010, Apple Inc. All rights reserved.<BR>
+Portions copyright (c) 2013, ARM Ltd. All rights reserved.<BR>
+Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+
+--*/
+
+#include <Library/MemoryAllocationLib.h>
+#include "CpuDxe.h"
+
+EFI_STATUS
+SectionToGcdAttributes (
+ IN UINT32 SectionAttributes,
+ OUT UINT64 *GcdAttributes
+ )
+{
+ *GcdAttributes = 0;
+
+ // determine cacheability attributes
+ switch(SectionAttributes & TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK) {
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_STRONGLY_ORDERED:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_SHAREABLE_DEVICE:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_THROUGH_NO_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WT;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_BACK_NO_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WB;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_NON_CACHEABLE:
+ *GcdAttributes |= EFI_MEMORY_WC;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_BACK_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WB;
+ break;
+ case TT_DESCRIPTOR_SECTION_CACHE_POLICY_NON_SHAREABLE_DEVICE:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ default:
+ return EFI_UNSUPPORTED;
+ }
+
+ // determine protection attributes
+ switch(SectionAttributes & TT_DESCRIPTOR_SECTION_AP_MASK) {
+ case TT_DESCRIPTOR_SECTION_AP_NO_NO: // no read, no write
+ //*GcdAttributes |= EFI_MEMORY_RO | EFI_MEMORY_RP;
+ break;
+
+ case TT_DESCRIPTOR_SECTION_AP_RW_NO:
+ case TT_DESCRIPTOR_SECTION_AP_RW_RW:
+ // normal read/write access, do not add additional attributes
+ break;
+
+ // read only cases map to write-protect
+ case TT_DESCRIPTOR_SECTION_AP_RO_NO:
+ case TT_DESCRIPTOR_SECTION_AP_RO_RO:
+ *GcdAttributes |= EFI_MEMORY_RO;
+ break;
+
+ default:
+ return EFI_UNSUPPORTED;
+ }
+
+ // now process eXectue Never attribute
+ if ((SectionAttributes & TT_DESCRIPTOR_SECTION_XN_MASK) != 0 ) {
+ *GcdAttributes |= EFI_MEMORY_XP;
+ }
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+PageToGcdAttributes (
+ IN UINT32 PageAttributes,
+ OUT UINT64 *GcdAttributes
+ )
+{
+ *GcdAttributes = 0;
+
+ // determine cacheability attributes
+ switch(PageAttributes & TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK) {
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_STRONGLY_ORDERED:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_SHAREABLE_DEVICE:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_WRITE_THROUGH_NO_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WT;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_WRITE_BACK_NO_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WB;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_NON_CACHEABLE:
+ *GcdAttributes |= EFI_MEMORY_WC;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_WRITE_BACK_ALLOC:
+ *GcdAttributes |= EFI_MEMORY_WB;
+ break;
+ case TT_DESCRIPTOR_PAGE_CACHE_POLICY_NON_SHAREABLE_DEVICE:
+ *GcdAttributes |= EFI_MEMORY_UC;
+ break;
+ default:
+ return EFI_UNSUPPORTED;
+ }
+
+ // determine protection attributes
+ switch(PageAttributes & TT_DESCRIPTOR_PAGE_AP_MASK) {
+ case TT_DESCRIPTOR_PAGE_AP_NO_NO: // no read, no write
+ //*GcdAttributes |= EFI_MEMORY_RO | EFI_MEMORY_RP;
+ break;
+
+ case TT_DESCRIPTOR_PAGE_AP_RW_NO:
+ case TT_DESCRIPTOR_PAGE_AP_RW_RW:
+ // normal read/write access, do not add additional attributes
+ break;
+
+ // read only cases map to write-protect
+ case TT_DESCRIPTOR_PAGE_AP_RO_NO:
+ case TT_DESCRIPTOR_PAGE_AP_RO_RO:
+ *GcdAttributes |= EFI_MEMORY_RO;
+ break;
+
+ default:
+ return EFI_UNSUPPORTED;
+ }
+
+ // now process eXectue Never attribute
+ if ((PageAttributes & TT_DESCRIPTOR_PAGE_XN_MASK) != 0 ) {
+ *GcdAttributes |= EFI_MEMORY_XP;
+ }
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+SyncCacheConfigPage (
+ IN UINT32 SectionIndex,
+ IN UINT32 FirstLevelDescriptor,
+ IN UINTN NumberOfDescriptors,
+ IN EFI_GCD_MEMORY_SPACE_DESCRIPTOR *MemorySpaceMap,
+ IN OUT EFI_PHYSICAL_ADDRESS *NextRegionBase,
+ IN OUT UINT64 *NextRegionLength,
+ IN OUT UINT32 *NextSectionAttributes
+ )
+{
+ EFI_STATUS Status;
+ UINT32 i;
+ volatile ARM_PAGE_TABLE_ENTRY *SecondLevelTable;
+ UINT32 NextPageAttributes = 0;
+ UINT32 PageAttributes = 0;
+ UINT32 BaseAddress;
+ UINT64 GcdAttributes;
+
+ // Get the Base Address from FirstLevelDescriptor;
+ BaseAddress = TT_DESCRIPTOR_PAGE_BASE_ADDRESS(SectionIndex << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
+
+ // Convert SectionAttributes into PageAttributes
+ NextPageAttributes =
+ TT_DESCRIPTOR_CONVERT_TO_PAGE_CACHE_POLICY(*NextSectionAttributes,0) |
+ TT_DESCRIPTOR_CONVERT_TO_PAGE_AP(*NextSectionAttributes);
+
+ // obtain page table base
+ SecondLevelTable = (ARM_PAGE_TABLE_ENTRY *)(FirstLevelDescriptor & TT_DESCRIPTOR_SECTION_PAGETABLE_ADDRESS_MASK);
+
+ for (i=0; i < TRANSLATION_TABLE_PAGE_COUNT; i++) {
+ if ((SecondLevelTable[i] & TT_DESCRIPTOR_PAGE_TYPE_MASK) == TT_DESCRIPTOR_PAGE_TYPE_PAGE) {
+ // extract attributes (cacheability and permissions)
+ PageAttributes = SecondLevelTable[i] & (TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK | TT_DESCRIPTOR_PAGE_AP_MASK);
+
+ if (NextPageAttributes == 0) {
+ // start on a new region
+ *NextRegionLength = 0;
+ *NextRegionBase = BaseAddress | (i << TT_DESCRIPTOR_PAGE_BASE_SHIFT);
+ NextPageAttributes = PageAttributes;
+ } else if (PageAttributes != NextPageAttributes) {
+ // Convert Section Attributes into GCD Attributes
+ Status = PageToGcdAttributes (NextPageAttributes, &GcdAttributes);
+ ASSERT_EFI_ERROR (Status);
+
+ // update GCD with these changes (this will recurse into our own CpuSetMemoryAttributes below which is OK)
+ SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors, *NextRegionBase, *NextRegionLength, GcdAttributes);
+
+ // start on a new region
+ *NextRegionLength = 0;
+ *NextRegionBase = BaseAddress | (i << TT_DESCRIPTOR_PAGE_BASE_SHIFT);
+ NextPageAttributes = PageAttributes;
+ }
+ } else if (NextPageAttributes != 0) {
+ // Convert Page Attributes into GCD Attributes
+ Status = PageToGcdAttributes (NextPageAttributes, &GcdAttributes);
+ ASSERT_EFI_ERROR (Status);
+
+ // update GCD with these changes (this will recurse into our own CpuSetMemoryAttributes below which is OK)
+ SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors, *NextRegionBase, *NextRegionLength, GcdAttributes);
+
+ *NextRegionLength = 0;
+ *NextRegionBase = BaseAddress | (i << TT_DESCRIPTOR_PAGE_BASE_SHIFT);
+ NextPageAttributes = 0;
+ }
+ *NextRegionLength += TT_DESCRIPTOR_PAGE_SIZE;
+ }
+
+ // Convert back PageAttributes into SectionAttributes
+ *NextSectionAttributes =
+ TT_DESCRIPTOR_CONVERT_TO_SECTION_CACHE_POLICY(NextPageAttributes,0) |
+ TT_DESCRIPTOR_CONVERT_TO_SECTION_AP(NextPageAttributes);
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+SyncCacheConfig (
+ IN EFI_CPU_ARCH_PROTOCOL *CpuProtocol
+ )
+{
+ EFI_STATUS Status;
+ UINT32 i;
+ EFI_PHYSICAL_ADDRESS NextRegionBase;
+ UINT64 NextRegionLength;
+ UINT32 NextSectionAttributes = 0;
+ UINT32 SectionAttributes = 0;
+ UINT64 GcdAttributes;
+ volatile ARM_FIRST_LEVEL_DESCRIPTOR *FirstLevelTable;
+ UINTN NumberOfDescriptors;
+ EFI_GCD_MEMORY_SPACE_DESCRIPTOR *MemorySpaceMap;
+
+
+ DEBUG ((DEBUG_PAGE, "SyncCacheConfig()\n"));
+
+ // This code assumes MMU is enabled and filed with section translations
+ ASSERT (ArmMmuEnabled ());
+
+ //
+ // Get the memory space map from GCD
+ //
+ MemorySpaceMap = NULL;
+ Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
+ ASSERT_EFI_ERROR (Status);
+
+
+ // The GCD implementation maintains its own copy of the state of memory space attributes. GCD needs
+ // to know what the initial memory space attributes are. The CPU Arch. Protocol does not provide a
+ // GetMemoryAttributes function for GCD to get this so we must resort to calling GCD (as if we were
+ // a client) to update its copy of the attributes. This is bad architecture and should be replaced
+ // with a way for GCD to query the CPU Arch. driver of the existing memory space attributes instead.
+
+ // obtain page table base
+ FirstLevelTable = (ARM_FIRST_LEVEL_DESCRIPTOR *)(ArmGetTTBR0BaseAddress ());
+
+ // Get the first region
+ NextSectionAttributes = FirstLevelTable[0] & (TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK | TT_DESCRIPTOR_SECTION_AP_MASK);
+
+ // iterate through each 1MB descriptor
+ NextRegionBase = NextRegionLength = 0;
+ for (i=0; i < TRANSLATION_TABLE_SECTION_COUNT; i++) {
+ if ((FirstLevelTable[i] & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_SECTION) {
+ // extract attributes (cacheability and permissions)
+ SectionAttributes = FirstLevelTable[i] & (TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK | TT_DESCRIPTOR_SECTION_AP_MASK);
+
+ if (NextSectionAttributes == 0) {
+ // start on a new region
+ NextRegionLength = 0;
+ NextRegionBase = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(i << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
+ NextSectionAttributes = SectionAttributes;
+ } else if (SectionAttributes != NextSectionAttributes) {
+ // Convert Section Attributes into GCD Attributes
+ Status = SectionToGcdAttributes (NextSectionAttributes, &GcdAttributes);
+ ASSERT_EFI_ERROR (Status);
+
+ // update GCD with these changes (this will recurse into our own CpuSetMemoryAttributes below which is OK)
+ SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors, NextRegionBase, NextRegionLength, GcdAttributes);
+
+ // start on a new region
+ NextRegionLength = 0;
+ NextRegionBase = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(i << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
+ NextSectionAttributes = SectionAttributes;
+ }
+ NextRegionLength += TT_DESCRIPTOR_SECTION_SIZE;
+ } else if (TT_DESCRIPTOR_SECTION_TYPE_IS_PAGE_TABLE(FirstLevelTable[i])) {
+ // In this case any bits set in the 'NextSectionAttributes' are garbage and were set from
+ // bits that are actually part of the pagetable address. We clear it out to zero so that
+ // the SyncCacheConfigPage will use the page attributes instead of trying to convert the
+ // section attributes into page attributes
+ NextSectionAttributes = 0;
+ Status = SyncCacheConfigPage (
+ i,FirstLevelTable[i],
+ NumberOfDescriptors, MemorySpaceMap,
+ &NextRegionBase,&NextRegionLength,&NextSectionAttributes);
+ ASSERT_EFI_ERROR (Status);
+ } else {
+ // We do not support yet 16MB sections
+ ASSERT ((FirstLevelTable[i] & TT_DESCRIPTOR_SECTION_TYPE_MASK) != TT_DESCRIPTOR_SECTION_TYPE_SUPERSECTION);
+
+ // start on a new region
+ if (NextSectionAttributes != 0) {
+ // Convert Section Attributes into GCD Attributes
+ Status = SectionToGcdAttributes (NextSectionAttributes, &GcdAttributes);
+ ASSERT_EFI_ERROR (Status);
+
+ // update GCD with these changes (this will recurse into our own CpuSetMemoryAttributes below which is OK)
+ SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors, NextRegionBase, NextRegionLength, GcdAttributes);
+
+ NextRegionLength = 0;
+ NextRegionBase = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(i << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
+ NextSectionAttributes = 0;
+ }
+ NextRegionLength += TT_DESCRIPTOR_SECTION_SIZE;
+ }
+ } // section entry loop
+
+ if (NextSectionAttributes != 0) {
+ // Convert Section Attributes into GCD Attributes
+ Status = SectionToGcdAttributes (NextSectionAttributes, &GcdAttributes);
+ ASSERT_EFI_ERROR (Status);
+
+ // update GCD with these changes (this will recurse into our own CpuSetMemoryAttributes below which is OK)
+ SetGcdMemorySpaceAttributes (MemorySpaceMap, NumberOfDescriptors, NextRegionBase, NextRegionLength, GcdAttributes);
+ }
+
+ FreePool (MemorySpaceMap);
+
+ return EFI_SUCCESS;
+}
+
+UINT64
+EfiAttributeToArmAttribute (
+ IN UINT64 EfiAttributes
+ )
+{
+ UINT64 ArmAttributes;
+
+ switch (EfiAttributes & EFI_MEMORY_CACHETYPE_MASK) {
+ case EFI_MEMORY_UC:
+ // Map to strongly ordered
+ ArmAttributes = TT_DESCRIPTOR_SECTION_CACHE_POLICY_STRONGLY_ORDERED; // TEX[2:0] = 0, C=0, B=0
+ break;
+
+ case EFI_MEMORY_WC:
+ // Map to normal non-cachable
+ ArmAttributes = TT_DESCRIPTOR_SECTION_CACHE_POLICY_NON_CACHEABLE; // TEX [2:0]= 001 = 0x2, B=0, C=0
+ break;
+
+ case EFI_MEMORY_WT:
+ // Write through with no-allocate
+ ArmAttributes = TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_THROUGH_NO_ALLOC; // TEX [2:0] = 0, C=1, B=0
+ break;
+
+ case EFI_MEMORY_WB:
+ // Write back (with allocate)
+ ArmAttributes = TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_BACK_ALLOC; // TEX [2:0] = 001, C=1, B=1
+ break;
+
+ case EFI_MEMORY_UCE:
+ default:
+ ArmAttributes = TT_DESCRIPTOR_SECTION_TYPE_FAULT;
+ break;
+ }
+
+ // Determine protection attributes
+ if (EfiAttributes & EFI_MEMORY_RO) {
+ ArmAttributes |= TT_DESCRIPTOR_SECTION_AP_RO_RO;
+ } else {
+ ArmAttributes |= TT_DESCRIPTOR_SECTION_AP_RW_RW;
+ }
+
+ // Determine eXecute Never attribute
+ if (EfiAttributes & EFI_MEMORY_XP) {
+ ArmAttributes |= TT_DESCRIPTOR_SECTION_XN_MASK;
+ }
+
+ return ArmAttributes;
+}
+
+EFI_STATUS
+GetMemoryRegionPage (
+ IN UINT32 *PageTable,
+ IN OUT UINTN *BaseAddress,
+ OUT UINTN *RegionLength,
+ OUT UINTN *RegionAttributes
+ )
+{
+ UINT32 PageAttributes;
+ UINT32 TableIndex;
+ UINT32 PageDescriptor;
+
+ // Convert the section attributes into page attributes
+ PageAttributes = ConvertSectionAttributesToPageAttributes (*RegionAttributes, 0);
+
+ // Calculate index into first level translation table for start of modification
+ TableIndex = ((*BaseAddress) & TT_DESCRIPTOR_PAGE_INDEX_MASK) >> TT_DESCRIPTOR_PAGE_BASE_SHIFT;
+ ASSERT (TableIndex < TRANSLATION_TABLE_PAGE_COUNT);
+
+ // Go through the page table to find the end of the section
+ for (; TableIndex < TRANSLATION_TABLE_PAGE_COUNT; TableIndex++) {
+ // Get the section at the given index
+ PageDescriptor = PageTable[TableIndex];
+
+ if ((PageDescriptor & TT_DESCRIPTOR_PAGE_TYPE_MASK) == TT_DESCRIPTOR_PAGE_TYPE_FAULT) {
+ // Case: End of the boundary of the region
+ return EFI_SUCCESS;
+ } else if ((PageDescriptor & TT_DESCRIPTOR_PAGE_TYPE_PAGE) == TT_DESCRIPTOR_PAGE_TYPE_PAGE) {
+ if ((PageDescriptor & TT_DESCRIPTOR_PAGE_ATTRIBUTE_MASK) == PageAttributes) {
+ *RegionLength = *RegionLength + TT_DESCRIPTOR_PAGE_SIZE;
+ } else {
+ // Case: End of the boundary of the region
+ return EFI_SUCCESS;
+ }
+ } else {
+ // We do not support Large Page yet. We return EFI_SUCCESS that means end of the region.
+ ASSERT(0);
+ return EFI_SUCCESS;
+ }
+ }
+
+ return EFI_NOT_FOUND;
+}
+
+EFI_STATUS
+GetMemoryRegion (
+ IN OUT UINTN *BaseAddress,
+ OUT UINTN *RegionLength,
+ OUT UINTN *RegionAttributes
+ )
+{
+ EFI_STATUS Status;
+ UINT32 TableIndex;
+ UINT32 PageAttributes;
+ UINT32 PageTableIndex;
+ UINT32 SectionDescriptor;
+ ARM_FIRST_LEVEL_DESCRIPTOR *FirstLevelTable;
+ UINT32 *PageTable;
+
+ // Initialize the arguments
+ *RegionLength = 0;
+
+ // Obtain page table base
+ FirstLevelTable = (ARM_FIRST_LEVEL_DESCRIPTOR *)ArmGetTTBR0BaseAddress ();
+
+ // Calculate index into first level translation table for start of modification
+ TableIndex = TT_DESCRIPTOR_SECTION_BASE_ADDRESS (*BaseAddress) >> TT_DESCRIPTOR_SECTION_BASE_SHIFT;
+ ASSERT (TableIndex < TRANSLATION_TABLE_SECTION_COUNT);
+
+ // Get the section at the given index
+ SectionDescriptor = FirstLevelTable[TableIndex];
+ if (!SectionDescriptor) {
+ return EFI_NOT_FOUND;
+ }
+
+ // If 'BaseAddress' belongs to the section then round it to the section boundary
+ if (((SectionDescriptor & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_SECTION) ||
+ ((SectionDescriptor & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_SUPERSECTION))
+ {
+ *BaseAddress = (*BaseAddress) & TT_DESCRIPTOR_SECTION_BASE_ADDRESS_MASK;
+ *RegionAttributes = SectionDescriptor & TT_DESCRIPTOR_SECTION_ATTRIBUTE_MASK;
+ } else {
+ // Otherwise, we round it to the page boundary
+ *BaseAddress = (*BaseAddress) & TT_DESCRIPTOR_PAGE_BASE_ADDRESS_MASK;
+
+ // Get the attribute at the page table level (Level 2)
+ PageTable = (UINT32*)(SectionDescriptor & TT_DESCRIPTOR_SECTION_PAGETABLE_ADDRESS_MASK);
+
+ // Calculate index into first level translation table for start of modification
+ PageTableIndex = ((*BaseAddress) & TT_DESCRIPTOR_PAGE_INDEX_MASK) >> TT_DESCRIPTOR_PAGE_BASE_SHIFT;
+ ASSERT (PageTableIndex < TRANSLATION_TABLE_PAGE_COUNT);
+
+ PageAttributes = PageTable[PageTableIndex] & TT_DESCRIPTOR_PAGE_ATTRIBUTE_MASK;
+ *RegionAttributes = TT_DESCRIPTOR_CONVERT_TO_SECTION_CACHE_POLICY (PageAttributes, 0) |
+ TT_DESCRIPTOR_CONVERT_TO_SECTION_AP (PageAttributes);
+ }
+
+ for (;TableIndex < TRANSLATION_TABLE_SECTION_COUNT; TableIndex++) {
+ // Get the section at the given index
+ SectionDescriptor = FirstLevelTable[TableIndex];
+
+ // If the entry is a level-2 page table then we scan it to find the end of the region
+ if (TT_DESCRIPTOR_SECTION_TYPE_IS_PAGE_TABLE (SectionDescriptor)) {
+ // Extract the page table location from the descriptor
+ PageTable = (UINT32*)(SectionDescriptor & TT_DESCRIPTOR_SECTION_PAGETABLE_ADDRESS_MASK);
+
+ // Scan the page table to find the end of the region.
+ Status = GetMemoryRegionPage (PageTable, BaseAddress, RegionLength, RegionAttributes);
+
+ // If we have found the end of the region (Status == EFI_SUCCESS) then we exit the for-loop
+ if (Status == EFI_SUCCESS) {
+ break;
+ }
+ } else if (((SectionDescriptor & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_SECTION) ||
+ ((SectionDescriptor & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_SUPERSECTION)) {
+ if ((SectionDescriptor & TT_DESCRIPTOR_SECTION_ATTRIBUTE_MASK) != *RegionAttributes) {
+ // If the attributes of the section differ from the one targeted then we exit the loop
+ break;
+ } else {
+ *RegionLength = *RegionLength + TT_DESCRIPTOR_SECTION_SIZE;
+ }
+ } else {
+ // If we are on an invalid section then it means it is the end of our section.
+ break;
+ }
+ }
+
+ return EFI_SUCCESS;
+}
|