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ArmPkg/AArch64Mmu: move page table traversal code to separate function 

Move the page table traversal and splitting logic to a separate function
UpdateRegionMapping() and refactor it slightly so we can reuse it later to
implement non-executable regions, for the stack. This primarly involves
adding a value/mask pair to the function prototype that allows us to flip
arbitrary bits on each block entry as the page tables are traversed.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18586 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Ard Biesheuvel 2015-10-08 18:52:06 +00:00 committed by abiesheuvel
parent 2afeabd1a9
commit 5ab77c6630
1 changed files with 31 additions and 19 deletions
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50
ArmPkg/Library/ArmLib/AArch64/AArch64Mmu.c
View File

@ -408,35 +408,30 @@ GetBlockEntryListFromAddress (
STATIC
RETURN_STATUS
FillTranslationTable (
IN UINT64 *RootTable,
IN ARM_MEMORY_REGION_DESCRIPTOR *MemoryRegion
UpdateRegionMapping (
IN UINT64 *RootTable,
IN UINT64 RegionStart,
IN UINT64 RegionLength,
IN UINT64 Attributes,
IN UINT64 BlockEntryMask
)
{
UINT64 Attributes;
UINT32 Type;
UINT64 RegionStart;
UINT64 RemainingRegionLength;
UINT64 *BlockEntry;
UINT64 *LastBlockEntry;
UINT64 *BlockEntry;
UINT64 *LastBlockEntry;
UINT64 BlockEntrySize;
UINTN TableLevel;
// Ensure the Length is aligned on 4KB boundary
if ((MemoryRegion->Length == 0) || ((MemoryRegion->Length & (SIZE_4KB - 1)) != 0)) {
if ((RegionLength == 0) || ((RegionLength & (SIZE_4KB - 1)) != 0)) {
ASSERT_EFI_ERROR (EFI_INVALID_PARAMETER);
return RETURN_INVALID_PARAMETER;
}
// Variable initialization
Attributes = ArmMemoryAttributeToPageAttribute (MemoryRegion->Attributes) | TT_AF;
RemainingRegionLength = MemoryRegion->Length;
RegionStart = MemoryRegion->VirtualBase;
do {
// Get the first Block Entry that matches the Virtual Address and also the information on the Table Descriptor
// such as the the size of the Block Entry and the address of the last BlockEntry of the Table Descriptor
BlockEntrySize = RemainingRegionLength;
BlockEntrySize = RegionLength;
BlockEntry = GetBlockEntryListFromAddress (RootTable, RegionStart, &TableLevel, &BlockEntrySize, &LastBlockEntry);
if (BlockEntry == NULL) {
// GetBlockEntryListFromAddress() return NULL when it fails to allocate new pages from the Translation Tables
@ -451,11 +446,12 @@ FillTranslationTable (
do {
// Fill the Block Entry with attribute and output block address
*BlockEntry = (RegionStart & TT_ADDRESS_MASK_BLOCK_ENTRY) | Attributes | Type;
*BlockEntry &= BlockEntryMask;
*BlockEntry |= (RegionStart & TT_ADDRESS_MASK_BLOCK_ENTRY) | Attributes | Type;
// Go to the next BlockEntry
RegionStart += BlockEntrySize;
RemainingRegionLength -= BlockEntrySize;
RegionLength -= BlockEntrySize;
BlockEntry++;
// Break the inner loop when next block is a table
@ -464,12 +460,28 @@ FillTranslationTable (
(*BlockEntry & TT_TYPE_MASK) == TT_TYPE_TABLE_ENTRY) {
break;
}
} while ((RemainingRegionLength >= BlockEntrySize) && (BlockEntry <= LastBlockEntry));
} while (RemainingRegionLength != 0);
} while ((RegionLength >= BlockEntrySize) && (BlockEntry <= LastBlockEntry));
} while (RegionLength != 0);
return RETURN_SUCCESS;
}
STATIC
RETURN_STATUS
FillTranslationTable (
IN UINT64 *RootTable,
IN ARM_MEMORY_REGION_DESCRIPTOR *MemoryRegion
)
{
return UpdateRegionMapping (
RootTable,
MemoryRegion->VirtualBase,
MemoryRegion->Length,
ArmMemoryAttributeToPageAttribute (MemoryRegion->Attributes) | TT_AF,
0
);
}
RETURN_STATUS
SetMemoryAttributes (
IN EFI_PHYSICAL_ADDRESS BaseAddress,