ArmPkg/CpuDxe: Added support to not set a memory region with the same attribute
Changing the attribute implies some cache management (clean & invalidate).
Preventing the cache management should improve the performance.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14568 6f19259b-4bc3-4df7-8a09-765794883524
diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
index 40a4c1b..72f9b3c 100644
--- a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
+++ b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
@@ -194,3 +194,149 @@
return EFI_SUCCESS;
}
+
+UINT64
+EfiAttributeToArmAttribute (
+ IN UINT64 EfiAttributes
+ )
+{
+ UINT64 ArmAttributes;
+
+ switch (EfiAttributes & EFI_MEMORY_CACHETYPE_MASK) {
+ case EFI_MEMORY_UC:
+ ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY;
+ break;
+ case EFI_MEMORY_WC:
+ ArmAttributes = TT_ATTR_INDX_MEMORY_NON_CACHEABLE;
+ break;
+ case EFI_MEMORY_WT:
+ ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_THROUGH;
+ break;
+ case EFI_MEMORY_WB:
+ ArmAttributes = TT_ATTR_INDX_MEMORY_WRITE_BACK;
+ break;
+ default:
+ DEBUG ((EFI_D_ERROR, "EfiAttributeToArmAttribute: 0x%lX attributes is not supported.\n", EfiAttributes));
+ ASSERT (0);
+ ArmAttributes = TT_ATTR_INDX_DEVICE_MEMORY;
+ }
+
+ // Set the access flag to match the block attributes
+ ArmAttributes |= TT_AF;
+
+ // Determine protection attributes
+ if (EfiAttributes & EFI_MEMORY_WP) {
+ ArmAttributes |= TT_AP_RO_RO;
+ }
+
+ // Process eXecute Never attribute
+ if (EfiAttributes & EFI_MEMORY_XP) {
+ ArmAttributes |= TT_PXN_MASK;
+ }
+
+ return ArmAttributes;
+}
+
+// This function will recursively go down the page table to find the first block address linked to 'BaseAddress'.
+// And then the function will identify the size of the region that has the same page table attribute.
+EFI_STATUS
+GetMemoryRegionRec (
+ IN UINT64 *TranslationTable,
+ IN UINTN TableLevel,
+ IN UINT64 *LastBlockEntry,
+ IN OUT UINTN *BaseAddress,
+ OUT UINTN *RegionLength,
+ OUT UINTN *RegionAttributes
+ )
+{
+ EFI_STATUS Status;
+ UINT64 *NextTranslationTable;
+ UINT64 *BlockEntry;
+ UINT64 BlockEntryType;
+ UINT64 EntryType;
+
+ if (TableLevel != 3) {
+ BlockEntryType = TT_TYPE_BLOCK_ENTRY;
+ } else {
+ BlockEntryType = TT_TYPE_BLOCK_ENTRY_LEVEL3;
+ }
+
+ // Find the block entry linked to the Base Address
+ BlockEntry = (UINT64*)TT_GET_ENTRY_FOR_ADDRESS (TranslationTable, TableLevel, *BaseAddress);
+ EntryType = *BlockEntry & TT_TYPE_MASK;
+
+ if (EntryType == TT_TYPE_TABLE_ENTRY) {
+ NextTranslationTable = (UINT64*)(*BlockEntry & TT_ADDRESS_MASK_DESCRIPTION_TABLE);
+
+ // The entry is a page table, so we go to the next level
+ Status = GetMemoryRegionRec (
+ NextTranslationTable, // Address of the next level page table
+ TableLevel + 1, // Next Page Table level
+ (UINTN*)TT_LAST_BLOCK_ADDRESS(NextTranslationTable, TT_ENTRY_COUNT),
+ BaseAddress, RegionLength, RegionAttributes);
+
+ // In case of 'Success', it means the end of the block region has been found into the upper
+ // level translation table
+ if (!EFI_ERROR(Status)) {
+ return EFI_SUCCESS;
+ }
+ } else if (EntryType == BlockEntryType) {
+ // We have found the BlockEntry attached to the address. We save its start address (the start
+ // address might be before the 'BaseAdress') and attributes
+ *BaseAddress = *BaseAddress & ~(TT_ADDRESS_AT_LEVEL(TableLevel) - 1);
+ *RegionLength = 0;
+ *RegionAttributes = *BlockEntry & TT_ATTRIBUTES_MASK;
+ } else {
+ // We have an 'Invalid' entry
+ return EFI_UNSUPPORTED;
+ }
+
+ while (BlockEntry <= LastBlockEntry) {
+ if ((*BlockEntry & TT_ATTRIBUTES_MASK) == *RegionAttributes) {
+ *RegionLength = *RegionLength + TT_BLOCK_ENTRY_SIZE_AT_LEVEL(TableLevel);
+ } else {
+ // In case we have found the end of the region we return success
+ return EFI_SUCCESS;
+ }
+ BlockEntry++;
+ }
+
+ // If we have reached the end of the TranslationTable and we have not found the end of the region then
+ // we return EFI_NOT_FOUND.
+ // The caller will continue to look for the memory region at its level
+ return EFI_NOT_FOUND;
+}
+
+EFI_STATUS
+GetMemoryRegion (
+ IN OUT UINTN *BaseAddress,
+ OUT UINTN *RegionLength,
+ OUT UINTN *RegionAttributes
+ )
+{
+ EFI_STATUS Status;
+ UINT64 *TranslationTable;
+ UINTN TableLevel;
+ UINTN EntryCount;
+ UINTN T0SZ;
+
+ ASSERT ((BaseAddress != NULL) && (RegionLength != NULL) && (RegionAttributes != NULL));
+
+ TranslationTable = ArmGetTTBR0BaseAddress ();
+
+ T0SZ = ArmGetTCR () & TCR_T0SZ_MASK;
+ // Get the Table info from T0SZ
+ GetRootTranslationTableInfo (T0SZ, &TableLevel, &EntryCount);
+
+ Status = GetMemoryRegionRec (TranslationTable, TableLevel,
+ (UINTN*)TT_LAST_BLOCK_ADDRESS(TranslationTable, EntryCount),
+ BaseAddress, RegionLength, RegionAttributes);
+
+ // If the region continues up to the end of the root table then GetMemoryRegionRec()
+ // will return EFI_NOT_FOUND
+ if (Status == EFI_NOT_FOUND) {
+ return EFI_SUCCESS;
+ } else {
+ return Status;
+ }
+}
diff --git a/ArmPkg/Drivers/CpuDxe/ArmV6/Mmu.c b/ArmPkg/Drivers/CpuDxe/ArmV6/Mmu.c
index 38b709d..474f105 100644
--- a/ArmPkg/Drivers/CpuDxe/ArmV6/Mmu.c
+++ b/ArmPkg/Drivers/CpuDxe/ArmV6/Mmu.c
@@ -696,3 +696,185 @@
return Status;
}
+
+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_WP:
+ case EFI_MEMORY_XP:
+ case EFI_MEMORY_RP:
+ case EFI_MEMORY_UCE:
+ default:
+ // Cannot be implemented UEFI definition unclear for ARM
+ // Cause a page fault if these ranges are accessed.
+ ArmAttributes = TT_DESCRIPTOR_SECTION_TYPE_FAULT;
+ DEBUG ((EFI_D_PAGE, "SetMemoryAttributes(): Unsupported attribute %x will page fault on access\n", EfiAttributes));
+ break;
+ }
+
+ // Determine protection attributes
+ if (EfiAttributes & EFI_MEMORY_WP) {
+ 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 = TT_DESCRIPTOR_PAGE_BASE_ADDRESS(*BaseAddress) >> 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 '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 = TT_DESCRIPTOR_PAGE_BASE_ADDRESS (*BaseAddress) >> 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 ((SectionDescriptor & TT_DESCRIPTOR_SECTION_TYPE_MASK) == TT_DESCRIPTOR_SECTION_TYPE_PAGE_TABLE) {
+ // 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;
+}
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.h b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
index 075f2a1..d5b5064 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.h
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
@@ -148,6 +148,19 @@
IN EFI_PHYSICAL_ADDRESS VirtualMask
);
+// The ARM Attributes might be defined on 64-bit (case of the long format description table)
+UINT64
+EfiAttributeToArmAttribute (
+ IN UINT64 EfiAttributes
+ );
+
+EFI_STATUS
+GetMemoryRegion (
+ IN OUT UINTN *BaseAddress,
+ OUT UINTN *RegionLength,
+ OUT UINTN *RegionAttributes
+ );
+
VOID
GetRootTranslationTableInfo (
IN UINTN T0SZ,
diff --git a/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c b/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
index e0ee9fc..723604d 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
+++ b/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
@@ -178,18 +178,37 @@
IN EFI_CPU_ARCH_PROTOCOL *This,
IN EFI_PHYSICAL_ADDRESS BaseAddress,
IN UINT64 Length,
- IN UINT64 Attributes
+ IN UINT64 EfiAttributes
)
{
- DEBUG ((EFI_D_PAGE, "CpuSetMemoryAttributes(%lx, %lx, %lx)\n", BaseAddress, Length, Attributes));
+ EFI_STATUS Status;
+ UINTN ArmAttributes;
+ UINTN RegionBaseAddress;
+ UINTN RegionLength;
+ UINTN RegionArmAttributes;
if ((BaseAddress & (SIZE_4KB - 1)) != 0) {
// Minimum granularity is SIZE_4KB (4KB on ARM)
- DEBUG ((EFI_D_PAGE, "CpuSetMemoryAttributes(%lx, %lx, %lx): Minimum ganularity is SIZE_4KB\n", BaseAddress, Length, Attributes));
+ DEBUG ((EFI_D_PAGE, "CpuSetMemoryAttributes(%lx, %lx, %lx): Minimum ganularity is SIZE_4KB\n", BaseAddress, Length, EfiAttributes));
return EFI_UNSUPPORTED;
}
- return SetMemoryAttributes (BaseAddress, Length, Attributes, 0);
+ // Convert the 'Attribute' into ARM Attribute
+ ArmAttributes = EfiAttributeToArmAttribute (EfiAttributes);
+
+ // Get the region starting from 'BaseAddress' and its 'Attribute'
+ RegionBaseAddress = BaseAddress;
+ Status = GetMemoryRegion (&RegionBaseAddress, &RegionLength, &RegionArmAttributes);
+
+ // Data & Instruction Caches are flushed when we set new memory attributes.
+ // So, we only set the attributes if the new region is different.
+ if (EFI_ERROR (Status) || (RegionArmAttributes != ArmAttributes) ||
+ ((BaseAddress + Length) > (RegionBaseAddress + RegionLength)))
+ {
+ return SetMemoryAttributes (BaseAddress, Length, EfiAttributes, 0);
+ } else {
+ return EFI_SUCCESS;
+ }
}
EFI_STATUS