ArmPkg/Drivers/CpuDxe/ArmV6/Mmu.c
/*++
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>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
--*/
#include <Library/MemoryAllocationLib.h>
#include "CpuDxe.h"
// First Level Descriptors
typedef UINT32 ARM_FIRST_LEVEL_DESCRIPTOR;
// Second Level Descriptors
typedef UINT32 ARM_PAGE_TABLE_ENTRY;
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_WP | 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_WP;
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_WP | 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_WP;
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 ((EFI_D_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])) {
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;
}
EFI_STATUS
UpdatePageEntries (
IN EFI_PHYSICAL_ADDRESS BaseAddress,
IN UINT64 Length,
IN UINT64 Attributes,
IN EFI_PHYSICAL_ADDRESS VirtualMask
)
{
EFI_STATUS Status;
UINT32 EntryValue;
UINT32 EntryMask;
UINT32 FirstLevelIdx;
UINT32 Offset;
UINT32 NumPageEntries;
UINT32 Descriptor;
UINT32 p;
UINT32 PageTableIndex;
UINT32 PageTableEntry;
UINT32 CurrentPageTableEntry;
VOID *Mva;
volatile ARM_FIRST_LEVEL_DESCRIPTOR *FirstLevelTable;
volatile ARM_PAGE_TABLE_ENTRY *PageTable;
Status = EFI_SUCCESS;
// EntryMask: bitmask of values to change (1 = change this value, 0 = leave alone)
// EntryValue: values at bit positions specified by EntryMask
EntryMask = TT_DESCRIPTOR_PAGE_TYPE_MASK;
EntryValue = TT_DESCRIPTOR_PAGE_TYPE_PAGE;
// Although the PI spec is unclear on this the GCD guarantees that only
// one Attribute bit is set at a time, so we can safely use a switch statement
switch (Attributes) {
case EFI_MEMORY_UC:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK;
// map to strongly ordered
EntryValue |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_STRONGLY_ORDERED; // TEX[2:0] = 0, C=0, B=0
break;
case EFI_MEMORY_WC:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK;
// map to normal non-cachable
EntryValue |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_NON_CACHEABLE; // TEX [2:0]= 001 = 0x2, B=0, C=0
break;
case EFI_MEMORY_WT:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK;
// write through with no-allocate
EntryValue |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_WRITE_THROUGH_NO_ALLOC; // TEX [2:0] = 0, C=1, B=0
break;
case EFI_MEMORY_WB:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_PAGE_CACHE_POLICY_MASK;
// write back (with allocate)
EntryValue |= TT_DESCRIPTOR_PAGE_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_UCE:
// cannot be implemented UEFI definition unclear for ARM
// Cause a page fault if these ranges are accessed.
EntryValue = TT_DESCRIPTOR_PAGE_TYPE_FAULT;
DEBUG ((EFI_D_PAGE, "SetMemoryAttributes(): setting page %lx with unsupported attribute %x will page fault on access\n", BaseAddress, Attributes));
break;
default:
return EFI_UNSUPPORTED;
}
// Obtain page table base
FirstLevelTable = (ARM_FIRST_LEVEL_DESCRIPTOR *)ArmGetTTBR0BaseAddress ();
// Calculate number of 4KB page table entries to change
NumPageEntries = Length / TT_DESCRIPTOR_PAGE_SIZE;
// Iterate for the number of 4KB pages to change
Offset = 0;
for(p = 0; p < NumPageEntries; p++) {
// Calculate index into first level translation table for page table value
FirstLevelIdx = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(BaseAddress + Offset) >> TT_DESCRIPTOR_SECTION_BASE_SHIFT;
ASSERT (FirstLevelIdx < TRANSLATION_TABLE_SECTION_COUNT);
// Read the descriptor from the first level page table
Descriptor = FirstLevelTable[FirstLevelIdx];
// Does this descriptor need to be converted from section entry to 4K pages?
if (!TT_DESCRIPTOR_SECTION_TYPE_IS_PAGE_TABLE(Descriptor)) {
Status = ConvertSectionToPages (FirstLevelIdx << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
if (EFI_ERROR(Status)) {
// Exit for loop
break;
}
// Re-read descriptor
Descriptor = FirstLevelTable[FirstLevelIdx];
}
// Obtain page table base address
PageTable = (ARM_PAGE_TABLE_ENTRY *)TT_DESCRIPTOR_PAGE_BASE_ADDRESS(Descriptor);
// Calculate index into the page table
PageTableIndex = ((BaseAddress + Offset) & TT_DESCRIPTOR_PAGE_INDEX_MASK) >> TT_DESCRIPTOR_PAGE_BASE_SHIFT;
ASSERT (PageTableIndex < TRANSLATION_TABLE_PAGE_COUNT);
// Get the entry
CurrentPageTableEntry = PageTable[PageTableIndex];
// Mask off appropriate fields
PageTableEntry = CurrentPageTableEntry & ~EntryMask;
// Mask in new attributes and/or permissions
PageTableEntry |= EntryValue;
if (VirtualMask != 0) {
// Make this virtual address point at a physical page
PageTableEntry &= ~VirtualMask;
}
if (CurrentPageTableEntry != PageTableEntry) {
Mva = (VOID *)(UINTN)((((UINTN)FirstLevelIdx) << TT_DESCRIPTOR_SECTION_BASE_SHIFT) + (PageTableIndex << TT_DESCRIPTOR_PAGE_BASE_SHIFT));
if ((CurrentPageTableEntry & TT_DESCRIPTOR_PAGE_CACHEABLE_MASK) == TT_DESCRIPTOR_PAGE_CACHEABLE_MASK) {
// The current section mapping is cacheable so Clean/Invalidate the MVA of the page
// Note assumes switch(Attributes), not ARMv7 possibilities
WriteBackInvalidateDataCacheRange (Mva, TT_DESCRIPTOR_PAGE_SIZE);
}
// Only need to update if we are changing the entry
PageTable[PageTableIndex] = PageTableEntry;
ArmUpdateTranslationTableEntry ((VOID *)&PageTable[PageTableIndex], Mva);
}
Status = EFI_SUCCESS;
Offset += TT_DESCRIPTOR_PAGE_SIZE;
} // End first level translation table loop
return Status;
}
EFI_STATUS
UpdateSectionEntries (
IN EFI_PHYSICAL_ADDRESS BaseAddress,
IN UINT64 Length,
IN UINT64 Attributes,
IN EFI_PHYSICAL_ADDRESS VirtualMask
)
{
EFI_STATUS Status = EFI_SUCCESS;
UINT32 EntryMask;
UINT32 EntryValue;
UINT32 FirstLevelIdx;
UINT32 NumSections;
UINT32 i;
UINT32 CurrentDescriptor;
UINT32 Descriptor;
VOID *Mva;
volatile ARM_FIRST_LEVEL_DESCRIPTOR *FirstLevelTable;
// EntryMask: bitmask of values to change (1 = change this value, 0 = leave alone)
// EntryValue: values at bit positions specified by EntryMask
// Make sure we handle a section range that is unmapped
EntryMask = TT_DESCRIPTOR_SECTION_TYPE_MASK;
EntryValue = TT_DESCRIPTOR_SECTION_TYPE_SECTION;
// Although the PI spec is unclear on this the GCD guarantees that only
// one Attribute bit is set at a time, so we can safely use a switch statement
switch(Attributes) {
case EFI_MEMORY_UC:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK;
// map to strongly ordered
EntryValue |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_STRONGLY_ORDERED; // TEX[2:0] = 0, C=0, B=0
break;
case EFI_MEMORY_WC:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK;
// map to normal non-cachable
EntryValue |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_NON_CACHEABLE; // TEX [2:0]= 001 = 0x2, B=0, C=0
break;
case EFI_MEMORY_WT:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK;
// write through with no-allocate
EntryValue |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_THROUGH_NO_ALLOC; // TEX [2:0] = 0, C=1, B=0
break;
case EFI_MEMORY_WB:
// modify cacheability attributes
EntryMask |= TT_DESCRIPTOR_SECTION_CACHE_POLICY_MASK;
// write back (with allocate)
EntryValue |= 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:
// cannot be implemented UEFI definition unclear for ARM
// Cause a page fault if these ranges are accessed.
EntryValue = TT_DESCRIPTOR_SECTION_TYPE_FAULT;
DEBUG ((EFI_D_PAGE, "SetMemoryAttributes(): setting section %lx with unsupported attribute %x will page fault on access\n", BaseAddress, Attributes));
break;
default:
return EFI_UNSUPPORTED;
}
// obtain page table base
FirstLevelTable = (ARM_FIRST_LEVEL_DESCRIPTOR *)ArmGetTTBR0BaseAddress ();
// calculate index into first level translation table for start of modification
FirstLevelIdx = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(BaseAddress) >> TT_DESCRIPTOR_SECTION_BASE_SHIFT;
ASSERT (FirstLevelIdx < TRANSLATION_TABLE_SECTION_COUNT);
// calculate number of 1MB first level entries this applies to
NumSections = Length / TT_DESCRIPTOR_SECTION_SIZE;
// iterate through each descriptor
for(i=0; i<NumSections; i++) {
CurrentDescriptor = FirstLevelTable[FirstLevelIdx + i];
// has this descriptor already been coverted to pages?
if (TT_DESCRIPTOR_SECTION_TYPE_IS_PAGE_TABLE(CurrentDescriptor)) {
// forward this 1MB range to page table function instead
Status = UpdatePageEntries ((FirstLevelIdx + i) << TT_DESCRIPTOR_SECTION_BASE_SHIFT, TT_DESCRIPTOR_SECTION_SIZE, Attributes, VirtualMask);
} else {
// still a section entry
// mask off appropriate fields
Descriptor = CurrentDescriptor & ~EntryMask;
// mask in new attributes and/or permissions
Descriptor |= EntryValue;
if (VirtualMask != 0) {
Descriptor &= ~VirtualMask;
}
if (CurrentDescriptor != Descriptor) {
Mva = (VOID *)(UINTN)(((UINTN)FirstLevelTable) << TT_DESCRIPTOR_SECTION_BASE_SHIFT);
if ((CurrentDescriptor & TT_DESCRIPTOR_SECTION_CACHEABLE_MASK) == TT_DESCRIPTOR_SECTION_CACHEABLE_MASK) {
// The current section mapping is cacheable so Clean/Invalidate the MVA of the section
// Note assumes switch(Attributes), not ARMv7 possabilities
WriteBackInvalidateDataCacheRange (Mva, SIZE_1MB);
}
// Only need to update if we are changing the descriptor
FirstLevelTable[FirstLevelIdx + i] = Descriptor;
ArmUpdateTranslationTableEntry ((VOID *)&FirstLevelTable[FirstLevelIdx + i], Mva);
}
Status = EFI_SUCCESS;
}
}
return Status;
}
EFI_STATUS
ConvertSectionToPages (
IN EFI_PHYSICAL_ADDRESS BaseAddress
)
{
EFI_STATUS Status;
EFI_PHYSICAL_ADDRESS PageTableAddr;
UINT32 FirstLevelIdx;
UINT32 SectionDescriptor;
UINT32 PageTableDescriptor;
UINT32 PageDescriptor;
UINT32 Index;
volatile ARM_FIRST_LEVEL_DESCRIPTOR *FirstLevelTable;
volatile ARM_PAGE_TABLE_ENTRY *PageTable;
DEBUG ((EFI_D_PAGE, "Converting section at 0x%x to pages\n", (UINTN)BaseAddress));
// Obtain page table base
FirstLevelTable = (ARM_FIRST_LEVEL_DESCRIPTOR *)ArmGetTTBR0BaseAddress ();
// Calculate index into first level translation table for start of modification
FirstLevelIdx = TT_DESCRIPTOR_SECTION_BASE_ADDRESS(BaseAddress) >> TT_DESCRIPTOR_SECTION_BASE_SHIFT;
ASSERT (FirstLevelIdx < TRANSLATION_TABLE_SECTION_COUNT);
// Get section attributes and convert to page attributes
SectionDescriptor = FirstLevelTable[FirstLevelIdx];
PageDescriptor = TT_DESCRIPTOR_PAGE_TYPE_PAGE | ConvertSectionAttributesToPageAttributes (SectionDescriptor, FALSE);
// Allocate a page table for the 4KB entries (we use up a full page even though we only need 1KB)
Status = gBS->AllocatePages (AllocateAnyPages, EfiBootServicesData, 1, &PageTableAddr);
if (EFI_ERROR(Status)) {
return Status;
}
PageTable = (volatile ARM_PAGE_TABLE_ENTRY *)(UINTN)PageTableAddr;
// Write the page table entries out
for (Index = 0; Index < TRANSLATION_TABLE_PAGE_COUNT; Index++) {
PageTable[Index] = TT_DESCRIPTOR_PAGE_BASE_ADDRESS(BaseAddress + (Index << 12)) | PageDescriptor;
}
// Flush d-cache so descriptors make it back to uncached memory for subsequent table walks
WriteBackInvalidateDataCacheRange ((VOID *)(UINTN)PageTableAddr, TT_DESCRIPTOR_PAGE_SIZE);
// Formulate page table entry, Domain=0, NS=0
PageTableDescriptor = (((UINTN)PageTableAddr) & TT_DESCRIPTOR_SECTION_PAGETABLE_ADDRESS_MASK) | TT_DESCRIPTOR_SECTION_TYPE_PAGE_TABLE;
// Write the page table entry out, replacing section entry
FirstLevelTable[FirstLevelIdx] = PageTableDescriptor;
return EFI_SUCCESS;
}
EFI_STATUS
SetMemoryAttributes (
IN EFI_PHYSICAL_ADDRESS BaseAddress,
IN UINT64 Length,
IN UINT64 Attributes,
IN EFI_PHYSICAL_ADDRESS VirtualMask
)
{
EFI_STATUS Status;
if(((BaseAddress & 0xFFFFF) == 0) && ((Length & 0xFFFFF) == 0)) {
// Is the base and length a multiple of 1 MB?
DEBUG ((EFI_D_PAGE, "SetMemoryAttributes(): MMU section 0x%x length 0x%x to %lx\n", (UINTN)BaseAddress, (UINTN)Length, Attributes));
Status = UpdateSectionEntries (BaseAddress, Length, Attributes, VirtualMask);
} else {
// Base and/or length is not a multiple of 1 MB
DEBUG ((EFI_D_PAGE, "SetMemoryAttributes(): MMU page 0x%x length 0x%x to %lx\n", (UINTN)BaseAddress, (UINTN)Length, Attributes));
Status = UpdatePageEntries (BaseAddress, Length, Attributes, VirtualMask);
}
// Flush d-cache so descriptors make it back to uncached memory for subsequent table walks
// flush and invalidate pages
//TODO: Do we really need to invalidate the caches everytime we change the memory attributes ?
ArmCleanInvalidateDataCache ();
ArmInvalidateInstructionCache ();
// Invalidate all TLB entries so changes are synced
ArmInvalidateTlb ();
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 = ((*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 '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;
}