ArmPkg/Drivers/CpuDxe: Use lower and upper attributes

`GetNextEntryAttribute()` is currently applying the 64-bit mask to a
32-bit descriptor value (the lower attributes).

`EntryType` (and `EntryTypeAttribute`) are 32-bit and
`TT_ATTRIBUTES_MASK` is 64-bit:

  #define TT_ATTRIBUTES_MASK  ((0xFFFULL << 52) | (0x3FFULL << 2))

In the 64-bit descriptor, there are 10 bits of lower attributes and
12 bits of upper attributes.

The descriptor is converted to a 32-bit value and assigned to
`EntryAttribute`.

This is assigned to `PrevEntryAttribute`:

        *PrevEntryAttribute = EntryAttribute;

Where `PrevEntryAttribute` is also a `UINT32`:

    IN OUT UINT32  *PrevEntryAttribute,

Which is passed to `PageAttributeToGcdAttribute()`:

          SetGcdMemorySpaceAttributes (
            MemorySpaceMap,
            NumberOfDescriptors,
            *StartGcdRegion,
            (BaseAddress + (Index * TT_ADDRESS_AT_LEVEL (TableLevel))) - *StartGcdRegion,
            PageAttributeToGcdAttribute (*PrevEntryAttribute)
            );

Which accepts a `UINT64`:

STATIC
UINT64
PageAttributeToGcdAttribute (
  IN UINT64  PageAttributes
  );

Which sets `EFI_MEMORY_XP` based on `TT_PXN_MASK | TT_UXN_MASK`:

  // Process eXecute Never attribute
  if ((PageAttributes & (TT_PXN_MASK | TT_UXN_MASK)) != 0) {
    GcdAttributes |= EFI_MEMORY_XP;
  }

Where those bits are in the upper attributes:

This change uses a 64-bit integer to hold the attributes to set
`EFI_MEMORY_XP`.

Signed-off-by: Michael Kubacki <[email protected]>

ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c

@@ -14,7 +14,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Chipset/AArch64Mmu.h>         // MU_CHANGE: Include header used in file
 #include "CpuDxe.h"
 
-#define INVALID_ENTRY  ((UINT32)~0)
+#define INVALID_ENTRY  ((UINT64)~0)     // MU_CHANGE: Use 64-bit entry value
 
 #define MIN_T0SZ        16
 #define BITS_PER_LEVEL  9
@@ -134,13 +134,13 @@ GetNextEntryAttribute (
   IN     UINTN   EntryCount,
   IN     UINTN   TableLevel,
   IN     UINT64  BaseAddress,
-  IN OUT UINT32  *PrevEntryAttribute,
+  IN OUT UINT64  *PrevEntryAttribute, // MU_CHANGE: Use 64-bit entry value
   IN OUT UINT64  *StartGcdRegion
   )
 {
   UINTN                            Index;
   UINT64                           Entry;
-  UINT32                           EntryAttribute;
+  UINT64                           EntryAttribute;  // MU_CHANGE: Use 64-bit entry value
   UINT32                           EntryType;
   EFI_STATUS                       Status;
   UINTN                            NumberOfDescriptors;
@@ -169,7 +169,8 @@ GetNextEntryAttribute (
 
     // MU_CHANGE [BEGIN]: Add UINT32 cast
     EntryType      = (UINT32)(Entry & TT_TYPE_MASK);
-    EntryAttribute = (UINT32)(Entry & TT_ATTRIBUTES_MASK);  // MU_CHANGE: Return all attributes from page table
+    EntryAttribute = Entry & TT_ATTRIBUTES_MASK;  // MU_CHANGE: Return all attributes from page table
+                                                  // MU_CHANGE: Use 64-bit entry value
     // MU_CHANGE [END]: Add UINT32 cast
 
     // If Entry is a Table Descriptor type entry then go through the sub-level table
@@ -236,7 +237,7 @@ SyncCacheConfig (
   )
 {
   EFI_STATUS                       Status;
-  UINT32                           PageAttribute;
+  UINT64                           PageAttribute;           // MU_CHANGE: Use 64-bit entry value
   UINT64                           *FirstLevelTableAddress;
   UINTN                            TableLevel;
   UINTN                            TableCount;
@@ -275,7 +276,7 @@ SyncCacheConfig (
   GetRootTranslationTableInfo (T0SZ, &TableLevel, &TableCount);
 
   // First Attribute of the Page Tables
-  PageAttribute = (UINT32)GetFirstPageAttribute (FirstLevelTableAddress, TableLevel);
+  PageAttribute = GetFirstPageAttribute (FirstLevelTableAddress, TableLevel); // MU_CHANGE: Use 64-bit entry value
 
   // We scan from the start of the memory map (ie: at the address 0x0)
   BaseAddressGcdRegion = 0x0;