[PATCH 1/5] ArmPkg/CpuDxe: use private copy of GetRootTranslationTableInfo()

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

Before getting rid of GetRootTranslationTableInfo() and the related
LookupAddresstoRootTable() in AARCH64's version of ArmMmuLib, add a
version of the former to CpuDxe, which will be its only remaining
user. While at it, simplify it a bit, since in the CpuDxe cases,
both OUT arguments are always provided.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c | 15 +++++++++++++++
 ArmPkg/Drivers/CpuDxe/CpuDxe.h      |  7 -------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
index 3b6c5e733709..24eb1c4221e3 100644
--- a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
+++ b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
@@ -15,6 +15,21 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #define TT_ATTR_INDX_INVALID    ((UINT32)~0)
 
+#define MIN_T0SZ        16
+#define BITS_PER_LEVEL  9
+
+STATIC
+VOID
+GetRootTranslationTableInfo (
+  IN  UINTN     T0SZ,
+  OUT UINTN     *RootTableLevel,
+  OUT UINTN     *RootTableEntryCount
+  )
+{
+  *RootTableLevel       = (T0SZ - MIN_T0SZ) / BITS_PER_LEVEL;
+  *RootTableEntryCount  = TT_ENTRY_COUNT >> (T0SZ - MIN_T0SZ) % BITS_PER_LEVEL;
+}
+
 STATIC
 UINT64
 GetFirstPageAttribute (
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.h b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
index b627c3c50ff8..3fe5c24d5e5b 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.h
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
@@ -134,13 +134,6 @@ GetMemoryRegion (
   OUT    UINTN                   *RegionAttributes
   );
 
-VOID
-GetRootTranslationTableInfo (
-  IN  UINTN    T0SZ,
-  OUT UINTN   *TableLevel,
-  OUT UINTN   *TableEntryCount
-  );
-
 EFI_STATUS
 SetGcdMemorySpaceAttributes (
   IN EFI_GCD_MEMORY_SPACE_DESCRIPTOR    *MemorySpaceMap,
-- 
2.17.1