MdeModulePkg/VariableRuntimeDxe: factor out boot service accesses

In preparation of providing a standalone MM based variable runtime
driver, move the existing SMM driver to the new MM services table,
and factor out some pieces that are specific to the traditional
driver, mainly related to the use of UEFI boot services, which are
not accessible to standalone MM drivers.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>

MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h

@@ -97,4 +97,67 @@ VariableSpeculationBarrier (
   VOID
   );
 
+/**
+  Notify the system that the SMM variable driver is ready
+**/
+VOID
+VariableNotifySmmReady (
+  VOID
+  );
+
+/**
+  Notify the system that the SMM variable write driver is ready
+**/
+VOID
+VariableNotifySmmWriteReady (
+  VOID
+  );
+
+/**
+  Variable Driver main entry point. The Variable driver places the 4 EFI
+  runtime services in the EFI System Table and installs arch protocols
+  for variable read and write services being available. It also registers
+  a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.
+
+  @retval EFI_SUCCESS       Variable service successfully initialized.
+**/
+EFI_STATUS
+EFIAPI
+MmVariableServiceInitialize (
+  VOID
+  );
+
+/**
+  This function checks if the buffer is valid per processor architecture and
+  does not overlap with SMRAM.
+
+  @param Buffer The buffer start address to be checked.
+  @param Length The buffer length to be checked.
+
+  @retval TRUE  This buffer is valid per processor architecture and does not
+                overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlaps
+                with SMRAM.
+**/
+BOOLEAN
+VariableSmmIsBufferOutsideSmmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  );
+
+/**
+  Whether the TCG or TCG2 protocols are installed in the UEFI protocol database.
+  This information is used by the MorLock code to infer whether an existing
+  MOR variable is legitimate or not.
+
+  @retval TRUE  Either the TCG or TCG2 protocol is installed in the UEFI
+                protocol database
+  @retval FALSE Neither the TCG nor the TCG2 protocol is installed in the UEFI
+                protocol database
+**/
+BOOLEAN
+VariableHaveTcgProtocols (
+  VOID
+  );
+
 #endif