[PATCH v7 04/21] ArmPkg: Add helper to read the Memory Model Features Register 2

["Rebecca Cran" <rebecca@nuviainc.com>]

Add helper function to read the MMFR2 register. We will need this to
determine CCIDX support.

Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
---
 ArmPkg/Library/ArmLib/AArch64/AArch64Lib.h     | 11 +++++++++++
 ArmPkg/Library/ArmLib/AArch64/AArch64Support.S |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.h b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.h
index 85bcecda730f..cfc0c878a415 100644
--- a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.h
+++ b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.h
@@ -41,5 +41,16 @@ EFIAPI
 ArmReadIdAA64Pfr0 (
   VOID
   );
+
+/** Reads the ID_AA64MMFR2_EL1 register.
+
+   @return The contents of the ID_AA64MMFR2_EL1 register.
+**/
+UINTN
+EFIAPI
+ArmReadIdAA64Mmfr2 (
+  VOID
+  );
+
 #endif // __AARCH64_LIB_H__
 
diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S b/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
index 129205d2ac27..d3cc1e86716b 100644
--- a/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
+++ b/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
@@ -425,6 +425,9 @@ ASM_FUNC(ArmCallWFI)
   wfi
   ret
 
+ASM_FUNC(ArmReadIdAA64Mmfr2)
+  mrs   x0, ID_AA64MMFR2_EL1           // read EL1 MMFR2
+  ret
 
 ASM_FUNC(ArmReadMpidr)
   mrs   x0, mpidr_el1           // read EL1 MPIDR
-- 
2.26.2