refactor(mte): remove mte, mte_perm
Currently both FEAT_MTE and FEAT_MTE_PERM aren't used for enabling
of any feature bits in EL3. So remove both FEAT handling.
All mte regs that are currently context saved/restored are needed
only when FEAT_MTE2 is enabled, so move to usage of FEAT_MTE2 and
remove FEAT_MTE usage.
BREAKING CHANGE: Any platform or downstream code trying to use
SCR_EL3.ATA bit(26) will see failures as this is now moved to be
used only with FEAT_MTE2 with
commit@ef0d0e5478a3f19cbe70a378b9b184036db38fe2
Change-Id: Id01e154156571f7792135639e17dc5c8d0e17cf8
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/docs/design/firmware-design.rst b/docs/design/firmware-design.rst
index fa06c8e..2ba54ea 100644
--- a/docs/design/firmware-design.rst
+++ b/docs/design/firmware-design.rst
@@ -2800,9 +2800,11 @@
- Branch Target Identification feature is selected by ``BRANCH_PROTECTION``
option set to 1. This option defaults to 0.
-- Memory Tagging Extension feature is unconditionally enabled for both worlds.
- To enable MTE at EL0 use ``ENABLE_FEAT_MTE`` is required and to enable MTE at
- ELX ``ENABLE_FEAT_MTE2`` is required.
+- Memory Tagging Extension feature has few variants but not all of them require
+ enablement from EL3 to be used at lower EL. e.g. Memory tagging only at
+ EL0(MTE) does not require EL3 configuration however memory tagging at
+ EL2/EL1 (MTE2) does require EL3 enablement and we need to set this option
+ ``ENABLE_FEAT_MTE2`` to 1. This option defaults to 0.
Armv7-A
~~~~~~~