commit 13ae0f4d8f86a6a24d7df9cfe9494e46967845c9
author Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com> Thu Nov 25 14:59:30 2021 +0000
committer Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com> Fri Dec 10 12:33:51 2021 +0000
tree 41726d15d8e4fc4df51af51f070fe899ee5be472
parent 166f598d2a36c7d70f3eb0037e9c659185b844d5

fix(amu): fault handling on EL2 context switch

The HAFGRTR_EL2 register is UNDEFINED unless the CPU supports both
FEAT_FGT and FEAT_AMUv1. FEAT_FGT is mandatory for v8.6-A and upwards,
but FEAT_AMUv1 is optional (from v8.4-A upwards), and as such any
8.6-A cores today without support for FEAT_AMUv1 will trigger an
undefined instruction exception on accessing this register.

Currently ARM_ARCH_AT_LEAST macro has been used to associate with an
architecture extension allowing to access HAFGRTR_EL2 register. This
condition should be replaced with macros specific to individual
features. This patch adds a new set of macros "ENABLE_FEAT_FGT,
ENABLE_FEAT_AMUv1, ENABLE_FEAT_ECV" under build options to provide
controlled access to the HAFGRTR_EL2 register.

Further to ensure that the the build options passed comply
with the given hardware implementation, a feature detection mechanism,
checking whether build options match with the architecture is required
at bootime. This will be implemented and pushed later in a separate
patch.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Ie390f4babe233b8b09455290277edbddecd33ead

Makefile

diff --git a/Makefile b/Makefile
index 73007b4..32eb501 100644
--- a/Makefile
+++ b/Makefile
@@ -267,6 +267,16 @@
 ENABLE_FEAT_SB		= 	1
 endif
 
+# Determine and enable FEAT_FGT to access HDFGRTR_EL2 register for v8.6 and higher versions.
+ifeq "8.6" "$(word 1, $(sort 8.6 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_FGT		=	1
+endif
+
+# Determine and enable FEAT_ECV to access CNTPOFF_EL2 register for v8.6 and higher versions.
+ifeq "8.6" "$(word 1, $(sort 8.6 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_ECV		=	1
+endif
+
 ifneq ($(findstring armclang,$(notdir $(CC))),)
 TF_CFLAGS_aarch32	=	-target arm-arm-none-eabi $(march32-directive)
 TF_CFLAGS_aarch64	=	-target aarch64-arm-none-eabi $(march64-directive)
@@ -1041,6 +1051,9 @@
         ENABLE_FEAT_HCX \
         ENABLE_MPMM \
         ENABLE_MPMM_FCONF \
+        ENABLE_FEAT_FGT \
+        ENABLE_FEAT_AMUv1 \
+        ENABLE_FEAT_ECV \
 )))
 
 $(eval $(call assert_numerics,\
@@ -1153,6 +1166,9 @@
         ENABLE_FEAT_HCX \
         ENABLE_MPMM \
         ENABLE_MPMM_FCONF \
+        ENABLE_FEAT_FGT \
+        ENABLE_FEAT_AMUv1 \
+        ENABLE_FEAT_ECV \
 )))
 
 ifeq (${SANITIZE_UB},trap)