refactor(el3-runtime): add arch-features detection mechanism

This patch adds architectural features detection procedure to ensure
features enabled are present in the given hardware implementation.

It verifies whether the architecture build flags passed during
compilation match the respective features by reading their ID
registers. It reads through all the enabled feature specific ID
registers at once and panics in case of mismatch(feature enabled
but not implemented in PE).

Feature flags are used at sections (context_management,
save and restore routines of registers) during context switch.
If the enabled feature flag is not supported by the PE, it causes an
exception while saving or restoring the registers guarded by them.

With this mechanism, the build flags are validated at an early
phase prior to their usage, thereby preventing any undefined action
under their control.

This implementation is based on tristate approach for each feature and
currently FEAT_STATE=0 and FEAT_STATE=1 are covered as part of this
patch. FEAT_STATE=2 is planned for phase-2 implementation and will be
taken care separately.

The patch has been explicitly tested, by adding a new test_config
with build config enabling majority of the features and detected
all of them under FVP launched with parameters enabling v8.7 features.

Note: This is an experimental procedure and the mechanism itself is
      guarded by a macro "FEATURE_DETECTION", which is currently being
      disabled by default.

The "FEATURE_DETECTION" macro is documented and the platforms are
encouraged to make use of this diagnostic tool by enabling this
"FEATURE_DETECTION" flag explicitly and get used to its behaviour
during booting before the procedure gets mandated.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Ia23d95430fe82d417a938b672bfb5edc401b0f43

1 files changed, 33 insertions, 32 deletions

diff --git a/Makefile b/Makefile
index 95c9075ee..f91699c44 100644
--- a/Makefile
+++ b/Makefile
@@ -263,24 +263,6 @@ ENABLE_FEAT_RNG		=	$(if $(findstring rng,${arch-features}),1,0)
 # Determine if FEAT_SB is supported
 ENABLE_FEAT_SB		=	$(if $(findstring sb,${arch-features}),1,0)
 
-ifeq "8.5" "$(word 1, $(sort 8.5 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-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
-
-ifeq "8.4" "$(word 1, $(sort 8.4 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-ENABLE_FEAT_DIT		= 	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)
@@ -474,6 +456,7 @@ endif
 ################################################################################
 # Common sources and include directories
 ################################################################################
+include ${MAKE_HELPERS_DIRECTORY}arch_features.mk
 include lib/compiler-rt/compiler-rt.mk
 
 BL_COMMON_SOURCES	+=	common/bl_common.c			\
@@ -776,6 +759,10 @@ ifeq ($(PSA_FWU_SUPPORT),1)
     $(info PSA_FWU_SUPPORT is an experimental feature)
 endif
 
+ifeq ($(FEATURE_DETECTION),1)
+    $(info FEATURE_DETECTION is an experimental feature)
+endif
+
 ifeq (${ARM_XLAT_TABLES_LIB_V1}, 1)
     ifeq (${ALLOW_RO_XLAT_TABLES}, 1)
         $(error "ALLOW_RO_XLAT_TABLES requires translation tables library v2")
@@ -980,10 +967,7 @@ $(eval $(call assert_booleans,\
         CREATE_KEYS \
         CTX_INCLUDE_AARCH32_REGS \
         CTX_INCLUDE_FPREGS \
-        CTX_INCLUDE_PAUTH_REGS \
-        CTX_INCLUDE_MTE_REGS \
         CTX_INCLUDE_EL2_REGS \
-        CTX_INCLUDE_NEVE_REGS \
         DEBUG \
         DISABLE_MTPMU \
         DYN_DISABLE_AUTH \
@@ -993,11 +977,9 @@ $(eval $(call assert_booleans,\
         ENABLE_AMU_FCONF \
         AMU_RESTRICT_COUNTERS \
         ENABLE_ASSERTIONS \
-        ENABLE_MPAM_FOR_LOWER_ELS \
         ENABLE_PIE \
         ENABLE_PMF \
         ENABLE_PSCI_STAT \
-        ENABLE_RME \
         ENABLE_RUNTIME_INSTRUMENTATION \
         ENABLE_SME_FOR_NS \
         ENABLE_SME_FOR_SWD \
@@ -1017,7 +999,6 @@ $(eval $(call assert_booleans,\
         PL011_GENERIC_UART \
         PROGRAMMABLE_RESET_ADDRESS \
         PSCI_EXTENDED_STATE_ID \
-        RAS_EXTENSION \
         RESET_TO_BL31 \
         SAVE_KEYS \
         SEPARATE_CODE_AND_RODATA \
@@ -1046,20 +1027,13 @@ $(eval $(call assert_booleans,\
         RAS_TRAP_LOWER_EL_ERR_ACCESS \
         COT_DESC_IN_DTB \
         USE_SP804_TIMER \
-        ENABLE_FEAT_RNG \
-        ENABLE_FEAT_SB \
-        ENABLE_FEAT_DIT \
         PSA_FWU_SUPPORT \
         ENABLE_TRBE_FOR_NS \
         ENABLE_SYS_REG_TRACE_FOR_NS \
-        ENABLE_TRF_FOR_NS \
-        ENABLE_FEAT_HCX \
         ENABLE_MPMM \
         ENABLE_MPMM_FCONF \
-        ENABLE_FEAT_FGT \
-        ENABLE_FEAT_AMUv1 \
-        ENABLE_FEAT_ECV \
         SIMICS_BUILD \
+        FEATURE_DETECTION \
 )))
 
 $(eval $(call assert_numerics,\
@@ -1067,9 +1041,30 @@ $(eval $(call assert_numerics,\
         ARM_ARCH_MAJOR \
         ARM_ARCH_MINOR \
         BRANCH_PROTECTION \
+        CTX_INCLUDE_PAUTH_REGS \
+        CTX_INCLUDE_MTE_REGS \
+        CTX_INCLUDE_NEVE_REGS \
+        ENABLE_BTI \
+        ENABLE_PAUTH \
+        ENABLE_FEAT_AMUv1 \
+        ENABLE_FEAT_AMUv1p1 \
+        ENABLE_FEAT_CSV2_2 \
+        ENABLE_FEAT_DIT \
+        ENABLE_FEAT_ECV \
+        ENABLE_FEAT_FGT \
+        ENABLE_FEAT_HCX \
+        ENABLE_FEAT_PAN \
+        ENABLE_FEAT_RNG \
+        ENABLE_FEAT_SB \
+        ENABLE_FEAT_SEL2 \
+        ENABLE_FEAT_VHE \
+        ENABLE_MPAM_FOR_LOWER_ELS \
+        ENABLE_RME \
+        ENABLE_TRF_FOR_NS \
         FW_ENC_STATUS \
         NR_OF_FW_BANKS \
         NR_OF_IMAGES_IN_FW_BANK \
+        RAS_EXTENSION \
 )))
 
 ifdef KEY_SIZE
@@ -1179,6 +1174,12 @@ $(eval $(call add_defines,\
         ENABLE_FEAT_AMUv1 \
         ENABLE_FEAT_ECV \
         SIMICS_BUILD \
+        ENABLE_FEAT_AMUv1p1 \
+        ENABLE_FEAT_SEL2 \
+        ENABLE_FEAT_VHE \
+        ENABLE_FEAT_CSV2_2 \
+        ENABLE_FEAT_PAN \
+        FEATURE_DETECTION \
 )))
 
 ifeq (${SANITIZE_UB},trap)