Current build infra defaults all cpufeats in defaults.mk and some
mandatory features are enabled in arch_features.mk and optional
arch features are enabled in platform specific makefile.
This fragmentation is sometime confusing to figure out which feature
is tied to which ARCH_MAJOR.ARCH_MINOR.
So, consolidating and grouping them for tracking and enabling makes
more sense. With this change we consolidate all ARCH feature handling
within arch_features.mk and disable all optional features that need
to be enabled to platform makefile.
This is an ongoing series of effort to consolidate and going forward
platform makefile should just specify ARCH_MAJOR and ARCH MINOR and
all mandatory feature should be selected based on arch_features.mk
any optional feature needed by the platform support can be enabled
by platform makefile.
It also makes it easier for platform ports to look upto arch_features.mk
and enable any optional feature that platform may need which are
supported from TF-A.
Change-Id: I18764008856d81414256b6cbabdfa42a16b8040d
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
The current usage of RAS_EXTENSION in TF-A codebase is to cater for two
things in TF-A :
1. Pull in necessary framework and platform hooks for Firmware first
handling(FFH) of RAS errors.
2. Manage the FEAT_RAS extension when switching the worlds.
FFH means that all the EAs from NS are trapped in EL3 first and signaled
to NS world later after the first handling is done in firmware. There is
an alternate way of handling RAS errors viz Kernel First handling(KFH).
Tying FEAT_RAS to RAS_EXTENSION build flag was not correct as the
feature is needed for proper handling KFH in as well.
This patch breaks down the RAS_EXTENSION flag into a flag to denote the
CPU architecture `ENABLE_FEAT_RAS` which is used in context management
during world switch and another flag `RAS_FFH_SUPPORT` to pull in
required framework and platform hooks for FFH.
Proper support for KFH will be added in future patches.
BREAKING CHANGE: The previous RAS_EXTENSION is now deprecated. The
equivalent functionality can be achieved by the following
2 options:
- ENABLE_FEAT_RAS
- RAS_FFH_SUPPORT
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I1abb9ab6622b8f1b15712b12f17612804d48a6ec
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
