feat(brbe): add brbe under feature detection mechanism
This change adds "FEAT_BRBE" to be part of feature detection mechanism.
Previously feature enablement flags were of boolean type, possessing
either 0 or 1. With the introduction of feature detection procedure
we now support three states for feature enablement build flags(0 to 2).
Accordingly, "ENABLE_BRBE_FOR_NS" flag is now modified from boolean
to numeric type to align with the feature detection.
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: I1eb52863b4afb10b808e2f0b6584a8a210d0f38c
diff --git a/Makefile b/Makefile
index 3941f86..e0fc0e0 100644
--- a/Makefile
+++ b/Makefile
@@ -1045,7 +1045,6 @@
COT_DESC_IN_DTB \
USE_SP804_TIMER \
PSA_FWU_SUPPORT \
- ENABLE_BRBE_FOR_NS \
ENABLE_TRBE_FOR_NS \
ENABLE_SYS_REG_TRACE_FOR_NS \
ENABLE_MPMM \
@@ -1062,6 +1061,7 @@
CTX_INCLUDE_PAUTH_REGS \
CTX_INCLUDE_MTE_REGS \
CTX_INCLUDE_NEVE_REGS \
+ ENABLE_BRBE_FOR_NS \
ENABLE_BTI \
ENABLE_PAUTH \
ENABLE_FEAT_AMUv1 \
diff --git a/common/feat_detect.c b/common/feat_detect.c
index 8f98876..9d0685b 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -234,6 +234,16 @@
#endif
}
+/******************************************************
+ * Feature : FEAT_BRBE (Branch Record Buffer Extension)
+ *****************************************************/
+static void read_feat_brbe(void)
+{
+#if (ENABLE_BRBE_FOR_NS == FEAT_STATE_1)
+ feat_detect_panic(is_feat_brbe_present(), "BRBE");
+#endif
+}
+
/***********************************************************************************
* TF-A supports many Arm architectural features starting from arch version
* (8.0 till 8.7+). These features are mostly enabled through build flags. This
@@ -294,6 +304,9 @@
/* v8.7 features */
read_feat_hcx();
+ /* v9.0 features */
+ read_feat_brbe();
+
/* v9.2 features */
read_feat_rme();
}
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index cfd7201..79159b7 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -982,10 +982,11 @@
functions that wait for an arbitrary time length (udelay and mdelay). The
default value is 0.
-- ``ENABLE_BRBE_FOR_NS``: This flag enables access to the branch record buffer
- registers from NS ELs when FEAT_BRBE is implemented. BRBE is an optional
- architectural feature for AArch64. The default is 0 and it is automatically
- disabled when the target architecture is AArch32.
+- ``ENABLE_BRBE_FOR_NS``: Numeric value to enable access to the branch record
+ buffer registers from NS ELs when FEAT_BRBE is implemented. BRBE is an
+ optional architectural feature for AArch64. This flag can take the values
+ 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism. The default is 0
+ and it is automatically disabled when the target architecture is AArch32.
- ``ENABLE_TRBE_FOR_NS``: This flag is used to enable access of trace buffer
control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 29710e7..cf39e10 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -224,4 +224,15 @@
ID_AA64MMFR2_EL1_NV_MASK));
}
+/*******************************************************************************
+ * Function to identify the presence of FEAT_BRBE (Branch Record Buffer
+ * Extension)
+ ******************************************************************************/
+static inline bool is_feat_brbe_present(void)
+{
+ return (((read_id_aa64dfr0_el1() >> ID_AA64DFR0_BRBE_SHIFT) &
+ ID_AA64DFR0_BRBE_MASK) == ID_AA64DFR0_BRBE_SUPPORTED);
+}
+
+
#endif /* ARCH_FEATURES_H */
diff --git a/lib/extensions/brbe/brbe.c b/lib/extensions/brbe/brbe.c
index 6975b04..1982619 100644
--- a/lib/extensions/brbe/brbe.c
+++ b/lib/extensions/brbe/brbe.c
@@ -5,22 +5,14 @@
*/
#include <arch.h>
+#include <arch_features.h>
#include <arch_helpers.h>
-static bool brbe_supported(void)
-{
- uint64_t features;
-
- features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_BRBE_SHIFT;
- return ((features & ID_AA64DFR0_BRBE_MASK) ==
- ID_AA64DFR0_BRBE_SUPPORTED);
-}
-
void brbe_enable(void)
{
uint64_t val;
- if (brbe_supported()) {
+ if (is_feat_brbe_present()) {
/*
* MDCR_EL3.SBRBE = 0b01
*