feat(cpufeat): enable FEAT_BTI to FEAT_STATE_CHECKED
Introduce the is_feat_bti_{supported, present}() helpers and replace
checks for ENABLE_BTI with it. Also factor out the setting of
SCTLR_EL3.BT out of the PAuth enablement and place it in the respective
entrypoints where we initialise SCTLR_EL3. This makes PAuth
self-contained and SCTLR_EL3 initialisation centralised.
Change-Id: I0c0657ff1e78a9652cd2cf1603478283dc01f17b
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/include/arch/aarch32/arch_features.h b/include/arch/aarch32/arch_features.h
index 243ac15..cc39a55 100644
--- a/include/arch/aarch32/arch_features.h
+++ b/include/arch/aarch32/arch_features.h
@@ -204,5 +204,7 @@
static inline bool is_feat_ls64_accdata_present(void) { return false; }
__attribute__((always_inline))
static inline bool is_feat_mops_supported(void) { return false; }
+__attribute__((always_inline))
+static inline bool is_feat_bti_supported(void) { return false; }
#endif /* ARCH_FEATURES_H */
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 43ff2cc..0dd44b4 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -199,8 +199,8 @@
ID_AA64MMFR2_EL1_ST_MASK, 1U)
/* FEAT_BTI: Branch target identification */
-CREATE_FEATURE_PRESENT(feat_bti, id_aa64pfr1_el1, ID_AA64PFR1_EL1_BT_SHIFT,
- ID_AA64PFR1_EL1_BT_MASK, BTI_IMPLEMENTED)
+CREATE_FEATURE_FUNCS(feat_bti, id_aa64pfr1_el1, ID_AA64PFR1_EL1_BT_SHIFT,
+ ID_AA64PFR1_EL1_BT_MASK, BTI_IMPLEMENTED, ENABLE_BTI)
/* FEAT_MTE2: Memory tagging extension */
CREATE_FEATURE_FUNCS(feat_mte2, id_aa64pfr1_el1, ID_AA64PFR1_EL1_MTE_SHIFT,
diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S
index 2f2aeaf..07dffb1 100644
--- a/include/arch/aarch64/el3_common_macros.S
+++ b/include/arch/aarch64/el3_common_macros.S
@@ -32,10 +32,15 @@
* load or store one or more registers have an alignment check that the
* address being accessed is aligned to the size of the data element(s)
* being accessed.
+ *
+ * SCTLR_EL3.BT: PAuth instructions are compatible with bti jc
* ---------------------------------------------------------------------
*/
- mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
+ mov_imm x1, (SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el3
+#if ENABLE_BTI
+ bic x0, x0, #SCTLR_BT_BIT
+#endif
orr x0, x0, x1
msr sctlr_el3, x0
isb