feat(cpufeat): add feature detection for FEAT_CSV2_3
This feature provides support to context save the
SCXTNUM_ELx register. FEAT_CSV2_3 implies the implementation
of FEAT_CSV2_2. FEAT_CSV2_3 is supported in AArch64 state only
and is an optional feature in Arm v8.0 implementations.
This patch adds feature detection for v8.9 feature FEAT_CSV2_3,
adds macros for ID_AA64PFR0_EL1.CSV2 bits [59:56] for detecting
FEAT_CSV2_3 and macro for ENABLE_FEAT_CSV2_3.
Change-Id: Ida9f31e832b5f11bd89eebd6cc9f10ddad755c14
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index deea6d4..c053c4d 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -187,10 +187,28 @@
return ISOLATE_FIELD(read_id_aa64isar1_el1(), ID_AA64ISAR1_SB_SHIFT);
}
-/* FEAT_CSV2_2: Cache Speculation Variant 2 */
-CREATE_FEATURE_FUNCS(feat_csv2, id_aa64pfr0_el1, ID_AA64PFR0_CSV2_SHIFT, 0)
+/*
+ * FEAT_CSV2: Cache Speculation Variant 2. This checks bit fields[56-59]
+ * of id_aa64pfr0_el1 register and can be used to check for below features:
+ * FEAT_CSV2_2: Cache Speculation Variant CSV2_2.
+ * FEAT_CSV2_3: Cache Speculation Variant CSV2_3.
+ * 0b0000 - Feature FEAT_CSV2 is not implemented.
+ * 0b0001 - Feature FEAT_CSV2 is implemented, but FEAT_CSV2_2 and FEAT_CSV2_3
+ * are not implemented.
+ * 0b0010 - Feature FEAT_CSV2_2 is implemented but FEAT_CSV2_3 is not
+ * implemented.
+ * 0b0011 - Feature FEAT_CSV2_3 is implemented.
+ */
+static inline unsigned int read_feat_csv2_id_field(void)
+{
+ return (unsigned int)(read_id_aa64pfr0_el1() >>
+ ID_AA64PFR0_CSV2_SHIFT) & ID_AA64PFR0_CSV2_MASK;
+}
+
CREATE_FEATURE_FUNCS_VER(feat_csv2_2, read_feat_csv2_id_field,
ID_AA64PFR0_CSV2_2_SUPPORTED, ENABLE_FEAT_CSV2_2)
+CREATE_FEATURE_FUNCS_VER(feat_csv2_3, read_feat_csv2_id_field,
+ ID_AA64PFR0_CSV2_3_SUPPORTED, ENABLE_FEAT_CSV2_3)
/* FEAT_SPE: Statistical Profiling Extension */
CREATE_FEATURE_FUNCS(feat_spe, id_aa64dfr0_el1, ID_AA64DFR0_PMS_SHIFT,