refactor(cpufeat): align FEAT_SB to new feature handling
FEAT_SB introduces a new speculation barrier instruction, that is more
lightweight than a "dsb; isb" combination. We use that in a hot path,
so cannot afford and don't want a runtime detection mechanism.
Nevertheless align the implementation of the feature detection part
with the other features, but renaming the detection function, and
updating the FEAT_DETECTION code. Also update the documentation.
Change-Id: I2b86dfd1ad259c3bb99ab5186e2911ace454b54c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/common/feat_detect.c b/common/feat_detect.c
index 7a6c919..4b5dcd4 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -60,16 +60,6 @@
}
}
-/******************************************
- * Feature : FEAT_SB (Speculation Barrier)
- *****************************************/
-static void read_feat_sb(void)
-{
-#if (ENABLE_FEAT_SB == FEAT_STATE_ALWAYS)
- feat_detect_panic(is_armv8_0_feat_sb_present(), "SB");
-#endif
-}
-
/******************************************************
* Feature : FEAT_CSV2_2 (Cache Speculation Variant 2)
*****************************************************/
@@ -256,7 +246,7 @@
tainted = false;
/* v8.0 features */
- read_feat_sb();
+ check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1);
read_feat_csv2_2();
/* v8.1 features */