refactor(cpufeat): enable FEAT_CSV2_2 for FEAT_STATE_CHECKED
At the moment we only support FEAT_CSV2_2 to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_FEAT_CSV2_2=2), by splitting
is_armv8_0_feat_csv2_2_present() into an ID register reading function
and a second function to report the support status. That function
considers both build time settings and runtime information (if needed),
and is used before we access the SCXTNUM_EL2 system register.
Also move the context saving code from assembly to C, and use the new
is_feat_csv2_2_supported() function to guard its execution.
Change the FVP platform default to the now supported dynamic option (=2),
so the right decision can be made by the code at runtime.
Change-Id: I89c7bc883e6a65727fdbdd36eb3bfbffb2196da7
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/common/feat_detect.c b/common/feat_detect.c
index 2f64deb..bdadde1 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -60,16 +60,6 @@
}
}
-/******************************************************
- * Feature : FEAT_CSV2_2 (Cache Speculation Variant 2)
- *****************************************************/
-static void read_feat_csv2_2(void)
-{
-#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS)
- feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2");
-#endif
-}
-
/*******************************************************************************
* Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
******************************************************************************/
@@ -224,7 +214,8 @@
/* v8.0 features */
check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1);
- read_feat_csv2_2();
+ check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(),
+ "CSV2_2", 2, 3);
/* v8.1 features */
check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3);