refactor(cpufeat): enable FEAT_ECV for FEAT_STATE_CHECKED
At the moment we only support FEAT_ECV to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_FEAT_ECV=2), by splitting
is_feat_ecv_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 CNTPOFF_EL2 system register.
Also move the context saving code from assembly to C, and use the new
is_feat_ecv_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: I4acd5384929f1902b62a87ae073aafa1472cd66b
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/common/feat_detect.c b/common/feat_detect.c
index c51da96..2f64deb 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -164,19 +164,6 @@
#endif
}
-/*******************************************************
- * Feature : FEAT_ECV (Enhanced Counter Virtualization)
- ******************************************************/
-static void read_feat_ecv(void)
-{
-#if (ENABLE_FEAT_ECV == FEAT_STATE_ALWAYS)
- unsigned int ecv = get_armv8_6_ecv_support();
-
- feat_detect_panic(((ecv == ID_AA64MMFR0_EL1_ECV_SUPPORTED) ||
- (ecv == ID_AA64MMFR0_EL1_ECV_SELF_SYNCH)), "ECV");
-#endif
-}
-
/***********************************************************
* Feature : FEAT_TWED (Delayed Trapping of WFE Instruction)
**********************************************************/
@@ -269,7 +256,7 @@
/* v8.6 features */
read_feat_amuv1p1();
check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1);
- read_feat_ecv();
+ check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2);
read_feat_twed();
/* v8.7 features */