refactor(cpufeat): enable FEAT_PAN for FEAT_STATE_CHECKED
At the moment we only support FEAT_PAN to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_FEAT_PAN=2), by splitting
is_armv8_1_pan_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 PAN specific setup.
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: I58e5fe8d3c9332820391c7d93a8fb9dba4cf754a
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/common/feat_detect.c b/common/feat_detect.c
index 4b5dcd4..c51da96 100644
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@@ -70,16 +70,6 @@
#endif
}
-/***********************************************
- * Feature : FEAT_PAN (Privileged Access Never)
- **********************************************/
-static void read_feat_pan(void)
-{
-#if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS)
- feat_detect_panic(is_armv8_1_pan_present(), "PAN");
-#endif
-}
-
/*******************************************************************************
* Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
******************************************************************************/
@@ -250,7 +240,7 @@
read_feat_csv2_2();
/* v8.1 features */
- read_feat_pan();
+ check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3);
check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1);
/* v8.2 features */
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 1af7758..bdfdc4c 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -21,10 +21,22 @@
return true;
}
-static inline bool is_armv8_1_pan_present(void)
+static inline unsigned int read_feat_pan_id_field(void)
+{
+ return ISOLATE_FIELD(read_id_aa64mmfr1_el1(), ID_AA64MMFR1_EL1_PAN);
+}
+
+static inline bool is_feat_pan_supported(void)
{
- return ((read_id_aa64mmfr1_el1() >> ID_AA64MMFR1_EL1_PAN_SHIFT) &
- ID_AA64MMFR1_EL1_PAN_MASK) != 0U;
+ if (ENABLE_FEAT_PAN == FEAT_STATE_DISABLED) {
+ return false;
+ }
+
+ if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS) {
+ return true;
+ }
+
+ return read_feat_pan_id_field() != 0U;
}
static inline unsigned int read_feat_vhe_id_field(void)
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index d5e59cd..3f18112 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -470,6 +470,7 @@
ENABLE_FEAT_HCX := 2
ENABLE_FEAT_TCR2 := 2
+ENABLE_FEAT_PAN := 2
ENABLE_FEAT_VHE := 2
ENABLE_MPAM_FOR_LOWER_ELS := 2
diff --git a/services/std_svc/sdei/sdei_intr_mgmt.c b/services/std_svc/sdei/sdei_intr_mgmt.c
index 9862e4f..3bdf4a2 100644
--- a/services/std_svc/sdei/sdei_intr_mgmt.c
+++ b/services/std_svc/sdei/sdei_intr_mgmt.c
@@ -274,7 +274,7 @@
(hcr_el2 & HCR_TGE_BIT) &&
(hcr_el2 & HCR_E2H_BIT);
- if (is_armv8_1_pan_present() &&
+ if (is_feat_pan_supported() &&
((client_el == MODE_EL1) ||
(client_el == MODE_EL2 && el_is_in_host)) &&
((client_el_sctlr & SCTLR_SPAN_BIT) == 0U)) {