RAS: Add fault injection support
The ARMv8.4 RAS extensions introduce architectural support for software
to inject faults into the system in order to test fault-handling
software. This patch introduces the build option FAULT_HANDLING_SUPPORT
to allow for lower ELs to use registers in the Standard Error Record to
inject fault. The build option RAS_EXTENSIONS must also be enabled along
with fault injection.
This feature is intended for testing purposes only, and is advisable to
keep disabled for production images.
Change-Id: I6f7a4454b15aec098f9505a10eb188c2f928f7ea
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/Makefile b/Makefile
index c588931..5132701 100644
--- a/Makefile
+++ b/Makefile
@@ -395,6 +395,13 @@
endif
endif
+# When FAULT_INJECTION_SUPPORT is used, require that RAS_EXTENSION is enabled
+ifeq ($(FAULT_INJECTION_SUPPORT),1)
+ ifneq ($(RAS_EXTENSION),1)
+ $(error For FAULT_INJECTION_SUPPORT, RAS_EXTENSION must also be 1)
+ endif
+endif
+
################################################################################
# Process platform overrideable behaviour
################################################################################
@@ -522,6 +529,7 @@
$(eval $(call assert_boolean,ENABLE_SPM))
$(eval $(call assert_boolean,ENABLE_SVE_FOR_NS))
$(eval $(call assert_boolean,ERROR_DEPRECATED))
+$(eval $(call assert_boolean,FAULT_INJECTION_SUPPORT))
$(eval $(call assert_boolean,GENERATE_COT))
$(eval $(call assert_boolean,GICV2_G0_FOR_EL3))
$(eval $(call assert_boolean,HANDLE_EA_EL3_FIRST))
@@ -571,6 +579,7 @@
$(eval $(call add_define,ENABLE_SPM))
$(eval $(call add_define,ENABLE_SVE_FOR_NS))
$(eval $(call add_define,ERROR_DEPRECATED))
+$(eval $(call add_define,FAULT_INJECTION_SUPPORT))
$(eval $(call add_define,GICV2_G0_FOR_EL3))
$(eval $(call add_define,HANDLE_EA_EL3_FIRST))
$(eval $(call add_define,HW_ASSISTED_COHERENCY))
diff --git a/docs/user-guide.rst b/docs/user-guide.rst
index 880fe7d..a1719ef 100644
--- a/docs/user-guide.rst
+++ b/docs/user-guide.rst
@@ -390,6 +390,14 @@
handled at EL3, and a panic will result. This is supported only for AArch64
builds.
+- ``FAULT_INJECTION_SUPPORT``: ARMv8.4 externsions introduced support for fault
+ injection from lower ELs, and this build option enables lower ELs to use
+ Error Records accessed via System Registers to inject faults. This is
+ applicable only to AArch64 builds.
+
+ This feature is intended for testing purposes only, and is advisable to keep
+ disabled for production images.
+
- ``FIP_NAME``: This is an optional build option which specifies the FIP
filename for the ``fip`` target. Default is ``fip.bin``.
diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index e836db1..92bb97d 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -215,6 +215,7 @@
/* SCR definitions */
#define SCR_RES1_BITS ((U(1) << 4) | (U(1) << 5))
+#define SCR_FIEN_BIT (U(1) << 21)
#define SCR_TWE_BIT (U(1) << 13)
#define SCR_TWI_BIT (U(1) << 12)
#define SCR_ST_BIT (U(1) << 11)
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 2608d1f..76eecc1 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -114,6 +114,11 @@
scr_el3 &= ~SCR_EA_BIT;
#endif
+#if FAULT_INJECTION_SUPPORT
+ /* Enable fault injection from lower ELs */
+ scr_el3 |= SCR_FIEN_BIT;
+#endif
+
#ifdef IMAGE_BL31
/*
* SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ rounting as
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 791a9c0..4bbff03 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -76,6 +76,9 @@
# Build flag to treat usage of deprecated platform and framework APIs as error.
ERROR_DEPRECATED := 0
+# Fault injection support
+FAULT_INJECTION_SUPPORT := 0
+
# Byte alignment that each component in FIP is aligned to
FIP_ALIGN := 0