Add support for dynamic mitigation for CVE-2018-3639
Some CPUS may benefit from using a dynamic mitigation approach for
CVE-2018-3639. A new SMC interface is defined to allow software
executing in lower ELs to enable or disable the mitigation for their
execution context.
It should be noted that regardless of the state of the mitigation for
lower ELs, code executing in EL3 is always mitigated against
CVE-2018-3639.
NOTE: This change is a compatibility break for any platform using
the declare_cpu_ops_workaround_cve_2017_5715 macro. Migrate to
the declare_cpu_ops_wa macro instead.
Change-Id: I3509a9337ad217bbd96de9f380c4ff8bf7917013
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 31cd837..434c13e 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -18,6 +18,7 @@
WORKAROUND_CVE_2017_5715 ?=1
WORKAROUND_CVE_2018_3639 ?=1
+DYNAMIC_WORKAROUND_CVE_2018_3639 ?=0
# Process SKIP_A57_L1_FLUSH_PWR_DWN flag
$(eval $(call assert_boolean,SKIP_A57_L1_FLUSH_PWR_DWN))
@@ -39,6 +40,15 @@
$(eval $(call assert_boolean,WORKAROUND_CVE_2018_3639))
$(eval $(call add_define,WORKAROUND_CVE_2018_3639))
+$(eval $(call assert_boolean,DYNAMIC_WORKAROUND_CVE_2018_3639))
+$(eval $(call add_define,DYNAMIC_WORKAROUND_CVE_2018_3639))
+
+ifneq (${DYNAMIC_WORKAROUND_CVE_2018_3639},0)
+ ifeq (${WORKAROUND_CVE_2018_3639},0)
+ $(error "Error: WORKAROUND_CVE_2018_3639 must be 1 if DYNAMIC_WORKAROUND_CVE_2018_3639 is 1")
+ endif
+endif
+
# CPU Errata Build flags.
# These should be enabled by the platform if the erratum workaround needs to be
# applied.