Reset CNTVOFF_EL2 register before exit into EL1 on warm boot
This patch resets the value of CNTVOFF_EL2 before exit to EL1 on
warm boot. This needs to be done if only the Trusted Firmware exits
to EL1 instead of EL2, otherwise the hypervisor would be responsible
for this.
Fixes ARM-software/tf-issues#240
Change-Id: I79d54831356cf3215bcf1f251c373bd8f89db0e0
diff --git a/bl31/context_mgmt.c b/bl31/context_mgmt.c
index 489d454..698fb6f 100644
--- a/bl31/context_mgmt.c
+++ b/bl31/context_mgmt.c
@@ -247,6 +247,9 @@
/* Enable EL1 access to timer */
write_cnthctl_el2(EL1PCEN_BIT | EL1PCTEN_BIT);
+ /* Reset CNTVOFF_EL2 */
+ write_cntvoff_el2(0);
+
/* Set VPIDR, VMPIDR to match MIDR, MPIDR */
write_vpidr_el2(read_midr_el1());
write_vmpidr_el2(read_mpidr_el1());
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index 09365fb..d431baa 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -262,6 +262,8 @@
DEFINE_SYSREG_RW_FUNCS(tpidr_el3)
+DEFINE_SYSREG_RW_FUNCS(cntvoff_el2)
+
DEFINE_SYSREG_RW_FUNCS(vpidr_el2)
DEFINE_SYSREG_RW_FUNCS(vmpidr_el2)