psci: fix error due to a non zero context id
In the previous psci implementation, the psci_afflvl_power_on_finish()
function would run into an error condition if the value of the context
id parameter in the cpu_on and cpu_suspend psci calls was != 0. The
parameter was being restored as the return value of the affinity level
0 finisher function. A non zero context id would be treated as an
error condition. This would prevent successful wake up of the cpu from
a power down state. Also, the contents of the general purpose
registers were not being cleared upon return to the non-secure world
after a cpu power up. This could potentially allow the non-secure
world to view secure data.
This patch ensures that all general purpose registers are set to ~0
prior to the final eret that drops the execution to the non-secure
world. The context id is used to initialize the general purpose
register x0 prior to re-entry into the non-secure world and is no
longer restored as a function return value. A platform helper
(platform_get_stack()) has been introduced to facilitate this change.
Change-Id: I2454911ffd75705d6aa8609a5d250d9b26fa097c
diff --git a/common/runtime_svc.c b/common/runtime_svc.c
index 0aa4460..431cfa3 100644
--- a/common/runtime_svc.c
+++ b/common/runtime_svc.c
@@ -38,6 +38,7 @@
#include <semihosting.h>
#include <bl_common.h>
#include <psci.h>
+#include <runtime_svc.h>
/*******************************************************************************
* Perform initialization of runtime services possibly across exception levels