PSCI: Add pwr_domain_pwr_down_wfi() hook in plat_psci_ops
This patch adds a new optional platform hook `pwr_domain_pwr_down_wfi()` in
the plat_psci_ops structure. This hook allows the platform to perform platform
specific actions including the wfi invocation to enter powerdown. This hook
is invoked by both psci_do_cpu_off() and psci_cpu_suspend_start() functions.
The porting-guide.md is also updated for the same.
This patch also modifies the `psci_power_down_wfi()` function to invoke
`plat_panic_handler` incase of panic instead of the busy while loop.
Fixes ARM-Software/tf-issues#375
Change-Id: Iba104469a1445ee8d59fb3a6fdd0a98e7f24dfa3
diff --git a/services/std_svc/psci/psci_entry.S b/services/std_svc/psci/psci_entry.S
index 5f4f91c..f8c0afa 100644
--- a/services/std_svc/psci/psci_entry.S
+++ b/services/std_svc/psci/psci_entry.S
@@ -106,7 +106,6 @@
func psci_power_down_wfi
dsb sy // ensure write buffer empty
wfi
-wfi_spill:
- b wfi_spill
+ bl plat_panic_handler
endfunc psci_power_down_wfi