arm: psci: save context id for cpu_on PSCI command

Save and use the 3rd parameter of PSCI CPU_ON request: context_id.

The context_id parameter is only meaningful to the caller.
U-Boot PSCI preserves a copy of the value passed in this parameter.
Following wakeup from a  powerdown state, U-BOOT PSCI places
this value in R0 when it first enters the OS.

NB: this context id is not (yet?) used by Linux but it is mandatory
    to be PSCI compliant.

update armv7 psci functions:
- psci_save_target_pc(): keep for backward compatibility with
  current platform (only save PC and force context id to 0)
  => should be removed when all platform migrate to the new API

- psci_save(): new API to use by ARMv7 platform with PSCI,
  save pc (= entry_point_address) and context_id

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index ac8b00d6fc1..b41524106b5 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -93,9 +93,11 @@
 #ifndef __ASSEMBLY__
 #include <asm/types.h>
 
-/* These 2 helper functions assume cpu < CONFIG_ARMV7_PSCI_NR_CPUS */
+/* These 4 helper functions assume cpu < CONFIG_ARMV7_PSCI_NR_CPUS */
 u32 psci_get_target_pc(int cpu);
+u32 psci_get_context_id(int cpu);
 void psci_save_target_pc(int cpu, u32 pc);
+void psci_save(int cpu, u32 pc, u32 context_id);
 
 void psci_cpu_entry(void);
 u32 psci_get_cpu_id(void);