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 ---
Changes in v2: None
arch/arm/cpu/armv7/psci-common.c | 14 ++++++++++++++ arch/arm/cpu/armv7/psci.S | 4 ++++ arch/arm/include/asm/psci.h | 4 +++- 3 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/psci-common.c b/arch/arm/cpu/armv7/psci-common.c index 8cb4107..73f986b 100644 --- a/arch/arm/cpu/armv7/psci-common.c +++ b/arch/arm/cpu/armv7/psci-common.c @@ -25,10 +25,19 @@ #include <linux/linkage.h>
static u32 psci_target_pc[CONFIG_ARMV7_PSCI_NR_CPUS] __secure_data = { 0 }; +static u32 psci_context_id[CONFIG_ARMV7_PSCI_NR_CPUS] __secure_data = { 0 };
void __secure psci_save_target_pc(int cpu, u32 pc) { psci_target_pc[cpu] = pc; + psci_context_id[cpu] = 0; + dsb(); +} + +void __secure psci_save(int cpu, u32 pc, u32 context_id) +{ + psci_target_pc[cpu] = pc; + psci_context_id[cpu] = context_id; dsb(); }
@@ -37,3 +46,8 @@ u32 __secure psci_get_target_pc(int cpu) return psci_target_pc[cpu]; }
+u32 __secure psci_get_context_id(int cpu) +{ + return psci_context_id[cpu]; +} + diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S index 95b962d..35fd955 100644 --- a/arch/arm/cpu/armv7/psci.S +++ b/arch/arm/cpu/armv7/psci.S @@ -327,6 +327,10 @@ ENTRY(psci_cpu_entry) bl _nonsec_init
bl psci_get_cpu_id @ CPU ID => r0 + mov r2, r0 @ CPU ID => r2 + bl psci_get_context_id @ context id => r0 + mov r1, r0 @ context id => r1 + mov r0, r2 @ CPU ID => r0 bl psci_get_target_pc @ target PC => r0 b _do_nonsec_entry ENDPROC(psci_cpu_entry) diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h index ac8b00d..b415241 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);