[RFC 4/7] psci: Add cpu_poke ops to support core poking

[Abel Vesa]

There can be platforms that need a dedicated work to be done
in TF-A before the specified core can be woken up through an IPI.
Allow those platforms to call into the TF-A to do that work
by making use of the cpu_poke operation.

Signed-off-by: Abel Vesa <abel.vesa@xxxxxxx>
---
 arch/arm64/include/asm/cpu_ops.h | 1 +
 arch/arm64/kernel/psci.c         | 1 +
 drivers/firmware/psci.c          | 6 ++++++
 include/linux/psci.h             | 1 +
 include/uapi/linux/psci.h        | 2 ++
 5 files changed, 11 insertions(+)

diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
index 8f03446..913afef 100644
--- a/arch/arm64/include/asm/cpu_ops.h
+++ b/arch/arm64/include/asm/cpu_ops.h
@@ -60,6 +60,7 @@ struct cpu_operations {
 #ifdef CONFIG_CPU_IDLE
 	int		(*cpu_init_idle)(unsigned int);
 	int		(*cpu_suspend)(unsigned long);
+	int		(*cpu_poke)(unsigned int);
 #endif
 };
 
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 8cdaf25..53227eb 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -115,6 +115,7 @@ const struct cpu_operations cpu_psci_ops = {
 #ifdef CONFIG_CPU_IDLE
 	.cpu_init_idle	= psci_cpu_init_idle,
 	.cpu_suspend	= psci_cpu_suspend_enter,
+	.cpu_poke	= psci_cpu_suspend_exit,
 #endif
 	.cpu_init	= cpu_psci_cpu_init,
 	.cpu_prepare	= cpu_psci_cpu_prepare,
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index c80ec1d..282bc47 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -73,6 +73,7 @@ enum psci_function {
 	PSCI_FN_CPU_ON,
 	PSCI_FN_CPU_OFF,
 	PSCI_FN_MIGRATE,
+	PSCI_FN_CPU_POKE,
 	PSCI_FN_MAX,
 };
 
@@ -424,6 +425,11 @@ int psci_cpu_suspend_enter(unsigned long index)
 	return ret;
 }
 
+int psci_cpu_suspend_exit(unsigned int index)
+{
+	return invoke_psci_fn(PSCI_0_2_FN_CPU_POKE, index, 0, 0);
+}
+
 /* ARM specific CPU idle operations */
 #ifdef CONFIG_ARM
 static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 8b1b3b5..d863733 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -24,6 +24,7 @@ bool psci_tos_resident_on(int cpu);
 
 int psci_cpu_init_idle(unsigned int cpu);
 int psci_cpu_suspend_enter(unsigned long index);
+int psci_cpu_suspend_exit(unsigned int index);
 
 enum psci_conduit {
 	PSCI_CONDUIT_NONE,
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index b3bcabe..19e7481 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -40,8 +40,10 @@
 #define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU		PSCI_0_2_FN(7)
 #define PSCI_0_2_FN_SYSTEM_OFF			PSCI_0_2_FN(8)
 #define PSCI_0_2_FN_SYSTEM_RESET		PSCI_0_2_FN(9)
+#define PSCI_0_2_FN_CPU_POKE			PSCI_0_2_FN(11)
 
 #define PSCI_0_2_FN64_CPU_SUSPEND		PSCI_0_2_FN64(1)
+#define PSCI_0_2_FN64_CPU_POKE			PSCI_0_2_FN64(11)
 #define PSCI_0_2_FN64_CPU_ON			PSCI_0_2_FN64(3)
 #define PSCI_0_2_FN64_AFFINITY_INFO		PSCI_0_2_FN64(4)
 #define PSCI_0_2_FN64_MIGRATE			PSCI_0_2_FN64(5)
-- 
2.7.4