SMCCC callers are currently amassing a collection of enums for the SMCCC
conduit, and are having to dig into the PSCI driver's internals in order
to figure out what to do.

Let's clean this up, with common SMCCC_CONDUIT_* definitions, and an
arm_smccc_1_1_get_conduit() helper that abstracts the PSCI driver's
internal state.

We can kill off the PSCI_CONDUIT_* definitions once we've migrated users
over to the new interface.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <redacted>
Acked-by: Will Deacon <redacted>
Cc: Catalin Marinas <catalin.marinas@arm.com>
---
 drivers/firmware/psci/psci.c | 15 +++++++++++++++
 include/linux/arm-smccc.h    | 16 ++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index f82ccd39a913..5f31f1bea1af 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c

@@ -57,6 +57,21 @@ struct psci_operations psci_ops = {
 	.smccc_version = SMCCC_VERSION_1_0,
 };
 
+enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)

+{
+	if (psci_ops.smccc_version < SMCCC_VERSION_1_1)
+		return SMCCC_CONDUIT_NONE;
+
+	switch (psci_ops.conduit) {
+	case PSCI_CONDUIT_SMC:
+		return SMCCC_CONDUIT_SMC;
+	case PSCI_CONDUIT_HVC:
+		return SMCCC_CONDUIT_HVC;
+	default:
+		return SMCCC_CONDUIT_NONE;
+	}
+}
+
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
 				unsigned long, unsigned long);
 static psci_fn *invoke_psci_fn;

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 080012a6f025..df01a8579034 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h

@@ -80,6 +80,22 @@
 
 #include <linux/linkage.h>
 #include <linux/types.h>
+
+enum arm_smccc_conduit {
+	SMCCC_CONDUIT_NONE,