arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

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 <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 84f4ff351c6290309db7afdada06fb470f3ffb82..eb797081d159647e06899cb0dbe9c340f6a142f8 100644 (file)
--- 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 080012a6f0254ee3124e5b8882eb668cb94ee85b..df01a857903491f22199a2b6cff891e09234fb0d 100644 (file)
--- 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,
+       SMCCC_CONDUIT_SMC,
+       SMCCC_CONDUIT_HVC,
+};
+
+/**
+ * arm_smccc_1_1_get_conduit()
+ *
+ * Returns the conduit to be used for SMCCCv1.1 or later.
+ *
+ * When SMCCCv1.1 is not present, returns SMCCC_CONDUIT_NONE.
+ */
+enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void);
+
 /**
  * struct arm_smccc_res - Result from SMC/HVC call
  * @a0-a3 result values from registers 0 to 3