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

commit 6b7fe77c334ae59fed9500140e08f4f896b36871 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index c80ec1d03274413863fb8e3f917f26daa8f868c2..d855c20de663cfbd38f0af1cbb8217d9a37f4206 100644 (file)
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -64,6 +64,21 @@ 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 5d883c4d82abeb7b0454ef9cd2841a4babb3fc41..6366b04c7d5f4459a91d9f58276c4cf17713268d 100644 (file)
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -89,6 +89,22 @@
 
 #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