[PATCH v3 14/18] firmware/psci: Expose SMCCC version through psci_ops

[Marc Zyngier]

Since PSCI 1.0 allows the SMCCC version to be (indirectly) probed,
let's do that at boot time, and expose the version of the calling
convention as part of the psci_ops structure.

Acked-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
 drivers/firmware/psci.c | 19 +++++++++++++++++++
 include/linux/psci.h    |  6 ++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index e9493da2b111..8631906c414c 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -61,6 +61,7 @@ bool psci_tos_resident_on(int cpu)
 
 struct psci_operations psci_ops = {
        .conduit = PSCI_CONDUIT_NONE,
+       .smccc_version = SMCCC_VERSION_1_0,
 };
 
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
@@ -511,6 +512,23 @@ static void __init psci_init_migrate(void)
        pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
 }
 
+static void __init psci_init_smccc(u32 ver)
+{
+       int feature;
+
+       feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
+
+       if (feature != PSCI_RET_NOT_SUPPORTED) {
+               ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
+               if (ver != ARM_SMCCC_VERSION_1_1)
+                       psci_ops.smccc_version = SMCCC_VERSION_1_0;
+               else
+                       psci_ops.smccc_version = SMCCC_VERSION_1_1;
+       }
+
+       pr_info("SMC Calling Convention v1.%d\n", psci_ops.smccc_version);
+}
+
 static void __init psci_0_2_set_functions(void)
 {
        pr_info("Using standard PSCI v0.2 function IDs\n");
@@ -559,6 +577,7 @@ static int __init psci_probe(void)
        psci_init_migrate();
 
        if (PSCI_VERSION_MAJOR(ver) >= 1) {
+               psci_init_smccc(ver);
                psci_init_cpu_suspend();
                psci_init_system_suspend();
        }
diff --git a/include/linux/psci.h b/include/linux/psci.h
index f2679e5faa4f..8b1b3b5935ab 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -31,6 +31,11 @@ enum psci_conduit {
        PSCI_CONDUIT_HVC,
 };
 
+enum smccc_version {
+       SMCCC_VERSION_1_0,
+       SMCCC_VERSION_1_1,
+};
+
 struct psci_operations {
        u32 (*get_version)(void);
        int (*cpu_suspend)(u32 state, unsigned long entry_point);
@@ -41,6 +46,7 @@ struct psci_operations {
                        unsigned long lowest_affinity_level);
        int (*migrate_info_type)(void);
        enum psci_conduit conduit;
+       enum smccc_version smccc_version;
 };
 
 extern struct psci_operations psci_ops;
-- 
2.14.2