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

Marc Zyngier marc.zyngier at arm.com
Thu Feb 1 03:46:53 PST 2018


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.pieralisi at arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier at 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




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