firmware/psci: Expose PSCI conduit

In order to call into the firmware to apply workarounds, it is
useful to find out whether we're using HVC or SMC. Let's expose
this through the psci_ops.

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 8b25d31e8401..e9493da2b111 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -59,7 +59,9 @@ bool psci_tos_resident_on(int cpu)
         return cpu == resident_cpu;
 }
 
-struct psci_operations psci_ops;
+struct psci_operations psci_ops = {
+        .conduit = PSCI_CONDUIT_NONE,
+};
 
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
                                 unsigned long, unsigned long);
@@ -210,6 +212,22 @@ static unsigned long psci_migrate_info_up_cpu(void)
                               0, 0, 0);
 }
 
+static void set_conduit(enum psci_conduit conduit)
+{
+        switch (conduit) {
+        case PSCI_CONDUIT_HVC:
+                invoke_psci_fn = __invoke_psci_fn_hvc;
+                break;
+        case PSCI_CONDUIT_SMC:
+                invoke_psci_fn = __invoke_psci_fn_smc;
+                break;
+        default:
+                WARN(1, "Unexpected PSCI conduit %d\n", conduit);
+        }
+
+        psci_ops.conduit = conduit;
+}
+
 static int get_set_conduit_method(struct device_node *np)
 {
         const char *method;
@@ -222,9 +240,9 @@ static int get_set_conduit_method(struct device_node *np)
         }
 
         if (!strcmp("hvc", method)) {
-                invoke_psci_fn = __invoke_psci_fn_hvc;
+                set_conduit(PSCI_CONDUIT_HVC);
         } else if (!strcmp("smc", method)) {
-                invoke_psci_fn = __invoke_psci_fn_smc;
+                set_conduit(PSCI_CONDUIT_SMC);
         } else {
                 pr_warn("invalid \"method\" property: %s\n", method);
                 return -EINVAL;
@@ -654,9 +672,9 @@ int __init psci_acpi_init(void)
         pr_info("probing for conduit method from ACPI.\n");
 
         if (acpi_psci_use_hvc())
-                invoke_psci_fn = __invoke_psci_fn_hvc;
+                set_conduit(PSCI_CONDUIT_HVC);
         else
-                invoke_psci_fn = __invoke_psci_fn_smc;
+                set_conduit(PSCI_CONDUIT_SMC);
 
         return psci_probe();
 }