diff mbox series

[v4.4,V2,37/43] firmware/psci: Expose PSCI conduit

Message ID 896d2efd09dbe687aa3132c5e03f6b11feb6da9b.1562908075.git.viresh.kumar@linaro.org (mailing list archive)
State New, archived
Headers show
Series V4.4 backport of arm64 Spectre patches | expand

Commit Message

Viresh Kumar July 12, 2019, 5:28 a.m. UTC 
From: Marc Zyngier <marc.zyngier@arm.com>

commit 09a8d6d48499f93e2abde691f5800081cd858726 upstream.

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>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/firmware/psci.c | 28 +++++++++++++++++++++++-----
 include/linux/psci.h    |  7 +++++++
 2 files changed, 30 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 290f8982e7b3..7b2665f6b38d 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -54,7 +54,9 @@  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);
@@ -187,6 +189,22 @@  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;
@@ -199,9 +217,9 @@  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;
@@ -463,9 +481,9 @@  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();
 }
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 04b4d92c7791..e071a1b8ddb5 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -24,6 +24,12 @@  bool psci_tos_resident_on(int cpu);
 bool psci_power_state_loses_context(u32 state);
 bool psci_power_state_is_valid(u32 state);
 
+enum psci_conduit {
+	PSCI_CONDUIT_NONE,
+	PSCI_CONDUIT_SMC,
+	PSCI_CONDUIT_HVC,
+};
+
 struct psci_operations {
 	u32 (*get_version)(void);
 	int (*cpu_suspend)(u32 state, unsigned long entry_point);
@@ -33,6 +39,7 @@  struct psci_operations {
 	int (*affinity_info)(unsigned long target_affinity,
 			unsigned long lowest_affinity_level);
 	int (*migrate_info_type)(void);
+	enum psci_conduit conduit;
 };
 
 extern struct psci_operations psci_ops;