9 files changed, 139 insertions, 184 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 67b76492c839..34181fa52e93 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -91,7 +91,6 @@ enum {
 };
 
 struct acpi_battery {
-	struct mutex lock;
 	struct mutex update_lock;
 	struct power_supply *bat;
 	struct power_supply_desc bat_desc;
@@ -535,11 +534,9 @@ static int acpi_battery_get_info(struct acpi_battery *battery)
 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 		acpi_status status = AE_ERROR;
 
-		mutex_lock(&battery->lock);
 		status = acpi_evaluate_object(battery->device->handle,
 					      use_bix ? "_BIX":"_BIF",
 					      NULL, &buffer);
-		mutex_unlock(&battery->lock);
 
 		if (ACPI_FAILURE(status)) {
 			acpi_handle_info(battery->device->handle,
@@ -576,11 +573,8 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
 			msecs_to_jiffies(cache_time)))
 		return 0;
 
-	mutex_lock(&battery->lock);
 	status = acpi_evaluate_object(battery->device->handle, "_BST",
 				      NULL, &buffer);
-	mutex_unlock(&battery->lock);
-
 	if (ACPI_FAILURE(status)) {
 		acpi_handle_info(battery->device->handle,
 				 "_BST evaluation failed: %s",
@@ -628,11 +622,8 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery)
 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
 		return -ENODEV;
 
-	mutex_lock(&battery->lock);
 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
 					    battery->alarm);
-	mutex_unlock(&battery->lock);
-
 	if (ACPI_FAILURE(status))
 		return -ENODEV;
 
@@ -1235,9 +1226,6 @@ static int acpi_battery_add(struct acpi_device *device)
 	strscpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 	device->driver_data = battery;
-	result = devm_mutex_init(&device->dev, &battery->lock);
-	if (result)
-		return result;
 
 	result = devm_mutex_init(&device->dev, &battery->update_lock);
 	if (result)
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 9b6b71a2ffb5..a4498357bd16 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -54,7 +54,7 @@ static int map_x2apic_id(struct acpi_subtable_header *entry,
 	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
 		return -ENODEV;
 
-	if (device_declaration && (apic->uid == acpi_id)) {
+	if (apic->uid == acpi_id && (device_declaration || acpi_id < 255)) {
 		*apic_id = apic->local_apic_id;
 		return 0;
 	}
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 5d824435b26b..65e779be64ff 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -166,7 +166,8 @@ static int __acpi_processor_start(struct acpi_device *device)
 	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 		dev_dbg(&device->dev, "CPPC data invalid or not present\n");
 
-	acpi_processor_power_init(pr);
+	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
+		acpi_processor_power_init(pr);
 
 	acpi_pss_perf_init(pr);
 
@@ -262,8 +263,6 @@ static int __init acpi_processor_driver_init(void)
 	if (result < 0)
 		return result;
 
-	acpi_processor_register_idle_driver();
-
 	result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 				   "acpi/cpu-drv:online",
 				   acpi_soft_cpu_online, NULL);
@@ -302,7 +301,6 @@ static void __exit acpi_processor_driver_exit(void)
 
 	cpuhp_remove_state_nocalls(hp_online);
 	cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
-	acpi_processor_unregister_idle_driver();
 	driver_unregister(&acpi_processor_driver);
 }
 
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 22b051b94a86..89f2f08b2554 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -51,7 +51,7 @@ module_param(latency_factor, uint, 0644);
 
 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
 
-static struct cpuidle_driver acpi_idle_driver = {
+struct cpuidle_driver acpi_idle_driver = {
 	.name =		"acpi_idle",
 	.owner =	THIS_MODULE,
 };
@@ -732,18 +732,16 @@ static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 	return 0;
 }
 
-static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
-					   struct cpuidle_device *dev)
+static void acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
+					    struct cpuidle_device *dev)
 {
 	int i, count = ACPI_IDLE_STATE_START;
 	struct acpi_processor_cx *cx;
-	struct cpuidle_state *state;
 
 	if (max_cstate == 0)
 		max_cstate = 1;
 
 	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
-		state = &acpi_idle_driver.states[count];
 		cx = &pr->power.states[i];
 
 		if (!cx->valid)
@@ -751,27 +749,13 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 
 		per_cpu(acpi_cstate[count], dev->cpu) = cx;
 
-		if (lapic_timer_needs_broadcast(pr, cx))
-			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
-
-		if (cx->type == ACPI_STATE_C3) {
-			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
-			if (pr->flags.bm_check)
-				state->flags |= CPUIDLE_FLAG_RCU_IDLE;
-		}
-
 		count++;
 		if (count == CPUIDLE_STATE_MAX)
 			break;
 	}
-
-	if (!count)
-		return -EINVAL;
-
-	return 0;
 }
 
-static int acpi_processor_setup_cstates(struct acpi_processor *pr)
+static void acpi_processor_setup_cstates(struct acpi_processor *pr)
 {
 	int i, count;
 	struct acpi_processor_cx *cx;
@@ -818,17 +802,21 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 		if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 			state->enter_s2idle = acpi_idle_enter_s2idle;
 
+		if (lapic_timer_needs_broadcast(pr, cx))
+			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
+
+		if (cx->type == ACPI_STATE_C3) {
+			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
+			if (pr->flags.bm_check)
+				state->flags |= CPUIDLE_FLAG_RCU_IDLE;
+		}
+
 		count++;
 		if (count == CPUIDLE_STATE_MAX)
 			break;
 	}
 
 	drv->state_count = count;
-
-	if (!count)
-		return -EINVAL;
-
-	return 0;
 }
 
 static inline void acpi_processor_cstate_first_run_checks(void)
@@ -1243,7 +1231,8 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 	if (pr->flags.has_lpi)
 		return acpi_processor_setup_lpi_states(pr);
 
-	return acpi_processor_setup_cstates(pr);
+	acpi_processor_setup_cstates(pr);
+	return 0;
 }
 
 /**
@@ -1263,7 +1252,8 @@ static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
 	if (pr->flags.has_lpi)
 		return acpi_processor_ffh_lpi_probe(pr->id);
 
-	return acpi_processor_setup_cpuidle_cx(pr, dev);
+	acpi_processor_setup_cpuidle_cx(pr, dev);
+	return 0;
 }
 
 static int acpi_processor_get_power_info(struct acpi_processor *pr)
@@ -1357,102 +1347,79 @@ int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
 	return 0;
 }
 
-void acpi_processor_register_idle_driver(void)
-{
-	struct acpi_processor *pr;
-	int ret = -ENODEV;
-	int cpu;
-
-	/*
-	 * Acpi idle driver is used by all possible CPUs.
-	 * Install the idle handler by the processor power info of one in them.
-	 * Note that we use previously set idle handler will be used on
-	 * platforms that only support C1.
-	 */
-	for_each_cpu(cpu, (struct cpumask *)cpu_possible_mask) {
-		pr = per_cpu(processors, cpu);
-		if (!pr)
-			continue;
-
-		ret = acpi_processor_get_power_info(pr);
-		if (!ret) {
-			pr->flags.power_setup_done = 1;
-			acpi_processor_setup_cpuidle_states(pr);
-			break;
-		}
-	}
-
-	if (ret) {
-		pr_debug("No ACPI power information from any CPUs.\n");
-		return;
-	}
-
-	ret = cpuidle_register_driver(&acpi_idle_driver);
-	if (ret) {
-		pr_debug("register %s failed.\n", acpi_idle_driver.name);
-		return;
-	}
-	pr_debug("%s registered with cpuidle.\n", acpi_idle_driver.name);
-}
-
-void acpi_processor_unregister_idle_driver(void)
-{
-	cpuidle_unregister_driver(&acpi_idle_driver);
-}
+static int acpi_processor_registered;
 
-void acpi_processor_power_init(struct acpi_processor *pr)
+int acpi_processor_power_init(struct acpi_processor *pr)
 {
+	int retval;
 	struct cpuidle_device *dev;
 
-	/*
-	 * The code below only works if the current cpuidle driver is the ACPI
-	 * idle driver.
-	 */
-	if (cpuidle_get_driver() != &acpi_idle_driver)
-		return;
-
 	if (disabled_by_idle_boot_param())
-		return;
+		return 0;
 
 	acpi_processor_cstate_first_run_checks();
 
 	if (!acpi_processor_get_power_info(pr))
 		pr->flags.power_setup_done = 1;
 
-	if (!pr->flags.power)
-		return;
-
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
-		return;
+	/*
+	 * Install the idle handler if processor power management is supported.
+	 * Note that we use previously set idle handler will be used on
+	 * platforms that only support C1.
+	 */
+	if (pr->flags.power) {
+		/* Register acpi_idle_driver if not already registered */
+		if (!acpi_processor_registered) {
+			acpi_processor_setup_cpuidle_states(pr);
+			retval = cpuidle_register_driver(&acpi_idle_driver);
+			if (retval)
+				return retval;
+			pr_debug("%s registered with cpuidle\n",
+				 acpi_idle_driver.name);
+		}
 
-	per_cpu(acpi_cpuidle_device, pr->id) = dev;
+		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+		if (!dev)
+			return -ENOMEM;
+		per_cpu(acpi_cpuidle_device, pr->id) = dev;
 
-	acpi_processor_setup_cpuidle_dev(pr, dev);
+		acpi_processor_setup_cpuidle_dev(pr, dev);
 
-	/*
-	 * Register a cpuidle device for this CPU.  The cpuidle driver using
-	 * this device is expected to be registered.
-	 */
-	if (cpuidle_register_device(dev)) {
-		per_cpu(acpi_cpuidle_device, pr->id) = NULL;
-		kfree(dev);
+		/* Register per-cpu cpuidle_device. Cpuidle driver
+		 * must already be registered before registering device
+		 */
+		retval = cpuidle_register_device(dev);
+		if (retval) {
+			if (acpi_processor_registered == 0)
+				cpuidle_unregister_driver(&acpi_idle_driver);
+
+			per_cpu(acpi_cpuidle_device, pr->id) = NULL;
+			kfree(dev);
+			return retval;
+		}
+		acpi_processor_registered++;
 	}
+	return 0;
 }
 
-void acpi_processor_power_exit(struct acpi_processor *pr)
+int acpi_processor_power_exit(struct acpi_processor *pr)
 {
 	struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
 
 	if (disabled_by_idle_boot_param())
-		return;
+		return 0;
 
 	if (pr->flags.power) {
 		cpuidle_unregister_device(dev);
+		acpi_processor_registered--;
+		if (acpi_processor_registered == 0)
+			cpuidle_unregister_driver(&acpi_idle_driver);
+
 		kfree(dev);
 	}
 
 	pr->flags.power_setup_done = 0;
+	return 0;
 }
 
 MODULE_IMPORT_NS("ACPI_PROCESSOR_IDLE");
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 43d5e457814e..18e90067d567 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1280,7 +1280,7 @@ static int acpi_data_prop_read(const struct acpi_device_data *data,
 		ret = acpi_copy_property_array_uint(items, (u64 *)val, nval);
 		break;
 	case DEV_PROP_STRING:
-		nval = min_t(u32, nval, obj->package.count);
+		nval = min(nval, obj->package.count);
 		if (nval == 0)
 			return -ENODATA;
 
@@ -1329,13 +1329,14 @@ static int stop_on_next(struct acpi_device *adev, void *data)
 	return 0;
 }
 
-/**
+/*
  * acpi_get_next_subnode - Return the next child node handle for a fwnode
  * @fwnode: Firmware node to find the next child node for.
  * @child: Handle to one of the device's child nodes or a null handle.
  */
-struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
-					    struct fwnode_handle *child)
+static struct fwnode_handle *
+acpi_get_next_subnode(const struct fwnode_handle *fwnode,
+		      struct fwnode_handle *child)
 {
 	struct acpi_device *adev = to_acpi_device_node(fwnode);
 
@@ -1472,7 +1473,7 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint(
 
 	if (!prev) {
 		do {
-			port = fwnode_get_next_child_node(fwnode, port);
+			port = acpi_get_next_subnode(fwnode, port);
 			/*
 			 * The names of the port nodes begin with "port@"
 			 * followed by the number of the port node and they also
@@ -1490,14 +1491,17 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint(
 	if (!port)
 		return NULL;
 
-	endpoint = fwnode_get_next_child_node(port, prev);
-	while (!endpoint) {
-		port = fwnode_get_next_child_node(fwnode, port);
-		if (!port)
+	do {
+		endpoint = acpi_get_next_subnode(port, prev);
+		if (endpoint)
 			break;
-		if (is_acpi_graph_node(port, "port"))
-			endpoint = fwnode_get_next_child_node(port, NULL);
-	}
+
+		prev = NULL;
+
+		do {
+			port = acpi_get_next_subnode(fwnode, port);
+		} while (port && !is_acpi_graph_node(port, "port"));
+	} while (port);
 
 	/*
 	 * The names of the endpoint nodes begin with "endpoint@" followed by
@@ -1714,6 +1718,7 @@ static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 	if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
 		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);
 
+	fwnode_handle_put(port_fwnode);
 	return 0;
 }
 
diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
index d960a238be4e..9c3cb109c5d2 100644
--- a/drivers/acpi/sleep.h
+++ b/drivers/acpi/sleep.h
@@ -17,10 +17,7 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
 
 extern int acpi_s2idle_begin(void);
 extern int acpi_s2idle_prepare(void);
-extern int acpi_s2idle_prepare_late(void);
-extern void acpi_s2idle_check(void);
 extern bool acpi_s2idle_wake(void);
-extern void acpi_s2idle_restore_early(void);
 extern void acpi_s2idle_restore(void);
 extern void acpi_s2idle_end(void);
 
diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index dd0b40b9bbe8..6d4d06236f61 100644
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -299,34 +299,13 @@ free_acpi_buffer:
 	ACPI_FREE(out_obj);
 }
 
-/**
- * acpi_get_lps0_constraint - Get the LPS0 constraint for a device.
- * @adev: Device to get the constraint for.
- *
- * The LPS0 constraint is the shallowest (minimum) power state in which the
- * device can be so as to allow the platform as a whole to achieve additional
- * energy conservation by utilizing a system-wide low-power state.
- *
- * Returns:
- *  - ACPI power state value of the constraint for @adev on success.
- *  - Otherwise, ACPI_STATE_UNKNOWN.
- */
-int acpi_get_lps0_constraint(struct acpi_device *adev)
-{
-	struct lpi_constraints *entry;
-
-	for_each_lpi_constraint(entry) {
-		if (adev->handle == entry->handle)
-			return entry->min_dstate;
-	}
-
-	return ACPI_STATE_UNKNOWN;
-}
-
 static void lpi_check_constraints(void)
 {
 	struct lpi_constraints *entry;
 
+	if (IS_ERR_OR_NULL(lpi_constraints_table))
+		return;
+
 	for_each_lpi_constraint(entry) {
 		struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle);
 
@@ -508,11 +487,6 @@ static int lps0_device_attach(struct acpi_device *adev,
 
 	lps0_device_handle = adev->handle;
 
-	if (acpi_s2idle_vendor_amd())
-		lpi_device_get_constraints_amd();
-	else
-		lpi_device_get_constraints();
-
 	/*
 	 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
 	 * the FADT and the default suspend mode was not set from the command
@@ -539,7 +513,26 @@ static struct acpi_scan_handler lps0_handler = {
 	.attach = lps0_device_attach,
 };
 
-int acpi_s2idle_prepare_late(void)
+static int acpi_s2idle_begin_lps0(void)
+{
+	if (pm_debug_messages_on && !lpi_constraints_table) {
+		if (acpi_s2idle_vendor_amd())
+			lpi_device_get_constraints_amd();
+		else
+			lpi_device_get_constraints();
+
+		/*
+		 * Try to retrieve the constraints only once because failures
+		 * to do so usually are sticky.
+		 */
+		if (!lpi_constraints_table)
+			lpi_constraints_table = ERR_PTR(-ENODATA);
+	}
+
+	return acpi_s2idle_begin();
+}
+
+static int acpi_s2idle_prepare_late_lps0(void)
 {
 	struct acpi_s2idle_dev_ops *handler;
 
@@ -585,7 +578,7 @@ int acpi_s2idle_prepare_late(void)
 	return 0;
 }
 
-void acpi_s2idle_check(void)
+static void acpi_s2idle_check_lps0(void)
 {
 	struct acpi_s2idle_dev_ops *handler;
 
@@ -598,7 +591,7 @@ void acpi_s2idle_check(void)
 	}
 }
 
-void acpi_s2idle_restore_early(void)
+static void acpi_s2idle_restore_early_lps0(void)
 {
 	struct acpi_s2idle_dev_ops *handler;
 
@@ -636,12 +629,12 @@ void acpi_s2idle_restore_early(void)
 }
 
 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
-	.begin = acpi_s2idle_begin,
+	.begin = acpi_s2idle_begin_lps0,
 	.prepare = acpi_s2idle_prepare,
-	.prepare_late = acpi_s2idle_prepare_late,
-	.check = acpi_s2idle_check,
+	.prepare_late = acpi_s2idle_prepare_late_lps0,
+	.check = acpi_s2idle_check_lps0,
 	.wake = acpi_s2idle_wake,
-	.restore_early = acpi_s2idle_restore_early,
+	.restore_early = acpi_s2idle_restore_early_lps0,
 	.restore = acpi_s2idle_restore,
 	.end = acpi_s2idle_end,
 };
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 7146a8e9e9c2..d0eccbd920e5 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -417,15 +417,32 @@ static inline void acpi_processor_throttling_init(void) {}
 #endif	/* CONFIG_ACPI_CPU_FREQ_PSS */
 
 /* in processor_idle.c */
+extern struct cpuidle_driver acpi_idle_driver;
 #ifdef CONFIG_ACPI_PROCESSOR_IDLE
-void acpi_processor_power_init(struct acpi_processor *pr);
-void acpi_processor_power_exit(struct acpi_processor *pr);
+int acpi_processor_power_init(struct acpi_processor *pr);
+int acpi_processor_power_exit(struct acpi_processor *pr);
 int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
 int acpi_processor_hotplug(struct acpi_processor *pr);
-void acpi_processor_register_idle_driver(void);
-void acpi_processor_unregister_idle_driver(void);
-int acpi_processor_ffh_lpi_probe(unsigned int cpu);
-int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi);
+#else
+static inline int acpi_processor_power_init(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_power_exit(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static inline int acpi_processor_hotplug(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_ACPI_PROCESSOR_IDLE */
 
 /* in processor_thermal.c */
@@ -448,6 +465,11 @@ static inline void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
 }
 #endif	/* CONFIG_CPU_FREQ */
 
+#ifdef CONFIG_ACPI_PROCESSOR_IDLE
+extern int acpi_processor_ffh_lpi_probe(unsigned int cpu);
+extern int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi);
+#endif
+
 void acpi_processor_init_invariance_cppc(void);
 
 #endif
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 5ff5d99f6ead..41f3bf6e4165 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1146,12 +1146,7 @@ struct acpi_s2idle_dev_ops {
 #if defined(CONFIG_SUSPEND) && defined(CONFIG_X86)
 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg);
 void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg);
-int acpi_get_lps0_constraint(struct acpi_device *adev);
 #else /* CONFIG_SUSPEND && CONFIG_X86 */
-static inline int acpi_get_lps0_constraint(struct device *dev)
-{
-	return ACPI_STATE_UNKNOWN;
-}
 static inline int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
 {
 	return -ENODEV;
@@ -1349,9 +1344,6 @@ acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
 int acpi_node_prop_get(const struct fwnode_handle *fwnode, const char *propname,
 		       void **valptr);
 
-struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
-					    struct fwnode_handle *child);
-
 struct acpi_probe_entry;
 typedef bool (*acpi_probe_entry_validate_subtbl)(struct acpi_subtable_header *,
 						 struct acpi_probe_entry *);
@@ -1451,13 +1443,6 @@ static inline int acpi_node_prop_get(const struct fwnode_handle *fwnode,
 }
 
 static inline struct fwnode_handle *
-acpi_get_next_subnode(const struct fwnode_handle *fwnode,
-		      struct fwnode_handle *child)
-{
-	return NULL;
-}
-
-static inline struct fwnode_handle *
 acpi_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
 			     struct fwnode_handle *prev)
 {