ACPI: utils: Add acpi_reduced_hardware() helper

Add a getter for the acpi_gbl_reduced_hardware variable so that modules
can check if they are running on an ACPI reduced-hw platform or not.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: jwrdegoede

drivers/acpi/utils.c

@@ -872,6 +872,17 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
 }
 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
 
+/**
+ * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
+ *
+ * Return true when running on an ACPI-reduced-hw machine, false otherwise.
+ */
+bool acpi_reduced_hardware(void)
+{
+	return acpi_gbl_reduced_hardware;
+}
+EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
+
 /*
  * acpi_backlight= handling, this is done here rather then in video_detect.c
  * because __setup cannot be used in modules.

include/acpi/acpi_bus.h

@@ -78,6 +78,7 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const guid_t *guid, u64 rev,
 
 bool acpi_dev_found(const char *hid);
 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv);
+bool acpi_reduced_hardware(void);
 
 #ifdef CONFIG_ACPI
 

include/linux/acpi.h

@@ -748,6 +748,11 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
 	return NULL;
 }
 
+static inline bool acpi_reduced_hardware(void)
+{
+	return false;
+}
+
 static inline void acpi_dev_put(struct acpi_device *adev) {}
 
 static inline bool is_acpi_node(const struct fwnode_handle *fwnode)