ACPI: introduce a function to find the first physical device
Factor out the code that finds the first physical device
of a given ACPI device. It is used in several places.
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 891c42d..0e85678 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -479,24 +479,38 @@
Device Matching
-------------------------------------------------------------------------- */
-static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
- const struct device *dev)
+/**
+ * acpi_get_first_physical_node - Get first physical node of an ACPI device
+ * @adev: ACPI device in question
+ *
+ * Return: First physical node of ACPI device @adev
+ */
+struct device *acpi_get_first_physical_node(struct acpi_device *adev)
{
struct mutex *physical_node_lock = &adev->physical_node_lock;
+ struct device *phys_dev;
mutex_lock(physical_node_lock);
if (list_empty(&adev->physical_node_list)) {
- adev = NULL;
+ phys_dev = NULL;
} else {
const struct acpi_device_physical_node *node;
node = list_first_entry(&adev->physical_node_list,
struct acpi_device_physical_node, node);
- if (node->dev != dev)
- adev = NULL;
+
+ phys_dev = node->dev;
}
mutex_unlock(physical_node_lock);
- return adev;
+ return phys_dev;
+}
+
+static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
+ const struct device *dev)
+{
+ const struct device *phys_dev = acpi_get_first_physical_node(adev);
+
+ return phys_dev && phys_dev == dev ? adev : NULL;
}
/**