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>

3 files changed, 23 insertions, 23 deletions

diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 296b7a14893a..c3af1088bf6b 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -43,7 +43,6 @@ static const struct acpi_device_id forbidden_id_list[] = {
 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
 {
         struct platform_device *pdev = NULL;
-        struct acpi_device *acpi_parent;
         struct platform_device_info pdevinfo;
         struct resource_entry *rentry;
         struct list_head resource_list;
@@ -82,22 +81,8 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
          * attached to it, that physical device should be the parent of the
          * platform device we are about to create.
          */
-        pdevinfo.parent = NULL;
-        acpi_parent = adev->parent;
-        if (acpi_parent) {
-                struct acpi_device_physical_node *entry;
-                struct list_head *list;
-
-                mutex_lock(&acpi_parent->physical_node_lock);
-                list = &acpi_parent->physical_node_list;
-                if (!list_empty(list)) {
-                        entry = list_first_entry(list,
-                                        struct acpi_device_physical_node,
-                                        node);
-                        pdevinfo.parent = entry->dev;
-                }
-                mutex_unlock(&acpi_parent->physical_node_lock);
-        }
+        pdevinfo.parent = adev->parent ?
+                acpi_get_first_physical_node(adev->parent) : NULL;
         pdevinfo.name = dev_name(&adev->dev);
         pdevinfo.id = -1;
         pdevinfo.res = resources;
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 891c42d1cd65..0e8567846f1a 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -479,24 +479,38 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device)
                              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;
 }
 
 /**
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 1e6833a5cd44..8668891cb1fa 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -106,6 +106,7 @@ bool acpi_device_is_present(struct acpi_device *adev);
 bool acpi_device_is_battery(struct acpi_device *adev);
 bool acpi_device_is_first_physical_node(struct acpi_device *adev,
                                         const struct device *dev);
+struct device *acpi_get_first_physical_node(struct acpi_device *adev);
 
 /* --------------------------------------------------------------------------
                      Device Matching and Notification