ACPI / driver core: Introduce struct acpi_dev_node and related macros

To avoid adding an ACPI handle pointer to struct device on
architectures that don't use ACPI, or generally when CONFIG_ACPI is
not set, in which cases that pointer is useless, define struct
acpi_dev_node that will contain the handle pointer if CONFIG_ACPI is
set and will be empty otherwise and use it to represent the ACPI
device node field in struct device.

In addition to that define macros for reading and setting the ACPI
handle of a device that don't generate code when CONFIG_ACPI is
unset.  Modify the ACPI subsystem to use those macros instead of
referring to the given device's ACPI handle directly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 16 insertions, 2 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index cc3aee57a46e..05292e488346 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -578,6 +578,12 @@ struct device_dma_parameters {
 	unsigned long segment_boundary_mask;
 };
 
+struct acpi_dev_node {
+#ifdef CONFIG_ACPI
+	void	*handle;
+#endif
+};
+
 /**
  * struct device - The basic device structure
  * @parent:	The device's "parent" device, the device to which it is attached.
@@ -618,7 +624,7 @@ struct device_dma_parameters {
  * @dma_mem:	Internal for coherent mem override.
  * @archdata:	For arch-specific additions.
  * @of_node:	Associated device tree node.
- * @acpi_handle: Associated ACPI device node's namespace handle.
+ * @acpi_node:	Associated ACPI device node.
  * @devt:	For creating the sysfs "dev".
  * @id:		device instance
  * @devres_lock: Spinlock to protect the resource of the device.
@@ -683,7 +689,7 @@ struct device {
 	struct dev_archdata	archdata;
 
 	struct device_node	*of_node; /* associated device tree node */
-	void			*acpi_handle; /* associated ACPI device node */
+	struct acpi_dev_node	acpi_node; /* associated ACPI device node */
 
 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
 	u32			id;	/* device instance */
@@ -704,6 +710,14 @@ static inline struct device *kobj_to_dev(struct kobject *kobj)
 	return container_of(kobj, struct device, kobj);
 }
 
+#ifdef CONFIG_ACPI
+#define ACPI_HANDLE(dev)	((dev)->acpi_node.handle)
+#define ACPI_HANDLE_SET(dev, _handle_)	(dev)->acpi_node.handle = (_handle_)
+#else
+#define ACPI_HANDLE(dev)	(NULL)
+#define ACPI_HANDLE_SET(dev, _handle_)	do { } while (0)
+#endif
+
 /* Get the wakeup routines, which depend on struct device */
 #include <linux/pm_wakeup.h>