Driver core: platform_driver_probe(), can save codespace
This defines a new platform_driver_probe() method allowing the driver's
probe() method, and its support code+data, to safely live in __init
sections for typical system configurations.
Many system-on-chip processors could benefit from this API, to the tune
of recovering hundreds to thousands of bytes per driver. That's memory
which is currently wasted holding code which can never be called after
system startup, yet can not be removed. It can't be removed because of
the linkage requirement that pointers to init section code (like, ideally,
probe support) must not live in other sections (like driver method tables)
after those pointers would be invalid.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 29cd6de..20f47b8 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -58,6 +58,12 @@
extern int platform_driver_register(struct platform_driver *);
extern void platform_driver_unregister(struct platform_driver *);
+/* non-hotpluggable platform devices may use this so that probe() and
+ * its support may live in __init sections, conserving runtime memory.
+ */
+extern int platform_driver_probe(struct platform_driver *driver,
+ int (*probe)(struct platform_device *));
+
#define platform_get_drvdata(_dev) dev_get_drvdata(&(_dev)->dev)
#define platform_set_drvdata(_dev,data) dev_set_drvdata(&(_dev)->dev, (data))