dynamic_debug: Add __dynamic_dev_dbg

Unlike dynamic_pr_debug, dynamic uses of dev_dbg can not
currently add task_pid/KBUILD_MODNAME/__func__/__LINE__
to selected debug output.

Add a new function similar to dynamic_pr_debug to
optionally emit these prefixes.

Cc: Aloisio Almeida <aloisio.almeida@openbossa.org>
Noticed-by: Aloisio Almeida <aloisio.almeida@openbossa.org>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/device.h b/include/linux/device.h
index c20dfbf..4639419 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -785,6 +785,8 @@
 
 #ifdef CONFIG_PRINTK
 
+extern int __dev_printk(const char *level, const struct device *dev,
+			struct va_format *vaf);
 extern int dev_printk(const char *level, const struct device *dev,
 		      const char *fmt, ...)
 	__attribute__ ((format (printf, 3, 4)));
@@ -805,6 +807,9 @@
 
 #else
 
+static inline int __dev_printk(const char *level, const struct device *dev,
+			       struct va_format *vaf)
+	 { return 0; }
 static inline int dev_printk(const char *level, const struct device *dev,
 		      const char *fmt, ...)
 	__attribute__ ((format (printf, 3, 4)));
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index e747ecd..bdf1531 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -47,6 +47,13 @@
 extern int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
 	__attribute__ ((format (printf, 2, 3)));
 
+struct device;
+
+extern int __dynamic_dev_dbg(struct _ddebug *descriptor,
+			     const struct device *dev,
+			     const char *fmt, ...)
+	__attribute__ ((format (printf, 3, 4)));
+
 #define dynamic_pr_debug(fmt, ...) do {					\
 	static struct _ddebug descriptor				\
 	__used								\
@@ -57,7 +64,6 @@
 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__); \
 	} while (0)
 
-
 #define dynamic_dev_dbg(dev, fmt, ...) do {				\
 	static struct _ddebug descriptor				\
 	__used								\
@@ -65,7 +71,7 @@
 	{ KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,		\
 		_DPRINTK_FLAGS_DEFAULT };				\
 	if (unlikely(descriptor.enabled))				\
-		dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);	\
+		__dynamic_dev_dbg(&descriptor, dev, fmt, ##__VA_ARGS__);	\
 	} while (0)
 
 #else