Add 'pr_fmt()' format modifier to pr_xyz macros.

A common reason for device drivers to implement their own printk macros
is the lack of a printk prefix with the standard pr_xyz macros.
Introduce a pr_fmt() macro that is applied for every pr_xyz macro to the
format string.

The most common use of the pr_fmt macro would be to add the name of the
device driver to all pr_xyz messages in a source file.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/kernel.h

@@ -318,32 +318,36 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
 	return buf;
 }
 
-#define pr_emerg(fmt, arg...) \
-	printk(KERN_EMERG fmt, ##arg)
-#define pr_alert(fmt, arg...) \
-	printk(KERN_ALERT fmt, ##arg)
-#define pr_crit(fmt, arg...) \
-	printk(KERN_CRIT fmt, ##arg)
-#define pr_err(fmt, arg...) \
-	printk(KERN_ERR fmt, ##arg)
-#define pr_warning(fmt, arg...) \
-	printk(KERN_WARNING fmt, ##arg)
-#define pr_notice(fmt, arg...) \
-	printk(KERN_NOTICE fmt, ##arg)
-#define pr_info(fmt, arg...) \
-	printk(KERN_INFO fmt, ##arg)
+#ifndef pr_fmt
+#define pr_fmt(fmt) fmt
+#endif
+
+#define pr_emerg(fmt, ...) \
+        printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_alert(fmt, ...) \
+        printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_crit(fmt, ...) \
+        printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_err(fmt, ...) \
+        printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_warning(fmt, ...) \
+        printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_notice(fmt, ...) \
+        printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
+#define pr_info(fmt, ...) \
+        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 
 /* If you are writing a driver, please use dev_dbg instead */
 #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
 #define pr_debug(fmt, ...) do { \
-	dynamic_pr_debug(fmt, ##__VA_ARGS__); \
+	dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
 	} while (0)
 #elif defined(DEBUG)
-#define pr_debug(fmt, arg...) \
-	printk(KERN_DEBUG fmt, ##arg)
+#define pr_debug(fmt, ...) \
+	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 #else
-#define pr_debug(fmt, arg...) \
-	({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
+#define pr_debug(fmt, ...) \
+	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
 #endif
 
 /*