printk: Rework parse_prefix into printk_parse_prefix

parse_prefix is needed externally by later patches, so move it into a
context where it can be used as such. Also give it the printk_ prefix to
reduce the chance of collisions.

Signed-off-by: Chris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/b22ba314a860e5c7f887958f1eab2649f9bd1d06.1623775748.git.chris@chrisdown.name

Author: cdown

kernel/printk/internal.h

@@ -57,6 +57,8 @@ bool printk_percpu_data_ready(void);
 
 void defer_console_output(void);
 
+u16 printk_parse_prefix(const char *text, int *level,
+			enum printk_info_flags *flags);
 #else
 
 /*

kernel/printk/printk.c

@@ -1956,7 +1956,7 @@ static inline u32 printk_caller_id(void)
 }
 
 /**
- * parse_prefix - Parse level and control flags.
+ * printk_parse_prefix - Parse level and control flags.
  *
  * @text:     The terminated text message.
  * @level:    A pointer to the current level value, will be updated.
@@ -1972,7 +1972,7 @@ static inline u32 printk_caller_id(void)
  *
  * Return: The length of the parsed level and control flags.
  */
-static u16 parse_prefix(char *text, int *level,
+u16 printk_parse_prefix(const char *text, int *level,
 			enum printk_info_flags *flags)
 {
 	u16 prefix_len = 0;
@@ -2018,7 +2018,7 @@ static u16 printk_sprint(char *text, u16 size, int facility,
 	if (facility == 0) {
 		u16 prefix_len;
 
-		prefix_len = parse_prefix(text, NULL, NULL);
+		prefix_len = printk_parse_prefix(text, NULL, NULL);
 		if (prefix_len) {
 			text_len -= prefix_len;
 			memmove(text, text + prefix_len, text_len);
@@ -2067,7 +2067,7 @@ int vprintk_store(int facility, int level,
 
 	/* Extract log level or control flags. */
 	if (facility == 0)
-		parse_prefix(&prefix_buf[0], &level, &flags);
+		printk_parse_prefix(&prefix_buf[0], &level, &flags);
 
 	if (level == LOGLEVEL_DEFAULT)
 		level = default_message_loglevel;