printk: add generic functions to find KERN_<LEVEL> headers

The current form of a KERN_<LEVEL> is "<.>".

Add printk_get_level and printk_skip_level functions to handle these
formats.

These functions centralize tests of KERN_<LEVEL> so a future modification
can change the KERN_<LEVEL> style and shorten the number of bytes consumed
by these headers.

[akpm@linux-foundation.org: fix build error and warning]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 1bec2f7a2d42..6e12e1f09047 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -24,6 +24,32 @@ extern const char linux_proc_banner[];
  */
 #define KERN_CONT       "<c>"
 
+static inline int printk_get_level(const char *buffer)
+{
+        if (buffer[0] == '<' && buffer[1] && buffer[2] == '>') {
+                switch (buffer[1]) {
+                case '0' ... '7':
+                case 'd':       /* KERN_DEFAULT */
+                case 'c':       /* KERN_CONT */
+                        return buffer[1];
+                }
+        }
+        return 0;
+}
+
+static inline const char *printk_skip_level(const char *buffer)
+{
+        if (printk_get_level(buffer)) {
+                switch (buffer[1]) {
+                case '0' ... '7':
+                case 'd':       /* KERN_DEFAULT */
+                case 'c':       /* KERN_CONT */
+                        return buffer + 3;
+                }
+        }
+        return buffer;
+}
+
 extern int console_printk[];
 
 #define console_loglevel (console_printk[0])