[S390] Add debug_register_mode() function to debug feature API

The new function supports setting of permissions for the debugfs files
created by the debug feature. In addition to that, the function provides
uid and gid as parameters for future use. Currently only root is allowed
for uid and gid.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/Documentation/s390/s390dbf.txt b/Documentation/s390/s390dbf.txt
index 0eb7c58..e054209 100644
--- a/Documentation/s390/s390dbf.txt
+++ b/Documentation/s390/s390dbf.txt
@@ -115,6 +115,27 @@
 Description:  Allocates memory for a debug log     
               Must not be called within an interrupt handler 
 
+----------------------------------------------------------------------------
+debug_info_t *debug_register_mode(char *name, int pages, int nr_areas,
+				  int buf_size, mode_t mode, uid_t uid,
+				  gid_t gid);
+
+Parameter:    name:	   Name of debug log (e.g. used for debugfs entry)
+	      pages:	   Number of pages, which will be allocated per area
+	      nr_areas:    Number of debug areas
+	      buf_size:    Size of data area in each debug entry
+	      mode:	   File mode for debugfs files. E.g. S_IRWXUGO
+	      uid:	   User ID for debugfs files. Currently only 0 is
+			   supported.
+	      gid:	   Group ID for debugfs files. Currently only 0 is
+			   supported.
+
+Return Value: Handle for generated debug area
+	      NULL if register failed
+
+Description:  Allocates memory for a debug log
+	      Must not be called within an interrupt handler
+
 ---------------------------------------------------------------------------
 void debug_unregister (debug_info_t * id);