[SCSI] zfcp: module parameter dbflevel for early debugging

So far, we could only increase the s390dbf log level after an FCP
device has been initially set online for it to create the dbf entries
required to adjust the level.

Introduce zfcp.dbflevel as counterpart to the already existing
zfcp.dbfsize to enable debugging of e.g. setting an FCP device online.
Signed-off-by: NSteffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

drivers/s390/scsi/zfcp_dbf.c

@@ -3,7 +3,7 @@
  *
  * Debug traces for zfcp.
  *
- * Copyright IBM Corp. 2002, 2010
+ * Copyright IBM Corp. 2002, 2013
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -23,6 +23,13 @@ module_param(dbfsize, uint, 0400);
 MODULE_PARM_DESC(dbfsize,
 		 "number of pages for each debug feature area (default 4)");
 
+static u32 dbflevel = 3;
+
+module_param(dbflevel, uint, 0400);
+MODULE_PARM_DESC(dbflevel,
+		 "log level for each debug feature area "
+		 "(default 3, range 0..6)");
+
 static inline unsigned int zfcp_dbf_plen(unsigned int offset)
 {
 	return sizeof(struct zfcp_dbf_pay) + offset - ZFCP_DBF_PAY_MAX_REC;
@@ -447,7 +454,7 @@ static debug_info_t *zfcp_dbf_reg(const char *name, int size, int rec_size)
 		return NULL;
 
 	debug_register_view(d, &debug_hex_ascii_view);
-	debug_set_level(d, 3);
+	debug_set_level(d, dbflevel);
 
 	return d;
 }