fcoe: Add runtime debug logging with module parameter debug_logging

This patch converts all FC_DBG statements to use new runtime tunable
debug macros. The fcoe.ko module now has a debug_logging module
parameter.

fcoe_debug_logging is an unsigned integer representing a bitmask of all
available logging levels. Currently only two logging levels are
supported-

   bit
LSB 0 = general fcoe logging
    1 = netdevice related logging

This patch also attempts to clean up some debug statement formatting
so it's more readable.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/scsi/fcoe/fcoe.h b/drivers/scsi/fcoe/fcoe.h
index a1eb8c1988b0..0d724fa0898f 100644
--- a/drivers/scsi/fcoe/fcoe.h
+++ b/drivers/scsi/fcoe/fcoe.h
@@ -40,6 +40,30 @@
 #define FCOE_MIN_XID            0x0001  /* the min xid supported by fcoe_sw */
 #define FCOE_MAX_XID            0x07ef  /* the max xid supported by fcoe_sw */
 
+unsigned int fcoe_debug_logging;
+module_param_named(debug_logging, fcoe_debug_logging, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
+
+#define FCOE_LOGGING        0x01 /* General logging, not categorized */
+#define FCOE_NETDEV_LOGGING 0x02 /* Netdevice logging */
+
+#define FCOE_CHECK_LOGGING(LEVEL, CMD)                                  \
+do {                                                                    \
+        if (unlikely(fcoe_debug_logging & LEVEL))                       \
+                do {                                                    \
+                        CMD;                                            \
+                } while (0);                                            \
+} while (0);
+
+#define FCOE_DBG(fmt, args...)                                          \
+        FCOE_CHECK_LOGGING(FCOE_LOGGING,                                \
+                           printk(KERN_INFO "fcoe: " fmt, ##args);)
+
+#define FCOE_NETDEV_DBG(netdev, fmt, args...)                   \
+        FCOE_CHECK_LOGGING(FCOE_NETDEV_LOGGING,                 \
+                           printk(KERN_INFO "fcoe: %s" fmt,     \
+                                  netdev->name, ##args);)
+
 /*
  * this percpu struct for fcoe
  */