scsi: qla2xxx: Enhance driver tracing with separate tunable and more

Older tracing of driver messages was to:

    - log only debug messages to kernel main trace buffer; and

    - log only if extended logging bits corresponding to this message is
      off

This has been modified and extended as follows:

    - Tracing is now controlled via ql2xextended_error_logging_ktrace
      module parameter. Bit usages same as ql2xextended_error_logging.

    - Tracing uses "qla2xxx" trace instance, unless instance creation have
      issues.

    - Tracing is enabled (compile time tunable).

    - All driver messages, include debug and log messages are now traced in
      kernel trace buffer.

Trace messages can be viewed by looking at the qla2xxx instance at:

    /sys/kernel/tracing/instances/qla2xxx/trace

Trace tunable that takes the same bit mask as ql2xextended_error_logging
is:

    ql2xextended_error_logging_ktrace (default=1)

Link: https://lore.kernel.org/r/20220826102559.17474-6-njavali@marvell.com
Suggested-by: Daniel Wagner <dwagner@suse.de>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index bb69fa8b956a..2fc280e61306 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -163,6 +163,7 @@ extern int ql2xrdpenable;
 extern int ql2xsmartsan;
 extern int ql2xallocfwdump;
 extern int ql2xextended_error_logging;
+extern int ql2xextended_error_logging_ktrace;
 extern int ql2xiidmaenable;
 extern int ql2xmqsupport;
 extern int ql2xfwloadbin;