scsi: qla2xxx: add ring buffer for tracing debug logs

Having this log in a ring buffer helps to diagnose qla2xxx driver and
firmware issues instead of having to reproduce the problem with
extended_logging enabled. This saves cycles and helps when it is hard
to reproduce problem.

Link: https://lore.kernel.org/r/1581557368-32080-1-git-send-email-rajan.shanmugavelu@oracle.com
Reviewed-by: Joe Jin <joe.jin@oracle.com>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Rajan Shanmugavelu <rajan.shanmugavelu@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_dbg.c b/drivers/scsi/qla2xxx/qla_dbg.c
index 88a56e8..f301a80 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_dbg.c
+++ b/drivers/scsi/qla2xxx/qla_dbg.c
@@ -73,6 +73,8 @@
 #include "qla_def.h"
 
 #include <linux/delay.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/qla.h>
 
 static uint32_t ql_dbg_offset = 0x800;
 
@@ -2537,15 +2539,30 @@ ql_dbg(uint level, scsi_qla_host_t *vha, uint id, const char *fmt, ...)
 {
        va_list va;
        struct va_format vaf;
-
-       if (!ql_mask_match(level))
-               return;
+       char pbuf[64];
 
        va_start(va, fmt);
 
        vaf.fmt = fmt;
        vaf.va = &va;
 
+       if (!ql_mask_match(level)) {
+               if (vha != NULL) {
+                       const struct pci_dev *pdev = vha->hw->pdev;
+                       /* <module-name> <msg-id>:<host> Message */
+                       snprintf(pbuf, sizeof(pbuf), "%s [%s]-%04x:%ld: ",
+                           QL_MSGHDR, dev_name(&(pdev->dev)), id,
+                           vha->host_no);
+               } else {
+                       snprintf(pbuf, sizeof(pbuf), "%s [%s]-%04x: : ",
+                           QL_MSGHDR, "0000:00:00.0", id);
+               }
+               pbuf[sizeof(pbuf) - 1] = 0;
+               trace_ql_dbg_log(pbuf, &vaf);
+               va_end(va);
+               return;
+       }
+
        if (vha != NULL) {
                const struct pci_dev *pdev = vha->hw->pdev;
                /* <module-name> <pci-name> <msg-id>:<host> Message */

diff --git a/include/trace/events/qla.h b/include/trace/events/qla.h
new file mode 100644 (file)
index 0000000..b71f680
--- /dev/null
+++ b/include/trace/events/qla.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(_TRACE_QLA_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_QLA_H_
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM qla
+
+#define QLA_MSG_MAX 256
+
+DECLARE_EVENT_CLASS(qla_log_event,
+       TP_PROTO(const char *buf,
+               struct va_format *vaf),
+
+       TP_ARGS(buf, vaf),
+
+       TP_STRUCT__entry(
+               __string(buf, buf)
+               __dynamic_array(char, msg, QLA_MSG_MAX)
+       ),
+       TP_fast_assign(
+               __assign_str(buf, buf);
+               vsnprintf(__get_str(msg), QLA_MSG_MAX, vaf->fmt, *vaf->va);
+       ),
+
+       TP_printk("%s %s", __get_str(buf), __get_str(msg))
+);
+
+DEFINE_EVENT(qla_log_event, ql_dbg_log,
+       TP_PROTO(const char *buf, struct va_format *vaf),
+       TP_ARGS(buf, vaf)
+);
+
+#endif /* _TRACE_QLA_H */
+
+#define TRACE_INCLUDE_FILE qla
+
+#include <trace/define_trace.h>