[PATCH 1/3] zfcp: Enhance fsf status read buffer tracing

[Nihar Panda <niharp@linux.ibm.com>]

From: Chinmaya Kajagar <chinmayk@linux.ibm.com>

SRB trace records are logged through hba trace event zfcp_dbf_hba_fsf_uss.
Presently, this trace event has few missing fields in fsf status read 
buffer trace records. To fully trace incoming fsf status read buffer (SRB),
the remaining fields are needed to be added to zfcp_dbf_hba_uss structure.

Append all the remaining SRB fields to the existing unsolicited status 
trace records.

Extend driver to get 3 bytes source id s_id value from fsf status read
buffer's existing reserved field res3.

To display this change, we also change the external tool `zfcpdbf` in the
s390-tools package.

zfcpdbf tool trace example for HBA area after changes:

Timestamp      : 2025-08-22-05:52:04:171750
Area           : HBA
Subarea        : 00
Level          : 2
Exception      : -
CPU ID         : 0003
Caller         : 0x0000021e278c07c8
Record ID      : 2
Tag            : fssrh_4
Description    : fssrh_4 HBA, FSF unsolicited status
Request ID     : 0x0000000000004bfc
Request status : 0x00000000
FSF cmnd       : 0x00006305
FSF sequence no: 0x00000000
SRB stat type  : 0x00000002
SRB stat sub   : 0x00000000
SRB D_ID       : 0x00fffffd
SRB LUN        : 0x0000000000000000
SRB q-design.  : 0x0000000000000000
SRB length     : 0x0000004c
SRB res1       : 00000000
SRB res2       : 00
SRB class      : 0x00000000
SRB res3       : 00
SRB S_ID       : 0x0033c048
SRB res4       : 00000000 00000000 00000000 00000000
                 00000000
SRB pay length : 12
Payload time   : 2025-08-22-05:52:04:171743
SRB info       : 6104000c 0033c024 0033c02e

Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Chinmaya Kajagar <chinmayk@linux.ibm.com>
Signed-off-by: Nihar Panda <niharp@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_dbf.c |  7 +++++++
 drivers/s390/scsi/zfcp_dbf.h | 14 ++++++++++++++
 drivers/s390/scsi/zfcp_fsf.h |  4 +++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 71f625926ae1..89b859176b8b 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -220,6 +220,13 @@ void zfcp_dbf_hba_fsf_uss(char *tag, struct zfcp_fsf_req *req)
 	rec->u.uss.lun = srb->fcp_lun;
 	memcpy(&rec->u.uss.queue_designator, &srb->queue_designator,
 	       sizeof(rec->u.uss.queue_designator));
+	rec->u.uss.length = srb->length;
+	rec->u.uss.res1 = srb->res1;
+	rec->u.uss.res2 = srb->res2;
+	rec->u.uss.class = srb->class;
+	rec->u.uss.res3 = srb->res3;
+	rec->u.uss.s_id = ntoh24(srb->s_id);
+	memcpy(&rec->u.uss.res4, &srb->res4, sizeof(rec->u.uss.res4));
 
 	/* status read buffer payload length */
 	rec->pl_len = (!srb->length) ? 0 : srb->length -
diff --git a/drivers/s390/scsi/zfcp_dbf.h b/drivers/s390/scsi/zfcp_dbf.h
index 4d1435c573bc..44ebad8c761c 100644
--- a/drivers/s390/scsi/zfcp_dbf.h
+++ b/drivers/s390/scsi/zfcp_dbf.h
@@ -149,6 +149,13 @@ struct zfcp_dbf_hba_res {
  * @d_id: destination ID
  * @lun: logical unit number
  * @queue_designator: queue designator
+ * @length: buffer length
+ * @res1: reserved field 1
+ * @res2: reserved field 2
+ * @class: class of service
+ * @res3: reserved field 3
+ * @s_id: source ID
+ * @res4: reserved field 4
  */
 struct zfcp_dbf_hba_uss {
 	u32 status_type;
@@ -156,6 +163,13 @@ struct zfcp_dbf_hba_uss {
 	u32 d_id;
 	u64 lun;
 	u64 queue_designator;
+	u32 length;
+	u32 res1;
+	u8 res2;
+	u32 class;
+	u8 res3;
+	u32 s_id;
+	u8 res4[20];
 } __packed;
 
 /**
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 5e6b601af980..4b92e85ec71d 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -246,7 +246,9 @@ struct fsf_status_read_buffer {
 	u8 d_id[3];
 	u32 class;
 	u64 fcp_lun;
-	u8  res3[24];
+	u8 res3;
+	u8 s_id[3];
+	u8 res4[20];
 	union {
 		u8  data[FSF_STATUS_READ_PAYLOAD_SIZE];
 		u32 word[FSF_STATUS_READ_PAYLOAD_SIZE/sizeof(u32)];
-- 
2.53.0