scsi: scsi_transport_fc: Add an additional flag to fc_host_fpin_rcv()

The LLDD and the stack currently process FPINs received from the fabric,
but the stack is not aware of any action taken by the driver to alleviate
congestion. The current interface between the driver and the SCSI stack is
limited to passing the notification mainly for statistics and heuristics.

The reaction to an FPIN could be handled either by the driver or by the
stack (marginal path and failover). Amend the interface to indicate if
action on an FPIN has already been reacted to by the LLDDs or not. Add an
additional flag to fc_host_fpin_rcv() to indicate if the FPIN has been
acknowledged/reacted to by the driver.

Also added a new event code FCH_EVT_LINK_FPIN_ACK to notify to the user
that the event has been acknowledged/reacted by the LLDD driver

Link: https://lore.kernel.org/r/20230209034326.882514-1-muneendra.kumar@broadcom.com
Co-developed-by: Anil Gurumurthy <agurumurthy@marvell.com>
Signed-off-by: Anil Gurumurthy <agurumurthy@marvell.com>
Co-developed-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/lpfc/lpfc_els.c b/drivers/scsi/lpfc/lpfc_els.c
index 569639dc8b2c8e162a712b727a9762a2cc77b911..aee5d0d1187d63bb8466eb6eae181f3babdd6532 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_els.c
+++ b/drivers/scsi/lpfc/lpfc_els.c
@@ -10287,7 +10287,7 @@ lpfc_els_rcv_fpin(struct lpfc_vport *vport, void *p, u32 fpin_length)
                /* Send every descriptor individually to the upper layer */
                if (deliver)
                        fc_host_fpin_rcv(lpfc_shost_from_vport(vport),
-                                        fpin_length, (char *)fpin);
+                                        fpin_length, (char *)fpin, 0);
                desc_cnt++;
        }
 }

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 46e8b38603f0495f1919d51cff583eeef1772e0a..030625ebb4e653a0da4df20f62751f4926332354 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -45,7 +45,7 @@ qla27xx_process_purex_fpin(struct scsi_qla_host *vha, struct purex_item *item)
        ql_dump_buffer(ql_dbg_init + ql_dbg_verbose, vha, 0x508f,
                       pkt, pkt_size);
 
-       fc_host_fpin_rcv(vha->host, pkt_size, (char *)pkt);
+       fc_host_fpin_rcv(vha->host, pkt_size, (char *)pkt, 0);
 }
 
 const char *const port_state_str[] = {

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 0965f8a7134f08079dab58fccd4b1f35bcba128a..f12e9467ebb430a1d9cfbcabccc708dded0cb128 100644 (file)
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -137,6 +137,7 @@ static const struct {
        { FCH_EVT_PORT_FABRIC,          "port_fabric" },
        { FCH_EVT_LINK_UNKNOWN,         "link_unknown" },
        { FCH_EVT_LINK_FPIN,            "link_FPIN" },
+       { FCH_EVT_LINK_FPIN_ACK,        "link_FPIN_ACK" },
        { FCH_EVT_VENDOR_UNIQUE,        "vendor_unique" },
 };
 fc_enum_name_search(host_event_code, fc_host_event_code,
@@ -894,17 +895,20 @@ fc_fpin_congn_stats_update(struct Scsi_Host *shost,
  * @shost:             host the FPIN was received on
  * @fpin_len:          length of FPIN payload, in bytes
  * @fpin_buf:          pointer to FPIN payload
- *
+ * @event_acknowledge: 1, if LLDD handles this event.
  * Notes:
  *     This routine assumes no locks are held on entry.
  */
 void
-fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf)
+fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf,
+               u8 event_acknowledge)
 {
        struct fc_els_fpin *fpin = (struct fc_els_fpin *)fpin_buf;
        struct fc_tlv_desc *tlv;
        u32 desc_cnt = 0, bytes_remain;
        u32 dtag;
+       enum fc_host_event_code event_code =
+               event_acknowledge ? FCH_EVT_LINK_FPIN_ACK : FCH_EVT_LINK_FPIN;
 
        /* Update Statistics */
        tlv = (struct fc_tlv_desc *)&fpin->fpin_desc[0];
@@ -934,7 +938,7 @@ fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf)
        }
 
        fc_host_post_fc_event(shost, fc_get_event_number(),
-                               FCH_EVT_LINK_FPIN, fpin_len, fpin_buf, 0);
+                               event_code, fpin_len, fpin_buf, 0);
 }
 EXPORT_SYMBOL(fc_host_fpin_rcv);
 

diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index 3dcda19d35202538e63fe028bead4597bb2e8ddb..483513c575976c48e9b89a4f6eac67c9c8e10827 100644 (file)
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -496,6 +496,7 @@ enum fc_host_event_code  {
        FCH_EVT_PORT_FABRIC             = 0x204,
        FCH_EVT_LINK_UNKNOWN            = 0x500,
        FCH_EVT_LINK_FPIN               = 0x501,
+       FCH_EVT_LINK_FPIN_ACK           = 0x502,
        FCH_EVT_VENDOR_UNIQUE           = 0xffff,
 };
 
@@ -856,7 +857,8 @@ void fc_host_post_fc_event(struct Scsi_Host *shost, u32 event_number,
         * Note: when calling fc_host_post_fc_event(), vendor_id may be
         *   specified as 0.
         */
-void fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf);
+void fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf,
+               u8 event_acknowledge);
 struct fc_vport *fc_vport_create(struct Scsi_Host *shost, int channel,
                struct fc_vport_identifiers *);
 int fc_vport_terminate(struct fc_vport *vport);