scsi: lpfc: Add MDS driver loopback diagnostics support

Added code to support driver loopback with MDS Diagnostics.  This style of
diagnostics passes frames from the fabric to the driver who then echo them
back out the link.  SEND_FRAME WQEs are used to transmit the frames.  Added
the SOF and EOF field location definitions for use by SEND_FRAME.

Also ensure that enable_mds_diags is a RW parameter.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_attr.c

@@ -5912,7 +5912,7 @@ lpfc_sg_seg_cnt_init(struct lpfc_hba *phba, int val)
  *       1  = MDS Diagnostics enabled
  * Value range is [0,1]. Default value is 0.
  */
-LPFC_ATTR_R(enable_mds_diags, 0, 0, 1, "Enable MDS Diagnostics");
+LPFC_ATTR_RW(enable_mds_diags, 0, 0, 1, "Enable MDS Diagnostics");
 
 /*
  * lpfc_ras_fwlog_buffsize: Firmware logging host buffer size

drivers/scsi/lpfc/lpfc_els.c

@@ -1052,17 +1052,18 @@ lpfc_cmpl_els_flogi(struct lpfc_hba *phba, struct lpfc_iocbq *cmdiocb,
 		if (lpfc_els_retry(phba, cmdiocb, rspiocb))
 			goto out;
 
+		lpfc_printf_vlog(vport, KERN_WARNING, LOG_ELS,
+				 "0150 FLOGI failure Status:x%x/x%x "
+				 "xri x%x TMO:x%x\n",
+				 irsp->ulpStatus, irsp->un.ulpWord[4],
+				 cmdiocb->sli4_xritag, irsp->ulpTimeout);
+
 		/* If this is not a loop open failure, bail out */
 		if (!(irsp->ulpStatus == IOSTAT_LOCAL_REJECT &&
 		      ((irsp->un.ulpWord[4] & IOERR_PARAM_MASK) ==
 					IOERR_LOOP_OPEN_FAILURE)))
 			goto flogifail;
 
-		lpfc_printf_vlog(vport, KERN_WARNING, LOG_ELS,
-				 "0150 FLOGI failure Status:x%x/x%x xri x%x TMO:x%x\n",
-				 irsp->ulpStatus, irsp->un.ulpWord[4],
-				 cmdiocb->sli4_xritag, irsp->ulpTimeout);
-
 		/* FLOGI failed, so there is no fabric */
 		spin_lock_irq(shost->host_lock);
 		vport->fc_flag &= ~(FC_FABRIC | FC_PUBLIC_LOOP);

drivers/scsi/lpfc/lpfc_hw4.h

@@ -4314,6 +4314,12 @@ struct wqe_common {
 #define wqe_rcvoxid_SHIFT     16
 #define wqe_rcvoxid_MASK      0x0000FFFF
 #define wqe_rcvoxid_WORD      word9
+#define wqe_sof_SHIFT         24
+#define wqe_sof_MASK          0x000000FF
+#define wqe_sof_WORD          word9
+#define wqe_eof_SHIFT         16
+#define wqe_eof_MASK          0x000000FF
+#define wqe_eof_WORD          word9
 	uint32_t word10;
 #define wqe_ebde_cnt_SHIFT    0
 #define wqe_ebde_cnt_MASK     0x0000000f

drivers/scsi/lpfc/lpfc_sli.c

@@ -9352,11 +9352,9 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
 		memset(wqe, 0, sizeof(union lpfc_wqe128));
 	/* Some of the fields are in the right position already */
 	memcpy(wqe, &iocbq->iocb, sizeof(union lpfc_wqe));
-	if (iocbq->iocb.ulpCommand != CMD_SEND_FRAME) {
-		/* The ct field has moved so reset */
-		wqe->generic.wqe_com.word7 = 0;
-		wqe->generic.wqe_com.word10 = 0;
-	}
+	/* The ct field has moved so reset */
+	wqe->generic.wqe_com.word7 = 0;
+	wqe->generic.wqe_com.word10 = 0;
 
 	abort_tag = (uint32_t) iocbq->iotag;
 	xritag = iocbq->sli4_xritag;
@@ -9862,6 +9860,15 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
 
 		break;
 	case CMD_SEND_FRAME:
+		bf_set(wqe_cmnd, &wqe->generic.wqe_com, CMD_SEND_FRAME);
+		bf_set(wqe_sof, &wqe->generic.wqe_com, 0x2E); /* SOF byte */
+		bf_set(wqe_eof, &wqe->generic.wqe_com, 0x41); /* EOF byte */
+		bf_set(wqe_lenloc, &wqe->generic.wqe_com, 1);
+		bf_set(wqe_xbl, &wqe->generic.wqe_com, 1);
+		bf_set(wqe_dbde, &wqe->generic.wqe_com, 1);
+		bf_set(wqe_xc, &wqe->generic.wqe_com, 1);
+		bf_set(wqe_cmd_type, &wqe->generic.wqe_com, 0xA);
+		bf_set(wqe_cqid, &wqe->generic.wqe_com, LPFC_WQE_CQ_ID_DEFAULT);
 		bf_set(wqe_xri_tag, &wqe->generic.wqe_com, xritag);
 		bf_set(wqe_reqtag, &wqe->generic.wqe_com, iocbq->iotag);
 		return 0;
@@ -16940,6 +16947,8 @@ lpfc_fc_frame_check(struct lpfc_hba *phba, struct fc_frame_header *fc_hdr)
 	struct fc_vft_header *fc_vft_hdr;
 	uint32_t *header = (uint32_t *) fc_hdr;
 
+#define FC_RCTL_MDS_DIAGS	0xF4
+
 	switch (fc_hdr->fh_r_ctl) {
 	case FC_RCTL_DD_UNCAT:		/* uncategorized information */
 	case FC_RCTL_DD_SOL_DATA:	/* solicited data */
@@ -17949,6 +17958,17 @@ lpfc_sli4_handle_received_buffer(struct lpfc_hba *phba,
 		fcfi = bf_get(lpfc_rcqe_fcf_id,
 			      &dmabuf->cq_event.cqe.rcqe_cmpl);
 
+	if (fc_hdr->fh_r_ctl == 0xF4 && fc_hdr->fh_type == 0xFF) {
+		vport = phba->pport;
+		lpfc_printf_log(phba, KERN_INFO, LOG_SLI,
+				"2023 MDS Loopback %d bytes\n",
+				bf_get(lpfc_rcqe_length,
+				       &dmabuf->cq_event.cqe.rcqe_cmpl));
+		/* Handle MDS Loopback frames */
+		lpfc_sli4_handle_mds_loopback(vport, dmabuf);
+		return;
+	}
+
 	/* d_id this frame is directed to */
 	did = sli4_did_from_fc_hdr(fc_hdr);