scsi: lpfc: Rework lpfc_fdmi_cmd() routine for cleanup and consistency

Switch case logics are reworked so they appear more similar and
consistent. This eliminates compiler errors indicating unaligned pointer
values and packed members.

Added comments to explain previous size offset accumulations.

Link: https://lore.kernel.org/r/20220911221505.117655-10-jsmart2021@gmail.comCo-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_ct.c

@@ -3533,7 +3533,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	uint32_t mask;
 	struct lpfc_fdmi_reg_hba *rh;
 	struct lpfc_fdmi_port_entry *pe;
-	struct lpfc_fdmi_reg_portattr *pab = NULL;
+	struct lpfc_fdmi_reg_portattr *pab = NULL, *base = NULL;
 	struct lpfc_fdmi_attr_block *ab = NULL;
 	int  (*func)(struct lpfc_vport *vport, struct lpfc_fdmi_attr_def *ad);
 	void (*cmpl)(struct lpfc_hba *, struct lpfc_iocbq *,
@@ -3566,6 +3566,10 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	INIT_LIST_HEAD(&rq->list);
 	INIT_LIST_HEAD(&rsp->list);
 
+	/* mbuf buffers are 1K in length - aka LPFC_BPL_SIZE */
+	memset(rq->virt, 0, LPFC_BPL_SIZE);
+	rsp_size = LPFC_BPL_SIZE;
+
 	/* FDMI request */
 	lpfc_printf_vlog(vport, KERN_INFO, LOG_DISCOVERY,
 			 "0218 FDMI Request x%x mask x%x Data: x%x x%x x%x\n",
@@ -3575,7 +3579,6 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	CtReq = (struct lpfc_sli_ct_request *)rq->virt;
 
 	/* First populate the CT_IU preamble */
-	memset(CtReq, 0, sizeof(struct lpfc_sli_ct_request));
 	CtReq->RevisionId.bits.Revision = SLI_CT_REVISION;
 	CtReq->RevisionId.bits.InId = 0;
 
@@ -3583,17 +3586,18 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	CtReq->FsSubType = SLI_CT_FDMI_Subtypes;
 
 	CtReq->CommandResponse.bits.CmdRsp = cpu_to_be16(cmdcode);
-	rsp_size = LPFC_BPL_SIZE;
+
 	size = 0;
 
 	/* Next fill in the specific FDMI cmd information */
 	switch (cmdcode) {
 	case SLI_MGMT_RHAT:
 	case SLI_MGMT_RHBA:
-		rh = (struct lpfc_fdmi_reg_hba *)&CtReq->un.PortID;
+		rh = (struct lpfc_fdmi_reg_hba *)&CtReq->un;
 		/* HBA Identifier */
 		memcpy(&rh->hi.PortName, &phba->pport->fc_sparam.portName,
 		       sizeof(struct lpfc_name));
+		size += sizeof(struct lpfc_fdmi_hba_ident);
 
 		if (cmdcode == SLI_MGMT_RHBA) {
 			/* Registered Port List */
@@ -3602,16 +3606,13 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 			memcpy(&rh->rpl.pe.PortName,
 			       &phba->pport->fc_sparam.portName,
 			       sizeof(struct lpfc_name));
-
-			/* point to the HBA attribute block */
-			size = 2 * sizeof(struct lpfc_name) +
-				FOURBYTES;
-		} else {
-			size = sizeof(struct lpfc_name);
+			size += sizeof(struct lpfc_fdmi_reg_port_list);
 		}
+
 		ab = (struct lpfc_fdmi_attr_block *)((uint8_t *)rh + size);
 		ab->EntryCnt = 0;
-		size += FOURBYTES;
+		size += FOURBYTES;	/* add length of EntryCnt field */
+
 		bit_pos = 0;
 		if (new_mask)
 			mask = new_mask;
@@ -3626,6 +3627,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 					     (struct lpfc_fdmi_attr_def *)
 					     ((uint8_t *)rh + size));
 				ab->EntryCnt++;
+				/* check if another attribute fits */
 				if ((size + 256) >
 				    (LPFC_BPL_SIZE - LPFC_CT_PREAMBLE))
 					goto hba_out;
@@ -3636,7 +3638,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 hba_out:
 		ab->EntryCnt = cpu_to_be32(ab->EntryCnt);
 		/* Total size */
-		size = GID_REQUEST_SZ - 4 + size;
+		size += GID_REQUEST_SZ - 4;
 		break;
 
 	case SLI_MGMT_RPRT:
@@ -3647,22 +3649,29 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		}
 		fallthrough;
 	case SLI_MGMT_RPA:
-		pab = (struct lpfc_fdmi_reg_portattr *)&CtReq->un.PortID;
+		/* Store base ptr right after preamble */
+		base = (struct lpfc_fdmi_reg_portattr *)&CtReq->un;
+
 		if (cmdcode == SLI_MGMT_RPRT) {
-			rh = (struct lpfc_fdmi_reg_hba *)pab;
+			rh = (struct lpfc_fdmi_reg_hba *)base;
 			/* HBA Identifier */
 			memcpy(&rh->hi.PortName,
 			       &phba->pport->fc_sparam.portName,
 			       sizeof(struct lpfc_name));
 			pab = (struct lpfc_fdmi_reg_portattr *)
-				((uint8_t *)pab +  sizeof(struct lpfc_name));
+				((uint8_t *)base + sizeof(struct lpfc_name));
+			size += sizeof(struct lpfc_name);
+		} else {
+			pab = base;
 		}
 
 		memcpy((uint8_t *)&pab->PortName,
 		       (uint8_t *)&vport->fc_sparam.portName,
 		       sizeof(struct lpfc_name));
-		size += sizeof(struct lpfc_name) + FOURBYTES;
 		pab->ab.EntryCnt = 0;
+		/* add length of name and EntryCnt field */
+		size += sizeof(struct lpfc_name) + FOURBYTES;
+
 		bit_pos = 0;
 		if (new_mask)
 			mask = new_mask;
@@ -3675,8 +3684,9 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 				func = lpfc_fdmi_port_action[bit_pos];
 				size += func(vport,
 					     (struct lpfc_fdmi_attr_def *)
-					     ((uint8_t *)pab + size));
+					     ((uint8_t *)base + size));
 				pab->ab.EntryCnt++;
+				/* check if another attribute fits */
 				if ((size + 256) >
 				    (LPFC_BPL_SIZE - LPFC_CT_PREAMBLE))
 					goto port_out;
@@ -3686,10 +3696,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		}
 port_out:
 		pab->ab.EntryCnt = cpu_to_be32(pab->ab.EntryCnt);
-		/* Total size */
-		if (cmdcode == SLI_MGMT_RPRT)
-			size += sizeof(struct lpfc_name);
-		size = GID_REQUEST_SZ - 4 + size;
+		size += GID_REQUEST_SZ - 4;
 		break;
 
 	case SLI_MGMT_GHAT:
@@ -3698,7 +3705,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		fallthrough;
 	case SLI_MGMT_DHBA:
 	case SLI_MGMT_DHAT:
-		pe = (struct lpfc_fdmi_port_entry *)&CtReq->un.PortID;
+		pe = (struct lpfc_fdmi_port_entry *)&CtReq->un;
 		memcpy((uint8_t *)&pe->PortName,
 		       (uint8_t *)&vport->fc_sparam.portName,
 		       sizeof(struct lpfc_name));
@@ -3717,7 +3724,7 @@ lpfc_fdmi_cmd(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 		}
 		fallthrough;
 	case SLI_MGMT_DPA:
-		pe = (struct lpfc_fdmi_port_entry *)&CtReq->un.PortID;
+		pe = (struct lpfc_fdmi_port_entry *)&CtReq->un;
 		memcpy((uint8_t *)&pe->PortName,
 		       (uint8_t *)&vport->fc_sparam.portName,
 		       sizeof(struct lpfc_name));