scsi: lpfc: Do not abuse UUID APIs and LPFC_COMPRESS_VMID_SIZE

The lpfc_vmid_host_uuid is not defined as uuid_t and its usage is not the
same as for uuid_t operations (like exporting or importing).  Hence replace
call to uuid_is_null() by respective memchr_inv() without abusing casting.

With that, replace LPFC_COMPRESS_VMID_SIZE with plain number and respective
sizeof() to make code robust to changes in the future, if any.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230818155452.875781-1-andriy.shevchenko@linux.intel.com
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: andy-shev

drivers/scsi/lpfc/lpfc.h

@@ -309,7 +309,6 @@ struct lpfc_hba;
 #define LPFC_VMID_TIMER   300	/* timer interval in seconds */
 
 #define LPFC_MAX_VMID_SIZE      256
-#define LPFC_COMPRESS_VMID_SIZE 16
 
 union lpfc_vmid_io_tag {
 	u32 app_id;	/* App Id vmid */
@@ -667,7 +666,7 @@ struct lpfc_vport {
 	uint32_t cfg_first_burst_size;
 	uint32_t dev_loss_tmo_changed;
 	/* VMID parameters */
-	u8 lpfc_vmid_host_uuid[LPFC_COMPRESS_VMID_SIZE];
+	u8 lpfc_vmid_host_uuid[16];
 	u32 max_vmid;	/* maximum VMIDs allowed per port */
 	u32 cur_vmid_cnt;	/* Current VMID count */
 #define LPFC_MIN_VMID	4

drivers/scsi/lpfc/lpfc_els.c

@@ -1331,7 +1331,8 @@ lpfc_issue_els_flogi(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp,
 	if (phba->cfg_vmid_priority_tagging) {
 		sp->cmn.priority_tagging = 1;
 		/* lpfc_vmid_host_uuid is combination of wwpn and wwnn */
-		if (uuid_is_null((uuid_t *)vport->lpfc_vmid_host_uuid)) {
+		if (!memchr_inv(vport->lpfc_vmid_host_uuid, 0,
+				sizeof(vport->lpfc_vmid_host_uuid))) {
 			memcpy(vport->lpfc_vmid_host_uuid, phba->wwpn,
 			       sizeof(phba->wwpn));
 			memcpy(&vport->lpfc_vmid_host_uuid[8], phba->wwnn,
@@ -12357,9 +12358,10 @@ lpfc_vmid_uvem(struct lpfc_vport *vport,
 	elsiocb->vmid_tag.vmid_context = vmid_context;
 	pcmd = (u8 *)elsiocb->cmd_dmabuf->virt;
 
-	if (uuid_is_null((uuid_t *)vport->lpfc_vmid_host_uuid))
+	if (!memchr_inv(vport->lpfc_vmid_host_uuid, 0,
+			sizeof(vport->lpfc_vmid_host_uuid)))
 		memcpy(vport->lpfc_vmid_host_uuid, vmid->host_vmid,
-		       LPFC_COMPRESS_VMID_SIZE);
+		       sizeof(vport->lpfc_vmid_host_uuid));
 
 	*((u32 *)(pcmd)) = ELS_CMD_UVEM;
 	len = (u32 *)(pcmd + 4);
@@ -12369,13 +12371,13 @@ lpfc_vmid_uvem(struct lpfc_vport *vport,
 	vem_id_desc->tag = be32_to_cpu(VEM_ID_DESC_TAG);
 	vem_id_desc->length = be32_to_cpu(LPFC_UVEM_VEM_ID_DESC_SIZE);
 	memcpy(vem_id_desc->vem_id, vport->lpfc_vmid_host_uuid,
-	       LPFC_COMPRESS_VMID_SIZE);
+	       sizeof(vem_id_desc->vem_id));
 
 	inst_desc = (struct instantiated_ve_desc *)(pcmd + 32);
 	inst_desc->tag = be32_to_cpu(INSTANTIATED_VE_DESC_TAG);
 	inst_desc->length = be32_to_cpu(LPFC_UVEM_VE_MAP_DESC_SIZE);
 	memcpy(inst_desc->global_vem_id, vmid->host_vmid,
-	       LPFC_COMPRESS_VMID_SIZE);
+	       sizeof(inst_desc->global_vem_id));
 
 	bf_set(lpfc_instantiated_nport_id, inst_desc, vport->fc_myDID);
 	bf_set(lpfc_instantiated_local_id, inst_desc,