+/**
+ * lpfc_sli4_scmd_to_wqidx_distr - scsi command to SLI4 WQ index distribution
+ * @phba: Pointer to HBA context object.
+ *
+ * This routine performs a roundrobin SCSI command to SLI4 FCP WQ index
+ * distribution. This is called by __lpfc_sli_issue_iocb_s4() with the hbalock
+ * held.
+ * If scsi-mq is enabled, get the default block layer mapping of software queues
+ * to hardware queues. This information is saved in request tag.
+ *
+ * Return: index into SLI4 fast-path FCP queue index.
+ **/
+int lpfc_sli4_scmd_to_wqidx_distr(struct lpfc_hba *phba,
+ struct lpfc_scsi_buf *lpfc_cmd)
+{
+ struct scsi_cmnd *cmnd = lpfc_cmd->pCmd;
+ struct lpfc_vector_map_info *cpup;
+ int chann, cpu;
+ uint32_t tag;
+ uint16_t hwq;
+
+ if (shost_use_blk_mq(cmnd->device->host)) {
+ tag = blk_mq_unique_tag(cmnd->request);
+ hwq = blk_mq_unique_tag_to_hwq(tag);
+
+ return hwq;
+ }
+
+ if (phba->cfg_fcp_io_sched == LPFC_FCP_SCHED_BY_CPU
+ && phba->cfg_fcp_io_channel > 1) {
+ cpu = smp_processor_id();
+ if (cpu < phba->sli4_hba.num_present_cpu) {
+ cpup = phba->sli4_hba.cpu_map;
+ cpup += cpu;
+ return cpup->channel_id;
+ }
+ }
+ chann = atomic_add_return(1, &phba->fcp_qidx);
+ chann = (chann % phba->cfg_fcp_io_channel);
+ return chann;
+}
+
+