ipr: add support for async scanning to speed up boot

Switch device scanning logic in the ipr driver to use
the async scan API. This speeds up boot times, particularly
on large systems.

Signed-off-by: Brian King <[e-mail]>
Reviewed-by: Wen Xiong<[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>

drivers/scsi/ipr.c

···
 		if (res->sdev) {
 			res->del_from_ml = 1;
 			res->res_handle = IPR_INVALID_RES_HANDLE;
-			if (ioa_cfg->allow_ml_add_del)
-				schedule_work(&ioa_cfg->work_q);
+			schedule_work(&ioa_cfg->work_q);
 		} else {
 			ipr_clear_res_target(res);
 			list_move_tail(&res->queue, &ioa_cfg->free_res_q);
 		}
 	} else if (!res->sdev || res->del_from_ml) {
 		res->add_to_ml = 1;
-		if (ioa_cfg->allow_ml_add_del)
-			schedule_work(&ioa_cfg->work_q);
+		schedule_work(&ioa_cfg->work_q);
 	}
 
 	ipr_send_hcam(ioa_cfg, IPR_HCAM_CDB_OP_CODE_CONFIG_CHANGE, hostrcb);
···
 restart:
 	do {
 		did_work = 0;
-		if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds ||
-		    !ioa_cfg->allow_ml_add_del) {
+		if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds) {
 			spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
 			return;
 		}
···
 		}
 	}
 
+	ioa_cfg->scan_done = 1;
 	spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
 	kobject_uevent(&ioa_cfg->host->shost_dev.kobj, KOBJ_CHANGE);
 	LEAVE;
···
  * @scsi_cmd:	scsi command struct
  *
  * Return value:
+ *	0 if scan in progress / 1 if scan is complete
+ **/
+static int ipr_scan_finished(struct Scsi_Host *shost, unsigned long elapsed_time)
+{
+	unsigned long lock_flags;
+	struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *) shost->hostdata;
+	int rc = 0;
+
+	spin_lock_irqsave(shost->host_lock, lock_flags);
+	if (ioa_cfg->hrrq[IPR_INIT_HRRQ].ioa_is_dead || ioa_cfg->scan_done)
+		rc = 1;
+	if ((elapsed_time/HZ) > (ioa_cfg->transop_timeout * 2))
+		rc = 1;
+	spin_unlock_irqrestore(shost->host_lock, lock_flags);
+	return rc;
+}
+
+/**
+ * ipr_eh_host_reset - Reset the host adapter
+ * @scsi_cmd:	scsi command struct
+ *
+ * Return value:
  * 	SUCCESS / FAILED
  **/
 static int ipr_eh_abort(struct scsi_cmnd *scsi_cmd)
···
 	.slave_alloc = ipr_slave_alloc,
 	.slave_configure = ipr_slave_configure,
 	.slave_destroy = ipr_slave_destroy,
+	.scan_finished = ipr_scan_finished,
 	.target_alloc = ipr_target_alloc,
 	.target_destroy = ipr_target_destroy,
 	.change_queue_depth = ipr_change_queue_depth,
···
 	ioa_cfg->doorbell |= IPR_RUNTIME_RESET;
 
 	list_for_each_entry(res, &ioa_cfg->used_res_q, queue) {
-		if (ioa_cfg->allow_ml_add_del && (res->add_to_ml || res->del_from_ml)) {
+		if (res->add_to_ml || res->del_from_ml) {
 			ipr_trace;
 			break;
 		}
···
 	if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds)
 		scsi_block_requests(ioa_cfg->host);
 
+	schedule_work(&ioa_cfg->work_q);
 	LEAVE;
 	return IPR_RC_JOB_RETURN;
 }
···
 	memcpy(type, ioa_cfg->vpd_cbs->ioa_vpd.std_inq_data.vpids.product_id, 4);
 	type[4] = '\0';
 	ioa_cfg->type = simple_strtoul((char *)type, NULL, 16);
+
+	if (ipr_invalid_adapter(ioa_cfg)) {
+		dev_err(&ioa_cfg->pdev->dev,
+			"Adapter not supported in this hardware configuration.\n");
+
+		if (!ipr_testmode) {
+			ioa_cfg->reset_retries += IPR_NUM_RESET_RELOAD_RETRIES;
+			ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NONE);
+			list_add_tail(&ipr_cmd->queue,
+					&ioa_cfg->hrrq->hrrq_free_q);
+			return IPR_RC_JOB_RETURN;
+		}
+	}
 
 	ipr_cmd->job_step = ipr_ioafp_page3_inquiry;
 
···
 		_ipr_initiate_ioa_reset(ioa_cfg, ipr_reset_enable_ioa,
 					IPR_SHUTDOWN_NONE);
 	spin_unlock_irqrestore(ioa_cfg->host->host_lock, host_lock_flags);
-	wait_event(ioa_cfg->reset_wait_q, !ioa_cfg->in_reset_reload);
-	spin_lock_irqsave(ioa_cfg->host->host_lock, host_lock_flags);
-
-	if (ioa_cfg->hrrq[IPR_INIT_HRRQ].ioa_is_dead) {
-		rc = -EIO;
-	} else if (ipr_invalid_adapter(ioa_cfg)) {
-		if (!ipr_testmode)
-			rc = -EIO;
-
-		dev_err(&ioa_cfg->pdev->dev,
-			"Adapter not supported in this hardware configuration.\n");
-	}
-
-	spin_unlock_irqrestore(ioa_cfg->host->host_lock, host_lock_flags);
 
 	LEAVE;
 	return rc;
···
 					       * ioa_cfg->max_devs_supported)));
 	}
 
-	host->max_channel = IPR_MAX_BUS_TO_SCAN;
+	host->max_channel = IPR_VSET_BUS;
 	host->unique_id = host->host_no;
 	host->max_cmd_len = IPR_MAX_CDB_LEN;
 	host->can_queue = ioa_cfg->max_cmds;
···
 }
 
 /**
- * ipr_scan_vsets - Scans for VSET devices
- * @ioa_cfg:	ioa config struct
- *
- * Description: Since the VSET resources do not follow SAM in that we can have
- * sparse LUNs with no LUN 0, we have to scan for these ourselves.
- *
- * Return value:
- * 	none
- **/
-static void ipr_scan_vsets(struct ipr_ioa_cfg *ioa_cfg)
-{
-	int target, lun;
-
-	for (target = 0; target < IPR_MAX_NUM_TARGETS_PER_BUS; target++)
-		for (lun = 0; lun < IPR_MAX_NUM_VSET_LUNS_PER_TARGET; lun++)
-			scsi_add_device(ioa_cfg->host, IPR_VSET_BUS, target, lun);
-}
-
-/**
  * ipr_initiate_ioa_bringdown - Bring down an adapter
  * @ioa_cfg:		ioa config struct
  * @shutdown_type:	shutdown type
···
 	}
 
 	scsi_scan_host(ioa_cfg->host);
-	ipr_scan_vsets(ioa_cfg);
-	scsi_add_device(ioa_cfg->host, IPR_IOA_BUS, IPR_IOA_TARGET, IPR_IOA_LUN);
-	ioa_cfg->allow_ml_add_del = 1;
-	ioa_cfg->host->max_channel = IPR_VSET_BUS;
 	ioa_cfg->iopoll_weight = ioa_cfg->chip_cfg->iopoll_weight;
 
 	if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {

drivers/scsi/ipr.h

···
 
 #define IPR_MAX_NUM_TARGETS_PER_BUS			256
 #define IPR_MAX_NUM_LUNS_PER_TARGET			256
-#define IPR_MAX_NUM_VSET_LUNS_PER_TARGET	8
 #define IPR_VSET_BUS					0xff
 #define IPR_IOA_BUS						0xff
 #define IPR_IOA_TARGET					0xff
 #define IPR_IOA_LUN						0xff
 #define IPR_MAX_NUM_BUSES				16
-#define IPR_MAX_BUS_TO_SCAN				IPR_MAX_NUM_BUSES
 
 #define IPR_NUM_RESET_RELOAD_RETRIES		3
 
···
 	u8 in_ioa_bringdown:1;
 	u8 ioa_unit_checked:1;
 	u8 dump_taken:1;
-	u8 allow_ml_add_del:1;
+	u8 scan_done:1;
 	u8 needs_hard_reset:1;
 	u8 dual_raid:1;
 	u8 needs_warm_reset:1;