--- zzzz-none-000/linux-3.10.107/drivers/scsi/hosts.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/scsi/hosts.c	2021-02-04 17:41:59.000000000 +0000
@@ -169,6 +169,7 @@
 	spin_unlock_irqrestore(shost->host_lock, flags);
 
 	scsi_autopm_get_host(shost);
+	flush_workqueue(shost->tmf_work_q);
 	scsi_forget_host(shost);
 	mutex_unlock(&shost->scan_mutex);
 	scsi_proc_host_rm(shost);
@@ -203,18 +204,40 @@
 	struct scsi_host_template *sht = shost->hostt;
 	int error = -EINVAL;
 
-	printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
+	shost_printk(KERN_INFO, shost, "%s\n",
 			sht->info ? sht->info(shost) : sht->name);
 
 	if (!shost->can_queue) {
-		printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
-				sht->name);
+		shost_printk(KERN_ERR, shost,
+			     "can_queue = 0 no longer supported\n");
 		goto fail;
 	}
 
+	if (shost_use_blk_mq(shost)) {
+		error = scsi_mq_setup_tags(shost);
+		if (error)
+			goto fail;
+	} else {
+		shost->bqt = blk_init_tags(shost->can_queue,
+				shost->hostt->tag_alloc_policy);
+		if (!shost->bqt) {
+			error = -ENOMEM;
+			goto fail;
+		}
+	}
+
+	/*
+	 * Note that we allocate the freelist even for the MQ case for now,
+	 * as we need a command set aside for scsi_reset_provider.  Having
+	 * the full host freelist and one command available for that is a
+	 * little heavy-handed, but avoids introducing a special allocator
+	 * just for this.  Eventually the structure of scsi_reset_provider
+	 * will need a major overhaul.
+	 */
 	error = scsi_setup_command_freelist(shost);
 	if (error)
-		goto fail;
+		goto out_destroy_tags;
+
 
 	if (!shost->shost_gendev.parent)
 		shost->shost_gendev.parent = dev ? dev : &platform_bus;
@@ -225,7 +248,7 @@
 
 	error = device_add(&shost->shost_gendev);
 	if (error)
-		goto out;
+		goto out_destroy_freelist;
 
 	pm_runtime_set_active(&shost->shost_gendev);
 	pm_runtime_enable(&shost->shost_gendev);
@@ -278,8 +301,11 @@
 	device_del(&shost->shost_dev);
  out_del_gendev:
 	device_del(&shost->shost_gendev);
- out:
+ out_destroy_freelist:
 	scsi_destroy_command_freelist(shost);
+ out_destroy_tags:
+	if (shost_use_blk_mq(shost))
+		scsi_mq_destroy_tags(shost);
  fail:
 	return error;
 }
@@ -294,6 +320,8 @@
 
 	scsi_proc_hostdir_rm(shost->hostt);
 
+	if (shost->tmf_work_q)
+		destroy_workqueue(shost->tmf_work_q);
 	if (shost->ehandler)
 		kthread_stop(shost->ehandler);
 	if (shost->work_q)
@@ -317,8 +345,13 @@
 	}
 
 	scsi_destroy_command_freelist(shost);
-	if (shost->bqt)
-		blk_free_tags(shost->bqt);
+	if (shost_use_blk_mq(shost)) {
+		if (shost->tag_set.tags)
+			scsi_mq_destroy_tags(shost);
+	} else {
+		if (shost->bqt)
+			blk_free_tags(shost->bqt);
+	}
 
 	kfree(shost->shost_data);
 
@@ -327,6 +360,12 @@
 	kfree(shost);
 }
 
+static int shost_eh_deadline = -1;
+
+module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(eh_deadline,
+		 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
+
 static struct device_type scsi_host_type = {
 	.name =		"scsi_host",
 	.release =	scsi_host_dev_release,
@@ -365,7 +404,6 @@
 	INIT_LIST_HEAD(&shost->eh_cmd_q);
 	INIT_LIST_HEAD(&shost->starved_list);
 	init_waitqueue_head(&shost->host_wait);
-
 	mutex_init(&shost->scan_mutex);
 
 	/*
@@ -398,9 +436,18 @@
 	shost->cmd_per_lun = sht->cmd_per_lun;
 	shost->unchecked_isa_dma = sht->unchecked_isa_dma;
 	shost->use_clustering = sht->use_clustering;
-	shost->ordered_tag = sht->ordered_tag;
 	shost->no_write_same = sht->no_write_same;
 
+	if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
+		shost->eh_deadline = -1;
+	else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
+		shost_printk(KERN_WARNING, shost,
+			     "eh_deadline %u too large, setting to %u\n",
+			     shost_eh_deadline, INT_MAX / HZ);
+		shost->eh_deadline = INT_MAX;
+	} else
+		shost->eh_deadline = shost_eh_deadline * HZ;
+
 	if (sht->supported_mode == MODE_UNKNOWN)
 		/* means we didn't set it ... default to INITIATOR */
 		shost->active_mode = MODE_INITIATOR;
@@ -429,6 +476,8 @@
 	else
 		shost->dma_boundary = 0xffffffff;
 
+	shost->use_blk_mq = scsi_use_blk_mq && !shost->hostt->disable_blk_mq;
+
 	device_initialize(&shost->shost_gendev);
 	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
 	shost->shost_gendev.bus = &scsi_bus_type;
@@ -443,14 +492,25 @@
 	shost->ehandler = kthread_run(scsi_error_handler, shost,
 			"scsi_eh_%d", shost->host_no);
 	if (IS_ERR(shost->ehandler)) {
-		printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
-			shost->host_no, PTR_ERR(shost->ehandler));
+		shost_printk(KERN_WARNING, shost,
+			"error handler thread failed to spawn, error = %ld\n",
+			PTR_ERR(shost->ehandler));
 		goto fail_kfree;
 	}
 
+	shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
+					    WQ_UNBOUND | WQ_MEM_RECLAIM,
+					   1, shost->host_no);
+	if (!shost->tmf_work_q) {
+		shost_printk(KERN_WARNING, shost,
+			     "failed to create tmf workq\n");
+		goto fail_kthread;
+	}
 	scsi_proc_hostdir_add(shost->hostt);
 	return shost;
 
+ fail_kthread:
+	kthread_stop(shost->ehandler);
  fail_kfree:
 	kfree(shost);
 	return NULL;
@@ -567,7 +627,7 @@
 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
 {
 	if (unlikely(!shost->work_q)) {
-		printk(KERN_ERR
+		shost_printk(KERN_ERR, shost,
 			"ERROR: Scsi host '%s' attempted to queue scsi-work, "
 			"when no workqueue created.\n", shost->hostt->name);
 		dump_stack();
@@ -586,7 +646,7 @@
 void scsi_flush_work(struct Scsi_Host *shost)
 {
 	if (!shost->work_q) {
-		printk(KERN_ERR
+		shost_printk(KERN_ERR, shost,
 			"ERROR: Scsi host '%s' attempted to flush scsi-work, "
 			"when no workqueue created.\n", shost->hostt->name);
 		dump_stack();