[SCSI] libsas: improve debug statements

It's difficult to determine which domain_device is triggering error recovery,
so convert messages like:

  sas: ex 5001b4da000e703f phy08:T attached: 5001b4da000e7028
  sas: ex 5001b4da000e703f phy09:T attached: 5001b4da000e7029
  ...
  ata7: sas eh calling libata port error handler
  ata8: sas eh calling libata port error handler

...into:

  sas: ex 5001517e85cfefff phy05:T:9 attached: 5001517e85cfefe5 (stp)
  sas: ex 5001517e3b0af0bf phy11:T:8 attached: 5001517e3b0af0ab (stp)
  ...
  sas: ata7: end_device-21:1: dev error handler
  sas: ata8: end_device-20:0:5: dev error handler

which shows attached link rate, device type, and associates a
domain_device with its ata_port id to correlate messages emitted from
libata-eh.

As Doug notes, we can also take the opportunity to clarify expander phy
routing capabilities.

[dgilbert@interlog.com: clarify table2table with 'U']
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/libsas/sas_ata.c

@@ -317,6 +317,28 @@ static int local_ata_check_ready(struct ata_link *link)
 	}
 }
 
+static int sas_ata_printk(const char *level, const struct domain_device *ddev,
+			  const char *fmt, ...)
+{
+	struct ata_port *ap = ddev->sata_dev.ap;
+	struct device *dev = &ddev->rphy->dev;
+	struct va_format vaf;
+	va_list args;
+	int r;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	r = printk("%ssas: ata%u: %s: %pV",
+		   level, ap->print_id, dev_name(dev), &vaf);
+
+	va_end(args);
+
+	return r;
+}
+
 static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 			      unsigned long deadline)
 {
@@ -333,7 +355,7 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 	res = i->dft->lldd_I_T_nexus_reset(dev);
 
 	if (res != TMF_RESP_FUNC_COMPLETE)
-		SAS_DPRINTK("%s: Unable to reset ata device?\n", __func__);
+		sas_ata_printk(KERN_DEBUG, dev, "Unable to reset ata device?\n");
 
 	phy = sas_get_local_phy(dev);
 	if (scsi_is_sas_phy_local(phy))
@@ -344,7 +366,7 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 
 	ret = ata_wait_after_reset(link, deadline, check_ready);
 	if (ret && ret != -EAGAIN)
-		ata_link_err(link, "COMRESET failed (errno=%d)\n", ret);
+		sas_ata_printk(KERN_ERR, dev, "reset failed (errno=%d)\n", ret);
 
 	/* XXX: if the class changes during the reset the upper layer
 	 * should be informed, if the device has gone away we assume
@@ -665,7 +687,7 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie)
 	 * remove once all commands are completed
 	 */
 	kref_get(&dev->kref);
-	ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
+	sas_ata_printk(KERN_DEBUG, dev, "dev error handler\n");
 	ata_scsi_port_error_handler(ha->core.shost, ap);
 	sas_put_device(dev);
 }
@@ -703,26 +725,27 @@ void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 		struct list_head *done_q)
 {
 	struct scsi_cmnd *cmd, *n;
-	struct ata_port *ap;
+	struct domain_device *eh_dev;
 
 	do {
 		LIST_HEAD(sata_q);
-
-		ap = NULL;
+		eh_dev = NULL;
 
 		list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
 			struct domain_device *ddev = cmd_to_domain_dev(cmd);
 
 			if (!dev_is_sata(ddev) || TO_SAS_TASK(cmd))
 				continue;
-			if (ap && ap != ddev->sata_dev.ap)
+			if (eh_dev && eh_dev != ddev)
 				continue;
-			ap = ddev->sata_dev.ap;
+			eh_dev = ddev;
 			list_move(&cmd->eh_entry, &sata_q);
 		}
 
 		if (!list_empty(&sata_q)) {
-			ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata cmd error handler\n");
+			struct ata_port *ap = eh_dev->sata_dev.ap;
+
+			sas_ata_printk(KERN_DEBUG, eh_dev, "cmd error handler\n");
 			ata_scsi_cmd_error_handler(shost, ap, &sata_q);
 			/*
 			 * ata's error handler may leave the cmd on the list
@@ -738,7 +761,7 @@ void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 			while (!list_empty(&sata_q))
 				list_del_init(sata_q.next);
 		}
-	} while (ap);
+	} while (eh_dev);
 }
 
 void sas_ata_schedule_reset(struct domain_device *dev)

drivers/scsi/libsas/sas_expander.c

@@ -166,7 +166,22 @@ static inline void *alloc_smp_resp(int size)
 	return kzalloc(size, GFP_KERNEL);
 }
 
-/* ---------- Expander configuration ---------- */
+static char sas_route_char(struct domain_device *dev, struct ex_phy *phy)
+{
+	switch (phy->routing_attr) {
+	case TABLE_ROUTING:
+		if (dev->ex_dev.t2t_supp)
+			return 'U';
+		else
+			return 'T';
+	case DIRECT_ROUTING:
+		return 'D';
+	case SUBTRACTIVE_ROUTING:
+		return 'S';
+	default:
+		return '?';
+	}
+}
 
 static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
 			   void *disc_resp)
@@ -176,9 +191,10 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
 	struct smp_resp *resp = disc_resp;
 	struct discover_resp *dr = &resp->disc;
 	struct sas_rphy *rphy = dev->rphy;
-	int rediscover = (phy->phy != NULL);
+	bool new_phy = !phy->phy;
+	char *type;
 
-	if (!rediscover) {
+	if (new_phy) {
 		phy->phy = sas_phy_alloc(&rphy->dev, phy_id);
 
 		/* FIXME: error_handling */
@@ -223,20 +239,41 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
 	phy->phy->maximum_linkrate = dr->pmax_linkrate;
 	phy->phy->negotiated_linkrate = phy->linkrate;
 
-	if (!rediscover)
+	if (new_phy)
 		if (sas_phy_add(phy->phy)) {
 			sas_phy_free(phy->phy);
 			return;
 		}
 
-	SAS_DPRINTK("ex %016llx phy%02d:%c attached: %016llx\n",
-		    SAS_ADDR(dev->sas_addr), phy->phy_id,
-		    phy->routing_attr == TABLE_ROUTING ? 'T' :
-		    phy->routing_attr == DIRECT_ROUTING ? 'D' :
-		    phy->routing_attr == SUBTRACTIVE_ROUTING ? 'S' : '?',
-		    SAS_ADDR(phy->attached_sas_addr));
+	switch (phy->attached_dev_type) {
+	case NO_DEVICE:
+		type = "no device";
+		break;
+	case SAS_END_DEV:
+		if (phy->attached_iproto) {
+			if (phy->attached_tproto)
+				type = "host+target";
+			else
+				type = "host";
+		} else {
+			if (dr->attached_sata_dev)
+				type = "stp";
+			else
+				type = "ssp";
+		}
+		break;
+	case EDGE_DEV:
+	case FANOUT_DEV:
+		type = "smp";
+		break;
+	default:
+		type = "unknown";
+	}
 
-	return;
+	SAS_DPRINTK("ex %016llx phy%02d:%c:%X attached: %016llx (%s)\n",
+		    SAS_ADDR(dev->sas_addr), phy->phy_id,
+		    sas_route_char(dev, phy), phy->linkrate,
+		    SAS_ADDR(phy->attached_sas_addr), type);
 }
 
 /* check if we have an existing attached ata device on this expander phy */
@@ -1176,32 +1213,25 @@ static void sas_print_parent_topology_bug(struct domain_device *child,
 						 struct ex_phy *parent_phy,
 						 struct ex_phy *child_phy)
 {
-	static const char ra_char[] = {
-		[DIRECT_ROUTING] = 'D',
-		[SUBTRACTIVE_ROUTING] = 'S',
-		[TABLE_ROUTING] = 'T',
-	};
 	static const char *ex_type[] = {
 		[EDGE_DEV] = "edge",
 		[FANOUT_DEV] = "fanout",
 	};
 	struct domain_device *parent = child->parent;
 
-	sas_printk("%s ex %016llx (T2T supp:%d) phy 0x%x <--> %s ex %016llx "
-		   "(T2T supp:%d) phy 0x%x has %c:%c routing link!\n",
+	sas_printk("%s ex %016llx phy 0x%x <--> %s ex %016llx "
+		   "phy 0x%x has %c:%c routing link!\n",
 
 		   ex_type[parent->dev_type],
 		   SAS_ADDR(parent->sas_addr),
-		   parent->ex_dev.t2t_supp,
 		   parent_phy->phy_id,
 
 		   ex_type[child->dev_type],
 		   SAS_ADDR(child->sas_addr),
-		   child->ex_dev.t2t_supp,
 		   child_phy->phy_id,
 
-		   ra_char[parent_phy->routing_attr],
-		   ra_char[child_phy->routing_attr]);
+		   sas_route_char(parent, parent_phy),
+		   sas_route_char(child, child_phy));
 }
 
 static int sas_check_eeds(struct domain_device *child,