1 files changed, 584 insertions, 0 deletions
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
new file mode 100644
index 000000000..d5bc1314c
--- /dev/null
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -0,0 +1,584 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Serial Attached SCSI (SAS) Discover process
+ *
+ * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
+ * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
+ */
+
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_eh.h>
+#include "sas_internal.h"
+
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_sas.h>
+#include <scsi/sas_ata.h>
+#include "scsi_sas_internal.h"
+
+/* ---------- Basic task processing for discovery purposes ---------- */
+
+void sas_init_dev(struct domain_device *dev)
+{
+	switch (dev->dev_type) {
+	case SAS_END_DEVICE:
+		INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
+		break;
+	case SAS_EDGE_EXPANDER_DEVICE:
+	case SAS_FANOUT_EXPANDER_DEVICE:
+		INIT_LIST_HEAD(&dev->ex_dev.children);
+		mutex_init(&dev->ex_dev.cmd_mutex);
+		break;
+	default:
+		break;
+	}
+}
+
+/* ---------- Domain device discovery ---------- */
+
+/**
+ * sas_get_port_device - Discover devices which caused port creation
+ * @port: pointer to struct sas_port of interest
+ *
+ * Devices directly attached to a HA port, have no parent.  This is
+ * how we know they are (domain) "root" devices.  All other devices
+ * do, and should have their "parent" pointer set appropriately as
+ * soon as a child device is discovered.
+ */
+static int sas_get_port_device(struct asd_sas_port *port)
+{
+	struct asd_sas_phy *phy;
+	struct sas_rphy *rphy;
+	struct domain_device *dev;
+	int rc = -ENODEV;
+
+	dev = sas_alloc_device();
+	if (!dev)
+		return -ENOMEM;
+
+	spin_lock_irq(&port->phy_list_lock);
+	if (list_empty(&port->phy_list)) {
+		spin_unlock_irq(&port->phy_list_lock);
+		sas_put_device(dev);
+		return -ENODEV;
+	}
+	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
+	spin_lock(&phy->frame_rcvd_lock);
+	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
+					     (size_t)phy->frame_rcvd_size));
+	spin_unlock(&phy->frame_rcvd_lock);
+	spin_unlock_irq(&port->phy_list_lock);
+
+	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
+		struct dev_to_host_fis *fis =
+			(struct dev_to_host_fis *) dev->frame_rcvd;
+		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
+		    fis->byte_count_low == 0x69 && fis->byte_count_high == 0x96
+		    && (fis->device & ~0x10) == 0)
+			dev->dev_type = SAS_SATA_PM;
+		else
+			dev->dev_type = SAS_SATA_DEV;
+		dev->tproto = SAS_PROTOCOL_SATA;
+	} else if (port->oob_mode == SAS_OOB_MODE) {
+		struct sas_identify_frame *id =
+			(struct sas_identify_frame *) dev->frame_rcvd;
+		dev->dev_type = id->dev_type;
+		dev->iproto = id->initiator_bits;
+		dev->tproto = id->target_bits;
+	} else {
+		/* If the oob mode is OOB_NOT_CONNECTED, the port is
+		 * disconnected due to race with PHY down. We cannot
+		 * continue to discover this port
+		 */
+		sas_put_device(dev);
+		pr_warn("Port %016llx is disconnected when discovering\n",
+			SAS_ADDR(port->attached_sas_addr));
+		return -ENODEV;
+	}
+
+	sas_init_dev(dev);
+
+	dev->port = port;
+	switch (dev->dev_type) {
+	case SAS_SATA_DEV:
+		rc = sas_ata_init(dev);
+		if (rc) {
+			rphy = NULL;
+			break;
+		}
+		fallthrough;
+	case SAS_END_DEVICE:
+		rphy = sas_end_device_alloc(port->port);
+		break;
+	case SAS_EDGE_EXPANDER_DEVICE:
+		rphy = sas_expander_alloc(port->port,
+					  SAS_EDGE_EXPANDER_DEVICE);
+		break;
+	case SAS_FANOUT_EXPANDER_DEVICE:
+		rphy = sas_expander_alloc(port->port,
+					  SAS_FANOUT_EXPANDER_DEVICE);
+		break;
+	default:
+		pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
+		rphy = NULL;
+		break;
+	}
+
+	if (!rphy) {
+		sas_put_device(dev);
+		return rc;
+	}
+
+	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
+	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
+	sas_fill_in_rphy(dev, rphy);
+	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
+	port->port_dev = dev;
+	dev->linkrate = port->linkrate;
+	dev->min_linkrate = port->linkrate;
+	dev->max_linkrate = port->linkrate;
+	dev->pathways = port->num_phys;
+	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
+	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
+	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
+	port->disc.max_level = 0;
+	sas_device_set_phy(dev, port->port);
+
+	dev->rphy = rphy;
+	get_device(&dev->rphy->dev);
+
+	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
+		list_add_tail(&dev->disco_list_node, &port->disco_list);
+	else {
+		spin_lock_irq(&port->dev_list_lock);
+		list_add_tail(&dev->dev_list_node, &port->dev_list);
+		spin_unlock_irq(&port->dev_list_lock);
+	}
+
+	spin_lock_irq(&port->phy_list_lock);
+	list_for_each_entry(phy, &port->phy_list, port_phy_el)
+		sas_phy_set_target(phy, dev);
+	spin_unlock_irq(&port->phy_list_lock);
+
+	return 0;
+}
+
+/* ---------- Discover and Revalidate ---------- */
+
+int sas_notify_lldd_dev_found(struct domain_device *dev)
+{
+	int res = 0;
+	struct sas_ha_struct *sas_ha = dev->port->ha;
+	struct Scsi_Host *shost = sas_ha->core.shost;
+	struct sas_internal *i = to_sas_internal(shost->transportt);
+
+	if (!i->dft->lldd_dev_found)
+		return 0;
+
+	res = i->dft->lldd_dev_found(dev);
+	if (res) {
+		pr_warn("driver on host %s cannot handle device %016llx, error:%d\n",
+			dev_name(sas_ha->dev),
+			SAS_ADDR(dev->sas_addr), res);
+		return res;
+	}
+	set_bit(SAS_DEV_FOUND, &dev->state);
+	kref_get(&dev->kref);
+	return 0;
+}
+
+
+void sas_notify_lldd_dev_gone(struct domain_device *dev)
+{
+	struct sas_ha_struct *sas_ha = dev->port->ha;
+	struct Scsi_Host *shost = sas_ha->core.shost;
+	struct sas_internal *i = to_sas_internal(shost->transportt);
+
+	if (!i->dft->lldd_dev_gone)
+		return;
+
+	if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
+		i->dft->lldd_dev_gone(dev);
+		sas_put_device(dev);
+	}
+}
+
+static void sas_probe_devices(struct asd_sas_port *port)
+{
+	struct domain_device *dev, *n;
+
+	/* devices must be domain members before link recovery and probe */
+	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
+		spin_lock_irq(&port->dev_list_lock);
+		list_add_tail(&dev->dev_list_node, &port->dev_list);
+		spin_unlock_irq(&port->dev_list_lock);
+	}
+
+	sas_probe_sata(port);
+
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+		int err;
+
+		err = sas_rphy_add(dev->rphy);
+		if (err)
+			sas_fail_probe(dev, __func__, err);
+		else
+			list_del_init(&dev->disco_list_node);
+	}
+}
+
+static void sas_suspend_devices(struct work_struct *work)
+{
+	struct asd_sas_phy *phy;
+	struct domain_device *dev;
+	struct sas_discovery_event *ev = to_sas_discovery_event(work);
+	struct asd_sas_port *port = ev->port;
+	struct Scsi_Host *shost = port->ha->core.shost;
+	struct sas_internal *si = to_sas_internal(shost->transportt);
+
+	clear_bit(DISCE_SUSPEND, &port->disc.pending);
+
+	sas_suspend_sata(port);
+
+	/* lldd is free to forget the domain_device across the
+	 * suspension, we force the issue here to keep the reference
+	 * counts aligned
+	 */
+	list_for_each_entry(dev, &port->dev_list, dev_list_node)
+		sas_notify_lldd_dev_gone(dev);
+
+	/* we are suspending, so we know events are disabled and
+	 * phy_list is not being mutated
+	 */
+	list_for_each_entry(phy, &port->phy_list, port_phy_el) {
+		if (si->dft->lldd_port_deformed)
+			si->dft->lldd_port_deformed(phy);
+		phy->suspended = 1;
+		port->suspended = 1;
+	}
+}
+
+static void sas_resume_devices(struct work_struct *work)
+{
+	struct sas_discovery_event *ev = to_sas_discovery_event(work);
+	struct asd_sas_port *port = ev->port;
+
+	clear_bit(DISCE_RESUME, &port->disc.pending);
+
+	sas_resume_sata(port);
+}
+
+/**
+ * sas_discover_end_dev - discover an end device (SSP, etc)
+ * @dev: pointer to domain device of interest
+ *
+ * See comment in sas_discover_sata().
+ */
+int sas_discover_end_dev(struct domain_device *dev)
+{
+	return sas_notify_lldd_dev_found(dev);
+}
+
+/* ---------- Device registration and unregistration ---------- */
+
+void sas_free_device(struct kref *kref)
+{
+	struct domain_device *dev = container_of(kref, typeof(*dev), kref);
+
+	put_device(&dev->rphy->dev);
+	dev->rphy = NULL;
+
+	if (dev->parent)
+		sas_put_device(dev->parent);
+
+	sas_port_put_phy(dev->phy);
+	dev->phy = NULL;
+
+	/* remove the phys and ports, everything else should be gone */
+	if (dev_is_expander(dev->dev_type))
+		kfree(dev->ex_dev.ex_phy);
+
+	if (dev_is_sata(dev) && dev->sata_dev.ap) {
+		ata_sas_tport_delete(dev->sata_dev.ap);
+		ata_sas_port_destroy(dev->sata_dev.ap);
+		ata_host_put(dev->sata_dev.ata_host);
+		dev->sata_dev.ata_host = NULL;
+		dev->sata_dev.ap = NULL;
+	}
+
+	kfree(dev);
+}
+
+static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
+{
+	struct sas_ha_struct *ha = port->ha;
+
+	sas_notify_lldd_dev_gone(dev);
+	if (!dev->parent)
+		dev->port->port_dev = NULL;
+	else
+		list_del_init(&dev->siblings);
+
+	spin_lock_irq(&port->dev_list_lock);
+	list_del_init(&dev->dev_list_node);
+	if (dev_is_sata(dev))
+		sas_ata_end_eh(dev->sata_dev.ap);
+	spin_unlock_irq(&port->dev_list_lock);
+
+	spin_lock_irq(&ha->lock);
+	if (dev->dev_type == SAS_END_DEVICE &&
+	    !list_empty(&dev->ssp_dev.eh_list_node)) {
+		list_del_init(&dev->ssp_dev.eh_list_node);
+		ha->eh_active--;
+	}
+	spin_unlock_irq(&ha->lock);
+
+	sas_put_device(dev);
+}
+
+void sas_destruct_devices(struct asd_sas_port *port)
+{
+	struct domain_device *dev, *n;
+
+	list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
+		list_del_init(&dev->disco_list_node);
+
+		sas_remove_children(&dev->rphy->dev);
+		sas_rphy_delete(dev->rphy);
+		sas_unregister_common_dev(port, dev);
+	}
+}
+
+static void sas_destruct_ports(struct asd_sas_port *port)
+{
+	struct sas_port *sas_port, *p;
+
+	list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
+		list_del_init(&sas_port->del_list);
+		sas_port_delete(sas_port);
+	}
+}
+
+void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
+{
+	if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
+	    !list_empty(&dev->disco_list_node)) {
+		/* this rphy never saw sas_rphy_add */
+		list_del_init(&dev->disco_list_node);
+		sas_rphy_free(dev->rphy);
+		sas_unregister_common_dev(port, dev);
+		return;
+	}
+
+	if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
+		sas_rphy_unlink(dev->rphy);
+		list_move_tail(&dev->disco_list_node, &port->destroy_list);
+	}
+}
+
+void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
+{
+	struct domain_device *dev, *n;
+
+	list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
+		if (gone)
+			set_bit(SAS_DEV_GONE, &dev->state);
+		sas_unregister_dev(port, dev);
+	}
+
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
+		sas_unregister_dev(port, dev);
+
+	port->port->rphy = NULL;
+
+}
+
+void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
+{
+	struct sas_ha_struct *ha;
+	struct sas_phy *new_phy;
+
+	if (!dev)
+		return;
+
+	ha = dev->port->ha;
+	new_phy = sas_port_get_phy(port);
+
+	/* pin and record last seen phy */
+	spin_lock_irq(&ha->phy_port_lock);
+	if (new_phy) {
+		sas_port_put_phy(dev->phy);
+		dev->phy = new_phy;
+	}
+	spin_unlock_irq(&ha->phy_port_lock);
+}
+
+/* ---------- Discovery and Revalidation ---------- */
+
+/**
+ * sas_discover_domain - discover the domain
+ * @work: work structure embedded in port domain device.
+ *
+ * NOTE: this process _must_ quit (return) as soon as any connection
+ * errors are encountered.  Connection recovery is done elsewhere.
+ * Discover process only interrogates devices in order to discover the
+ * domain.
+ */
+static void sas_discover_domain(struct work_struct *work)
+{
+	struct domain_device *dev;
+	int error = 0;
+	struct sas_discovery_event *ev = to_sas_discovery_event(work);
+	struct asd_sas_port *port = ev->port;
+
+	clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
+
+	if (port->port_dev)
+		return;
+
+	error = sas_get_port_device(port);
+	if (error)
+		return;
+	dev = port->port_dev;
+
+	pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
+		 task_pid_nr(current));
+
+	switch (dev->dev_type) {
+	case SAS_END_DEVICE:
+		error = sas_discover_end_dev(dev);
+		break;
+	case SAS_EDGE_EXPANDER_DEVICE:
+	case SAS_FANOUT_EXPANDER_DEVICE:
+		error = sas_discover_root_expander(dev);
+		break;
+	case SAS_SATA_DEV:
+	case SAS_SATA_PM:
+#ifdef CONFIG_SCSI_SAS_ATA
+		error = sas_discover_sata(dev);
+		break;
+#else
+		pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
+		fallthrough;
+#endif
+		/* Fall through - only for the #else condition above. */
+	default:
+		error = -ENXIO;
+		pr_err("unhandled device %d\n", dev->dev_type);
+		break;
+	}
+
+	if (error) {
+		sas_rphy_free(dev->rphy);
+		list_del_init(&dev->disco_list_node);
+		spin_lock_irq(&port->dev_list_lock);
+		list_del_init(&dev->dev_list_node);
+		spin_unlock_irq(&port->dev_list_lock);
+
+		sas_put_device(dev);
+		port->port_dev = NULL;
+	}
+
+	sas_probe_devices(port);
+
+	pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
+		 task_pid_nr(current), error);
+}
+
+static void sas_revalidate_domain(struct work_struct *work)
+{
+	int res = 0;
+	struct sas_discovery_event *ev = to_sas_discovery_event(work);
+	struct asd_sas_port *port = ev->port;
+	struct sas_ha_struct *ha = port->ha;
+	struct domain_device *ddev = port->port_dev;
+
+	/* prevent revalidation from finding sata links in recovery */
+	mutex_lock(&ha->disco_mutex);
+	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
+		pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
+			 port->id, task_pid_nr(current));
+		goto out;
+	}
+
+	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
+
+	pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
+		 task_pid_nr(current));
+
+	if (ddev && dev_is_expander(ddev->dev_type))
+		res = sas_ex_revalidate_domain(ddev);
+
+	pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
+		 port->id, task_pid_nr(current), res);
+ out:
+	mutex_unlock(&ha->disco_mutex);
+
+	sas_destruct_devices(port);
+	sas_destruct_ports(port);
+	sas_probe_devices(port);
+}
+
+/* ---------- Events ---------- */
+
+static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
+{
+	/* chained work is not subject to SA_HA_DRAINING or
+	 * SAS_HA_REGISTERED, because it is either submitted in the
+	 * workqueue, or known to be submitted from a context that is
+	 * not racing against draining
+	 */
+	queue_work(ha->disco_q, &sw->work);
+}
+
+static void sas_chain_event(int event, unsigned long *pending,
+			    struct sas_work *sw,
+			    struct sas_ha_struct *ha)
+{
+	if (!test_and_set_bit(event, pending)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&ha->lock, flags);
+		sas_chain_work(ha, sw);
+		spin_unlock_irqrestore(&ha->lock, flags);
+	}
+}
+
+void sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
+{
+	struct sas_discovery *disc;
+
+	if (!port)
+		return;
+	disc = &port->disc;
+
+	BUG_ON(ev >= DISC_NUM_EVENTS);
+
+	sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
+}
+
+/**
+ * sas_init_disc - initialize the discovery struct in the port
+ * @disc: port discovery structure
+ * @port: pointer to struct port
+ *
+ * Called when the ports are being initialized.
+ */
+void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
+{
+	int i;
+
+	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
+		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
+		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
+		[DISCE_SUSPEND] = sas_suspend_devices,
+		[DISCE_RESUME] = sas_resume_devices,
+	};
+
+	disc->pending = 0;
+	for (i = 0; i < DISC_NUM_EVENTS; i++) {
+		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
+		disc->disc_work[i].port = port;
+	}
+}