[SCSI] scsi_transport_sas: introduce a sas_port entity

this patch introduces a port object, separates out ports and phys,
with ports becoming the primary objects of the tree.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

3 files changed, 372 insertions, 46 deletions

diff --git a/drivers/scsi/scsi_sas_internal.h b/drivers/scsi/scsi_sas_internal.h
index d76e6e3d8ca5..e1edab45a37b 100644
--- a/drivers/scsi/scsi_sas_internal.h
+++ b/drivers/scsi/scsi_sas_internal.h
@@ -2,7 +2,8 @@
 #define _SCSI_SAS_INTERNAL_H
 
 #define SAS_HOST_ATTRS          0
-#define SAS_PORT_ATTRS          17
+#define SAS_PHY_ATTRS           17
+#define SAS_PORT_ATTRS          1
 #define SAS_RPORT_ATTRS         7
 #define SAS_END_DEV_ATTRS       3
 #define SAS_EXPANDER_ATTRS      7
@@ -13,12 +14,14 @@ struct sas_internal {
         struct sas_domain_function_template *dft;
 
         struct class_device_attribute private_host_attrs[SAS_HOST_ATTRS];
-        struct class_device_attribute private_phy_attrs[SAS_PORT_ATTRS];
+        struct class_device_attribute private_phy_attrs[SAS_PHY_ATTRS];
+        struct class_device_attribute private_port_attrs[SAS_PORT_ATTRS];
         struct class_device_attribute private_rphy_attrs[SAS_RPORT_ATTRS];
         struct class_device_attribute private_end_dev_attrs[SAS_END_DEV_ATTRS];
         struct class_device_attribute private_expander_attrs[SAS_EXPANDER_ATTRS];
 
         struct transport_container phy_attr_cont;
+        struct transport_container port_attr_cont;
         struct transport_container rphy_attr_cont;
         struct transport_container end_dev_attr_cont;
         struct transport_container expander_attr_cont;
@@ -28,7 +31,8 @@ struct sas_internal {
          * needed by scsi_sysfs.c
          */
         struct class_device_attribute *host_attrs[SAS_HOST_ATTRS + 1];
-        struct class_device_attribute *phy_attrs[SAS_PORT_ATTRS + 1];
+        struct class_device_attribute *phy_attrs[SAS_PHY_ATTRS + 1];
+        struct class_device_attribute *port_attrs[SAS_PORT_ATTRS + 1];
         struct class_device_attribute *rphy_attrs[SAS_RPORT_ATTRS + 1];
         struct class_device_attribute *end_dev_attrs[SAS_END_DEV_ATTRS + 1];
         struct class_device_attribute *expander_attrs[SAS_EXPANDER_ATTRS + 1];
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 1fe6b2d01853..dd075627e605 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -174,12 +174,29 @@ static int sas_host_match(struct attribute_container *cont,
 
 static int do_sas_phy_delete(struct device *dev, void *data)
 {
-        if (scsi_is_sas_phy(dev))
+        int pass = (int)(unsigned long)data;
+
+        if (pass == 0 && scsi_is_sas_port(dev))
+                sas_port_delete(dev_to_sas_port(dev));
+        else if (pass == 1 && scsi_is_sas_phy(dev))
                 sas_phy_delete(dev_to_phy(dev));
         return 0;
 }
 
 /**
+ * sas_remove_children  --  tear down a devices SAS data structures
+ * @dev:        device belonging to the sas object
+ *
+ * Removes all SAS PHYs and remote PHYs for a given object
+ */
+void sas_remove_children(struct device *dev)
+{
+        device_for_each_child(dev, (void *)0, do_sas_phy_delete);
+        device_for_each_child(dev, (void *)1, do_sas_phy_delete);
+}
+EXPORT_SYMBOL(sas_remove_children);
+
+/**
  * sas_remove_host  --  tear down a Scsi_Host's SAS data structures
  * @shost:      Scsi Host that is torn down
  *
@@ -188,13 +205,13 @@ static int do_sas_phy_delete(struct device *dev, void *data)
  */
 void sas_remove_host(struct Scsi_Host *shost)
 {
-        device_for_each_child(&shost->shost_gendev, NULL, do_sas_phy_delete);
+        sas_remove_children(&shost->shost_gendev);
 }
 EXPORT_SYMBOL(sas_remove_host);
 
 
 /*
- * SAS Port attributes
+ * SAS Phy attributes
  */
 
 #define sas_phy_show_simple(field, name, format_string, cast)           \
@@ -310,7 +327,7 @@ sas_phy_protocol_attr(identify.target_port_protocols,
 sas_phy_simple_attr(identify.sas_address, sas_address, "0x%016llx\n",
                 unsigned long long);
 sas_phy_simple_attr(identify.phy_identifier, phy_identifier, "%d\n", u8);
-sas_phy_simple_attr(port_identifier, port_identifier, "%d\n", u8);
+//sas_phy_simple_attr(port_identifier, port_identifier, "%d\n", u8);
 sas_phy_linkspeed_attr(negotiated_linkrate);
 sas_phy_linkspeed_attr(minimum_linkrate_hw);
 sas_phy_linkspeed_attr(minimum_linkrate);
@@ -378,9 +395,10 @@ struct sas_phy *sas_phy_alloc(struct device *parent, int number)
         device_initialize(&phy->dev);
         phy->dev.parent = get_device(parent);
         phy->dev.release = sas_phy_release;
+        INIT_LIST_HEAD(&phy->port_siblings);
         if (scsi_is_sas_expander_device(parent)) {
                 struct sas_rphy *rphy = dev_to_rphy(parent);
-                sprintf(phy->dev.bus_id, "phy-%d-%d:%d", shost->host_no,
+                sprintf(phy->dev.bus_id, "phy-%d:%d:%d", shost->host_no,
                         rphy->scsi_target_id, number);
         } else
                 sprintf(phy->dev.bus_id, "phy-%d:%d", shost->host_no, number);
@@ -440,8 +458,8 @@ sas_phy_delete(struct sas_phy *phy)
 {
         struct device *dev = &phy->dev;
 
-        if (phy->rphy)
-                sas_rphy_delete(phy->rphy);
+        /* this happens if the phy is still part of a port when deleted */
+        BUG_ON(!list_empty(&phy->port_siblings));
 
         transport_remove_device(dev);
         device_del(dev);
@@ -464,6 +482,258 @@ int scsi_is_sas_phy(const struct device *dev)
 EXPORT_SYMBOL(scsi_is_sas_phy);
 
 /*
+ * SAS Port attributes
+ */
+#define sas_port_show_simple(field, name, format_string, cast)          \
+static ssize_t                                                          \
+show_sas_port_##name(struct class_device *cdev, char *buf)              \
+{                                                                       \
+        struct sas_port *port = transport_class_to_sas_port(cdev);      \
+                                                                        \
+        return snprintf(buf, 20, format_string, cast port->field);      \
+}
+
+#define sas_port_simple_attr(field, name, format_string, type)          \
+        sas_port_show_simple(field, name, format_string, (type))        \
+static CLASS_DEVICE_ATTR(name, S_IRUGO, show_sas_port_##name, NULL)
+
+sas_port_simple_attr(num_phys, num_phys, "%d\n", int);
+
+static DECLARE_TRANSPORT_CLASS(sas_port_class,
+                               "sas_port", NULL, NULL, NULL);
+
+static int sas_port_match(struct attribute_container *cont, struct device *dev)
+{
+        struct Scsi_Host *shost;
+        struct sas_internal *i;
+
+        if (!scsi_is_sas_port(dev))
+                return 0;
+        shost = dev_to_shost(dev->parent);
+
+        if (!shost->transportt)
+                return 0;
+        if (shost->transportt->host_attrs.ac.class !=
+                        &sas_host_class.class)
+                return 0;
+
+        i = to_sas_internal(shost->transportt);
+        return &i->port_attr_cont.ac == cont;
+}
+
+
+static void sas_port_release(struct device *dev)
+{
+        struct sas_port *port = dev_to_sas_port(dev);
+
+        BUG_ON(!list_empty(&port->phy_list));
+
+        put_device(dev->parent);
+        kfree(port);
+}
+
+static void sas_port_create_link(struct sas_port *port,
+                                 struct sas_phy *phy)
+{
+        sysfs_create_link(&port->dev.kobj, &phy->dev.kobj, phy->dev.bus_id);
+        sysfs_create_link(&phy->dev.kobj, &port->dev.kobj, "port");
+}
+
+static void sas_port_delete_link(struct sas_port *port,
+                                 struct sas_phy *phy)
+{
+        sysfs_remove_link(&port->dev.kobj, phy->dev.bus_id);
+        sysfs_remove_link(&phy->dev.kobj, "port");
+}
+
+/** sas_port_alloc - allocate and initialize a SAS port structure
+ *
+ * @parent:     parent device
+ * @port_id:    port number
+ *
+ * Allocates a SAS port structure.  It will be added to the device tree
+ * below the device specified by @parent which must be either a Scsi_Host
+ * or a sas_expander_device.
+ *
+ * Returns %NULL on error
+ */
+struct sas_port *sas_port_alloc(struct device *parent, int port_id)
+{
+        struct Scsi_Host *shost = dev_to_shost(parent);
+        struct sas_port *port;
+
+        port = kzalloc(sizeof(*port), GFP_KERNEL);
+        if (!port)
+                return NULL;
+
+        port->port_identifier = port_id;
+
+        device_initialize(&port->dev);
+
+        port->dev.parent = get_device(parent);
+        port->dev.release = sas_port_release;
+
+        mutex_init(&port->phy_list_mutex);
+        INIT_LIST_HEAD(&port->phy_list);
+
+        if (scsi_is_sas_expander_device(parent)) {
+                struct sas_rphy *rphy = dev_to_rphy(parent);
+                sprintf(port->dev.bus_id, "port-%d:%d:%d", shost->host_no,
+                        rphy->scsi_target_id, port->port_identifier);
+        } else
+                sprintf(port->dev.bus_id, "port-%d:%d", shost->host_no,
+                        port->port_identifier);
+
+        transport_setup_device(&port->dev);
+
+        return port;
+}
+EXPORT_SYMBOL(sas_port_alloc);
+
+/**
+ * sas_port_add - add a SAS port to the device hierarchy
+ *
+ * @port:       port to be added
+ *
+ * publishes a port to the rest of the system
+ */
+int sas_port_add(struct sas_port *port)
+{
+        int error;
+
+        /* No phys should be added until this is made visible */
+        BUG_ON(!list_empty(&port->phy_list));
+
+        error = device_add(&port->dev);
+
+        if (error)
+                return error;
+
+        transport_add_device(&port->dev);
+        transport_configure_device(&port->dev);
+
+        return 0;
+}
+EXPORT_SYMBOL(sas_port_add);
+
+/**
+ * sas_port_free  --  free a SAS PORT
+ * @port:       SAS PORT to free
+ *
+ * Frees the specified SAS PORT.
+ *
+ * Note:
+ *   This function must only be called on a PORT that has not
+ *   sucessfully been added using sas_port_add().
+ */
+void sas_port_free(struct sas_port *port)
+{
+        transport_destroy_device(&port->dev);
+        put_device(&port->dev);
+}
+EXPORT_SYMBOL(sas_port_free);
+
+/**
+ * sas_port_delete  --  remove SAS PORT
+ * @port:       SAS PORT to remove
+ *
+ * Removes the specified SAS PORT.  If the SAS PORT has an
+ * associated phys, unlink them from the port as well.
+ */
+void sas_port_delete(struct sas_port *port)
+{
+        struct device *dev = &port->dev;
+        struct sas_phy *phy, *tmp_phy;
+
+        if (port->rphy) {
+                sas_rphy_delete(port->rphy);
+                port->rphy = NULL;
+        }
+
+        mutex_lock(&port->phy_list_mutex);
+        list_for_each_entry_safe(phy, tmp_phy, &port->phy_list,
+                                 port_siblings) {
+                sas_port_delete_link(port, phy);
+                list_del_init(&phy->port_siblings);
+        }
+        mutex_unlock(&port->phy_list_mutex);
+
+        transport_remove_device(dev);
+        device_del(dev);
+        transport_destroy_device(dev);
+        put_device(dev);
+}
+EXPORT_SYMBOL(sas_port_delete);
+
+/**
+ * scsi_is_sas_port --  check if a struct device represents a SAS port
+ * @dev:        device to check
+ *
+ * Returns:
+ *      %1 if the device represents a SAS Port, %0 else
+ */
+int scsi_is_sas_port(const struct device *dev)
+{
+        return dev->release == sas_port_release;
+}
+EXPORT_SYMBOL(scsi_is_sas_port);
+
+/**
+ * sas_port_add_phy - add another phy to a port to form a wide port
+ * @port:       port to add the phy to
+ * @phy:        phy to add
+ *
+ * When a port is initially created, it is empty (has no phys).  All
+ * ports must have at least one phy to operated, and all wide ports
+ * must have at least two.  The current code makes no difference
+ * between ports and wide ports, but the only object that can be
+ * connected to a remote device is a port, so ports must be formed on
+ * all devices with phys if they're connected to anything.
+ */
+void sas_port_add_phy(struct sas_port *port, struct sas_phy *phy)
+{
+        mutex_lock(&port->phy_list_mutex);
+        if (unlikely(!list_empty(&phy->port_siblings))) {
+                /* make sure we're already on this port */
+                struct sas_phy *tmp;
+
+                list_for_each_entry(tmp, &port->phy_list, port_siblings)
+                        if (tmp == phy)
+                                break;
+                /* If this trips, you added a phy that was already
+                 * part of a different port */
+                if (unlikely(tmp != phy)) {
+                        dev_printk(KERN_ERR, &port->dev, "trying to add phy %s fails: it's already part of another port\n", phy->dev.bus_id);
+                        BUG();
+                }
+        } else {
+                sas_port_create_link(port, phy);
+                list_add_tail(&phy->port_siblings, &port->phy_list);
+                port->num_phys++;
+        }
+        mutex_unlock(&port->phy_list_mutex);
+}
+EXPORT_SYMBOL(sas_port_add_phy);
+
+/**
+ * sas_port_delete_phy - remove a phy from a port or wide port
+ * @port:       port to remove the phy from
+ * @phy:        phy to remove
+ *
+ * This operation is used for tearing down ports again.  It must be
+ * done to every port or wide port before calling sas_port_delete.
+ */
+void sas_port_delete_phy(struct sas_port *port, struct sas_phy *phy)
+{
+        mutex_lock(&port->phy_list_mutex);
+        sas_port_delete_link(port, phy);
+        list_del_init(&phy->port_siblings);
+        port->num_phys--;
+        mutex_unlock(&port->phy_list_mutex);
+}
+EXPORT_SYMBOL(sas_port_delete_phy);
+
+/*
  * SAS remote PHY attributes.
  */
 
@@ -767,7 +1037,7 @@ static void sas_rphy_initialize(struct sas_rphy *rphy)
  * Returns:
  *      SAS PHY allocated or %NULL if the allocation failed.
  */
-struct sas_rphy *sas_end_device_alloc(struct sas_phy *parent)
+struct sas_rphy *sas_end_device_alloc(struct sas_port *parent)
 {
         struct Scsi_Host *shost = dev_to_shost(&parent->dev);
         struct sas_end_device *rdev;
@@ -780,8 +1050,13 @@ struct sas_rphy *sas_end_device_alloc(struct sas_phy *parent)
         device_initialize(&rdev->rphy.dev);
         rdev->rphy.dev.parent = get_device(&parent->dev);
         rdev->rphy.dev.release = sas_end_device_release;
-        sprintf(rdev->rphy.dev.bus_id, "end_device-%d:%d-%d",
-                shost->host_no, parent->port_identifier, parent->number);
+        if (scsi_is_sas_expander_device(parent->dev.parent)) {
+                struct sas_rphy *rphy = dev_to_rphy(parent->dev.parent);
+                sprintf(rdev->rphy.dev.bus_id, "end_device-%d:%d:%d",
+                        shost->host_no, rphy->scsi_target_id, parent->port_identifier);
+        } else
+                sprintf(rdev->rphy.dev.bus_id, "end_device-%d:%d",
+                        shost->host_no, parent->port_identifier);
         rdev->rphy.identify.device_type = SAS_END_DEVICE;
         sas_rphy_initialize(&rdev->rphy);
         transport_setup_device(&rdev->rphy.dev);
@@ -798,7 +1073,7 @@ EXPORT_SYMBOL(sas_end_device_alloc);
  * Returns:
  *      SAS PHY allocated or %NULL if the allocation failed.
  */
-struct sas_rphy *sas_expander_alloc(struct sas_phy *parent,
+struct sas_rphy *sas_expander_alloc(struct sas_port *parent,
                                     enum sas_device_type type)
 {
         struct Scsi_Host *shost = dev_to_shost(&parent->dev);
@@ -837,7 +1112,7 @@ EXPORT_SYMBOL(sas_expander_alloc);
  */
 int sas_rphy_add(struct sas_rphy *rphy)
 {
-        struct sas_phy *parent = dev_to_phy(rphy->dev.parent);
+        struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
         struct Scsi_Host *shost = dev_to_shost(parent->dev.parent);
         struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
         struct sas_identify *identify = &rphy->identify;
@@ -910,7 +1185,7 @@ void
 sas_rphy_delete(struct sas_rphy *rphy)
 {
         struct device *dev = &rphy->dev;
-        struct sas_phy *parent = dev_to_phy(dev->parent);
+        struct sas_port *parent = dev_to_sas_port(dev->parent);
         struct Scsi_Host *shost = dev_to_shost(parent->dev.parent);
         struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
 
@@ -920,7 +1195,7 @@ sas_rphy_delete(struct sas_rphy *rphy)
                 break;
         case SAS_EDGE_EXPANDER_DEVICE:
         case SAS_FANOUT_EXPANDER_DEVICE:
-                device_for_each_child(dev, NULL, do_sas_phy_delete);
+                sas_remove_children(dev);
                 break;
         default:
                 break;
@@ -967,7 +1242,7 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel,
 
         mutex_lock(&sas_host->lock);
         list_for_each_entry(rphy, &sas_host->rphy_list, list) {
-                struct sas_phy *parent = dev_to_phy(rphy->dev.parent);
+                struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
 
                 if (rphy->identify.device_type != SAS_END_DEVICE ||
                     rphy->scsi_target_id == -1)
@@ -1003,16 +1278,19 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel,
 #define SETUP_OPTIONAL_RPORT_ATTRIBUTE(field, func)                     \
         SETUP_TEMPLATE(rphy_attrs, field, S_IRUGO, i->f->func)
 
-#define SETUP_PORT_ATTRIBUTE(field)                                     \
+#define SETUP_PHY_ATTRIBUTE(field)                                      \
         SETUP_TEMPLATE(phy_attrs, field, S_IRUGO, 1)
 
-#define SETUP_OPTIONAL_PORT_ATTRIBUTE(field, func)                      \
+#define SETUP_PORT_ATTRIBUTE(field)                                     \
+        SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
+
+#define SETUP_OPTIONAL_PHY_ATTRIBUTE(field, func)                       \
         SETUP_TEMPLATE(phy_attrs, field, S_IRUGO, i->f->func)
 
-#define SETUP_PORT_ATTRIBUTE_WRONLY(field)                              \
+#define SETUP_PHY_ATTRIBUTE_WRONLY(field)                               \
         SETUP_TEMPLATE(phy_attrs, field, S_IWUGO, 1)
 
-#define SETUP_OPTIONAL_PORT_ATTRIBUTE_WRONLY(field, func)               \
+#define SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(field, func)                \
         SETUP_TEMPLATE(phy_attrs, field, S_IWUGO, i->f->func)
 
 #define SETUP_END_DEV_ATTRIBUTE(field)                                  \
@@ -1048,6 +1326,11 @@ sas_attach_transport(struct sas_function_template *ft)
         i->phy_attr_cont.ac.match = sas_phy_match;
         transport_container_register(&i->phy_attr_cont);
 
+        i->port_attr_cont.ac.class = &sas_port_class.class;
+        i->port_attr_cont.ac.attrs = &i->port_attrs[0];
+        i->port_attr_cont.ac.match = sas_port_match;
+        transport_container_register(&i->port_attr_cont);
+
         i->rphy_attr_cont.ac.class = &sas_rphy_class.class;
         i->rphy_attr_cont.ac.attrs = &i->rphy_attrs[0];
         i->rphy_attr_cont.ac.match = sas_rphy_match;
@@ -1066,30 +1349,35 @@ sas_attach_transport(struct sas_function_template *ft)
         i->f = ft;
 
         count = 0;
+        SETUP_PORT_ATTRIBUTE(num_phys);
         i->host_attrs[count] = NULL;
 
         count = 0;
-        SETUP_PORT_ATTRIBUTE(initiator_port_protocols);
-        SETUP_PORT_ATTRIBUTE(target_port_protocols);
-        SETUP_PORT_ATTRIBUTE(device_type);
-        SETUP_PORT_ATTRIBUTE(sas_address);
-        SETUP_PORT_ATTRIBUTE(phy_identifier);
-        SETUP_PORT_ATTRIBUTE(port_identifier);
-        SETUP_PORT_ATTRIBUTE(negotiated_linkrate);
-        SETUP_PORT_ATTRIBUTE(minimum_linkrate_hw);
-        SETUP_PORT_ATTRIBUTE(minimum_linkrate);
-        SETUP_PORT_ATTRIBUTE(maximum_linkrate_hw);
-        SETUP_PORT_ATTRIBUTE(maximum_linkrate);
-
-        SETUP_PORT_ATTRIBUTE(invalid_dword_count);
-        SETUP_PORT_ATTRIBUTE(running_disparity_error_count);
-        SETUP_PORT_ATTRIBUTE(loss_of_dword_sync_count);
-        SETUP_PORT_ATTRIBUTE(phy_reset_problem_count);
-        SETUP_OPTIONAL_PORT_ATTRIBUTE_WRONLY(link_reset, phy_reset);
-        SETUP_OPTIONAL_PORT_ATTRIBUTE_WRONLY(hard_reset, phy_reset);
+        SETUP_PHY_ATTRIBUTE(initiator_port_protocols);
+        SETUP_PHY_ATTRIBUTE(target_port_protocols);
+        SETUP_PHY_ATTRIBUTE(device_type);
+        SETUP_PHY_ATTRIBUTE(sas_address);
+        SETUP_PHY_ATTRIBUTE(phy_identifier);
+        //SETUP_PHY_ATTRIBUTE(port_identifier);
+        SETUP_PHY_ATTRIBUTE(negotiated_linkrate);
+        SETUP_PHY_ATTRIBUTE(minimum_linkrate_hw);
+        SETUP_PHY_ATTRIBUTE(minimum_linkrate);
+        SETUP_PHY_ATTRIBUTE(maximum_linkrate_hw);
+        SETUP_PHY_ATTRIBUTE(maximum_linkrate);
+
+        SETUP_PHY_ATTRIBUTE(invalid_dword_count);
+        SETUP_PHY_ATTRIBUTE(running_disparity_error_count);
+        SETUP_PHY_ATTRIBUTE(loss_of_dword_sync_count);
+        SETUP_PHY_ATTRIBUTE(phy_reset_problem_count);
+        SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(link_reset, phy_reset);
+        SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(hard_reset, phy_reset);
         i->phy_attrs[count] = NULL;
 
         count = 0;
+        SETUP_PORT_ATTRIBUTE(num_phys);
+        i->port_attrs[count] = NULL;
+
+        count = 0;
         SETUP_RPORT_ATTRIBUTE(rphy_initiator_port_protocols);
         SETUP_RPORT_ATTRIBUTE(rphy_target_port_protocols);
         SETUP_RPORT_ATTRIBUTE(rphy_device_type);
@@ -1131,6 +1419,7 @@ void sas_release_transport(struct scsi_transport_template *t)
 
         transport_container_unregister(&i->t.host_attrs);
         transport_container_unregister(&i->phy_attr_cont);
+        transport_container_unregister(&i->port_attr_cont);
         transport_container_unregister(&i->rphy_attr_cont);
         transport_container_unregister(&i->end_dev_attr_cont);
         transport_container_unregister(&i->expander_attr_cont);
@@ -1149,9 +1438,12 @@ static __init int sas_transport_init(void)
         error = transport_class_register(&sas_phy_class);
         if (error)
                 goto out_unregister_transport;
-        error = transport_class_register(&sas_rphy_class);
+        error = transport_class_register(&sas_port_class);
         if (error)
                 goto out_unregister_phy;
+        error = transport_class_register(&sas_rphy_class);
+        if (error)
+                goto out_unregister_port;
         error = transport_class_register(&sas_end_dev_class);
         if (error)
                 goto out_unregister_rphy;
@@ -1165,6 +1457,8 @@ static __init int sas_transport_init(void)
         transport_class_unregister(&sas_end_dev_class);
  out_unregister_rphy:
         transport_class_unregister(&sas_rphy_class);
+ out_unregister_port:
+        transport_class_unregister(&sas_port_class);
  out_unregister_phy:
         transport_class_unregister(&sas_phy_class);
  out_unregister_transport:
@@ -1178,6 +1472,7 @@ static void __exit sas_transport_exit(void)
 {
         transport_class_unregister(&sas_host_class);
         transport_class_unregister(&sas_phy_class);
+        transport_class_unregister(&sas_port_class);
         transport_class_unregister(&sas_rphy_class);
         transport_class_unregister(&sas_end_dev_class);
         transport_class_unregister(&sas_expander_class);
diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index 93cfb4bf4211..e3c503cd175e 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -3,6 +3,7 @@
 
 #include <linux/transport_class.h>
 #include <linux/types.h>
+#include <linux/mutex.h>
 
 struct scsi_transport_template;
 struct sas_rphy;
@@ -55,7 +56,6 @@ struct sas_phy {
         enum sas_linkrate       minimum_linkrate;
         enum sas_linkrate       maximum_linkrate_hw;
         enum sas_linkrate       maximum_linkrate;
-        u8                      port_identifier;
 
         /* internal state */
         unsigned int            local_attached : 1;
@@ -66,8 +66,8 @@ struct sas_phy {
         u32                     loss_of_dword_sync_count;
         u32                     phy_reset_problem_count;
 
-        /* the other end of the link */
-        struct sas_rphy         *rphy;
+        /* for the list of phys belonging to a port */
+        struct list_head        port_siblings;
 };
 
 #define dev_to_phy(d) \
@@ -124,6 +124,24 @@ struct sas_expander_device {
 #define rphy_to_expander_device(r) \
         container_of((r), struct sas_expander_device, rphy)
 
+struct sas_port {
+        struct device           dev;
+
+        u8                      port_identifier;
+        int                     num_phys;
+
+        /* the other end of the link */
+        struct sas_rphy         *rphy;
+
+        struct mutex            phy_list_mutex;
+        struct list_head        phy_list;
+};
+
+#define dev_to_sas_port(d) \
+        container_of((d), struct sas_port, dev)
+#define transport_class_to_sas_port(cdev) \
+        dev_to_sas_port((cdev)->dev)
+
 /* The functions by which the transport class and the driver communicate */
 struct sas_function_template {
         int (*get_linkerrors)(struct sas_phy *);
@@ -133,6 +151,7 @@ struct sas_function_template {
 };
 
 
+void sas_remove_children(struct device *);
 extern void sas_remove_host(struct Scsi_Host *);
 
 extern struct sas_phy *sas_phy_alloc(struct device *, int);
@@ -141,13 +160,21 @@ extern int sas_phy_add(struct sas_phy *);
 extern void sas_phy_delete(struct sas_phy *);
 extern int scsi_is_sas_phy(const struct device *);
 
-extern struct sas_rphy *sas_end_device_alloc(struct sas_phy *);
-extern struct sas_rphy *sas_expander_alloc(struct sas_phy *, enum sas_device_type);
+extern struct sas_rphy *sas_end_device_alloc(struct sas_port *);
+extern struct sas_rphy *sas_expander_alloc(struct sas_port *, enum sas_device_type);
 void sas_rphy_free(struct sas_rphy *);
 extern int sas_rphy_add(struct sas_rphy *);
 extern void sas_rphy_delete(struct sas_rphy *);
 extern int scsi_is_sas_rphy(const struct device *);
 
+struct sas_port *sas_port_alloc(struct device *, int);
+int sas_port_add(struct sas_port *);
+void sas_port_free(struct sas_port *);
+void sas_port_delete(struct sas_port *);
+void sas_port_add_phy(struct sas_port *, struct sas_phy *);
+void sas_port_delete_phy(struct sas_port *, struct sas_phy *);
+int scsi_is_sas_port(const struct device *);
+
 extern struct scsi_transport_template *
 sas_attach_transport(struct sas_function_template *);
 extern void sas_release_transport(struct scsi_transport_template *);