firewire: fw-sbp2: add support for multiple logical units per target

Fixes "New firewire stack only recognizing half of a chain of drives",
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=242254

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

2 files changed, 324 insertions, 256 deletions

diff --git a/drivers/firewire/fw-device.h b/drivers/firewire/fw-device.h
index d13e6a69707f..894d4a92a18e 100644
--- a/drivers/firewire/fw-device.h
+++ b/drivers/firewire/fw-device.h
@@ -102,11 +102,6 @@ fw_unit(struct device *dev)
 #define CSR_INSTANCE            0x18
 #define CSR_DIRECTORY_ID        0x20
 
-#define SBP2_COMMAND_SET_SPECIFIER      0x38
-#define SBP2_COMMAND_SET                0x39
-#define SBP2_COMMAND_SET_REVISION       0x3b
-#define SBP2_FIRMWARE_REVISION          0x3c
-
 struct fw_csr_iterator {
         u32 *p;
         u32 *end;
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 7ecc154a8274..1efc67b1d26e 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -41,7 +41,6 @@
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
-#include <scsi/scsi_dbg.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 
@@ -66,31 +65,49 @@ typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
 
 static const char sbp2_driver_name[] = "sbp2";
 
-struct sbp2_device {
-        struct kref kref;
-        struct fw_unit *unit;
+/*
+ * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
+ * and one struct scsi_device per sbp2_logical_unit.
+ */
+struct sbp2_logical_unit {
+        struct sbp2_target *tgt;
+        struct list_head link;
+        struct scsi_device *sdev;
         struct fw_address_handler address_handler;
         struct list_head orb_list;
-        u64 management_agent_address;
+
         u64 command_block_agent_address;
-        u32 workarounds;
+        u16 lun;
         int login_id;
 
         /*
-         * We cache these addresses and only update them once we've
-         * logged in or reconnected to the sbp2 device.  That way, any
-         * IO to the device will automatically fail and get retried if
-         * it happens in a window where the device is not ready to
-         * handle it (e.g. after a bus reset but before we reconnect).
+         * The generation is updated once we've logged in or reconnected
+         * to the logical unit.  Thus, I/O to the device will automatically
+         * fail and get retried if it happens in a window where the device
+         * is not ready, e.g. after a bus reset but before we reconnect.
          */
-        int node_id;
-        int address_high;
         int generation;
-
         int retries;
         struct delayed_work work;
 };
 
+/*
+ * We create one struct sbp2_target per IEEE 1212 Unit Directory
+ * and one struct Scsi_Host per sbp2_target.
+ */
+struct sbp2_target {
+        struct kref kref;
+        struct fw_unit *unit;
+
+        u64 management_agent_address;
+        int directory_id;
+        int node_id;
+        int address_high;
+
+        unsigned workarounds;
+        struct list_head lu_list;
+};
+
 #define SBP2_MAX_SG_ELEMENT_LENGTH      0xf000
 #define SBP2_MAX_SECTORS                255     /* Max sectors supported */
 #define SBP2_ORB_TIMEOUT                2000    /* Timeout in ms */
@@ -101,10 +118,9 @@ struct sbp2_device {
 #define SBP2_DIRECTION_FROM_MEDIA       0x1
 
 /* Unit directory keys */
-#define SBP2_COMMAND_SET_SPECIFIER      0x38
-#define SBP2_COMMAND_SET                0x39
-#define SBP2_COMMAND_SET_REVISION       0x3b
-#define SBP2_FIRMWARE_REVISION          0x3c
+#define SBP2_CSR_FIRMWARE_REVISION      0x3c
+#define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
+#define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 
 /* Flags for detected oddities and brokeness */
 #define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
@@ -219,7 +235,7 @@ struct sbp2_command_orb {
         } request;
         struct scsi_cmnd *cmd;
         scsi_done_fn_t done;
-        struct fw_unit *unit;
+        struct sbp2_logical_unit *lu;
 
         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
         dma_addr_t page_table_bus;
@@ -295,7 +311,7 @@ sbp2_status_write(struct fw_card *card, struct fw_request *request,
                   unsigned long long offset,
                   void *payload, size_t length, void *callback_data)
 {
-        struct sbp2_device *sd = callback_data;
+        struct sbp2_logical_unit *lu = callback_data;
         struct sbp2_orb *orb;
         struct sbp2_status status;
         size_t header_size;
@@ -319,7 +335,7 @@ sbp2_status_write(struct fw_card *card, struct fw_request *request,
 
         /* Lookup the orb corresponding to this status write. */
         spin_lock_irqsave(&card->lock, flags);
-        list_for_each_entry(orb, &sd->orb_list, link) {
+        list_for_each_entry(orb, &lu->orb_list, link) {
                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
                         orb->rcode = RCODE_COMPLETE;
@@ -329,7 +345,7 @@ sbp2_status_write(struct fw_card *card, struct fw_request *request,
         }
         spin_unlock_irqrestore(&card->lock, flags);
 
-        if (&orb->link != &sd->orb_list)
+        if (&orb->link != &lu->orb_list)
                 orb->callback(orb, &status);
         else
                 fw_error("status write for unknown orb\n");
@@ -371,11 +387,10 @@ complete_transaction(struct fw_card *card, int rcode,
 }
 
 static void
-sbp2_send_orb(struct sbp2_orb *orb, struct fw_unit *unit,
+sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
               int node_id, int generation, u64 offset)
 {
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd = unit->device.driver_data;
+        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
         unsigned long flags;
 
         orb->pointer.high = 0;
@@ -383,7 +398,7 @@ sbp2_send_orb(struct sbp2_orb *orb, struct fw_unit *unit,
         fw_memcpy_to_be32(&orb->pointer, &orb->pointer, sizeof(orb->pointer));
 
         spin_lock_irqsave(&device->card->lock, flags);
-        list_add_tail(&orb->link, &sd->orb_list);
+        list_add_tail(&orb->link, &lu->orb_list);
         spin_unlock_irqrestore(&device->card->lock, flags);
 
         /* Take a ref for the orb list and for the transaction callback. */
@@ -396,10 +411,9 @@ sbp2_send_orb(struct sbp2_orb *orb, struct fw_unit *unit,
                         complete_transaction, orb);
 }
 
-static int sbp2_cancel_orbs(struct fw_unit *unit)
+static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 {
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd = unit->device.driver_data;
+        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
         struct sbp2_orb *orb, *next;
         struct list_head list;
         unsigned long flags;
@@ -407,7 +421,7 @@ static int sbp2_cancel_orbs(struct fw_unit *unit)
 
         INIT_LIST_HEAD(&list);
         spin_lock_irqsave(&device->card->lock, flags);
-        list_splice_init(&sd->orb_list, &list);
+        list_splice_init(&lu->orb_list, &list);
         spin_unlock_irqrestore(&device->card->lock, flags);
 
         list_for_each_entry_safe(orb, next, &list, link) {
@@ -434,11 +448,11 @@ complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 }
 
 static int
-sbp2_send_management_orb(struct fw_unit *unit, int node_id, int generation,
-                         int function, int lun, void *response)
+sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
+                         int generation, int function, int lun_or_login_id,
+                         void *response)
 {
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd = unit->device.driver_data;
+        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
         struct sbp2_management_orb *orb;
         int retval = -ENOMEM;
 
@@ -459,12 +473,12 @@ sbp2_send_management_orb(struct fw_unit *unit, int node_id, int generation,
         orb->request.misc =
                 MANAGEMENT_ORB_NOTIFY |
                 MANAGEMENT_ORB_FUNCTION(function) |
-                MANAGEMENT_ORB_LUN(lun);
+                MANAGEMENT_ORB_LUN(lun_or_login_id);
         orb->request.length =
                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response));
 
-        orb->request.status_fifo.high = sd->address_handler.offset >> 32;
-        orb->request.status_fifo.low  = sd->address_handler.offset;
+        orb->request.status_fifo.high = lu->address_handler.offset >> 32;
+        orb->request.status_fifo.low  = lu->address_handler.offset;
 
         if (function == SBP2_LOGIN_REQUEST) {
                 orb->request.misc |=
@@ -483,14 +497,14 @@ sbp2_send_management_orb(struct fw_unit *unit, int node_id, int generation,
         if (dma_mapping_error(orb->base.request_bus))
                 goto fail_mapping_request;
 
-        sbp2_send_orb(&orb->base, unit,
-                      node_id, generation, sd->management_agent_address);
+        sbp2_send_orb(&orb->base, lu, node_id, generation,
+                      lu->tgt->management_agent_address);
 
         wait_for_completion_timeout(&orb->done,
                                     msecs_to_jiffies(SBP2_ORB_TIMEOUT));
 
         retval = -EIO;
-        if (sbp2_cancel_orbs(unit) == 0) {
+        if (sbp2_cancel_orbs(lu) == 0) {
                 fw_error("orb reply timed out, rcode=0x%02x\n",
                          orb->base.rcode);
                 goto out;
@@ -535,10 +549,9 @@ complete_agent_reset_write(struct fw_card *card, int rcode,
         kfree(t);
 }
 
-static int sbp2_agent_reset(struct fw_unit *unit)
+static int sbp2_agent_reset(struct sbp2_logical_unit *lu)
 {
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd = unit->device.driver_data;
+        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
         struct fw_transaction *t;
         static u32 zero;
 
@@ -547,181 +560,261 @@ static int sbp2_agent_reset(struct fw_unit *unit)
                 return -ENOMEM;
 
         fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
-                        sd->node_id, sd->generation, device->max_speed,
-                        sd->command_block_agent_address + SBP2_AGENT_RESET,
+                        lu->tgt->node_id, lu->generation, device->max_speed,
+                        lu->command_block_agent_address + SBP2_AGENT_RESET,
                         &zero, sizeof(zero), complete_agent_reset_write, t);
 
         return 0;
 }
 
-static void sbp2_reconnect(struct work_struct *work);
-static struct scsi_host_template scsi_driver_template;
-
-static void release_sbp2_device(struct kref *kref)
+static void sbp2_release_target(struct kref *kref)
 {
-        struct sbp2_device *sd = container_of(kref, struct sbp2_device, kref);
-        struct Scsi_Host *host =
-                container_of((void *)sd, struct Scsi_Host, hostdata[0]);
-
-        scsi_remove_host(host);
-        sbp2_send_management_orb(sd->unit, sd->node_id, sd->generation,
-                                 SBP2_LOGOUT_REQUEST, sd->login_id, NULL);
-        fw_core_remove_address_handler(&sd->address_handler);
-        fw_notify("removed sbp2 unit %s\n", sd->unit->device.bus_id);
-        put_device(&sd->unit->device);
-        scsi_host_put(host);
+        struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
+        struct sbp2_logical_unit *lu, *next;
+        struct Scsi_Host *shost =
+                container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+
+        list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
+                if (lu->sdev)
+                        scsi_remove_device(lu->sdev);
+
+                sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
+                                SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+                fw_core_remove_address_handler(&lu->address_handler);
+                list_del(&lu->link);
+                kfree(lu);
+        }
+        scsi_remove_host(shost);
+        fw_notify("released %s\n", tgt->unit->device.bus_id);
+
+        put_device(&tgt->unit->device);
+        scsi_host_put(shost);
 }
 
+static void sbp2_reconnect(struct work_struct *work);
+
 static void sbp2_login(struct work_struct *work)
 {
-        struct sbp2_device *sd =
-                container_of(work, struct sbp2_device, work.work);
-        struct Scsi_Host *host =
-                container_of((void *)sd, struct Scsi_Host, hostdata[0]);
-        struct fw_unit *unit = sd->unit;
+        struct sbp2_logical_unit *lu =
+                container_of(work, struct sbp2_logical_unit, work.work);
+        struct Scsi_Host *shost =
+                container_of((void *)lu->tgt, struct Scsi_Host, hostdata[0]);
+        struct scsi_device *sdev;
+        struct scsi_lun eight_bytes_lun;
+        struct fw_unit *unit = lu->tgt->unit;
         struct fw_device *device = fw_device(unit->device.parent);
         struct sbp2_login_response response;
-        int generation, node_id, local_node_id, lun, retval;
-
-        /* FIXME: Make this work for multi-lun devices. */
-        lun = 0;
+        int generation, node_id, local_node_id;
 
         generation    = device->card->generation;
         node_id       = device->node->node_id;
         local_node_id = device->card->local_node->node_id;
 
-        if (sbp2_send_management_orb(unit, node_id, generation,
-                                     SBP2_LOGIN_REQUEST, lun, &response) < 0) {
-                if (sd->retries++ < 5) {
-                        schedule_delayed_work(&sd->work, DIV_ROUND_UP(HZ, 5));
+        if (sbp2_send_management_orb(lu, node_id, generation,
+                                SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
+                if (lu->retries++ < 5) {
+                        schedule_delayed_work(&lu->work, DIV_ROUND_UP(HZ, 5));
                 } else {
-                        fw_error("failed to login to %s\n",
-                                 unit->device.bus_id);
-                        kref_put(&sd->kref, release_sbp2_device);
+                        fw_error("failed to login to %s LUN %04x\n",
+                                 unit->device.bus_id, lu->lun);
+                        kref_put(&lu->tgt->kref, sbp2_release_target);
                 }
                 return;
         }
 
-        sd->generation   = generation;
-        sd->node_id      = node_id;
-        sd->address_high = local_node_id << 16;
+        lu->generation        = generation;
+        lu->tgt->node_id      = node_id;
+        lu->tgt->address_high = local_node_id << 16;
 
         /* Get command block agent offset and login id. */
-        sd->command_block_agent_address =
+        lu->command_block_agent_address =
                 ((u64) (response.command_block_agent.high & 0xffff) << 32) |
                 response.command_block_agent.low;
-        sd->login_id = LOGIN_RESPONSE_GET_LOGIN_ID(response);
+        lu->login_id = LOGIN_RESPONSE_GET_LOGIN_ID(response);
 
-        fw_notify("logged in to sbp2 unit %s (%d retries)\n",
-                  unit->device.bus_id, sd->retries);
-        fw_notify(" - management_agent_address:    0x%012llx\n",
-                  (unsigned long long) sd->management_agent_address);
-        fw_notify(" - command_block_agent_address: 0x%012llx\n",
-                  (unsigned long long) sd->command_block_agent_address);
-        fw_notify(" - status write address:        0x%012llx\n",
-                  (unsigned long long) sd->address_handler.offset);
+        fw_notify("logged in to %s LUN %04x (%d retries)\n",
+                  unit->device.bus_id, lu->lun, lu->retries);
 
 #if 0
         /* FIXME: The linux1394 sbp2 does this last step. */
         sbp2_set_busy_timeout(scsi_id);
 #endif
 
-        PREPARE_DELAYED_WORK(&sd->work, sbp2_reconnect);
-        sbp2_agent_reset(unit);
+        PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
+        sbp2_agent_reset(lu);
+
+        memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
+        eight_bytes_lun.scsi_lun[0] = (lu->lun >> 8) & 0xff;
+        eight_bytes_lun.scsi_lun[1] = lu->lun & 0xff;
 
-        /* FIXME: Loop over luns here. */
-        lun = 0;
-        retval = scsi_add_device(host, 0, 0, lun);
-        if (retval < 0) {
-                sbp2_send_management_orb(unit, sd->node_id, sd->generation,
-                                         SBP2_LOGOUT_REQUEST, sd->login_id,
-                                         NULL);
+        sdev = __scsi_add_device(shost, 0, 0,
+                                 scsilun_to_int(&eight_bytes_lun), lu);
+        if (IS_ERR(sdev)) {
+                sbp2_send_management_orb(lu, node_id, generation,
+                                SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
                 /*
                  * Set this back to sbp2_login so we fall back and
                  * retry login on bus reset.
                  */
-                PREPARE_DELAYED_WORK(&sd->work, sbp2_login);
+                PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
+        } else {
+                lu->sdev = sdev;
+                scsi_device_put(sdev);
         }
-        kref_put(&sd->kref, release_sbp2_device);
+        kref_put(&lu->tgt->kref, sbp2_release_target);
 }
 
-static int sbp2_probe(struct device *dev)
+static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 {
-        struct fw_unit *unit = fw_unit(dev);
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd;
-        struct fw_csr_iterator ci;
-        struct Scsi_Host *host;
-        int i, key, value, err;
-        u32 model, firmware_revision;
+        struct sbp2_logical_unit *lu;
 
-        err = -ENOMEM;
-        host = scsi_host_alloc(&scsi_driver_template, sizeof(*sd));
-        if (host == NULL)
-                goto fail;
+        lu = kmalloc(sizeof(*lu), GFP_KERNEL);
+        if (!lu)
+                return -ENOMEM;
 
-        sd = (struct sbp2_device *) host->hostdata;
-        unit->device.driver_data = sd;
-        sd->unit = unit;
-        INIT_LIST_HEAD(&sd->orb_list);
-        kref_init(&sd->kref);
+        lu->address_handler.length           = 0x100;
+        lu->address_handler.address_callback = sbp2_status_write;
+        lu->address_handler.callback_data    = lu;
 
-        sd->address_handler.length = 0x100;
-        sd->address_handler.address_callback = sbp2_status_write;
-        sd->address_handler.callback_data = sd;
+        if (fw_core_add_address_handler(&lu->address_handler,
+                                        &fw_high_memory_region) < 0) {
+                kfree(lu);
+                return -ENOMEM;
+        }
 
-        err = fw_core_add_address_handler(&sd->address_handler,
-                                          &fw_high_memory_region);
-        if (err < 0)
-                goto fail_host;
+        lu->tgt  = tgt;
+        lu->sdev = NULL;
+        lu->lun  = lun_entry & 0xffff;
+        lu->retries = 0;
+        INIT_LIST_HEAD(&lu->orb_list);
+        INIT_DELAYED_WORK(&lu->work, sbp2_login);
 
-        err = fw_device_enable_phys_dma(device);
-        if (err < 0)
-                goto fail_address_handler;
+        list_add_tail(&lu->link, &tgt->lu_list);
+        return 0;
+}
 
-        err = scsi_add_host(host, &unit->device);
-        if (err < 0)
-                goto fail_address_handler;
+static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
+{
+        struct fw_csr_iterator ci;
+        int key, value;
 
-        /*
-         * Scan unit directory to get management agent address,
-         * firmware revison and model.  Initialize firmware_revision
-         * and model to values that wont match anything in our table.
-         */
-        firmware_revision = 0xff000000;
-        model = 0xff000000;
-        fw_csr_iterator_init(&ci, unit->directory);
+        fw_csr_iterator_init(&ci, directory);
+        while (fw_csr_iterator_next(&ci, &key, &value))
+                if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
+                    sbp2_add_logical_unit(tgt, value) < 0)
+                        return -ENOMEM;
+        return 0;
+}
+
+static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
+                              u32 *model, u32 *firmware_revision)
+{
+        struct fw_csr_iterator ci;
+        int key, value;
+
+        fw_csr_iterator_init(&ci, directory);
         while (fw_csr_iterator_next(&ci, &key, &value)) {
                 switch (key) {
+
                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
-                        sd->management_agent_address =
-                                0xfffff0000000ULL + 4 * value;
+                        tgt->management_agent_address =
+                                        CSR_REGISTER_BASE + 4 * value;
                         break;
-                case SBP2_FIRMWARE_REVISION:
-                        firmware_revision = value;
+
+                case CSR_DIRECTORY_ID:
+                        tgt->directory_id = value;
                         break;
+
                 case CSR_MODEL:
-                        model = value;
+                        *model = value;
+                        break;
+
+                case SBP2_CSR_FIRMWARE_REVISION:
+                        *firmware_revision = value;
+                        break;
+
+                case SBP2_CSR_LOGICAL_UNIT_NUMBER:
+                        if (sbp2_add_logical_unit(tgt, value) < 0)
+                                return -ENOMEM;
+                        break;
+
+                case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
+                        if (sbp2_scan_logical_unit_dir(tgt, ci.p + value) < 0)
+                                return -ENOMEM;
                         break;
                 }
         }
+        return 0;
+}
+
+static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
+                                  u32 firmware_revision)
+{
+        int i;
+
+        tgt->workarounds = 0;
 
         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
+
                 if (sbp2_workarounds_table[i].firmware_revision !=
                     (firmware_revision & 0xffffff00))
                         continue;
+
                 if (sbp2_workarounds_table[i].model != model &&
                     sbp2_workarounds_table[i].model != ~0)
                         continue;
-                sd->workarounds |= sbp2_workarounds_table[i].workarounds;
+
+                tgt->workarounds |= sbp2_workarounds_table[i].workarounds;
                 break;
         }
 
-        if (sd->workarounds)
-                fw_notify("Workarounds for node %s: 0x%x "
+        if (tgt->workarounds)
+                fw_notify("Workarounds for %s: 0x%x "
                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
-                          unit->device.bus_id,
-                          sd->workarounds, firmware_revision, model);
+                          tgt->unit->device.bus_id,
+                          tgt->workarounds, firmware_revision, model);
+}
+
+static struct scsi_host_template scsi_driver_template;
+
+static int sbp2_probe(struct device *dev)
+{
+        struct fw_unit *unit = fw_unit(dev);
+        struct fw_device *device = fw_device(unit->device.parent);
+        struct sbp2_target *tgt;
+        struct sbp2_logical_unit *lu;
+        struct Scsi_Host *shost;
+        u32 model, firmware_revision;
+
+        shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
+        if (shost == NULL)
+                return -ENOMEM;
+
+        tgt = (struct sbp2_target *)shost->hostdata;
+        unit->device.driver_data = tgt;
+        tgt->unit = unit;
+        kref_init(&tgt->kref);
+        INIT_LIST_HEAD(&tgt->lu_list);
+
+        if (fw_device_enable_phys_dma(device) < 0)
+                goto fail_shost_put;
+
+        if (scsi_add_host(shost, &unit->device) < 0)
+                goto fail_shost_put;
+
+        /* Initialize to values that won't match anything in our table. */
+        firmware_revision = 0xff000000;
+        model = 0xff000000;
+
+        /* implicit directory ID */
+        tgt->directory_id = ((unit->directory - device->config_rom) * 4
+                             + CSR_CONFIG_ROM) & 0xffffff;
+
+        if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
+                               &firmware_revision) < 0)
+                goto fail_tgt_put;
+
+        sbp2_init_workarounds(tgt, model, firmware_revision);
 
         get_device(&unit->device);
 
@@ -730,35 +823,34 @@ static int sbp2_probe(struct device *dev)
          * reschedule retries. Always get the ref before scheduling
          * work.
          */
-        INIT_DELAYED_WORK(&sd->work, sbp2_login);
-        if (schedule_delayed_work(&sd->work, 0))
-                kref_get(&sd->kref);
-
+        list_for_each_entry(lu, &tgt->lu_list, link)
+                if (schedule_delayed_work(&lu->work, 0))
+                        kref_get(&tgt->kref);
         return 0;
 
- fail_address_handler:
-        fw_core_remove_address_handler(&sd->address_handler);
- fail_host:
-        scsi_host_put(host);
- fail:
-        return err;
+ fail_tgt_put:
+        kref_put(&tgt->kref, sbp2_release_target);
+        return -ENOMEM;
+
+ fail_shost_put:
+        scsi_host_put(shost);
+        return -ENOMEM;
 }
 
 static int sbp2_remove(struct device *dev)
 {
         struct fw_unit *unit = fw_unit(dev);
-        struct sbp2_device *sd = unit->device.driver_data;
-
-        kref_put(&sd->kref, release_sbp2_device);
+        struct sbp2_target *tgt = unit->device.driver_data;
 
+        kref_put(&tgt->kref, sbp2_release_target);
         return 0;
 }
 
 static void sbp2_reconnect(struct work_struct *work)
 {
-        struct sbp2_device *sd =
-                container_of(work, struct sbp2_device, work.work);
-        struct fw_unit *unit = sd->unit;
+        struct sbp2_logical_unit *lu =
+                container_of(work, struct sbp2_logical_unit, work.work);
+        struct fw_unit *unit = lu->tgt->unit;
         struct fw_device *device = fw_device(unit->device.parent);
         int generation, node_id, local_node_id;
 
@@ -766,40 +858,49 @@ static void sbp2_reconnect(struct work_struct *work)
         node_id       = device->node->node_id;
         local_node_id = device->card->local_node->node_id;
 
-        if (sbp2_send_management_orb(unit, node_id, generation,
+        if (sbp2_send_management_orb(lu, node_id, generation,
                                      SBP2_RECONNECT_REQUEST,
-                                     sd->login_id, NULL) < 0) {
-                if (sd->retries++ >= 5) {
+                                     lu->login_id, NULL) < 0) {
+                if (lu->retries++ >= 5) {
                         fw_error("failed to reconnect to %s\n",
                                  unit->device.bus_id);
                         /* Fall back and try to log in again. */
-                        sd->retries = 0;
-                        PREPARE_DELAYED_WORK(&sd->work, sbp2_login);
+                        lu->retries = 0;
+                        PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
                 }
-                schedule_delayed_work(&sd->work, DIV_ROUND_UP(HZ, 5));
+                schedule_delayed_work(&lu->work, DIV_ROUND_UP(HZ, 5));
                 return;
         }
 
-        sd->generation   = generation;
-        sd->node_id      = node_id;
-        sd->address_high = local_node_id << 16;
+        lu->generation        = generation;
+        lu->tgt->node_id      = node_id;
+        lu->tgt->address_high = local_node_id << 16;
 
-        fw_notify("reconnected to unit %s (%d retries)\n",
-                  unit->device.bus_id, sd->retries);
-        sbp2_agent_reset(unit);
-        sbp2_cancel_orbs(unit);
-        kref_put(&sd->kref, release_sbp2_device);
+        fw_notify("reconnected to %s LUN %04x (%d retries)\n",
+                  unit->device.bus_id, lu->lun, lu->retries);
+
+        sbp2_agent_reset(lu);
+        sbp2_cancel_orbs(lu);
+
+        kref_put(&lu->tgt->kref, sbp2_release_target);
 }
 
 static void sbp2_update(struct fw_unit *unit)
 {
-        struct fw_device *device = fw_device(unit->device.parent);
-        struct sbp2_device *sd = unit->device.driver_data;
+        struct sbp2_target *tgt = unit->device.driver_data;
+        struct sbp2_logical_unit *lu;
 
-        sd->retries = 0;
-        fw_device_enable_phys_dma(device);
-        if (schedule_delayed_work(&sd->work, 0))
-                kref_get(&sd->kref);
+        fw_device_enable_phys_dma(fw_device(unit->device.parent));
+
+        /*
+         * Fw-core serializes sbp2_update() against sbp2_remove().
+         * Iteration over tgt->lu_list is therefore safe here.
+         */
+        list_for_each_entry(lu, &tgt->lu_list, link) {
+                lu->retries = 0;
+                if (schedule_delayed_work(&lu->work, 0))
+                        kref_get(&tgt->kref);
+        }
 }
 
 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
@@ -869,13 +970,12 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 {
         struct sbp2_command_orb *orb =
                 container_of(base_orb, struct sbp2_command_orb, base);
-        struct fw_unit *unit = orb->unit;
-        struct fw_device *device = fw_device(unit->device.parent);
+        struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
         int result;
 
         if (status != NULL) {
                 if (STATUS_GET_DEAD(*status))
-                        sbp2_agent_reset(unit);
+                        sbp2_agent_reset(orb->lu);
 
                 switch (STATUS_GET_RESPONSE(*status)) {
                 case SBP2_STATUS_REQUEST_COMPLETE:
@@ -919,12 +1019,10 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
         orb->done(orb->cmd);
 }
 
-static int sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
+static int
+sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
+                     struct sbp2_logical_unit *lu)
 {
-        struct sbp2_device *sd =
-                (struct sbp2_device *)orb->cmd->device->host->hostdata;
-        struct fw_unit *unit = sd->unit;
-        struct fw_device *device = fw_device(unit->device.parent);
         struct scatterlist *sg;
         int sg_len, l, i, j, count;
         dma_addr_t sg_addr;
@@ -943,10 +1041,9 @@ static int sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
          * tables.
          */
         if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
-                orb->request.data_descriptor.high = sd->address_high;
+                orb->request.data_descriptor.high = lu->tgt->address_high;
                 orb->request.data_descriptor.low  = sg_dma_address(sg);
-                orb->request.misc |=
-                        COMMAND_ORB_DATA_SIZE(sg_dma_len(sg));
+                orb->request.misc |= COMMAND_ORB_DATA_SIZE(sg_dma_len(sg));
                 return 0;
         }
 
@@ -990,7 +1087,7 @@ static int sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
          * initiator (i.e. us), but data_descriptor can refer to data
          * on other nodes so we need to put our ID in descriptor.high.
          */
-        orb->request.data_descriptor.high = sd->address_high;
+        orb->request.data_descriptor.high = lu->tgt->address_high;
         orb->request.data_descriptor.low  = orb->page_table_bus;
         orb->request.misc |=
                 COMMAND_ORB_PAGE_TABLE_PRESENT |
@@ -1009,12 +1106,11 @@ static int sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
 
 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
 {
-        struct sbp2_device *sd =
-                (struct sbp2_device *)cmd->device->host->hostdata;
-        struct fw_unit *unit = sd->unit;
-        struct fw_device *device = fw_device(unit->device.parent);
+        struct sbp2_logical_unit *lu = cmd->device->hostdata;
+        struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
         struct sbp2_command_orb *orb;
         unsigned max_payload;
+        int retval = SCSI_MLQUEUE_HOST_BUSY;
 
         /*
          * Bidirectional commands are not yet implemented, and unknown
@@ -1030,14 +1126,14 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
         if (orb == NULL) {
                 fw_notify("failed to alloc orb\n");
-                goto fail_alloc;
+                return SCSI_MLQUEUE_HOST_BUSY;
         }
 
         /* Initialize rcode to something not RCODE_COMPLETE. */
         orb->base.rcode = -1;
         kref_init(&orb->base.kref);
 
-        orb->unit = unit;
+        orb->lu   = lu;
         orb->done = done;
         orb->cmd  = cmd;
 
@@ -1063,8 +1159,8 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
                 orb->request.misc |=
                         COMMAND_ORB_DIRECTION(SBP2_DIRECTION_TO_MEDIA);
 
-        if (scsi_sg_count(cmd) && sbp2_command_orb_map_scatterlist(orb) < 0)
-                goto fail_mapping;
+        if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
+                goto out;
 
         fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
 
@@ -1077,49 +1173,47 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
                 dma_map_single(device->card->device, &orb->request,
                                sizeof(orb->request), DMA_TO_DEVICE);
         if (dma_mapping_error(orb->base.request_bus))
-                goto fail_mapping;
-
-        sbp2_send_orb(&orb->base, unit, sd->node_id, sd->generation,
-                      sd->command_block_agent_address + SBP2_ORB_POINTER);
-
-        kref_put(&orb->base.kref, free_orb);
-        return 0;
+                goto out;
 
- fail_mapping:
+        sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, lu->generation,
+                      lu->command_block_agent_address + SBP2_ORB_POINTER);
+        retval = 0;
+ out:
         kref_put(&orb->base.kref, free_orb);
- fail_alloc:
-        return SCSI_MLQUEUE_HOST_BUSY;
+        return retval;
 }
 
 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
 {
-        struct sbp2_device *sd = (struct sbp2_device *)sdev->host->hostdata;
+        struct sbp2_logical_unit *lu = sdev->hostdata;
 
         sdev->allow_restart = 1;
 
-        if (sd->workarounds & SBP2_WORKAROUND_INQUIRY_36)
+        if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
                 sdev->inquiry_len = 36;
+
         return 0;
 }
 
 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
 {
-        struct sbp2_device *sd = (struct sbp2_device *)sdev->host->hostdata;
-        struct fw_unit *unit = sd->unit;
+        struct sbp2_logical_unit *lu = sdev->hostdata;
 
         sdev->use_10_for_rw = 1;
 
         if (sdev->type == TYPE_ROM)
                 sdev->use_10_for_ms = 1;
+
         if (sdev->type == TYPE_DISK &&
-            sd->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
+            lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
                 sdev->skip_ms_page_8 = 1;
-        if (sd->workarounds & SBP2_WORKAROUND_FIX_CAPACITY) {
-                fw_notify("setting fix_capacity for %s\n", unit->device.bus_id);
+
+        if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
                 sdev->fix_capacity = 1;
-        }
-        if (sd->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
+
+        if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
+
         return 0;
 }
 
@@ -1129,13 +1223,11 @@ static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
  */
 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
 {
-        struct sbp2_device *sd =
-                (struct sbp2_device *)cmd->device->host->hostdata;
-        struct fw_unit *unit = sd->unit;
+        struct sbp2_logical_unit *lu = cmd->device->hostdata;
 
         fw_notify("sbp2_scsi_abort\n");
-        sbp2_agent_reset(unit);
-        sbp2_cancel_orbs(unit);
+        sbp2_agent_reset(lu);
+        sbp2_cancel_orbs(lu);
 
         return SUCCESS;
 }
@@ -1152,37 +1244,18 @@ sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
         struct scsi_device *sdev = to_scsi_device(dev);
-        struct sbp2_device *sd;
-        struct fw_unit *unit;
+        struct sbp2_logical_unit *lu;
         struct fw_device *device;
-        u32 directory_id;
-        struct fw_csr_iterator ci;
-        int key, value, lun;
 
         if (!sdev)
                 return 0;
-        sd = (struct sbp2_device *)sdev->host->hostdata;
-        unit = sd->unit;
-        device = fw_device(unit->device.parent);
-
-        /* implicit directory ID */
-        directory_id = ((unit->directory - device->config_rom) * 4
-                        + CSR_CONFIG_ROM) & 0xffffff;
-
-        /* explicit directory ID, overrides implicit ID if present */
-        fw_csr_iterator_init(&ci, unit->directory);
-        while (fw_csr_iterator_next(&ci, &key, &value))
-                if (key == CSR_DIRECTORY_ID) {
-                        directory_id = value;
-                        break;
-                }
 
-        /* FIXME: Make this work for multi-lun devices. */
-        lun = 0;
+        lu = sdev->hostdata;
+        device = fw_device(lu->tgt->unit->device.parent);
 
         return sprintf(buf, "%08x%08x:%06x:%04x\n",
                         device->config_rom[3], device->config_rom[4],
-                        directory_id, lun);
+                        lu->tgt->directory_id, lu->lun);
 }
 
 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);