sbp-target: Initial merge of firewire/ieee-1394 target mode support

The FireWire SBP-2 Target is a driver for using an IEEE-1394 connection
as a SCSI transport. This module uses the SCSI Target framework to
expose LUNs to other machines attached to a FireWire bus, in effect
acting as a FireWire hard disk similar to FireWire Target Disk mode
on many Apple computers.

This commit contains the squashed pull from Chris Boot's SBP-2-Target:

      https://github.com/bootc/Linux-SBP-2-Target.git patch-v3

firewire-sbp-target: Add sbp_base.h header
firewire-sbp-target: Add sbp_configfs.c
firewire-sbp-target: Add sbp_fabric.{c,h}
firewire-sbp-target: Add sbp_management_agent.{c,h}
firewire-sbp-target: Add sbp_login.{c,h}
firewire-sbp-target: Add sbp_target_agent.{c,h}
firewire-sbp-target: Add sbp_scsi_cmnd.{c,h}
firewire-sbp-target: Add to target Kconfig and Makefile

Also add bootc's entry to the MAINTAINERS file.  Great work Chris !!

Signed-off-by: Chris Boot <bootc@bootc.net>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 2621 insertions, 0 deletions

diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
new file mode 100644
index 00000000000..37c609898f8
--- /dev/null
+++ b/drivers/target/sbp/sbp_target.c
@@ -0,0 +1,2621 @@
+/*
+ * SBP2 target driver (SCSI over IEEE1394 in target mode)
+ *
+ * Copyright (C) 2011  Chris Boot <bootc@bootc.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define KMSG_COMPONENT "sbp_target"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/configfs.h>
+#include <linux/ctype.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_tcq.h>
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_fabric_configfs.h>
+#include <target/target_core_configfs.h>
+#include <target/configfs_macros.h>
+#include <asm/unaligned.h>
+
+#include "sbp_target.h"
+
+/* Local pointer to allocated TCM configfs fabric module */
+static struct target_fabric_configfs *sbp_fabric_configfs;
+
+/* FireWire address region for management and command block address handlers */
+static const struct fw_address_region sbp_register_region = {
+	.start	= CSR_REGISTER_BASE + 0x10000,
+	.end	= 0x1000000000000ULL,
+};
+
+static const u32 sbp_unit_directory_template[] = {
+	0x1200609e, /* unit_specifier_id: NCITS/T10 */
+	0x13010483, /* unit_sw_version: 1155D Rev 4 */
+	0x3800609e, /* command_set_specifier_id: NCITS/T10 */
+	0x390104d8, /* command_set: SPC-2 */
+	0x3b000000, /* command_set_revision: 0 */
+	0x3c000001, /* firmware_revision: 1 */
+};
+
+#define SESSION_MAINTENANCE_INTERVAL HZ
+
+static atomic_t login_id = ATOMIC_INIT(0);
+
+static void session_maintenance_work(struct work_struct *);
+static int sbp_run_transaction(struct fw_card *, int, int, int, int,
+		unsigned long long, void *, size_t);
+
+static int read_peer_guid(u64 *guid, const struct sbp_management_request *req)
+{
+	int ret;
+	__be32 high, low;
+
+	ret = sbp_run_transaction(req->card, TCODE_READ_QUADLET_REQUEST,
+			req->node_addr, req->generation, req->speed,
+			(CSR_REGISTER_BASE | CSR_CONFIG_ROM) + 3 * 4,
+			&high, sizeof(high));
+	if (ret != RCODE_COMPLETE)
+		return ret;
+
+	ret = sbp_run_transaction(req->card, TCODE_READ_QUADLET_REQUEST,
+			req->node_addr, req->generation, req->speed,
+			(CSR_REGISTER_BASE | CSR_CONFIG_ROM) + 4 * 4,
+			&low, sizeof(low));
+	if (ret != RCODE_COMPLETE)
+		return ret;
+
+	*guid = (u64)be32_to_cpu(high) << 32 | be32_to_cpu(low);
+
+	return RCODE_COMPLETE;
+}
+
+static struct sbp_session *sbp_session_find_by_guid(
+	struct sbp_tpg *tpg, u64 guid)
+{
+	struct se_session *se_sess;
+	struct sbp_session *sess, *found = NULL;
+
+	spin_lock_bh(&tpg->se_tpg.session_lock);
+	list_for_each_entry(se_sess, &tpg->se_tpg.tpg_sess_list, sess_list) {
+		sess = se_sess->fabric_sess_ptr;
+		if (sess->guid == guid)
+			found = sess;
+	}
+	spin_unlock_bh(&tpg->se_tpg.session_lock);
+
+	return found;
+}
+
+static struct sbp_login_descriptor *sbp_login_find_by_lun(
+		struct sbp_session *session, struct se_lun *lun)
+{
+	struct sbp_login_descriptor *login, *found = NULL;
+
+	spin_lock_bh(&session->lock);
+	list_for_each_entry(login, &session->login_list, link) {
+		if (login->lun == lun)
+			found = login;
+	}
+	spin_unlock_bh(&session->lock);
+
+	return found;
+}
+
+static int sbp_login_count_all_by_lun(
+		struct sbp_tpg *tpg,
+		struct se_lun *lun,
+		int exclusive)
+{
+	struct se_session *se_sess;
+	struct sbp_session *sess;
+	struct sbp_login_descriptor *login;
+	int count = 0;
+
+	spin_lock_bh(&tpg->se_tpg.session_lock);
+	list_for_each_entry(se_sess, &tpg->se_tpg.tpg_sess_list, sess_list) {
+		sess = se_sess->fabric_sess_ptr;
+
+		spin_lock_bh(&sess->lock);
+		list_for_each_entry(login, &sess->login_list, link) {
+			if (login->lun != lun)
+				continue;
+
+			if (!exclusive || login->exclusive)
+				count++;
+		}
+		spin_unlock_bh(&sess->lock);
+	}
+	spin_unlock_bh(&tpg->se_tpg.session_lock);
+
+	return count;
+}
+
+static struct sbp_login_descriptor *sbp_login_find_by_id(
+	struct sbp_tpg *tpg, int login_id)
+{
+	struct se_session *se_sess;
+	struct sbp_session *sess;
+	struct sbp_login_descriptor *login, *found = NULL;
+
+	spin_lock_bh(&tpg->se_tpg.session_lock);
+	list_for_each_entry(se_sess, &tpg->se_tpg.tpg_sess_list, sess_list) {
+		sess = se_sess->fabric_sess_ptr;
+
+		spin_lock_bh(&sess->lock);
+		list_for_each_entry(login, &sess->login_list, link) {
+			if (login->login_id == login_id)
+				found = login;
+		}
+		spin_unlock_bh(&sess->lock);
+	}
+	spin_unlock_bh(&tpg->se_tpg.session_lock);
+
+	return found;
+}
+
+static struct se_lun *sbp_get_lun_from_tpg(struct sbp_tpg *tpg, int lun)
+{
+	struct se_portal_group *se_tpg = &tpg->se_tpg;
+	struct se_lun *se_lun;
+
+	if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
+		return ERR_PTR(-EINVAL);
+
+	spin_lock(&se_tpg->tpg_lun_lock);
+	se_lun = se_tpg->tpg_lun_list[lun];
+
+	if (se_lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE)
+		se_lun = ERR_PTR(-ENODEV);
+
+	spin_unlock(&se_tpg->tpg_lun_lock);
+
+	return se_lun;
+}
+
+static struct sbp_session *sbp_session_create(
+		struct sbp_tpg *tpg,
+		u64 guid)
+{
+	struct sbp_session *sess;
+	int ret;
+	char guid_str[17];
+	struct se_node_acl *se_nacl;
+
+	sess = kmalloc(sizeof(*sess), GFP_KERNEL);
+	if (!sess) {
+		pr_err("failed to allocate session descriptor\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	sess->se_sess = transport_init_session();
+	if (IS_ERR(sess->se_sess)) {
+		pr_err("failed to init se_session\n");
+
+		ret = PTR_ERR(sess->se_sess);
+		kfree(sess);
+		return ERR_PTR(ret);
+	}
+
+	snprintf(guid_str, sizeof(guid_str), "%016llx", guid);
+
+	se_nacl = core_tpg_check_initiator_node_acl(&tpg->se_tpg, guid_str);
+	if (!se_nacl) {
+		pr_warn("Node ACL not found for %s\n", guid_str);
+
+		transport_free_session(sess->se_sess);
+		kfree(sess);
+
+		return ERR_PTR(-EPERM);
+	}
+
+	sess->se_sess->se_node_acl = se_nacl;
+
+	spin_lock_init(&sess->lock);
+	INIT_LIST_HEAD(&sess->login_list);
+	INIT_DELAYED_WORK(&sess->maint_work, session_maintenance_work);
+
+	sess->guid = guid;
+
+	transport_register_session(&tpg->se_tpg, se_nacl, sess->se_sess, sess);
+
+	return sess;
+}
+
+static void sbp_session_release(struct sbp_session *sess, bool cancel_work)
+{
+	spin_lock_bh(&sess->lock);
+	if (!list_empty(&sess->login_list)) {
+		spin_unlock_bh(&sess->lock);
+		return;
+	}
+	spin_unlock_bh(&sess->lock);
+
+	if (cancel_work)
+		cancel_delayed_work_sync(&sess->maint_work);
+
+	transport_deregister_session_configfs(sess->se_sess);
+	transport_deregister_session(sess->se_sess);
+
+	if (sess->card)
+		fw_card_put(sess->card);
+
+	kfree(sess);
+}
+
+static void sbp_target_agent_unregister(struct sbp_target_agent *);
+
+static void sbp_login_release(struct sbp_login_descriptor *login,
+	bool cancel_work)
+{
+	struct sbp_session *sess = login->sess;
+
+	/* FIXME: abort/wait on tasks */
+
+	sbp_target_agent_unregister(login->tgt_agt);
+
+	if (sess) {
+		spin_lock_bh(&sess->lock);
+		list_del(&login->link);
+		spin_unlock_bh(&sess->lock);
+
+		sbp_session_release(sess, cancel_work);
+	}
+
+	kfree(login);
+}
+
+static struct sbp_target_agent *sbp_target_agent_register(
+	struct sbp_login_descriptor *);
+
+static void sbp_management_request_login(
+	struct sbp_management_agent *agent, struct sbp_management_request *req,
+	int *status_data_size)
+{
+	struct sbp_tport *tport = agent->tport;
+	struct sbp_tpg *tpg = tport->tpg;
+	struct se_lun *se_lun;
+	int ret;
+	u64 guid;
+	struct sbp_session *sess;
+	struct sbp_login_descriptor *login;
+	struct sbp_login_response_block *response;
+	int login_response_len;
+
+	se_lun = sbp_get_lun_from_tpg(tpg,
+			LOGIN_ORB_LUN(be32_to_cpu(req->orb.misc)));
+	if (IS_ERR(se_lun)) {
+		pr_notice("login to unknown LUN: %d\n",
+			LOGIN_ORB_LUN(be32_to_cpu(req->orb.misc)));
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_LUN_NOTSUPP));
+		return;
+	}
+
+	ret = read_peer_guid(&guid, req);
+	if (ret != RCODE_COMPLETE) {
+		pr_warn("failed to read peer GUID: %d\n", ret);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		return;
+	}
+
+	pr_notice("mgt_agent LOGIN to LUN %d from %016llx\n",
+		se_lun->unpacked_lun, guid);
+
+	sess = sbp_session_find_by_guid(tpg, guid);
+	if (sess) {
+		login = sbp_login_find_by_lun(sess, se_lun);
+		if (login) {
+			pr_notice("initiator already logged-in\n");
+
+			/*
+			 * SBP-2 R4 says we should return access denied, but
+			 * that can confuse initiators. Instead we need to
+			 * treat this like a reconnect, but send the login
+			 * response block like a fresh login.
+			 *
+			 * This is required particularly in the case of Apple
+			 * devices booting off the FireWire target, where
+			 * the firmware has an active login to the target. When
+			 * the OS takes control of the session it issues its own
+			 * LOGIN rather than a RECONNECT. To avoid the machine
+			 * waiting until the reconnect_hold expires, we can skip
+			 * the ACCESS_DENIED errors to speed things up.
+			 */
+
+			goto already_logged_in;
+		}
+	}
+
+	/*
+	 * check exclusive bit in login request
+	 * reject with access_denied if any logins present
+	 */
+	if (LOGIN_ORB_EXCLUSIVE(be32_to_cpu(req->orb.misc)) &&
+			sbp_login_count_all_by_lun(tpg, se_lun, 0)) {
+		pr_warn("refusing exclusive login with other active logins\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_ACCESS_DENIED));
+		return;
+	}
+
+	/*
+	 * check exclusive bit in any existing login descriptor
+	 * reject with access_denied if any exclusive logins present
+	 */
+	if (sbp_login_count_all_by_lun(tpg, se_lun, 1)) {
+		pr_warn("refusing login while another exclusive login present\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_ACCESS_DENIED));
+		return;
+	}
+
+	/*
+	 * check we haven't exceeded the number of allowed logins
+	 * reject with resources_unavailable if we have
+	 */
+	if (sbp_login_count_all_by_lun(tpg, se_lun, 0) >=
+			tport->max_logins_per_lun) {
+		pr_warn("max number of logins reached\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_RESOURCES_UNAVAIL));
+		return;
+	}
+
+	if (!sess) {
+		sess = sbp_session_create(tpg, guid);
+		if (IS_ERR(sess)) {
+			switch (PTR_ERR(sess)) {
+			case -EPERM:
+				ret = SBP_STATUS_ACCESS_DENIED;
+				break;
+			default:
+				ret = SBP_STATUS_RESOURCES_UNAVAIL;
+				break;
+			}
+
+			req->status.status = cpu_to_be32(
+				STATUS_BLOCK_RESP(
+					STATUS_RESP_REQUEST_COMPLETE) |
+				STATUS_BLOCK_SBP_STATUS(ret));
+			return;
+		}
+
+		sess->node_id = req->node_addr;
+		sess->card = fw_card_get(req->card);
+		sess->generation = req->generation;
+		sess->speed = req->speed;
+
+		schedule_delayed_work(&sess->maint_work,
+				SESSION_MAINTENANCE_INTERVAL);
+	}
+
+	/* only take the latest reconnect_hold into account */
+	sess->reconnect_hold = min(
+		1 << LOGIN_ORB_RECONNECT(be32_to_cpu(req->orb.misc)),
+		tport->max_reconnect_timeout) - 1;
+
+	login = kmalloc(sizeof(*login), GFP_KERNEL);
+	if (!login) {
+		pr_err("failed to allocate login descriptor\n");
+
+		sbp_session_release(sess, true);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_RESOURCES_UNAVAIL));
+		return;
+	}
+
+	login->sess = sess;
+	login->lun = se_lun;
+	login->status_fifo_addr = sbp2_pointer_to_addr(&req->orb.status_fifo);
+	login->exclusive = LOGIN_ORB_EXCLUSIVE(be32_to_cpu(req->orb.misc));
+	login->login_id = atomic_inc_return(&login_id);
+
+	login->tgt_agt = sbp_target_agent_register(login);
+	if (IS_ERR(login->tgt_agt)) {
+		ret = PTR_ERR(login->tgt_agt);
+		pr_err("failed to map command block handler: %d\n", ret);
+
+		sbp_session_release(sess, true);
+		kfree(login);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_RESOURCES_UNAVAIL));
+		return;
+	}
+
+	spin_lock_bh(&sess->lock);
+	list_add_tail(&login->link, &sess->login_list);
+	spin_unlock_bh(&sess->lock);
+
+already_logged_in:
+	response = kzalloc(sizeof(*response), GFP_KERNEL);
+	if (!response) {
+		pr_err("failed to allocate login response block\n");
+
+		sbp_login_release(login, true);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_RESOURCES_UNAVAIL));
+		return;
+	}
+
+	login_response_len = clamp_val(
+			LOGIN_ORB_RESPONSE_LENGTH(be32_to_cpu(req->orb.length)),
+			12, sizeof(*response));
+	response->misc = cpu_to_be32(
+		((login_response_len & 0xffff) << 16) |
+		(login->login_id & 0xffff));
+	response->reconnect_hold = cpu_to_be32(sess->reconnect_hold & 0xffff);
+	addr_to_sbp2_pointer(login->tgt_agt->handler.offset,
+		&response->command_block_agent);
+
+	ret = sbp_run_transaction(sess->card, TCODE_WRITE_BLOCK_REQUEST,
+		sess->node_id, sess->generation, sess->speed,
+		sbp2_pointer_to_addr(&req->orb.ptr2), response,
+		login_response_len);
+	if (ret != RCODE_COMPLETE) {
+		pr_debug("failed to write login response block: %x\n", ret);
+
+		kfree(response);
+		sbp_login_release(login, true);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		return;
+	}
+
+	kfree(response);
+
+	req->status.status = cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+}
+
+static void sbp_management_request_query_logins(
+	struct sbp_management_agent *agent, struct sbp_management_request *req,
+	int *status_data_size)
+{
+	pr_notice("QUERY LOGINS not implemented\n");
+	/* FIXME: implement */
+
+	req->status.status = cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+}
+
+static void sbp_management_request_reconnect(
+	struct sbp_management_agent *agent, struct sbp_management_request *req,
+	int *status_data_size)
+{
+	struct sbp_tport *tport = agent->tport;
+	struct sbp_tpg *tpg = tport->tpg;
+	int ret;
+	u64 guid;
+	struct sbp_login_descriptor *login;
+
+	ret = read_peer_guid(&guid, req);
+	if (ret != RCODE_COMPLETE) {
+		pr_warn("failed to read peer GUID: %d\n", ret);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		return;
+	}
+
+	pr_notice("mgt_agent RECONNECT from %016llx\n", guid);
+
+	login = sbp_login_find_by_id(tpg,
+		RECONNECT_ORB_LOGIN_ID(be32_to_cpu(req->orb.misc)));
+
+	if (!login) {
+		pr_err("mgt_agent RECONNECT unknown login ID\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_ACCESS_DENIED));
+		return;
+	}
+
+	if (login->sess->guid != guid) {
+		pr_err("mgt_agent RECONNECT login GUID doesn't match\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_ACCESS_DENIED));
+		return;
+	}
+
+	spin_lock_bh(&login->sess->lock);
+	if (login->sess->card)
+		fw_card_put(login->sess->card);
+
+	/* update the node details */
+	login->sess->generation = req->generation;
+	login->sess->node_id = req->node_addr;
+	login->sess->card = fw_card_get(req->card);
+	login->sess->speed = req->speed;
+	spin_unlock_bh(&login->sess->lock);
+
+	req->status.status = cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+}
+
+static void sbp_management_request_logout(
+	struct sbp_management_agent *agent, struct sbp_management_request *req,
+	int *status_data_size)
+{
+	struct sbp_tport *tport = agent->tport;
+	struct sbp_tpg *tpg = tport->tpg;
+	int login_id;
+	struct sbp_login_descriptor *login;
+
+	login_id = LOGOUT_ORB_LOGIN_ID(be32_to_cpu(req->orb.misc));
+
+	login = sbp_login_find_by_id(tpg, login_id);
+	if (!login) {
+		pr_warn("cannot find login: %d\n", login_id);
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_LOGIN_ID_UNKNOWN));
+		return;
+	}
+
+	pr_info("mgt_agent LOGOUT from LUN %d session %d\n",
+		login->lun->unpacked_lun, login->login_id);
+
+	if (req->node_addr != login->sess->node_id) {
+		pr_warn("logout from different node ID\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_ACCESS_DENIED));
+		return;
+	}
+
+	sbp_login_release(login, true);
+
+	req->status.status = cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+}
+
+static void session_check_for_reset(struct sbp_session *sess)
+{
+	bool card_valid = false;
+
+	spin_lock_bh(&sess->lock);
+
+	if (sess->card) {
+		spin_lock_irq(&sess->card->lock);
+		card_valid = (sess->card->local_node != NULL);
+		spin_unlock_irq(&sess->card->lock);
+
+		if (!card_valid) {
+			fw_card_put(sess->card);
+			sess->card = NULL;
+		}
+	}
+
+	if (!card_valid || (sess->generation != sess->card->generation)) {
+		pr_info("Waiting for reconnect from node: %016llx\n",
+				sess->guid);
+
+		sess->node_id = -1;
+		sess->reconnect_expires = get_jiffies_64() +
+			((sess->reconnect_hold + 1) * HZ);
+	}
+
+	spin_unlock_bh(&sess->lock);
+}
+
+static void session_reconnect_expired(struct sbp_session *sess)
+{
+	struct sbp_login_descriptor *login, *temp;
+	LIST_HEAD(login_list);
+
+	pr_info("Reconnect timer expired for node: %016llx\n", sess->guid);
+
+	spin_lock_bh(&sess->lock);
+	list_for_each_entry_safe(login, temp, &sess->login_list, link) {
+		login->sess = NULL;
+		list_del(&login->link);
+		list_add_tail(&login->link, &login_list);
+	}
+	spin_unlock_bh(&sess->lock);
+
+	list_for_each_entry_safe(login, temp, &login_list, link) {
+		list_del(&login->link);
+		sbp_login_release(login, false);
+	}
+
+	sbp_session_release(sess, false);
+}
+
+static void session_maintenance_work(struct work_struct *work)
+{
+	struct sbp_session *sess = container_of(work, struct sbp_session,
+			maint_work.work);
+
+	/* could be called while tearing down the session */
+	spin_lock_bh(&sess->lock);
+	if (list_empty(&sess->login_list)) {
+		spin_unlock_bh(&sess->lock);
+		return;
+	}
+	spin_unlock_bh(&sess->lock);
+
+	if (sess->node_id != -1) {
+		/* check for bus reset and make node_id invalid */
+		session_check_for_reset(sess);
+
+		schedule_delayed_work(&sess->maint_work,
+				SESSION_MAINTENANCE_INTERVAL);
+	} else if (!time_after64(get_jiffies_64(), sess->reconnect_expires)) {
+		/* still waiting for reconnect */
+		schedule_delayed_work(&sess->maint_work,
+				SESSION_MAINTENANCE_INTERVAL);
+	} else {
+		/* reconnect timeout has expired */
+		session_reconnect_expired(sess);
+	}
+}
+
+static int tgt_agent_rw_agent_state(struct fw_card *card, int tcode, void *data,
+		struct sbp_target_agent *agent)
+{
+	__be32 state;
+
+	switch (tcode) {
+	case TCODE_READ_QUADLET_REQUEST:
+		pr_debug("tgt_agent AGENT_STATE READ\n");
+
+		spin_lock_bh(&agent->lock);
+		state = cpu_to_be32(agent->state);
+		spin_unlock_bh(&agent->lock);
+		memcpy(data, &state, sizeof(state));
+
+		return RCODE_COMPLETE;
+
+	case TCODE_WRITE_QUADLET_REQUEST:
+		/* ignored */
+		return RCODE_COMPLETE;
+
+	default:
+		return RCODE_TYPE_ERROR;
+	}
+}
+
+static int tgt_agent_rw_agent_reset(struct fw_card *card, int tcode, void *data,
+		struct sbp_target_agent *agent)
+{
+	switch (tcode) {
+	case TCODE_WRITE_QUADLET_REQUEST:
+		pr_debug("tgt_agent AGENT_RESET\n");
+		spin_lock_bh(&agent->lock);
+		agent->state = AGENT_STATE_RESET;
+		spin_unlock_bh(&agent->lock);
+		return RCODE_COMPLETE;
+
+	default:
+		return RCODE_TYPE_ERROR;
+	}
+}
+
+static int tgt_agent_rw_orb_pointer(struct fw_card *card, int tcode, void *data,
+		struct sbp_target_agent *agent)
+{
+	struct sbp2_pointer *ptr = data;
+
+	switch (tcode) {
+	case TCODE_WRITE_BLOCK_REQUEST:
+		spin_lock_bh(&agent->lock);
+		if (agent->state != AGENT_STATE_SUSPENDED &&
+				agent->state != AGENT_STATE_RESET) {
+			spin_unlock_bh(&agent->lock);
+			pr_notice("Ignoring ORB_POINTER write while active.\n");
+			return RCODE_CONFLICT_ERROR;
+		}
+		agent->state = AGENT_STATE_ACTIVE;
+		spin_unlock_bh(&agent->lock);
+
+		agent->orb_pointer = sbp2_pointer_to_addr(ptr);
+		agent->doorbell = false;
+
+		pr_debug("tgt_agent ORB_POINTER write: 0x%llx\n",
+				agent->orb_pointer);
+
+		queue_work(system_unbound_wq, &agent->work);
+
+		return RCODE_COMPLETE;
+
+	case TCODE_READ_BLOCK_REQUEST:
+		pr_debug("tgt_agent ORB_POINTER READ\n");
+		spin_lock_bh(&agent->lock);
+		addr_to_sbp2_pointer(agent->orb_pointer, ptr);
+		spin_unlock_bh(&agent->lock);
+		return RCODE_COMPLETE;
+
+	default:
+		return RCODE_TYPE_ERROR;
+	}
+}
+
+static int tgt_agent_rw_doorbell(struct fw_card *card, int tcode, void *data,
+		struct sbp_target_agent *agent)
+{
+	switch (tcode) {
+	case TCODE_WRITE_QUADLET_REQUEST:
+		spin_lock_bh(&agent->lock);
+		if (agent->state != AGENT_STATE_SUSPENDED) {
+			spin_unlock_bh(&agent->lock);
+			pr_debug("Ignoring DOORBELL while active.\n");
+			return RCODE_CONFLICT_ERROR;
+		}
+		agent->state = AGENT_STATE_ACTIVE;
+		spin_unlock_bh(&agent->lock);
+
+		agent->doorbell = true;
+
+		pr_debug("tgt_agent DOORBELL\n");
+
+		queue_work(system_unbound_wq, &agent->work);
+
+		return RCODE_COMPLETE;
+
+	case TCODE_READ_QUADLET_REQUEST:
+		return RCODE_COMPLETE;
+
+	default:
+		return RCODE_TYPE_ERROR;
+	}
+}
+
+static int tgt_agent_rw_unsolicited_status_enable(struct fw_card *card,
+		int tcode, void *data, struct sbp_target_agent *agent)
+{
+	switch (tcode) {
+	case TCODE_WRITE_QUADLET_REQUEST:
+		pr_debug("tgt_agent UNSOLICITED_STATUS_ENABLE\n");
+		/* ignored as we don't send unsolicited status */
+		return RCODE_COMPLETE;
+
+	case TCODE_READ_QUADLET_REQUEST:
+		return RCODE_COMPLETE;
+
+	default:
+		return RCODE_TYPE_ERROR;
+	}
+}
+
+static void tgt_agent_rw(struct fw_card *card, struct fw_request *request,
+		int tcode, int destination, int source, int generation,
+		unsigned long long offset, void *data, size_t length,
+		void *callback_data)
+{
+	struct sbp_target_agent *agent = callback_data;
+	struct sbp_session *sess = agent->login->sess;
+	int sess_gen, sess_node, rcode;
+
+	spin_lock_bh(&sess->lock);
+	sess_gen = sess->generation;
+	sess_node = sess->node_id;
+	spin_unlock_bh(&sess->lock);
+
+	if (generation != sess_gen) {
+		pr_notice("ignoring request with wrong generation\n");
+		rcode = RCODE_TYPE_ERROR;
+		goto out;
+	}
+
+	if (source != sess_node) {
+		pr_notice("ignoring request from foreign node (%x != %x)\n",
+				source, sess_node);
+		rcode = RCODE_TYPE_ERROR;
+		goto out;
+	}
+
+	/* turn offset into the offset from the start of the block */
+	offset -= agent->handler.offset;
+
+	if (offset == 0x00 && length == 4) {
+		/* AGENT_STATE */
+		rcode = tgt_agent_rw_agent_state(card, tcode, data, agent);
+	} else if (offset == 0x04 && length == 4) {
+		/* AGENT_RESET */
+		rcode = tgt_agent_rw_agent_reset(card, tcode, data, agent);
+	} else if (offset == 0x08 && length == 8) {
+		/* ORB_POINTER */
+		rcode = tgt_agent_rw_orb_pointer(card, tcode, data, agent);
+	} else if (offset == 0x10 && length == 4) {
+		/* DOORBELL */
+		rcode = tgt_agent_rw_doorbell(card, tcode, data, agent);
+	} else if (offset == 0x14 && length == 4) {
+		/* UNSOLICITED_STATUS_ENABLE */
+		rcode = tgt_agent_rw_unsolicited_status_enable(card, tcode,
+				data, agent);
+	} else {
+		rcode = RCODE_ADDRESS_ERROR;
+	}
+
+out:
+	fw_send_response(card, request, rcode);
+}
+
+static void sbp_handle_command(struct sbp_target_request *);
+static int sbp_send_status(struct sbp_target_request *);
+static void sbp_free_request(struct sbp_target_request *);
+
+static void tgt_agent_process_work(struct work_struct *work)
+{
+	struct sbp_target_request *req =
+		container_of(work, struct sbp_target_request, work);
+
+	pr_debug("tgt_orb ptr:0x%llx next_ORB:0x%llx data_descriptor:0x%llx misc:0x%x\n",
+			req->orb_pointer,
+			sbp2_pointer_to_addr(&req->orb.next_orb),
+			sbp2_pointer_to_addr(&req->orb.data_descriptor),
+			be32_to_cpu(req->orb.misc));
+
+	if (req->orb_pointer >> 32)
+		pr_debug("ORB with high bits set\n");
+
+	switch (ORB_REQUEST_FORMAT(be32_to_cpu(req->orb.misc))) {
+		case 0:/* Format specified by this standard */
+			sbp_handle_command(req);
+			return;
+		case 1: /* Reserved for future standardization */
+		case 2: /* Vendor-dependent */
+			req->status.status |= cpu_to_be32(
+					STATUS_BLOCK_RESP(
+						STATUS_RESP_REQUEST_COMPLETE) |
+					STATUS_BLOCK_DEAD(0) |
+					STATUS_BLOCK_LEN(1) |
+					STATUS_BLOCK_SBP_STATUS(
+						SBP_STATUS_REQ_TYPE_NOTSUPP));
+			sbp_send_status(req);
+			sbp_free_request(req);
+			return;
+		case 3: /* Dummy ORB */
+			req->status.status |= cpu_to_be32(
+					STATUS_BLOCK_RESP(
+						STATUS_RESP_REQUEST_COMPLETE) |
+					STATUS_BLOCK_DEAD(0) |
+					STATUS_BLOCK_LEN(1) |
+					STATUS_BLOCK_SBP_STATUS(
+						SBP_STATUS_DUMMY_ORB_COMPLETE));
+			sbp_send_status(req);
+			sbp_free_request(req);
+			return;
+		default:
+			BUG();
+	}
+}
+
+/* used to double-check we haven't been issued an AGENT_RESET */
+static inline bool tgt_agent_check_active(struct sbp_target_agent *agent)
+{
+	bool active;
+
+	spin_lock_bh(&agent->lock);
+	active = (agent->state == AGENT_STATE_ACTIVE);
+	spin_unlock_bh(&agent->lock);
+
+	return active;
+}
+
+static void tgt_agent_fetch_work(struct work_struct *work)
+{
+	struct sbp_target_agent *agent =
+		container_of(work, struct sbp_target_agent, work);
+	struct sbp_session *sess = agent->login->sess;
+	struct sbp_target_request *req;
+	int ret;
+	bool doorbell = agent->doorbell;
+	u64 next_orb = agent->orb_pointer;
+
+	while (next_orb && tgt_agent_check_active(agent)) {
+		req = kzalloc(sizeof(*req), GFP_KERNEL);
+		if (!req) {
+			spin_lock_bh(&agent->lock);
+			agent->state = AGENT_STATE_DEAD;
+			spin_unlock_bh(&agent->lock);
+			return;
+		}
+
+		req->login = agent->login;
+		req->orb_pointer = next_orb;
+
+		req->status.status = cpu_to_be32(STATUS_BLOCK_ORB_OFFSET_HIGH(
+					req->orb_pointer >> 32));
+		req->status.orb_low = cpu_to_be32(
+				req->orb_pointer & 0xfffffffc);
+
+		/* read in the ORB */
+		ret = sbp_run_transaction(sess->card, TCODE_READ_BLOCK_REQUEST,
+				sess->node_id, sess->generation, sess->speed,
+				req->orb_pointer, &req->orb, sizeof(req->orb));
+		if (ret != RCODE_COMPLETE) {
+			pr_debug("tgt_orb fetch failed: %x\n", ret);
+			req->status.status |= cpu_to_be32(
+					STATUS_BLOCK_SRC(
+						STATUS_SRC_ORB_FINISHED) |
+					STATUS_BLOCK_RESP(
+						STATUS_RESP_TRANSPORT_FAILURE) |
+					STATUS_BLOCK_DEAD(1) |
+					STATUS_BLOCK_LEN(1) |
+					STATUS_BLOCK_SBP_STATUS(
+						SBP_STATUS_UNSPECIFIED_ERROR));
+			spin_lock_bh(&agent->lock);
+			agent->state = AGENT_STATE_DEAD;
+			spin_unlock_bh(&agent->lock);
+
+			sbp_send_status(req);
+			sbp_free_request(req);
+			return;
+		}
+
+		/* check the next_ORB field */
+		if (be32_to_cpu(req->orb.next_orb.high) & 0x80000000) {
+			next_orb = 0;
+			req->status.status |= cpu_to_be32(STATUS_BLOCK_SRC(
+						STATUS_SRC_ORB_FINISHED));
+		} else {
+			next_orb = sbp2_pointer_to_addr(&req->orb.next_orb);
+			req->status.status |= cpu_to_be32(STATUS_BLOCK_SRC(
+						STATUS_SRC_ORB_CONTINUING));
+		}
+
+		if (tgt_agent_check_active(agent) && !doorbell) {
+			INIT_WORK(&req->work, tgt_agent_process_work);
+			queue_work(system_unbound_wq, &req->work);
+		} else {
+			/* don't process this request, just check next_ORB */
+			sbp_free_request(req);
+		}
+
+		spin_lock_bh(&agent->lock);
+		doorbell = agent->doorbell = false;
+
+		/* check if we should carry on processing */
+		if (next_orb)
+			agent->orb_pointer = next_orb;
+		else
+			agent->state = AGENT_STATE_SUSPENDED;
+
+		spin_unlock_bh(&agent->lock);
+	};
+}
+
+static struct sbp_target_agent *sbp_target_agent_register(
+		struct sbp_login_descriptor *login)
+{
+	struct sbp_target_agent *agent;
+	int ret;
+
+	agent = kmalloc(sizeof(*agent), GFP_KERNEL);
+	if (!agent)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&agent->lock);
+
+	agent->handler.length = 0x20;
+	agent->handler.address_callback = tgt_agent_rw;
+	agent->handler.callback_data = agent;
+
+	agent->login = login;
+	agent->state = AGENT_STATE_RESET;
+	INIT_WORK(&agent->work, tgt_agent_fetch_work);
+	agent->orb_pointer = 0;
+	agent->doorbell = false;
+
+	ret = fw_core_add_address_handler(&agent->handler,
+			&sbp_register_region);
+	if (ret < 0) {
+		kfree(agent);
+		return ERR_PTR(ret);
+	}
+
+	return agent;
+}
+
+static void sbp_target_agent_unregister(struct sbp_target_agent *agent)
+{
+	fw_core_remove_address_handler(&agent->handler);
+	cancel_work_sync(&agent->work);
+	kfree(agent);
+}
+
+/*
+ * Simple wrapper around fw_run_transaction that retries the transaction several
+ * times in case of failure, with an exponential backoff.
+ */
+static int sbp_run_transaction(struct fw_card *card, int tcode, int destination_id,
+		int generation, int speed, unsigned long long offset,
+		void *payload, size_t length)
+{
+	int attempt, ret, delay;
+
+	for (attempt = 1; attempt <= 5; attempt++) {
+		ret = fw_run_transaction(card, tcode, destination_id,
+				generation, speed, offset, payload, length);
+
+		switch (ret) {
+		case RCODE_COMPLETE:
+		case RCODE_TYPE_ERROR:
+		case RCODE_ADDRESS_ERROR:
+		case RCODE_GENERATION:
+			return ret;
+
+		default:
+			delay = 5 * attempt * attempt;
+			usleep_range(delay, delay * 2);
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Wrapper around sbp_run_transaction that gets the card, destination,
+ * generation and speed out of the request's session.
+ */
+static int sbp_run_request_transaction(struct sbp_target_request *req,
+		int tcode, unsigned long long offset, void *payload,
+		size_t length)
+{
+	struct sbp_login_descriptor *login = req->login;
+	struct sbp_session *sess = login->sess;
+	struct fw_card *card;
+	int node_id, generation, speed, ret;
+
+	spin_lock_bh(&sess->lock);
+	card = fw_card_get(sess->card);
+	node_id = sess->node_id;
+	generation = sess->generation;
+	speed = sess->speed;
+	spin_unlock_bh(&sess->lock);
+
+	ret = sbp_run_transaction(card, tcode, node_id, generation, speed,
+			offset, payload, length);
+
+	fw_card_put(card);
+
+	return ret;
+}
+
+static int sbp_fetch_command(struct sbp_target_request *req)
+{
+	int ret, cmd_len, copy_len;
+
+	cmd_len = scsi_command_size(req->orb.command_block);
+
+	req->cmd_buf = kmalloc(cmd_len, GFP_KERNEL);
+	if (!req->cmd_buf)
+		return -ENOMEM;
+
+	memcpy(req->cmd_buf, req->orb.command_block,
+		min_t(int, cmd_len, sizeof(req->orb.command_block)));
+
+	if (cmd_len > sizeof(req->orb.command_block)) {
+		pr_debug("sbp_fetch_command: filling in long command\n");
+		copy_len = cmd_len - sizeof(req->orb.command_block);
+
+		ret = sbp_run_request_transaction(req,
+				TCODE_READ_BLOCK_REQUEST,
+				req->orb_pointer + sizeof(req->orb),
+				req->cmd_buf + sizeof(req->orb.command_block),
+				copy_len);
+		if (ret != RCODE_COMPLETE)
+			return -EIO;
+	}
+
+	return 0;
+}
+
+static int sbp_fetch_page_table(struct sbp_target_request *req)
+{
+	int pg_tbl_sz, ret;
+	struct sbp_page_table_entry *pg_tbl;
+
+	if (!CMDBLK_ORB_PG_TBL_PRESENT(be32_to_cpu(req->orb.misc)))
+		return 0;
+
+	pg_tbl_sz = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc)) *
+		sizeof(struct sbp_page_table_entry);
+
+	pg_tbl = kmalloc(pg_tbl_sz, GFP_KERNEL);
+	if (!pg_tbl)
+		return -ENOMEM;
+
+	ret = sbp_run_request_transaction(req, TCODE_READ_BLOCK_REQUEST,
+			sbp2_pointer_to_addr(&req->orb.data_descriptor),
+			pg_tbl, pg_tbl_sz);
+	if (ret != RCODE_COMPLETE) {
+		kfree(pg_tbl);
+		return -EIO;
+	}
+
+	req->pg_tbl = pg_tbl;
+	return 0;
+}
+
+static void sbp_calc_data_length_direction(struct sbp_target_request *req,
+	u32 *data_len, enum dma_data_direction *data_dir)
+{
+	int data_size, direction, idx;
+
+	data_size = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc));
+	direction = CMDBLK_ORB_DIRECTION(be32_to_cpu(req->orb.misc));
+
+	if (!data_size) {
+		*data_len = 0;
+		*data_dir = DMA_NONE;
+		return;
+	}
+
+	*data_dir = direction ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	if (req->pg_tbl) {
+		*data_len = 0;
+		for (idx = 0; idx < data_size; idx++) {
+			*data_len += be16_to_cpu(
+					req->pg_tbl[idx].segment_length);
+		}
+	} else {
+		*data_len = data_size;
+	}
+}
+
+static void sbp_handle_command(struct sbp_target_request *req)
+{
+	struct sbp_login_descriptor *login = req->login;
+	struct sbp_session *sess = login->sess;
+	int ret, unpacked_lun;
+	u32 data_length;
+	enum dma_data_direction data_dir;
+
+	ret = sbp_fetch_command(req);
+	if (ret) {
+		pr_debug("sbp_handle_command: fetch command failed: %d\n", ret);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		sbp_free_request(req);
+		return;
+	}
+
+	ret = sbp_fetch_page_table(req);
+	if (ret) {
+		pr_debug("sbp_handle_command: fetch page table failed: %d\n",
+			ret);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		sbp_free_request(req);
+		return;
+	}
+
+	unpacked_lun = req->login->lun->unpacked_lun;
+	sbp_calc_data_length_direction(req, &data_length, &data_dir);
+
+	pr_debug("sbp_handle_command ORB:0x%llx unpacked_lun:%d data_len:%d data_dir:%d\n",
+			req->orb_pointer, unpacked_lun, data_length, data_dir);
+
+	target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
+			req->sense_buf, unpacked_lun, data_length,
+			MSG_SIMPLE_TAG, data_dir, 0);
+}
+
+/*
+ * DMA_TO_DEVICE = read from initiator (SCSI WRITE)
+ * DMA_FROM_DEVICE = write to initiator (SCSI READ)
+ */
+static int sbp_rw_data(struct sbp_target_request *req)
+{
+	struct sbp_session *sess = req->login->sess;
+	int tcode, sg_miter_flags, max_payload, pg_size, speed, node_id,
+		generation, num_pte, length, tfr_length,
+		rcode = RCODE_COMPLETE;
+	struct sbp_page_table_entry *pte;
+	unsigned long long offset;
+	struct fw_card *card;
+	struct sg_mapping_iter iter;
+
+	if (req->se_cmd.data_direction == DMA_FROM_DEVICE) {
+		tcode = TCODE_WRITE_BLOCK_REQUEST;
+		sg_miter_flags = SG_MITER_FROM_SG;
+	} else {
+		tcode = TCODE_READ_BLOCK_REQUEST;
+		sg_miter_flags = SG_MITER_TO_SG;
+	}
+
+	max_payload = 4 << CMDBLK_ORB_MAX_PAYLOAD(be32_to_cpu(req->orb.misc));
+	speed = CMDBLK_ORB_SPEED(be32_to_cpu(req->orb.misc));
+
+	pg_size = CMDBLK_ORB_PG_SIZE(be32_to_cpu(req->orb.misc));
+	if (pg_size) {
+		pr_err("sbp_run_transaction: page size ignored\n");
+		pg_size = 0x100 << pg_size;
+	}
+
+	spin_lock_bh(&sess->lock);
+	card = fw_card_get(sess->card);
+	node_id = sess->node_id;
+	generation = sess->generation;
+	spin_unlock_bh(&sess->lock);
+
+	if (req->pg_tbl) {
+		pte = req->pg_tbl;
+		num_pte = CMDBLK_ORB_DATA_SIZE(be32_to_cpu(req->orb.misc));
+
+		offset = 0;
+		length = 0;
+	} else {
+		pte = NULL;
+		num_pte = 0;
+
+		offset = sbp2_pointer_to_addr(&req->orb.data_descriptor);
+		length = req->se_cmd.data_length;
+	}
+
+	sg_miter_start(&iter, req->se_cmd.t_data_sg, req->se_cmd.t_data_nents,
+		sg_miter_flags);
+
+	while (length || num_pte) {
+		if (!length) {
+			offset = (u64)be16_to_cpu(pte->segment_base_hi) << 32 |
+				be32_to_cpu(pte->segment_base_lo);
+			length = be16_to_cpu(pte->segment_length);
+
+			pte++;
+			num_pte--;
+		}
+
+		sg_miter_next(&iter);
+
+		tfr_length = min3(length, max_payload, (int)iter.length);
+
+		/* FIXME: take page_size into account */
+
+		rcode = sbp_run_transaction(card, tcode, node_id,
+				generation, speed,
+				offset, iter.addr, tfr_length);
+
+		if (rcode != RCODE_COMPLETE)
+			break;
+
+		length -= tfr_length;
+		offset += tfr_length;
+		iter.consumed = tfr_length;
+	}
+
+	sg_miter_stop(&iter);
+	fw_card_put(card);
+
+	if (rcode == RCODE_COMPLETE) {
+		WARN_ON(length != 0);
+		return 0;
+	} else {
+		return -EIO;
+	}
+}
+
+static int sbp_send_status(struct sbp_target_request *req)
+{
+	int ret, length;
+	struct sbp_login_descriptor *login = req->login;
+
+	length = (((be32_to_cpu(req->status.status) >> 24) & 0x07) + 1) * 4;
+
+	ret = sbp_run_request_transaction(req, TCODE_WRITE_BLOCK_REQUEST,
+			login->status_fifo_addr, &req->status, length);
+	if (ret != RCODE_COMPLETE) {
+		pr_debug("sbp_send_status: write failed: 0x%x\n", ret);
+		return -EIO;
+	}
+
+	pr_debug("sbp_send_status: status write complete for ORB: 0x%llx\n",
+			req->orb_pointer);
+
+	return 0;
+}
+
+static void sbp_sense_mangle(struct sbp_target_request *req)
+{
+	struct se_cmd *se_cmd = &req->se_cmd;
+	u8 *sense = req->sense_buf;
+	u8 *status = req->status.data;
+
+	WARN_ON(se_cmd->scsi_sense_length < 18);
+
+	switch (sense[0] & 0x7f) { 		/* sfmt */
+	case 0x70: /* current, fixed */
+		status[0] = 0 << 6;
+		break;
+	case 0x71: /* deferred, fixed */
+		status[0] = 1 << 6;
+		break;
+	case 0x72: /* current, descriptor */
+	case 0x73: /* deferred, descriptor */
+	default:
+		/*
+		 * TODO: SBP-3 specifies what we should do with descriptor
+		 * format sense data
+		 */
+		pr_err("sbp_send_sense: unknown sense format: 0x%x\n",
+			sense[0]);
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQUEST_ABORTED));
+		return;
+	}
+
+	status[0] |= se_cmd->scsi_status & 0x3f;/* status */
+	status[1] =
+		(sense[0] & 0x80) |		/* valid */
+		((sense[2] & 0xe0) >> 1) |	/* mark, eom, ili */
+		(sense[2] & 0x0f);		/* sense_key */
+	status[2] = se_cmd->scsi_asc;		/* sense_code */
+	status[3] = se_cmd->scsi_ascq;		/* sense_qualifier */
+
+	/* information */
+	status[4] = sense[3];
+	status[5] = sense[4];
+	status[6] = sense[5];
+	status[7] = sense[6];
+
+	/* CDB-dependent */
+	status[8] = sense[8];
+	status[9] = sense[9];
+	status[10] = sense[10];
+	status[11] = sense[11];
+
+	/* fru */
+	status[12] = sense[14];
+
+	/* sense_key-dependent */
+	status[13] = sense[15];
+	status[14] = sense[16];
+	status[15] = sense[17];
+
+	req->status.status |= cpu_to_be32(
+		STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+		STATUS_BLOCK_DEAD(0) |
+		STATUS_BLOCK_LEN(5) |
+		STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+}
+
+static int sbp_send_sense(struct sbp_target_request *req)
+{
+	struct se_cmd *se_cmd = &req->se_cmd;
+
+	if (se_cmd->scsi_sense_length) {
+		sbp_sense_mangle(req);
+	} else {
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_OK));
+	}
+
+	return sbp_send_status(req);
+}
+
+static void sbp_free_request(struct sbp_target_request *req)
+{
+	kfree(req->pg_tbl);
+	kfree(req->cmd_buf);
+	kfree(req);
+}
+
+static void sbp_mgt_agent_process(struct work_struct *work)
+{
+	struct sbp_management_agent *agent =
+		container_of(work, struct sbp_management_agent, work);
+	struct sbp_management_request *req = agent->request;
+	int ret;
+	int status_data_len = 0;
+
+	/* fetch the ORB from the initiator */
+	ret = sbp_run_transaction(req->card, TCODE_READ_BLOCK_REQUEST,
+		req->node_addr, req->generation, req->speed,
+		agent->orb_offset, &req->orb, sizeof(req->orb));
+	if (ret != RCODE_COMPLETE) {
+		pr_debug("mgt_orb fetch failed: %x\n", ret);
+		goto out;
+	}
+
+	pr_debug("mgt_orb ptr1:0x%llx ptr2:0x%llx misc:0x%x len:0x%x status_fifo:0x%llx\n",
+		sbp2_pointer_to_addr(&req->orb.ptr1),
+		sbp2_pointer_to_addr(&req->orb.ptr2),
+		be32_to_cpu(req->orb.misc), be32_to_cpu(req->orb.length),
+		sbp2_pointer_to_addr(&req->orb.status_fifo));
+
+	if (!ORB_NOTIFY(be32_to_cpu(req->orb.misc)) ||
+		ORB_REQUEST_FORMAT(be32_to_cpu(req->orb.misc)) != 0) {
+		pr_err("mgt_orb bad request\n");
+		goto out;
+	}
+
+	switch (MANAGEMENT_ORB_FUNCTION(be32_to_cpu(req->orb.misc))) {
+	case MANAGEMENT_ORB_FUNCTION_LOGIN:
+		sbp_management_request_login(agent, req, &status_data_len);
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_QUERY_LOGINS:
+		sbp_management_request_query_logins(agent, req,
+				&status_data_len);
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_RECONNECT:
+		sbp_management_request_reconnect(agent, req, &status_data_len);
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_SET_PASSWORD:
+		pr_notice("SET PASSWORD not implemented\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_LOGOUT:
+		sbp_management_request_logout(agent, req, &status_data_len);
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_ABORT_TASK:
+		pr_notice("ABORT TASK not implemented\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_ABORT_TASK_SET:
+		pr_notice("ABORT TASK SET not implemented\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_LOGICAL_UNIT_RESET:
+		pr_notice("LOGICAL UNIT RESET not implemented\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+
+	case MANAGEMENT_ORB_FUNCTION_TARGET_RESET:
+		pr_notice("TARGET RESET not implemented\n");
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+
+	default:
+		pr_notice("unknown management function 0x%x\n",
+			MANAGEMENT_ORB_FUNCTION(be32_to_cpu(req->orb.misc)));
+
+		req->status.status = cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_REQUEST_COMPLETE) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_REQ_TYPE_NOTSUPP));
+
+		break;
+	}
+
+	req->status.status |= cpu_to_be32(
+		STATUS_BLOCK_SRC(1) | /* Response to ORB, next_ORB absent */
+		STATUS_BLOCK_LEN(DIV_ROUND_UP(status_data_len, 4) + 1) |
+		STATUS_BLOCK_ORB_OFFSET_HIGH(agent->orb_offset >> 32));
+	req->status.orb_low = cpu_to_be32(agent->orb_offset);
+
+	/* write the status block back to the initiator */
+	ret = sbp_run_transaction(req->card, TCODE_WRITE_BLOCK_REQUEST,
+		req->node_addr, req->generation, req->speed,
+		sbp2_pointer_to_addr(&req->orb.status_fifo),
+		&req->status, 8 + status_data_len);
+	if (ret != RCODE_COMPLETE) {
+		pr_debug("mgt_orb status write failed: %x\n", ret);
+		goto out;
+	}
+
+out:
+	fw_card_put(req->card);
+	kfree(req);
+
+	spin_lock_bh(&agent->lock);
+	agent->state = MANAGEMENT_AGENT_STATE_IDLE;
+	spin_unlock_bh(&agent->lock);
+}
+
+static void sbp_mgt_agent_rw(struct fw_card *card,
+	struct fw_request *request, int tcode, int destination, int source,
+	int generation, unsigned long long offset, void *data, size_t length,
+	void *callback_data)
+{
+	struct sbp_management_agent *agent = callback_data;
+	struct sbp2_pointer *ptr = data;
+	int rcode = RCODE_ADDRESS_ERROR;
+
+	if (!agent->tport->enable)
+		goto out;
+
+	if ((offset != agent->handler.offset) || (length != 8))
+		goto out;
+
+	if (tcode == TCODE_WRITE_BLOCK_REQUEST) {
+		struct sbp_management_request *req;
+		int prev_state;
+
+		spin_lock_bh(&agent->lock);
+		prev_state = agent->state;
+		agent->state = MANAGEMENT_AGENT_STATE_BUSY;
+		spin_unlock_bh(&agent->lock);
+
+		if (prev_state == MANAGEMENT_AGENT_STATE_BUSY) {
+			pr_notice("ignoring management request while busy\n");
+			rcode = RCODE_CONFLICT_ERROR;
+			goto out;
+		}
+
+		req = kzalloc(sizeof(*req), GFP_ATOMIC);
+		if (!req) {
+			rcode = RCODE_CONFLICT_ERROR;
+			goto out;
+		}
+
+		req->card = fw_card_get(card);
+		req->generation = generation;
+		req->node_addr = source;
+		req->speed = fw_get_request_speed(request);
+
+		agent->orb_offset = sbp2_pointer_to_addr(ptr);
+		agent->request = req;
+
+		queue_work(system_unbound_wq, &agent->work);
+		rcode = RCODE_COMPLETE;
+	} else if (tcode == TCODE_READ_BLOCK_REQUEST) {
+		addr_to_sbp2_pointer(agent->orb_offset, ptr);
+		rcode = RCODE_COMPLETE;
+	} else {
+		rcode = RCODE_TYPE_ERROR;
+	}
+
+out:
+	fw_send_response(card, request, rcode);
+}
+
+static struct sbp_management_agent *sbp_management_agent_register(
+		struct sbp_tport *tport)
+{
+	int ret;
+	struct sbp_management_agent *agent;
+
+	agent = kmalloc(sizeof(*agent), GFP_KERNEL);
+	if (!agent)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&agent->lock);
+	agent->tport = tport;
+	agent->handler.length = 0x08;
+	agent->handler.address_callback = sbp_mgt_agent_rw;
+	agent->handler.callback_data = agent;
+	agent->state = MANAGEMENT_AGENT_STATE_IDLE;
+	INIT_WORK(&agent->work, sbp_mgt_agent_process);
+	agent->orb_offset = 0;
+	agent->request = NULL;
+
+	ret = fw_core_add_address_handler(&agent->handler,
+			&sbp_register_region);
+	if (ret < 0) {
+		kfree(agent);
+		return ERR_PTR(ret);
+	}
+
+	return agent;
+}
+
+static void sbp_management_agent_unregister(struct sbp_management_agent *agent)
+{
+	fw_core_remove_address_handler(&agent->handler);
+	cancel_work_sync(&agent->work);
+	kfree(agent);
+}
+
+static int sbp_check_true(struct se_portal_group *se_tpg)
+{
+	return 1;
+}
+
+static int sbp_check_false(struct se_portal_group *se_tpg)
+{
+	return 0;
+}
+
+static char *sbp_get_fabric_name(void)
+{
+	return "sbp";
+}
+
+static char *sbp_get_fabric_wwn(struct se_portal_group *se_tpg)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+
+	return &tport->tport_name[0];
+}
+
+static u16 sbp_get_tag(struct se_portal_group *se_tpg)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	return tpg->tport_tpgt;
+}
+
+static u32 sbp_get_default_depth(struct se_portal_group *se_tpg)
+{
+	return 1;
+}
+
+static struct se_node_acl *sbp_alloc_fabric_acl(struct se_portal_group *se_tpg)
+{
+	struct sbp_nacl *nacl;
+
+	nacl = kzalloc(sizeof(struct sbp_nacl), GFP_KERNEL);
+	if (!nacl) {
+		pr_err("Unable to alocate struct sbp_nacl\n");
+		return NULL;
+	}
+
+	return &nacl->se_node_acl;
+}
+
+static void sbp_release_fabric_acl(
+	struct se_portal_group *se_tpg,
+	struct se_node_acl *se_nacl)
+{
+	struct sbp_nacl *nacl =
+		container_of(se_nacl, struct sbp_nacl, se_node_acl);
+	kfree(nacl);
+}
+
+static u32 sbp_tpg_get_inst_index(struct se_portal_group *se_tpg)
+{
+	return 1;
+}
+
+static void sbp_release_cmd(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+
+	sbp_free_request(req);
+}
+
+static int sbp_shutdown_session(struct se_session *se_sess)
+{
+	return 0;
+}
+
+static void sbp_close_session(struct se_session *se_sess)
+{
+	return;
+}
+
+static u32 sbp_sess_get_index(struct se_session *se_sess)
+{
+	return 0;
+}
+
+static int sbp_write_pending(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+	int ret;
+
+	ret = sbp_rw_data(req);
+	if (ret) {
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(
+				STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(
+				SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		return ret;
+	}
+
+	transport_generic_process_write(se_cmd);
+
+	return 0;
+}
+
+static int sbp_write_pending_status(struct se_cmd *se_cmd)
+{
+	return 0;
+}
+
+static void sbp_set_default_node_attrs(struct se_node_acl *nacl)
+{
+	return;
+}
+
+static u32 sbp_get_task_tag(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+
+	/* only used for printk until we do TMRs */
+	return (u32)req->orb_pointer;
+}
+
+static int sbp_get_cmd_state(struct se_cmd *se_cmd)
+{
+	return 0;
+}
+
+static int sbp_queue_data_in(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+	int ret;
+
+	ret = sbp_rw_data(req);
+	if (ret) {
+		req->status.status |= cpu_to_be32(
+			STATUS_BLOCK_RESP(STATUS_RESP_TRANSPORT_FAILURE) |
+			STATUS_BLOCK_DEAD(0) |
+			STATUS_BLOCK_LEN(1) |
+			STATUS_BLOCK_SBP_STATUS(SBP_STATUS_UNSPECIFIED_ERROR));
+		sbp_send_status(req);
+		return ret;
+	}
+
+	return sbp_send_sense(req);
+}
+
+/*
+ * Called after command (no data transfer) or after the write (to device)
+ * operation is completed
+ */
+static int sbp_queue_status(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+
+	return sbp_send_sense(req);
+}
+
+static int sbp_queue_tm_rsp(struct se_cmd *se_cmd)
+{
+	return 0;
+}
+
+static u16 sbp_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
+{
+	return 0;
+}
+
+static u16 sbp_get_fabric_sense_len(void)
+{
+	return 0;
+}
+
+static int sbp_check_stop_free(struct se_cmd *se_cmd)
+{
+	struct sbp_target_request *req = container_of(se_cmd,
+			struct sbp_target_request, se_cmd);
+
+	transport_generic_free_cmd(&req->se_cmd, 0);
+	return 1;
+}
+
+/*
+ * Handlers for Serial Bus Protocol 2/3 (SBP-2 / SBP-3)
+ */
+static u8 sbp_get_fabric_proto_ident(struct se_portal_group *se_tpg)
+{
+	/*
+	 * Return a IEEE 1394 SCSI Protocol identifier for loopback operations
+	 * This is defined in section 7.5.1 Table 362 in spc4r17
+	 */
+	return SCSI_PROTOCOL_SBP;
+}
+
+static u32 sbp_get_pr_transport_id(
+	struct se_portal_group *se_tpg,
+	struct se_node_acl *se_nacl,
+	struct t10_pr_registration *pr_reg,
+	int *format_code,
+	unsigned char *buf)
+{
+	int ret;
+
+	/*
+	 * Set PROTOCOL IDENTIFIER to 3h for SBP
+	 */
+	buf[0] = SCSI_PROTOCOL_SBP;
+	/*
+	 * From spc4r17, 7.5.4.4 TransportID for initiator ports using SCSI
+	 * over IEEE 1394
+	 */
+	ret = hex2bin(&buf[8], se_nacl->initiatorname, 8);
+	if (ret < 0)
+		pr_debug("sbp transport_id: invalid hex string\n");
+
+	/*
+	 * The IEEE 1394 Transport ID is a hardcoded 24-byte length
+	 */
+	return 24;
+}
+
+static u32 sbp_get_pr_transport_id_len(
+	struct se_portal_group *se_tpg,
+	struct se_node_acl *se_nacl,
+	struct t10_pr_registration *pr_reg,
+	int *format_code)
+{
+	*format_code = 0;
+	/*
+	 * From spc4r17, 7.5.4.4 TransportID for initiator ports using SCSI
+	 * over IEEE 1394
+	 *
+	 * The SBP Transport ID is a hardcoded 24-byte length
+	 */
+	return 24;
+}
+
+/*
+ * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
+ * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
+ */
+static char *sbp_parse_pr_out_transport_id(
+	struct se_portal_group *se_tpg,
+	const char *buf,
+	u32 *out_tid_len,
+	char **port_nexus_ptr)
+{
+	/*
+	 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.4 TransportID
+	 * for initiator ports using SCSI over SBP Serial SCSI Protocol
+	 *
+	 * The TransportID for a IEEE 1394 Initiator Port is of fixed size of
+	 * 24 bytes, and IEEE 1394 does not contain a I_T nexus identifier,
+	 * so we return the **port_nexus_ptr set to NULL.
+	 */
+	*port_nexus_ptr = NULL;
+	*out_tid_len = 24;
+
+	return (char *)&buf[8];
+}
+
+static int sbp_count_se_tpg_luns(struct se_portal_group *tpg)
+{
+	int i, count = 0;
+
+	spin_lock(&tpg->tpg_lun_lock);
+	for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
+		struct se_lun *se_lun = tpg->tpg_lun_list[i];
+
+		if (se_lun->lun_status == TRANSPORT_LUN_STATUS_FREE)
+			continue;
+
+		count++;
+	}
+	spin_unlock(&tpg->tpg_lun_lock);
+
+	return count;
+}
+
+static int sbp_update_unit_directory(struct sbp_tport *tport)
+{
+	int num_luns, num_entries, idx = 0, mgt_agt_addr, ret, i;
+	u32 *data;
+
+	if (tport->unit_directory.data) {
+		fw_core_remove_descriptor(&tport->unit_directory);
+		kfree(tport->unit_directory.data);
+		tport->unit_directory.data = NULL;
+	}
+
+	if (!tport->enable || !tport->tpg)
+		return 0;
+
+	num_luns = sbp_count_se_tpg_luns(&tport->tpg->se_tpg);
+
+	/*
+	 * Number of entries in the final unit directory:
+	 *  - all of those in the template
+	 *  - management_agent
+	 *  - unit_characteristics
+	 *  - reconnect_timeout
+	 *  - unit unique ID
+	 *  - one for each LUN
+	 *
+	 *  MUST NOT include leaf or sub-directory entries
+	 */
+	num_entries = ARRAY_SIZE(sbp_unit_directory_template) + 4 + num_luns;
+
+	if (tport->directory_id != -1)
+		num_entries++;
+
+	/* allocate num_entries + 4 for the header and unique ID leaf */
+	data = kcalloc((num_entries + 4), sizeof(u32), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* directory_length */
+	data[idx++] = num_entries << 16;
+
+	/* directory_id */
+	if (tport->directory_id != -1)
+		data[idx++] = (CSR_DIRECTORY_ID << 24) | tport->directory_id;
+
+	/* unit directory template */
+	memcpy(&data[idx], sbp_unit_directory_template,
+			sizeof(sbp_unit_directory_template));
+	idx += ARRAY_SIZE(sbp_unit_directory_template);
+
+	/* management_agent */
+	mgt_agt_addr = (tport->mgt_agt->handler.offset - CSR_REGISTER_BASE) / 4;
+	data[idx++] = 0x54000000 | (mgt_agt_addr & 0x00ffffff);
+
+	/* unit_characteristics */
+	data[idx++] = 0x3a000000 |
+		(((tport->mgt_orb_timeout * 2) << 8) & 0xff00) |
+		SBP_ORB_FETCH_SIZE;
+
+	/* reconnect_timeout */
+	data[idx++] = 0x3d000000 | (tport->max_reconnect_timeout & 0xffff);
+
+	/* unit unique ID (leaf is just after LUNs) */
+	data[idx++] = 0x8d000000 | (num_luns + 1);
+
+	spin_lock(&tport->tpg->se_tpg.tpg_lun_lock);
+	for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
+		struct se_lun *se_lun = tport->tpg->se_tpg.tpg_lun_list[i];
+		struct se_device *dev;
+		int type;
+
+		if (se_lun->lun_status == TRANSPORT_LUN_STATUS_FREE)
+			continue;
+
+		spin_unlock(&tport->tpg->se_tpg.tpg_lun_lock);
+
+		dev = se_lun->lun_se_dev;
+		type = dev->transport->get_device_type(dev);
+
+		/* logical_unit_number */
+		data[idx++] = 0x14000000 |
+			((type << 16) & 0x1f0000) |
+			(se_lun->unpacked_lun & 0xffff);
+
+		spin_lock(&tport->tpg->se_tpg.tpg_lun_lock);
+	}
+	spin_unlock(&tport->tpg->se_tpg.tpg_lun_lock);
+
+	/* unit unique ID leaf */
+	data[idx++] = 2 << 16;
+	data[idx++] = tport->guid >> 32;
+	data[idx++] = tport->guid;
+
+	tport->unit_directory.length = idx;
+	tport->unit_directory.key = (CSR_DIRECTORY | CSR_UNIT) << 24;
+	tport->unit_directory.data = data;
+
+	ret = fw_core_add_descriptor(&tport->unit_directory);
+	if (ret < 0) {
+		kfree(tport->unit_directory.data);
+		tport->unit_directory.data = NULL;
+	}
+
+	return ret;
+}
+
+static ssize_t sbp_parse_wwn(const char *name, u64 *wwn, int strict)
+{
+	const char *cp;
+	char c, nibble;
+	int pos = 0, err;
+
+	*wwn = 0;
+	for (cp = name; cp < &name[SBP_NAMELEN - 1]; cp++) {
+		c = *cp;
+		if (c == '\n' && cp[1] == '\0')
+			continue;
+		if (c == '\0') {
+			err = 2;
+			if (pos != 16)
+				goto fail;
+			return cp - name;
+		}
+		err = 3;
+		if (isdigit(c))
+			nibble = c - '0';
+		else if (isxdigit(c) && (islower(c) || !strict))
+			nibble = tolower(c) - 'a' + 10;
+		else
+			goto fail;
+		*wwn = (*wwn << 4) | nibble;
+		pos++;
+	}
+	err = 4;
+fail:
+	printk(KERN_INFO "err %u len %zu pos %u\n",
+			err, cp - name, pos);
+	return -1;
+}
+
+static ssize_t sbp_format_wwn(char *buf, size_t len, u64 wwn)
+{
+	return snprintf(buf, len, "%016llx", wwn);
+}
+
+static struct se_node_acl *sbp_make_nodeacl(
+		struct se_portal_group *se_tpg,
+		struct config_group *group,
+		const char *name)
+{
+	struct se_node_acl *se_nacl, *se_nacl_new;
+	struct sbp_nacl *nacl;
+	u64 guid = 0;
+	u32 nexus_depth = 1;
+
+	if (sbp_parse_wwn(name, &guid, 1) < 0)
+		return ERR_PTR(-EINVAL);
+
+	se_nacl_new = sbp_alloc_fabric_acl(se_tpg);
+	if (!se_nacl_new)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
+	 * when converting a NodeACL from demo mode -> explict
+	 */
+	se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
+			name, nexus_depth);
+	if (IS_ERR(se_nacl)) {
+		sbp_release_fabric_acl(se_tpg, se_nacl_new);
+		return se_nacl;
+	}
+
+	nacl = container_of(se_nacl, struct sbp_nacl, se_node_acl);
+	nacl->guid = guid;
+	sbp_format_wwn(nacl->iport_name, SBP_NAMELEN, guid);
+
+	return se_nacl;
+}
+
+static void sbp_drop_nodeacl(struct se_node_acl *se_acl)
+{
+	struct sbp_nacl *nacl =
+		container_of(se_acl, struct sbp_nacl, se_node_acl);
+
+	core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
+	kfree(nacl);
+}
+
+static int sbp_post_link_lun(
+		struct se_portal_group *se_tpg,
+		struct se_lun *se_lun)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+
+	return sbp_update_unit_directory(tpg->tport);
+}
+
+static void sbp_pre_unlink_lun(
+		struct se_portal_group *se_tpg,
+		struct se_lun *se_lun)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	int ret;
+
+	if (sbp_count_se_tpg_luns(&tpg->se_tpg) == 0)
+		tport->enable = 0;
+
+	ret = sbp_update_unit_directory(tport);
+	if (ret < 0)
+		pr_err("unlink LUN: failed to update unit directory\n");
+}
+
+static struct se_portal_group *sbp_make_tpg(
+		struct se_wwn *wwn,
+		struct config_group *group,
+		const char *name)
+{
+	struct sbp_tport *tport =
+		container_of(wwn, struct sbp_tport, tport_wwn);
+
+	struct sbp_tpg *tpg;
+	unsigned long tpgt;
+	int ret;
+
+	if (strstr(name, "tpgt_") != name)
+		return ERR_PTR(-EINVAL);
+	if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
+		return ERR_PTR(-EINVAL);
+
+	if (tport->tpg) {
+		pr_err("Only one TPG per Unit is possible.\n");
+		return ERR_PTR(-EBUSY);
+	}
+
+	tpg = kzalloc(sizeof(*tpg), GFP_KERNEL);
+	if (!tpg) {
+		pr_err("Unable to allocate struct sbp_tpg\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	tpg->tport = tport;
+	tpg->tport_tpgt = tpgt;
+	tport->tpg = tpg;
+
+	/* default attribute values */
+	tport->enable = 0;
+	tport->directory_id = -1;
+	tport->mgt_orb_timeout = 15;
+	tport->max_reconnect_timeout = 5;
+	tport->max_logins_per_lun = 1;
+
+	tport->mgt_agt = sbp_management_agent_register(tport);
+	if (IS_ERR(tport->mgt_agt)) {
+		ret = PTR_ERR(tport->mgt_agt);
+		kfree(tpg);
+		return ERR_PTR(ret);
+	}
+
+	ret = core_tpg_register(&sbp_fabric_configfs->tf_ops, wwn,
+			&tpg->se_tpg, (void *)tpg,
+			TRANSPORT_TPG_TYPE_NORMAL);
+	if (ret < 0) {
+		sbp_management_agent_unregister(tport->mgt_agt);
+		kfree(tpg);
+		return ERR_PTR(ret);
+	}
+
+	return &tpg->se_tpg;
+}
+
+static void sbp_drop_tpg(struct se_portal_group *se_tpg)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+
+	core_tpg_deregister(se_tpg);
+	sbp_management_agent_unregister(tport->mgt_agt);
+	tport->tpg = NULL;
+	kfree(tpg);
+}
+
+static struct se_wwn *sbp_make_tport(
+		struct target_fabric_configfs *tf,
+		struct config_group *group,
+		const char *name)
+{
+	struct sbp_tport *tport;
+	u64 guid = 0;
+
+	if (sbp_parse_wwn(name, &guid, 1) < 0)
+		return ERR_PTR(-EINVAL);
+
+	tport = kzalloc(sizeof(*tport), GFP_KERNEL);
+	if (!tport) {
+		pr_err("Unable to allocate struct sbp_tport\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	tport->guid = guid;
+	sbp_format_wwn(tport->tport_name, SBP_NAMELEN, guid);
+
+	return &tport->tport_wwn;
+}
+
+static void sbp_drop_tport(struct se_wwn *wwn)
+{
+	struct sbp_tport *tport =
+		container_of(wwn, struct sbp_tport, tport_wwn);
+
+	kfree(tport);
+}
+
+static ssize_t sbp_wwn_show_attr_version(
+		struct target_fabric_configfs *tf,
+		char *page)
+{
+	return sprintf(page, "FireWire SBP fabric module %s\n", SBP_VERSION);
+}
+
+TF_WWN_ATTR_RO(sbp, version);
+
+static struct configfs_attribute *sbp_wwn_attrs[] = {
+	&sbp_wwn_version.attr,
+	NULL,
+};
+
+static ssize_t sbp_tpg_show_directory_id(
+		struct se_portal_group *se_tpg,
+		char *page)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+
+	if (tport->directory_id == -1)
+		return sprintf(page, "implicit\n");
+	else
+		return sprintf(page, "%06x\n", tport->directory_id);
+}
+
+static ssize_t sbp_tpg_store_directory_id(
+		struct se_portal_group *se_tpg,
+		const char *page,
+		size_t count)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	unsigned long val;
+
+	if (tport->enable) {
+		pr_err("Cannot change the directory_id on an active target.\n");
+		return -EBUSY;
+	}
+
+	if (strstr(page, "implicit") == page) {
+		tport->directory_id = -1;
+	} else {
+		if (kstrtoul(page, 16, &val) < 0)
+			return -EINVAL;
+		if (val > 0xffffff)
+			return -EINVAL;
+
+		tport->directory_id = val;
+	}
+
+	return count;
+}
+
+static ssize_t sbp_tpg_show_enable(
+		struct se_portal_group *se_tpg,
+		char *page)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	return sprintf(page, "%d\n", tport->enable);
+}
+
+static ssize_t sbp_tpg_store_enable(
+		struct se_portal_group *se_tpg,
+		const char *page,
+		size_t count)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(page, 0, &val) < 0)
+		return -EINVAL;
+	if ((val != 0) && (val != 1))
+		return -EINVAL;
+
+	if (tport->enable == val)
+		return count;
+
+	if (val) {
+		if (sbp_count_se_tpg_luns(&tpg->se_tpg) == 0) {
+			pr_err("Cannot enable a target with no LUNs!\n");
+			return -EINVAL;
+		}
+	} else {
+		/* XXX: force-shutdown sessions instead? */
+		spin_lock_bh(&se_tpg->session_lock);
+		if (!list_empty(&se_tpg->tpg_sess_list)) {
+			spin_unlock_bh(&se_tpg->session_lock);
+			return -EBUSY;
+		}
+		spin_unlock_bh(&se_tpg->session_lock);
+	}
+
+	tport->enable = val;
+
+	ret = sbp_update_unit_directory(tport);
+	if (ret < 0) {
+		pr_err("Could not update Config ROM\n");
+		return ret;
+	}
+
+	return count;
+}
+
+TF_TPG_BASE_ATTR(sbp, directory_id, S_IRUGO | S_IWUSR);
+TF_TPG_BASE_ATTR(sbp, enable, S_IRUGO | S_IWUSR);
+
+static struct configfs_attribute *sbp_tpg_base_attrs[] = {
+	&sbp_tpg_directory_id.attr,
+	&sbp_tpg_enable.attr,
+	NULL,
+};
+
+static ssize_t sbp_tpg_attrib_show_mgt_orb_timeout(
+		struct se_portal_group *se_tpg,
+		char *page)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	return sprintf(page, "%d\n", tport->mgt_orb_timeout);
+}
+
+static ssize_t sbp_tpg_attrib_store_mgt_orb_timeout(
+		struct se_portal_group *se_tpg,
+		const char *page,
+		size_t count)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(page, 0, &val) < 0)
+		return -EINVAL;
+	if ((val < 1) || (val > 127))
+		return -EINVAL;
+
+	if (tport->mgt_orb_timeout == val)
+		return count;
+
+	tport->mgt_orb_timeout = val;
+
+	ret = sbp_update_unit_directory(tport);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t sbp_tpg_attrib_show_max_reconnect_timeout(
+		struct se_portal_group *se_tpg,
+		char *page)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	return sprintf(page, "%d\n", tport->max_reconnect_timeout);
+}
+
+static ssize_t sbp_tpg_attrib_store_max_reconnect_timeout(
+		struct se_portal_group *se_tpg,
+		const char *page,
+		size_t count)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(page, 0, &val) < 0)
+		return -EINVAL;
+	if ((val < 1) || (val > 32767))
+		return -EINVAL;
+
+	if (tport->max_reconnect_timeout == val)
+		return count;
+
+	tport->max_reconnect_timeout = val;
+
+	ret = sbp_update_unit_directory(tport);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static ssize_t sbp_tpg_attrib_show_max_logins_per_lun(
+		struct se_portal_group *se_tpg,
+		char *page)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	return sprintf(page, "%d\n", tport->max_logins_per_lun);
+}
+
+static ssize_t sbp_tpg_attrib_store_max_logins_per_lun(
+		struct se_portal_group *se_tpg,
+		const char *page,
+		size_t count)
+{
+	struct sbp_tpg *tpg = container_of(se_tpg, struct sbp_tpg, se_tpg);
+	struct sbp_tport *tport = tpg->tport;
+	unsigned long val;
+
+	if (kstrtoul(page, 0, &val) < 0)
+		return -EINVAL;
+	if ((val < 1) || (val > 127))
+		return -EINVAL;
+
+	/* XXX: also check against current count? */
+
+	tport->max_logins_per_lun = val;
+
+	return count;
+}
+
+TF_TPG_ATTRIB_ATTR(sbp, mgt_orb_timeout, S_IRUGO | S_IWUSR);
+TF_TPG_ATTRIB_ATTR(sbp, max_reconnect_timeout, S_IRUGO | S_IWUSR);
+TF_TPG_ATTRIB_ATTR(sbp, max_logins_per_lun, S_IRUGO | S_IWUSR);
+
+static struct configfs_attribute *sbp_tpg_attrib_attrs[] = {
+	&sbp_tpg_attrib_mgt_orb_timeout.attr,
+	&sbp_tpg_attrib_max_reconnect_timeout.attr,
+	&sbp_tpg_attrib_max_logins_per_lun.attr,
+	NULL,
+};
+
+static struct target_core_fabric_ops sbp_ops = {
+	.get_fabric_name		= sbp_get_fabric_name,
+	.get_fabric_proto_ident		= sbp_get_fabric_proto_ident,
+	.tpg_get_wwn			= sbp_get_fabric_wwn,
+	.tpg_get_tag			= sbp_get_tag,
+	.tpg_get_default_depth		= sbp_get_default_depth,
+	.tpg_get_pr_transport_id	= sbp_get_pr_transport_id,
+	.tpg_get_pr_transport_id_len	= sbp_get_pr_transport_id_len,
+	.tpg_parse_pr_out_transport_id	= sbp_parse_pr_out_transport_id,
+	.tpg_check_demo_mode		= sbp_check_true,
+	.tpg_check_demo_mode_cache	= sbp_check_true,
+	.tpg_check_demo_mode_write_protect = sbp_check_false,
+	.tpg_check_prod_mode_write_protect = sbp_check_false,
+	.tpg_alloc_fabric_acl		= sbp_alloc_fabric_acl,
+	.tpg_release_fabric_acl		= sbp_release_fabric_acl,
+	.tpg_get_inst_index		= sbp_tpg_get_inst_index,
+	.release_cmd			= sbp_release_cmd,
+	.shutdown_session		= sbp_shutdown_session,
+	.close_session			= sbp_close_session,
+	.sess_get_index			= sbp_sess_get_index,
+	.write_pending			= sbp_write_pending,
+	.write_pending_status		= sbp_write_pending_status,
+	.set_default_node_attributes	= sbp_set_default_node_attrs,
+	.get_task_tag			= sbp_get_task_tag,
+	.get_cmd_state			= sbp_get_cmd_state,
+	.queue_data_in			= sbp_queue_data_in,
+	.queue_status			= sbp_queue_status,
+	.queue_tm_rsp			= sbp_queue_tm_rsp,
+	.get_fabric_sense_len		= sbp_get_fabric_sense_len,
+	.set_fabric_sense_len		= sbp_set_fabric_sense_len,
+	.check_stop_free		= sbp_check_stop_free,
+
+	.fabric_make_wwn		= sbp_make_tport,
+	.fabric_drop_wwn		= sbp_drop_tport,
+	.fabric_make_tpg		= sbp_make_tpg,
+	.fabric_drop_tpg		= sbp_drop_tpg,
+	.fabric_post_link		= sbp_post_link_lun,
+	.fabric_pre_unlink		= sbp_pre_unlink_lun,
+	.fabric_make_np			= NULL,
+	.fabric_drop_np			= NULL,
+	.fabric_make_nodeacl		= sbp_make_nodeacl,
+	.fabric_drop_nodeacl		= sbp_drop_nodeacl,
+};
+
+static int sbp_register_configfs(void)
+{
+	struct target_fabric_configfs *fabric;
+	int ret;
+
+	fabric = target_fabric_configfs_init(THIS_MODULE, "sbp");
+	if (!fabric) {
+		pr_err("target_fabric_configfs_init() failed\n");
+		return -ENOMEM;
+	}
+
+	fabric->tf_ops = sbp_ops;
+
+	/*
+	 * Setup default attribute lists for various fabric->tf_cit_tmpl
+	 */
+	TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = sbp_wwn_attrs;
+	TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = sbp_tpg_base_attrs;
+	TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = sbp_tpg_attrib_attrs;
+	TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
+	TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
+	TF_CIT_TMPL(fabric)->tfc_tpg_nacl_base_cit.ct_attrs = NULL;
+	TF_CIT_TMPL(fabric)->tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
+	TF_CIT_TMPL(fabric)->tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
+	TF_CIT_TMPL(fabric)->tfc_tpg_nacl_param_cit.ct_attrs = NULL;
+
+	ret = target_fabric_configfs_register(fabric);
+	if (ret < 0) {
+		pr_err("target_fabric_configfs_register() failed for SBP\n");
+		return ret;
+	}
+
+	sbp_fabric_configfs = fabric;
+
+	return 0;
+};
+
+static void sbp_deregister_configfs(void)
+{
+	if (!sbp_fabric_configfs)
+		return;
+
+	target_fabric_configfs_deregister(sbp_fabric_configfs);
+	sbp_fabric_configfs = NULL;
+};
+
+static int __init sbp_init(void)
+{
+	int ret;
+
+	ret = sbp_register_configfs();
+	if (ret < 0)
+		return ret;
+
+	return 0;
+};
+
+static void sbp_exit(void)
+{
+	sbp_deregister_configfs();
+};
+
+MODULE_DESCRIPTION("FireWire SBP fabric driver");
+MODULE_LICENSE("GPL");
+module_init(sbp_init);
+module_exit(sbp_exit);