Merge branch 'sbp-target-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull sbp-2 (firewire) target mode support from Nicholas Bellinger:
 "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.

  Also included are the two drivers/firewire/ patches required by
  sbp-target to access fw_request fabric speed needed for mgt_agent
  TCODE_WRITE_BLOCK_REQUEST ops, and exporting fw_card kref logic used
  when creating/destroying active session references to individual
  endpoints.

  A credit goes to Chris in being able to get this code up and running
  so quickly w/o any target core changes, and special thanks goes out to
  Stefan Richter + Clemens Ladisch + Andy Grover for their help in
  getting this driver ready for mainline.  Also, one of Chris's goals
  was to be able to connect sbp-target to a PowerPC based MacOS-X based
  client, that he accomplished along the way in this obligatory
  screenshot:

    http://linux-iscsi.org/wiki/File:Linux-fireware-target-bootc-macosx.png

  Great work Chris + linux-1394 team !!"

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

* 'sbp-target-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  sbp-target: Initial merge of firewire/ieee-1394 target mode support
  firewire: Move fw_card kref functions into linux/firewire.h
  firewire: Add function to get speed from opaque struct fw_request

11 files changed, 2920 insertions, 15 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 61dd168d349a..96ec7b2e2522 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2776,6 +2776,15 @@ T:	git git://git.alsa-project.org/alsa-kernel.git
 S:	Maintained
 F:	sound/firewire/
 
+FIREWIRE SBP-2 TARGET
+M:	Chris Boot <bootc@bootc.net>
+L:	linux-scsi@vger.kernel.org
+L:	target-devel@vger.kernel.org
+L:	linux1394-devel@lists.sourceforge.net
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/nab/lio-core-2.6.git master
+S:	Maintained
+F:	drivers/target/sbp/
+
 FIREWIRE SUBSYSTEM
 M:	Stefan Richter <stefanr@s5r6.in-berlin.de>
 L:	linux1394-devel@lists.sourceforge.net
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index cc595eba7ba9..f5552b362efc 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -676,6 +676,7 @@ void fw_card_release(struct kref *kref)
 
 	complete(&card->done);
 }
+EXPORT_SYMBOL_GPL(fw_card_release);
 
 void fw_core_remove_card(struct fw_card *card)
 {
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index dea2dcc9310d..db8a965cf712 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -820,6 +820,15 @@ void fw_send_response(struct fw_card *card,
 }
 EXPORT_SYMBOL(fw_send_response);
 
+/**
+ * fw_get_request_speed() - returns speed at which the @request was received
+ */
+int fw_get_request_speed(struct fw_request *request)
+{
+	return request->response.speed;
+}
+EXPORT_SYMBOL(fw_get_request_speed);
+
 static void handle_exclusive_region_request(struct fw_card *card,
 					    struct fw_packet *p,
 					    struct fw_request *request,
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 9047f5547d98..b5a2f6197053 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -120,21 +120,6 @@ int fw_compute_block_crc(__be32 *block);
 void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset);
 void fw_schedule_bm_work(struct fw_card *card, unsigned long delay);
 
-static inline struct fw_card *fw_card_get(struct fw_card *card)
-{
-	kref_get(&card->kref);
-
-	return card;
-}
-
-void fw_card_release(struct kref *kref);
-
-static inline void fw_card_put(struct fw_card *card)
-{
-	kref_put(&card->kref, fw_card_release);
-}
-
-
 /* -cdev */
 
 extern const struct file_operations fw_device_ops;
diff --git a/drivers/target/Kconfig b/drivers/target/Kconfig
index b28794b72125..18303686eb58 100644
--- a/drivers/target/Kconfig
+++ b/drivers/target/Kconfig
@@ -32,5 +32,6 @@ config TCM_PSCSI
 source "drivers/target/loopback/Kconfig"
 source "drivers/target/tcm_fc/Kconfig"
 source "drivers/target/iscsi/Kconfig"
+source "drivers/target/sbp/Kconfig"
 
 endif
diff --git a/drivers/target/Makefile b/drivers/target/Makefile
index 62e54053bcd8..61648d84fbb6 100644
--- a/drivers/target/Makefile
+++ b/drivers/target/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_TCM_PSCSI)		+= target_core_pscsi.o
 obj-$(CONFIG_LOOPBACK_TARGET)	+= loopback/
 obj-$(CONFIG_TCM_FC)		+= tcm_fc/
 obj-$(CONFIG_ISCSI_TARGET)	+= iscsi/
+obj-$(CONFIG_SBP_TARGET)	+= sbp/
diff --git a/drivers/target/sbp/Kconfig b/drivers/target/sbp/Kconfig
new file mode 100644
index 000000000000..132da544eafc
--- /dev/null
+++ b/drivers/target/sbp/Kconfig
@@ -0,0 +1,11 @@
+config SBP_TARGET
+	tristate "FireWire SBP-2 fabric module"
+	depends on FIREWIRE && EXPERIMENTAL
+	help
+	  Say Y or M here to enable SCSI target functionality over FireWire.
+	  This enables you to expose SCSI devices to other nodes on the FireWire
+	  bus, for example hard disks. Similar to FireWire Target Disk mode on
+	  many Apple computers.
+
+	  To compile this driver as a module, say M here: The module will be
+	  called sbp-target.
diff --git a/drivers/target/sbp/Makefile b/drivers/target/sbp/Makefile
new file mode 100644
index 000000000000..27747ad054c4
--- /dev/null
+++ b/drivers/target/sbp/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SBP_TARGET) += sbp_target.o
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
new file mode 100644
index 000000000000..37c609898f84
--- /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_tar