Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1627 insertions, 0 deletions

diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
new file mode 100644
index 0000000000..e779d86602
--- /dev/null
+++ b/drivers/firewire/sbp2.c
@@ -0,0 +1,1627 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SBP2 driver (SCSI over IEEE1394)
+ *
+ * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
+ */
+
+/*
+ * The basic structure of this driver is based on the old storage driver,
+ * drivers/ieee1394/sbp2.c, originally written by
+ *     James Goodwin <jamesg@filanet.com>
+ * with later contributions and ongoing maintenance from
+ *     Ben Collins <bcollins@debian.org>,
+ *     Stefan Richter <stefanr@s5r6.in-berlin.de>
+ * and many others.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/bug.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/stringify.h>
+#include <linux/workqueue.h>
+
+#include <asm/byteorder.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+/*
+ * So far only bridges from Oxford Semiconductor are known to support
+ * concurrent logins. Depending on firmware, four or two concurrent logins
+ * are possible on OXFW911 and newer Oxsemi bridges.
+ *
+ * Concurrent logins are useful together with cluster filesystems.
+ */
+static bool sbp2_param_exclusive_login = 1;
+module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
+MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
+		 "(default = Y, use N for concurrent initiators)");
+
+/*
+ * Flags for firmware oddities
+ *
+ * - 128kB max transfer
+ *   Limit transfer size. Necessary for some old bridges.
+ *
+ * - 36 byte inquiry
+ *   When scsi_mod probes the device, let the inquiry command look like that
+ *   from MS Windows.
+ *
+ * - skip mode page 8
+ *   Suppress sending of mode_sense for mode page 8 if the device pretends to
+ *   support the SCSI Primary Block commands instead of Reduced Block Commands.
+ *
+ * - fix capacity
+ *   Tell sd_mod to correct the last sector number reported by read_capacity.
+ *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
+ *   Don't use this with devices which don't have this bug.
+ *
+ * - delay inquiry
+ *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
+ *
+ * - power condition
+ *   Set the power condition field in the START STOP UNIT commands sent by
+ *   sd_mod on suspend, resume, and shutdown (if manage_system_start_stop or
+ *   manage_runtime_start_stop is on).
+ *   Some disks need this to spin down or to resume properly.
+ *
+ * - override internal blacklist
+ *   Instead of adding to the built-in blacklist, use only the workarounds
+ *   specified in the module load parameter.
+ *   Useful if a blacklist entry interfered with a non-broken device.
+ */
+#define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
+#define SBP2_WORKAROUND_INQUIRY_36	0x2
+#define SBP2_WORKAROUND_MODE_SENSE_8	0x4
+#define SBP2_WORKAROUND_FIX_CAPACITY	0x8
+#define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
+#define SBP2_INQUIRY_DELAY		12
+#define SBP2_WORKAROUND_POWER_CONDITION	0x20
+#define SBP2_WORKAROUND_OVERRIDE	0x100
+
+static int sbp2_param_workarounds;
+module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
+MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
+	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
+	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
+	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
+	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
+	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
+	", set power condition in start stop unit = "
+				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
+	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
+	", or a combination)");
+
+/*
+ * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
+ * and one struct scsi_device per sbp2_logical_unit.
+ */
+struct sbp2_logical_unit {
+	struct sbp2_target *tgt;
+	struct list_head link;
+	struct fw_address_handler address_handler;
+	struct list_head orb_list;
+
+	u64 command_block_agent_address;
+	u16 lun;
+	int login_id;
+
+	/*
+	 * The generation is updated once we've logged in or reconnected
+	 * to the logical unit.  Thus, I/O to the device will automatically
+	 * fail and get retried if it happens in a window where the device
+	 * is not ready, e.g. after a bus reset but before we reconnect.
+	 */
+	int generation;
+	int retries;
+	work_func_t workfn;
+	struct delayed_work work;
+	bool has_sdev;
+	bool blocked;
+};
+
+static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
+{
+	queue_delayed_work(fw_workqueue, &lu->work, delay);
+}
+
+/*
+ * We create one struct sbp2_target per IEEE 1212 Unit Directory
+ * and one struct Scsi_Host per sbp2_target.
+ */
+struct sbp2_target {
+	struct fw_unit *unit;
+	struct list_head lu_list;
+
+	u64 management_agent_address;
+	u64 guid;
+	int directory_id;
+	int node_id;
+	int address_high;
+	unsigned int workarounds;
+	unsigned int mgt_orb_timeout;
+	unsigned int max_payload;
+
+	spinlock_t lock;
+	int dont_block;	/* counter for each logical unit */
+	int blocked;	/* ditto */
+};
+
+static struct fw_device *target_parent_device(struct sbp2_target *tgt)
+{
+	return fw_parent_device(tgt->unit);
+}
+
+static const struct device *tgt_dev(const struct sbp2_target *tgt)
+{
+	return &tgt->unit->device;
+}
+
+static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
+{
+	return &lu->tgt->unit->device;
+}
+
+/* Impossible login_id, to detect logout attempt before successful login */
+#define INVALID_LOGIN_ID 0x10000
+
+#define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
+#define SBP2_ORB_NULL			0x80000000
+#define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
+#define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
+
+/*
+ * There is no transport protocol limit to the CDB length,  but we implement
+ * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
+ */
+#define SBP2_MAX_CDB_SIZE		16
+
+/*
+ * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
+ * for compatibility with earlier versions of this driver.
+ */
+#define SBP2_MAX_SEG_SIZE		0xfffc
+
+/* Unit directory keys */
+#define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
+#define SBP2_CSR_FIRMWARE_REVISION	0x3c
+#define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
+#define SBP2_CSR_UNIT_UNIQUE_ID		0x8d
+#define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
+
+/* Management orb opcodes */
+#define SBP2_LOGIN_REQUEST		0x0
+#define SBP2_QUERY_LOGINS_REQUEST	0x1
+#define SBP2_RECONNECT_REQUEST		0x3
+#define SBP2_SET_PASSWORD_REQUEST	0x4
+#define SBP2_LOGOUT_REQUEST		0x7
+#define SBP2_ABORT_TASK_REQUEST		0xb
+#define SBP2_ABORT_TASK_SET		0xc
+#define SBP2_LOGICAL_UNIT_RESET		0xe
+#define SBP2_TARGET_RESET_REQUEST	0xf
+
+/* Offsets for command block agent registers */
+#define SBP2_AGENT_STATE		0x00
+#define SBP2_AGENT_RESET		0x04
+#define SBP2_ORB_POINTER		0x08
+#define SBP2_DOORBELL			0x10
+#define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
+
+/* Status write response codes */
+#define SBP2_STATUS_REQUEST_COMPLETE	0x0
+#define SBP2_STATUS_TRANSPORT_FAILURE	0x1
+#define SBP2_STATUS_ILLEGAL_REQUEST	0x2
+#define SBP2_STATUS_VENDOR_DEPENDENT	0x3
+
+#define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
+#define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
+#define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
+#define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
+#define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
+#define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
+#define STATUS_GET_ORB_LOW(v)		((v).orb_low)
+#define STATUS_GET_DATA(v)		((v).data)
+
+struct sbp2_status {
+	u32 status;
+	u32 orb_low;
+	u8 data[24];
+};
+
+struct sbp2_pointer {
+	__be32 high;
+	__be32 low;
+};
+
+struct sbp2_orb {
+	struct fw_transaction t;
+	struct kref kref;
+	dma_addr_t request_bus;
+	int rcode;
+	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
+	struct sbp2_logical_unit *lu;
+	struct list_head link;
+};
+
+#define MANAGEMENT_ORB_LUN(v)			((v))
+#define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
+#define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
+#define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
+#define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
+#define MANAGEMENT_ORB_NOTIFY			((1) << 31)
+
+#define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
+#define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
+
+struct sbp2_management_orb {
+	struct sbp2_orb base;
+	struct {
+		struct sbp2_pointer password;
+		struct sbp2_pointer response;
+		__be32 misc;
+		__be32 length;
+		struct sbp2_pointer status_fifo;
+	} request;
+	__be32 response[4];
+	dma_addr_t response_bus;
+	struct completion done;
+	struct sbp2_status status;
+};
+
+struct sbp2_login_response {
+	__be32 misc;
+	struct sbp2_pointer command_block_agent;
+	__be32 reconnect_hold;
+};
+#define COMMAND_ORB_DATA_SIZE(v)	((v))
+#define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
+#define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
+#define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
+#define COMMAND_ORB_SPEED(v)		((v) << 24)
+#define COMMAND_ORB_DIRECTION		((1) << 27)
+#define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
+#define COMMAND_ORB_NOTIFY		((1) << 31)
+
+struct sbp2_command_orb {
+	struct sbp2_orb base;
+	struct {
+		struct sbp2_pointer next;
+		struct sbp2_pointer data_descriptor;
+		__be32 misc;
+		u8 command_block[SBP2_MAX_CDB_SIZE];
+	} request;
+	struct scsi_cmnd *cmd;
+
+	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
+	dma_addr_t page_table_bus;
+};
+
+#define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
+#define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
+
+/*
+ * List of devices with known bugs.
+ *
+ * The firmware_revision field, masked with 0xffff00, is the best
+ * indicator for the type of bridge chip of a device.  It yields a few
+ * false positives but this did not break correctly behaving devices
+ * so far.
+ */
+static const struct {
+	u32 firmware_revision;
+	u32 model;
+	unsigned int workarounds;
+} sbp2_workarounds_table[] = {
+	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
+		.firmware_revision	= 0x002800,
+		.model			= 0x001010,
+		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
+					  SBP2_WORKAROUND_MODE_SENSE_8 |
+					  SBP2_WORKAROUND_POWER_CONDITION,
+	},
+	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
+		.firmware_revision	= 0x002800,
+		.model			= 0x000000,
+		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
+	},
+	/* Initio bridges, actually only needed for some older ones */ {
+		.firmware_revision	= 0x000200,
+		.model			= SBP2_ROM_VALUE_WILDCARD,
+		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
+	},
+	/* PL-3507 bridge with Prolific firmware */ {
+		.firmware_revision	= 0x012800,
+		.model			= SBP2_ROM_VALUE_WILDCARD,
+		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
+	},
+	/* Symbios bridge */ {
+		.firmware_revision	= 0xa0b800,
+		.model			= SBP2_ROM_VALUE_WILDCARD,
+		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
+	},
+	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
+		.firmware_revision	= 0x002600,
+		.model			= SBP2_ROM_VALUE_WILDCARD,
+		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
+	},
+	/*
+	 * iPod 2nd generation: needs 128k max transfer size workaround
+	 * iPod 3rd generation: needs fix capacity workaround
+	 */
+	{
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x000000,
+		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
+					  SBP2_WORKAROUND_FIX_CAPACITY,
+	},
+	/* iPod 4th generation */ {
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x000021,
+		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
+	},
+	/* iPod mini */ {
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x000022,
+		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
+	},
+	/* iPod mini */ {
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x000023,
+		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
+	},
+	/* iPod Photo */ {
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x00007e,
+		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
+	}
+};
+
+static void free_orb(struct kref *kref)
+{
+	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
+
+	kfree(orb);
+}
+
+static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
+			      int tcode, int destination, int source,
+			      int generation, unsigned long long offset,
+			      void *payload, size_t length, void *callback_data)
+{
+	struct sbp2_logical_unit *lu = callback_data;
+	struct sbp2_orb *orb = NULL, *iter;
+	struct sbp2_status status;
+	unsigned long flags;
+
+	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
+	    length < 8 || length > sizeof(status)) {
+		fw_send_response(card, request, RCODE_TYPE_ERROR);
+		return;
+	}
+
+	status.status  = be32_to_cpup(payload);
+	status.orb_low = be32_to_cpup(payload + 4);
+	memset(status.data, 0, sizeof(status.data));
+	if (length > 8)
+		memcpy(status.data, payload + 8, length - 8);
+
+	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
+		dev_notice(lu_dev(lu),
+			   "non-ORB related status write, not handled\n");
+		fw_send_response(card, request, RCODE_COMPLETE);
+		return;
+	}
+
+	/* Lookup the orb corresponding to this status write. */
+	spin_lock_irqsave(&lu->tgt->lock, flags);
+	list_for_each_entry(iter, &lu->orb_list, link) {
+		if (STATUS_GET_ORB_HIGH(status) == 0 &&
+		    STATUS_GET_ORB_LOW(status) == iter->request_bus) {
+			iter->rcode = RCODE_COMPLETE;
+			list_del(&iter->link);
+			orb = iter;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&lu->tgt->lock, flags);
+
+	if (orb) {
+		orb->callback(orb, &status);
+		kref_put(&orb->kref, free_orb); /* orb callback reference */
+	} else {
+		dev_err(lu_dev(lu), "status write for unknown ORB\n");
+	}
+
+	fw_send_response(card, request, RCODE_COMPLETE);
+}
+
+static void complete_transaction(struct fw_card *card, int rcode,
+				 void *payload, size_t length, void *data)
+{
+	struct sbp2_orb *orb = data;
+	unsigned long flags;
+
+	/*
+	 * This is a little tricky.  We can get the status write for
+	 * the orb before we get this callback.  The status write
+	 * handler above will assume the orb pointer transaction was
+	 * successful and set the rcode to RCODE_COMPLETE for the orb.
+	 * So this callback only sets the rcode if it hasn't already
+	 * been set and only does the cleanup if the transaction
+	 * failed and we didn't already get a status write.
+	 */
+	spin_lock_irqsave(&orb->lu->tgt->lock, flags);
+
+	if (orb->rcode == -1)
+		orb->rcode = rcode;
+	if (orb->rcode != RCODE_COMPLETE) {
+		list_del(&orb->link);
+		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
+
+		orb->callback(orb, NULL);
+		kref_put(&orb->kref, free_orb); /* orb callback reference */
+	} else {
+		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
+	}
+
+	kref_put(&orb->kref, free_orb); /* transaction callback reference */
+}
+
+static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
+			  int node_id, int generation, u64 offset)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	struct sbp2_pointer orb_pointer;
+	unsigned long flags;
+
+	orb_pointer.high = 0;
+	orb_pointer.low = cpu_to_be32(orb->request_bus);
+
+	orb->lu = lu;
+	spin_lock_irqsave(&lu->tgt->lock, flags);
+	list_add_tail(&orb->link, &lu->orb_list);
+	spin_unlock_irqrestore(&lu->tgt->lock, flags);
+
+	kref_get(&orb->kref); /* transaction callback reference */
+	kref_get(&orb->kref); /* orb callback reference */
+
+	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
+			node_id, generation, device->max_speed, offset,
+			&orb_pointer, 8, complete_transaction, orb);
+}
+
+static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	struct sbp2_orb *orb, *next;
+	struct list_head list;
+	int retval = -ENOENT;
+
+	INIT_LIST_HEAD(&list);
+	spin_lock_irq(&lu->tgt->lock);
+	list_splice_init(&lu->orb_list, &list);
+	spin_unlock_irq(&lu->tgt->lock);
+
+	list_for_each_entry_safe(orb, next, &list, link) {
+		retval = 0;
+		if (fw_cancel_transaction(device->card, &orb->t) == 0)
+			continue;
+
+		orb->rcode = RCODE_CANCELLED;
+		orb->callback(orb, NULL);
+		kref_put(&orb->kref, free_orb); /* orb callback reference */
+	}
+
+	return retval;
+}
+
+static void complete_management_orb(struct sbp2_orb *base_orb,
+				    struct sbp2_status *status)
+{
+	struct sbp2_management_orb *orb =
+		container_of(base_orb, struct sbp2_management_orb, base);
+
+	if (status)
+		memcpy(&orb->status, status, sizeof(*status));
+	complete(&orb->done);
+}
+
+static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
+				    int generation, int function,
+				    int lun_or_login_id, void *response)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	struct sbp2_management_orb *orb;
+	unsigned int timeout;
+	int retval = -ENOMEM;
+
+	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
+		return 0;
+
+	orb = kzalloc(sizeof(*orb), GFP_NOIO);
+	if (orb == NULL)
+		return -ENOMEM;
+
+	kref_init(&orb->base.kref);
+	orb->response_bus =
+		dma_map_single(device->card->device, &orb->response,
+			       sizeof(orb->response), DMA_FROM_DEVICE);
+	if (dma_mapping_error(device->card->device, orb->response_bus))
+		goto fail_mapping_response;
+
+	orb->request.response.high = 0;
+	orb->request.response.low  = cpu_to_be32(orb->response_bus);
+
+	orb->request.misc = cpu_to_be32(
+		MANAGEMENT_ORB_NOTIFY |
+		MANAGEMENT_ORB_FUNCTION(function) |
+		MANAGEMENT_ORB_LUN(lun_or_login_id));
+	orb->request.length = cpu_to_be32(
+		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
+
+	orb->request.status_fifo.high =
+		cpu_to_be32(lu->address_handler.offset >> 32);
+	orb->request.status_fifo.low  =
+		cpu_to_be32(lu->address_handler.offset);
+
+	if (function == SBP2_LOGIN_REQUEST) {
+		/* Ask for 2^2 == 4 seconds reconnect grace period */
+		orb->request.misc |= cpu_to_be32(
+			MANAGEMENT_ORB_RECONNECT(2) |
+			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
+		timeout = lu->tgt->mgt_orb_timeout;
+	} else {
+		timeout = SBP2_ORB_TIMEOUT;
+	}
+
+	init_completion(&orb->done);
+	orb->base.callback = complete_management_orb;
+
+	orb->base.request_bus =
+		dma_map_single(device->card->device, &orb->request,
+			       sizeof(orb->request), DMA_TO_DEVICE);
+	if (dma_mapping_error(device->card->device, orb->base.request_bus))
+		goto fail_mapping_request;
+
+	sbp2_send_orb(&orb->base, lu, node_id, generation,
+		      lu->tgt->management_agent_address);
+
+	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
+
+	retval = -EIO;
+	if (sbp2_cancel_orbs(lu) == 0) {
+		dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
+			orb->base.rcode);
+		goto out;
+	}
+
+	if (orb->base.rcode != RCODE_COMPLETE) {
+		dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
+			orb->base.rcode);
+		goto out;
+	}
+
+	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
+	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
+		dev_err(lu_dev(lu), "error status: %d:%d\n",
+			 STATUS_GET_RESPONSE(orb->status),
+			 STATUS_GET_SBP_STATUS(orb->status));
+		goto out;
+	}
+
+	retval = 0;
+ out:
+	dma_unmap_single(device->card->device, orb->base.request_bus,
+			 sizeof(orb->request), DMA_TO_DEVICE);
+ fail_mapping_request:
+	dma_unmap_single(device->card->device, orb->response_bus,
+			 sizeof(orb->response), DMA_FROM_DEVICE);
+ fail_mapping_response:
+	if (response)
+		memcpy(response, orb->response, sizeof(orb->response));
+	kref_put(&orb->base.kref, free_orb);
+
+	return retval;
+}
+
+static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	__be32 d = 0;
+
+	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
+			   lu->tgt->node_id, lu->generation, device->max_speed,
+			   lu->command_block_agent_address + SBP2_AGENT_RESET,
+			   &d, 4);
+}
+
+static void complete_agent_reset_write_no_wait(struct fw_card *card,
+		int rcode, void *payload, size_t length, void *data)
+{
+	kfree(data);
+}
+
+static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	struct fw_transaction *t;
+	static __be32 d;
+
+	t = kmalloc(sizeof(*t), GFP_ATOMIC);
+	if (t == NULL)
+		return;
+
+	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
+			lu->tgt->node_id, lu->generation, device->max_speed,
+			lu->command_block_agent_address + SBP2_AGENT_RESET,
+			&d, 4, complete_agent_reset_write_no_wait, t);
+}
+
+static inline void sbp2_allow_block(struct sbp2_target *tgt)
+{
+	spin_lock_irq(&tgt->lock);
+	--tgt->dont_block;
+	spin_unlock_irq(&tgt->lock);
+}
+
+/*
+ * Blocks lu->tgt if all of the following conditions are met:
+ *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
+ *     logical units have been finished (indicated by dont_block == 0).
+ *   - lu->generation is stale.
+ *
+ * Note, scsi_block_requests() must be called while holding tgt->lock,
+ * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
+ * unblock the target.
+ */
+static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
+{
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_card *card = target_parent_device(tgt)->card;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgt->lock, flags);
+	if (!tgt->dont_block && !lu->blocked &&
+	    lu->generation != card->generation) {
+		lu->blocked = true;
+		if (++tgt->blocked == 1)
+			scsi_block_requests(shost);
+	}
+	spin_unlock_irqrestore(&tgt->lock, flags);
+}
+
+/*
+ * Unblocks lu->tgt as soon as all its logical units can be unblocked.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * tgt->lock protected section.  On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
+{
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_card *card = target_parent_device(tgt)->card;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	bool unblock = false;
+
+	spin_lock_irq(&tgt->lock);
+	if (lu->blocked && lu->generation == card->generation) {
+		lu->blocked = false;
+		unblock = --tgt->blocked == 0;
+	}
+	spin_unlock_irq(&tgt->lock);
+
+	if (unblock)
+		scsi_unblock_requests(shost);
+}
+
+/*
+ * Prevents future blocking of tgt and unblocks it.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * tgt->lock protected section.  On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_unblock(struct sbp2_target *tgt)
+{
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+
+	spin_lock_irq(&tgt->lock);
+	++tgt->dont_block;
+	spin_unlock_irq(&tgt->lock);
+
+	scsi_unblock_requests(shost);
+}
+
+static int sbp2_lun2int(u16 lun)
+{
+	struct scsi_lun eight_bytes_lun;
+
+	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
+	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
+	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
+
+	return scsilun_to_int(&eight_bytes_lun);
+}
+
+/*
+ * Write retransmit retry values into the BUSY_TIMEOUT register.
+ * - The single-phase retry protocol is supported by all SBP-2 devices, but the
+ *   default retry_limit value is 0 (i.e. never retry transmission). We write a
+ *   saner value after logging into the device.
+ * - The dual-phase retry protocol is optional to implement, and if not
+ *   supported, writes to the dual-phase portion of the register will be
+ *   ignored. We try to write the original 1394-1995 default here.
+ * - In the case of devices that are also SBP-3-compliant, all writes are
+ *   ignored, as the register is read-only, but contains single-phase retry of
+ *   15, which is what we're trying to set for all SBP-2 device anyway, so this
+ *   write attempt is safe and yields more consistent behavior for all devices.
+ *
+ * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
+ * and section 6.4 of the SBP-3 spec for further details.
+ */
+static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
+{
+	struct fw_device *device = target_parent_device(lu->tgt);
+	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
+
+	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
+			   lu->tgt->node_id, lu->generation, device->max_speed,
+			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
+}
+
+static void sbp2_reconnect(struct work_struct *work);
+
+static void sbp2_login(struct work_struct *work)
+{
+	struct sbp2_logical_unit *lu =
+		container_of(work, struct sbp2_logical_unit, work.work);
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_device *device = target_parent_device(tgt);
+	struct Scsi_Host *shost;
+	struct scsi_device *sdev;
+	struct sbp2_login_response response;
+	int generation, node_id, local_node_id;
+
+	if (fw_device_is_shutdown(device))
+		return;
+
+	generation    = device->generation;
+	smp_rmb();    /* node IDs must not be older than generation */
+	node_id       = device->node_id;
+	local_node_id = device->card->node_id;
+
+	/* If this is a re-login attempt, log out, or we might be rejected. */
+	if (lu->has_sdev)
+		sbp2_send_management_orb(lu, device->node_id, generation,
+				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+
+	if (sbp2_send_management_orb(lu, node_id, generation,
+				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
+		if (lu->retries++ < 5) {
+			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
+		} else {
+			dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
+				lu->lun);
+			/* Let any waiting I/O fail from now on. */
+			sbp2_unblock(lu->tgt);
+		}
+		return;
+	}
+
+	tgt->node_id	  = node_id;
+	tgt->address_high = local_node_id << 16;
+	smp_wmb();	  /* node IDs must not be older than generation */
+	lu->generation	  = generation;
+
+	lu->command_block_agent_address =
+		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
+		      << 32) | be32_to_cpu(response.command_block_agent.low);
+	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
+
+	dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
+		   lu->lun, lu->retries);
+
+	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
+	sbp2_set_busy_timeout(lu);
+
+	lu->workfn = sbp2_reconnect;
+	sbp2_agent_reset(lu);
+
+	/* This was a re-login. */
+	if (lu->has_sdev) {
+		sbp2_cancel_orbs(lu);
+		sbp2_conditionally_unblock(lu);
+
+		return;
+	}
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
+		ssleep(SBP2_INQUIRY_DELAY);
+
+	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
+	/*
+	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
+	 * Therefore __scsi_add_device() will get into trouble if a bus reset
+	 * happens in parallel.  It will either fail or leave us with an
+	 * unusable sdev.  As a workaround we check for this and retry the
+	 * whole login and SCSI probing.
+	 */
+
+	/* Reported error during __scsi_add_device() */
+	if (IS_ERR(sdev))
+		goto out_logout_login;
+
+	/* Unreported error during __scsi_add_device() */
+	smp_rmb(); /* get current card generation */
+	if (generation != device->card->generation) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+		goto out_logout_login;
+	}
+
+	/* No error during __scsi_add_device() */
+	lu->has_sdev = true;
+	scsi_device_put(sdev);
+	sbp2_allow_block(tgt);
+
+	return;
+
+ out_logout_login:
+	smp_rmb(); /* generation may have changed */
+	generation = device->generation;
+	smp_rmb(); /* node_id must not be older than generation */
+
+	sbp2_send_management_orb(lu, device->node_id, generation,
+				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+	/*
+	 * If a bus reset happened, sbp2_update will have requeued
+	 * lu->work already.  Reset the work from reconnect to login.
+	 */
+	lu->workfn = sbp2_login;
+}
+
+static void sbp2_reconnect(struct work_struct *work)
+{
+	struct sbp2_logical_unit *lu =
+		container_of(work, struct sbp2_logical_unit, work.work);
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_device *device = target_parent_device(tgt);
+	int generation, node_id, local_node_id;
+
+	if (fw_device_is_shutdown(device))
+		return;
+
+	generation    = device->generation;
+	smp_rmb();    /* node IDs must not be older than generation */
+	node_id       = device->node_id;
+	local_node_id = device->card->node_id;
+
+	if (sbp2_send_management_orb(lu, node_id, generation,
+				     SBP2_RECONNECT_REQUEST,
+				     lu->login_id, NULL) < 0) {
+		/*
+		 * If reconnect was impossible even though we are in the
+		 * current generation, fall back and try to log in again.
+		 *
+		 * We could check for "Function rejected" status, but
+		 * looking at the bus generation as simpler and more general.
+		 */
+		smp_rmb(); /* get current card generation */
+		if (generation == device->card->generation ||
+		    lu->retries++ >= 5) {
+			dev_err(tgt_dev(tgt), "failed to reconnect\n");
+			lu->retries = 0;
+			lu->workfn = sbp2_login;
+		}
+		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
+
+		return;
+	}
+
+	tgt->node_id      = node_id;
+	tgt->address_high = local_node_id << 16;
+	smp_wmb();	  /* node IDs must not be older than generation */
+	lu->generation	  = generation;
+
+	dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
+		   lu->lun, lu->retries);
+
+	sbp2_agent_reset(lu);
+	sbp2_cancel_orbs(lu);
+	sbp2_conditionally_unblock(lu);
+}
+
+static void sbp2_lu_workfn(struct work_struct *work)
+{
+	struct sbp2_logical_unit *lu = container_of(to_delayed_work(work),
+						struct sbp2_logical_unit, work);
+	lu->workfn(work);
+}
+
+static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
+{
+	struct sbp2_logical_unit *lu;
+
+	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
+	if (!lu)
+		return -ENOMEM;
+
+	lu->address_handler.length           = 0x100;
+	lu->address_handler.address_callback = sbp2_status_write;
+	lu->address_handler.callback_data    = lu;
+
+	if (fw_core_add_address_handler(&lu->address_handler,
+					&fw_high_memory_region) < 0) {
+		kfree(lu);
+		return -ENOMEM;
+	}
+
+	lu->tgt      = tgt;
+	lu->lun      = lun_entry & 0xffff;
+	lu->login_id = INVALID_LOGIN_ID;
+	lu->retries  = 0;
+	lu->has_sdev = false;
+	lu->blocked  = false;
+	++tgt->dont_block;
+	INIT_LIST_HEAD(&lu->orb_list);
+	lu->workfn = sbp2_login;
+	INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn);
+
+	list_add_tail(&lu->link, &tgt->lu_list);
+	return 0;
+}
+
+static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
+				    const u32 *leaf)
+{
+	if ((leaf[0] & 0xffff0000) == 0x00020000)
+		tgt->guid = (u64)leaf[1] << 32 | leaf[2];
+}
+
+static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
+				      const u32 *directory)
+{
+	struct fw_csr_iterator ci;
+	int key, value;
+
+	fw_csr_iterator_init(&ci, directory);
+	while (fw_csr_iterator_next(&ci, &key, &value))
+		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
+		    sbp2_add_logical_unit(tgt, value) < 0)
+			return -ENOMEM;
+	return 0;
+}
+
+static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
+			      u32 *model, u32 *firmware_revision)
+{
+	struct fw_csr_iterator ci;
+	int key, value;
+
+	fw_csr_iterator_init(&ci, directory);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		switch (key) {
+
+		case CSR_DEPENDENT_INFO | CSR_OFFSET:
+			tgt->management_agent_address =
+					CSR_REGISTER_BASE + 4 * value;
+			break;
+
+		case CSR_DIRECTORY_ID:
+			tgt->directory_id = value;
+			break;
+
+		case CSR_MODEL:
+			*model = value;
+			break;
+
+		case SBP2_CSR_FIRMWARE_REVISION:
+			*firmware_revision = value;
+			break;
+
+		case SBP2_CSR_UNIT_CHARACTERISTICS:
+			/* the timeout value is stored in 500ms units */
+			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
+			break;
+
+		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
+			if (sbp2_add_logical_unit(tgt, value) < 0)
+				return -ENOMEM;
+			break;
+
+		case SBP2_CSR_UNIT_UNIQUE_ID:
+			sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
+			break;
+
+		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
+			/* Adjust for the increment in the iterator */
+			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
+				return -ENOMEM;
+			break;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
+ * provided in the config rom. Most devices do provide a value, which
+ * we'll use for login management orbs, but with some sane limits.
+ */
+static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
+{
+	unsigned int timeout = tgt->mgt_orb_timeout;
+
+	if (timeout > 40000)
+		dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
+			   timeout / 1000);
+
+	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
+}
+
+static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
+				  u32 firmware_revision)
+{
+	int i;
+	unsigned int w = sbp2_param_workarounds;
+
+	if (w)
+		dev_notice(tgt_dev(tgt),
+			   "Please notify linux1394-devel@lists.sf.net "
+			   "if you need the workarounds parameter\n");
+
+	if (w & SBP2_WORKAROUND_OVERRIDE)
+		goto out;
+
+	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
+
+		if (sbp2_workarounds_table[i].firmware_revision !=
+		    (firmware_revision & 0xffffff00))
+			continue;
+
+		if (sbp2_workarounds_table[i].model != model &&
+		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
+			continue;
+
+		w |= sbp2_workarounds_table[i].workarounds;
+		break;
+	}
+ out:
+	if (w)
+		dev_notice(tgt_dev(tgt), "workarounds 0x%x "
+			   "(firmware_revision 0x%06x, model_id 0x%06x)\n",
+			   w, firmware_revision, model);
+	tgt->workarounds = w;
+}
+
+static const struct scsi_host_template scsi_driver_template;
+static void sbp2_remove(struct fw_unit *unit);
+
+static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
+{
+	struct fw_device *device = fw_parent_device(unit);
+	struct sbp2_target *tgt;
+	struct sbp2_logical_unit *lu;
+	struct Scsi_Host *shost;
+	u32 model, firmware_revision;
+
+	/* cannot (or should not) handle targets on the local node */
+	if (device->is_local)
+		return -ENODEV;
+
+	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
+	if (shost == NULL)
+		return -ENOMEM;
+
+	tgt = (struct sbp2_target *)shost->hostdata;
+	dev_set_drvdata(&unit->device, tgt);
+	tgt->unit = unit;
+	INIT_LIST_HEAD(&tgt->lu_list);
+	spin_lock_init(&tgt->lock);
+	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
+
+	if (fw_device_enable_phys_dma(device) < 0)
+		goto fail_shost_put;
+
+	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
+
+	if (scsi_add_host_with_dma(shost, &unit->device,
+				   device->card->device) < 0)
+		goto fail_shost_put;
+
+	/* implicit directory ID */
+	tgt->directory_id = ((unit->directory - device->config_rom) * 4
+			     + CSR_CONFIG_ROM) & 0xffffff;
+
+	firmware_revision = SBP2_ROM_VALUE_MISSING;
+	model		  = SBP2_ROM_VALUE_MISSING;
+
+	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
+			       &firmware_revision) < 0)
+		goto fail_remove;
+
+	sbp2_clamp_management_orb_timeout(tgt);
+	sbp2_init_workarounds(tgt, model, firmware_revision);
+
+	/*
+	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
+	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
+	 * specifies the max payload size as 2 ^ (max_payload + 2), so
+	 * if we set this to max_speed + 7, we get the right value.
+	 */
+	tgt->max_payload = min3(device->max_speed + 7, 10U,
+				device->card->max_receive - 1);
+
+	/* Do the login in a workqueue so we can easily reschedule retries. */
+	list_for_each_entry(lu, &tgt->lu_list, link)
+		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
+
+	return 0;
+
+ fail_remove:
+	sbp2_remove(unit);
+	return -ENOMEM;
+
+ fail_shost_put:
+	scsi_host_put(shost);
+	return -ENOMEM;
+}
+
+static void sbp2_update(struct fw_unit *unit)
+{
+	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
+	struct sbp2_logical_unit *lu;
+
+	fw_device_enable_phys_dma(fw_parent_device(unit));
+
+	/*
+	 * Fw-core serializes sbp2_update() against sbp2_remove().
+	 * Iteration over tgt->lu_list is therefore safe here.
+	 */
+	list_for_each_entry(lu, &tgt->lu_list, link) {
+		sbp2_conditionally_block(lu);
+		lu->retries = 0;
+		sbp2_queue_work(lu, 0);
+	}
+}
+
+static void sbp2_remove(struct fw_unit *unit)
+{
+	struct fw_device *device = fw_parent_device(unit);
+	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
+	struct sbp2_logical_unit *lu, *next;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	struct scsi_device *sdev;
+
+	/* prevent deadlocks */
+	sbp2_unblock(tgt);
+
+	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
+		cancel_delayed_work_sync(&lu->work);
+		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
+		if (sdev) {
+			scsi_remove_device(sdev);
+			scsi_device_put(sdev);
+		}
+		if (lu->login_id != INVALID_LOGIN_ID) {
+			int generation, node_id;
+			/*
+			 * tgt->node_id may be obsolete here if we failed
+			 * during initial login or after a bus reset where
+			 * the topology changed.
+			 */
+			generation = device->generation;
+			smp_rmb(); /* node_id vs. generation */
+			node_id    = device->node_id;
+			sbp2_send_management_orb(lu, node_id, generation,
+						 SBP2_LOGOUT_REQUEST,
+						 lu->login_id, NULL);
+		}
+		fw_core_remove_address_handler(&lu->address_handler);
+		list_del(&lu->link);
+		kfree(lu);
+	}
+	scsi_remove_host(shost);
+	dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
+
+	scsi_host_put(shost);
+}
+
+#define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
+#define SBP2_SW_VERSION_ENTRY	0x00010483
+
+static const struct ieee1394_device_id sbp2_id_table[] = {
+	{
+		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
+				IEEE1394_MATCH_VERSION,
+		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
+		.version      = SBP2_SW_VERSION_ENTRY,
+	},
+	{ }
+};
+
+static struct fw_driver sbp2_driver = {
+	.driver   = {
+		.owner  = THIS_MODULE,
+		.name   = KBUILD_MODNAME,
+		.bus    = &fw_bus_type,
+	},
+	.probe    = sbp2_probe,
+	.update   = sbp2_update,
+	.remove   = sbp2_remove,
+	.id_table = sbp2_id_table,
+};
+
+static void sbp2_unmap_scatterlist(struct device *card_device,
+				   struct sbp2_command_orb *orb)
+{
+	scsi_dma_unmap(orb->cmd);
+
+	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
+		dma_unmap_single(card_device, orb->page_table_bus,
+				 sizeof(orb->page_table), DMA_TO_DEVICE);
+}
+
+static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
+{
+	int sam_status;
+	int sfmt = (sbp2_status[0] >> 6) & 0x03;
+
+	if (sfmt == 2 || sfmt == 3) {
+		/*
+		 * Reserved for future standardization (2) or
+		 * Status block format vendor-dependent (3)
+		 */
+		return DID_ERROR << 16;
+	}
+
+	sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
+	sense_data[1] = 0x0;
+	sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
+	sense_data[3] = sbp2_status[4];
+	sense_data[4] = sbp2_status[5];
+	sense_data[5] = sbp2_status[6];
+	sense_data[6] = sbp2_status[7];
+	sense_data[7] = 10;
+	sense_data[8] = sbp2_status[8];
+	sense_data[9] = sbp2_status[9];
+	sense_data[10] = sbp2_status[10];
+	sense_data[11] = sbp2_status[11];
+	sense_data[12] = sbp2_status[2];
+	sense_data[13] = sbp2_status[3];
+	sense_data[14] = sbp2_status[12];
+	sense_data[15] = sbp2_status[13];
+
+	sam_status = sbp2_status[0] & 0x3f;
+
+	switch (sam_status) {
+	case SAM_STAT_GOOD:
+	case SAM_STAT_CHECK_CONDITION:
+	case SAM_STAT_CONDITION_MET:
+	case SAM_STAT_BUSY:
+	case SAM_STAT_RESERVATION_CONFLICT:
+	case SAM_STAT_COMMAND_TERMINATED:
+		return DID_OK << 16 | sam_status;
+
+	default:
+		return DID_ERROR << 16;
+	}
+}
+
+static void complete_command_orb(struct sbp2_orb *base_orb,
+				 struct sbp2_status *status)
+{
+	struct sbp2_command_orb *orb =
+		container_of(base_orb, struct sbp2_command_orb, base);
+	struct fw_device *device = target_parent_device(base_orb->lu->tgt);
+	int result;
+
+	if (status != NULL) {
+		if (STATUS_GET_DEAD(*status))
+			sbp2_agent_reset_no_wait(base_orb->lu);
+
+		switch (STATUS_GET_RESPONSE(*status)) {
+		case SBP2_STATUS_REQUEST_COMPLETE:
+			result = DID_OK << 16;
+			break;
+		case SBP2_STATUS_TRANSPORT_FAILURE:
+			result = DID_BUS_BUSY << 16;
+			break;
+		case SBP2_STATUS_ILLEGAL_REQUEST:
+		case SBP2_STATUS_VENDOR_DEPENDENT:
+		default:
+			result = DID_ERROR << 16;
+			break;
+		}
+
+		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
+			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
+							   orb->cmd->sense_buffer);
+	} else {
+		/*
+		 * If the orb completes with status == NULL, something
+		 * went wrong, typically a bus reset happened mid-orb
+		 * or when sending the write (less likely).
+		 */
+		result = DID_BUS_BUSY << 16;
+		sbp2_conditionally_block(base_orb->lu);
+	}
+
+	dma_unmap_single(device->card->device, orb->base.request_bus,
+			 sizeof(orb->request), DMA_TO_DEVICE);
+	sbp2_unmap_scatterlist(device->card->device, orb);
+
+	orb->cmd->result = result;
+	scsi_done(orb->cmd);
+}
+
+static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
+		struct fw_device *device, struct sbp2_logical_unit *lu)
+{
+	struct scatterlist *sg = scsi_sglist(orb->cmd);
+	int i, n;
+
+	n = scsi_dma_map(orb->cmd);
+	if (n <= 0)
+		goto fail;
+
+	/*
+	 * Handle the special case where there is only one element in
+	 * the scatter list by converting it to an immediate block
+	 * request. This is also a workaround for broken devices such
+	 * as the second generation iPod which doesn't support page
+	 * tables.
+	 */
+	if (n == 1) {
+		orb->request.data_descriptor.high =
+			cpu_to_be32(lu->tgt->address_high);
+		orb->request.data_descriptor.low  =
+			cpu_to_be32(sg_dma_address(sg));
+		orb->request.misc |=
+			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
+		return 0;
+	}
+
+	for_each_sg(sg, sg, n, i) {
+		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
+		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
+	}
+
+	orb->page_table_bus =
+		dma_map_single(device->card->device, orb->page_table,
+			       sizeof(orb->page_table), DMA_TO_DEVICE);
+	if (dma_mapping_error(device->card->device, orb->page_table_bus))
+		goto fail_page_table;
+
+	/*
+	 * The data_descriptor pointer is the one case where we need
+	 * to fill in the node ID part of the address.  All other
+	 * pointers assume that the data referenced reside on the
+	 * initiator (i.e. us), but data_descriptor can refer to data
+	 * on other nodes so we need to put our ID in descriptor.high.
+	 */
+	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
+	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
+	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
+					 COMMAND_ORB_DATA_SIZE(n));
+
+	return 0;
+
+ fail_page_table:
+	scsi_dma_unmap(orb->cmd);
+ fail:
+	return -ENOMEM;
+}
+
+/* SCSI stack integration */
+
+static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
+				  struct scsi_cmnd *cmd)
+{
+	struct sbp2_logical_unit *lu = cmd->device->hostdata;
+	struct fw_device *device = target_parent_device(lu->tgt);
+	struct sbp2_command_orb *orb;
+	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
+
+	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
+	if (orb == NULL)
+		return SCSI_MLQUEUE_HOST_BUSY;
+
+	/* Initialize rcode to something not RCODE_COMPLETE. */
+	orb->base.rcode = -1;
+	kref_init(&orb->base.kref);
+	orb->cmd = cmd;
+	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
+	orb->request.misc = cpu_to_be32(
+		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
+		COMMAND_ORB_SPEED(device->max_speed) |
+		COMMAND_ORB_NOTIFY);
+
+	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
+		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
+
+	generation = device->generation;
+	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
+
+	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
+		goto out;
+
+	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
+
+	orb->base.callback = complete_command_orb;
+	orb->base.request_bus =
+		dma_map_single(device->card->device, &orb->request,
+			       sizeof(orb->request), DMA_TO_DEVICE);
+	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
+		sbp2_unmap_scatterlist(device->card->device, orb);
+		goto out;
+	}
+
+	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
+		      lu->command_block_agent_address + SBP2_ORB_POINTER);
+	retval = 0;
+ out:
+	kref_put(&orb->base.kref, free_orb);
+	return retval;
+}
+
+static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
+{
+	struct sbp2_logical_unit *lu = sdev->hostdata;
+
+	/* (Re-)Adding logical units via the SCSI stack is not supported. */
+	if (!lu)
+		return -ENOSYS;
+
+	sdev->allow_restart = 1;
+
+	/*
+	 * SBP-2 does not require any alignment, but we set it anyway
+	 * for compatibility with earlier versions of this driver.
+	 */
+	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
+		sdev->inquiry_len = 36;
+
+	return 0;
+}
+
+static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
+{
+	struct sbp2_logical_unit *lu = sdev->hostdata;
+
+	sdev->use_10_for_rw = 1;
+
+	if (sbp2_param_exclusive_login) {
+		sdev->manage_system_start_stop = 1;
+		sdev->manage_runtime_start_stop = 1;
+		sdev->manage_shutdown = 1;
+	}
+
+	if (sdev->type == TYPE_ROM)
+		sdev->use_10_for_ms = 1;
+
+	if (sdev->type == TYPE_DISK &&
+	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
+		sdev->skip_ms_page_8 = 1;
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
+		sdev->fix_capacity = 1;
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
+		sdev->start_stop_pwr_cond = 1;
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
+		blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
+
+	return 0;
+}
+
+/*
+ * Called by scsi stack when something has really gone wrong.  Usually
+ * called when a command has timed-out for some reason.
+ */
+static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
+{
+	struct sbp2_logical_unit *lu = cmd->device->hostdata;
+
+	dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
+	sbp2_agent_reset(lu);
+	sbp2_cancel_orbs(lu);
+
+	return SUCCESS;
+}
+
+/*
+ * Format of /sys/bus/scsi/devices/.../ieee1394_id:
+ * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
+ *
+ * This is the concatenation of target port identifier and logical unit
+ * identifier as per SAM-2...SAM-4 annex A.
+ */
+static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct sbp2_logical_unit *lu;
+
+	if (!sdev)
+		return 0;
+
+	lu = sdev->hostdata;
+
+	return sprintf(buf, "%016llx:%06x:%04x\n",
+			(unsigned long long)lu->tgt->guid,
+			lu->tgt->directory_id, lu->lun);
+}
+
+static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
+
+static struct attribute *sbp2_scsi_sysfs_attrs[] = {
+	&dev_attr_ieee1394_id.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(sbp2_scsi_sysfs);
+
+static const struct scsi_host_template scsi_driver_template = {
+	.module			= THIS_MODULE,
+	.name			= "SBP-2 IEEE-1394",
+	.proc_name		= "sbp2",
+	.queuecommand		= sbp2_scsi_queuecommand,
+	.slave_alloc		= sbp2_scsi_slave_alloc,
+	.slave_configure	= sbp2_scsi_slave_configure,
+	.eh_abort_handler	= sbp2_scsi_abort,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.max_segment_size	= SBP2_MAX_SEG_SIZE,
+	.can_queue		= 1,
+	.sdev_groups		= sbp2_scsi_sysfs_groups,
+};
+
+MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
+MODULE_DESCRIPTION("SCSI over IEEE1394");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
+
+/* Provide a module alias so root-on-sbp2 initrds don't break. */
+MODULE_ALIAS("sbp2");
+
+static int __init sbp2_init(void)
+{
+	return driver_register(&sbp2_driver.driver);
+}
+
+static void __exit sbp2_cleanup(void)
+{
+	driver_unregister(&sbp2_driver.driver);
+}
+
+module_init(sbp2_init);
+module_exit(sbp2_cleanup);