firewire: Add SBP-2 protocol driver for storage devices.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 1073 insertions, 0 deletions

diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
new file mode 100644
index 000000000000..2756e0c2f9cd
--- /dev/null
+++ b/drivers/firewire/fw-sbp2.c
@@ -0,0 +1,1073 @@
+/*						-*- c-basic-offset: 8 -*-
+ * fw-sbp2.c -- SBP2 driver (SCSI over IEEE1394)
+ *
+ * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "fw-transaction.h"
+#include "fw-topology.h"
+#include "fw-device.h"
+
+/* I don't know why the SCSI stack doesn't define something like this... */
+typedef void (*scsi_done_fn_t) (struct scsi_cmnd *);
+
+static const char sbp2_driver_name[] = "sbp2";
+
+struct sbp2_device {
+	struct fw_unit *unit;
+	struct fw_address_handler address_handler;
+	struct list_head orb_list;
+	u64 management_agent_address;
+	u64 command_block_agent_address;
+	u32 workarounds;
+	int login_id;
+
+	/* We cache these addresses and only update them once we've
+	 * logged in or reconnected to the sbp2 device.  That way, any
+	 * IO to the device will automatically fail and get retried if
+	 * it happens in a window where the device is not ready to
+	 * handle it (e.g. after a bus reset but before we reconnect). */
+	int node_id;
+	int address_high;
+	int generation;
+
+	struct work_struct work;
+	struct Scsi_Host *scsi_host;
+};
+
+#define SBP2_MAX_SG_ELEMENT_LENGTH	0xf000
+#define SBP2_MAX_SECTORS		255	/* Max sectors supported */
+#define SBP2_MAX_CMDS			8	/* This should be safe */
+
+#define SBP2_ORB_NULL			0x80000000
+
+#define SBP2_DIRECTION_TO_MEDIA		0x0
+#define SBP2_DIRECTION_FROM_MEDIA	0x1
+
+/* Unit directory keys */
+#define SBP2_COMMAND_SET_SPECIFIER	0x38
+#define SBP2_COMMAND_SET		0x39
+#define SBP2_COMMAND_SET_REVISION	0x3b
+#define SBP2_FIRMWARE_REVISION		0x3c
+
+/* Flags for detected oddities and brokeness */
+#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_OVERRIDE	0x100
+
+/* 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 {
+	u32 high;
+	u32 low;
+};
+
+struct sbp2_orb {
+	struct fw_transaction t;
+	dma_addr_t request_bus;
+	int rcode;
+	struct sbp2_pointer pointer;
+	void (*callback) (struct sbp2_orb * orb, struct sbp2_status * status);
+	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		((1) << 28)
+#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;
+		u32 misc;
+		u32 length;
+		struct sbp2_pointer status_fifo;
+	} request;
+	__be32 response[4];
+	dma_addr_t response_bus;
+	struct completion done;
+	struct sbp2_status status;
+};
+
+#define login_response_get_login_id(v)	((v).misc & 0xffff)
+#define login_response_get_length(v)	(((v).misc >> 16) & 0xffff)
+
+struct sbp2_login_response {
+	u32 misc;
+	struct sbp2_pointer command_block_agent;
+	u32 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(v)	((v) << 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;
+		u32 misc;
+		u8 command_block[12];
+	} request;
+	struct scsi_cmnd *cmd;
+	scsi_done_fn_t done;
+	struct fw_unit *unit;
+
+	struct sbp2_pointer page_table[SG_ALL];
+	dma_addr_t page_table_bus;
+	dma_addr_t request_buffer_bus;
+};
+
+/*
+ * 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.  We use ~0 as a wildcard, since the 24 bit values we get
+ * from the config rom can never match that.
+ */
+static const struct {
+	u32 firmware_revision;
+	u32 model;
+	unsigned 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,
+	},
+	/* Initio bridges, actually only needed for some older ones */ {
+		.firmware_revision	= 0x000200,
+		.model			= ~0,
+		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
+	},
+	/* Symbios bridge */ {
+		.firmware_revision	= 0xa0b800,
+		.model			= ~0,
+		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
+	},
+	/* There are iPods (2nd gen, 3rd gen) with model_id == 0, but
+	 * these iPods do not feature the read_capacity bug according
+	 * to one report.  Read_capacity behaviour as well as model_id
+	 * could change due to Apple-supplied firmware updates though. */
+	/* iPod 4th generation. */ {
+		.firmware_revision	= 0x0a2700,
+		.model			= 0x000021,
+		.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
+sbp2_status_write(struct fw_card *card, struct fw_request *request,
+		  int tcode, int destination, int source,
+		  int generation, int speed,
+		  unsigned long long offset,
+		  void *payload, size_t length, void *callback_data)
+{
+	struct sbp2_device *sd = callback_data;
+	struct sbp2_orb *orb;
+	struct sbp2_status status;
+	size_t header_size;
+	unsigned long flags;
+
+	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
+	    length == 0 || length > sizeof status) {
+		fw_send_response(card, request, RCODE_TYPE_ERROR);
+		return;
+	}
+
+	header_size = min(length, 2 * sizeof(u32));
+	fw_memcpy_from_be32(&status, payload, header_size);
+	if (length > header_size)
+		memcpy(status.data, payload + 8, length - header_size);
+	if (status_get_source(status) == 2 || status_get_source(status) == 3) {
+		fw_notify("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(&card->lock, flags);
+	list_for_each_entry(orb, &sd->orb_list, link) {
+		if (status_get_orb_high(status) == 0 &&
+		    status_get_orb_low(status) == orb->request_bus) {
+			list_del(&orb->link);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+
+	if (&orb->link != &sd->orb_list)
+		orb->callback(orb, &status);
+	else
+		fw_error("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;
+
+	orb->rcode = rcode;
+	if (rcode != RCODE_COMPLETE) {
+		spin_lock_irqsave(&card->lock, flags);
+		list_del(&orb->link);
+		spin_unlock_irqrestore(&card->lock, flags);
+		orb->callback(orb, NULL);
+	}
+}
+
+static void
+sbp2_send_orb(struct sbp2_orb *orb, struct fw_unit *unit,
+	      int node_id, int generation, u64 offset)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	unsigned long flags;
+
+	orb->pointer.high = 0;
+	orb->pointer.low = orb->request_bus;
+	fw_memcpy_to_be32(&orb->pointer, &orb->pointer, sizeof orb->pointer);
+
+	spin_lock_irqsave(&device->card->lock, flags);
+	list_add_tail(&orb->link, &sd->orb_list);
+	spin_unlock_irqrestore(&device->card->lock, flags);
+
+	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
+			node_id | LOCAL_BUS, generation,
+			device->node->max_speed, offset,
+			&orb->pointer, sizeof orb->pointer,
+			complete_transaction, orb);
+}
+
+static void sbp2_cancel_orbs(struct fw_unit *unit)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	struct sbp2_orb *orb, *next;
+	struct list_head list;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&list);
+	spin_lock_irqsave(&device->card->lock, flags);
+	list_splice_init(&sd->orb_list, &list);
+	spin_unlock_irqrestore(&device->card->lock, flags);
+
+	list_for_each_entry_safe(orb, next, &list, link) {
+		orb->rcode = RCODE_CANCELLED;
+		orb->callback(orb, NULL);
+	}
+}
+
+static void
+complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
+{
+	struct sbp2_management_orb *orb =
+	    (struct sbp2_management_orb *)base_orb;
+
+	if (status)
+		memcpy(&orb->status, status, sizeof *status);
+	complete(&orb->done);
+}
+
+static int
+sbp2_send_management_orb(struct fw_unit *unit, int node_id, int generation,
+			 int function, int lun, void *response)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	struct sbp2_management_orb *orb;
+	unsigned long timeout;
+	int retval = -ENOMEM;
+
+	orb = kzalloc(sizeof *orb, GFP_ATOMIC);
+	if (orb == NULL)
+		return -ENOMEM;
+
+	/* The sbp2 device is going to send a block read request to
+	 * read out the request from host memory, so map it for
+	 * dma. */
+	orb->base.request_bus =
+		dma_map_single(device->card->device, &orb->request,
+			       sizeof orb->request, DMA_TO_DEVICE);
+	if (orb->base.request_bus == 0)
+		goto out;
+
+	orb->response_bus =
+		dma_map_single(device->card->device, &orb->response,
+			       sizeof orb->response, DMA_FROM_DEVICE);
+	if (orb->response_bus == 0)
+		goto out;
+
+	orb->request.response.high    = 0;
+	orb->request.response.low     = orb->response_bus;
+
+	orb->request.misc =
+		management_orb_notify |
+		management_orb_function(function) |
+		management_orb_lun(lun);
+	orb->request.length =
+		management_orb_response_length(sizeof orb->response);
+
+	orb->request.status_fifo.high = sd->address_handler.offset >> 32;
+	orb->request.status_fifo.low  = sd->address_handler.offset;
+
+	/* FIXME: Yeah, ok this isn't elegant, we hardwire exclusive
+	 * login and 1 second reconnect time.  The reconnect setting
+	 * is probably fine, but the exclusive login should be an
+	 * option. */
+	if (function == SBP2_LOGIN_REQUEST) {
+		orb->request.misc |=
+			management_orb_exclusive |
+			management_orb_reconnect(0);
+	}
+
+	fw_memcpy_to_be32(&orb->request, &orb->request, sizeof orb->request);
+
+	init_completion(&orb->done);
+	orb->base.callback = complete_management_orb;
+	sbp2_send_orb(&orb->base, unit,
+		      node_id, generation, sd->management_agent_address);
+
+	timeout = wait_for_completion_timeout(&orb->done, 10 * HZ);
+
+	/* FIXME: Handle bus reset race here. */
+
+	retval = -EIO;
+	if (orb->base.rcode != RCODE_COMPLETE) {
+		fw_error("management write failed, rcode 0x%02x\n",
+			 orb->base.rcode);
+		goto out;
+	}
+
+	if (timeout == 0) {
+		fw_error("orb reply timed out, rcode=0x%02x\n",
+			 orb->base.rcode);
+		goto out;
+	}
+
+	if (status_get_response(orb->status) != 0 ||
+	    status_get_sbp_status(orb->status) != 0) {
+		fw_error("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);
+	dma_unmap_single(device->card->device, orb->response_bus,
+			 sizeof orb->response, DMA_FROM_DEVICE);
+
+	if (response)
+		fw_memcpy_from_be32(response,
+				    orb->response, sizeof orb->response);
+	kfree(orb);
+
+	return retval;
+}
+
+static void
+complete_agent_reset_write(struct fw_card *card, int rcode,
+			   void *payload, size_t length, void *data)
+{
+	struct fw_transaction *t = data;
+
+	fw_notify("agent reset write rcode=%d\n", rcode);
+	kfree(t);
+}
+
+static int sbp2_agent_reset(struct fw_unit *unit)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	struct fw_transaction *t;
+	static u32 zero;
+
+	t = kzalloc(sizeof *t, GFP_ATOMIC);
+	if (t == NULL)
+		return -ENOMEM;
+
+	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
+			sd->node_id | LOCAL_BUS, sd->generation, SCODE_400,
+			sd->command_block_agent_address + SBP2_AGENT_RESET,
+			&zero, sizeof zero, complete_agent_reset_write, t);
+
+	return 0;
+}
+
+static int add_scsi_devices(struct fw_unit *unit);
+static void remove_scsi_devices(struct fw_unit *unit);
+
+static int sbp2_probe(struct device *dev)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd;
+	struct fw_csr_iterator ci;
+	int i, key, value, lun, retval;
+	int node_id, generation, local_node_id;
+	struct sbp2_login_response response;
+	u32 model, firmware_revision;
+
+	sd = kzalloc(sizeof *sd, GFP_KERNEL);
+	if (sd == NULL)
+		return -ENOMEM;
+
+	unit->device.driver_data = sd;
+	sd->unit = unit;
+	INIT_LIST_HEAD(&sd->orb_list);
+
+	sd->address_handler.length = 0x100;
+	sd->address_handler.address_callback = sbp2_status_write;
+	sd->address_handler.callback_data = sd;
+
+	if (fw_core_add_address_handler(&sd->address_handler,
+					&fw_high_memory_region) < 0) {
+		kfree(sd);
+		return -EBUSY;
+	}
+
+	if (fw_device_enable_phys_dma(device) < 0) {
+		fw_core_remove_address_handler(&sd->address_handler);
+		kfree(sd);
+		return -EBUSY;
+	}
+
+	/* Scan unit directory to get management agent address,
+	 * firmware revison and model.  Initialize firmware_revision
+	 * and model to values that wont match anything in our table. */
+	firmware_revision = 0xff000000;
+	model = 0xff000000;
+	fw_csr_iterator_init(&ci, unit->directory);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		switch (key) {
+		case CSR_DEPENDENT_INFO | CSR_OFFSET:
+			sd->management_agent_address =
+				0xfffff0000000ULL + 4 * value;
+			break;
+		case SBP2_FIRMWARE_REVISION:
+			firmware_revision = value;
+			break;
+		case CSR_MODEL:
+			model = value;
+			break;
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
+		if (sbp2_workarounds_table[i].firmware_revision !=
+		    (firmware_revision & 0xffffff00))
+			continue;
+		if (sbp2_workarounds_table[i].model != model &&
+		    sbp2_workarounds_table[i].model != ~0)
+			continue;
+		sd->workarounds |= sbp2_workarounds_table[i].workarounds;
+		break;
+	}
+
+	if (sd->workarounds)
+		fw_notify("Workarounds for node %s: 0x%x "
+			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
+			  unit->device.bus_id,
+			  sd->workarounds, firmware_revision, model);
+
+	/* FIXME: Make this work for multi-lun devices. */
+	lun = 0;
+
+	generation    = device->card->generation;
+	node_id       = device->node->node_id;
+	local_node_id = device->card->local_node->node_id;
+
+	/* FIXME: We should probably do this from a keventd callback
+	 * and handle retries by rescheduling the work. */
+	if (sbp2_send_management_orb(unit, node_id, generation,
+				     SBP2_LOGIN_REQUEST, lun, &response) < 0) {
+		fw_core_remove_address_handler(&sd->address_handler);
+		kfree(sd);
+		return -EBUSY;
+	}
+
+	sd->generation   = generation;
+	sd->node_id      = node_id;
+	sd->address_high = (LOCAL_BUS | local_node_id) << 16;
+
+	/* Get command block agent offset and login id. */
+	sd->command_block_agent_address =
+		((u64) response.command_block_agent.high << 32) |
+		response.command_block_agent.low;
+	sd->login_id = login_response_get_login_id(response);
+
+	fw_notify("logged in to sbp2 unit %s\n", unit->device.bus_id);
+	fw_notify(" - management_agent_address: 0x%012llx\n",
+		  (unsigned long long) sd->management_agent_address);
+	fw_notify(" - command_block_agent_address: 0x%012llx\n",
+		  (unsigned long long) sd->command_block_agent_address);
+	fw_notify(" - status write address: 0x%012llx\n",
+		  (unsigned long long) sd->address_handler.offset);
+
+#if 0
+	/* FIXME: The linux1394 sbp2 does this last step. */
+	sbp2_set_busy_timeout(scsi_id);
+#endif
+
+	sbp2_agent_reset(unit);
+
+	retval = add_scsi_devices(unit);
+	if (retval < 0) {
+		sbp2_send_management_orb(unit, sd->node_id, sd->generation,
+					 SBP2_LOGOUT_REQUEST, sd->login_id,
+					 NULL);
+		fw_core_remove_address_handler(&sd->address_handler);
+		kfree(sd);
+		return retval;
+	}
+
+	return 0;
+}
+
+static int sbp2_remove(struct device *dev)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	struct sbp2_device *sd = unit->device.driver_data;
+
+	sbp2_send_management_orb(unit, sd->node_id, sd->generation,
+				 SBP2_LOGOUT_REQUEST, sd->login_id, NULL);
+
+	remove_scsi_devices(unit);
+
+	fw_core_remove_address_handler(&sd->address_handler);
+	kfree(sd);
+
+	fw_notify("removed sbp2 unit %s\n", dev->bus_id);
+
+	return 0;
+}
+
+static void sbp2_reconnect(struct work_struct *work)
+{
+	struct sbp2_device *sd = container_of(work, struct sbp2_device, work);
+	struct fw_unit *unit = sd->unit;
+	struct fw_device *device = fw_device(unit->device.parent);
+	int generation, node_id, local_node_id;
+
+	fw_notify("in sbp2_reconnect, reconnecting to unit %s\n",
+		  unit->device.bus_id);
+
+	generation    = device->card->generation;
+	node_id       = device->node->node_id;
+	local_node_id = device->card->local_node->node_id;
+
+	sbp2_send_management_orb(unit, node_id, generation,
+				 SBP2_RECONNECT_REQUEST, sd->login_id, NULL);
+
+	/* FIXME: handle reconnect failures. */
+
+	sbp2_cancel_orbs(unit);
+
+	sd->generation   = generation;
+	sd->node_id      = node_id;
+	sd->address_high = (LOCAL_BUS | local_node_id) << 16;
+}
+
+static void sbp2_update(struct fw_unit *unit)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+
+	fw_device_enable_phys_dma(device);
+
+	INIT_WORK(&sd->work, sbp2_reconnect);
+	schedule_work(&sd->work);
+}
+
+#define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
+#define SBP2_SW_VERSION_ENTRY	0x00010483
+
+static struct fw_device_id sbp2_id_table[] = {
+	{
+		.match_flags  = FW_MATCH_SPECIFIER_ID | FW_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   = sbp2_driver_name,
+		.bus    = &fw_bus_type,
+		.probe  = sbp2_probe,
+		.remove = sbp2_remove,
+	},
+	.update   = sbp2_update,
+	.id_table = sbp2_id_table,
+};
+
+static unsigned int sbp2_status_to_sense_data(u8 * sbp2_status, u8 * sense_data)
+{
+	sense_data[0] = 0x70;
+	sense_data[1] = 0x0;
+	sense_data[2] = sbp2_status[1];
+	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];
+
+	switch (sbp2_status[0] & 0x3f) {
+	case SAM_STAT_GOOD:
+		return DID_OK;
+
+	case SAM_STAT_CHECK_CONDITION:
+		/* return CHECK_CONDITION << 1 | DID_OK << 16; */
+		return DID_OK;
+
+	case SAM_STAT_BUSY:
+		return DID_BUS_BUSY;
+
+	case SAM_STAT_CONDITION_MET:
+	case SAM_STAT_RESERVATION_CONFLICT:
+	case SAM_STAT_COMMAND_TERMINATED:
+	default:
+		return DID_ERROR;
+	}
+}
+
+static void
+complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
+{
+	struct sbp2_command_orb *orb = (struct sbp2_command_orb *)base_orb;
+	struct fw_unit *unit = orb->unit;
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct scatterlist *sg;
+	int result;
+
+	if (status != NULL) {
+		if (status_get_dead(*status)) {
+			fw_notify("agent died, issuing agent reset\n");
+			sbp2_agent_reset(unit);
+		}
+
+		switch (status_get_response(*status)) {
+		case SBP2_STATUS_REQUEST_COMPLETE:
+			result = DID_OK;
+			break;
+		case SBP2_STATUS_TRANSPORT_FAILURE:
+			result = DID_BUS_BUSY;
+			break;
+		case SBP2_STATUS_ILLEGAL_REQUEST:
+		case SBP2_STATUS_VENDOR_DEPENDENT:
+		default:
+			result = DID_ERROR;
+			break;
+		}
+
+		if (result == DID_OK && 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). */
+		fw_notify("no command orb status, rcode=%d\n",
+			  orb->base.rcode);
+		result = DID_ERROR;
+	}
+
+	dma_unmap_single(device->card->device, orb->base.request_bus,
+			 sizeof orb->request, DMA_TO_DEVICE);
+
+	if (orb->cmd->use_sg > 0) {
+		sg = (struct scatterlist *)orb->cmd->request_buffer;
+		dma_unmap_sg(device->card->device, sg, orb->cmd->use_sg,
+			     orb->cmd->sc_data_direction);
+	}
+
+	if (orb->page_table_bus != 0)
+		dma_unmap_single(device->card->device, orb->page_table_bus,
+				 sizeof orb->page_table_bus, DMA_TO_DEVICE);
+
+	if (orb->request_buffer_bus != 0)
+		dma_unmap_single(device->card->device, orb->request_buffer_bus,
+				 sizeof orb->request_buffer_bus,
+				 DMA_FROM_DEVICE);
+
+	orb->cmd->result = result << 16;
+	orb->done(orb->cmd);
+
+	kfree(orb);
+}
+
+static void sbp2_command_orb_map_scatterlist(struct sbp2_command_orb *orb)
+{
+	struct fw_unit *unit =
+		(struct fw_unit *)orb->cmd->device->host->hostdata[0];
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	struct scatterlist *sg;
+	int sg_len, l, i, j, count;
+	size_t size;
+	dma_addr_t sg_addr;
+
+	sg = (struct scatterlist *)orb->cmd->request_buffer;
+	count = dma_map_sg(device->card->device, sg, orb->cmd->use_sg,
+			   orb->cmd->sc_data_direction);
+
+	/* 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 (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
+		orb->request.data_descriptor.high = sd->address_high;
+		orb->request.data_descriptor.low  = sg_dma_address(sg);
+		orb->request.misc |=
+			command_orb_data_size(sg_dma_len(sg));
+		return;
+	}
+
+	/* Convert the scatterlist to an sbp2 page table.  If any
+	 * scatterlist entries are too big for sbp2 we split the as we go. */
+	for (i = 0, j = 0; i < count; i++) {
+		sg_len = sg_dma_len(sg + i);
+		sg_addr = sg_dma_address(sg + i);
+		while (sg_len) {
+			l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
+			orb->page_table[j].low = sg_addr;
+			orb->page_table[j].high = (l << 16);
+			sg_addr += l;
+			sg_len -= l;
+			j++;
+		}
+	}
+
+	size = sizeof orb->page_table[0] * j;
+
+	/* 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->page_table_bus =
+		dma_map_single(device->card->device, orb->page_table,
+			       size, DMA_TO_DEVICE);
+	orb->request.data_descriptor.high = sd->address_high;
+	orb->request.data_descriptor.low  = orb->page_table_bus;
+	orb->request.misc |=
+		command_orb_page_table_present |
+		command_orb_data_size(j);
+
+	fw_memcpy_to_be32(orb->page_table, orb->page_table, size);
+}
+
+static void sbp2_command_orb_map_buffer(struct sbp2_command_orb *orb)
+{
+	struct fw_unit *unit =
+		(struct fw_unit *)orb->cmd->device->host->hostdata[0];
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+
+	/* As for map_scatterlist, we need to fill in the high bits of
+	 * the data_descriptor pointer. */
+
+	orb->request_buffer_bus =
+		dma_map_single(device->card->device,
+			       orb->cmd->request_buffer,
+			       orb->cmd->request_bufflen,
+			       orb->cmd->sc_data_direction);
+	orb->request.data_descriptor.high = sd->address_high;
+	orb->request.data_descriptor.low  = orb->request_buffer_bus;
+	orb->request.misc |=
+		command_orb_data_size(orb->cmd->request_bufflen);
+}
+
+/* SCSI stack integration */
+
+static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
+{
+	struct fw_unit *unit = (struct fw_unit *)cmd->device->host->hostdata[0];
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_device *sd = unit->device.driver_data;
+	struct sbp2_command_orb *orb;
+
+	/* Bidirectional commands are not yet implemented, and unknown
+	 * transfer direction not handled. */
+	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
+		fw_error("Cannot handle DMA_BIDIRECTIONAL - rejecting command");
+		cmd->result = DID_ERROR << 16;
+		done(cmd);
+		return 0;
+	}
+
+	orb = kzalloc(sizeof *orb, GFP_ATOMIC);
+	if (orb == NULL) {
+		fw_notify("failed to alloc orb\n");
+		cmd->result = DID_NO_CONNECT << 16;
+		done(cmd);
+		return 0;
+	}
+
+	orb->base.request_bus =
+		dma_map_single(device->card->device, &orb->request,
+			       sizeof orb->request, DMA_TO_DEVICE);
+
+	orb->unit = unit;
+	orb->done = done;
+	orb->cmd  = cmd;
+
+	orb->request.next.high   = SBP2_ORB_NULL;
+	orb->request.next.low    = 0x0;
+	/* At speed 100 we can do 512 bytes per packet, at speed 200,
+	 * 1024 bytes per packet etc.  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. */
+	orb->request.misc =
+		command_orb_max_payload(device->node->max_speed + 7) |
+		command_orb_speed(device->node->max_speed) |
+		command_orb_notify;
+
+	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
+		orb->request.misc |=
+			command_orb_direction(SBP2_DIRECTION_FROM_MEDIA);
+	else if (cmd->sc_data_direction == DMA_TO_DEVICE)
+		orb->request.misc |=
+			command_orb_direction(SBP2_DIRECTION_TO_MEDIA);
+
+	if (cmd->use_sg) {
+		sbp2_command_orb_map_scatterlist(orb);
+	} else if (cmd->request_bufflen > SBP2_MAX_SG_ELEMENT_LENGTH) {
+		/* FIXME: Need to split this into a sg list... but
+		 * could we get the scsi or blk layer to do that by
+		 * reporting our max supported block size? */
+		fw_error("command > 64k\n");
+		cmd->result = DID_ERROR << 16;
+		done(cmd);
+		return 0;
+	} else if (cmd->request_bufflen > 0) {
+		sbp2_command_orb_map_buffer(orb);
+	}
+
+	fw_memcpy_to_be32(&orb->request, &orb->request, sizeof orb->request);
+
+	memset(orb->request.command_block,
+	       0, sizeof orb->request.command_block);
+	memcpy(orb->request.command_block, cmd->cmnd, COMMAND_SIZE(*cmd->cmnd));
+
+	orb->base.callback = complete_command_orb;
+
+	sbp2_send_orb(&orb->base, unit, sd->node_id, sd->generation,
+		      sd->command_block_agent_address + SBP2_ORB_POINTER);
+
+	return 0;
+}
+
+static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
+{
+	struct fw_unit *unit = (struct fw_unit *)sdev->host->hostdata[0];
+	struct sbp2_device *sd = unit->device.driver_data;
+
+	if (sdev->type == TYPE_DISK &&
+	    sd->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
+		sdev->skip_ms_page_8 = 1;
+	if (sd->workarounds & SBP2_WORKAROUND_FIX_CAPACITY) {
+		fw_notify("setting fix_capacity for %s\n", unit->device.bus_id);
+		sdev->fix_capacity = 1;
+	}
+
+	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 fw_unit *unit = (struct fw_unit *)cmd->device->host->hostdata[0];
+
+	fw_notify("sbp2_scsi_abort\n");
+
+	sbp2_cancel_orbs(unit);
+
+	return SUCCESS;
+}
+
+static struct scsi_host_template scsi_driver_template = {
+	.module			= THIS_MODULE,
+	.name			= "SBP-2 IEEE-1394",
+	.proc_name		= (char *)sbp2_driver_name,
+	.queuecommand		= sbp2_scsi_queuecommand,
+	.slave_configure	= sbp2_scsi_slave_configure,
+	.eh_abort_handler	= sbp2_scsi_abort,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.use_clustering		= ENABLE_CLUSTERING,
+	.cmd_per_lun		= 1,	/* SBP2_MAX_CMDS, */
+	.can_queue		= 1,		/* SBP2_MAX_CMDS, */
+	.emulated		= 1,
+};
+
+static int add_scsi_devices(struct fw_unit *unit)
+{
+	struct sbp2_device *sd = unit->device.driver_data;
+	int retval, lun;
+
+	sd->scsi_host = scsi_host_alloc(&scsi_driver_template,
+					sizeof(unsigned long));
+	if (sd->scsi_host == NULL) {
+		fw_error("failed to register scsi host\n");
+		return -1;
+	}
+
+	sd->scsi_host->hostdata[0] = (unsigned long)unit;
+	retval = scsi_add_host(sd->scsi_host, &unit->device);
+	if (retval < 0) {
+		fw_error("failed to add scsi host\n");
+		scsi_host_put(sd->scsi_host);
+		return retval;
+	}
+
+	/* FIXME: Loop over luns here. */
+	lun = 0;
+	retval = scsi_add_device(sd->scsi_host, 0, 0, lun);
+	if (retval < 0) {
+		fw_error("failed to add scsi device\n");
+		scsi_remove_host(sd->scsi_host);
+		scsi_host_put(sd->scsi_host);
+		return retval;
+	}
+
+	return 0;
+}
+
+static void remove_scsi_devices(struct fw_unit *unit)
+{
+	struct sbp2_device *sd = unit->device.driver_data;
+
+	scsi_remove_host(sd->scsi_host);
+	scsi_host_put(sd->scsi_host);
+}
+
+MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
+MODULE_DESCRIPTION("SCSI over IEEE1394");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
+
+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);