ieee1394: sbp2: handle "sbp2util_node_write_no_wait failed"

[deliverable/linux.git] / drivers / ieee1394 / sbp2.c

/*
 * sbp2.c - SBP-2 protocol driver for IEEE-1394
 *
 * Copyright (C) 2000 James Goodwin, Filanet Corporation (www.filanet.com)
 * jamesg@filanet.com (JSG)
 *
 * Copyright (C) 2003 Ben Collins <bcollins@debian.org>
 *
 * 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.
 */

/*
 * Brief Description:
 *
 * This driver implements the Serial Bus Protocol 2 (SBP-2) over IEEE-1394
 * under Linux. The SBP-2 driver is implemented as an IEEE-1394 high-level
 * driver. It also registers as a SCSI lower-level driver in order to accept
 * SCSI commands for transport using SBP-2.
 *
 * You may access any attached SBP-2 storage devices as if they were SCSI
 * devices (e.g. mount /dev/sda1,  fdisk, mkfs, etc.).
 *
 * Current Issues:
 *
 *      - Error Handling: SCSI aborts and bus reset requests are handled somewhat
 *        but the code needs additional debugging.
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/stringify.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/blkdev.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/wait.h>

#include <asm/current.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/scatterlist.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 "csr1212.h"
#include "ieee1394.h"
#include "ieee1394_types.h"
#include "ieee1394_core.h"
#include "nodemgr.h"
#include "hosts.h"
#include "highlevel.h"
#include "ieee1394_transactions.h"
#include "sbp2.h"

/*
 * Module load parameter definitions
 */

/*
 * Change max_speed on module load if you have a bad IEEE-1394
 * controller that has trouble running 2KB packets at 400mb.
 *
 * NOTE: On certain OHCI parts I have seen short packets on async transmit
 * (probably due to PCI latency/throughput issues with the part). You can
 * bump down the speed if you are running into problems.
 */
static int max_speed = IEEE1394_SPEED_MAX;
module_param(max_speed, int, 0644);
MODULE_PARM_DESC(max_speed, "Force max speed (3 = 800mb, 2 = 400mb, 1 = 200mb, 0 = 100mb)");

/*
 * Set serialize_io to 1 if you'd like only one scsi command sent
 * down to us at a time (debugging). This might be necessary for very
 * badly behaved sbp2 devices.
 *
 * TODO: Make this configurable per device.
 */
static int serialize_io = 1;
module_param(serialize_io, int, 0444);
MODULE_PARM_DESC(serialize_io, "Serialize I/O coming from scsi drivers (default = 1, faster = 0)");

/*
 * Bump up max_sectors if you'd like to support very large sized
 * transfers. Please note that some older sbp2 bridge chips are broken for
 * transfers greater or equal to 128KB.  Default is a value of 255
 * sectors, or just under 128KB (at 512 byte sector size). I can note that
 * the Oxsemi sbp2 chipsets have no problems supporting very large
 * transfer sizes.
 */
static int max_sectors = SBP2_MAX_SECTORS;
module_param(max_sectors, int, 0444);
MODULE_PARM_DESC(max_sectors, "Change max sectors per I/O supported (default = "
                 __stringify(SBP2_MAX_SECTORS) ")");

/*
 * Exclusive login to sbp2 device? In most cases, the sbp2 driver should
 * do an exclusive login, as it's generally unsafe to have two hosts
 * talking to a single sbp2 device at the same time (filesystem coherency,
 * etc.). If you're running an sbp2 device that supports multiple logins,
 * and you're either running read-only filesystems or some sort of special
 * filesystem supporting multiple hosts, e.g. OpenGFS, Oracle Cluster
 * File System, or Lustre, then set exclusive_login to zero.
 *
 * 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.
 */
static int exclusive_login = 1;
module_param(exclusive_login, int, 0644);
MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device (default = 1)");

/*
 * If any of the following workarounds is required for your device to work,
 * please submit the kernel messages logged by sbp2 to the linux1394-devel
 * mailing list.
 *
 * - 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.
 *
 * - 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.
 */
static int sbp2_default_workarounds;
module_param_named(workarounds, sbp2_default_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)
        ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
        ", or a combination)");

/*
 * Export information about protocols/devices supported by this driver.
 */
static struct ieee1394_device_id sbp2_id_table[] = {
        {
         .match_flags = IEEE1394_MATCH_SPECIFIER_ID | IEEE1394_MATCH_VERSION,
         .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY & 0xffffff,
         .version = SBP2_SW_VERSION_ENTRY & 0xffffff},
        {}
};

MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);

/*
 * Debug levels, configured via kernel config, or enable here.
 */

#define CONFIG_IEEE1394_SBP2_DEBUG 0
/* #define CONFIG_IEEE1394_SBP2_DEBUG_ORBS */
/* #define CONFIG_IEEE1394_SBP2_DEBUG_DMA */
/* #define CONFIG_IEEE1394_SBP2_DEBUG 1 */
/* #define CONFIG_IEEE1394_SBP2_DEBUG 2 */
/* #define CONFIG_IEEE1394_SBP2_PACKET_DUMP */

#ifdef CONFIG_IEEE1394_SBP2_DEBUG_ORBS
#define SBP2_ORB_DEBUG(fmt, args...)    HPSB_ERR("sbp2(%s): "fmt, __FUNCTION__, ## args)
static u32 global_outstanding_command_orbs = 0;
#define outstanding_orb_incr global_outstanding_command_orbs++
#define outstanding_orb_decr global_outstanding_command_orbs--
#else
#define SBP2_ORB_DEBUG(fmt, args...)    do {} while (0)
#define outstanding_orb_incr            do {} while (0)
#define outstanding_orb_decr            do {} while (0)
#endif

#ifdef CONFIG_IEEE1394_SBP2_DEBUG_DMA
#define SBP2_DMA_ALLOC(fmt, args...) \
        HPSB_ERR("sbp2(%s)alloc(%d): "fmt, __FUNCTION__, \
                 ++global_outstanding_dmas, ## args)
#define SBP2_DMA_FREE(fmt, args...) \
        HPSB_ERR("sbp2(%s)free(%d): "fmt, __FUNCTION__, \
                 --global_outstanding_dmas, ## args)
static u32 global_outstanding_dmas = 0;
#else
#define SBP2_DMA_ALLOC(fmt, args...)    do {} while (0)
#define SBP2_DMA_FREE(fmt, args...)     do {} while (0)
#endif

#if CONFIG_IEEE1394_SBP2_DEBUG >= 2
#define SBP2_DEBUG(fmt, args...)        HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_INFO(fmt, args...)         HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)       HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)         HPSB_ERR("sbp2: "fmt, ## args)
#elif CONFIG_IEEE1394_SBP2_DEBUG == 1
#define SBP2_DEBUG(fmt, args...)        HPSB_DEBUG("sbp2: "fmt, ## args)
#define SBP2_INFO(fmt, args...)         HPSB_INFO("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)       HPSB_NOTICE("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)         HPSB_WARN("sbp2: "fmt, ## args)
#else
#define SBP2_DEBUG(fmt, args...)        do {} while (0)
#define SBP2_INFO(fmt, args...)         HPSB_INFO("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)       HPSB_NOTICE("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)         HPSB_WARN("sbp2: "fmt, ## args)
#endif

#define SBP2_ERR(fmt, args...)          HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_DEBUG_ENTER()              SBP2_DEBUG("%s", __FUNCTION__)

/*
 * Globals
 */

static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id,
                                           u32 status);

static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id,
                                      u32 scsi_status, struct scsi_cmnd *SCpnt,
                                      void (*done)(struct scsi_cmnd *));

static struct scsi_host_template scsi_driver_template;

static const u8 sbp2_speedto_max_payload[] = { 0x7, 0x8, 0x9, 0xA, 0xB, 0xC };

static void sbp2_host_reset(struct hpsb_host *host);

static int sbp2_probe(struct device *dev);
static int sbp2_remove(struct device *dev);
static int sbp2_update(struct unit_directory *ud);

static struct hpsb_highlevel sbp2_highlevel = {
        .name =         SBP2_DEVICE_NAME,
        .host_reset =   sbp2_host_reset,
};

static struct hpsb_address_ops sbp2_ops = {
        .write = sbp2_handle_status_write
};

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
static struct hpsb_address_ops sbp2_physdma_ops = {
        .read = sbp2_handle_physdma_read,
        .write = sbp2_handle_physdma_write,
};
#endif

static struct hpsb_protocol_driver sbp2_driver = {
        .name           = "SBP2 Driver",
        .id_table       = sbp2_id_table,
        .update         = sbp2_update,
        .driver         = {
                .name           = SBP2_DEVICE_NAME,
                .bus            = &ieee1394_bus_type,
                .probe          = sbp2_probe,
                .remove         = sbp2_remove,
        },
};

/*
 * 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_id;
        unsigned workarounds;
} sbp2_workarounds_table[] = {
        /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
                .firmware_revision      = 0x002800,
                .model_id               = 0x001010,
                .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
                                          SBP2_WORKAROUND_MODE_SENSE_8,
        },
        /* Initio bridges, actually only needed for some older ones */ {
                .firmware_revision      = 0x000200,
                .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
        },
        /* Symbios bridge */ {
                .firmware_revision      = 0xa0b800,
                .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
        },
        /*
         * Note about the following Apple iPod blacklist entries:
         *
         * There are iPods (2nd gen, 3rd gen) with model_id==0.  Since our
         * matching logic treats 0 as a wildcard, we cannot match this ID
         * without rewriting the matching routine.  Fortunately 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_id               = 0x000021,
                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
        },
        /* iPod mini */ {
                .firmware_revision      = 0x0a2700,
                .model_id               = 0x000023,
                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
        },
        /* iPod Photo */ {
                .firmware_revision      = 0x0a2700,
                .model_id               = 0x00007e,
                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
        }
};

/**************************************
 * General utility functions
 **************************************/

#ifndef __BIG_ENDIAN
/*
 * Converts a buffer from be32 to cpu byte ordering. Length is in bytes.
 */
static inline void sbp2util_be32_to_cpu_buffer(void *buffer, int length)
{
        u32 *temp = buffer;

        for (length = (length >> 2); length--; )
                temp[length] = be32_to_cpu(temp[length]);

        return;
}

/*
 * Converts a buffer from cpu to be32 byte ordering. Length is in bytes.
 */
static inline void sbp2util_cpu_to_be32_buffer(void *buffer, int length)
{
        u32 *temp = buffer;

        for (length = (length >> 2); length--; )
                temp[length] = cpu_to_be32(temp[length]);

        return;
}
#else /* BIG_ENDIAN */
/* Why waste the cpu cycles? */
#define sbp2util_be32_to_cpu_buffer(x,y) do {} while (0)
#define sbp2util_cpu_to_be32_buffer(x,y) do {} while (0)
#endif

#ifdef CONFIG_IEEE1394_SBP2_PACKET_DUMP
/*
 * Debug packet dump routine. Length is in bytes.
 */
static void sbp2util_packet_dump(void *buffer, int length, char *dump_name,
                                 u32 dump_phys_addr)
{
        int i;
        unsigned char *dump = buffer;

        if (!dump || !length || !dump_name)
                return;

        if (dump_phys_addr)
                printk("[%s, 0x%x]", dump_name, dump_phys_addr);
        else
                printk("[%s]", dump_name);
        for (i = 0; i < length; i++) {
                if (i > 0x3f) {
                        printk("\n   ...");
                        break;
                }
                if ((i & 0x3) == 0)
                        printk("  ");
                if ((i & 0xf) == 0)
                        printk("\n   ");
                printk("%02x ", (int)dump[i]);
        }
        printk("\n");

        return;
}
#else
#define sbp2util_packet_dump(w,x,y,z) do {} while (0)
#endif

static DECLARE_WAIT_QUEUE_HEAD(access_wq);

/*
 * Waits for completion of an SBP-2 access request.
 * Returns nonzero if timed out or prematurely interrupted.
 */
static int sbp2util_access_timeout(struct scsi_id_instance_data *scsi_id,
                                   int timeout)
{
        long leftover = wait_event_interruptible_timeout(
                                access_wq, scsi_id->access_complete, timeout);

        scsi_id->access_complete = 0;
        return leftover <= 0;
}

/* Frees an allocated packet */
static void sbp2_free_packet(struct hpsb_packet *packet)
{
        hpsb_free_tlabel(packet);
        hpsb_free_packet(packet);
}

/* This is much like hpsb_node_write(), except it ignores the response
 * subaction and returns immediately. Can be used from interrupts.
 */
static int sbp2util_node_write_no_wait(struct node_entry *ne, u64 addr,
                                       quadlet_t *buffer, size_t length)
{
        struct hpsb_packet *packet;

        packet = hpsb_make_writepacket(ne->host, ne->nodeid,
                                       addr, buffer, length);
        if (!packet)
                return -ENOMEM;

        hpsb_set_packet_complete_task(packet,
                                      (void (*)(void *))sbp2_free_packet,
                                      packet);

        hpsb_node_fill_packet(ne, packet);

        if (hpsb_send_packet(packet) < 0) {
                sbp2_free_packet(packet);
                return -EIO;
        }

        return 0;
}

static void sbp2util_notify_fetch_agent(struct scsi_id_instance_data *scsi_id,
                                        u64 offset, quadlet_t *data, size_t len)
{
        /*
         * There is a small window after a bus reset within which the node
         * entry's generation is current but the reconnect wasn't completed.
         */
        if (atomic_read(&scsi_id->unfinished_reset))
                return;

        if (hpsb_node_write(scsi_id->ne,
                            scsi_id->sbp2_command_block_agent_addr + offset,
                            data, len))
                SBP2_ERR("sbp2util_notify_fetch_agent failed.");
        /*
         * Now accept new SCSI commands, unless a bus reset happended during
         * hpsb_node_write.
         */
        if (!atomic_read(&scsi_id->unfinished_reset))
                scsi_unblock_requests(scsi_id->scsi_host);
}

static void sbp2util_write_orb_pointer(void *p)
{
        quadlet_t data[2];

        data[0] = ORB_SET_NODE_ID(
                        ((struct scsi_id_instance_data *)p)->hi->host->node_id);
        data[1] = ((struct scsi_id_instance_data *)p)->last_orb_dma;
        sbp2util_cpu_to_be32_buffer(data, 8);
        sbp2util_notify_fetch_agent(p, SBP2_ORB_POINTER_OFFSET, data, 8);
}

static void sbp2util_write_doorbell(void *p)
{
        sbp2util_notify_fetch_agent(p, SBP2_DOORBELL_OFFSET, NULL, 4);
}

/*
 * This function is called to create a pool of command orbs used for
 * command processing. It is called when a new sbp2 device is detected.
 */
static int sbp2util_create_command_orb_pool(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        int i;
        unsigned long flags, orbs;
        struct sbp2_command_info *command;

        orbs = serialize_io ? 2 : SBP2_MAX_CMDS;

        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        for (i = 0; i < orbs; i++) {
                command = kzalloc(sizeof(*command), GFP_ATOMIC);
                if (!command) {
                        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock,
                                               flags);
                        return -ENOMEM;
                }
                command->command_orb_dma =
                    pci_map_single(hi->host->pdev, &command->command_orb,
                                   sizeof(struct sbp2_command_orb),
                                   PCI_DMA_TODEVICE);
                SBP2_DMA_ALLOC("single command orb DMA");
                command->sge_dma =
                    pci_map_single(hi->host->pdev,
                                   &command->scatter_gather_element,
                                   sizeof(command->scatter_gather_element),
                                   PCI_DMA_BIDIRECTIONAL);
                SBP2_DMA_ALLOC("scatter_gather_element");
                INIT_LIST_HEAD(&command->list);
                list_add_tail(&command->list, &scsi_id->sbp2_command_orb_completed);
        }
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
        return 0;
}

/*
 * This function is called to delete a pool of command orbs.
 */
static void sbp2util_remove_command_orb_pool(struct scsi_id_instance_data *scsi_id)
{
        struct hpsb_host *host = scsi_id->hi->host;
        struct list_head *lh, *next;
        struct sbp2_command_info *command;
        unsigned long flags;

        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        if (!list_empty(&scsi_id->sbp2_command_orb_completed)) {
                list_for_each_safe(lh, next, &scsi_id->sbp2_command_orb_completed) {
                        command = list_entry(lh, struct sbp2_command_info, list);

                        /* Release our generic DMA's */
                        pci_unmap_single(host->pdev, command->command_orb_dma,
                                         sizeof(struct sbp2_command_orb),
                                         PCI_DMA_TODEVICE);
                        SBP2_DMA_FREE("single command orb DMA");
                        pci_unmap_single(host->pdev, command->sge_dma,
                                         sizeof(command->scatter_gather_element),
                                         PCI_DMA_BIDIRECTIONAL);
                        SBP2_DMA_FREE("scatter_gather_element");

                        kfree(command);
                }
        }
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
        return;
}

/*
 * This function finds the sbp2_command for a given outstanding command
 * orb.Only looks at the inuse list.
 */
static struct sbp2_command_info *sbp2util_find_command_for_orb(
                struct scsi_id_instance_data *scsi_id, dma_addr_t orb)
{
        struct sbp2_command_info *command;
        unsigned long flags;

        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        if (!list_empty(&scsi_id->sbp2_command_orb_inuse)) {
                list_for_each_entry(command, &scsi_id->sbp2_command_orb_inuse, list) {
                        if (command->command_orb_dma == orb) {
                                spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
                                return command;
                        }
                }
        }
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

        SBP2_ORB_DEBUG("could not match command orb %x", (unsigned int)orb);

        return NULL;
}

/*
 * This function finds the sbp2_command for a given outstanding SCpnt.
 * Only looks at the inuse list.
 * Must be called with scsi_id->sbp2_command_orb_lock held.
 */
static struct sbp2_command_info *sbp2util_find_command_for_SCpnt(
                struct scsi_id_instance_data *scsi_id, void *SCpnt)
{
        struct sbp2_command_info *command;

        if (!list_empty(&scsi_id->sbp2_command_orb_inuse))
                list_for_each_entry(command, &scsi_id->sbp2_command_orb_inuse, list)
                        if (command->Current_SCpnt == SCpnt)
                                return command;
        return NULL;
}

/*
 * This function allocates a command orb used to send a scsi command.
 */
static struct sbp2_command_info *sbp2util_allocate_command_orb(
                struct scsi_id_instance_data *scsi_id,
                struct scsi_cmnd *Current_SCpnt,
                void (*Current_done)(struct scsi_cmnd *))
{
        struct list_head *lh;
        struct sbp2_command_info *command = NULL;
        unsigned long flags;

        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        if (!list_empty(&scsi_id->sbp2_command_orb_completed)) {
                lh = scsi_id->sbp2_command_orb_completed.next;
                list_del(lh);
                command = list_entry(lh, struct sbp2_command_info, list);
                command->Current_done = Current_done;
                command->Current_SCpnt = Current_SCpnt;
                list_add_tail(&command->list, &scsi_id->sbp2_command_orb_inuse);
        } else {
                SBP2_ERR("%s: no orbs available", __FUNCTION__);
        }
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
        return command;
}

/* Free our DMA's */
static void sbp2util_free_command_dma(struct sbp2_command_info *command)
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)command->Current_SCpnt->device->host->hostdata[0];
        struct hpsb_host *host;

        if (!scsi_id) {
                SBP2_ERR("%s: scsi_id == NULL", __FUNCTION__);
                return;
        }

        host = scsi_id->ud->ne->host;

        if (command->cmd_dma) {
                if (command->dma_type == CMD_DMA_SINGLE) {
                        pci_unmap_single(host->pdev, command->cmd_dma,
                                         command->dma_size, command->dma_dir);
                        SBP2_DMA_FREE("single bulk");
                } else if (command->dma_type == CMD_DMA_PAGE) {
                        pci_unmap_page(host->pdev, command->cmd_dma,
                                       command->dma_size, command->dma_dir);
                        SBP2_DMA_FREE("single page");
                } /* XXX: Check for CMD_DMA_NONE bug */
                command->dma_type = CMD_DMA_NONE;
                command->cmd_dma = 0;
        }

        if (command->sge_buffer) {
                pci_unmap_sg(host->pdev, command->sge_buffer,
                             command->dma_size, command->dma_dir);
                SBP2_DMA_FREE("scatter list");
                command->sge_buffer = NULL;
        }
}

/*
 * This function moves a command to the completed orb list.
 * Must be called with scsi_id->sbp2_command_orb_lock held.
 */
static void sbp2util_mark_command_completed(
                struct scsi_id_instance_data *scsi_id,
                struct sbp2_command_info *command)
{
        list_del(&command->list);
        sbp2util_free_command_dma(command);
        list_add_tail(&command->list, &scsi_id->sbp2_command_orb_completed);
}

/*
 * Is scsi_id valid? Is the 1394 node still present?
 */
static inline int sbp2util_node_is_available(struct scsi_id_instance_data *scsi_id)
{
        return scsi_id && scsi_id->ne && !scsi_id->ne->in_limbo;
}

/*********************************************
 * IEEE-1394 core driver stack related section
 *********************************************/
static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud);

static int sbp2_probe(struct device *dev)
{
        struct unit_directory *ud;
        struct scsi_id_instance_data *scsi_id;

        SBP2_DEBUG_ENTER();

        ud = container_of(dev, struct unit_directory, device);

        /* Don't probe UD's that have the LUN flag. We'll probe the LUN(s)
         * instead. */
        if (ud->flags & UNIT_DIRECTORY_HAS_LUN_DIRECTORY)
                return -ENODEV;

        scsi_id = sbp2_alloc_device(ud);

        if (!scsi_id)
                return -ENOMEM;

        sbp2_parse_unit_directory(scsi_id, ud);

        return sbp2_start_device(scsi_id);
}

static int sbp2_remove(struct device *dev)
{
        struct unit_directory *ud;
        struct scsi_id_instance_data *scsi_id;
        struct scsi_device *sdev;

        SBP2_DEBUG_ENTER();

        ud = container_of(dev, struct unit_directory, device);
        scsi_id = ud->device.driver_data;
        if (!scsi_id)
                return 0;

        if (scsi_id->scsi_host) {
                /* Get rid of enqueued commands if there is no chance to
                 * send them. */
                if (!sbp2util_node_is_available(scsi_id))
                        sbp2scsi_complete_all_commands(scsi_id, DID_NO_CONNECT);
                /* scsi_remove_device() will trigger shutdown functions of SCSI
                 * highlevel drivers which would deadlock if blocked. */
                atomic_set(&scsi_id->unfinished_reset, 0);
                scsi_unblock_requests(scsi_id->scsi_host);
        }
        sdev = scsi_id->sdev;
        if (sdev) {
                scsi_id->sdev = NULL;
                scsi_remove_device(sdev);
        }

        sbp2_logout_device(scsi_id);
        sbp2_remove_device(scsi_id);

        return 0;
}

static int sbp2_update(struct unit_directory *ud)
{
        struct scsi_id_instance_data *scsi_id = ud->device.driver_data;

        SBP2_DEBUG_ENTER();

        if (sbp2_reconnect_device(scsi_id)) {

                /*
                 * Ok, reconnect has failed. Perhaps we didn't
                 * reconnect fast enough. Try doing a regular login, but
                 * first do a logout just in case of any weirdness.
                 */
                sbp2_logout_device(scsi_id);

                if (sbp2_login_device(scsi_id)) {
                        /* Login failed too, just fail, and the backend
                         * will call our sbp2_remove for us */
                        SBP2_ERR("Failed to reconnect to sbp2 device!");
                        return -EBUSY;
                }
        }

        /* Set max retries to something large on the device. */
        sbp2_set_busy_timeout(scsi_id);

        /* Do a SBP-2 fetch agent reset. */
        sbp2_agent_reset(scsi_id, 1);

        /* Get the max speed and packet size that we can use. */
        sbp2_max_speed_and_size(scsi_id);

        /* Complete any pending commands with busy (so they get
         * retried) and remove them from our queue
         */
        sbp2scsi_complete_all_commands(scsi_id, DID_BUS_BUSY);

        /* Make sure we unblock requests (since this is likely after a bus
         * reset). */
        atomic_set(&scsi_id->unfinished_reset, 0);
        scsi_unblock_requests(scsi_id->scsi_host);

        return 0;
}

/* This functions is called by the sbp2_probe, for each new device. We now
 * allocate one scsi host for each scsi_id (unit directory). */
static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud)
{
        struct sbp2scsi_host_info *hi;
        struct Scsi_Host *scsi_host = NULL;
        struct scsi_id_instance_data *scsi_id = NULL;

        SBP2_DEBUG_ENTER();

        scsi_id = kzalloc(sizeof(*scsi_id), GFP_KERNEL);
        if (!scsi_id) {
                SBP2_ERR("failed to create scsi_id");
                goto failed_alloc;
        }

        scsi_id->ne = ud->ne;
        scsi_id->ud = ud;
        scsi_id->speed_code = IEEE1394_SPEED_100;
        scsi_id->max_payload_size = sbp2_speedto_max_payload[IEEE1394_SPEED_100];
        scsi_id->status_fifo_addr = CSR1212_INVALID_ADDR_SPACE;
        INIT_LIST_HEAD(&scsi_id->sbp2_command_orb_inuse);
        INIT_LIST_HEAD(&scsi_id->sbp2_command_orb_completed);
        INIT_LIST_HEAD(&scsi_id->scsi_list);
        spin_lock_init(&scsi_id->sbp2_command_orb_lock);
        atomic_set(&scsi_id->unfinished_reset, 0);
        INIT_WORK(&scsi_id->protocol_work, NULL, NULL);

        ud->device.driver_data = scsi_id;

        hi = hpsb_get_hostinfo(&sbp2_highlevel, ud->ne->host);
        if (!hi) {
                hi = hpsb_create_hostinfo(&sbp2_highlevel, ud->ne->host, sizeof(*hi));
                if (!hi) {
                        SBP2_ERR("failed to allocate hostinfo");
                        goto failed_alloc;
                }
                SBP2_DEBUG("sbp2_alloc_device: allocated hostinfo");
                hi->host = ud->ne->host;
                INIT_LIST_HEAD(&hi->scsi_ids);

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
                /* Handle data movement if physical dma is not
                 * enabled or not supported on host controller */
                if (!hpsb_register_addrspace(&sbp2_highlevel, ud->ne->host,
                                             &sbp2_physdma_ops,
                                             0x0ULL, 0xfffffffcULL)) {
                        SBP2_ERR("failed to register lower 4GB address range");
                        goto failed_alloc;
                }
#endif
        }

        /* Prevent unloading of the 1394 host */
        if (!try_module_get(hi->host->driver->owner)) {
                SBP2_ERR("failed to get a reference on 1394 host driver");
                goto failed_alloc;
        }

        scsi_id->hi = hi;

        list_add_tail(&scsi_id->scsi_list, &hi->scsi_ids);

        /* Register the status FIFO address range. We could use the same FIFO
         * for targets at different nodes. However we need different FIFOs per
         * target in order to support multi-unit devices.
         * The FIFO is located out of the local host controller's physical range
         * but, if possible, within the posted write area. Status writes will
         * then be performed as unified transactions. This slightly reduces
         * bandwidth usage, and some Prolific based devices seem to require it.
         */
        scsi_id->status_fifo_addr = hpsb_allocate_and_register_addrspace(
                        &sbp2_highlevel, ud->ne->host, &sbp2_ops,
                        sizeof(struct sbp2_status_block), sizeof(quadlet_t),
                        ud->ne->host->low_addr_space, CSR1212_ALL_SPACE_END);
        if (scsi_id->status_fifo_addr == CSR1212_INVALID_ADDR_SPACE) {
                SBP2_ERR("failed to allocate status FIFO address range");
                goto failed_alloc;
        }

        /* Register our host with the SCSI stack. */
        scsi_host = scsi_host_alloc(&scsi_driver_template,
                                    sizeof(unsigned long));
        if (!scsi_host) {
                SBP2_ERR("failed to register scsi host");
                goto failed_alloc;
        }

        scsi_host->hostdata[0] = (unsigned long)scsi_id;

        if (!scsi_add_host(scsi_host, &ud->device)) {
                scsi_id->scsi_host = scsi_host;
                return scsi_id;
        }

        SBP2_ERR("failed to add scsi host");
        scsi_host_put(scsi_host);

failed_alloc:
        sbp2_remove_device(scsi_id);
        return NULL;
}

static void sbp2_host_reset(struct hpsb_host *host)
{
        struct sbp2scsi_host_info *hi;
        struct scsi_id_instance_data *scsi_id;

        hi = hpsb_get_hostinfo(&sbp2_highlevel, host);

        if (hi) {
                list_for_each_entry(scsi_id, &hi->scsi_ids, scsi_list) {
                        atomic_set(&scsi_id->unfinished_reset, 1);
                        scsi_block_requests(scsi_id->scsi_host);
                }
        }
}

/*
 * This function is where we first pull the node unique ids, and then
 * allocate memory and register a SBP-2 device.
 */
static int sbp2_start_device(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        int error;

        SBP2_DEBUG_ENTER();

        /* Login FIFO DMA */
        scsi_id->login_response =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_login_response),
                                     &scsi_id->login_response_dma);
        if (!scsi_id->login_response)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for login FIFO");

        /* Query logins ORB DMA */
        scsi_id->query_logins_orb =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_query_logins_orb),
                                     &scsi_id->query_logins_orb_dma);
        if (!scsi_id->query_logins_orb)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for query logins ORB");

        /* Query logins response DMA */
        scsi_id->query_logins_response =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_query_logins_response),
                                     &scsi_id->query_logins_response_dma);
        if (!scsi_id->query_logins_response)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for query logins response");

        /* Reconnect ORB DMA */
        scsi_id->reconnect_orb =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_reconnect_orb),
                                     &scsi_id->reconnect_orb_dma);
        if (!scsi_id->reconnect_orb)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for reconnect ORB");

        /* Logout ORB DMA */
        scsi_id->logout_orb =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_logout_orb),
                                     &scsi_id->logout_orb_dma);
        if (!scsi_id->logout_orb)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for logout ORB");

        /* Login ORB DMA */
        scsi_id->login_orb =
                pci_alloc_consistent(hi->host->pdev,
                                     sizeof(struct sbp2_login_orb),
                                     &scsi_id->login_orb_dma);
        if (!scsi_id->login_orb)
                goto alloc_fail;
        SBP2_DMA_ALLOC("consistent DMA region for login ORB");

        SBP2_DEBUG("New SBP-2 device inserted, SCSI ID = %x", scsi_id->ud->id);

        /*
         * Create our command orb pool
         */
        if (sbp2util_create_command_orb_pool(scsi_id)) {
                SBP2_ERR("sbp2util_create_command_orb_pool failed!");
                sbp2_remove_device(scsi_id);
                return -ENOMEM;
        }

        /* Schedule a timeout here. The reason is that we may be so close
         * to a bus reset, that the device is not available for logins.
         * This can happen when the bus reset is caused by the host
         * connected to the sbp2 device being removed. That host would
         * have a certain amount of time to relogin before the sbp2 device
         * allows someone else to login instead. One second makes sense. */
        msleep_interruptible(1000);
        if (signal_pending(current)) {
                sbp2_remove_device(scsi_id);
                return -EINTR;
        }

        /*
         * Login to the sbp-2 device
         */
        if (sbp2_login_device(scsi_id)) {
                /* Login failed, just remove the device. */
                sbp2_remove_device(scsi_id);
                return -EBUSY;
        }

        /*
         * Set max retries to something large on the device
         */
        sbp2_set_busy_timeout(scsi_id);

        /*
         * Do a SBP-2 fetch agent reset
         */
        sbp2_agent_reset(scsi_id, 1);

        /*
         * Get the max speed and packet size that we can use
         */
        sbp2_max_speed_and_size(scsi_id);

        /* Add this device to the scsi layer now */
        error = scsi_add_device(scsi_id->scsi_host, 0, scsi_id->ud->id, 0);
        if (error) {
                SBP2_ERR("scsi_add_device failed");
                sbp2_logout_device(scsi_id);
                sbp2_remove_device(scsi_id);
                return error;
        }

        return 0;

alloc_fail:
        SBP2_ERR("Could not allocate memory for scsi_id");
        sbp2_remove_device(scsi_id);
        return -ENOMEM;
}

/*
 * This function removes an sbp2 device from the sbp2scsi_host_info struct.
 */
static void sbp2_remove_device(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi;

        SBP2_DEBUG_ENTER();

        if (!scsi_id)
                return;

        hi = scsi_id->hi;

        /* This will remove our scsi device aswell */
        if (scsi_id->scsi_host) {
                scsi_remove_host(scsi_id->scsi_host);
                scsi_host_put(scsi_id->scsi_host);
        }
        flush_scheduled_work();
        sbp2util_remove_command_orb_pool(scsi_id);

        list_del(&scsi_id->scsi_list);

        if (scsi_id->login_response) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_login_response),
                                    scsi_id->login_response,
                                    scsi_id->login_response_dma);
                SBP2_DMA_FREE("single login FIFO");
        }

        if (scsi_id->login_orb) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_login_orb),
                                    scsi_id->login_orb,
                                    scsi_id->login_orb_dma);
                SBP2_DMA_FREE("single login ORB");
        }

        if (scsi_id->reconnect_orb) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_reconnect_orb),
                                    scsi_id->reconnect_orb,
                                    scsi_id->reconnect_orb_dma);
                SBP2_DMA_FREE("single reconnect orb");
        }

        if (scsi_id->logout_orb) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_logout_orb),
                                    scsi_id->logout_orb,
                                    scsi_id->logout_orb_dma);
                SBP2_DMA_FREE("single logout orb");
        }

        if (scsi_id->query_logins_orb) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_query_logins_orb),
                                    scsi_id->query_logins_orb,
                                    scsi_id->query_logins_orb_dma);
                SBP2_DMA_FREE("single query logins orb");
        }

        if (scsi_id->query_logins_response) {
                pci_free_consistent(hi->host->pdev,
                                    sizeof(struct sbp2_query_logins_response),
                                    scsi_id->query_logins_response,
                                    scsi_id->query_logins_response_dma);
                SBP2_DMA_FREE("single query logins data");
        }

        if (scsi_id->status_fifo_addr != CSR1212_INVALID_ADDR_SPACE)
                hpsb_unregister_addrspace(&sbp2_highlevel, hi->host,
                                          scsi_id->status_fifo_addr);

        scsi_id->ud->device.driver_data = NULL;

        if (hi)
                module_put(hi->host->driver->owner);

        SBP2_DEBUG("SBP-2 device removed, SCSI ID = %d", scsi_id->ud->id);

        kfree(scsi_id);
}

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
/*
 * This function deals with physical dma write requests (for adapters that do not support
 * physical dma in hardware). Mostly just here for debugging...
 */
static int sbp2_handle_physdma_write(struct hpsb_host *host, int nodeid,
                                     int destid, quadlet_t *data, u64 addr,
                                     size_t length, u16 flags)
{

        /*
         * Manually put the data in the right place.
         */
        memcpy(bus_to_virt((u32) addr), data, length);
        sbp2util_packet_dump(data, length, "sbp2 phys dma write by device",
                             (u32) addr);
        return RCODE_COMPLETE;
}

/*
 * This function deals with physical dma read requests (for adapters that do not support
 * physical dma in hardware). Mostly just here for debugging...
 */
static int sbp2_handle_physdma_read(struct hpsb_host *host, int nodeid,
                                    quadlet_t *data, u64 addr, size_t length,
                                    u16 flags)
{

        /*
         * Grab data from memory and send a read response.
         */
        memcpy(data, bus_to_virt((u32) addr), length);
        sbp2util_packet_dump(data, length, "sbp2 phys dma read by device",
                             (u32) addr);
        return RCODE_COMPLETE;
}
#endif

/**************************************
 * SBP-2 protocol related section
 **************************************/

/*
 * This function queries the device for the maximum concurrent logins it
 * supports.
 */
static int sbp2_query_logins(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        quadlet_t data[2];
        int max_logins;
        int active_logins;

        SBP2_DEBUG_ENTER();

        scsi_id->query_logins_orb->reserved1 = 0x0;
        scsi_id->query_logins_orb->reserved2 = 0x0;

        scsi_id->query_logins_orb->query_response_lo = scsi_id->query_logins_response_dma;
        scsi_id->query_logins_orb->query_response_hi = ORB_SET_NODE_ID(hi->host->node_id);

        scsi_id->query_logins_orb->lun_misc = ORB_SET_FUNCTION(SBP2_QUERY_LOGINS_REQUEST);
        scsi_id->query_logins_orb->lun_misc |= ORB_SET_NOTIFY(1);
        scsi_id->query_logins_orb->lun_misc |= ORB_SET_LUN(scsi_id->sbp2_lun);

        scsi_id->query_logins_orb->reserved_resp_length =
                ORB_SET_QUERY_LOGINS_RESP_LENGTH(sizeof(struct sbp2_query_logins_response));

        scsi_id->query_logins_orb->status_fifo_hi =
                ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
        scsi_id->query_logins_orb->status_fifo_lo =
                ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

        sbp2util_cpu_to_be32_buffer(scsi_id->query_logins_orb, sizeof(struct sbp2_query_logins_orb));

        sbp2util_packet_dump(scsi_id->query_logins_orb, sizeof(struct sbp2_query_logins_orb),
                             "sbp2 query logins orb", scsi_id->query_logins_orb_dma);

        memset(scsi_id->query_logins_response, 0, sizeof(struct sbp2_query_logins_response));

        data[0] = ORB_SET_NODE_ID(hi->host->node_id);
        data[1] = scsi_id->query_logins_orb_dma;
        sbp2util_cpu_to_be32_buffer(data, 8);

        hpsb_node_write(scsi_id->ne, scsi_id->sbp2_management_agent_addr, data, 8);

        if (sbp2util_access_timeout(scsi_id, 2*HZ)) {
                SBP2_INFO("Error querying logins to SBP-2 device - timed out");
                return -EIO;
        }

        if (scsi_id->status_block.ORB_offset_lo != scsi_id->query_logins_orb_dma) {
                SBP2_INFO("Error querying logins to SBP-2 device - timed out");
                return -EIO;
        }

        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
                SBP2_INFO("Error querying logins to SBP-2 device - failed");
                return -EIO;
        }

        sbp2util_cpu_to_be32_buffer(scsi_id->query_logins_response, sizeof(struct sbp2_query_logins_response));

        SBP2_DEBUG("length_max_logins = %x",
                   (unsigned int)scsi_id->query_logins_response->length_max_logins);

        max_logins = RESPONSE_GET_MAX_LOGINS(scsi_id->query_logins_response->length_max_logins);
        SBP2_INFO("Maximum concurrent logins supported: %d", max_logins);

        active_logins = RESPONSE_GET_ACTIVE_LOGINS(scsi_id->query_logins_response->length_max_logins);
        SBP2_INFO("Number of active logins: %d", active_logins);

        if (active_logins >= max_logins) {
                return -EIO;
        }

        return 0;
}

/*
 * This function is called in order to login to a particular SBP-2 device,
 * after a bus reset.
 */
static int sbp2_login_device(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        quadlet_t data[2];

        SBP2_DEBUG_ENTER();

        if (!scsi_id->login_orb) {
                SBP2_DEBUG("%s: login_orb not alloc'd!", __FUNCTION__);
                return -EIO;
        }

        if (!exclusive_login) {
                if (sbp2_query_logins(scsi_id)) {
                        SBP2_INFO("Device does not support any more concurrent logins");
                        return -EIO;
                }
        }

        /* Set-up login ORB, assume no password */
        scsi_id->login_orb->password_hi = 0;
        scsi_id->login_orb->password_lo = 0;

        scsi_id->login_orb->login_response_lo = scsi_id->login_response_dma;
        scsi_id->login_orb->login_response_hi = ORB_SET_NODE_ID(hi->host->node_id);

        scsi_id->login_orb->lun_misc = ORB_SET_FUNCTION(SBP2_LOGIN_REQUEST);
        scsi_id->login_orb->lun_misc |= ORB_SET_RECONNECT(0);   /* One second reconnect time */
        scsi_id->login_orb->lun_misc |= ORB_SET_EXCLUSIVE(exclusive_login);     /* Exclusive access to device */
        scsi_id->login_orb->lun_misc |= ORB_SET_NOTIFY(1);      /* Notify us of login complete */
        scsi_id->login_orb->lun_misc |= ORB_SET_LUN(scsi_id->sbp2_lun);

        scsi_id->login_orb->passwd_resp_lengths =
                ORB_SET_LOGIN_RESP_LENGTH(sizeof(struct sbp2_login_response));

        scsi_id->login_orb->status_fifo_hi =
                ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
        scsi_id->login_orb->status_fifo_lo =
                ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

        sbp2util_cpu_to_be32_buffer(scsi_id->login_orb, sizeof(struct sbp2_login_orb));

        sbp2util_packet_dump(scsi_id->login_orb, sizeof(struct sbp2_login_orb),
                             "sbp2 login orb", scsi_id->login_orb_dma);

        memset(scsi_id->login_response, 0, sizeof(struct sbp2_login_response));

        data[0] = ORB_SET_NODE_ID(hi->host->node_id);
        data[1] = scsi_id->login_orb_dma;
        sbp2util_cpu_to_be32_buffer(data, 8);

        hpsb_node_write(scsi_id->ne, scsi_id->sbp2_management_agent_addr, data, 8);

        /*
         * Wait for login status (up to 20 seconds)...
         */
        if (sbp2util_access_timeout(scsi_id, 20*HZ)) {
                SBP2_ERR("Error logging into SBP-2 device - timed out");
                return -EIO;
        }

        /*
         * Sanity. Make sure status returned matches login orb.
         */
        if (scsi_id->status_block.ORB_offset_lo != scsi_id->login_orb_dma) {
                SBP2_ERR("Error logging into SBP-2 device - timed out");
                return -EIO;
        }

        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
                SBP2_ERR("Error logging into SBP-2 device - failed");
                return -EIO;
        }

        /*
         * Byte swap the login response, for use when reconnecting or
         * logging out.
         */
        sbp2util_cpu_to_be32_buffer(scsi_id->login_response, sizeof(struct sbp2_login_response));

        /*
         * Grab our command block agent address from the login response.
         */
        SBP2_DEBUG("command_block_agent_hi = %x",
                   (unsigned int)scsi_id->login_response->command_block_agent_hi);
        SBP2_DEBUG("command_block_agent_lo = %x",
                   (unsigned int)scsi_id->login_response->command_block_agent_lo);

        scsi_id->sbp2_command_block_agent_addr =
                ((u64)scsi_id->login_response->command_block_agent_hi) << 32;
        scsi_id->sbp2_command_block_agent_addr |= ((u64)scsi_id->login_response->command_block_agent_lo);
        scsi_id->sbp2_command_block_agent_addr &= 0x0000ffffffffffffULL;

        SBP2_INFO("Logged into SBP-2 device");
        return 0;
}

/*
 * This function is called in order to logout from a particular SBP-2
 * device, usually called during driver unload.
 */
static int sbp2_logout_device(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        quadlet_t data[2];
        int error;

        SBP2_DEBUG_ENTER();

        /*
         * Set-up logout ORB
         */
        scsi_id->logout_orb->reserved1 = 0x0;
        scsi_id->logout_orb->reserved2 = 0x0;
        scsi_id->logout_orb->reserved3 = 0x0;
        scsi_id->logout_orb->reserved4 = 0x0;

        scsi_id->logout_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_LOGOUT_REQUEST);
        scsi_id->logout_orb->login_ID_misc |= ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID);

        /* Notify us when complete */
        scsi_id->logout_orb->login_ID_misc |= ORB_SET_NOTIFY(1);

        scsi_id->logout_orb->reserved5 = 0x0;
        scsi_id->logout_orb->status_fifo_hi =
                ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
        scsi_id->logout_orb->status_fifo_lo =
                ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

        /*
         * Byte swap ORB if necessary
         */
        sbp2util_cpu_to_be32_buffer(scsi_id->logout_orb, sizeof(struct sbp2_logout_orb));

        sbp2util_packet_dump(scsi_id->logout_orb, sizeof(struct sbp2_logout_orb),
                             "sbp2 logout orb", scsi_id->logout_orb_dma);

        /*
         * Ok, let's write to the target's management agent register
         */
        data[0] = ORB_SET_NODE_ID(hi->host->node_id);
        data[1] = scsi_id->logout_orb_dma;
        sbp2util_cpu_to_be32_buffer(data, 8);

        error = hpsb_node_write(scsi_id->ne,
                                scsi_id->sbp2_management_agent_addr, data, 8);
        if (error)
                return error;

        /* Wait for device to logout...1 second. */
        if (sbp2util_access_timeout(scsi_id, HZ))
                return -EIO;

        SBP2_INFO("Logged out of SBP-2 device");
        return 0;
}

/*
 * This function is called in order to reconnect to a particular SBP-2
 * device, after a bus reset.
 */
static int sbp2_reconnect_device(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        quadlet_t data[2];
        int error;

        SBP2_DEBUG_ENTER();

        /*
         * Set-up reconnect ORB
         */
        scsi_id->reconnect_orb->reserved1 = 0x0;
        scsi_id->reconnect_orb->reserved2 = 0x0;
        scsi_id->reconnect_orb->reserved3 = 0x0;
        scsi_id->reconnect_orb->reserved4 = 0x0;

        scsi_id->reconnect_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_RECONNECT_REQUEST);
        scsi_id->reconnect_orb->login_ID_misc |=
                ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID);

        /* Notify us when complete */
        scsi_id->reconnect_orb->login_ID_misc |= ORB_SET_NOTIFY(1);

        scsi_id->reconnect_orb->reserved5 = 0x0;
        scsi_id->reconnect_orb->status_fifo_hi =
                ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
        scsi_id->reconnect_orb->status_fifo_lo =
                ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

        /*
         * Byte swap ORB if necessary
         */
        sbp2util_cpu_to_be32_buffer(scsi_id->reconnect_orb, sizeof(struct sbp2_reconnect_orb));

        sbp2util_packet_dump(scsi_id->reconnect_orb, sizeof(struct sbp2_reconnect_orb),
                             "sbp2 reconnect orb", scsi_id->reconnect_orb_dma);

        data[0] = ORB_SET_NODE_ID(hi->host->node_id);
        data[1] = scsi_id->reconnect_orb_dma;
        sbp2util_cpu_to_be32_buffer(data, 8);

        error = hpsb_node_write(scsi_id->ne,
                                scsi_id->sbp2_management_agent_addr, data, 8);
        if (error)
                return error;

        /*
         * Wait for reconnect status (up to 1 second)...
         */
        if (sbp2util_access_timeout(scsi_id, HZ)) {
                SBP2_ERR("Error reconnecting to SBP-2 device - timed out");
                return -EIO;
        }

        /*
         * Sanity. Make sure status returned matches reconnect orb.
         */
        if (scsi_id->status_block.ORB_offset_lo != scsi_id->reconnect_orb_dma) {
                SBP2_ERR("Error reconnecting to SBP-2 device - timed out");
                return -EIO;
        }

        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
                SBP2_ERR("Error reconnecting to SBP-2 device - failed");
                return -EIO;
        }

        HPSB_DEBUG("Reconnected to SBP-2 device");
        return 0;
}

/*
 * This function is called in order to set the busy timeout (number of
 * retries to attempt) on the sbp2 device.
 */
static int sbp2_set_busy_timeout(struct scsi_id_instance_data *scsi_id)
{
        quadlet_t data;

        SBP2_DEBUG_ENTER();

        data = cpu_to_be32(SBP2_BUSY_TIMEOUT_VALUE);
        if (hpsb_node_write(scsi_id->ne, SBP2_BUSY_TIMEOUT_ADDRESS, &data, 4))
                SBP2_ERR("%s error", __FUNCTION__);
        return 0;
}

/*
 * This function is called to parse sbp2 device's config rom unit
 * directory. Used to determine things like sbp2 management agent offset,
 * and command set used (SCSI or RBC).
 */
static void sbp2_parse_unit_directory(struct scsi_id_instance_data *scsi_id,
                                      struct unit_directory *ud)
{
        struct csr1212_keyval *kv;
        struct csr1212_dentry *dentry;
        u64 management_agent_addr;
        u32 command_set_spec_id, command_set, unit_characteristics,
            firmware_revision;
        unsigned workarounds;
        int i;

        SBP2_DEBUG_ENTER();

        management_agent_addr = 0x0;
        command_set_spec_id = 0x0;
        command_set = 0x0;
        unit_characteristics = 0x0;
        firmware_revision = 0x0;

        /* Handle different fields in the unit directory, based on keys */
        csr1212_for_each_dir_entry(ud->ne->csr, kv, ud->ud_kv, dentry) {
                switch (kv->key.id) {
                case CSR1212_KV_ID_DEPENDENT_INFO:
                        if (kv->key.type == CSR1212_KV_TYPE_CSR_OFFSET) {
                                /* Save off the management agent address */
                                management_agent_addr =
                                    CSR1212_REGISTER_SPACE_BASE +
                                    (kv->value.csr_offset << 2);

                                SBP2_DEBUG("sbp2_management_agent_addr = %x",
                                           (unsigned int)management_agent_addr);
                        } else if (kv->key.type == CSR1212_KV_TYPE_IMMEDIATE) {
                                scsi_id->sbp2_lun =
                                    ORB_SET_LUN(kv->value.immediate);
                        }
                        break;

                case SBP2_COMMAND_SET_SPEC_ID_KEY:
                        /* Command spec organization */
                        command_set_spec_id = kv->value.immediate;
                        SBP2_DEBUG("sbp2_command_set_spec_id = %x",
                                   (unsigned int)command_set_spec_id);
                        break;

                case SBP2_COMMAND_SET_KEY:
                        /* Command set used by sbp2 device */
                        command_set = kv->value.immediate;
                        SBP2_DEBUG("sbp2_command_set = %x",
                                   (unsigned int)command_set);
                        break;

                case SBP2_UNIT_CHARACTERISTICS_KEY:
                        /*
                         * Unit characterisitcs (orb related stuff
                         * that I'm not yet paying attention to)
                         */
                        unit_characteristics = kv->value.immediate;
                        SBP2_DEBUG("sbp2_unit_characteristics = %x",
                                   (unsigned int)unit_characteristics);
                        break;

                case SBP2_FIRMWARE_REVISION_KEY:
                        /* Firmware revision */
                        firmware_revision = kv->value.immediate;
                        SBP2_DEBUG("sbp2_firmware_revision = %x",
                                   (unsigned int)firmware_revision);
                        break;

                default:
                        break;
                }
        }

        workarounds = sbp2_default_workarounds;

        if (!(workarounds & SBP2_WORKAROUND_OVERRIDE))
                for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
                        if (sbp2_workarounds_table[i].firmware_revision &&
                            sbp2_workarounds_table[i].firmware_revision !=
                            (firmware_revision & 0xffff00))
                                continue;
                        if (sbp2_workarounds_table[i].model_id &&
                            sbp2_workarounds_table[i].model_id != ud->model_id)
                                continue;
                        workarounds |= sbp2_workarounds_table[i].workarounds;
                        break;
                }

        if (workarounds)
                SBP2_INFO("Workarounds for node " NODE_BUS_FMT ": 0x%x "
                          "(firmware_revision 0x%06x, vendor_id 0x%06x,"
                          " model_id 0x%06x)",
                          NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
                          workarounds, firmware_revision,
                          ud->vendor_id ? ud->vendor_id : ud->ne->vendor_id,
                          ud->model_id);

        /* We would need one SCSI host template for each target to adjust
         * max_sectors on the fly, therefore warn only. */
        if (workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
            (max_sectors * 512) > (128 * 1024))
                SBP2_WARN("Node " NODE_BUS_FMT ": Bridge only supports 128KB "
                          "max transfer size. WARNING: Current max_sectors "
                          "setting is larger than 128KB (%d sectors)",
                          NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
                          max_sectors);

        /* If this is a logical unit directory entry, process the parent
         * to get the values. */
        if (ud->flags & UNIT_DIRECTORY_LUN_DIRECTORY) {
                struct unit_directory *parent_ud =
                        container_of(ud->device.parent, struct unit_directory, device);
                sbp2_parse_unit_directory(scsi_id, parent_ud);
        } else {
                scsi_id->sbp2_management_agent_addr = management_agent_addr;
                scsi_id->sbp2_command_set_spec_id = command_set_spec_id;
                scsi_id->sbp2_command_set = command_set;
                scsi_id->sbp2_unit_characteristics = unit_characteristics;
                scsi_id->sbp2_firmware_revision = firmware_revision;
                scsi_id->workarounds = workarounds;
                if (ud->flags & UNIT_DIRECTORY_HAS_LUN)
                        scsi_id->sbp2_lun = ORB_SET_LUN(ud->lun);
        }
}

#define SBP2_PAYLOAD_TO_BYTES(p) (1 << ((p) + 2))

/*
 * This function is called in order to determine the max speed and packet
 * size we can use in our ORBs. Note, that we (the driver and host) only
 * initiate the transaction. The SBP-2 device actually transfers the data
 * (by reading from the DMA area we tell it). This means that the SBP-2
 * device decides the actual maximum data it can transfer. We just tell it
 * the speed that it needs to use, and the max_rec the host supports, and
 * it takes care of the rest.
 */
static int sbp2_max_speed_and_size(struct scsi_id_instance_data *scsi_id)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        u8 payload;

        SBP2_DEBUG_ENTER();

        scsi_id->speed_code =
            hi->host->speed[NODEID_TO_NODE(scsi_id->ne->nodeid)];

        /* Bump down our speed if the user requested it */
        if (scsi_id->speed_code > max_speed) {
                scsi_id->speed_code = max_speed;
                SBP2_ERR("Forcing SBP-2 max speed down to %s",
                         hpsb_speedto_str[scsi_id->speed_code]);
        }

        /* Payload size is the lesser of what our speed supports and what
         * our host supports.  */
        payload = min(sbp2_speedto_max_payload[scsi_id->speed_code],
                      (u8) (hi->host->csr.max_rec - 1));

        /* If physical DMA is off, work around limitation in ohci1394:
         * packet size must not exceed PAGE_SIZE */
        if (scsi_id->ne->host->low_addr_space < (1ULL << 32))
                while (SBP2_PAYLOAD_TO_BYTES(payload) + 24 > PAGE_SIZE &&
                       payload)
                        payload--;

        HPSB_DEBUG("Node " NODE_BUS_FMT ": Max speed [%s] - Max payload [%u]",
                   NODE_BUS_ARGS(hi->host, scsi_id->ne->nodeid),
                   hpsb_speedto_str[scsi_id->speed_code],
                   SBP2_PAYLOAD_TO_BYTES(payload));

        scsi_id->max_payload_size = payload;
        return 0;
}

/*
 * This function is called in order to perform a SBP-2 agent reset.
 */
static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait)
{
        quadlet_t data;
        u64 addr;
        int retval;
        unsigned long flags;

        SBP2_DEBUG_ENTER();

        cancel_delayed_work(&scsi_id->protocol_work);
        if (wait)
                flush_scheduled_work();

        data = ntohl(SBP2_AGENT_RESET_DATA);
        addr = scsi_id->sbp2_command_block_agent_addr + SBP2_AGENT_RESET_OFFSET;

        if (wait)
                retval = hpsb_node_write(scsi_id->ne, addr, &data, 4);
        else
                retval = sbp2util_node_write_no_wait(scsi_id->ne, addr, &data, 4);

        if (retval < 0) {
                SBP2_ERR("hpsb_node_write failed.\n");
                return -EIO;
        }

        /*
         * Need to make sure orb pointer is written on next command
         */
        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        scsi_id->last_orb = NULL;
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

        return 0;
}

static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
                                     struct sbp2scsi_host_info *hi,
                                     struct sbp2_command_info *command,
                                     unsigned int scsi_use_sg,
                                     struct scatterlist *sgpnt,
                                     u32 orb_direction,
                                     enum dma_data_direction dma_dir)
{
        command->dma_dir = dma_dir;
        orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
        orb->misc |= ORB_SET_DIRECTION(orb_direction);

        /* Special case if only one element (and less than 64KB in size) */
        if ((scsi_use_sg == 1) &&
            (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {

                SBP2_DEBUG("Only one s/g element");
                command->dma_size = sgpnt[0].length;
                command->dma_type = CMD_DMA_PAGE;
                command->cmd_dma = pci_map_page(hi->host->pdev,
                                                sgpnt[0].page,
                                                sgpnt[0].offset,
                                                command->dma_size,
                                                command->dma_dir);
                SBP2_DMA_ALLOC("single page scatter element");

                orb->data_descriptor_lo = command->cmd_dma;
                orb->misc |= ORB_SET_DATA_SIZE(command->dma_size);

        } else {
                struct sbp2_unrestricted_page_table *sg_element =
                                        &command->scatter_gather_element[0];
                u32 sg_count, sg_len;
                dma_addr_t sg_addr;
                int i, count = pci_map_sg(hi->host->pdev, sgpnt, scsi_use_sg,
                                          dma_dir);

                SBP2_DMA_ALLOC("scatter list");

                command->dma_size = scsi_use_sg;
                command->sge_buffer = sgpnt;

                /* use page tables (s/g) */
                orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
                orb->data_descriptor_lo = command->sge_dma;

                /*
                 * Loop through and fill out our sbp-2 page tables
                 * (and split up anything too large)
                 */
                for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
                        sg_len = sg_dma_len(sgpnt);
                        sg_addr = sg_dma_address(sgpnt);
                        while (sg_len) {
                                sg_element[sg_count].segment_base_lo = sg_addr;
                                if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
                                        sg_element[sg_count].length_segment_base_hi =
                                                PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
                                        sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
                                        sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
                                } else {
                                        sg_element[sg_count].length_segment_base_hi =
                                                PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
                                        sg_len = 0;
                                }
                                sg_count++;
                        }
                }

                /* Number of page table (s/g) elements */
                orb->misc |= ORB_SET_DATA_SIZE(sg_count);

                sbp2util_packet_dump(sg_element,
                                     (sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
                                     "sbp2 s/g list", command->sge_dma);

                /* Byte swap page tables if necessary */
                sbp2util_cpu_to_be32_buffer(sg_element,
                                            (sizeof(struct sbp2_unrestricted_page_table)) *
                                            sg_count);
        }
}

static void sbp2_prep_command_orb_no_sg(struct sbp2_command_orb *orb,
                                        struct sbp2scsi_host_info *hi,
                                        struct sbp2_command_info *command,
                                        struct scatterlist *sgpnt,
                                        u32 orb_direction,
                                        unsigned int scsi_request_bufflen,
                                        void *scsi_request_buffer,
                                        enum dma_data_direction dma_dir)
{
        command->dma_dir = dma_dir;
        command->dma_size = scsi_request_bufflen;
        command->dma_type = CMD_DMA_SINGLE;
        command->cmd_dma = pci_map_single(hi->host->pdev, scsi_request_buffer,
                                          command->dma_size, command->dma_dir);
        orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
        orb->misc |= ORB_SET_DIRECTION(orb_direction);

        SBP2_DMA_ALLOC("single bulk");

        /*
         * Handle case where we get a command w/o s/g enabled (but
         * check for transfers larger than 64K)
         */
        if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) {

                orb->data_descriptor_lo = command->cmd_dma;
                orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen);

        } else {
                struct sbp2_unrestricted_page_table *sg_element =
                        &command->scatter_gather_element[0];
                u32 sg_count, sg_len;
                dma_addr_t sg_addr;

                /*
                 * Need to turn this into page tables, since the
                 * buffer is too large.
                 */
                orb->data_descriptor_lo = command->sge_dma;

                /* Use page tables (s/g) */
                orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);

                /*
                 * fill out our sbp-2 page tables (and split up
                 * the large buffer)
                 */
                sg_count = 0;
                sg_len = scsi_request_bufflen;
                sg_addr = command->cmd_dma;
                while (sg_len) {
                        sg_element[sg_count].segment_base_lo = sg_addr;
                        if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
                                sg_element[sg_count].length_segment_base_hi =
                                        PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
                                sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
                                sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
                        } else {
                                sg_element[sg_count].length_segment_base_hi =
                                        PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
                                sg_len = 0;
                        }
                        sg_count++;
                }

                /* Number of page table (s/g) elements */
                orb->misc |= ORB_SET_DATA_SIZE(sg_count);

                sbp2util_packet_dump(sg_element,
                                     (sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
                                     "sbp2 s/g list", command->sge_dma);

                /* Byte swap page tables if necessary */
                sbp2util_cpu_to_be32_buffer(sg_element,
                                            (sizeof(struct sbp2_unrestricted_page_table)) *
                                             sg_count);
        }
}

/*
 * This function is called to create the actual command orb and s/g list
 * out of the scsi command itself.
 */
static void sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id,
                                    struct sbp2_command_info *command,
                                    unchar *scsi_cmd,
                                    unsigned int scsi_use_sg,
                                    unsigned int scsi_request_bufflen,
                                    void *scsi_request_buffer,
                                    enum dma_data_direction dma_dir)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        struct scatterlist *sgpnt = (struct scatterlist *)scsi_request_buffer;
        struct sbp2_command_orb *command_orb = &command->command_orb;
        u32 orb_direction;

        /*
         * Set-up our command ORB..
         *
         * NOTE: We're doing unrestricted page tables (s/g), as this is
         * best performance (at least with the devices I have). This means
         * that data_size becomes the number of s/g elements, and
         * page_size should be zero (for unrestricted).
         */
        command_orb->next_ORB_hi = ORB_SET_NULL_PTR(1);
        command_orb->next_ORB_lo = 0x0;
        command_orb->misc = ORB_SET_MAX_PAYLOAD(scsi_id->max_payload_size);
        command_orb->misc |= ORB_SET_SPEED(scsi_id->speed_code);
        command_orb->misc |= ORB_SET_NOTIFY(1); /* Notify us when complete */

        if (dma_dir == DMA_NONE)
                orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
        else if (dma_dir == DMA_TO_DEVICE && scsi_request_bufflen)
                orb_direction = ORB_DIRECTION_WRITE_TO_MEDIA;
        else if (dma_dir == DMA_FROM_DEVICE && scsi_request_bufflen)
                orb_direction = ORB_DIRECTION_READ_FROM_MEDIA;
        else {
                SBP2_WARN("Falling back to DMA_NONE");
                orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
        }

        /* Set-up our pagetable stuff */
        if (orb_direction == ORB_DIRECTION_NO_DATA_TRANSFER) {
                SBP2_DEBUG("No data transfer");
                command_orb->data_descriptor_hi = 0x0;
                command_orb->data_descriptor_lo = 0x0;
                command_orb->misc |= ORB_SET_DIRECTION(1);
        } else if (scsi_use_sg) {
                SBP2_DEBUG("Use scatter/gather");
                sbp2_prep_command_orb_sg(command_orb, hi, command, scsi_use_sg,
                                         sgpnt, orb_direction, dma_dir);
        } else {
                SBP2_DEBUG("No scatter/gather");
                sbp2_prep_command_orb_no_sg(command_orb, hi, command, sgpnt,
                                            orb_direction, scsi_request_bufflen,
                                            scsi_request_buffer, dma_dir);
        }

        /* Byte swap command ORB if necessary */
        sbp2util_cpu_to_be32_buffer(command_orb, sizeof(struct sbp2_command_orb));

        /* Put our scsi command in the command ORB */
        memset(command_orb->cdb, 0, 12);
        memcpy(command_orb->cdb, scsi_cmd, COMMAND_SIZE(*scsi_cmd));
}

/*
 * This function is called in order to begin a regular SBP-2 command.
 */
static void sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
                                 struct sbp2_command_info *command)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        struct sbp2_command_orb *command_orb = &command->command_orb;
        struct sbp2_command_orb *last_orb;
        dma_addr_t last_orb_dma;
        u64 addr = scsi_id->sbp2_command_block_agent_addr;
        quadlet_t data[2];
        size_t length;
        unsigned long flags;

        outstanding_orb_incr;
        SBP2_ORB_DEBUG("sending command orb %p, total orbs = %x",
                       command_orb, global_outstanding_command_orbs);

        pci_dma_sync_single_for_device(hi->host->pdev, command->command_orb_dma,
                                       sizeof(struct sbp2_command_orb),
                                       PCI_DMA_TODEVICE);
        pci_dma_sync_single_for_device(hi->host->pdev, command->sge_dma,
                                       sizeof(command->scatter_gather_element),
                                       PCI_DMA_BIDIRECTIONAL);
        /*
         * Check to see if there are any previous orbs to use
         */
        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        last_orb = scsi_id->last_orb;
        last_orb_dma = scsi_id->last_orb_dma;
        if (!last_orb) {
                /*
                 * last_orb == NULL means: We know that the target's fetch agent
                 * is not active right now.
                 */
                addr += SBP2_ORB_POINTER_OFFSET;
                data[0] = ORB_SET_NODE_ID(hi->host->node_id);
                data[1] = command->command_orb_dma;
                sbp2util_cpu_to_be32_buffer(data, 8);
                length = 8;
        } else {
                /*
                 * last_orb != NULL means: We know that the target's fetch agent
                 * is (very probably) not dead or in reset state right now.
                 * We have an ORB already sent that we can append a new one to.
                 * The target's fetch agent may or may not have read this
                 * previous ORB yet.
                 */
                pci_dma_sync_single_for_cpu(hi->host->pdev, last_orb_dma,
                                            sizeof(struct sbp2_command_orb),
                                            PCI_DMA_TODEVICE);
                last_orb->next_ORB_lo = cpu_to_be32(command->command_orb_dma);
                wmb();
                /* Tells hardware that this pointer is valid */
                last_orb->next_ORB_hi = 0;
                pci_dma_sync_single_for_device(hi->host->pdev, last_orb_dma,
                                               sizeof(struct sbp2_command_orb),
                                               PCI_DMA_TODEVICE);
                addr += SBP2_DOORBELL_OFFSET;
                data[0] = 0;
                length = 4;
        }
        scsi_id->last_orb = command_orb;
        scsi_id->last_orb_dma = command->command_orb_dma;
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

        SBP2_ORB_DEBUG("write to %s register, command orb %p",
                        last_orb ? "DOORBELL" : "ORB_POINTER", command_orb);
        if (sbp2util_node_write_no_wait(scsi_id->ne, addr, data, length)) {
                /*
                 * sbp2util_node_write_no_wait failed. We certainly ran out
                 * of transaction labels, perhaps just because there were no
                 * context switches which gave khpsbpkt a chance to collect
                 * free tlabels. Try again in non-atomic context. If necessary,
                 * the workqueue job will sleep to guaranteedly get a tlabel.
                 * We do not accept new commands until the job is over.
                 */
                scsi_block_requests(scsi_id->scsi_host);
                PREPARE_WORK(&scsi_id->protocol_work,
                             last_orb ? sbp2util_write_doorbell:
                                        sbp2util_write_orb_pointer,
                             scsi_id);
                schedule_work(&scsi_id->protocol_work);
        }
}

/*
 * This function is called in order to begin a regular SBP-2 command.
 */
static int sbp2_send_command(struct scsi_id_instance_data *scsi_id,
                             struct scsi_cmnd *SCpnt,
                             void (*done)(struct scsi_cmnd *))
{
        unchar *cmd = (unchar *) SCpnt->cmnd;
        unsigned int request_bufflen = SCpnt->request_bufflen;
        struct sbp2_command_info *command;

        SBP2_DEBUG_ENTER();
        SBP2_DEBUG("SCSI transfer size = %x", request_bufflen);
        SBP2_DEBUG("SCSI s/g elements = %x", (unsigned int)SCpnt->use_sg);

        /*
         * Allocate a command orb and s/g structure
         */
        command = sbp2util_allocate_command_orb(scsi_id, SCpnt, done);
        if (!command) {
                return -EIO;
        }

        /*
         * Now actually fill in the comamnd orb and sbp2 s/g list
         */
        sbp2_create_command_orb(scsi_id, command, cmd, SCpnt->use_sg,
                                request_bufflen, SCpnt->request_buffer,
                                SCpnt->sc_data_direction);

        sbp2util_packet_dump(&command->command_orb, sizeof(struct sbp2_command_orb),
                             "sbp2 command orb", command->command_orb_dma);

        /*
         * Link up the orb, and ring the doorbell if needed
         */
        sbp2_link_orb_command(scsi_id, command);

        return 0;
}

/*
 * Translates SBP-2 status into SCSI sense data for check conditions
 */
static unsigned int sbp2_status_to_sense_data(unchar *sbp2_status, unchar *sense_data)
{
        SBP2_DEBUG_ENTER();

        /*
         * Ok, it's pretty ugly...   ;-)
         */
        sense_data[0] = 0x70;
        sense_data[1] = 0x0;
        sense_data[2] = sbp2_status[9];
        sense_data[3] = sbp2_status[12];
        sense_data[4] = sbp2_status[13];
        sense_data[5] = sbp2_status[14];
        sense_data[6] = sbp2_status[15];
        sense_data[7] = 10;
        sense_data[8] = sbp2_status[16];
        sense_data[9] = sbp2_status[17];
        sense_data[10] = sbp2_status[18];
        sense_data[11] = sbp2_status[19];
        sense_data[12] = sbp2_status[10];
        sense_data[13] = sbp2_status[11];
        sense_data[14] = sbp2_status[20];
        sense_data[15] = sbp2_status[21];

        return sbp2_status[8] & 0x3f;   /* return scsi status */
}

/*
 * This function deals with status writes from the SBP-2 device
 */
static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
                                    int destid, quadlet_t *data, u64 addr,
                                    size_t length, u16 fl)
{
        struct sbp2scsi_host_info *hi;
        struct scsi_id_instance_data *scsi_id = NULL, *scsi_id_tmp;
        struct scsi_cmnd *SCpnt = NULL;
        struct sbp2_status_block *sb;
        u32 scsi_status = SBP2_SCSI_STATUS_GOOD;
        struct sbp2_command_info *command;
        unsigned long flags;

        SBP2_DEBUG_ENTER();

        sbp2util_packet_dump(data, length, "sbp2 status write by device", (u32)addr);

        if (unlikely(length < 8 || length > sizeof(struct sbp2_status_block))) {
                SBP2_ERR("Wrong size of status block");
                return RCODE_ADDRESS_ERROR;
        }
        if (unlikely(!host)) {
                SBP2_ERR("host is NULL - this is bad!");
                return RCODE_ADDRESS_ERROR;
        }
        hi = hpsb_get_hostinfo(&sbp2_highlevel, host);
        if (unlikely(!hi)) {
                SBP2_ERR("host info is NULL - this is bad!");
                return RCODE_ADDRESS_ERROR;
        }
        /*
         * Find our scsi_id structure by looking at the status fifo address
         * written to by the sbp2 device.
         */
        list_for_each_entry(scsi_id_tmp, &hi->scsi_ids, scsi_list) {
                if (scsi_id_tmp->ne->nodeid == nodeid &&
                    scsi_id_tmp->status_fifo_addr == addr) {
                        scsi_id = scsi_id_tmp;
                        break;
                }
        }
        if (unlikely(!scsi_id)) {
                SBP2_ERR("scsi_id is NULL - device is gone?");
                return RCODE_ADDRESS_ERROR;
        }

        /*
         * Put response into scsi_id status fifo buffer. The first two bytes
         * come in big endian bit order. Often the target writes only a
         * truncated status block, minimally the first two quadlets. The rest
         * is implied to be zeros.
         */
        sb = &scsi_id->status_block;
        memset(sb->command_set_dependent, 0, sizeof(sb->command_set_dependent));
        memcpy(sb, data, length);
        sbp2util_be32_to_cpu_buffer(sb, 8);

        /*
         * Ignore unsolicited status. Handle command ORB status.
         */
        if (unlikely(STATUS_GET_SRC(sb->ORB_offset_hi_misc) == 2))
                command = NULL;
        else
                command = sbp2util_find_command_for_orb(scsi_id,
                                                        sb->ORB_offset_lo);
        if (command) {
                SBP2_DEBUG("Found status for command ORB");
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                            sizeof(struct sbp2_command_orb),
                                            PCI_DMA_TODEVICE);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                            sizeof(command->scatter_gather_element),
                                            PCI_DMA_BIDIRECTIONAL);

                SBP2_ORB_DEBUG("matched command orb %p", &command->command_orb);
                outstanding_orb_decr;

                /*
                 * Matched status with command, now grab scsi command pointers
                 * and check status.
                 */
                /*
                 * FIXME: If the src field in the status is 1, the ORB DMA must
                 * not be reused until status for a subsequent ORB is received.
                 */
                SCpnt = command->Current_SCpnt;
                spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
                sbp2util_mark_command_completed(scsi_id, command);
                spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

                if (SCpnt) {
                        if (STATUS_TEST_RS(sb->ORB_offset_hi_misc))
                                scsi_status =
                                        SBP2_SCSI_STATUS_COMMAND_TERMINATED;
                        /*
                         * See if the target stored any scsi status information.
                         */
                        if (STATUS_GET_LEN(sb->ORB_offset_hi_misc) > 1) {
                                SBP2_DEBUG("CHECK CONDITION");
                                scsi_status = sbp2_status_to_sense_data(
                                        (unchar *)sb, SCpnt->sense_buffer);
                        }

                        /*
                         * Check to see if the dead bit is set. If so, we'll
                         * have to initiate a fetch agent reset.
                         */
                        if (STATUS_TEST_D(sb->ORB_offset_hi_misc)) {
                                SBP2_DEBUG("Dead bit set - "
                                           "initiating fetch agent reset");
                                sbp2_agent_reset(scsi_id, 0);
                        }

                        SBP2_ORB_DEBUG("completing command orb %p", &command->command_orb);
                }

                /*
                 * Check here to see if there are no commands in-use. If there
                 * are none, we know that the fetch agent left the active state
                 * _and_ that we did not reactivate it yet. Therefore clear
                 * last_orb so that next time we write directly to the
                 * ORB_POINTER register. That way the fetch agent does not need
                 * to refetch the next_ORB.
                 */
                spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
                if (list_empty(&scsi_id->sbp2_command_orb_inuse))
                        scsi_id->last_orb = NULL;
                spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

        } else {
                /*
                 * It's probably a login/logout/reconnect status.
                 */
                if ((sb->ORB_offset_lo == scsi_id->reconnect_orb_dma) ||
                    (sb->ORB_offset_lo == scsi_id->login_orb_dma) ||
                    (sb->ORB_offset_lo == scsi_id->query_logins_orb_dma) ||
                    (sb->ORB_offset_lo == scsi_id->logout_orb_dma)) {
                        scsi_id->access_complete = 1;
                        wake_up_interruptible(&access_wq);
                }
        }

        if (SCpnt) {
                SBP2_DEBUG("Completing SCSI command");
                sbp2scsi_complete_command(scsi_id, scsi_status, SCpnt,
                                          command->Current_done);
                SBP2_ORB_DEBUG("command orb completed");
        }

        return RCODE_COMPLETE;
}

/**************************************
 * SCSI interface related section
 **************************************/

/*
 * This routine is the main request entry routine for doing I/O. It is
 * called from the scsi stack directly.
 */
static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
                                 void (*done)(struct scsi_cmnd *))
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
        struct sbp2scsi_host_info *hi;
        int result = DID_NO_CONNECT << 16;

        SBP2_DEBUG_ENTER();
#if (CONFIG_IEEE1394_SBP2_DEBUG >= 2) || defined(CONFIG_IEEE1394_SBP2_PACKET_DUMP)
        scsi_print_command(SCpnt);
#endif

        if (!sbp2util_node_is_available(scsi_id))
                goto done;

        hi = scsi_id->hi;

        if (!hi) {
                SBP2_ERR("sbp2scsi_host_info is NULL - this is bad!");
                goto done;
        }

        /*
         * Until we handle multiple luns, just return selection time-out
         * to any IO directed at non-zero LUNs
         */
        if (SCpnt->device->lun)
                goto done;

        /*
         * Check for request sense command, and handle it here
         * (autorequest sense)
         */
        if (SCpnt->cmnd[0] == REQUEST_SENSE) {
                SBP2_DEBUG("REQUEST_SENSE");
                memcpy(SCpnt->request_buffer, SCpnt->sense_buffer, SCpnt->request_bufflen);
                memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer));
                sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_GOOD, SCpnt, done);
                return 0;
        }

        /*
         * Check to see if we are in the middle of a bus reset.
         */
        if (!hpsb_node_entry_valid(scsi_id->ne)) {
                SBP2_ERR("Bus reset in progress - rejecting command");
                result = DID_BUS_BUSY << 16;
                goto done;
        }

        /*
         * Bidirectional commands are not yet implemented,
         * and unknown transfer direction not handled.
         */
        if (SCpnt->sc_data_direction == DMA_BIDIRECTIONAL) {
                SBP2_ERR("Cannot handle DMA_BIDIRECTIONAL - rejecting command");
                result = DID_ERROR << 16;
                goto done;
        }

        /*
         * Try and send our SCSI command
         */
        if (sbp2_send_command(scsi_id, SCpnt, done)) {
                SBP2_ERR("Error sending SCSI command");
                sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_SELECTION_TIMEOUT,
                                          SCpnt, done);
        }
        return 0;

done:
        SCpnt->result = result;
        done(SCpnt);
        return 0;
}

/*
 * This function is called in order to complete all outstanding SBP-2
 * commands (in case of resets, etc.).
 */
static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id,
                                           u32 status)
{
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        struct list_head *lh;
        struct sbp2_command_info *command;
        unsigned long flags;

        SBP2_DEBUG_ENTER();

        spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
        while (!list_empty(&scsi_id->sbp2_command_orb_inuse)) {
                SBP2_DEBUG("Found pending command to complete");
                lh = scsi_id->sbp2_command_orb_inuse.next;
                command = list_entry(lh, struct sbp2_command_info, list);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                            sizeof(struct sbp2_command_orb),
                                            PCI_DMA_TODEVICE);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                            sizeof(command->scatter_gather_element),
                                            PCI_DMA_BIDIRECTIONAL);
                sbp2util_mark_command_completed(scsi_id, command);
                if (command->Current_SCpnt) {
                        command->Current_SCpnt->result = status << 16;
                        command->Current_done(command->Current_SCpnt);
                }
        }
        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

        return;
}

/*
 * This function is called in order to complete a regular SBP-2 command.
 *
 * This can be called in interrupt context.
 */
static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id,
                                      u32 scsi_status, struct scsi_cmnd *SCpnt,
                                      void (*done)(struct scsi_cmnd *))
{
        SBP2_DEBUG_ENTER();

        /*
         * Sanity
         */
        if (!SCpnt) {
                SBP2_ERR("SCpnt is NULL");
                return;
        }

        /*
         * If a bus reset is in progress and there was an error, don't
         * complete the command, just let it get retried at the end of the
         * bus reset.
         */
        if (!hpsb_node_entry_valid(scsi_id->ne)
            && (scsi_status != SBP2_SCSI_STATUS_GOOD)) {
                SBP2_ERR("Bus reset in progress - retry command later");
                return;
        }

        /*
         * Switch on scsi status
         */
        switch (scsi_status) {
        case SBP2_SCSI_STATUS_GOOD:
                SCpnt->result = DID_OK << 16;
                break;

        case SBP2_SCSI_STATUS_BUSY:
                SBP2_ERR("SBP2_SCSI_STATUS_BUSY");
                SCpnt->result = DID_BUS_BUSY << 16;
                break;

        case SBP2_SCSI_STATUS_CHECK_CONDITION:
                SBP2_DEBUG("SBP2_SCSI_STATUS_CHECK_CONDITION");
                SCpnt->result = CHECK_CONDITION << 1 | DID_OK << 16;
#if CONFIG_IEEE1394_SBP2_DEBUG >= 1
                scsi_print_command(SCpnt);
                scsi_print_sense(SBP2_DEVICE_NAME, SCpnt);
#endif
                break;

        case SBP2_SCSI_STATUS_SELECTION_TIMEOUT:
                SBP2_ERR("SBP2_SCSI_STATUS_SELECTION_TIMEOUT");
                SCpnt->result = DID_NO_CONNECT << 16;
                scsi_print_command(SCpnt);
                break;

        case SBP2_SCSI_STATUS_CONDITION_MET:
        case SBP2_SCSI_STATUS_RESERVATION_CONFLICT:
        case SBP2_SCSI_STATUS_COMMAND_TERMINATED:
                SBP2_ERR("Bad SCSI status = %x", scsi_status);
                SCpnt->result = DID_ERROR << 16;
                scsi_print_command(SCpnt);
                break;

        default:
                SBP2_ERR("Unsupported SCSI status = %x", scsi_status);
                SCpnt->result = DID_ERROR << 16;
        }

        /*
         * If a bus reset is in progress and there was an error, complete
         * the command as busy so that it will get retried.
         */
        if (!hpsb_node_entry_valid(scsi_id->ne)
            && (scsi_status != SBP2_SCSI_STATUS_GOOD)) {
                SBP2_ERR("Completing command with busy (bus reset)");
                SCpnt->result = DID_BUS_BUSY << 16;
        }

        /*
         * If a unit attention occurs, return busy status so it gets
         * retried... it could have happened because of a 1394 bus reset
         * or hot-plug...
         * XXX  DID_BUS_BUSY is actually a bad idea because it will defy
         * the scsi layer's retry logic.
         */
#if 0
        if ((scsi_status == SBP2_SCSI_STATUS_CHECK_CONDITION) &&
            (SCpnt->sense_buffer[2] == UNIT_ATTENTION)) {
                SBP2_DEBUG("UNIT ATTENTION - return busy");
                SCpnt->result = DID_BUS_BUSY << 16;
        }
#endif

        /*
         * Tell scsi stack that we're done with this command
         */
        done(SCpnt);
}

static int sbp2scsi_slave_alloc(struct scsi_device *sdev)
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)sdev->host->hostdata[0];

        scsi_id->sdev = sdev;

        if (scsi_id->workarounds & SBP2_WORKAROUND_INQUIRY_36)
                sdev->inquiry_len = 36;
        return 0;
}

static int sbp2scsi_slave_configure(struct scsi_device *sdev)
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)sdev->host->hostdata[0];

        blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
        sdev->use_10_for_rw = 1;
        sdev->use_10_for_ms = 1;

        if (sdev->type == TYPE_DISK &&
            scsi_id->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
                sdev->skip_ms_page_8 = 1;
        if (scsi_id->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
                sdev->fix_capacity = 1;
        if (scsi_id->ne->guid_vendor_id == 0x0010b9 && /* Maxtor's OUI */
            (sdev->type == TYPE_DISK || sdev->type == TYPE_RBC))
                sdev->allow_restart = 1;
        return 0;
}

static void sbp2scsi_slave_destroy(struct scsi_device *sdev)
{
        ((struct scsi_id_instance_data *)sdev->host->hostdata[0])->sdev = NULL;
        return;
}

/*
 * Called by scsi stack when something has really gone wrong.  Usually
 * called when a command has timed-out for some reason.
 */
static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
        struct sbp2scsi_host_info *hi = scsi_id->hi;
        struct sbp2_command_info *command;
        unsigned long flags;

        SBP2_ERR("aborting sbp2 command");
        scsi_print_command(SCpnt);

        if (sbp2util_node_is_available(scsi_id)) {

                /*
                 * Right now, just return any matching command structures
                 * to the free pool.
                 */
                spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
                command = sbp2util_find_command_for_SCpnt(scsi_id, SCpnt);
                if (command) {
                        SBP2_DEBUG("Found command to abort");
                        pci_dma_sync_single_for_cpu(hi->host->pdev,
                                                    command->command_orb_dma,
                                                    sizeof(struct sbp2_command_orb),
                                                    PCI_DMA_TODEVICE);
                        pci_dma_sync_single_for_cpu(hi->host->pdev,
                                                    command->sge_dma,
                                                    sizeof(command->scatter_gather_element),
                                                    PCI_DMA_BIDIRECTIONAL);
                        sbp2util_mark_command_completed(scsi_id, command);
                        if (command->Current_SCpnt) {
                                command->Current_SCpnt->result = DID_ABORT << 16;
                                command->Current_done(command->Current_SCpnt);
                        }
                }
                spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

                /*
                 * Initiate a fetch agent reset.
                 */
                sbp2_agent_reset(scsi_id, 0);
                sbp2scsi_complete_all_commands(scsi_id, DID_BUS_BUSY);
        }

        return SUCCESS;
}

/*
 * Called by scsi stack when something has really gone wrong.
 */
static int sbp2scsi_reset(struct scsi_cmnd *SCpnt)
{
        struct scsi_id_instance_data *scsi_id =
                (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];

        SBP2_ERR("reset requested");

        if (sbp2util_node_is_available(scsi_id)) {
                SBP2_ERR("Generating sbp2 fetch agent reset");
                sbp2_agent_reset(scsi_id, 0);
        }

        return SUCCESS;
}

static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct scsi_device *sdev;
        struct scsi_id_instance_data *scsi_id;
        int lun;

        if (!(sdev = to_scsi_device(dev)))
                return 0;

        if (!(scsi_id = (struct scsi_id_instance_data *)sdev->host->hostdata[0]))
                return 0;

        lun = ORB_SET_LUN(scsi_id->sbp2_lun);

        return sprintf(buf, "%016Lx:%d:%d\n", (unsigned long long)scsi_id->ne->guid,
                       scsi_id->ud->id, lun);
}
static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);

static struct device_attribute *sbp2_sysfs_sdev_attrs[] = {
        &dev_attr_ieee1394_id,
        NULL
};

MODULE_AUTHOR("Ben Collins <bcollins@debian.org>");
MODULE_DESCRIPTION("IEEE-1394 SBP-2 protocol driver");
MODULE_SUPPORTED_DEVICE(SBP2_DEVICE_NAME);
MODULE_LICENSE("GPL");

/* SCSI host template */
static struct scsi_host_template scsi_driver_template = {
        .module =                       THIS_MODULE,
        .name =                         "SBP-2 IEEE-1394",
        .proc_name =                    SBP2_DEVICE_NAME,
        .queuecommand =                 sbp2scsi_queuecommand,
        .eh_abort_handler =             sbp2scsi_abort,
        .eh_device_reset_handler =      sbp2scsi_reset,
        .slave_alloc =                  sbp2scsi_slave_alloc,
        .slave_configure =              sbp2scsi_slave_configure,
        .slave_destroy =                sbp2scsi_slave_destroy,
        .this_id =                      -1,
        .sg_tablesize =                 SG_ALL,
        .use_clustering =               ENABLE_CLUSTERING,
        .cmd_per_lun =                  SBP2_MAX_CMDS,
        .can_queue =                    SBP2_MAX_CMDS,
        .emulated =                     1,
        .sdev_attrs =                   sbp2_sysfs_sdev_attrs,
};

static int sbp2_module_init(void)
{
        int ret;

        SBP2_DEBUG_ENTER();

        /* Module load debug option to force one command at a time (serializing I/O) */
        if (serialize_io) {
                SBP2_INFO("Driver forced to serialize I/O (serialize_io=1)");
                SBP2_INFO("Try serialize_io=0 for better performance");
                scsi_driver_template.can_queue = 1;
                scsi_driver_template.cmd_per_lun = 1;
        }

        if (sbp2_default_workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
            (max_sectors * 512) > (128 * 1024))
                max_sectors = 128 * 1024 / 512;
        scsi_driver_template.max_sectors = max_sectors;

        /* Register our high level driver with 1394 stack */
        hpsb_register_highlevel(&sbp2_highlevel);

        ret = hpsb_register_protocol(&sbp2_driver);
        if (ret) {
                SBP2_ERR("Failed to register protocol");
                hpsb_unregister_highlevel(&sbp2_highlevel);
                return ret;
        }

        return 0;
}

static void __exit sbp2_module_exit(void)
{
        SBP2_DEBUG_ENTER();

        hpsb_unregister_protocol(&sbp2_driver);

        hpsb_unregister_highlevel(&sbp2_highlevel);
}

module_init(sbp2_module_init);
module_exit(sbp2_module_exit);