3w-9xxx.c

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/*
   3w-9xxx.c -- 3ware 9000 Storage Controller device driver for Linux.

   Written By: Adam Radford <[email protected]>
   Modifications By: Tom Couch <[email protected]>

   Copyright (C) 2004-2009 Applied Micro Circuits Corporation.
   Copyright (C) 2010 LSI Corporation.

   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; version 2 of the License.

   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.

   NO WARRANTY
   THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT
   LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT,
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is
   solely responsible for determining the appropriateness of using and
   distributing the Program and assumes all risks associated with its
   exercise of rights under this Agreement, including but not limited to
   the risks and costs of program errors, damage to or loss of data,
   programs or equipment, and unavailability or interruption of operations.

   DISCLAIMER OF LIABILITY
   NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY
   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND
   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
   TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
   USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED
   HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES

   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

   Bugs/Comments/Suggestions should be mailed to:
   [email protected]

   For more information, goto:
   http://www.lsi.com

   Note: This version of the driver does not contain a bundled firmware
         image.

   History
   -------
   2.26.02.000 - Driver cleanup for kernel submission.
   2.26.02.001 - Replace schedule_timeout() calls with msleep().
   2.26.02.002 - Add support for PAE mode.
                 Add lun support.
                 Fix twa_remove() to free irq handler/unregister_chrdev()
                 before shutting down card.
                 Change to new 'change_queue_depth' api.
                 Fix 'handled=1' ISR usage, remove bogus IRQ check.
                 Remove un-needed eh_abort handler.
                 Add support for embedded firmware error strings.
   2.26.02.003 - Correctly handle single sgl's with use_sg=1.
   2.26.02.004 - Add support for 9550SX controllers.
   2.26.02.005 - Fix use_sg == 0 mapping on systems with 4GB or higher.
   2.26.02.006 - Fix 9550SX pchip reset timeout.
                 Add big endian support.
   2.26.02.007 - Disable local interrupts during kmap/unmap_atomic().
   2.26.02.008 - Free irq handler in __twa_shutdown().
                 Serialize reset code.
                 Add support for 9650SE controllers.
   2.26.02.009 - Fix dma mask setting to fallback to 32-bit if 64-bit fails.
   2.26.02.010 - Add support for 9690SA controllers.
   2.26.02.011 - Increase max AENs drained to 256.
                 Add MSI support and "use_msi" module parameter.
                 Fix bug in twa_get_param() on 4GB+.
                 Use pci_resource_len() for ioremap().
   2.26.02.012 - Add power management support.
   2.26.02.013 - Fix bug in twa_load_sgl().
   2.26.02.014 - Force 60 second timeout default.
*/

#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_cmnd.h>
#include "3w-9xxx.h"

/* Globals */
#define TW_DRIVER_VERSION "2.26.02.014"
static DEFINE_MUTEX(twa_chrdev_mutex);
static TW_Device_Extension *twa_device_extension_list[TW_MAX_SLOT];
static unsigned int twa_device_extension_count;
static int twa_major = -1;
extern struct timezone sys_tz;

/* Module parameters */
MODULE_AUTHOR ("LSI");
MODULE_DESCRIPTION ("3ware 9000 Storage Controller Linux Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(TW_DRIVER_VERSION);

static int use_msi = 0;
module_param(use_msi, int, S_IRUGO);
MODULE_PARM_DESC(use_msi, "Use Message Signaled Interrupts.  Default: 0");

/* Function prototypes */
static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header);
static int twa_aen_read_queue(TW_Device_Extension *tw_dev, int request_id);
static char *twa_aen_severity_lookup(unsigned char severity_code);
static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id);
static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
static int twa_chrdev_open(struct inode *inode, struct file *file);
static int twa_fill_sense(TW_Device_Extension *tw_dev, int request_id, int copy_sense, int print_host);
static void twa_free_request_id(TW_Device_Extension *tw_dev,int request_id);
static void twa_get_request_id(TW_Device_Extension *tw_dev, int *request_id);
static int twa_initconnection(TW_Device_Extension *tw_dev, int message_credits,
                  u32 set_features, unsigned short current_fw_srl, 
                  unsigned short current_fw_arch_id, 
                  unsigned short current_fw_branch, 
                  unsigned short current_fw_build, 
                  unsigned short *fw_on_ctlr_srl, 
                  unsigned short *fw_on_ctlr_arch_id, 
                  unsigned short *fw_on_ctlr_branch, 
                  unsigned short *fw_on_ctlr_build, 
                  u32 *init_connect_result);
static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_command_packet, int request_id, dma_addr_t dma_handle, int length);
static int twa_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds);
static int twa_poll_status_gone(TW_Device_Extension *tw_dev, u32 flag, int seconds);
static int twa_post_command_packet(TW_Device_Extension *tw_dev, int request_id, char internal);
static int twa_reset_device_extension(TW_Device_Extension *tw_dev);
static int twa_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset);
static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg);
static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int request_id);
static char *twa_string_lookup(twa_message_type *table, unsigned int aen_code);
static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id);

/* Functions */

/* Show some statistics about the card */
static ssize_t twa_show_stats(struct device *dev,
                  struct device_attribute *attr, char *buf)
{
    struct Scsi_Host *host = class_to_shost(dev);
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
    unsigned long flags = 0;
    ssize_t len;

    spin_lock_irqsave(tw_dev->host->host_lock, flags);
    len = snprintf(buf, PAGE_SIZE, "3w-9xxx Driver version: %s\n"
               "Current commands posted:   %4d\n"
               "Max commands posted:       %4d\n"
               "Current pending commands:  %4d\n"
               "Max pending commands:      %4d\n"
               "Last sgl length:           %4d\n"
               "Max sgl length:            %4d\n"
               "Last sector count:         %4d\n"
               "Max sector count:          %4d\n"
               "SCSI Host Resets:          %4d\n"
               "AEN's:                     %4d\n", 
               TW_DRIVER_VERSION,
               tw_dev->posted_request_count,
               tw_dev->max_posted_request_count,
               tw_dev->pending_request_count,
               tw_dev->max_pending_request_count,
               tw_dev->sgl_entries,
               tw_dev->max_sgl_entries,
               tw_dev->sector_count,
               tw_dev->max_sector_count,
               tw_dev->num_resets,
               tw_dev->aen_count);
    spin_unlock_irqrestore(tw_dev->host->host_lock, flags);
    return len;
} /* End twa_show_stats() */

/* This function will set a devices queue depth */
static int twa_change_queue_depth(struct scsi_device *sdev, int queue_depth,
                  int reason)
{
    if (reason != SCSI_QDEPTH_DEFAULT)
        return -EOPNOTSUPP;

    if (queue_depth > TW_Q_LENGTH-2)
        queue_depth = TW_Q_LENGTH-2;
    scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, queue_depth);
    return queue_depth;
} /* End twa_change_queue_depth() */

/* Create sysfs 'stats' entry */
static struct device_attribute twa_host_stats_attr = {
    .attr = {
        .name =     "stats",
        .mode =     S_IRUGO,
    },
    .show = twa_show_stats
};

/* Host attributes initializer */
static struct device_attribute *twa_host_attrs[] = {
    &twa_host_stats_attr,
    NULL,
};

/* File operations struct for character device */
static const struct file_operations twa_fops = {
    .owner      = THIS_MODULE,
    .unlocked_ioctl = twa_chrdev_ioctl,
    .open       = twa_chrdev_open,
    .release    = NULL,
    .llseek     = noop_llseek,
};

/* This function will complete an aen request from the isr */
static int twa_aen_complete(TW_Device_Extension *tw_dev, int request_id)
{
    TW_Command_Full *full_command_packet;
    TW_Command *command_packet;
    TW_Command_Apache_Header *header;
    unsigned short aen;
    int retval = 1;

    header = (TW_Command_Apache_Header *)tw_dev->generic_buffer_virt[request_id];
    tw_dev->posted_request_count--;
    aen = le16_to_cpu(header->status_block.error);
    full_command_packet = tw_dev->command_packet_virt[request_id];
    command_packet = &full_command_packet->command.oldcommand;

    /* First check for internal completion of set param for time sync */
    if (TW_OP_OUT(command_packet->opcode__sgloffset) == TW_OP_SET_PARAM) {
        /* Keep reading the queue in case there are more aen's */
        if (twa_aen_read_queue(tw_dev, request_id))
            goto out2;
            else {
            retval = 0;
            goto out;
        }
    }

    switch (aen) {
    case TW_AEN_QUEUE_EMPTY:
        /* Quit reading the queue if this is the last one */
        break;
    case TW_AEN_SYNC_TIME_WITH_HOST:
        twa_aen_sync_time(tw_dev, request_id);
        retval = 0;
        goto out;
    default:
        twa_aen_queue_event(tw_dev, header);

        /* If there are more aen's, keep reading the queue */
        if (twa_aen_read_queue(tw_dev, request_id))
            goto out2;
        else {
            retval = 0;
            goto out;
        }
    }
    retval = 0;
out2:
    tw_dev->state[request_id] = TW_S_COMPLETED;
    twa_free_request_id(tw_dev, request_id);
    clear_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags);
out:
    return retval;
} /* End twa_aen_complete() */

/* This function will drain aen queue */
static int twa_aen_drain_queue(TW_Device_Extension *tw_dev, int no_check_reset)
{
    int request_id = 0;
    char cdb[TW_MAX_CDB_LEN];
    TW_SG_Entry sglist[1];
    int finished = 0, count = 0;
    TW_Command_Full *full_command_packet;
    TW_Command_Apache_Header *header;
    unsigned short aen;
    int first_reset = 0, queue = 0, retval = 1;

    if (no_check_reset)
        first_reset = 0;
    else
        first_reset = 1;

    full_command_packet = tw_dev->command_packet_virt[request_id];
    memset(full_command_packet, 0, sizeof(TW_Command_Full));

    /* Initialize cdb */
    memset(&cdb, 0, TW_MAX_CDB_LEN);
    cdb[0] = REQUEST_SENSE; /* opcode */
    cdb[4] = TW_ALLOCATION_LENGTH; /* allocation length */

    /* Initialize sglist */
    memset(&sglist, 0, sizeof(TW_SG_Entry));
    sglist[0].length = TW_SECTOR_SIZE;
    sglist[0].address = tw_dev->generic_buffer_phys[request_id];

    if (sglist[0].address & TW_ALIGNMENT_9000_SGL) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1, "Found unaligned address during AEN drain");
        goto out;
    }

    /* Mark internal command */
    tw_dev->srb[request_id] = NULL;

    do {
        /* Send command to the board */
        if (twa_scsiop_execute_scsi(tw_dev, request_id, cdb, 1, sglist)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x2, "Error posting request sense");
            goto out;
        }

        /* Now poll for completion */
        if (twa_poll_response(tw_dev, request_id, 30)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x3, "No valid response while draining AEN queue");
            tw_dev->posted_request_count--;
            goto out;
        }

        tw_dev->posted_request_count--;
        header = (TW_Command_Apache_Header *)tw_dev->generic_buffer_virt[request_id];
        aen = le16_to_cpu(header->status_block.error);
        queue = 0;
        count++;

        switch (aen) {
        case TW_AEN_QUEUE_EMPTY:
            if (first_reset != 1)
                goto out;
            else
                finished = 1;
            break;
        case TW_AEN_SOFT_RESET:
            if (first_reset == 0)
                first_reset = 1;
            else
                queue = 1;
            break;
        case TW_AEN_SYNC_TIME_WITH_HOST:
            break;
        default:
            queue = 1;
        }

        /* Now queue an event info */
        if (queue)
            twa_aen_queue_event(tw_dev, header);
    } while ((finished == 0) && (count < TW_MAX_AEN_DRAIN));

    if (count == TW_MAX_AEN_DRAIN)
        goto out;

    retval = 0;
out:
    tw_dev->state[request_id] = TW_S_INITIAL;
    return retval;
} /* End twa_aen_drain_queue() */

/* This function will queue an event */
static void twa_aen_queue_event(TW_Device_Extension *tw_dev, TW_Command_Apache_Header *header)
{
    u32 local_time;
    struct timeval time;
    TW_Event *event;
    unsigned short aen;
    char host[16];
    char *error_str;

    tw_dev->aen_count++;

    /* Fill out event info */
    event = tw_dev->event_queue[tw_dev->error_index];

    /* Check for clobber */
    host[0] = '\0';
    if (tw_dev->host) {
        sprintf(host, " scsi%d:", tw_dev->host->host_no);
        if (event->retrieved == TW_AEN_NOT_RETRIEVED)
            tw_dev->aen_clobber = 1;
    }

    aen = le16_to_cpu(header->status_block.error);
    memset(event, 0, sizeof(TW_Event));

    event->severity = TW_SEV_OUT(header->status_block.severity__reserved);
    do_gettimeofday(&time);
    local_time = (u32)(time.tv_sec - (sys_tz.tz_minuteswest * 60));
    event->time_stamp_sec = local_time;
    event->aen_code = aen;
    event->retrieved = TW_AEN_NOT_RETRIEVED;
    event->sequence_id = tw_dev->error_sequence_id;
    tw_dev->error_sequence_id++;

    /* Check for embedded error string */
    error_str = &(header->err_specific_desc[strlen(header->err_specific_desc)+1]);

    header->err_specific_desc[sizeof(header->err_specific_desc) - 1] = '\0';
    event->parameter_len = strlen(header->err_specific_desc);
    memcpy(event->parameter_data, header->err_specific_desc, event->parameter_len + (error_str[0] == '\0' ? 0 : (1 + strlen(error_str))));
    if (event->severity != TW_AEN_SEVERITY_DEBUG)
        printk(KERN_WARNING "3w-9xxx:%s AEN: %s (0x%02X:0x%04X): %s:%s.\n",
               host,
               twa_aen_severity_lookup(TW_SEV_OUT(header->status_block.severity__reserved)),
               TW_MESSAGE_SOURCE_CONTROLLER_EVENT, aen,
               error_str[0] == '\0' ? twa_string_lookup(twa_aen_table, aen) : error_str,
               header->err_specific_desc);
    else
        tw_dev->aen_count--;

    if ((tw_dev->error_index + 1) == TW_Q_LENGTH)
        tw_dev->event_queue_wrapped = 1;
    tw_dev->error_index = (tw_dev->error_index + 1 ) % TW_Q_LENGTH;
} /* End twa_aen_queue_event() */

/* This function will read the aen queue from the isr */
static int twa_aen_read_queue(TW_Device_Extension *tw_dev, int request_id)
{
    char cdb[TW_MAX_CDB_LEN];
    TW_SG_Entry sglist[1];
    TW_Command_Full *full_command_packet;
    int retval = 1;

    full_command_packet = tw_dev->command_packet_virt[request_id];
    memset(full_command_packet, 0, sizeof(TW_Command_Full));

    /* Initialize cdb */
    memset(&cdb, 0, TW_MAX_CDB_LEN);
    cdb[0] = REQUEST_SENSE; /* opcode */
    cdb[4] = TW_ALLOCATION_LENGTH; /* allocation length */

    /* Initialize sglist */
    memset(&sglist, 0, sizeof(TW_SG_Entry));
    sglist[0].length = TW_SECTOR_SIZE;
    sglist[0].address = tw_dev->generic_buffer_phys[request_id];

    /* Mark internal command */
    tw_dev->srb[request_id] = NULL;

    /* Now post the command packet */
    if (twa_scsiop_execute_scsi(tw_dev, request_id, cdb, 1, sglist)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x4, "Post failed while reading AEN queue");
        goto out;
    }
    retval = 0;
out:
    return retval;
} /* End twa_aen_read_queue() */

/* This function will look up an AEN severity string */
static char *twa_aen_severity_lookup(unsigned char severity_code)
{
    char *retval = NULL;

    if ((severity_code < (unsigned char) TW_AEN_SEVERITY_ERROR) ||
        (severity_code > (unsigned char) TW_AEN_SEVERITY_DEBUG))
        goto out;

    retval = twa_aen_severity_table[severity_code];
out:
    return retval;
} /* End twa_aen_severity_lookup() */

/* This function will sync firmware time with the host time */
static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
{
    u32 schedulertime;
    struct timeval utc;
    TW_Command_Full *full_command_packet;
    TW_Command *command_packet;
    TW_Param_Apache *param;
    u32 local_time;

    /* Fill out the command packet */
    full_command_packet = tw_dev->command_packet_virt[request_id];
    memset(full_command_packet, 0, sizeof(TW_Command_Full));
    command_packet = &full_command_packet->command.oldcommand;
    command_packet->opcode__sgloffset = TW_OPSGL_IN(2, TW_OP_SET_PARAM);
    command_packet->request_id = request_id;
    command_packet->byte8_offset.param.sgl[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
    command_packet->byte8_offset.param.sgl[0].length = cpu_to_le32(TW_SECTOR_SIZE);
    command_packet->size = TW_COMMAND_SIZE;
    command_packet->byte6_offset.parameter_count = cpu_to_le16(1);

    /* Setup the param */
    param = (TW_Param_Apache *)tw_dev->generic_buffer_virt[request_id];
    memset(param, 0, TW_SECTOR_SIZE);
    param->table_id = cpu_to_le16(TW_TIMEKEEP_TABLE | 0x8000); /* Controller time keep table */
    param->parameter_id = cpu_to_le16(0x3); /* SchedulerTime */
    param->parameter_size_bytes = cpu_to_le16(4);

    /* Convert system time in UTC to local time seconds since last 
           Sunday 12:00AM */
    do_gettimeofday(&utc);
    local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
    schedulertime = local_time - (3 * 86400);
    schedulertime = cpu_to_le32(schedulertime % 604800);

    memcpy(param->data, &schedulertime, sizeof(u32));

    /* Mark internal command */
    tw_dev->srb[request_id] = NULL;

    /* Now post the command */
    twa_post_command_packet(tw_dev, request_id, 1);
} /* End twa_aen_sync_time() */

/* This function will allocate memory and check if it is correctly aligned */
static int twa_allocate_memory(TW_Device_Extension *tw_dev, int size, int which)
{
    int i;
    dma_addr_t dma_handle;
    unsigned long *cpu_addr;
    int retval = 1;

    cpu_addr = pci_alloc_consistent(tw_dev->tw_pci_dev, size*TW_Q_LENGTH, &dma_handle);
    if (!cpu_addr) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x5, "Memory allocation failed");
        goto out;
    }

    if ((unsigned long)cpu_addr % (TW_ALIGNMENT_9000)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x6, "Failed to allocate correctly aligned memory");
        pci_free_consistent(tw_dev->tw_pci_dev, size*TW_Q_LENGTH, cpu_addr, dma_handle);
        goto out;
    }

    memset(cpu_addr, 0, size*TW_Q_LENGTH);

    for (i = 0; i < TW_Q_LENGTH; i++) {
        switch(which) {
        case 0:
            tw_dev->command_packet_phys[i] = dma_handle+(i*size);
            tw_dev->command_packet_virt[i] = (TW_Command_Full *)((unsigned char *)cpu_addr + (i*size));
            break;
        case 1:
            tw_dev->generic_buffer_phys[i] = dma_handle+(i*size);
            tw_dev->generic_buffer_virt[i] = (unsigned long *)((unsigned char *)cpu_addr + (i*size));
            break;
        }
    }
    retval = 0;
out:
    return retval;
} /* End twa_allocate_memory() */

/* This function will check the status register for unexpected bits */
static int twa_check_bits(u32 status_reg_value)
{
    int retval = 1;

    if ((status_reg_value & TW_STATUS_EXPECTED_BITS) != TW_STATUS_EXPECTED_BITS)
        goto out;
    if ((status_reg_value & TW_STATUS_UNEXPECTED_BITS) != 0)
        goto out;

    retval = 0;
out:
    return retval;
} /* End twa_check_bits() */

/* This function will check the srl and decide if we are compatible  */
static int twa_check_srl(TW_Device_Extension *tw_dev, int *flashed)
{
    int retval = 1;
    unsigned short fw_on_ctlr_srl = 0, fw_on_ctlr_arch_id = 0;
    unsigned short fw_on_ctlr_branch = 0, fw_on_ctlr_build = 0;
    u32 init_connect_result = 0;

    if (twa_initconnection(tw_dev, TW_INIT_MESSAGE_CREDITS,
                   TW_EXTENDED_INIT_CONNECT, TW_CURRENT_DRIVER_SRL,
                   TW_9000_ARCH_ID, TW_CURRENT_DRIVER_BRANCH,
                   TW_CURRENT_DRIVER_BUILD, &fw_on_ctlr_srl,
                   &fw_on_ctlr_arch_id, &fw_on_ctlr_branch,
                   &fw_on_ctlr_build, &init_connect_result)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x7, "Initconnection failed while checking SRL");
        goto out;
    }

    tw_dev->tw_compat_info.working_srl = fw_on_ctlr_srl;
    tw_dev->tw_compat_info.working_branch = fw_on_ctlr_branch;
    tw_dev->tw_compat_info.working_build = fw_on_ctlr_build;

    /* Try base mode compatibility */
    if (!(init_connect_result & TW_CTLR_FW_COMPATIBLE)) {
        if (twa_initconnection(tw_dev, TW_INIT_MESSAGE_CREDITS,
                       TW_EXTENDED_INIT_CONNECT,
                       TW_BASE_FW_SRL, TW_9000_ARCH_ID,
                       TW_BASE_FW_BRANCH, TW_BASE_FW_BUILD,
                       &fw_on_ctlr_srl, &fw_on_ctlr_arch_id,
                       &fw_on_ctlr_branch, &fw_on_ctlr_build,
                       &init_connect_result)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0xa, "Initconnection (base mode) failed while checking SRL");
            goto out;
        }
        if (!(init_connect_result & TW_CTLR_FW_COMPATIBLE)) {
            if (TW_CURRENT_DRIVER_SRL > fw_on_ctlr_srl) {
                TW_PRINTK(tw_dev->host, TW_DRIVER, 0x32, "Firmware and driver incompatibility: please upgrade firmware");
            } else {
                TW_PRINTK(tw_dev->host, TW_DRIVER, 0x33, "Firmware and driver incompatibility: please upgrade driver");
            }
            goto out;
        }
        tw_dev->tw_compat_info.working_srl = TW_BASE_FW_SRL;
        tw_dev->tw_compat_info.working_branch = TW_BASE_FW_BRANCH;
        tw_dev->tw_compat_info.working_build = TW_BASE_FW_BUILD;
    }

    /* Load rest of compatibility struct */
    strncpy(tw_dev->tw_compat_info.driver_version, TW_DRIVER_VERSION, strlen(TW_DRIVER_VERSION));
    tw_dev->tw_compat_info.driver_srl_high = TW_CURRENT_DRIVER_SRL;
    tw_dev->tw_compat_info.driver_branch_high = TW_CURRENT_DRIVER_BRANCH;
    tw_dev->tw_compat_info.driver_build_high = TW_CURRENT_DRIVER_BUILD;
    tw_dev->tw_compat_info.driver_srl_low = TW_BASE_FW_SRL;
    tw_dev->tw_compat_info.driver_branch_low = TW_BASE_FW_BRANCH;
    tw_dev->tw_compat_info.driver_build_low = TW_BASE_FW_BUILD;
    tw_dev->tw_compat_info.fw_on_ctlr_srl = fw_on_ctlr_srl;
    tw_dev->tw_compat_info.fw_on_ctlr_branch = fw_on_ctlr_branch;
    tw_dev->tw_compat_info.fw_on_ctlr_build = fw_on_ctlr_build;

    retval = 0;
out:
    return retval;
} /* End twa_check_srl() */

/* This function handles ioctl for the character device */
static long twa_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    long timeout;
    unsigned long *cpu_addr, data_buffer_length_adjusted = 0, flags = 0;
    dma_addr_t dma_handle;
    int request_id = 0;
    unsigned int sequence_id = 0;
    unsigned char event_index, start_index;
    TW_Ioctl_Driver_Command driver_command;
    TW_Ioctl_Buf_Apache *tw_ioctl;
    TW_Lock *tw_lock;
    TW_Command_Full *full_command_packet;
    TW_Compatibility_Info *tw_compat_info;
    TW_Event *event;
    struct timeval current_time;
    u32 current_time_ms;
    TW_Device_Extension *tw_dev = twa_device_extension_list[iminor(inode)];
    int retval = TW_IOCTL_ERROR_OS_EFAULT;
    void __user *argp = (void __user *)arg;

    mutex_lock(&twa_chrdev_mutex);

    /* Only let one of these through at a time */
    if (mutex_lock_interruptible(&tw_dev->ioctl_lock)) {
        retval = TW_IOCTL_ERROR_OS_EINTR;
        goto out;
    }

    /* First copy down the driver command */
    if (copy_from_user(&driver_command, argp, sizeof(TW_Ioctl_Driver_Command)))
        goto out2;

    /* Check data buffer size */
    if (driver_command.buffer_length > TW_MAX_SECTORS * 2048) {
        retval = TW_IOCTL_ERROR_OS_EINVAL;
        goto out2;
    }

    /* Hardware can only do multiple of 512 byte transfers */
    data_buffer_length_adjusted = (driver_command.buffer_length + 511) & ~511;

    /* Now allocate ioctl buf memory */
    cpu_addr = dma_alloc_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted+sizeof(TW_Ioctl_Buf_Apache) - 1, &dma_handle, GFP_KERNEL);
    if (!cpu_addr) {
        retval = TW_IOCTL_ERROR_OS_ENOMEM;
        goto out2;
    }

    tw_ioctl = (TW_Ioctl_Buf_Apache *)cpu_addr;

    /* Now copy down the entire ioctl */
    if (copy_from_user(tw_ioctl, argp, driver_command.buffer_length + sizeof(TW_Ioctl_Buf_Apache) - 1))
        goto out3;

    /* See which ioctl we are doing */
    switch (cmd) {
    case TW_IOCTL_FIRMWARE_PASS_THROUGH:
        spin_lock_irqsave(tw_dev->host->host_lock, flags);
        twa_get_request_id(tw_dev, &request_id);

        /* Flag internal command */
        tw_dev->srb[request_id] = NULL;

        /* Flag chrdev ioctl */
        tw_dev->chrdev_request_id = request_id;

        full_command_packet = &tw_ioctl->firmware_command;

        /* Load request id and sglist for both command types */
        twa_load_sgl(tw_dev, full_command_packet, request_id, dma_handle, data_buffer_length_adjusted);

        memcpy(tw_dev->command_packet_virt[request_id], &(tw_ioctl->firmware_command), sizeof(TW_Command_Full));

        /* Now post the command packet to the controller */
        twa_post_command_packet(tw_dev, request_id, 1);
        spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

        timeout = TW_IOCTL_CHRDEV_TIMEOUT*HZ;

        /* Now wait for command to complete */
        timeout = wait_event_timeout(tw_dev->ioctl_wqueue, tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE, timeout);

        /* We timed out, and didn't get an interrupt */
        if (tw_dev->chrdev_request_id != TW_IOCTL_CHRDEV_FREE) {
            /* Now we need to reset the board */
            printk(KERN_WARNING "3w-9xxx: scsi%d: WARNING: (0x%02X:0x%04X): Character ioctl (0x%x) timed out, resetting card.\n",
                   tw_dev->host->host_no, TW_DRIVER, 0x37,
                   cmd);
            retval = TW_IOCTL_ERROR_OS_EIO;
            twa_reset_device_extension(tw_dev);
            goto out3;
        }

        /* Now copy in the command packet response */
        memcpy(&(tw_ioctl->firmware_command), tw_dev->command_packet_virt[request_id], sizeof(TW_Command_Full));
        
        /* Now complete the io */
        spin_lock_irqsave(tw_dev->host->host_lock, flags);
        tw_dev->posted_request_count--;
        tw_dev->state[request_id] = TW_S_COMPLETED;
        twa_free_request_id(tw_dev, request_id);
        spin_unlock_irqrestore(tw_dev->host->host_lock, flags);
        break;
    case TW_IOCTL_GET_COMPATIBILITY_INFO:
        tw_ioctl->driver_command.status = 0;
        /* Copy compatibility struct into ioctl data buffer */
        tw_compat_info = (TW_Compatibility_Info *)tw_ioctl->data_buffer;
        memcpy(tw_compat_info, &tw_dev->tw_compat_info, sizeof(TW_Compatibility_Info));
        break;
    case TW_IOCTL_GET_LAST_EVENT:
        if (tw_dev->event_queue_wrapped) {
            if (tw_dev->aen_clobber) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_AEN_CLOBBER;
                tw_dev->aen_clobber = 0;
            } else
                tw_ioctl->driver_command.status = 0;
        } else {
            if (!tw_dev->error_index) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
                break;
            }
            tw_ioctl->driver_command.status = 0;
        }
        event_index = (tw_dev->error_index - 1 + TW_Q_LENGTH) % TW_Q_LENGTH;
        memcpy(tw_ioctl->data_buffer, tw_dev->event_queue[event_index], sizeof(TW_Event));
        tw_dev->event_queue[event_index]->retrieved = TW_AEN_RETRIEVED;
        break;
    case TW_IOCTL_GET_FIRST_EVENT:
        if (tw_dev->event_queue_wrapped) {
            if (tw_dev->aen_clobber) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_AEN_CLOBBER;
                tw_dev->aen_clobber = 0;
            } else 
                tw_ioctl->driver_command.status = 0;
            event_index = tw_dev->error_index;
        } else {
            if (!tw_dev->error_index) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
                break;
            }
            tw_ioctl->driver_command.status = 0;
            event_index = 0;
        }
        memcpy(tw_ioctl->data_buffer, tw_dev->event_queue[event_index], sizeof(TW_Event));
        tw_dev->event_queue[event_index]->retrieved = TW_AEN_RETRIEVED;
        break;
    case TW_IOCTL_GET_NEXT_EVENT:
        event = (TW_Event *)tw_ioctl->data_buffer;
        sequence_id = event->sequence_id;
        tw_ioctl->driver_command.status = 0;

        if (tw_dev->event_queue_wrapped) {
            if (tw_dev->aen_clobber) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_AEN_CLOBBER;
                tw_dev->aen_clobber = 0;
            }
            start_index = tw_dev->error_index;
        } else {
            if (!tw_dev->error_index) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
                break;
            }
            start_index = 0;
        }
        event_index = (start_index + sequence_id - tw_dev->event_queue[start_index]->sequence_id + 1) % TW_Q_LENGTH;

        if (!(tw_dev->event_queue[event_index]->sequence_id > sequence_id)) {
            if (tw_ioctl->driver_command.status == TW_IOCTL_ERROR_STATUS_AEN_CLOBBER)
                tw_dev->aen_clobber = 1;
            tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
            break;
        }
        memcpy(tw_ioctl->data_buffer, tw_dev->event_queue[event_index], sizeof(TW_Event));
        tw_dev->event_queue[event_index]->retrieved = TW_AEN_RETRIEVED;
        break;
    case TW_IOCTL_GET_PREVIOUS_EVENT:
        event = (TW_Event *)tw_ioctl->data_buffer;
        sequence_id = event->sequence_id;
        tw_ioctl->driver_command.status = 0;

        if (tw_dev->event_queue_wrapped) {
            if (tw_dev->aen_clobber) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_AEN_CLOBBER;
                tw_dev->aen_clobber = 0;
            }
            start_index = tw_dev->error_index;
        } else {
            if (!tw_dev->error_index) {
                tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
                break;
            }
            start_index = 0;
        }
        event_index = (start_index + sequence_id - tw_dev->event_queue[start_index]->sequence_id - 1) % TW_Q_LENGTH;

        if (!(tw_dev->event_queue[event_index]->sequence_id < sequence_id)) {
            if (tw_ioctl->driver_command.status == TW_IOCTL_ERROR_STATUS_AEN_CLOBBER)
                tw_dev->aen_clobber = 1;
            tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NO_MORE_EVENTS;
            break;
        }
        memcpy(tw_ioctl->data_buffer, tw_dev->event_queue[event_index], sizeof(TW_Event));
        tw_dev->event_queue[event_index]->retrieved = TW_AEN_RETRIEVED;
        break;
    case TW_IOCTL_GET_LOCK:
        tw_lock = (TW_Lock *)tw_ioctl->data_buffer;
        do_gettimeofday(&current_time);
        current_time_ms = (current_time.tv_sec * 1000) + (current_time.tv_usec / 1000);

        if ((tw_lock->force_flag == 1) || (tw_dev->ioctl_sem_lock == 0) || (current_time_ms >= tw_dev->ioctl_msec)) {
            tw_dev->ioctl_sem_lock = 1;
            tw_dev->ioctl_msec = current_time_ms + tw_lock->timeout_msec;
            tw_ioctl->driver_command.status = 0;
            tw_lock->time_remaining_msec = tw_lock->timeout_msec;
        } else {
            tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_LOCKED;
            tw_lock->time_remaining_msec = tw_dev->ioctl_msec - current_time_ms;
        }
        break;
    case TW_IOCTL_RELEASE_LOCK:
        if (tw_dev->ioctl_sem_lock == 1) {
            tw_dev->ioctl_sem_lock = 0;
            tw_ioctl->driver_command.status = 0;
        } else {
            tw_ioctl->driver_command.status = TW_IOCTL_ERROR_STATUS_NOT_LOCKED;
        }
        break;
    default:
        retval = TW_IOCTL_ERROR_OS_ENOTTY;
        goto out3;
    }

    /* Now copy the entire response to userspace */
    if (copy_to_user(argp, tw_ioctl, sizeof(TW_Ioctl_Buf_Apache) + driver_command.buffer_length - 1) == 0)
        retval = 0;
out3:
    /* Now free ioctl buf memory */
    dma_free_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted+sizeof(TW_Ioctl_Buf_Apache) - 1, cpu_addr, dma_handle);
out2:
    mutex_unlock(&tw_dev->ioctl_lock);
out:
    mutex_unlock(&twa_chrdev_mutex);
    return retval;
} /* End twa_chrdev_ioctl() */

/* This function handles open for the character device */
/* NOTE that this function will race with remove. */
static int twa_chrdev_open(struct inode *inode, struct file *file)
{
    unsigned int minor_number;
    int retval = TW_IOCTL_ERROR_OS_ENODEV;

    minor_number = iminor(inode);
    if (minor_number >= twa_device_extension_count)
        goto out;
    retval = 0;
out:
    return retval;
} /* End twa_chrdev_open() */

/* This function will print readable messages from status register errors */
static int twa_decode_bits(TW_Device_Extension *tw_dev, u32 status_reg_value)
{
    int retval = 1;

    /* Check for various error conditions and handle them appropriately */
    if (status_reg_value & TW_STATUS_PCI_PARITY_ERROR) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0xc, "PCI Parity Error: clearing");
        writel(TW_CONTROL_CLEAR_PARITY_ERROR, TW_CONTROL_REG_ADDR(tw_dev));
    }

    if (status_reg_value & TW_STATUS_PCI_ABORT) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0xd, "PCI Abort: clearing");
        writel(TW_CONTROL_CLEAR_PCI_ABORT, TW_CONTROL_REG_ADDR(tw_dev));
        pci_write_config_word(tw_dev->tw_pci_dev, PCI_STATUS, TW_PCI_CLEAR_PCI_ABORT);
    }

    if (status_reg_value & TW_STATUS_QUEUE_ERROR) {
        if (((tw_dev->tw_pci_dev->device != PCI_DEVICE_ID_3WARE_9650SE) &&
             (tw_dev->tw_pci_dev->device != PCI_DEVICE_ID_3WARE_9690SA)) ||
            (!test_bit(TW_IN_RESET, &tw_dev->flags)))
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0xe, "Controller Queue Error: clearing");
        writel(TW_CONTROL_CLEAR_QUEUE_ERROR, TW_CONTROL_REG_ADDR(tw_dev));
    }

    if (status_reg_value & TW_STATUS_MICROCONTROLLER_ERROR) {
        if (tw_dev->reset_print == 0) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x10, "Microcontroller Error: clearing");
            tw_dev->reset_print = 1;
        }
        goto out;
    }
    retval = 0;
out:
    return retval;
} /* End twa_decode_bits() */

/* This function will empty the response queue */
static int twa_empty_response_queue(TW_Device_Extension *tw_dev)
{
    u32 status_reg_value, response_que_value;
    int count = 0, retval = 1;

    status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));

    while (((status_reg_value & TW_STATUS_RESPONSE_QUEUE_EMPTY) == 0) && (count < TW_MAX_RESPONSE_DRAIN)) {
        response_que_value = readl(TW_RESPONSE_QUEUE_REG_ADDR(tw_dev));
        status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));
        count++;
    }
    if (count == TW_MAX_RESPONSE_DRAIN)
        goto out;

    retval = 0;
out:
    return retval;
} /* End twa_empty_response_queue() */

/* This function will clear the pchip/response queue on 9550SX */
static int twa_empty_response_queue_large(TW_Device_Extension *tw_dev)
{
    u32 response_que_value = 0;
    unsigned long before;
    int retval = 1;

    if (tw_dev->tw_pci_dev->device != PCI_DEVICE_ID_3WARE_9000) {
        before = jiffies;
        while ((response_que_value & TW_9550SX_DRAIN_COMPLETED) != TW_9550SX_DRAIN_COMPLETED) {
            response_que_value = readl(TW_RESPONSE_QUEUE_REG_ADDR_LARGE(tw_dev));
            msleep(1);
            if (time_after(jiffies, before + HZ * 30))
                goto out;
        }
        /* P-chip settle time */
        msleep(500);
        retval = 0;
    } else
        retval = 0;
out:
    return retval;
} /* End twa_empty_response_queue_large() */

/* This function passes sense keys from firmware to scsi layer */
static int twa_fill_sense(TW_Device_Extension *tw_dev, int request_id, int copy_sense, int print_host)
{
    TW_Command_Full *full_command_packet;
    unsigned short error;
    int retval = 1;
    char *error_str;

    full_command_packet = tw_dev->command_packet_virt[request_id];

    /* Check for embedded error string */
    error_str = &(full_command_packet->header.err_specific_desc[strlen(full_command_packet->header.err_specific_desc) + 1]);

    /* Don't print error for Logical unit not supported during rollcall */
    error = le16_to_cpu(full_command_packet->header.status_block.error);
    if ((error != TW_ERROR_LOGICAL_UNIT_NOT_SUPPORTED) && (error != TW_ERROR_UNIT_OFFLINE)) {
        if (print_host)
            printk(KERN_WARNING "3w-9xxx: scsi%d: ERROR: (0x%02X:0x%04X): %s:%s.\n",
                   tw_dev->host->host_no,
                   TW_MESSAGE_SOURCE_CONTROLLER_ERROR,
                   full_command_packet->header.status_block.error,
                   error_str[0] == '\0' ?
                   twa_string_lookup(twa_error_table,
                         full_command_packet->header.status_block.error) : error_str,
                   full_command_packet->header.err_specific_desc);
        else
            printk(KERN_WARNING "3w-9xxx: ERROR: (0x%02X:0x%04X): %s:%s.\n",
                   TW_MESSAGE_SOURCE_CONTROLLER_ERROR,
                   full_command_packet->header.status_block.error,
                   error_str[0] == '\0' ?
                   twa_string_lookup(twa_error_table,
                         full_command_packet->header.status_block.error) : error_str,
                   full_command_packet->header.err_specific_desc);
    }

    if (copy_sense) {
        memcpy(tw_dev->srb[request_id]->sense_buffer, full_command_packet->header.sense_data, TW_SENSE_DATA_LENGTH);
        tw_dev->srb[request_id]->result = (full_command_packet->command.newcommand.status << 1);
        retval = TW_ISR_DONT_RESULT;
        goto out;
    }
    retval = 0;
out:
    return retval;
} /* End twa_fill_sense() */

/* This function will free up device extension resources */
static void twa_free_device_extension(TW_Device_Extension *tw_dev)
{
    if (tw_dev->command_packet_virt[0])
        pci_free_consistent(tw_dev->tw_pci_dev,
                    sizeof(TW_Command_Full)*TW_Q_LENGTH,
                    tw_dev->command_packet_virt[0],
                    tw_dev->command_packet_phys[0]);

    if (tw_dev->generic_buffer_virt[0])
        pci_free_consistent(tw_dev->tw_pci_dev,
                    TW_SECTOR_SIZE*TW_Q_LENGTH,
                    tw_dev->generic_buffer_virt[0],
                    tw_dev->generic_buffer_phys[0]);

    kfree(tw_dev->event_queue[0]);
} /* End twa_free_device_extension() */

/* This function will free a request id */
static void twa_free_request_id(TW_Device_Extension *tw_dev, int request_id)
{
    tw_dev->free_queue[tw_dev->free_tail] = request_id;
    tw_dev->state[request_id] = TW_S_FINISHED;
    tw_dev->free_tail = (tw_dev->free_tail + 1) % TW_Q_LENGTH;
} /* End twa_free_request_id() */

/* This function will get parameter table entries from the firmware */
static void *twa_get_param(TW_Device_Extension *tw_dev, int request_id, int table_id, int parameter_id, int parameter_size_bytes)
{
    TW_Command_Full *full_command_packet;
    TW_Command *command_packet;
    TW_Param_Apache *param;
    void *retval = NULL;

    /* Setup the command packet */
    full_command_packet = tw_dev->command_packet_virt[request_id];
    memset(full_command_packet, 0, sizeof(TW_Command_Full));
    command_packet = &full_command_packet->command.oldcommand;

    command_packet->opcode__sgloffset = TW_OPSGL_IN(2, TW_OP_GET_PARAM);
    command_packet->size              = TW_COMMAND_SIZE;
    command_packet->request_id        = request_id;
    command_packet->byte6_offset.block_count = cpu_to_le16(1);

    /* Now setup the param */
    param = (TW_Param_Apache *)tw_dev->generic_buffer_virt[request_id];
    memset(param, 0, TW_SECTOR_SIZE);
    param->table_id = cpu_to_le16(table_id | 0x8000);
    param->parameter_id = cpu_to_le16(parameter_id);
    param->parameter_size_bytes = cpu_to_le16(parameter_size_bytes);

    command_packet->byte8_offset.param.sgl[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
    command_packet->byte8_offset.param.sgl[0].length = cpu_to_le32(TW_SECTOR_SIZE);

    /* Post the command packet to the board */
    twa_post_command_packet(tw_dev, request_id, 1);

    /* Poll for completion */
    if (twa_poll_response(tw_dev, request_id, 30))
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x13, "No valid response during get param")
    else
        retval = (void *)&(param->data[0]);

    tw_dev->posted_request_count--;
    tw_dev->state[request_id] = TW_S_INITIAL;

    return retval;
} /* End twa_get_param() */

/* This function will assign an available request id */
static void twa_get_request_id(TW_Device_Extension *tw_dev, int *request_id)
{
    *request_id = tw_dev->free_queue[tw_dev->free_head];
    tw_dev->free_head = (tw_dev->free_head + 1) % TW_Q_LENGTH;
    tw_dev->state[*request_id] = TW_S_STARTED;
} /* End twa_get_request_id() */

/* This function will send an initconnection command to controller */
static int twa_initconnection(TW_Device_Extension *tw_dev, int message_credits,
                  u32 set_features, unsigned short current_fw_srl, 
                  unsigned short current_fw_arch_id, 
                  unsigned short current_fw_branch, 
                  unsigned short current_fw_build, 
                  unsigned short *fw_on_ctlr_srl, 
                  unsigned short *fw_on_ctlr_arch_id, 
                  unsigned short *fw_on_ctlr_branch, 
                  unsigned short *fw_on_ctlr_build, 
                  u32 *init_connect_result)
{
    TW_Command_Full *full_command_packet;
    TW_Initconnect *tw_initconnect;
    int request_id = 0, retval = 1;

    /* Initialize InitConnection command packet */
    full_command_packet = tw_dev->command_packet_virt[request_id];
    memset(full_command_packet, 0, sizeof(TW_Command_Full));
    full_command_packet->header.header_desc.size_header = 128;
    
    tw_initconnect = (TW_Initconnect *)&full_command_packet->command.oldcommand;
    tw_initconnect->opcode__reserved = TW_OPRES_IN(0, TW_OP_INIT_CONNECTION);
    tw_initconnect->request_id = request_id;
    tw_initconnect->message_credits = cpu_to_le16(message_credits);
    tw_initconnect->features = set_features;

    /* Turn on 64-bit sgl support if we need to */
    tw_initconnect->features |= sizeof(dma_addr_t) > 4 ? 1 : 0;

    tw_initconnect->features = cpu_to_le32(tw_initconnect->features);

    if (set_features & TW_EXTENDED_INIT_CONNECT) {
        tw_initconnect->size = TW_INIT_COMMAND_PACKET_SIZE_EXTENDED;
        tw_initconnect->fw_srl = cpu_to_le16(current_fw_srl);
        tw_initconnect->fw_arch_id = cpu_to_le16(current_fw_arch_id);
        tw_initconnect->fw_branch = cpu_to_le16(current_fw_branch);
        tw_initconnect->fw_build = cpu_to_le16(current_fw_build);
    } else 
        tw_initconnect->size = TW_INIT_COMMAND_PACKET_SIZE;

    /* Send command packet to the board */
    twa_post_command_packet(tw_dev, request_id, 1);

    /* Poll for completion */
    if (twa_poll_response(tw_dev, request_id, 30)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x15, "No valid response during init connection");
    } else {
        if (set_features & TW_EXTENDED_INIT_CONNECT) {
            *fw_on_ctlr_srl = le16_to_cpu(tw_initconnect->fw_srl);
            *fw_on_ctlr_arch_id = le16_to_cpu(tw_initconnect->fw_arch_id);
            *fw_on_ctlr_branch = le16_to_cpu(tw_initconnect->fw_branch);
            *fw_on_ctlr_build = le16_to_cpu(tw_initconnect->fw_build);
            *init_connect_result = le32_to_cpu(tw_initconnect->result);
        }
        retval = 0;
    }

    tw_dev->posted_request_count--;
    tw_dev->state[request_id] = TW_S_INITIAL;

    return retval;
} /* End twa_initconnection() */

/* This function will initialize the fields of a device extension */
static int twa_initialize_device_extension(TW_Device_Extension *tw_dev)
{
    int i, retval = 1;

    /* Initialize command packet buffers */
    if (twa_allocate_memory(tw_dev, sizeof(TW_Command_Full), 0)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x16, "Command packet memory allocation failed");
        goto out;
    }

    /* Initialize generic buffer */
    if (twa_allocate_memory(tw_dev, TW_SECTOR_SIZE, 1)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x17, "Generic memory allocation failed");
        goto out;
    }

    /* Allocate event info space */
    tw_dev->event_queue[0] = kcalloc(TW_Q_LENGTH, sizeof(TW_Event), GFP_KERNEL);
    if (!tw_dev->event_queue[0]) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x18, "Event info memory allocation failed");
        goto out;
    }


    for (i = 0; i < TW_Q_LENGTH; i++) {
        tw_dev->event_queue[i] = (TW_Event *)((unsigned char *)tw_dev->event_queue[0] + (i * sizeof(TW_Event)));
        tw_dev->free_queue[i] = i;
        tw_dev->state[i] = TW_S_INITIAL;
    }

    tw_dev->pending_head = TW_Q_START;
    tw_dev->pending_tail = TW_Q_START;
    tw_dev->free_head = TW_Q_START;
    tw_dev->free_tail = TW_Q_START;
    tw_dev->error_sequence_id = 1;
    tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;

    mutex_init(&tw_dev->ioctl_lock);
    init_waitqueue_head(&tw_dev->ioctl_wqueue);

    retval = 0;
out:
    return retval;
} /* End twa_initialize_device_extension() */

/* This function is the interrupt service routine */
static irqreturn_t twa_interrupt(int irq, void *dev_instance)
{
    int request_id, error = 0;
    u32 status_reg_value;
    TW_Response_Queue response_que;
    TW_Command_Full *full_command_packet;
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)dev_instance;
    int handled = 0;

    /* Get the per adapter lock */
    spin_lock(tw_dev->host->host_lock);

    /* Read the registers */
    status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));

    /* Check if this is our interrupt, otherwise bail */
    if (!(status_reg_value & TW_STATUS_VALID_INTERRUPT))
        goto twa_interrupt_bail;

    handled = 1;

    /* If we are resetting, bail */
    if (test_bit(TW_IN_RESET, &tw_dev->flags))
        goto twa_interrupt_bail;

    /* Check controller for errors */
    if (twa_check_bits(status_reg_value)) {
        if (twa_decode_bits(tw_dev, status_reg_value)) {
            TW_CLEAR_ALL_INTERRUPTS(tw_dev);
            goto twa_interrupt_bail;
        }
    }

    /* Handle host interrupt */
    if (status_reg_value & TW_STATUS_HOST_INTERRUPT)
        TW_CLEAR_HOST_INTERRUPT(tw_dev);

    /* Handle attention interrupt */
    if (status_reg_value & TW_STATUS_ATTENTION_INTERRUPT) {
        TW_CLEAR_ATTENTION_INTERRUPT(tw_dev);
        if (!(test_and_set_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags))) {
            twa_get_request_id(tw_dev, &request_id);

            error = twa_aen_read_queue(tw_dev, request_id);
            if (error) {
                tw_dev->state[request_id] = TW_S_COMPLETED;
                twa_free_request_id(tw_dev, request_id);
                clear_bit(TW_IN_ATTENTION_LOOP, &tw_dev->flags);
            }
        }
    }

    /* Handle command interrupt */
    if (status_reg_value & TW_STATUS_COMMAND_INTERRUPT) {
        TW_MASK_COMMAND_INTERRUPT(tw_dev);
        /* Drain as many pending commands as we can */
        while (tw_dev->pending_request_count > 0) {
            request_id = tw_dev->pending_queue[tw_dev->pending_head];
            if (tw_dev->state[request_id] != TW_S_PENDING) {
                TW_PRINTK(tw_dev->host, TW_DRIVER, 0x19, "Found request id that wasn't pending");
                TW_CLEAR_ALL_INTERRUPTS(tw_dev);
                goto twa_interrupt_bail;
            }
            if (twa_post_command_packet(tw_dev, request_id, 1)==0) {
                tw_dev->pending_head = (tw_dev->pending_head + 1) % TW_Q_LENGTH;
                tw_dev->pending_request_count--;
            } else {
                /* If we get here, we will continue re-posting on the next command interrupt */
                break;
            }
        }
    }

    /* Handle response interrupt */
    if (status_reg_value & TW_STATUS_RESPONSE_INTERRUPT) {

        /* Drain the response queue from the board */
        while ((status_reg_value & TW_STATUS_RESPONSE_QUEUE_EMPTY) == 0) {
            /* Complete the response */
            response_que.value = readl(TW_RESPONSE_QUEUE_REG_ADDR(tw_dev));
            request_id = TW_RESID_OUT(response_que.response_id);
            full_command_packet = tw_dev->command_packet_virt[request_id];
            error = 0;
            /* Check for command packet errors */
            if (full_command_packet->command.newcommand.status != 0) {
                if (tw_dev->srb[request_id] != NULL) {
                    error = twa_fill_sense(tw_dev, request_id, 1, 1);
                } else {
                    /* Skip ioctl error prints */
                    if (request_id != tw_dev->chrdev_request_id) {
                        error = twa_fill_sense(tw_dev, request_id, 0, 1);
                    }
                }
            }

            /* Check for correct state */
            if (tw_dev->state[request_id] != TW_S_POSTED) {
                if (tw_dev->srb[request_id] != NULL) {
                    TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1a, "Received a request id that wasn't posted");
                    TW_CLEAR_ALL_INTERRUPTS(tw_dev);
                    goto twa_interrupt_bail;
                }
            }

            /* Check for internal command completion */
            if (tw_dev->srb[request_id] == NULL) {
                if (request_id != tw_dev->chrdev_request_id) {
                    if (twa_aen_complete(tw_dev, request_id))
                        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1b, "Error completing AEN during attention interrupt");
                } else {
                    tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;
                    wake_up(&tw_dev->ioctl_wqueue);
                }
            } else {
                struct scsi_cmnd *cmd;

                cmd = tw_dev->srb[request_id];

                twa_scsiop_execute_scsi_complete(tw_dev, request_id);
                /* If no error command was a success */
                if (error == 0) {
                    cmd->result = (DID_OK << 16);
                }

                /* If error, command failed */
                if (error == 1) {
                    /* Ask for a host reset */
                    cmd->result = (DID_OK << 16) | (CHECK_CONDITION << 1);
                }

                /* Report residual bytes for single sgl */
                if ((scsi_sg_count(cmd) <= 1) && (full_command_packet->command.newcommand.status == 0)) {
                    if (full_command_packet->command.newcommand.sg_list[0].length < scsi_bufflen(tw_dev->srb[request_id]))
                        scsi_set_resid(cmd, scsi_bufflen(cmd) - full_command_packet->command.newcommand.sg_list[0].length);
                }

                /* Now complete the io */
                tw_dev->state[request_id] = TW_S_COMPLETED;
                twa_free_request_id(tw_dev, request_id);
                tw_dev->posted_request_count--;
                tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
                twa_unmap_scsi_data(tw_dev, request_id);
            }

            /* Check for valid status after each drain */
            status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));
            if (twa_check_bits(status_reg_value)) {
                if (twa_decode_bits(tw_dev, status_reg_value)) {
                    TW_CLEAR_ALL_INTERRUPTS(tw_dev);
                    goto twa_interrupt_bail;
                }
            }
        }
    }

twa_interrupt_bail:
    spin_unlock(tw_dev->host->host_lock);
    return IRQ_RETVAL(handled);
} /* End twa_interrupt() */

/* This function will load the request id and various sgls for ioctls */
static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_command_packet, int request_id, dma_addr_t dma_handle, int length)
{
    TW_Command *oldcommand;
    TW_Command_Apache *newcommand;
    TW_SG_Entry *sgl;
    unsigned int pae = 0;

    if ((sizeof(long) < 8) && (sizeof(dma_addr_t) > 4))
        pae = 1;

    if (TW_OP_OUT(full_command_packet->command.newcommand.opcode__reserved) == TW_OP_EXECUTE_SCSI) {
        newcommand = &full_command_packet->command.newcommand;
        newcommand->request_id__lunl =
            cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->request_id__lunl), request_id));
        if (length) {
            newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
            newcommand->sg_list[0].length = cpu_to_le32(length);
        }
        newcommand->sgl_entries__lunh =
            cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->sgl_entries__lunh), length ? 1 : 0));
    } else {
        oldcommand = &full_command_packet->command.oldcommand;
        oldcommand->request_id = request_id;

        if (TW_SGL_OUT(oldcommand->opcode__sgloffset)) {
            /* Load the sg list */
            if (tw_dev->tw_pci_dev->device == PCI_DEVICE_ID_3WARE_9690SA)
                sgl = (TW_SG_Entry *)((u32 *)oldcommand+oldcommand->size - (sizeof(TW_SG_Entry)/4) + pae);
            else
                sgl = (TW_SG_Entry *)((u32 *)oldcommand+TW_SGL_OUT(oldcommand->opcode__sgloffset));
            sgl->address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
            sgl->length = cpu_to_le32(length);

            oldcommand->size += pae;
        }
    }
} /* End twa_load_sgl() */

/* This function will perform a pci-dma mapping for a scatter gather list */
static int twa_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
{
    int use_sg;
    struct scsi_cmnd *cmd = tw_dev->srb[request_id];

    use_sg = scsi_dma_map(cmd);
    if (!use_sg)
        return 0;
    else if (use_sg < 0) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1c, "Failed to map scatter gather list");
        return 0;
    }

    cmd->SCp.phase = TW_PHASE_SGLIST;
    cmd->SCp.have_data_in = use_sg;

    return use_sg;
} /* End twa_map_scsi_sg_data() */

/* This function will poll for a response interrupt of a request */
static int twa_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds)
{
    int retval = 1, found = 0, response_request_id;
    TW_Response_Queue response_queue;
    TW_Command_Full *full_command_packet = tw_dev->command_packet_virt[request_id];

    if (twa_poll_status_gone(tw_dev, TW_STATUS_RESPONSE_QUEUE_EMPTY, seconds) == 0) {
        response_queue.value = readl(TW_RESPONSE_QUEUE_REG_ADDR(tw_dev));
        response_request_id = TW_RESID_OUT(response_queue.response_id);
        if (request_id != response_request_id) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1e, "Found unexpected request id while polling for response");
            goto out;
        }
        if (TW_OP_OUT(full_command_packet->command.newcommand.opcode__reserved) == TW_OP_EXECUTE_SCSI) {
            if (full_command_packet->command.newcommand.status != 0) {
                /* bad response */
                twa_fill_sense(tw_dev, request_id, 0, 0);
                goto out;
            }
            found = 1;
        } else {
            if (full_command_packet->command.oldcommand.status != 0) {
                /* bad response */
                twa_fill_sense(tw_dev, request_id, 0, 0);
                goto out;
            }
            found = 1;
        }
    }

    if (found)
        retval = 0;
out:
    return retval;
} /* End twa_poll_response() */

/* This function will poll the status register for a flag */
static int twa_poll_status(TW_Device_Extension *tw_dev, u32 flag, int seconds)
{
    u32 status_reg_value; 
    unsigned long before;
    int retval = 1;

    status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));
    before = jiffies;

    if (twa_check_bits(status_reg_value))
        twa_decode_bits(tw_dev, status_reg_value);

    while ((status_reg_value & flag) != flag) {
        status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));

        if (twa_check_bits(status_reg_value))
            twa_decode_bits(tw_dev, status_reg_value);

        if (time_after(jiffies, before + HZ * seconds))
            goto out;

        msleep(50);
    }
    retval = 0;
out:
    return retval;
} /* End twa_poll_status() */

/* This function will poll the status register for disappearance of a flag */
static int twa_poll_status_gone(TW_Device_Extension *tw_dev, u32 flag, int seconds)
{
    u32 status_reg_value;
    unsigned long before;
    int retval = 1;

    status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));
    before = jiffies;

    if (twa_check_bits(status_reg_value))
        twa_decode_bits(tw_dev, status_reg_value);

    while ((status_reg_value & flag) != 0) {
        status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));
        if (twa_check_bits(status_reg_value))
            twa_decode_bits(tw_dev, status_reg_value);

        if (time_after(jiffies, before + HZ * seconds))
            goto out;

        msleep(50);
    }
    retval = 0;
out:
    return retval;
} /* End twa_poll_status_gone() */

/* This function will attempt to post a command packet to the board */
static int twa_post_command_packet(TW_Device_Extension *tw_dev, int request_id, char internal)
{
    u32 status_reg_value;
    dma_addr_t command_que_value;
    int retval = 1;

    command_que_value = tw_dev->command_packet_phys[request_id];

    /* For 9650SE write low 4 bytes first */
    if ((tw_dev->tw_pci_dev->device == PCI_DEVICE_ID_3WARE_9650SE) ||
        (tw_dev->tw_pci_dev->device == PCI_DEVICE_ID_3WARE_9690SA)) {
        command_que_value += TW_COMMAND_OFFSET;
        writel((u32)command_que_value, TW_COMMAND_QUEUE_REG_ADDR_LARGE(tw_dev));
    }

    status_reg_value = readl(TW_STATUS_REG_ADDR(tw_dev));

    if (twa_check_bits(status_reg_value))
        twa_decode_bits(tw_dev, status_reg_value);

    if (((tw_dev->pending_request_count > 0) && (tw_dev->state[request_id] != TW_S_PENDING)) || (status_reg_value & TW_STATUS_COMMAND_QUEUE_FULL)) {

        /* Only pend internal driver commands */
        if (!internal) {
            retval = SCSI_MLQUEUE_HOST_BUSY;
            goto out;
        }

        /* Couldn't post the command packet, so we do it later */
        if (tw_dev->state[request_id] != TW_S_PENDING) {
            tw_dev->state[request_id] = TW_S_PENDING;
            tw_dev->pending_request_count++;
            if (tw_dev->pending_request_count > tw_dev->max_pending_request_count) {
                tw_dev->max_pending_request_count = tw_dev->pending_request_count;
            }
            tw_dev->pending_queue[tw_dev->pending_tail] = request_id;
            tw_dev->pending_tail = (tw_dev->pending_tail + 1) % TW_Q_LENGTH;
        }
        TW_UNMASK_COMMAND_INTERRUPT(tw_dev);
        goto out;
    } else {
        if ((tw_dev->tw_pci_dev->device == PCI_DEVICE_ID_3WARE_9650SE) ||
            (tw_dev->tw_pci_dev->device == PCI_DEVICE_ID_3WARE_9690SA)) {
            /* Now write upper 4 bytes */
            writel((u32)((u64)command_que_value >> 32), TW_COMMAND_QUEUE_REG_ADDR_LARGE(tw_dev) + 0x4);
        } else {
            if (sizeof(dma_addr_t) > 4) {
                command_que_value += TW_COMMAND_OFFSET;
                writel((u32)command_que_value, TW_COMMAND_QUEUE_REG_ADDR(tw_dev));
                writel((u32)((u64)command_que_value >> 32), TW_COMMAND_QUEUE_REG_ADDR(tw_dev) + 0x4);
            } else {
                writel(TW_COMMAND_OFFSET + command_que_value, TW_COMMAND_QUEUE_REG_ADDR(tw_dev));
            }
        }
        tw_dev->state[request_id] = TW_S_POSTED;
        tw_dev->posted_request_count++;
        if (tw_dev->posted_request_count > tw_dev->max_posted_request_count) {
            tw_dev->max_posted_request_count = tw_dev->posted_request_count;
        }
    }
    retval = 0;
out:
    return retval;
} /* End twa_post_command_packet() */

/* This function will reset a device extension */
static int twa_reset_device_extension(TW_Device_Extension *tw_dev)
{
    int i = 0;
    int retval = 1;
    unsigned long flags = 0;

    set_bit(TW_IN_RESET, &tw_dev->flags);
    TW_DISABLE_INTERRUPTS(tw_dev);
    TW_MASK_COMMAND_INTERRUPT(tw_dev);
    spin_lock_irqsave(tw_dev->host->host_lock, flags);

    /* Abort all requests that are in progress */
    for (i = 0; i < TW_Q_LENGTH; i++) {
        if ((tw_dev->state[i] != TW_S_FINISHED) &&
            (tw_dev->state[i] != TW_S_INITIAL) &&
            (tw_dev->state[i] != TW_S_COMPLETED)) {
            if (tw_dev->srb[i]) {
                tw_dev->srb[i]->result = (DID_RESET << 16);
                tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
                twa_unmap_scsi_data(tw_dev, i);
            }
        }
    }

    /* Reset queues and counts */
    for (i = 0; i < TW_Q_LENGTH; i++) {
        tw_dev->free_queue[i] = i;
        tw_dev->state[i] = TW_S_INITIAL;
    }
    tw_dev->free_head = TW_Q_START;
    tw_dev->free_tail = TW_Q_START;
    tw_dev->posted_request_count = 0;
    tw_dev->pending_request_count = 0;
    tw_dev->pending_head = TW_Q_START;
    tw_dev->pending_tail = TW_Q_START;
    tw_dev->reset_print = 0;

    spin_unlock_irqrestore(tw_dev->host->host_lock, flags);

    if (twa_reset_sequence(tw_dev, 1))
        goto out;

    TW_ENABLE_AND_CLEAR_INTERRUPTS(tw_dev);
    clear_bit(TW_IN_RESET, &tw_dev->flags);
    tw_dev->chrdev_request_id = TW_IOCTL_CHRDEV_FREE;

    retval = 0;
out:
    return retval;
} /* End twa_reset_device_extension() */

/* This function will reset a controller */
static int twa_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset)
{
    int tries = 0, retval = 1, flashed = 0, do_soft_reset = soft_reset;

    while (tries < TW_MAX_RESET_TRIES) {
        if (do_soft_reset) {
            TW_SOFT_RESET(tw_dev);
            /* Clear pchip/response queue on 9550SX */
            if (twa_empty_response_queue_large(tw_dev)) {
                TW_PRINTK(tw_dev->host, TW_DRIVER, 0x36, "Response queue (large) empty failed during reset sequence");
                do_soft_reset = 1;
                tries++;
                continue;
            }
        }

        /* Make sure controller is in a good state */
        if (twa_poll_status(tw_dev, TW_STATUS_MICROCONTROLLER_READY | (do_soft_reset == 1 ? TW_STATUS_ATTENTION_INTERRUPT : 0), 60)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1f, "Microcontroller not ready during reset sequence");
            do_soft_reset = 1;
            tries++;
            continue;
        }

        /* Empty response queue */
        if (twa_empty_response_queue(tw_dev)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x20, "Response queue empty failed during reset sequence");
            do_soft_reset = 1;
            tries++;
            continue;
        }

        flashed = 0;

        /* Check for compatibility/flash */
        if (twa_check_srl(tw_dev, &flashed)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x21, "Compatibility check failed during reset sequence");
            do_soft_reset = 1;
            tries++;
            continue;
        } else {
            if (flashed) {
                tries++;
                continue;
            }
        }

        /* Drain the AEN queue */
        if (twa_aen_drain_queue(tw_dev, soft_reset)) {
            TW_PRINTK(tw_dev->host, TW_DRIVER, 0x22, "AEN drain failed during reset sequence");
            do_soft_reset = 1;
            tries++;
            continue;
        }

        /* If we got here, controller is in a good state */
        retval = 0;
        goto out;
    }
out:
    return retval;
} /* End twa_reset_sequence() */

/* This funciton returns unit geometry in cylinders/heads/sectors */
static int twa_scsi_biosparam(struct scsi_device *sdev, struct block_device *bdev, sector_t capacity, int geom[])
{
    int heads, sectors, cylinders;
    TW_Device_Extension *tw_dev;

    tw_dev = (TW_Device_Extension *)sdev->host->hostdata;

    if (capacity >= 0x200000) {
        heads = 255;
        sectors = 63;
        cylinders = sector_div(capacity, heads * sectors);
    } else {
        heads = 64;
        sectors = 32;
        cylinders = sector_div(capacity, heads * sectors);
    }

    geom[0] = heads;
    geom[1] = sectors;
    geom[2] = cylinders;

    return 0;
} /* End twa_scsi_biosparam() */

/* This is the new scsi eh reset function */
static int twa_scsi_eh_reset(struct scsi_cmnd *SCpnt)
{
    TW_Device_Extension *tw_dev = NULL;
    int retval = FAILED;

    tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;

    tw_dev->num_resets++;

    sdev_printk(KERN_WARNING, SCpnt->device,
        "WARNING: (0x%02X:0x%04X): Command (0x%x) timed out, resetting card.\n",
        TW_DRIVER, 0x2c, SCpnt->cmnd[0]);

    /* Make sure we are not issuing an ioctl or resetting from ioctl */
    mutex_lock(&tw_dev->ioctl_lock);

    /* Now reset the card and some of the device extension data */
    if (twa_reset_device_extension(tw_dev)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x2b, "Controller reset failed during scsi host reset");
        goto out;
    }

    retval = SUCCESS;
out:
    mutex_unlock(&tw_dev->ioctl_lock);
    return retval;
} /* End twa_scsi_eh_reset() */

/* This is the main scsi queue function to handle scsi opcodes */
static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
{
    int request_id, retval;
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;

    /* If we are resetting due to timed out ioctl, report as busy */
    if (test_bit(TW_IN_RESET, &tw_dev->flags)) {
        retval = SCSI_MLQUEUE_HOST_BUSY;
        goto out;
    }

    /* Check if this FW supports luns */
    if ((SCpnt->device->lun != 0) && (tw_dev->tw_compat_info.working_srl < TW_FW_SRL_LUNS_SUPPORTED)) {
        SCpnt->result = (DID_BAD_TARGET << 16);
        done(SCpnt);
        retval = 0;
        goto out;
    }

    /* Save done function into scsi_cmnd struct */
    SCpnt->scsi_done = done;
        
    /* Get a free request id */
    twa_get_request_id(tw_dev, &request_id);

    /* Save the scsi command for use by the ISR */
    tw_dev->srb[request_id] = SCpnt;

    /* Initialize phase to zero */
    SCpnt->SCp.phase = TW_PHASE_INITIAL;

    retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
    switch (retval) {
    case SCSI_MLQUEUE_HOST_BUSY:
        twa_free_request_id(tw_dev, request_id);
        twa_unmap_scsi_data(tw_dev, request_id);
        break;
    case 1:
        tw_dev->state[request_id] = TW_S_COMPLETED;
        twa_free_request_id(tw_dev, request_id);
        twa_unmap_scsi_data(tw_dev, request_id);
        SCpnt->result = (DID_ERROR << 16);
        done(SCpnt);
        retval = 0;
    }
out:
    return retval;
} /* End twa_scsi_queue() */

static DEF_SCSI_QCMD(twa_scsi_queue)

/* This function hands scsi cdb's to the firmware */
static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg)
{
    TW_Command_Full *full_command_packet;
    TW_Command_Apache *command_packet;
    u32 num_sectors = 0x0;
    int i, sg_count;
    struct scsi_cmnd *srb = NULL;
    struct scatterlist *sglist = NULL, *sg;
    int retval = 1;

    if (tw_dev->srb[request_id]) {
        srb = tw_dev->srb[request_id];
        if (scsi_sglist(srb))
            sglist = scsi_sglist(srb);
    }

    /* Initialize command packet */
    full_command_packet = tw_dev->command_packet_virt[request_id];
    full_command_packet->header.header_desc.size_header = 128;
    full_command_packet->header.status_block.error = 0;
    full_command_packet->header.status_block.severity__reserved = 0;

    command_packet = &full_command_packet->command.newcommand;
    command_packet->status = 0;
    command_packet->opcode__reserved = TW_OPRES_IN(0, TW_OP_EXECUTE_SCSI);

    /* We forced 16 byte cdb use earlier */
    if (!cdb)
        memcpy(command_packet->cdb, srb->cmnd, TW_MAX_CDB_LEN);
    else
        memcpy(command_packet->cdb, cdb, TW_MAX_CDB_LEN);

    if (srb) {
        command_packet->unit = srb->device->id;
        command_packet->request_id__lunl =
            cpu_to_le16(TW_REQ_LUN_IN(srb->device->lun, request_id));
    } else {
        command_packet->request_id__lunl =
            cpu_to_le16(TW_REQ_LUN_IN(0, request_id));
        command_packet->unit = 0;
    }

    command_packet->sgl_offset = 16;

    if (!sglistarg) {
        /* Map sglist from scsi layer to cmd packet */

        if (scsi_sg_count(srb)) {
            if ((scsi_sg_count(srb) == 1) &&
                (scsi_bufflen(srb) < TW_MIN_SGL_LENGTH)) {
                if (srb->sc_data_direction == DMA_TO_DEVICE ||
                    srb->sc_data_direction == DMA_BIDIRECTIONAL)
                    scsi_sg_copy_to_buffer(srb,
                                   tw_dev->generic_buffer_virt[request_id],
                                   TW_SECTOR_SIZE);
                command_packet->sg_list[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
                command_packet->sg_list[0].length = cpu_to_le32(TW_MIN_SGL_LENGTH);
            } else {
                sg_count = twa_map_scsi_sg_data(tw_dev, request_id);
                if (sg_count == 0)
                    goto out;

                scsi_for_each_sg(srb, sg, sg_count, i) {
                    command_packet->sg_list[i].address = TW_CPU_TO_SGL(sg_dma_address(sg));
                    command_packet->sg_list[i].length = cpu_to_le32(sg_dma_len(sg));
                    if (command_packet->sg_list[i].address & TW_CPU_TO_SGL(TW_ALIGNMENT_9000_SGL)) {
                        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x2e, "Found unaligned sgl address during execute scsi");
                        goto out;
                    }
                }
            }
            command_packet->sgl_entries__lunh = cpu_to_le16(TW_REQ_LUN_IN((srb->device->lun >> 4), scsi_sg_count(tw_dev->srb[request_id])));
        }
    } else {
        /* Internal cdb post */
        for (i = 0; i < use_sg; i++) {
            command_packet->sg_list[i].address = TW_CPU_TO_SGL(sglistarg[i].address);
            command_packet->sg_list[i].length = cpu_to_le32(sglistarg[i].length);
            if (command_packet->sg_list[i].address & TW_CPU_TO_SGL(TW_ALIGNMENT_9000_SGL)) {
                TW_PRINTK(tw_dev->host, TW_DRIVER, 0x2f, "Found unaligned sgl address during internal post");
                goto out;
            }
        }
        command_packet->sgl_entries__lunh = cpu_to_le16(TW_REQ_LUN_IN(0, use_sg));
    }

    if (srb) {
        if (srb->cmnd[0] == READ_6 || srb->cmnd[0] == WRITE_6)
            num_sectors = (u32)srb->cmnd[4];

        if (srb->cmnd[0] == READ_10 || srb->cmnd[0] == WRITE_10)
            num_sectors = (u32)srb->cmnd[8] | ((u32)srb->cmnd[7] << 8);
    }

    /* Update sector statistic */
    tw_dev->sector_count = num_sectors;
    if (tw_dev->sector_count > tw_dev->max_sector_count)
        tw_dev->max_sector_count = tw_dev->sector_count;

    /* Update SG statistics */
    if (srb) {
        tw_dev->sgl_entries = scsi_sg_count(tw_dev->srb[request_id]);
        if (tw_dev->sgl_entries > tw_dev->max_sgl_entries)
            tw_dev->max_sgl_entries = tw_dev->sgl_entries;
    }

    /* Now post the command to the board */
    if (srb) {
        retval = twa_post_command_packet(tw_dev, request_id, 0);
    } else {
        twa_post_command_packet(tw_dev, request_id, 1);
        retval = 0;
    }
out:
    return retval;
} /* End twa_scsiop_execute_scsi() */

/* This function completes an execute scsi operation */
static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int request_id)
{
    struct scsi_cmnd *cmd = tw_dev->srb[request_id];

    if (scsi_bufflen(cmd) < TW_MIN_SGL_LENGTH &&
        (cmd->sc_data_direction == DMA_FROM_DEVICE ||
         cmd->sc_data_direction == DMA_BIDIRECTIONAL)) {
        if (scsi_sg_count(cmd) == 1) {
            void *buf = tw_dev->generic_buffer_virt[request_id];

            scsi_sg_copy_from_buffer(cmd, buf, TW_SECTOR_SIZE);
        }
    }
} /* End twa_scsiop_execute_scsi_complete() */

/* This function tells the controller to shut down */
static void __twa_shutdown(TW_Device_Extension *tw_dev)
{
    /* Disable interrupts */
    TW_DISABLE_INTERRUPTS(tw_dev);

    /* Free up the IRQ */
    free_irq(tw_dev->tw_pci_dev->irq, tw_dev);

    printk(KERN_WARNING "3w-9xxx: Shutting down host %d.\n", tw_dev->host->host_no);

    /* Tell the card we are shutting down */
    if (twa_initconnection(tw_dev, 1, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x31, "Connection shutdown failed");
    } else {
        printk(KERN_WARNING "3w-9xxx: Shutdown complete.\n");
    }

    /* Clear all interrupts just before exit */
    TW_CLEAR_ALL_INTERRUPTS(tw_dev);
} /* End __twa_shutdown() */

/* Wrapper for __twa_shutdown */
static void twa_shutdown(struct pci_dev *pdev)
{
    struct Scsi_Host *host = pci_get_drvdata(pdev);
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

    __twa_shutdown(tw_dev);
} /* End twa_shutdown() */

/* This function will look up a string */
static char *twa_string_lookup(twa_message_type *table, unsigned int code)
{
    int index;

    for (index = 0; ((code != table[index].code) &&
              (table[index].text != (char *)0)); index++);
    return(table[index].text);
} /* End twa_string_lookup() */

/* This function will perform a pci-dma unmap */
static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
{
    struct scsi_cmnd *cmd = tw_dev->srb[request_id];

    if (cmd->SCp.phase == TW_PHASE_SGLIST)
        scsi_dma_unmap(cmd);
} /* End twa_unmap_scsi_data() */

/* This function gets called when a disk is coming on-line */
static int twa_slave_configure(struct scsi_device *sdev)
{
    /* Force 60 second timeout */
    blk_queue_rq_timeout(sdev->request_queue, 60 * HZ);

    return 0;
} /* End twa_slave_configure() */

/* scsi_host_template initializer */
static struct scsi_host_template driver_template = {
    .module         = THIS_MODULE,
    .name           = "3ware 9000 Storage Controller",
    .queuecommand       = twa_scsi_queue,
    .eh_host_reset_handler  = twa_scsi_eh_reset,
    .bios_param     = twa_scsi_biosparam,
    .change_queue_depth = twa_change_queue_depth,
    .can_queue      = TW_Q_LENGTH-2,
    .slave_configure    = twa_slave_configure,
    .this_id        = -1,
    .sg_tablesize       = TW_APACHE_MAX_SGL_LENGTH,
    .max_sectors        = TW_MAX_SECTORS,
    .cmd_per_lun        = TW_MAX_CMDS_PER_LUN,
    .use_clustering     = ENABLE_CLUSTERING,
    .shost_attrs        = twa_host_attrs,
    .emulated       = 1
};

/* This function will probe and initialize a card */
static int __devinit twa_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
{
    struct Scsi_Host *host = NULL;
    TW_Device_Extension *tw_dev;
    unsigned long mem_addr, mem_len;
    int retval = -ENODEV;

    retval = pci_enable_device(pdev);
    if (retval) {
        TW_PRINTK(host, TW_DRIVER, 0x34, "Failed to enable pci device");
        goto out_disable_device;
    }

    pci_set_master(pdev);
    pci_try_set_mwi(pdev);

    if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64))
        || pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)))
        if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))
            || pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32))) {
            TW_PRINTK(host, TW_DRIVER, 0x23, "Failed to set dma mask");
            retval = -ENODEV;
            goto out_disable_device;
        }

    host = scsi_host_alloc(&driver_template, sizeof(TW_Device_Extension));
    if (!host) {
        TW_PRINTK(host, TW_DRIVER, 0x24, "Failed to allocate memory for device extension");
        retval = -ENOMEM;
        goto out_disable_device;
    }
    tw_dev = (TW_Device_Extension *)host->hostdata;

    /* Save values to device extension */
    tw_dev->host = host;
    tw_dev->tw_pci_dev = pdev;

    if (twa_initialize_device_extension(tw_dev)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x25, "Failed to initialize device extension");
        goto out_free_device_extension;
    }

    /* Request IO regions */
    retval = pci_request_regions(pdev, "3w-9xxx");
    if (retval) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x26, "Failed to get mem region");
        goto out_free_device_extension;
    }

    if (pdev->device == PCI_DEVICE_ID_3WARE_9000) {
        mem_addr = pci_resource_start(pdev, 1);
        mem_len = pci_resource_len(pdev, 1);
    } else {
        mem_addr = pci_resource_start(pdev, 2);
        mem_len = pci_resource_len(pdev, 2);
    }

    /* Save base address */
    tw_dev->base_addr = ioremap(mem_addr, mem_len);
    if (!tw_dev->base_addr) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x35, "Failed to ioremap");
        goto out_release_mem_region;
    }

    /* Disable interrupts on the card */
    TW_DISABLE_INTERRUPTS(tw_dev);

    /* Initialize the card */
    if (twa_reset_sequence(tw_dev, 0))
        goto out_iounmap;

    /* Set host specific parameters */
    if ((pdev->device == PCI_DEVICE_ID_3WARE_9650SE) ||
        (pdev->device == PCI_DEVICE_ID_3WARE_9690SA))
        host->max_id = TW_MAX_UNITS_9650SE;
    else
        host->max_id = TW_MAX_UNITS;

    host->max_cmd_len = TW_MAX_CDB_LEN;

    /* Channels aren't supported by adapter */
    host->max_lun = TW_MAX_LUNS(tw_dev->tw_compat_info.working_srl);
    host->max_channel = 0;

    /* Register the card with the kernel SCSI layer */
    retval = scsi_add_host(host, &pdev->dev);
    if (retval) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x27, "scsi add host failed");
        goto out_iounmap;
    }

    pci_set_drvdata(pdev, host);

    printk(KERN_WARNING "3w-9xxx: scsi%d: Found a 3ware 9000 Storage Controller at 0x%lx, IRQ: %d.\n",
           host->host_no, mem_addr, pdev->irq);
    printk(KERN_WARNING "3w-9xxx: scsi%d: Firmware %s, BIOS %s, Ports: %d.\n",
           host->host_no,
           (char *)twa_get_param(tw_dev, 0, TW_VERSION_TABLE,
                     TW_PARAM_FWVER, TW_PARAM_FWVER_LENGTH),
           (char *)twa_get_param(tw_dev, 1, TW_VERSION_TABLE,
                     TW_PARAM_BIOSVER, TW_PARAM_BIOSVER_LENGTH),
           le32_to_cpu(*(int *)twa_get_param(tw_dev, 2, TW_INFORMATION_TABLE,
                     TW_PARAM_PORTCOUNT, TW_PARAM_PORTCOUNT_LENGTH)));

    /* Try to enable MSI */
    if (use_msi && (pdev->device != PCI_DEVICE_ID_3WARE_9000) &&
        !pci_enable_msi(pdev))
        set_bit(TW_USING_MSI, &tw_dev->flags);

    /* Now setup the interrupt handler */
    retval = request_irq(pdev->irq, twa_interrupt, IRQF_SHARED, "3w-9xxx", tw_dev);
    if (retval) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x30, "Error requesting IRQ");
        goto out_remove_host;
    }

    twa_device_extension_list[twa_device_extension_count] = tw_dev;
    twa_device_extension_count++;

    /* Re-enable interrupts on the card */
    TW_ENABLE_AND_CLEAR_INTERRUPTS(tw_dev);

    /* Finally, scan the host */
    scsi_scan_host(host);

    if (twa_major == -1) {
        if ((twa_major = register_chrdev (0, "twa", &twa_fops)) < 0)
            TW_PRINTK(host, TW_DRIVER, 0x29, "Failed to register character device");
    }
    return 0;

out_remove_host:
    if (test_bit(TW_USING_MSI, &tw_dev->flags))
        pci_disable_msi(pdev);
    scsi_remove_host(host);
out_iounmap:
    iounmap(tw_dev->base_addr);
out_release_mem_region:
    pci_release_regions(pdev);
out_free_device_extension:
    twa_free_device_extension(tw_dev);
    scsi_host_put(host);
out_disable_device:
    pci_disable_device(pdev);

    return retval;
} /* End twa_probe() */

/* This function is called to remove a device */
static void twa_remove(struct pci_dev *pdev)
{
    struct Scsi_Host *host = pci_get_drvdata(pdev);
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

    scsi_remove_host(tw_dev->host);

    /* Unregister character device */
    if (twa_major >= 0) {
        unregister_chrdev(twa_major, "twa");
        twa_major = -1;
    }

    /* Shutdown the card */
    __twa_shutdown(tw_dev);

    /* Disable MSI if enabled */
    if (test_bit(TW_USING_MSI, &tw_dev->flags))
        pci_disable_msi(pdev);

    /* Free IO remapping */
    iounmap(tw_dev->base_addr);

    /* Free up the mem region */
    pci_release_regions(pdev);

    /* Free up device extension resources */
    twa_free_device_extension(tw_dev);

    scsi_host_put(tw_dev->host);
    pci_disable_device(pdev);
    twa_device_extension_count--;
} /* End twa_remove() */

#ifdef CONFIG_PM
/* This function is called on PCI suspend */
static int twa_suspend(struct pci_dev *pdev, pm_message_t state)
{
    struct Scsi_Host *host = pci_get_drvdata(pdev);
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

    printk(KERN_WARNING "3w-9xxx: Suspending host %d.\n", tw_dev->host->host_no);

    TW_DISABLE_INTERRUPTS(tw_dev);
    free_irq(tw_dev->tw_pci_dev->irq, tw_dev);

    if (test_bit(TW_USING_MSI, &tw_dev->flags))
        pci_disable_msi(pdev);

    /* Tell the card we are shutting down */
    if (twa_initconnection(tw_dev, 1, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL)) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x38, "Connection shutdown failed during suspend");
    } else {
        printk(KERN_WARNING "3w-9xxx: Suspend complete.\n");
    }
    TW_CLEAR_ALL_INTERRUPTS(tw_dev);

    pci_save_state(pdev);
    pci_disable_device(pdev);
    pci_set_power_state(pdev, pci_choose_state(pdev, state));

    return 0;
} /* End twa_suspend() */

/* This function is called on PCI resume */
static int twa_resume(struct pci_dev *pdev)
{
    int retval = 0;
    struct Scsi_Host *host = pci_get_drvdata(pdev);
    TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;

    printk(KERN_WARNING "3w-9xxx: Resuming host %d.\n", tw_dev->host->host_no);
    pci_set_power_state(pdev, PCI_D0);
    pci_enable_wake(pdev, PCI_D0, 0);
    pci_restore_state(pdev);

    retval = pci_enable_device(pdev);
    if (retval) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x39, "Enable device failed during resume");
        return retval;
    }

    pci_set_master(pdev);
    pci_try_set_mwi(pdev);

    if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64))
        || pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)))
        if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))
            || pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32))) {
            TW_PRINTK(host, TW_DRIVER, 0x40, "Failed to set dma mask during resume");
            retval = -ENODEV;
            goto out_disable_device;
        }

    /* Initialize the card */
    if (twa_reset_sequence(tw_dev, 0)) {
        retval = -ENODEV;
        goto out_disable_device;
    }

    /* Now setup the interrupt handler */
    retval = request_irq(pdev->irq, twa_interrupt, IRQF_SHARED, "3w-9xxx", tw_dev);
    if (retval) {
        TW_PRINTK(tw_dev->host, TW_DRIVER, 0x42, "Error requesting IRQ during resume");
        retval = -ENODEV;
        goto out_disable_device;
    }

    /* Now enable MSI if enabled */
    if (test_bit(TW_USING_MSI, &tw_dev->flags))
        pci_enable_msi(pdev);

    /* Re-enable interrupts on the card */
    TW_ENABLE_AND_CLEAR_INTERRUPTS(tw_dev);

    printk(KERN_WARNING "3w-9xxx: Resume complete.\n");
    return 0;

out_disable_device:
    scsi_remove_host(host);
    pci_disable_device(pdev);

    return retval;
} /* End twa_resume() */
#endif

/* PCI Devices supported by this driver */
static struct pci_device_id twa_pci_tbl[] __devinitdata = {
    { PCI_VENDOR_ID_3WARE, PCI_DEVICE_ID_3WARE_9000,
      PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    { PCI_VENDOR_ID_3WARE, PCI_DEVICE_ID_3WARE_9550SX,
      PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    { PCI_VENDOR_ID_3WARE, PCI_DEVICE_ID_3WARE_9650SE,
      PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    { PCI_VENDOR_ID_3WARE, PCI_DEVICE_ID_3WARE_9690SA,
      PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
    { }
};
MODULE_DEVICE_TABLE(pci, twa_pci_tbl);

/* pci_driver initializer */
static struct pci_driver twa_driver = {
    .name       = "3w-9xxx",
    .id_table   = twa_pci_tbl,
    .probe      = twa_probe,
    .remove     = twa_remove,
#ifdef CONFIG_PM
    .suspend    = twa_suspend,
    .resume     = twa_resume,
#endif
    .shutdown   = twa_shutdown
};

/* This function is called on driver initialization */
static int __init twa_init(void)
{
    printk(KERN_WARNING "3ware 9000 Storage Controller device driver for Linux v%s.\n", TW_DRIVER_VERSION);

    return pci_register_driver(&twa_driver);
} /* End twa_init() */

/* This function is called on driver exit */
static void __exit twa_exit(void)
{
    pci_unregister_driver(&twa_driver);
} /* End twa_exit() */

module_init(twa_init);
module_exit(twa_exit);