/*
 * dc395x.c
 *
 * Device Driver for Tekram DC395(U/UW/F), DC315(U)
 * PCI SCSI Bus Master Host Adapter
 * (SCSI chip set used Tekram ASIC TRM-S1040)
 *
 * Authors:
 *  C.L. Huang <ching@tekram.com.tw>
 *  Erich Chen <erich@tekram.com.tw>
 *  (C) Copyright 1995-1999 Tekram Technology Co., Ltd.
 *
 *  Kurt Garloff <garloff@suse.de>
 *  (C) 1999-2000 Kurt Garloff
 *
 *  Oliver Neukum <oliver@neukum.name>
 *  Ali Akcaagac <aliakc@web.de>
 *  Jamie Lenehan <lenehan@twibble.org>
 *  (C) 2003
 *
 * License: GNU GPL
 *
 *************************************************************************
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 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 OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ************************************************************************
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
#include <linux/ctype.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <asm/io.h>

#include <scsi/scsi.h>
#include <scsi/scsicam.h>       /* needed for scsicam_bios_param */
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>

#include "dc395x.h"

#define DC395X_NAME     "dc395x"
#define DC395X_BANNER   "Tekram DC395(U/UW/F), DC315(U) - ASIC TRM-S1040"
#define DC395X_VERSION  "v2.05, 2004/03/08"

/*---------------------------------------------------------------------------
                                  Features
 ---------------------------------------------------------------------------*/
/*
 * Set to disable parts of the driver
 */
/*#define DC395x_NO_DISCONNECT*/
/*#define DC395x_NO_TAGQ*/
/*#define DC395x_NO_SYNC*/
/*#define DC395x_NO_WIDE*/

/*---------------------------------------------------------------------------
                                  Debugging
 ---------------------------------------------------------------------------*/
/*
 * Types of debugging that can be enabled and disabled
 */
#define DBG_KG          0x0001
#define DBG_0           0x0002
#define DBG_1           0x0004
#define DBG_SG          0x0020
#define DBG_FIFO        0x0040
#define DBG_PIO         0x0080


/*
 * Set set of things to output debugging for.
 * Undefine to remove all debugging
 */
/*#define DEBUG_MASK (DBG_0|DBG_1|DBG_SG|DBG_FIFO|DBG_PIO)*/
/*#define  DEBUG_MASK   DBG_0*/


/*
 * Output a kernel mesage at the specified level and append the
 * driver name and a ": " to the start of the message
 */
#define dprintkl(level, format, arg...)  \
    printk(level DC395X_NAME ": " format , ## arg)


#ifdef DEBUG_MASK
/*
 * print a debug message - this is formated with KERN_DEBUG, then the
 * driver name followed by a ": " and then the message is output. 
 * This also checks that the specified debug level is enabled before
 * outputing the message
 */
#define dprintkdbg(type, format, arg...) \
        do { \
                if ((type) & (DEBUG_MASK)) \
                        dprintkl(KERN_DEBUG , format , ## arg); \
        } while (0)

/*
 * Check if the specified type of debugging is enabled
 */
#define debug_enabled(type)     ((DEBUG_MASK) & (type))

#else
/*
 * No debugging. Do nothing
 */
#define dprintkdbg(type, format, arg...) \
        do {} while (0)
#define debug_enabled(type)     (0)

#endif


#ifndef PCI_VENDOR_ID_TEKRAM
#define PCI_VENDOR_ID_TEKRAM                    0x1DE1  /* Vendor ID    */
#endif
#ifndef PCI_DEVICE_ID_TEKRAM_TRMS1040
#define PCI_DEVICE_ID_TEKRAM_TRMS1040           0x0391  /* Device ID    */
#endif


#define DC395x_LOCK_IO(dev,flags)               spin_lock_irqsave(((struct Scsi_Host *)dev)->host_lock, flags)
#define DC395x_UNLOCK_IO(dev,flags)             spin_unlock_irqrestore(((struct Scsi_Host *)dev)->host_lock, flags)

#define DC395x_read8(acb,address)               (u8)(inb(acb->io_port_base + (address)))
#define DC395x_read16(acb,address)              (u16)(inw(acb->io_port_base + (address)))
#define DC395x_read32(acb,address)              (u32)(inl(acb->io_port_base + (address)))
#define DC395x_write8(acb,address,value)        outb((value), acb->io_port_base + (address))
#define DC395x_write16(acb,address,value)       outw((value), acb->io_port_base + (address))
#define DC395x_write32(acb,address,value)       outl((value), acb->io_port_base + (address))

/* cmd->result */
#define RES_TARGET              0x000000FF      /* Target State */
#define RES_TARGET_LNX  STATUS_MASK     /* Only official ... */
#define RES_ENDMSG              0x0000FF00      /* End Message */
#define RES_DID                 0x00FF0000      /* DID_ codes */
#define RES_DRV                 0xFF000000      /* DRIVER_ codes */

#define MK_RES(drv,did,msg,tgt) ((int)(drv)<<24 | (int)(did)<<16 | (int)(msg)<<8 | (int)(tgt))
#define MK_RES_LNX(drv,did,msg,tgt) ((int)(drv)<<24 | (int)(did)<<16 | (int)(msg)<<8 | (int)(tgt)<<1)

#define SET_RES_TARGET(who,tgt) { who &= ~RES_TARGET; who |= (int)(tgt); }
#define SET_RES_TARGET_LNX(who,tgt) { who &= ~RES_TARGET_LNX; who |= (int)(tgt) << 1; }
#define SET_RES_MSG(who,msg) { who &= ~RES_ENDMSG; who |= (int)(msg) << 8; }
#define SET_RES_DID(who,did) { who &= ~RES_DID; who |= (int)(did) << 16; }
#define SET_RES_DRV(who,drv) { who &= ~RES_DRV; who |= (int)(drv) << 24; }

#define TAG_NONE 255

/*
 * srb->segement_x is the hw sg list. It is always allocated as a
 * DC395x_MAX_SG_LISTENTRY entries in a linear block which does not
 * cross a page boundy.
 */
#define SEGMENTX_LEN    (sizeof(struct SGentry)*DC395x_MAX_SG_LISTENTRY)


struct SGentry {
        u32 address;            /* bus! address */
        u32 length;
};

/* The SEEPROM structure for TRM_S1040 */
struct NVRamTarget {
        u8 cfg0;                /* Target configuration byte 0  */
        u8 period;              /* Target period                */
        u8 cfg2;                /* Target configuration byte 2  */
        u8 cfg3;                /* Target configuration byte 3  */
};

struct NvRamType {
        u8 sub_vendor_id[2];    /* 0,1  Sub Vendor ID   */
        u8 sub_sys_id[2];       /* 2,3  Sub System ID   */
        u8 sub_class;           /* 4    Sub Class       */
        u8 vendor_id[2];        /* 5,6  Vendor ID       */
        u8 device_id[2];        /* 7,8  Device ID       */
        u8 reserved;            /* 9    Reserved        */
        struct NVRamTarget target[DC395x_MAX_SCSI_ID];
                                                /** 10,11,12,13
                                                 ** 14,15,16,17
                                                 ** ....
                                                 ** ....
                                                 ** 70,71,72,73
                                                 */
        u8 scsi_id;             /* 74 Host Adapter SCSI ID      */
        u8 channel_cfg;         /* 75 Channel configuration     */
        u8 delay_time;          /* 76 Power on delay time       */
        u8 max_tag;             /* 77 Maximum tags              */
        u8 reserved0;           /* 78  */
        u8 boot_target;         /* 79  */
        u8 boot_lun;            /* 80  */
        u8 reserved1;           /* 81  */
        u16 reserved2[22];      /* 82,..125 */
        u16 cksum;              /* 126,127 */
};

struct ScsiReqBlk {
        struct list_head list;          /* next/prev ptrs for srb lists */
        struct DeviceCtlBlk *dcb;
        struct scsi_cmnd *cmd;

        struct SGentry *segment_x;      /* Linear array of hw sg entries (up to 64 entries) */
        dma_addr_t sg_bus_addr;         /* Bus address of sg list (ie, of segment_x) */

        u8 sg_count;                    /* No of HW sg entries for this request */
        u8 sg_index;                    /* Index of HW sg entry for this request */
        size_t total_xfer_length;       /* Total number of bytes remaining to be transferred */
        size_t request_length;          /* Total number of bytes in this request */
        /*
         * The sense buffer handling function, request_sense, uses
         * the first hw sg entry (segment_x[0]) and the transfer
         * length (total_xfer_length). While doing this it stores the
         * original values into the last sg hw list
         * (srb->segment_x[DC395x_MAX_SG_LISTENTRY - 1] and the
         * total_xfer_length in xferred. These values are restored in
         * pci_unmap_srb_sense. This is the only place xferred is used.
         */
        size_t xferred;                 /* Saved copy of total_xfer_length */

        u16 state;

        u8 msgin_buf[6];
        u8 msgout_buf[6];

        u8 adapter_status;
        u8 target_status;
        u8 msg_count;
        u8 end_message;

        u8 tag_number;
        u8 status;
        u8 retry_count;
        u8 flag;

        u8 scsi_phase;
};

struct DeviceCtlBlk {
        struct list_head list;          /* next/prev ptrs for the dcb list */
        struct AdapterCtlBlk *acb;
        struct list_head srb_going_list;        /* head of going srb list */
        struct list_head srb_waiting_list;      /* head of waiting srb list */

        struct ScsiReqBlk *active_srb;
        u32 tag_mask;

        u16 max_command;

        u8 target_id;           /* SCSI Target ID  (SCSI Only) */
        u8 target_lun;          /* SCSI Log.  Unit (SCSI Only) */
        u8 identify_msg;
        u8 dev_mode;

        u8 inquiry7;            /* To store Inquiry flags */
        u8 sync_mode;           /* 0:async mode */
        u8 min_nego_period;     /* for nego. */
        u8 sync_period;         /* for reg.  */

        u8 sync_offset;         /* for reg. and nego.(low nibble) */
        u8 flag;
        u8 dev_type;
        u8 init_tcq_flag;
};

struct AdapterCtlBlk {
        struct Scsi_Host *scsi_host;

        unsigned long io_port_base;
        unsigned long io_port_len;

        struct list_head dcb_list;              /* head of going dcb list */
        struct DeviceCtlBlk *dcb_run_robin;
        struct DeviceCtlBlk *active_dcb;

        struct list_head srb_free_list;         /* head of free srb list */
        struct ScsiReqBlk *tmp_srb;
        struct timer_list waiting_timer;
        struct timer_list selto_timer;

        unsigned long last_reset;

        u16 srb_count;

        u8 sel_timeout;

        unsigned int irq_level;
        u8 tag_max_num;
        u8 acb_flag;
        u8 gmode2;

        u8 config;
        u8 lun_chk;
        u8 scan_devices;
        u8 hostid_bit;

        u8 dcb_map[DC395x_MAX_SCSI_ID];
        struct DeviceCtlBlk *children[DC395x_MAX_SCSI_ID][32];

        struct pci_dev *dev;

        u8 msg_len;

        struct ScsiReqBlk srb_array[DC395x_MAX_SRB_CNT];
        struct ScsiReqBlk srb;

        struct NvRamType eeprom;        /* eeprom settings for this adapter */
};


/*---------------------------------------------------------------------------
                            Forward declarations
 ---------------------------------------------------------------------------*/
static void data_out_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void command_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void status_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void msgout_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void msgin_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void data_out_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void data_in_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void command_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void status_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void msgout_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void msgin_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void nop0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status);
static void nop1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb, 
                u16 *pscsi_status);
static void set_basic_config(struct AdapterCtlBlk *acb);
static void cleanup_after_transfer(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb);
static void reset_scsi_bus(struct AdapterCtlBlk *acb);
static void data_io_transfer(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb, u16 io_dir);
static void disconnect(struct AdapterCtlBlk *acb);
static void reselect(struct AdapterCtlBlk *acb);
static u8 start_scsi(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb);
static inline void enable_msgout_abort(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb);
static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb);
static void doing_srb_done(struct AdapterCtlBlk *acb, u8 did_code,
                struct scsi_cmnd *cmd, u8 force);
static void scsi_reset_detect(struct AdapterCtlBlk *acb);
static void pci_unmap_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb);
static void pci_unmap_srb_sense(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb);
static void srb_done(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb);
static void request_sense(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb);
static void set_xfer_rate(struct AdapterCtlBlk *acb,
                struct DeviceCtlBlk *dcb);
static void waiting_timeout(struct timer_list *t);


/*---------------------------------------------------------------------------
                                 Static Data
 ---------------------------------------------------------------------------*/
static u16 current_sync_offset = 0;

static void *dc395x_scsi_phase0[] = {
        data_out_phase0,/* phase:0 */
        data_in_phase0, /* phase:1 */
        command_phase0, /* phase:2 */
        status_phase0,  /* phase:3 */
        nop0,           /* phase:4 PH_BUS_FREE .. initial phase */
        nop0,           /* phase:5 PH_BUS_FREE .. initial phase */
        msgout_phase0,  /* phase:6 */
        msgin_phase0,   /* phase:7 */
};

static void *dc395x_scsi_phase1[] = {
        data_out_phase1,/* phase:0 */
        data_in_phase1, /* phase:1 */
        command_phase1, /* phase:2 */
        status_phase1,  /* phase:3 */
        nop1,           /* phase:4 PH_BUS_FREE .. initial phase */
        nop1,           /* phase:5 PH_BUS_FREE .. initial phase */
        msgout_phase1,  /* phase:6 */
        msgin_phase1,   /* phase:7 */
};

/*
 *Fast20:       000      50ns, 20.0 MHz
 *              001      75ns, 13.3 MHz
 *              010     100ns, 10.0 MHz
 *              011     125ns,  8.0 MHz
 *              100     150ns,  6.6 MHz
 *              101     175ns,  5.7 MHz
 *              110     200ns,  5.0 MHz
 *              111     250ns,  4.0 MHz
 *
 *Fast40(LVDS): 000      25ns, 40.0 MHz
 *              001      50ns, 20.0 MHz
 *              010      75ns, 13.3 MHz
 *              011     100ns, 10.0 MHz
 *              100     125ns,  8.0 MHz
 *              101     150ns,  6.6 MHz
 *              110     175ns,  5.7 MHz
 *              111     200ns,  5.0 MHz
 */
/*static u8     clock_period[] = {12,19,25,31,37,44,50,62};*/

/* real period:48ns,76ns,100ns,124ns,148ns,176ns,200ns,248ns */
static u8 clock_period[] = { 12, 18, 25, 31, 37, 43, 50, 62 };
static u16 clock_speed[] = { 200, 133, 100, 80, 67, 58, 50, 40 };


/*---------------------------------------------------------------------------
                                Configuration
  ---------------------------------------------------------------------------*/
/*
 * Module/boot parameters currently effect *all* instances of the
 * card in the system.
 */

/*
 * Command line parameters are stored in a structure below.
 * These are the index's into the structure for the various
 * command line options.
 */
#define CFG_ADAPTER_ID          0
#define CFG_MAX_SPEED           1
#define CFG_DEV_MODE            2
#define CFG_ADAPTER_MODE        3
#define CFG_TAGS                4
#define CFG_RESET_DELAY         5

#define CFG_NUM                 6       /* number of configuration items */


/*
 * Value used to indicate that a command line override
 * hasn't been used to modify the value.
 */
#define CFG_PARAM_UNSET -1


/*
 * Hold command line parameters.
 */
struct ParameterData {
        int value;              /* value of this setting */
        int min;                /* minimum value */
        int max;                /* maximum value */
        int def;                /* default value */
        int safe;               /* safe value */
};
static struct ParameterData cfg_data[] = {
        { /* adapter id */
                CFG_PARAM_UNSET,
                0,
                15,
                7,
                7
        },
        { /* max speed */
                CFG_PARAM_UNSET,
                  0,
                  7,
                  1,    /* 13.3Mhz */
                  4,    /*  6.7Hmz */
        },
        { /* dev mode */
                CFG_PARAM_UNSET,
                0,
                0x3f,
                NTC_DO_PARITY_CHK | NTC_DO_DISCONNECT | NTC_DO_SYNC_NEGO |
                        NTC_DO_WIDE_NEGO | NTC_DO_TAG_QUEUEING |
                        NTC_DO_SEND_START,
                NTC_DO_PARITY_CHK | NTC_DO_SEND_START
        },
        { /* adapter mode */
                CFG_PARAM_UNSET,
                0,
                0x2f,
                NAC_SCANLUN |
                NAC_GT2DRIVES | NAC_GREATER_1G | NAC_POWERON_SCSI_RESET
                        /*| NAC_ACTIVE_NEG*/,
                NAC_GT2DRIVES | NAC_GREATER_1G | NAC_POWERON_SCSI_RESET | 0x08
        },
        { /* tags */
                CFG_PARAM_UNSET,
                0,
                5,
                3,      /* 16 tags (??) */
                2,
        },
        { /* reset delay */
                CFG_PARAM_UNSET,
                0,
                180,
                1,      /* 1 second */
                10,     /* 10 seconds */
        }
};


/*
 * Safe settings. If set to zero the BIOS/default values with
 * command line overrides will be used. If set to 1 then safe and
 * slow settings will be used.
 */
static bool use_safe_settings = 0;
module_param_named(safe, use_safe_settings, bool, 0);
MODULE_PARM_DESC(safe, "Use safe and slow settings only. Default: false");


module_param_named(adapter_id, cfg_data[CFG_ADAPTER_ID].value, int, 0);
MODULE_PARM_DESC(adapter_id, "Adapter SCSI ID. Default 7 (0-15)");

module_param_named(max_speed, cfg_data[CFG_MAX_SPEED].value, int, 0);
MODULE_PARM_DESC(max_speed, "Maximum bus speed. Default 1 (0-7) Speeds: 0=20, 1=13.3, 2=10, 3=8, 4=6.7, 5=5.8, 6=5, 7=4 Mhz");

module_param_named(dev_mode, cfg_data[CFG_DEV_MODE].value, int, 0);
MODULE_PARM_DESC(dev_mode, "Device mode.");

module_param_named(adapter_mode, cfg_data[CFG_ADAPTER_MODE].value, int, 0);
MODULE_PARM_DESC(adapter_mode, "Adapter mode.");

module_param_named(tags, cfg_data[CFG_TAGS].value, int, 0);
MODULE_PARM_DESC(tags, "Number of tags (1<<x). Default 3 (0-5)");

module_param_named(reset_delay, cfg_data[CFG_RESET_DELAY].value, int, 0);
MODULE_PARM_DESC(reset_delay, "Reset delay in seconds. Default 1 (0-180)");


/**
 * set_safe_settings - if the use_safe_settings option is set then
 * set all values to the safe and slow values.
 **/
static void set_safe_settings(void)
{
        if (use_safe_settings)
        {
                int i;

                dprintkl(KERN_INFO, "Using safe settings.\n");
                for (i = 0; i < CFG_NUM; i++)
                {
                        cfg_data[i].value = cfg_data[i].safe;
                }
        }
}


/**
 * fix_settings - reset any boot parameters which are out of range
 * back to the default values.
 **/
static void fix_settings(void)
{
        int i;

        dprintkdbg(DBG_1,
                "setup: AdapterId=%08x MaxSpeed=%08x DevMode=%08x "
                "AdapterMode=%08x Tags=%08x ResetDelay=%08x\n",
                cfg_data[CFG_ADAPTER_ID].value,
                cfg_data[CFG_MAX_SPEED].value,
                cfg_data[CFG_DEV_MODE].value,
                cfg_data[CFG_ADAPTER_MODE].value,
                cfg_data[CFG_TAGS].value,
                cfg_data[CFG_RESET_DELAY].value);
        for (i = 0; i < CFG_NUM; i++)
        {
                if (cfg_data[i].value < cfg_data[i].min
                    || cfg_data[i].value > cfg_data[i].max)
                        cfg_data[i].value = cfg_data[i].def;
        }
}



/*
 * Mapping from the eeprom delay index value (index into this array)
 * to the number of actual seconds that the delay should be for.
 */
static char eeprom_index_to_delay_map[] =
        { 1, 3, 5, 10, 16, 30, 60, 120 };


/**
 * eeprom_index_to_delay - Take the eeprom delay setting and convert it
 * into a number of seconds.
 *
 * @eeprom: The eeprom structure in which we find the delay index to map.
 **/
static void eeprom_index_to_delay(struct NvRamType *eeprom)
{
        eeprom->delay_time = eeprom_index_to_delay_map[eeprom->delay_time];
}


/**
 * delay_to_eeprom_index - Take a delay in seconds and return the
 * closest eeprom index which will delay for at least that amount of
 * seconds.
 *
 * @delay: The delay, in seconds, to find the eeprom index for.
 **/
static int delay_to_eeprom_index(int delay)
{
        u8 idx = 0;
        while (idx < 7 && eeprom_index_to_delay_map[idx] < delay)
                idx++;
        return idx;
}


/**
 * eeprom_override - Override the eeprom settings, in the provided
 * eeprom structure, with values that have been set on the command
 * line.
 *
 * @eeprom: The eeprom data to override with command line options.
 **/
static void eeprom_override(struct NvRamType *eeprom)
{
        u8 id;

        /* Adapter Settings */
        if (cfg_data[CFG_ADAPTER_ID].value != CFG_PARAM_UNSET)
                eeprom->scsi_id = (u8)cfg_data[CFG_ADAPTER_ID].value;

        if (cfg_data[CFG_ADAPTER_MODE].value != CFG_PARAM_UNSET)
                eeprom->channel_cfg = (u8)cfg_data[CFG_ADAPTER_MODE].value;

        if (cfg_data[CFG_RESET_DELAY].value != CFG_PARAM_UNSET)
                eeprom->delay_time = delay_to_eeprom_index(
                                        cfg_data[CFG_RESET_DELAY].value);

        if (cfg_data[CFG_TAGS].value != CFG_PARAM_UNSET)
                eeprom->max_tag = (u8)cfg_data[CFG_TAGS].value;

        /* Device Settings */
        for (id = 0; id < DC395x_MAX_SCSI_ID; id++) {
                if (cfg_data[CFG_DEV_MODE].value != CFG_PARAM_UNSET)
                        eeprom->target[id].cfg0 =
                                (u8)cfg_data[CFG_DEV_MODE].value;

                if (cfg_data[CFG_MAX_SPEED].value != CFG_PARAM_UNSET)
                        eeprom->target[id].period =
                                (u8)cfg_data[CFG_MAX_SPEED].value;

        }
}


/*---------------------------------------------------------------------------
 ---------------------------------------------------------------------------*/

static unsigned int list_size(struct list_head *head)
{
        unsigned int count = 0;
        struct list_head *pos;
        list_for_each(pos, head)
                count++;
        return count;
}


static struct DeviceCtlBlk *dcb_get_next(struct list_head *head,
                struct DeviceCtlBlk *pos)
{
        int use_next = 0;
        struct DeviceCtlBlk* next = NULL;
        struct DeviceCtlBlk* i;

        if (list_empty(head))
                return NULL;

        /* find supplied dcb and then select the next one */
        list_for_each_entry(i, head, list)
                if (use_next) {
                        next = i;
                        break;
                } else if (i == pos) {
                        use_next = 1;
                }
        /* if no next one take the head one (ie, wraparound) */
        if (!next)
                list_for_each_entry(i, head, list) {
                        next = i;
                        break;
                }

        return next;
}


static void free_tag(struct DeviceCtlBlk *dcb, struct ScsiReqBlk *srb)
{
        if (srb->tag_number < 255) {
                dcb->tag_mask &= ~(1 << srb->tag_number);       /* free tag mask */
                srb->tag_number = 255;
        }
}


/* Find cmd in SRB list */
static inline struct ScsiReqBlk *find_cmd(struct scsi_cmnd *cmd,
                struct list_head *head)
{
        struct ScsiReqBlk *i;
        list_for_each_entry(i, head, list)
                if (i->cmd == cmd)
                        return i;
        return NULL;
}

/* Sets the timer to wake us up */
static void waiting_set_timer(struct AdapterCtlBlk *acb, unsigned long to)
{
        if (timer_pending(&acb->waiting_timer))
                return;
        if (time_before(jiffies + to, acb->last_reset - HZ / 2))
                acb->waiting_timer.expires =
                    acb->last_reset - HZ / 2 + 1;
        else
                acb->waiting_timer.expires = jiffies + to + 1;
        add_timer(&acb->waiting_timer);
}


/* Send the next command from the waiting list to the bus */
static void waiting_process_next(struct AdapterCtlBlk *acb)
{
        struct DeviceCtlBlk *start = NULL;
        struct DeviceCtlBlk *pos;
        struct DeviceCtlBlk *dcb;
        struct ScsiReqBlk *srb;
        struct list_head *dcb_list_head = &acb->dcb_list;

        if (acb->active_dcb
            || (acb->acb_flag & (RESET_DETECT + RESET_DONE + RESET_DEV)))
                return;

        if (timer_pending(&acb->waiting_timer))
                del_timer(&acb->waiting_timer);

        if (list_empty(dcb_list_head))
                return;

        /*
         * Find the starting dcb. Need to find it again in the list
         * since the list may have changed since we set the ptr to it
         */
        list_for_each_entry(dcb, dcb_list_head, list)
                if (dcb == acb->dcb_run_robin) {
                        start = dcb;
                        break;
                }
        if (!start) {
                /* This can happen! */
                start = list_entry(dcb_list_head->next, typeof(*start), list);
                acb->dcb_run_robin = start;
        }


        /*
         * Loop over the dcb, but we start somewhere (potentially) in
         * the middle of the loop so we need to manully do this.
         */
        pos = start;
        do {
                struct list_head *waiting_list_head = &pos->srb_waiting_list;

                /* Make sure, the next another device gets scheduled ... */
                acb->dcb_run_robin = dcb_get_next(dcb_list_head,
                                                  acb->dcb_run_robin);

                if (list_empty(waiting_list_head) ||
                    pos->max_command <= list_size(&pos->srb_going_list)) {
                        /* move to next dcb */
                        pos = dcb_get_next(dcb_list_head, pos);
                } else {
                        srb = list_entry(waiting_list_head->next,
                                         struct ScsiReqBlk, list);

                        /* Try to send to the bus */
                        if (!start_scsi(acb, pos, srb))
                                list_move(&srb->list, &pos->srb_going_list);
                        else
                                waiting_set_timer(acb, HZ/50);
                        break;
                }
        } while (pos != start);
}


/* Wake up waiting queue */
static void waiting_timeout(struct timer_list *t)
{
        unsigned long flags;
        struct AdapterCtlBlk *acb = from_timer(acb, t, waiting_timer);
        dprintkdbg(DBG_1,
                "waiting_timeout: Queue woken up by timer. acb=%p\n", acb);
        DC395x_LOCK_IO(acb->scsi_host, flags);
        waiting_process_next(acb);
        DC395x_UNLOCK_IO(acb->scsi_host, flags);
}


/* Get the DCB for a given ID/LUN combination */
static struct DeviceCtlBlk *find_dcb(struct AdapterCtlBlk *acb, u8 id, u8 lun)
{
        return acb->children[id][lun];
}


/* Send SCSI Request Block (srb) to adapter (acb) */
static void send_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
{
        struct DeviceCtlBlk *dcb = srb->dcb;

        if (dcb->max_command <= list_size(&dcb->srb_going_list) ||
            acb->active_dcb ||
            (acb->acb_flag & (RESET_DETECT + RESET_DONE + RESET_DEV))) {
                list_add_tail(&srb->list, &dcb->srb_waiting_list);
                waiting_process_next(acb);
                return;
        }

        if (!start_scsi(acb, dcb, srb)) {
                list_add_tail(&srb->list, &dcb->srb_going_list);
        } else {
                list_add(&srb->list, &dcb->srb_waiting_list);
                waiting_set_timer(acb, HZ / 50);
        }
}

/* Prepare SRB for being sent to Device DCB w/ command *cmd */
static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb)
{
        int nseg;
        enum dma_data_direction dir = cmd->sc_data_direction;
        dprintkdbg(DBG_0, "build_srb: (0x%p) <%02i-%i>\n",
                cmd, dcb->target_id, dcb->target_lun);

        srb->dcb = dcb;
        srb->cmd = cmd;
        srb->sg_count = 0;
        srb->total_xfer_length = 0;
        srb->sg_bus_addr = 0;
        srb->sg_index = 0;
        srb->adapter_status = 0;
        srb->target_status = 0;
        srb->msg_count = 0;
        srb->status = 0;
        srb->flag = 0;
        srb->state = 0;
        srb->retry_count = 0;
        srb->tag_number = TAG_NONE;
        srb->scsi_phase = PH_BUS_FREE;  /* initial phase */
        srb->end_message = 0;

        nseg = scsi_dma_map(cmd);
        BUG_ON(nseg < 0);

        if (dir == PCI_DMA_NONE || !nseg) {
                dprintkdbg(DBG_0,
                        "build_srb: [0] len=%d buf=%p use_sg=%d !MAP=%08x\n",
                           cmd->bufflen, scsi_sglist(cmd), scsi_sg_count(cmd),
                           srb->segment_x[0].address);
        } else {
                int i;
                u32 reqlen = scsi_bufflen(cmd);
                struct scatterlist *sg;
                struct SGentry *sgp = srb->segment_x;

                srb->sg_count = nseg;

                dprintkdbg(DBG_0,
                           "build_srb: [n] len=%d buf=%p use_sg=%d segs=%d\n",
                           reqlen, scsi_sglist(cmd), scsi_sg_count(cmd),
                           srb->sg_count);

                scsi_for_each_sg(cmd, sg, srb->sg_count, i) {
                        u32 busaddr = (u32)sg_dma_address(sg);
                        u32 seglen = (u32)sg->length;
                        sgp[i].address = busaddr;
                        sgp[i].length = seglen;
                        srb->total_xfer_length += seglen;
                }
                sgp += srb->sg_count - 1;

                /*
                 * adjust last page if too big as it is allocated
                 * on even page boundaries
                 */
                if (srb->total_xfer_length > reqlen) {
                        sgp->length -= (srb->total_xfer_length - reqlen);
                        srb->total_xfer_length = reqlen;
                }

                /* Fixup for WIDE padding - make sure length is even */
                if (dcb->sync_period & WIDE_SYNC &&
                    srb->total_xfer_length % 2) {
                        srb->total_xfer_length++;
                        sgp->length++;
                }

                srb->sg_bus_addr = dma_map_single(&dcb->acb->dev->dev,
                                srb->segment_x, SEGMENTX_LEN, DMA_TO_DEVICE);

                dprintkdbg(DBG_SG, "build_srb: [n] map sg %p->%08x(%05x)\n",
                        srb->segment_x, srb->sg_bus_addr, SEGMENTX_LEN);
        }

        srb->request_length = srb->total_xfer_length;
}


/**
 * dc395x_queue_command - queue scsi command passed from the mid
 * layer, invoke 'done' on completion
 *
 * @cmd: pointer to scsi command object
 * @done: function pointer to be invoked on completion
 *
 * Returns 1 if the adapter (host) is busy, else returns 0. One
 * reason for an adapter to be busy is that the number
 * of outstanding queued commands is already equal to
 * struct Scsi_Host::can_queue .
 *
 * Required: if struct Scsi_Host::can_queue is ever non-zero
 *           then this function is required.
 *
 * Locks: struct Scsi_Host::host_lock held on entry (with "irqsave")
 *        and is expected to be held on return.
 *
 **/
static int dc395x_queue_command_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
        struct DeviceCtlBlk *dcb;
        struct ScsiReqBlk *srb;
        struct AdapterCtlBlk *acb =
            (struct AdapterCtlBlk *)cmd->device->host->hostdata;
        dprintkdbg(DBG_0, "queue_command: (0x%p) <%02i-%i> cmnd=0x%02x\n",
                cmd, cmd->device->id, (u8)cmd->device->lun, cmd->cmnd[0]);

        /* Assume BAD_TARGET; will be cleared later */
        cmd->result = DID_BAD_TARGET << 16;

        /* ignore invalid targets */
        if (cmd->device->id >= acb->scsi_host->max_id ||
            cmd->device->lun >= acb->scsi_host->max_lun ||
            cmd->device->lun >31) {
                goto complete;
        }

        /* does the specified lun on the specified device exist */
        if (!(acb->dcb_map[cmd->device->id] & (1 << cmd->device->lun))) {
                dprintkl(KERN_INFO, "queue_command: Ignore target <%02i-%i>\n",

                        cmd->device->id, (u8)cmd->device->lun);
                goto complete;
        }

        /* do we have a DCB for the device */
        dcb = find_dcb(acb, cmd->device->id, cmd->device->lun);
        if (!dcb) {
                /* should never happen */
                dprintkl(KERN_ERR, "queue_command: No such device <%02i-%i>",
                        cmd->device->id, (u8)cmd->device->lun);
                goto complete;
        }

        /* set callback and clear result in the command */
        cmd->scsi_done = done;
        cmd->result = 0;

        srb = list_first_entry_or_null(&acb->srb_free_list,
                        struct ScsiReqBlk, list);
        if (!srb) {
                /*
                 * Return 1 since we are unable to queue this command at this
                 * point in time.
                 */
                dprintkdbg(DBG_0, "queue_command: No free srb's\n");
                return 1;
        }
        list_del(&srb->list);

        build_srb(cmd, dcb, srb);

        if (!list_empty(&dcb->srb_waiting_list)) {
                /* append to waiting queue */
                list_add_tail(&srb->list, &dcb->srb_waiting_list);
                waiting_process_next(acb);
        } else {
                /* process immediately */
                send_srb(acb, srb);
        }
        dprintkdbg(DBG_1, "queue_command: (0x%p) done\n", cmd);
        return 0;

complete:
        /*
         * Complete the command immediatey, and then return 0 to
         * indicate that we have handled the command. This is usually
         * done when the commad is for things like non existent
         * devices.
         */
        done(cmd);
        return 0;
}

static DEF_SCSI_QCMD(dc395x_queue_command)

/*
 * Return the disk geometry for the given SCSI device.
 */
static int dc395x_bios_param(struct scsi_device *sdev,
                struct block_device *bdev, sector_t capacity, int *info)
{
#ifdef CONFIG_SCSI_DC395x_TRMS1040_TRADMAP
        int heads, sectors, cylinders;
        struct AdapterCtlBlk *acb;
        int size = capacity;

        dprintkdbg(DBG_0, "dc395x_bios_param..............\n");
        acb = (struct AdapterCtlBlk *)sdev->host->hostdata;
        heads = 64;
        sectors = 32;
        cylinders = size / (heads * sectors);

        if ((acb->gmode2 & NAC_GREATER_1G) && (cylinders > 1024)) {
                heads = 255;
                sectors = 63;
                cylinders = size / (heads * sectors);
        }
        geom[0] = heads;
        geom[1] = sectors;
        geom[2] = cylinders;
        return 0;
#else
        return scsicam_bios_param(bdev, capacity, info);
#endif
}


static void dump_register_info(struct AdapterCtlBlk *acb,
                struct DeviceCtlBlk *dcb, struct ScsiReqBlk *srb)
{
        u16 pstat;
        struct pci_dev *dev = acb->dev;
        pci_read_config_word(dev, PCI_STATUS, &pstat);
        if (!dcb)
                dcb = acb->active_dcb;
        if (!srb && dcb)
                srb = dcb->active_srb;
        if (srb) {
                if (!srb->cmd)
                        dprintkl(KERN_INFO, "dump: srb=%p cmd=%p OOOPS!\n",
                                srb, srb->cmd);
                else
                        dprintkl(KERN_INFO, "dump: srb=%p cmd=%p "
                                 "cmnd=0x%02x <%02i-%i>\n",
                                srb, srb->cmd,
                                srb->cmd->cmnd[0], srb->cmd->device->id,
                                (u8)srb->cmd->device->lun);
                printk("  sglist=%p cnt=%i idx=%i len=%zu\n",
                       srb->segment_x, srb->sg_count, srb->sg_index,
                       srb->total_xfer_length);
                printk("  state=0x%04x status=0x%02x phase=0x%02x (%sconn.)\n",
                       srb->state, srb->status, srb->scsi_phase,
                       (acb->active_dcb) ? "" : "not");
        }
        dprintkl(KERN_INFO, "dump: SCSI{status=0x%04x fifocnt=0x%02x "
                "signals=0x%02x irqstat=0x%02x sync=0x%02x target=0x%02x "
                "rselid=0x%02x ctr=0x%08x irqen=0x%02x config=0x%04x "
                "config2=0x%02x cmd=0x%02x selto=0x%02x}\n",
                DC395x_read16(acb, TRM_S1040_SCSI_STATUS),
                DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT),
                DC395x_read8(acb, TRM_S1040_SCSI_SIGNAL),
                DC395x_read8(acb, TRM_S1040_SCSI_INTSTATUS),
                DC395x_read8(acb, TRM_S1040_SCSI_SYNC),
                DC395x_read8(acb, TRM_S1040_SCSI_TARGETID),
                DC395x_read8(acb, TRM_S1040_SCSI_IDMSG),
                DC395x_read32(acb, TRM_S1040_SCSI_COUNTER),
                DC395x_read8(acb, TRM_S1040_SCSI_INTEN),
                DC395x_read16(acb, TRM_S1040_SCSI_CONFIG0),
                DC395x_read8(acb, TRM_S1040_SCSI_CONFIG2),
                DC395x_read8(acb, TRM_S1040_SCSI_COMMAND),
                DC395x_read8(acb, TRM_S1040_SCSI_TIMEOUT));
        dprintkl(KERN_INFO, "dump: DMA{cmd=0x%04x fifocnt=0x%02x fstat=0x%02x "
                "irqstat=0x%02x irqen=0x%02x cfg=0x%04x tctr=0x%08x "
                "ctctr=0x%08x addr=0x%08x:0x%08x}\n",
                DC395x_read16(acb, TRM_S1040_DMA_COMMAND),
                DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
                DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
                DC395x_read8(acb, TRM_S1040_DMA_STATUS),
                DC395x_read8(acb, TRM_S1040_DMA_INTEN),
                DC395x_read16(acb, TRM_S1040_DMA_CONFIG),
                DC395x_read32(acb, TRM_S1040_DMA_XCNT),
                DC395x_read32(acb, TRM_S1040_DMA_CXCNT),
                DC395x_read32(acb, TRM_S1040_DMA_XHIGHADDR),
                DC395x_read32(acb, TRM_S1040_DMA_XLOWADDR));
        dprintkl(KERN_INFO, "dump: gen{gctrl=0x%02x gstat=0x%02x gtmr=0x%02x} "
                "pci{status=0x%04x}\n",
                DC395x_read8(acb, TRM_S1040_GEN_CONTROL),
                DC395x_read8(acb, TRM_S1040_GEN_STATUS),
                DC395x_read8(acb, TRM_S1040_GEN_TIMER),
                pstat);
}


static inline void clear_fifo(struct AdapterCtlBlk *acb, char *txt)
{
#if debug_enabled(DBG_FIFO)
        u8 lines = DC395x_read8(acb, TRM_S1040_SCSI_SIGNAL);
        u8 fifocnt = DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT);
        if (!(fifocnt & 0x40))
                dprintkdbg(DBG_FIFO,
                        "clear_fifo: (%i bytes) on phase %02x in %s\n",
                        fifocnt & 0x3f, lines, txt);
#endif
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_CLRFIFO);
}


static void reset_dev_param(struct AdapterCtlBlk *acb)
{
        struct DeviceCtlBlk *dcb;
        struct NvRamType *eeprom = &acb->eeprom;
        dprintkdbg(DBG_0, "reset_dev_param: acb=%p\n", acb);

        list_for_each_entry(dcb, &acb->dcb_list, list) {
                u8 period_index;

                dcb->sync_mode &= ~(SYNC_NEGO_DONE + WIDE_NEGO_DONE);
                dcb->sync_period = 0;
                dcb->sync_offset = 0;

                dcb->dev_mode = eeprom->target[dcb->target_id].cfg0;
                period_index = eeprom->target[dcb->target_id].period & 0x07;
                dcb->min_nego_period = clock_period[period_index];
                if (!(dcb->dev_mode & NTC_DO_WIDE_NEGO)
                    || !(acb->config & HCC_WIDE_CARD))
                        dcb->sync_mode &= ~WIDE_NEGO_ENABLE;
        }
}


/*
 * perform a hard reset on the SCSI bus
 * @cmd - some command for this host (for fetching hooks)
 * Returns: SUCCESS (0x2002) on success, else FAILED (0x2003).
 */
static int __dc395x_eh_bus_reset(struct scsi_cmnd *cmd)
{
        struct AdapterCtlBlk *acb =
                (struct AdapterCtlBlk *)cmd->device->host->hostdata;
        dprintkl(KERN_INFO,
                "eh_bus_reset: (0%p) target=<%02i-%i> cmd=%p\n",
                cmd, cmd->device->id, (u8)cmd->device->lun, cmd);

        if (timer_pending(&acb->waiting_timer))
                del_timer(&acb->waiting_timer);

        /*
         * disable interrupt    
         */
        DC395x_write8(acb, TRM_S1040_DMA_INTEN, 0x00);
        DC395x_write8(acb, TRM_S1040_SCSI_INTEN, 0x00);
        DC395x_write8(acb, TRM_S1040_SCSI_CONTROL, DO_RSTMODULE);
        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, DMARESETMODULE);

        reset_scsi_bus(acb);
        udelay(500);

        /* We may be in serious trouble. Wait some seconds */
        acb->last_reset =
            jiffies + 3 * HZ / 2 +
            HZ * acb->eeprom.delay_time;

        /*
         * re-enable interrupt      
         */
        /* Clear SCSI FIFO          */
        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, CLRXFIFO);
        clear_fifo(acb, "eh_bus_reset");
        /* Delete pending IRQ */
        DC395x_read8(acb, TRM_S1040_SCSI_INTSTATUS);
        set_basic_config(acb);

        reset_dev_param(acb);
        doing_srb_done(acb, DID_RESET, cmd, 0);
        acb->active_dcb = NULL;
        acb->acb_flag = 0;      /* RESET_DETECT, RESET_DONE ,RESET_DEV */
        waiting_process_next(acb);

        return SUCCESS;
}

static int dc395x_eh_bus_reset(struct scsi_cmnd *cmd)
{
        int rc;

        spin_lock_irq(cmd->device->host->host_lock);
        rc = __dc395x_eh_bus_reset(cmd);
        spin_unlock_irq(cmd->device->host->host_lock);

        return rc;
}

/*
 * abort an errant SCSI command
 * @cmd - command to be aborted
 * Returns: SUCCESS (0x2002) on success, else FAILED (0x2003).
 */
static int dc395x_eh_abort(struct scsi_cmnd *cmd)
{
        /*
         * Look into our command queues: If it has not been sent already,
         * we remove it and return success. Otherwise fail.
         */
        struct AdapterCtlBlk *acb =
            (struct AdapterCtlBlk *)cmd->device->host->hostdata;
        struct DeviceCtlBlk *dcb;
        struct ScsiReqBlk *srb;
        dprintkl(KERN_INFO, "eh_abort: (0x%p) target=<%02i-%i> cmd=%p\n",
                cmd, cmd->device->id, (u8)cmd->device->lun, cmd);

        dcb = find_dcb(acb, cmd->device->id, cmd->device->lun);
        if (!dcb) {
                dprintkl(KERN_DEBUG, "eh_abort: No such device\n");
                return FAILED;
        }

        srb = find_cmd(cmd, &dcb->srb_waiting_list);
        if (srb) {
                list_del(&srb->list);
                pci_unmap_srb_sense(acb, srb);
                pci_unmap_srb(acb, srb);
                free_tag(dcb, srb);
                list_add_tail(&srb->list, &acb->srb_free_list);
                dprintkl(KERN_DEBUG, "eh_abort: Command was waiting\n");
                cmd->result = DID_ABORT << 16;
                return SUCCESS;
        }
        srb = find_cmd(cmd, &dcb->srb_going_list);
        if (srb) {
                dprintkl(KERN_DEBUG, "eh_abort: Command in progress\n");
                /* XXX: Should abort the command here */
        } else {
                dprintkl(KERN_DEBUG, "eh_abort: Command not found\n");
        }
        return FAILED;
}


/* SDTR */
static void build_sdtr(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb)
{
        u8 *ptr = srb->msgout_buf + srb->msg_count;
        if (srb->msg_count > 1) {
                dprintkl(KERN_INFO,
                        "build_sdtr: msgout_buf BUSY (%i: %02x %02x)\n",
                        srb->msg_count, srb->msgout_buf[0],
                        srb->msgout_buf[1]);
                return;
        }
        if (!(dcb->dev_mode & NTC_DO_SYNC_NEGO)) {
                dcb->sync_offset = 0;
                dcb->min_nego_period = 200 >> 2;
        } else if (dcb->sync_offset == 0)
                dcb->sync_offset = SYNC_NEGO_OFFSET;

        *ptr++ = MSG_EXTENDED;  /* (01h) */
        *ptr++ = 3;             /* length */
        *ptr++ = EXTENDED_SDTR; /* (01h) */
        *ptr++ = dcb->min_nego_period;  /* Transfer period (in 4ns) */
        *ptr++ = dcb->sync_offset;      /* Transfer period (max. REQ/ACK dist) */
        srb->msg_count += 5;
        srb->state |= SRB_DO_SYNC_NEGO;
}


/* WDTR */
static void build_wdtr(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
                struct ScsiReqBlk *srb)
{
        u8 wide = ((dcb->dev_mode & NTC_DO_WIDE_NEGO) &
                   (acb->config & HCC_WIDE_CARD)) ? 1 : 0;
        u8 *ptr = srb->msgout_buf + srb->msg_count;
        if (srb->msg_count > 1) {
                dprintkl(KERN_INFO,
                        "build_wdtr: msgout_buf BUSY (%i: %02x %02x)\n",
                        srb->msg_count, srb->msgout_buf[0],
                        srb->msgout_buf[1]);
                return;
        }
        *ptr++ = MSG_EXTENDED;  /* (01h) */
        *ptr++ = 2;             /* length */
        *ptr++ = EXTENDED_WDTR; /* (03h) */
        *ptr++ = wide;
        srb->msg_count += 4;
        srb->state |= SRB_DO_WIDE_NEGO;
}


#if 0
/* Timer to work around chip flaw: When selecting and the bus is 
 * busy, we sometimes miss a Selection timeout IRQ */
void selection_timeout_missed(unsigned long ptr);
/* Sets the timer to wake us up */
static void selto_timer(struct AdapterCtlBlk *acb)
{
        if (timer_pending(&acb->selto_timer))
                return;
        acb->selto_timer.function = selection_timeout_missed;
        acb->selto_timer.data = (unsigned long) acb;
        if (time_before
            (jiffies + HZ, acb->last_reset + HZ / 2))
                acb->selto_timer.expires =
                    acb->last_reset + HZ / 2 + 1;
        else
                acb->selto_timer.expires = jiffies + HZ + 1;
        add_timer(&acb->selto_timer);
}


void selection_timeout_missed(unsigned long ptr)
{
        unsigned long flags;
        struct AdapterCtlBlk *acb = (struct AdapterCtlBlk *)ptr;
        struct ScsiReqBlk *srb;
        dprintkl(KERN_DEBUG, "Chip forgot to produce SelTO IRQ!\n");
        if (!acb->active_dcb || !acb->active_dcb->active_srb) {
                dprintkl(KERN_DEBUG, "... but no cmd pending? Oops!\n");
                return;
        }
        DC395x_LOCK_IO(acb->scsi_host, flags);
        srb = acb->active_dcb->active_srb;
        disconnect(acb);
        DC395x_UNLOCK_IO(acb->scsi_host, flags);
}
#endif


static u8 start_scsi(struct AdapterCtlBlk* acb, struct DeviceCtlBlk* dcb,
                struct ScsiReqBlk* srb)
{
        u16 s_stat2, return_code;
        u8 s_stat, scsicommand, i, identify_message;
        u8 *ptr;
        dprintkdbg(DBG_0, "start_scsi: (0x%p) <%02i-%i> srb=%p\n",
                dcb->target_id, dcb->target_lun, srb);

        srb->tag_number = TAG_NONE;     /* acb->tag_max_num: had error read in eeprom */

        s_stat = DC395x_read8(acb, TRM_S1040_SCSI_SIGNAL);
        s_stat2 = 0;
        s_stat2 = DC395x_read16(acb, TRM_S1040_SCSI_STATUS);
#if 1
        if (s_stat & 0x20 /* s_stat2 & 0x02000 */ ) {
                dprintkdbg(DBG_KG, "start_scsi: (0x%p) BUSY %02x %04x\n",
                        s_stat, s_stat2);
                /*
                 * Try anyway?
                 *
                 * We could, BUT: Sometimes the TRM_S1040 misses to produce a Selection
                 * Timeout, a Disconnect or a Reselection IRQ, so we would be screwed!
                 * (This is likely to be a bug in the hardware. Obviously, most people
                 *  only have one initiator per SCSI bus.)
                 * Instead let this fail and have the timer make sure the command is 
                 * tried again after a short time
                 */
                /*selto_timer (acb); */
                return 1;
        }
#endif
        if (acb->active_dcb) {
                dprintkl(KERN_DEBUG, "start_scsi: (0x%p) Attempt to start a"
                        "command while another command (0x%p) is active.",
                        srb->cmd,
                        acb->active_dcb->active_srb ?
                            acb->active_dcb->active_srb->cmd : 0);
                return 1;
        }
        if (DC395x_read16(acb, TRM_S1040_SCSI_STATUS) & SCSIINTERRUPT) {
                dprintkdbg(DBG_KG, "start_scsi: (0x%p) Failed (busy)\n", srb->cmd);
                return 1;
        }
        /* Allow starting of SCSI commands half a second before we allow the mid-level
         * to queue them again after a reset */
        if (time_before(jiffies, acb->last_reset - HZ / 2)) {
                dprintkdbg(DBG_KG, "start_scsi: Refuse cmds (reset wait)\n");
                return 1;
        }

        /* Flush FIFO */
        clear_fifo(acb, "start_scsi");
        DC395x_write8(acb, TRM_S1040_SCSI_HOSTID, acb->scsi_host->this_id);
        DC395x_write8(acb, TRM_S1040_SCSI_TARGETID, dcb->target_id);
        DC395x_write8(acb, TRM_S1040_SCSI_SYNC, dcb->sync_period);
        DC395x_write8(acb, TRM_S1040_SCSI_OFFSET, dcb->sync_offset);
        srb->scsi_phase = PH_BUS_FREE;  /* initial phase */

        identify_message = dcb->identify_msg;
        /*DC395x_TRM_write8(TRM_S1040_SCSI_IDMSG, identify_message); */
        /* Don't allow disconnection for AUTO_REQSENSE: Cont.All.Cond.! */
        if (srb->flag & AUTO_REQSENSE)
                identify_message &= 0xBF;

        if (((srb->cmd->cmnd[0] == INQUIRY)
             || (srb->cmd->cmnd[0] == REQUEST_SENSE)
             || (srb->flag & AUTO_REQSENSE))
            && (((dcb->sync_mode & WIDE_NEGO_ENABLE)
                 && !(dcb->sync_mode & WIDE_NEGO_DONE))
                || ((dcb->sync_mode & SYNC_NEGO_ENABLE)
                    && !(dcb->sync_mode & SYNC_NEGO_DONE)))
            && (dcb->target_lun == 0)) {
                srb->msgout_buf[0] = identify_message;
                srb->msg_count = 1;
                scsicommand = SCMD_SEL_ATNSTOP;
                srb->state = SRB_MSGOUT;
#ifndef SYNC_FIRST
                if (dcb->sync_mode & WIDE_NEGO_ENABLE
                    && dcb->inquiry7 & SCSI_INQ_WBUS16) {
                        build_wdtr(acb, dcb, srb);
                        goto no_cmd;
                }
#endif
                if (dcb->sync_mode & SYNC_NEGO_ENABLE
                    && dcb->inquiry7 & SCSI_INQ_SYNC) {
                        build_sdtr(acb, dcb, srb);
                        goto no_cmd;
                }
                if (dcb->sync_mode & WIDE_NEGO_ENABLE
                    && dcb->inquiry7 & SCSI_INQ_WBUS16) {
                        build_wdtr(acb, dcb, srb);
                        goto no_cmd;
                }
                srb->msg_count = 0;
        }
        /* Send identify message */
        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, identify_message);

        scsicommand = SCMD_SEL_ATN;
        srb->state = SRB_START_;
#ifndef DC395x_NO_TAGQ
        if ((dcb->sync_mode & EN_TAG_QUEUEING)
            && (identify_message & 0xC0)) {
                /* Send Tag message */
                u32 tag_mask = 1;
                u8 tag_number = 0;
                while (tag_mask & dcb->tag_mask
                       && tag_number < dcb->max_command) {
                        tag_mask = tag_mask << 1;
                        tag_number++;
                }
                if (tag_number >= dcb->max_command) {
                        dprintkl(KERN_WARNING, "start_scsi: (0x%p) "
                                "Out of tags target=<%02i-%i>)\n",
                                srb->cmd, srb->cmd->device->id,
                                (u8)srb->cmd->device->lun);
                        srb->state = SRB_READY;
                        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL,
                                       DO_HWRESELECT);
                        return 1;
                }
                /* Send Tag id */
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, MSG_SIMPLE_QTAG);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, tag_number);
                dcb->tag_mask |= tag_mask;
                srb->tag_number = tag_number;
                scsicommand = SCMD_SEL_ATN3;
                srb->state = SRB_START_;
        }
#endif
/*polling:*/
        /* Send CDB ..command block ......... */
        dprintkdbg(DBG_KG, "start_scsi: (0x%p) <%02i-%i> cmnd=0x%02x tag=%i\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun,
                srb->cmd->cmnd[0], srb->tag_number);
        if (srb->flag & AUTO_REQSENSE) {
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, REQUEST_SENSE);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, (dcb->target_lun << 5));
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, SCSI_SENSE_BUFFERSIZE);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
        } else {
                ptr = (u8 *)srb->cmd->cmnd;
                for (i = 0; i < srb->cmd->cmd_len; i++)
                        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, *ptr++);
        }
      no_cmd:
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL,
                       DO_HWRESELECT | DO_DATALATCH);
        if (DC395x_read16(acb, TRM_S1040_SCSI_STATUS) & SCSIINTERRUPT) {
                /* 
                 * If start_scsi return 1:
                 * we caught an interrupt (must be reset or reselection ... )
                 * : Let's process it first!
                 */
                dprintkdbg(DBG_0, "start_scsi: (0x%p) <%02i-%i> Failed - busy\n",
                        srb->cmd, dcb->target_id, dcb->target_lun);
                srb->state = SRB_READY;
                free_tag(dcb, srb);
                srb->msg_count = 0;
                return_code = 1;
                /* This IRQ should NOT get lost, as we did not acknowledge it */
        } else {
                /* 
                 * If start_scsi returns 0:
                 * we know that the SCSI processor is free
                 */
                srb->scsi_phase = PH_BUS_FREE;  /* initial phase */
                dcb->active_srb = srb;
                acb->active_dcb = dcb;
                return_code = 0;
                /* it's important for atn stop */
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL,
                               DO_DATALATCH | DO_HWRESELECT);
                /* SCSI command */
                DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, scsicommand);
        }
        return return_code;
}


#define DC395x_ENABLE_MSGOUT \
 DC395x_write16 (acb, TRM_S1040_SCSI_CONTROL, DO_SETATN); \
 srb->state |= SRB_MSGOUT


/* abort command */
static inline void enable_msgout_abort(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb)
{
        srb->msgout_buf[0] = ABORT;
        srb->msg_count = 1;
        DC395x_ENABLE_MSGOUT;
        srb->state &= ~SRB_MSGIN;
        srb->state |= SRB_MSGOUT;
}


/**
 * dc395x_handle_interrupt - Handle an interrupt that has been confirmed to
 *                           have been triggered for this card.
 *
 * @acb:         a pointer to the adpter control block
 * @scsi_status: the status return when we checked the card
 **/
static void dc395x_handle_interrupt(struct AdapterCtlBlk *acb,
                u16 scsi_status)
{
        struct DeviceCtlBlk *dcb;
        struct ScsiReqBlk *srb;
        u16 phase;
        u8 scsi_intstatus;
        unsigned long flags;
        void (*dc395x_statev)(struct AdapterCtlBlk *, struct ScsiReqBlk *, 
                              u16 *);

        DC395x_LOCK_IO(acb->scsi_host, flags);

        /* This acknowledges the IRQ */
        scsi_intstatus = DC395x_read8(acb, TRM_S1040_SCSI_INTSTATUS);
        if ((scsi_status & 0x2007) == 0x2002)
                dprintkl(KERN_DEBUG,
                        "COP after COP completed? %04x\n", scsi_status);
        if (debug_enabled(DBG_KG)) {
                if (scsi_intstatus & INT_SELTIMEOUT)
                        dprintkdbg(DBG_KG, "handle_interrupt: Selection timeout\n");
        }
        /*dprintkl(KERN_DEBUG, "handle_interrupt: intstatus = 0x%02x ", scsi_intstatus); */

        if (timer_pending(&acb->selto_timer))
                del_timer(&acb->selto_timer);

        if (scsi_intstatus & (INT_SELTIMEOUT | INT_DISCONNECT)) {
                disconnect(acb);        /* bus free interrupt  */
                goto out_unlock;
        }
        if (scsi_intstatus & INT_RESELECTED) {
                reselect(acb);
                goto out_unlock;
        }
        if (scsi_intstatus & INT_SELECT) {
                dprintkl(KERN_INFO, "Host does not support target mode!\n");
                goto out_unlock;
        }
        if (scsi_intstatus & INT_SCSIRESET) {
                scsi_reset_detect(acb);
                goto out_unlock;
        }
        if (scsi_intstatus & (INT_BUSSERVICE | INT_CMDDONE)) {
                dcb = acb->active_dcb;
                if (!dcb) {
                        dprintkl(KERN_DEBUG,
                                "Oops: BusService (%04x %02x) w/o ActiveDCB!\n",
                                scsi_status, scsi_intstatus);
                        goto out_unlock;
                }
                srb = dcb->active_srb;
                if (dcb->flag & ABORT_DEV_) {
                        dprintkdbg(DBG_0, "MsgOut Abort Device.....\n");
                        enable_msgout_abort(acb, srb);
                }

                /* software sequential machine */
                phase = (u16)srb->scsi_phase;

                /* 
                 * 62037 or 62137
                 * call  dc395x_scsi_phase0[]... "phase entry"
                 * handle every phase before start transfer
                 */
                /* data_out_phase0,     phase:0 */
                /* data_in_phase0,      phase:1 */
                /* command_phase0,      phase:2 */
                /* status_phase0,       phase:3 */
                /* nop0,                phase:4 PH_BUS_FREE .. initial phase */
                /* nop0,                phase:5 PH_BUS_FREE .. initial phase */
                /* msgout_phase0,       phase:6 */
                /* msgin_phase0,        phase:7 */
                dc395x_statev = dc395x_scsi_phase0[phase];
                dc395x_statev(acb, srb, &scsi_status);

                /* 
                 * if there were any exception occurred scsi_status
                 * will be modify to bus free phase new scsi_status
                 * transfer out from ... previous dc395x_statev
                 */
                srb->scsi_phase = scsi_status & PHASEMASK;
                phase = (u16)scsi_status & PHASEMASK;

                /* 
                 * call  dc395x_scsi_phase1[]... "phase entry" handle
                 * every phase to do transfer
                 */
                /* data_out_phase1,     phase:0 */
                /* data_in_phase1,      phase:1 */
                /* command_phase1,      phase:2 */
                /* status_phase1,       phase:3 */
                /* nop1,                phase:4 PH_BUS_FREE .. initial phase */
                /* nop1,                phase:5 PH_BUS_FREE .. initial phase */
                /* msgout_phase1,       phase:6 */
                /* msgin_phase1,        phase:7 */
                dc395x_statev = dc395x_scsi_phase1[phase];
                dc395x_statev(acb, srb, &scsi_status);
        }
      out_unlock:
        DC395x_UNLOCK_IO(acb->scsi_host, flags);
}


static irqreturn_t dc395x_interrupt(int irq, void *dev_id)
{
        struct AdapterCtlBlk *acb = dev_id;
        u16 scsi_status;
        u8 dma_status;
        irqreturn_t handled = IRQ_NONE;

        /*
         * Check for pending interrupt
         */
        scsi_status = DC395x_read16(acb, TRM_S1040_SCSI_STATUS);
        dma_status = DC395x_read8(acb, TRM_S1040_DMA_STATUS);
        if (scsi_status & SCSIINTERRUPT) {
                /* interrupt pending - let's process it! */
                dc395x_handle_interrupt(acb, scsi_status);
                handled = IRQ_HANDLED;
        }
        else if (dma_status & 0x20) {
                /* Error from the DMA engine */
                dprintkl(KERN_INFO, "Interrupt from DMA engine: 0x%02x!\n", dma_status);
#if 0
                dprintkl(KERN_INFO, "This means DMA error! Try to handle ...\n");
                if (acb->active_dcb) {
                        acb->active_dcb-> flag |= ABORT_DEV_;
                        if (acb->active_dcb->active_srb)
                                enable_msgout_abort(acb, acb->active_dcb->active_srb);
                }
                DC395x_write8(acb, TRM_S1040_DMA_CONTROL, ABORTXFER | CLRXFIFO);
#else
                dprintkl(KERN_INFO, "Ignoring DMA error (probably a bad thing) ...\n");
                acb = NULL;
#endif
                handled = IRQ_HANDLED;
        }

        return handled;
}


static void msgout_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "msgout_phase0: (0x%p)\n", srb->cmd);
        if (srb->state & (SRB_UNEXPECT_RESEL + SRB_ABORT_SENT))
                *pscsi_status = PH_BUS_FREE;    /*.. initial phase */

        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
        srb->state &= ~SRB_MSGOUT;
}


static void msgout_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        u16 i;
        u8 *ptr;
        dprintkdbg(DBG_0, "msgout_phase1: (0x%p)\n", srb->cmd);

        clear_fifo(acb, "msgout_phase1");
        if (!(srb->state & SRB_MSGOUT)) {
                srb->state |= SRB_MSGOUT;
                dprintkl(KERN_DEBUG,
                        "msgout_phase1: (0x%p) Phase unexpected\n",
                        srb->cmd);      /* So what ? */
        }
        if (!srb->msg_count) {
                dprintkdbg(DBG_0, "msgout_phase1: (0x%p) NOP msg\n",
                        srb->cmd);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, MSG_NOP);
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
                DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_FIFO_OUT);
                return;
        }
        ptr = (u8 *)srb->msgout_buf;
        for (i = 0; i < srb->msg_count; i++)
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, *ptr++);
        srb->msg_count = 0;
        if (srb->msgout_buf[0] == MSG_ABORT)
                srb->state = SRB_ABORT_SENT;

        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_FIFO_OUT);
}


static void command_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "command_phase0: (0x%p)\n", srb->cmd);
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);
}


static void command_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        struct DeviceCtlBlk *dcb;
        u8 *ptr;
        u16 i;
        dprintkdbg(DBG_0, "command_phase1: (0x%p)\n", srb->cmd);

        clear_fifo(acb, "command_phase1");
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_CLRATN);
        if (!(srb->flag & AUTO_REQSENSE)) {
                ptr = (u8 *)srb->cmd->cmnd;
                for (i = 0; i < srb->cmd->cmd_len; i++) {
                        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, *ptr);
                        ptr++;
                }
        } else {
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, REQUEST_SENSE);
                dcb = acb->active_dcb;
                /* target id */
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, (dcb->target_lun << 5));
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, SCSI_SENSE_BUFFERSIZE);
                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
        }
        srb->state |= SRB_COMMAND;
        /* it's important for atn stop */
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);
        /* SCSI command */
        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_FIFO_OUT);
}


/*
 * Verify that the remaining space in the hw sg lists is the same as
 * the count of remaining bytes in srb->total_xfer_length
 */
static void sg_verify_length(struct ScsiReqBlk *srb)
{
        if (debug_enabled(DBG_SG)) {
                unsigned len = 0;
                unsigned idx = srb->sg_index;
                struct SGentry *psge = srb->segment_x + idx;
                for (; idx < srb->sg_count; psge++, idx++)
                        len += psge->length;
                if (len != srb->total_xfer_length)
                        dprintkdbg(DBG_SG,
                               "Inconsistent SRB S/G lengths (Tot=%i, Count=%i) !!\n",
                               srb->total_xfer_length, len);
        }                              
}


/*
 * Compute the next Scatter Gather list index and adjust its length
 * and address if necessary
 */
static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
{
        u8 idx;
        u32 xferred = srb->total_xfer_length - left; /* bytes transferred */
        struct SGentry *psge = srb->segment_x + srb->sg_index;

        dprintkdbg(DBG_0,
                "sg_update_list: Transferred %i of %i bytes, %i remain\n",
                xferred, srb->total_xfer_length, left);
        if (xferred == 0) {
                /* nothing to update since we did not transfer any data */
                return;
        }

        sg_verify_length(srb);
        srb->total_xfer_length = left;  /* update remaining count */
        for (idx = srb->sg_index; idx < srb->sg_count; idx++) {
                if (xferred >= psge->length) {
                        /* Complete SG entries done */
                        xferred -= psge->length;
                } else {
                        /* Partial SG entry done */
                        dma_sync_single_for_cpu(&srb->dcb->acb->dev->dev,
                                        srb->sg_bus_addr, SEGMENTX_LEN,
                                        DMA_TO_DEVICE);
                        psge->length -= xferred;
                        psge->address += xferred;
                        srb->sg_index = idx;
                        dma_sync_single_for_device(&srb->dcb->acb->dev->dev,
                                        srb->sg_bus_addr, SEGMENTX_LEN,
                                        DMA_TO_DEVICE);
                        break;
                }
                psge++;
        }
        sg_verify_length(srb);
}


/*
 * We have transferred a single byte (PIO mode?) and need to update
 * the count of bytes remaining (total_xfer_length) and update the sg
 * entry to either point to next byte in the current sg entry, or of
 * already at the end to point to the start of the next sg entry
 */
static void sg_subtract_one(struct ScsiReqBlk *srb)
{
        sg_update_list(srb, srb->total_xfer_length - 1);
}


/* 
 * cleanup_after_transfer
 * 
 * Makes sure, DMA and SCSI engine are empty, after the transfer has finished
 * KG: Currently called from  StatusPhase1 ()
 * Should probably also be called from other places
 * Best might be to call it in DataXXPhase0, if new phase will differ 
 */
static void cleanup_after_transfer(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb)
{
        /*DC395x_write8 (TRM_S1040_DMA_STATUS, FORCEDMACOMP); */
        if (DC395x_read16(acb, TRM_S1040_DMA_COMMAND) & 0x0001) {       /* read */
                if (!(DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) & 0x40))
                        clear_fifo(acb, "cleanup/in");
                if (!(DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT) & 0x80))
                        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, CLRXFIFO);
        } else {                /* write */
                if (!(DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT) & 0x80))
                        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, CLRXFIFO);
                if (!(DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) & 0x40))
                        clear_fifo(acb, "cleanup/out");
        }
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);
}


/*
 * Those no of bytes will be transferred w/ PIO through the SCSI FIFO
 * Seems to be needed for unknown reasons; could be a hardware bug :-(
 */
#define DC395x_LASTPIO 4


static void data_out_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        u16 scsi_status = *pscsi_status;
        u32 d_left_counter = 0;
        dprintkdbg(DBG_0, "data_out_phase0: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);

        /*
         * KG: We need to drain the buffers before we draw any conclusions!
         * This means telling the DMA to push the rest into SCSI, telling
         * SCSI to push the rest to the bus.
         * However, the device might have been the one to stop us (phase
         * change), and the data in transit just needs to be accounted so
         * it can be retransmitted.)
         */
        /* 
         * KG: Stop DMA engine pushing more data into the SCSI FIFO
         * If we need more data, the DMA SG list will be freshly set up, anyway
         */
        dprintkdbg(DBG_PIO, "data_out_phase0: "
                "DMA{fifocnt=0x%02x fifostat=0x%02x} "
                "SCSI{fifocnt=0x%02x cnt=0x%06x status=0x%04x} total=0x%06x\n",
                DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
                DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
                DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT),
                DC395x_read32(acb, TRM_S1040_SCSI_COUNTER), scsi_status,
                srb->total_xfer_length);
        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, STOPDMAXFER | CLRXFIFO);

        if (!(srb->state & SRB_XFERPAD)) {
                if (scsi_status & PARITYERROR)
                        srb->status |= PARITY_ERROR;

                /*
                 * KG: Right, we can't just rely on the SCSI_COUNTER, because this
                 * is the no of bytes it got from the DMA engine not the no it 
                 * transferred successfully to the device. (And the difference could
                 * be as much as the FIFO size, I guess ...)
                 */
                if (!(scsi_status & SCSIXFERDONE)) {
                        /*
                         * when data transfer from DMA FIFO to SCSI FIFO
                         * if there was some data left in SCSI FIFO
                         */
                        d_left_counter =
                            (u32)(DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) &
                                  0x1F);
                        if (dcb->sync_period & WIDE_SYNC)
                                d_left_counter <<= 1;

                        dprintkdbg(DBG_KG, "data_out_phase0: FIFO contains %i %s\n"
                                "SCSI{fifocnt=0x%02x cnt=0x%08x} "
                                "DMA{fifocnt=0x%04x cnt=0x%02x ctr=0x%08x}\n",
                                DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT),
                                (dcb->sync_period & WIDE_SYNC) ? "words" : "bytes",
                                DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT),
                                DC395x_read32(acb, TRM_S1040_SCSI_COUNTER),
                                DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
                                DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
                                DC395x_read32(acb, TRM_S1040_DMA_CXCNT));
                }
                /*
                 * calculate all the residue data that not yet tranfered
                 * SCSI transfer counter + left in SCSI FIFO data

                 *
                 * .....TRM_S1040_SCSI_COUNTER (24bits)
                 * The counter always decrement by one for every SCSI byte transfer.
                 * .....TRM_S1040_SCSI_FIFOCNT ( 5bits)
                 * The counter is SCSI FIFO offset counter (in units of bytes or! words)
                 */
                if (srb->total_xfer_length > DC395x_LASTPIO)
                        d_left_counter +=
                            DC395x_read32(acb, TRM_S1040_SCSI_COUNTER);

                /* Is this a good idea? */
                /*clear_fifo(acb, "DOP1"); */
                /* KG: What is this supposed to be useful for? WIDE padding stuff? */
                if (d_left_counter == 1 && dcb->sync_period & WIDE_SYNC
                    && scsi_bufflen(srb->cmd) % 2) {
                        d_left_counter = 0;
                        dprintkl(KERN_INFO,
                                "data_out_phase0: Discard 1 byte (0x%02x)\n",
                                scsi_status);
                }
                /*
                 * KG: Oops again. Same thinko as above: The SCSI might have been
                 * faster than the DMA engine, so that it ran out of data.
                 * In that case, we have to do just nothing! 
                 * But: Why the interrupt: No phase change. No XFERCNT_2_ZERO. Or?
                 */
                /*
                 * KG: This is nonsense: We have been WRITING data to the bus
                 * If the SCSI engine has no bytes left, how should the DMA engine?
                 */
                if (d_left_counter == 0) {
                        srb->total_xfer_length = 0;
                } else {
                        /*
                         * if transfer not yet complete
                         * there were some data residue in SCSI FIFO or
                         * SCSI transfer counter not empty
                         */
                        long oldxferred =
                            srb->total_xfer_length - d_left_counter;
                        const int diff =
                            (dcb->sync_period & WIDE_SYNC) ? 2 : 1;
                        sg_update_list(srb, d_left_counter);
                        /* KG: Most ugly hack! Apparently, this works around a chip bug */
                        if ((srb->segment_x[srb->sg_index].length ==
                             diff && scsi_sg_count(srb->cmd))
                            || ((oldxferred & ~PAGE_MASK) ==
                                (PAGE_SIZE - diff))
                            ) {
                                dprintkl(KERN_INFO, "data_out_phase0: "
                                        "Work around chip bug (%i)?\n", diff);
                                d_left_counter =
                                    srb->total_xfer_length - diff;
                                sg_update_list(srb, d_left_counter);
                                /*srb->total_xfer_length -= diff; */
                                /*srb->virt_addr += diff; */
                                /*if (srb->cmd->use_sg) */
                                /*      srb->sg_index++; */
                        }
                }
        }
        if ((*pscsi_status & PHASEMASK) != PH_DATA_OUT) {
                cleanup_after_transfer(acb, srb);
        }
}


static void data_out_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "data_out_phase1: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);
        clear_fifo(acb, "data_out_phase1");
        /* do prepare before transfer when data out phase */
        data_io_transfer(acb, srb, XFERDATAOUT);
}

static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        u16 scsi_status = *pscsi_status;

        dprintkdbg(DBG_0, "data_in_phase0: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);

        /*
         * KG: DataIn is much more tricky than DataOut. When the device is finished
         * and switches to another phase, the SCSI engine should be finished too.
         * But: There might still be bytes left in its FIFO to be fetched by the DMA
         * engine and transferred to memory.
         * We should wait for the FIFOs to be emptied by that (is there any way to 
         * enforce this?) and then stop the DMA engine, because it might think, that
         * there are more bytes to follow. Yes, the device might disconnect prior to
         * having all bytes transferred! 
         * Also we should make sure that all data from the DMA engine buffer's really
         * made its way to the system memory! Some documentation on this would not
         * seem to be a bad idea, actually.
         */
        if (!(srb->state & SRB_XFERPAD)) {
                u32 d_left_counter;
                unsigned int sc, fc;

                if (scsi_status & PARITYERROR) {
                        dprintkl(KERN_INFO, "data_in_phase0: (0x%p) "
                                "Parity Error\n", srb->cmd);
                        srb->status |= PARITY_ERROR;
                }
                /*
                 * KG: We should wait for the DMA FIFO to be empty ...
                 * but: it would be better to wait first for the SCSI FIFO and then the
                 * the DMA FIFO to become empty? How do we know, that the device not already
                 * sent data to the FIFO in a MsgIn phase, eg.?
                 */
                if (!(DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT) & 0x80)) {
#if 0
                        int ctr = 6000000;
                        dprintkl(KERN_DEBUG,
                                "DIP0: Wait for DMA FIFO to flush ...\n");
                        /*DC395x_write8  (TRM_S1040_DMA_CONTROL, STOPDMAXFER); */
                        /*DC395x_write32 (TRM_S1040_SCSI_COUNTER, 7); */
                        /*DC395x_write8  (TRM_S1040_SCSI_COMMAND, SCMD_DMA_IN); */
                        while (!
                               (DC395x_read16(acb, TRM_S1040_DMA_FIFOSTAT) &
                                0x80) && --ctr);
                        if (ctr < 6000000 - 1)
                                dprintkl(KERN_DEBUG
                                       "DIP0: Had to wait for DMA ...\n");
                        if (!ctr)
                                dprintkl(KERN_ERR,
                                       "Deadlock in DIP0 waiting for DMA FIFO empty!!\n");
                        /*DC395x_write32 (TRM_S1040_SCSI_COUNTER, 0); */
#endif
                        dprintkdbg(DBG_KG, "data_in_phase0: "
                                "DMA{fifocnt=0x%02x fifostat=0x%02x}\n",
                                DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
                                DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT));
                }
                /* Now: Check remainig data: The SCSI counters should tell us ... */
                sc = DC395x_read32(acb, TRM_S1040_SCSI_COUNTER);
                fc = DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT);
                d_left_counter = sc + ((fc & 0x1f)
                       << ((srb->dcb->sync_period & WIDE_SYNC) ? 1 :
                           0));
                dprintkdbg(DBG_KG, "data_in_phase0: "
                        "SCSI{fifocnt=0x%02x%s ctr=0x%08x} "
                        "DMA{fifocnt=0x%02x fifostat=0x%02x ctr=0x%08x} "
                        "Remain{totxfer=%i scsi_fifo+ctr=%i}\n",
                        fc,
                        (srb->dcb->sync_period & WIDE_SYNC) ? "words" : "bytes",
                        sc,
                        fc,
                        DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
                        DC395x_read32(acb, TRM_S1040_DMA_CXCNT),
                        srb->total_xfer_length, d_left_counter);
#if DC395x_LASTPIO
                /* KG: Less than or equal to 4 bytes can not be transferred via DMA, it seems. */
                if (d_left_counter
                    && srb->total_xfer_length <= DC395x_LASTPIO) {
                        size_t left_io = srb->total_xfer_length;

                        /*u32 addr = (srb->segment_x[srb->sg_index].address); */
                        /*sg_update_list (srb, d_left_counter); */
                        dprintkdbg(DBG_PIO, "data_in_phase0: PIO (%i %s) "
                                   "for remaining %i bytes:",
                                fc & 0x1f,
                                (srb->dcb->sync_period & WIDE_SYNC) ?
                                    "words" : "bytes",
                                srb->total_xfer_length);
                        if (srb->dcb->sync_period & WIDE_SYNC)
                                DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2,
                                              CFG2_WIDEFIFO);
                        while (left_io) {
                                unsigned char *virt, *base = NULL;
                                unsigned long flags = 0;
                                size_t len = left_io;
                                size_t offset = srb->request_length - left_io;

                                local_irq_save(flags);
                                /* Assumption: it's inside one page as it's at most 4 bytes and
                                   I just assume it's on a 4-byte boundary */
                                base = scsi_kmap_atomic_sg(scsi_sglist(srb->cmd),
                                                           srb->sg_count, &offset, &len);
                                virt = base + offset;

                                left_io -= len;

                                while (len) {
                                        u8 byte;
                                        byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
                                        *virt++ = byte;

                                        if (debug_enabled(DBG_PIO))
                                                printk(" %02x", byte);

                                        d_left_counter--;
                                        sg_subtract_one(srb);

                                        len--;

                                        fc = DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT);

                                        if (fc == 0x40) {
                                                left_io = 0;
                                                break;
                                        }
                                }

                                WARN_ON((fc != 0x40) == !d_left_counter);

                                if (fc == 0x40 && (srb->dcb->sync_period & WIDE_SYNC)) {
                                        /* Read the last byte ... */
                                        if (srb->total_xfer_length > 0) {
                                                u8 byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);

                                                *virt++ = byte;
                                                srb->total_xfer_length--;
                                                if (debug_enabled(DBG_PIO))
                                                        printk(" %02x", byte);
                                        }

                                        DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2, 0);
                                }

                                scsi_kunmap_atomic_sg(base);
                                local_irq_restore(flags);
                        }
                        /*printk(" %08x", *(u32*)(bus_to_virt (addr))); */
                        /*srb->total_xfer_length = 0; */
                        if (debug_enabled(DBG_PIO))
                                printk("\n");
                }
#endif                          /* DC395x_LASTPIO */

#if 0
                /*
                 * KG: This was in DATAOUT. Does it also belong here?
                 * Nobody seems to know what counter and fifo_cnt count exactly ...
                 */
                if (!(scsi_status & SCSIXFERDONE)) {
                        /*
                         * when data transfer from DMA FIFO to SCSI FIFO
                         * if there was some data left in SCSI FIFO
                         */
                        d_left_counter =
                            (u32)(DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) &
                                  0x1F);
                        if (srb->dcb->sync_period & WIDE_SYNC)
                                d_left_counter <<= 1;
                        /*
                         * if WIDE scsi SCSI FIFOCNT unit is word !!!
                         * so need to *= 2
                         * KG: Seems to be correct ...
                         */
                }
#endif
                /* KG: This should not be needed any more! */
                if (d_left_counter == 0
                    || (scsi_status & SCSIXFERCNT_2_ZERO)) {
#if 0
                        int ctr = 6000000;
                        u8 TempDMAstatus;
                        do {
                                TempDMAstatus =
                                    DC395x_read8(acb, TRM_S1040_DMA_STATUS);
                        } while (!(TempDMAstatus & DMAXFERCOMP) && --ctr);
                        if (!ctr)
                                dprintkl(KERN_ERR,
                                       "Deadlock in DataInPhase0 waiting for DMA!!\n");
                        srb->total_xfer_length = 0;
#endif
                        srb->total_xfer_length = d_left_counter;
                } else {        /* phase changed */
                        /*
                         * parsing the case:
                         * when a transfer not yet complete 
                         * but be disconnected by target
                         * if transfer not yet complete
                         * there were some data residue in SCSI FIFO or
                         * SCSI transfer counter not empty
                         */
                        sg_update_list(srb, d_left_counter);
                }
        }
        /* KG: The target may decide to disconnect: Empty FIFO before! */
        if ((*pscsi_status & PHASEMASK) != PH_DATA_IN) {
                cleanup_after_transfer(acb, srb);
        }
}


static void data_in_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "data_in_phase1: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);
        data_io_transfer(acb, srb, XFERDATAIN);
}


static void data_io_transfer(struct AdapterCtlBlk *acb, 
                struct ScsiReqBlk *srb, u16 io_dir)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        u8 bval;
        dprintkdbg(DBG_0,
                "data_io_transfer: (0x%p) <%02i-%i> %c len=%i, sg=(%i/%i)\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun,
                ((io_dir & DMACMD_DIR) ? 'r' : 'w'),
                srb->total_xfer_length, srb->sg_index, srb->sg_count);
        if (srb == acb->tmp_srb)
                dprintkl(KERN_ERR, "data_io_transfer: Using tmp_srb!\n");
        if (srb->sg_index >= srb->sg_count) {
                /* can't happen? out of bounds error */
                return;
        }

        if (srb->total_xfer_length > DC395x_LASTPIO) {
                u8 dma_status = DC395x_read8(acb, TRM_S1040_DMA_STATUS);
                /*
                 * KG: What should we do: Use SCSI Cmd 0x90/0x92?
                 * Maybe, even ABORTXFER would be appropriate
                 */
                if (dma_status & XFERPENDING) {
                        dprintkl(KERN_DEBUG, "data_io_transfer: Xfer pending! "
                                "Expect trouble!\n");
                        dump_register_info(acb, dcb, srb);
                        DC395x_write8(acb, TRM_S1040_DMA_CONTROL, CLRXFIFO);
                }
                /* clear_fifo(acb, "IO"); */
                /* 
                 * load what physical address of Scatter/Gather list table
                 * want to be transfer
                 */
                srb->state |= SRB_DATA_XFER;
                DC395x_write32(acb, TRM_S1040_DMA_XHIGHADDR, 0);
                if (scsi_sg_count(srb->cmd)) {  /* with S/G */
                        io_dir |= DMACMD_SG;
                        DC395x_write32(acb, TRM_S1040_DMA_XLOWADDR,
                                       srb->sg_bus_addr +
                                       sizeof(struct SGentry) *
                                       srb->sg_index);
                        /* load how many bytes in the sg list table */
                        DC395x_write32(acb, TRM_S1040_DMA_XCNT,
                                       ((u32)(srb->sg_count -
                                              srb->sg_index) << 3));
                } else {        /* without S/G */
                        io_dir &= ~DMACMD_SG;
                        DC395x_write32(acb, TRM_S1040_DMA_XLOWADDR,
                                       srb->segment_x[0].address);
                        DC395x_write32(acb, TRM_S1040_DMA_XCNT,
                                       srb->segment_x[0].length);
                }
                /* load total transfer length (24bits) max value 16Mbyte */
                DC395x_write32(acb, TRM_S1040_SCSI_COUNTER,
                               srb->total_xfer_length);
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
                if (io_dir & DMACMD_DIR) {      /* read */
                        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND,
                                      SCMD_DMA_IN);
                        DC395x_write16(acb, TRM_S1040_DMA_COMMAND, io_dir);
                } else {
                        DC395x_write16(acb, TRM_S1040_DMA_COMMAND, io_dir);
                        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND,
                                      SCMD_DMA_OUT);
                }

        }
#if DC395x_LASTPIO
        else if (srb->total_xfer_length > 0) {  /* The last four bytes: Do PIO */
                /* 
                 * load what physical address of Scatter/Gather list table
                 * want to be transfer
                 */
                srb->state |= SRB_DATA_XFER;
                /* load total transfer length (24bits) max value 16Mbyte */
                DC395x_write32(acb, TRM_S1040_SCSI_COUNTER,
                               srb->total_xfer_length);
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
                if (io_dir & DMACMD_DIR) {      /* read */
                        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND,
                                      SCMD_FIFO_IN);
                } else {        /* write */
                        int ln = srb->total_xfer_length;
                        size_t left_io = srb->total_xfer_length;

                        if (srb->dcb->sync_period & WIDE_SYNC)
                                DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2,
                                     CFG2_WIDEFIFO);

                        while (left_io) {
                                unsigned char *virt, *base = NULL;
                                unsigned long flags = 0;
                                size_t len = left_io;
                                size_t offset = srb->request_length - left_io;

                                local_irq_save(flags);
                                /* Again, max 4 bytes */
                                base = scsi_kmap_atomic_sg(scsi_sglist(srb->cmd),
                                                           srb->sg_count, &offset, &len);
                                virt = base + offset;

                                left_io -= len;

                                while (len--) {
                                        if (debug_enabled(DBG_PIO))
                                                printk(" %02x", *virt);

                                        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, *virt++);

                                        sg_subtract_one(srb);
                                }

                                scsi_kunmap_atomic_sg(base);
                                local_irq_restore(flags);
                        }
                        if (srb->dcb->sync_period & WIDE_SYNC) {
                                if (ln % 2) {
                                        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 0);
                                        if (debug_enabled(DBG_PIO))
                                                printk(" |00");
                                }
                                DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2, 0);
                        }
                        /*DC395x_write32(acb, TRM_S1040_SCSI_COUNTER, ln); */
                        if (debug_enabled(DBG_PIO))
                                printk("\n");
                        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND,
                                          SCMD_FIFO_OUT);
                }
        }
#endif                          /* DC395x_LASTPIO */
        else {          /* xfer pad */
                u8 data = 0, data2 = 0;
                if (srb->sg_count) {
                        srb->adapter_status = H_OVER_UNDER_RUN;
                        srb->status |= OVER_RUN;
                }
                /*
                 * KG: despite the fact that we are using 16 bits I/O ops
                 * the SCSI FIFO is only 8 bits according to the docs
                 * (we can set bit 1 in 0x8f to serialize FIFO access ...)
                 */
                if (dcb->sync_period & WIDE_SYNC) {
                        DC395x_write32(acb, TRM_S1040_SCSI_COUNTER, 2);
                        DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2,
                                      CFG2_WIDEFIFO);
                        if (io_dir & DMACMD_DIR) {
                                data = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
                                data2 = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
                        } else {
                                /* Danger, Robinson: If you find KGs
                                 * scattered over the wide disk, the driver
                                 * or chip is to blame :-( */
                                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 'K');
                                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 'G');
                        }
                        DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2, 0);
                } else {
                        DC395x_write32(acb, TRM_S1040_SCSI_COUNTER, 1);
                        /* Danger, Robinson: If you find a collection of Ks on your disk
                         * something broke :-( */
                        if (io_dir & DMACMD_DIR)
                                data = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
                        else
                                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 'K');
                }
                srb->state |= SRB_XFERPAD;
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
                /* SCSI command */
                bval = (io_dir & DMACMD_DIR) ? SCMD_FIFO_IN : SCMD_FIFO_OUT;
                DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, bval);
        }
}


static void status_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "status_phase0: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);
        srb->target_status = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
        srb->end_message = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);      /* get message */
        srb->state = SRB_COMPLETED;
        *pscsi_status = PH_BUS_FREE;    /*.. initial phase */
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_MSGACCEPT);
}


static void status_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "status_phase1: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->cmd->device->id, (u8)srb->cmd->device->lun);
        srb->state = SRB_STATUS;
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_COMP);
}


/* Check if the message is complete */
static inline u8 msgin_completed(u8 * msgbuf, u32 len)
{
        if (*msgbuf == EXTENDED_MESSAGE) {
                if (len < 2)
                        return 0;
                if (len < msgbuf[1] + 2)
                        return 0;
        } else if (*msgbuf >= 0x20 && *msgbuf <= 0x2f)  /* two byte messages */
                if (len < 2)
                        return 0;
        return 1;
}

/* reject_msg */
static inline void msgin_reject(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb)
{
        srb->msgout_buf[0] = MESSAGE_REJECT;
        srb->msg_count = 1;
        DC395x_ENABLE_MSGOUT;
        srb->state &= ~SRB_MSGIN;
        srb->state |= SRB_MSGOUT;
        dprintkl(KERN_INFO, "msgin_reject: 0x%02x <%02i-%i>\n",
                srb->msgin_buf[0],
                srb->dcb->target_id, srb->dcb->target_lun);
}


static struct ScsiReqBlk *msgin_qtag(struct AdapterCtlBlk *acb,
                struct DeviceCtlBlk *dcb, u8 tag)
{
        struct ScsiReqBlk *srb = NULL;
        struct ScsiReqBlk *i;
        dprintkdbg(DBG_0, "msgin_qtag: (0x%p) tag=%i srb=%p\n",
                   srb->cmd, tag, srb);

        if (!(dcb->tag_mask & (1 << tag)))
                dprintkl(KERN_DEBUG,
                        "msgin_qtag: tag_mask=0x%08x does not reserve tag %i!\n",
                        dcb->tag_mask, tag);

        if (list_empty(&dcb->srb_going_list))
                goto mingx0;
        list_for_each_entry(i, &dcb->srb_going_list, list) {
                if (i->tag_number == tag) {
                        srb = i;
                        break;
                }
        }
        if (!srb)
                goto mingx0;

        dprintkdbg(DBG_0, "msgin_qtag: (0x%p) <%02i-%i>\n",
                srb->cmd, srb->dcb->target_id, srb->dcb->target_lun);
        if (dcb->flag & ABORT_DEV_) {
                /*srb->state = SRB_ABORT_SENT; */
                enable_msgout_abort(acb, srb);
        }

        if (!(srb->state & SRB_DISCONNECT))
                goto mingx0;

        memcpy(srb->msgin_buf, dcb->active_srb->msgin_buf, acb->msg_len);
        srb->state |= dcb->active_srb->state;
        srb->state |= SRB_DATA_XFER;
        dcb->active_srb = srb;
        /* How can we make the DORS happy? */
        return srb;

      mingx0:
        srb = acb->tmp_srb;
        srb->state = SRB_UNEXPECT_RESEL;
        dcb->active_srb = srb;
        srb->msgout_buf[0] = MSG_ABORT_TAG;
        srb->msg_count = 1;
        DC395x_ENABLE_MSGOUT;
        dprintkl(KERN_DEBUG, "msgin_qtag: Unknown tag %i - abort\n", tag);
        return srb;
}


static inline void reprogram_regs(struct AdapterCtlBlk *acb,
                struct DeviceCtlBlk *dcb)
{
        DC395x_write8(acb, TRM_S1040_SCSI_TARGETID, dcb->target_id);
        DC395x_write8(acb, TRM_S1040_SCSI_SYNC, dcb->sync_period);
        DC395x_write8(acb, TRM_S1040_SCSI_OFFSET, dcb->sync_offset);
        set_xfer_rate(acb, dcb);
}


/* set async transfer mode */
static void msgin_set_async(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        dprintkl(KERN_DEBUG, "msgin_set_async: No sync transfers <%02i-%i>\n",
                dcb->target_id, dcb->target_lun);

        dcb->sync_mode &= ~(SYNC_NEGO_ENABLE);
        dcb->sync_mode |= SYNC_NEGO_DONE;
        /*dcb->sync_period &= 0; */
        dcb->sync_offset = 0;
        dcb->min_nego_period = 200 >> 2;        /* 200ns <=> 5 MHz */
        srb->state &= ~SRB_DO_SYNC_NEGO;
        reprogram_regs(acb, dcb);
        if ((dcb->sync_mode & WIDE_NEGO_ENABLE)
            && !(dcb->sync_mode & WIDE_NEGO_DONE)) {
                build_wdtr(acb, dcb, srb);
                DC395x_ENABLE_MSGOUT;
                dprintkdbg(DBG_0, "msgin_set_async(rej): Try WDTR anyway\n");
        }
}


/* set sync transfer mode */
static void msgin_set_sync(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        u8 bval;
        int fact;
        dprintkdbg(DBG_1, "msgin_set_sync: <%02i> Sync: %ins "
                "(%02i.%01i MHz) Offset %i\n",
                dcb->target_id, srb->msgin_buf[3] << 2,
                (250 / srb->msgin_buf[3]),
                ((250 % srb->msgin_buf[3]) * 10) / srb->msgin_buf[3],
                srb->msgin_buf[4]);

        if (srb->msgin_buf[4] > 15)
                srb->msgin_buf[4] = 15;
        if (!(dcb->dev_mode & NTC_DO_SYNC_NEGO))
                dcb->sync_offset = 0;
        else if (dcb->sync_offset == 0)
                dcb->sync_offset = srb->msgin_buf[4];
        if (srb->msgin_buf[4] > dcb->sync_offset)
                srb->msgin_buf[4] = dcb->sync_offset;
        else
                dcb->sync_offset = srb->msgin_buf[4];
        bval = 0;
        while (bval < 7 && (srb->msgin_buf[3] > clock_period[bval]
                            || dcb->min_nego_period >
                            clock_period[bval]))
                bval++;
        if (srb->msgin_buf[3] < clock_period[bval])
                dprintkl(KERN_INFO,
                        "msgin_set_sync: Increase sync nego period to %ins\n",
                        clock_period[bval] << 2);
        srb->msgin_buf[3] = clock_period[bval];
        dcb->sync_period &= 0xf0;
        dcb->sync_period |= ALT_SYNC | bval;
        dcb->min_nego_period = srb->msgin_buf[3];

        if (dcb->sync_period & WIDE_SYNC)
                fact = 500;
        else
                fact = 250;

        dprintkl(KERN_INFO,
                "Target %02i: %s Sync: %ins Offset %i (%02i.%01i MB/s)\n",
                dcb->target_id, (fact == 500) ? "Wide16" : "",
                dcb->min_nego_period << 2, dcb->sync_offset,
                (fact / dcb->min_nego_period),
                ((fact % dcb->min_nego_period) * 10 +
                dcb->min_nego_period / 2) / dcb->min_nego_period);

        if (!(srb->state & SRB_DO_SYNC_NEGO)) {
                /* Reply with corrected SDTR Message */
                dprintkl(KERN_DEBUG, "msgin_set_sync: answer w/%ins %i\n",
                        srb->msgin_buf[3] << 2, srb->msgin_buf[4]);

                memcpy(srb->msgout_buf, srb->msgin_buf, 5);
                srb->msg_count = 5;
                DC395x_ENABLE_MSGOUT;
                dcb->sync_mode |= SYNC_NEGO_DONE;
        } else {
                if ((dcb->sync_mode & WIDE_NEGO_ENABLE)
                    && !(dcb->sync_mode & WIDE_NEGO_DONE)) {
                        build_wdtr(acb, dcb, srb);
                        DC395x_ENABLE_MSGOUT;
                        dprintkdbg(DBG_0, "msgin_set_sync: Also try WDTR\n");
                }
        }
        srb->state &= ~SRB_DO_SYNC_NEGO;
        dcb->sync_mode |= SYNC_NEGO_DONE | SYNC_NEGO_ENABLE;

        reprogram_regs(acb, dcb);
}


static inline void msgin_set_nowide(struct AdapterCtlBlk *acb,
                struct ScsiReqBlk *srb)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        dprintkdbg(DBG_1, "msgin_set_nowide: <%02i>\n", dcb->target_id);

        dcb->sync_period &= ~WIDE_SYNC;
        dcb->sync_mode &= ~(WIDE_NEGO_ENABLE);
        dcb->sync_mode |= WIDE_NEGO_DONE;
        srb->state &= ~SRB_DO_WIDE_NEGO;
        reprogram_regs(acb, dcb);
        if ((dcb->sync_mode & SYNC_NEGO_ENABLE)
            && !(dcb->sync_mode & SYNC_NEGO_DONE)) {
                build_sdtr(acb, dcb, srb);
                DC395x_ENABLE_MSGOUT;
                dprintkdbg(DBG_0, "msgin_set_nowide: Rejected. Try SDTR anyway\n");
        }
}

static void msgin_set_wide(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
{
        struct DeviceCtlBlk *dcb = srb->dcb;
        u8 wide = (dcb->dev_mode & NTC_DO_WIDE_NEGO
                   && acb->config & HCC_WIDE_CARD) ? 1 : 0;
        dprintkdbg(DBG_1, "msgin_set_wide: <%02i>\n", dcb->target_id);

        if (srb->msgin_buf[3] > wide)
                srb->msgin_buf[3] = wide;
        /* Completed */
        if (!(srb->state & SRB_DO_WIDE_NEGO)) {
                dprintkl(KERN_DEBUG,
                        "msgin_set_wide: Wide nego initiated <%02i>\n",
                        dcb->target_id);
                memcpy(srb->msgout_buf, srb->msgin_buf, 4);
                srb->msg_count = 4;
                srb->state |= SRB_DO_WIDE_NEGO;
                DC395x_ENABLE_MSGOUT;
        }

        dcb->sync_mode |= (WIDE_NEGO_ENABLE | WIDE_NEGO_DONE);
        if (srb->msgin_buf[3] > 0)
                dcb->sync_period |= WIDE_SYNC;
        else
                dcb->sync_period &= ~WIDE_SYNC;
        srb->state &= ~SRB_DO_WIDE_NEGO;
        /*dcb->sync_mode &= ~(WIDE_NEGO_ENABLE+WIDE_NEGO_DONE); */
        dprintkdbg(DBG_1,
                "msgin_set_wide: Wide (%i bit) negotiated <%02i>\n",
                (8 << srb->msgin_buf[3]), dcb->target_id);
        reprogram_regs(acb, dcb);
        if ((dcb->sync_mode & SYNC_NEGO_ENABLE)
            && !(dcb->sync_mode & SYNC_NEGO_DONE)) {
                build_sdtr(acb, dcb, srb);
                DC395x_ENABLE_MSGOUT;
                dprintkdbg(DBG_0, "msgin_set_wide: Also try SDTR.\n");
        }
}


/*
 * extended message codes:
 *
 *      code    description
 *
 *      02h     Reserved
 *      00h     MODIFY DATA  POINTER
 *      01h     SYNCHRONOUS DATA TRANSFER REQUEST
 *      03h     WIDE DATA TRANSFER REQUEST
 *   04h - 7Fh  Reserved
 *   80h - FFh  Vendor specific
 */
static void msgin_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        struct DeviceCtlBlk *dcb = acb->active_dcb;
        dprintkdbg(DBG_0, "msgin_phase0: (0x%p)\n", srb->cmd);

        srb->msgin_buf[acb->msg_len++] = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
        if (msgin_completed(srb->msgin_buf, acb->msg_len)) {
                /* Now eval the msg */
                switch (srb->msgin_buf[0]) {
                case DISCONNECT:
                        srb->state = SRB_DISCONNECT;
                        break;

                case SIMPLE_QUEUE_TAG:
                case HEAD_OF_QUEUE_TAG:
                case ORDERED_QUEUE_TAG:
                        srb =
                            msgin_qtag(acb, dcb,
                                              srb->msgin_buf[1]);
                        break;

                case MESSAGE_REJECT:
                        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL,
                                       DO_CLRATN | DO_DATALATCH);
                        /* A sync nego message was rejected ! */
                        if (srb->state & SRB_DO_SYNC_NEGO) {
                                msgin_set_async(acb, srb);
                                break;
                        }
                        /* A wide nego message was rejected ! */
                        if (srb->state & SRB_DO_WIDE_NEGO) {
                                msgin_set_nowide(acb, srb);
                                break;
                        }
                        enable_msgout_abort(acb, srb);
                        /*srb->state |= SRB_ABORT_SENT */
                        break;

                case EXTENDED_MESSAGE:
                        /* SDTR */
                        if (srb->msgin_buf[1] == 3
                            && srb->msgin_buf[2] == EXTENDED_SDTR) {
                                msgin_set_sync(acb, srb);
                                break;
                        }
                        /* WDTR */
                        if (srb->msgin_buf[1] == 2
                            && srb->msgin_buf[2] == EXTENDED_WDTR
                            && srb->msgin_buf[3] <= 2) { /* sanity check ... */
                                msgin_set_wide(acb, srb);
                                break;
                        }
                        msgin_reject(acb, srb);
                        break;

                case MSG_IGNOREWIDE:
                        /* Discard  wide residual */
                        dprintkdbg(DBG_0, "msgin_phase0: Ignore Wide Residual!\n");
                        break;

                case COMMAND_COMPLETE:
                        /* nothing has to be done */
                        break;

                case SAVE_POINTERS:
                        /*
                         * SAVE POINTER may be ignored as we have the struct
                         * ScsiReqBlk* associated with the scsi command.
                         */
                        dprintkdbg(DBG_0, "msgin_phase0: (0x%p) "
                                "SAVE POINTER rem=%i Ignore\n",
                                srb->cmd, srb->total_xfer_length);
                        break;

                case RESTORE_POINTERS:
                        dprintkdbg(DBG_0, "msgin_phase0: RESTORE POINTER. Ignore\n");
                        break;

                case ABORT:
                        dprintkdbg(DBG_0, "msgin_phase0: (0x%p) "
                                "<%02i-%i> ABORT msg\n",
                                srb->cmd, dcb->target_id,
                                dcb->target_lun);
                        dcb->flag |= ABORT_DEV_;
                        enable_msgout_abort(acb, srb);
                        break;

                default:
                        /* reject unknown messages */
                        if (srb->msgin_buf[0] & IDENTIFY_BASE) {
                                dprintkdbg(DBG_0, "msgin_phase0: Identify msg\n");
                                srb->msg_count = 1;
                                srb->msgout_buf[0] = dcb->identify_msg;
                                DC395x_ENABLE_MSGOUT;
                                srb->state |= SRB_MSGOUT;
                                /*break; */
                        }
                        msgin_reject(acb, srb);
                }

                /* Clear counter and MsgIn state */
                srb->state &= ~SRB_MSGIN;
                acb->msg_len = 0;
        }
        *pscsi_status = PH_BUS_FREE;
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important ... you know! */
        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_MSGACCEPT);
}


static void msgin_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
        dprintkdbg(DBG_0, "msgin_phase1: (0x%p)\n", srb->cmd);
        clear_fifo(acb, "msgin_phase1");
        DC395x_write32(acb, TRM_S1040_SCSI_COUNTER, 1);
        if (!(srb->state & SRB_MSGIN)) {
                srb->state &= ~SRB_DISCONNECT;
                srb->state |= SRB_MSGIN;
        }
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_DATALATCH);      /* it's important for atn stop */
        /* SCSI command */
        DC395x_write8(acb, TRM_S1040_SCSI_COMMAND, SCMD_FIFO_IN);
}


static void nop0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
}


static void nop1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                u16 *pscsi_status)
{
}


static void set_xfer_rate(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb)
{
        struct DeviceCtlBlk *i;

        /* set all lun device's  period, offset */
        if (dcb->identify_msg & 0x07)
                return;

        if (acb->scan_devices) {
                current_sync_offset = dcb->sync_offset;
                return;
        }

        list_for_each_entry(i, &acb->dcb_list, list)
                if (i->target_id == dcb->target_id) {
                        i->sync_period = dcb->sync_period;
                        i->sync_offset = dcb->sync_offset;
                        i->sync_mode = dcb->sync_mode;
                        i->min_nego_period = dcb->min_nego_period;
                }
}


static void disconnect(struct AdapterCtlBlk *acb)
{
        struct DeviceCtlBlk *dcb = acb->active_dcb;
        struct ScsiReqBlk *srb;

        if (!dcb) {
                dprintkl(KERN_ERR, "disconnect: No such device\n");
                udelay(500);
                /* Suspend queue for a while */
                acb->last_reset =
                    jiffies + HZ / 2 +
                    HZ * acb->eeprom.delay_time;
                clear_fifo(acb, "disconnectEx");
                DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_HWRESELECT);
                return;
        }
        srb = dcb->active_srb;
        acb->active_dcb = NULL;
        dprintkdbg(DBG_0, "disconnect: (0x%p)\n", srb->cmd);

        srb->scsi_phase = PH_BUS_FREE;  /* initial phase */
        clear_fifo(acb, "disconnect");
        DC395x_write16(acb, TRM_S1040_SCSI_CONTROL, DO_HWRESELECT);
        if (srb->state & SRB_UNEXPECT_RESEL) {
                dprintkl(KERN_ERR,
                        "disconnect: Unexpected reselection <%02i-%i>\n",
                        dcb->target_id, dcb->target_lun);
                srb->state = 0;
                waiting_process_next(acb);
        } else if (srb->state & SRB_ABORT_SENT) {
                dcb->flag &= ~ABORT_DEV_;
                acb->last_reset = jiffies + HZ / 2 + 1;
                dprintkl(KERN_ERR, "disconnect: SRB_ABORT_SENT\n");
                doing_srb_done(acb, DID_ABORT, srb->cmd, 1);
                waiting_process_next(acb);
        } else {
                if ((srb->state & (SRB_START_ + SRB_MSGOUT))
                    || !(srb->
                         state & (SRB_DISCONNECT + SRB_COMPLETED))) {
                        /*
                         * Selection time out 
                         * SRB_START_ || SRB_MSGOUT || (!SRB_DISCONNECT && !SRB_COMPLETED)
                         */
                        /* Unexp. Disc / Sel Timeout */
                        if (srb->state != SRB_START_
                            && srb->state != SRB_MSGOUT) {
                                srb->state = SRB_READY;
                                dprintkl(KERN_DEBUG,
                                        "disconnect: (0x%p) Unexpected\n",
                                        srb->cmd);
                                srb->target_status = SCSI_STAT_SEL_TIMEOUT;
                                goto disc1;
                        } else {
                                /* Normal selection timeout */
                                dprintkdbg(DBG_KG, "disconnect: (0x%p) "
                                        "<%02i-%i> SelTO\n", srb->cmd,
                                        dcb->target_id, dcb->target_lun);
                                if (srb->retry_count++ > DC395x_MAX_RETRIES
                                    || acb->scan_devices) {
                                        srb->target_status =
                                            SCSI_STAT_SEL_TIMEOUT;
                                        goto disc1;
                                }
                                free_tag(dcb, srb);
                                list_move(&srb->list, &dcb->srb_waiting_list);
                                dprintkdbg(DBG_KG,
                                        "disconnect: (0x%p) Retry\n",
                                        srb->cmd);
                                waiting_set_timer(acb, HZ / 20);
                        }
                } else if (srb->state & SRB_DISCONNECT) {
                        u8 bval = DC395x_read8(acb, TRM_S1040_SCSI_SIGNAL);
                        /*
                         * SRB_DISCONNECT (This is what we expect!)
                         */
                        if (bval & 0x40) {
                                dprintkdbg(DBG_0, "disconnect: SCSI bus stat "
                                        " 0x%02x: ACK set! Other controllers?\n",