/*+M*************************************************************************
 * Adaptec AIC7xxx device driver for Linux.
 *
 * Copyright (c) 1994 John Aycock
 *   The University of Calgary Department of Computer Science.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Sources include the Adaptec 1740 driver (aha1740.c), the Ultrastor 24F
 * driver (ultrastor.c), various Linux kernel source, the Adaptec EISA
 * config file (!adp7771.cfg), the Adaptec AHA-2740A Series User's Guide,
 * the Linux Kernel Hacker's Guide, Writing a SCSI Device Driver for Linux,
 * the Adaptec 1542 driver (aha1542.c), the Adaptec EISA overlay file
 * (adp7770.ovl), the Adaptec AHA-2740 Series Technical Reference Manual,
 * the Adaptec AIC-7770 Data Book, the ANSI SCSI specification, the
 * ANSI SCSI-2 specification (draft 10c), ...
 *
 * --------------------------------------------------------------------------
 *
 *  Modifications by Daniel M. Eischen (deischen@iworks.InterWorks.org):
 *
 *  Substantially modified to include support for wide and twin bus
 *  adapters, DMAing of SCBs, tagged queueing, IRQ sharing, bug fixes,
 *  SCB paging, and other rework of the code.
 *
 *  Parts of this driver were also based on the FreeBSD driver by
 *  Justin T. Gibbs.  His copyright follows:
 *
 * --------------------------------------------------------------------------  
 * Copyright (c) 1994-1997 Justin Gibbs.
 * All rights reserved.
 *
 * 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,
 *    without modification, immediately at the beginning of the file.
 * 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.
 *
 * Where this Software is combined with software released under the terms of 
 * the GNU General Public License ("GPL") and the terms of the GPL would require the 
 * combined work to also be released under the terms of the GPL, the terms
 * and conditions of this License will apply in addition to those of the
 * GPL with the exception of any terms or conditions of this License that
 * conflict with, or are expressly prohibited by, the GPL.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 *
 *      $Id: aic7xxx.c,v 1.119 1997/06/27 19:39:18 gibbs Exp $
 *---------------------------------------------------------------------------
 *
 *  Thanks also go to (in alphabetical order) the following:
 *
 *    Rory Bolt     - Sequencer bug fixes
 *    Jay Estabrook - Initial DEC Alpha support
 *    Doug Ledford  - Much needed abort/reset bug fixes
 *    Kai Makisara  - DMAing of SCBs
 *
 *  A Boot time option was also added for not resetting the scsi bus.
 *
 *    Form:  aic7xxx=extended
 *           aic7xxx=no_reset
 *           aic7xxx=ultra
 *           aic7xxx=irq_trigger:[0,1]  # 0 edge, 1 level
 *           aic7xxx=verbose
 *
 *  Daniel M. Eischen, deischen@iworks.InterWorks.org, 1/23/97
 *
 *  $Id: aic7xxx.c,v 4.1 1997/06/12 08:23:42 deang Exp $
 *-M*************************************************************************/

/*+M**************************************************************************
 *
 * Further driver modifications made by Doug Ledford <dledford@redhat.com>
 *
 * Copyright (c) 1997-1999 Doug Ledford
 *
 * These changes are released under the same licensing terms as the FreeBSD
 * driver written by Justin Gibbs.  Please see his Copyright notice above
 * for the exact terms and conditions covering my changes as well as the
 * warranty statement.
 *
 * Modifications made to the aic7xxx.c,v 4.1 driver from Dan Eischen include
 * but are not limited to:
 *
 *  1: Import of the latest FreeBSD sequencer code for this driver
 *  2: Modification of kernel code to accommodate different sequencer semantics
 *  3: Extensive changes throughout kernel portion of driver to improve
 *     abort/reset processing and error hanndling
 *  4: Other work contributed by various people on the Internet
 *  5: Changes to printk information and verbosity selection code
 *  6: General reliability related changes, especially in IRQ management
 *  7: Modifications to the default probe/attach order for supported cards
 *  8: SMP friendliness has been improved
 *
 * Overall, this driver represents a significant departure from the official
 * aic7xxx driver released by Dan Eischen in two ways.  First, in the code
 * itself.  A diff between the two version of the driver is now a several
 * thousand line diff.  Second, in approach to solving the same problem.  The
 * problem is importing the FreeBSD aic7xxx driver code to linux can be a
 * difficult and time consuming process, that also can be error prone.  Dan
 * Eischen's official driver uses the approach that the linux and FreeBSD
 * drivers should be as identical as possible.  To that end, his next version
 * of this driver will be using a mid-layer code library that he is developing
 * to moderate communications between the linux mid-level SCSI code and the
 * low level FreeBSD driver.  He intends to be able to essentially drop the
 * FreeBSD driver into the linux kernel with only a few minor tweaks to some
 * include files and the like and get things working, making for fast easy
 * imports of the FreeBSD code into linux.
 *
 * I disagree with Dan's approach.  Not that I don't think his way of doing
 * things would be nice, easy to maintain, and create a more uniform driver
 * between FreeBSD and Linux.  I have no objection to those issues.  My
 * disagreement is on the needed functionality.  There simply are certain
 * things that are done differently in FreeBSD than linux that will cause
 * problems for this driver regardless of any middle ware Dan implements.
 * The biggest example of this at the moment is interrupt semantics.  Linux
 * doesn't provide the same protection techniques as FreeBSD does, nor can
 * they be easily implemented in any middle ware code since they would truly
 * belong in the kernel proper and would effect all drivers.  For the time
 * being, I see issues such as these as major stumbling blocks to the 
 * reliability of code based upon such middle ware.  Therefore, I choose to
 * use a different approach to importing the FreeBSD code that doesn't
 * involve any middle ware type code.  My approach is to import the sequencer
 * code from FreeBSD wholesale.  Then, to only make changes in the kernel
 * portion of the driver as they are needed for the new sequencer semantics.
 * In this way, the portion of the driver that speaks to the rest of the
 * linux kernel is fairly static and can be changed/modified to solve
 * any problems one might encounter without concern for the FreeBSD driver.
 *
 * Note: If time and experience should prove me wrong that the middle ware
 * code Dan writes is reliable in its operation, then I'll retract my above
 * statements.  But, for those that don't know, I'm from Missouri (in the US)
 * and our state motto is "The Show-Me State".  Well, before I will put
 * faith into it, you'll have to show me that it works :)
 *
 *_M*************************************************************************/

/*
 * The next three defines are user configurable.  These should be the only
 * defines a user might need to get in here and change.  There are other
 * defines buried deeper in the code, but those really shouldn't need touched
 * under normal conditions.
 */

/*
 * AIC7XXX_STRICT_PCI_SETUP
 *   Should we assume the PCI config options on our controllers are set with
 *   sane and proper values, or should we be anal about our PCI config
 *   registers and force them to what we want?  The main advantage to
 *   defining this option is on non-Intel hardware where the BIOS may not
 *   have been run to set things up, or if you have one of the BIOSless
 *   Adaptec controllers, such as a 2910, that don't get set up by the
 *   BIOS.  However, keep in mind that we really do set the most important
 *   items in the driver regardless of this setting, this only controls some
 *   of the more esoteric PCI options on these cards.  In that sense, I
 *   would default to leaving this off.  However, if people wish to try
 *   things both ways, that would also help me to know if there are some
 *   machines where it works one way but not another.
 *
 *   -- July 7, 17:09
 *     OK...I need this on my machine for testing, so the default is to
 *     leave it defined.
 *
 *   -- July 7, 18:49
 *     I needed it for testing, but it didn't make any difference, so back
 *     off she goes.
 *
 *   -- July 16, 23:04
 *     I turned it back on to try and compensate for the 2.1.x PCI code
 *     which no longer relies solely on the BIOS and now tries to set
 *     things itself.
 */

#define AIC7XXX_STRICT_PCI_SETUP

/*
 * AIC7XXX_VERBOSE_DEBUGGING
 *   This option enables a lot of extra printk();s in the code, surrounded
 *   by if (aic7xxx_verbose ...) statements.  Executing all of those if
 *   statements and the extra checks can get to where it actually does have
 *   an impact on CPU usage and such, as well as code size.  Disabling this
 *   define will keep some of those from becoming part of the code.
 *
 *   NOTE:  Currently, this option has no real effect, I will be adding the
 *   various #ifdef's in the code later when I've decided a section is
 *   complete and no longer needs debugging.  OK...a lot of things are now
 *   surrounded by this define, so turning this off does have an impact.
 */
 
/*
 * #define AIC7XXX_VERBOSE_DEBUGGING
 */
 
#include <linux/module.h>
#include <stdarg.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/byteorder.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include "scsi.h"
#include <scsi/scsi_host.h>
#include "aic7xxx_old/aic7xxx.h"

#include "aic7xxx_old/sequencer.h"
#include "aic7xxx_old/scsi_message.h"
#include "aic7xxx_old/aic7xxx_reg.h"
#include <scsi/scsicam.h>

#include <linux/stat.h>
#include <linux/slab.h>        /* for kmalloc() */

#define AIC7XXX_C_VERSION  "5.2.6"

#define ALL_TARGETS -1
#define ALL_CHANNELS -1
#define ALL_LUNS -1
#define MAX_TARGETS  16
#define MAX_LUNS     8
#ifndef TRUE
#  define TRUE 1
#endif
#ifndef FALSE
#  define FALSE 0
#endif

#if defined(__powerpc__) || defined(__i386__) || defined(__x86_64__)
#  define MMAPIO
#endif

/*
 * You can try raising me for better performance or lowering me if you have
 * flaky devices that go off the scsi bus when hit with too many tagged
 * commands (like some IBM SCSI-3 LVD drives).
 */
#define AIC7XXX_CMDS_PER_DEVICE 32

typedef struct
{
  unsigned char tag_commands[16];   /* Allow for wide/twin adapters. */
} adapter_tag_info_t;

/*
 * Make a define that will tell the driver not to the default tag depth
 * everywhere.
 */
#define DEFAULT_TAG_COMMANDS {0, 0, 0, 0, 0, 0, 0, 0,\
                              0, 0, 0, 0, 0, 0, 0, 0}

/*
 * Modify this as you see fit for your system.  By setting tag_commands
 * to 0, the driver will use it's own algorithm for determining the
 * number of commands to use (see above).  When 255, the driver will
 * not enable tagged queueing for that particular device.  When positive
 * (> 0) and (< 255) the values in the array are used for the queue_depth.
 * Note that the maximum value for an entry is 254, but you're insane if
 * you try to use that many commands on one device.
 *
 * In this example, the first line will disable tagged queueing for all
 * the devices on the first probed aic7xxx adapter.
 *
 * The second line enables tagged queueing with 4 commands/LUN for IDs
 * (1, 2-11, 13-15), disables tagged queueing for ID 12, and tells the
 * driver to use its own algorithm for ID 1.
 *
 * The third line is the same as the first line.
 *
 * The fourth line disables tagged queueing for devices 0 and 3.  It
 * enables tagged queueing for the other IDs, with 16 commands/LUN
 * for IDs 1 and 4, 127 commands/LUN for ID 8, and 4 commands/LUN for
 * IDs 2, 5-7, and 9-15.
 */

/*
 * NOTE: The below structure is for reference only, the actual structure
 *       to modify in order to change things is found after this fake one.
 *
adapter_tag_info_t aic7xxx_tag_info[] =
{
  {DEFAULT_TAG_COMMANDS},
  {{4, 0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 255, 4, 4, 4}},
  {DEFAULT_TAG_COMMANDS},
  {{255, 16, 4, 255, 16, 4, 4, 4, 127, 4, 4, 4, 4, 4, 4, 4}}
};
*/

static adapter_tag_info_t aic7xxx_tag_info[] =
{
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS},
  {DEFAULT_TAG_COMMANDS}
};


/*
 * Define an array of board names that can be indexed by aha_type.
 * Don't forget to change this when changing the types!
 */
static const char *board_names[] = {
  "AIC-7xxx Unknown",                                   /* AIC_NONE */
  "Adaptec AIC-7810 Hardware RAID Controller",          /* AIC_7810 */
  "Adaptec AIC-7770 SCSI host adapter",                 /* AIC_7770 */
  "Adaptec AHA-274X SCSI host adapter",                 /* AIC_7771 */
  "Adaptec AHA-284X SCSI host adapter",                 /* AIC_284x */
  "Adaptec AIC-7850 SCSI host adapter",                 /* AIC_7850 */
  "Adaptec AIC-7855 SCSI host adapter",                 /* AIC_7855 */
  "Adaptec AIC-7860 Ultra SCSI host adapter",           /* AIC_7860 */
  "Adaptec AHA-2940A Ultra SCSI host adapter",          /* AIC_7861 */
  "Adaptec AIC-7870 SCSI host adapter",                 /* AIC_7870 */
  "Adaptec AHA-294X SCSI host adapter",                 /* AIC_7871 */
  "Adaptec AHA-394X SCSI host adapter",                 /* AIC_7872 */
  "Adaptec AHA-398X SCSI host adapter",                 /* AIC_7873 */
  "Adaptec AHA-2944 SCSI host adapter",                 /* AIC_7874 */
  "Adaptec AIC-7880 Ultra SCSI host adapter",           /* AIC_7880 */
  "Adaptec AHA-294X Ultra SCSI host adapter",           /* AIC_7881 */
  "Adaptec AHA-394X Ultra SCSI host adapter",           /* AIC_7882 */
  "Adaptec AHA-398X Ultra SCSI host adapter",           /* AIC_7883 */
  "Adaptec AHA-2944 Ultra SCSI host adapter",           /* AIC_7884 */
  "Adaptec AHA-2940UW Pro Ultra SCSI host adapter",     /* AIC_7887 */
  "Adaptec AIC-7895 Ultra SCSI host adapter",           /* AIC_7895 */
  "Adaptec AIC-7890/1 Ultra2 SCSI host adapter",        /* AIC_7890 */
  "Adaptec AHA-293X Ultra2 SCSI host adapter",          /* AIC_7890 */
  "Adaptec AHA-294X Ultra2 SCSI host adapter",          /* AIC_7890 */
  "Adaptec AIC-7896/7 Ultra2 SCSI host adapter",        /* AIC_7896 */
  "Adaptec AHA-394X Ultra2 SCSI host adapter",          /* AIC_7897 */
  "Adaptec AHA-395X Ultra2 SCSI host adapter",          /* AIC_7897 */
  "Adaptec PCMCIA SCSI controller",                     /* card bus stuff */
  "Adaptec AIC-7892 Ultra 160/m SCSI host adapter",     /* AIC_7892 */
  "Adaptec AIC-7899 Ultra 160/m SCSI host adapter",     /* AIC_7899 */
};

/*
 * There should be a specific return value for this in scsi.h, but
 * it seems that most drivers ignore it.
 */
#define DID_UNDERFLOW   DID_ERROR

/*
 *  What we want to do is have the higher level scsi driver requeue
 *  the command to us. There is no specific driver status for this
 *  condition, but the higher level scsi driver will requeue the
 *  command on a DID_BUS_BUSY error.
 *
 *  Upon further inspection and testing, it seems that DID_BUS_BUSY
 *  will *always* retry the command.  We can get into an infinite loop
 *  if this happens when we really want some sort of counter that
 *  will automatically abort/reset the command after so many retries.
 *  Using DID_ERROR will do just that.  (Made by a suggestion by
 *  Doug Ledford 8/1/96)
 */
#define DID_RETRY_COMMAND DID_ERROR

#define HSCSIID        0x07
#define SCSI_RESET     0x040

/*
 * EISA/VL-bus stuff
 */
#define MINSLOT                1
#define MAXSLOT                15
#define SLOTBASE(x)        ((x) << 12)
#define BASE_TO_SLOT(x) ((x) >> 12)

/*
 * Standard EISA Host ID regs  (Offset from slot base)
 */
#define AHC_HID0              0x80   /* 0,1: msb of ID2, 2-7: ID1      */
#define AHC_HID1              0x81   /* 0-4: ID3, 5-7: LSB ID2         */
#define AHC_HID2              0x82   /* product                        */
#define AHC_HID3              0x83   /* firmware revision              */

/*
 * AIC-7770 I/O range to reserve for a card
 */
#define MINREG                0xC00
#define MAXREG                0xCFF

#define INTDEF                0x5C      /* Interrupt Definition Register */

/*
 * AIC-78X0 PCI registers
 */
#define        CLASS_PROGIF_REVID        0x08
#define                DEVREVID        0x000000FFul
#define                PROGINFC        0x0000FF00ul
#define                SUBCLASS        0x00FF0000ul
#define                BASECLASS        0xFF000000ul

#define        CSIZE_LATTIME                0x0C
#define                CACHESIZE        0x0000003Ful        /* only 5 bits */
#define                LATTIME                0x0000FF00ul

#define        DEVCONFIG                0x40
#define                SCBSIZE32        0x00010000ul        /* aic789X only */
#define                MPORTMODE        0x00000400ul        /* aic7870 only */
#define                RAMPSM           0x00000200ul        /* aic7870 only */
#define                RAMPSM_ULTRA2    0x00000004
#define                VOLSENSE         0x00000100ul
#define                SCBRAMSEL        0x00000080ul
#define                SCBRAMSEL_ULTRA2 0x00000008
#define                MRDCEN           0x00000040ul
#define                EXTSCBTIME       0x00000020ul        /* aic7870 only */
#define                EXTSCBPEN        0x00000010ul        /* aic7870 only */
#define                BERREN           0x00000008ul
#define                DACEN            0x00000004ul
#define                STPWLEVEL        0x00000002ul
#define                DIFACTNEGEN      0x00000001ul        /* aic7870 only */

#define        SCAMCTL                  0x1a                /* Ultra2 only  */
#define        CCSCBBADDR               0xf0                /* aic7895/6/7  */

/*
 * Define the different types of SEEPROMs on aic7xxx adapters
 * and make it also represent the address size used in accessing
 * its registers.  The 93C46 chips have 1024 bits organized into
 * 64 16-bit words, while the 93C56 chips have 2048 bits organized
 * into 128 16-bit words.  The C46 chips use 6 bits to address
 * each word, while the C56 and C66 (4096 bits) use 8 bits to
 * address each word.
 */
typedef enum {C46 = 6, C56_66 = 8} seeprom_chip_type;

/*
 *
 * Define the format of the SEEPROM registers (16 bits).
 *
 */
struct seeprom_config {

/*
 * SCSI ID Configuration Flags
 */
#define CFXFER                0x0007      /* synchronous transfer rate */
#define CFSYNCH               0x0008      /* enable synchronous transfer */
#define CFDISC                0x0010      /* enable disconnection */
#define CFWIDEB               0x0020      /* wide bus device (wide card) */
#define CFSYNCHISULTRA        0x0040      /* CFSYNC is an ultra offset */
#define CFNEWULTRAFORMAT      0x0080      /* Use the Ultra2 SEEPROM format */
#define CFSTART               0x0100      /* send start unit SCSI command */
#define CFINCBIOS             0x0200      /* include in BIOS scan */
#define CFRNFOUND             0x0400      /* report even if not found */
#define CFMULTILUN            0x0800      /* probe mult luns in BIOS scan */
#define CFWBCACHEYES          0x4000      /* Enable W-Behind Cache on drive */
#define CFWBCACHENC           0xc000      /* Don't change W-Behind Cache */
/* UNUSED                0x3000 */
  unsigned short device_flags[16];        /* words 0-15 */

/*
 * BIOS Control Bits
 */
#define CFSUPREM        0x0001  /* support all removable drives */
#define CFSUPREMB       0x0002  /* support removable drives for boot only */
#define CFBIOSEN        0x0004  /* BIOS enabled */
/* UNUSED                0x0008 */
#define CFSM2DRV        0x0010  /* support more than two drives */
#define CF284XEXTEND    0x0020  /* extended translation (284x cards) */
/* UNUSED                0x0040 */
#define CFEXTEND        0x0080  /* extended translation enabled */
/* UNUSED                0xFF00 */
  unsigned short bios_control;  /* word 16 */

/*
 * Host Adapter Control Bits
 */
#define CFAUTOTERM      0x0001  /* Perform Auto termination */
#define CFULTRAEN       0x0002  /* Ultra SCSI speed enable (Ultra cards) */
#define CF284XSELTO     0x0003  /* Selection timeout (284x cards) */
#define CF284XFIFO      0x000C  /* FIFO Threshold (284x cards) */
#define CFSTERM         0x0004  /* SCSI low byte termination */
#define CFWSTERM        0x0008  /* SCSI high byte termination (wide card) */
#define CFSPARITY       0x0010  /* SCSI parity */
#define CF284XSTERM     0x0020  /* SCSI low byte termination (284x cards) */
#define CFRESETB        0x0040  /* reset SCSI bus at boot */
#define CFBPRIMARY      0x0100  /* Channel B primary on 7895 chipsets */
#define CFSEAUTOTERM    0x0400  /* aic7890 Perform SE Auto Term */
#define CFLVDSTERM      0x0800  /* aic7890 LVD Termination */
/* UNUSED                0xF280 */
  unsigned short adapter_control;        /* word 17 */

/*
 * Bus Release, Host Adapter ID
 */
#define CFSCSIID        0x000F                /* host adapter SCSI ID */
/* UNUSED                0x00F0 */
#define CFBRTIME        0xFF00                /* bus release time */
  unsigned short brtime_id;                /* word 18 */

/*
 * Maximum targets
 */
#define CFMAXTARG        0x00FF        /* maximum targets */
/* UNUSED                0xFF00 */
  unsigned short max_targets;                /* word 19 */

  unsigned short res_1[11];                /* words 20-30 */
  unsigned short checksum;                /* word 31 */
};

#define SELBUS_MASK                0x0a
#define         SELNARROW        0x00
#define         SELBUSB                0x08
#define SINGLE_BUS                0x00

#define SCB_TARGET(scb)         \
       (((scb)->hscb->target_channel_lun & TID) >> 4)
#define SCB_LUN(scb)            \
       ((scb)->hscb->target_channel_lun & LID)
#define SCB_IS_SCSIBUS_B(scb)   \
       (((scb)->hscb->target_channel_lun & SELBUSB) != 0)

/*
 * If an error occurs during a data transfer phase, run the command
 * to completion - it's easier that way - making a note of the error
 * condition in this location. This then will modify a DID_OK status
 * into an appropriate error for the higher-level SCSI code.
 */
#define aic7xxx_error(cmd)        ((cmd)->SCp.Status)

/*
 * Keep track of the targets returned status.
 */
#define aic7xxx_status(cmd)        ((cmd)->SCp.sent_command)

/*
 * The position of the SCSI commands scb within the scb array.
 */
#define aic7xxx_position(cmd)        ((cmd)->SCp.have_data_in)

/*
 * The stored DMA mapping for single-buffer data transfers.
 */
#define aic7xxx_mapping(cmd)         ((cmd)->SCp.phase)

/*
 * Get out private data area from a scsi cmd pointer
 */
#define AIC_DEV(cmd)    ((struct aic_dev_data *)(cmd)->device->hostdata)

/*
 * So we can keep track of our host structs
 */
static struct aic7xxx_host *first_aic7xxx = NULL;

/*
 * As of Linux 2.1, the mid-level SCSI code uses virtual addresses
 * in the scatter-gather lists.  We need to convert the virtual
 * addresses to physical addresses.
 */
struct hw_scatterlist {
  unsigned int address;
  unsigned int length;
};

/*
 * Maximum number of SG segments these cards can support.
 */
#define        AIC7XXX_MAX_SG 128

/*
 * The maximum number of SCBs we could have for ANY type
 * of card. DON'T FORGET TO CHANGE THE SCB MASK IN THE
 * SEQUENCER CODE IF THIS IS MODIFIED!
 */
#define AIC7XXX_MAXSCB        255


struct aic7xxx_hwscb {
/* ------------    Begin hardware supported fields    ---------------- */
/* 0*/  unsigned char control;
/* 1*/  unsigned char target_channel_lun;       /* 4/1/3 bits */
/* 2*/  unsigned char target_status;
/* 3*/  unsigned char SG_segment_count;
/* 4*/  unsigned int  SG_list_pointer;
/* 8*/  unsigned char residual_SG_segment_count;
/* 9*/  unsigned char residual_data_count[3];
/*12*/  unsigned int  data_pointer;
/*16*/  unsigned int  data_count;
/*20*/  unsigned int  SCSI_cmd_pointer;
/*24*/  unsigned char SCSI_cmd_length;
/*25*/  unsigned char tag;          /* Index into our kernel SCB array.
                                     * Also used as the tag for tagged I/O
                                     */
#define SCB_PIO_TRANSFER_SIZE  26   /* amount we need to upload/download
                                     * via PIO to initialize a transaction.
                                     */
/*26*/  unsigned char next;         /* Used to thread SCBs awaiting selection
                                     * or disconnected down in the sequencer.
                                     */
/*27*/  unsigned char prev;
/*28*/  unsigned int pad;           /*
                                     * Unused by the kernel, but we require
                                     * the padding so that the array of
                                     * hardware SCBs is aligned on 32 byte
                                     * boundaries so the sequencer can index
                                     */
};

typedef enum {
        SCB_FREE                = 0x0000,
        SCB_DTR_SCB             = 0x0001,
        SCB_WAITINGQ            = 0x0002,
        SCB_ACTIVE              = 0x0004,
        SCB_SENSE               = 0x0008,
        SCB_ABORT               = 0x0010,
        SCB_DEVICE_RESET        = 0x0020,
        SCB_RESET               = 0x0040,
        SCB_RECOVERY_SCB        = 0x0080,
        SCB_MSGOUT_PPR          = 0x0100,
        SCB_MSGOUT_SENT         = 0x0200,
        SCB_MSGOUT_SDTR         = 0x0400,
        SCB_MSGOUT_WDTR         = 0x0800,
        SCB_MSGOUT_BITS         = SCB_MSGOUT_PPR |
                                  SCB_MSGOUT_SENT | 
                                  SCB_MSGOUT_SDTR |
                                  SCB_MSGOUT_WDTR,
        SCB_QUEUED_ABORT        = 0x1000,
        SCB_QUEUED_FOR_DONE     = 0x2000,
        SCB_WAS_BUSY            = 0x4000,
        SCB_QUEUE_FULL          = 0x8000
} scb_flag_type;

typedef enum {
        AHC_FNONE                 = 0x00000000,
        AHC_PAGESCBS              = 0x00000001,
        AHC_CHANNEL_B_PRIMARY     = 0x00000002,
        AHC_USEDEFAULTS           = 0x00000004,
        AHC_INDIRECT_PAGING       = 0x00000008,
        AHC_CHNLB                 = 0x00000020,
        AHC_CHNLC                 = 0x00000040,
        AHC_EXTEND_TRANS_A        = 0x00000100,
        AHC_EXTEND_TRANS_B        = 0x00000200,
        AHC_TERM_ENB_A            = 0x00000400,
        AHC_TERM_ENB_SE_LOW       = 0x00000400,
        AHC_TERM_ENB_B            = 0x00000800,
        AHC_TERM_ENB_SE_HIGH      = 0x00000800,
        AHC_HANDLING_REQINITS     = 0x00001000,
        AHC_TARGETMODE            = 0x00002000,
        AHC_NEWEEPROM_FMT         = 0x00004000,
 /*
  *  Here ends the FreeBSD defined flags and here begins the linux defined
  *  flags.  NOTE: I did not preserve the old flag name during this change
  *  specifically to force me to evaluate what flags were being used properly
  *  and what flags weren't.  This way, I could clean up the flag usage on
  *  a use by use basis.  Doug Ledford
  */
        AHC_MOTHERBOARD           = 0x00020000,
        AHC_NO_STPWEN             = 0x00040000,
        AHC_RESET_DELAY           = 0x00080000,
        AHC_A_SCANNED             = 0x00100000,
        AHC_B_SCANNED             = 0x00200000,
        AHC_MULTI_CHANNEL         = 0x00400000,
        AHC_BIOS_ENABLED          = 0x00800000,
        AHC_SEEPROM_FOUND         = 0x01000000,
        AHC_TERM_ENB_LVD          = 0x02000000,
        AHC_ABORT_PENDING         = 0x04000000,
        AHC_RESET_PENDING         = 0x08000000,
#define AHC_IN_ISR_BIT              28
        AHC_IN_ISR                = 0x10000000,
        AHC_IN_ABORT              = 0x20000000,
        AHC_IN_RESET              = 0x40000000,
        AHC_EXTERNAL_SRAM         = 0x80000000
} ahc_flag_type;

typedef enum {
  AHC_NONE             = 0x0000,
  AHC_CHIPID_MASK      = 0x00ff,
  AHC_AIC7770          = 0x0001,
  AHC_AIC7850          = 0x0002,
  AHC_AIC7860          = 0x0003,
  AHC_AIC7870          = 0x0004,
  AHC_AIC7880          = 0x0005,
  AHC_AIC7890          = 0x0006,
  AHC_AIC7895          = 0x0007,
  AHC_AIC7896          = 0x0008,
  AHC_AIC7892          = 0x0009,
  AHC_AIC7899          = 0x000a,
  AHC_VL               = 0x0100,
  AHC_EISA             = 0x0200,
  AHC_PCI              = 0x0400,
} ahc_chip;

typedef enum {
  AHC_FENONE           = 0x0000,
  AHC_ULTRA            = 0x0001,
  AHC_ULTRA2           = 0x0002,
  AHC_WIDE             = 0x0004,
  AHC_TWIN             = 0x0008,
  AHC_MORE_SRAM        = 0x0010,
  AHC_CMD_CHAN         = 0x0020,
  AHC_QUEUE_REGS       = 0x0040,
  AHC_SG_PRELOAD       = 0x0080,
  AHC_SPIOCAP          = 0x0100,
  AHC_ULTRA3           = 0x0200,
  AHC_NEW_AUTOTERM     = 0x0400,
  AHC_AIC7770_FE       = AHC_FENONE,
  AHC_AIC7850_FE       = AHC_SPIOCAP,
  AHC_AIC7860_FE       = AHC_ULTRA|AHC_SPIOCAP,
  AHC_AIC7870_FE       = AHC_FENONE,
  AHC_AIC7880_FE       = AHC_ULTRA,
  AHC_AIC7890_FE       = AHC_MORE_SRAM|AHC_CMD_CHAN|AHC_ULTRA2|
                         AHC_QUEUE_REGS|AHC_SG_PRELOAD|AHC_NEW_AUTOTERM,
  AHC_AIC7895_FE       = AHC_MORE_SRAM|AHC_CMD_CHAN|AHC_ULTRA,
  AHC_AIC7896_FE       = AHC_AIC7890_FE,
  AHC_AIC7892_FE       = AHC_AIC7890_FE|AHC_ULTRA3,
  AHC_AIC7899_FE       = AHC_AIC7890_FE|AHC_ULTRA3,
} ahc_feature;

#define SCB_DMA_ADDR(scb, addr) ((unsigned long)(addr) + (scb)->scb_dma->dma_offset)

struct aic7xxx_scb_dma {
        unsigned long          dma_offset;    /* Correction you have to add
                                               * to virtual address to get
                                               * dma handle in this region */
        dma_addr_t             dma_address;   /* DMA handle of the start,
                                               * for unmap */
        unsigned int           dma_len;       /* DMA length */
};

typedef enum {
  AHC_BUG_NONE            = 0x0000,
  AHC_BUG_TMODE_WIDEODD   = 0x0001,
  AHC_BUG_AUTOFLUSH       = 0x0002,
  AHC_BUG_CACHETHEN       = 0x0004,
  AHC_BUG_CACHETHEN_DIS   = 0x0008,
  AHC_BUG_PCI_2_1_RETRY   = 0x0010,
  AHC_BUG_PCI_MWI         = 0x0020,
  AHC_BUG_SCBCHAN_UPLOAD  = 0x0040,
} ahc_bugs;

struct aic7xxx_scb {
        struct aic7xxx_hwscb    *hscb;          /* corresponding hardware scb */
        struct scsi_cmnd        *cmd;           /* scsi_cmnd for this scb */
        struct aic7xxx_scb      *q_next;        /* next scb in queue */
        volatile scb_flag_type  flags;          /* current state of scb */
        struct hw_scatterlist   *sg_list;       /* SG list in adapter format */
        unsigned char           tag_action;
        unsigned char           sg_count;
        unsigned char           *sense_cmd;     /*
                                                 * Allocate 6 characters for
                                                 * sense command.
                                                 */
        unsigned char           *cmnd;
        unsigned int            sg_length;      /*
                                                 * We init this during
                                                 * buildscb so we don't have
                                                 * to calculate anything during
                                                 * underflow/overflow/stat code
                                                 */
        void                    *kmalloc_ptr;
        struct aic7xxx_scb_dma  *scb_dma;
};

/*
 * Define a linked list of SCBs.
 */
typedef struct {
  struct aic7xxx_scb *head;
  struct aic7xxx_scb *tail;
} scb_queue_type;

static struct {
  unsigned char errno;
  const char *errmesg;
} hard_error[] = {
  { ILLHADDR,  "Illegal Host Access" },
  { ILLSADDR,  "Illegal Sequencer Address referenced" },
  { ILLOPCODE, "Illegal Opcode in sequencer program" },
  { SQPARERR,  "Sequencer Ram Parity Error" },
  { DPARERR,   "Data-Path Ram Parity Error" },
  { MPARERR,   "Scratch Ram/SCB Array Ram Parity Error" },
  { PCIERRSTAT,"PCI Error detected" },
  { CIOPARERR, "CIOBUS Parity Error" }
};

static unsigned char
generic_sense[] = { REQUEST_SENSE, 0, 0, 0, 255, 0 };

typedef struct {
  scb_queue_type free_scbs;        /*
                                    * SCBs assigned to free slot on
                                    * card (no paging required)
                                    */
  struct aic7xxx_scb   *scb_array[AIC7XXX_MAXSCB];
  struct aic7xxx_hwscb *hscbs;
  unsigned char  numscbs;          /* current number of scbs */
  unsigned char  maxhscbs;         /* hardware scbs */
  unsigned char  maxscbs;          /* max scbs including pageable scbs */
  dma_addr_t     hscbs_dma;        /* DMA handle to hscbs */
  unsigned int   hscbs_dma_len;    /* length of the above DMA area */
  void          *hscb_kmalloc_ptr;
} scb_data_type;

struct target_cmd {
  unsigned char mesg_bytes[4];
  unsigned char command[28];
};

#define AHC_TRANS_CUR    0x0001
#define AHC_TRANS_ACTIVE 0x0002
#define AHC_TRANS_GOAL   0x0004
#define AHC_TRANS_USER   0x0008
#define AHC_TRANS_QUITE  0x0010
typedef struct {
  unsigned char width;
  unsigned char period;
  unsigned char offset;
  unsigned char options;
} transinfo_type;

struct aic_dev_data {
  volatile scb_queue_type  delayed_scbs;
  volatile unsigned short  temp_q_depth;
  unsigned short           max_q_depth;
  volatile unsigned char   active_cmds;
  /*
   * Statistics Kept:
   *
   * Total Xfers (count for each command that has a data xfer),
   * broken down by reads && writes.
   *
   * Further sorted into a few bins for keeping tabs on how many commands
   * we get of various sizes.
   *
   */
  long w_total;                          /* total writes */
  long r_total;                          /* total reads */
  long barrier_total;                    /* total num of REQ_BARRIER commands */
  long ordered_total;                    /* How many REQ_BARRIER commands we
                                            used ordered tags to satisfy */
  long w_bins[6];                       /* binned write */
  long r_bins[6];                       /* binned reads */
  transinfo_type        cur;
  transinfo_type        goal;
#define  BUS_DEVICE_RESET_PENDING       0x01
#define  DEVICE_RESET_DELAY             0x02
#define  DEVICE_PRINT_DTR               0x04
#define  DEVICE_WAS_BUSY                0x08
#define  DEVICE_DTR_SCANNED             0x10
#define  DEVICE_SCSI_3                  0x20
  volatile unsigned char   flags;
  unsigned needppr:1;
  unsigned needppr_copy:1;
  unsigned needsdtr:1;
  unsigned needsdtr_copy:1;
  unsigned needwdtr:1;
  unsigned needwdtr_copy:1;
  unsigned dtr_pending:1;
  struct scsi_device *SDptr;
  struct list_head list;
};

/*
 * Define a structure used for each host adapter.  Note, in order to avoid
 * problems with architectures I can't test on (because I don't have one,
 * such as the Alpha based systems) which happen to give faults for
 * non-aligned memory accesses, care was taken to align this structure
 * in a way that gauranteed all accesses larger than 8 bits were aligned
 * on the appropriate boundary.  It's also organized to try and be more
 * cache line efficient.  Be careful when changing this lest you might hurt
 * overall performance and bring down the wrath of the masses.
 */
struct aic7xxx_host {
  /*
   *  This is the first 64 bytes in the host struct
   */

  /*
   * We are grouping things here....first, items that get either read or
   * written with nearly every interrupt
   */
        volatile long   flags;
        ahc_feature     features;       /* chip features */
        unsigned long   base;           /* card base address */
        volatile unsigned char  __iomem *maddr; /* memory mapped address */
        unsigned long   isr_count;      /* Interrupt count */
        unsigned long   spurious_int;
        scb_data_type   *scb_data;
        struct aic7xxx_cmd_queue {
                struct scsi_cmnd *head;
                struct scsi_cmnd *tail;
        } completeq;

        /*
        * Things read/written on nearly every entry into aic7xxx_queue()
        */
        volatile scb_queue_type waiting_scbs;
        unsigned char   unpause;        /* unpause value for HCNTRL */
        unsigned char   pause;          /* pause value for HCNTRL */
        volatile unsigned char  qoutfifonext;
        volatile unsigned char  activescbs;     /* active scbs */
        volatile unsigned char  max_activescbs;
        volatile unsigned char  qinfifonext;
        volatile unsigned char  *untagged_scbs;
        volatile unsigned char  *qoutfifo;
        volatile unsigned char  *qinfifo;

        unsigned char   dev_last_queue_full[MAX_TARGETS];
        unsigned char   dev_last_queue_full_count[MAX_TARGETS];
        unsigned short  ultraenb; /* Gets downloaded to card as a bitmap */
        unsigned short  discenable; /* Gets downloaded to card as a bitmap */
        transinfo_type  user[MAX_TARGETS];

        unsigned char   msg_buf[13];    /* The message for the target */
        unsigned char   msg_type;
#define MSG_TYPE_NONE              0x00
#define MSG_TYPE_INITIATOR_MSGOUT  0x01
#define MSG_TYPE_INITIATOR_MSGIN   0x02
        unsigned char   msg_len;        /* Length of message */
        unsigned char   msg_index;      /* Index into msg_buf array */


        /*
         * We put the less frequently used host structure items
         * after the more frequently used items to try and ease
         * the burden on the cache subsystem.
         * These entries are not *commonly* accessed, whereas
         * the preceding entries are accessed very often.
         */

        unsigned int    irq;            /* IRQ for this adapter */
        int             instance;       /* aic7xxx instance number */
        int             scsi_id;        /* host adapter SCSI ID */
        int             scsi_id_b;      /* channel B for twin adapters */
        unsigned int    bios_address;
        int             board_name_index;
        unsigned short  bios_control;           /* bios control - SEEPROM */
        unsigned short  adapter_control;        /* adapter control - SEEPROM */
        struct pci_dev  *pdev;
        unsigned char   pci_bus;
        unsigned char   pci_device_fn;
        struct seeprom_config   sc;
        unsigned short  sc_type;
        unsigned short  sc_size;
        struct aic7xxx_host     *next;  /* allow for multiple IRQs */
        struct Scsi_Host        *host;  /* pointer to scsi host */
        struct list_head         aic_devs; /* all aic_dev structs on host */
        int             host_no;        /* SCSI host number */
        unsigned long   mbase;          /* I/O memory address */
        ahc_chip        chip;           /* chip type */
        ahc_bugs        bugs;
        dma_addr_t      fifo_dma;       /* DMA handle for fifo arrays */
};

/*
 * Valid SCSIRATE values. (p. 3-17)
 * Provides a mapping of transfer periods in ns/4 to the proper value to
 * stick in the SCSIRATE reg to use that transfer rate.
 */
#define AHC_SYNCRATE_ULTRA3 0

#define AHC_SYNCRATE_ULTRA2 1
#define AHC_SYNCRATE_ULTRA  3
#define AHC_SYNCRATE_FAST   6
#define AHC_SYNCRATE_CRC 0x40
#define AHC_SYNCRATE_SE  0x10
static struct aic7xxx_syncrate {
  /* Rates in Ultra mode have bit 8 of sxfr set */
#define                ULTRA_SXFR 0x100
  int sxfr_ultra2;
  int sxfr;
  unsigned char period;
  const char *rate[2];
} aic7xxx_syncrates[] = {
  { 0x42,  0x000,   9,  {"80.0", "160.0"} },
  { 0x13,  0x000,  10,  {"40.0", "80.0"} },
  { 0x14,  0x000,  11,  {"33.0", "66.6"} },
  { 0x15,  0x100,  12,  {"20.0", "40.0"} },
  { 0x16,  0x110,  15,  {"16.0", "32.0"} },
  { 0x17,  0x120,  18,  {"13.4", "26.8"} },
  { 0x18,  0x000,  25,  {"10.0", "20.0"} },
  { 0x19,  0x010,  31,  {"8.0",  "16.0"} },
  { 0x1a,  0x020,  37,  {"6.67", "13.3"} },
  { 0x1b,  0x030,  43,  {"5.7",  "11.4"} },
  { 0x10,  0x040,  50,  {"5.0",  "10.0"} },
  { 0x00,  0x050,  56,  {"4.4",  "8.8" } },
  { 0x00,  0x060,  62,  {"4.0",  "8.0" } },
  { 0x00,  0x070,  68,  {"3.6",  "7.2" } },
  { 0x00,  0x000,  0,   {NULL, NULL}   },
};

#define CTL_OF_SCB(scb) (((scb->hscb)->target_channel_lun >> 3) & 0x1),  \
                        (((scb->hscb)->target_channel_lun >> 4) & 0xf), \
                        ((scb->hscb)->target_channel_lun & 0x07)

#define CTL_OF_CMD(cmd) ((cmd->device->channel) & 0x01),  \
                        ((cmd->device->id) & 0x0f), \
                        ((cmd->device->lun) & 0x07)

#define TARGET_INDEX(cmd)  ((cmd)->device->id | ((cmd)->device->channel << 3))

/*
 * A nice little define to make doing our printks a little easier
 */

#define WARN_LEAD KERN_WARNING "(scsi%d:%d:%d:%d) "
#define INFO_LEAD KERN_INFO "(scsi%d:%d:%d:%d) "

/*
 * XXX - these options apply unilaterally to _all_ 274x/284x/294x
 *       cards in the system.  This should be fixed.  Exceptions to this
 *       rule are noted in the comments.
 */

/*
 * Use this as the default queue depth when setting tagged queueing on.
 */
static unsigned int aic7xxx_default_queue_depth = AIC7XXX_CMDS_PER_DEVICE;

/*
 * Skip the scsi bus reset.  Non 0 make us skip the reset at startup.  This
 * has no effect on any later resets that might occur due to things like
 * SCSI bus timeouts.
 */
static unsigned int aic7xxx_no_reset = 0;
/*
 * Certain PCI motherboards will scan PCI devices from highest to lowest,
 * others scan from lowest to highest, and they tend to do all kinds of
 * strange things when they come into contact with PCI bridge chips.  The
 * net result of all this is that the PCI card that is actually used to boot
 * the machine is very hard to detect.  Most motherboards go from lowest
 * PCI slot number to highest, and the first SCSI controller found is the
 * one you boot from.  The only exceptions to this are when a controller
 * has its BIOS disabled.  So, we by default sort all of our SCSI controllers
 * from lowest PCI slot number to highest PCI slot number.  We also force
 * all controllers with their BIOS disabled to the end of the list.  This
 * works on *almost* all computers.  Where it doesn't work, we have this
 * option.  Setting this option to non-0 will reverse the order of the sort
 * to highest first, then lowest, but will still leave cards with their BIOS
 * disabled at the very end.  That should fix everyone up unless there are
 * really strange cirumstances.
 */
static int aic7xxx_reverse_scan = 0;
/*
 * Should we force EXTENDED translation on a controller.
 *     0 == Use whatever is in the SEEPROM or default to off
 *     1 == Use whatever is in the SEEPROM or default to on
 */
static unsigned int aic7xxx_extended = 0;
/*
 * The IRQ trigger method used on EISA controllers. Does not effect PCI cards.
 *   -1 = Use detected settings.
 *    0 = Force Edge triggered mode.
 *    1 = Force Level triggered mode.
 */
static int aic7xxx_irq_trigger = -1;
/*
 * This variable is used to override the termination settings on a controller.
 * This should not be used under normal conditions.  However, in the case
 * that a controller does not have a readable SEEPROM (so that we can't
 * read the SEEPROM settings directly) and that a controller has a buggered
 * version of the cable detection logic, this can be used to force the 
 * correct termination.  It is preferable to use the manual termination
 * settings in the BIOS if possible, but some motherboard controllers store
 * those settings in a format we can't read.  In other cases, auto term
 * should also work, but the chipset was put together with no auto term
 * logic (common on motherboard controllers).  In those cases, we have
 * 32 bits here to work with.  That's good for 8 controllers/channels.  The
 * bits are organized as 4 bits per channel, with scsi0 getting the lowest
 * 4 bits in the int.  A 1 in a bit position indicates the termination setting
 * that corresponds to that bit should be enabled, a 0 is disabled.
 * It looks something like this:
 *
 *    0x0f =  1111-Single Ended Low Byte Termination on/off
 *            ||\-Single Ended High Byte Termination on/off
 *            |\-LVD Low Byte Termination on/off
 *            \-LVD High Byte Termination on/off
 *
 * For non-Ultra2 controllers, the upper 2 bits are not important.  So, to
 * enable both high byte and low byte termination on scsi0, I would need to
 * make sure that the override_term variable was set to 0x03 (bits 0011).
 * To make sure that all termination is enabled on an Ultra2 controller at
 * scsi2 and only high byte termination on scsi1 and high and low byte
 * termination on scsi0, I would set override_term=0xf23 (bits 1111 0010 0011)
 *
 * For the most part, users should never have to use this, that's why I
 * left it fairly cryptic instead of easy to understand.  If you need it,
 * most likely someone will be telling you what your's needs to be set to.
 */
static int aic7xxx_override_term = -1;
/*
 * Certain motherboard chipset controllers tend to screw
 * up the polarity of the term enable output pin.  Use this variable
 * to force the correct polarity for your system.  This is a bitfield variable
 * similar to the previous one, but this one has one bit per channel instead
 * of four.
 *    0 = Force the setting to active low.
 *    1 = Force setting to active high.
 * Most Adaptec cards are active high, several motherboards are active low.
 * To force a 2940 card at SCSI 0 to active high and a motherboard 7895
 * controller at scsi1 and scsi2 to active low, and a 2910 card at scsi3
 * to active high, you would need to set stpwlev=0x9 (bits 1001).
 *
 * People shouldn't need to use this, but if you are experiencing lots of
 * SCSI timeout problems, this may help.  There is one sure way to test what
 * this option needs to be.  Using a boot floppy to boot the system, configure
 * your system to enable all SCSI termination (in the Adaptec SCSI BIOS) and
 * if needed then also pass a value to override_term to make sure that the
 * driver is enabling SCSI termination, then set this variable to either 0
 * or 1.  When the driver boots, make sure there are *NO* SCSI cables
 * connected to your controller.  If it finds and inits the controller
 * without problem, then the setting you passed to stpwlev was correct.  If
 * the driver goes into a reset loop and hangs the system, then you need the
 * other setting for this variable.  If neither setting lets the machine
 * boot then you have definite termination problems that may not be fixable.
 */
static int aic7xxx_stpwlev = -1;
/*
 * Set this to non-0 in order to force the driver to panic the kernel
 * and print out debugging info on a SCSI abort or reset cycle.
 */
static int aic7xxx_panic_on_abort = 0;
/*
 * PCI bus parity checking of the Adaptec controllers.  This is somewhat
 * dubious at best.  To my knowledge, this option has never actually
 * solved a PCI parity problem, but on certain machines with broken PCI
 * chipset configurations, it can generate tons of false error messages.
 * It's included in the driver for completeness.
 *   0 = Shut off PCI parity check
 *  -1 = Normal polarity pci parity checking
 *   1 = reverse polarity pci parity checking
 *
 * NOTE: you can't actually pass -1 on the lilo prompt.  So, to set this
 * variable to -1 you would actually want to simply pass the variable
 * name without a number.  That will invert the 0 which will result in
 * -1.
 */
static int aic7xxx_pci_parity = 0;
/*
 * Set this to any non-0 value to cause us to dump the contents of all
 * the card's registers in a hex dump format tailored to each model of
 * controller.
 * 
 * NOTE: THE CONTROLLER IS LEFT IN AN UNUSEABLE STATE BY THIS OPTION.
 *       YOU CANNOT BOOT UP WITH THIS OPTION, IT IS FOR DEBUGGING PURPOSES
 *       ONLY
 */
static int aic7xxx_dump_card = 0;
/*
 * Set this to a non-0 value to make us dump out the 32 bit instruction
 * registers on the card after completing the sequencer download.  This
 * allows the actual sequencer download to be verified.  It is possible
 * to use this option and still boot up and run your system.  This is
 * only intended for debugging purposes.
 */
static int aic7xxx_dump_sequencer = 0;
/*
 * Certain newer motherboards have put new PCI based devices into the
 * IO spaces that used to typically be occupied by VLB or EISA cards.
 * This overlap can cause these newer motherboards to lock up when scanned
 * for older EISA and VLB devices.  Setting this option to non-0 will
 * cause the driver to skip scanning for any VLB or EISA controllers and
 * only support the PCI controllers.  NOTE: this means that if the kernel
 * os compiled with PCI support disabled, then setting this to non-0
 * would result in never finding any devices :)
 */
static int aic7xxx_no_probe = 0;
/*
 * On some machines, enabling the external SCB RAM isn't reliable yet.  I
 * haven't had time to make test patches for things like changing the
 * timing mode on that external RAM either.  Some of those changes may
 * fix the problem.  Until then though, we default to external SCB RAM
 * off and give a command line option to enable it.
 */
static int aic7xxx_scbram = 0;
/*
 * So that we can set how long each device is given as a selection timeout.
 * The table of values goes like this:
 *   0 - 256ms
 *   1 - 128ms
 *   2 - 64ms
 *   3 - 32ms
 * We default to 64ms because it's fast.  Some old SCSI-I devices need a
 * longer time.  The final value has to be left shifted by 3, hence 0x10
 * is the final value.
 */
static int aic7xxx_seltime = 0x10;
/*
 * So that insmod can find the variable and make it point to something
 */
#ifdef MODULE
static char * aic7xxx = NULL;
module_param(aic7xxx, charp, 0);
#endif

#define VERBOSE_NORMAL         0x0000
#define VERBOSE_NEGOTIATION    0x0001
#define VERBOSE_SEQINT         0x0002
#define VERBOSE_SCSIINT        0x0004
#define VERBOSE_PROBE          0x0008
#define VERBOSE_PROBE2         0x0010
#define VERBOSE_NEGOTIATION2   0x0020
#define VERBOSE_MINOR_ERROR    0x0040
#define VERBOSE_TRACING        0x0080
#define VERBOSE_ABORT          0x0f00
#define VERBOSE_ABORT_MID      0x0100
#define VERBOSE_ABORT_FIND     0x0200
#define VERBOSE_ABORT_PROCESS  0x0400
#define VERBOSE_ABORT_RETURN   0x0800
#define VERBOSE_RESET          0xf000
#define VERBOSE_RESET_MID      0x1000
#define VERBOSE_RESET_FIND     0x2000
#define VERBOSE_RESET_PROCESS  0x4000
#define VERBOSE_RESET_RETURN   0x8000
static int aic7xxx_verbose = VERBOSE_NORMAL | VERBOSE_NEGOTIATION |
           VERBOSE_PROBE;                     /* verbose messages */


/****************************************************************************
 *
 * We're going to start putting in function declarations so that order of
 * functions is no longer important.  As needed, they are added here.
 *
 ***************************************************************************/

static int aic7xxx_release(struct Scsi_Host *host);
static void aic7xxx_set_syncrate(struct aic7xxx_host *p, 
                struct aic7xxx_syncrate *syncrate, int target, int channel,
                unsigned int period, unsigned int offset, unsigned char options,
                unsigned int type, struct aic_dev_data *aic_dev);
static void aic7xxx_set_width(struct aic7xxx_host *p, int target, int channel,
                int lun, unsigned int width, unsigned int type,
                struct aic_dev_data *aic_dev);
static void aic7xxx_panic_abort(struct aic7xxx_host *p, struct scsi_cmnd *cmd);
static void aic7xxx_print_card(struct aic7xxx_host *p);
static void aic7xxx_print_scratch_ram(struct aic7xxx_host *p);
static void aic7xxx_print_sequencer(struct aic7xxx_host *p, int downloaded);
#ifdef AIC7XXX_VERBOSE_DEBUGGING
static void aic7xxx_check_scbs(struct aic7xxx_host *p, char *buffer);
#endif

/****************************************************************************
 *
 * These functions are now used.  They happen to be wrapped in useless
 * inb/outb port read/writes around the real reads and writes because it
 * seems that certain very fast CPUs have a problem dealing with us when
 * going at full speed.
 *
 ***************************************************************************/

static unsigned char
aic_inb(struct aic7xxx_host *p, long port)
{
#ifdef MMAPIO
  unsigned char x;
  if(p->maddr)
  {
    x = readb(p->maddr + port);
  }
  else
  {
    x = inb(p->base + port);
  }
  return(x);
#else
  return(inb(p->base + port));
#endif
}

static void
aic_outb(struct aic7xxx_host *p, unsigned char val, long port)
{
#ifdef MMAPIO
  if(p->maddr)
  {
    writeb(val, p->maddr + port);
    mb(); /* locked operation in order to force CPU ordering */
    readb(p->maddr + HCNTRL); /* dummy read to flush the PCI write */
  }
  else
  {
    outb(val, p->base + port);
    mb(); /* locked operation in order to force CPU ordering */
  }
#else
  outb(val, p->base + port);
  mb(); /* locked operation in order to force CPU ordering */
#endif
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_setup
 *
 * Description:
 *   Handle Linux boot parameters. This routine allows for assigning a value
 *   to a parameter with a ':' between the parameter and the value.
 *   ie. aic7xxx=unpause:0x0A,extended
 *-F*************************************************************************/
static int
aic7xxx_setup(char *s)
{
  int   i, n;
  char *p;
  char *end;

  static struct {
    const char *name;
    unsigned int *flag;
  } options[] = {
    { "extended",    &aic7xxx_extended },
    { "no_reset",    &aic7xxx_no_reset },
    { "irq_trigger", &aic7xxx_irq_trigger },
    { "verbose",     &aic7xxx_verbose },
    { "reverse_scan",&aic7xxx_reverse_scan },
    { "override_term", &aic7xxx_override_term },
    { "stpwlev", &aic7xxx_stpwlev },
    { "no_probe", &aic7xxx_no_probe },
    { "panic_on_abort", &aic7xxx_panic_on_abort },
    { "pci_parity", &aic7xxx_pci_parity },
    { "dump_card", &aic7xxx_dump_card },
    { "dump_sequencer", &aic7xxx_dump_sequencer },
    { "default_queue_depth", &aic7xxx_default_queue_depth },
    { "scbram", &aic7xxx_scbram },
    { "seltime", &aic7xxx_seltime },
    { "tag_info",    NULL }
  };

  end = strchr(s, '\0');

  while ((p = strsep(&s, ",.")) != NULL)
  {
    for (i = 0; i < ARRAY_SIZE(options); i++)
    {
      n = strlen(options[i].name);
      if (!strncmp(options[i].name, p, n))
      {
        if (!strncmp(p, "tag_info", n))
        {
          if (p[n] == ':')
          {
            char *base;
            char *tok, *tok_end, *tok_end2;
            char tok_list[] = { '.', ',', '{', '}', '\0' };
            int i, instance = -1, device = -1;
            unsigned char done = FALSE;

            base = p;
            tok = base + n + 1;  /* Forward us just past the ':' */
            tok_end = strchr(tok, '\0');
            if (tok_end < end)
              *tok_end = ',';
            while(!done)
            {
              switch(*tok)
              {
                case '{':
                  if (instance == -1)
                    instance = 0;
                  else if (device == -1)
                    device = 0;
                  tok++;
                  break;
                case '}':
                  if (device != -1)
                    device = -1;
                  else if (instance != -1)
                    instance = -1;
                  tok++;
                  break;
                case ',':
                case '.':
                  if (instance == -1)
                    done = TRUE;
                  else if (device >= 0)
                    device++;
                  else if (instance >= 0)
                    instance++;
                  if ( (device >= MAX_TARGETS) || 
                       (instance >= ARRAY_SIZE(aic7xxx_tag_info)) )
                    done = TRUE;
                  tok++;
                  if (!done)
                  {
                    base = tok;
                  }
                  break;
                case '\0':
                  done = TRUE;
                  break;
                default:
                  done = TRUE;
                  tok_end = strchr(tok, '\0');
                  for(i=0; tok_list[i]; i++)
                  {
                    tok_end2 = strchr(tok, tok_list[i]);
                    if ( (tok_end2) && (tok_end2 < tok_end) )
                    {
                      tok_end = tok_end2;
                      done = FALSE;
                    }
                  }
                  if ( (instance >= 0) && (device >= 0) &&
                       (instance < ARRAY_SIZE(aic7xxx_tag_info)) &&
                       (device < MAX_TARGETS) )
                    aic7xxx_tag_info[instance].tag_commands[device] =
                      simple_strtoul(tok, NULL, 0) & 0xff;
                  tok = tok_end;
                  break;
              }
            }
            while((p != base) && (p != NULL))
              p = strsep(&s, ",.");
          }
        }
        else if (p[n] == ':')
        {
          *(options[i].flag) = simple_strtoul(p + n + 1, NULL, 0);
          if(!strncmp(p, "seltime", n))
          {
            *(options[i].flag) = (*(options[i].flag) % 4) << 3;
          }
        }
        else if (!strncmp(p, "verbose", n))
        {
          *(options[i].flag) = 0xff29;
        }
        else
        {
          *(options[i].flag) = ~(*(options[i].flag));
          if(!strncmp(p, "seltime", n))
          {
            *(options[i].flag) = (*(options[i].flag) % 4) << 3;
          }
        }
      }
    }
  }
  return 1;
}

__setup("aic7xxx=", aic7xxx_setup);

/*+F*************************************************************************
 * Function:
 *   pause_sequencer
 *
 * Description:
 *   Pause the sequencer and wait for it to actually stop - this
 *   is important since the sequencer can disable pausing for critical
 *   sections.
 *-F*************************************************************************/
static void
pause_sequencer(struct aic7xxx_host *p)
{
  aic_outb(p, p->pause, HCNTRL);
  while ((aic_inb(p, HCNTRL) & PAUSE) == 0)
  {
    ;
  }
  if(p->features & AHC_ULTRA2)
  {
    aic_inb(p, CCSCBCTL);
  }
}

/*+F*************************************************************************
 * Function:
 *   unpause_sequencer
 *
 * Description:
 *   Unpause the sequencer. Unremarkable, yet done often enough to
 *   warrant an easy way to do it.
 *-F*************************************************************************/
static void
unpause_sequencer(struct aic7xxx_host *p, int unpause_always)
{
  if (unpause_always ||
      ( !(aic_inb(p, INTSTAT) & (SCSIINT | SEQINT | BRKADRINT)) &&
        !(p->flags & AHC_HANDLING_REQINITS) ) )
  {
    aic_outb(p, p->unpause, HCNTRL);
  }
}

/*+F*************************************************************************
 * Function:
 *   restart_sequencer
 *
 * Description:
 *   Restart the sequencer program from address zero.  This assumes
 *   that the sequencer is already paused.
 *-F*************************************************************************/
static void
restart_sequencer(struct aic7xxx_host *p)
{
  aic_outb(p, 0, SEQADDR0);
  aic_outb(p, 0, SEQADDR1);
  aic_outb(p, FASTMODE, SEQCTL);
}

/*
 * We include the aic7xxx_seq.c file here so that the other defines have
 * already been made, and so that it comes before the code that actually
 * downloads the instructions (since we don't typically use function
 * prototype, our code has to be ordered that way, it's a left-over from
 * the original driver days.....I should fix it some time DL).
 */
#include "aic7xxx_old/aic7xxx_seq.c"

/*+F*************************************************************************
 * Function:
 *   aic7xxx_check_patch
 *
 * Description:
 *   See if the next patch to download should be downloaded.
 *-F*************************************************************************/
static int
aic7xxx_check_patch(struct aic7xxx_host *p,
  struct sequencer_patch **start_patch, int start_instr, int *skip_addr)
{
  struct sequencer_patch *cur_patch;
  struct sequencer_patch *last_patch;
  int num_patches;

  num_patches = ARRAY_SIZE(sequencer_patches);
  last_patch = &sequencer_patches[num_patches];
  cur_patch = *start_patch;

  while ((cur_patch < last_patch) && (start_instr == cur_patch->begin))
  {
    if (cur_patch->patch_func(p) == 0)
    {
      /*
       * Start rejecting code.
       */
      *skip_addr = start_instr + cur_patch->skip_instr;
      cur_patch += cur_patch->skip_patch;
    }
    else
    {
      /*
       * Found an OK patch.  Advance the patch pointer to the next patch
       * and wait for our instruction pointer to get here.
       */
      cur_patch++;
    }
  }

  *start_patch = cur_patch;
  if (start_instr < *skip_addr)
    /*
     * Still skipping
     */
    return (0);
  return(1);
}


/*+F*************************************************************************
 * Function:
 *   aic7xxx_download_instr
 *
 * Description:
 *   Find the next patch to download.
 *-F*************************************************************************/
static void
aic7xxx_download_instr(struct aic7xxx_host *p, int instrptr,
  unsigned char *dconsts)
{
  union ins_formats instr;
  struct ins_format1 *fmt1_ins;
  struct ins_format3 *fmt3_ins;
  unsigned char opcode;

  instr = *(union ins_formats*) &seqprog[instrptr * 4];

  instr.integer = le32_to_cpu(instr.integer);
  
  fmt1_ins = &instr.format1;
  fmt3_ins = NULL;

  /* Pull the opcode */
  opcode = instr.format1.opcode;
  switch (opcode)
  {
    case AIC_OP_JMP:
    case AIC_OP_JC:
    case AIC_OP_JNC:
    case AIC_OP_CALL:
    case AIC_OP_JNE:
    case AIC_OP_JNZ:
    case AIC_OP_JE:
    case AIC_OP_JZ:
    {
      struct sequencer_patch *cur_patch;
      int address_offset;
      unsigned int address;
      int skip_addr;
      int i;

      fmt3_ins = &instr.format3;
      address_offset = 0;
      address = fmt3_ins->address;
      cur_patch = sequencer_patches;
      skip_addr = 0;

      for (i = 0; i < address;)
      {
        aic7xxx_check_patch(p, &cur_patch, i, &skip_addr);
        if (skip_addr > i)
        {
          int end_addr;

          end_addr = min_t(int, address, skip_addr);
          address_offset += end_addr - i;
          i = skip_addr;
        }
        else
        {
          i++;
        }
      }
      address -= address_offset;
      fmt3_ins->address = address;
      /* Fall Through to the next code section */
    }
    case AIC_OP_OR:
    case AIC_OP_AND:
    case AIC_OP_XOR:
    case AIC_OP_ADD:
    case AIC_OP_ADC:
    case AIC_OP_BMOV:
      if (fmt1_ins->parity != 0)
      {
        fmt1_ins->immediate = dconsts[fmt1_ins->immediate];
      }
      fmt1_ins->parity = 0;
      /* Fall Through to the next code section */
    case AIC_OP_ROL:
      if ((p->features & AHC_ULTRA2) != 0)
      {
        int i, count;

        /* Calculate odd parity for the instruction */
        for ( i=0, count=0; i < 31; i++)
        {
          unsigned int mask;

          mask = 0x01 << i;
          if ((instr.integer & mask) != 0)
            count++;
        }
        if (!(count & 0x01))
          instr.format1.parity = 1;
      }
      else
      {
        if (fmt3_ins != NULL)
        {
          instr.integer =  fmt3_ins->immediate |
                          (fmt3_ins->source << 8) |
                          (fmt3_ins->address << 16) |
                          (fmt3_ins->opcode << 25);
        }
        else
        {
          instr.integer =  fmt1_ins->immediate |
                          (fmt1_ins->source << 8) |
                          (fmt1_ins->destination << 16) |
                          (fmt1_ins->ret << 24) |
                          (fmt1_ins->opcode << 25);
        }
      }
      aic_outb(p, (instr.integer & 0xff), SEQRAM);
      aic_outb(p, ((instr.integer >> 8) & 0xff), SEQRAM);
      aic_outb(p, ((instr.integer >> 16) & 0xff), SEQRAM);
      aic_outb(p, ((instr.integer >> 24) & 0xff), SEQRAM);
      udelay(10);
      break;

    default:
      panic("aic7xxx: Unknown opcode encountered in sequencer program.");
      break;
  }
}


/*+F*************************************************************************
 * Function:
 *   aic7xxx_loadseq
 *
 * Description:
 *   Load the sequencer code into the controller memory.
 *-F*************************************************************************/
static void
aic7xxx_loadseq(struct aic7xxx_host *p)
{
  struct sequencer_patch *cur_patch;
  int i;
  int downloaded;
  int skip_addr;
  unsigned char download_consts[4] = {0, 0, 0, 0};

  if (aic7xxx_verbose & VERBOSE_PROBE)
  {
    printk(KERN_INFO "(scsi%d) Downloading sequencer code...", p->host_no);
  }
#if 0
  download_consts[TMODE_NUMCMDS] = p->num_targetcmds;
#endif
  download_consts[TMODE_NUMCMDS] = 0;
  cur_patch = &sequencer_patches[0];
  downloaded = 0;
  skip_addr = 0;

  aic_outb(p, PERRORDIS|LOADRAM|FAILDIS|FASTMODE, SEQCTL);
  aic_outb(p, 0, SEQADDR0);
  aic_outb(p, 0, SEQADDR1);

  for (i = 0; i < sizeof(seqprog) / 4;  i++)
  {
    if (aic7xxx_check_patch(p, &cur_patch, i, &skip_addr) == 0)
    {
      /* Skip this instruction for this configuration. */
      continue;
    }
    aic7xxx_download_instr(p, i, &download_consts[0]);
    downloaded++;
  }

  aic_outb(p, 0, SEQADDR0);
  aic_outb(p, 0, SEQADDR1);
  aic_outb(p, FASTMODE | FAILDIS, SEQCTL);
  unpause_sequencer(p, TRUE);
  mdelay(1);
  pause_sequencer(p);
  aic_outb(p, FASTMODE, SEQCTL);
  if (aic7xxx_verbose & VERBOSE_PROBE)
  {
    printk(" %d instructions downloaded\n", downloaded);
  }
  if (aic7xxx_dump_sequencer)
    aic7xxx_print_sequencer(p, downloaded);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_print_sequencer
 *
 * Description:
 *   Print the contents of the sequencer memory to the screen.
 *-F*************************************************************************/
static void
aic7xxx_print_sequencer(struct aic7xxx_host *p, int downloaded)
{
  int i, k, temp;
  
  aic_outb(p, PERRORDIS|LOADRAM|FAILDIS|FASTMODE, SEQCTL);
  aic_outb(p, 0, SEQADDR0);
  aic_outb(p, 0, SEQADDR1);

  k = 0;
  for (i=0; i < downloaded; i++)
  {
    if ( k == 0 )
      printk("%03x: ", i);
    temp = aic_inb(p, SEQRAM);
    temp |= (aic_inb(p, SEQRAM) << 8);
    temp |= (aic_inb(p, SEQRAM) << 16);
    temp |= (aic_inb(p, SEQRAM) << 24);
    printk("%08x", temp);
    if ( ++k == 8 )
    {
      printk("\n");
      k = 0;
    }
    else
      printk(" ");
  }
  aic_outb(p, 0, SEQADDR0);
  aic_outb(p, 0, SEQADDR1);
  aic_outb(p, FASTMODE | FAILDIS, SEQCTL);
  unpause_sequencer(p, TRUE);
  mdelay(1);
  pause_sequencer(p);
  aic_outb(p, FASTMODE, SEQCTL);
  printk("\n");
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_info
 *
 * Description:
 *   Return a string describing the driver.
 *-F*************************************************************************/
static const char *
aic7xxx_info(struct Scsi_Host *dooh)
{
  static char buffer[256];
  char *bp;
  struct aic7xxx_host *p;

  bp = &buffer[0];
  p = (struct aic7xxx_host *)dooh->hostdata;
  memset(bp, 0, sizeof(buffer));
  strcpy(bp, "Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) ");
  strcat(bp, AIC7XXX_C_VERSION);
  strcat(bp, "/");
  strcat(bp, AIC7XXX_H_VERSION);
  strcat(bp, "\n");
  strcat(bp, "       <");
  strcat(bp, board_names[p->board_name_index]);
  strcat(bp, ">");

  return(bp);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_find_syncrate
 *
 * Description:
 *   Look up the valid period to SCSIRATE conversion in our table
 *-F*************************************************************************/
static struct aic7xxx_syncrate *
aic7xxx_find_syncrate(struct aic7xxx_host *p, unsigned int *period,
  unsigned int maxsync, unsigned char *options)
{
  struct aic7xxx_syncrate *syncrate;
  int done = FALSE;

  switch(*options)
  {
    case MSG_EXT_PPR_OPTION_DT_CRC:
    case MSG_EXT_PPR_OPTION_DT_UNITS:
      if(!(p->features & AHC_ULTRA3))
      {
        *options = 0;
        maxsync = max_t(unsigned int, maxsync, AHC_SYNCRATE_ULTRA2);
      }
      break;
    case MSG_EXT_PPR_OPTION_DT_CRC_QUICK:
    case MSG_EXT_PPR_OPTION_DT_UNITS_QUICK:
      if(!(p->features & AHC_ULTRA3))
      {
        *options = 0;
        maxsync = max_t(unsigned int, maxsync, AHC_SYNCRATE_ULTRA2);
      }
      else
      {
        /*
         * we don't support the Quick Arbitration variants of dual edge
         * clocking.  As it turns out, we want to send back the
         * same basic option, but without the QA attribute.
         * We know that we are responding because we would never set
         * these options ourself, we would only respond to them.
         */
        switch(*options)
        {
          case MSG_EXT_PPR_OPTION_DT_CRC_QUICK:
            *options = MSG_EXT_PPR_OPTION_DT_CRC;
            break;
          case MSG_EXT_PPR_OPTION_DT_UNITS_QUICK:
            *options = MSG_EXT_PPR_OPTION_DT_UNITS;
            break;
        }
      }
      break;
    default:
      *options = 0;
      maxsync = max_t(unsigned int, maxsync, AHC_SYNCRATE_ULTRA2);
      break;
  }
  syncrate = &aic7xxx_syncrates[maxsync];
  while ( (syncrate->rate[0] != NULL) &&
         (!(p->features & AHC_ULTRA2) || syncrate->sxfr_ultra2) )
  {
    if (*period <= syncrate->period) 
    {
      switch(*options)
      {
        case MSG_EXT_PPR_OPTION_DT_CRC:
        case MSG_EXT_PPR_OPTION_DT_UNITS:
          if(!(syncrate->sxfr_ultra2 & AHC_SYNCRATE_CRC))
          {
            done = TRUE;
            /*
             * oops, we went too low for the CRC/DualEdge signalling, so
             * clear the options byte
             */
            *options = 0;
            /*
             * We'll be sending a reply to this packet to set the options
             * properly, so unilaterally set the period as well.
             */
            *period = syncrate->period;
          }
          else
          {
            done = TRUE;
            if(syncrate == &aic7xxx_syncrates[maxsync])
            {
              *period = syncrate->period;
            }
          }
          break;
        default:
          if(!(syncrate->sxfr_ultra2 & AHC_SYNCRATE_CRC))
          {
            done = TRUE;
            if(syncrate == &aic7xxx_syncrates[maxsync])
            {
              *period = syncrate->period;
            }
          }
          break;
      }
      if(done)
      {
        break;
      }
    }
    syncrate++;
  }
  if ( (*period == 0) || (syncrate->rate[0] == NULL) ||
       ((p->features & AHC_ULTRA2) && (syncrate->sxfr_ultra2 == 0)) )
  {
    /*
     * Use async transfers for this target
     */
    *options = 0;
    *period = 255;
    syncrate = NULL;
  }
  return (syncrate);
}


/*+F*************************************************************************
 * Function:
 *   aic7xxx_find_period
 *
 * Description:
 *   Look up the valid SCSIRATE to period conversion in our table
 *-F*************************************************************************/
static unsigned int
aic7xxx_find_period(struct aic7xxx_host *p, unsigned int scsirate,
  unsigned int maxsync)
{
  struct aic7xxx_syncrate *syncrate;

  if (p->features & AHC_ULTRA2)
  {
    scsirate &= SXFR_ULTRA2;
  }
  else
  {
    scsirate &= SXFR;
  }

  syncrate = &aic7xxx_syncrates[maxsync];
  while (syncrate->rate[0] != NULL)
  {
    if (p->features & AHC_ULTRA2)
    {
      if (syncrate->sxfr_ultra2 == 0)
        break;
      else if (scsirate == syncrate->sxfr_ultra2)
        return (syncrate->period);
      else if (scsirate == (syncrate->sxfr_ultra2 & ~AHC_SYNCRATE_CRC))
        return (syncrate->period);
    }
    else if (scsirate == (syncrate->sxfr & ~ULTRA_SXFR))
    {
      return (syncrate->period);
    }
    syncrate++;
  }
  return (0); /* async */
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_validate_offset
 *
 * Description:
 *   Set a valid offset value for a particular card in use and transfer
 *   settings in use.
 *-F*************************************************************************/
static void
aic7xxx_validate_offset(struct aic7xxx_host *p,
  struct aic7xxx_syncrate *syncrate, unsigned int *offset, int wide)
{
  unsigned int maxoffset;

  /* Limit offset to what the card (and device) can do */
  if (syncrate == NULL)
  {
    maxoffset = 0;
  }
  else if (p->features & AHC_ULTRA2)
  {
    maxoffset = MAX_OFFSET_ULTRA2;
  }
  else
  {
    if (wide)
      maxoffset = MAX_OFFSET_16BIT;
    else
      maxoffset = MAX_OFFSET_8BIT;
  }
  *offset = min(*offset, maxoffset);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_set_syncrate
 *
 * Description:
 *   Set the actual syncrate down in the card and in our host structs
 *-F*************************************************************************/
static void
aic7xxx_set_syncrate(struct aic7xxx_host *p, struct aic7xxx_syncrate *syncrate,
    int target, int channel, unsigned int period, unsigned int offset,
    unsigned char options, unsigned int type, struct aic_dev_data *aic_dev)
{
  unsigned char tindex;
  unsigned short target_mask;
  unsigned char lun, old_options;
  unsigned int old_period, old_offset;

  tindex = target | (channel << 3);
  target_mask = 0x01 << tindex;
  lun = aic_inb(p, SCB_TCL) & 0x07;

  if (syncrate == NULL)
  {
    period = 0;
    offset = 0;
  }

  old_period = aic_dev->cur.period;
  old_offset = aic_dev->cur.offset;
  old_options = aic_dev->cur.options;

  
  if (type & AHC_TRANS_CUR)
  {
    unsigned int scsirate;

    scsirate = aic_inb(p, TARG_SCSIRATE + tindex);
    if (p->features & AHC_ULTRA2)
    {
      scsirate &= ~SXFR_ULTRA2;
      if (syncrate != NULL)
      {
        switch(options)
        {
          case MSG_EXT_PPR_OPTION_DT_UNITS:
            /*
             * mask off the CRC bit in the xfer settings
             */
            scsirate |= (syncrate->sxfr_ultra2 & ~AHC_SYNCRATE_CRC);
            break;
          default:
            scsirate |= syncrate->sxfr_ultra2;
            break;
        }
      }
      if (type & AHC_TRANS_ACTIVE)
      {
        aic_outb(p, offset, SCSIOFFSET);
      }
      aic_outb(p, offset, TARG_OFFSET + tindex);
    }
    else /* Not an Ultra2 controller */
    {
      scsirate &= ~(SXFR|SOFS);
      p->ultraenb &= ~target_mask;
      if (syncrate != NULL)
      {
        if (syncrate->sxfr & ULTRA_SXFR)
        {
          p->ultraenb |= target_mask;
        }
        scsirate |= (syncrate->sxfr & SXFR);
        scsirate |= (offset & SOFS);
      }
      if (type & AHC_TRANS_ACTIVE)
      {
        unsigned char sxfrctl0;

        sxfrctl0 = aic_inb(p, SXFRCTL0);
        sxfrctl0 &= ~FAST20;
        if (p->ultraenb & target_mask)
          sxfrctl0 |= FAST20;
        aic_outb(p, sxfrctl0, SXFRCTL0);
      }
      aic_outb(p, p->ultraenb & 0xff, ULTRA_ENB);
      aic_outb(p, (p->ultraenb >> 8) & 0xff, ULTRA_ENB + 1 );
    }
    if (type & AHC_TRANS_ACTIVE)
    {
      aic_outb(p, scsirate, SCSIRATE);
    }
    aic_outb(p, scsirate, TARG_SCSIRATE + tindex);
    aic_dev->cur.period = period;
    aic_dev->cur.offset = offset;
    aic_dev->cur.options = options;
    if ( !(type & AHC_TRANS_QUITE) &&
         (aic7xxx_verbose & VERBOSE_NEGOTIATION) &&
         (aic_dev->flags & DEVICE_PRINT_DTR) )
    {
      if (offset)
      {
        int rate_mod = (scsirate & WIDEXFER) ? 1 : 0;
      
        printk(INFO_LEAD "Synchronous at %s Mbyte/sec, "
               "offset %d.\n", p->host_no, channel, target, lun,
               syncrate->rate[rate_mod], offset);
      }
      else
      {
        printk(INFO_LEAD "Using asynchronous transfers.\n",
               p->host_no, channel, target, lun);
      }
      aic_dev->flags &= ~DEVICE_PRINT_DTR;
    }
  }

  if (type & AHC_TRANS_GOAL)
  {
    aic_dev->goal.period = period;
    aic_dev->goal.offset = offset;
    aic_dev->goal.options = options;
  }

  if (type & AHC_TRANS_USER)
  {
    p->user[tindex].period = period;
    p->user[tindex].offset = offset;
    p->user[tindex].options = options;
  }
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_set_width
 *
 * Description:
 *   Set the actual width down in the card and in our host structs
 *-F*************************************************************************/
static void
aic7xxx_set_width(struct aic7xxx_host *p, int target, int channel, int lun,
    unsigned int width, unsigned int type, struct aic_dev_data *aic_dev)
{
  unsigned char tindex;
  unsigned short target_mask;
  unsigned int old_width;

  tindex = target | (channel << 3);
  target_mask = 1 << tindex;
  
  old_width = aic_dev->cur.width;

  if (type & AHC_TRANS_CUR) 
  {
    unsigned char scsirate;

    scsirate = aic_inb(p, TARG_SCSIRATE + tindex);

    scsirate &= ~WIDEXFER;
    if (width == MSG_EXT_WDTR_BUS_16_BIT)
      scsirate |= WIDEXFER;

    aic_outb(p, scsirate, TARG_SCSIRATE + tindex);

    if (type & AHC_TRANS_ACTIVE)
      aic_outb(p, scsirate, SCSIRATE);

    aic_dev->cur.width = width;

    if ( !(type & AHC_TRANS_QUITE) &&
          (aic7xxx_verbose & VERBOSE_NEGOTIATION2) && 
          (aic_dev->flags & DEVICE_PRINT_DTR) )
    {
      printk(INFO_LEAD "Using %s transfers\n", p->host_no, channel, target,
        lun, (scsirate & WIDEXFER) ? "Wide(16bit)" : "Narrow(8bit)" );
    }
  }

  if (type & AHC_TRANS_GOAL)
    aic_dev->goal.width = width;
  if (type & AHC_TRANS_USER)
    p->user[tindex].width = width;

  if (aic_dev->goal.offset)
  {
    if (p->features & AHC_ULTRA2)
    {
      aic_dev->goal.offset = MAX_OFFSET_ULTRA2;
    }
    else if (width == MSG_EXT_WDTR_BUS_16_BIT)
    {
      aic_dev->goal.offset = MAX_OFFSET_16BIT;
    }
    else
    {
      aic_dev->goal.offset = MAX_OFFSET_8BIT;
    }
  }
}
      
/*+F*************************************************************************
 * Function:
 *   scbq_init
 *
 * Description:
 *   SCB queue initialization.
 *
 *-F*************************************************************************/
static void
scbq_init(volatile scb_queue_type *queue)
{
  queue->head = NULL;
  queue->tail = NULL;
}

/*+F*************************************************************************
 * Function:
 *   scbq_insert_head
 *
 * Description:
 *   Add an SCB to the head of the list.
 *
 *-F*************************************************************************/
static inline void
scbq_insert_head(volatile scb_queue_type *queue, struct aic7xxx_scb *scb)
{
  scb->q_next = queue->head;
  queue->head = scb;
  if (queue->tail == NULL)       /* If list was empty, update tail. */
    queue->tail = queue->head;
}

/*+F*************************************************************************
 * Function:
 *   scbq_remove_head
 *
 * Description:
 *   Remove an SCB from the head of the list.
 *
 *-F*************************************************************************/
static inline struct aic7xxx_scb *
scbq_remove_head(volatile scb_queue_type *queue)
{
  struct aic7xxx_scb * scbp;

  scbp = queue->head;
  if (queue->head != NULL)
    queue->head = queue->head->q_next;
  if (queue->head == NULL)       /* If list is now empty, update tail. */
    queue->tail = NULL;
  return(scbp);
}

/*+F*************************************************************************
 * Function:
 *   scbq_remove
 *
 * Description:
 *   Removes an SCB from the list.
 *
 *-F*************************************************************************/
static inline void
scbq_remove(volatile scb_queue_type *queue, struct aic7xxx_scb *scb)
{
  if (queue->head == scb)
  {
    /* At beginning of queue, remove from head. */
    scbq_remove_head(queue);
  }
  else
  {
    struct aic7xxx_scb *curscb = queue->head;

    /*
     * Search until the next scb is the one we're looking for, or
     * we run out of queue.
     */
    while ((curscb != NULL) && (curscb->q_next != scb))
    {
      curscb = curscb->q_next;
    }
    if (curscb != NULL)
    {
      /* Found it. */
      curscb->q_next = scb->q_next;
      if (scb->q_next == NULL)
      {
        /* Update the tail when removing the tail. */
        queue->tail = curscb;
      }
    }
  }
}

/*+F*************************************************************************
 * Function:
 *   scbq_insert_tail
 *
 * Description:
 *   Add an SCB at the tail of the list.
 *
 *-F*************************************************************************/
static inline void
scbq_insert_tail(volatile scb_queue_type *queue, struct aic7xxx_scb *scb)
{
  scb->q_next = NULL;
  if (queue->tail != NULL)       /* Add the scb at the end of the list. */
    queue->tail->q_next = scb;
  queue->tail = scb;             /* Update the tail. */
  if (queue->head == NULL)       /* If list was empty, update head. */
    queue->head = queue->tail;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_match_scb
 *
 * Description:
 *   Checks to see if an scb matches the target/channel as specified.
 *   If target is ALL_TARGETS (-1), then we're looking for any device
 *   on the specified channel; this happens when a channel is going
 *   to be reset and all devices on that channel must be aborted.
 *-F*************************************************************************/
static int
aic7xxx_match_scb(struct aic7xxx_host *p, struct aic7xxx_scb *scb,
    int target, int channel, int lun, unsigned char tag)
{
  int targ = (scb->hscb->target_channel_lun >> 4) & 0x0F;
  int chan = (scb->hscb->target_channel_lun >> 3) & 0x01;
  int slun = scb->hscb->target_channel_lun & 0x07;
  int match;

  match = ((chan == channel) || (channel == ALL_CHANNELS));
  if (match != 0)
    match = ((targ == target) || (target == ALL_TARGETS));
  if (match != 0)
    match = ((lun == slun) || (lun == ALL_LUNS));
  if (match != 0)
    match = ((tag == scb->hscb->tag) || (tag == SCB_LIST_NULL));

  return (match);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_add_curscb_to_free_list
 *
 * Description:
 *   Adds the current scb (in SCBPTR) to the list of free SCBs.
 *-F*************************************************************************/
static void
aic7xxx_add_curscb_to_free_list(struct aic7xxx_host *p)
{
  /*
   * Invalidate the tag so that aic7xxx_find_scb doesn't think
   * it's active
   */
  aic_outb(p, SCB_LIST_NULL, SCB_TAG);
  aic_outb(p, 0, SCB_CONTROL);

  aic_outb(p, aic_inb(p, FREE_SCBH), SCB_NEXT);
  aic_outb(p, aic_inb(p, SCBPTR), FREE_SCBH);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_rem_scb_from_disc_list
 *
 * Description:
 *   Removes the current SCB from the disconnected list and adds it
 *   to the free list.
 *-F*************************************************************************/
static unsigned char
aic7xxx_rem_scb_from_disc_list(struct aic7xxx_host *p, unsigned char scbptr,
                               unsigned char prev)
{
  unsigned char next;

  aic_outb(p, scbptr, SCBPTR);
  next = aic_inb(p, SCB_NEXT);
  aic7xxx_add_curscb_to_free_list(p);

  if (prev != SCB_LIST_NULL)
  {
    aic_outb(p, prev, SCBPTR);
    aic_outb(p, next, SCB_NEXT);
  }
  else
  {
    aic_outb(p, next, DISCONNECTED_SCBH);
  }

  return next;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_busy_target
 *
 * Description:
 *   Set the specified target busy.
 *-F*************************************************************************/
static inline void
aic7xxx_busy_target(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
  p->untagged_scbs[scb->hscb->target_channel_lun] = scb->hscb->tag;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_index_busy_target
 *
 * Description:
 *   Returns the index of the busy target, and optionally sets the
 *   target inactive.
 *-F*************************************************************************/
static inline unsigned char
aic7xxx_index_busy_target(struct aic7xxx_host *p, unsigned char tcl,
    int unbusy)
{
  unsigned char busy_scbid;

  busy_scbid = p->untagged_scbs[tcl];
  if (unbusy)
  {
    p->untagged_scbs[tcl] = SCB_LIST_NULL;
  }
  return (busy_scbid);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_find_scb
 *
 * Description:
 *   Look through the SCB array of the card and attempt to find the
 *   hardware SCB that corresponds to the passed in SCB.  Return
 *   SCB_LIST_NULL if unsuccessful.  This routine assumes that the
 *   card is already paused.
 *-F*************************************************************************/
static unsigned char
aic7xxx_find_scb(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
  unsigned char saved_scbptr;
  unsigned char curindex;

  saved_scbptr = aic_inb(p, SCBPTR);
  curindex = 0;
  for (curindex = 0; curindex < p->scb_data->maxhscbs; curindex++)
  {
    aic_outb(p, curindex, SCBPTR);
    if (aic_inb(p, SCB_TAG) == scb->hscb->tag)
    {
      break;
    }
  }
  aic_outb(p, saved_scbptr, SCBPTR);
  if (curindex >= p->scb_data->maxhscbs)
  {
    curindex = SCB_LIST_NULL;
  }

  return (curindex);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_allocate_scb
 *
 * Description:
 *   Get an SCB from the free list or by allocating a new one.
 *-F*************************************************************************/
static int
aic7xxx_allocate_scb(struct aic7xxx_host *p)
{
  struct aic7xxx_scb   *scbp = NULL;
  int scb_size = (sizeof (struct hw_scatterlist) * AIC7XXX_MAX_SG) + 12 + 6;
  int i;
  int step = PAGE_SIZE / 1024;
  unsigned long scb_count = 0;
  struct hw_scatterlist *hsgp;
  struct aic7xxx_scb *scb_ap;
  struct aic7xxx_scb_dma *scb_dma;
  unsigned char *bufs;

  if (p->scb_data->numscbs < p->scb_data->maxscbs)
  {
    /*
     * Calculate the optimal number of SCBs to allocate.
     *
     * NOTE: This formula works because the sizeof(sg_array) is always
     * 1024.  Therefore, scb_size * i would always be > PAGE_SIZE *
     * (i/step).  The (i-1) allows the left hand side of the equation
     * to grow into the right hand side to a point of near perfect
     * efficiency since scb_size * (i -1) is growing slightly faster
     * than the right hand side.  If the number of SG array elements
     * is changed, this function may not be near so efficient any more.
     *
     * Since the DMA'able buffers are now allocated in a separate
     * chunk this algorithm has been modified to match.  The '12'
     * and '6' factors in scb_size are for the DMA'able command byte
     * and sensebuffers respectively.  -DaveM
     */
    for ( i=step;; i *= 2 )
    {
      if ( (scb_size * (i-1)) >= ( (PAGE_SIZE * (i/step)) - 64 ) )
      {
        i /= 2;
        break;
      }
    }
    scb_count = min( (i-1), p->scb_data->maxscbs - p->scb_data->numscbs);
    scb_ap = kmalloc(sizeof (struct aic7xxx_scb) * scb_count
                                           + sizeof(struct aic7xxx_scb_dma), GFP_ATOMIC);
    if (scb_ap == NULL)
      return(0);
    scb_dma = (struct aic7xxx_scb_dma *)&scb_ap[scb_count];
    hsgp = (struct hw_scatterlist *)
      pci_alloc_consistent(p->pdev, scb_size * scb_count,
                           &scb_dma->dma_address);
    if (hsgp == NULL)
    {
      kfree(scb_ap);
      return(0);
    }
    bufs = (unsigned char *)&hsgp[scb_count * AIC7XXX_MAX_SG];
#ifdef AIC7XXX_VERBOSE_DEBUGGING
    if (aic7xxx_verbose > 0xffff)
    {
      if (p->scb_data->numscbs == 0)
        printk(INFO_LEAD "Allocating initial %ld SCB structures.\n",
          p->host_no, -1, -1, -1, scb_count);
      else
        printk(INFO_LEAD "Allocating %ld additional SCB structures.\n",
          p->host_no, -1, -1, -1, scb_count);
    }
#endif
    memset(scb_ap, 0, sizeof (struct aic7xxx_scb) * scb_count);
    scb_dma->dma_offset = (unsigned long)scb_dma->dma_address
                          - (unsigned long)hsgp;
    scb_dma->dma_len = scb_size * scb_count;
    for (i=0; i < scb_count; i++)
    {
      scbp = &scb_ap[i];
      scbp->hscb = &p->scb_data->hscbs[p->scb_data->numscbs];
      scbp->sg_list = &hsgp[i * AIC7XXX_MAX_SG];
      scbp->sense_cmd = bufs;
      scbp->cmnd = bufs + 6;
      bufs += 12 + 6;
      scbp->scb_dma = scb_dma;
      memset(scbp->hscb, 0, sizeof(struct aic7xxx_hwscb));
      scbp->hscb->tag = p->scb_data->numscbs;
      /*
       * Place in the scb array; never is removed
       */
      p->scb_data->scb_array[p->scb_data->numscbs++] = scbp;
      scbq_insert_tail(&p->scb_data->free_scbs, scbp);
    }
    scbp->kmalloc_ptr = scb_ap;
  }
  return(scb_count);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_queue_cmd_complete
 *
 * Description:
 *   Due to race conditions present in the SCSI subsystem, it is easier
 *   to queue completed commands, then call scsi_done() on them when
 *   we're finished.  This function queues the completed commands.
 *-F*************************************************************************/
static void
aic7xxx_queue_cmd_complete(struct aic7xxx_host *p, struct scsi_cmnd *cmd)
{
  aic7xxx_position(cmd) = SCB_LIST_NULL;
  cmd->host_scribble = (char *)p->completeq.head;
  p->completeq.head = cmd;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_done_cmds_complete
 *
 * Description:
 *   Process the completed command queue.
 *-F*************************************************************************/
static void aic7xxx_done_cmds_complete(struct aic7xxx_host *p)
{
        struct scsi_cmnd *cmd;

        while (p->completeq.head != NULL) {
                cmd = p->completeq.head;
                p->completeq.head = (struct scsi_cmnd *) cmd->host_scribble;
                cmd->host_scribble = NULL;
                cmd->scsi_done(cmd);
        }
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_free_scb
 *
 * Description:
 *   Free the scb and insert into the free scb list.
 *-F*************************************************************************/
static void
aic7xxx_free_scb(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{

  scb->flags = SCB_FREE;
  scb->cmd = NULL;
  scb->sg_count = 0;
  scb->sg_length = 0;
  scb->tag_action = 0;
  scb->hscb->control = 0;
  scb->hscb->target_status = 0;
  scb->hscb->target_channel_lun = SCB_LIST_NULL;

  scbq_insert_head(&p->scb_data->free_scbs, scb);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_done
 *
 * Description:
 *   Calls the higher level scsi done function and frees the scb.
 *-F*************************************************************************/
static void
aic7xxx_done(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
        struct scsi_cmnd *cmd = scb->cmd;
        struct aic_dev_data *aic_dev = cmd->device->hostdata;
        int tindex = TARGET_INDEX(cmd);
        struct aic7xxx_scb *scbp;
        unsigned char queue_depth;

        scsi_dma_unmap(cmd);

  if (scb->flags & SCB_SENSE)
  {
    pci_unmap_single(p->pdev,
                     le32_to_cpu(scb->sg_list[0].address),
                     SCSI_SENSE_BUFFERSIZE,
                     PCI_DMA_FROMDEVICE);
  }
  if (scb->flags & SCB_RECOVERY_SCB)
  {
    p->flags &= ~AHC_ABORT_PENDING;
  }
  if (scb->flags & (SCB_RESET|SCB_ABORT))
  {
    cmd->result |= (DID_RESET << 16);
  }

  if ((scb->flags & SCB_MSGOUT_BITS) != 0)
  {
    unsigned short mask;
    int message_error = FALSE;

    mask = 0x01 << tindex;
 
    /*
     * Check to see if we get an invalid message or a message error
     * after failing to negotiate a wide or sync transfer message.
     */
    if ((scb->flags & SCB_SENSE) && 
          ((scb->cmd->sense_buffer[12] == 0x43) ||  /* INVALID_MESSAGE */
          (scb->cmd->sense_buffer[12] == 0x49))) /* MESSAGE_ERROR  */
    {
      message_error = TRUE;
    }

    if (scb->flags & SCB_MSGOUT_WDTR)
    {
      if (message_error)
      {
        if ( (aic7xxx_verbose & VERBOSE_NEGOTIATION2) &&
             (aic_dev->flags & DEVICE_PRINT_DTR) )
        {
          printk(INFO_LEAD "Device failed to complete Wide Negotiation "
            "processing and\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "returned a sense error code for invalid message, "
            "disabling future\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "Wide negotiation to this device.\n", p->host_no,
            CTL_OF_SCB(scb));
        }
        aic_dev->needwdtr = aic_dev->needwdtr_copy = 0;
      }
    }
    if (scb->flags & SCB_MSGOUT_SDTR)
    {
      if (message_error)
      {
        if ( (aic7xxx_verbose & VERBOSE_NEGOTIATION2) &&
             (aic_dev->flags & DEVICE_PRINT_DTR) )
        {
          printk(INFO_LEAD "Device failed to complete Sync Negotiation "
            "processing and\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "returned a sense error code for invalid message, "
            "disabling future\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "Sync negotiation to this device.\n", p->host_no,
            CTL_OF_SCB(scb));
          aic_dev->flags &= ~DEVICE_PRINT_DTR;
        }
        aic_dev->needsdtr = aic_dev->needsdtr_copy = 0;
      }
    }
    if (scb->flags & SCB_MSGOUT_PPR)
    {
      if(message_error)
      {
        if ( (aic7xxx_verbose & VERBOSE_NEGOTIATION2) &&
             (aic_dev->flags & DEVICE_PRINT_DTR) )
        {
          printk(INFO_LEAD "Device failed to complete Parallel Protocol "
            "Request processing and\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "returned a sense error code for invalid message, "
            "disabling future\n", p->host_no, CTL_OF_SCB(scb));
          printk(INFO_LEAD "Parallel Protocol Request negotiation to this "
            "device.\n", p->host_no, CTL_OF_SCB(scb));
        }
        /*
         * Disable PPR negotiation and revert back to WDTR and SDTR setup
         */
        aic_dev->needppr = aic_dev->needppr_copy = 0;
        aic_dev->needsdtr = aic_dev->needsdtr_copy = 1;
        aic_dev->needwdtr = aic_dev->needwdtr_copy = 1;
      }
    }
  }

  queue_depth = aic_dev->temp_q_depth;
  if (queue_depth >= aic_dev->active_cmds)
  {
    scbp = scbq_remove_head(&aic_dev->delayed_scbs);
    if (scbp)
    {
      if (queue_depth == 1)
      {
        /*
         * Give extra preference to untagged devices, such as CD-R devices
         * This makes it more likely that a drive *won't* stuff up while
         * waiting on data at a critical time, such as CD-R writing and
         * audio CD ripping operations.  Should also benefit tape drives.
         */
        scbq_insert_head(&p->waiting_scbs, scbp);
      }
      else
      {
        scbq_insert_tail(&p->waiting_scbs, scbp);
      }
#ifdef AIC7XXX_VERBOSE_DEBUGGING
      if (aic7xxx_verbose > 0xffff)
        printk(INFO_LEAD "Moving SCB from delayed to waiting queue.\n",
               p->host_no, CTL_OF_SCB(scbp));
#endif
      if (queue_depth > aic_dev->active_cmds)
      {
        scbp = scbq_remove_head(&aic_dev->delayed_scbs);
        if (scbp)
          scbq_insert_tail(&p->waiting_scbs, scbp);
      }
    }
  }
  if (!(scb->tag_action))
  {
    aic7xxx_index_busy_target(p, scb->hscb->target_channel_lun,
                              /* unbusy */ TRUE);
    if (cmd->device->simple_tags)
    {
      aic_dev->temp_q_depth = aic_dev->max_q_depth;
    }
  }
  if(scb->flags & SCB_DTR_SCB)
  {
    aic_dev->dtr_pending = 0;
  }
  aic_dev->active_cmds--;
  p->activescbs--;

  if ((scb->sg_length >= 512) && (((cmd->result >> 16) & 0xf) == DID_OK))
  {
    long *ptr;
    int x, i;


    if (rq_data_dir(cmd->request) == WRITE)
    {
      aic_dev->w_total++;
      ptr = aic_dev->w_bins;
    }
    else
    {
      aic_dev->r_total++;
      ptr = aic_dev->r_bins;
    }
    if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER)
    {
      aic_dev->barrier_total++;
      if(scb->tag_action == MSG_ORDERED_Q_TAG)
        aic_dev->ordered_total++;
    }
    x = scb->sg_length;
    x >>= 10;
    for(i=0; i<6; i++)
    {
      x >>= 2;
      if(!x) {
        ptr[i]++;
        break;
      }
    }
    if(i == 6 && x)
      ptr[5]++;
  }
  aic7xxx_free_scb(p, scb);
  aic7xxx_queue_cmd_complete(p, cmd);

}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_run_done_queue
 *
 * Description:
 *   Calls the aic7xxx_done() for the scsi_cmnd of each scb in the
 *   aborted list, and adds each scb to the free list.  If complete
 *   is TRUE, we also process the commands complete list.
 *-F*************************************************************************/
static void
aic7xxx_run_done_queue(struct aic7xxx_host *p, /*complete*/ int complete)
{
  struct aic7xxx_scb *scb;
  int i, found = 0;

  for (i = 0; i < p->scb_data->numscbs; i++)
  {
    scb = p->scb_data->scb_array[i];
    if (scb->flags & SCB_QUEUED_FOR_DONE)
    {
      if (scb->flags & SCB_QUEUE_FULL)
      {
        scb->cmd->result = QUEUE_FULL << 1;
      }
      else
      {
        if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
          printk(INFO_LEAD "Aborting scb %d\n",
               p->host_no, CTL_OF_SCB(scb), scb->hscb->tag);
        /*
         * Clear any residual information since the normal aic7xxx_done() path
         * doesn't touch the residuals.
         */
        scb->hscb->residual_SG_segment_count = 0;
        scb->hscb->residual_data_count[0] = 0;
        scb->hscb->residual_data_count[1] = 0;
        scb->hscb->residual_data_count[2] = 0;
      }
      found++;
      aic7xxx_done(p, scb);
    }
  }
  if (aic7xxx_verbose & (VERBOSE_ABORT_RETURN | VERBOSE_RESET_RETURN))
  {
    printk(INFO_LEAD "%d commands found and queued for "
        "completion.\n", p->host_no, -1, -1, -1, found);
  }
  if (complete)
  {
    aic7xxx_done_cmds_complete(p);
  }
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_abort_waiting_scb
 *
 * Description:
 *   Manipulate the waiting for selection list and return the
 *   scb that follows the one that we remove.
 *-F*************************************************************************/
static unsigned char
aic7xxx_abort_waiting_scb(struct aic7xxx_host *p, struct aic7xxx_scb *scb,
    unsigned char scbpos, unsigned char prev)
{
  unsigned char curscb, next;

  /*
   * Select the SCB we want to abort and pull the next pointer out of it.
   */
  curscb = aic_inb(p, SCBPTR);
  aic_outb(p, scbpos, SCBPTR);
  next = aic_inb(p, SCB_NEXT);

  aic7xxx_add_curscb_to_free_list(p);

  /*
   * Update the waiting list
   */
  if (prev == SCB_LIST_NULL)
  {
    /*
     * First in the list
     */
    aic_outb(p, next, WAITING_SCBH);
  }
  else
  {
    /*
     * Select the scb that pointed to us and update its next pointer.
     */
    aic_outb(p, prev, SCBPTR);
    aic_outb(p, next, SCB_NEXT);
  }
  /*
   * Point us back at the original scb position and inform the SCSI
   * system that the command has been aborted.
   */
  aic_outb(p, curscb, SCBPTR);
  return (next);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_search_qinfifo
 *
 * Description:
 *   Search the queue-in FIFO for matching SCBs and conditionally
 *   requeue.  Returns the number of matching SCBs.
 *-F*************************************************************************/
static int
aic7xxx_search_qinfifo(struct aic7xxx_host *p, int target, int channel,
    int lun, unsigned char tag, int flags, int requeue,
    volatile scb_queue_type *queue)
{
  int      found;
  unsigned char qinpos, qintail;
  struct aic7xxx_scb *scbp;

  found = 0;
  qinpos = aic_inb(p, QINPOS);
  qintail = p->qinfifonext;

  p->qinfifonext = qinpos;

  while (qinpos != qintail)
  {
    scbp = p->scb_data->scb_array[p->qinfifo[qinpos++]];
    if (aic7xxx_match_scb(p, scbp, target, channel, lun, tag))
    {
       /*
        * We found an scb that needs to be removed.
        */
       if (requeue && (queue != NULL))
       {
         if (scbp->flags & SCB_WAITINGQ)
         {
           scbq_remove(queue, scbp);
           scbq_remove(&p->waiting_scbs, scbp);
           scbq_remove(&AIC_DEV(scbp->cmd)->delayed_scbs, scbp);
           AIC_DEV(scbp->cmd)->active_cmds++;
           p->activescbs++;
         }
         scbq_insert_tail(queue, scbp);
         AIC_DEV(scbp->cmd)->active_cmds--;
         p->activescbs--;
         scbp->flags |= SCB_WAITINGQ;
         if ( !(scbp->tag_action & TAG_ENB) )
         {
           aic7xxx_index_busy_target(p, scbp->hscb->target_channel_lun,
             TRUE);
         }
       }
       else if (requeue)
       {
         p->qinfifo[p->qinfifonext++] = scbp->hscb->tag;
       }
       else
       {
        /*
         * Preserve any SCB_RECOVERY_SCB flags on this scb then set the
         * flags we were called with, presumeably so aic7xxx_run_done_queue
         * can find this scb
         */
         scbp->flags = flags | (scbp->flags & SCB_RECOVERY_SCB);
         if (aic7xxx_index_busy_target(p, scbp->hscb->target_channel_lun,
                                       FALSE) == scbp->hscb->tag)
         {
           aic7xxx_index_busy_target(p, scbp->hscb->target_channel_lun,
             TRUE);
         }
       }
       found++;
    }
    else
    {
      p->qinfifo[p->qinfifonext++] = scbp->hscb->tag;
    }
  }
  /*
   * Now that we've done the work, clear out any left over commands in the
   * qinfifo and update the KERNEL_QINPOS down on the card.
   *
   *  NOTE: This routine expect the sequencer to already be paused when
   *        it is run....make sure it's that way!
   */
  qinpos = p->qinfifonext;
  while(qinpos != qintail)
  {
    p->qinfifo[qinpos++] = SCB_LIST_NULL;
  }
  if (p->features & AHC_QUEUE_REGS)
    aic_outb(p, p->qinfifonext, HNSCB_QOFF);
  else
    aic_outb(p, p->qinfifonext, KERNEL_QINPOS);

  return (found);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_scb_on_qoutfifo
 *
 * Description:
 *   Is the scb that was passed to us currently on the qoutfifo?
 *-F*************************************************************************/
static int
aic7xxx_scb_on_qoutfifo(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
  int i=0;

  while(p->qoutfifo[(p->qoutfifonext + i) & 0xff ] != SCB_LIST_NULL)
  {
    if(p->qoutfifo[(p->qoutfifonext + i) & 0xff ] == scb->hscb->tag)
      return TRUE;
    else
      i++;
  }
  return FALSE;
}


/*+F*************************************************************************
 * Function:
 *   aic7xxx_reset_device
 *
 * Description:
 *   The device at the given target/channel has been reset.  Abort
 *   all active and queued scbs for that target/channel.  This function
 *   need not worry about linked next pointers because if was a MSG_ABORT_TAG
 *   then we had a tagged command (no linked next), if it was MSG_ABORT or
 *   MSG_BUS_DEV_RESET then the device won't know about any commands any more
 *   and no busy commands will exist, and if it was a bus reset, then nothing
 *   knows about any linked next commands any more.  In all cases, we don't
 *   need to worry about the linked next or busy scb, we just need to clear
 *   them.
 *-F*************************************************************************/
static void
aic7xxx_reset_device(struct aic7xxx_host *p, int target, int channel,
                     int lun, unsigned char tag)
{
  struct aic7xxx_scb *scbp, *prev_scbp;
  struct scsi_device *sd;
  unsigned char active_scb, tcl, scb_tag;
  int i = 0, init_lists = FALSE;
  struct aic_dev_data *aic_dev;

  /*
   * Restore this when we're done
   */
  active_scb = aic_inb(p, SCBPTR);
  scb_tag = aic_inb(p, SCB_TAG);

  if (aic7xxx_verbose & (VERBOSE_RESET_PROCESS | VERBOSE_ABORT_PROCESS))
  {
    printk(INFO_LEAD "Reset device, hardware_scb %d,\n",
         p->host_no, channel, target, lun, active_scb);
    printk(INFO_LEAD "Current scb %d, SEQADDR 0x%x, LASTPHASE "
           "0x%x\n",
         p->host_no, channel, target, lun, scb_tag,
         aic_inb(p, SEQADDR0) | (aic_inb(p, SEQADDR1) << 8),
         aic_inb(p, LASTPHASE));
    printk(INFO_LEAD "SG_CACHEPTR 0x%x, SG_COUNT %d, SCSISIGI 0x%x\n",
         p->host_no, channel, target, lun,
         (p->features & AHC_ULTRA2) ?  aic_inb(p, SG_CACHEPTR) : 0,
         aic_inb(p, SG_COUNT), aic_inb(p, SCSISIGI));
    printk(INFO_LEAD "SSTAT0 0x%x, SSTAT1 0x%x, SSTAT2 0x%x\n",
         p->host_no, channel, target, lun, aic_inb(p, SSTAT0),
         aic_inb(p, SSTAT1), aic_inb(p, SSTAT2));
  }

  /*
   * Deal with the busy target and linked next issues.
   */
  list_for_each_entry(aic_dev, &p->aic_devs, list)
  {
    if (aic7xxx_verbose & (VERBOSE_RESET_PROCESS | VERBOSE_ABORT_PROCESS))
      printk(INFO_LEAD "processing aic_dev %p\n", p->host_no, channel, target,
                    lun, aic_dev);
    sd = aic_dev->SDptr;

    if((target != ALL_TARGETS && target != sd->id) ||
       (channel != ALL_CHANNELS && channel != sd->channel))
      continue;
    if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
        printk(INFO_LEAD "Cleaning up status information "
          "and delayed_scbs.\n", p->host_no, sd->channel, sd->id, sd->lun);
    aic_dev->flags &= ~BUS_DEVICE_RESET_PENDING;
    if ( tag == SCB_LIST_NULL )
    {
      aic_dev->dtr_pending = 0;
      aic_dev->needppr = aic_dev->needppr_copy;
      aic_dev->needsdtr = aic_dev->needsdtr_copy;
      aic_dev->needwdtr = aic_dev->needwdtr_copy;
      aic_dev->flags = DEVICE_PRINT_DTR;
      aic_dev->temp_q_depth = aic_dev->max_q_depth;
    }
    tcl = (sd->id << 4) | (sd->channel << 3) | sd->lun;
    if ( (aic7xxx_index_busy_target(p, tcl, FALSE) == tag) ||
         (tag == SCB_LIST_NULL) )
      aic7xxx_index_busy_target(p, tcl, /* unbusy */ TRUE);
    prev_scbp = NULL; 
    scbp = aic_dev->delayed_scbs.head;
    while (scbp != NULL)
    {
      prev_scbp = scbp;
      scbp = scbp->q_next;
      if (aic7xxx_match_scb(p, prev_scbp, target, channel, lun, tag))
      {
        scbq_remove(&aic_dev->delayed_scbs, prev_scbp);
        if (prev_scbp->flags & SCB_WAITINGQ)
        {
          aic_dev->active_cmds++;
          p->activescbs++;
        }
        prev_scbp->flags &= ~(SCB_ACTIVE | SCB_WAITINGQ);
        prev_scbp->flags |= SCB_RESET | SCB_QUEUED_FOR_DONE;
      }
    }
  }

  if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
    printk(INFO_LEAD "Cleaning QINFIFO.\n", p->host_no, channel, target, lun );
  aic7xxx_search_qinfifo(p, target, channel, lun, tag,
      SCB_RESET | SCB_QUEUED_FOR_DONE, /* requeue */ FALSE, NULL);

/*
 *  Search the waiting_scbs queue for matches, this catches any SCB_QUEUED
 *  ABORT/RESET commands.
 */
  if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
    printk(INFO_LEAD "Cleaning waiting_scbs.\n", p->host_no, channel,
      target, lun );
  {
    struct aic7xxx_scb *scbp, *prev_scbp;

    prev_scbp = NULL; 
    scbp = p->waiting_scbs.head;
    while (scbp != NULL)
    {
      prev_scbp = scbp;
      scbp = scbp->q_next;
      if (aic7xxx_match_scb(p, prev_scbp, target, channel, lun, tag))
      {
        scbq_remove(&p->waiting_scbs, prev_scbp);
        if (prev_scbp->flags & SCB_WAITINGQ)
        {
          AIC_DEV(prev_scbp->cmd)->active_cmds++;
          p->activescbs++;
        }
        prev_scbp->flags &= ~(SCB_ACTIVE | SCB_WAITINGQ);
        prev_scbp->flags |= SCB_RESET | SCB_QUEUED_FOR_DONE;
      }
    }
  }


  /*
   * Search waiting for selection list.
   */
  if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
    printk(INFO_LEAD "Cleaning waiting for selection "
      "list.\n", p->host_no, channel, target, lun);
  {
    unsigned char next, prev, scb_index;

    next = aic_inb(p, WAITING_SCBH);  /* Start at head of list. */
    prev = SCB_LIST_NULL;
    while (next != SCB_LIST_NULL)
    {
      aic_outb(p, next, SCBPTR);
      scb_index = aic_inb(p, SCB_TAG);
      if (scb_index >= p->scb_data->numscbs)
      {
       /*
        * No aic7xxx_verbose check here.....we want to see this since it
        * means either the kernel driver or the sequencer screwed things up
        */
        printk(WARN_LEAD "Waiting List inconsistency; SCB index=%d, "
          "numscbs=%d\n", p->host_no, channel, target, lun, scb_index,
          p->scb_data->numscbs);
        next = aic_inb(p, SCB_NEXT);
        aic7xxx_add_curscb_to_free_list(p);
      }
      else
      {
        scbp = p->scb_data->scb_array[scb_index];
        if (aic7xxx_match_scb(p, scbp, target, channel, lun, tag))
        {
          next = aic7xxx_abort_waiting_scb(p, scbp, next, prev);
          if (scbp->flags & SCB_WAITINGQ)
          {
            AIC_DEV(scbp->cmd)->active_cmds++;
            p->activescbs++;
          }
          scbp->flags &= ~(SCB_ACTIVE | SCB_WAITINGQ);
          scbp->flags |= SCB_RESET | SCB_QUEUED_FOR_DONE;
          if (prev == SCB_LIST_NULL)
          {
            /*
             * This is either the first scb on the waiting list, or we
             * have already yanked the first and haven't left any behind.
             * Either way, we need to turn off the selection hardware if
             * it isn't already off.
             */
            aic_outb(p, aic_inb(p, SCSISEQ) & ~ENSELO, SCSISEQ);
            aic_outb(p, CLRSELTIMEO, CLRSINT1);
          }
        }
        else
        {
          prev = next;
          next = aic_inb(p, SCB_NEXT);
        }
      }
    }
  }

  /*
   * Go through disconnected list and remove any entries we have queued
   * for completion, zeroing their control byte too.
   */
  if (aic7xxx_verbose & (VERBOSE_ABORT_PROCESS | VERBOSE_RESET_PROCESS))
    printk(INFO_LEAD "Cleaning disconnected scbs "
      "list.\n", p->host_no, channel, target, lun);
  if (p->flags & AHC_PAGESCBS)
  {
    unsigned char next, prev, scb_index;

    next = aic_inb(p, DISCONNECTED_SCBH);
    prev = SCB_LIST_NULL;
    while (next != SCB_LIST_NULL)
    {
      aic_outb(p, next, SCBPTR);
      scb_index = aic_inb(p, SCB_TAG);
      if (scb_index > p->scb_data->numscbs)
      {
        printk(WARN_LEAD "Disconnected List inconsistency; SCB index=%d, "
          "numscbs=%d\n", p->host_no, channel, target, lun, scb_index,
          p->scb_data->numscbs);
        next = aic7xxx_rem_scb_from_disc_list(p, next, prev);
      }
      else
      {
        scbp = p->scb_data->scb_array[scb_index];
        if (aic7xxx_match_scb(p, scbp, target, channel, lun, tag))
        {
          next = aic7xxx_rem_scb_from_disc_list(p, next, prev);
          if (scbp->flags & SCB_WAITINGQ)
          {
            AIC_DEV(scbp->cmd)->active_cmds++;
            p->activescbs++;
          }
          scbp->flags &= ~(SCB_ACTIVE | SCB_WAITINGQ);
          scbp->flags |= SCB_RESET | SCB_QUEUED_FOR_DONE;
          scbp->hscb->control = 0;
        }
        else
        {
          prev = next;
          next = aic_inb(p, SCB_NEXT);
        }
      }
    }
  }

  /*
   * Walk the free list making sure no entries on the free list have
   * a valid SCB_TAG value or SCB_CONTROL byte.
   */
  if (p->flags & AHC_PAGESCBS)
  {
    unsigned char next;

    next = aic_inb(p, FREE_SCBH);
    while (next != SCB_LIST_NULL)
    {
      aic_outb(p, next, SCBPTR);
      if (aic_inb(p, SCB_TAG) < p->scb_data->numscbs)
      {
        printk(WARN_LEAD "Free list inconsistency!.\n", p->host_no, channel,
          target, lun);
        init_lists = TRUE;
        next = SCB_LIST_NULL;
      }
      else
      {
        aic_outb(p, SCB_LIST_NULL, SCB_TAG);
        aic_outb(p, 0, SCB_CONTROL);
        next = aic_inb(p, SCB_NEXT);
      }
    }
  }

  /*
   * Go through the hardware SCB array looking for commands that
   * were active but not on any list.
   */
  if (init_lists)
  {
    aic_outb(p, SCB_LIST_NULL, FREE_SCBH);
    aic_outb(p, SCB_LIST_NULL, WAITING_SCBH);
    aic_outb(p, SCB_LIST_NULL, DISCONNECTED_SCBH);
  }
  for (i = p->scb_data->maxhscbs - 1; i >= 0; i--)
  {
    unsigned char scbid;

    aic_outb(p, i, SCBPTR);
    if (init_lists)
    {
      aic_outb(p, SCB_LIST_NULL, SCB_TAG);
      aic_outb(p, SCB_LIST_NULL, SCB_NEXT);
      aic_outb(p, 0, SCB_CONTROL);
      aic7xxx_add_curscb_to_free_list(p);
    }
    else
    {
      scbid = aic_inb(p, SCB_TAG);
      if (scbid < p->scb_data->numscbs)
      {
        scbp = p->scb_data->scb_array[scbid];
        if (aic7xxx_match_scb(p, scbp, target, channel, lun, tag))
        {
          aic_outb(p, 0, SCB_CONTROL);
          aic_outb(p, SCB_LIST_NULL, SCB_TAG);
          aic7xxx_add_curscb_to_free_list(p);
        }
      }
    }
  }

  /*
   * Go through the entire SCB array now and look for commands for
   * for this target that are stillactive.  These are other (most likely
   * tagged) commands that were disconnected when the reset occurred.
   * Any commands we find here we know this about, it wasn't on any queue,
   * it wasn't in the qinfifo, it wasn't in the disconnected or waiting
   * lists, so it really must have been a paged out SCB.  In that case,
   * we shouldn't need to bother with updating any counters, just mark
   * the correct flags and go on.
   */
  for (i = 0; i < p->scb_data->numscbs; i++)
  {
    scbp = p->scb_data->scb_array[i];
    if ((scbp->flags & SCB_ACTIVE) &&
        aic7xxx_match_scb(p, scbp, target, channel, lun, tag) &&
        !aic7xxx_scb_on_qoutfifo(p, scbp))
    {
      if (scbp->flags & SCB_WAITINGQ)
      {
        scbq_remove(&p->waiting_scbs, scbp);
        scbq_remove(&AIC_DEV(scbp->cmd)->delayed_scbs, scbp);
        AIC_DEV(scbp->cmd)->active_cmds++;
        p->activescbs++;
      }
      scbp->flags |= SCB_RESET | SCB_QUEUED_FOR_DONE;
      scbp->flags &= ~(SCB_ACTIVE | SCB_WAITINGQ);
    }
  }

  aic_outb(p, active_scb, SCBPTR);
}


/*+F*************************************************************************
 * Function:
 *   aic7xxx_clear_intstat
 *
 * Description:
 *   Clears the interrupt status.
 *-F*************************************************************************/
static void
aic7xxx_clear_intstat(struct aic7xxx_host *p)
{
  /* Clear any interrupt conditions this may have caused. */
  aic_outb(p, CLRSELDO | CLRSELDI | CLRSELINGO, CLRSINT0);
  aic_outb(p, CLRSELTIMEO | CLRATNO | CLRSCSIRSTI | CLRBUSFREE | CLRSCSIPERR |
       CLRPHASECHG | CLRREQINIT, CLRSINT1);
  aic_outb(p, CLRSCSIINT | CLRSEQINT | CLRBRKADRINT | CLRPARERR, CLRINT);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_reset_current_bus
 *
 * Description:
 *   Reset the current SCSI bus.
 *-F*************************************************************************/
static void
aic7xxx_reset_current_bus(struct aic7xxx_host *p)
{

  /* Disable reset interrupts. */
  aic_outb(p, aic_inb(p, SIMODE1) & ~ENSCSIRST, SIMODE1);

  /* Turn off the bus' current operations, after all, we shouldn't have any
   * valid commands left to cause a RSELI and SELO once we've tossed the
   * bus away with this reset, so we might as well shut down the sequencer
   * until the bus is restarted as oppossed to saving the current settings
   * and restoring them (which makes no sense to me). */

  /* Turn on the bus reset. */
  aic_outb(p, aic_inb(p, SCSISEQ) | SCSIRSTO, SCSISEQ);
  while ( (aic_inb(p, SCSISEQ) & SCSIRSTO) == 0)
    mdelay(5);

  /*
   * Some of the new Ultra2 chipsets need a longer delay after a chip
   * reset than just the init setup creates, so we have to delay here
   * before we go into a reset in order to make the chips happy.
   */
  if (p->features & AHC_ULTRA2)
    mdelay(250);
  else
    mdelay(50);

  /* Turn off the bus reset. */
  aic_outb(p, 0, SCSISEQ);
  mdelay(10);

  aic7xxx_clear_intstat(p);
  /* Re-enable reset interrupts. */
  aic_outb(p, aic_inb(p, SIMODE1) | ENSCSIRST, SIMODE1);

}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_reset_channel
 *
 * Description:
 *   Reset the channel.
 *-F*************************************************************************/
static void
aic7xxx_reset_channel(struct aic7xxx_host *p, int channel, int initiate_reset)
{
  unsigned long offset_min, offset_max;
  unsigned char sblkctl;
  int cur_channel;

  if (aic7xxx_verbose & VERBOSE_RESET_PROCESS)
    printk(INFO_LEAD "Reset channel called, %s initiate reset.\n",
      p->host_no, channel, -1, -1, (initiate_reset==TRUE) ? "will" : "won't" );


  if (channel == 1)
  {
    offset_min = 8;
    offset_max = 16;
  }
  else
  {
    if (p->features & AHC_TWIN)
    {
      /* Channel A */
      offset_min = 0;
      offset_max = 8;
    }
    else
    {
      offset_min = 0;
      if (p->features & AHC_WIDE)
      {
        offset_max = 16;
      }
      else
      {
        offset_max = 8;
      }
    }
  }

  while (offset_min < offset_max)
  {
    /*
     * Revert to async/narrow transfers until we renegotiate.
     */
    aic_outb(p, 0, TARG_SCSIRATE + offset_min);
    if (p->features & AHC_ULTRA2)
    {
      aic_outb(p, 0, TARG_OFFSET + offset_min);
    }
    offset_min++;
  }

  /*
   * Reset the bus and unpause/restart the controller
   */
  sblkctl = aic_inb(p, SBLKCTL);
  if ( (p->chip & AHC_CHIPID_MASK) == AHC_AIC7770 )
    cur_channel = (sblkctl & SELBUSB) >> 3;
  else
    cur_channel = 0;
  if ( (cur_channel != channel) && (p->features & AHC_TWIN) )
  {
    /*
     * Case 1: Command for another bus is active
     */
    if (aic7xxx_verbose & VERBOSE_RESET_PROCESS)
      printk(INFO_LEAD "Stealthily resetting idle channel.\n", p->host_no,
        channel, -1, -1);
    /*
     * Stealthily reset the other bus without upsetting the current bus.
     */
    aic_outb(p, sblkctl ^ SELBUSB, SBLKCTL);
    aic_outb(p, aic_inb(p, SIMODE1) & ~ENBUSFREE, SIMODE1);
    if (initiate_reset)
    {
      aic7xxx_reset_current_bus(p);
    }
    aic_outb(p, aic_inb(p, SCSISEQ) & (ENSELI|ENRSELI|ENAUTOATNP), SCSISEQ);
    aic7xxx_clear_intstat(p);
    aic_outb(p, sblkctl, SBLKCTL);
  }
  else
  {
    /*
     * Case 2: A command from this bus is active or we're idle.
     */
    if (aic7xxx_verbose & VERBOSE_RESET_PROCESS)
      printk(INFO_LEAD "Resetting currently active channel.\n", p->host_no,
        channel, -1, -1);
    aic_outb(p, aic_inb(p, SIMODE1) & ~(ENBUSFREE|ENREQINIT),
      SIMODE1);
    p->flags &= ~AHC_HANDLING_REQINITS;
    p->msg_type = MSG_TYPE_NONE;
    p->msg_len = 0;
    if (initiate_reset)
    {
      aic7xxx_reset_current_bus(p);
    }
    aic_outb(p, aic_inb(p, SCSISEQ) & (ENSELI|ENRSELI|ENAUTOATNP), SCSISEQ);
    aic7xxx_clear_intstat(p);
  }
  if (aic7xxx_verbose & VERBOSE_RESET_RETURN)
    printk(INFO_LEAD "Channel reset\n", p->host_no, channel, -1, -1);
  /*
   * Clean up all the state information for the pending transactions
   * on this bus.
   */
  aic7xxx_reset_device(p, ALL_TARGETS, channel, ALL_LUNS, SCB_LIST_NULL);

  if ( !(p->features & AHC_TWIN) )
  {
    restart_sequencer(p);
  }

  return;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_run_waiting_queues
 *
 * Description:
 *   Scan the awaiting_scbs queue downloading and starting as many
 *   scbs as we can.
 *-F*************************************************************************/
static void
aic7xxx_run_waiting_queues(struct aic7xxx_host *p)
{
  struct aic7xxx_scb *scb;
  struct aic_dev_data *aic_dev;
  int sent;


  if (p->waiting_scbs.head == NULL)
    return;

  sent = 0;

  /*
   * First handle SCBs that are waiting but have been assigned a slot.
   */
  while ((scb = scbq_remove_head(&p->waiting_scbs)) != NULL)
  {
    aic_dev = scb->cmd->device->hostdata;
    if ( !scb->tag_action )
    {
      aic_dev->temp_q_depth = 1;
    }
    if ( aic_dev->active_cmds >= aic_dev->temp_q_depth)
    {
      scbq_insert_tail(&aic_dev->delayed_scbs, scb);
    }
    else
    {
        scb->flags &= ~SCB_WAITINGQ;
        aic_dev->active_cmds++;
        p->activescbs++;
        if ( !(scb->tag_action) )
        {
          aic7xxx_busy_target(p, scb);
        }
        p->qinfifo[p->qinfifonext++] = scb->hscb->tag;
        sent++;
    }
  }
  if (sent)
  {
    if (p->features & AHC_QUEUE_REGS)
      aic_outb(p, p->qinfifonext, HNSCB_QOFF);
    else
    {
      pause_sequencer(p);
      aic_outb(p, p->qinfifonext, KERNEL_QINPOS);
      unpause_sequencer(p, FALSE);
    }
    if (p->activescbs > p->max_activescbs)
      p->max_activescbs = p->activescbs;
  }
}

#ifdef CONFIG_PCI

#define  DPE 0x80
#define  SSE 0x40
#define  RMA 0x20
#define  RTA 0x10
#define  STA 0x08
#define  DPR 0x01

/*+F*************************************************************************
 * Function:
 *   aic7xxx_pci_intr
 *
 * Description:
 *   Check the scsi card for PCI errors and clear the interrupt
 *
 *   NOTE: If you don't have this function and a 2940 card encounters
 *         a PCI error condition, the machine will end up locked as the
 *         interrupt handler gets slammed with non-stop PCI error interrupts
 *-F*************************************************************************/
static void
aic7xxx_pci_intr(struct aic7xxx_host *p)
{
  unsigned char status1;

  pci_read_config_byte(p->pdev, PCI_STATUS + 1, &status1);

  if ( (status1 & DPE) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Data Parity Error during PCI address or PCI write"
      "phase.\n", p->host_no, -1, -1, -1);
  if ( (status1 & SSE) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Signal System Error Detected\n", p->host_no,
      -1, -1, -1);
  if ( (status1 & RMA) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Received a PCI Master Abort\n", p->host_no,
      -1, -1, -1);
  if ( (status1 & RTA) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Received a PCI Target Abort\n", p->host_no,
      -1, -1, -1);
  if ( (status1 & STA) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Signaled a PCI Target Abort\n", p->host_no,
      -1, -1, -1);
  if ( (status1 & DPR) && (aic7xxx_verbose & VERBOSE_MINOR_ERROR) )
    printk(WARN_LEAD "Data Parity Error has been reported via PCI pin "
      "PERR#\n", p->host_no, -1, -1, -1);
  
  pci_write_config_byte(p->pdev, PCI_STATUS + 1, status1);
  if (status1 & (DPR|RMA|RTA))
    aic_outb(p,  CLRPARERR, CLRINT);

  if ( (aic7xxx_panic_on_abort) && (p->spurious_int > 500) )
    aic7xxx_panic_abort(p, NULL);

}
#endif /* CONFIG_PCI */

/*+F*************************************************************************
 * Function:
 *   aic7xxx_construct_ppr
 *
 * Description:
 *   Build up a Parallel Protocol Request message for use with SCSI-3
 *   devices.
 *-F*************************************************************************/
static void
aic7xxx_construct_ppr(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
  p->msg_buf[p->msg_index++] = MSG_EXTENDED;
  p->msg_buf[p->msg_index++] = MSG_EXT_PPR_LEN;
  p->msg_buf[p->msg_index++] = MSG_EXT_PPR;
  p->msg_buf[p->msg_index++] = AIC_DEV(scb->cmd)->goal.period;
  p->msg_buf[p->msg_index++] = 0;
  p->msg_buf[p->msg_index++] = AIC_DEV(scb->cmd)->goal.offset;
  p->msg_buf[p->msg_index++] = AIC_DEV(scb->cmd)->goal.width;
  p->msg_buf[p->msg_index++] = AIC_DEV(scb->cmd)->goal.options;
  p->msg_len += 8;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_construct_sdtr
 *
 * Description:
 *   Constucts a synchronous data transfer message in the message
 *   buffer on the sequencer.
 *-F*************************************************************************/
static void
aic7xxx_construct_sdtr(struct aic7xxx_host *p, unsigned char period,
        unsigned char offset)
{
  p->msg_buf[p->msg_index++] = MSG_EXTENDED;
  p->msg_buf[p->msg_index++] = MSG_EXT_SDTR_LEN;
  p->msg_buf[p->msg_index++] = MSG_EXT_SDTR;
  p->msg_buf[p->msg_index++] = period;
  p->msg_buf[p->msg_index++] = offset;
  p->msg_len += 5;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_construct_wdtr
 *
 * Description:
 *   Constucts a wide data transfer message in the message buffer
 *   on the sequencer.
 *-F*************************************************************************/
static void
aic7xxx_construct_wdtr(struct aic7xxx_host *p, unsigned char bus_width)
{
  p->msg_buf[p->msg_index++] = MSG_EXTENDED;
  p->msg_buf[p->msg_index++] = MSG_EXT_WDTR_LEN;
  p->msg_buf[p->msg_index++] = MSG_EXT_WDTR;
  p->msg_buf[p->msg_index++] = bus_width;
  p->msg_len += 4;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_calc_residual
 *
 * Description:
 *   Calculate the residual data not yet transferred.
 *-F*************************************************************************/
static void
aic7xxx_calculate_residual (struct aic7xxx_host *p, struct aic7xxx_scb *scb)
{
        struct aic7xxx_hwscb *hscb;
        struct scsi_cmnd *cmd;
        int actual, i;

  cmd = scb->cmd;
  hscb = scb->hscb;

  /*
   *  Don't destroy valid residual information with
   *  residual coming from a check sense operation.
   */
  if (((scb->hscb->control & DISCONNECTED) == 0) &&
      (scb->flags & SCB_SENSE) == 0)
  {
    /*
     *  We had an underflow. At this time, there's only
     *  one other driver that bothers to check for this,
     *  and cmd->underflow seems to be set rather half-
     *  heartedly in the higher-level SCSI code.
     */
    actual = scb->sg_length;
    for (i=1; i < hscb->residual_SG_segment_count; i++)
    {
      actual -= scb->sg_list[scb->sg_count - i].length;
    }
    actual -= (hscb->residual_data_count[2] << 16) |
              (hscb->residual_data_count[1] <<  8) |
              hscb->residual_data_count[0];

    if (actual < cmd->underflow)
    {
      if (aic7xxx_verbose & VERBOSE_MINOR_ERROR)
      {
        printk(INFO_LEAD "Underflow - Wanted %u, %s %u, residual SG "
          "count %d.\n", p->host_no, CTL_OF_SCB(scb), cmd->underflow,
          (rq_data_dir(cmd->request) == WRITE) ? "wrote" : "read", actual,
          hscb->residual_SG_segment_count);
        printk(INFO_LEAD "status 0x%x.\n", p->host_no, CTL_OF_SCB(scb),
          hscb->target_status);
      }
      /*
       * In 2.4, only send back the residual information, don't flag this
       * as an error.  Before 2.4 we had to flag this as an error because
       * the mid layer didn't check residual data counts to see if the
       * command needs retried.
       */
      scsi_set_resid(cmd, scb->sg_length - actual);
      aic7xxx_status(cmd) = hscb->target_status;
    }
  }

  /*
   * Clean out the residual information in the SCB for the
   * next consumer.
   */
  hscb->residual_data_count[2] = 0;
  hscb->residual_data_count[1] = 0;
  hscb->residual_data_count[0] = 0;
  hscb->residual_SG_segment_count = 0;
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_handle_device_reset
 *
 * Description:
 *   Interrupt handler for sequencer interrupts (SEQINT).
 *-F*************************************************************************/
static void
aic7xxx_handle_device_reset(struct aic7xxx_host *p, int target, int channel)
{
  unsigned char tindex = target;

  tindex |= ((channel & 0x01) << 3);

  /*
   * Go back to async/narrow transfers and renegotiate.
   */
  aic_outb(p, 0, TARG_SCSIRATE + tindex);
  if (p->features & AHC_ULTRA2)
    aic_outb(p, 0, TARG_OFFSET + tindex);
  aic7xxx_reset_device(p, target, channel, ALL_LUNS, SCB_LIST_NULL);
  if (aic7xxx_verbose & VERBOSE_RESET_PROCESS)
    printk(INFO_LEAD "Bus Device Reset delivered.\n", p->host_no, channel,
      target, -1);
  aic7xxx_run_done_queue(p, /*complete*/ TRUE);
}

/*+F*************************************************************************
 * Function:
 *   aic7xxx_handle_seqint
 *
 * Description:
 *   Interrupt handler for sequencer interrupts (SEQINT).
 *-F*************************************************************************/
static void
aic7xxx_handle_seqint(struct aic7xxx_host *p, unsigned char intstat)
{
  struct aic7xxx_scb *scb;
  struct aic_dev_data *aic_dev;
  unsigned short target_mask;
  unsigned char target, lun, tindex;
  unsigned char queue_flag = FALSE;
  char channel;
  int result;

  target = ((aic_inb(p, SAVED_TCL) >> 4) & 0x0f);
  if ( (p->chip & AHC_CHIPID_MASK) == AHC_AIC7770 )
    channel = (aic_inb(p, SBLKCTL) & SELBUSB) >> 3;
  else
    channel = 0;
  tindex = target + (channel << 3);
  lun = aic_inb(p, SAVED_TCL) & 0x07;
  target_mask = (0x01 << tindex);

  /*
   * Go ahead and clear the SEQINT now, that avoids any interrupt race
   * conditions later on in case we enable some other interrupt.
   */
  aic_outb(p, CLRSEQINT, CLRINT);
  switch (intstat & SEQINT_MASK)
  {
    case NO_MATCH:
      {
        aic_outb(p, aic_inb(p, SCSISEQ) & (ENSELI|ENRSELI|ENAUTOATNP),
                 SCSISEQ);
        printk(WARN_LEAD "No active SCB for reconnecting target - Issuing "
               "BUS DEVICE RESET.\n", p->host_no, channel, target, lun);
        printk(WARN_LEAD "      SAVED_TCL=0x%x, ARG_1=0x%x, SEQADDR=0x%x\n",
               p->host_no, channel, target, lun,
               aic_inb(p, SAVED_TCL), aic_inb(p, ARG_1),
               (aic_inb(p, SEQADDR1) << 8) | aic_inb(p, SEQADDR0));
        if (aic7xxx_panic_on_abort)
          aic7xxx_panic_abort(p, NULL);
      }
      break;

    case SEND_REJECT:
      {
        if (aic7xxx_verbose & VERBOSE_MINOR_ERROR)
          printk(INFO_LEAD "Rejecting unknown message (0x%x) received from "
            "target, SEQ_FLAGS=0x%x\n", p->host_no, channel, target, lun,
            aic_inb(p, ACCUM), aic_inb(p, SEQ_FLAGS));
      }
      break;

    case NO_IDENT:
      {
        /*
         * The reconnecting target either did not send an identify
         * message, or did, but we didn't find an SCB to match and
         * before it could respond to our ATN/abort, it hit a dataphase.
         * The only safe thing to do is to blow it away with a bus
         * reset.
         */
        if (aic7xxx_verbose & (VERBOSE_SEQINT | VERBOSE_RESET_MID))
          printk(INFO_LEAD "Target did not send an IDENTIFY message; "
            "LASTPHASE 0x%x, SAVED_TCL 0x%x\n", p->host_no, channel, target,
            lun, aic_inb(p, LASTPHASE), aic_inb(p, SAVED_TCL));

        aic7xxx_reset_channel(p, channel, /*initiate reset*/ TRUE);
        aic7xxx_run_done_queue(p, TRUE);

      }
      break;

    case BAD_PHASE:
      if (aic_inb(p, LASTPHASE) == P_BUSFREE)
      {
        if (aic7xxx_verbose & VERBOSE_SEQINT)
          printk(INFO_LEAD "Missed busfree.\n", p->host_no, channel,
            target, lun);
        restart_sequencer(p);
      }
      else
      {
        if (aic7xxx_verbose & VERBOSE_SEQINT)
          printk(INFO_LEAD "Unknown scsi bus phase, continuing\n", p->host_no,
            channel, target, lun);
      }
      break;

    case EXTENDED_MSG:
      {