/* $Id: $
 *  linux/drivers/scsi/wd7000.c
 *
 *  Copyright (C) 1992  Thomas Wuensche
 *	closely related to the aha1542 driver from Tommy Thorn
 *	( as close as different hardware allows on a lowlevel-driver :-) )
 *
 *  Revised (and renamed) by John Boyd <boyd@cis.ohio-state.edu> to
 *  accommodate Eric Youngdale's modifications to scsi.c.  Nov 1992.
 *
 *  Additional changes to support scatter/gather.  Dec. 1992.  tw/jb
 *
 *  No longer tries to reset SCSI bus at boot (it wasn't working anyway).
 *  Rewritten to support multiple host adapters.
 *  Miscellaneous cleanup.
 *  So far, still doesn't do reset or abort correctly, since I have no idea
 *  how to do them with this board (8^(.                      Jan 1994 jb
 *
 * This driver now supports both of the two standard configurations (per
 * the 3.36 Owner's Manual, my latest reference) by the same method as
 * before; namely, by looking for a BIOS signature.  Thus, the location of
 * the BIOS signature determines the board configuration.  Until I have
 * time to do something more flexible, users should stick to one of the
 * following:
 *
 * Standard configuration for single-adapter systems:
 *    - BIOS at CE00h
 *    - I/O base address 350h
 *    - IRQ level 15
 *    - DMA channel 6
 * Standard configuration for a second adapter in a system:
 *    - BIOS at C800h
 *    - I/O base address 330h
 *    - IRQ level 11
 *    - DMA channel 5
 *
 * Anyone who can recompile the kernel is welcome to add others as need
 * arises, but unpredictable results may occur if there are conflicts.
 * In any event, if there are multiple adapters in a system, they MUST
 * use different I/O bases, IRQ levels, and DMA channels, since they will be
 * indistinguishable (and in direct conflict) otherwise.
 *
 *   As a point of information, the NO_OP command toggles the CMD_RDY bit
 * of the status port, and this fact could be used as a test for the I/O
 * base address (or more generally, board detection).  There is an interrupt
 * status port, so IRQ probing could also be done.  I suppose the full
 * DMA diagnostic could be used to detect the DMA channel being used.  I
 * haven't done any of this, though, because I think there's too much of
 * a chance that such explorations could be destructive, if some other
 * board's resources are used inadvertently.  So, call me a wimp, but I
 * don't want to try it.  The only kind of exploration I trust is memory
 * exploration, since it's more certain that reading memory won't be
 * destructive.
 *
 * More to my liking would be a LILO boot command line specification, such
 * as is used by the aha152x driver (and possibly others).  I'll look into
 * it, as I have time...
 *
 *   I get mail occasionally from people who either are using or are
 * considering using a WD7000 with Linux.  There is a variety of
 * nomenclature describing WD7000's.  To the best of my knowledge, the
 * following is a brief summary (from an old WD doc - I don't work for
 * them or anything like that):
 *
 * WD7000-FASST2: This is a WD7000 board with the real-mode SST ROM BIOS
 *        installed.  Last I heard, the BIOS was actually done by Columbia
 *        Data Products.  The BIOS is only used by this driver (and thus
 *        by Linux) to identify the board; none of it can be executed under
 *        Linux.
 *
 * WD7000-ASC: This is the original adapter board, with or without BIOS.
 *        The board uses a WD33C93 or WD33C93A SBIC, which in turn is
 *        controlled by an onboard Z80 processor.  The board interface
 *        visible to the host CPU is defined effectively by the Z80's
 *        firmware, and it is this firmware's revision level that is
 *        determined and reported by this driver.  (The version of the
 *        on-board BIOS is of no interest whatsoever.)  The host CPU has
 *        no access to the SBIC; hence the fact that it is a WD33C93 is
 *        also of no interest to this driver.
 *
 * WD7000-AX:
 * WD7000-MX:
 * WD7000-EX: These are newer versions of the WD7000-ASC.  The -ASC is
 *        largely built from discrete components; these boards use more
 *        integration.  The -AX is an ISA bus board (like the -ASC),
 *        the -MX is an MCA (i.e., PS/2) bus board), and the -EX is an
 *        EISA bus board.
 *
 *  At the time of my documentation, the -?X boards were "future" products,
 *  and were not yet available.  However, I vaguely recall that Thomas
 *  Wuensche had an -AX, so I believe at least it is supported by this
 *  driver.  I have no personal knowledge of either -MX or -EX boards.
 *
 *  P.S. Just recently, I've discovered (directly from WD and Future
 *  Domain) that all but the WD7000-EX have been out of production for
 *  two years now.  FD has production rights to the 7000-EX, and are
 *  producing it under a new name, and with a new BIOS.  If anyone has
 *  one of the FD boards, it would be nice to come up with a signature
 *  for it.
 *                                                           J.B. Jan 1994.
 *
 *
 *  Revisions by Miroslav Zagorac <zaga@fly.cc.fer.hr>
 *
 *  08/24/1996.
 *
 *  Enhancement for wd7000_detect function has been made, so you don't have
 *  to enter BIOS ROM address in initialisation data (see struct Config).
 *  We cannot detect IRQ, DMA and I/O base address for now, so we have to
 *  enter them as arguments while wd_7000 is detected. If someone has IRQ,
 *  DMA or I/O base address set to some other value, he can enter them in
 *  configuration without any problem. Also I wrote a function wd7000_setup,
 *  so now you can enter WD-7000 definition as kernel arguments,
 *  as in lilo.conf:
 *
 *     append="wd7000=IRQ,DMA,IO"
 *
 *  PS: If card BIOS ROM is disabled, function wd7000_detect now will recognize
 *      adapter, unlike the old one. Anyway, BIOS ROM from WD7000 adapter is
 *      useless for Linux. B^)
 *
 *
 *  09/06/1996.
 *
 *  Autodetecting of I/O base address from wd7000_detect function is removed,
 *  some little bugs removed, etc...
 *
 *  Thanks to Roger Scott for driver debugging.
 *
 *  06/07/1997
 *
 *  Added support for /proc file system (/proc/scsi/wd7000/[0...] files).
 *  Now, driver can handle hard disks with capacity >1GB.
 *
 *  01/15/1998
 *
 *  Added support for BUS_ON and BUS_OFF parameters in config line.
 *  Miscellaneous cleanup.
 *
 *  03/01/1998
 *
 *  WD7000 driver now work on kernels >= 2.1.x
 */

#ifdef MODULE
#include <linux/module.h>
#endif

#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/malloc.h>
#include <asm/system.h>
#include <asm/spinlock.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/blk.h>
#include <linux/version.h>
#include "scsi.h"
#include "hosts.h"
#include "sd.h"
#include <scsi/scsicam.h>

#define ANY2SCSI_INLINE		/* undef this to use old macros */
#undef  WD7000_DEBUG		/* general debug                */

#include "wd7000.h"
#include <linux/stat.h>


struct proc_dir_entry proc_scsi_wd7000 =
{
    PROC_SCSI_7000FASST,
    6,
    "wd7000",
    S_IFDIR | S_IRUGO | S_IXUGO,
    2
};


/*
 *  Mailbox structure sizes.
 *  I prefer to keep the number of ICMBs much larger than the number of
 *  OGMBs.  OGMBs are used very quickly by the driver to start one or
 *  more commands, while ICMBs are used by the host adapter per command.
 */
#define OGMB_CNT	16
#define ICMB_CNT	32

/*
 *  Scb's are shared by all active adapters.  So, if they all become busy,
 *  callers may be made to wait in alloc_scbs for them to free.  That can
 *  be avoided by setting MAX_SCBS to NUM_CONFIG * WD7000_Q.  If you'd
 *  rather conserve memory, use a smaller number (> 0, of course) - things
 *  will should still work OK.
 */
#define MAX_SCBS        32

/*
 *  WD7000-specific mailbox structure
 *
 */
typedef volatile struct mailbox {
    unchar status;
    unchar scbptr[3];		/* SCSI-style - MSB first (big endian) */
} Mailbox;

/*
 *  This structure should contain all per-adapter global data.  I.e., any
 *  new global per-adapter data should put in here.
 */
typedef struct adapter {
    struct Scsi_Host *sh;	/* Pointer to Scsi_Host structure    */
    int iobase;			/* This adapter's I/O base address   */
    int irq;			/* This adapter's IRQ level          */
    int dma;			/* This adapter's DMA channel        */
    int int_counter;		/* This adapter's interrupt counter  */
    int bus_on;			/* This adapter's BUS_ON time        */
    int bus_off;		/* This adapter's BUS_OFF time       */
    struct {			/* This adapter's mailboxes          */
	Mailbox ogmb[OGMB_CNT];	/* Outgoing mailboxes                */
	Mailbox icmb[ICMB_CNT];	/* Incoming mailboxes                */
    } mb;
    int next_ogmb;		/* to reduce contention at mailboxes */
    unchar control;		/* shadows CONTROL port value        */
    unchar rev1, rev2;		/* filled in by wd7000_revision      */
} Adapter;

/*
 * (linear) base address for ROM BIOS
 */
static const long wd7000_biosaddr[] =
{
    0xc0000, 0xc2000, 0xc4000, 0xc6000, 0xc8000, 0xca000, 0xcc000, 0xce000,
    0xd0000, 0xd2000, 0xd4000, 0xd6000, 0xd8000, 0xda000, 0xdc000, 0xde000
};
#define NUM_ADDRS (sizeof(wd7000_biosaddr)/sizeof(long))

static const unsigned short wd7000_iobase[] =
{
    0x0300, 0x0308, 0x0310, 0x0318, 0x0320, 0x0328, 0x0330, 0x0338,
    0x0340, 0x0348, 0x0350, 0x0358, 0x0360, 0x0368, 0x0370, 0x0378,
    0x0380, 0x0388, 0x0390, 0x0398, 0x03a0, 0x03a8, 0x03b0, 0x03b8,
    0x03c0, 0x03c8, 0x03d0, 0x03d8, 0x03e0, 0x03e8, 0x03f0, 0x03f8
};
#define NUM_IOPORTS (sizeof(wd7000_iobase)/sizeof(unsigned short))

static const short wd7000_irq[] = { 3, 4, 5, 7, 9, 10, 11, 12, 14, 15 };
#define NUM_IRQS (sizeof(wd7000_irq)/sizeof(short))

static const short wd7000_dma[] = { 5, 6, 7 };
#define NUM_DMAS (sizeof(wd7000_dma)/sizeof(short))

/*
 * possible irq range
 */
#define IRQ_MIN   3
#define IRQ_MAX   15
#define IRQS      (IRQ_MAX - IRQ_MIN + 1)

/*
 * The following is set up by wd7000_detect, and used thereafter by
 * wd7000_intr_handle to map the irq level to the corresponding Adapter.
 * Note that if SA_INTERRUPT is not used, wd7000_intr_handle must be
 * changed to pick up the IRQ level correctly.
 */
static struct Scsi_Host *wd7000_host[IRQS];

#define BUS_ON    64	/* x 125ns = 8000ns (BIOS default) */
#define BUS_OFF   15	/* x 125ns = 1875ns (BIOS default) */

/*
 *  Standard Adapter Configurations - used by wd7000_detect
 */
typedef struct {
    short irq;		/* IRQ level                                  */
    short dma;		/* DMA channel                                */
    unsigned iobase;	/* I/O base address                           */
    short bus_on;	/* Time that WD7000 spends on the AT-bus when */
			/* transferring data. BIOS default is 8000ns. */
    short bus_off;	/* Time that WD7000 spends OFF THE BUS after  */
			/* while it is transferring data.             */
			/* BIOS default is 1875ns                     */
} Config;

/*
 * Add here your configuration...
 */
static Config configs[] =
{
    { 15,  6, 0x350, BUS_ON, BUS_OFF },	/* defaults for single adapter */
    { 11,  5, 0x320, BUS_ON, BUS_OFF },	/* defaults for second adapter */
    {  7,  6, 0x350, BUS_ON, BUS_OFF },	/* My configuration (Zaga)     */
    { -1, -1, 0x0,   BUS_ON, BUS_OFF }	/* Empty slot                  */
};
#define NUM_CONFIGS (sizeof(configs)/sizeof(Config))

/*
 *  The following list defines strings to look for in the BIOS that identify
 *  it as the WD7000-FASST2 SST BIOS.  I suspect that something should be
 *  added for the Future Domain version.
 */
typedef struct signature {
    const char *sig;		/* String to look for            */
    unsigned long ofs;		/* offset from BIOS base address */
    unsigned len;		/* length of string              */
} Signature;

static const Signature signatures[] =
{
    {"SSTBIOS", 0x0000d, 7}	/* "SSTBIOS" @ offset 0x0000d */
};
#define NUM_SIGNATURES (sizeof(signatures)/sizeof(Signature))


/*
 *  I/O Port Offsets and Bit Definitions
 *  4 addresses are used.  Those not defined here are reserved.
 */
#define ASC_STAT        0	/* Status,  Read          */
#define ASC_COMMAND     0	/* Command, Write         */
#define ASC_INTR_STAT   1	/* Interrupt Status, Read */
#define ASC_INTR_ACK    1	/* Acknowledge, Write     */
#define ASC_CONTROL     2	/* Control, Write         */

/*
 * ASC Status Port
 */
#define INT_IM		0x80	/* Interrupt Image Flag           */
#define CMD_RDY		0x40	/* Command Port Ready             */
#define CMD_REJ		0x20	/* Command Port Byte Rejected     */
#define ASC_INIT        0x10	/* ASC Initialized Flag           */
#define ASC_STATMASK    0xf0	/* The lower 4 Bytes are reserved */

/*
 * COMMAND opcodes
 *
 *  Unfortunately, I have no idea how to properly use some of these commands,
 *  as the OEM manual does not make it clear.  I have not been able to use
 *  enable/disable unsolicited interrupts or the reset commands with any
 *  discernible effect whatsoever.  I think they may be related to certain
 *  ICB commands, but again, the OEM manual doesn't make that clear.
 */
#define NO_OP             0	/* NO-OP toggles CMD_RDY bit in ASC_STAT  */
#define INITIALIZATION    1	/* initialization (10 bytes)              */
#define DISABLE_UNS_INTR  2	/* disable unsolicited interrupts         */
#define ENABLE_UNS_INTR   3	/* enable unsolicited interrupts          */
#define INTR_ON_FREE_OGMB 4	/* interrupt on free OGMB                 */
#define SOFT_RESET        5	/* SCSI bus soft reset                    */
#define HARD_RESET_ACK    6	/* SCSI bus hard reset acknowledge        */
#define START_OGMB        0x80	/* start command in OGMB (n)              */
#define SCAN_OGMBS        0xc0	/* start multiple commands, signature (n) */
				/*    where (n) = lower 6 bits            */
/*
 * For INITIALIZATION:
 */
typedef struct initCmd {
    unchar op;			/* command opcode (= 1)                    */
    unchar ID;			/* Adapter's SCSI ID                       */
    unchar bus_on;		/* Bus on time, x 125ns (see below)        */
    unchar bus_off;		/* Bus off time, ""         ""             */
    unchar rsvd;		/* Reserved                                */
    unchar mailboxes[3];	/* Address of Mailboxes, MSB first         */
    unchar ogmbs;		/* Number of outgoing MBs, max 64, 0,1 = 1 */
    unchar icmbs;		/* Number of incoming MBs,   ""       ""   */
} InitCmd;

/*
 * Interrupt Status Port - also returns diagnostic codes at ASC reset
 *
 * if msb is zero, the lower bits are diagnostic status
 * Diagnostics:
 * 01   No diagnostic error occurred
 * 02   RAM failure
 * 03   FIFO R/W failed
 * 04   SBIC register read/write failed
 * 05   Initialization D-FF failed
 * 06   Host IRQ D-FF failed
 * 07   ROM checksum error
 * Interrupt status (bitwise):
 * 10NNNNNN   outgoing mailbox NNNNNN is free
 * 11NNNNNN   incoming mailbox NNNNNN needs service
 */
#define MB_INTR    0xC0		/* Mailbox Service possible/required */
#define IMB_INTR   0x40		/* 1 Incoming / 0 Outgoing           */
#define MB_MASK    0x3f		/* mask for mailbox number           */

/*
 * CONTROL port bits
 */
#define INT_EN     0x08		/* Interrupt Enable */
#define DMA_EN     0x04		/* DMA Enable       */
#define SCSI_RES   0x02		/* SCSI Reset       */
#define ASC_RES    0x01		/* ASC Reset        */

/*
 * Driver data structures:
 *   - mb and scbs are required for interfacing with the host adapter.
 *     An SCB has extra fields not visible to the adapter; mb's
 *     _cannot_ do this, since the adapter assumes they are contiguous in
 *     memory, 4 bytes each, with ICMBs following OGMBs, and uses this fact
 *     to access them.
 *   - An icb is for host-only (non-SCSI) commands.  ICBs are 16 bytes each;
 *     the additional bytes are used only by the driver.
 *   - For now, a pool of SCBs are kept in global storage by this driver,
 *     and are allocated and freed as needed.
 *
 *  The 7000-FASST2 marks OGMBs empty as soon as it has _started_ a command,
 *  not when it has finished.  Since the SCB must be around for completion,
 *  problems arise when SCBs correspond to OGMBs, which may be reallocated
 *  earlier (or delayed unnecessarily until a command completes).
 *  Mailboxes are used as transient data structures, simply for
 *  carrying SCB addresses to/from the 7000-FASST2.
 *
 *  Note also since SCBs are not "permanently" associated with mailboxes,
 *  there is no need to keep a global list of Scsi_Cmnd pointers indexed
 *  by OGMB.   Again, SCBs reference their Scsi_Cmnds directly, so mailbox
 *  indices need not be involved.
 */

/*
 *  WD7000-specific scatter/gather element structure
 */
typedef struct sgb {
    unchar len[3];
    unchar ptr[3];		/* Also SCSI-style - MSB first */
} Sgb;

typedef struct scb {		/* Command Control Block 5.4.1               */
    unchar op;			/* Command Control Block Operation Code      */
    unchar idlun;		/* op=0,2:Target Id, op=1:Initiator Id       */
				/* Outbound data transfer, length is checked */
				/* Inbound data transfer, length is checked  */
				/* Logical Unit Number                       */
    unchar cdb[12];		/* SCSI Command Block                        */
    volatile unchar status;	/* SCSI Return Status                        */
    volatile unchar vue;	/* Vendor Unique Error Code                  */
    unchar maxlen[3];		/* Maximum Data Transfer Length              */
    unchar dataptr[3];		/* SCSI Data Block Pointer                   */
    unchar linkptr[3];		/* Next Command Link Pointer                 */
    unchar direc;		/* Transfer Direction                        */
    unchar reserved2[6];	/* SCSI Command Descriptor Block             */
				/* end of hardware SCB                       */
    Scsi_Cmnd *SCpnt;		/* Scsi_Cmnd using this SCB                  */
    Sgb sgb[WD7000_SG];		/* Scatter/gather list for this SCB          */
    Adapter *host;		/* host adapter                              */
    struct scb *next;		/* for lists of scbs                         */
} Scb;

/*
 *  This driver is written to allow host-only commands to be executed.
 *  These use a 16-byte block called an ICB.  The format is extended by the
 *  driver to 18 bytes, to support the status returned in the ICMB and
 *  an execution phase code.
 *
 *  There are other formats besides these; these are the ones I've tried
 *  to use.  Formats for some of the defined ICB opcodes are not defined
 *  (notably, get/set unsolicited interrupt status) in my copy of the OEM
 *  manual, and others are ambiguous/hard to follow.
 */
#define ICB_OP_MASK           0x80	/* distinguishes scbs from icbs        */
#define ICB_OP_OPEN_RBUF      0x80	/* open receive buffer                 */
#define ICB_OP_RECV_CMD       0x81	/* receive command from initiator      */
#define ICB_OP_RECV_DATA      0x82	/* receive data from initiator         */
#define ICB_OP_RECV_SDATA     0x83	/* receive data with status from init. */
#define ICB_OP_SEND_DATA      0x84	/* send data with status to initiator  */
#define ICB_OP_SEND_STAT      0x86	/* send command status to initiator    */
					/* 0x87 is reserved                    */
#define ICB_OP_READ_INIT      0x88	/* read initialization bytes           */
#define ICB_OP_READ_ID        0x89	/* read adapter's SCSI ID              */
#define ICB_OP_SET_UMASK      0x8A	/* set unsolicited interrupt mask      */
#define ICB_OP_GET_UMASK      0x8B	/* read unsolicited interrupt mask     */
#define ICB_OP_GET_REVISION   0x8C	/* read firmware revision level        */
#define ICB_OP_DIAGNOSTICS    0x8D	/* execute diagnostics                 */
#define ICB_OP_SET_EPARMS     0x8E	/* set execution parameters            */
#define ICB_OP_GET_EPARMS     0x8F	/* read execution parameters           */

typedef struct icbRecvCmd {
    unchar op;
    unchar IDlun;		/* Initiator SCSI ID/lun     */
    unchar len[3];		/* command buffer length     */
    unchar ptr[3];		/* command buffer address    */
    unchar rsvd[7];		/* reserved                  */
    volatile unchar vue;	/* vendor-unique error code  */
    volatile unchar status;	/* returned (icmb) status    */
    volatile unchar phase;	/* used by interrupt handler */
} IcbRecvCmd;

typedef struct icbSendStat {
    unchar op;
    unchar IDlun;		/* Target SCSI ID/lun                  */
    unchar stat;		/* (outgoing) completion status byte 1 */
    unchar rsvd[12];		/* reserved                            */
    volatile unchar vue;	/* vendor-unique error code            */
    volatile unchar status;	/* returned (icmb) status              */
    volatile unchar phase;	/* used by interrupt handler           */
} IcbSendStat;

typedef struct icbRevLvl {
    unchar op;
    volatile unchar primary;	/* primary revision level (returned)   */
    volatile unchar secondary;	/* secondary revision level (returned) */
    unchar rsvd[12];		/* reserved                            */
    volatile unchar vue;	/* vendor-unique error code            */
    volatile unchar status;	/* returned (icmb) status              */
    volatile unchar phase;	/* used by interrupt handler           */
} IcbRevLvl;

typedef struct icbUnsMask {	/* I'm totally guessing here */
    unchar op;
    volatile unchar mask[14];	/* mask bits                 */
#if 0
    unchar rsvd[12];		/* reserved                  */
#endif
    volatile unchar vue;	/* vendor-unique error code  */
    volatile unchar status;	/* returned (icmb) status    */
    volatile unchar phase;	/* used by interrupt handler */
} IcbUnsMask;

typedef struct icbDiag {
    unchar op;
    unchar type;		/* diagnostics type code (0-3) */
    unchar len[3];		/* buffer length               */
    unchar ptr[3];		/* buffer address              */
    unchar rsvd[7];		/* reserved                    */
    volatile unchar vue;	/* vendor-unique error code    */
    volatile unchar status;	/* returned (icmb) status      */
    volatile unchar phase;	/* used by interrupt handler   */
} IcbDiag;

#define ICB_DIAG_POWERUP   0	/* Power-up diags only       */
#define ICB_DIAG_WALKING   1	/* walking 1's pattern       */
#define ICB_DIAG_DMA       2	/* DMA - system memory diags */
#define ICB_DIAG_FULL      3	/* do both 1 & 2             */

typedef struct icbParms {
    unchar op;
    unchar rsvd1;		/* reserved                  */
    unchar len[3];		/* parms buffer length       */
    unchar ptr[3];		/* parms buffer address      */
    unchar idx[2];		/* index (MSB-LSB)           */
    unchar rsvd2[5];		/* reserved                  */
    volatile unchar vue;	/* vendor-unique error code  */
    volatile unchar status;	/* returned (icmb) status    */
    volatile unchar phase;	/* used by interrupt handler */
} IcbParms;

typedef struct icbAny {
    unchar op;
    unchar data[14];		/* format-specific data      */
    volatile unchar vue;	/* vendor-unique error code  */
    volatile unchar status;	/* returned (icmb) status    */
    volatile unchar phase;	/* used by interrupt handler */
} IcbAny;

typedef union icb {
    unchar op;			/* ICB opcode                     */
    IcbRecvCmd recv_cmd;	/* format for receive command     */
    IcbSendStat send_stat;	/* format for send status         */
    IcbRevLvl rev_lvl;		/* format for get revision level  */
    IcbDiag diag;		/* format for execute diagnostics */
    IcbParms eparms;		/* format for get/set exec parms  */
    IcbAny icb;			/* generic format                 */
    unchar data[18];
} Icb;


/*
 *  Driver SCB structure pool.
 *
 *  The SCBs declared here are shared by all host adapters; hence, this
 *  structure is not part of the Adapter structure.
 */
static Scb scbs[MAX_SCBS];
static Scb *scbfree = NULL;	/* free list         */
static int freescbs = MAX_SCBS;	/* free list counter */

/*
 *  END of data/declarations - code follows.
 */
static void setup_error (char *mesg, int *ints)
{
    if (ints[0] == 3)
        printk ("wd7000_setup: \"wd7000=%d,%d,0x%x\" -> %s\n",
                ints[1], ints[2], ints[3], mesg);
    else if (ints[0] == 4)
        printk ("wd7000_setup: \"wd7000=%d,%d,0x%x,%d\" -> %s\n",
                ints[1], ints[2], ints[3], ints[4], mesg);
    else
        printk ("wd7000_setup: \"wd7000=%d,%d,0x%x,%d,%d\" -> %s\n",
                ints[1], ints[2], ints[3], ints[4], ints[5], mesg);
}


/*
 * Note: You can now set these options from the kernel's "command line".
 * The syntax is:
 *
 *     wd7000=<IRQ>,<DMA>,<IO>[,<BUS_ON>[,<BUS_OFF>]]
 *
 * , where BUS_ON and BUS_OFF are in nanoseconds. BIOS default values
 * are 8000ns for BUS_ON and 1875ns for BUS_OFF.
 * eg:
 *     wd7000=7,6,0x350
 *
 * will configure the driver for a WD-7000 controller
 * using IRQ 15 with a DMA channel 6, at IO base address 0x350.
 */
void wd7000_setup (char *str, int *ints)
{
    static short wd7000_card_num = 0;
    short i, j;

    if (wd7000_card_num >= NUM_CONFIGS) {
	printk ("wd7000_setup: Too many \"wd7000=\" configurations in "
		"command line!\n");
	return;
    }

    if ((ints[0] < 3) || (ints[0] > 5))
	printk ("wd7000_setup: Error in command line!  "
		"Usage: wd7000=<IRQ>,<DMA>,IO>[,<BUS_ON>[,<BUS_OFF>]]\n");
    else {
	for (i = 0; i < NUM_IRQS; i++)
	    if (ints[1] == wd7000_irq[i])
		break;

	if (i == NUM_IRQS) {
	    setup_error ("invalid IRQ.", ints);
	    return;
	}
	else
	    configs[wd7000_card_num].irq = ints[1];

	for (i = 0; i < NUM_DMAS; i++)
	    if (ints[2] == wd7000_dma[i])
		break;

	if (i == NUM_DMAS) {
	    setup_error ("invalid DMA channel.", ints);
	    return;
	}
	else
	    configs[wd7000_card_num].dma = ints[2];

	for (i = 0; i < NUM_IOPORTS; i++)
	    if (ints[3] == wd7000_iobase[i])
		break;

	if (i == NUM_IOPORTS) {
	    setup_error ("invalid I/O base address.", ints);
	    return;
	}
	else
	    configs[wd7000_card_num].iobase = ints[3];

	if (ints[0] > 3) {
	    if ((ints[4] < 500) || (ints[4] > 31875)) {
	        setup_error ("BUS_ON value is out of range (500 to 31875 nanoseconds)!",
		             ints);
	        configs[wd7000_card_num].bus_on = BUS_ON;
	    }
	    else
	        configs[wd7000_card_num].bus_on = ints[4] / 125;
	}
	else
	    configs[wd7000_card_num].bus_on = BUS_ON;

	if (ints[0] > 4) {
	    if ((ints[5] < 500) || (ints[5] > 31875)) {
	        setup_error ("BUS_OFF value is out of range (500 to 31875 nanoseconds)!",
		             ints);
	        configs[wd7000_card_num].bus_off = BUS_OFF;
	    }
	    else
	        configs[wd7000_card_num].bus_off = ints[5] / 125;
	}
	else
	    configs[wd7000_card_num].bus_off = BUS_OFF;

	if (wd7000_card_num) {
	    for (i = 0; i < (wd7000_card_num - 1); i++)
		for (j = i + 1; j < wd7000_card_num; j++)
		    if (configs[i].irq == configs[j].irq) {
	                setup_error ("duplicated IRQ!", ints);
			return;
		    }
		    else if (configs[i].dma == configs[j].dma) {
	                setup_error ("duplicated DMA channel!", ints);
			return;
		    }
		    else if (configs[i].iobase == configs[j].iobase) {
	                setup_error ("duplicated I/O base address!", ints);
			return;
		    }
	}

#ifdef WD7000_DEBUG
	printk ("wd7000_setup: IRQ=%d, DMA=%d, I/O=0x%x, BUS_ON=%dns, BUS_OFF=%dns\n",
		configs[wd7000_card_num].irq,
		configs[wd7000_card_num].dma,
		configs[wd7000_card_num].iobase,
		configs[wd7000_card_num].bus_on * 125,
		configs[wd7000_card_num].bus_off * 125);
#endif

	wd7000_card_num++;
    }
}


#ifdef ANY2SCSI_INLINE
/*
 * Since they're used a lot, I've redone the following from the macros
 * formerly in wd7000.h, hopefully to speed them up by getting rid of
 * all the shifting (it may not matter; GCC might have done as well anyway).
 *
 * xany2scsi and xscsi2int were not being used, and are no longer defined.
 * (They were simply 4-byte versions of these routines).
 */
typedef union {			/* let's cheat... */
    int i;
    unchar u[sizeof (int)];	/* the sizeof(int) makes it more portable */
} i_u;


static inline void any2scsi (unchar * scsi, int any)
{
    *scsi++ = ((i_u) any).u[2];
    *scsi++ = ((i_u) any).u[1];
    *scsi++ = ((i_u) any).u[0];
}


static inline int scsi2int (unchar * scsi)
{
    i_u result;

    result.i = 0;		/* clears unused bytes */
    result.u[2] = *scsi++;
    result.u[1] = *scsi++;
    result.u[0] = *scsi++;

    return (result.i);
}
#else
/*
 * These are the old ones - I've just moved them here...
 */
#undef any2scsi
#define any2scsi(up, p)   (up)[0] = (((unsigned long) (p)) >> 16);	\
			  (up)[1] = ((unsigned long) (p)) >> 8;		\
			  (up)[2] = ((unsigned long) (p));

#undef scsi2int
#define scsi2int(up)   ( (((unsigned long) *(up)) << 16) +	\
			 (((unsigned long) (up)[1]) << 8) +	\
			 ((unsigned long) (up)[2]) )
#endif


static inline void wd7000_enable_intr (Adapter *host)
{
    host->control |= INT_EN;
    outb (host->control, host->iobase + ASC_CONTROL);
}


static inline void wd7000_enable_dma (Adapter *host)
{
    unsigned long flags;
    host->control |= DMA_EN;
    outb (host->control, host->iobase + ASC_CONTROL);
    
    flags = claim_dma_lock();
    set_dma_mode (host->dma, DMA_MODE_CASCADE);
    enable_dma (host->dma);
    release_dma_lock(flags);
    
}


#define WAITnexttimeout 200	/* 2 seconds */

static inline short WAIT (unsigned port, unsigned mask, unsigned allof, unsigned noneof)
{
    register unsigned WAITbits;
    register unsigned long WAITtimeout = jiffies + WAITnexttimeout;

    while (time_before_eq(jiffies, WAITtimeout)) {
	WAITbits = inb (port) & mask;

	if (((WAITbits & allof) == allof) && ((WAITbits & noneof) == 0))
	    return (0);
    }

    return (1);
}


static inline void delay (unsigned how_long)
{
    register unsigned long time = jiffies + how_long;

    while (time_before(jiffies, time));
}


static inline int command_out (Adapter * host, unchar * cmd, int len)
{
    if (!WAIT (host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0)) {
	while (len--) {
	    do {
		outb (*cmd, host->iobase + ASC_COMMAND);
		WAIT (host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0);
	    } while (inb (host->iobase + ASC_STAT) & CMD_REJ);

	    cmd++;
	}

	return (1);
    }

    printk ("wd7000 command_out: WAIT failed(%d)\n", len + 1);

    return (0);
}


/*
 *  This version of alloc_scbs is in preparation for supporting multiple
 *  commands per lun and command chaining, by queueing pending commands.
 *  We will need to allocate Scbs in blocks since they will wait to be
 *  executed so there is the possibility of deadlock otherwise.
 *  Also, to keep larger requests from being starved by smaller requests,
 *  we limit access to this routine with an internal busy flag, so that
 *  the satisfiability of a request is not dependent on the size of the
 *  request.
 */
static inline Scb *alloc_scbs (int needed)
{
    register Scb *scb, *p;
    register unsigned long flags;
    register unsigned long timeout = jiffies + WAITnexttimeout;
    register unsigned long now;
    static int busy = 0;
    int i;

    if (needed <= 0)
	return (NULL);		/* sanity check */

    save_flags (flags);
    cli ();
    while (busy) {		/* someone else is allocating */
	spin_unlock_irq(&io_request_lock);
	for (now = jiffies; now == jiffies; );	/* wait a jiffy */
	spin_lock_irq(&io_request_lock);
    }
    busy = 1;			/* not busy now; it's our turn */

    while (freescbs < needed) {
	timeout = jiffies + WAITnexttimeout;
	do {
	    spin_unlock_irq(&io_request_lock);
	    for (now = jiffies; now == jiffies; );	/* wait a jiffy */
	    spin_lock_irq(&io_request_lock);
	} while (freescbs < needed && time_before_eq(jiffies, timeout));
	/*
	 *  If we get here with enough free Scbs, we can take them.
	 *  Otherwise, we timed out and didn't get enough.
	 */
	if (freescbs < needed) {
	    busy = 0;
	    panic ("wd7000: can't get enough free SCBs.\n");
	    restore_flags (flags);
	    return (NULL);
	}
    }
    scb = scbfree;
    freescbs -= needed;
    for (i = 0; i < needed; i++) {
	p = scbfree;
	scbfree = p->next;
    }
    p->next = NULL;
    busy = 0;			/* we're done */

    restore_flags (flags);

    return (scb);
}


static inline void free_scb (Scb *scb)
{
    register unsigned long flags;

    save_flags (flags);
    cli ();

    memset (scb, 0, sizeof (Scb));
    scb->next = scbfree;
    scbfree = scb;
    freescbs++;

    restore_flags (flags);
}


static inline void init_scbs (void)
{
    int i;
    unsigned long flags;

    save_flags (flags);
    cli ();

    scbfree = &(scbs[0]);
    memset (scbs, 0, sizeof (scbs));
    for (i = 0; i < MAX_SCBS - 1; i++) {
	scbs[i].next = &(scbs[i + 1]);
	scbs[i].SCpnt = NULL;
    }
    scbs[MAX_SCBS - 1].next = NULL;
    scbs[MAX_SCBS - 1].SCpnt = NULL;

    restore_flags (flags);
}


static int mail_out (Adapter *host, Scb *scbptr)
/*
 *  Note: this can also be used for ICBs; just cast to the parm type.
 */
{
    register int i, ogmb;
    register unsigned long flags;
    unchar start_ogmb;
    Mailbox *ogmbs = host->mb.ogmb;
    int *next_ogmb = &(host->next_ogmb);

#ifdef WD7000_DEBUG
    printk ("wd7000_mail_out: 0x%06lx", (long) scbptr);
#endif

    /* We first look for a free outgoing mailbox */
    save_flags (flags);
    cli ();
    ogmb = *next_ogmb;
    for (i = 0; i < OGMB_CNT; i++) {
	if (ogmbs[ogmb].status == 0) {
#ifdef WD7000_DEBUG
	    printk (" using OGMB 0x%x", ogmb);
#endif
	    ogmbs[ogmb].status = 1;
	    any2scsi ((unchar *) ogmbs[ogmb].scbptr, (int) scbptr);

	    *next_ogmb = (ogmb + 1) % OGMB_CNT;
	    break;
	}
	else
	    ogmb = (++ogmb) % OGMB_CNT;
    }
    restore_flags (flags);

#ifdef WD7000_DEBUG
    printk (", scb is 0x%06lx", (long) scbptr);
#endif

    if (i >= OGMB_CNT) {
	/*
	 *  Alternatively, we might issue the "interrupt on free OGMB",
	 *  and sleep, but it must be ensured that it isn't the init
	 *  task running.  Instead, this version assumes that the caller
	 *  will be persistent, and try again.  Since it's the adapter
	 *  that marks OGMB's free, waiting even with interrupts off
	 *  should work, since they are freed very quickly in most cases.
	 */
#ifdef WD7000_DEBUG
	printk (", no free OGMBs.\n");
#endif
	return (0);
    }

    wd7000_enable_intr (host);

    start_ogmb = START_OGMB | ogmb;
    command_out (host, &start_ogmb, 1);

#ifdef WD7000_DEBUG
    printk (", awaiting interrupt.\n");
#endif

    return (1);
}


int make_code (unsigned hosterr, unsigned scsierr)
{
#ifdef WD7000_DEBUG
    int in_error = hosterr;
#endif

    switch ((hosterr >> 8) & 0xff) {
	case 0:  /* Reserved */
                 hosterr = DID_ERROR;
                 break;
	case 1:  /* Command Complete, no errors */
                 hosterr = DID_OK;
                 break;
	case 2:  /* Command complete, error logged in scb status (scsierr) */
                 hosterr = DID_OK;
                 break;
	case 4:  /* Command failed to complete - timeout */
                 hosterr = DID_TIME_OUT;
                 break;
	case 5:  /* Command terminated; Bus reset by external device */
                 hosterr = DID_RESET;
                 break;
	case 6:  /* Unexpected Command Received w/ host as target */
                 hosterr = DID_BAD_TARGET;
                 break;
	case 80: /* Unexpected Reselection */
	case 81: /* Unexpected Selection */
                 hosterr = DID_BAD_INTR;
                 break;
	case 82: /* Abort Command Message  */
                 hosterr = DID_ABORT;
                 break;
	case 83: /* SCSI Bus Software Reset */
	case 84: /* SCSI Bus Hardware Reset */
                 hosterr = DID_RESET;
                 break;
	default: /* Reserved */
                 hosterr = DID_ERROR;
    }
#ifdef WD7000_DEBUG
    if (scsierr || hosterr)
	printk ("\nSCSI command error: SCSI 0x%02x host 0x%04x return %d\n",
		scsierr, in_error, hosterr);
#endif
    return (scsierr | (hosterr << 16));
}


static void wd7000_scsi_done (Scsi_Cmnd *SCpnt)
{
#ifdef WD7000_DEBUG
    printk ("wd7000_scsi_done: 0x%06lx\n", (long) SCpnt);
#endif

    SCpnt->SCp.phase = 0;
}


#define wd7000_intr_ack(host)   outb (0, host->iobase + ASC_INTR_ACK)

void wd7000_intr_handle (int irq, void *dev_id, struct pt_regs *regs)
{
    register int flag, icmb, errstatus, icmb_status;
    register int host_error, scsi_error;
    register Scb *scb;		/* for SCSI commands */
    register IcbAny *icb;	/* for host commands */
    register Scsi_Cmnd *SCpnt;
    Adapter *host = (Adapter *) wd7000_host[irq - IRQ_MIN]->hostdata;	/* This MUST be set!!! */
    Mailbox *icmbs = host->mb.icmb;

    host->int_counter++;

#ifdef WD7000_DEBUG
    printk ("wd7000_intr_handle: irq = %d, host = 0x%06lx\n", irq, (long) host);
#endif

    flag = inb (host->iobase + ASC_INTR_STAT);

#ifdef WD7000_DEBUG
    printk ("wd7000_intr_handle: intr stat = 0x%02x\n", flag);
#endif

    if (!(inb (host->iobase + ASC_STAT) & INT_IM)) {
	/* NB: these are _very_ possible if IRQ 15 is being used, since
	 * it's the "garbage collector" on the 2nd 8259 PIC.  Specifically,
	 * any interrupt signal into the 8259 which can't be identified
	 * comes out as 7 from the 8259, which is 15 to the host.  Thus, it
	 * is a good thing the WD7000 has an interrupt status port, so we
	 * can sort these out.  Otherwise, electrical noise and other such
	 * problems would be indistinguishable from valid interrupts...
	 */
#ifdef WD7000_DEBUG
	printk ("wd7000_intr_handle: phantom interrupt...\n");
#endif
	wd7000_intr_ack (host);
	return;
    }

    if (flag & MB_INTR) {
	/* The interrupt is for a mailbox */
	if (!(flag & IMB_INTR)) {
#ifdef WD7000_DEBUG
	    printk ("wd7000_intr_handle: free outgoing mailbox\n");
#endif
	    /*
	     * If sleep_on() and the "interrupt on free OGMB" command are
	     * used in mail_out(), wake_up() should correspondingly be called
	     * here.  For now, we don't need to do anything special.
	     */
	    wd7000_intr_ack (host);
	    return;
	}
	else {
	    /* The interrupt is for an incoming mailbox */
	    icmb = flag & MB_MASK;
	    icmb_status = icmbs[icmb].status;
	    if (icmb_status & 0x80) {	/* unsolicited - result in ICMB */
#ifdef WD7000_DEBUG
		printk ("wd7000_intr_handle: unsolicited interrupt 0x%02x\n",
			icmb_status);
#endif
		wd7000_intr_ack (host);
		return;
	    }
	    /* Aaaargh! (Zaga) */
	    scb = bus_to_virt(scsi2int ((unchar *) icmbs[icmb].scbptr));
	    icmbs[icmb].status = 0;
	    if (!(scb->op & ICB_OP_MASK)) {	/* an SCB is done */
		SCpnt = scb->SCpnt;
		if (--(SCpnt->SCp.phase) <= 0) {	/* all scbs are done */
		    host_error = scb->vue | (icmb_status << 8);
		    scsi_error = scb->status;
		    errstatus = make_code (host_error, scsi_error);
		    SCpnt->result = errstatus;

		    free_scb (scb);

		    SCpnt->scsi_done (SCpnt);
		}
	    }
	    else {		/* an ICB is done */
		icb = (IcbAny *) scb;
		icb->status = icmb_status;
		icb->phase = 0;
	    }
	}			/* incoming mailbox */
    }

    wd7000_intr_ack (host);

#ifdef WD7000_DEBUG
    printk ("wd7000_intr_handle: return from interrupt handler\n");
#endif
}

void do_wd7000_intr_handle (int irq, void *dev_id, struct pt_regs *regs)
{
    unsigned long flags;

    spin_lock_irqsave(&io_request_lock, flags);
    wd7000_intr_handle(irq, dev_id, regs);
    spin_unlock_irqrestore(&io_request_lock, flags);
}


int wd7000_queuecommand (Scsi_Cmnd *SCpnt, void (*done) (Scsi_Cmnd *))
{
    register Scb *scb;
    register Sgb *sgb;
    register unchar *cdb = (unchar *) SCpnt->cmnd;
    register unchar idlun;
    register short cdblen;
    Adapter *host = (Adapter *) SCpnt->host->hostdata;

    cdblen = SCpnt->cmd_len;
    idlun = ((SCpnt->target << 5) & 0xe0) | (SCpnt->lun & 7);
    SCpnt->scsi_done = done;
    SCpnt->SCp.phase = 1;
    scb = alloc_scbs (1);
    scb->idlun = idlun;
    memcpy (scb->cdb, cdb, cdblen);
    scb->direc = 0x40;		/* Disable direction check */

    scb->SCpnt = SCpnt;		/* so we can find stuff later */
    SCpnt->host_scribble = (unchar *) scb;
    scb->host = host;

    if (SCpnt->use_sg) {
	struct scatterlist *sg = (struct scatterlist *) SCpnt->request_buffer;
	unsigned i;

	if (SCpnt->host->sg_tablesize == SG_NONE) {
	    panic ("wd7000_queuecommand: scatter/gather not supported.\n");
	}
#ifdef WD7000_DEBUG
	printk ("Using scatter/gather with %d elements.\n", SCpnt->use_sg);
#endif

	sgb = scb->sgb;
	scb->op = 1;
	any2scsi (scb->dataptr, (int) sgb);
	any2scsi (scb->maxlen, SCpnt->use_sg * sizeof (Sgb));

	for (i = 0; i < SCpnt->use_sg; i++) {
	    any2scsi (sgb[i].ptr, (int) sg[i].address);
	    any2scsi (sgb[i].len, sg[i].length);
	}
    }
    else {
	scb->op = 0;
	any2scsi (scb->dataptr, (int) SCpnt->request_buffer);
	any2scsi (scb->maxlen, SCpnt->request_bufflen);
    }

    while (!mail_out (host, scb));	/* keep trying */

    return (1);
}


int wd7000_command (Scsi_Cmnd *SCpnt)
{
    wd7000_queuecommand (SCpnt, wd7000_scsi_done);

    while (SCpnt->SCp.phase > 0)
	barrier ();		/* phase counts scbs down to 0 */

    return (SCpnt->result);
}


int wd7000_diagnostics (Adapter *host, int code)
{
    static IcbDiag icb = {ICB_OP_DIAGNOSTICS};
    static unchar buf[256];
    unsigned long timeout;

    icb.type = code;
    any2scsi (icb.len, sizeof (buf));
    any2scsi (icb.ptr, (int) &buf);
    icb.phase = 1;
    /*
     * This routine is only called at init, so there should be OGMBs
     * available.  I'm assuming so here.  If this is going to
     * fail, I can just let the timeout catch the failure.
     */
    mail_out (host, (struct scb *) &icb);
    timeout = jiffies + WAITnexttimeout;	/* wait up to 2 seconds */
    while (icb.phase && time_before(jiffies, timeout))
	barrier ();		/* wait for completion */

    if (icb.phase) {
	printk ("wd7000_diagnostics: timed out.\n");
	return (0);
    }
    if (make_code (icb.vue | (icb.status << 8), 0)) {
	printk ("wd7000_diagnostics: failed (0x%02x,0x%02x)\n",
		icb.vue, icb.status);
	return (0);
    }

    return (1);
}


int wd7000_init (Adapter *host)
{
    InitCmd init_cmd =
    {
	INITIALIZATION,
 	7,
	host->bus_on,
	host->bus_off,
	0,
	{ 0, 0, 0 },
	OGMB_CNT,
	ICMB_CNT
    };
    int diag;

    /*
     *  Reset the adapter - only.  The SCSI bus was initialized at power-up,
     *  and we need to do this just so we control the mailboxes, etc.
     */
    outb (ASC_RES, host->iobase + ASC_CONTROL);
    delay (1);			/* reset pulse: this is 10ms, only need 25us */
    outb (0, host->iobase + ASC_CONTROL);
    host->control = 0;		/* this must always shadow ASC_CONTROL */

    if (WAIT (host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0)) {
	printk ("wd7000_init: WAIT timed out.\n");
	return (0);		/* 0 = not ok */
    }

    if ((diag = inb (host->iobase + ASC_INTR_STAT)) != 1) {
	printk ("wd7000_init: ");

	switch (diag) {
	    case 2:  printk ("RAM failure.\n");
		     break;
	    case 3:  printk ("FIFO R/W failed\n");
		     break;
	    case 4:  printk ("SBIC register R/W failed\n");
		     break;
	    case 5:  printk ("Initialization D-FF failed.\n");
		     break;
	    case 6:  printk ("Host IRQ D-FF failed.\n");
		     break;
	    case 7:  printk ("ROM checksum error.\n");
		     break;
	    default: printk ("diagnostic code 0x%02Xh received.\n", diag);
	}
	return (0);
    }

    /* Clear mailboxes */
    memset (&(host->mb), 0, sizeof (host->mb));

    /* Execute init command */
    any2scsi ((unchar *) & (init_cmd.mailboxes), (int) &(host->mb));
    if (!command_out (host, (unchar *) &init_cmd, sizeof (init_cmd))) {
	printk ("wd7000_init: adapter initialization failed.\n");
	return (0);
    }

    if (WAIT (host->iobase + ASC_STAT, ASC_STATMASK, ASC_INIT, 0)) {
	printk ("wd7000_init: WAIT timed out.\n");
	return (0);
    }

    if (request_irq (host->irq, do_wd7000_intr_handle, SA_INTERRUPT, "wd7000", NULL)) {
	printk ("wd7000_init: can't get IRQ %d.\n", host->irq);
	return (0);
    }
    if (request_dma (host->dma, "wd7000")) {
	printk ("wd7000_init: can't get DMA channel %d.\n", host->dma);
	free_irq (host->irq, NULL);
	return (0);
    }
    wd7000_enable_dma (host);
    wd7000_enable_intr (host);

    if (!wd7000_diagnostics (host, ICB_DIAG_FULL)) {
	free_dma (host->dma);
	free_irq (host->irq, NULL);
	return (0);
    }

    return (1);
}


void wd7000_revision (Adapter *host)
{
    static IcbRevLvl icb =
    {ICB_OP_GET_REVISION};

    icb.phase = 1;
    /*
     * Like diagnostics, this is only done at init time, in fact, from
     * wd7000_detect, so there should be OGMBs available.  If it fails,
     * the only damage will be that the revision will show up as 0.0,
     * which in turn means that scatter/gather will be disabled.
     */
    mail_out (host, (struct scb *) &icb);
    while (icb.phase)
	barrier ();		/* wait for completion */
    host->rev1 = icb.primary;
    host->rev2 = icb.secondary;
}


#undef SPRINTF
#define SPRINTF(args...) { if (pos < (buffer + length)) pos += sprintf (pos, ## args); }

int wd7000_set_info (char *buffer, int length, struct Scsi_Host *host)
{
    unsigned long flags;

    save_flags (flags);
    cli ();

#ifdef WD7000_DEBUG
    printk ("Buffer = <%.*s>, length = %d\n", length, buffer, length);
#endif

    /*
     * Currently this is a no-op
     */
    printk ("Sorry, this function is currently out of order...\n");

    restore_flags (flags);

    return (length);
}


int wd7000_proc_info (char *buffer, char **start, off_t offset, int length, int hostno, int inout)
{
    struct Scsi_Host *host = NULL;
    Scsi_Device *scd;
    Adapter *adapter;
    unsigned long flags;
    char *pos = buffer;
    short i;

#ifdef WD7000_DEBUG
    Mailbox *ogmbs, *icmbs;
    short count;
#endif

    /*
     * Find the specified host board.
     */
    for (i = 0; i < IRQS; i++)
	if (wd7000_host[i] && (wd7000_host[i]->host_no == hostno)) {
	    host = wd7000_host[i];

	    break;
	}

    /*
     * Host not found!
     */
    if (! host)
	return (-ESRCH);

    /*
     * Has data been written to the file ?
     */
    if (inout)
	return (wd7000_set_info (buffer, length, host));

    adapter = (Adapter *) host->hostdata;

    save_flags (flags);
    cli ();

    SPRINTF ("Host scsi%d: Western Digital WD-7000 (rev %d.%d)\n", hostno, adapter->rev1, adapter->rev2);
    SPRINTF ("  IO base:      0x%x\n", adapter->iobase);
    SPRINTF ("  IRQ:          %d\n", adapter->irq);
    SPRINTF ("  DMA channel:  %d\n", adapter->dma);
    SPRINTF ("  Interrupts:   %d\n", adapter->int_counter);
    SPRINTF ("  BUS_ON time:  %d nanoseconds\n", adapter->bus_on * 125);
    SPRINTF ("  BUS_OFF time: %d nanoseconds\n", adapter->bus_off * 125);

#ifdef WD7000_DEBUG
    ogmbs = adapter->mb.ogmb;
    icmbs = adapter->mb.icmb;

    SPRINTF ("\nControl port value: 0x%x\n", adapter->control);
    SPRINTF ("Incoming mailbox:\n");
    SPRINTF ("  size: %d\n", ICMB_CNT);
    SPRINTF ("  queued messages: ");

    for (i = count = 0; i < ICMB_CNT; i++)
	if (icmbs[i].status) {
	    count++;
	    SPRINTF ("0x%x ", i);
	}

    SPRINTF (count ? "\n" : "none\n");

    SPRINTF ("Outgoing mailbox:\n");
    SPRINTF ("  size: %d\n", OGMB_CNT);
    SPRINTF ("  next message: 0x%x\n", adapter->next_ogmb);
    SPRINTF ("  queued messages: ");

    for (i = count = 0; i < OGMB_CNT; i++)
	if (ogmbs[i].status) {
	    count++;
	    SPRINTF ("0x%x ", i);
	}

    SPRINTF (count ? "\n" : "none\n");
#endif

    /*
     * Display driver information for each device attached to the board.
     */
    scd = host->host_queue;
   
    SPRINTF ("\nAttached devices: %s\n", scd ? "" : "none");

    for ( ; scd; scd = scd->next)
	if (scd->host->host_no == hostno) {
	    SPRINTF ("  [Channel: %02d, Id: %02d, Lun: %02d]  ",
		     scd->channel, scd->id, scd->lun);
	    SPRINTF ("%s ", (scd->type < MAX_SCSI_DEVICE_CODE) ?
		     scsi_device_types[(short) scd->type] : "Unknown device");

	    for (i = 0; (i < 8) && (scd->vendor[i] >= 0x20); i++)
		SPRINTF ("%c", scd->vendor[i]);
	    SPRINTF (" ");

	    for (i = 0; (i < 16) && (scd->model[i] >= 0x20); i++)
		SPRINTF ("%c", scd->model[i]);
	    SPRINTF ("\n");
	}

    SPRINTF ("\n");

    restore_flags (flags);

    /*
     * Calculate start of next buffer, and return value.
     */
    *start = buffer + offset;

    if ((pos - buffer) < offset)
	return (0);
    else if ((pos - buffer - offset) < length)
	return (pos - buffer - offset);
    else
	return (length);
}


/*
 *  Returns the number of adapters this driver is supporting.
 *
 *  The source for hosts.c says to wait to call scsi_register until 100%
 *  sure about an adapter.  We need to do it a little sooner here; we
 *  need the storage set up by scsi_register before wd7000_init, and
 *  changing the location of an Adapter structure is more trouble than
 *  calling scsi_unregister.
 *
 */
int wd7000_detect (Scsi_Host_Template *tpnt)
{
    short present = 0, biosaddr_ptr, sig_ptr, i, pass;
    short biosptr[NUM_CONFIGS];
    unsigned iobase;
    Adapter *host = NULL;
    struct Scsi_Host *sh;

#ifdef WD7000_DEBUG
    printk ("wd7000_detect: started\n");
#endif

    for (i = 0; i < IRQS; wd7000_host[i++] = NULL) ;
    for (i = 0; i < NUM_CONFIGS; biosptr[i++] = -1) ;

    tpnt->proc_dir = &proc_scsi_wd7000;
    tpnt->proc_info = &wd7000_proc_info;

    /*
     * Set up SCB free list, which is shared by all adapters
     */
    init_scbs ();

    for (pass = 0; pass < NUM_CONFIGS; pass++) {
	/*
	 * First, search for BIOS SIGNATURE...
	 */
	for (biosaddr_ptr = 0; biosaddr_ptr < NUM_ADDRS; biosaddr_ptr++)
	    for (sig_ptr = 0; sig_ptr < NUM_SIGNATURES; sig_ptr++) {
		for (i = 0; i < pass; i++)
		    if (biosptr[i] == biosaddr_ptr)
			break;

		if (i == pass) {
		    void *biosaddr = ioremap (wd7000_biosaddr[biosaddr_ptr] +
			                      signatures[sig_ptr].ofs,
					      signatures[sig_ptr].len);
		    short bios_match=0;
		    
		    if(biosaddr)
		    	bios_match = memcmp ((char *) biosaddr, signatures[sig_ptr].sig,
			                       signatures[sig_ptr].len);

		    iounmap (biosaddr);

		    if (! bios_match)
		        goto bios_matched;
		}
	    }

      bios_matched:
	/*
	 * BIOS SIGNATURE has been found.
	 */
#ifdef WD7000_DEBUG
	printk ("wd7000_detect: pass %d\n", pass + 1);

	if (biosaddr_ptr == NUM_ADDRS)
	    printk ("WD-7000 SST BIOS not detected...\n");
	else
	    printk ("WD-7000 SST BIOS detected at 0x%lx: checking...\n",
		    wd7000_biosaddr[biosaddr_ptr]);
#endif

	if (configs[pass].irq < 0)
	    continue;

	iobase = configs[pass].iobase;

#ifdef WD7000_DEBUG
	printk ("wd7000_detect: check IO 0x%x region...\n", iobase);
#endif

	if (!check_region (iobase, 4)) {

#ifdef WD7000_DEBUG
	    printk ("wd7000_detect: ASC reset (IO 0x%x) ...", iobase);
#endif
	    /*
	     * ASC reset...
	     */
	    outb (ASC_RES, iobase + ASC_CONTROL);
	    delay (1);
	    outb (0, iobase + ASC_CONTROL);

	    if (WAIT (iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0))
#ifdef WD7000_DEBUG
	    {
		printk ("failed!\n");
		continue;
	    }
	    else
		printk ("ok!\n");
#else
		continue;
#endif

	    if (inb (iobase + ASC_INTR_STAT) == 1) {
		/*
		 *  We register here, to get a pointer to the extra space,
		 *  which we'll use as the Adapter structure (host) for
		 *  this adapter.  It is located just after the registered
		 *  Scsi_Host structure (sh), and is located by the empty
		 *  array hostdata.
		 */
		sh = scsi_register (tpnt, sizeof (Adapter));
		host = (Adapter *) sh->hostdata;

#ifdef WD7000_DEBUG
		printk ("wd7000_detect: adapter allocated at 0x%x\n", (int) host);
#endif

		memset (host, 0, sizeof (Adapter));

		host->irq = configs[pass].irq;
		host->dma = configs[pass].dma;
		host->iobase = iobase;
		host->int_counter = 0;
		host->bus_on = configs[pass].bus_on;
		host->bus_off = configs[pass].bus_off;
		host->sh = wd7000_host[host->irq - IRQ_MIN] = sh;

#ifdef WD7000_DEBUG
		printk ("wd7000_detect: Trying init WD-7000 card at IO "
			"0x%x, IRQ %d, DMA %d...\n",
			host->iobase, host->irq, host->dma);
#endif

		if (!wd7000_init (host)) {	/* Initialization failed */
		    scsi_unregister (sh);

		    continue;
		}

		/*
		 *  OK from here - we'll use this adapter/configuration.
		 */
		wd7000_revision (host);		/* important for scatter/gather */

		/*
		 * Register our ports.
		 */
		request_region (host->iobase, 4, "wd7000");

		/*
		 *  For boards before rev 6.0, scatter/gather isn't supported.
		 */
		if (host->rev1 < 6)
		    sh->sg_tablesize = SG_NONE;

		present++;	/* count it */

		if (biosaddr_ptr != NUM_ADDRS)
		    biosptr[pass] = biosaddr_ptr;

		printk ("Western Digital WD-7000 (rev %d.%d) ",
			host->rev1, host->rev2);
		printk ("using IO 0x%x, IRQ %d, DMA %d.\n",
			host->iobase, host->irq, host->dma);
                printk ("  BUS_ON time: %dns, BUS_OFF time: %dns\n",
                        host->bus_on * 125, host->bus_off * 125);
	    }
	}

#ifdef WD7000_DEBUG
	else
	    printk ("wd7000_detect: IO 0x%x region already allocated!\n", iobase);
#endif

    }

    if (!present)
	printk ("Failed initialization of WD-7000 SCSI card!\n");

    return (present);
}


/*
 *  I have absolutely NO idea how to do an abort with the WD7000...
 */
int wd7000_abort (Scsi_Cmnd *SCpnt)
{
    Adapter *host = (Adapter *) SCpnt->host->hostdata;

    if (inb (host->iobase + ASC_STAT) & INT_IM) {
	printk ("wd7000_abort: lost interrupt\n");
	wd7000_intr_handle (host->irq, NULL, NULL);

	return (SCSI_ABORT_SUCCESS);
    }

    return (SCSI_ABORT_SNOOZE);
}


/*
 *  I also have no idea how to do a reset...
 */
int wd7000_reset (Scsi_Cmnd *SCpnt, unsigned int unused)
{
    return (SCSI_RESET_PUNT);
}


/*
 *  This was borrowed directly from aha1542.c. (Zaga)
 */
int wd7000_biosparam (Disk *disk, kdev_t dev, int *ip)
{
#ifdef WD7000_DEBUG
    printk ("wd7000_biosparam: dev=%s, size=%d, ", kdevname (dev), disk->capacity);
#endif

    /*
     * try default translation
     */
    ip[0] = 64;
    ip[1] = 32;
    ip[2] = disk->capacity / (64 * 32);

    /*
     * for disks >1GB do some guessing
     */
    if (ip[2] >= 1024) {
	int info[3];

	/*
	 * try to figure out the geometry from the partition table
	 */
	if ((scsicam_bios_param (disk, dev, info) < 0) ||
	    !(((info[0] == 64) && (info[1] == 32)) ||
	      ((info[0] == 255) && (info[1] == 63)))) {
	    printk ("wd7000_biosparam: unable to verify geometry for disk with >1GB.\n"
		    "                  using extended translation.\n");

	    ip[0] = 255;
	    ip[1] = 63;
	    ip[2] = disk->capacity / (255 * 63);
	}
	else {
	    ip[0] = info[0];
	    ip[1] = info[1];
	    ip[2] = info[2];

	    if (info[0] == 255)
		printk ("wd7000_biosparam: current partition table is using extended translation.\n");
	}
    }

#ifdef WD7000_DEBUG
    printk ("bios geometry: head=%d, sec=%d, cyl=%d\n", ip[0], ip[1], ip[2]);
    printk ("WARNING: check, if the bios geometry is correct.\n");
#endif

    return (0);
}

#ifdef MODULE
/* Eventually this will go into an include file, but this will be later */
Scsi_Host_Template driver_template = WD7000;

#include "scsi_module.c"
#endif