/*
 *  linux/drivers/block/floppy.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1993, 1994  Alain Knaff
 *  Copyright (C) 1998 Alan Cox
 */
/*
 * 02.12.91 - Changed to static variables to indicate need for reset
 * and recalibrate. This makes some things easier (output_byte reset
 * checking etc), and means less interrupt jumping in case of errors,
 * so the code is hopefully easier to understand.
 */

/*
 * This file is certainly a mess. I've tried my best to get it working,
 * but I don't like programming floppies, and I have only one anyway.
 * Urgel. I should check for more errors, and do more graceful error
 * recovery. Seems there are problems with several drives. I've tried to
 * correct them. No promises.
 */

/*
 * As with hd.c, all routines within this file can (and will) be called
 * by interrupts, so extreme caution is needed. A hardware interrupt
 * handler may not sleep, or a kernel panic will happen. Thus I cannot
 * call "floppy-on" directly, but have to set a special timer interrupt
 * etc.
 */

/*
 * 28.02.92 - made track-buffering routines, based on the routines written
 * by entropy@wintermute.wpi.edu (Lawrence Foard). Linus.
 */

/*
 * Automatic floppy-detection and formatting written by Werner Almesberger
 * (almesber@nessie.cs.id.ethz.ch), who also corrected some problems with
 * the floppy-change signal detection.
 */

/*
 * 1992/7/22 -- Hennus Bergman: Added better error reporting, fixed
 * FDC data overrun bug, added some preliminary stuff for vertical
 * recording support.
 *
 * 1992/9/17: Added DMA allocation & DMA functions. -- hhb.
 *
 * TODO: Errors are still not counted properly.
 */

/* 1992/9/20
 * Modifications for ``Sector Shifting'' by Rob Hooft (hooft@chem.ruu.nl)
 * modeled after the freeware MS-DOS program fdformat/88 V1.8 by
 * Christoph H. Hochst\"atter.
 * I have fixed the shift values to the ones I always use. Maybe a new
 * ioctl() should be created to be able to modify them.
 * There is a bug in the driver that makes it impossible to format a
 * floppy as the first thing after bootup.
 */

/*
 * 1993/4/29 -- Linus -- cleaned up the timer handling in the kernel, and
 * this helped the floppy driver as well. Much cleaner, and still seems to
 * work.
 */

/* 1994/6/24 --bbroad-- added the floppy table entries and made
 * minor modifications to allow 2.88 floppies to be run.
 */

/* 1994/7/13 -- Paul Vojta -- modified the probing code to allow three or more
 * disk types.
 */

/*
 * 1994/8/8 -- Alain Knaff -- Switched to fdpatch driver: Support for bigger
 * format bug fixes, but unfortunately some new bugs too...
 */

/* 1994/9/17 -- Koen Holtman -- added logging of physical floppy write
 * errors to allow safe writing by specialized programs.
 */

/* 1995/4/24 -- Dan Fandrich -- added support for Commodore 1581 3.5" disks
 * by defining bit 1 of the "stretch" parameter to mean put sectors on the
 * opposite side of the disk, leaving the sector IDs alone (i.e. Commodore's
 * drives are "upside-down").
 */

/*
 * 1995/8/26 -- Andreas Busse -- added Mips support.
 */

/*
 * 1995/10/18 -- Ralf Baechle -- Portability cleanup; move machine dependent
 * features to asm/floppy.h.
 */

/*
 * 1998/05/07 -- Russell King -- More portability cleanups; moved definition of
 * interrupt and dma channel to asm/floppy.h. Cleaned up some formatting &
 * use of '0' for NULL.
 */
 
/*
 * 1998/06/07 -- Alan Cox -- Merged the 2.0.34 fixes for resource allocation
 * failures.
 */

/*
 * 1998/09/20 -- David Weinehall -- Added slow-down code for buggy PS/2-drives.
 */

/*
 * 1999/08/13 -- Paul Slootman -- floppy stopped working on Alpha after 24
 * days, 6 hours, 32 minutes and 32 seconds (i.e. MAXINT jiffies; ints were
 * being used to store jiffies, which are unsigned longs).
 */

/*
 * 2000/08/28 -- Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 * - get rid of check_region
 * - s/suser/capable/
 */

/*
 * 2001/08/26 -- Paul Gortmaker - fix insmod oops on machines with no
 * floppy controller (lingering task on list after module is gone... boom.)
 */

/*
 * 2002/02/07 -- Anton Altaparmakov - Fix io ports reservation to correct range
 * (0x3f2-0x3f5, 0x3f7). This fix is a bit of a hack but the proper fix
 * requires many non-obvious changes in arch dependent code.
 */

#define FLOPPY_SANITY_CHECK
#undef  FLOPPY_SILENT_DCL_CLEAR

#define REALLY_SLOW_IO

#define DEBUGT 2
#define DCL_DEBUG /* debug disk change line */

/* do print messages for unexpected interrupts */
static int print_unex=1;
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/tqueue.h>
#define FDPATCHES
#include <linux/fdreg.h>

/*
 * 1998/1/21 -- Richard Gooch <rgooch@atnf.csiro.au> -- devfs support
 */


#include <linux/fd.h>
#include <linux/hdreg.h>

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/mc146818rtc.h> /* CMOS defines */
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>

/*
 * PS/2 floppies have much slower step rates than regular floppies.
 * It's been recommended that take about 1/4 of the default speed
 * in some more extreme cases.
 */
static int slow_floppy;

#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>

static int FLOPPY_IRQ=6;
static int FLOPPY_DMA=2;
static int can_use_virtual_dma=2;
/* =======
 * can use virtual DMA:
 * 0 = use of virtual DMA disallowed by config
 * 1 = use of virtual DMA prescribed by config
 * 2 = no virtual DMA preference configured.  By default try hard DMA,
 * but fall back on virtual DMA when not enough memory available
 */

static int use_virtual_dma;
/* =======
 * use virtual DMA
 * 0 using hard DMA
 * 1 using virtual DMA
 * This variable is set to virtual when a DMA mem problem arises, and
 * reset back in floppy_grab_irq_and_dma.
 * It is not safe to reset it in other circumstances, because the floppy
 * driver may have several buffers in use at once, and we do currently not
 * record each buffers capabilities
 */

static unsigned short virtual_dma_port=0x3f0;
void floppy_interrupt(int irq, void *dev_id, struct pt_regs * regs);
static int set_dor(int fdc, char mask, char data);
static void register_devfs_entries (int drive) __init;
static devfs_handle_t devfs_handle;

#define K_64    0x10000         /* 64KB */

/* the following is the mask of allowed drives. By default units 2 and
 * 3 of both floppy controllers are disabled, because switching on the
 * motor of these drives causes system hangs on some PCI computers. drive
 * 0 is the low bit (0x1), and drive 7 is the high bit (0x80). Bits are on if
 * a drive is allowed.
 *
 * NOTE: This must come before we include the arch floppy header because
 *       some ports reference this variable from there. -DaveM
 */

static int allowed_drive_mask = 0x33;

#include <asm/floppy.h>

static int irqdma_allocated;

#define MAJOR_NR FLOPPY_MAJOR

#include <linux/blk.h>
#include <linux/blkpg.h>
#include <linux/cdrom.h> /* for the compatibility eject ioctl */

#ifndef fd_get_dma_residue
#define fd_get_dma_residue() get_dma_residue(FLOPPY_DMA)
#endif

/* Dma Memory related stuff */

#ifndef fd_dma_mem_free
#define fd_dma_mem_free(addr, size) free_pages(addr, get_order(size))
#endif

#ifndef fd_dma_mem_alloc
#define fd_dma_mem_alloc(size) __get_dma_pages(GFP_KERNEL,get_order(size))
#endif

static inline void fallback_on_nodma_alloc(char **addr, size_t l)
{
#ifdef FLOPPY_CAN_FALLBACK_ON_NODMA
        if (*addr)
                return; /* we have the memory */
        if (can_use_virtual_dma != 2)
                return; /* no fallback allowed */
        printk("DMA memory shortage. Temporarily falling back on virtual DMA\n");
        *addr = (char *) nodma_mem_alloc(l);
#else
        return;
#endif
}

/* End dma memory related stuff */

static unsigned long fake_change;
static int initialising=1;

static inline int TYPE(kdev_t x) {
        return  (MINOR(x)>>2) & 0x1f;
}
static inline int DRIVE(kdev_t x) {
        return (MINOR(x)&0x03) | ((MINOR(x)&0x80) >> 5);
}
#define ITYPE(x) (((x)>>2) & 0x1f)
#define TOMINOR(x) ((x & 3) | ((x & 4) << 5))
#define UNIT(x) ((x) & 0x03)            /* drive on fdc */
#define FDC(x) (((x) & 0x04) >> 2)  /* fdc of drive */
#define REVDRIVE(fdc, unit) ((unit) + ((fdc) << 2))
                                /* reverse mapping from unit and fdc to drive */
#define DP (&drive_params[current_drive])
#define DRS (&drive_state[current_drive])
#define DRWE (&write_errors[current_drive])
#define FDCS (&fdc_state[fdc])
#define CLEARF(x) (clear_bit(x##_BIT, &DRS->flags))
#define SETF(x) (set_bit(x##_BIT, &DRS->flags))
#define TESTF(x) (test_bit(x##_BIT, &DRS->flags))

#define UDP (&drive_params[drive])
#define UDRS (&drive_state[drive])
#define UDRWE (&write_errors[drive])
#define UFDCS (&fdc_state[FDC(drive)])
#define UCLEARF(x) (clear_bit(x##_BIT, &UDRS->flags))
#define USETF(x) (set_bit(x##_BIT, &UDRS->flags))
#define UTESTF(x) (test_bit(x##_BIT, &UDRS->flags))

#define DPRINT(format, args...) printk(DEVICE_NAME "%d: " format, current_drive , ## args)

#define PH_HEAD(floppy,head) (((((floppy)->stretch & 2) >>1) ^ head) << 2)
#define STRETCH(floppy) ((floppy)->stretch & FD_STRETCH)

#define CLEARSTRUCT(x) memset((x), 0, sizeof(*(x)))

/* read/write */
#define COMMAND raw_cmd->cmd[0]
#define DR_SELECT raw_cmd->cmd[1]
#define TRACK raw_cmd->cmd[2]
#define HEAD raw_cmd->cmd[3]
#define SECTOR raw_cmd->cmd[4]
#define SIZECODE raw_cmd->cmd[5]
#define SECT_PER_TRACK raw_cmd->cmd[6]
#define GAP raw_cmd->cmd[7]
#define SIZECODE2 raw_cmd->cmd[8]
#define NR_RW 9

/* format */
#define F_SIZECODE raw_cmd->cmd[2]
#define F_SECT_PER_TRACK raw_cmd->cmd[3]
#define F_GAP raw_cmd->cmd[4]
#define F_FILL raw_cmd->cmd[5]
#define NR_F 6

/*
 * Maximum disk size (in kilobytes). This default is used whenever the
 * current disk size is unknown.
 * [Now it is rather a minimum]
 */
#define MAX_DISK_SIZE 4 /* 3984*/


/*
 * globals used by 'result()'
 */
#define MAX_REPLIES 16
static unsigned char reply_buffer[MAX_REPLIES];
static int inr; /* size of reply buffer, when called from interrupt */
#define ST0 (reply_buffer[0])
#define ST1 (reply_buffer[1])
#define ST2 (reply_buffer[2])
#define ST3 (reply_buffer[0]) /* result of GETSTATUS */
#define R_TRACK (reply_buffer[3])
#define R_HEAD (reply_buffer[4])
#define R_SECTOR (reply_buffer[5])
#define R_SIZECODE (reply_buffer[6])

#define SEL_DLY (2*HZ/100)

/*
 * this struct defines the different floppy drive types.
 */
static struct {
        struct floppy_drive_params params;
        const char *name; /* name printed while booting */
} default_drive_params[]= {
/* NOTE: the time values in jiffies should be in msec!
 CMOS drive type
  |     Maximum data rate supported by drive type
  |     |   Head load time, msec
  |     |   |   Head unload time, msec (not used)
  |     |   |   |     Step rate interval, usec
  |     |   |   |     |       Time needed for spinup time (jiffies)
  |     |   |   |     |       |      Timeout for spinning down (jiffies)
  |     |   |   |     |       |      |   Spindown offset (where disk stops)
  |     |   |   |     |       |      |   |     Select delay
  |     |   |   |     |       |      |   |     |     RPS
  |     |   |   |     |       |      |   |     |     |    Max number of tracks
  |     |   |   |     |       |      |   |     |     |    |     Interrupt timeout
  |     |   |   |     |       |      |   |     |     |    |     |   Max nonintlv. sectors
  |     |   |   |     |       |      |   |     |     |    |     |   | -Max Errors- flags */
{{0,  500, 16, 16, 8000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  80, 3*HZ, 20, {3,1,2,0,2}, 0,
      0, { 7, 4, 8, 2, 1, 5, 3,10}, 3*HZ/2, 0 }, "unknown" },

{{1,  300, 16, 16, 8000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  40, 3*HZ, 17, {3,1,2,0,2}, 0,
      0, { 1, 0, 0, 0, 0, 0, 0, 0}, 3*HZ/2, 1 }, "360K PC" }, /*5 1/4 360 KB PC*/

{{2,  500, 16, 16, 6000, 4*HZ/10, 3*HZ, 14, SEL_DLY, 6,  83, 3*HZ, 17, {3,1,2,0,2}, 0,
      0, { 2, 5, 6,23,10,20,12, 0}, 3*HZ/2, 2 }, "1.2M" }, /*5 1/4 HD AT*/

{{3,  250, 16, 16, 3000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  83, 3*HZ, 20, {3,1,2,0,2}, 0,
      0, { 4,22,21,30, 3, 0, 0, 0}, 3*HZ/2, 4 }, "720k" }, /*3 1/2 DD*/

{{4,  500, 16, 16, 4000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 20, {3,1,2,0,2}, 0,
      0, { 7, 4,25,22,31,21,29,11}, 3*HZ/2, 7 }, "1.44M" }, /*3 1/2 HD*/

{{5, 1000, 15,  8, 3000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 40, {3,1,2,0,2}, 0,
      0, { 7, 8, 4,25,28,22,31,21}, 3*HZ/2, 8 }, "2.88M AMI BIOS" }, /*3 1/2 ED*/

{{6, 1000, 15,  8, 3000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 40, {3,1,2,0,2}, 0,
      0, { 7, 8, 4,25,28,22,31,21}, 3*HZ/2, 8 }, "2.88M" } /*3 1/2 ED*/
/*    |  --autodetected formats---    |      |      |
 *    read_track                      |      |    Name printed when booting
 *                                    |     Native format
 *                  Frequency of disk change checks */
};

static struct floppy_drive_params drive_params[N_DRIVE];
static struct floppy_drive_struct drive_state[N_DRIVE];
static struct floppy_write_errors write_errors[N_DRIVE];
static struct timer_list motor_off_timer[N_DRIVE];
static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;

/*
 * This struct defines the different floppy types.
 *
 * Bit 0 of 'stretch' tells if the tracks need to be doubled for some
 * types (e.g. 360kB diskette in 1.2MB drive, etc.).  Bit 1 of 'stretch'
 * tells if the disk is in Commodore 1581 format, which means side 0 sectors
 * are located on side 1 of the disk but with a side 0 ID, and vice-versa.
 * This is the same as the Sharp MZ-80 5.25" CP/M disk format, except that the
 * 1581's logical side 0 is on physical side 1, whereas the Sharp's logical
 * side 0 is on physical side 0 (but with the misnamed sector IDs).
 * 'stretch' should probably be renamed to something more general, like
 * 'options'.  Other parameters should be self-explanatory (see also
 * setfdprm(8)).
 */
/*
            Size
             |  Sectors per track
             |  | Head
             |  | |  Tracks
             |  | |  | Stretch
             |  | |  | |  Gap 1 size
             |  | |  | |    |  Data rate, | 0x40 for perp
             |  | |  | |    |    |  Spec1 (stepping rate, head unload
             |  | |  | |    |    |    |    /fmt gap (gap2) */
static struct floppy_struct floppy_type[32] = {
        {    0, 0,0, 0,0,0x00,0x00,0x00,0x00,NULL    }, /*  0 no testing    */
        {  720, 9,2,40,0,0x2A,0x02,0xDF,0x50,"d360"  }, /*  1 360KB PC      */
        { 2400,15,2,80,0,0x1B,0x00,0xDF,0x54,"h1200" }, /*  2 1.2MB AT      */
        {  720, 9,1,80,0,0x2A,0x02,0xDF,0x50,"D360"  }, /*  3 360KB SS 3.5" */
        { 1440, 9,2,80,0,0x2A,0x02,0xDF,0x50,"D720"  }, /*  4 720KB 3.5"    */
        {  720, 9,2,40,1,0x23,0x01,0xDF,0x50,"h360"  }, /*  5 360KB AT      */
        { 1440, 9,2,80,0,0x23,0x01,0xDF,0x50,"h720"  }, /*  6 720KB AT      */
        { 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,"H1440" }, /*  7 1.44MB 3.5"   */
        { 5760,36,2,80,0,0x1B,0x43,0xAF,0x54,"E2880" }, /*  8 2.88MB 3.5"   */
        { 6240,39,2,80,0,0x1B,0x43,0xAF,0x28,"E3120" }, /*  9 3.12MB 3.5"   */

        { 2880,18,2,80,0,0x25,0x00,0xDF,0x02,"h1440" }, /* 10 1.44MB 5.25"  */
        { 3360,21,2,80,0,0x1C,0x00,0xCF,0x0C,"H1680" }, /* 11 1.68MB 3.5"   */
        {  820,10,2,41,1,0x25,0x01,0xDF,0x2E,"h410"  }, /* 12 410KB 5.25"   */
        { 1640,10,2,82,0,0x25,0x02,0xDF,0x2E,"H820"  }, /* 13 820KB 3.5"    */
        { 2952,18,2,82,0,0x25,0x00,0xDF,0x02,"h1476" }, /* 14 1.48MB 5.25"  */
        { 3444,21,2,82,0,0x25,0x00,0xDF,0x0C,"H1722" }, /* 15 1.72MB 3.5"   */
        {  840,10,2,42,1,0x25,0x01,0xDF,0x2E,"h420"  }, /* 16 420KB 5.25"   */
        { 1660,10,2,83,0,0x25,0x02,0xDF,0x2E,"H830"  }, /* 17 830KB 3.5"    */
        { 2988,18,2,83,0,0x25,0x00,0xDF,0x02,"h1494" }, /* 18 1.49MB 5.25"  */
        { 3486,21,2,83,0,0x25,0x00,0xDF,0x0C,"H1743" }, /* 19 1.74 MB 3.5"  */

        { 1760,11,2,80,0,0x1C,0x09,0xCF,0x00,"h880"  }, /* 20 880KB 5.25"   */
        { 2080,13,2,80,0,0x1C,0x01,0xCF,0x00,"D1040" }, /* 21 1.04MB 3.5"   */
        { 2240,14,2,80,0,0x1C,0x19,0xCF,0x00,"D1120" }, /* 22 1.12MB 3.5"   */
        { 3200,20,2,80,0,0x1C,0x20,0xCF,0x2C,"h1600" }, /* 23 1.6MB 5.25"   */
        { 3520,22,2,80,0,0x1C,0x08,0xCF,0x2e,"H1760" }, /* 24 1.76MB 3.5"   */
        { 3840,24,2,80,0,0x1C,0x20,0xCF,0x00,"H1920" }, /* 25 1.92MB 3.5"   */
        { 6400,40,2,80,0,0x25,0x5B,0xCF,0x00,"E3200" }, /* 26 3.20MB 3.5"   */
        { 7040,44,2,80,0,0x25,0x5B,0xCF,0x00,"E3520" }, /* 27 3.52MB 3.5"   */
        { 7680,48,2,80,0,0x25,0x63,0xCF,0x00,"E3840" }, /* 28 3.84MB 3.5"   */

        { 3680,23,2,80,0,0x1C,0x10,0xCF,0x00,"H1840" }, /* 29 1.84MB 3.5"   */
        { 1600,10,2,80,0,0x25,0x02,0xDF,0x2E,"D800"  }, /* 30 800KB 3.5"    */
        { 3200,20,2,80,0,0x1C,0x00,0xCF,0x2C,"H1600" }, /* 31 1.6MB 3.5"    */
};

#define NUMBER(x)       (sizeof(x) / sizeof(*(x)))
#define SECTSIZE (_FD_SECTSIZE(*floppy))

/* Auto-detection: Disk type used until the next media change occurs. */
static struct floppy_struct *current_type[N_DRIVE];

/*
 * User-provided type information. current_type points to
 * the respective entry of this array.
 */
static struct floppy_struct user_params[N_DRIVE];

static int floppy_sizes[256];
static int floppy_blocksizes[256];
static int floppy_maxsectors[256];

/*
 * The driver is trying to determine the correct media format
 * while probing is set. rw_interrupt() clears it after a
 * successful access.
 */
static int probing;

/* Synchronization of FDC access. */
#define FD_COMMAND_NONE -1
#define FD_COMMAND_ERROR 2
#define FD_COMMAND_OKAY 3

static volatile int command_status = FD_COMMAND_NONE;
static unsigned long fdc_busy;
static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
static DECLARE_WAIT_QUEUE_HEAD(command_done);

#define NO_SIGNAL (!interruptible || !signal_pending(current))
#define CALL(x) if ((x) == -EINTR) return -EINTR
#define ECALL(x) if ((ret = (x))) return ret;
#define _WAIT(x,i) CALL(ret=wait_til_done((x),i))
#define WAIT(x) _WAIT((x),interruptible)
#define IWAIT(x) _WAIT((x),1)

/* Errors during formatting are counted here. */
static int format_errors;

/* Format request descriptor. */
static struct format_descr format_req;

/*
 * Rate is 0 for 500kb/s, 1 for 300kbps, 2 for 250kbps
 * Spec1 is 0xSH, where S is stepping rate (F=1ms, E=2ms, D=3ms etc),
 * H is head unload time (1=16ms, 2=32ms, etc)
 */

/*
 * Track buffer
 * Because these are written to by the DMA controller, they must
 * not contain a 64k byte boundary crossing, or data will be
 * corrupted/lost.
 */
static char *floppy_track_buffer;
static int max_buffer_sectors;

static int *errors;
typedef void (*done_f)(int);
static struct cont_t {
        void (*interrupt)(void); /* this is called after the interrupt of the
                                  * main command */
        void (*redo)(void); /* this is called to retry the operation */
        void (*error)(void); /* this is called to tally an error */
        done_f done; /* this is called to say if the operation has 
                      * succeeded/failed */
} *cont;

static void floppy_ready(void);
static void floppy_start(void);
static void process_fd_request(void);
static void recalibrate_floppy(void);
static void floppy_shutdown(void);

static int floppy_grab_irq_and_dma(void);
static void floppy_release_irq_and_dma(void);

/*
 * The "reset" variable should be tested whenever an interrupt is scheduled,
 * after the commands have been sent. This is to ensure that the driver doesn't
 * get wedged when the interrupt doesn't come because of a failed command.
 * reset doesn't need to be tested before sending commands, because
 * output_byte is automatically disabled when reset is set.
 */
#define CHECK_RESET { if (FDCS->reset){ reset_fdc(); return; } }
static void reset_fdc(void);

/*
 * These are global variables, as that's the easiest way to give
 * information to interrupts. They are the data used for the current
 * request.
 */
#define NO_TRACK -1
#define NEED_1_RECAL -2
#define NEED_2_RECAL -3

static int usage_count;

/* buffer related variables */
static int buffer_track = -1;
static int buffer_drive = -1;
static int buffer_min = -1;
static int buffer_max = -1;

/* fdc related variables, should end up in a struct */
static struct floppy_fdc_state fdc_state[N_FDC];
static int fdc; /* current fdc */

static struct floppy_struct *_floppy = floppy_type;
static unsigned char current_drive;
static long current_count_sectors;
static unsigned char sector_t; /* sector in track */
static unsigned char in_sector_offset;  /* offset within physical sector,
                                         * expressed in units of 512 bytes */

#ifndef fd_eject
#define fd_eject(x) -EINVAL
#endif

#ifdef DEBUGT
static long unsigned debugtimer;
#endif

/*
 * Debugging
 * =========
 */
static inline void set_debugt(void)
{
#ifdef DEBUGT
        debugtimer = jiffies;
#endif
}

static inline void debugt(const char *message)
{
#ifdef DEBUGT
        if (DP->flags & DEBUGT)
                printk("%s dtime=%lu\n", message, jiffies-debugtimer);
#endif
}

typedef void (*timeout_fn)(unsigned long);
static struct timer_list fd_timeout ={ function: (timeout_fn) floppy_shutdown };

static const char *timeout_message;

#ifdef FLOPPY_SANITY_CHECK
static void is_alive(const char *message)
{
        /* this routine checks whether the floppy driver is "alive" */
        if (test_bit(0, &fdc_busy) && command_status < 2
            && !timer_pending(&fd_timeout)){
                DPRINT("timeout handler died: %s\n",message);
        }
}
#endif

#ifdef FLOPPY_SANITY_CHECK

#define OLOGSIZE 20

static void (*lasthandler)(void);
static unsigned long interruptjiffies;
static unsigned long resultjiffies;
static int resultsize;
static unsigned long lastredo;

static struct output_log {
        unsigned char data;
        unsigned char status;
        unsigned long jiffies;
} output_log[OLOGSIZE];

static int output_log_pos;
#endif

#define CURRENTD -1
#define MAXTIMEOUT -2

static void __reschedule_timeout(int drive, const char *message, int marg)
{
        if (drive == CURRENTD)
                drive = current_drive;
        del_timer(&fd_timeout);
        if (drive < 0 || drive > N_DRIVE) {
                fd_timeout.expires = jiffies + 20UL*HZ;
                drive=0;
        } else
                fd_timeout.expires = jiffies + UDP->timeout;
        add_timer(&fd_timeout);
        if (UDP->flags & FD_DEBUG){
                DPRINT("reschedule timeout ");
                printk(message, marg);
                printk("\n");
        }
        timeout_message = message;
}


static void reschedule_timeout(int drive, const char *message, int marg)
{
        unsigned long flags;

        spin_lock_irqsave(&io_request_lock, flags);
        __reschedule_timeout(drive, message, marg);
        spin_unlock_irqrestore(&io_request_lock, flags);
}

static int maximum(int a, int b)
{
        if (a > b)
                return a;
        else
                return b;
}
#define INFBOUND(a,b) (a)=maximum((a),(b));

static int minimum(int a, int b)
{
        if (a < b)
                return a;
        else
                return b;
}
#define SUPBOUND(a,b) (a)=minimum((a),(b));


/*
 * Bottom half floppy driver.
 * ==========================
 *
 * This part of the file contains the code talking directly to the hardware,
 * and also the main service loop (seek-configure-spinup-command)
 */

/*
 * disk change.
 * This routine is responsible for maintaining the FD_DISK_CHANGE flag,
 * and the last_checked date.
 *
 * last_checked is the date of the last check which showed 'no disk change'
 * FD_DISK_CHANGE is set under two conditions:
 * 1. The floppy has been changed after some i/o to that floppy already
 *    took place.
 * 2. No floppy disk is in the drive. This is done in order to ensure that
 *    requests are quickly flushed in case there is no disk in the drive. It
 *    follows that FD_DISK_CHANGE can only be cleared if there is a disk in
 *    the drive.
 *
 * For 1., maxblock is observed. Maxblock is 0 if no i/o has taken place yet.
 * For 2., FD_DISK_NEWCHANGE is watched. FD_DISK_NEWCHANGE is cleared on
 *  each seek. If a disk is present, the disk change line should also be
 *  cleared on each seek. Thus, if FD_DISK_NEWCHANGE is clear, but the disk
 *  change line is set, this means either that no disk is in the drive, or
 *  that it has been removed since the last seek.
 *
 * This means that we really have a third possibility too:
 *  The floppy has been changed after the last seek.
 */

static int disk_change(int drive)
{
        int fdc=FDC(drive);
#ifdef FLOPPY_SANITY_CHECK
        if (jiffies - UDRS->select_date < UDP->select_delay)
                DPRINT("WARNING disk change called early\n");
        if (!(FDCS->dor & (0x10 << UNIT(drive))) ||
            (FDCS->dor & 3) != UNIT(drive) ||
            fdc != FDC(drive)){
                DPRINT("probing disk change on unselected drive\n");
                DPRINT("drive=%d fdc=%d dor=%x\n",drive, FDC(drive),
                        (unsigned int)FDCS->dor);
        }
#endif

#ifdef DCL_DEBUG
        if (UDP->flags & FD_DEBUG){
                DPRINT("checking disk change line for drive %d\n",drive);
                DPRINT("jiffies=%lu\n", jiffies);
                DPRINT("disk change line=%x\n",fd_inb(FD_DIR)&0x80);
                DPRINT("flags=%lx\n",UDRS->flags);
        }
#endif
        if (UDP->flags & FD_BROKEN_DCL)
                return UTESTF(FD_DISK_CHANGED);
        if ((fd_inb(FD_DIR) ^ UDP->flags) & 0x80){
                USETF(FD_VERIFY); /* verify write protection */
                if (UDRS->maxblock){
                        /* mark it changed */
                        USETF(FD_DISK_CHANGED);
                }

                /* invalidate its geometry */
                if (UDRS->keep_data >= 0) {
                        if ((UDP->flags & FTD_MSG) &&
                            current_type[drive] != NULL)
                                DPRINT("Disk type is undefined after "
                                       "disk change\n");
                        current_type[drive] = NULL;
                        floppy_sizes[TOMINOR(drive)] = MAX_DISK_SIZE;
                }

                /*USETF(FD_DISK_NEWCHANGE);*/
                return 1;
        } else {
                UDRS->last_checked=jiffies;
                UCLEARF(FD_DISK_NEWCHANGE);
        }
        return 0;
}

static inline int is_selected(int dor, int unit)
{
        return ((dor  & (0x10 << unit)) && (dor &3) == unit);
}

static int set_dor(int fdc, char mask, char data)
{
        register unsigned char drive, unit, newdor,olddor;

        if (FDCS->address == -1)
                return -1;

        olddor = FDCS->dor;
        newdor =  (olddor & mask) | data;
        if (newdor != olddor){
                unit = olddor & 0x3;
                if (is_selected(olddor, unit) && !is_selected(newdor,unit)){
                        drive = REVDRIVE(fdc,unit);
#ifdef DCL_DEBUG
                        if (UDP->flags & FD_DEBUG){
                                DPRINT("calling disk change from set_dor\n");
                        }
#endif
                        disk_change(drive);
                }
                FDCS->dor = newdor;
                fd_outb(newdor, FD_DOR);

                unit = newdor & 0x3;
                if (!is_selected(olddor, unit) && is_selected(newdor,unit)){
                        drive = REVDRIVE(fdc,unit);
                        UDRS->select_date = jiffies;
                }
        }
        /*
         *      We should propogate failures to grab the resources back
         *      nicely from here. Actually we ought to rewrite the fd
         *      driver some day too.
         */
        if (newdor & FLOPPY_MOTOR_MASK)
                floppy_grab_irq_and_dma();
        if (olddor & FLOPPY_MOTOR_MASK)
                floppy_release_irq_and_dma();
        return olddor;
}

static void twaddle(void)
{
        if (DP->select_delay)
                return;
        fd_outb(FDCS->dor & ~(0x10<<UNIT(current_drive)), FD_DOR);
        fd_outb(FDCS->dor, FD_DOR);
        DRS->select_date = jiffies;
}

/* reset all driver information about the current fdc. This is needed after
 * a reset, and after a raw command. */
static void reset_fdc_info(int mode)
{
        int drive;

        FDCS->spec1 = FDCS->spec2 = -1;
        FDCS->need_configure = 1;
        FDCS->perp_mode = 1;
        FDCS->rawcmd = 0;
        for (drive = 0; drive < N_DRIVE; drive++)
                if (FDC(drive) == fdc &&
                    (mode || UDRS->track != NEED_1_RECAL))
                        UDRS->track = NEED_2_RECAL;
}

/* selects the fdc and drive, and enables the fdc's input/dma. */
static void set_fdc(int drive)
{
        if (drive >= 0 && drive < N_DRIVE){
                fdc = FDC(drive);
                current_drive = drive;
        }
        if (fdc != 1 && fdc != 0) {
                printk("bad fdc value\n");
                return;
        }
        set_dor(fdc,~0,8);
#if N_FDC > 1
        set_dor(1-fdc, ~8, 0);
#endif
        if (FDCS->rawcmd == 2)
                reset_fdc_info(1);
        if (fd_inb(FD_STATUS) != STATUS_READY)
                FDCS->reset = 1;
}

/* locks the driver */
static int _lock_fdc(int drive, int interruptible, int line)
{
        if (!usage_count){
                printk(KERN_ERR "Trying to lock fdc while usage count=0 at line %d\n", line);
                return -1;
        }
        if(floppy_grab_irq_and_dma()==-1)
                return -EBUSY;

        if (test_and_set_bit(0, &fdc_busy)) {
                DECLARE_WAITQUEUE(wait, current);
                add_wait_queue(&fdc_wait, &wait);

                for (;;) {
                        set_current_state(TASK_INTERRUPTIBLE);

                        if (!test_and_set_bit(0, &fdc_busy))
                                break;

                        schedule();

                        if (!NO_SIGNAL) {
                                remove_wait_queue(&fdc_wait, &wait);
                                return -EINTR;
                        }
                }

                set_current_state(TASK_RUNNING);
                remove_wait_queue(&fdc_wait, &wait);
        }
        command_status = FD_COMMAND_NONE;

        __reschedule_timeout(drive, "lock fdc", 0);
        set_fdc(drive);
        return 0;
}

#define lock_fdc(drive,interruptible) _lock_fdc(drive,interruptible, __LINE__)

#define LOCK_FDC(drive,interruptible) \
if (lock_fdc(drive,interruptible)) return -EINTR;


/* unlocks the driver */
static inline void unlock_fdc(void)
{
        unsigned long flags;

        raw_cmd = 0;
        if (!test_bit(0, &fdc_busy))
                DPRINT("FDC access conflict!\n");

        if (DEVICE_INTR)
                DPRINT("device interrupt still active at FDC release: %p!\n",
                        DEVICE_INTR);
        command_status = FD_COMMAND_NONE;
        spin_lock_irqsave(&io_request_lock, flags);
        del_timer(&fd_timeout);
        cont = NULL;
        clear_bit(0, &fdc_busy);
        if (!QUEUE_EMPTY)
                do_fd_request(BLK_DEFAULT_QUEUE(MAJOR_NR));
        spin_unlock_irqrestore(&io_request_lock, flags);
        floppy_release_irq_and_dma();
        wake_up(&fdc_wait);
}

/* switches the motor off after a given timeout */
static void motor_off_callback(unsigned long nr)
{
        unsigned char mask = ~(0x10 << UNIT(nr));

        set_dor(FDC(nr), mask, 0);
}

/* schedules motor off */
static void floppy_off(unsigned int drive)
{
        unsigned long volatile delta;
        register int fdc=FDC(drive);

        if (!(FDCS->dor & (0x10 << UNIT(drive))))
                return;

        del_timer(motor_off_timer+drive);

        /* make spindle stop in a position which minimizes spinup time
         * next time */
        if (UDP->rps){
                delta = jiffies - UDRS->first_read_date + HZ -
                        UDP->spindown_offset;
                delta = ((delta * UDP->rps) % HZ) / UDP->rps;
                motor_off_timer[drive].expires = jiffies + UDP->spindown - delta;
        }
        add_timer(motor_off_timer+drive);
}

/*
 * cycle through all N_DRIVE floppy drives, for disk change testing.
 * stopping at current drive. This is done before any long operation, to
 * be sure to have up to date disk change information.
 */
static void scandrives(void)
{
        int i, drive, saved_drive;

        if (DP->select_delay)
                return;

        saved_drive = current_drive;
        for (i=0; i < N_DRIVE; i++){
                drive = (saved_drive + i + 1) % N_DRIVE;
                if (UDRS->fd_ref == 0 || UDP->select_delay != 0)
                        continue; /* skip closed drives */
                set_fdc(drive);
                if (!(set_dor(fdc, ~3, UNIT(drive) | (0x10 << UNIT(drive))) &
                      (0x10 << UNIT(drive))))
                        /* switch the motor off again, if it was off to
                         * begin with */
                        set_dor(fdc, ~(0x10 << UNIT(drive)), 0);
        }

        set_fdc(saved_drive);
}

static void empty(void)
{
}

static struct tq_struct floppy_tq;

static void schedule_bh( void (*handler)(void*) )
{
        floppy_tq.routine = (void *)(void *) handler;
        queue_task(&floppy_tq, &tq_immediate);
        mark_bh(IMMEDIATE_BH);
}

static struct timer_list fd_timer;

static void cancel_activity(void)
{
        unsigned long flags;

        spin_lock_irqsave(&io_request_lock, flags);
        CLEAR_INTR;
        floppy_tq.routine = (void *)(void *) empty;
        del_timer(&fd_timer);
        spin_unlock_irqrestore(&io_request_lock, flags);
}

/* this function makes sure that the disk stays in the drive during the
 * transfer */
static void fd_watchdog(void)
{
#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("calling disk change from watchdog\n");
        }
#endif

        if (disk_change(current_drive)){
                DPRINT("disk removed during i/o\n");
                cancel_activity();
                cont->done(0);
                reset_fdc();
        } else {
                del_timer(&fd_timer);
                fd_timer.function = (timeout_fn) fd_watchdog;
                fd_timer.expires = jiffies + HZ / 10;
                add_timer(&fd_timer);
        }
}

static void main_command_interrupt(void)
{
        del_timer(&fd_timer);
        cont->interrupt();
}

/* waits for a delay (spinup or select) to pass */
static int fd_wait_for_completion(unsigned long delay, timeout_fn function)
{
        if (FDCS->reset){
                reset_fdc(); /* do the reset during sleep to win time
                              * if we don't need to sleep, it's a good
                              * occasion anyways */
                return 1;
        }

        if ((signed) (jiffies - delay) < 0){
                del_timer(&fd_timer);
                fd_timer.function = function;
                fd_timer.expires = delay;
                add_timer(&fd_timer);
                return 1;
        }
        return 0;
}

static spinlock_t floppy_hlt_lock = SPIN_LOCK_UNLOCKED;
static int hlt_disabled;
static void floppy_disable_hlt(void)
{
        unsigned long flags;

        spin_lock_irqsave(&floppy_hlt_lock, flags);
        if (!hlt_disabled) {
                hlt_disabled=1;
#ifdef HAVE_DISABLE_HLT
                disable_hlt();
#endif
        }
        spin_unlock_irqrestore(&floppy_hlt_lock, flags);
}

static void floppy_enable_hlt(void)
{
        unsigned long flags;

        spin_lock_irqsave(&floppy_hlt_lock, flags);
        if (hlt_disabled){
                hlt_disabled=0;
#ifdef HAVE_DISABLE_HLT
                enable_hlt();
#endif
        }
        spin_unlock_irqrestore(&floppy_hlt_lock, flags);
}


static void setup_DMA(void)
{
        unsigned long f;

#ifdef FLOPPY_SANITY_CHECK
        if (raw_cmd->length == 0){
                int i;

                printk("zero dma transfer size:");
                for (i=0; i < raw_cmd->cmd_count; i++)
                        printk("%x,", raw_cmd->cmd[i]);
                printk("\n");
                cont->done(0);
                FDCS->reset = 1;
                return;
        }
        if (((unsigned long) raw_cmd->kernel_data) % 512){
                printk("non aligned address: %p\n", raw_cmd->kernel_data);
                cont->done(0);
                FDCS->reset=1;
                return;
        }
#endif
        f=claim_dma_lock();
        fd_disable_dma();
#ifdef fd_dma_setup
        if (fd_dma_setup(raw_cmd->kernel_data, raw_cmd->length, 
                        (raw_cmd->flags & FD_RAW_READ)?
                        DMA_MODE_READ : DMA_MODE_WRITE,
                        FDCS->address) < 0) {
                release_dma_lock(f);
                cont->done(0);
                FDCS->reset=1;
                return;
        }
        release_dma_lock(f);
#else   
        fd_clear_dma_ff();
        fd_cacheflush(raw_cmd->kernel_data, raw_cmd->length);
        fd_set_dma_mode((raw_cmd->flags & FD_RAW_READ)?
                        DMA_MODE_READ : DMA_MODE_WRITE);
        fd_set_dma_addr(raw_cmd->kernel_data);
        fd_set_dma_count(raw_cmd->length);
        virtual_dma_port = FDCS->address;
        fd_enable_dma();
        release_dma_lock(f);
#endif
        floppy_disable_hlt();
}

static void show_floppy(void);

/* waits until the fdc becomes ready */
static int wait_til_ready(void)
{
        int counter, status;
        if (FDCS->reset)
                return -1;
        for (counter = 0; counter < 10000; counter++) {
                status = fd_inb(FD_STATUS);             
                if (status & STATUS_READY)
                        return status;
        }
        if (!initialising) {
                DPRINT("Getstatus times out (%x) on fdc %d\n",
                        status, fdc);
                show_floppy();
        }
        FDCS->reset = 1;
        return -1;
}

/* sends a command byte to the fdc */
static int output_byte(char byte)
{
        int status;

        if ((status = wait_til_ready()) < 0)
                return -1;
        if ((status & (STATUS_READY|STATUS_DIR|STATUS_DMA)) == STATUS_READY){
                fd_outb(byte,FD_DATA);
#ifdef FLOPPY_SANITY_CHECK
                output_log[output_log_pos].data = byte;
                output_log[output_log_pos].status = status;
                output_log[output_log_pos].jiffies = jiffies;
                output_log_pos = (output_log_pos + 1) % OLOGSIZE;
#endif
                return 0;
        }
        FDCS->reset = 1;
        if (!initialising) {
                DPRINT("Unable to send byte %x to FDC. Fdc=%x Status=%x\n",
                       byte, fdc, status);
                show_floppy();
        }
        return -1;
}
#define LAST_OUT(x) if (output_byte(x)<0){ reset_fdc();return;}

/* gets the response from the fdc */
static int result(void)
{
        int i, status=0;

        for(i=0; i < MAX_REPLIES; i++) {
                if ((status = wait_til_ready()) < 0)
                        break;
                status &= STATUS_DIR|STATUS_READY|STATUS_BUSY|STATUS_DMA;
                if ((status & ~STATUS_BUSY) == STATUS_READY){
#ifdef FLOPPY_SANITY_CHECK
                        resultjiffies = jiffies;
                        resultsize = i;
#endif
                        return i;
                }
                if (status == (STATUS_DIR|STATUS_READY|STATUS_BUSY))
                        reply_buffer[i] = fd_inb(FD_DATA);
                else
                        break;
        }
        if (!initialising) {
                DPRINT("get result error. Fdc=%d Last status=%x Read bytes=%d\n",
                       fdc, status, i);
                show_floppy();
        }
        FDCS->reset = 1;
        return -1;
}

#define MORE_OUTPUT -2
/* does the fdc need more output? */
static int need_more_output(void)
{
        int status;
        if ((status = wait_til_ready()) < 0)
                return -1;
        if ((status & (STATUS_READY|STATUS_DIR|STATUS_DMA)) == STATUS_READY)
                return MORE_OUTPUT;
        return result();
}

/* Set perpendicular mode as required, based on data rate, if supported.
 * 82077 Now tested. 1Mbps data rate only possible with 82077-1.
 */
static inline void perpendicular_mode(void)
{
        unsigned char perp_mode;

        if (raw_cmd->rate & 0x40){
                switch(raw_cmd->rate & 3){
                        case 0:
                                perp_mode=2;
                                break;
                        case 3:
                                perp_mode=3;
                                break;
                        default:
                                DPRINT("Invalid data rate for perpendicular mode!\n");
                                cont->done(0);
                                FDCS->reset = 1; /* convenient way to return to
                                                  * redo without to much hassle (deep
                                                  * stack et al. */
                                return;
                }
        } else
                perp_mode = 0;

        if (FDCS->perp_mode == perp_mode)
                return;
        if (FDCS->version >= FDC_82077_ORIG) {
                output_byte(FD_PERPENDICULAR);
                output_byte(perp_mode);
                FDCS->perp_mode = perp_mode;
        } else if (perp_mode) {
                DPRINT("perpendicular mode not supported by this FDC.\n");
        }
} /* perpendicular_mode */

static int fifo_depth = 0xa;
static int no_fifo;

static int fdc_configure(void)
{
        /* Turn on FIFO */
        output_byte(FD_CONFIGURE);
        if (need_more_output() != MORE_OUTPUT)
                return 0;
        output_byte(0);
        output_byte(0x10 | (no_fifo & 0x20) | (fifo_depth & 0xf));
        output_byte(0); /* pre-compensation from track 
                           0 upwards */
        return 1;
}       

#define NOMINAL_DTR 500

/* Issue a "SPECIFY" command to set the step rate time, head unload time,
 * head load time, and DMA disable flag to values needed by floppy.
 *
 * The value "dtr" is the data transfer rate in Kbps.  It is needed
 * to account for the data rate-based scaling done by the 82072 and 82077
 * FDC types.  This parameter is ignored for other types of FDCs (i.e.
 * 8272a).
 *
 * Note that changing the data transfer rate has a (probably deleterious)
 * effect on the parameters subject to scaling for 82072/82077 FDCs, so
 * fdc_specify is called again after each data transfer rate
 * change.
 *
 * srt: 1000 to 16000 in microseconds
 * hut: 16 to 240 milliseconds
 * hlt: 2 to 254 milliseconds
 *
 * These values are rounded up to the next highest available delay time.
 */
static void fdc_specify(void)
{
        unsigned char spec1, spec2;
        unsigned long srt, hlt, hut;
        unsigned long dtr = NOMINAL_DTR;
        unsigned long scale_dtr = NOMINAL_DTR;
        int hlt_max_code = 0x7f;
        int hut_max_code = 0xf;

        if (FDCS->need_configure && FDCS->version >= FDC_82072A) {
                fdc_configure();
                FDCS->need_configure = 0;
                /*DPRINT("FIFO enabled\n");*/
        }

        switch (raw_cmd->rate & 0x03) {
                case 3:
                        dtr = 1000;
                        break;
                case 1:
                        dtr = 300;
                        if (FDCS->version >= FDC_82078) {
                                /* chose the default rate table, not the one
                                 * where 1 = 2 Mbps */
                                output_byte(FD_DRIVESPEC);
                                if (need_more_output() == MORE_OUTPUT) {
                                        output_byte(UNIT(current_drive));
                                        output_byte(0xc0);
                                }
                        }
                        break;
                case 2:
                        dtr = 250;
                        break;
        }

        if (FDCS->version >= FDC_82072) {
                scale_dtr = dtr;
                hlt_max_code = 0x00; /* 0==256msec*dtr0/dtr (not linear!) */
                hut_max_code = 0x0; /* 0==256msec*dtr0/dtr (not linear!) */
        }

        /* Convert step rate from microseconds to milliseconds and 4 bits */
        srt = 16 - (DP->srt*scale_dtr/1000 + NOMINAL_DTR - 1)/NOMINAL_DTR;
        if( slow_floppy ) {
                srt = srt / 4;
        }
        SUPBOUND(srt, 0xf);
        INFBOUND(srt, 0);

        hlt = (DP->hlt*scale_dtr/2 + NOMINAL_DTR - 1)/NOMINAL_DTR;
        if (hlt < 0x01)
                hlt = 0x01;
        else if (hlt > 0x7f)
                hlt = hlt_max_code;

        hut = (DP->hut*scale_dtr/16 + NOMINAL_DTR - 1)/NOMINAL_DTR;
        if (hut < 0x1)
                hut = 0x1;
        else if (hut > 0xf)
                hut = hut_max_code;

        spec1 = (srt << 4) | hut;
        spec2 = (hlt << 1) | (use_virtual_dma & 1);

        /* If these parameters did not change, just return with success */
        if (FDCS->spec1 != spec1 || FDCS->spec2 != spec2) {
                /* Go ahead and set spec1 and spec2 */
                output_byte(FD_SPECIFY);
                output_byte(FDCS->spec1 = spec1);
                output_byte(FDCS->spec2 = spec2);
        }
} /* fdc_specify */

/* Set the FDC's data transfer rate on behalf of the specified drive.
 * NOTE: with 82072/82077 FDCs, changing the data rate requires a reissue
 * of the specify command (i.e. using the fdc_specify function).
 */
static int fdc_dtr(void)
{
        /* If data rate not already set to desired value, set it. */
        if ((raw_cmd->rate & 3) == FDCS->dtr)
                return 0;

        /* Set dtr */
        fd_outb(raw_cmd->rate & 3, FD_DCR);

        /* TODO: some FDC/drive combinations (C&T 82C711 with TEAC 1.2MB)
         * need a stabilization period of several milliseconds to be
         * enforced after data rate changes before R/W operations.
         * Pause 5 msec to avoid trouble. (Needs to be 2 jiffies)
         */
        FDCS->dtr = raw_cmd->rate & 3;
        return(fd_wait_for_completion(jiffies+2UL*HZ/100,
                                   (timeout_fn) floppy_ready));
} /* fdc_dtr */

static void tell_sector(void)
{
        printk(": track %d, head %d, sector %d, size %d",
               R_TRACK, R_HEAD, R_SECTOR, R_SIZECODE);
} /* tell_sector */


/*
 * OK, this error interpreting routine is called after a
 * DMA read/write has succeeded
 * or failed, so we check the results, and copy any buffers.
 * hhb: Added better error reporting.
 * ak: Made this into a separate routine.
 */
static int interpret_errors(void)
{
        char bad;

        if (inr!=7) {
                DPRINT("-- FDC reply error");
                FDCS->reset = 1;
                return 1;
        }

        /* check IC to find cause of interrupt */
        switch (ST0 & ST0_INTR) {
                case 0x40:      /* error occurred during command execution */
                        if (ST1 & ST1_EOC)
                                return 0; /* occurs with pseudo-DMA */
                        bad = 1;
                        if (ST1 & ST1_WP) {
                                DPRINT("Drive is write protected\n");
                                CLEARF(FD_DISK_WRITABLE);
                                cont->done(0);
                                bad = 2;
                        } else if (ST1 & ST1_ND) {
                                SETF(FD_NEED_TWADDLE);
                        } else if (ST1 & ST1_OR) {
                                if (DP->flags & FTD_MSG)
                                        DPRINT("Over/Underrun - retrying\n");
                                bad = 0;
                        }else if (*errors >= DP->max_errors.reporting){
                                DPRINT("");
                                if (ST0 & ST0_ECE) {
                                        printk("Recalibrate failed!");
                                } else if (ST2 & ST2_CRC) {
                                        printk("data CRC error");
                                        tell_sector();
                                } else if (ST1 & ST1_CRC) {
                                        printk("CRC error");
                                        tell_sector();
                                } else if ((ST1 & (ST1_MAM|ST1_ND)) || (ST2 & ST2_MAM)) {
                                        if (!probing) {
                                                printk("sector not found");
                                                tell_sector();
                                        } else
                                                printk("probe failed...");
                                } else if (ST2 & ST2_WC) {      /* seek error */
                                        printk("wrong cylinder");
                                } else if (ST2 & ST2_BC) {      /* cylinder marked as bad */
                                        printk("bad cylinder");
                                } else {
                                        printk("unknown error. ST[0..2] are: 0x%x 0x%x 0x%x", ST0, ST1, ST2);
                                        tell_sector();
                                }
                                printk("\n");

                        }
                        if (ST2 & ST2_WC || ST2 & ST2_BC)
                                /* wrong cylinder => recal */
                                DRS->track = NEED_2_RECAL;
                        return bad;
                case 0x80: /* invalid command given */
                        DPRINT("Invalid FDC command given!\n");
                        cont->done(0);
                        return 2;
                case 0xc0:
                        DPRINT("Abnormal termination caused by polling\n");
                        cont->error();
                        return 2;
                default: /* (0) Normal command termination */
                        return 0;
        }
}

/*
 * This routine is called when everything should be correctly set up
 * for the transfer (i.e. floppy motor is on, the correct floppy is
 * selected, and the head is sitting on the right track).
 */
static void setup_rw_floppy(void)
{
        int i,r, flags,dflags;
        unsigned long ready_date;
        timeout_fn function;

        flags = raw_cmd->flags;
        if (flags & (FD_RAW_READ | FD_RAW_WRITE))
                flags |= FD_RAW_INTR;

        if ((flags & FD_RAW_SPIN) && !(flags & FD_RAW_NO_MOTOR)){
                ready_date = DRS->spinup_date + DP->spinup;
                /* If spinup will take a long time, rerun scandrives
                 * again just before spinup completion. Beware that
                 * after scandrives, we must again wait for selection.
                 */
                if ((signed) (ready_date - jiffies) > DP->select_delay){
                        ready_date -= DP->select_delay;
                        function = (timeout_fn) floppy_start;
                } else
                        function = (timeout_fn) setup_rw_floppy;

                /* wait until the floppy is spinning fast enough */
                if (fd_wait_for_completion(ready_date,function))
                        return;
        }
        dflags = DRS->flags;

        if ((flags & FD_RAW_READ) || (flags & FD_RAW_WRITE))
                setup_DMA();

        if (flags & FD_RAW_INTR)
                SET_INTR(main_command_interrupt);

        r=0;
        for (i=0; i< raw_cmd->cmd_count; i++)
                r|=output_byte(raw_cmd->cmd[i]);

#ifdef DEBUGT
        debugt("rw_command: ");
#endif
        if (r){
                cont->error();
                reset_fdc();
                return;
        }

        if (!(flags & FD_RAW_INTR)){
                inr = result();
                cont->interrupt();
        } else if (flags & FD_RAW_NEED_DISK)
                fd_watchdog();
}

static int blind_seek;

/*
 * This is the routine called after every seek (or recalibrate) interrupt
 * from the floppy controller.
 */
static void seek_interrupt(void)
{
#ifdef DEBUGT
        debugt("seek interrupt:");
#endif
        if (inr != 2 || (ST0 & 0xF8) != 0x20) {
                DPRINT("seek failed\n");
                DRS->track = NEED_2_RECAL;
                cont->error();
                cont->redo();
                return;
        }
        if (DRS->track >= 0 && DRS->track != ST1 && !blind_seek){
#ifdef DCL_DEBUG
                if (DP->flags & FD_DEBUG){
                        DPRINT("clearing NEWCHANGE flag because of effective seek\n");
                        DPRINT("jiffies=%lu\n", jiffies);
                }
#endif
                CLEARF(FD_DISK_NEWCHANGE); /* effective seek */
                DRS->select_date = jiffies;
        }
        DRS->track = ST1;
        floppy_ready();
}

static void check_wp(void)
{
        if (TESTF(FD_VERIFY)) {
                /* check write protection */
                output_byte(FD_GETSTATUS);
                output_byte(UNIT(current_drive));
                if (result() != 1){
                        FDCS->reset = 1;
                        return;
                }
                CLEARF(FD_VERIFY);
                CLEARF(FD_NEED_TWADDLE);
#ifdef DCL_DEBUG
                if (DP->flags & FD_DEBUG){
                        DPRINT("checking whether disk is write protected\n");
                        DPRINT("wp=%x\n",ST3 & 0x40);
                }
#endif
                if (!(ST3  & 0x40))
                        SETF(FD_DISK_WRITABLE);
                else
                        CLEARF(FD_DISK_WRITABLE);
        }
}

static void seek_floppy(void)
{
        int track;

        blind_seek=0;

#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("calling disk change from seek\n");
        }
#endif

        if (!TESTF(FD_DISK_NEWCHANGE) &&
            disk_change(current_drive) &&
            (raw_cmd->flags & FD_RAW_NEED_DISK)){
                /* the media changed flag should be cleared after the seek.
                 * If it isn't, this means that there is really no disk in
                 * the drive.
                 */
                SETF(FD_DISK_CHANGED);
                cont->done(0);
                cont->redo();
                return;
        }
        if (DRS->track <= NEED_1_RECAL){
                recalibrate_floppy();
                return;
        } else if (TESTF(FD_DISK_NEWCHANGE) &&
                   (raw_cmd->flags & FD_RAW_NEED_DISK) &&
                   (DRS->track <= NO_TRACK || DRS->track == raw_cmd->track)) {
                /* we seek to clear the media-changed condition. Does anybody
                 * know a more elegant way, which works on all drives? */
                if (raw_cmd->track)
                        track = raw_cmd->track - 1;
                else {
                        if (DP->flags & FD_SILENT_DCL_CLEAR){
                                set_dor(fdc, ~(0x10 << UNIT(current_drive)), 0);
                                blind_seek = 1;
                                raw_cmd->flags |= FD_RAW_NEED_SEEK;
                        }
                        track = 1;
                }
        } else {
                check_wp();
                if (raw_cmd->track != DRS->track &&
                    (raw_cmd->flags & FD_RAW_NEED_SEEK))
                        track = raw_cmd->track;
                else {
                        setup_rw_floppy();
                        return;
                }
        }

        SET_INTR(seek_interrupt);
        output_byte(FD_SEEK);
        output_byte(UNIT(current_drive));
        LAST_OUT(track);
#ifdef DEBUGT
        debugt("seek command:");
#endif
}

static void recal_interrupt(void)
{
#ifdef DEBUGT
        debugt("recal interrupt:");
#endif
        if (inr !=2)
                FDCS->reset = 1;
        else if (ST0 & ST0_ECE) {
                switch(DRS->track){
                        case NEED_1_RECAL:
#ifdef DEBUGT
                                debugt("recal interrupt need 1 recal:");
#endif
                                /* after a second recalibrate, we still haven't
                                 * reached track 0. Probably no drive. Raise an
                                 * error, as failing immediately might upset
                                 * computers possessed by the Devil :-) */
                                cont->error();
                                cont->redo();
                                return;
                        case NEED_2_RECAL:
#ifdef DEBUGT
                                debugt("recal interrupt need 2 recal:");
#endif
                                /* If we already did a recalibrate,
                                 * and we are not at track 0, this
                                 * means we have moved. (The only way
                                 * not to move at recalibration is to
                                 * be already at track 0.) Clear the
                                 * new change flag */
#ifdef DCL_DEBUG
                                if (DP->flags & FD_DEBUG){
                                        DPRINT("clearing NEWCHANGE flag because of second recalibrate\n");
                                }
#endif

                                CLEARF(FD_DISK_NEWCHANGE);
                                DRS->select_date = jiffies;
                                /* fall through */
                        default:
#ifdef DEBUGT
                                debugt("recal interrupt default:");
#endif
                                /* Recalibrate moves the head by at
                                 * most 80 steps. If after one
                                 * recalibrate we don't have reached
                                 * track 0, this might mean that we
                                 * started beyond track 80.  Try
                                 * again.  */
                                DRS->track = NEED_1_RECAL;
                                break;
                }
        } else
                DRS->track = ST1;
        floppy_ready();
}

static void print_result(char *message, int inr)
{
        int i;

        DPRINT("%s ", message);
        if (inr >= 0)
                for (i=0; i<inr; i++)
                        printk("repl[%d]=%x ", i, reply_buffer[i]);
        printk("\n");
}

/* interrupt handler. Note that this can be called externally on the Sparc */
void floppy_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
        void (*handler)(void) = DEVICE_INTR;
        int do_print;
        unsigned long f;

        lasthandler = handler;
        interruptjiffies = jiffies;

        f=claim_dma_lock();
        fd_disable_dma();
        release_dma_lock(f);
        
        floppy_enable_hlt();
        CLEAR_INTR;
        if (fdc >= N_FDC || FDCS->address == -1){
                /* we don't even know which FDC is the culprit */
                printk("DOR0=%x\n", fdc_state[0].dor);
                printk("floppy interrupt on bizarre fdc %d\n",fdc);
                printk("handler=%p\n", handler);
                is_alive("bizarre fdc");
                return;
        }

        FDCS->reset = 0;
        /* We have to clear the reset flag here, because apparently on boxes
         * with level triggered interrupts (PS/2, Sparc, ...), it is needed to
         * emit SENSEI's to clear the interrupt line. And FDCS->reset blocks the
         * emission of the SENSEI's.
         * It is OK to emit floppy commands because we are in an interrupt
         * handler here, and thus we have to fear no interference of other
         * activity.
         */

        do_print = !handler && print_unex && !initialising;

        inr = result();
        if (do_print)
                print_result("unexpected interrupt", inr);
        if (inr == 0){
                int max_sensei = 4;
                do {
                        output_byte(FD_SENSEI);
                        inr = result();
                        if (do_print)
                                print_result("sensei", inr);
                        max_sensei--;
                } while ((ST0 & 0x83) != UNIT(current_drive) && inr == 2 && max_sensei);
        }
        if (handler) {
                schedule_bh( (void *)(void *) handler);
        } else
                FDCS->reset = 1;
        is_alive("normal interrupt end");
}

static void recalibrate_floppy(void)
{
#ifdef DEBUGT
        debugt("recalibrate floppy:");
#endif
        SET_INTR(recal_interrupt);
        output_byte(FD_RECALIBRATE);
        LAST_OUT(UNIT(current_drive));
}

/*
 * Must do 4 FD_SENSEIs after reset because of ``drive polling''.
 */
static void reset_interrupt(void)
{
#ifdef DEBUGT
        debugt("reset interrupt:");
#endif
        result();               /* get the status ready for set_fdc */
        if (FDCS->reset) {
                printk("reset set in interrupt, calling %p\n", cont->error);
                cont->error(); /* a reset just after a reset. BAD! */
        }
        cont->redo();
}

/*
 * reset is done by pulling bit 2 of DOR low for a while (old FDCs),
 * or by setting the self clearing bit 7 of STATUS (newer FDCs)
 */
static void reset_fdc(void)
{
        unsigned long flags;
        
        SET_INTR(reset_interrupt);
        FDCS->reset = 0;
        reset_fdc_info(0);

        /* Pseudo-DMA may intercept 'reset finished' interrupt.  */
        /* Irrelevant for systems with true DMA (i386).          */
        
        flags=claim_dma_lock();
        fd_disable_dma();
        release_dma_lock(flags);

        if (FDCS->version >= FDC_82072A)
                fd_outb(0x80 | (FDCS->dtr &3), FD_STATUS);
        else {
                fd_outb(FDCS->dor & ~0x04, FD_DOR);
                udelay(FD_RESET_DELAY);
                fd_outb(FDCS->dor, FD_DOR);
        }
}

static void show_floppy(void)
{
        int i;

        printk("\n");
        printk("floppy driver state\n");
        printk("-------------------\n");
        printk("now=%lu last interrupt=%lu diff=%lu last called handler=%p\n",
               jiffies, interruptjiffies, jiffies-interruptjiffies, lasthandler);


#ifdef FLOPPY_SANITY_CHECK
        printk("timeout_message=%s\n", timeout_message);
        printk("last output bytes:\n");
        for (i=0; i < OLOGSIZE; i++)
                printk("%2x %2x %lu\n",
                       output_log[(i+output_log_pos) % OLOGSIZE].data,
                       output_log[(i+output_log_pos) % OLOGSIZE].status,
                       output_log[(i+output_log_pos) % OLOGSIZE].jiffies);
        printk("last result at %lu\n", resultjiffies);
        printk("last redo_fd_request at %lu\n", lastredo);
        for (i=0; i<resultsize; i++){
                printk("%2x ", reply_buffer[i]);
        }
        printk("\n");
#endif

        printk("status=%x\n", fd_inb(FD_STATUS));
        printk("fdc_busy=%lu\n", fdc_busy);
        if (DEVICE_INTR)
                printk("DEVICE_INTR=%p\n", DEVICE_INTR);
        if (floppy_tq.sync)
                printk("floppy_tq.routine=%p\n", floppy_tq.routine);
        if (timer_pending(&fd_timer))
                printk("fd_timer.function=%p\n", fd_timer.function);
        if (timer_pending(&fd_timeout)){
                printk("timer_function=%p\n",fd_timeout.function);
                printk("expires=%lu\n",fd_timeout.expires-jiffies);
                printk("now=%lu\n",jiffies);
        }
        printk("cont=%p\n", cont);
        printk("CURRENT=%p\n", CURRENT);
        printk("command_status=%d\n", command_status);
        printk("\n");
}

static void floppy_shutdown(void)
{
        unsigned long flags;
        
        if (!initialising)
                show_floppy();
        cancel_activity();

        floppy_enable_hlt();
        
        flags=claim_dma_lock();
        fd_disable_dma();
        release_dma_lock(flags);
        
        /* avoid dma going to a random drive after shutdown */

        if (!initialising)
                DPRINT("floppy timeout called\n");
        FDCS->reset = 1;
        if (cont){
                cont->done(0);
                cont->redo(); /* this will recall reset when needed */
        } else {
                printk("no cont in shutdown!\n");
                process_fd_request();
        }
        is_alive("floppy shutdown");
}
/*typedef void (*timeout_fn)(unsigned long);*/

/* start motor, check media-changed condition and write protection */
static int start_motor(void (*function)(void) )
{
        int mask, data;

        mask = 0xfc;
        data = UNIT(current_drive);
        if (!(raw_cmd->flags & FD_RAW_NO_MOTOR)){
                if (!(FDCS->dor & (0x10 << UNIT(current_drive)))){
                        set_debugt();
                        /* no read since this drive is running */
                        DRS->first_read_date = 0;
                        /* note motor start time if motor is not yet running */
                        DRS->spinup_date = jiffies;
                        data |= (0x10 << UNIT(current_drive));
                }
        } else
                if (FDCS->dor & (0x10 << UNIT(current_drive)))
                        mask &= ~(0x10 << UNIT(current_drive));

        /* starts motor and selects floppy */
        del_timer(motor_off_timer + current_drive);
        set_dor(fdc, mask, data);

        /* wait_for_completion also schedules reset if needed. */
        return(fd_wait_for_completion(DRS->select_date+DP->select_delay,
                                   (timeout_fn) function));
}

static void floppy_ready(void)
{
        CHECK_RESET;
        if (start_motor(floppy_ready)) return;
        if (fdc_dtr()) return;

#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("calling disk change from floppy_ready\n");
        }
#endif
        if (!(raw_cmd->flags & FD_RAW_NO_MOTOR) &&
           disk_change(current_drive) &&
           !DP->select_delay)
                twaddle(); /* this clears the dcl on certain drive/controller
                            * combinations */

#ifdef fd_chose_dma_mode
        if ((raw_cmd->flags & FD_RAW_READ) || 
            (raw_cmd->flags & FD_RAW_WRITE))
        {
                unsigned long flags = claim_dma_lock();
                fd_chose_dma_mode(raw_cmd->kernel_data,
                                  raw_cmd->length);
                release_dma_lock(flags);
        }
#endif

        if (raw_cmd->flags & (FD_RAW_NEED_SEEK | FD_RAW_NEED_DISK)){
                perpendicular_mode();
                fdc_specify(); /* must be done here because of hut, hlt ... */
                seek_floppy();

        } else {
                if ((raw_cmd->flags & FD_RAW_READ) || 
                    (raw_cmd->flags & FD_RAW_WRITE))
                        fdc_specify();
                setup_rw_floppy();
        }
}

static void floppy_start(void)
{
        reschedule_timeout(CURRENTD, "floppy start", 0);

        scandrives();
#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("setting NEWCHANGE in floppy_start\n");
        }
#endif
        SETF(FD_DISK_NEWCHANGE);
        floppy_ready();
}

/*
 * ========================================================================
 * here ends the bottom half. Exported routines are:
 * floppy_start, floppy_off, floppy_ready, lock_fdc, unlock_fdc, set_fdc,
 * start_motor, reset_fdc, reset_fdc_info, interpret_errors.
 * Initialization also uses output_byte, result, set_dor, floppy_interrupt
 * and set_dor.
 * ========================================================================
 */
/*
 * General purpose continuations.
 * ==============================
 */

static void do_wakeup(void)
{
        reschedule_timeout(MAXTIMEOUT, "do wakeup", 0);
        cont = 0;
        command_status += 2;
        wake_up(&command_done);
}

static struct cont_t wakeup_cont={
        empty,
        do_wakeup,
        empty,
        (done_f)empty
};


static struct cont_t intr_cont={
        empty,
        process_fd_request,
        empty,
        (done_f) empty
};

static int wait_til_done(void (*handler)(void), int interruptible)
{
        int ret;

        schedule_bh((void *)(void *)handler);

        if (command_status < 2 && NO_SIGNAL) {
                DECLARE_WAITQUEUE(wait, current);

                add_wait_queue(&command_done, &wait);
                for (;;) {
                        set_current_state(interruptible?
                                          TASK_INTERRUPTIBLE:
                                          TASK_UNINTERRUPTIBLE);

                        if (command_status >= 2 || !NO_SIGNAL)
                                break;

                        is_alive("wait_til_done");

                        schedule();
                }

                set_current_state(TASK_RUNNING);
                remove_wait_queue(&command_done, &wait);
        }

        if (command_status < 2){
                cancel_activity();
                cont = &intr_cont;
                reset_fdc();
                return -EINTR;
        }

        if (FDCS->reset)
                command_status = FD_COMMAND_ERROR;
        if (command_status == FD_COMMAND_OKAY)
                ret=0;
        else
                ret=-EIO;
        command_status = FD_COMMAND_NONE;
        return ret;
}

static void generic_done(int result)
{
        command_status = result;
        cont = &wakeup_cont;
}

static void generic_success(void)
{
        cont->done(1);
}

static void generic_failure(void)
{
        cont->done(0);
}

static void success_and_wakeup(void)
{
        generic_success();
        cont->redo();
}


/*
 * formatting and rw support.
 * ==========================
 */

static int next_valid_format(void)
{
        int probed_format;

        probed_format = DRS->probed_format;
        while(1){
                if (probed_format >= 8 ||
                     !DP->autodetect[probed_format]){
                        DRS->probed_format = 0;
                        return 1;
                }
                if (floppy_type[DP->autodetect[probed_format]].sect){
                        DRS->probed_format = probed_format;
                        return 0;
                }
                probed_format++;
        }
}

static void bad_flp_intr(void)
{
        if (probing){
                DRS->probed_format++;
                if (!next_valid_format())
                        return;
        }
        (*errors)++;
        INFBOUND(DRWE->badness, *errors);
        if (*errors > DP->max_errors.abort)
                cont->done(0);
        if (*errors > DP->max_errors.reset)
                FDCS->reset = 1;
        else if (*errors > DP->max_errors.recal)
                DRS->track = NEED_2_RECAL;
}

static void set_floppy(kdev_t device)
{
        if (TYPE(device))
                _floppy = TYPE(device) + floppy_type;
        else
                _floppy = current_type[ DRIVE(device) ];
}

/*
 * formatting support.
 * ===================
 */
static void format_interrupt(void)
{
        switch (interpret_errors()){
                case 1:
                        cont->error();
                case 2:
                        break;
                case 0:
                        cont->done(1);
        }
        cont->redo();
}

#define CODE2SIZE (ssize = ((1 << SIZECODE) + 3) >> 2)
#define FM_MODE(x,y) ((y) & ~(((x)->rate & 0x80) >>1))
#define CT(x) ((x) | 0xc0)
static void setup_format_params(int track)
{
        struct fparm {
                unsigned char track,head,sect,size;
        } *here = (struct fparm *)floppy_track_buffer;
        int il,n;
        int count,head_shift,track_shift;

        raw_cmd = &default_raw_cmd;
        raw_cmd->track = track;

        raw_cmd->flags = FD_RAW_WRITE | FD_RAW_INTR | FD_RAW_SPIN |
                FD_RAW_NEED_DISK | FD_RAW_NEED_SEEK;
        raw_cmd->rate = _floppy->rate & 0x43;
        raw_cmd->cmd_count = NR_F;
        COMMAND = FM_MODE(_floppy,FD_FORMAT);
        DR_SELECT = UNIT(current_drive) + PH_HEAD(_floppy,format_req.head);
        F_SIZECODE = FD_SIZECODE(_floppy);
        F_SECT_PER_TRACK = _floppy->sect << 2 >> F_SIZECODE;
        F_GAP = _floppy->fmt_gap;
        F_FILL = FD_FILL_BYTE;

        raw_cmd->kernel_data = floppy_track_buffer;
        raw_cmd->length = 4 * F_SECT_PER_TRACK;

        /* allow for about 30ms for data transport per track */
        head_shift  = (F_SECT_PER_TRACK + 5) / 6;

        /* a ``cylinder'' is two tracks plus a little stepping time */
        track_shift = 2 * head_shift + 3;

        /* position of logical sector 1 on this track */
        n = (track_shift * format_req.track + head_shift * format_req.head)
                % F_SECT_PER_TRACK;

        /* determine interleave */
        il = 1;
        if (_floppy->fmt_gap < 0x22)
                il++;

        /* initialize field */
        for (count = 0; count < F_SECT_PER_TRACK; ++count) {
                here[count].track = format_req.track;
                here[count].head = format_req.head;
                here[count].sect = 0;
                here[count].size = F_SIZECODE;
        }
        /* place logical sectors */
        for (count = 1; count <= F_SECT_PER_TRACK; ++count) {
                here[n].sect = count;
                n = (n+il) % F_SECT_PER_TRACK;
                if (here[n].sect) { /* sector busy, find next free sector */
                        ++n;
                        if (n>= F_SECT_PER_TRACK) {
                                n-=F_SECT_PER_TRACK;
                                while (here[n].sect) ++n;
                        }
                }
        }
}

static void redo_format(void)
{
        buffer_track = -1;
        setup_format_params(format_req.track << STRETCH(_floppy));
        floppy_start();
#ifdef DEBUGT
        debugt("queue format request");
#endif
}

static struct cont_t format_cont={
        format_interrupt,
        redo_format,
        bad_flp_intr,
        generic_done };

static int do_format(kdev_t device, struct format_descr *tmp_format_req)
{
        int ret;
        int drive=DRIVE(device);

        LOCK_FDC(drive,1);
        set_floppy(device);
        if (!_floppy ||
            _floppy->track > DP->tracks ||
            tmp_format_req->track >= _floppy->track ||
            tmp_format_req->head >= _floppy->head ||
            (_floppy->sect << 2) % (1 <<  FD_SIZECODE(_floppy)) ||
            !_floppy->fmt_gap) {
                process_fd_request();
                return -EINVAL;
        }
        format_req = *tmp_format_req;
        format_errors = 0;
        cont = &format_cont;
        errors = &format_errors;
        IWAIT(redo_format);
        process_fd_request();
        return ret;
}

/*
 * Buffer read/write and support
 * =============================
 */

/* new request_done. Can handle physical sectors which are smaller than a
 * logical buffer */
static void request_done(int uptodate)
{
        int block;
        unsigned long flags;

        probing = 0;
        reschedule_timeout(MAXTIMEOUT, "request done %d", uptodate);

        if (QUEUE_EMPTY){
                DPRINT("request list destroyed in floppy request done\n");
                return;
        }

        if (uptodate){
                /* maintain values for invalidation on geometry
                 * change */
                block = current_count_sectors + CURRENT->sector;
                INFBOUND(DRS->maxblock, block);
                if (block > _floppy->sect)
                        DRS->maxtrack = 1;

                /* unlock chained buffers */
                spin_lock_irqsave(&io_request_lock, flags);
                while (current_count_sectors && !QUEUE_EMPTY &&
                       current_count_sectors >= CURRENT->current_nr_sectors){
                        current_count_sectors -= CURRENT->current_nr_sectors;
                        CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
                        CURRENT->sector += CURRENT->current_nr_sectors;
                        end_request(1);
                }
                spin_unlock_irqrestore(&io_request_lock, flags);

                if (current_count_sectors && !QUEUE_EMPTY){
                        /* "unlock" last subsector */
                        CURRENT->buffer += current_count_sectors <<9;
                        CURRENT->current_nr_sectors -= current_count_sectors;
                        CURRENT->nr_sectors -= current_count_sectors;
                        CURRENT->sector += current_count_sectors;
                        return;
                }

                if (current_count_sectors && QUEUE_EMPTY)
                        DPRINT("request list destroyed in floppy request done\n");

        } else {
                if (CURRENT->cmd == WRITE) {
                        /* record write error information */
                        DRWE->write_errors++;
                        if (DRWE->write_errors == 1) {
                                DRWE->first_error_sector = CURRENT->sector;
                                DRWE->first_error_generation = DRS->generation;
                        }
                        DRWE->last_error_sector = CURRENT->sector;
                        DRWE->last_error_generation = DRS->generation;
                }
                spin_lock_irqsave(&io_request_lock, flags);
                end_request(0);
                spin_unlock_irqrestore(&io_request_lock, flags);
        }
}

/* Interrupt handler evaluating the result of the r/w operation */
static void rw_interrupt(void)
{
        int nr_sectors, ssize, eoc, heads;

        if (R_HEAD >= 2) {
            /* some Toshiba floppy controllers occasionnally seem to
             * return bogus interrupts after read/write operations, which
             * can be recognized by a bad head number (>= 2) */
             return;
        }  

        if (!DRS->first_read_date)
                DRS->first_read_date = jiffies;

        nr_sectors = 0;
        CODE2SIZE;

        if (ST1 & ST1_EOC)
                eoc = 1;
        else
                eoc = 0;

        if (COMMAND & 0x80)
                heads = 2;
        else
                heads = 1;

        nr_sectors = (((R_TRACK-TRACK) * heads +
                                   R_HEAD-HEAD) * SECT_PER_TRACK +
                                   R_SECTOR-SECTOR + eoc) << SIZECODE >> 2;

#ifdef FLOPPY_SANITY_CHECK
        if (nr_sectors / ssize > 
                (in_sector_offset + current_count_sectors + ssize - 1) / ssize) {
                DPRINT("long rw: %x instead of %lx\n",
                        nr_sectors, current_count_sectors);
                printk("rs=%d s=%d\n", R_SECTOR, SECTOR);
                printk("rh=%d h=%d\n", R_HEAD, HEAD);
                printk("rt=%d t=%d\n", R_TRACK, TRACK);
                printk("heads=%d eoc=%d\n", heads, eoc);
                printk("spt=%d st=%d ss=%d\n", SECT_PER_TRACK,
                       sector_t, ssize);
                printk("in_sector_offset=%d\n", in_sector_offset);
        }
#endif

        nr_sectors -= in_sector_offset;
        INFBOUND(nr_sectors,0);
        SUPBOUND(current_count_sectors, nr_sectors);

        switch (interpret_errors()){
                case 2:
                        cont->redo();
                        return;
                case 1:
                        if (!current_count_sectors){
                                cont->error();
                                cont->redo();
                                return;
                        }
                        break;
                case 0:
                        if (!current_count_sectors){
                                cont->redo();
                                return;
                        }
                        current_type[current_drive] = _floppy;
                        floppy_sizes[TOMINOR(current_drive) ]= 
                                (_floppy->size+1)>>1;
                        break;
        }

        if (probing) {
                if (DP->flags & FTD_MSG)
                        DPRINT("Auto-detected floppy type %s in fd%d\n",
                                _floppy->name,current_drive);
                current_type[current_drive] = _floppy;
                floppy_sizes[TOMINOR(current_drive)] = (_floppy->size+1) >> 1;
                probing = 0;
        }

        if (CT(COMMAND) != FD_READ || 
             raw_cmd->kernel_data == CURRENT->buffer){
                /* transfer directly from buffer */
                cont->done(1);
        } else if (CT(COMMAND) == FD_READ){
                buffer_track = raw_cmd->track;
                buffer_drive = current_drive;
                INFBOUND(buffer_max, nr_sectors + sector_t);
        }
        cont->redo();
}

/* Compute maximal contiguous buffer size. */
static int buffer_chain_size(void)
{
        struct buffer_head *bh;
        int size;
        char *base;

        base = CURRENT->buffer;
        size = CURRENT->current_nr_sectors << 9;
        bh = CURRENT->bh;

        if (bh){
                bh = bh->b_reqnext;
                while (bh && bh->b_data == base + size){
                        size += bh->b_size;
                        bh = bh->b_reqnext;
                }
        }
        return size >> 9;
}

/* Compute the maximal transfer size */
static int transfer_size(int ssize, int max_sector, int max_size)
{
        SUPBOUND(max_sector, sector_t + max_size);

        /* alignment */
        max_sector -= (max_sector % _floppy->sect) % ssize;

        /* transfer size, beginning not aligned */
        current_count_sectors = max_sector - sector_t ;

        return max_sector;
}

/*
 * Move data from/to the track buffer to/from the buffer cache.
 */
static void copy_buffer(int ssize, int max_sector, int max_sector_2)
{
        int remaining; /* number of transferred 512-byte sectors */
        struct buffer_head *bh;
        char *buffer, *dma_buffer;
        int size;

        max_sector = transfer_size(ssize,
                                   minimum(max_sector, max_sector_2),
                                   CURRENT->nr_sectors);

        if (current_count_sectors <= 0 && CT(COMMAND) == FD_WRITE &&
            buffer_max > sector_t + CURRENT->nr_sectors)
                current_count_sectors = minimum(buffer_max - sector_t,
                                                CURRENT->nr_sectors);

        remaining = current_count_sectors << 9;
#ifdef FLOPPY_SANITY_CHECK
        if ((remaining >> 9) > CURRENT->nr_sectors  &&
            CT(COMMAND) == FD_WRITE){
                DPRINT("in copy buffer\n");
                printk("current_count_sectors=%ld\n", current_count_sectors);
                printk("remaining=%d\n", remaining >> 9);
                printk("CURRENT->nr_sectors=%ld\n",CURRENT->nr_sectors);
                printk("CURRENT->current_nr_sectors=%ld\n",
                       CURRENT->current_nr_sectors);
                printk("max_sector=%d\n", max_sector);
                printk("ssize=%d\n", ssize);
        }
#endif

        buffer_max = maximum(max_sector, buffer_max);

        dma_buffer = floppy_track_buffer + ((sector_t - buffer_min) << 9);

        bh = CURRENT->bh;
        size = CURRENT->current_nr_sectors << 9;
        buffer = CURRENT->buffer;

        while (remaining > 0){
                SUPBOUND(size, remaining);
#ifdef FLOPPY_SANITY_CHECK
                if (dma_buffer + size >
                    floppy_track_buffer + (max_buffer_sectors << 10) ||
                    dma_buffer < floppy_track_buffer){
                        DPRINT("buffer overrun in copy buffer %d\n",
                                (int) ((floppy_track_buffer - dma_buffer) >>9));
                        printk("sector_t=%d buffer_min=%d\n",
                               sector_t, buffer_min);
                        printk("current_count_sectors=%ld\n",
                               current_count_sectors);
                        if (CT(COMMAND) == FD_READ)
                                printk("read\n");
                        if (CT(COMMAND) == FD_READ)
                                printk("write\n");
                        break;
                }
                if (((unsigned long)buffer) % 512)
                        DPRINT("%p buffer not aligned\n", buffer);
#endif
                if (CT(COMMAND) == FD_READ)
                        memcpy(buffer, dma_buffer, size);
                else
                        memcpy(dma_buffer, buffer, size);
                remaining -= size;
                if (!remaining)
                        break;

                dma_buffer += size;
                bh = bh->b_reqnext;
#ifdef FLOPPY_SANITY_CHECK
                if (!bh){
                        DPRINT("bh=null in copy buffer after copy\n");
                        break;
                }
#endif
                size = bh->b_size;
                buffer = bh->b_data;
        }
#ifdef FLOPPY_SANITY_CHECK
        if (remaining){
                if (remaining > 0)
                        max_sector -= remaining >> 9;
                DPRINT("weirdness: remaining %d\n", remaining>>9);
        }
#endif
}

#if 0
static inline int check_dma_crossing(char *start, 
                                     unsigned long length, char *message)
{
        if (CROSS_64KB(start, length)) {
                printk("DMA xfer crosses 64KB boundary in %s %p-%p\n", 
                       message, start, start+length);
                return 1;
        } else
                return 0;
}
#endif

/* work around a bug in pseudo DMA
 * (on some FDCs) pseudo DMA does not stop when the CPU stops
 * sending data.  Hence we need a different way to signal the
 * transfer length:  We use SECT_PER_TRACK.  Unfortunately, this
 * does not work with MT, hence we can only transfer one head at
 * a time
 */
static void virtualdmabug_workaround(void)
{
        int hard_sectors, end_sector;

        if(CT(COMMAND) == FD_WRITE) {
                COMMAND &= ~0x80; /* switch off multiple track mode */

                hard_sectors = raw_cmd->length >> (7 + SIZECODE);
                end_sector = SECTOR + hard_sectors - 1;
#ifdef FLOPPY_SANITY_CHECK
                if(end_sector > SECT_PER_TRACK) {
                        printk("too many sectors %d > %d\n",
                               end_sector, SECT_PER_TRACK);
                        return;
                }
#endif
                SECT_PER_TRACK = end_sector; /* make sure SECT_PER_TRACK points
                                              * to end of transfer */
        }
}

/*
 * Formulate a read/write request.
 * this routine decides where to load the data (directly to buffer, or to
 * tmp floppy area), how much data to load (the size of the buffer, the whole
 * track, or a single sector)
 * All floppy_track_buffer handling goes in here. If we ever add track buffer
 * allocation on the fly, it should be done here. No other part should need
 * modification.
 */

static int make_raw_rw_request(void)
{
        int aligned_sector_t;
        int max_sector, max_size, tracksize, ssize;

        if(max_buffer_sectors == 0) {
                printk("VFS: Block I/O scheduled on unopened device\n");
                return 0;
        }

        set_fdc(DRIVE(CURRENT->rq_dev));

        raw_cmd = &default_raw_cmd;
        raw_cmd->flags = FD_RAW_SPIN | FD_RAW_NEED_DISK | FD_RAW_NEED_DISK |
                FD_RAW_NEED_SEEK;
        raw_cmd->cmd_count = NR_RW;
        if (CURRENT->cmd == READ){
                raw_cmd->flags |= FD_RAW_READ;
                COMMAND = FM_MODE(_floppy,FD_READ);
        } else if (CURRENT->cmd == WRITE){
                raw_cmd->flags |= FD_RAW_WRITE;
                COMMAND = FM_MODE(_floppy,FD_WRITE);
        } else {
                DPRINT("make_raw_rw_request: unknown command\n");
                return 0;
        }

        max_sector = _floppy->sect * _floppy->head;

        TRACK = CURRENT->sector / max_sector;
        sector_t = CURRENT->sector % max_sector;
        if (_floppy->track && TRACK >= _floppy->track) {
                if (CURRENT->current_nr_sectors & 1) {
                        current_count_sectors = 1;
                        return 1;
                } else
                        return 0;
        }
        HEAD = sector_t / _floppy->sect;

        if (((_floppy->stretch & FD_SWAPSIDES) || TESTF(FD_NEED_TWADDLE)) &&
            sector_t < _floppy->sect)
                max_sector = _floppy->sect;

        /* 2M disks have phantom sectors on the first track */
        if ((_floppy->rate & FD_2M) && (!TRACK) && (!HEAD)){
                max_sector = 2 * _floppy->sect / 3;
                if (sector_t >= max_sector){
                        current_count_sectors = minimum(_floppy->sect - sector_t,
                                                        CURRENT->nr_sectors);
                        return 1;
                }
                SIZECODE = 2;
        } else
                SIZECODE = FD_SIZECODE(_floppy);
        raw_cmd->rate = _floppy->rate & 0x43;
        if ((_floppy->rate & FD_2M) &&
            (TRACK || HEAD) &&
            raw_cmd->rate == 2)
                raw_cmd->rate = 1;

        if (SIZECODE)
                SIZECODE2 = 0xff;
        else
                SIZECODE2 = 0x80;
        raw_cmd->track = TRACK << STRETCH(_floppy);
        DR_SELECT = UNIT(current_drive) + PH_HEAD(_floppy,HEAD);
        GAP = _floppy->gap;
        CODE2SIZE;
        SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE;
        SECTOR = ((sector_t % _floppy->sect) << 2 >> SIZECODE) + 1;

        /* tracksize describes the size which can be filled up with sectors
         * of size ssize.
         */
        tracksize = _floppy->sect - _floppy->sect % ssize;
        if (tracksize < _floppy->sect){
                SECT_PER_TRACK ++;
                if (tracksize <= sector_t % _floppy->sect)
                        SECTOR--;

                /* if we are beyond tracksize, fill up using smaller sectors */
                while (tracksize <= sector_t % _floppy->sect){
                        while(tracksize + ssize > _floppy->sect){
                                SIZECODE--;
                                ssize >>= 1;
                        }
                        SECTOR++; SECT_PER_TRACK ++;
                        tracksize += ssize;
                }
                max_sector = HEAD * _floppy->sect + tracksize;
        } else if (!TRACK && !HEAD && !(_floppy->rate & FD_2M) && probing) {
                max_sector = _floppy->sect;
        } else if (!HEAD && CT(COMMAND) == FD_WRITE) {
                /* for virtual DMA bug workaround */
                max_sector = _floppy->sect;
        }

        in_sector_offset = (sector_t % _floppy->sect) % ssize;
        aligned_sector_t = sector_t - in_sector_offset;
        max_size = CURRENT->nr_sectors;
        if ((raw_cmd->track == buffer_track) && 
            (current_drive == buffer_drive) &&
            (sector_t >= buffer_min) && (sector_t < buffer_max)) {
                /* data already in track buffer */
                if (CT(COMMAND) == FD_READ) {
                        copy_buffer(1, max_sector, buffer_max);
                        return 1;
                }
        } else if (in_sector_offset || CURRENT->nr_sectors < ssize){
                if (CT(COMMAND) == FD_WRITE){
                        if (sector_t + CURRENT->nr_sectors > ssize &&
                            sector_t + CURRENT->nr_sectors < ssize + ssize)
                                max_size = ssize + ssize;
                        else
                                max_size = ssize;
                }
                raw_cmd->flags &= ~FD_RAW_WRITE;
                raw_cmd->flags |= FD_RAW_READ;
                COMMAND = FM_MODE(_floppy,FD_READ);
        } else if ((unsigned long)CURRENT->buffer < MAX_DMA_ADDRESS) {
                unsigned long dma_limit;
                int direct, indirect;

                indirect= transfer_size(ssize,max_sector,max_buffer_sectors*2) -
                        sector_t;

                /*
                 * Do NOT use minimum() here---MAX_DMA_ADDRESS is 64 bits wide
                 * on a 64 bit machine!
                 */
                max_size = buffer_chain_size();
                dma_limit = (MAX_DMA_ADDRESS - ((unsigned long) CURRENT->buffer)) >> 9;
                if ((unsigned long) max_size > dma_limit) {
                        max_size = dma_limit;
                }
                /* 64 kb boundaries */
                if (CROSS_64KB(CURRENT->buffer, max_size << 9))
                        max_size = (K_64 - 
                                    ((unsigned long)CURRENT->buffer) % K_64)>>9;
                direct = transfer_size(ssize,max_sector,max_size) - sector_t;
                /*
                 * We try to read tracks, but if we get too many errors, we
                 * go back to reading just one sector at a time.
                 *
                 * This means we should be able to read a sector even if there
                 * are other bad sectors on this track.
                 */
                if (!direct ||
                    (indirect * 2 > direct * 3 &&
                     *errors < DP->max_errors.read_track &&
                     /*!TESTF(FD_NEED_TWADDLE) &&*/
                     ((!probing || (DP->read_track&(1<<DRS->probed_format)))))){
                        max_size = CURRENT->nr_sectors;
                } else {
                        raw_cmd->kernel_data = CURRENT->buffer;
                        raw_cmd->length = current_count_sectors << 9;
                        if (raw_cmd->length == 0){
                                DPRINT("zero dma transfer attempted from make_raw_request\n");
                                DPRINT("indirect=%d direct=%d sector_t=%d",
                                        indirect, direct, sector_t);
                                return 0;
                        }
/*                      check_dma_crossing(raw_cmd->kernel_data, 
                                           raw_cmd->length, 
                                           "end of make_raw_request [1]");*/

                        virtualdmabug_workaround();
                        return 2;
                }
        }

        if (CT(COMMAND) == FD_READ)
                max_size = max_sector; /* unbounded */

        /* claim buffer track if needed */
        if (buffer_track != raw_cmd->track ||  /* bad track */
            buffer_drive !=current_drive || /* bad drive */
            sector_t > buffer_max ||
            sector_t < buffer_min ||
            ((CT(COMMAND) == FD_READ ||
              (!in_sector_offset && CURRENT->nr_sectors >= ssize))&&
             max_sector > 2 * max_buffer_sectors + buffer_min &&
             max_size + sector_t > 2 * max_buffer_sectors + buffer_min)
            /* not enough space */){
                buffer_track = -1;
                buffer_drive = current_drive;
                buffer_max = buffer_min = aligned_sector_t;
        }
        raw_cmd->kernel_data = floppy_track_buffer + 
                ((aligned_sector_t-buffer_min)<<9);

        if (CT(COMMAND) == FD_WRITE){
                /* copy write buffer to track buffer.
                 * if we get here, we know that the write
                 * is either aligned or the data already in the buffer
                 * (buffer will be overwritten) */
#ifdef FLOPPY_SANITY_CHECK
                if (in_sector_offset && buffer_track == -1)
                        DPRINT("internal error offset !=0 on write\n");
#endif
                buffer_track = raw_cmd->track;
                buffer_drive = current_drive;
                copy_buffer(ssize, max_sector, 2*max_buffer_sectors+buffer_min);
        } else
                transfer_size(ssize, max_sector,
                              2*max_buffer_sectors+buffer_min-aligned_sector_t);

        /* round up current_count_sectors to get dma xfer size */
        raw_cmd->length = in_sector_offset+current_count_sectors;
        raw_cmd->length = ((raw_cmd->length -1)|(ssize-1))+1;
        raw_cmd->length <<= 9;
#ifdef FLOPPY_SANITY_CHECK
        /*check_dma_crossing(raw_cmd->kernel_data, raw_cmd->length, 
          "end of make_raw_request");*/
        if ((raw_cmd->length < current_count_sectors << 9) ||
            (raw_cmd->kernel_data != CURRENT->buffer &&
             CT(COMMAND) == FD_WRITE &&
             (aligned_sector_t + (raw_cmd->length >> 9) > buffer_max ||
              aligned_sector_t < buffer_min)) ||
            raw_cmd->length % (128 << SIZECODE) ||
            raw_cmd->length <= 0 || current_count_sectors <= 0){
                DPRINT("fractionary current count b=%lx s=%lx\n",
                        raw_cmd->length, current_count_sectors);
                if (raw_cmd->kernel_data != CURRENT->buffer)
                        printk("addr=%d, length=%ld\n",
                               (int) ((raw_cmd->kernel_data - 
                                       floppy_track_buffer) >> 9),
                               current_count_sectors);
                printk("st=%d ast=%d mse=%d msi=%d\n",
                       sector_t, aligned_sector_t, max_sector, max_size);
                printk("ssize=%x SIZECODE=%d\n", ssize, SIZECODE);
                printk("command=%x SECTOR=%d HEAD=%d, TRACK=%d\n",
                       COMMAND, SECTOR, HEAD, TRACK);
                printk("buffer drive=%d\n", buffer_drive);
                printk("buffer track=%d\n", buffer_track);
                printk("buffer_min=%d\n", buffer_min);
                printk("buffer_max=%d\n", buffer_max);
                return 0;
        }

        if (raw_cmd->kernel_data != CURRENT->buffer){
                if (raw_cmd->kernel_data < floppy_track_buffer ||
                    current_count_sectors < 0 ||
                    raw_cmd->length < 0 ||
                    raw_cmd->kernel_data + raw_cmd->length >
                    floppy_track_buffer + (max_buffer_sectors  << 10)){
                        DPRINT("buffer overrun in schedule dma\n");
                        printk("sector_t=%d buffer_min=%d current_count=%ld\n",
                               sector_t, buffer_min,
                               raw_cmd->length >> 9);
                        printk("current_count_sectors=%ld\n",
                               current_count_sectors);
                        if (CT(COMMAND) == FD_READ)
                                printk("read\n");
                        if (CT(COMMAND) == FD_READ)
                                printk("write\n");
                        return 0;
                }
        } else if (raw_cmd->length > CURRENT->nr_sectors << 9 ||
                   current_count_sectors > CURRENT->nr_sectors){
                DPRINT("buffer overrun in direct transfer\n");
                return 0;
        } else if (raw_cmd->length < current_count_sectors << 9){
                DPRINT("more sectors than bytes\n");
                printk("bytes=%ld\n", raw_cmd->length >> 9);
                printk("sectors=%ld\n", current_count_sectors);
        }
        if (raw_cmd->length == 0){
                DPRINT("zero dma transfer attempted from make_raw_request\n");
                return 0;
        }
#endif

        virtualdmabug_workaround();
        return 2;
}

static void redo_fd_request(void)
{
#define REPEAT {request_done(0); continue; }
        kdev_t device;
        int tmp;

        lastredo = jiffies;
        if (current_drive < N_DRIVE)
                floppy_off(current_drive);

        if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE){
                CLEAR_INTR;
                unlock_fdc();
                return;
        }

        while(1){
                if (QUEUE_EMPTY) {
                        CLEAR_INTR;
                        unlock_fdc();
                        return;
                }
                if (MAJOR(CURRENT->rq_dev) != MAJOR_NR)
                        panic(DEVICE_NAME ": request list destroyed");
                if (CURRENT->bh && !buffer_locked(CURRENT->bh))
                        panic(DEVICE_NAME ": block not locked");

                device = CURRENT->rq_dev;
                set_fdc(DRIVE(device));
                reschedule_timeout(CURRENTD, "redo fd request", 0);

                set_floppy(device);
                raw_cmd = & default_raw_cmd;
                raw_cmd->flags = 0;
                if (start_motor(redo_fd_request)) return;
                disk_change(current_drive);
                if (test_bit(current_drive, &fake_change) ||
                   TESTF(FD_DISK_CHANGED)){
                        DPRINT("disk absent or changed during operation\n");
                        REPEAT;
                }
                if (!_floppy) { /* Autodetection */
                        if (!probing){
                                DRS->probed_format = 0;
                                if (next_valid_format()){
                                        DPRINT("no autodetectable formats\n");
                                        _floppy = NULL;
                                        REPEAT;
                                }
                        }
                        probing = 1;
                        _floppy = floppy_type+DP->autodetect[DRS->probed_format];
                } else
                        probing = 0;
                errors = & (CURRENT->errors);
                tmp = make_raw_rw_request();
                if (tmp < 2){
                        request_done(tmp);
                        continue;
                }

                if (TESTF(FD_NEED_TWADDLE))
                        twaddle();
                schedule_bh( (void *)(void *) floppy_start);
#ifdef DEBUGT
                debugt("queue fd request");
#endif
                return;
        }
#undef REPEAT
}

static struct cont_t rw_cont={
        rw_interrupt,
        redo_fd_request,
        bad_flp_intr,
        request_done };

static void process_fd_request(void)
{
        cont = &rw_cont;
        schedule_bh( (void *)(void *) redo_fd_request);
}

static void do_fd_request(request_queue_t * q)
{

        if(max_buffer_sectors == 0) {
                printk("VFS: do_fd_request called on non-open device\n");
                return;
        }

        if (usage_count == 0) {
                printk("warning: usage count=0, CURRENT=%p exiting\n", CURRENT);
                printk("sect=%ld cmd=%d\n", CURRENT->sector, CURRENT->cmd);
                return;
        }
        if (test_bit(0, &fdc_busy)) {
                /* fdc busy, this new request will be treated when the
                   current one is done */
                is_alive("do fd request, old request running");
                return;
        }
        lock_fdc(MAXTIMEOUT,0);
        process_fd_request();
        is_alive("do fd request");
}

static struct cont_t poll_cont={
        success_and_wakeup,
        floppy_ready,
        generic_failure,
        generic_done };

static int poll_drive(int interruptible, int flag)
{
        int ret;
        /* no auto-sense, just clear dcl */
        raw_cmd = &default_raw_cmd;
        raw_cmd->flags= flag;
        raw_cmd->track=0;
        raw_cmd->cmd_count=0;
        cont = &poll_cont;
#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("setting NEWCHANGE in poll_drive\n");
        }
#endif
        SETF(FD_DISK_NEWCHANGE);
        WAIT(floppy_ready);
        return ret;
}

/*
 * User triggered reset
 * ====================
 */

static void reset_intr(void)
{
        printk("weird, reset interrupt called\n");
}

static struct cont_t reset_cont={
        reset_intr,
        success_and_wakeup,
        generic_failure,
        generic_done };

static int user_reset_fdc(int drive, int arg, int interruptible)
{
        int ret;

        ret=0;
        LOCK_FDC(drive,interruptible);
        if (arg == FD_RESET_ALWAYS)
                FDCS->reset=1;
        if (FDCS->reset){
                cont = &reset_cont;
                WAIT(reset_fdc);
        }
        process_fd_request();
        return ret;
}

/*
 * Misc Ioctl's and support
 * ========================
 */
static inline int fd_copyout(void *param, const void *address, unsigned long size)
{
        return copy_to_user(param,address, size) ? -EFAULT : 0;
}

static inline int fd_copyin(void *param, void *address, unsigned long size)
{
        return copy_from_user(address, param, size) ? -EFAULT : 0;
}

#define _COPYOUT(x) (copy_to_user((void *)param, &(x), sizeof(x)) ? -EFAULT : 0)
#define _COPYIN(x) (copy_from_user(&(x), (void *)param, sizeof(x)) ? -EFAULT : 0)

#define COPYOUT(x) ECALL(_COPYOUT(x))
#define COPYIN(x) ECALL(_COPYIN(x))

static inline const char *drive_name(int type, int drive)
{
        struct floppy_struct *floppy;

        if (type)
                floppy = floppy_type + type;
        else {
                if (UDP->native_format)
                        floppy = floppy_type + UDP->native_format;
                else
                        return "(null)";
        }
        if (floppy->name)
                return floppy->name;
        else
                return "(null)";
}


/* raw commands */
static void raw_cmd_done(int flag)
{
        int i;

        if (!flag) {
                raw_cmd->flags |= FD_RAW_FAILURE;
                raw_cmd->flags |= FD_RAW_HARDFAILURE;
        } else {
                raw_cmd->reply_count = inr;
                if (raw_cmd->reply_count > MAX_REPLIES)
                        raw_cmd->reply_count=0;
                for (i=0; i< raw_cmd->reply_count; i++)
                        raw_cmd->reply[i] = reply_buffer[i];

                if (raw_cmd->flags & (FD_RAW_READ | FD_RAW_WRITE))
                {
                        unsigned long flags;
                        flags=claim_dma_lock();
                        raw_cmd->length = fd_get_dma_residue();
                        release_dma_lock(flags);
                }
                
                if ((raw_cmd->flags & FD_RAW_SOFTFAILURE) &&
                    (!raw_cmd->reply_count || (raw_cmd->reply[0] & 0xc0)))
                        raw_cmd->flags |= FD_RAW_FAILURE;

                if (disk_change(current_drive))
                        raw_cmd->flags |= FD_RAW_DISK_CHANGE;
                else
                        raw_cmd->flags &= ~FD_RAW_DISK_CHANGE;
                if (raw_cmd->flags & FD_RAW_NO_MOTOR_AFTER)
                        motor_off_callback(current_drive);

                if (raw_cmd->next &&
                   (!(raw_cmd->flags & FD_RAW_FAILURE) ||
                    !(raw_cmd->flags & FD_RAW_STOP_IF_FAILURE)) &&
                   ((raw_cmd->flags & FD_RAW_FAILURE) ||
                    !(raw_cmd->flags &FD_RAW_STOP_IF_SUCCESS))) {
                        raw_cmd = raw_cmd->next;
                        return;
                }
        }
        generic_done(flag);
}


static struct cont_t raw_cmd_cont={
        success_and_wakeup,
        floppy_start,
        generic_failure,
        raw_cmd_done
};

static inline int raw_cmd_copyout(int cmd, char *param,
                                  struct floppy_raw_cmd *ptr)
{
        int ret;

        while(ptr) {
                COPYOUT(*ptr);
                param += sizeof(struct floppy_raw_cmd);
                if ((ptr->flags & FD_RAW_READ) && ptr->buffer_length){
                        if (ptr->length>=0 && ptr->length<=ptr->buffer_length)
                                ECALL(fd_copyout(ptr->data, 
                                                 ptr->kernel_data, 
                                                 ptr->buffer_length - 
                                                 ptr->length));
                }
                ptr = ptr->next;
        }
        return 0;
}


static void raw_cmd_free(struct floppy_raw_cmd **ptr)
{
        struct floppy_raw_cmd *next,*this;

        this = *ptr;
        *ptr = 0;
        while(this) {
                if (this->buffer_length) {
                        fd_dma_mem_free((unsigned long)this->kernel_data,
                                        this->buffer_length);
                        this->buffer_length = 0;
                }
                next = this->next;
                kfree(this);
                this = next;
        }
}


static inline int raw_cmd_copyin(int cmd, char *param,
                                 struct floppy_raw_cmd **rcmd)
{
        struct floppy_raw_cmd *ptr;
        int ret;
        int i;
        
        *rcmd = 0;
        while(1) {
                ptr = (struct floppy_raw_cmd *) 
                        kmalloc(sizeof(struct floppy_raw_cmd), GFP_USER);
                if (!ptr)
                        return -ENOMEM;
                *rcmd = ptr;
                COPYIN(*ptr);
                ptr->next = 0;
                ptr->buffer_length = 0;
                param += sizeof(struct floppy_raw_cmd);
                if (ptr->cmd_count > 33)
                        /* the command may now also take up the space
                         * initially intended for the reply & the
                         * reply count. Needed for long 82078 commands
                         * such as RESTORE, which takes ... 17 command
                         * bytes. Murphy's law #137: When you reserve
                         * 16 bytes for a structure, you'll one day
                         * discover that you really need 17...
                         */
                        return -EINVAL;

                for (i=0; i< 16; i++)
                        ptr->reply[i] = 0;
                ptr->resultcode = 0;
                ptr->kernel_data = 0;

                if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) {
                        if (ptr->length <= 0)
                                return -EINVAL;
                        ptr->kernel_data =(char*)fd_dma_mem_alloc(ptr->length);
                        fallback_on_nodma_alloc(&ptr->kernel_data,
                                                ptr->length);
                        if (!ptr->kernel_data)
                                return -ENOMEM;
                        ptr->buffer_length = ptr->length;
                }
                if (ptr->flags & FD_RAW_WRITE)
                        ECALL(fd_copyin(ptr->data, ptr->kernel_data, 
                                        ptr->length));
                rcmd = & (ptr->next);
                if (!(ptr->flags & FD_RAW_MORE))
                        return 0;
                ptr->rate &= 0x43;
        }
}


static int raw_cmd_ioctl(int cmd, void *param)
{
        int drive, ret, ret2;
        struct floppy_raw_cmd *my_raw_cmd;

        if (FDCS->rawcmd <= 1)
                FDCS->rawcmd = 1;
        for (drive= 0; drive < N_DRIVE; drive++){
                if (FDC(drive) != fdc)
                        continue;
                if (drive == current_drive){
                        if (UDRS->fd_ref > 1){
                                FDCS->rawcmd = 2;
                                break;
                        }
                } else if (UDRS->fd_ref){
                        FDCS->rawcmd = 2;
                        break;
                }
        }

        if (FDCS->reset)
                return -EIO;

        ret = raw_cmd_copyin(cmd, param, &my_raw_cmd);
        if (ret) {
                raw_cmd_free(&my_raw_cmd);
                return ret;
        }

        raw_cmd = my_raw_cmd;
        cont = &raw_cmd_cont;
        ret=wait_til_done(floppy_start,1);
#ifdef DCL_DEBUG
        if (DP->flags & FD_DEBUG){
                DPRINT("calling disk change from raw_cmd ioctl\n");
        }
#endif

        if (ret != -EINTR && FDCS->reset)
                ret = -EIO;

        DRS->track = NO_TRACK;

        ret2 = raw_cmd_copyout(cmd, param, my_raw_cmd);
        if (!ret)
                ret = ret2;
        raw_cmd_free(&my_raw_cmd);
        return ret;
}

static int invalidate_drive(kdev_t rdev)
{
        /* invalidate the buffer track to force a reread */
        set_bit(DRIVE(rdev), &fake_change);
        process_fd_request();
        check_disk_change(rdev);
        return 0;
}


static inline void clear_write_error(int drive)
{
        CLEARSTRUCT(UDRWE);
}

static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
                               int drive, int type, kdev_t device)
{
        int cnt;

        /* sanity checking for parameters.*/
        if (g->sect <= 0 ||
            g->head <= 0 ||
            g->track <= 0 ||
            g->track > UDP->tracks>>STRETCH(g) ||
            /* check if reserved bits are set */
            (g->stretch&~(FD_STRETCH|FD_SWAPSIDES)) != 0)
                return -EINVAL;
        if (type){
                if (!capable(CAP_SYS_ADMIN))
                        return -EPERM;
                LOCK_FDC(drive,1);
                for (cnt = 0; cnt < N_DRIVE; cnt++){
                        if (ITYPE(drive_state[cnt].fd_device) == type &&
                            drive_state[cnt].fd_ref)
                                set_bit(drive, &fake_change);
                }
                floppy_type[type] = *g;
                floppy_type[type].name="user format";
                for (cnt = type << 2; cnt < (type << 2) + 4; cnt++)
                        floppy_sizes[cnt]= floppy_sizes[cnt+0x80]=
                                (floppy_type[type].size+1)>>1;
                process_fd_request();
                for (cnt = 0; cnt < N_DRIVE; cnt++){
                        if (ITYPE(drive_state[cnt].fd_device) == type &&
                            drive_state[cnt].fd_ref)
                                check_disk_change(
                                        MKDEV(FLOPPY_MAJOR,
                                              drive_state[cnt].fd_device));
                }
        } else {
                LOCK_FDC(drive,1);
                if (cmd != FDDEFPRM)
                        /* notice a disk change immediately, else
                         * we lose our settings immediately*/
                        CALL(poll_drive(1, FD_RAW_NEED_DISK));
                user_params[drive] = *g;
                if (buffer_drive == drive)
                        SUPBOUND(buffer_max, user_params[drive].sect);
                current_type[drive] = &user_params[drive];
                floppy_sizes[drive] = (user_params[drive].size+1) >> 1;
                if (cmd == FDDEFPRM)
                        DRS->keep_data = -1;
                else
                        DRS->keep_data = 1;
                /* invalidation. Invalidate only when needed, i.e.
                 * when there are already sectors in the buffer cache
                 * whose number will change. This is useful, because
                 * mtools often changes the geometry of the disk after
                 * looking at the boot block */
                if (DRS->maxblock > user_params[drive].sect || DRS->maxtrack)
                        invalidate_drive(device);
                else
                        process_fd_request();
        }
        return 0;
}

/* handle obsolete ioctl's */
static int ioctl_table[]= {
        FDCLRPRM,
        FDSETPRM,
        FDDEFPRM,
        FDGETPRM,
        FDMSGON,
        FDMSGOFF,
        FDFMTBEG,
        FDFMTTRK,
        FDFMTEND,
        FDSETEMSGTRESH,
        FDFLUSH,
        FDSETMAXERRS,
        FDGETMAXERRS,
        FDGETDRVTYP,
        FDSETDRVPRM,
        FDGETDRVPRM,
        FDGETDRVSTAT,
        FDPOLLDRVSTAT,
        FDRESET,
        FDGETFDCSTAT,
        FDWERRORCLR,
        FDWERRORGET,
        FDRAWCMD,
        FDEJECT,
        FDTWADDLE
};

static inline int normalize_ioctl(int *cmd, int *size)
{
        int i;

        for (i=0; i < ARRAY_SIZE(ioctl_table); i++) {
                if ((*cmd & 0xffff) == (ioctl_table[i] & 0xffff)){
                        *size = _IOC_SIZE(*cmd);
                        *cmd = ioctl_table[i];
                        if (*size > _IOC_SIZE(*cmd)) {
                                printk("ioctl not yet supported\n");
                                return -EFAULT;
                        }
                        return 0;
                }
        }
        return -EINVAL;
}

static int get_floppy_geometry(int drive, int type, struct floppy_struct **g)
{
        if (type)
                *g = &floppy_type[type];
        else {
                LOCK_FDC(drive,0);
                CALL(poll_drive(0,0));
                process_fd_request();           
                *g = current_type[drive];
        }
        if (!*g)
                return -ENODEV;
        return 0;
}

static int fd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                    unsigned long param)
{
#define FD_IOCTL_ALLOWED ((filp) && (filp)->private_data)
#define OUT(c,x) case c: outparam = (const char *) (x); break
#define IN(c,x,tag) case c: *(x) = inparam. tag ; return 0

        int i,drive,type;
        kdev_t device;
        int ret;
        int size;
        union inparam {
                struct floppy_struct g; /* geometry */
                struct format_descr f;
                struct floppy_max_errors max_errors;
                struct floppy_drive_params dp;
        } inparam; /* parameters coming from user space */
        const char *outparam; /* parameters passed back to user space */

        device = inode->i_rdev;
        switch (cmd) {
                case BLKROSET:
                case BLKROGET:
                case BLKRASET:
                case BLKRAGET:
                case BLKFLSBUF:
                        return blk_ioctl(device, cmd, param);
        }
        type = TYPE(device);
        drive = DRIVE(device);

        /* convert compatibility eject ioctls into floppy eject ioctl.
         * We do this in order to provide a means to eject floppy disks before
         * installing the new fdutils package */
        if (cmd == CDROMEJECT || /* CD-ROM eject */
            cmd == 0x6470 /* SunOS floppy eject */) {
                DPRINT("obsolete eject ioctl\n");
                DPRINT("please use floppycontrol --eject\n");
                cmd = FDEJECT;
        }

        /* generic block device ioctls */
        switch(cmd) {
                /* the following have been inspired by the corresponding
                 * code for other block devices. */
                struct floppy_struct *g;
                case HDIO_GETGEO:
                {
                        struct hd_geometry loc;
                        ECALL(get_floppy_geometry(drive, type, &g));
                        loc.heads = g->head;
                        loc.sectors = g->sect;
                        loc.cylinders = g->track;
                        loc.start = 0;
                        return _COPYOUT(loc);
                }

                case BLKGETSIZE:
                        ECALL(get_floppy_geometry(drive, type, &g));
                        return put_user(g->size, (unsigned long *) param);

                case BLKGETSIZE64:
                        ECALL(get_floppy_geometry(drive, type, &g));
                        return put_user((u64)g->size << 9, (u64 *) param);
                /* BLKRRPART is not defined as floppies don't have
                 * partition tables */
        }

        /* convert the old style command into a new style command */
        if ((cmd & 0xff00) == 0x0200) {
                ECALL(normalize_ioctl(&cmd, &size));
        } else
                return -EINVAL;

        /* permission checks */
        if (((cmd & 0x40) && !FD_IOCTL_ALLOWED) ||
            ((cmd & 0x80) && !capable(CAP_SYS_ADMIN)))
                return -EPERM;

        /* copyin */
        CLEARSTRUCT(&inparam);
        if (_IOC_DIR(cmd) & _IOC_WRITE)
                ECALL(fd_copyin((void *)param, &inparam, size))

        switch (cmd) {
                case FDEJECT:
                        if (UDRS->fd_ref != 1)
                                /* somebody else has this drive open */
                                return -EBUSY;
                        LOCK_FDC(drive,1);

                        /* do the actual eject. Fails on
                         * non-Sparc architectures */
                        ret=fd_eject(UNIT(drive));

                        USETF(FD_DISK_CHANGED);
                        USETF(FD_VERIFY);
                        process_fd_request();
                        return ret;                     
                case FDCLRPRM:
                        LOCK_FDC(drive,1);
                        current_type[drive] = NULL;
                        floppy_sizes[drive] = MAX_DISK_SIZE;
                        UDRS->keep_data = 0;
                        return invalidate_drive(device);
                case FDSETPRM:
                case FDDEFPRM:
                        return set_geometry(cmd, & inparam.g,
                                            drive, type, device);
                case FDGETPRM:
                        ECALL(get_floppy_geometry(drive, type, 
                                                  (struct floppy_struct**)
                                                  &outparam));
                        break;

                case FDMSGON:
                        UDP->flags |= FTD_MSG;
                        return 0;
                case FDMSGOFF:
                        UDP->flags &= ~FTD_MSG;
                        return 0;

                case FDFMTBEG:
                        LOCK_FDC(drive,1);
                        CALL(poll_drive(1, FD_RAW_NEED_DISK));
                        ret = UDRS->flags;
                        process_fd_request();
                        if (ret & FD_VERIFY)
                                return -ENODEV;
                        if (!(ret & FD_DISK_WRITABLE))
                                return -EROFS;
                        return 0;
                case FDFMTTRK:
                        if (UDRS->fd_ref != 1)
                                return -EBUSY;
                        return do_format(device, &inparam.f);
                case FDFMTEND:
                case FDFLUSH:
                        LOCK_FDC(drive,1);
                        return invalidate_drive(device);

                case FDSETEMSGTRESH:
                        UDP->max_errors.reporting =
                                (unsigned short) (param & 0x0f);
                        return 0;
                OUT(FDGETMAXERRS, &UDP->max_errors);
                IN(FDSETMAXERRS, &UDP->max_errors, max_errors);

                case FDGETDRVTYP:
                        outparam = drive_name(type,drive);
                        SUPBOUND(size,strlen(outparam)+1);
                        break;

                IN(FDSETDRVPRM, UDP, dp);
                OUT(FDGETDRVPRM, UDP);

                case FDPOLLDRVSTAT:
                        LOCK_FDC(drive,1);
                        CALL(poll_drive(1, FD_RAW_NEED_DISK));
                        process_fd_request();
                        /* fall through */
                OUT(FDGETDRVSTAT, UDRS);

                case FDRESET:
                        return user_reset_fdc(drive, (int)param, 1);

                OUT(FDGETFDCSTAT,UFDCS);

                case FDWERRORCLR:
                        CLEARSTRUCT(UDRWE);
                        return 0;
                OUT(FDWERRORGET,UDRWE);

                case FDRAWCMD:
                        if (type)
                                return -EINVAL;
                        LOCK_FDC(drive,1);
                        set_floppy(device);
                        CALL(i = raw_cmd_ioctl(cmd,(void *) param));
                        process_fd_request();
                        return i;

                case FDTWADDLE:
                        LOCK_FDC(drive,1);
                        twaddle();
                        process_fd_request();
                        return 0;

                default:
                        return -EINVAL;
        }

        if (_IOC_DIR(cmd) & _IOC_READ)
                return fd_copyout((void *)param, outparam, size);
        else
                return 0;
#undef OUT
#undef IN
}

static void __init config_types(void)
{
        int first=1;
        int drive;

        /* read drive info out of physical CMOS */
        drive=0;
        if (!UDP->cmos)
                UDP->cmos = FLOPPY0_TYPE;
        drive=1;
        if (!UDP->cmos && FLOPPY1_TYPE)
                UDP->cmos = FLOPPY1_TYPE;

        /* XXX */
        /* additional physical CMOS drive detection should go here */

        for (drive=0; drive < N_DRIVE; drive++){
                unsigned int type = UDP->cmos;
                struct floppy_drive_params *params;
                const char *name = NULL;
                static char temparea[32];

                if (type < NUMBER(default_drive_params)) {
                        params = &default_drive_params[type].params;
                        if (type) {
                                name = default_drive_params[type].name;
                                allowed_drive_mask |= 1 << drive;
                        }
                } else {
                        params = &default_drive_params[0].params;
                        sprintf(temparea, "unknown type %d (usb?)", type);
                        name = temparea;
                }
                if (name) {
                        const char * prepend = ",";
                        if (first) {
                                prepend = KERN_INFO "Floppy drive(s):";
                                first = 0;
                        }
                        printk("%s fd%d is %s", prepend, drive, name);
                        register_devfs_entries (drive);
                }
                *UDP = *params;
        }
        if (!first)
                printk("\n");
}

static int floppy_release(struct inode * inode, struct file * filp)
{
        int drive = DRIVE(inode->i_rdev);

        if (UDRS->fd_ref < 0)
                UDRS->fd_ref=0;
        else if (!UDRS->fd_ref--) {
                DPRINT("floppy_release with fd_ref == 0");
                UDRS->fd_ref = 0;
        }
        floppy_release_irq_and_dma();
        return 0;
}

/*
 * floppy_open check for aliasing (/dev/fd0 can be the same as
 * /dev/PS0 etc), and disallows simultaneous access to the same
 * drive with different device numbers.
 */
#define RETERR(x) do{floppy_release(inode,filp); return -(x);}while(0)

static int floppy_open(struct inode * inode, struct file * filp)
{
        int drive;
        int old_dev;
        int try;
        char *tmp;

        if (!filp) {
                DPRINT("Weird, open called with filp=0\n");
                return -EIO;
        }

        filp->private_data = (void*) 0;

        drive = DRIVE(inode->i_rdev);
        if (drive >= N_DRIVE ||
            !(allowed_drive_mask & (1 << drive)) ||
            fdc_state[FDC(drive)].version == FDC_NONE)
                return -ENXIO;

        if (TYPE(inode->i_rdev) >= NUMBER(floppy_type))
                return -ENXIO;
        old_dev = UDRS->fd_device;
        if (UDRS->fd_ref && old_dev != MINOR(inode->i_rdev))
                return -EBUSY;

        if (!UDRS->fd_ref && (UDP->flags & FD_BROKEN_DCL)){
                USETF(FD_DISK_CHANGED);
                USETF(FD_VERIFY);
        }

        if (UDRS->fd_ref == -1 ||
           (UDRS->fd_ref && (filp->f_flags & O_EXCL)))
                return -EBUSY;

        if (floppy_grab_irq_and_dma())
                return -EBUSY;

        if (filp->f_flags & O_EXCL)
                UDRS->fd_ref = -1;
        else
                UDRS->fd_ref++;

        if (!floppy_track_buffer){
                /* if opening an ED drive, reserve a big buffer,
                 * else reserve a small one */
                if ((UDP->cmos == 6) || (UDP->cmos == 5))
                        try = 64; /* Only 48 actually useful */
                else
                        try = 32; /* Only 24 actually useful */

                tmp=(char *)fd_dma_mem_alloc(1024 * try);
                if (!tmp && !floppy_track_buffer) {
                        try >>= 1; /* buffer only one side */
                        INFBOUND(try, 16);
                        tmp= (char *)fd_dma_mem_alloc(1024*try);
                }
                if (!tmp && !floppy_track_buffer) {
                        fallback_on_nodma_alloc(&tmp, 2048 * try);
                }
                if (!tmp && !floppy_track_buffer) {
                        DPRINT("Unable to allocate DMA memory\n");
                        RETERR(ENXIO);
                }
                if (floppy_track_buffer) {
                        if (tmp)
                                fd_dma_mem_free((unsigned long)tmp,try*1024);
                } else {
                        buffer_min = buffer_max = -1;
                        floppy_track_buffer = tmp;
                        max_buffer_sectors = try;
                }
        }

        UDRS->fd_device = MINOR(inode->i_rdev);
        if (old_dev != -1 && old_dev != MINOR(inode->i_rdev)) {
                if (buffer_drive == drive)
                        buffer_track = -1;
                invalidate_buffers(MKDEV(FLOPPY_MAJOR,old_dev));
        }

        /* Allow ioctls if we have write-permissions even if read-only open.
         * Needed so that programs such as fdrawcmd still can work on write
         * protected disks */
        if ((filp->f_mode & 2) || 
            (inode->i_sb && (permission(inode,2) == 0)))
            filp->private_data = (void*) 8;

        if (UFDCS->rawcmd == 1)
                UFDCS->rawcmd = 2;

        if (filp->f_flags & O_NDELAY)
                return 0;
        if (filp->f_mode & 3) {
                UDRS->last_checked = 0;
                check_disk_change(inode->i_rdev);
                if (UTESTF(FD_DISK_CHANGED))
                        RETERR(ENXIO);
        }
        if ((filp->f_mode & 2) && !(UTESTF(FD_DISK_WRITABLE)))
                RETERR(EROFS);
        return 0;
#undef RETERR
}

/*
 * Check if the disk has been changed or if a change has been faked.
 */
static int check_floppy_change(kdev_t dev)
{
        int drive = DRIVE(dev);

        if (MAJOR(dev) != MAJOR_NR) {
                DPRINT("check_floppy_change: not a floppy\n");
                return 0;
        }

        if (UTESTF(FD_DISK_CHANGED) || UTESTF(FD_VERIFY))
                return 1;

        if (UDP->checkfreq < (int)(jiffies - UDRS->last_checked)) {
                if(floppy_grab_irq_and_dma()) {
                        return 1;
                }

                lock_fdc(drive,0);
                poll_drive(0,0);
                process_fd_request();
                floppy_release_irq_and_dma();
        }

        if (UTESTF(FD_DISK_CHANGED) ||
           UTESTF(FD_VERIFY) ||
           test_bit(drive, &fake_change) ||
           (!TYPE(dev) && !current_type[drive]))
                return 1;
        return 0;
}

/* revalidate the floppy disk, i.e. trigger format autodetection by reading
 * the bootblock (block 0). "Autodetection" is also needed to check whether
 * there is a disk in the drive at all... Thus we also do it for fixed
 * geometry formats */
static int floppy_revalidate(kdev_t dev)
{
#define NO_GEOM (!current_type[drive] && !TYPE(dev))
        struct buffer_head * bh;
        int drive=DRIVE(dev);
        int cf;

        if (UTESTF(FD_DISK_CHANGED) ||
            UTESTF(FD_VERIFY) ||
            test_bit(drive, &fake_change) ||
            NO_GEOM){
                if(usage_count == 0) {
                        printk("VFS: revalidate called on non-open device.\n");
                        return -EFAULT;
                }
                lock_fdc(drive,0);
                cf = UTESTF(FD_DISK_CHANGED) || UTESTF(FD_VERIFY);
                if (!(cf || test_bit(drive, &fake_change) || NO_GEOM)){
                        process_fd_request(); /*already done by another thread*/
                        return 0;
                }
                UDRS->maxblock = 0;
                UDRS->maxtrack = 0;
                if (buffer_drive == drive)
                        buffer_track = -1;
                clear_bit(drive, &fake_change);
                UCLEARF(FD_DISK_CHANGED);
                if (cf)
                        UDRS->generation++;
                if (NO_GEOM){
                        /* auto-sensing */
                        int size = floppy_blocksizes[MINOR(dev)];
                        if (!size)
                                size = 512;
                        if (!(bh = getblk(dev,0,size))){
                                process_fd_request();
                                return -ENXIO;
                        }
                        if (bh && !buffer_uptodate(bh))
                                ll_rw_block(READ, 1, &bh);
                        process_fd_request();
                        wait_on_buffer(bh);
                        brelse(bh);
                        return 0;
                }
                if (cf)
                        poll_drive(0, FD_RAW_NEED_DISK);
                process_fd_request();
        }
        return 0;
}

static struct block_device_operations floppy_fops = {
        owner:                  THIS_MODULE,
        open:                   floppy_open,
        release:                floppy_release,
        ioctl:                  fd_ioctl,
        check_media_change:     check_floppy_change,
        revalidate:             floppy_revalidate,
};

static void __init register_devfs_entries (int drive)
{
    int base_minor, i;
    static char *table[] =
    {"", "d360", "h1200", "u360", "u720", "h360", "h720",
     "u1440", "u2880", "CompaQ", "h1440", "u1680", "h410",
     "u820", "h1476", "u1722", "h420", "u830", "h1494", "u1743",
     "h880", "u1040", "u1120", "h1600", "u1760", "u1920",
     "u3200", "u3520", "u3840", "u1840", "u800", "u1600",
     NULL
    };
    static int t360[] = {1,0}, t1200[] = {2,5,6,10,12,14,16,18,20,23,0},
      t3in[] = {8,9,26,27,28, 7,11,15,19,24,25,29,31, 3,4,13,17,21,22,30,0};
    static int *table_sup[] = 
    {NULL, t360, t1200, t3in+5+8, t3in+5, t3in, t3in};

    base_minor = (drive < 4) ? drive : (124 + drive);
    if (UDP->cmos < NUMBER(default_drive_params)) {
        i = 0;
        do {
            char name[16];

            sprintf (name, "%d%s", drive, table[table_sup[UDP->cmos][i]]);
            devfs_register (devfs_handle, name, DEVFS_FL_DEFAULT, MAJOR_NR,
                            base_minor + (table_sup[UDP->cmos][i] << 2),
                            S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP |S_IWGRP,
                            &floppy_fops, NULL);
        } while (table_sup[UDP->cmos][i++]);
    }
}

/*
 * Floppy Driver initialization
 * =============================
 */

/* Determine the floppy disk controller type */
/* This routine was written by David C. Niemi */
static char __init get_fdc_version(void)
{
        int r;

        output_byte(FD_DUMPREGS);       /* 82072 and better know DUMPREGS */
        if (FDCS->reset)
                return FDC_NONE;
        if ((r = result()) <= 0x00)
                return FDC_NONE;        /* No FDC present ??? */
        if ((r==1) && (reply_buffer[0] == 0x80)){
                printk(KERN_INFO "FDC %d is an 8272A\n",fdc);
                return FDC_8272A;       /* 8272a/765 don't know DUMPREGS */
        }
        if (r != 10) {
                printk("FDC %d init: DUMPREGS: unexpected return of %d bytes.\n",
                       fdc, r);
                return FDC_UNKNOWN;
        }

        if (!fdc_configure()) {
                printk(KERN_INFO "FDC %d is an 82072\n",fdc);
                return FDC_82072;       /* 82072 doesn't know CONFIGURE */
        }

        output_byte(FD_PERPENDICULAR);
        if (need_more_output() == MORE_OUTPUT) {
                output_byte(0);
        } else {
                printk(KERN_INFO "FDC %d is an 82072A\n", fdc);
                return FDC_82072A;      /* 82072A as found on Sparcs. */
        }