// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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.
 */

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

/*
 * 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.
 */

/* 2003/07/28 -- Daniele Bellucci <bellucda@tiscali.it>.
 * Better audit of register_blkdev.
 */

#undef  FLOPPY_SILENT_DCL_CLEAR

#define REALLY_SLOW_IO

#define DEBUGT 2

#define DPRINT(format, args ...) \
    pr_info("floppy%d: " format, current_drive, ## args)

#define DCL_DEBUG       /* debug disk change line */
#ifdef DCL_DEBUG
#define debug_dcl(test, fmt, args ...) \
    do { if ((test) & FD_DEBUG) DPRINT(fmt, ## args); } while (0)
#else
#define debug_dcl(test, fmt, args ...) \
    do { if (0) DPRINT(fmt, ## args); } while (0)
#endif

/* 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/workqueue.h>
#define FDPATCHES
#include <linux/fdreg.h>
#include <linux/fd.h>
#include <linux/hdreg.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/string.h>
#include <linux/jiffies.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/platform_device.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/async.h>
#include <linux/compat.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 DEFINE_MUTEX(floppy_mutex);
static int slow_floppy;

#include <asm/dma.h>
#include <asm/irq.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 DEFINE_SPINLOCK(floppy_lock);

static unsigned short virtual_dma_port = 0x3f0;
irqreturn_t floppy_interrupt(int irq, void *dev_id);
static int set_dor(int fdc, char mask, char data);

#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;

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

static LIST_HEAD(floppy_reqs);
static struct request *current_req;
static int set_next_request(void);

#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

#ifndef fd_cacheflush
#define fd_cacheflush(addr, size) /* nothing... */
#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 */
    pr_info("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 bool initialized;

#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 */
/* reverse mapping from unit and fdc to drive */
#define REVDRIVE(fdc, unit) ((unit) + ((fdc) << 2))

#define DP  (&drive_params[current_drive])
#define DRS (&drive_state[current_drive])
#define DRWE    (&write_errors[current_drive])
#define FDCS    (&fdc_state[fdc])

#define UDP (&drive_params[drive])
#define UDRS    (&drive_state[drive])
#define UDRWE   (&write_errors[drive])
#define UFDCS   (&fdc_state[FDC(drive)])

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

/* 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 gendisk *disks[N_DRIVE];
static struct blk_mq_tag_set tag_sets[N_DRIVE];
static struct block_device *opened_bdev[N_DRIVE];
static DEFINE_MUTEX(open_lock);
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'.
 *
 * Bits 2 through 9 of 'stretch' tell the number of the first sector.
 * The LSB (bit 2) is flipped. For most disks, the first sector
 * is 1 (represented by 0x00<<2).  For some CP/M and music sampler
 * disks (such as Ensoniq EPS 16plus) it is 0 (represented as 0x01<<2).
 * For Amstrad CPC disks it is 0xC1 (represented as 0xC0<<2).
 *
 * 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 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 sector_t floppy_sizes[256];

static char floppy_device_name[] = "floppy";

/*
 * 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);

/* 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 const 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(struct work_struct *);

static int floppy_request_regions(int);
static void floppy_release_regions(int);
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.
 */
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 atomic_t usage_count = ATOMIC_INIT(0);

/* 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 workqueue_struct *floppy_wq;

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

static inline bool drive_no_geom(int drive)
{
    return !current_type[drive] && !ITYPE(UDRS->fd_device);
}

#ifndef fd_eject
static inline int fd_eject(int drive)
{
    return -EINVAL;
}
#endif

/*
 * Debugging
 * =========
 */
#ifdef DEBUGT
static long unsigned debugtimer;

static inline void set_debugt(void)
{
    debugtimer = jiffies;
}

static inline void debugt(const char *func, const char *msg)
{
    if (DP->flags & DEBUGT)
        pr_info("%s:%s dtime=%lu\n", func, msg, jiffies - debugtimer);
}
#else
static inline void set_debugt(void) {}
static inline void debugt(const char *func, const char *msg) {}
#endif /* DEBUGT */


static DECLARE_DELAYED_WORK(fd_timeout, floppy_shutdown);
static const char *timeout_message;

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

static void (*do_floppy)(void) = NULL;

#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;

#define current_reqD -1
#define MAXTIMEOUT -2

static void __reschedule_timeout(int drive, const char *message)
{
    unsigned long delay;

    if (drive == current_reqD)
        drive = current_drive;

    if (drive < 0 || drive >= N_DRIVE) {
        delay = 20UL * HZ;
        drive = 0;
    } else
        delay = UDP->timeout;

    mod_delayed_work(floppy_wq, &fd_timeout, delay);
    if (UDP->flags & FD_DEBUG)
        DPRINT("reschedule timeout %s\n", message);
    timeout_message = message;
}

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

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

#define INFBOUND(a, b) (a) = max_t(int, a, b)
#define SUPBOUND(a, b) (a) = min_t(int, 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);

    if (time_before(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);
    }

    debug_dcl(UDP->flags,
              "checking disk change line for drive %d\n", drive);
    debug_dcl(UDP->flags, "jiffies=%lu\n", jiffies);
    debug_dcl(UDP->flags, "disk change line=%x\n", fd_inb(FD_DIR) & 0x80);
    debug_dcl(UDP->flags, "flags=%lx\n", UDRS->flags);

    if (UDP->flags & FD_BROKEN_DCL)
        return test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);
    if ((fd_inb(FD_DIR) ^ UDP->flags) & 0x80) {
        set_bit(FD_VERIFY_BIT, &UDRS->flags);
        /* verify write protection */

        if (UDRS->maxblock) /* mark it changed */
            set_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);

        /* 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 << 1;
        }

        return 1;
    } else {
        UDRS->last_checked = jiffies;
        clear_bit(FD_DISK_NEWCHANGE_BIT, &UDRS->flags);
    }
    return 0;
}

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

static bool is_ready_state(int status)
{
    int state = status & (STATUS_READY | STATUS_DIR | STATUS_DMA);
    return state == STATUS_READY;
}

static int set_dor(int fdc, char mask, char data)
{
    unsigned char unit;
    unsigned char drive;
    unsigned char newdor;
    unsigned char 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);
            debug_dcl(UDP->flags,
                      "calling disk change from set_dor\n");
            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;
        }
    }
    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) {
        pr_info("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)
{
    if (WARN(atomic_read(&usage_count) == 0,
             "Trying to lock fdc while usage count=0\n"))
        return -1;

    if (wait_event_interruptible(fdc_wait, !test_and_set_bit(0, &fdc_busy)))
        return -EINTR;

    command_status = FD_COMMAND_NONE;

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

/* unlocks the driver */
static void unlock_fdc(void)
{
    if (!test_bit(0, &fdc_busy))
        DPRINT("FDC access conflict!\n");

    raw_cmd = NULL;
    command_status = FD_COMMAND_NONE;
    cancel_delayed_work(&fd_timeout);
    do_floppy = NULL;
    cont = NULL;
    clear_bit(0, &fdc_busy);
    wake_up(&fdc_wait);
}

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

    if (WARN_ON_ONCE(nr >= N_DRIVE))
        return;

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

/* schedules motor off */
static void floppy_off(unsigned int drive)
{
    unsigned long volatile delta;
    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;
    int drive;
    int 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 void (*floppy_work_fn)(void);

static void floppy_work_workfn(struct work_struct *work)
{
    floppy_work_fn();
}

static DECLARE_WORK(floppy_work, floppy_work_workfn);

static void schedule_bh(void (*handler)(void))
{
    WARN_ON(work_pending(&floppy_work));

    floppy_work_fn = handler;
    queue_work(floppy_wq, &floppy_work);
}

static void (*fd_timer_fn)(void) = NULL;

static void fd_timer_workfn(struct work_struct *work)
{
    fd_timer_fn();
}

static DECLARE_DELAYED_WORK(fd_timer, fd_timer_workfn);

static void cancel_activity(void)
{
    do_floppy = NULL;
    cancel_delayed_work_sync(&fd_timer);
    cancel_work_sync(&floppy_work);
}

/* this function makes sure that the disk stays in the drive during the
 * transfer */
static void fd_watchdog(void)
{
    debug_dcl(DP->flags, "calling disk change from watchdog\n");

    if (disk_change(current_drive)) {
        DPRINT("disk removed during i/o\n");
        cancel_activity();
        cont->done(0);
        reset_fdc();
    } else {
        cancel_delayed_work(&fd_timer);
        fd_timer_fn = fd_watchdog;
        queue_delayed_work(floppy_wq, &fd_timer, HZ / 10);
    }
}

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

/* waits for a delay (spinup or select) to pass */
static int fd_wait_for_completion(unsigned long expires,
                                  void (*function)(void))
{
    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 (time_before(jiffies, expires)) {
        cancel_delayed_work(&fd_timer);
        fd_timer_fn = function;
        queue_delayed_work(floppy_wq, &fd_timer, expires - jiffies);
        return 1;
    }
    return 0;
}

static void setup_DMA(void)
{
    unsigned long f;

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

        pr_info("zero dma transfer size:");
        for (i = 0; i < raw_cmd->cmd_count; i++)
            pr_cont("%x,", raw_cmd->cmd[i]);
        pr_cont("\n");
        cont->done(0);
        FDCS->reset = 1;
        return;
    }
    if (((unsigned long)raw_cmd->kernel_data) % 512) {
        pr_info("non aligned address: %p\n", raw_cmd->kernel_data);
        cont->done(0);
        FDCS->reset = 1;
        return;
    }
    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
}

static void show_floppy(void);

/* waits until the fdc becomes ready */
static int wait_til_ready(void)
{
    int status;
    int counter;

    if (FDCS->reset)
        return -1;
    for (counter = 0; counter < 10000; counter++) {
        status = fd_inb(FD_STATUS);
        if (status & STATUS_READY)
            return status;
    }
    if (initialized) {
        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 = wait_til_ready();

    if (status < 0)
        return -1;

    if (is_ready_state(status)) {
        fd_outb(byte, FD_DATA);
        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;
        return 0;
    }
    FDCS->reset = 1;
    if (initialized) {
        DPRINT("Unable to send byte %x to FDC. Fdc=%x Status=%x\n",
               byte, fdc, status);
        show_floppy();
    }
    return -1;
}

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

    for (i = 0; i < MAX_REPLIES; i++) {
        status = wait_til_ready();
        if (status < 0)
            break;
        status &= STATUS_DIR | STATUS_READY | STATUS_BUSY | STATUS_DMA;
        if ((status & ~STATUS_BUSY) == STATUS_READY) {
            resultjiffies = jiffies;
            resultsize = i;
            return i;
        }
        if (status == (STATUS_DIR | STATUS_READY | STATUS_BUSY))
            reply_buffer[i] = fd_inb(FD_DATA);
        else
            break;
    }
    if (initialized) {
        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 = wait_til_ready();

    if (status < 0)
        return -1;

    if (is_ready_state(status))
        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 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 too 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;
    unsigned char spec2;
    unsigned long srt;
    unsigned long hlt;
    unsigned long 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;
    }

    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 - DIV_ROUND_UP(DP->srt * scale_dtr / 1000, NOMINAL_DTR);
    if (slow_floppy)
        srt = srt / 4;

    SUPBOUND(srt, 0xf);
    INFBOUND(srt, 0);

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

    hut = DIV_ROUND_UP(DP->hut * scale_dtr / 16, 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, floppy_ready);
}               /* fdc_dtr */

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

static void print_errors(void)
{
    DPRINT("");
    if (ST0 & ST0_ECE) {
        pr_cont("Recalibrate failed!");
    } else if (ST2 & ST2_CRC) {
        pr_cont("data CRC error");
        tell_sector();
    } else if (ST1 & ST1_CRC) {
        pr_cont("CRC error");
        tell_sector();
    } else if ((ST1 & (ST1_MAM | ST1_ND)) ||
               (ST2 & ST2_MAM)) {
        if (!probing) {
            pr_cont("sector not found");
            tell_sector();
        } else
            pr_cont("probe failed...");
    } else if (ST2 & ST2_WC) {  /* seek error */
        pr_cont("wrong cylinder");
    } else if (ST2 & ST2_BC) {  /* cylinder marked as bad */
        pr_cont("bad cylinder");
    } else {
        pr_cont("unknown error. ST[0..2] are: 0x%x 0x%x 0x%x",
                ST0, ST1, ST2);
        tell_sector();
    }
    pr_cont("\n");
}

/*
 * 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\n");
        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");
            clear_bit(FD_DISK_WRITABLE_BIT, &DRS->flags);
            cont->done(0);
            bad = 2;
        } else if (ST1 & ST1_ND) {
            set_bit(FD_NEED_TWADDLE_BIT, &DRS->flags);
        } else if (ST1 & ST1_OR) {
            if (DP->flags & FTD_MSG)
                DPRINT("Over/Underrun - retrying\n");
            bad = 0;
        } else if (*errors >= DP->max_errors.reporting) {
            print_errors();
        }
        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;
    int r;
    int flags;
    unsigned long ready_date;
    void (*function)(void);

    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 (time_after(ready_date, jiffies + DP->select_delay)) {
            ready_date -= DP->select_delay;
            function = floppy_start;
        } else
            function = setup_rw_floppy;

        /* wait until the floppy is spinning fast enough */
        if (fd_wait_for_completion(ready_date, function))
            return;
    }
    if ((flags & FD_RAW_READ) || (flags & FD_RAW_WRITE))
        setup_DMA();

    if (flags & FD_RAW_INTR)
        do_floppy = main_command_interrupt;

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

    debugt(__func__, "rw_command");

    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)
{
    debugt(__func__, "");
    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) {
        debug_dcl(DP->flags,
                  "clearing NEWCHANGE flag because of effective seek\n");
        debug_dcl(DP->flags, "jiffies=%lu\n", jiffies);
        clear_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags);
        /* effective seek */
        DRS->select_date = jiffies;
    }
    DRS->track = ST1;
    floppy_ready();
}

static void check_wp(void)
{
    if (test_bit(FD_VERIFY_BIT, &DRS->flags)) {
        /* check write protection */
        output_byte(FD_GETSTATUS);
        output_byte(UNIT(current_drive));
        if (result() != 1) {
            FDCS->reset = 1;
            return;
        }
        clear_bit(FD_VERIFY_BIT, &DRS->flags);
        clear_bit(FD_NEED_TWADDLE_BIT, &DRS->flags);
        debug_dcl(DP->flags,
                  "checking whether disk is write protected\n");
        debug_dcl(DP->flags, "wp=%x\n", ST3 & 0x40);
        if (!(ST3 & 0x40))
            set_bit(FD_DISK_WRITABLE_BIT, &DRS->flags);
        else
            clear_bit(FD_DISK_WRITABLE_BIT, &DRS->flags);
    }
}

static void seek_floppy(void)
{
    int track;

    blind_seek = 0;

    debug_dcl(DP->flags, "calling disk change from %s\n", __func__);

    if (!test_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags) &&
        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.
         */
        set_bit(FD_DISK_CHANGED_BIT, &DRS->flags);
        cont->done(0);
        cont->redo();
        return;
    }
    if (DRS->track <= NEED_1_RECAL) {
        recalibrate_floppy();
        return;
    } else if (test_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags) &&
               (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;
        }
    }

    do_floppy = seek_interrupt;
    output_byte(FD_SEEK);
    output_byte(UNIT(current_drive));
    if (output_byte(track) < 0) {
        reset_fdc();
        return;
    }
    debugt(__func__, "");
}

static void recal_interrupt(void)
{
    debugt(__func__, "");
    if (inr != 2)
        FDCS->reset = 1;
    else if (ST0 & ST0_ECE) {
        switch (DRS->track) {
        case NEED_1_RECAL:
            debugt(__func__, "need 1 recal");
            /* 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:
            debugt(__func__, "need 2 recal");
            /* 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 */
            debug_dcl(DP->flags,
                      "clearing NEWCHANGE flag because of second recalibrate\n");

            clear_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags);
            DRS->select_date = jiffies;
        /* fall through */
        default:
            debugt(__func__, "default");
            /* 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++)
            pr_cont("repl[%d]=%x ", i, reply_buffer[i]);
    pr_cont("\n");
}

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

    lasthandler = handler;
    interruptjiffies = jiffies;

    f = claim_dma_lock();
    fd_disable_dma();
    release_dma_lock(f);

    do_floppy = NULL;
    if (fdc >= N_FDC || FDCS->address == -1) {
        /* we don't even know which FDC is the culprit */
        pr_info("DOR0=%x\n", fdc_state[0].dor);
        pr_info("floppy interrupt on bizarre fdc %d\n", fdc);
        pr_info("handler=%ps\n", handler);
        is_alive(__func__, "bizarre fdc");
        return IRQ_NONE;
    }

    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 && initialized;

    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) {
        FDCS->reset = 1;
        return IRQ_NONE;
    }
    schedule_bh(handler);
    is_alive(__func__, "normal interrupt end");

    /* FIXME! Was it really for us? */
    return IRQ_HANDLED;
}

static void recalibrate_floppy(void)
{
    debugt(__func__, "");
    do_floppy = recal_interrupt;
    output_byte(FD_RECALIBRATE);
    if (output_byte(UNIT(current_drive)) < 0)
        reset_fdc();
}

/*
 * Must do 4 FD_SENSEIs after reset because of ``drive polling''.
 */
static void reset_interrupt(void)
{
    debugt(__func__, "");
    result();       /* get the status ready for set_fdc */
    if (FDCS->reset) {
        pr_info("reset set in interrupt, calling %ps\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;

    do_floppy = 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;

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

    pr_info("timeout_message=%s\n", timeout_message);
    pr_info("last output bytes:\n");
    for (i = 0; i < OLOGSIZE; i++)
        pr_info("%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);
    pr_info("last result at %lu\n", resultjiffies);
    pr_info("last redo_fd_request at %lu\n", lastredo);
    print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1,
                   reply_buffer, resultsize, true);

    pr_info("status=%x\n", fd_inb(FD_STATUS));
    pr_info("fdc_busy=%lu\n", fdc_busy);
    if (do_floppy)
        pr_info("do_floppy=%ps\n", do_floppy);
    if (work_pending(&floppy_work))
        pr_info("floppy_work.func=%ps\n", floppy_work.func);
    if (delayed_work_pending(&fd_timer))
        pr_info("delayed work.function=%p expires=%ld\n",
                fd_timer.work.func,
                fd_timer.timer.expires - jiffies);
    if (delayed_work_pending(&fd_timeout))
        pr_info("timer_function=%p expires=%ld\n",
                fd_timeout.work.func,
                fd_timeout.timer.expires - jiffies);

    pr_info("cont=%p\n", cont);
    pr_info("current_req=%p\n", current_req);
    pr_info("command_status=%d\n", command_status);
    pr_info("\n");
}

static void floppy_shutdown(struct work_struct *arg)
{
    unsigned long flags;

    if (initialized)
        show_floppy();
    cancel_activity();

    flags = claim_dma_lock();
    fd_disable_dma();
    release_dma_lock(flags);

    /* avoid dma going to a random drive after shutdown */

    if (initialized)
        DPRINT("floppy timeout called\n");
    FDCS->reset = 1;
    if (cont) {
        cont->done(0);
        cont->redo();   /* this will recall reset when needed */
    } else {
        pr_info("no cont in shutdown!\n");
        process_fd_request();
    }
    is_alive(__func__, "");
}

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

static void floppy_ready(void)
{
    if (FDCS->reset) {
        reset_fdc();
        return;
    }
    if (start_motor(floppy_ready))
        return;
    if (fdc_dtr())
        return;

    debug_dcl(DP->flags, "calling disk change from floppy_ready\n");
    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(current_reqD, "floppy start");

    scandrives();
    debug_dcl(DP->flags, "setting NEWCHANGE in floppy_start\n");
    set_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags);
    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");
    cont = NULL;
    command_status += 2;
    wake_up(&command_done);
}

static const struct cont_t wakeup_cont = {
    .interrupt  = empty,
    .redo       = do_wakeup,
    .error      = empty,
    .done       = (done_f)empty
};

static const struct cont_t intr_cont = {
    .interrupt  = empty,
    .redo       = process_fd_request,
    .error      = empty,
    .done       = (done_f)empty
};

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

    schedule_bh(handler);

    if (interruptible)
        wait_event_interruptible(command_done, command_status >= 2);
    else
        wait_event(command_done, command_status >= 2);

    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)
{
    int err_count;

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

static void set_floppy(int drive)
{
    int type = ITYPE(UDRS->fd_device);

    if (type)
        _floppy = floppy_type + type;
    else
        _floppy = current_type[drive];
}

/*
 * 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 FM_MODE(x, y) ((y) & ~(((x)->rate & 0x80) >> 1))
#define CT(x) ((x) | 0xc0)

static void setup_format_params(int track)
{
    int n;
    int il;
    int count;
    int head_shift;
    int track_shift;
    struct fparm {
        unsigned char track, head, sect, size;
    } *here = (struct fparm *)floppy_track_buffer;

    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;
            }
        }
    }
    if (_floppy->stretch & FD_SECTBASEMASK) {
        for (count = 0; count < F_SECT_PER_TRACK; count++)
            here[count].sect += FD_SECTBASE(_floppy) - 1;
    }
}

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

static const struct cont_t format_cont = {
    .interrupt  = format_interrupt,
    .redo       = redo_format,
    .error      = bad_flp_intr,
    .done       = generic_done
};

static int do_format(int drive, struct format_descr *tmp_format_req)
{
    int ret;

    if (lock_fdc(drive))
        return -EINTR;

    set_floppy(drive);
    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;
    ret = wait_til_done(redo_format, true);
    if (ret == -EINTR)
        return -EINTR;
    process_fd_request();
    return ret;
}

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

static void floppy_end_request(struct request *req, blk_status_t error)
{
    unsigned int nr_sectors = current_count_sectors;
    unsigned int drive = (unsigned long)req->rq_disk->private_data;

    /* current_count_sectors can be zero if transfer failed */
    if (error)
        nr_sectors = blk_rq_cur_sectors(req);
    if (blk_update_request(req, error, nr_sectors << 9))
        return;
    __blk_mq_end_request(req, error);

    /* We're done with the request */
    floppy_off(drive);
    current_req = NULL;
}

/* new request_done. Can handle physical sectors which are smaller than a
 * logical buffer */
static void request_done(int uptodate)
{
    struct request *req = current_req;
    int block;
    char msg[sizeof("request done ") + sizeof(int) * 3];

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

    if (!req) {
        pr_info("floppy.c: no request in request_done\n");
        return;
    }

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

        floppy_end_request(req, 0);
    } else {
        if (rq_data_dir(req) == WRITE) {
            /* record write error information */
            DRWE->write_errors++;
            if (DRWE->write_errors == 1) {
                DRWE->first_error_sector = blk_rq_pos(req);
                DRWE->first_error_generation = DRS->generation;
            }
            DRWE->last_error_sector = blk_rq_pos(req);
            DRWE->last_error_generation = DRS->generation;
        }
        floppy_end_request(req, BLK_STS_IOERR);
    }
}

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

    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;
    ssize = DIV_ROUND_UP(1 << SIZECODE, 4);

    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;

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

    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;
        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;
        probing = 0;
    }

    if (CT(COMMAND) != FD_READ ||
        raw_cmd->kernel_data == bio_data(current_req->bio)) {
        /* 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 + fsector_t);
    }
    cont->redo();
}

/* Compute maximal contiguous buffer size. */
static int buffer_chain_size(void)
{
    struct bio_vec bv;
    int size;
    struct req_iterator iter;
    char *base;

    base = bio_data(current_req->bio);
    size = 0;

    rq_for_each_segment(bv, current_req, iter) {
        if (page_address(bv.bv_page) + bv.bv_offset != base + size)
            break;

        size += bv.bv_len;
    }

    return size >> 9;
}

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

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

    /* transfer size, beginning not aligned */
    current_count_sectors = max_sector - fsector_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 bio_vec bv;
    char *buffer;
    char *dma_buffer;
    int size;
    struct req_iterator iter;

    max_sector = transfer_size(ssize,
                               min(max_sector, max_sector_2),
                               blk_rq_sectors(current_req));

    if (current_count_sectors <= 0 && CT(COMMAND) == FD_WRITE &&
        buffer_max > fsector_t + blk_rq_sectors(current_req))
        current_count_sectors = min_t(int, buffer_max - fsector_t,
                                      blk_rq_sectors(current_req));

    remaining = current_count_sectors << 9;
    if (remaining > blk_rq_bytes(current_req) && CT(COMMAND) == FD_WRITE) {
        DPRINT("in copy buffer\n");
        pr_info("current_count_sectors=%ld\n", current_count_sectors);
        pr_info("remaining=%d\n", remaining >> 9);
        pr_info("current_req->nr_sectors=%u\n",
                blk_rq_sectors(current_req));
        pr_info("current_req->current_nr_sectors=%u\n",
                blk_rq_cur_sectors(current_req));
        pr_info("max_sector=%d\n", max_sector);
        pr_info("ssize=%d\n", ssize);
    }

    buffer_max = max(max_sector, buffer_max);

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

    size = blk_rq_cur_bytes(current_req);

    rq_for_each_segment(bv, current_req, iter) {
        if (!remaining)
            break;

        size = bv.bv_len;
        SUPBOUND(size, remaining);

        buffer = page_address(bv.bv_page) + bv.bv_offset;
        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));
            pr_info("fsector_t=%d buffer_min=%d\n",
                    fsector_t, buffer_min);
            pr_info("current_count_sectors=%ld\n",
                    current_count_sectors);
            if (CT(COMMAND) == FD_READ)
                pr_info("read\n");
            if (CT(COMMAND) == FD_WRITE)
                pr_info("write\n");
            break;
        }
        if (((unsigned long)buffer) % 512)
            DPRINT("%p buffer not aligned\n", buffer);

        if (CT(COMMAND) == FD_READ)
            memcpy(buffer, dma_buffer, size);
        else
            memcpy(dma_buffer, buffer, size);

        remaining -= size;
        dma_buffer += size;
    }
    if (remaining) {
        if (remaining > 0)
            max_sector -= remaining >> 9;
        DPRINT("weirdness: remaining %d\n", remaining >> 9);
    }
}

/* 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;
    int 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;
        if (end_sector > SECT_PER_TRACK) {
            pr_info("too many sectors %d > %d\n",
                    end_sector, SECT_PER_TRACK);
            return;
        }
        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;
    int max_size;
    int tracksize;
    int ssize;

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

    set_fdc((long)current_req->rq_disk->private_data);

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

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

    TRACK = (int)blk_rq_pos(current_req) / max_sector;
    fsector_t = (int)blk_rq_pos(current_req) % max_sector;
    if (_floppy->track && TRACK >= _floppy->track) {
        if (blk_rq_cur_sectors(current_req) & 1) {
            current_count_sectors = 1;
            return 1;
        } else
            return 0;
    }
    HEAD = fsector_t / _floppy->sect;

    if (((_floppy->stretch & (FD_SWAPSIDES | FD_SECTBASEMASK)) ||
         test_bit(FD_NEED_TWADDLE_BIT, &DRS->flags)) &&
        fsector_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 (fsector_t >= max_sector) {
            current_count_sectors =
                min_t(int, _floppy->sect - fsector_t,
                      blk_rq_sectors(current_req));
            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;
    ssize = DIV_ROUND_UP(1 << SIZECODE, 4);
    SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE;
    SECTOR = ((fsector_t % _floppy->sect) << 2 >> SIZECODE) +
             FD_SECTBASE(_floppy);

    /* 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 <= fsector_t % _floppy->sect)
            SECTOR--;

        /* if we are beyond tracksize, fill up using smaller sectors */
        while (tracksize <= fsector_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 = (fsector_t % _floppy->sect) % ssize;
    aligned_sector_t = fsector_t - in_sector_offset;
    max_size = blk_rq_sectors(current_req);
    if ((raw_cmd->track == buffer_track) &&
        (current_drive == buffer_drive) &&
        (fsector_t >= buffer_min) && (fsector_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 || blk_rq_sectors(current_req) < ssize) {
        if (CT(COMMAND) == FD_WRITE) {
            unsigned int sectors;

            sectors = fsector_t + blk_rq_sectors(current_req);
            if (sectors > ssize && 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)bio_data(current_req->bio) < MAX_DMA_ADDRESS) {
        unsigned long dma_limit;
        int direct, indirect;

        indirect =
            transfer_size(ssize, max_sector,
                          max_buffer_sectors * 2) - fsector_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)bio_data(current_req->bio))) >> 9;
        if ((unsigned long)max_size > dma_limit)
            max_size = dma_limit;
        /* 64 kb boundaries */
        if (CROSS_64KB(bio_data(current_req->bio), max_size << 9))
            max_size = (K_64 -
                        ((unsigned long)bio_data(current_req->bio)) %
                        K_64) >> 9;
        direct = transfer_size(ssize, max_sector, max_size) - fsector_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 &&
             ((!probing ||
               (DP->read_track & (1 << DRS->probed_format)))))) {
            max_size = blk_rq_sectors(current_req);
        } else {
            raw_cmd->kernel_data = bio_data(current_req->bio);
            raw_cmd->length = current_count_sectors << 9;
            if (raw_cmd->length == 0) {
                DPRINT("%s: zero dma transfer attempted\n", __func__);
                DPRINT("indirect=%d direct=%d fsector_t=%d\n",
                       indirect, direct, fsector_t);
                return 0;
            }
            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 */
        fsector_t > buffer_max ||
        fsector_t < buffer_min ||
        ((CT(COMMAND) == FD_READ ||
          (!in_sector_offset && blk_rq_sectors(current_req) >= ssize)) &&
         max_sector > 2 * max_buffer_sectors + buffer_min &&
         max_size + fsector_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) */
        if (in_sector_offset && buffer_track == -1)
            DPRINT("internal error offset !=0 on write\n");
        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;
    if ((raw_cmd->length < current_count_sectors << 9) ||
        (raw_cmd->kernel_data != bio_data(current_req->bio) &&
         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 != bio_data(current_req->bio))
            pr_info("addr=%d, length=%ld\n",
                    (int)((raw_cmd->kernel_data -
                           floppy_track_buffer) >> 9),
                    current_count_sectors);
        pr_info("st=%d ast=%d mse=%d msi=%d\n",
                fsector_t, aligned_sector_t, max_sector, max_size);
        pr_info("ssize=%x SIZECODE=%d\n", ssize, SIZECODE);
        pr_info("command=%x SECTOR=%d HEAD=%d, TRACK=%d\n",
                COMMAND, SECTOR, HEAD, TRACK);
        pr_info("buffer drive=%d\n", buffer_drive);
        pr_info("buffer track=%d\n", buffer_track);
        pr_info("buffer_min=%d\n", buffer_min);
        pr_info("buffer_max=%d\n", buffer_max);
        return 0;
    }

    if (raw_cmd->kernel_data != bio_data(current_req->bio)) {
        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");
            pr_info("fsector_t=%d buffer_min=%d current_count=%ld\n",
                    fsector_t, buffer_min, raw_cmd->length >> 9);
            pr_info("current_count_sectors=%ld\n",
                    current_count_sectors);
            if (CT(COMMAND) == FD_READ)
                pr_info("read\n");
            if (CT(COMMAND) == FD_WRITE)
                pr_info("write\n");
            return 0;
        }
    } else if (raw_cmd->length > blk_rq_bytes(current_req) ||
               current_count_sectors > blk_rq_sectors(current_req)) {
        DPRINT("buffer overrun in direct transfer\n");
        return 0;
    } else if (raw_cmd->length < current_count_sectors << 9) {
        DPRINT("more sectors than bytes\n");
        pr_info("bytes=%ld\n", raw_cmd->length >> 9);
        pr_info("sectors=%ld\n", current_count_sectors);
    }
    if (raw_cmd->length == 0) {
        DPRINT("zero dma transfer attempted from make_raw_request\n");
        return 0;
    }

    virtualdmabug_workaround();
    return 2;
}

static int set_next_request(void)
{
    current_req = list_first_entry_or_null(&floppy_reqs, struct request,
                                           queuelist);
    if (current_req) {
        current_req->error_count = 0;
        list_del_init(&current_req->queuelist);
    }
    return current_req != NULL;
}

static void redo_fd_request(void)
{
    int drive;
    int tmp;

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

do_request:
    if (!current_req) {
        int pending;

        spin_lock_irq(&floppy_lock);
        pending = set_next_request();
        spin_unlock_irq(&floppy_lock);
        if (!pending) {
            do_floppy = NULL;
            unlock_fdc();
            return;
        }
    }
    drive = (long)current_req->rq_disk->private_data;
    set_fdc(drive);
    reschedule_timeout(current_reqD, "redo fd request");

    set_floppy(drive);
    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) ||
        test_bit(FD_DISK_CHANGED_BIT, &DRS->flags)) {
        DPRINT("disk absent or changed during operation\n");
        request_done(0);
        goto do_request;
    }
    if (!_floppy) { /* Autodetection */
        if (!probing) {
            DRS->probed_format = 0;
            if (next_valid_format()) {
                DPRINT("no autodetectable formats\n");
                _floppy = NULL;
                request_done(0);
                goto do_request;
            }
        }
        probing = 1;
        _floppy = floppy_type + DP->autodetect[DRS->probed_format];
    } else
        probing = 0;
    errors = &(current_req->error_count);
    tmp = make_raw_rw_request();
    if (tmp < 2) {
        request_done(tmp);
        goto do_request;
    }

    if (test_bit(FD_NEED_TWADDLE_BIT, &DRS->flags))
        twaddle();
    schedule_bh(floppy_start);
    debugt(__func__, "queue fd request");
    return;
}

static const struct cont_t rw_cont = {
    .interrupt  = rw_interrupt,
    .redo       = redo_fd_request,
    .error      = bad_flp_intr,
    .done       = request_done
};

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

static blk_status_t floppy_queue_rq(struct blk_mq_hw_ctx *hctx,
                                    const struct blk_mq_queue_data *bd)
{
    blk_mq_start_request(bd->rq);

    if (WARN(max_buffer_sectors == 0,
             "VFS: %s called on non-open device\n", __func__))
        return BLK_STS_IOERR;

    if (WARN(atomic_read(&usage_count) == 0,
             "warning: usage count=0, current_req=%p sect=%ld flags=%llx\n",
             current_req, (long)blk_rq_pos(current_req),
             (unsigned long long) current_req->cmd_flags))
        return BLK_STS_IOERR;

    spin_lock_irq(&floppy_lock);
    list_add_tail(&bd->rq->queuelist, &floppy_reqs);
    spin_unlock_irq(&floppy_lock);

    if (test_and_set_bit(0, &fdc_busy)) {
        /* fdc busy, this new request will be treated when the
           current one is done */
        is_alive(__func__, "old request running");
        return BLK_STS_OK;
    }

    command_status = FD_COMMAND_NONE;
    __reschedule_timeout(MAXTIMEOUT, "fd_request");
    set_fdc(0);
    process_fd_request();
    is_alive(__func__, "");
    return BLK_STS_OK;
}

static const struct cont_t poll_cont = {
    .interrupt  = success_and_wakeup,
    .redo       = floppy_ready,
    .error      = generic_failure,
    .done       = generic_done
};

static int poll_drive(bool interruptible, int flag)
{
    /* 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;
    debug_dcl(DP->flags, "setting NEWCHANGE in poll_drive\n");
    set_bit(FD_DISK_NEWCHANGE_BIT, &DRS->flags);

    return wait_til_done(floppy_ready, interruptible);
}

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

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

static const struct cont_t reset_cont = {
    .interrupt  = reset_intr,
    .redo       = success_and_wakeup,
    .error      = generic_failure,
    .done       = generic_done
};

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

    if (lock_fdc(drive))
        return -EINTR;

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

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

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

static 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(&motor_off_timer[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 const struct cont_t raw_cmd_cont = {
    .interrupt  = success_and_wakeup,
    .redo       = floppy_start,
    .error      = generic_failure,
    .done       = raw_cmd_done
};

static int raw_cmd_copyout(int cmd, void __user *param,
                           struct floppy_raw_cmd *ptr)
{
    int ret;

    while (ptr) {
        struct floppy_raw_cmd cmd = *ptr;
        cmd.next = NULL;
        cmd.kernel_data = NULL;
        ret = copy_to_user(param, &cmd, sizeof(cmd));
        if (ret)
            return -EFAULT;
        param += sizeof(struct floppy_raw_cmd);
        if ((ptr->flags & FD_RAW_READ) && ptr->buffer_length) {
            if (ptr->length >= 0 &&
                ptr->length <= ptr->buffer_length) {
                long length = ptr->buffer_length - ptr->length;
                ret = fd_copyout(ptr->data, ptr->kernel_data,
                                 length);
                if (ret)
                    return ret;
            }
        }
        ptr = ptr->next;
    }

    return 0;
}

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

    this = *ptr;
    *ptr = NULL;
    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 int raw_cmd_copyin(int cmd, void __user *param,
                          struct floppy_raw_cmd **rcmd)
{
    struct floppy_raw_cmd *ptr;
    int ret;
    int i;

    *rcmd = NULL;

loop:
    ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL);
    if (!ptr)
        return -ENOMEM;
    *rcmd = ptr;
    ret = copy_from_user(ptr, param, sizeof(*ptr));
    ptr->next = NULL;
    ptr->buffer_length = 0;
    ptr->kernel_data = NULL;
    if (ret)
        return -EFAULT;
    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;

    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) {
        ret = fd_copyin(ptr->data, ptr->kernel_data, ptr->length);
        if (ret)
            return ret;
    }

    if (ptr->flags & FD_RAW_MORE) {
        rcmd = &(ptr->next);
        ptr->rate &= 0x43;
        goto loop;
    }

    return 0;
}

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

    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, true);
    debug_dcl(DP->flags, "calling disk change from raw_cmd ioctl\n");

    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(struct block_device *bdev)
{
    /* invalidate the buffer track to force a reread */
    set_bit((long)bdev->bd_disk->private_data, &fake_change);
    process_fd_request();
    check_disk_change(bdev);
    return 0;
}

static int set_geometry(unsigned int cmd, struct floppy_struct *g,
                        int drive, int type, struct block_device *bdev)
{
    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 | FD_SECTBASEMASK)) != 0)
        return -EINVAL;
    if (type) {
        if (!capable(CAP_SYS_ADMIN))
            return -EPERM;
        mutex_lock(&open_lock);
        if (lock_fdc(drive)) {
            mutex_unlock(&open_lock);
            return -EINTR;
        }
        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;
        process_fd_request();
        for (cnt = 0; cnt < N_DRIVE; cnt++) {
            struct block_device *bdev = opened_bdev[cnt];
            if (!bdev || ITYPE(drive_state[cnt].fd_device) != type)
                continue;
            __invalidate_device(bdev, true);
        }
        mutex_unlock(&open_lock);
    } else {
        int oldStretch;

        if (lock_fdc(drive))
            return -EINTR;
        if (cmd != FDDEFPRM) {
            /* notice a disk change immediately, else
             * we lose our settings immediately*/
            if (poll_drive(true, FD_RAW_NEED_DISK) == -EINTR)
                return -EINTR;
        }
        oldStretch = g->stretch;
        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;
        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 ||
            ((user_params[drive].sect ^ oldStretch) &
             (FD_SWAPSIDES | FD_SECTBASEMASK)))
            invalidate_drive(bdev);
        else
            process_fd_request();
    }
    return 0;
}

/* handle obsolete ioctl's */
static unsigned 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 int normalize_ioctl(unsigned 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)) {
                pr_info("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 {
        if (lock_fdc(drive))
            return -EINTR;
        if (poll_drive(false, 0) == -EINTR)
            return -EINTR;
        process_fd_request();
        *g = current_type[drive];
    }
    if (!*g)
        return -ENODEV;
    return 0;
}

static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
    int drive = (long)bdev->bd_disk->private_data;
    int type = ITYPE(drive_state[drive].fd_device);
    struct floppy_struct *g;
    int ret;

    ret = get_floppy_geometry(drive, type, &g);
    if (ret)
        return ret;

    geo->heads = g->head;
    geo->sectors = g->sect;
    geo->cylinders = g->track;
    return 0;
}

static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                           unsigned long param)
{
    int drive = (long)bdev->bd_disk->private_data;
    int type = ITYPE(UDRS->fd_device);
    int i;
    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 void *outparam;   /* parameters passed back to user space */

    /* 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;
    }

    if (!((cmd & 0xff00) == 0x0200))
        return -EINVAL;

    /* convert the old style command into a new style command */
    ret = normalize_ioctl(&cmd, &size);
    if (ret)
        return ret;

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

    if (WARN_ON(size < 0 || size > sizeof(inparam)))
        return -EINVAL;

    /* copyin */
    memset(&inparam, 0, sizeof(inparam));
    if (_IOC_DIR(cmd) & _IOC_WRITE) {
        ret = fd_copyin((void __user *)param, &inparam, size);
        if (ret)
            return ret;
    }

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

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

        set_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);
        set_bit(FD_VERIFY_BIT, &UDRS->flags);
        process_fd_request();
        return ret;
    case FDCLRPRM:
        if (lock_fdc(drive))
            return -EINTR;
        current_type[drive] = NULL;
        floppy_sizes[drive] = MAX_DISK_SIZE << 1;
        UDRS->keep_data = 0;
        return invalidate_drive(bdev);
    case FDSETPRM:
    case FDDEFPRM:
        return set_geometry(cmd, &inparam.g, drive, type, bdev);
    case FDGETPRM:
        ret = get_floppy_geometry(drive, type,
                                  (struct floppy_struct **)&outparam);
        if (ret)
            return ret;
        memcpy(&inparam.g, outparam,
               offsetof(struct floppy_struct, name));
        outparam = &inparam.g;
        break;
    case FDMSGON:
        UDP->flags |= FTD_MSG;
        return 0;
    case FDMSGOFF:
        UDP->flags &= ~FTD_MSG;
        return 0;
    case FDFMTBEG:
        if (lock_fdc(drive))
            return -EINTR;
        if (poll_drive(true, FD_RAW_NEED_DISK) == -EINTR)
            return -EINTR;
        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(drive, &inparam.f);
    case FDFMTEND:
    case FDFLUSH:
        if (lock_fdc(drive))
            return -EINTR;
        return invalidate_drive(bdev);
    case FDSETEMSGTRESH:
        UDP->max_errors.reporting = (unsigned short)(param & 0x0f);
        return 0;
    case FDGETMAXERRS:
        outparam = &UDP->max_errors;
        break;
    case FDSETMAXERRS:
        UDP->max_errors = inparam.max_errors;
        break;
    case FDGETDRVTYP:
        outparam = drive_name(type, drive);
        SUPBOUND(size, strlen((const char *)outparam) + 1);
        break;
    case FDSETDRVPRM:
        *UDP = inparam.dp;
        break;
    case FDGETDRVPRM:
        outparam = UDP;
        break;
    case FDPOLLDRVSTAT:
        if (lock_fdc(drive))
            return -EINTR;
        if (poll_drive(true, FD_RAW_NEED_DISK) == -EINTR)
            return -EINTR;
        process_fd_request();
    /* fall through */
    case FDGETDRVSTAT:
        outparam = UDRS;
        break;
    case FDRESET:
        return user_reset_fdc(drive, (int)param, true);
    case FDGETFDCSTAT:
        outparam = UFDCS;
        break;
    case FDWERRORCLR:
        memset(UDRWE, 0, sizeof(*UDRWE));
        return 0;
    case FDWERRORGET:
        outparam = UDRWE;
        break;
    case FDRAWCMD:
        if (type)
            return -EINVAL;
        if (lock_fdc(drive))
            return -EINTR;
        set_floppy(drive);
        i = raw_cmd_ioctl(cmd, (void __user *)param);
        if (i == -EINTR)
            return -EINTR;
        process_fd_request();
        return i;
    case FDTWADDLE:
        if (lock_fdc(drive))
            return -EINTR;
        twaddle();
        process_fd_request();
        return 0;
    default:
        return -EINVAL;
    }

    if (_IOC_DIR(cmd) & _IOC_READ)
        return fd_copyout((void __user *)param, outparam, size);

    return 0;
}

static int fd_ioctl(struct block_device *bdev, fmode_t mode,
                    unsigned int cmd, unsigned long param)
{
    int ret;

    mutex_lock(&floppy_mutex);
    ret = fd_locked_ioctl(bdev, mode, cmd, param);
    mutex_unlock(&floppy_mutex);

    return ret;
}

#ifdef CONFIG_COMPAT

struct compat_floppy_drive_params {
    char cmos;
    compat_ulong_t max_dtr;
    compat_ulong_t hlt;
    compat_ulong_t hut;
    compat_ulong_t srt;
    compat_ulong_t spinup;
    compat_ulong_t spindown;
    unsigned char spindown_offset;
    unsigned char select_delay;
    unsigned char rps;
    unsigned char tracks;
    compat_ulong_t timeout;
    unsigned char interleave_sect;
    struct floppy_max_errors max_errors;
    char flags;
    char read_track;
    short autodetect[8];
    compat_int_t checkfreq;
    compat_int_t native_format;
};

struct compat_floppy_drive_struct {
    signed char flags;
    compat_ulong_t spinup_date;
    compat_ulong_t select_date;
    compat_ulong_t first_read_date;
    short probed_format;
    short track;
    short maxblock;
    short maxtrack;
    compat_int_t generation;
    compat_int_t keep_data;
    compat_int_t fd_ref;
    compat_int_t fd_device;
    compat_int_t last_checked;
    compat_caddr_t dmabuf;
    compat_int_t bufblocks;
};

struct compat_floppy_fdc_state {
    compat_int_t spec1;
    compat_int_t spec2;
    compat_int_t dtr;
    unsigned char version;
    unsigned char dor;
    compat_ulong_t address;
    unsigned int rawcmd : 2;
    unsigned int reset : 1;
    unsigned int need_configure : 1;
    unsigned int perp_mode : 2;
    unsigned int has_fifo : 1;
    unsigned int driver_version;
    unsigned char track[4];
};

struct compat_floppy_write_errors {
    unsigned int write_errors;
    compat_ulong_t first_error_sector;
    compat_int_t first_error_generation;
    compat_ulong_t last_error_sector;
    compat_int_t last_error_generation;
    compat_uint_t badness;
};

#define FDSETPRM32 _IOW(2, 0x42, struct compat_floppy_struct)
#define FDDEFPRM32 _IOW(2, 0x43, struct compat_floppy_struct)
#define FDSETDRVPRM32 _IOW(2, 0x90, struct compat_floppy_drive_params)
#define FDGETDRVPRM32 _IOR(2, 0x11, struct compat_floppy_drive_params)
#define FDGETDRVSTAT32 _IOR(2, 0x12, struct compat_floppy_drive_struct)
#define FDPOLLDRVSTAT32 _IOR(2, 0x13, struct compat_floppy_drive_struct)
#define FDGETFDCSTAT32 _IOR(2, 0x15, struct compat_floppy_fdc_state)
#define FDWERRORGET32  _IOR(2, 0x17, struct compat_floppy_write_errors)

static int compat_set_geometry(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                               struct compat_floppy_struct __user *arg)
{
    struct floppy_struct v;
    int drive, type;
    int err;

    BUILD_BUG_ON(offsetof(struct floppy_struct, name) !=
                 offsetof(struct compat_floppy_struct, name));

    if (!(mode & (FMODE_WRITE | FMODE_WRITE_IOCTL)))
        return -EPERM;

    memset(&v, 0, sizeof(struct floppy_struct));
    if (copy_from_user(&v, arg, offsetof(struct floppy_struct, name)))
        return -EFAULT;

    mutex_lock(&floppy_mutex);
    drive = (long)bdev->bd_disk->private_data;
    type = ITYPE(UDRS->fd_device);
    err = set_geometry(cmd == FDSETPRM32 ? FDSETPRM : FDDEFPRM,
                       &v, drive, type, bdev);
    mutex_unlock(&floppy_mutex);
    return err;
}

static int compat_get_prm(int drive,
                          struct compat_floppy_struct __user *arg)
{
    struct compat_floppy_struct v;
    struct floppy_struct *p;
    int err;

    memset(&v, 0, sizeof(v));
    mutex_lock(&floppy_mutex);
    err = get_floppy_geometry(drive, ITYPE(UDRS->fd_device), &p);
    if (err) {
        mutex_unlock(&floppy_mutex);
        return err;
    }
    memcpy(&v, p, offsetof(struct floppy_struct, name));
    mutex_unlock(&floppy_mutex);
    if (copy_to_user(arg, &v, sizeof(struct compat_floppy_struct)))
        return -EFAULT;
    return 0;
}

static int compat_setdrvprm(int drive,
                            struct compat_floppy_drive_params __user *arg)
{
    struct compat_floppy_drive_params v;

    if (!capable(CAP_SYS_ADMIN))
        return -EPERM;
    if (copy_from_user(&v, arg, sizeof(struct compat_floppy_drive_params)))
        return -EFAULT;
    mutex_lock(&floppy_mutex);
    UDP->cmos = v.cmos;
    UDP->max_dtr = v.max_dtr;
    UDP->hlt = v.hlt;
    UDP->hut = v.hut;
    UDP->srt = v.srt;
    UDP->spinup = v.spinup;
    UDP->spindown = v.spindown;
    UDP->spindown_offset = v.spindown_offset;
    UDP->select_delay = v.select_delay;
    UDP->rps = v.rps;
    UDP->tracks = v.tracks;
    UDP->timeout = v.timeout;
    UDP->interleave_sect = v.interleave_sect;
    UDP->max_errors = v.max_errors;
    UDP->flags = v.flags;
    UDP->read_track = v.read_track;
    memcpy(UDP->autodetect, v.autodetect, sizeof(v.autodetect));
    UDP->checkfreq = v.checkfreq;
    UDP->native_format = v.native_format;
    mutex_unlock(&floppy_mutex);
    return 0;
}

static int compat_getdrvprm(int drive,
                            struct compat_floppy_drive_params __user *arg)
{
    struct compat_floppy_drive_params v;

    memset(&v, 0, sizeof(struct compat_floppy_drive_params));
    mutex_lock(&floppy_mutex);
    v.cmos = UDP->cmos;
    v.max_dtr = UDP->max_dtr;
    v.hlt = UDP->hlt;
    v.hut = UDP->hut;
    v.srt = UDP->srt;
    v.spinup = UDP->spinup;
    v.spindown = UDP->spindown;
    v.spindown_offset = UDP->spindown_offset;
    v.select_delay = UDP->select_delay;
    v.rps = UDP->rps;
    v.tracks = UDP->tracks;
    v.timeout = UDP->timeout;
    v.interleave_sect = UDP->interleave_sect;
    v.max_errors = UDP->max_errors;
    v.flags = UDP->flags;
    v.read_track = UDP->read_track;
    memcpy(v.autodetect, UDP->autodetect, sizeof(v.autodetect));
    v.checkfreq = UDP->checkfreq;
    v.native_format = UDP->native_format;
    mutex_unlock(&floppy_mutex);

    if (copy_from_user(arg, &v, sizeof(struct compat_floppy_drive_params)))
        return -EFAULT;
    return 0;
}

static int compat_getdrvstat(int drive, bool poll,
                             struct compat_floppy_drive_struct __user *arg)
{
    struct compat_floppy_drive_struct v;

    memset(&v, 0, sizeof(struct compat_floppy_drive_struct));
    mutex_lock(&floppy_mutex);

    if (poll) {
        if (lock_fdc(drive))
            goto Eintr;
        if (poll_drive(true, FD_RAW_NEED_DISK) == -EINTR)
            goto Eintr;
        process_fd_request();
    }
    v.spinup_date = UDRS->spinup_date;
    v.select_date = UDRS->select_date;
    v.first_read_date = UDRS->first_read_date;
    v.probed_format = UDRS->probed_format;
    v.track = UDRS->track;
    v.maxblock = UDRS->maxblock;
    v.maxtrack = UDRS->maxtrack;
    v.generation = UDRS->generation;
    v.keep_data = UDRS->keep_data;
    v.fd_ref = UDRS->fd_ref;
    v.fd_device = UDRS->fd_device;
    v.last_checked = UDRS->last_checked;
    v.dmabuf = (uintptr_t)UDRS->dmabuf;
    v.bufblocks = UDRS->bufblocks;
    mutex_unlock(&floppy_mutex);

    if (copy_from_user(arg, &v, sizeof(struct compat_floppy_drive_struct)))
        return -EFAULT;
    return 0;
Eintr:
    mutex_unlock(&floppy_mutex);
    return -EINTR;
}

static int compat_getfdcstat(int drive,
                             struct compat_floppy_fdc_state __user *arg)
{
    struct compat_floppy_fdc_state v32;
    struct floppy_fdc_state v;

    mutex_lock(&floppy_mutex);
    v = *UFDCS;
    mutex_unlock(&floppy_mutex);

    memset(&v32, 0, sizeof(struct compat_floppy_fdc_state));
    v32.spec1 = v.spec1;
    v32.spec2 = v.spec2;
    v32.dtr = v.dtr;
    v32.version = v.version;
    v32.dor = v.dor;
    v32.address = v.address;
    v32.rawcmd = v.rawcmd;
    v32.reset = v.reset;
    v32.need_configure = v.need_configure;
    v32.perp_mode = v.perp_mode;
    v32.has_fifo = v.has_fifo;
    v32.driver_version = v.driver_version;
    memcpy(v32.track, v.track, 4);
    if (copy_to_user(arg, &v32, sizeof(struct compat_floppy_fdc_state)))
        return -EFAULT;
    return 0;
}

static int compat_werrorget(int drive,
                            struct compat_floppy_write_errors __user *arg)
{
    struct compat_floppy_write_errors v32;
    struct floppy_write_errors v;

    memset(&v32, 0, sizeof(struct compat_floppy_write_errors));
    mutex_lock(&floppy_mutex);
    v = *UDRWE;
    mutex_unlock(&floppy_mutex);
    v32.write_errors = v.write_errors;
    v32.first_error_sector = v.first_error_sector;
    v32.first_error_generation = v.first_error_generation;
    v32.last_error_sector = v.last_error_sector;
    v32.last_error_generation = v.last_error_generation;
    v32.badness = v.badness;
    if (copy_to_user(arg, &v32, sizeof(struct compat_floppy_write_errors)))
        return -EFAULT;
    return 0;
}

static int fd_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
                           unsigned long param)
{
    int drive = (long)bdev->bd_disk->private_data;
    switch (cmd) {
    case FDMSGON:
    case FDMSGOFF:
    case FDSETEMSGTRESH:
    case FDFLUSH:
    case FDWERRORCLR:
    case FDEJECT:
    case FDCLRPRM:
    case FDFMTBEG:
    case FDRESET:
    case FDTWADDLE:
        return fd_ioctl(bdev, mode, cmd, param);
    case FDSETMAXERRS:
    case FDGETMAXERRS:
    case FDGETDRVTYP:
    case FDFMTEND:
    case FDFMTTRK:
    case FDRAWCMD:
        return fd_ioctl(bdev, mode, cmd,
                        (unsigned long)compat_ptr(param));
    case FDSETPRM32:
    case FDDEFPRM32:
        return compat_set_geometry(bdev, mode, cmd, compat_ptr(param));
    case FDGETPRM32:
        return compat_get_prm(drive, compat_ptr(param));
    case FDSETDRVPRM32:
        return compat_setdrvprm(drive, compat_ptr(param));
    case FDGETDRVPRM32:
        return compat_getdrvprm(drive, compat_ptr(param));
    case FDPOLLDRVSTAT32:
        return compat_getdrvstat(drive, true, compat_ptr(param));
    case FDGETDRVSTAT32:
        return compat_getdrvstat(drive, false, compat_ptr(param));
    case FDGETFDCSTAT32:
        return compat_getfdcstat(drive, compat_ptr(param));
    case FDWERRORGET32:
        return compat_werrorget(drive, compat_ptr(param));
    }
    return -EINVAL;
}
#endif

static void __init config_types(void)
{
    bool has_drive = false;
    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;

    /* FIXME: 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;
        char temparea[32];

        if (type < ARRAY_SIZE(default_drive_params)) {
            params = &default_drive_params[type].params;
            if (type) {
                name = default_drive_params[type].name;
                allowed_drive_mask |= 1 << drive;
            } else
                allowed_drive_mask &= ~(1 << drive);
        } else {
            params = &default_drive_params[0].params;
            snprintf(temparea, sizeof(temparea),
                     "unknown type %d (usb?)", type);
            name = temparea;
        }
        if (name) {
            const char *prepend;
            if (!has_drive) {
                prepend = "";
                has_drive = true;
                pr_info("Floppy drive(s):");
            } else {
                prepend = ",";
            }

            pr_cont("%s fd%d is %s", prepend, drive, name);
        }
        *UDP = *params;
    }

    if (has_drive)
        pr_cont("\n");
}

static void floppy_release(struct gendisk *disk, fmode_t mode)
{
    int drive = (long)disk->private_data;

    mutex_lock(&floppy_mutex);
    mutex_lock(&open_lock);
    if (!UDRS->fd_ref--) {
        DPRINT("floppy_release with fd_ref == 0");
        UDRS->fd_ref = 0;
    }
    if (!UDRS->fd_ref)
        opened_bdev[drive] = NULL;
    mutex_unlock(&open_lock);
    mutex_unlock(&floppy_mutex);
}

/*
 * 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.
 */
static int floppy_open(struct block_device *bdev, fmode_t mode)
{
    int drive = (long)bdev->bd_disk->private_data;
    int old_dev, new_dev;
    int try;
    int res = -EBUSY;
    char *tmp;

    mutex_lock(&floppy_mutex);
    mutex_lock(&open_lock);
    old_dev = UDRS->fd_device;
    if (opened_bdev[drive] && opened_bdev[drive] != bdev)
        goto out2;

    if (!UDRS->fd_ref && (UDP->flags & FD_BROKEN_DCL)) {
        set_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);
        set_bit(FD_VERIFY_BIT, &UDRS->flags);
    }

    UDRS->fd_ref++;

    opened_bdev[drive] = bdev;

    res = -ENXIO;

    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");
            goto out;
        }
        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;
        }
    }

    new_dev = MINOR(bdev->bd_dev);
    UDRS->fd_device = new_dev;
    set_capacity(disks[drive], floppy_sizes[new_dev]);
    if (old_dev != -1 && old_dev != new_dev) {
        if (buffer_drive == drive)
            buffer_track = -1;
    }

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

    if (!(mode & FMODE_NDELAY)) {
        if (mode & (FMODE_READ|FMODE_WRITE)) {
            UDRS->last_checked = 0;
            clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
            check_disk_change(bdev);
            if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags))
                goto out;
            if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
                goto out;
        }
        res = -EROFS;
        if ((mode & FMODE_WRITE) &&
            !test_bit(FD_DISK_WRITABLE_BIT, &UDRS->flags))
            goto out;
    }
    mutex_unlock(&open_lock);
    mutex_unlock(&floppy_mutex);
    return 0;
out:
    UDRS->fd_ref--;

    if (!UDRS->fd_ref)
        opened_bdev[drive] = NULL;
out2:
    mutex_unlock(&open_lock);
    mutex_unlock(&floppy_mutex);
    return res;
}

/*
 * Check if the disk has been changed or if a change has been faked.
 */
static unsigned int floppy_check_events(struct gendisk *disk,
                                        unsigned int clearing)
{
    int drive = (long)disk->private_data;

    if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags) ||
        test_bit(FD_VERIFY_BIT, &UDRS->flags))
        return DISK_EVENT_MEDIA_CHANGE;

    if (time_after(jiffies, UDRS->last_checked + UDP->checkfreq)) {
        if (lock_fdc(drive))
            return 0;
        poll_drive(false, 0);
        process_fd_request();
    }

    if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags) ||
        test_bit(FD_VERIFY_BIT, &UDRS->flags) ||
        test_bit(drive, &fake_change) ||
        drive_no_geom(drive))
        return DISK_EVENT_MEDIA_CHANGE;
    return 0;
}

/*
 * This implements "read block 0" for floppy_revalidate().
 * Needed for format autodetection, checking whether there is
 * a disk in the drive, and whether that disk is writable.
 */

struct rb0_cbdata {
    int drive;
    struct completion complete;
};

static void floppy_rb0_cb(struct bio *bio)
{
    struct rb0_cbdata *cbdata = (struct rb0_cbdata *)bio->bi_private;
    int drive = cbdata->drive;

    if (bio->bi_status) {
        pr_info("floppy: error %d while reading block 0\n",
                bio->bi_status);
        set_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
    }
    complete(&cbdata->complete);
}

static int __floppy_read_block_0(struct block_device *bdev, int drive)
{
    struct bio bio;
    struct bio_vec bio_vec;
    struct page *page;
    struct rb0_cbdata cbdata;
    size_t size;

    page = alloc_page(GFP_NOIO);
    if (!page) {
        process_fd_request();
        return -ENOMEM;
    }

    size = bdev->bd_block_size;
    if (!size)
        size = 1024;

    cbdata.drive = drive;

    bio_init(&bio, &bio_vec, 1);
    bio_set_dev(&bio, bdev);
    bio_add_page(&bio, page, size, 0);

    bio.bi_iter.bi_sector = 0;
    bio.bi_flags |= (1 << BIO_QUIET);
    bio.bi_private = &cbdata;
    bio.bi_end_io = floppy_rb0_cb;
    bio_set_op_attrs(&bio, REQ_OP_READ, 0);

    init_completion(&cbdata.complete);

    submit_bio(&bio);
    process_fd_request();

    wait_for_completion(&cbdata.complete);

    __free_page(page);

    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(struct gendisk *disk)
{
    int drive = (long)disk->private_data;
    int cf;
    int res = 0;

    if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags) ||
        test_bit(FD_VERIFY_BIT, &UDRS->flags) ||
        test_bit(drive, &fake_change) ||
        drive_no_geom(drive)) {
        if (WARN(atomic_read(&usage_count) == 0,
                 "VFS: revalidate called on non-open device.\n"))
            return -EFAULT;

        res = lock_fdc(drive);
        if (res)
            return res;
        cf = (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags) ||
              test_bit(FD_VERIFY_BIT, &UDRS->flags));
        if (!(cf || test_bit(drive, &fake_change) || drive_no_geom(drive))) {
            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);
        clear_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);
        if (cf)
            UDRS->generation++;
        if (drive_no_geom(drive)) {
            /* auto-sensing */
            res = __floppy_read_block_0(opened_bdev[drive], drive);
        } else {
            if (cf)
                poll_drive(false, FD_RAW_NEED_DISK);
            process_fd_request();
        }
    }
    set_capacity(disk, floppy_sizes[UDRS->fd_device]);
    return res;
}

static const struct block_device_operations floppy_fops = {
    .owner          = THIS_MODULE,
    .open           = floppy_open,
    .release        = floppy_release,
    .ioctl          = fd_ioctl,
    .getgeo         = fd_getgeo,
    .check_events       = floppy_check_events,
    .revalidate_disk    = floppy_revalidate,
#ifdef CONFIG_COMPAT
    .compat_ioctl       = fd_compat_ioctl,
#endif
};

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

    if (!fdc_configure()) {
        pr_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 {
        pr_info("FDC %d is an 82072A\n", fdc);
        return FDC_82072A;  /* 82072A as found on Sparcs. */
    }

    output_byte(FD_UNLOCK);
    r = result();
    if ((r == 1) && (reply_buffer[0] == 0x80)) {
        pr_info("FDC %d is a pre-1991 82077\n", fdc);
        return FDC_82077_ORIG;  /* Pre-1991 82077, doesn't know
                                 * LOCK/UNLOCK */
    }
    if ((r != 1) || (reply_buffer[0] != 0x00)) {
        pr_info("FDC %d init: UNLOCK: unexpected return of %d bytes.\n",
                fdc, r);
        return FDC_UNKNOWN;
    }
    output_byte(FD_PARTID);
    r = result();
    if (r != 1) {
        pr_info("FDC %d init: PARTID: unexpected return of %d bytes.\n",
                fdc, r);
        return FDC_UNKNOWN;
    }
    if (reply_buffer[0] == 0x80) {
        pr_info("FDC %d is a post-1991 82077\n", fdc);
        return FDC_82077;   /* Revised 82077AA passes all the tests */
    }
    switch (reply_buffer[0] >> 5) {
    case 0x0:
        /* Either a 82078-1 or a 82078SL running at 5Volt */
        pr_info("FDC %d is an 82078.\n", fdc);
        return FDC_82078;
    case 0x1:
        pr_info("FDC %d is a 44pin 82078\n", fdc);
        return FDC_82078;
    case 0x2:
        pr_info("FDC %d is a S82078B\n", fdc);
        return FDC_S82078B;
    case 0x3:
        pr_info("FDC %d is a National Semiconductor PC87306\n", fdc);
        return FDC_87306;
    default:
        pr_info("FDC %d init: 82078 variant with unknown PARTID=%d.\n",
                fdc, reply_buffer[0] >> 5);
        return FDC_82078_UNKN;
    }
}               /* get_fdc_version */

/* lilo configuration */

static void __init floppy_set_flags(int *ints, int param, int param2)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(default_drive_params); i++) {
        if (param)
            default_drive_params[i].params.flags |= param2;
        else
            default_drive_params[i].params.flags &= ~param2;
    }
    DPRINT("%s flag 0x%x\n", param2 ? "Setting" : "Clearing", param);
}

static void __init daring(int *ints, int param, int param2)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(default_drive_params); i++) {
        if (param) {
            default_drive_params[i].params.select_delay = 0;
            default_drive_params[i].params.flags |=
                FD_SILENT_DCL_CLEAR;
        } else {
            default_drive_params[i].params.select_delay =
                2 * HZ / 100;
            default_drive_params[i].params.flags &=
                ~FD_SILENT_DCL_CLEAR;
        }
    }
    DPRINT("Assuming %s floppy hardware\n", param ? "standard" : "broken");
}

static void __init set_cmos(int *ints, int dummy, int dummy2)
{
    int current_drive = 0;

    if (ints[0] != 2) {
        DPRINT("wrong number of parameters for CMOS\n");
        return;
    }
    current_drive = ints[1];
    if (current_drive < 0 || current_drive >= 8) {
        DPRINT("bad drive for set_cmos\n");
        return;
    }
#if N_FDC > 1
    if (current_drive >= 4 && !FDC2)
        FDC2 = 0x370;
#endif
    DP->cmos = ints[2];
    DPRINT("setting CMOS code to %d\n", ints[2]);
}

static struct param_table {
    const char *name;
    void (*fn) (int *ints, int param, int param2);
    int *var;
    int def_param;
    int param2;
} config_params[] __initdata = {
    {"allowed_drive_mask", NULL, &allowed_drive_mask, 0xff, 0}, /* obsolete */
    {"all_drives", NULL, &allowed_drive_mask, 0xff, 0}, /* obsolete */
    {"asus_pci", NULL, &allowed_drive_mask, 0x33, 0},
    {"irq", NULL, &FLOPPY_IRQ, 6, 0},
    {"dma", NULL, &FLOPPY_DMA, 2, 0},
    {"daring", daring, NULL, 1, 0},
#if N_FDC > 1
    {"two_fdc", NULL, &FDC2, 0x370, 0},
    {"one_fdc", NULL, &FDC2, 0, 0},
#endif
    {"thinkpad", floppy_set_flags, NULL, 1, FD_INVERTED_DCL},
    {"broken_dcl", floppy_set_flags, NULL, 1, FD_BROKEN_DCL},
    {"messages", floppy_set_flags, NULL, 1, FTD_MSG},
    {"silent_dcl_clear", floppy_set_flags, NULL, 1, FD_SILENT_DCL_CLEAR},
    {"debug", floppy_set_flags, NULL, 1, FD_DEBUG},
    {"nodma", NULL, &can_use_virtual_dma, 1, 0},
    {"omnibook", NULL, &can_use_virtual_dma, 1, 0},
    {"yesdma", NULL, &can_use_virtual_dma, 0, 0},
    {"fifo_depth", NULL, &fifo_depth, 0xa, 0},
    {"nofifo", NULL, &no_fifo, 0x20, 0},
    {"usefifo", NULL, &no_fifo, 0, 0},
    {"cmos", set_cmos, NULL, 0, 0},
    {"slow", NULL, &slow_floppy, 1, 0},
    {"unexpected_interrupts", NULL, &print_unex, 1, 0},
    {"no_unexpected_interrupts", NULL, &print_unex, 0, 0},
    {"L40SX", NULL, &print_unex, 0, 0}

    EXTRA_FLOPPY_PARAMS
};

static int __init floppy_setup(char *str)
{
    int i;
    int param;
    int ints[11];

    str = get_options(str, ARRAY_SIZE(ints), ints);
    if (str) {
        for (i = 0; i < ARRAY_SIZE(config_params); i++) {
            if (strcmp(str, config_params[i].name) == 0) {
                if (ints[0])
                    param = ints[1];
                else
                    param = config_params[i].def_param;
                if (config_params[i].fn)
                    config_params[i].fn(ints, param,
                                        config_params[i].
                                        param2);
                if (config_params[i].var) {
                    DPRINT("%s=%d\n", str, param);
                    *config_params[i].var = param;
                }
                return 1;
            }
        }
    }
    if (str) {
        DPRINT("unknown floppy option [%s]\n", str);

        DPRINT("allowed options are:");
        for (i = 0; i < ARRAY_SIZE(config_params); i++)
            pr_cont(" %s", config_params[i].name);
        pr_cont("\n");
    } else
        DPRINT("botched floppy option\n");
    DPRINT("Read Documentation/blockdev/floppy.txt\n");
    return 0;
}

static int have_no_fdc = -ENODEV;

static ssize_t floppy_cmos_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
    struct platform_device *p = to_platform_device(dev);
    int drive;

    drive = p->id;
    return sprintf(buf, "%X\n", UDP->cmos);
}

static DEVICE_ATTR(cmos, 0444, floppy_cmos_show, NULL);

static struct attribute *floppy_dev_attrs[] = {
    &dev_attr_cmos.attr,
    NULL
};

ATTRIBUTE_GROUPS(floppy_dev);

static void floppy_device_release(struct device *dev)
{}

static int floppy_resume(struct device *dev)
{
    int fdc;

    for (fdc = 0; fdc < N_FDC; fdc++)
        if (FDCS->address != -1)
            user_reset_fdc(-1, FD_RESET_ALWAYS, false);

    return 0;
}

static const struct dev_pm_ops floppy_pm_ops = {
    .resume = floppy_resume,
    .restore = floppy_resume,
};

static struct platform_driver floppy_driver = {
    .driver = {
        .name = "floppy",
        .pm = &floppy_pm_ops,
    },
};

static const struct blk_mq_ops floppy_mq_ops = {
    .queue_rq = floppy_queue_rq,
};

static struct platform_device floppy_device[N_DRIVE];

static bool floppy_available(int drive)
{
    if (!(allowed_drive_mask & (1 << drive)))
        return false;
    if (fdc_state[FDC(drive)].version == FDC_NONE)
        return false;
    return true;
}

static struct kobject *floppy_find(dev_t dev, int *part, void *data)
{
    int drive = (*part & 3) | ((*part & 0x80) >> 5);
    if (drive >= N_DRIVE || !floppy_available(drive))
        return NULL;
    if (((*part >> 2) & 0x1f) >= ARRAY_SIZE(floppy_type))
        return NULL;
    *part = 0;
    return get_disk_and_module(disks[drive]);
}

static int __init do_floppy_init(void)
{
    int i, unit, drive, err;

    set_debugt();
    interruptjiffies = resultjiffies = jiffies;

#if defined(CONFIG_PPC)
    if (check_legacy_ioport(FDC1))
        return -ENODEV;
#endif

    raw_cmd = NULL;

    floppy_wq = alloc_ordered_workqueue("floppy", 0);
    if (!floppy_wq)
        return -ENOMEM;

    for (drive = 0; drive < N_DRIVE; drive++) {
        disks[drive] = alloc_disk(1);
        if (!disks[drive]) {
            err = -ENOMEM;
            goto out_put_disk;
        }

        disks[drive]->queue = blk_mq_init_sq_queue(&tag_sets[drive],
                                                   &floppy_mq_ops, 2,
                                                   BLK_MQ_F_SHOULD_MERGE);
        if (IS_ERR(disks[drive]->queue)) {
            err = PTR_ERR(disks[drive]->queue);
            disks[drive]->queue = NULL;
            goto out_put_disk;
        }

        blk_queue_bounce_limit(disks[drive]->queue, BLK_BOUNCE_HIGH);
        blk_queue_max_hw_sectors(disks[drive]->queue, 64);
        disks[drive]->major = FLOPPY_MAJOR;
        disks[drive]->first_minor = TOMINOR(drive);
        disks[drive]->fops = &floppy_fops;
        disks[drive]->events = DISK_EVENT_MEDIA_CHANGE;
        sprintf(disks[drive]->disk_name, "fd%d", drive);

        timer_setup(&motor_off_timer[drive], motor_off_callback, 0);
    }

    err = register_blkdev(FLOPPY_MAJOR, "fd");
    if (err)
        goto out_put_disk;

    err = platform_driver_register(&floppy_driver);
    if (err)
        goto out_unreg_blkdev;

    blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
                        floppy_find, NULL, NULL);

    for (i = 0; i < 256; i++)
        if (ITYPE(i))
            floppy_sizes[i] = floppy_type[ITYPE(i)].size;
        else
            floppy_sizes[i] = MAX_DISK_SIZE << 1;

    reschedule_timeout(MAXTIMEOUT, "floppy init");
    config_types();

    for (i = 0; i < N_FDC; i++) {
        fdc = i;
        memset(FDCS, 0, sizeof(*FDCS));
        FDCS->dtr = -1;
        FDCS->dor = 0x4;
#if defined(__sparc__) || defined(__mc68000__)
        /*sparcs/sun3x don't have a DOR reset which we can fall back on to */
#ifdef __mc68000__
        if (MACH_IS_SUN3X)
#endif
        FDCS->version = FDC_82072A;
#endif
    }

    use_virtual_dma = can_use_virtual_dma & 1;
    fdc_state[0].address = FDC1;
    if (fdc_state[0].address == -1) {
        cancel_delayed_work(&fd_timeout);
        err = -ENODEV;
        goto out_unreg_region;
    }
#if N_FDC > 1
    fdc_state[1].address = FDC2;
#endif

    fdc = 0;        /* reset fdc in case of unexpected interrupt */
    err = floppy_grab_irq_and_dma();
    if (err) {
        cancel_delayed_work(&fd_timeout);
        err = -EBUSY;
        goto out_unreg_region;
    }

    /* initialise drive state */
    for (drive = 0; drive < N_DRIVE; drive++) {
        memset(UDRS, 0, sizeof(*UDRS));
        memset(UDRWE, 0, sizeof(*UDRWE));
        set_bit(FD_DISK_NEWCHANGE_BIT, &UDRS->flags);
        set_bit(FD_DISK_CHANGED_BIT, &UDRS->flags);
        set_bit(FD_VERIFY_BIT, &UDRS->flags);
        UDRS->fd_device = -1;
        floppy_track_buffer = NULL;
        max_buffer_sectors = 0;
    }
    /*
     * Small 10 msec delay to let through any interrupt that
     * initialization might have triggered, to not
     * confuse detection:
     */
    msleep(10);

    for (i = 0; i < N_FDC; i++) {
        fdc = i;
        FDCS->driver_version = FD_DRIVER_VERSION;
        for (unit = 0; unit < 4; unit++)
            FDCS->track[unit] = 0;
        if (FDCS->address == -1)
            continue;
        FDCS->rawcmd = 2;
        if (user_reset_fdc(-1, FD_RESET_ALWAYS, false)) {
            /* free ioports reserved by floppy_grab_irq_and_dma() */
            floppy_release_regions(fdc);
            FDCS->address = -1;
            FDCS->version = FDC_NONE;
            continue;
        }
        /* Try to determine the floppy controller type */
        FDCS->version = get_fdc_version();
        if (FDCS->version == FDC_NONE) {
            /* free ioports reserved by floppy_grab_irq_and_dma() */
            floppy_release_regions(fdc);
            FDCS->address = -1;
            continue;
        }
        if (can_use_virtual_dma == 2 && FDCS->version < FDC_82072A)
            can_use_virtual_dma = 0;

        have_no_fdc = 0;
        /* Not all FDCs seem to be able to handle the version command
         * properly, so force a reset for the standard FDC clones,
         * to avoid interrupt garbage.
         */
        user_reset_fdc(-1, FD_RESET_ALWAYS, false);
    }
    fdc = 0;
    cancel_delayed_work(&fd_timeout);
    current_drive = 0;
    initialized = true;
    if (have_no_fdc) {
        DPRINT("no floppy controllers found\n");
        err = have_no_fdc;
        goto out_release_dma;
    }

    for (drive = 0; drive < N_DRIVE; drive++) {
        if (!floppy_available(drive))
            continue;

        floppy_device[drive].name = floppy_device_name;
        floppy_device[drive].id = drive;
        floppy_device[drive].dev.release = floppy_device_release;
        floppy_device[drive].dev.groups = floppy_dev_groups;

        err = platform_device_register(&floppy_device[drive]);
        if (err)
            goto out_remove_drives;

        /* to be cleaned up... */
        disks[drive]->private_data = (void *)(long)drive;
        disks[drive]->flags |= GENHD_FL_REMOVABLE;
        device_add_disk(&floppy_device[drive].dev, disks[drive], NULL);
    }

    return 0;

out_remove_drives:
    while (drive--) {
        if (floppy_available(drive)) {
            del_gendisk(disks[drive]);
            platform_device_unregister(&floppy_device[drive]);
        }
    }
out_release_dma:
    if (atomic_read(&usage_count))
        floppy_release_irq_and_dma();
out_unreg_region:
    blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
    platform_driver_unregister(&floppy_driver);
out_unreg_blkdev:
    unregister_blkdev(FLOPPY_MAJOR, "fd");
out_put_disk:
    destroy_workqueue(floppy_wq);
    for (drive = 0; drive < N_DRIVE; drive++) {
        if (!disks[drive])
            break;
        if (disks[drive]->queue) {
            del_timer_sync(&motor_off_timer[drive]);
            blk_cleanup_queue(disks[drive]->queue);
            disks[drive]->queue = NULL;
            blk_mq_free_tag_set(&tag_sets[drive]);
        }
        put_disk(disks[drive]);
    }
    return err;
}

#ifndef MODULE
static __init void floppy_async_init(void *data, async_cookie_t cookie)
{
    do_floppy_init();
}
#endif

static int __init floppy_init(void)
{
#ifdef MODULE
    return do_floppy_init();
#else
    /* Don't hold up the bootup by the floppy initialization */
    async_schedule(floppy_async_init, NULL);
    return 0;
#endif
}

static const struct io_region {
    int offset;
    int size;
} io_regions[] = {
    { 2, 1 },
    /* address + 3 is sometimes reserved by pnp bios for motherboard */
    { 4, 2 },
    /* address + 6 is reserved, and may be taken by IDE.
     * Unfortunately, Adaptec doesn't know this :-(, */
    { 7, 1 },
};

static void floppy_release_allocated_regions(int fdc, const struct io_region *p)
{
    while (p != io_regions) {
        p--;
        release_region(FDCS->address + p->offset, p->size);
    }
}

#define ARRAY_END(X) (&((X)[ARRAY_SIZE(X)]))

static int floppy_request_regions(int fdc)
{
    const struct io_region *p;

    for (p = io_regions; p < ARRAY_END(io_regions); p++) {
        if (!request_region(FDCS->address + p->offset,
                            p->size, "floppy")) {
            DPRINT("Floppy io-port 0x%04lx in use\n",
                   FDCS->address + p->offset);
            floppy_release_allocated_regions(fdc, p);
            return -EBUSY;
        }
    }
    return 0;
}

static void floppy_release_regions(int fdc)
{
    floppy_release_allocated_regions(fdc, ARRAY_END(io_regions));
}

static int floppy_grab_irq_and_dma(void)
{
    if (atomic_inc_return(&usage_count) > 1)
        return 0;

    /*
     * We might have scheduled a free_irq(), wait it to
     * drain first:
     */
    flush_workqueue(floppy_wq);

    if (fd_request_irq()) {
        DPRINT("Unable to grab IRQ%d for the floppy driver\n",
               FLOPPY_IRQ);
        atomic_dec(&usage_count);
        return -1;
    }
    if (fd_request_dma()) {
        DPRINT("Unable to grab DMA%d for the floppy driver\n",
               FLOPPY_DMA);
        if (can_use_virtual_dma & 2)
            use_virtual_dma = can_use_virtual_dma = 1;
        if (!(can_use_virtual_dma & 1)) {
            fd_free_irq();
            atomic_dec(&usage_count);
            return -1;
        }
    }

    for (fdc = 0; fdc < N_FDC; fdc++) {
        if (FDCS->address != -1) {
            if (floppy_request_regions(fdc))
                goto cleanup;
        }
    }
    for (fdc = 0; fdc < N_FDC; fdc++) {
        if (FDCS->address != -1) {
            reset_fdc_info(1);
            fd_outb(FDCS->dor, FD_DOR);
        }
    }
    fdc = 0;
    set_dor(0, ~0, 8);  /* avoid immediate interrupt */

    for (fdc = 0; fdc < N_FDC; fdc++)
        if (FDCS->address != -1)
            fd_outb(FDCS->dor, FD_DOR);
    /*
     * The driver will try and free resources and relies on us
     * to know if they were allocated or not.
     */
    fdc = 0;
    irqdma_allocated = 1;
    return 0;
cleanup:
    fd_free_irq();
    fd_free_dma();
    while (--fdc >= 0)
        floppy_release_regions(fdc);
    atomic_dec(&usage_count);
    return -1;
}

static void floppy_release_irq_and_dma(void)
{
    int old_fdc;
#ifndef __sparc__
    int drive;
#endif
    long tmpsize;
    unsigned long tmpaddr;

    if (!atomic_dec_and_test(&usage_count))
        return;

    if (irqdma_allocated) {
        fd_disable_dma();
        fd_free_dma();
        fd_free_irq();
        irqdma_allocated = 0;
    }
    set_dor(0, ~0, 8);
#if N_FDC > 1
    set_dor(1, ~8, 0);
#endif

    if (floppy_track_buffer && max_buffer_sectors) {
        tmpsize = max_buffer_sectors * 1024;
        tmpaddr = (unsigned long)floppy_track_buffer;
        floppy_track_buffer = NULL;
        max_buffer_sectors = 0;
        buffer_min = buffer_max = -1;
        fd_dma_mem_free(tmpaddr, tmpsize);
    }
#ifndef __sparc__
    for (drive = 0; drive < N_FDC * 4; drive++)
        if (timer_pending(motor_off_timer + drive))
            pr_info("motor off timer %d still active\n", drive);
#endif

    if (delayed_work_pending(&fd_timeout))
        pr_info("floppy timer still active:%s\n", timeout_message);
    if (delayed_work_pending(&fd_timer))
        pr_info("auxiliary floppy timer still active\n");
    if (work_pending(&floppy_work))
        pr_info("work still pending\n");
    old_fdc = fdc;
    for (fdc = 0; fdc < N_FDC; fdc++)
        if (FDCS->address != -1)
            floppy_release_regions(fdc);
    fdc = old_fdc;
}

#ifdef MODULE

static char *floppy;

static void __init parse_floppy_cfg_string(char *cfg)
{
    char *ptr;

    while (*cfg) {
        ptr = cfg;
        while (*cfg && *cfg != ' ' && *cfg != '\t')
            cfg++;
        if (*cfg) {
            *cfg = '\0';
            cfg++;
        }
        if (*ptr)
            floppy_setup(ptr);
    }
}

static int __init floppy_module_init(void)
{
    if (floppy)
        parse_floppy_cfg_string(floppy);
    return floppy_init();
}
module_init(floppy_module_init);

static void __exit floppy_module_exit(void)
{
    int drive;

    blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
    unregister_blkdev(FLOPPY_MAJOR, "fd");
    platform_driver_unregister(&floppy_driver);

    destroy_workqueue(floppy_wq);

    for (drive = 0; drive < N_DRIVE; drive++) {
        del_timer_sync(&motor_off_timer[drive]);

        if (floppy_available(drive)) {
            del_gendisk(disks[drive]);
            platform_device_unregister(&floppy_device[drive]);
        }
        blk_cleanup_queue(disks[drive]->queue);
        blk_mq_free_tag_set(&tag_sets[drive]);

        /*
         * These disks have not called add_disk().  Don't put down
         * queue reference in put_disk().
         */
        if (!(allowed_drive_mask & (1 << drive)) ||
            fdc_state[FDC(drive)].version == FDC_NONE)
            disks[drive]->queue = NULL;

        put_disk(disks[drive]);
    }

    cancel_delayed_work_sync(&fd_timeout);
    cancel_delayed_work_sync(&fd_timer);

    if (atomic_read(&usage_count))
        floppy_release_irq_and_dma();

    /* eject disk, if any */
    fd_eject(0);
}

module_exit(floppy_module_exit);

module_param(floppy, charp, 0);
module_param(FLOPPY_IRQ, int, 0);
module_param(FLOPPY_DMA, int, 0);
MODULE_AUTHOR("Alain L. Knaff");
MODULE_SUPPORTED_DEVICE("fd");
MODULE_LICENSE("GPL");

/* This doesn't actually get used other than for module information */
static const struct pnp_device_id floppy_pnpids[] = {
    {"PNP0700", 0},
    {}
};

MODULE_DEVICE_TABLE(pnp, floppy_pnpids);

#else

__setup("floppy=", floppy_setup);
module_init(floppy_init)
#endif

MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);
