FreeBSD/Linux Kernel Cross Reference
sys/drivers/block/floppy.c

     /*
      *  linux/drivers/block/floppy.c
      *
      *  Copyright (C) 1991, 1992  Linus Torvalds
      *  Copyright (C) 1993, 1994  Alain Knaff
      *  Copyright (C) 1998 Alan Cox
      */
     /*
      * 02.12.91 - Changed to static variables to indicate need for reset
     * and recalibrate. This makes some things easier (output_byte reset
     * checking etc), and means less interrupt jumping in case of errors,
     * so the code is hopefully easier to understand.
     */
    
    /*
     * This file is certainly a mess. I've tried my best to get it working,
     * but I don't like programming floppies, and I have only one anyway.
     * Urgel. I should check for more errors, and do more graceful error
     * recovery. Seems there are problems with several drives. I've tried to
     * correct them. No promises.
     */
    
    /*
     * As with hd.c, all routines within this file can (and will) be called
     * by interrupts, so extreme caution is needed. A hardware interrupt
     * handler may not sleep, or a kernel panic will happen. Thus I cannot
     * call "floppy-on" directly, but have to set a special timer interrupt
     * etc.
     */
    
    /*
     * 28.02.92 - made track-buffering routines, based on the routines written
     * by entropy@wintermute.wpi.edu (Lawrence Foard). Linus.
     */
    
    /*
     * Automatic floppy-detection and formatting written by Werner Almesberger
     * (almesber@nessie.cs.id.ethz.ch), who also corrected some problems with
     * the floppy-change signal detection.
     */
    
    /*
     * 1992/7/22 -- Hennus Bergman: Added better error reporting, fixed
     * FDC data overrun bug, added some preliminary stuff for vertical
     * recording support.
     *
     * 1992/9/17: Added DMA allocation & DMA functions. -- hhb.
     *
     * TODO: Errors are still not counted properly.
     */
    
    /* 1992/9/20
     * Modifications for ``Sector Shifting'' by Rob Hooft (hooft@chem.ruu.nl)
     * modeled after the freeware MS-DOS program fdformat/88 V1.8 by
     * Christoph H. Hochst\"atter.
     * I have fixed the shift values to the ones I always use. Maybe a new
     * ioctl() should be created to be able to modify them.
     * There is a bug in the driver that makes it impossible to format a
     * floppy as the first thing after bootup.
     */
    
    /*
     * 1993/4/29 -- Linus -- cleaned up the timer handling in the kernel, and
     * this helped the floppy driver as well. Much cleaner, and still seems to
     * work.
     */
    
    /* 1994/6/24 --bbroad-- added the floppy table entries and made
     * minor modifications to allow 2.88 floppies to be run.
     */
    
    /* 1994/7/13 -- Paul Vojta -- modified the probing code to allow three or more
     * disk types.
     */
    
    /*
     * 1994/8/8 -- Alain Knaff -- Switched to fdpatch driver: Support for bigger
     * format bug fixes, but unfortunately some new bugs too...
     */
    
    /* 1994/9/17 -- Koen Holtman -- added logging of physical floppy write
     * errors to allow safe writing by specialized programs.
     */
    
    /* 1995/4/24 -- Dan Fandrich -- added support for Commodore 1581 3.5" disks
     * by defining bit 1 of the "stretch" parameter to mean put sectors on the
     * opposite side of the disk, leaving the sector IDs alone (i.e. Commodore's
     * drives are "upside-down").
     */
    
    /*
     * 1995/8/26 -- Andreas Busse -- added Mips support.
     */
    
    /*
     * 1995/10/18 -- Ralf Baechle -- Portability cleanup; move machine dependent
     * features to asm/floppy.h.
     */
    
   /*
    * 1998/05/07 -- Russell King -- More portability cleanups; moved definition of
    * interrupt and dma channel to asm/floppy.h. Cleaned up some formatting &
    * use of '' for NULL.
    */
    
   /*
    * 1998/06/07 -- Alan Cox -- Merged the 2.0.34 fixes for resource allocation
    * failures.
    */
   
   /*
    * 1998/09/20 -- David Weinehall -- Added slow-down code for buggy PS/2-drives.
    */
   
   /*
    * 1999/08/13 -- Paul Slootman -- floppy stopped working on Alpha after 24
    * days, 6 hours, 32 minutes and 32 seconds (i.e. MAXINT jiffies; ints were
    * being used to store jiffies, which are unsigned longs).
    */
   
   /*
    * 2000/08/28 -- Arnaldo Carvalho de Melo <acme@conectiva.com.br>
    * - get rid of check_region
    * - s/suser/capable/
    */
   
   /*
    * 2001/08/26 -- Paul Gortmaker - fix insmod oops on machines with no
    * floppy controller (lingering task on list after module is gone... boom.)
    */
   
   /*
    * 2002/02/07 -- Anton Altaparmakov - Fix io ports reservation to correct range
    * (0x3f2-0x3f5, 0x3f7). This fix is a bit of a hack but the proper fix
    * requires many non-obvious changes in arch dependent code.
    */
   
   #define FLOPPY_SANITY_CHECK
   #undef  FLOPPY_SILENT_DCL_CLEAR
   
   #define REALLY_SLOW_IO
   
   #define DEBUGT 2
   #define DCL_DEBUG /* debug disk change line */
   
   /* do print messages for unexpected interrupts */
   static int print_unex=1;
   #include <linux/module.h>
   #include <linux/sched.h>
   #include <linux/fs.h>
   #include <linux/kernel.h>
   #include <linux/timer.h>
   #include <linux/tqueue.h>
   #define FDPATCHES
   #include <linux/fdreg.h>
   
   /*
    * 1998/1/21 -- Richard Gooch <rgooch@atnf.csiro.au> -- devfs support
    */
   
   
   #include <linux/fd.h>
   #include <linux/hdreg.h>
   
   #include <linux/errno.h>
   #include <linux/slab.h>
   #include <linux/mm.h>
   #include <linux/string.h>
   #include <linux/fcntl.h>
   #include <linux/delay.h>
   #include <linux/mc146818rtc.h> /* CMOS defines */
   #include <linux/ioport.h>
   #include <linux/interrupt.h>
   #include <linux/init.h>
   #include <linux/devfs_fs_kernel.h>
   
   /*
    * PS/2 floppies have much slower step rates than regular floppies.
    * It's been recommended that take about 1/4 of the default speed
    * in some more extreme cases.
    */
   static int slow_floppy;
   
   #include <asm/dma.h>
   #include <asm/irq.h>
   #include <asm/system.h>
   #include <asm/io.h>
   #include <asm/uaccess.h>
   
   static int FLOPPY_IRQ=6;
   static int FLOPPY_DMA=2;
   static int can_use_virtual_dma=2;
   /* =======
    * can use virtual DMA:
    * 0 = use of virtual DMA disallowed by config
    * 1 = use of virtual DMA prescribed by config
    * 2 = no virtual DMA preference configured.  By default try hard DMA,
    * but fall back on virtual DMA when not enough memory available
    */
   
   static int use_virtual_dma;
   /* =======
    * use virtual DMA
    * 0 using hard DMA
    * 1 using virtual DMA
    * This variable is set to virtual when a DMA mem problem arises, and
    * reset back in floppy_grab_irq_and_dma.
    * It is not safe to reset it in other circumstances, because the floppy
    * driver may have several buffers in use at once, and we do currently not
    * record each buffers capabilities
    */
   
   static unsigned short virtual_dma_port=0x3f0;
   void floppy_interrupt(int irq, void *dev_id, struct pt_regs * regs);
   static int set_dor(int fdc, char mask, char data);
   static void register_devfs_entries (int drive) __init;
   static devfs_handle_t devfs_handle;
   
   #define K_64    0x10000         /* 64KB */
   
   /* the following is the mask of allowed drives. By default units 2 and
    * 3 of both floppy controllers are disabled, because switching on the
    * motor of these drives causes system hangs on some PCI computers. drive
    * 0 is the low bit (0x1), and drive 7 is the high bit (0x80). Bits are on if
    * a drive is allowed.
    *
    * NOTE: This must come before we include the arch floppy header because
    *       some ports reference this variable from there. -DaveM
    */
   
   static int allowed_drive_mask = 0x33;
   
   #include <asm/floppy.h>
   
   static int irqdma_allocated;
   
   #define MAJOR_NR FLOPPY_MAJOR
   
   #include <linux/blk.h>
   #include <linux/blkpg.h>
   #include <linux/cdrom.h> /* for the compatibility eject ioctl */
   
   #ifndef fd_get_dma_residue
   #define fd_get_dma_residue() get_dma_residue(FLOPPY_DMA)
   #endif
   
   /* Dma Memory related stuff */
   
   #ifndef fd_dma_mem_free
   #define fd_dma_mem_free(addr, size) free_pages(addr, get_order(size))
   #endif
   
   #ifndef fd_dma_mem_alloc
   #define fd_dma_mem_alloc(size) __get_dma_pages(GFP_KERNEL,get_order(size))
   #endif
   
   static inline void fallback_on_nodma_alloc(char **addr, size_t l)
   {
   #ifdef FLOPPY_CAN_FALLBACK_ON_NODMA
           if (*addr)
                   return; /* we have the memory */
           if (can_use_virtual_dma != 2)
                   return; /* no fallback allowed */
           printk("DMA memory shortage. Temporarily falling back on virtual DMA\n");
           *addr = (char *) nodma_mem_alloc(l);
   #else
           return;
   #endif
   }
   
   /* End dma memory related stuff */
   
   static unsigned long fake_change;
   static int initialising=1;
   
   static inline int TYPE(kdev_t x) {
           return  (MINOR(x)>>2) & 0x1f;
   }
   static inline int DRIVE(kdev_t x) {
           return (MINOR(x)&0x03) | ((MINOR(x)&0x80) >> 5);
   }
   #define ITYPE(x) (((x)>>2) & 0x1f)
   #define TOMINOR(x) ((x & 3) | ((x & 4) << 5))
   #define UNIT(x) ((x) & 0x03)            /* drive on fdc */
   #define FDC(x) (((x) & 0x04) >> 2)  /* fdc of drive */
   #define REVDRIVE(fdc, unit) ((unit) + ((fdc) << 2))
                                   /* reverse mapping from unit and fdc to drive */
   #define DP (&drive_params[current_drive])
   #define DRS (&drive_state[current_drive])
   #define DRWE (&write_errors[current_drive])
   #define FDCS (&fdc_state[fdc])
   #define CLEARF(x) (clear_bit(x##_BIT, &DRS->flags))
   #define SETF(x) (set_bit(x##_BIT, &DRS->flags))
   #define TESTF(x) (test_bit(x##_BIT, &DRS->flags))
   
   #define UDP (&drive_params[drive])
   #define UDRS (&drive_state[drive])
   #define UDRWE (&write_errors[drive])
   #define UFDCS (&fdc_state[FDC(drive)])
   #define UCLEARF(x) (clear_bit(x##_BIT, &UDRS->flags))
   #define USETF(x) (set_bit(x##_BIT, &UDRS->flags))
   #define UTESTF(x) (test_bit(x##_BIT, &UDRS->flags))
   
   #define DPRINT(format, args...) printk(DEVICE_NAME "%d: " format, current_drive , ## args)
   
   #define PH_HEAD(floppy,head) (((((floppy)->stretch & 2) >>1) ^ head) << 2)
   #define STRETCH(floppy) ((floppy)->stretch & FD_STRETCH)
   
   #define CLEARSTRUCT(x) memset((x), 0, sizeof(*(x)))
   
   /* read/write */
   #define COMMAND raw_cmd->cmd[0]
   #define DR_SELECT raw_cmd->cmd[1]
   #define TRACK raw_cmd->cmd[2]
   #define HEAD raw_cmd->cmd[3]
   #define SECTOR raw_cmd->cmd[4]
   #define SIZECODE raw_cmd->cmd[5]
   #define SECT_PER_TRACK raw_cmd->cmd[6]
   #define GAP raw_cmd->cmd[7]
   #define SIZECODE2 raw_cmd->cmd[8]
   #define NR_RW 9
   
   /* format */
   #define F_SIZECODE raw_cmd->cmd[2]
   #define F_SECT_PER_TRACK raw_cmd->cmd[3]
   #define F_GAP raw_cmd->cmd[4]
   #define F_FILL raw_cmd->cmd[5]
   #define NR_F 6
   
   /*
    * Maximum disk size (in kilobytes). This default is used whenever the
    * current disk size is unknown.
    * [Now it is rather a minimum]
    */
   #define MAX_DISK_SIZE 4 /* 3984*/
   
   
   /*
    * globals used by 'result()'
    */
   #define MAX_REPLIES 16
   static unsigned char reply_buffer[MAX_REPLIES];
   static int inr; /* size of reply buffer, when called from interrupt */
   #define ST0 (reply_buffer[0])
   #define ST1 (reply_buffer[1])
   #define ST2 (reply_buffer[2])
   #define ST3 (reply_buffer[0]) /* result of GETSTATUS */
   #define R_TRACK (reply_buffer[3])
   #define R_HEAD (reply_buffer[4])
   #define R_SECTOR (reply_buffer[5])
   #define R_SIZECODE (reply_buffer[6])
   
   #define SEL_DLY (2*HZ/100)
   
   /*
    * this struct defines the different floppy drive types.
    */
   static struct {
           struct floppy_drive_params params;
           const char *name; /* name printed while booting */
   } default_drive_params[]= {
   /* NOTE: the time values in jiffies should be in msec!
    CMOS drive type
     |     Maximum data rate supported by drive type
     |     |   Head load time, msec
     |     |   |   Head unload time, msec (not used)
     |     |   |   |     Step rate interval, usec
     |     |   |   |     |       Time needed for spinup time (jiffies)
     |     |   |   |     |       |      Timeout for spinning down (jiffies)
     |     |   |   |     |       |      |   Spindown offset (where disk stops)
     |     |   |   |     |       |      |   |     Select delay
     |     |   |   |     |       |      |   |     |     RPS
     |     |   |   |     |       |      |   |     |     |    Max number of tracks
     |     |   |   |     |       |      |   |     |     |    |     Interrupt timeout
     |     |   |   |     |       |      |   |     |     |    |     |   Max nonintlv. sectors
     |     |   |   |     |       |      |   |     |     |    |     |   | -Max Errors- flags */
   {{0,  500, 16, 16, 8000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  80, 3*HZ, 20, {3,1,2,0,2}, 0,
         0, { 7, 4, 8, 2, 1, 5, 3,10}, 3*HZ/2, 0 }, "unknown" },
   
   {{1,  300, 16, 16, 8000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  40, 3*HZ, 17, {3,1,2,0,2}, 0,
         0, { 1, 0, 0, 0, 0, 0, 0, 0}, 3*HZ/2, 1 }, "360K PC" }, /*5 1/4 360 KB PC*/
   
   {{2,  500, 16, 16, 6000, 4*HZ/10, 3*HZ, 14, SEL_DLY, 6,  83, 3*HZ, 17, {3,1,2,0,2}, 0,
         0, { 2, 5, 6,23,10,20,12, 0}, 3*HZ/2, 2 }, "1.2M" }, /*5 1/4 HD AT*/
   
   {{3,  250, 16, 16, 3000,    1*HZ, 3*HZ,  0, SEL_DLY, 5,  83, 3*HZ, 20, {3,1,2,0,2}, 0,
         0, { 4,22,21,30, 3, 0, 0, 0}, 3*HZ/2, 4 }, "720k" }, /*3 1/2 DD*/
   
   {{4,  500, 16, 16, 4000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 20, {3,1,2,0,2}, 0,
         0, { 7, 4,25,22,31,21,29,11}, 3*HZ/2, 7 }, "1.44M" }, /*3 1/2 HD*/
   
   {{5, 1000, 15,  8, 3000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 40, {3,1,2,0,2}, 0,
         0, { 7, 8, 4,25,28,22,31,21}, 3*HZ/2, 8 }, "2.88M AMI BIOS" }, /*3 1/2 ED*/
   
   {{6, 1000, 15,  8, 3000, 4*HZ/10, 3*HZ, 10, SEL_DLY, 5,  83, 3*HZ, 40, {3,1,2,0,2}, 0,
         0, { 7, 8, 4,25,28,22,31,21}, 3*HZ/2, 8 }, "2.88M" } /*3 1/2 ED*/
   /*    |  --autodetected formats---    |      |      |
    *    read_track                      |      |    Name printed when booting
    *                                    |     Native format
    *                  Frequency of disk change checks */
   };
   
   static struct floppy_drive_params drive_params[N_DRIVE];
   static struct floppy_drive_struct drive_state[N_DRIVE];
   static struct floppy_write_errors write_errors[N_DRIVE];
   static struct timer_list motor_off_timer[N_DRIVE];
   static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;
   
   /*
    * This struct defines the different floppy types.
    *
    * Bit 0 of 'stretch' tells if the tracks need to be doubled for some
    * types (e.g. 360kB diskette in 1.2MB drive, etc.).  Bit 1 of 'stretch'
    * tells if the disk is in Commodore 1581 format, which means side 0 sectors
    * are located on side 1 of the disk but with a side 0 ID, and vice-versa.
    * This is the same as the Sharp MZ-80 5.25" CP/M disk format, except that the
    * 1581's logical side 0 is on physical side 1, whereas the Sharp's logical
    * side 0 is on physical side 0 (but with the misnamed sector IDs).
    * 'stretch' should probably be renamed to something more general, like
    * 'options'.  Other parameters should be self-explanatory (see also
    * setfdprm(8)).
    */
   /*
               Size
                |  Sectors per track
                |  | Head
                |  | |  Tracks
                |  | |  | Stretch
                |  | |  | |  Gap 1 size
                |  | |  | |    |  Data rate, | 0x40 for perp
                |  | |  | |    |    |  Spec1 (stepping rate, head unload
                |  | |  | |    |    |    |    /fmt gap (gap2) */
   static struct floppy_struct floppy_type[32] = {
           {    0, 0,0, 0,0,0x00,0x00,0x00,0x00,NULL    }, /*  0 no testing    */
           {  720, 9,2,40,0,0x2A,0x02,0xDF,0x50,"d360"  }, /*  1 360KB PC      */
           { 2400,15,2,80,0,0x1B,0x00,0xDF,0x54,"h1200" }, /*  2 1.2MB AT      */
           {  720, 9,1,80,0,0x2A,0x02,0xDF,0x50,"D360"  }, /*  3 360KB SS 3.5" */
           { 1440, 9,2,80,0,0x2A,0x02,0xDF,0x50,"D720"  }, /*  4 720KB 3.5"    */
           {  720, 9,2,40,1,0x23,0x01,0xDF,0x50,"h360"  }, /*  5 360KB AT      */
           { 1440, 9,2,80,0,0x23,0x01,0xDF,0x50,"h720"  }, /*  6 720KB AT      */
           { 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,"H1440" }, /*  7 1.44MB 3.5"   */
           { 5760,36,2,80,0,0x1B,0x43,0xAF,0x54,"E2880" }, /*  8 2.88MB 3.5"   */
           { 6240,39,2,80,0,0x1B,0x43,0xAF,0x28,"E3120" }, /*  9 3.12MB 3.5"   */
   
           { 2880,18,2,80,0,0x25,0x00,0xDF,0x02,"h1440" }, /* 10 1.44MB 5.25"  */
           { 3360,21,2,80,0,0x1C,0x00,0xCF,0x0C,"H1680" }, /* 11 1.68MB 3.5"   */
           {  820,10,2,41,1,0x25,0x01,0xDF,0x2E,"h410"  }, /* 12 410KB 5.25"   */
           { 1640,10,2,82,0,0x25,0x02,0xDF,0x2E,"H820"  }, /* 13 820KB 3.5"    */
           { 2952,18,2,82,0,0x25,0x00,0xDF,0x02,"h1476" }, /* 14 1.48MB 5.25"  */
           { 3444,21,2,82,0,0x25,0x00,0xDF,0x0C,"H1722" }, /* 15 1.72MB 3.5"   */
           {  840,10,2,42,1,0x25,0x01,0xDF,0x2E,"h420"  }, /* 16 420KB 5.25"   */
           { 1660,10,2,83,0,0x25,0x02,0xDF,0x2E,"H830"  }, /* 17 830KB 3.5"    */
           { 2988,18,2,83,0,0x25,0x00,0xDF,0x02,"h1494" }, /* 18 1.49MB 5.25"  */
           { 3486,21,2,83,0,0x25,0x00,0xDF,0x0C,"H1743" }, /* 19 1.74 MB 3.5"  */
   
           { 1760,11,2,80,0,0x1C,0x09,0xCF,0x00,"h880"  }, /* 20 880KB 5.25"   */
           { 2080,13,2,80,0,0x1C,0x01,0xCF,0x00,"D1040" }, /* 21 1.04MB 3.5"   */
           { 2240,14,2,80,0,0x1C,0x19,0xCF,0x00,"D1120" }, /* 22 1.12MB 3.5"   */
           { 3200,20,2,80,0,0x1C,0x20,0xCF,0x2C,"h1600" }, /* 23 1.6MB 5.25"   */
           { 3520,22,2,80,0,0x1C,0x08,0xCF,0x2e,"H1760" }, /* 24 1.76MB 3.5"   */
           { 3840,24,2,80,0,0x1C,0x20,0xCF,0x00,"H1920" }, /* 25 1.92MB 3.5"   */
           { 6400,40,2,80,0,0x25,0x5B,0xCF,0x00,"E3200" }, /* 26 3.20MB 3.5"   */
           { 7040,44,2,80,0,0x25,0x5B,0xCF,0x00,"E3520" }, /* 27 3.52MB 3.5"   */
           { 7680,48,2,80,0,0x25,0x63,0xCF,0x00,"E3840" }, /* 28 3.84MB 3.5"   */
   
           { 3680,23,2,80,0,0x1C,0x10,0xCF,0x00,"H1840" }, /* 29 1.84MB 3.5"   */
           { 1600,10,2,80,0,0x25,0x02,0xDF,0x2E,"D800"  }, /* 30 800KB 3.5"    */
           { 3200,20,2,80,0,0x1C,0x00,0xCF,0x2C,"H1600" }, /* 31 1.6MB 3.5"    */
   };
   
   #define NUMBER(x)       (sizeof(x) / sizeof(*(x)))
   #define SECTSIZE (_FD_SECTSIZE(*floppy))
   
   /* Auto-detection: Disk type used until the next media change occurs. */
   static struct floppy_struct *current_type[N_DRIVE];
   
   /*
    * User-provided type information. current_type points to
    * the respective entry of this array.
    */
   static struct floppy_struct user_params[N_DRIVE];
   
   static int floppy_sizes[256];
   static int floppy_blocksizes[256];
   static int floppy_maxsectors[256];
   
   /*
    * The driver is trying to determine the correct media format
    * while probing is set. rw_interrupt() clears it after a
    * successful access.
    */
   static int probing;
   
   /* Synchronization of FDC access. */
   #define FD_COMMAND_NONE -1
   #define FD_COMMAND_ERROR 2
   #define FD_COMMAND_OKAY 3
   
   static volatile int command_status = FD_COMMAND_NONE;
   static unsigned long fdc_busy;
   static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
   static DECLARE_WAIT_QUEUE_HEAD(command_done);
   
   #define NO_SIGNAL (!interruptible || !signal_pending(current))
   #define CALL(x) if ((x) == -EINTR) return -EINTR
   #define ECALL(x) if ((ret = (x))) return ret;
   #define _WAIT(x,i) CALL(ret=wait_til_done((x),i))
   #define WAIT(x) _WAIT((x),interruptible)
   #define IWAIT(x) _WAIT((x),1)
   
   /* Errors during formatting are counted here. */
   static int format_errors;
   
   /* Format request descriptor. */
   static struct format_descr format_req;
   
   /*
    * Rate is 0 for 500kb/s, 1 for 300kbps, 2 for 250kbps
    * Spec1 is 0xSH, where S is stepping rate (F=1ms, E=2ms, D=3ms etc),
    * H is head unload time (1=16ms, 2=32ms, etc)
    */
   
   /*
    * Track buffer
    * Because these are written to by the DMA controller, they must
    * not contain a 64k byte boundary crossing, or data will be
    * corrupted/lost.
    */
   static char *floppy_track_buffer;
   static int max_buffer_sectors;
   
   static int *errors;
   typedef void (*done_f)(int);
   static struct cont_t {
           void (*interrupt)(void); /* this is called after the interrupt of the
                                     * main command */
           void (*redo)(void); /* this is called to retry the operation */
           void (*error)(void); /* this is called to tally an error */
           done_f done; /* this is called to say if the operation has 
                         * succeeded/failed */
   } *cont;
   
   static void floppy_ready(void);
   static void floppy_start(void);
   static void process_fd_request(void);
   static void recalibrate_floppy(void);
   static void floppy_shutdown(void);
   
   static int floppy_grab_irq_and_dma(void);
   static void floppy_release_irq_and_dma(void);
   
   /*
    * The "reset" variable should be tested whenever an interrupt is scheduled,
    * after the commands have been sent. This is to ensure that the driver doesn't
    * get wedged when the interrupt doesn't come because of a failed command.
    * reset doesn't need to be tested before sending commands, because
    * output_byte is automatically disabled when reset is set.
    */
   #define CHECK_RESET { if (FDCS->reset){ reset_fdc(); return; } }
   static void reset_fdc(void);
   
   /*
    * These are global variables, as that's the easiest way to give
    * information to interrupts. They are the data used for the current
    * request.
    */
   #define NO_TRACK -1
   #define NEED_1_RECAL -2
   #define NEED_2_RECAL -3
   
   static int usage_count;
   
   /* buffer related variables */
   static int buffer_track = -1;
   static int buffer_drive = -1;
   static int buffer_min = -1;
   static int buffer_max = -1;
   
   /* fdc related variables, should end up in a struct */
   static struct floppy_fdc_state fdc_state[N_FDC];
   static int fdc; /* current fdc */
   
   static struct floppy_struct *_floppy = floppy_type;
   static unsigned char current_drive;
   static long current_count_sectors;
   static unsigned char sector_t; /* sector in track */
   static unsigned char in_sector_offset;  /* offset within physical sector,
                                            * expressed in units of 512 bytes */
   
   #ifndef fd_eject
   #define fd_eject(x) -EINVAL
   #endif
   
   #ifdef DEBUGT
   static long unsigned debugtimer;
   #endif
   
   /*
    * Debugging
    * =========
    */
   static inline void set_debugt(void)
   {
   #ifdef DEBUGT
           debugtimer = jiffies;
   #endif
   }
   
   static inline void debugt(const char *message)
   {
   #ifdef DEBUGT
           if (DP->flags & DEBUGT)
                   printk("%s dtime=%lu\n", message, jiffies-debugtimer);
   #endif
   }
   
   typedef void (*timeout_fn)(unsigned long);
   static struct timer_list fd_timeout ={ function: (timeout_fn) floppy_shutdown };
   
   static const char *timeout_message;
   
   #ifdef FLOPPY_SANITY_CHECK
   static void is_alive(const char *message)
   {
           /* this routine checks whether the floppy driver is "alive" */
           if (test_bit(0, &fdc_busy) && command_status < 2
               && !timer_pending(&fd_timeout)){
                   DPRINT("timeout handler died: %s\n",message);
           }
   }
   #endif
   
   #ifdef FLOPPY_SANITY_CHECK
   
   #define OLOGSIZE 20
   
   static void (*lasthandler)(void);
   static unsigned long interruptjiffies;
   static unsigned long resultjiffies;
   static int resultsize;
   static unsigned long lastredo;
   
   static struct output_log {
           unsigned char data;
           unsigned char status;
           unsigned long jiffies;
   } output_log[OLOGSIZE];
   
   static int output_log_pos;
   #endif
   
   #define CURRENTD -1
   #define MAXTIMEOUT -2
   
   static void __reschedule_timeout(int drive, const char *message, int marg)
   {
           if (drive == CURRENTD)
                   drive = current_drive;
           del_timer(&fd_timeout);
           if (drive < 0 || drive > N_DRIVE) {
                   fd_timeout.expires = jiffies + 20UL*HZ;
                   drive=0;
           } else
                   fd_timeout.expires = jiffies + UDP->timeout;
           add_timer(&fd_timeout);
           if (UDP->flags & FD_DEBUG){
                   DPRINT("reschedule timeout ");
                   printk(message, marg);
                   printk("\n");
           }
           timeout_message = message;
   }
   
   
   static void reschedule_timeout(int drive, const char *message, int marg)
   {
           unsigned long flags;
   
           spin_lock_irqsave(&io_request_lock, flags);
           __reschedule_timeout(drive, message, marg);
           spin_unlock_irqrestore(&io_request_lock, flags);
   }
   
   static int maximum(int a, int b)
   {
           if (a > b)
                   return a;
           else
                   return b;
   }
   #define INFBOUND(a,b) (a)=maximum((a),(b));
   
   static int minimum(int a, int b)
   {
           if (a < b)
                   return a;
           else
                   return b;
   }
   #define SUPBOUND(a,b) (a)=minimum((a),(b));
   
   
   /*
    * Bottom half floppy driver.
    * ==========================
    *
    * This part of the file contains the code talking directly to the hardware,
    * and also the main service loop (seek-configure-spinup-command)
    */
   
   /*
    * disk change.
    * This routine is responsible for maintaining the FD_DISK_CHANGE flag,
    * and the last_checked date.
    *
    * last_checked is the date of the last check which showed 'no disk change'
    * FD_DISK_CHANGE is set under two conditions:
    * 1. The floppy has been changed after some i/o to that floppy already
    *    took place.
    * 2. No floppy disk is in the drive. This is done in order to ensure that
    *    requests are quickly flushed in case there is no disk in the drive. It
    *    follows that FD_DISK_CHANGE can only be cleared if there is a disk in
    *    the drive.
    *
    * For 1., maxblock is observed. Maxblock is 0 if no i/o has taken place yet.
    * For 2., FD_DISK_NEWCHANGE is watched. FD_DISK_NEWCHANGE is cleared on
    *  each seek. If a disk is present, the disk change line should also be
    *  cleared on each seek. Thus, if FD_DISK_NEWCHANGE is clear, but the disk
    *  change line is set, this means either that no disk is in the drive, or
    *  that it has been removed since the last seek.
    *
    * This means that we really have a third possibility too:
    *  The floppy has been changed after the last seek.
    */
   
   static int disk_change(int drive)
   {
           int fdc=FDC(drive);
   #ifdef FLOPPY_SANITY_CHECK
           if (jiffies - UDRS->select_date < UDP->select_delay)
                   DPRINT("WARNING disk change called early\n");
           if (!(FDCS->dor & (0x10 << UNIT(drive))) ||
               (FDCS->dor & 3) != UNIT(drive) ||
               fdc != FDC(drive)){
                   DPRINT("probing disk change on unselected drive\n");
                   DPRINT("drive=%d fdc=%d dor=%x\n",drive, FDC(drive),
                           (unsigned int)FDCS->dor);
           }
   #endif
   
   #ifdef DCL_DEBUG
           if (UDP->flags & FD_DEBUG){
                   DPRINT("checking disk change line for drive %d\n",drive);
                   DPRINT("jiffies=%lu\n", jiffies);
                   DPRINT("disk change line=%x\n",fd_inb(FD_DIR)&0x80);
                   DPRINT("flags=%lx\n",UDRS->flags);
           }
   #endif
           if (UDP->flags & FD_BROKEN_DCL)
                   return UTESTF(FD_DISK_CHANGED);
           if ((fd_inb(FD_DIR) ^ UDP->flags) & 0x80){
                   USETF(FD_VERIFY); /* verify write protection */
                   if (UDRS->maxblock){
                           /* mark it changed */
                           USETF(FD_DISK_CHANGED);
                   }
   
                   /* invalidate its geometry */
                   if (UDRS->keep_data >= 0) {
                           if ((UDP->flags & FTD_MSG) &&
                               current_type[drive] != NULL)
                                   DPRINT("Disk type is undefined after "
                                          "disk change\n");
                           current_type[drive] = NULL;
                           floppy_sizes[TOMINOR(drive)] = MAX_DISK_SIZE;
                   }
   
                   /*USETF(FD_DISK_NEWCHANGE);*/
                   return 1;
           } else {
                   UDRS->last_checked=jiffies;
                   UCLEARF(FD_DISK_NEWCHANGE);
           }
           return 0;
   }
   
   static inline int is_selected(int dor, int unit)
   {
           return ((dor  & (0x10 << unit)) && (dor &3) == unit);
   }
   
   static int set_dor(int fdc, char mask, char data)
   {
           register unsigned char drive, unit, newdor,olddor;
   
           if (FDCS->address == -1)
                   return -1;
   
           olddor = FDCS->dor;
           newdor =  (olddor & mask) | data;
           if (newdor != olddor){
                   unit = olddor & 0x3;
                   if (is_selected(olddor, unit) && !is_selected(newdor,unit)){
                           drive = REVDRIVE(fdc,unit);
   #ifdef DCL_DEBUG
                           if (UDP->flags & FD_DEBUG){
                                   DPRINT("calling disk change from set_dor\n");
                           }
   #endif
                           disk_change(drive);
                   }
                   FDCS->dor = newdor;
                   fd_outb(newdor, FD_DOR);
   
                   unit = newdor & 0x3;
                   if (!is_selected(olddor, unit) && is_selected(newdor,unit)){
                           drive = REVDRIVE(fdc,unit);
                           UDRS->select_date = jiffies;
                   }
           }
           /*
            *      We should propogate failures to grab the resources back
            *      nicely from here. Actually we ought to rewrite the fd
            *      driver some day too.
            */
           if (newdor & FLOPPY_MOTOR_MASK)
                   floppy_grab_irq_and_dma();
           if (olddor & FLOPPY_MOTOR_MASK)
                   floppy_release_irq_and_dma();
           return olddor;
   }
   
   static void twaddle(void)
   {
           if (DP->select_delay)
                   return;
           fd_outb(FDCS->dor & ~(0x10<<UNIT(current_drive)), FD_DOR);
           fd_outb(FDCS->dor, FD_DOR);
           DRS->select_date = jiffies;
   }
   
   /* reset all driver information about the current fdc. This is needed after
    * a reset, and after a raw command. */
   static void reset_fdc_info(int mode)
   {
           int drive;
   
           FDCS->spec1 = FDCS->spec2 = -1;
           FDCS->need_configure = 1;
           FDCS->perp_mode = 1;
           FDCS->rawcmd = 0;
           for (drive = 0; drive < N_DRIVE; drive++)
                   if (FDC(drive) == fdc &&
                       (mode || UDRS->track != NEED_1_RECAL))
                           UDRS->track = NEED_2_RECAL;
   }
   
   /* selects the fdc and drive, and enables the fdc's input/dma. */
   static void set_fdc(int drive)
   {
           if (drive >= 0 && drive < N_DRIVE){
                   fdc = FDC(drive);
                   current_drive = drive;
           }
           if (fdc != 1 && fdc != 0) {
                   printk("bad fdc value\n");
                   return;
           }
           set_dor(fdc,~0,8);
   #if N_FDC > 1
           set_dor(1-fdc, ~8, 0);
   #endif
           if (FDCS->rawcmd == 2)
                   reset_fdc_info(1);
           if (fd_inb(FD_STATUS) != STATUS_READY)
                   FDCS->reset = 1;
   }
   
   /* locks the driver */
   static int _lock_fdc(int drive, int interruptible, int line)
   {
           if (!usage_count){
                   printk(KERN_ERR "Trying to lock fdc while usage count=0 at line %d\n", line);
                   return -1;
           }
           if(floppy_grab_irq_and_dma()==-1)
                   return -EBUSY;
   
           if (test_and_set_bit(0, &fdc_busy)) {
                   DECLARE_WAITQUEUE(wait, current);
                   add_wait_queue(&fdc_wait, &wait);
   
                   for (;;) {
                           set_current_state(TASK_INTERRUPTIBLE);
   
                           if (!test_and_set_bit(0, &fdc_busy))
                                   break;
   
                           schedule();
   
                           if (!NO_SIGNAL) {
                                   remove_wait_queue(&fdc_wait, &wait);
                                   return -EINTR;
                           }
                   }
   
                   set_current_state(TASK_RUNNING);
                   remove_wait_queue(&fdc_wait, &wait);
           }
           command_status = FD_COMMAND_NONE;
   
           __reschedule_timeout(drive, "lock fdc", 0);
           set_fdc(drive);
           return 0;
   }
   
   #define lock_fdc(drive,interruptible) _lock_fdc(drive,interruptible, __LINE__)
   
   #define LOCK_FDC(drive,interruptible) \
   if (lock_fdc(drive,interruptible)) return -EINTR;
   
   
   /* unlocks the driver */
   static inline void unlock_fdc(void)
   {
           unsigned long flags;
   
           raw_cmd = 0;
           if (!test_bit(0, &fdc_busy))
                   DPRINT("FDC access conflict!\n");
   
           if (DEVICE_INTR)
                   DPRINT("device interrupt still active at FDC release: %p!\n",
                           DEVICE_INTR);
           command_status = FD_COMMAND_NONE;
           spin_lock_irqsave(&io_request_lock, flags);
           del_timer(&fd_timeout);
           cont = NULL;
           clear_bit(0, &fdc_busy);
           if (!QUEUE_EMPTY)
                   do_fd_request(BLK_DEFAULT_QUEUE(MAJOR_NR));
           spin_unlock_irqrestore(&io_request_lock, flags);
           floppy_release_irq_and_dma();
           wake_up(&fdc_wait);
   }
   
   /* switches the motor off after a given timeout */
   static void motor_off_callback(unsigned long nr)
   {
           unsigned char mask = ~(0x10 << UNIT(nr));
   
           set_dor(FDC(nr), mask, 0);
   }
   
   /* schedules motor off */
   static void floppy_off(unsigned int drive)
   {
           unsigned long volatile delta;
           register int fdc=FDC(drive);
   
           if (!(FDCS->dor & (0x10 << UNIT(drive))))
                   return;
   
           del_timer(motor_off_timer+drive);
   
           /* make spindle stop in a position which minimizes spinup time
            * next time */
           if (UDP->rps){
                   delta = jiffies - UDRS->first_read_date + HZ -
                           UDP->spindown_offset;
                   delta = ((delta * UDP->rps) % HZ) / UDP->rps;
                   motor_off_timer[drive].expires = jiffies + UDP->spindown - delta;
           }
           add_timer(motor_off_timer+drive);
   }
   
   /*
    * cycle through all N_DRIVE floppy drives, for disk change testing.
    * stopping at current drive. This is done before any long operation, to
    * be sure to have up to date disk change information.
    */
   static void scandrives(void)
   {
           int i, drive, saved_drive;
   
           if (DP->select_delay)
                   return;
   
           saved_drive = current_drive;
           for (i=0; i < N_DRIVE; i++){
                   drive = (saved_drive + i + 1) % N_DRIVE;
                   if (UDRS->fd_ref == 0 || UDP->select_delay != 0)
                           continue; /* skip closed drives */
                   set_fdc(drive);
                   if (!(set_dor(fdc, ~3, UNIT(drive) | (0x10 << UNIT(drive))) &
                         (0x10 << UNIT(drive))))
                           /* switch the motor off again, if it was off to
                            * begin with */
                           set_dor(fdc, ~(0x10 << UNIT(drive)), 0);
          }
          set_fdc(saved_drive);
  }
  
  static void empty(void)
  {
  }
  
  static struct tq_struct floppy_tq;
  
  static void schedule_bh( void (*handler)(void*) )
  {
          floppy_tq.routine = (void *)(void *) handler;
          queue_task(&floppy_tq, &tq_immediate);
          mark_bh(IMMEDIATE_BH);
  }
  
  static struct timer_list fd_timer;
  
  static void cancel_activity(void)
  {
          unsigned long flags;
  
          spin_lock_irqsave(&io_request_lock, flags);
          CLEAR_INTR;
          floppy_tq.routine = (void *)(void *) empty;
          del_timer(&fd_timer);
          spin_unlock_irqrestore(&io_request_lock, flags);
  }
  
  /* this function makes sure that the disk stays in the drive during the
   * transfer */
  static void fd_watchdog(void)
  {
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("calling disk change from watchdog\n");
          }
  #endif
  
          if (disk_change(current_drive)){
                  DPRINT("disk removed during i/o\n");
                  cancel_activity();
                  cont->done(0);
                  reset_fdc();
          } else {
                  del_timer(&fd_timer);
                  fd_timer.function = (timeout_fn) fd_watchdog;
                  fd_timer.expires = jiffies + HZ / 10;
                  add_timer(&fd_timer);
          }
  }
  
  static void main_command_interrupt(void)
  {
          del_timer(&fd_timer);
          cont->interrupt();
  }
  
  /* waits for a delay (spinup or select) to pass */
  static int fd_wait_for_completion(unsigned long delay, timeout_fn function)
  {
          if (FDCS->reset){
                  reset_fdc(); /* do the reset during sleep to win time
                                * if we don't need to sleep, it's a good
                                * occasion anyways */
                  return 1;
          }
  
          if ((signed) (jiffies - delay) < 0){
                  del_timer(&fd_timer);
                  fd_timer.function = function;
                  fd_timer.expires = delay;
                  add_timer(&fd_timer);
                  return 1;
          }
          return 0;
  }
  
  static spinlock_t floppy_hlt_lock = SPIN_LOCK_UNLOCKED;
  static int hlt_disabled;
  static void floppy_disable_hlt(void)
  {
          unsigned long flags;
  
          spin_lock_irqsave(&floppy_hlt_lock, flags);
          if (!hlt_disabled) {
                  hlt_disabled=1;
  #ifdef HAVE_DISABLE_HLT
                  disable_hlt();
  #endif
          }
          spin_unlock_irqrestore(&floppy_hlt_lock, flags);
  }
  
  static void floppy_enable_hlt(void)
  {
          unsigned long flags;
  
          spin_lock_irqsave(&floppy_hlt_lock, flags);
          if (hlt_disabled){
                  hlt_disabled=0;
  #ifdef HAVE_DISABLE_HLT
                  enable_hlt();
  #endif
          }
          spin_unlock_irqrestore(&floppy_hlt_lock, flags);
  }
  
  
  static void setup_DMA(void)
  {
          unsigned long f;
  
  #ifdef FLOPPY_SANITY_CHECK
          if (raw_cmd->length == 0){
                  int i;
  
                  printk("zero dma transfer size:");
                  for (i=0; i < raw_cmd->cmd_count; i++)
                          printk("%x,", raw_cmd->cmd[i]);
                  printk("\n");
                  cont->done(0);
                  FDCS->reset = 1;
                  return;
          }
          if (((unsigned long) raw_cmd->kernel_data) % 512){
                  printk("non aligned address: %p\n", raw_cmd->kernel_data);
                  cont->done(0);
                  FDCS->reset=1;
                  return;
          }
  #endif
          f=claim_dma_lock();
          fd_disable_dma();
  #ifdef fd_dma_setup
          if (fd_dma_setup(raw_cmd->kernel_data, raw_cmd->length, 
                          (raw_cmd->flags & FD_RAW_READ)?
                          DMA_MODE_READ : DMA_MODE_WRITE,
                          FDCS->address) < 0) {
                  release_dma_lock(f);
                  cont->done(0);
                  FDCS->reset=1;
                  return;
          }
          release_dma_lock(f);
  #else   
          fd_clear_dma_ff();
          fd_cacheflush(raw_cmd->kernel_data, raw_cmd->length);
          fd_set_dma_mode((raw_cmd->flags & FD_RAW_READ)?
                          DMA_MODE_READ : DMA_MODE_WRITE);
          fd_set_dma_addr(raw_cmd->kernel_data);
          fd_set_dma_count(raw_cmd->length);
          virtual_dma_port = FDCS->address;
          fd_enable_dma();
          release_dma_lock(f);
  #endif
          floppy_disable_hlt();
  }
  
  static void show_floppy(void);
  
  /* waits until the fdc becomes ready */
  static int wait_til_ready(void)
  {
          int counter, status;
          if (FDCS->reset)
                  return -1;
          for (counter = 0; counter < 10000; counter++) {
                  status = fd_inb(FD_STATUS);             
                  if (status & STATUS_READY)
                          return status;
          }
          if (!initialising) {
                  DPRINT("Getstatus times out (%x) on fdc %d\n",
                          status, fdc);
                  show_floppy();
          }
          FDCS->reset = 1;
          return -1;
  }
  
  /* sends a command byte to the fdc */
  static int output_byte(char byte)
  {
          int status;
  
          if ((status = wait_til_ready()) < 0)
                  return -1;
          if ((status & (STATUS_READY|STATUS_DIR|STATUS_DMA)) == STATUS_READY){
                  fd_outb(byte,FD_DATA);
  #ifdef FLOPPY_SANITY_CHECK
                  output_log[output_log_pos].data = byte;
                  output_log[output_log_pos].status = status;
                  output_log[output_log_pos].jiffies = jiffies;
                  output_log_pos = (output_log_pos + 1) % OLOGSIZE;
  #endif
                  return 0;
          }
          FDCS->reset = 1;
          if (!initialising) {
                  DPRINT("Unable to send byte %x to FDC. Fdc=%x Status=%x\n",
                         byte, fdc, status);
                  show_floppy();
          }
          return -1;
  }
  #define LAST_OUT(x) if (output_byte(x)<0){ reset_fdc();return;}
  
  /* gets the response from the fdc */
  static int result(void)
  {
          int i, status=0;
  
          for(i=0; i < MAX_REPLIES; i++) {
                  if ((status = wait_til_ready()) < 0)
                          break;
                  status &= STATUS_DIR|STATUS_READY|STATUS_BUSY|STATUS_DMA;
                  if ((status & ~STATUS_BUSY) == STATUS_READY){
  #ifdef FLOPPY_SANITY_CHECK
                          resultjiffies = jiffies;
                          resultsize = i;
  #endif
                          return i;
                  }
                  if (status == (STATUS_DIR|STATUS_READY|STATUS_BUSY))
                          reply_buffer[i] = fd_inb(FD_DATA);
                  else
                          break;
          }
          if (!initialising) {
                  DPRINT("get result error. Fdc=%d Last status=%x Read bytes=%d\n",
                         fdc, status, i);
                  show_floppy();
          }
          FDCS->reset = 1;
          return -1;
  }
  
  #define MORE_OUTPUT -2
  /* does the fdc need more output? */
  static int need_more_output(void)
  {
          int status;
          if ((status = wait_til_ready()) < 0)
                  return -1;
          if ((status & (STATUS_READY|STATUS_DIR|STATUS_DMA)) == STATUS_READY)
                  return MORE_OUTPUT;
          return result();
  }
  
  /* Set perpendicular mode as required, based on data rate, if supported.
   * 82077 Now tested. 1Mbps data rate only possible with 82077-1.
   */
  static inline void perpendicular_mode(void)
  {
          unsigned char perp_mode;
  
          if (raw_cmd->rate & 0x40){
                  switch(raw_cmd->rate & 3){
                          case 0:
                                  perp_mode=2;
                                  break;
                          case 3:
                                  perp_mode=3;
                                  break;
                          default:
                                  DPRINT("Invalid data rate for perpendicular mode!\n");
                                  cont->done(0);
                                  FDCS->reset = 1; /* convenient way to return to
                                                    * redo without to much hassle (deep
                                                    * stack et al. */
                                  return;
                  }
          } else
                  perp_mode = 0;
  
          if (FDCS->perp_mode == perp_mode)
                  return;
          if (FDCS->version >= FDC_82077_ORIG) {
                  output_byte(FD_PERPENDICULAR);
                  output_byte(perp_mode);
                  FDCS->perp_mode = perp_mode;
          } else if (perp_mode) {
                  DPRINT("perpendicular mode not supported by this FDC.\n");
          }
  } /* perpendicular_mode */
  
  static int fifo_depth = 0xa;
  static int no_fifo;
  
  static int fdc_configure(void)
  {
          /* Turn on FIFO */
          output_byte(FD_CONFIGURE);
          if (need_more_output() != MORE_OUTPUT)
                  return 0;
          output_byte(0);
          output_byte(0x10 | (no_fifo & 0x20) | (fifo_depth & 0xf));
          output_byte(0); /* pre-compensation from track 
                             0 upwards */
          return 1;
  }       
  
  #define NOMINAL_DTR 500
  
  /* Issue a "SPECIFY" command to set the step rate time, head unload time,
   * head load time, and DMA disable flag to values needed by floppy.
   *
   * The value "dtr" is the data transfer rate in Kbps.  It is needed
   * to account for the data rate-based scaling done by the 82072 and 82077
   * FDC types.  This parameter is ignored for other types of FDCs (i.e.
   * 8272a).
   *
   * Note that changing the data transfer rate has a (probably deleterious)
   * effect on the parameters subject to scaling for 82072/82077 FDCs, so
   * fdc_specify is called again after each data transfer rate
   * change.
   *
   * srt: 1000 to 16000 in microseconds
   * hut: 16 to 240 milliseconds
   * hlt: 2 to 254 milliseconds
   *
   * These values are rounded up to the next highest available delay time.
   */
  static void fdc_specify(void)
  {
          unsigned char spec1, spec2;
          unsigned long srt, hlt, hut;
          unsigned long dtr = NOMINAL_DTR;
          unsigned long scale_dtr = NOMINAL_DTR;
          int hlt_max_code = 0x7f;
          int hut_max_code = 0xf;
  
          if (FDCS->need_configure && FDCS->version >= FDC_82072A) {
                  fdc_configure();
                  FDCS->need_configure = 0;
                  /*DPRINT("FIFO enabled\n");*/
          }
  
          switch (raw_cmd->rate & 0x03) {
                  case 3:
                          dtr = 1000;
                          break;
                  case 1:
                          dtr = 300;
                          if (FDCS->version >= FDC_82078) {
                                  /* chose the default rate table, not the one
                                   * where 1 = 2 Mbps */
                                  output_byte(FD_DRIVESPEC);
                                  if (need_more_output() == MORE_OUTPUT) {
                                          output_byte(UNIT(current_drive));
                                          output_byte(0xc0);
                                  }
                          }
                          break;
                  case 2:
                          dtr = 250;
                          break;
          }
  
          if (FDCS->version >= FDC_82072) {
                  scale_dtr = dtr;
                  hlt_max_code = 0x00; /* 0==256msec*dtr0/dtr (not linear!) */
                  hut_max_code = 0x0; /* 0==256msec*dtr0/dtr (not linear!) */
          }
  
          /* Convert step rate from microseconds to milliseconds and 4 bits */
          srt = 16 - (DP->srt*scale_dtr/1000 + NOMINAL_DTR - 1)/NOMINAL_DTR;
          if( slow_floppy ) {
                  srt = srt / 4;
          }
          SUPBOUND(srt, 0xf);
          INFBOUND(srt, 0);
  
          hlt = (DP->hlt*scale_dtr/2 + NOMINAL_DTR - 1)/NOMINAL_DTR;
          if (hlt < 0x01)
                  hlt = 0x01;
          else if (hlt > 0x7f)
                  hlt = hlt_max_code;
  
          hut = (DP->hut*scale_dtr/16 + NOMINAL_DTR - 1)/NOMINAL_DTR;
          if (hut < 0x1)
                  hut = 0x1;
          else if (hut > 0xf)
                  hut = hut_max_code;
  
          spec1 = (srt << 4) | hut;
          spec2 = (hlt << 1) | (use_virtual_dma & 1);
  
          /* If these parameters did not change, just return with success */
          if (FDCS->spec1 != spec1 || FDCS->spec2 != spec2) {
                  /* Go ahead and set spec1 and spec2 */
                  output_byte(FD_SPECIFY);
                  output_byte(FDCS->spec1 = spec1);
                  output_byte(FDCS->spec2 = spec2);
          }
  } /* fdc_specify */
  
  /* Set the FDC's data transfer rate on behalf of the specified drive.
   * NOTE: with 82072/82077 FDCs, changing the data rate requires a reissue
   * of the specify command (i.e. using the fdc_specify function).
   */
  static int fdc_dtr(void)
  {
          /* If data rate not already set to desired value, set it. */
          if ((raw_cmd->rate & 3) == FDCS->dtr)
                  return 0;
  
          /* Set dtr */
          fd_outb(raw_cmd->rate & 3, FD_DCR);
  
          /* TODO: some FDC/drive combinations (C&T 82C711 with TEAC 1.2MB)
           * need a stabilization period of several milliseconds to be
           * enforced after data rate changes before R/W operations.
           * Pause 5 msec to avoid trouble. (Needs to be 2 jiffies)
           */
          FDCS->dtr = raw_cmd->rate & 3;
          return(fd_wait_for_completion(jiffies+2UL*HZ/100,
                                     (timeout_fn) floppy_ready));
  } /* fdc_dtr */
  
  static void tell_sector(void)
  {
          printk(": track %d, head %d, sector %d, size %d",
                 R_TRACK, R_HEAD, R_SECTOR, R_SIZECODE);
  } /* tell_sector */
  
  
  /*
   * OK, this error interpreting routine is called after a
   * DMA read/write has succeeded
   * or failed, so we check the results, and copy any buffers.
   * hhb: Added better error reporting.
   * ak: Made this into a separate routine.
   */
  static int interpret_errors(void)
  {
          char bad;
  
          if (inr!=7) {
                  DPRINT("-- FDC reply error");
                  FDCS->reset = 1;
                  return 1;
          }
  
          /* check IC to find cause of interrupt */
          switch (ST0 & ST0_INTR) {
                  case 0x40:      /* error occurred during command execution */
                          if (ST1 & ST1_EOC)
                                  return 0; /* occurs with pseudo-DMA */
                          bad = 1;
                          if (ST1 & ST1_WP) {
                                  DPRINT("Drive is write protected\n");
                                  CLEARF(FD_DISK_WRITABLE);
                                  cont->done(0);
                                  bad = 2;
                          } else if (ST1 & ST1_ND) {
                                  SETF(FD_NEED_TWADDLE);
                          } else if (ST1 & ST1_OR) {
                                  if (DP->flags & FTD_MSG)
                                          DPRINT("Over/Underrun - retrying\n");
                                  bad = 0;
                          }else if (*errors >= DP->max_errors.reporting){
                                  DPRINT("");
                                  if (ST0 & ST0_ECE) {
                                          printk("Recalibrate failed!");
                                  } else if (ST2 & ST2_CRC) {
                                          printk("data CRC error");
                                          tell_sector();
                                  } else if (ST1 & ST1_CRC) {
                                          printk("CRC error");
                                          tell_sector();
                                  } else if ((ST1 & (ST1_MAM|ST1_ND)) || (ST2 & ST2_MAM)) {
                                          if (!probing) {
                                                  printk("sector not found");
                                                  tell_sector();
                                          } else
                                                  printk("probe failed...");
                                  } else if (ST2 & ST2_WC) {      /* seek error */
                                          printk("wrong cylinder");
                                  } else if (ST2 & ST2_BC) {      /* cylinder marked as bad */
                                          printk("bad cylinder");
                                  } else {
                                          printk("unknown error. ST[0..2] are: 0x%x 0x%x 0x%x", ST0, ST1, ST2);
                                          tell_sector();
                                  }
                                  printk("\n");
  
                          }
                          if (ST2 & ST2_WC || ST2 & ST2_BC)
                                  /* wrong cylinder => recal */
                                  DRS->track = NEED_2_RECAL;
                          return bad;
                  case 0x80: /* invalid command given */
                          DPRINT("Invalid FDC command given!\n");
                          cont->done(0);
                          return 2;
                  case 0xc0:
                          DPRINT("Abnormal termination caused by polling\n");
                          cont->error();
                          return 2;
                  default: /* (0) Normal command termination */
                          return 0;
          }
  }
  
  /*
   * This routine is called when everything should be correctly set up
   * for the transfer (i.e. floppy motor is on, the correct floppy is
   * selected, and the head is sitting on the right track).
   */
  static void setup_rw_floppy(void)
  {
          int i,r, flags,dflags;
          unsigned long ready_date;
          timeout_fn function;
  
          flags = raw_cmd->flags;
          if (flags & (FD_RAW_READ | FD_RAW_WRITE))
                  flags |= FD_RAW_INTR;
  
          if ((flags & FD_RAW_SPIN) && !(flags & FD_RAW_NO_MOTOR)){
                  ready_date = DRS->spinup_date + DP->spinup;
                  /* If spinup will take a long time, rerun scandrives
                   * again just before spinup completion. Beware that
                   * after scandrives, we must again wait for selection.
                   */
                  if ((signed) (ready_date - jiffies) > DP->select_delay){
                          ready_date -= DP->select_delay;
                          function = (timeout_fn) floppy_start;
                  } else
                          function = (timeout_fn) setup_rw_floppy;
  
                  /* wait until the floppy is spinning fast enough */
                  if (fd_wait_for_completion(ready_date,function))
                          return;
          }
          dflags = DRS->flags;
  
          if ((flags & FD_RAW_READ) || (flags & FD_RAW_WRITE))
                  setup_DMA();
  
          if (flags & FD_RAW_INTR)
                  SET_INTR(main_command_interrupt);
  
          r=0;
          for (i=0; i< raw_cmd->cmd_count; i++)
                  r|=output_byte(raw_cmd->cmd[i]);
  
  #ifdef DEBUGT
          debugt("rw_command: ");
  #endif
          if (r){
                  cont->error();
                  reset_fdc();
                  return;
          }
  
          if (!(flags & FD_RAW_INTR)){
                  inr = result();
                  cont->interrupt();
          } else if (flags & FD_RAW_NEED_DISK)
                  fd_watchdog();
  }
  
  static int blind_seek;
  
  /*
   * This is the routine called after every seek (or recalibrate) interrupt
   * from the floppy controller.
   */
  static void seek_interrupt(void)
  {
  #ifdef DEBUGT
          debugt("seek interrupt:");
  #endif
          if (inr != 2 || (ST0 & 0xF8) != 0x20) {
                  DPRINT("seek failed\n");
                  DRS->track = NEED_2_RECAL;
                  cont->error();
                  cont->redo();
                  return;
          }
          if (DRS->track >= 0 && DRS->track != ST1 && !blind_seek){
  #ifdef DCL_DEBUG
                  if (DP->flags & FD_DEBUG){
                          DPRINT("clearing NEWCHANGE flag because of effective seek\n");
                          DPRINT("jiffies=%lu\n", jiffies);
                  }
  #endif
                  CLEARF(FD_DISK_NEWCHANGE); /* effective seek */
                  DRS->select_date = jiffies;
          }
          DRS->track = ST1;
          floppy_ready();
  }
  
  static void check_wp(void)
  {
          if (TESTF(FD_VERIFY)) {
                  /* check write protection */
                  output_byte(FD_GETSTATUS);
                  output_byte(UNIT(current_drive));
                  if (result() != 1){
                          FDCS->reset = 1;
                          return;
                  }
                  CLEARF(FD_VERIFY);
                  CLEARF(FD_NEED_TWADDLE);
  #ifdef DCL_DEBUG
                  if (DP->flags & FD_DEBUG){
                          DPRINT("checking whether disk is write protected\n");
                          DPRINT("wp=%x\n",ST3 & 0x40);
                  }
  #endif
                  if (!(ST3  & 0x40))
                          SETF(FD_DISK_WRITABLE);
                  else
                          CLEARF(FD_DISK_WRITABLE);
          }
  }
  
  static void seek_floppy(void)
  {
          int track;
  
          blind_seek=0;
  
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("calling disk change from seek\n");
          }
  #endif
  
          if (!TESTF(FD_DISK_NEWCHANGE) &&
              disk_change(current_drive) &&
              (raw_cmd->flags & FD_RAW_NEED_DISK)){
                  /* the media changed flag should be cleared after the seek.
                   * If it isn't, this means that there is really no disk in
                   * the drive.
                   */
                  SETF(FD_DISK_CHANGED);
                  cont->done(0);
                  cont->redo();
                  return;
          }
          if (DRS->track <= NEED_1_RECAL){
                  recalibrate_floppy();
                  return;
          } else if (TESTF(FD_DISK_NEWCHANGE) &&
                     (raw_cmd->flags & FD_RAW_NEED_DISK) &&
                     (DRS->track <= NO_TRACK || DRS->track == raw_cmd->track)) {
                  /* we seek to clear the media-changed condition. Does anybody
                   * know a more elegant way, which works on all drives? */
                  if (raw_cmd->track)
                          track = raw_cmd->track - 1;
                  else {
                          if (DP->flags & FD_SILENT_DCL_CLEAR){
                                  set_dor(fdc, ~(0x10 << UNIT(current_drive)), 0);
                                  blind_seek = 1;
                                  raw_cmd->flags |= FD_RAW_NEED_SEEK;
                          }
                          track = 1;
                  }
          } else {
                  check_wp();
                  if (raw_cmd->track != DRS->track &&
                      (raw_cmd->flags & FD_RAW_NEED_SEEK))
                          track = raw_cmd->track;
                  else {
                          setup_rw_floppy();
                          return;
                  }
          }
  
          SET_INTR(seek_interrupt);
          output_byte(FD_SEEK);
          output_byte(UNIT(current_drive));
          LAST_OUT(track);
  #ifdef DEBUGT
          debugt("seek command:");
  #endif
  }
  
  static void recal_interrupt(void)
  {
  #ifdef DEBUGT
          debugt("recal interrupt:");
  #endif
          if (inr !=2)
                  FDCS->reset = 1;
          else if (ST0 & ST0_ECE) {
                  switch(DRS->track){
                          case NEED_1_RECAL:
  #ifdef DEBUGT
                                  debugt("recal interrupt need 1 recal:");
  #endif
                                  /* after a second recalibrate, we still haven't
                                   * reached track 0. Probably no drive. Raise an
                                   * error, as failing immediately might upset
                                   * computers possessed by the Devil :-) */
                                  cont->error();
                                  cont->redo();
                                  return;
                          case NEED_2_RECAL:
  #ifdef DEBUGT
                                  debugt("recal interrupt need 2 recal:");
  #endif
                                  /* If we already did a recalibrate,
                                   * and we are not at track 0, this
                                   * means we have moved. (The only way
                                   * not to move at recalibration is to
                                   * be already at track 0.) Clear the
                                   * new change flag */
  #ifdef DCL_DEBUG
                                  if (DP->flags & FD_DEBUG){
                                          DPRINT("clearing NEWCHANGE flag because of second recalibrate\n");
                                  }
  #endif
  
                                  CLEARF(FD_DISK_NEWCHANGE);
                                  DRS->select_date = jiffies;
                                  /* fall through */
                          default:
  #ifdef DEBUGT
                                  debugt("recal interrupt default:");
  #endif
                                  /* Recalibrate moves the head by at
                                   * most 80 steps. If after one
                                   * recalibrate we don't have reached
                                   * track 0, this might mean that we
                                   * started beyond track 80.  Try
                                   * again.  */
                                  DRS->track = NEED_1_RECAL;
                                  break;
                  }
          } else
                  DRS->track = ST1;
          floppy_ready();
  }
  
  static void print_result(char *message, int inr)
  {
          int i;
  
          DPRINT("%s ", message);
          if (inr >= 0)
                  for (i=0; i<inr; i++)
                          printk("repl[%d]=%x ", i, reply_buffer[i]);
          printk("\n");
  }
  
  /* interrupt handler. Note that this can be called externally on the Sparc */
  void floppy_interrupt(int irq, void *dev_id, struct pt_regs * regs)
  {
          void (*handler)(void) = DEVICE_INTR;
          int do_print;
          unsigned long f;
  
          lasthandler = handler;
          interruptjiffies = jiffies;
  
          f=claim_dma_lock();
          fd_disable_dma();
          release_dma_lock(f);
          
          floppy_enable_hlt();
          CLEAR_INTR;
          if (fdc >= N_FDC || FDCS->address == -1){
                  /* we don't even know which FDC is the culprit */
                  printk("DOR0=%x\n", fdc_state[0].dor);
                  printk("floppy interrupt on bizarre fdc %d\n",fdc);
                  printk("handler=%p\n", handler);
                  is_alive("bizarre fdc");
                  return;
          }
  
          FDCS->reset = 0;
          /* We have to clear the reset flag here, because apparently on boxes
           * with level triggered interrupts (PS/2, Sparc, ...), it is needed to
           * emit SENSEI's to clear the interrupt line. And FDCS->reset blocks the
           * emission of the SENSEI's.
           * It is OK to emit floppy commands because we are in an interrupt
           * handler here, and thus we have to fear no interference of other
           * activity.
           */
  
          do_print = !handler && print_unex && !initialising;
  
          inr = result();
          if (do_print)
                  print_result("unexpected interrupt", inr);
          if (inr == 0){
                  int max_sensei = 4;
                  do {
                          output_byte(FD_SENSEI);
                          inr = result();
                          if (do_print)
                                  print_result("sensei", inr);
                          max_sensei--;
                  } while ((ST0 & 0x83) != UNIT(current_drive) && inr == 2 && max_sensei);
          }
          if (handler) {
                  schedule_bh( (void *)(void *) handler);
          } else
                  FDCS->reset = 1;
          is_alive("normal interrupt end");
  }
  
  static void recalibrate_floppy(void)
  {
  #ifdef DEBUGT
          debugt("recalibrate floppy:");
  #endif
          SET_INTR(recal_interrupt);
          output_byte(FD_RECALIBRATE);
          LAST_OUT(UNIT(current_drive));
  }
  
  /*
   * Must do 4 FD_SENSEIs after reset because of ``drive polling''.
   */
  static void reset_interrupt(void)
  {
  #ifdef DEBUGT
          debugt("reset interrupt:");
  #endif
          result();               /* get the status ready for set_fdc */
          if (FDCS->reset) {
                  printk("reset set in interrupt, calling %p\n", cont->error);
                  cont->error(); /* a reset just after a reset. BAD! */
          }
          cont->redo();
  }
  
  /*
   * reset is done by pulling bit 2 of DOR low for a while (old FDCs),
   * or by setting the self clearing bit 7 of STATUS (newer FDCs)
   */
  static void reset_fdc(void)
  {
          unsigned long flags;
          
          SET_INTR(reset_interrupt);
          FDCS->reset = 0;
          reset_fdc_info(0);
  
          /* Pseudo-DMA may intercept 'reset finished' interrupt.  */
          /* Irrelevant for systems with true DMA (i386).          */
          
          flags=claim_dma_lock();
          fd_disable_dma();
          release_dma_lock(flags);
  
          if (FDCS->version >= FDC_82072A)
                  fd_outb(0x80 | (FDCS->dtr &3), FD_STATUS);
          else {
                  fd_outb(FDCS->dor & ~0x04, FD_DOR);
                  udelay(FD_RESET_DELAY);
                  fd_outb(FDCS->dor, FD_DOR);
          }
  }
  
  static void show_floppy(void)
  {
          int i;
  
          printk("\n");
          printk("floppy driver state\n");
          printk("-------------------\n");
          printk("now=%lu last interrupt=%lu diff=%lu last called handler=%p\n",
                 jiffies, interruptjiffies, jiffies-interruptjiffies, lasthandler);
  
  
  #ifdef FLOPPY_SANITY_CHECK
          printk("timeout_message=%s\n", timeout_message);
          printk("last output bytes:\n");
          for (i=0; i < OLOGSIZE; i++)
                  printk("%2x %2x %lu\n",
                         output_log[(i+output_log_pos) % OLOGSIZE].data,
                         output_log[(i+output_log_pos) % OLOGSIZE].status,
                         output_log[(i+output_log_pos) % OLOGSIZE].jiffies);
          printk("last result at %lu\n", resultjiffies);
          printk("last redo_fd_request at %lu\n", lastredo);
          for (i=0; i<resultsize; i++){
                  printk("%2x ", reply_buffer[i]);
          }
          printk("\n");
  #endif
  
          printk("status=%x\n", fd_inb(FD_STATUS));
          printk("fdc_busy=%lu\n", fdc_busy);
          if (DEVICE_INTR)
                  printk("DEVICE_INTR=%p\n", DEVICE_INTR);
          if (floppy_tq.sync)
                  printk("floppy_tq.routine=%p\n", floppy_tq.routine);
          if (timer_pending(&fd_timer))
                  printk("fd_timer.function=%p\n", fd_timer.function);
          if (timer_pending(&fd_timeout)){
                  printk("timer_function=%p\n",fd_timeout.function);
                  printk("expires=%lu\n",fd_timeout.expires-jiffies);
                  printk("now=%lu\n",jiffies);
          }
          printk("cont=%p\n", cont);
          printk("CURRENT=%p\n", CURRENT);
          printk("command_status=%d\n", command_status);
          printk("\n");
  }
  
  static void floppy_shutdown(void)
  {
          unsigned long flags;
          
          if (!initialising)
                  show_floppy();
          cancel_activity();
  
          floppy_enable_hlt();
          
          flags=claim_dma_lock();
          fd_disable_dma();
          release_dma_lock(flags);
          
          /* avoid dma going to a random drive after shutdown */
  
          if (!initialising)
                  DPRINT("floppy timeout called\n");
          FDCS->reset = 1;
          if (cont){
                  cont->done(0);
                  cont->redo(); /* this will recall reset when needed */
          } else {
                  printk("no cont in shutdown!\n");
                  process_fd_request();
          }
          is_alive("floppy shutdown");
  }
  /*typedef void (*timeout_fn)(unsigned long);*/
  
  /* start motor, check media-changed condition and write protection */
  static int start_motor(void (*function)(void) )
  {
          int mask, data;
  
          mask = 0xfc;
          data = UNIT(current_drive);
          if (!(raw_cmd->flags & FD_RAW_NO_MOTOR)){
                  if (!(FDCS->dor & (0x10 << UNIT(current_drive)))){
                          set_debugt();
                          /* no read since this drive is running */
                          DRS->first_read_date = 0;
                          /* note motor start time if motor is not yet running */
                          DRS->spinup_date = jiffies;
                          data |= (0x10 << UNIT(current_drive));
                  }
          } else
                  if (FDCS->dor & (0x10 << UNIT(current_drive)))
                          mask &= ~(0x10 << UNIT(current_drive));
  
          /* starts motor and selects floppy */
          del_timer(motor_off_timer + current_drive);
          set_dor(fdc, mask, data);
  
          /* wait_for_completion also schedules reset if needed. */
          return(fd_wait_for_completion(DRS->select_date+DP->select_delay,
                                     (timeout_fn) function));
  }
  
  static void floppy_ready(void)
  {
          CHECK_RESET;
          if (start_motor(floppy_ready)) return;
          if (fdc_dtr()) return;
  
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("calling disk change from floppy_ready\n");
          }
  #endif
          if (!(raw_cmd->flags & FD_RAW_NO_MOTOR) &&
             disk_change(current_drive) &&
             !DP->select_delay)
                  twaddle(); /* this clears the dcl on certain drive/controller
                              * combinations */
  
  #ifdef fd_chose_dma_mode
          if ((raw_cmd->flags & FD_RAW_READ) || 
              (raw_cmd->flags & FD_RAW_WRITE))
          {
                  unsigned long flags = claim_dma_lock();
                  fd_chose_dma_mode(raw_cmd->kernel_data,
                                    raw_cmd->length);
                  release_dma_lock(flags);
          }
  #endif
  
          if (raw_cmd->flags & (FD_RAW_NEED_SEEK | FD_RAW_NEED_DISK)){
                  perpendicular_mode();
                  fdc_specify(); /* must be done here because of hut, hlt ... */
                  seek_floppy();
          } else {
                  if ((raw_cmd->flags & FD_RAW_READ) || 
                      (raw_cmd->flags & FD_RAW_WRITE))
                          fdc_specify();
                  setup_rw_floppy();
          }
  }
  
  static void floppy_start(void)
  {
          reschedule_timeout(CURRENTD, "floppy start", 0);
  
          scandrives();
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("setting NEWCHANGE in floppy_start\n");
          }
  #endif
          SETF(FD_DISK_NEWCHANGE);
          floppy_ready();
  }
  
  /*
   * ========================================================================
   * here ends the bottom half. Exported routines are:
   * floppy_start, floppy_off, floppy_ready, lock_fdc, unlock_fdc, set_fdc,
   * start_motor, reset_fdc, reset_fdc_info, interpret_errors.
   * Initialization also uses output_byte, result, set_dor, floppy_interrupt
   * and set_dor.
   * ========================================================================
   */
  /*
   * General purpose continuations.
   * ==============================
   */
  
  static void do_wakeup(void)
  {
          reschedule_timeout(MAXTIMEOUT, "do wakeup", 0);
          cont = 0;
          command_status += 2;
          wake_up(&command_done);
  }
  
  static struct cont_t wakeup_cont={
          empty,
          do_wakeup,
          empty,
          (done_f)empty
  };
  
  
  static struct cont_t intr_cont={
          empty,
          process_fd_request,
          empty,
          (done_f) empty
  };
  
  static int wait_til_done(void (*handler)(void), int interruptible)
  {
          int ret;
  
          schedule_bh((void *)(void *)handler);
  
          if (command_status < 2 && NO_SIGNAL) {
                  DECLARE_WAITQUEUE(wait, current);
  
                  add_wait_queue(&command_done, &wait);
                  for (;;) {
                          set_current_state(interruptible?
                                            TASK_INTERRUPTIBLE:
                                            TASK_UNINTERRUPTIBLE);
  
                          if (command_status >= 2 || !NO_SIGNAL)
                                  break;
  
                          is_alive("wait_til_done");
  
                          schedule();
                  }
  
                  set_current_state(TASK_RUNNING);
                  remove_wait_queue(&command_done, &wait);
          }
  
          if (command_status < 2){
                  cancel_activity();
                  cont = &intr_cont;
                  reset_fdc();
                  return -EINTR;
          }
  
          if (FDCS->reset)
                  command_status = FD_COMMAND_ERROR;
          if (command_status == FD_COMMAND_OKAY)
                  ret=0;
          else
                  ret=-EIO;
          command_status = FD_COMMAND_NONE;
          return ret;
  }
  
  static void generic_done(int result)
  {
          command_status = result;
          cont = &wakeup_cont;
  }
  
  static void generic_success(void)
  {
          cont->done(1);
  }
  
  static void generic_failure(void)
  {
          cont->done(0);
  }
  
  static void success_and_wakeup(void)
  {
          generic_success();
          cont->redo();
  }
  
  
  /*
   * formatting and rw support.
   * ==========================
   */
  
  static int next_valid_format(void)
  {
          int probed_format;
  
          probed_format = DRS->probed_format;
          while(1){
                  if (probed_format >= 8 ||
                       !DP->autodetect[probed_format]){
                          DRS->probed_format = 0;
                          return 1;
                  }
                  if (floppy_type[DP->autodetect[probed_format]].sect){
                          DRS->probed_format = probed_format;
                          return 0;
                  }
                  probed_format++;
          }
  }
  
  static void bad_flp_intr(void)
  {
          if (probing){
                  DRS->probed_format++;
                  if (!next_valid_format())
                          return;
          }
          (*errors)++;
          INFBOUND(DRWE->badness, *errors);
          if (*errors > DP->max_errors.abort)
                  cont->done(0);
          if (*errors > DP->max_errors.reset)
                  FDCS->reset = 1;
          else if (*errors > DP->max_errors.recal)
                  DRS->track = NEED_2_RECAL;
  }
  
  static void set_floppy(kdev_t device)
  {
          if (TYPE(device))
                  _floppy = TYPE(device) + floppy_type;
          else
                  _floppy = current_type[ DRIVE(device) ];
  }
  
  /*
   * formatting support.
   * ===================
   */
  static void format_interrupt(void)
  {
          switch (interpret_errors()){
                  case 1:
                          cont->error();
                  case 2:
                          break;
                  case 0:
                          cont->done(1);
          }
          cont->redo();
  }
  
  #define CODE2SIZE (ssize = ((1 << SIZECODE) + 3) >> 2)
  #define FM_MODE(x,y) ((y) & ~(((x)->rate & 0x80) >>1))
  #define CT(x) ((x) | 0xc0)
  static void setup_format_params(int track)
  {
          struct fparm {
                  unsigned char track,head,sect,size;
          } *here = (struct fparm *)floppy_track_buffer;
          int il,n;
          int count,head_shift,track_shift;
  
          raw_cmd = &default_raw_cmd;
          raw_cmd->track = track;
  
          raw_cmd->flags = FD_RAW_WRITE | FD_RAW_INTR | FD_RAW_SPIN |
                  FD_RAW_NEED_DISK | FD_RAW_NEED_SEEK;
          raw_cmd->rate = _floppy->rate & 0x43;
          raw_cmd->cmd_count = NR_F;
          COMMAND = FM_MODE(_floppy,FD_FORMAT);
          DR_SELECT = UNIT(current_drive) + PH_HEAD(_floppy,format_req.head);
          F_SIZECODE = FD_SIZECODE(_floppy);
          F_SECT_PER_TRACK = _floppy->sect << 2 >> F_SIZECODE;
          F_GAP = _floppy->fmt_gap;
          F_FILL = FD_FILL_BYTE;
  
          raw_cmd->kernel_data = floppy_track_buffer;
          raw_cmd->length = 4 * F_SECT_PER_TRACK;
  
          /* allow for about 30ms for data transport per track */
          head_shift  = (F_SECT_PER_TRACK + 5) / 6;
  
          /* a ``cylinder'' is two tracks plus a little stepping time */
          track_shift = 2 * head_shift + 3;
  
          /* position of logical sector 1 on this track */
          n = (track_shift * format_req.track + head_shift * format_req.head)
                  % F_SECT_PER_TRACK;
  
          /* determine interleave */
          il = 1;
          if (_floppy->fmt_gap < 0x22)
                  il++;
  
          /* initialize field */
          for (count = 0; count < F_SECT_PER_TRACK; ++count) {
                  here[count].track = format_req.track;
                  here[count].head = format_req.head;
                  here[count].sect = 0;
                  here[count].size = F_SIZECODE;
          }
          /* place logical sectors */
          for (count = 1; count <= F_SECT_PER_TRACK; ++count) {
                  here[n].sect = count;
                  n = (n+il) % F_SECT_PER_TRACK;
                  if (here[n].sect) { /* sector busy, find next free sector */
                          ++n;
                          if (n>= F_SECT_PER_TRACK) {
                                  n-=F_SECT_PER_TRACK;
                                  while (here[n].sect) ++n;
                          }
                  }
          }
  }
  
  static void redo_format(void)
  {
          buffer_track = -1;
          setup_format_params(format_req.track << STRETCH(_floppy));
          floppy_start();
  #ifdef DEBUGT
          debugt("queue format request");
  #endif
  }
  
  static struct cont_t format_cont={
          format_interrupt,
          redo_format,
          bad_flp_intr,
          generic_done };
  
  static int do_format(kdev_t device, struct format_descr *tmp_format_req)
  {
          int ret;
          int drive=DRIVE(device);
  
          LOCK_FDC(drive,1);
          set_floppy(device);
          if (!_floppy ||
              _floppy->track > DP->tracks ||
              tmp_format_req->track >= _floppy->track ||
              tmp_format_req->head >= _floppy->head ||
              (_floppy->sect << 2) % (1 <<  FD_SIZECODE(_floppy)) ||
              !_floppy->fmt_gap) {
                  process_fd_request();
                  return -EINVAL;
          }
          format_req = *tmp_format_req;
          format_errors = 0;
          cont = &format_cont;
          errors = &format_errors;
          IWAIT(redo_format);
          process_fd_request();
          return ret;
  }
  
  /*
   * Buffer read/write and support
   * =============================
   */
  
  /* new request_done. Can handle physical sectors which are smaller than a
   * logical buffer */
  static void request_done(int uptodate)
  {
          int block;
          unsigned long flags;
  
          probing = 0;
          reschedule_timeout(MAXTIMEOUT, "request done %d", uptodate);
  
          if (QUEUE_EMPTY){
                  DPRINT("request list destroyed in floppy request done\n");
                  return;
          }
  
          if (uptodate){
                  /* maintain values for invalidation on geometry
                   * change */
                  block = current_count_sectors + CURRENT->sector;
                  INFBOUND(DRS->maxblock, block);
                  if (block > _floppy->sect)
                          DRS->maxtrack = 1;
  
                  /* unlock chained buffers */
                  spin_lock_irqsave(&io_request_lock, flags);
                  while (current_count_sectors && !QUEUE_EMPTY &&
                         current_count_sectors >= CURRENT->current_nr_sectors){
                          current_count_sectors -= CURRENT->current_nr_sectors;
                          CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
                          CURRENT->sector += CURRENT->current_nr_sectors;
                          end_request(1);
                  }
                  spin_unlock_irqrestore(&io_request_lock, flags);
  
                  if (current_count_sectors && !QUEUE_EMPTY){
                          /* "unlock" last subsector */
                          CURRENT->buffer += current_count_sectors <<9;
                          CURRENT->current_nr_sectors -= current_count_sectors;
                          CURRENT->nr_sectors -= current_count_sectors;
                          CURRENT->sector += current_count_sectors;
                          return;
                  }
  
                  if (current_count_sectors && QUEUE_EMPTY)
                          DPRINT("request list destroyed in floppy request done\n");
  
          } else {
                  if (CURRENT->cmd == WRITE) {
                          /* record write error information */
                          DRWE->write_errors++;
                          if (DRWE->write_errors == 1) {
                                  DRWE->first_error_sector = CURRENT->sector;
                                  DRWE->first_error_generation = DRS->generation;
                          }
                          DRWE->last_error_sector = CURRENT->sector;
                          DRWE->last_error_generation = DRS->generation;
                  }
                  spin_lock_irqsave(&io_request_lock, flags);
                  end_request(0);
                  spin_unlock_irqrestore(&io_request_lock, flags);
          }
  }
  
  /* Interrupt handler evaluating the result of the r/w operation */
  static void rw_interrupt(void)
  {
          int nr_sectors, ssize, eoc, heads;
  
          if (R_HEAD >= 2) {
              /* some Toshiba floppy controllers occasionnally seem to
               * return bogus interrupts after read/write operations, which
               * can be recognized by a bad head number (>= 2) */
               return;
          }  
  
          if (!DRS->first_read_date)
                  DRS->first_read_date = jiffies;
  
          nr_sectors = 0;
          CODE2SIZE;
  
          if (ST1 & ST1_EOC)
                  eoc = 1;
          else
                  eoc = 0;
  
          if (COMMAND & 0x80)
                  heads = 2;
          else
                  heads = 1;
  
          nr_sectors = (((R_TRACK-TRACK) * heads +
                                     R_HEAD-HEAD) * SECT_PER_TRACK +
                                     R_SECTOR-SECTOR + eoc) << SIZECODE >> 2;
  
  #ifdef FLOPPY_SANITY_CHECK
          if (nr_sectors / ssize > 
                  (in_sector_offset + current_count_sectors + ssize - 1) / ssize) {
                  DPRINT("long rw: %x instead of %lx\n",
                          nr_sectors, current_count_sectors);
                  printk("rs=%d s=%d\n", R_SECTOR, SECTOR);
                  printk("rh=%d h=%d\n", R_HEAD, HEAD);
                  printk("rt=%d t=%d\n", R_TRACK, TRACK);
                  printk("heads=%d eoc=%d\n", heads, eoc);
                  printk("spt=%d st=%d ss=%d\n", SECT_PER_TRACK,
                         sector_t, ssize);
                  printk("in_sector_offset=%d\n", in_sector_offset);
          }
  #endif
  
          nr_sectors -= in_sector_offset;
          INFBOUND(nr_sectors,0);
          SUPBOUND(current_count_sectors, nr_sectors);
  
          switch (interpret_errors()){
                  case 2:
                          cont->redo();
                          return;
                  case 1:
                          if (!current_count_sectors){
                                  cont->error();
                                  cont->redo();
                                  return;
                          }
                          break;
                  case 0:
                          if (!current_count_sectors){
                                  cont->redo();
                                  return;
                          }
                          current_type[current_drive] = _floppy;
                          floppy_sizes[TOMINOR(current_drive) ]= 
                                  (_floppy->size+1)>>1;
                          break;
          }
  
          if (probing) {
                  if (DP->flags & FTD_MSG)
                          DPRINT("Auto-detected floppy type %s in fd%d\n",
                                  _floppy->name,current_drive);
                  current_type[current_drive] = _floppy;
                  floppy_sizes[TOMINOR(current_drive)] = (_floppy->size+1) >> 1;
                  probing = 0;
          }
  
          if (CT(COMMAND) != FD_READ || 
               raw_cmd->kernel_data == CURRENT->buffer){
                  /* transfer directly from buffer */
                  cont->done(1);
          } else if (CT(COMMAND) == FD_READ){
                  buffer_track = raw_cmd->track;
                  buffer_drive = current_drive;
                  INFBOUND(buffer_max, nr_sectors + sector_t);
          }
          cont->redo();
  }
  
  /* Compute maximal contiguous buffer size. */
  static int buffer_chain_size(void)
  {
          struct buffer_head *bh;
          int size;
          char *base;
  
          base = CURRENT->buffer;
          size = CURRENT->current_nr_sectors << 9;
          bh = CURRENT->bh;
  
          if (bh){
                  bh = bh->b_reqnext;
                  while (bh && bh->b_data == base + size){
                          size += bh->b_size;
                          bh = bh->b_reqnext;
                  }
          }
          return size >> 9;
  }
  
  /* Compute the maximal transfer size */
  static int transfer_size(int ssize, int max_sector, int max_size)
  {
          SUPBOUND(max_sector, sector_t + max_size);
  
          /* alignment */
          max_sector -= (max_sector % _floppy->sect) % ssize;
  
          /* transfer size, beginning not aligned */
          current_count_sectors = max_sector - sector_t ;
  
          return max_sector;
  }
  
  /*
   * Move data from/to the track buffer to/from the buffer cache.
   */
  static void copy_buffer(int ssize, int max_sector, int max_sector_2)
  {
          int remaining; /* number of transferred 512-byte sectors */
          struct buffer_head *bh;
          char *buffer, *dma_buffer;
          int size;
  
          max_sector = transfer_size(ssize,
                                     minimum(max_sector, max_sector_2),
                                     CURRENT->nr_sectors);
  
          if (current_count_sectors <= 0 && CT(COMMAND) == FD_WRITE &&
              buffer_max > sector_t + CURRENT->nr_sectors)
                  current_count_sectors = minimum(buffer_max - sector_t,
                                                  CURRENT->nr_sectors);
  
          remaining = current_count_sectors << 9;
  #ifdef FLOPPY_SANITY_CHECK
          if ((remaining >> 9) > CURRENT->nr_sectors  &&
              CT(COMMAND) == FD_WRITE){
                  DPRINT("in copy buffer\n");
                  printk("current_count_sectors=%ld\n", current_count_sectors);
                  printk("remaining=%d\n", remaining >> 9);
                  printk("CURRENT->nr_sectors=%ld\n",CURRENT->nr_sectors);
                  printk("CURRENT->current_nr_sectors=%ld\n",
                         CURRENT->current_nr_sectors);
                  printk("max_sector=%d\n", max_sector);
                  printk("ssize=%d\n", ssize);
          }
  #endif
  
          buffer_max = maximum(max_sector, buffer_max);
  
          dma_buffer = floppy_track_buffer + ((sector_t - buffer_min) << 9);
  
          bh = CURRENT->bh;
          size = CURRENT->current_nr_sectors << 9;
          buffer = CURRENT->buffer;
  
          while (remaining > 0){
                  SUPBOUND(size, remaining);
  #ifdef FLOPPY_SANITY_CHECK
                  if (dma_buffer + size >
                      floppy_track_buffer + (max_buffer_sectors << 10) ||
                      dma_buffer < floppy_track_buffer){
                          DPRINT("buffer overrun in copy buffer %d\n",
                                  (int) ((floppy_track_buffer - dma_buffer) >>9));
                          printk("sector_t=%d buffer_min=%d\n",
                                 sector_t, buffer_min);
                          printk("current_count_sectors=%ld\n",
                                 current_count_sectors);
                          if (CT(COMMAND) == FD_READ)
                                  printk("read\n");
                          if (CT(COMMAND) == FD_READ)
                                  printk("write\n");
                          break;
                  }
                  if (((unsigned long)buffer) % 512)
                          DPRINT("%p buffer not aligned\n", buffer);
  #endif
                  if (CT(COMMAND) == FD_READ)
                          memcpy(buffer, dma_buffer, size);
                  else
                          memcpy(dma_buffer, buffer, size);
                  remaining -= size;
                  if (!remaining)
                          break;
  
                  dma_buffer += size;
                  bh = bh->b_reqnext;
  #ifdef FLOPPY_SANITY_CHECK
                  if (!bh){
                          DPRINT("bh=null in copy buffer after copy\n");
                          break;
                  }
  #endif
                  size = bh->b_size;
                  buffer = bh->b_data;
          }
  #ifdef FLOPPY_SANITY_CHECK
          if (remaining){
                  if (remaining > 0)
                          max_sector -= remaining >> 9;
                  DPRINT("weirdness: remaining %d\n", remaining>>9);
          }
  #endif
  }
  
  #if 0
  static inline int check_dma_crossing(char *start, 
                                       unsigned long length, char *message)
  {
          if (CROSS_64KB(start, length)) {
                  printk("DMA xfer crosses 64KB boundary in %s %p-%p\n", 
                         message, start, start+length);
                  return 1;
          } else
                  return 0;
  }
  #endif
  
  /* work around a bug in pseudo DMA
   * (on some FDCs) pseudo DMA does not stop when the CPU stops
   * sending data.  Hence we need a different way to signal the
   * transfer length:  We use SECT_PER_TRACK.  Unfortunately, this
   * does not work with MT, hence we can only transfer one head at
   * a time
   */
  static void virtualdmabug_workaround(void)
  {
          int hard_sectors, end_sector;
  
          if(CT(COMMAND) == FD_WRITE) {
                  COMMAND &= ~0x80; /* switch off multiple track mode */
  
                  hard_sectors = raw_cmd->length >> (7 + SIZECODE);
                  end_sector = SECTOR + hard_sectors - 1;
  #ifdef FLOPPY_SANITY_CHECK
                  if(end_sector > SECT_PER_TRACK) {
                          printk("too many sectors %d > %d\n",
                                 end_sector, SECT_PER_TRACK);
                          return;
                  }
  #endif
                  SECT_PER_TRACK = end_sector; /* make sure SECT_PER_TRACK points
                                                * to end of transfer */
          }
  }
  
  /*
   * Formulate a read/write request.
   * this routine decides where to load the data (directly to buffer, or to
   * tmp floppy area), how much data to load (the size of the buffer, the whole
   * track, or a single sector)
   * All floppy_track_buffer handling goes in here. If we ever add track buffer
   * allocation on the fly, it should be done here. No other part should need
   * modification.
   */
  
  static int make_raw_rw_request(void)
  {
          int aligned_sector_t;
          int max_sector, max_size, tracksize, ssize;
  
          if(max_buffer_sectors == 0) {
                  printk("VFS: Block I/O scheduled on unopened device\n");
                  return 0;
          }
  
          set_fdc(DRIVE(CURRENT->rq_dev));
  
          raw_cmd = &default_raw_cmd;
          raw_cmd->flags = FD_RAW_SPIN | FD_RAW_NEED_DISK | FD_RAW_NEED_DISK |
                  FD_RAW_NEED_SEEK;
          raw_cmd->cmd_count = NR_RW;
          if (CURRENT->cmd == READ){
                  raw_cmd->flags |= FD_RAW_READ;
                  COMMAND = FM_MODE(_floppy,FD_READ);
          } else if (CURRENT->cmd == WRITE){
                  raw_cmd->flags |= FD_RAW_WRITE;
                  COMMAND = FM_MODE(_floppy,FD_WRITE);
          } else {
                  DPRINT("make_raw_rw_request: unknown command\n");
                  return 0;
          }
  
          max_sector = _floppy->sect * _floppy->head;
  
          TRACK = CURRENT->sector / max_sector;
          sector_t = CURRENT->sector % max_sector;
          if (_floppy->track && TRACK >= _floppy->track) {
                  if (CURRENT->current_nr_sectors & 1) {
                          current_count_sectors = 1;
                          return 1;
                  } else
                          return 0;
          }
          HEAD = sector_t / _floppy->sect;
  
          if (((_floppy->stretch & FD_SWAPSIDES) || TESTF(FD_NEED_TWADDLE)) &&
              sector_t < _floppy->sect)
                  max_sector = _floppy->sect;
  
          /* 2M disks have phantom sectors on the first track */
          if ((_floppy->rate & FD_2M) && (!TRACK) && (!HEAD)){
                  max_sector = 2 * _floppy->sect / 3;
                  if (sector_t >= max_sector){
                          current_count_sectors = minimum(_floppy->sect - sector_t,
                                                          CURRENT->nr_sectors);
                          return 1;
                  }
                  SIZECODE = 2;
          } else
                  SIZECODE = FD_SIZECODE(_floppy);
          raw_cmd->rate = _floppy->rate & 0x43;
          if ((_floppy->rate & FD_2M) &&
              (TRACK || HEAD) &&
              raw_cmd->rate == 2)
                  raw_cmd->rate = 1;
  
          if (SIZECODE)
                  SIZECODE2 = 0xff;
          else
                  SIZECODE2 = 0x80;
          raw_cmd->track = TRACK << STRETCH(_floppy);
          DR_SELECT = UNIT(current_drive) + PH_HEAD(_floppy,HEAD);
          GAP = _floppy->gap;
          CODE2SIZE;
          SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE;
          SECTOR = ((sector_t % _floppy->sect) << 2 >> SIZECODE) + 1;
  
          /* tracksize describes the size which can be filled up with sectors
           * of size ssize.
           */
          tracksize = _floppy->sect - _floppy->sect % ssize;
          if (tracksize < _floppy->sect){
                  SECT_PER_TRACK ++;
                  if (tracksize <= sector_t % _floppy->sect)
                          SECTOR--;
  
                  /* if we are beyond tracksize, fill up using smaller sectors */
                  while (tracksize <= sector_t % _floppy->sect){
                          while(tracksize + ssize > _floppy->sect){
                                  SIZECODE--;
                                  ssize >>= 1;
                          }
                          SECTOR++; SECT_PER_TRACK ++;
                          tracksize += ssize;
                  }
                  max_sector = HEAD * _floppy->sect + tracksize;
          } else if (!TRACK && !HEAD && !(_floppy->rate & FD_2M) && probing) {
                  max_sector = _floppy->sect;
          } else if (!HEAD && CT(COMMAND) == FD_WRITE) {
                  /* for virtual DMA bug workaround */
                  max_sector = _floppy->sect;
          }
  
          in_sector_offset = (sector_t % _floppy->sect) % ssize;
          aligned_sector_t = sector_t - in_sector_offset;
          max_size = CURRENT->nr_sectors;
          if ((raw_cmd->track == buffer_track) && 
              (current_drive == buffer_drive) &&
              (sector_t >= buffer_min) && (sector_t < buffer_max)) {
                  /* data already in track buffer */
                  if (CT(COMMAND) == FD_READ) {
                          copy_buffer(1, max_sector, buffer_max);
                          return 1;
                  }
          } else if (in_sector_offset || CURRENT->nr_sectors < ssize){
                  if (CT(COMMAND) == FD_WRITE){
                          if (sector_t + CURRENT->nr_sectors > ssize &&
                              sector_t + CURRENT->nr_sectors < ssize + ssize)
                                  max_size = ssize + ssize;
                          else
                                  max_size = ssize;
                  }
                  raw_cmd->flags &= ~FD_RAW_WRITE;
                  raw_cmd->flags |= FD_RAW_READ;
                  COMMAND = FM_MODE(_floppy,FD_READ);
          } else if ((unsigned long)CURRENT->buffer < MAX_DMA_ADDRESS) {
                  unsigned long dma_limit;
                  int direct, indirect;
  
                  indirect= transfer_size(ssize,max_sector,max_buffer_sectors*2) -
                          sector_t;
  
                  /*
                   * Do NOT use minimum() here---MAX_DMA_ADDRESS is 64 bits wide
                   * on a 64 bit machine!
                   */
                  max_size = buffer_chain_size();
                  dma_limit = (MAX_DMA_ADDRESS - ((unsigned long) CURRENT->buffer)) >> 9;
                  if ((unsigned long) max_size > dma_limit) {
                          max_size = dma_limit;
                  }
                  /* 64 kb boundaries */
                  if (CROSS_64KB(CURRENT->buffer, max_size << 9))
                          max_size = (K_64 - 
                                      ((unsigned long)CURRENT->buffer) % K_64)>>9;
                  direct = transfer_size(ssize,max_sector,max_size) - sector_t;
                  /*
                   * We try to read tracks, but if we get too many errors, we
                   * go back to reading just one sector at a time.
                   *
                   * This means we should be able to read a sector even if there
                   * are other bad sectors on this track.
                   */
                  if (!direct ||
                      (indirect * 2 > direct * 3 &&
                       *errors < DP->max_errors.read_track &&
                       /*!TESTF(FD_NEED_TWADDLE) &&*/
                       ((!probing || (DP->read_track&(1<<DRS->probed_format)))))){
                          max_size = CURRENT->nr_sectors;
                  } else {
                          raw_cmd->kernel_data = CURRENT->buffer;
                          raw_cmd->length = current_count_sectors << 9;
                          if (raw_cmd->length == 0){
                                  DPRINT("zero dma transfer attempted from make_raw_request\n");
                                  DPRINT("indirect=%d direct=%d sector_t=%d",
                                          indirect, direct, sector_t);
                                  return 0;
                          }
  /*                      check_dma_crossing(raw_cmd->kernel_data, 
                                             raw_cmd->length, 
                                             "end of make_raw_request [1]");*/
  
                          virtualdmabug_workaround();
                          return 2;
                  }
          }
  
          if (CT(COMMAND) == FD_READ)
                  max_size = max_sector; /* unbounded */
  
          /* claim buffer track if needed */
          if (buffer_track != raw_cmd->track ||  /* bad track */
              buffer_drive !=current_drive || /* bad drive */
              sector_t > buffer_max ||
              sector_t < buffer_min ||
              ((CT(COMMAND) == FD_READ ||
                (!in_sector_offset && CURRENT->nr_sectors >= ssize))&&
               max_sector > 2 * max_buffer_sectors + buffer_min &&
               max_size + sector_t > 2 * max_buffer_sectors + buffer_min)
              /* not enough space */){
                  buffer_track = -1;
                  buffer_drive = current_drive;
                  buffer_max = buffer_min = aligned_sector_t;
          }
          raw_cmd->kernel_data = floppy_track_buffer + 
                  ((aligned_sector_t-buffer_min)<<9);
  
          if (CT(COMMAND) == FD_WRITE){
                  /* copy write buffer to track buffer.
                   * if we get here, we know that the write
                   * is either aligned or the data already in the buffer
                   * (buffer will be overwritten) */
  #ifdef FLOPPY_SANITY_CHECK
                  if (in_sector_offset && buffer_track == -1)
                          DPRINT("internal error offset !=0 on write\n");
  #endif
                  buffer_track = raw_cmd->track;
                  buffer_drive = current_drive;
                  copy_buffer(ssize, max_sector, 2*max_buffer_sectors+buffer_min);
          } else
                  transfer_size(ssize, max_sector,
                                2*max_buffer_sectors+buffer_min-aligned_sector_t);
  
          /* round up current_count_sectors to get dma xfer size */
          raw_cmd->length = in_sector_offset+current_count_sectors;
          raw_cmd->length = ((raw_cmd->length -1)|(ssize-1))+1;
          raw_cmd->length <<= 9;
  #ifdef FLOPPY_SANITY_CHECK
          /*check_dma_crossing(raw_cmd->kernel_data, raw_cmd->length, 
            "end of make_raw_request");*/
          if ((raw_cmd->length < current_count_sectors << 9) ||
              (raw_cmd->kernel_data != CURRENT->buffer &&
               CT(COMMAND) == FD_WRITE &&
               (aligned_sector_t + (raw_cmd->length >> 9) > buffer_max ||
                aligned_sector_t < buffer_min)) ||
              raw_cmd->length % (128 << SIZECODE) ||
              raw_cmd->length <= 0 || current_count_sectors <= 0){
                  DPRINT("fractionary current count b=%lx s=%lx\n",
                          raw_cmd->length, current_count_sectors);
                  if (raw_cmd->kernel_data != CURRENT->buffer)
                          printk("addr=%d, length=%ld\n",
                                 (int) ((raw_cmd->kernel_data - 
                                         floppy_track_buffer) >> 9),
                                 current_count_sectors);
                  printk("st=%d ast=%d mse=%d msi=%d\n",
                         sector_t, aligned_sector_t, max_sector, max_size);
                  printk("ssize=%x SIZECODE=%d\n", ssize, SIZECODE);
                  printk("command=%x SECTOR=%d HEAD=%d, TRACK=%d\n",
                         COMMAND, SECTOR, HEAD, TRACK);
                  printk("buffer drive=%d\n", buffer_drive);
                  printk("buffer track=%d\n", buffer_track);
                  printk("buffer_min=%d\n", buffer_min);
                  printk("buffer_max=%d\n", buffer_max);
                  return 0;
          }
  
          if (raw_cmd->kernel_data != CURRENT->buffer){
                  if (raw_cmd->kernel_data < floppy_track_buffer ||
                      current_count_sectors < 0 ||
                      raw_cmd->length < 0 ||
                      raw_cmd->kernel_data + raw_cmd->length >
                      floppy_track_buffer + (max_buffer_sectors  << 10)){
                          DPRINT("buffer overrun in schedule dma\n");
                          printk("sector_t=%d buffer_min=%d current_count=%ld\n",
                                 sector_t, buffer_min,
                                 raw_cmd->length >> 9);
                          printk("current_count_sectors=%ld\n",
                                 current_count_sectors);
                          if (CT(COMMAND) == FD_READ)
                                  printk("read\n");
                          if (CT(COMMAND) == FD_READ)
                                  printk("write\n");
                          return 0;
                  }
          } else if (raw_cmd->length > CURRENT->nr_sectors << 9 ||
                     current_count_sectors > CURRENT->nr_sectors){
                  DPRINT("buffer overrun in direct transfer\n");
                  return 0;
          } else if (raw_cmd->length < current_count_sectors << 9){
                  DPRINT("more sectors than bytes\n");
                  printk("bytes=%ld\n", raw_cmd->length >> 9);
                  printk("sectors=%ld\n", current_count_sectors);
          }
          if (raw_cmd->length == 0){
                  DPRINT("zero dma transfer attempted from make_raw_request\n");
                  return 0;
          }
  #endif
  
          virtualdmabug_workaround();
          return 2;
  }
  
  static void redo_fd_request(void)
  {
  #define REPEAT {request_done(0); continue; }
          kdev_t device;
          int tmp;
  
          lastredo = jiffies;
          if (current_drive < N_DRIVE)
                  floppy_off(current_drive);
  
          if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE){
                  CLEAR_INTR;
                  unlock_fdc();
                  return;
          }
  
          while(1){
                  if (QUEUE_EMPTY) {
                          CLEAR_INTR;
                          unlock_fdc();
                          return;
                  }
                  if (MAJOR(CURRENT->rq_dev) != MAJOR_NR)
                          panic(DEVICE_NAME ": request list destroyed");
                  if (CURRENT->bh && !buffer_locked(CURRENT->bh))
                          panic(DEVICE_NAME ": block not locked");
  
                  device = CURRENT->rq_dev;
                  set_fdc(DRIVE(device));
                  reschedule_timeout(CURRENTD, "redo fd request", 0);
  
                  set_floppy(device);
                  raw_cmd = & default_raw_cmd;
                  raw_cmd->flags = 0;
                  if (start_motor(redo_fd_request)) return;
                  disk_change(current_drive);
                  if (test_bit(current_drive, &fake_change) ||
                     TESTF(FD_DISK_CHANGED)){
                          DPRINT("disk absent or changed during operation\n");
                          REPEAT;
                  }
                  if (!_floppy) { /* Autodetection */
                          if (!probing){
                                  DRS->probed_format = 0;
                                  if (next_valid_format()){
                                          DPRINT("no autodetectable formats\n");
                                          _floppy = NULL;
                                          REPEAT;
                                  }
                          }
                          probing = 1;
                          _floppy = floppy_type+DP->autodetect[DRS->probed_format];
                  } else
                          probing = 0;
                  errors = & (CURRENT->errors);
                  tmp = make_raw_rw_request();
                  if (tmp < 2){
                          request_done(tmp);
                          continue;
                  }
  
                  if (TESTF(FD_NEED_TWADDLE))
                          twaddle();
                  schedule_bh( (void *)(void *) floppy_start);
  #ifdef DEBUGT
                  debugt("queue fd request");
  #endif
                  return;
          }
  #undef REPEAT
  }
  
  static struct cont_t rw_cont={
          rw_interrupt,
          redo_fd_request,
          bad_flp_intr,
          request_done };
  
  static void process_fd_request(void)
  {
          cont = &rw_cont;
          schedule_bh( (void *)(void *) redo_fd_request);
  }
  
  static void do_fd_request(request_queue_t * q)
  {
          if(max_buffer_sectors == 0) {
                  printk("VFS: do_fd_request called on non-open device\n");
                  return;
          }
  
          if (usage_count == 0) {
                  printk("warning: usage count=0, CURRENT=%p exiting\n", CURRENT);
                  printk("sect=%ld cmd=%d\n", CURRENT->sector, CURRENT->cmd);
                  return;
          }
          if (test_bit(0, &fdc_busy)) {
                  /* fdc busy, this new request will be treated when the
                     current one is done */
                  is_alive("do fd request, old request running");
                  return;
          }
          lock_fdc(MAXTIMEOUT,0);
          process_fd_request();
          is_alive("do fd request");
  }
  
  static struct cont_t poll_cont={
          success_and_wakeup,
          floppy_ready,
          generic_failure,
          generic_done };
  
  static int poll_drive(int interruptible, int flag)
  {
          int ret;
          /* no auto-sense, just clear dcl */
          raw_cmd = &default_raw_cmd;
          raw_cmd->flags= flag;
          raw_cmd->track=0;
          raw_cmd->cmd_count=0;
          cont = &poll_cont;
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("setting NEWCHANGE in poll_drive\n");
          }
  #endif
          SETF(FD_DISK_NEWCHANGE);
          WAIT(floppy_ready);
          return ret;
  }
  
  /*
   * User triggered reset
   * ====================
   */
  
  static void reset_intr(void)
  {
          printk("weird, reset interrupt called\n");
  }
  
  static struct cont_t reset_cont={
          reset_intr,
          success_and_wakeup,
          generic_failure,
          generic_done };
  
  static int user_reset_fdc(int drive, int arg, int interruptible)
  {
          int ret;
  
          ret=0;
          LOCK_FDC(drive,interruptible);
          if (arg == FD_RESET_ALWAYS)
                  FDCS->reset=1;
          if (FDCS->reset){
                  cont = &reset_cont;
                  WAIT(reset_fdc);
          }
          process_fd_request();
          return ret;
  }
  
  /*
   * Misc Ioctl's and support
   * ========================
   */
  static inline int fd_copyout(void *param, const void *address, unsigned long size)
  {
          return copy_to_user(param,address, size) ? -EFAULT : 0;
  }
  
  static inline int fd_copyin(void *param, void *address, unsigned long size)
  {
          return copy_from_user(address, param, size) ? -EFAULT : 0;
  }
  
  #define _COPYOUT(x) (copy_to_user((void *)param, &(x), sizeof(x)) ? -EFAULT : 0)
  #define _COPYIN(x) (copy_from_user(&(x), (void *)param, sizeof(x)) ? -EFAULT : 0)
  
  #define COPYOUT(x) ECALL(_COPYOUT(x))
  #define COPYIN(x) ECALL(_COPYIN(x))
  
  static inline const char *drive_name(int type, int drive)
  {
          struct floppy_struct *floppy;
  
          if (type)
                  floppy = floppy_type + type;
          else {
                  if (UDP->native_format)
                          floppy = floppy_type + UDP->native_format;
                  else
                          return "(null)";
          }
          if (floppy->name)
                  return floppy->name;
          else
                  return "(null)";
  }
  
  
  /* raw commands */
  static void raw_cmd_done(int flag)
  {
          int i;
  
          if (!flag) {
                  raw_cmd->flags |= FD_RAW_FAILURE;
                  raw_cmd->flags |= FD_RAW_HARDFAILURE;
          } else {
                  raw_cmd->reply_count = inr;
                  if (raw_cmd->reply_count > MAX_REPLIES)
                          raw_cmd->reply_count=0;
                  for (i=0; i< raw_cmd->reply_count; i++)
                          raw_cmd->reply[i] = reply_buffer[i];
  
                  if (raw_cmd->flags & (FD_RAW_READ | FD_RAW_WRITE))
                  {
                          unsigned long flags;
                          flags=claim_dma_lock();
                          raw_cmd->length = fd_get_dma_residue();
                          release_dma_lock(flags);
                  }
                  
                  if ((raw_cmd->flags & FD_RAW_SOFTFAILURE) &&
                      (!raw_cmd->reply_count || (raw_cmd->reply[0] & 0xc0)))
                          raw_cmd->flags |= FD_RAW_FAILURE;
  
                  if (disk_change(current_drive))
                          raw_cmd->flags |= FD_RAW_DISK_CHANGE;
                  else
                          raw_cmd->flags &= ~FD_RAW_DISK_CHANGE;
                  if (raw_cmd->flags & FD_RAW_NO_MOTOR_AFTER)
                          motor_off_callback(current_drive);
  
                  if (raw_cmd->next &&
                     (!(raw_cmd->flags & FD_RAW_FAILURE) ||
                      !(raw_cmd->flags & FD_RAW_STOP_IF_FAILURE)) &&
                     ((raw_cmd->flags & FD_RAW_FAILURE) ||
                      !(raw_cmd->flags &FD_RAW_STOP_IF_SUCCESS))) {
                          raw_cmd = raw_cmd->next;
                          return;
                  }
          }
          generic_done(flag);
  }
  
  
  static struct cont_t raw_cmd_cont={
          success_and_wakeup,
          floppy_start,
          generic_failure,
          raw_cmd_done
  };
  
  static inline int raw_cmd_copyout(int cmd, char *param,
                                    struct floppy_raw_cmd *ptr)
  {
          int ret;
  
          while(ptr) {
                  COPYOUT(*ptr);
                  param += sizeof(struct floppy_raw_cmd);
                  if ((ptr->flags & FD_RAW_READ) && ptr->buffer_length){
                          if (ptr->length>=0 && ptr->length<=ptr->buffer_length)
                                  ECALL(fd_copyout(ptr->data, 
                                                   ptr->kernel_data, 
                                                   ptr->buffer_length - 
                                                   ptr->length));
                  }
                  ptr = ptr->next;
          }
          return 0;
  }
  
  
  static void raw_cmd_free(struct floppy_raw_cmd **ptr)
  {
          struct floppy_raw_cmd *next,*this;
  
          this = *ptr;
          *ptr = 0;
          while(this) {
                  if (this->buffer_length) {
                          fd_dma_mem_free((unsigned long)this->kernel_data,
                                          this->buffer_length);
                          this->buffer_length = 0;
                  }
                  next = this->next;
                  kfree(this);
                  this = next;
          }
  }
  
  
  static inline int raw_cmd_copyin(int cmd, char *param,
                                   struct floppy_raw_cmd **rcmd)
  {
          struct floppy_raw_cmd *ptr;
          int ret;
          int i;
          
          *rcmd = 0;
          while(1) {
                  ptr = (struct floppy_raw_cmd *) 
                          kmalloc(sizeof(struct floppy_raw_cmd), GFP_USER);
                  if (!ptr)
                          return -ENOMEM;
                  *rcmd = ptr;
                  COPYIN(*ptr);
                  ptr->next = 0;
                  ptr->buffer_length = 0;
                  param += sizeof(struct floppy_raw_cmd);
                  if (ptr->cmd_count > 33)
                          /* the command may now also take up the space
                           * initially intended for the reply & the
                           * reply count. Needed for long 82078 commands
                           * such as RESTORE, which takes ... 17 command
                           * bytes. Murphy's law #137: When you reserve
                           * 16 bytes for a structure, you'll one day
                           * discover that you really need 17...
                           */
                          return -EINVAL;
  
                  for (i=0; i< 16; i++)
                          ptr->reply[i] = 0;
                  ptr->resultcode = 0;
                  ptr->kernel_data = 0;
  
                  if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) {
                          if (ptr->length <= 0)
                                  return -EINVAL;
                          ptr->kernel_data =(char*)fd_dma_mem_alloc(ptr->length);
                          fallback_on_nodma_alloc(&ptr->kernel_data,
                                                  ptr->length);
                          if (!ptr->kernel_data)
                                  return -ENOMEM;
                          ptr->buffer_length = ptr->length;
                  }
                  if (ptr->flags & FD_RAW_WRITE)
                          ECALL(fd_copyin(ptr->data, ptr->kernel_data, 
                                          ptr->length));
                  rcmd = & (ptr->next);
                  if (!(ptr->flags & FD_RAW_MORE))
                          return 0;
                  ptr->rate &= 0x43;
          }
  }
  
  
  static int raw_cmd_ioctl(int cmd, void *param)
  {
          int drive, ret, ret2;
          struct floppy_raw_cmd *my_raw_cmd;
  
          if (FDCS->rawcmd <= 1)
                  FDCS->rawcmd = 1;
          for (drive= 0; drive < N_DRIVE; drive++){
                  if (FDC(drive) != fdc)
                          continue;
                  if (drive == current_drive){
                          if (UDRS->fd_ref > 1){
                                  FDCS->rawcmd = 2;
                                  break;
                          }
                  } else if (UDRS->fd_ref){
                          FDCS->rawcmd = 2;
                          break;
                  }
          }
  
          if (FDCS->reset)
                  return -EIO;
  
          ret = raw_cmd_copyin(cmd, param, &my_raw_cmd);
          if (ret) {
                  raw_cmd_free(&my_raw_cmd);
                  return ret;
          }
  
          raw_cmd = my_raw_cmd;
          cont = &raw_cmd_cont;
          ret=wait_til_done(floppy_start,1);
  #ifdef DCL_DEBUG
          if (DP->flags & FD_DEBUG){
                  DPRINT("calling disk change from raw_cmd ioctl\n");
          }
  #endif
  
          if (ret != -EINTR && FDCS->reset)
                  ret = -EIO;
  
          DRS->track = NO_TRACK;
  
          ret2 = raw_cmd_copyout(cmd, param, my_raw_cmd);
          if (!ret)
                  ret = ret2;
          raw_cmd_free(&my_raw_cmd);
          return ret;
  }
  
  static int invalidate_drive(kdev_t rdev)
  {
          /* invalidate the buffer track to force a reread */
          set_bit(DRIVE(rdev), &fake_change);
          process_fd_request();
          check_disk_change(rdev);
          return 0;
  }
  
  
  static inline void clear_write_error(int drive)
  {
          CLEARSTRUCT(UDRWE);
  }
  
  static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
                                 int drive, int type, kdev_t device)
  {
          int cnt;
  
          /* sanity checking for parameters.*/
          if (g->sect <= 0 ||
              g->head <= 0 ||
              g->track <= 0 ||
              g->track > UDP->tracks>>STRETCH(g) ||
              /* check if reserved bits are set */
              (g->stretch&~(FD_STRETCH|FD_SWAPSIDES)) != 0)
                  return -EINVAL;
          if (type){
                  if (!capable(CAP_SYS_ADMIN))
                          return -EPERM;
                  LOCK_FDC(drive,1);
                  for (cnt = 0; cnt < N_DRIVE; cnt++){
                          if (ITYPE(drive_state[cnt].fd_device) == type &&
                              drive_state[cnt].fd_ref)
                                  set_bit(drive, &fake_change);
                  }
                  floppy_type[type] = *g;
                  floppy_type[type].name="user format";
                  for (cnt = type << 2; cnt < (type << 2) + 4; cnt++)
                          floppy_sizes[cnt]= floppy_sizes[cnt+0x80]=
                                  (floppy_type[type].size+1)>>1;
                  process_fd_request();
                  for (cnt = 0; cnt < N_DRIVE; cnt++){
                          if (ITYPE(drive_state[cnt].fd_device) == type &&
                              drive_state[cnt].fd_ref)
                                  check_disk_change(
                                          MKDEV(FLOPPY_MAJOR,
                                                drive_state[cnt].fd_device));
                  }
          } else {
                  LOCK_FDC(drive,1);
                  if (cmd != FDDEFPRM)
                          /* notice a disk change immediately, else
                           * we lose our settings immediately*/
                          CALL(poll_drive(1, FD_RAW_NEED_DISK));
                  user_params[drive] = *g;
                  if (buffer_drive == drive)
                          SUPBOUND(buffer_max, user_params[drive].sect);
                  current_type[drive] = &user_params[drive];
                  floppy_sizes[drive] = (user_params[drive].size+1) >> 1;
                  if (cmd == FDDEFPRM)
                          DRS->keep_data = -1;
                  else
                          DRS->keep_data = 1;
                  /* invalidation. Invalidate only when needed, i.e.
                   * when there are already sectors in the buffer cache
                   * whose number will change. This is useful, because
                   * mtools often changes the geometry of the disk after
                   * looking at the boot block */
                  if (DRS->maxblock > user_params[drive].sect || DRS->maxtrack)
                          invalidate_drive(device);
                  else
                          process_fd_request();
          }
          return 0;
  }
  
  /* handle obsolete ioctl's */
  static int ioctl_table[]= {
          FDCLRPRM,
          FDSETPRM,
          FDDEFPRM,
          FDGETPRM,
          FDMSGON,
          FDMSGOFF,
          FDFMTBEG,
          FDFMTTRK,
          FDFMTEND,
          FDSETEMSGTRESH,
          FDFLUSH,
          FDSETMAXERRS,
          FDGETMAXERRS,
          FDGETDRVTYP,
          FDSETDRVPRM,
          FDGETDRVPRM,
          FDGETDRVSTAT,
          FDPOLLDRVSTAT,
          FDRESET,
          FDGETFDCSTAT,
          FDWERRORCLR,
          FDWERRORGET,
          FDRAWCMD,
          FDEJECT,
          FDTWADDLE
  };
  
  static inline int normalize_ioctl(int *cmd, int *size)
  {
          int i;
  
          for (i=0; i < ARRAY_SIZE(ioctl_table); i++) {
                  if ((*cmd & 0xffff) == (ioctl_table[i] & 0xffff)){
                          *size = _IOC_SIZE(*cmd);
                          *cmd = ioctl_table[i];
                          if (*size > _IOC_SIZE(*cmd)) {
                                  printk("ioctl not yet supported\n");
                                  return -EFAULT;
                          }
                          return 0;
                  }
          }
          return -EINVAL;
  }
  
  static int get_floppy_geometry(int drive, int type, struct floppy_struct **g)
  {
          if (type)
                  *g = &floppy_type[type];
          else {
                  LOCK_FDC(drive,0);
                  CALL(poll_drive(0,0));
                  process_fd_request();           
                  *g = current_type[drive];
          }
          if (!*g)
                  return -ENODEV;
          return 0;
  }
  
  static int fd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                      unsigned long param)
  {
  #define FD_IOCTL_ALLOWED ((filp) && (filp)->private_data)
  #define OUT(c,x) case c: outparam = (const char *) (x); break
  #define IN(c,x,tag) case c: *(x) = inparam. tag ; return 0
  
          int i,drive,type;
          kdev_t device;
          int ret;
          int size;
          union inparam {
                  struct floppy_struct g; /* geometry */
                  struct format_descr f;
                  struct floppy_max_errors max_errors;
                  struct floppy_drive_params dp;
          } inparam; /* parameters coming from user space */
          const char *outparam; /* parameters passed back to user space */
  
          device = inode->i_rdev;
          switch (cmd) {
                  case BLKROSET:
                  case BLKROGET:
                  case BLKRASET:
                  case BLKRAGET:
                  case BLKFLSBUF:
                          return blk_ioctl(device, cmd, param);
          }
          type = TYPE(device);
          drive = DRIVE(device);
  
          /* convert compatibility eject ioctls into floppy eject ioctl.
           * We do this in order to provide a means to eject floppy disks before
           * installing the new fdutils package */
          if (cmd == CDROMEJECT || /* CD-ROM eject */
              cmd == 0x6470 /* SunOS floppy eject */) {
                  DPRINT("obsolete eject ioctl\n");
                  DPRINT("please use floppycontrol --eject\n");
                  cmd = FDEJECT;
          }
  
          /* generic block device ioctls */
          switch(cmd) {
                  /* the following have been inspired by the corresponding
                   * code for other block devices. */
                  struct floppy_struct *g;
                  case HDIO_GETGEO:
                  {
                          struct hd_geometry loc;
                          ECALL(get_floppy_geometry(drive, type, &g));
                          loc.heads = g->head;
                          loc.sectors = g->sect;
                          loc.cylinders = g->track;
                          loc.start = 0;
                          return _COPYOUT(loc);
                  }
  
                  case BLKGETSIZE:
                          ECALL(get_floppy_geometry(drive, type, &g));
                          return put_user(g->size, (unsigned long *) param);
  
                  case BLKGETSIZE64:
                          ECALL(get_floppy_geometry(drive, type, &g));
                          return put_user((u64)g->size << 9, (u64 *) param);
                  /* BLKRRPART is not defined as floppies don't have
                   * partition tables */
          }
  
          /* convert the old style command into a new style command */
          if ((cmd & 0xff00) == 0x0200) {
                  ECALL(normalize_ioctl(&cmd, &size));
          } else
                  return -EINVAL;
  
          /* permission checks */
          if (((cmd & 0x40) && !FD_IOCTL_ALLOWED) ||
              ((cmd & 0x80) && !capable(CAP_SYS_ADMIN)))
                  return -EPERM;
  
          /* copyin */
          CLEARSTRUCT(&inparam);
          if (_IOC_DIR(cmd) & _IOC_WRITE)
                  ECALL(fd_copyin((void *)param, &inparam, size))
  
          switch (cmd) {
                  case FDEJECT:
                          if (UDRS->fd_ref != 1)
                                  /* somebody else has this drive open */
                                  return -EBUSY;
                          LOCK_FDC(drive,1);
  
                          /* do the actual eject. Fails on
                           * non-Sparc architectures */
                          ret=fd_eject(UNIT(drive));
  
                          USETF(FD_DISK_CHANGED);
                          USETF(FD_VERIFY);
                          process_fd_request();
                          return ret;                     
                  case FDCLRPRM:
                          LOCK_FDC(drive,1);
                          current_type[drive] = NULL;
                          floppy_sizes[drive] = MAX_DISK_SIZE;
                          UDRS->keep_data = 0;
                          return invalidate_drive(device);
                  case FDSETPRM:
                  case FDDEFPRM:
                          return set_geometry(cmd, & inparam.g,
                                              drive, type, device);
                  case FDGETPRM:
                          ECALL(get_floppy_geometry(drive, type, 
                                                    (struct floppy_struct**)
                                                    &outparam));
                          break;
  
                  case FDMSGON:
                          UDP->flags |= FTD_MSG;
                          return 0;
                  case FDMSGOFF:
                          UDP->flags &= ~FTD_MSG;
                          return 0;
  
                  case FDFMTBEG:
                          LOCK_FDC(drive,1);
                          CALL(poll_drive(1, FD_RAW_NEED_DISK));
                          ret = UDRS->flags;
                          process_fd_request();
                          if (ret & FD_VERIFY)
                                  return -ENODEV;
                          if (!(ret & FD_DISK_WRITABLE))
                                  return -EROFS;
                          return 0;
                  case FDFMTTRK:
                          if (UDRS->fd_ref != 1)
                                  return -EBUSY;
                          return do_format(device, &inparam.f);
                  case FDFMTEND:
                  case FDFLUSH:
                          LOCK_FDC(drive,1);
                          return invalidate_drive(device);
  
                  case FDSETEMSGTRESH:
                          UDP->max_errors.reporting =
                                  (unsigned short) (param & 0x0f);
                          return 0;
                  OUT(FDGETMAXERRS, &UDP->max_errors);
                  IN(FDSETMAXERRS, &UDP->max_errors, max_errors);
  
                  case FDGETDRVTYP:
                          outparam = drive_name(type,drive);
                          SUPBOUND(size,strlen(outparam)+1);
                          break;
  
                  IN(FDSETDRVPRM, UDP, dp);
                  OUT(FDGETDRVPRM, UDP);
  
                  case FDPOLLDRVSTAT:
                          LOCK_FDC(drive,1);
                          CALL(poll_drive(1, FD_RAW_NEED_DISK));
                          process_fd_request();
                          /* fall through */
                  OUT(FDGETDRVSTAT, UDRS);
  
                  case FDRESET:
                          return user_reset_fdc(drive, (int)param, 1);
  
                  OUT(FDGETFDCSTAT,UFDCS);
  
                  case FDWERRORCLR:
                          CLEARSTRUCT(UDRWE);
                          return 0;
                  OUT(FDWERRORGET,UDRWE);
  
                  case FDRAWCMD:
                          if (type)
                                  return -EINVAL;
                          LOCK_FDC(drive,1);
                          set_floppy(device);
                          CALL(i = raw_cmd_ioctl(cmd,(void *) param));
                          process_fd_request();
                          return i;
  
                  case FDTWADDLE:
                          LOCK_FDC(drive,1);
                          twaddle();
                          process_fd_request();
                          return 0;
  
                  default:
                          return -EINVAL;
          }
  
          if (_IOC_DIR(cmd) & _IOC_READ)
                  return fd_copyout((void *)param, outparam, size);
          else
                  return 0;
  #undef OUT
  #undef IN
  }
  
  static void __init config_types(void)
  {
          int first=1;
          int drive;
  
          /* read drive info out of physical CMOS */
          drive=0;
          if (!UDP->cmos)
                  UDP->cmos = FLOPPY0_TYPE;
          drive=1;
          if (!UDP->cmos && FLOPPY1_TYPE)
                  UDP->cmos = FLOPPY1_TYPE;
  
          /* XXX */
          /* additional physical CMOS drive detection should go here */
  
          for (drive=0; drive < N_DRIVE; drive++){
                  unsigned int type = UDP->cmos;
                  struct floppy_drive_params *params;
                  const char *name = NULL;
                  static char temparea[32];
  
                  if (type < NUMBER(default_drive_params)) {
                          params = &default_drive_params[type].params;
                          if (type) {
                                  name = default_drive_params[type].name;
                                  allowed_drive_mask |= 1 << drive;
                          }
                  } else {
                          params = &default_drive_params[0].params;
                          sprintf(temparea, "unknown type %d (usb?)", type);
                          name = temparea;
                  }
                  if (name) {
                          const char * prepend = ",";
                          if (first) {
                                  prepend = KERN_INFO "Floppy drive(s):";
                                  first = 0;
                          }
                          printk("%s fd%d is %s", prepend, drive, name);
                          register_devfs_entries (drive);
                  }
                  *UDP = *params;
          }
          if (!first)
                  printk("\n");
  }
  
  static int floppy_release(struct inode * inode, struct file * filp)
  {
          int drive = DRIVE(inode->i_rdev);
  
          if (UDRS->fd_ref < 0)
                  UDRS->fd_ref=0;
          else if (!UDRS->fd_ref--) {
                  DPRINT("floppy_release with fd_ref == 0");
                  UDRS->fd_ref = 0;
          }
          floppy_release_irq_and_dma();
          return 0;
  }
  
  /*
   * floppy_open check for aliasing (/dev/fd0 can be the same as
   * /dev/PS0 etc), and disallows simultaneous access to the same
   * drive with different device numbers.
   */
  #define RETERR(x) do{floppy_release(inode,filp); return -(x);}while(0)
  
  static int floppy_open(struct inode * inode, struct file * filp)
  {
          int drive;
          int old_dev;
          int try;
          char *tmp;
  
          if (!filp) {
                  DPRINT("Weird, open called with filp=0\n");
                  return -EIO;
          }
  
          filp->private_data = (void*) 0;
  
          drive = DRIVE(inode->i_rdev);
          if (drive >= N_DRIVE ||
              !(allowed_drive_mask & (1 << drive)) ||
              fdc_state[FDC(drive)].version == FDC_NONE)
                  return -ENXIO;
  
          if (TYPE(inode->i_rdev) >= NUMBER(floppy_type))
                  return -ENXIO;
          old_dev = UDRS->fd_device;
          if (UDRS->fd_ref && old_dev != MINOR(inode->i_rdev))
                  return -EBUSY;
  
          if (!UDRS->fd_ref && (UDP->flags & FD_BROKEN_DCL)){
                  USETF(FD_DISK_CHANGED);
                  USETF(FD_VERIFY);
          }
  
          if (UDRS->fd_ref == -1 ||
             (UDRS->fd_ref && (filp->f_flags & O_EXCL)))
                  return -EBUSY;
  
          if (floppy_grab_irq_and_dma())
                  return -EBUSY;
  
          if (filp->f_flags & O_EXCL)
                  UDRS->fd_ref = -1;
          else
                  UDRS->fd_ref++;
  
          if (!floppy_track_buffer){
                  /* if opening an ED drive, reserve a big buffer,
                   * else reserve a small one */
                  if ((UDP->cmos == 6) || (UDP->cmos == 5))
                          try = 64; /* Only 48 actually useful */
                  else
                          try = 32; /* Only 24 actually useful */
  
                  tmp=(char *)fd_dma_mem_alloc(1024 * try);
                  if (!tmp && !floppy_track_buffer) {
                          try >>= 1; /* buffer only one side */
                          INFBOUND(try, 16);
                          tmp= (char *)fd_dma_mem_alloc(1024*try);
                  }
                  if (!tmp && !floppy_track_buffer) {
                          fallback_on_nodma_alloc(&tmp, 2048 * try);
                  }
                  if (!tmp && !floppy_track_buffer) {
                          DPRINT("Unable to allocate DMA memory\n");
                          RETERR(ENXIO);
                  }
                  if (floppy_track_buffer) {
                          if (tmp)
                                  fd_dma_mem_free((unsigned long)tmp,try*1024);
                  } else {
                          buffer_min = buffer_max = -1;
                          floppy_track_buffer = tmp;
                          max_buffer_sectors = try;
                  }
          }
  
          UDRS->fd_device = MINOR(inode->i_rdev);
          if (old_dev != -1 && old_dev != MINOR(inode->i_rdev)) {
                  if (buffer_drive == drive)
                          buffer_track = -1;
                  invalidate_buffers(MKDEV(FLOPPY_MAJOR,old_dev));
          }
  
          /* Allow ioctls if we have write-permissions even if read-only open.
           * Needed so that programs such as fdrawcmd still can work on write
           * protected disks */
          if ((filp->f_mode & 2) || 
              (inode->i_sb && (permission(inode,2) == 0)))
              filp->private_data = (void*) 8;
  
          if (UFDCS->rawcmd == 1)
                  UFDCS->rawcmd = 2;
  
          if (filp->f_flags & O_NDELAY)
                  return 0;
          if (filp->f_mode & 3) {
                  UDRS->last_checked = 0;
                  check_disk_change(inode->i_rdev);
                  if (UTESTF(FD_DISK_CHANGED))
                          RETERR(ENXIO);
          }
          if ((filp->f_mode & 2) && !(UTESTF(FD_DISK_WRITABLE)))
                  RETERR(EROFS);
          return 0;
  #undef RETERR
  }
  
  /*
   * Check if the disk has been changed or if a change has been faked.
   */
  static int check_floppy_change(kdev_t dev)
  {
          int drive = DRIVE(dev);
  
          if (MAJOR(dev) != MAJOR_NR) {
                  DPRINT("check_floppy_change: not a floppy\n");
                  return 0;
          }
  
          if (UTESTF(FD_DISK_CHANGED) || UTESTF(FD_VERIFY))
                  return 1;
  
          if (UDP->checkfreq < (int)(jiffies - UDRS->last_checked)) {
                  if(floppy_grab_irq_and_dma()) {
                          return 1;
                  }
  
                  lock_fdc(drive,0);
                  poll_drive(0,0);
                  process_fd_request();
                  floppy_release_irq_and_dma();
          }
  
          if (UTESTF(FD_DISK_CHANGED) ||
             UTESTF(FD_VERIFY) ||
             test_bit(drive, &fake_change) ||
             (!TYPE(dev) && !current_type[drive]))
                  return 1;
          return 0;
  }
  
  /* revalidate the floppy disk, i.e. trigger format autodetection by reading
   * the bootblock (block 0). "Autodetection" is also needed to check whether
   * there is a disk in the drive at all... Thus we also do it for fixed
   * geometry formats */
  static int floppy_revalidate(kdev_t dev)
  {
  #define NO_GEOM (!current_type[drive] && !TYPE(dev))
          struct buffer_head * bh;
          int drive=DRIVE(dev);
          int cf;
  
          if (UTESTF(FD_DISK_CHANGED) ||
              UTESTF(FD_VERIFY) ||
              test_bit(drive, &fake_change) ||
              NO_GEOM){
                  if(usage_count == 0) {
                          printk("VFS: revalidate called on non-open device.\n");
                          return -EFAULT;
                  }
                  lock_fdc(drive,0);
                  cf = UTESTF(FD_DISK_CHANGED) || UTESTF(FD_VERIFY);
                  if (!(cf || test_bit(drive, &fake_change) || NO_GEOM)){
                          process_fd_request(); /*already done by another thread*/
                          return 0;
                  }
                  UDRS->maxblock = 0;
                  UDRS->maxtrack = 0;
                  if (buffer_drive == drive)
                          buffer_track = -1;
                  clear_bit(drive, &fake_change);
                  UCLEARF(FD_DISK_CHANGED);
                  if (cf)
                          UDRS->generation++;
                  if (NO_GEOM){
                          /* auto-sensing */
                          int size = floppy_blocksizes[MINOR(dev)];
                          if (!size)
                                  size = 512;
                          if (!(bh = getblk(dev,0,size))){
                                  process_fd_request();
                                  return -ENXIO;
                          }
                          if (bh && !buffer_uptodate(bh))
                                  ll_rw_block(READ, 1, &bh);
                          process_fd_request();
                          wait_on_buffer(bh);
                          brelse(bh);
                          return 0;
                  }
                  if (cf)
                          poll_drive(0, FD_RAW_NEED_DISK);
                  process_fd_request();
          }
          return 0;
  }
  
  static struct block_device_operations floppy_fops = {
          owner:                  THIS_MODULE,
          open:                   floppy_open,
          release:                floppy_release,
          ioctl:                  fd_ioctl,
          check_media_change:     check_floppy_change,
          revalidate:             floppy_revalidate,
  };
  
  static void __init register_devfs_entries (int drive)
  {
      int base_minor, i;
      static char *table[] =
      {"", "d360", "h1200", "u360", "u720", "h360", "h720",
       "u1440", "u2880", "CompaQ", "h1440", "u1680", "h410",
       "u820", "h1476", "u1722", "h420", "u830", "h1494", "u1743",
       "h880", "u1040", "u1120", "h1600", "u1760", "u1920",
       "u3200", "u3520", "u3840", "u1840", "u800", "u1600",
       NULL
      };
      static int t360[] = {1,0}, t1200[] = {2,5,6,10,12,14,16,18,20,23,0},
        t3in[] = {8,9,26,27,28, 7,11,15,19,24,25,29,31, 3,4,13,17,21,22,30,0};
      static int *table_sup[] = 
      {NULL, t360, t1200, t3in+5+8, t3in+5, t3in, t3in};
  
      base_minor = (drive < 4) ? drive : (124 + drive);
      if (UDP->cmos < NUMBER(default_drive_params)) {
          i = 0;
          do {
              char name[16];
  
              sprintf (name, "%d%s", drive, table[table_sup[UDP->cmos][i]]);
              devfs_register (devfs_handle, name, DEVFS_FL_DEFAULT, MAJOR_NR,
                              base_minor + (table_sup[UDP->cmos][i] << 2),
                              S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP |S_IWGRP,
                              &floppy_fops, NULL);
          } while (table_sup[UDP->cmos][i++]);
      }
  }
  
  /*
   * Floppy Driver initialization
   * =============================
   */
  
  /* Determine the floppy disk controller type */
  /* This routine was written by David C. Niemi */
  static char __init get_fdc_version(void)
  {
          int r;
  
          output_byte(FD_DUMPREGS);       /* 82072 and better know DUMPREGS */
          if (FDCS->reset)
                  return FDC_NONE;
          if ((r = result()) <= 0x00)
                  return FDC_NONE;        /* No FDC present ??? */
          if ((r==1) && (reply_buffer[0] == 0x80)){
                  printk(KERN_INFO "FDC %d is an 8272A\n",fdc);
                  return FDC_8272A;       /* 8272a/765 don't know DUMPREGS */
          }
          if (r != 10) {
                  printk("FDC %d init: DUMPREGS: unexpected return of %d bytes.\n",
                         fdc, r);
                  return FDC_UNKNOWN;
          }
  
          if (!fdc_configure()) {
                  printk(KERN_INFO "FDC %d is an 82072\n",fdc);
                  return FDC_82072;       /* 82072 doesn't know CONFIGURE */
          }
  
          output_byte(FD_PERPENDICULAR);
          if (need_more_output() == MORE_OUTPUT) {
                  output_byte(0);
          } else {
                  printk(KERN_INFO "FDC %d is an 82072A\n", fdc);
                  return FDC_82072A;      /* 82072A as found on Sparcs. */
          }
  
          output_byte(FD_UNLOCK);
          r = result();
          if ((r == 1) && (reply_buffer[0] == 0x80)){
                  printk(KERN_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)) {
                  printk("FDC %d init: UNLOCK: unexpected return of %d bytes.\n",
                         fdc, r);
                  return FDC_UNKNOWN;
          }
          output_byte(FD_PARTID);
          r = result();
          if (r != 1) {
                  printk("FDC %d init: PARTID: unexpected return of %d bytes.\n",
                         fdc, r);
                  return FDC_UNKNOWN;
          }
          if (reply_buffer[0] == 0x80) {
                  printk(KERN_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 */
                          printk(KERN_INFO "FDC %d is an 82078.\n",fdc);
                          return FDC_82078;
                  case 0x1:
                          printk(KERN_INFO "FDC %d is a 44pin 82078\n",fdc);
                          return FDC_82078;
                  case 0x2:
                          printk(KERN_INFO "FDC %d is a S82078B\n", fdc);
                          return FDC_S82078B;
                  case 0x3:
                          printk(KERN_INFO "FDC %d is a National Semiconductor PC87306\n", fdc);
                          return FDC_87306;
                  default:
                          printk(KERN_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[]={
          { "allowed_drive_mask", 0, &allowed_drive_mask, 0xff, 0}, /* obsolete */
          { "all_drives", 0, &allowed_drive_mask, 0xff, 0 }, /* obsolete */
          { "asus_pci", 0, &allowed_drive_mask, 0x33, 0},
  
          { "irq", 0, &FLOPPY_IRQ, 6, 0 },
          { "dma", 0, &FLOPPY_DMA, 2, 0 },
  
          { "daring", daring, 0, 1, 0},
  #if N_FDC > 1
          { "two_fdc",  0, &FDC2, 0x370, 0 },
          { "one_fdc", 0, &FDC2, 0, 0 },
  #endif
          { "thinkpad", floppy_set_flags, 0, 1, FD_INVERTED_DCL },
          { "broken_dcl", floppy_set_flags, 0, 1, FD_BROKEN_DCL },
          { "messages", floppy_set_flags, 0, 1, FTD_MSG },
          { "silent_dcl_clear", floppy_set_flags, 0, 1, FD_SILENT_DCL_CLEAR },
          { "debug", floppy_set_flags, 0, 1, FD_DEBUG },
  
          { "nodma", 0, &can_use_virtual_dma, 1, 0 },
          { "omnibook", 0, &can_use_virtual_dma, 1, 0 },
          { "yesdma", 0, &can_use_virtual_dma, 0, 0 },
  
          { "fifo_depth", 0, &fifo_depth, 0xa, 0 },
          { "nofifo", 0, &no_fifo, 0x20, 0 },
          { "usefifo", 0, &no_fifo, 0, 0 },
  
          { "cmos", set_cmos, 0, 0, 0 },
          { "slow", 0, &slow_floppy, 1, 0 },
  
          { "unexpected_interrupts", 0, &print_unex, 1, 0 },
          { "no_unexpected_interrupts", 0, &print_unex, 0, 0 },
          { "L40SX", 0, &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++)
                          printk(" %s",config_params[i].name);
                  printk("\n");
          } else
                  DPRINT("botched floppy option\n");
          DPRINT("Read linux/Documentation/floppy.txt\n");
          return 0;
  }
  
  static int have_no_fdc= -ENODEV;
  
  
  int __init floppy_init(void)
  {
          int i,unit,drive;
  
  
          raw_cmd = NULL;
  
          devfs_handle = devfs_mk_dir (NULL, "floppy", NULL);
          if (devfs_register_blkdev(MAJOR_NR,"fd",&floppy_fops)) {
                  printk("Unable to get major %d for floppy\n",MAJOR_NR);
                  return -EBUSY;
          }
  
          for (i=0; i<256; i++) {
                  if (ITYPE(i))
                          floppy_sizes[i] = (floppy_type[ITYPE(i)].size+1) >> 1;
                  else
                          floppy_sizes[i] = MAX_DISK_SIZE;
  
                  floppy_blocksizes[i] = 512;
                  floppy_maxsectors[i] = 64;
          }
  
          blk_size[MAJOR_NR] = floppy_sizes;
          blksize_size[MAJOR_NR] = floppy_blocksizes;
          max_sectors[MAJOR_NR] = floppy_maxsectors;
          blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
          reschedule_timeout(MAXTIMEOUT, "floppy init", MAXTIMEOUT);
          config_types();
  
          for (i = 0; i < N_FDC; i++) {
                  fdc = i;
                  CLEARSTRUCT(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) {
                  devfs_unregister_blkdev(MAJOR_NR,"fd");
                  del_timer(&fd_timeout);
                  blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
                  return -ENODEV;
          }
  #if N_FDC > 1
          fdc_state[1].address = FDC2;
  #endif
  
          fdc = 0; /* reset fdc in case of unexpected interrupt */
          if (floppy_grab_irq_and_dma()){
                  del_timer(&fd_timeout);
                  blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
                  devfs_unregister_blkdev(MAJOR_NR,"fd");
                  return -EBUSY;
          }
  
          /* initialise drive state */
          for (drive = 0; drive < N_DRIVE; drive++) {
                  CLEARSTRUCT(UDRS);
                  CLEARSTRUCT(UDRWE);
                  USETF(FD_DISK_NEWCHANGE);
                  USETF(FD_DISK_CHANGED);
                  USETF(FD_VERIFY);
                  UDRS->fd_device = -1;
                  floppy_track_buffer = NULL;
                  max_buffer_sectors = 0;
          }
  
          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,0)){
                          /* free ioports reserved by floppy_grab_irq_and_dma() */
                          release_region(FDCS->address+2, 4);
                          release_region(FDCS->address+7, 1);
                          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() */
                          release_region(FDCS->address+2, 4);
                          release_region(FDCS->address+7, 1);
                          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,0);
          }
          fdc=0;
          del_timer(&fd_timeout);
          current_drive = 0;
          floppy_release_irq_and_dma();
          initialising=0;
          if (have_no_fdc) 
          {
                  DPRINT("no floppy controllers found\n");
                  run_task_queue(&tq_immediate);
                  if (usage_count)
                          floppy_release_irq_and_dma();
                  blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
                  devfs_unregister_blkdev(MAJOR_NR,"fd");
          }
          
          for (drive = 0; drive < N_DRIVE; drive++) {
                  motor_off_timer[drive].data = drive;
                  motor_off_timer[drive].function = motor_off_callback;
                  if (!(allowed_drive_mask & (1 << drive)))
                          continue;
                  if (fdc_state[FDC(drive)].version == FDC_NONE)
                          continue;
                  for (i = 0; i<NUMBER(floppy_type); i++)
                          register_disk(NULL, MKDEV(MAJOR_NR,TOMINOR(drive)+i*4),
                                          1, &floppy_fops, 0);
          }
          return have_no_fdc;
  }
  
  static spinlock_t floppy_usage_lock = SPIN_LOCK_UNLOCKED;
  
  static int floppy_grab_irq_and_dma(void)
  {
          unsigned long flags;
  
          spin_lock_irqsave(&floppy_usage_lock, flags);
          if (usage_count++){
                  spin_unlock_irqrestore(&floppy_usage_lock, flags);
                  return 0;
          }
          spin_unlock_irqrestore(&floppy_usage_lock, flags);
          MOD_INC_USE_COUNT;
          if (fd_request_irq()) {
                  DPRINT("Unable to grab IRQ%d for the floppy driver\n",
                          FLOPPY_IRQ);
                  MOD_DEC_USE_COUNT;
                  spin_lock_irqsave(&floppy_usage_lock, flags);
                  usage_count--;
                  spin_unlock_irqrestore(&floppy_usage_lock, flags);
                  return -1;
          }
          if (fd_request_dma()) {
                  DPRINT("Unable to grab DMA%d for the floppy driver\n",
                          FLOPPY_DMA);
                  fd_free_irq();
                  MOD_DEC_USE_COUNT;
                  spin_lock_irqsave(&floppy_usage_lock, flags);
                  usage_count--;
                  spin_unlock_irqrestore(&floppy_usage_lock, flags);
                  return -1;
          }
  
          for (fdc=0; fdc< N_FDC; fdc++){
                  if (FDCS->address != -1){
                          if (!request_region(FDCS->address+2, 4, "floppy")) {
                                  DPRINT("Floppy io-port 0x%04lx in use\n", FDCS->address + 2);
                                  goto cleanup1;
                          }
                          if (!request_region(FDCS->address+7, 1, "floppy DIR")) {
                                  DPRINT("Floppy io-port 0x%04lx in use\n", FDCS->address + 7);
                                  goto cleanup2;
                          }
                          /* address + 6 is reserved, and may be taken by IDE.
                           * Unfortunately, Adaptec doesn't know this :-(, */
                  }
          }
          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;
  cleanup2:
          release_region(FDCS->address + 2, 4);
  cleanup1:
          fd_free_irq();
          fd_free_dma();
          while(--fdc >= 0) {
                  release_region(FDCS->address + 2, 4);
                  release_region(FDCS->address + 7, 1);
          }
          MOD_DEC_USE_COUNT;
          spin_lock_irqsave(&floppy_usage_lock, flags);
          usage_count--;
          spin_unlock_irqrestore(&floppy_usage_lock, flags);
          return -1;
  }
  
  static void floppy_release_irq_and_dma(void)
  {
          int old_fdc;
  #ifdef FLOPPY_SANITY_CHECK
  #ifndef __sparc__
          int drive;
  #endif
  #endif
          long tmpsize;
          unsigned long tmpaddr;
          unsigned long flags;
  
          spin_lock_irqsave(&floppy_usage_lock, flags);
          if (--usage_count){
                  spin_unlock_irqrestore(&floppy_usage_lock, flags);
                  return;
          }
          spin_unlock_irqrestore(&floppy_usage_lock, flags);
          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
          floppy_enable_hlt();
  
          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);
          }
  
  #ifdef FLOPPY_SANITY_CHECK
  #ifndef __sparc__
          for (drive=0; drive < N_FDC * 4; drive++)
                  if (timer_pending(motor_off_timer + drive))
                          printk("motor off timer %d still active\n", drive);
  #endif
  
          if (timer_pending(&fd_timeout))
                  printk("floppy timer still active:%s\n", timeout_message);
          if (timer_pending(&fd_timer))
                  printk("auxiliary floppy timer still active\n");
          if (floppy_tq.sync)
                  printk("task queue still active\n");
  #endif
          old_fdc = fdc;
          for (fdc = 0; fdc < N_FDC; fdc++)
                  if (FDCS->address != -1) {
                          release_region(FDCS->address+2, 4);
                          release_region(FDCS->address+7, 1);
                  }
          fdc = old_fdc;
          MOD_DEC_USE_COUNT;
  }
  
  
  #ifdef MODULE
  
  char *floppy;
  
  static void __init parse_floppy_cfg_string(char *cfg)
  {
          char *ptr;
  
          while(*cfg) {
                  for(ptr = cfg;*cfg && *cfg != ' ' && *cfg != '\t'; cfg++);
                  if (*cfg) {
                          *cfg = '\0';
                          cfg++;
                  }
                  if (*ptr)
                          floppy_setup(ptr);
          }
  }
  
  int init_module(void)
  {
          printk(KERN_INFO "inserting floppy driver for " UTS_RELEASE "\n");
                  
          if (floppy)
                  parse_floppy_cfg_string(floppy);
          return floppy_init();
  }
  
  void cleanup_module(void)
  {
          int dummy;
                  
          devfs_unregister (devfs_handle);
          devfs_unregister_blkdev(MAJOR_NR, "fd");
  
          blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
          /* eject disk, if any */
          dummy = fd_eject(0);
  }
  
  MODULE_PARM(floppy,"s");
  MODULE_PARM(FLOPPY_IRQ,"i");
  MODULE_PARM(FLOPPY_DMA,"i");
  MODULE_AUTHOR("Alain L. Knaff");
  MODULE_SUPPORTED_DEVICE("fd");
  MODULE_LICENSE("GPL");
  
  #else
  
  __setup ("floppy=", floppy_setup);
  
  #endif
  
  EXPORT_NO_SYMBOLS;