Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2063 insertions, 0 deletions

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
new file mode 100644
index 000000000..822e3060d
--- /dev/null
+++ b/drivers/block/ataflop.c
@@ -0,0 +1,2063 @@
+/*
+ *  drivers/block/ataflop.c
+ *
+ *  Copyright (C) 1993  Greg Harp
+ *  Atari Support by Bjoern Brauel, Roman Hodek
+ *
+ *  Big cleanup Sep 11..14 1994 Roman Hodek:
+ *   - Driver now works interrupt driven
+ *   - Support for two drives; should work, but I cannot test that :-(
+ *   - Reading is done in whole tracks and buffered to speed up things
+ *   - Disk change detection and drive deselecting after motor-off
+ *     similar to TOS
+ *   - Autodetection of disk format (DD/HD); untested yet, because I
+ *     don't have an HD drive :-(
+ *
+ *  Fixes Nov 13 1994 Martin Schaller:
+ *   - Autodetection works now
+ *   - Support for 5 1/4'' disks
+ *   - Removed drive type (unknown on atari)
+ *   - Do seeks with 8 Mhz
+ *
+ *  Changes by Andreas Schwab:
+ *   - After errors in multiple read mode try again reading single sectors
+ *  (Feb 1995):
+ *   - Clean up error handling
+ *   - Set blk_size for proper size checking
+ *   - Initialize track register when testing presence of floppy
+ *   - Implement some ioctl's
+ *
+ *  Changes by Torsten Lang:
+ *   - When probing the floppies we should add the FDCCMDADD_H flag since
+ *     the FDC will otherwise wait forever when no disk is inserted...
+ *
+ * ++ Freddi Aschwanden (fa) 20.9.95 fixes for medusa:
+ *  - MFPDELAY() after each FDC access -> atari 
+ *  - more/other disk formats
+ *  - DMA to the block buffer directly if we have a 32bit DMA
+ *  - for medusa, the step rate is always 3ms
+ *  - on medusa, use only cache_push()
+ * Roman:
+ *  - Make disk format numbering independent from minors
+ *  - Let user set max. supported drive type (speeds up format
+ *    detection, saves buffer space)
+ *
+ * Roman 10/15/95:
+ *  - implement some more ioctls
+ *  - disk formatting
+ *  
+ * Andreas 95/12/12:
+ *  - increase gap size at start of track for HD/ED disks
+ *
+ * Michael (MSch) 11/07/96:
+ *  - implemented FDSETPRM and FDDEFPRM ioctl
+ *
+ * Andreas (97/03/19):
+ *  - implemented missing BLK* ioctls
+ *
+ *  Things left to do:
+ *   - Formatting
+ *   - Maybe a better strategy for disk change detection (does anyone
+ *     know one?)
+ */
+
+#include <linux/module.h>
+
+#include <linux/fd.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/mutex.h>
+#include <linux/completion.h>
+#include <linux/wait.h>
+
+#include <asm/atafd.h>
+#include <asm/atafdreg.h>
+#include <asm/atariints.h>
+#include <asm/atari_stdma.h>
+#include <asm/atari_stram.h>
+
+#define	FD_MAX_UNITS 2
+
+#undef DEBUG
+
+static DEFINE_MUTEX(ataflop_mutex);
+static struct request *fd_request;
+static int fdc_queue;
+
+/* Disk types: DD, HD, ED */
+static struct atari_disk_type {
+	const char	*name;
+	unsigned	spt;		/* sectors per track */
+	unsigned	blocks;		/* total number of blocks */
+	unsigned	fdc_speed;	/* fdc_speed setting */
+	unsigned 	stretch;	/* track doubling ? */
+} atari_disk_type[] = {
+	{ "d360",  9, 720, 0, 0},	/*  0: 360kB diskette */
+	{ "D360",  9, 720, 0, 1},	/*  1: 360kb in 720k or 1.2MB drive */
+	{ "D720",  9,1440, 0, 0},	/*  2: 720kb in 720k or 1.2MB drive */
+	{ "D820", 10,1640, 0, 0},	/*  3: DD disk with 82 tracks/10 sectors */
+/* formats above are probed for type DD */
+#define	MAX_TYPE_DD 3
+	{ "h1200",15,2400, 3, 0},	/*  4: 1.2MB diskette */
+	{ "H1440",18,2880, 3, 0},	/*  5: 1.4 MB diskette (HD) */
+	{ "H1640",20,3280, 3, 0},	/*  6: 1.64MB diskette (fat HD) 82 tr 20 sec */
+/* formats above are probed for types DD and HD */
+#define	MAX_TYPE_HD 6
+	{ "E2880",36,5760, 3, 0},	/*  7: 2.8 MB diskette (ED) */
+	{ "E3280",40,6560, 3, 0},	/*  8: 3.2 MB diskette (fat ED) 82 tr 40 sec */
+/* formats above are probed for types DD, HD and ED */
+#define	MAX_TYPE_ED 8
+/* types below are never autoprobed */
+	{ "H1680",21,3360, 3, 0},	/*  9: 1.68MB diskette (fat HD) 80 tr 21 sec */
+	{ "h410",10,820, 0, 1},		/* 10: 410k diskette 41 tr 10 sec, stretch */
+	{ "h1476",18,2952, 3, 0},	/* 11: 1.48MB diskette 82 tr 18 sec */
+	{ "H1722",21,3444, 3, 0},	/* 12: 1.72MB diskette 82 tr 21 sec */
+	{ "h420",10,840, 0, 1},		/* 13: 420k diskette 42 tr 10 sec, stretch */
+	{ "H830",10,1660, 0, 0},	/* 14: 820k diskette 83 tr 10 sec */
+	{ "h1494",18,2952, 3, 0},	/* 15: 1.49MB diskette 83 tr 18 sec */
+	{ "H1743",21,3486, 3, 0},	/* 16: 1.74MB diskette 83 tr 21 sec */
+	{ "h880",11,1760, 0, 0},	/* 17: 880k diskette 80 tr 11 sec */
+	{ "D1040",13,2080, 0, 0},	/* 18: 1.04MB diskette 80 tr 13 sec */
+	{ "D1120",14,2240, 0, 0},	/* 19: 1.12MB diskette 80 tr 14 sec */
+	{ "h1600",20,3200, 3, 0},	/* 20: 1.60MB diskette 80 tr 20 sec */
+	{ "H1760",22,3520, 3, 0},	/* 21: 1.76MB diskette 80 tr 22 sec */
+	{ "H1920",24,3840, 3, 0},	/* 22: 1.92MB diskette 80 tr 24 sec */
+	{ "E3200",40,6400, 3, 0},	/* 23: 3.2MB diskette 80 tr 40 sec */
+	{ "E3520",44,7040, 3, 0},	/* 24: 3.52MB diskette 80 tr 44 sec */
+	{ "E3840",48,7680, 3, 0},	/* 25: 3.84MB diskette 80 tr 48 sec */
+	{ "H1840",23,3680, 3, 0},	/* 26: 1.84MB diskette 80 tr 23 sec */
+	{ "D800",10,1600, 0, 0},	/* 27: 800k diskette 80 tr 10 sec */
+};
+
+static int StartDiskType[] = {
+	MAX_TYPE_DD,
+	MAX_TYPE_HD,
+	MAX_TYPE_ED
+};
+
+#define	TYPE_DD		0
+#define	TYPE_HD		1
+#define	TYPE_ED		2
+
+static int DriveType = TYPE_HD;
+
+static DEFINE_SPINLOCK(ataflop_lock);
+
+/* Array for translating minors into disk formats */
+static struct {
+	int 	 index;
+	unsigned drive_types;
+} minor2disktype[] = {
+	{  0, TYPE_DD },	/*  1: d360 */
+	{  4, TYPE_HD },	/*  2: h1200 */
+	{  1, TYPE_DD },	/*  3: D360 */
+	{  2, TYPE_DD },	/*  4: D720 */
+	{  1, TYPE_DD },	/*  5: h360 = D360 */
+	{  2, TYPE_DD },	/*  6: h720 = D720 */
+	{  5, TYPE_HD },	/*  7: H1440 */
+	{  7, TYPE_ED },	/*  8: E2880 */
+/* some PC formats :-) */
+	{  8, TYPE_ED },	/*  9: E3280    <- was "CompaQ" == E2880 for PC */
+	{  5, TYPE_HD },	/* 10: h1440 = H1440 */
+	{  9, TYPE_HD },	/* 11: H1680 */
+	{ 10, TYPE_DD },	/* 12: h410  */
+	{  3, TYPE_DD },	/* 13: H820     <- == D820, 82x10 */
+	{ 11, TYPE_HD },	/* 14: h1476 */
+	{ 12, TYPE_HD },	/* 15: H1722 */
+	{ 13, TYPE_DD },	/* 16: h420  */
+	{ 14, TYPE_DD },	/* 17: H830  */
+	{ 15, TYPE_HD },	/* 18: h1494 */
+	{ 16, TYPE_HD },	/* 19: H1743 */
+	{ 17, TYPE_DD },	/* 20: h880  */
+	{ 18, TYPE_DD },	/* 21: D1040 */
+	{ 19, TYPE_DD },	/* 22: D1120 */
+	{ 20, TYPE_HD },	/* 23: h1600 */
+	{ 21, TYPE_HD },	/* 24: H1760 */
+	{ 22, TYPE_HD },	/* 25: H1920 */
+	{ 23, TYPE_ED },	/* 26: E3200 */
+	{ 24, TYPE_ED },	/* 27: E3520 */
+	{ 25, TYPE_ED },	/* 28: E3840 */
+	{ 26, TYPE_HD },	/* 29: H1840 */
+	{ 27, TYPE_DD },	/* 30: D800  */
+	{  6, TYPE_HD },	/* 31: H1640    <- was H1600 == h1600 for PC */
+};
+
+#define NUM_DISK_MINORS ARRAY_SIZE(minor2disktype)
+
+/*
+ * Maximum disk size (in kilobytes). This default is used whenever the
+ * current disk size is unknown.
+ */
+#define MAX_DISK_SIZE 3280
+
+/*
+ * MSch: User-provided type information. 'drive' points to
+ * the respective entry of this array. Set by FDSETPRM ioctls.
+ */
+static struct atari_disk_type user_params[FD_MAX_UNITS];
+
+/*
+ * User-provided permanent type information. 'drive' points to
+ * the respective entry of this array.  Set by FDDEFPRM ioctls, 
+ * restored upon disk change by floppy_revalidate() if valid (as seen by
+ * default_params[].blocks > 0 - a bit in unit[].flags might be used for this?)
+ */
+static struct atari_disk_type default_params[FD_MAX_UNITS];
+
+/* current info on each unit */
+static struct atari_floppy_struct {
+	int connected;				/* !=0 : drive is connected */
+	int autoprobe;				/* !=0 : do autoprobe	    */
+
+	struct atari_disk_type	*disktype;	/* current type of disk */
+
+	int track;		/* current head position or -1 if
+				   unknown */
+	unsigned int steprate;	/* steprate setting */
+	unsigned int wpstat;	/* current state of WP signal (for
+				   disk change detection) */
+	int flags;		/* flags */
+	struct gendisk *disk;
+	int ref;
+	int type;
+} unit[FD_MAX_UNITS];
+
+#define	UD	unit[drive]
+#define	UDT	unit[drive].disktype
+#define	SUD	unit[SelectedDrive]
+#define	SUDT	unit[SelectedDrive].disktype
+
+
+#define FDC_READ(reg) ({			\
+    /* unsigned long __flags; */		\
+    unsigned short __val;			\
+    /* local_irq_save(__flags); */		\
+    dma_wd.dma_mode_status = 0x80 | (reg);	\
+    udelay(25);					\
+    __val = dma_wd.fdc_acces_seccount;		\
+    MFPDELAY();					\
+    /* local_irq_restore(__flags); */		\
+    __val & 0xff;				\
+})
+
+#define FDC_WRITE(reg,val)			\
+    do {					\
+	/* unsigned long __flags; */		\
+	/* local_irq_save(__flags); */		\
+	dma_wd.dma_mode_status = 0x80 | (reg);	\
+	udelay(25);				\
+	dma_wd.fdc_acces_seccount = (val);	\
+	MFPDELAY();				\
+        /* local_irq_restore(__flags); */	\
+    } while(0)
+
+
+/* Buffering variables:
+ * First, there is a DMA buffer in ST-RAM that is used for floppy DMA
+ * operations. Second, a track buffer is used to cache a whole track
+ * of the disk to save read operations. These are two separate buffers
+ * because that allows write operations without clearing the track buffer.
+ */
+
+static int MaxSectors[] = {
+	11, 22, 44
+};
+static int BufferSize[] = {
+	15*512, 30*512, 60*512
+};
+
+#define	BUFFER_SIZE	(BufferSize[DriveType])
+
+unsigned char *DMABuffer;			  /* buffer for writes */
+static unsigned long PhysDMABuffer;   /* physical address */
+
+static int UseTrackbuffer = -1;		  /* Do track buffering? */
+module_param(UseTrackbuffer, int, 0);
+
+unsigned char *TrackBuffer;			  /* buffer for reads */
+static unsigned long PhysTrackBuffer; /* physical address */
+static int BufferDrive, BufferSide, BufferTrack;
+static int read_track;		/* non-zero if we are reading whole tracks */
+
+#define	SECTOR_BUFFER(sec)	(TrackBuffer + ((sec)-1)*512)
+#define	IS_BUFFERED(drive,side,track) \
+    (BufferDrive == (drive) && BufferSide == (side) && BufferTrack == (track))
+
+/*
+ * These are global variables, as that's the easiest way to give
+ * information to interrupts. They are the data used for the current
+ * request.
+ */
+static int SelectedDrive = 0;
+static int ReqCmd, ReqBlock;
+static int ReqSide, ReqTrack, ReqSector, ReqCnt;
+static int HeadSettleFlag = 0;
+static unsigned char *ReqData, *ReqBuffer;
+static int MotorOn = 0, MotorOffTrys;
+static int IsFormatting = 0, FormatError;
+
+static int UserSteprate[FD_MAX_UNITS] = { -1, -1 };
+module_param_array(UserSteprate, int, NULL, 0);
+
+/* Synchronization of FDC access. */
+static volatile int fdc_busy = 0;
+static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
+static DECLARE_COMPLETION(format_wait);
+
+static unsigned long changed_floppies = 0xff, fake_change = 0;
+#define	CHECK_CHANGE_DELAY	HZ/2
+
+#define	FD_MOTOR_OFF_DELAY	(3*HZ)
+#define	FD_MOTOR_OFF_MAXTRY	(10*20)
+
+#define FLOPPY_TIMEOUT		(6*HZ)
+#define RECALIBRATE_ERRORS	4	/* After this many errors the drive
+					 * will be recalibrated. */
+#define MAX_ERRORS		8	/* After this many errors the driver
+					 * will give up. */
+
+
+/*
+ * The driver is trying to determine the correct media format
+ * while Probing is set. fd_rwsec_done() clears it after a
+ * successful access.
+ */
+static int Probing = 0;
+
+/* This flag is set when a dummy seek is necessary to make the WP
+ * status bit accessible.
+ */
+static int NeedSeek = 0;
+
+
+#ifdef DEBUG
+#define DPRINT(a)	printk a
+#else
+#define DPRINT(a)
+#endif
+
+/***************************** Prototypes *****************************/
+
+static void fd_select_side( int side );
+static void fd_select_drive( int drive );
+static void fd_deselect( void );
+static void fd_motor_off_timer(struct timer_list *unused);
+static void check_change(struct timer_list *unused);
+static irqreturn_t floppy_irq (int irq, void *dummy);
+static void fd_error( void );
+static int do_format(int drive, int type, struct atari_format_descr *desc);
+static void do_fd_action( int drive );
+static void fd_calibrate( void );
+static void fd_calibrate_done( int status );
+static void fd_seek( void );
+static void fd_seek_done( int status );
+static void fd_rwsec( void );
+static void fd_readtrack_check(struct timer_list *unused);
+static void fd_rwsec_done( int status );
+static void fd_rwsec_done1(int status);
+static void fd_writetrack( void );
+static void fd_writetrack_done( int status );
+static void fd_times_out(struct timer_list *unused);
+static void finish_fdc( void );
+static void finish_fdc_done( int dummy );
+static void setup_req_params( int drive );
+static void redo_fd_request( void);
+static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
+                     cmd, unsigned long param);
+static void fd_probe( int drive );
+static int fd_test_drive_present( int drive );
+static void config_types( void );
+static int floppy_open(struct block_device *bdev, fmode_t mode);
+static void floppy_release(struct gendisk *disk, fmode_t mode);
+
+/************************* End of Prototypes **************************/
+
+static DEFINE_TIMER(motor_off_timer, fd_motor_off_timer);
+static DEFINE_TIMER(readtrack_timer, fd_readtrack_check);
+static DEFINE_TIMER(timeout_timer, fd_times_out);
+static DEFINE_TIMER(fd_timer, check_change);
+	
+static void fd_end_request_cur(blk_status_t err)
+{
+	if (!__blk_end_request_cur(fd_request, err))
+		fd_request = NULL;
+}
+
+static inline void start_motor_off_timer(void)
+{
+	mod_timer(&motor_off_timer, jiffies + FD_MOTOR_OFF_DELAY);
+	MotorOffTrys = 0;
+}
+
+static inline void start_check_change_timer( void )
+{
+	mod_timer(&fd_timer, jiffies + CHECK_CHANGE_DELAY);
+}
+
+static inline void start_timeout(void)
+{
+	mod_timer(&timeout_timer, jiffies + FLOPPY_TIMEOUT);
+}
+
+static inline void stop_timeout(void)
+{
+	del_timer(&timeout_timer);
+}
+
+/* Select the side to use. */
+
+static void fd_select_side( int side )
+{
+	unsigned long flags;
+
+	/* protect against various other ints mucking around with the PSG */
+	local_irq_save(flags);
+  
+	sound_ym.rd_data_reg_sel = 14; /* Select PSG Port A */
+	sound_ym.wd_data = (side == 0) ? sound_ym.rd_data_reg_sel | 0x01 :
+	                                 sound_ym.rd_data_reg_sel & 0xfe;
+
+	local_irq_restore(flags);
+}
+
+
+/* Select a drive, update the FDC's track register and set the correct
+ * clock speed for this disk's type.
+ */
+
+static void fd_select_drive( int drive )
+{
+	unsigned long flags;
+	unsigned char tmp;
+  
+	if (drive == SelectedDrive)
+	  return;
+
+	/* protect against various other ints mucking around with the PSG */
+	local_irq_save(flags);
+	sound_ym.rd_data_reg_sel = 14; /* Select PSG Port A */
+	tmp = sound_ym.rd_data_reg_sel;
+	sound_ym.wd_data = (tmp | DSKDRVNONE) & ~(drive == 0 ? DSKDRV0 : DSKDRV1);
+	atari_dont_touch_floppy_select = 1;
+	local_irq_restore(flags);
+
+	/* restore track register to saved value */
+	FDC_WRITE( FDCREG_TRACK, UD.track );
+	udelay(25);
+
+	/* select 8/16 MHz */
+	if (UDT)
+		if (ATARIHW_PRESENT(FDCSPEED))
+			dma_wd.fdc_speed = UDT->fdc_speed;
+	
+	SelectedDrive = drive;
+}
+
+
+/* Deselect both drives. */
+
+static void fd_deselect( void )
+{
+	unsigned long flags;
+
+	/* protect against various other ints mucking around with the PSG */
+	local_irq_save(flags);
+	atari_dont_touch_floppy_select = 0;
+	sound_ym.rd_data_reg_sel=14;	/* Select PSG Port A */
+	sound_ym.wd_data = (sound_ym.rd_data_reg_sel |
+			    (MACH_IS_FALCON ? 3 : 7)); /* no drives selected */
+	/* On Falcon, the drive B select line is used on the printer port, so
+	 * leave it alone... */
+	SelectedDrive = -1;
+	local_irq_restore(flags);
+}
+
+
+/* This timer function deselects the drives when the FDC switched the
+ * motor off. The deselection cannot happen earlier because the FDC
+ * counts the index signals, which arrive only if one drive is selected.
+ */
+
+static void fd_motor_off_timer(struct timer_list *unused)
+{
+	unsigned char status;
+
+	if (SelectedDrive < 0)
+		/* no drive selected, needn't deselect anyone */
+		return;
+
+	if (stdma_islocked())
+		goto retry;
+
+	status = FDC_READ( FDCREG_STATUS );
+
+	if (!(status & 0x80)) {
+		/* motor already turned off by FDC -> deselect drives */
+		MotorOn = 0;
+		fd_deselect();
+		return;
+	}
+	/* not yet off, try again */
+
+  retry:
+	/* Test again later; if tested too often, it seems there is no disk
+	 * in the drive and the FDC will leave the motor on forever (or,
+	 * at least until a disk is inserted). So we'll test only twice
+	 * per second from then on...
+	 */
+	mod_timer(&motor_off_timer,
+		  jiffies + (MotorOffTrys++ < FD_MOTOR_OFF_MAXTRY ? HZ/20 : HZ/2));
+}
+
+
+/* This function is repeatedly called to detect disk changes (as good
+ * as possible) and keep track of the current state of the write protection.
+ */
+
+static void check_change(struct timer_list *unused)
+{
+	static int    drive = 0;
+
+	unsigned long flags;
+	unsigned char old_porta;
+	int			  stat;
+
+	if (++drive > 1 || !UD.connected)
+		drive = 0;
+
+	/* protect against various other ints mucking around with the PSG */
+	local_irq_save(flags);
+
+	if (!stdma_islocked()) {
+		sound_ym.rd_data_reg_sel = 14;
+		old_porta = sound_ym.rd_data_reg_sel;
+		sound_ym.wd_data = (old_porta | DSKDRVNONE) &
+			               ~(drive == 0 ? DSKDRV0 : DSKDRV1);
+		stat = !!(FDC_READ( FDCREG_STATUS ) & FDCSTAT_WPROT);
+		sound_ym.wd_data = old_porta;
+
+		if (stat != UD.wpstat) {
+			DPRINT(( "wpstat[%d] = %d\n", drive, stat ));
+			UD.wpstat = stat;
+			set_bit (drive, &changed_floppies);
+		}
+	}
+	local_irq_restore(flags);
+
+	start_check_change_timer();
+}
+
+ 
+/* Handling of the Head Settling Flag: This flag should be set after each
+ * seek operation, because we don't use seeks with verify.
+ */
+
+static inline void set_head_settle_flag(void)
+{
+	HeadSettleFlag = FDCCMDADD_E;
+}
+
+static inline int get_head_settle_flag(void)
+{
+	int	tmp = HeadSettleFlag;
+	HeadSettleFlag = 0;
+	return( tmp );
+}
+
+static inline void copy_buffer(void *from, void *to)
+{
+	ulong *p1 = (ulong *)from, *p2 = (ulong *)to;
+	int cnt;
+
+	for (cnt = 512/4; cnt; cnt--)
+		*p2++ = *p1++;
+}
+
+  
+  
+
+/* General Interrupt Handling */
+
+static void (*FloppyIRQHandler)( int status ) = NULL;
+
+static irqreturn_t floppy_irq (int irq, void *dummy)
+{
+	unsigned char status;
+	void (*handler)( int );
+
+	handler = xchg(&FloppyIRQHandler, NULL);
+
+	if (handler) {
+		nop();
+		status = FDC_READ( FDCREG_STATUS );
+		DPRINT(("FDC irq, status = %02x handler = %08lx\n",status,(unsigned long)handler));
+		handler( status );
+	}
+	else {
+		DPRINT(("FDC irq, no handler\n"));
+	}
+	return IRQ_HANDLED;
+}
+
+
+/* Error handling: If some error happened, retry some times, then
+ * recalibrate, then try again, and fail after MAX_ERRORS.
+ */
+
+static void fd_error( void )
+{
+	if (IsFormatting) {
+		IsFormatting = 0;
+		FormatError = 1;
+		complete(&format_wait);
+		return;
+	}
+
+	if (!fd_request)
+		return;
+
+	fd_request->error_count++;
+	if (fd_request->error_count >= MAX_ERRORS) {
+		printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
+		fd_end_request_cur(BLK_STS_IOERR);
+	}
+	else if (fd_request->error_count == RECALIBRATE_ERRORS) {
+		printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive );
+		if (SelectedDrive != -1)
+			SUD.track = -1;
+	}
+	redo_fd_request();
+}
+
+
+
+#define	SET_IRQ_HANDLER(proc) do { FloppyIRQHandler = (proc); } while(0)
+
+
+/* ---------- Formatting ---------- */
+
+#define FILL(n,val)		\
+    do {			\
+	memset( p, val, n );	\
+	p += n;			\
+    } while(0)
+
+static int do_format(int drive, int type, struct atari_format_descr *desc)
+{
+	unsigned char	*p;
+	int sect, nsect;
+	unsigned long	flags;
+
+	DPRINT(("do_format( dr=%d tr=%d he=%d offs=%d )\n",
+		drive, desc->track, desc->head, desc->sect_offset ));
+
+	wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
+	local_irq_save(flags);
+	stdma_lock(floppy_irq, NULL);
+	atari_turnon_irq( IRQ_MFP_FDC ); /* should be already, just to be sure */
+	local_irq_restore(flags);
+
+	if (type) {
+		if (--type >= NUM_DISK_MINORS ||
+		    minor2disktype[type].drive_types > DriveType) {
+			redo_fd_request();
+			return -EINVAL;
+		}
+		type = minor2disktype[type].index;
+		UDT = &atari_disk_type[type];
+	}
+
+	if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) {
+		redo_fd_request();
+		return -EINVAL;
+	}
+
+	nsect = UDT->spt;
+	p = TrackBuffer;
+	/* The track buffer is used for the raw track data, so its
+	   contents become invalid! */
+	BufferDrive = -1;
+	/* stop deselect timer */
+	del_timer( &motor_off_timer );
+
+	FILL( 60 * (nsect / 9), 0x4e );
+	for( sect = 0; sect < nsect; ++sect ) {
+		FILL( 12, 0 );
+		FILL( 3, 0xf5 );
+		*p++ = 0xfe;
+		*p++ = desc->track;
+		*p++ = desc->head;
+		*p++ = (nsect + sect - desc->sect_offset) % nsect + 1;
+		*p++ = 2;
+		*p++ = 0xf7;
+		FILL( 22, 0x4e );
+		FILL( 12, 0 );
+		FILL( 3, 0xf5 );
+		*p++ = 0xfb;
+		FILL( 512, 0xe5 );
+		*p++ = 0xf7;
+		FILL( 40, 0x4e );
+	}
+	FILL( TrackBuffer+BUFFER_SIZE-p, 0x4e );
+
+	IsFormatting = 1;
+	FormatError = 0;
+	ReqTrack = desc->track;
+	ReqSide  = desc->head;
+	do_fd_action( drive );
+
+	wait_for_completion(&format_wait);
+
+	redo_fd_request();
+	return( FormatError ? -EIO : 0 );	
+}
+
+
+/* do_fd_action() is the general procedure for a fd request: All
+ * required parameter settings (drive select, side select, track
+ * position) are checked and set if needed. For each of these
+ * parameters and the actual reading or writing exist two functions:
+ * one that starts the setting (or skips it if possible) and one
+ * callback for the "done" interrupt. Each done func calls the next
+ * set function to propagate the request down to fd_rwsec_done().
+ */
+
+static void do_fd_action( int drive )
+{
+	DPRINT(("do_fd_action\n"));
+	
+	if (UseTrackbuffer && !IsFormatting) {
+	repeat:
+	    if (IS_BUFFERED( drive, ReqSide, ReqTrack )) {
+		if (ReqCmd == READ) {
+		    copy_buffer( SECTOR_BUFFER(ReqSector), ReqData );
+		    if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
+			/* read next sector */
+			setup_req_params( drive );
+			goto repeat;
+		    }
+		    else {
+			/* all sectors finished */
+			fd_end_request_cur(BLK_STS_OK);
+			redo_fd_request();
+			return;
+		    }
+		}
+		else {
+		    /* cmd == WRITE, pay attention to track buffer
+		     * consistency! */
+		    copy_buffer( ReqData, SECTOR_BUFFER(ReqSector) );
+		}
+	    }
+	}
+
+	if (SelectedDrive != drive)
+		fd_select_drive( drive );
+    
+	if (UD.track == -1)
+		fd_calibrate();
+	else if (UD.track != ReqTrack << UDT->stretch)
+		fd_seek();
+	else if (IsFormatting)
+		fd_writetrack();
+	else
+		fd_rwsec();
+}
+
+
+/* Seek to track 0 if the current track is unknown */
+
+static void fd_calibrate( void )
+{
+	if (SUD.track >= 0) {
+		fd_calibrate_done( 0 );
+		return;
+	}
+
+	if (ATARIHW_PRESENT(FDCSPEED))
+		dma_wd.fdc_speed = 0; 	/* always seek with 8 Mhz */;
+	DPRINT(("fd_calibrate\n"));
+	SET_IRQ_HANDLER( fd_calibrate_done );
+	/* we can't verify, since the speed may be incorrect */
+	FDC_WRITE( FDCREG_CMD, FDCCMD_RESTORE | SUD.steprate );
+
+	NeedSeek = 1;
+	MotorOn = 1;
+	start_timeout();
+	/* wait for IRQ */
+}
+
+
+static void fd_calibrate_done( int status )
+{
+	DPRINT(("fd_calibrate_done()\n"));
+	stop_timeout();
+    
+	/* set the correct speed now */
+	if (ATARIHW_PRESENT(FDCSPEED))
+		dma_wd.fdc_speed = SUDT->fdc_speed;
+	if (status & FDCSTAT_RECNF) {
+		printk(KERN_ERR "fd%d: restore failed\n", SelectedDrive );
+		fd_error();
+	}
+	else {
+		SUD.track = 0;
+		fd_seek();
+	}
+}
+  
+  
+/* Seek the drive to the requested track. The drive must have been
+ * calibrated at some point before this.
+ */
+  
+static void fd_seek( void )
+{
+	if (SUD.track == ReqTrack << SUDT->stretch) {
+		fd_seek_done( 0 );
+		return;
+	}
+
+	if (ATARIHW_PRESENT(FDCSPEED)) {
+		dma_wd.fdc_speed = 0;	/* always seek witch 8 Mhz */
+		MFPDELAY();
+	}
+
+	DPRINT(("fd_seek() to track %d\n",ReqTrack));
+	FDC_WRITE( FDCREG_DATA, ReqTrack << SUDT->stretch);
+	udelay(25);
+	SET_IRQ_HANDLER( fd_seek_done );
+	FDC_WRITE( FDCREG_CMD, FDCCMD_SEEK | SUD.steprate );
+
+	MotorOn = 1;
+	set_head_settle_flag();
+	start_timeout();
+	/* wait for IRQ */
+}
+
+
+static void fd_seek_done( int status )
+{
+	DPRINT(("fd_seek_done()\n"));
+	stop_timeout();
+	
+	/* set the correct speed */
+	if (ATARIHW_PRESENT(FDCSPEED))
+		dma_wd.fdc_speed = SUDT->fdc_speed;
+	if (status & FDCSTAT_RECNF) {
+		printk(KERN_ERR "fd%d: seek error (to track %d)\n",
+				SelectedDrive, ReqTrack );
+		/* we don't know exactly which track we are on now! */
+		SUD.track = -1;
+		fd_error();
+	}
+	else {
+		SUD.track = ReqTrack << SUDT->stretch;
+		NeedSeek = 0;
+		if (IsFormatting)
+			fd_writetrack();
+		else
+			fd_rwsec();
+	}
+}
+
+
+/* This does the actual reading/writing after positioning the head
+ * over the correct track.
+ */
+
+static int MultReadInProgress = 0;
+
+
+static void fd_rwsec( void )
+{
+	unsigned long paddr, flags;
+	unsigned int  rwflag, old_motoron;
+	unsigned int track;
+	
+	DPRINT(("fd_rwsec(), Sec=%d, Access=%c\n",ReqSector, ReqCmd == WRITE ? 'w' : 'r' ));
+	if (ReqCmd == WRITE) {
+		if (ATARIHW_PRESENT(EXTD_DMA)) {
+			paddr = virt_to_phys(ReqData);
+		}
+		else {
+			copy_buffer( ReqData, DMABuffer );
+			paddr = PhysDMABuffer;
+		}
+		dma_cache_maintenance( paddr, 512, 1 );
+		rwflag = 0x100;
+	}
+	else {
+		if (read_track)
+			paddr = PhysTrackBuffer;
+		else
+			paddr = ATARIHW_PRESENT(EXTD_DMA) ? 
+				virt_to_phys(ReqData) : PhysDMABuffer;
+		rwflag = 0;
+	}
+
+	fd_select_side( ReqSide );
+  
+	/* Start sector of this operation */
+	FDC_WRITE( FDCREG_SECTOR, read_track ? 1 : ReqSector );
+	MFPDELAY();
+	/* Cheat for track if stretch != 0 */
+	if (SUDT->stretch) {
+		track = FDC_READ( FDCREG_TRACK);
+		MFPDELAY();
+		FDC_WRITE( FDCREG_TRACK, track >> SUDT->stretch);
+	}
+	udelay(25);
+  
+	/* Setup DMA */
+	local_irq_save(flags);
+	dma_wd.dma_lo = (unsigned char)paddr;
+	MFPDELAY();
+	paddr >>= 8;
+	dma_wd.dma_md = (unsigned char)paddr;
+	MFPDELAY();
+	paddr >>= 8;
+	if (ATARIHW_PRESENT(EXTD_DMA))
+		st_dma_ext_dmahi = (unsigned short)paddr;
+	else
+		dma_wd.dma_hi = (unsigned char)paddr;
+	MFPDELAY();
+	local_irq_restore(flags);
+  
+	/* Clear FIFO and switch DMA to correct mode */  
+	dma_wd.dma_mode_status = 0x90 | rwflag;  
+	MFPDELAY();
+	dma_wd.dma_mode_status = 0x90 | (rwflag ^ 0x100);  
+	MFPDELAY();
+	dma_wd.dma_mode_status = 0x90 | rwflag;
+	MFPDELAY();
+  
+	/* How many sectors for DMA */
+	dma_wd.fdc_acces_seccount = read_track ? SUDT->spt : 1;
+  
+	udelay(25);  
+  
+	/* Start operation */
+	dma_wd.dma_mode_status = FDCSELREG_STP | rwflag;
+	udelay(25);
+	SET_IRQ_HANDLER( fd_rwsec_done );
+	dma_wd.fdc_acces_seccount =
+	  (get_head_settle_flag() |
+	   (rwflag ? FDCCMD_WRSEC : (FDCCMD_RDSEC | (read_track ? FDCCMDADD_M : 0))));
+
+	old_motoron = MotorOn;
+	MotorOn = 1;
+	NeedSeek = 1;
+	/* wait for interrupt */
+
+	if (read_track) {
+		/* If reading a whole track, wait about one disk rotation and
+		 * then check if all sectors are read. The FDC will even
+		 * search for the first non-existent sector and need 1 sec to
+		 * recognise that it isn't present :-(
+		 */
+		MultReadInProgress = 1;
+		mod_timer(&readtrack_timer,
+			  /* 1 rot. + 5 rot.s if motor was off  */
+			  jiffies + HZ/5 + (old_motoron ? 0 : HZ));
+	}
+	start_timeout();
+}
+
+    
+static void fd_readtrack_check(struct timer_list *unused)
+{
+	unsigned long flags, addr, addr2;
+
+	local_irq_save(flags);
+
+	if (!MultReadInProgress) {
+		/* This prevents a race condition that could arise if the
+		 * interrupt is triggered while the calling of this timer
+		 * callback function takes place. The IRQ function then has
+		 * already cleared 'MultReadInProgress'  when flow of control
+		 * gets here.
+		 */
+		local_irq_restore(flags);
+		return;
+	}
+
+	/* get the current DMA address */
+	/* ++ f.a. read twice to avoid being fooled by switcher */
+	addr = 0;
+	do {
+		addr2 = addr;
+		addr = dma_wd.dma_lo & 0xff;
+		MFPDELAY();
+		addr |= (dma_wd.dma_md & 0xff) << 8;
+		MFPDELAY();
+		if (ATARIHW_PRESENT( EXTD_DMA ))
+			addr |= (st_dma_ext_dmahi & 0xffff) << 16;
+		else
+			addr |= (dma_wd.dma_hi & 0xff) << 16;
+		MFPDELAY();
+	} while(addr != addr2);
+  
+	if (addr >= PhysTrackBuffer + SUDT->spt*512) {
+		/* already read enough data, force an FDC interrupt to stop
+		 * the read operation
+		 */
+		SET_IRQ_HANDLER( NULL );
+		MultReadInProgress = 0;
+		local_irq_restore(flags);
+		DPRINT(("fd_readtrack_check(): done\n"));
+		FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
+		udelay(25);
+
+		/* No error until now -- the FDC would have interrupted
+		 * otherwise!
+		 */
+		fd_rwsec_done1(0);
+	}
+	else {
+		/* not yet finished, wait another tenth rotation */
+		local_irq_restore(flags);
+		DPRINT(("fd_readtrack_check(): not yet finished\n"));
+		mod_timer(&readtrack_timer, jiffies + HZ/5/10);
+	}
+}
+
+
+static void fd_rwsec_done( int status )
+{
+	DPRINT(("fd_rwsec_done()\n"));
+
+	if (read_track) {
+		del_timer(&readtrack_timer);
+		if (!MultReadInProgress)
+			return;
+		MultReadInProgress = 0;
+	}
+	fd_rwsec_done1(status);
+}
+
+static void fd_rwsec_done1(int status)
+{
+	unsigned int track;
+
+	stop_timeout();
+	
+	/* Correct the track if stretch != 0 */
+	if (SUDT->stretch) {
+		track = FDC_READ( FDCREG_TRACK);
+		MFPDELAY();
+		FDC_WRITE( FDCREG_TRACK, track << SUDT->stretch);
+	}
+
+	if (!UseTrackbuffer) {
+		dma_wd.dma_mode_status = 0x90;
+		MFPDELAY();
+		if (!(dma_wd.dma_mode_status & 0x01)) {
+			printk(KERN_ERR "fd%d: DMA error\n", SelectedDrive );
+			goto err_end;
+		}
+	}
+	MFPDELAY();
+
+	if (ReqCmd == WRITE && (status & FDCSTAT_WPROT)) {
+		printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
+		goto err_end;
+	}	
+	if ((status & FDCSTAT_RECNF) &&
+	    /* RECNF is no error after a multiple read when the FDC
+	       searched for a non-existent sector! */
+	    !(read_track && FDC_READ(FDCREG_SECTOR) > SUDT->spt)) {
+		if (Probing) {
+			if (SUDT > atari_disk_type) {
+			    if (SUDT[-1].blocks > ReqBlock) {
+				/* try another disk type */
+				SUDT--;
+				set_capacity(unit[SelectedDrive].disk,
+							SUDT->blocks);
+			    } else
+				Probing = 0;
+			}
+			else {
+				if (SUD.flags & FTD_MSG)
+					printk(KERN_INFO "fd%d: Auto-detected floppy type %s\n",
+					       SelectedDrive, SUDT->name );
+				Probing=0;
+			}
+		} else {	
+/* record not found, but not probing. Maybe stretch wrong ? Restart probing */
+			if (SUD.autoprobe) {
+				SUDT = atari_disk_type + StartDiskType[DriveType];
+				set_capacity(unit[SelectedDrive].disk,
+							SUDT->blocks);
+				Probing = 1;
+			}
+		}
+		if (Probing) {
+			if (ATARIHW_PRESENT(FDCSPEED)) {
+				dma_wd.fdc_speed = SUDT->fdc_speed;
+				MFPDELAY();
+			}
+			setup_req_params( SelectedDrive );
+			BufferDrive = -1;
+			do_fd_action( SelectedDrive );
+			return;
+		}
+
+		printk(KERN_ERR "fd%d: sector %d not found (side %d, track %d)\n",
+		       SelectedDrive, FDC_READ (FDCREG_SECTOR), ReqSide, ReqTrack );
+		goto err_end;
+	}
+	if (status & FDCSTAT_CRC) {
+		printk(KERN_ERR "fd%d: CRC error (side %d, track %d, sector %d)\n",
+		       SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
+		goto err_end;
+	}
+	if (status & FDCSTAT_LOST) {
+		printk(KERN_ERR "fd%d: lost data (side %d, track %d, sector %d)\n",
+		       SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
+		goto err_end;
+	}
+
+	Probing = 0;
+	
+	if (ReqCmd == READ) {
+		if (!read_track) {
+			void *addr;
+			addr = ATARIHW_PRESENT( EXTD_DMA ) ? ReqData : DMABuffer;
+			dma_cache_maintenance( virt_to_phys(addr), 512, 0 );
+			if (!ATARIHW_PRESENT( EXTD_DMA ))
+				copy_buffer (addr, ReqData);
+		} else {
+			dma_cache_maintenance( PhysTrackBuffer, MaxSectors[DriveType] * 512, 0 );
+			BufferDrive = SelectedDrive;
+			BufferSide  = ReqSide;
+			BufferTrack = ReqTrack;
+			copy_buffer (SECTOR_BUFFER (ReqSector), ReqData);
+		}
+	}
+  
+	if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
+		/* read next sector */
+		setup_req_params( SelectedDrive );
+		do_fd_action( SelectedDrive );
+	}
+	else {
+		/* all sectors finished */
+		fd_end_request_cur(BLK_STS_OK);
+		redo_fd_request();
+	}
+	return;
+  
+  err_end:
+	BufferDrive = -1;
+	fd_error();
+}
+
+
+static void fd_writetrack( void )
+{
+	unsigned long paddr, flags;
+	unsigned int track;
+	
+	DPRINT(("fd_writetrack() Tr=%d Si=%d\n", ReqTrack, ReqSide ));
+
+	paddr = PhysTrackBuffer;
+	dma_cache_maintenance( paddr, BUFFER_SIZE, 1 );
+
+	fd_select_side( ReqSide );
+  
+	/* Cheat for track if stretch != 0 */
+	if (SUDT->stretch) {
+		track = FDC_READ( FDCREG_TRACK);
+		MFPDELAY();
+		FDC_WRITE(FDCREG_TRACK,track >> SUDT->stretch);
+	}
+	udelay(40);
+  
+	/* Setup DMA */
+	local_irq_save(flags);
+	dma_wd.dma_lo = (unsigned char)paddr;
+	MFPDELAY();
+	paddr >>= 8;
+	dma_wd.dma_md = (unsigned char)paddr;
+	MFPDELAY();
+	paddr >>= 8;
+	if (ATARIHW_PRESENT( EXTD_DMA ))
+		st_dma_ext_dmahi = (unsigned short)paddr;
+	else
+		dma_wd.dma_hi = (unsigned char)paddr;
+	MFPDELAY();
+	local_irq_restore(flags);
+  
+	/* Clear FIFO and switch DMA to correct mode */  
+	dma_wd.dma_mode_status = 0x190;  
+	MFPDELAY();
+	dma_wd.dma_mode_status = 0x90;  
+	MFPDELAY();
+	dma_wd.dma_mode_status = 0x190;
+	MFPDELAY();
+  
+	/* How many sectors for DMA */
+	dma_wd.fdc_acces_seccount = BUFFER_SIZE/512;
+	udelay(40);  
+  
+	/* Start operation */
+	dma_wd.dma_mode_status = FDCSELREG_STP | 0x100;
+	udelay(40);
+	SET_IRQ_HANDLER( fd_writetrack_done );
+	dma_wd.fdc_acces_seccount = FDCCMD_WRTRA | get_head_settle_flag(); 
+
+	MotorOn = 1;
+	start_timeout();
+	/* wait for interrupt */
+}
+
+
+static void fd_writetrack_done( int status )
+{
+	DPRINT(("fd_writetrack_done()\n"));
+
+	stop_timeout();
+
+	if (status & FDCSTAT_WPROT) {
+		printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
+		goto err_end;
+	}	
+	if (status & FDCSTAT_LOST) {
+		printk(KERN_ERR "fd%d: lost data (side %d, track %d)\n",
+				SelectedDrive, ReqSide, ReqTrack );
+		goto err_end;
+	}
+
+	complete(&format_wait);
+	return;
+
+  err_end:
+	fd_error();
+}
+
+static void fd_times_out(struct timer_list *unused)
+{
+	atari_disable_irq( IRQ_MFP_FDC );
+	if (!FloppyIRQHandler) goto end; /* int occurred after timer was fired, but
+					  * before we came here... */
+
+	SET_IRQ_HANDLER( NULL );
+	/* If the timeout occurred while the readtrack_check timer was
+	 * active, we need to cancel it, else bad things will happen */
+	if (UseTrackbuffer)
+		del_timer( &readtrack_timer );
+	FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
+	udelay( 25 );
+	
+	printk(KERN_ERR "floppy timeout\n" );
+	fd_error();
+  end:
+	atari_enable_irq( IRQ_MFP_FDC );
+}
+
+
+/* The (noop) seek operation here is needed to make the WP bit in the
+ * FDC status register accessible for check_change. If the last disk
+ * operation would have been a RDSEC, this bit would always read as 0
+ * no matter what :-( To save time, the seek goes to the track we're
+ * already on.
+ */
+
+static void finish_fdc( void )
+{
+	if (!NeedSeek) {
+		finish_fdc_done( 0 );
+	}
+	else {
+		DPRINT(("finish_fdc: dummy seek started\n"));
+		FDC_WRITE (FDCREG_DATA, SUD.track);
+		SET_IRQ_HANDLER( finish_fdc_done );
+		FDC_WRITE (FDCREG_CMD, FDCCMD_SEEK);
+		MotorOn = 1;
+		start_timeout();
+		/* we must wait for the IRQ here, because the ST-DMA
+		   is released immediately afterwards and the interrupt
+		   may be delivered to the wrong driver. */
+	  }
+}
+
+
+static void finish_fdc_done( int dummy )
+{
+	unsigned long flags;
+
+	DPRINT(("finish_fdc_done entered\n"));
+	stop_timeout();
+	NeedSeek = 0;
+
+	if (timer_pending(&fd_timer) && time_before(fd_timer.expires, jiffies + 5))
+		/* If the check for a disk change is done too early after this
+		 * last seek command, the WP bit still reads wrong :-((
+		 */
+		mod_timer(&fd_timer, jiffies + 5);
+	else
+		start_check_change_timer();
+	start_motor_off_timer();
+
+	local_irq_save(flags);
+	stdma_release();
+	fdc_busy = 0;
+	wake_up( &fdc_wait );
+	local_irq_restore(flags);
+
+	DPRINT(("finish_fdc() finished\n"));
+}
+
+/* The detection of disk changes is a dark chapter in Atari history :-(
+ * Because the "Drive ready" signal isn't present in the Atari
+ * hardware, one has to rely on the "Write Protect". This works fine,
+ * as long as no write protected disks are used. TOS solves this
+ * problem by introducing tri-state logic ("maybe changed") and
+ * looking at the serial number in block 0. This isn't possible for
+ * Linux, since the floppy driver can't make assumptions about the
+ * filesystem used on the disk and thus the contents of block 0. I've
+ * chosen the method to always say "The disk was changed" if it is
+ * unsure whether it was. This implies that every open or mount
+ * invalidates the disk buffers if you work with write protected
+ * disks. But at least this is better than working with incorrect data
+ * due to unrecognised disk changes.
+ */
+
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing)
+{
+	struct atari_floppy_struct *p = disk->private_data;
+	unsigned int drive = p - unit;
+	if (test_bit (drive, &fake_change)) {
+		/* simulated change (e.g. after formatting) */
+		return DISK_EVENT_MEDIA_CHANGE;
+	}
+	if (test_bit (drive, &changed_floppies)) {
+		/* surely changed (the WP signal changed at least once) */
+		return DISK_EVENT_MEDIA_CHANGE;
+	}
+	if (UD.wpstat) {
+		/* WP is on -> could be changed: to be sure, buffers should be
+		 * invalidated...
+		 */
+		return DISK_EVENT_MEDIA_CHANGE;
+	}
+
+	return 0;
+}
+
+static int floppy_revalidate(struct gendisk *disk)
+{
+	struct atari_floppy_struct *p = disk->private_data;
+	unsigned int drive = p - unit;
+
+	if (test_bit(drive, &changed_floppies) ||
+	    test_bit(drive, &fake_change) ||
+	    p->disktype == 0) {
+		if (UD.flags & FTD_MSG)
+			printk(KERN_ERR "floppy: clear format %p!\n", UDT);
+		BufferDrive = -1;
+		clear_bit(drive, &fake_change);
+		clear_bit(drive, &changed_floppies);
+		/* MSch: clearing geometry makes sense only for autoprobe
+		   formats, for 'permanent user-defined' parameter:
+		   restore default_params[] here if flagged valid! */
+		if (default_params[drive].blocks == 0)
+			UDT = NULL;
+		else
+			UDT = &default_params[drive];
+	}
+	return 0;
+}
+
+
+/* This sets up the global variables describing the current request. */
+
+static void setup_req_params( int drive )
+{
+	int block = ReqBlock + ReqCnt;
+
+	ReqTrack = block / UDT->spt;
+	ReqSector = block - ReqTrack * UDT->spt + 1;
+	ReqSide = ReqTrack & 1;
+	ReqTrack >>= 1;
+	ReqData = ReqBuffer + 512 * ReqCnt;
+
+	if (UseTrackbuffer)
+		read_track = (ReqCmd == READ && fd_request->error_count == 0);
+	else
+		read_track = 0;
+
+	DPRINT(("Request params: Si=%d Tr=%d Se=%d Data=%08lx\n",ReqSide,
+			ReqTrack, ReqSector, (unsigned long)ReqData ));
+}
+
+/*
+ * Round-robin between our available drives, doing one request from each
+ */
+static struct request *set_next_request(void)
+{
+	struct request_queue *q;
+	int old_pos = fdc_queue;
+	struct request *rq = NULL;
+
+	do {
+		q = unit[fdc_queue].disk->queue;
+		if (++fdc_queue == FD_MAX_UNITS)
+			fdc_queue = 0;
+		if (q) {
+			rq = blk_fetch_request(q);
+			if (rq) {
+				rq->error_count = 0;
+				break;
+			}
+		}
+	} while (fdc_queue != old_pos);
+
+	return rq;
+}
+
+
+static void redo_fd_request(void)
+{
+	int drive, type;
+	struct atari_floppy_struct *floppy;
+
+	DPRINT(("redo_fd_request: fd_request=%p dev=%s fd_request->sector=%ld\n",
+		fd_request, fd_request ? fd_request->rq_disk->disk_name : "",
+		fd_request ? blk_rq_pos(fd_request) : 0 ));
+
+	IsFormatting = 0;
+
+repeat:
+	if (!fd_request) {
+		fd_request = set_next_request();
+		if (!fd_request)
+			goto the_end;
+	}
+
+	floppy = fd_request->rq_disk->private_data;
+	drive = floppy - unit;
+	type = floppy->type;
+	
+	if (!UD.connected) {
+		/* drive not connected */
+		printk(KERN_ERR "Unknown Device: fd%d\n", drive );
+		fd_end_request_cur(BLK_STS_IOERR);
+		goto repeat;
+	}
+		
+	if (type == 0) {
+		if (!UDT) {
+			Probing = 1;
+			UDT = atari_disk_type + StartDiskType[DriveType];
+			set_capacity(floppy->disk, UDT->blocks);
+			UD.autoprobe = 1;
+		}
+	} 
+	else {
+		/* user supplied disk type */
+		if (--type >= NUM_DISK_MINORS) {
+			printk(KERN_WARNING "fd%d: invalid disk format", drive );
+			fd_end_request_cur(BLK_STS_IOERR);
+			goto repeat;
+		}
+		if (minor2disktype[type].drive_types > DriveType)  {
+			printk(KERN_WARNING "fd%d: unsupported disk format", drive );
+			fd_end_request_cur(BLK_STS_IOERR);
+			goto repeat;
+		}
+		type = minor2disktype[type].index;
+		UDT = &atari_disk_type[type];
+		set_capacity(floppy->disk, UDT->blocks);
+		UD.autoprobe = 0;
+	}
+	
+	if (blk_rq_pos(fd_request) + 1 > UDT->blocks) {
+		fd_end_request_cur(BLK_STS_IOERR);
+		goto repeat;
+	}
+
+	/* stop deselect timer */
+	del_timer( &motor_off_timer );
+		
+	ReqCnt = 0;
+	ReqCmd = rq_data_dir(fd_request);
+	ReqBlock = blk_rq_pos(fd_request);
+	ReqBuffer = bio_data(fd_request->bio);
+	setup_req_params( drive );
+	do_fd_action( drive );
+
+	return;
+
+  the_end:
+	finish_fdc();
+}
+
+
+void do_fd_request(struct request_queue * q)
+{
+	DPRINT(("do_fd_request for pid %d\n",current->pid));
+	wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
+	stdma_lock(floppy_irq, NULL);
+
+	atari_disable_irq( IRQ_MFP_FDC );
+	redo_fd_request();
+	atari_enable_irq( IRQ_MFP_FDC );
+}
+
+static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
+		    unsigned int cmd, unsigned long param)
+{
+	struct gendisk *disk = bdev->bd_disk;
+	struct atari_floppy_struct *floppy = disk->private_data;
+	int drive = floppy - unit;
+	int type = floppy->type;
+	struct atari_format_descr fmt_desc;
+	struct atari_disk_type *dtp;
+	struct floppy_struct getprm;
+	int settype;
+	struct floppy_struct setprm;
+	void __user *argp = (void __user *)param;
+
+	switch (cmd) {
+	case FDGETPRM:
+		if (type) {
+			if (--type >= NUM_DISK_MINORS)
+				return -ENODEV;
+			if (minor2disktype[type].drive_types > DriveType)
+				return -ENODEV;
+			type = minor2disktype[type].index;
+			dtp = &atari_disk_type[type];
+			if (UD.flags & FTD_MSG)
+			    printk (KERN_ERR "floppy%d: found dtp %p name %s!\n",
+			        drive, dtp, dtp->name);
+		}
+		else {
+			if (!UDT)
+				return -ENXIO;
+			else
+				dtp = UDT;
+		}
+		memset((void *)&getprm, 0, sizeof(getprm));
+		getprm.size = dtp->blocks;
+		getprm.sect = dtp->spt;
+		getprm.head = 2;
+		getprm.track = dtp->blocks/dtp->spt/2;
+		getprm.stretch = dtp->stretch;
+		if (copy_to_user(argp, &getprm, sizeof(getprm)))
+			return -EFAULT;
+		return 0;
+	}
+	switch (cmd) {
+	case FDSETPRM:
+	case FDDEFPRM:
+	        /* 
+		 * MSch 7/96: simple 'set geometry' case: just set the
+		 * 'default' device params (minor == 0).
+		 * Currently, the drive geometry is cleared after each
+		 * disk change and subsequent revalidate()! simple
+		 * implementation of FDDEFPRM: save geometry from a
+		 * FDDEFPRM call and restore it in floppy_revalidate() !
+		 */
+
+		/* get the parameters from user space */
+		if (floppy->ref != 1 && floppy->ref != -1)
+			return -EBUSY;
+		if (copy_from_user(&setprm, argp, sizeof(setprm)))
+			return -EFAULT;
+		/* 
+		 * first of all: check for floppy change and revalidate, 
+		 * or the next access will revalidate - and clear UDT :-(
+		 */
+
+		if (floppy_check_events(disk, 0))
+		        floppy_revalidate(disk);
+
+		if (UD.flags & FTD_MSG)
+		    printk (KERN_INFO "floppy%d: setting size %d spt %d str %d!\n",
+			drive, setprm.size, setprm.sect, setprm.stretch);
+
+		/* what if type > 0 here? Overwrite specified entry ? */
+		if (type) {
+		        /* refuse to re-set a predefined type for now */
+			redo_fd_request();
+			return -EINVAL;
+		}
+
+		/* 
+		 * type == 0: first look for a matching entry in the type list,
+		 * and set the UD.disktype field to use the perdefined entry.
+		 * TODO: add user-defined format to head of autoprobe list ? 
+		 * Useful to include the user-type for future autodetection!
+		 */
+
+		for (settype = 0; settype < NUM_DISK_MINORS; settype++) {
+			int setidx = 0;
+			if (minor2disktype[settype].drive_types > DriveType) {
+				/* skip this one, invalid for drive ... */
+				continue;
+			}
+			setidx = minor2disktype[settype].index;
+			dtp = &atari_disk_type[setidx];
+
+			/* found matching entry ?? */
+			if (   dtp->blocks  == setprm.size 
+			    && dtp->spt     == setprm.sect
+			    && dtp->stretch == setprm.stretch ) {
+				if (UD.flags & FTD_MSG)
+				    printk (KERN_INFO "floppy%d: setting %s %p!\n",
+				        drive, dtp->name, dtp);
+				UDT = dtp;
+				set_capacity(floppy->disk, UDT->blocks);
+
+				if (cmd == FDDEFPRM) {
+				  /* save settings as permanent default type */
+				  default_params[drive].name    = dtp->name;
+				  default_params[drive].spt     = dtp->spt;
+				  default_params[drive].blocks  = dtp->blocks;
+				  default_params[drive].fdc_speed = dtp->fdc_speed;
+				  default_params[drive].stretch = dtp->stretch;
+				}
+				
+				return 0;
+			}
+
+		}
+
+		/* no matching disk type found above - setting user_params */
+
+	       	if (cmd == FDDEFPRM) {
+			/* set permanent type */
+			dtp = &default_params[drive];
+		} else
+			/* set user type (reset by disk change!) */
+			dtp = &user_params[drive];
+
+		dtp->name   = "user format";
+		dtp->blocks = setprm.size;
+		dtp->spt    = setprm.sect;
+		if (setprm.sect > 14) 
+			dtp->fdc_speed = 3;
+		else
+			dtp->fdc_speed = 0;
+		dtp->stretch = setprm.stretch;
+
+		if (UD.flags & FTD_MSG)
+			printk (KERN_INFO "floppy%d: blk %d spt %d str %d!\n",
+				drive, dtp->blocks, dtp->spt, dtp->stretch);
+
+		/* sanity check */
+		if (setprm.track != dtp->blocks/dtp->spt/2 ||
+		    setprm.head != 2) {
+			redo_fd_request();
+			return -EINVAL;
+		}
+
+		UDT = dtp;
+		set_capacity(floppy->disk, UDT->blocks);
+
+		return 0;
+	case FDMSGON:
+		UD.flags |= FTD_MSG;
+		return 0;
+	case FDMSGOFF:
+		UD.flags &= ~FTD_MSG;
+		return 0;
+	case FDSETEMSGTRESH:
+		return -EINVAL;
+	case FDFMTBEG:
+		return 0;
+	case FDFMTTRK:
+		if (floppy->ref != 1 && floppy->ref != -1)
+			return -EBUSY;
+		if (copy_from_user(&fmt_desc, argp, sizeof(fmt_desc)))
+			return -EFAULT;
+		return do_format(drive, type, &fmt_desc);
+	case FDCLRPRM:
+		UDT = NULL;
+		/* MSch: invalidate default_params */
+		default_params[drive].blocks  = 0;
+		set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
+	case FDFMTEND:
+	case FDFLUSH:
+		/* invalidate the buffer track to force a reread */
+		BufferDrive = -1;
+		set_bit(drive, &fake_change);
+		check_disk_change(bdev);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int fd_ioctl(struct block_device *bdev, fmode_t mode,
+			     unsigned int cmd, unsigned long arg)
+{
+	int ret;
+
+	mutex_lock(&ataflop_mutex);
+	ret = fd_locked_ioctl(bdev, mode, cmd, arg);
+	mutex_unlock(&ataflop_mutex);
+
+	return ret;
+}
+
+/* Initialize the 'unit' variable for drive 'drive' */
+
+static void __init fd_probe( int drive )
+{
+	UD.connected = 0;
+	UDT  = NULL;
+
+	if (!fd_test_drive_present( drive ))
+		return;
+
+	UD.connected = 1;
+	UD.track     = 0;
+	switch( UserSteprate[drive] ) {
+	case 2:
+		UD.steprate = FDCSTEP_2;
+		break;
+	case 3:
+		UD.steprate = FDCSTEP_3;
+		break;
+	case 6:
+		UD.steprate = FDCSTEP_6;
+		break;
+	case 12:
+		UD.steprate = FDCSTEP_12;
+		break;
+	default: /* should be -1 for "not set by user" */
+		if (ATARIHW_PRESENT( FDCSPEED ) || MACH_IS_MEDUSA)
+			UD.steprate = FDCSTEP_3;
+		else
+			UD.steprate = FDCSTEP_6;
+		break;
+	}
+	MotorOn = 1;	/* from probe restore operation! */
+}
+
+
+/* This function tests the physical presence of a floppy drive (not
+ * whether a disk is inserted). This is done by issuing a restore
+ * command, waiting max. 2 seconds (that should be enough to move the
+ * head across the whole disk) and looking at the state of the "TR00"
+ * signal. This should now be raised if there is a drive connected
+ * (and there is no hardware failure :-) Otherwise, the drive is
+ * declared absent.
+ */
+
+static int __init fd_test_drive_present( int drive )
+{
+	unsigned long timeout;
+	unsigned char status;
+	int ok;
+	
+	if (drive >= (MACH_IS_FALCON ? 1 : 2)) return( 0 );
+	fd_select_drive( drive );
+
+	/* disable interrupt temporarily */
+	atari_turnoff_irq( IRQ_MFP_FDC );
+	FDC_WRITE (FDCREG_TRACK, 0xff00);
+	FDC_WRITE( FDCREG_CMD, FDCCMD_RESTORE | FDCCMDADD_H | FDCSTEP_6 );
+
+	timeout = jiffies + 2*HZ+HZ/2;
+	while (time_before(jiffies, timeout))
+		if (!(st_mfp.par_dt_reg & 0x20))
+			break;
+
+	status = FDC_READ( FDCREG_STATUS );
+	ok = (status & FDCSTAT_TR00) != 0;
+
+	/* force interrupt to abort restore operation (FDC would try
+	 * about 50 seconds!) */
+	FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
+	udelay(500);
+	status = FDC_READ( FDCREG_STATUS );
+	udelay(20);
+
+	if (ok) {
+		/* dummy seek command to make WP bit accessible */
+		FDC_WRITE( FDCREG_DATA, 0 );
+		FDC_WRITE( FDCREG_CMD, FDCCMD_SEEK );
+		while( st_mfp.par_dt_reg & 0x20 )
+			;
+		status = FDC_READ( FDCREG_STATUS );
+	}
+
+	atari_turnon_irq( IRQ_MFP_FDC );
+	return( ok );
+}
+
+
+/* Look how many and which kind of drives are connected. If there are
+ * floppies, additionally start the disk-change and motor-off timers.
+ */
+
+static void __init config_types( void )
+{
+	int drive, cnt = 0;
+
+	/* for probing drives, set the FDC speed to 8 MHz */
+	if (ATARIHW_PRESENT(FDCSPEED))
+		dma_wd.fdc_speed = 0;
+
+	printk(KERN_INFO "Probing floppy drive(s):\n");
+	for( drive = 0; drive < FD_MAX_UNITS; drive++ ) {
+		fd_probe( drive );
+		if (UD.connected) {
+			printk(KERN_INFO "fd%d\n", drive);
+			++cnt;
+		}
+	}
+
+	if (FDC_READ( FDCREG_STATUS ) & FDCSTAT_BUSY) {
+		/* If FDC is still busy from probing, give it another FORCI
+		 * command to abort the operation. If this isn't done, the FDC
+		 * will interrupt later and its IRQ line stays low, because
+		 * the status register isn't read. And this will block any
+		 * interrupts on this IRQ line :-(
+		 */
+		FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
+		udelay(500);
+		FDC_READ( FDCREG_STATUS );
+		udelay(20);
+	}
+	
+	if (cnt > 0) {
+		start_motor_off_timer();
+		if (cnt == 1) fd_select_drive( 0 );
+		start_check_change_timer();
+	}
+}
+
+/*
+ * floppy_open check for aliasing (/dev/fd0 can be the same as
+ * /dev/PS0 etc), and disallows simultaneous access to the same
+ * drive with different device numbers.
+ */
+
+static int floppy_open(struct block_device *bdev, fmode_t mode)
+{
+	struct atari_floppy_struct *p = bdev->bd_disk->private_data;
+	int type  = MINOR(bdev->bd_dev) >> 2;
+
+	DPRINT(("fd_open: type=%d\n",type));
+	if (p->ref && p->type != type)
+		return -EBUSY;
+
+	if (p->ref == -1 || (p->ref && mode & FMODE_EXCL))
+		return -EBUSY;
+
+	if (mode & FMODE_EXCL)
+		p->ref = -1;
+	else
+		p->ref++;
+
+	p->type = type;
+
+	if (mode & FMODE_NDELAY)
+		return 0;
+
+	if (mode & (FMODE_READ|FMODE_WRITE)) {
+		check_disk_change(bdev);
+		if (mode & FMODE_WRITE) {
+			if (p->wpstat) {
+				if (p->ref < 0)
+					p->ref = 0;
+				else
+					p->ref--;
+				return -EROFS;
+			}
+		}
+	}
+	return 0;
+}
+
+static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
+{
+	int ret;
+
+	mutex_lock(&ataflop_mutex);
+	ret = floppy_open(bdev, mode);
+	mutex_unlock(&ataflop_mutex);
+
+	return ret;
+}
+
+static void floppy_release(struct gendisk *disk, fmode_t mode)
+{
+	struct atari_floppy_struct *p = disk->private_data;
+	mutex_lock(&ataflop_mutex);
+	if (p->ref < 0)
+		p->ref = 0;
+	else if (!p->ref--) {
+		printk(KERN_ERR "floppy_release with fd_ref == 0");
+		p->ref = 0;
+	}
+	mutex_unlock(&ataflop_mutex);
+}
+
+static const struct block_device_operations floppy_fops = {
+	.owner		= THIS_MODULE,
+	.open		= floppy_unlocked_open,
+	.release	= floppy_release,
+	.ioctl		= fd_ioctl,
+	.check_events	= floppy_check_events,
+	.revalidate_disk= floppy_revalidate,
+};
+
+static struct kobject *floppy_find(dev_t dev, int *part, void *data)
+{
+	int drive = *part & 3;
+	int type  = *part >> 2;
+	if (drive >= FD_MAX_UNITS || type > NUM_DISK_MINORS)
+		return NULL;
+	*part = 0;
+	return get_disk_and_module(unit[drive].disk);
+}
+
+static int __init atari_floppy_init (void)
+{
+	int i;
+
+	if (!MACH_IS_ATARI)
+		/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
+		return -ENODEV;
+
+	if (register_blkdev(FLOPPY_MAJOR,"fd"))
+		return -EBUSY;
+
+	for (i = 0; i < FD_MAX_UNITS; i++) {
+		unit[i].disk = alloc_disk(1);
+		if (!unit[i].disk)
+			goto Enomem;
+
+		unit[i].disk->queue = blk_init_queue(do_fd_request,
+						     &ataflop_lock);
+		if (!unit[i].disk->queue)
+			goto Enomem;
+	}
+
+	if (UseTrackbuffer < 0)
+		/* not set by user -> use default: for now, we turn
+		   track buffering off for all Medusas, though it
+		   could be used with ones that have a counter
+		   card. But the test is too hard :-( */
+		UseTrackbuffer = !MACH_IS_MEDUSA;
+
+	/* initialize variables */
+	SelectedDrive = -1;
+	BufferDrive = -1;
+
+	DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
+	if (!DMABuffer) {
+		printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n");
+		goto Enomem;
+	}
+	TrackBuffer = DMABuffer + 512;
+	PhysDMABuffer = atari_stram_to_phys(DMABuffer);
+	PhysTrackBuffer = virt_to_phys(TrackBuffer);
+	BufferDrive = BufferSide = BufferTrack = -1;
+
+	for (i = 0; i < FD_MAX_UNITS; i++) {
+		unit[i].track = -1;
+		unit[i].flags = 0;
+		unit[i].disk->major = FLOPPY_MAJOR;
+		unit[i].disk->first_minor = i;
+		sprintf(unit[i].disk->disk_name, "fd%d", i);
+		unit[i].disk->fops = &floppy_fops;
+		unit[i].disk->private_data = &unit[i];
+		set_capacity(unit[i].disk, MAX_DISK_SIZE * 2);
+		add_disk(unit[i].disk);
+	}
+
+	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
+				floppy_find, NULL, NULL);
+
+	printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
+	       DriveType == 0 ? 'D' : DriveType == 1 ? 'H' : 'E',
+	       UseTrackbuffer ? "" : "no ");
+	config_types();
+
+	return 0;
+Enomem:
+	do {
+		struct gendisk *disk = unit[i].disk;
+
+		if (disk) {
+			if (disk->queue) {
+				blk_cleanup_queue(disk->queue);
+				disk->queue = NULL;
+			}
+			put_disk(unit[i].disk);
+		}
+	} while (i--);
+
+	unregister_blkdev(FLOPPY_MAJOR, "fd");
+	return -ENOMEM;
+}
+
+#ifndef MODULE
+static int __init atari_floppy_setup(char *str)
+{
+	int ints[3 + FD_MAX_UNITS];
+	int i;
+
+	if (!MACH_IS_ATARI)
+		return 0;
+
+	str = get_options(str, 3 + FD_MAX_UNITS, ints);
+	
+	if (ints[0] < 1) {
+		printk(KERN_ERR "ataflop_setup: no arguments!\n" );
+		return 0;
+	}
+	else if (ints[0] > 2+FD_MAX_UNITS) {
+		printk(KERN_ERR "ataflop_setup: too many arguments\n" );
+	}
+
+	if (ints[1] < 0 || ints[1] > 2)
+		printk(KERN_ERR "ataflop_setup: bad drive type\n" );
+	else
+		DriveType = ints[1];
+
+	if (ints[0] >= 2)
+		UseTrackbuffer = (ints[2] > 0);
+
+	for( i = 3; i <= ints[0] && i-3 < FD_MAX_UNITS; ++i ) {
+		if (ints[i] != 2 && ints[i] != 3 && ints[i] != 6 && ints[i] != 12)
+			printk(KERN_ERR "ataflop_setup: bad steprate\n" );
+		else
+			UserSteprate[i-3] = ints[i];
+	}
+	return 1;
+}
+
+__setup("floppy=", atari_floppy_setup);
+#endif
+
+static void __exit atari_floppy_exit(void)
+{
+	int i;
+	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
+	for (i = 0; i < FD_MAX_UNITS; i++) {
+		struct request_queue *q = unit[i].disk->queue;
+
+		del_gendisk(unit[i].disk);
+		put_disk(unit[i].disk);
+		blk_cleanup_queue(q);
+	}
+	unregister_blkdev(FLOPPY_MAJOR, "fd");
+
+	del_timer_sync(&fd_timer);
+	atari_stram_free( DMABuffer );
+}
+
+module_init(atari_floppy_init)
+module_exit(atari_floppy_exit)
+
+MODULE_LICENSE("GPL");