Initial source

1 files changed, 3087 insertions, 0 deletions

diff --git a/i386/i386at/gpl/linux/block/ide.c b/i386/i386at/gpl/linux/block/ide.c
new file mode 100644
index 0000000..4b7c5e9
--- /dev/null
+++ b/i386/i386at/gpl/linux/block/ide.c
@@ -0,0 +1,3087 @@
+/*
+ *  linux/drivers/block/ide.c	Version 5.28  Feb 11, 1996
+ *
+ *  Copyright (C) 1994-1996  Linus Torvalds & authors (see below)
+ */
+#define _IDE_C		/* needed by <linux/blk.h> */
+
+/*
+ * This is the multiple IDE interface driver, as evolved from hd.c.
+ * It supports up to four IDE interfaces, on one or more IRQs (usually 14 & 15).
+ * There can be up to two drives per interface, as per the ATA-2 spec.
+ *
+ * Primary i/f:    ide0: major=3;  (hda)         minor=0; (hdb)         minor=64
+ * Secondary i/f:  ide1: major=22; (hdc or hd1a) minor=0; (hdd or hd1b) minor=64
+ * Tertiary i/f:   ide2: major=33; (hde)         minor=0; (hdf)         minor=64
+ * Quaternary i/f: ide3: major=34; (hdg)         minor=0; (hdh)         minor=64
+ *
+ * It is easy to extend ide.c to handle more than four interfaces:
+ *
+ *	Change the MAX_HWIFS constant in ide.h.
+ *
+ *	Define some new major numbers (in major.h), and insert them into
+ *	the ide_hwif_to_major table in ide.c.
+ *
+ *	Fill in the extra values for the new interfaces into the two tables
+ *	inside ide.c:  default_io_base[]  and  default_irqs[].
+ *
+ *	Create the new request handlers by cloning "do_ide3_request()"
+ *	for each new interface, and add them to the switch statement
+ *	in the ide_init() function in ide.c.
+ *
+ *	Recompile, create the new /dev/ entries, and it will probably work.
+ *
+ *  From hd.c:
+ *  |
+ *  | It traverses the request-list, using interrupts to jump between functions.
+ *  | As nearly all functions can be called within interrupts, we may not sleep.
+ *  | Special care is recommended.  Have Fun!
+ *  |
+ *  | modified by Drew Eckhardt to check nr of hd's from the CMOS.
+ *  |
+ *  | Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
+ *  | in the early extended-partition checks and added DM partitions.
+ *  |
+ *  | Early work on error handling by Mika Liljeberg (liljeber@cs.Helsinki.FI).
+ *  |
+ *  | IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
+ *  | and general streamlining by Mark Lord (mlord@bnr.ca).
+ *
+ *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
+ *
+ *	Mark Lord	(mlord@bnr.ca)			(IDE Perf.Pkg)
+ *	Delman Lee	(delman@mipg.upenn.edu)		("Mr. atdisk2")
+ *	Petri Mattila	(ptjmatti@kruuna.helsinki.fi)	(EIDE stuff)
+ *	Scott Snyder	(snyder@fnald0.fnal.gov)	(ATAPI IDE cd-rom)
+ *
+ *  Maintained by Mark Lord (mlord@bnr.ca):  ide.c, ide.h, triton.c, hd.c, ..
+ *
+ *  This was a rewrite of just about everything from hd.c, though some original
+ *  code is still sprinkled about.  Think of it as a major evolution, with
+ *  inspiration from lots of linux users, esp.  hamish@zot.apana.org.au
+ *
+ *  Version 1.0 ALPHA	initial code, primary i/f working okay
+ *  Version 1.3 BETA	dual i/f on shared irq tested & working!
+ *  Version 1.4 BETA	added auto probing for irq(s)
+ *  Version 1.5 BETA	added ALPHA (untested) support for IDE cd-roms,
+ *  ...
+ *  Version 3.5		correct the bios_cyl field if it's too small
+ *  (linux 1.1.76)	 (to help fdisk with brain-dead BIOSs)
+ *  Version 3.6		cosmetic corrections to comments and stuff
+ *  (linux 1.1.77)	reorganise probing code to make it understandable
+ *			added halfway retry to probing for drive identification
+ *			added "hdx=noprobe" command line option
+ *			allow setting multmode even when identification fails
+ *  Version 3.7		move set_geometry=1 from do_identify() to ide_init()
+ *			increase DRQ_WAIT to eliminate nuisance messages
+ *			wait for DRQ_STAT instead of DATA_READY during probing
+ *			  (courtesy of Gary Thomas gary@efland.UU.NET)
+ *  Version 3.8		fixed byte-swapping for confused Mitsumi cdrom drives
+ *			update of ide-cd.c from Scott, allows blocksize=1024
+ *			cdrom probe fixes, inspired by jprang@uni-duisburg.de
+ *  Version 3.9		don't use LBA if lba_capacity looks funny
+ *			correct the drive capacity calculations
+ *			fix probing for old Seagates without IDE_ALTSTATUS_REG
+ *			fix byte-ordering for some NEC cdrom drives
+ *  Version 3.10	disable multiple mode by default; was causing trouble
+ *  Version 3.11	fix mis-identification of old WD disks as cdroms
+ *  Version 3,12	simplify logic for selecting initial mult_count
+ *			  (fixes problems with buggy WD drives)
+ *  Version 3.13	remove excess "multiple mode disabled" messages
+ *  Version 3.14	fix ide_error() handling of BUSY_STAT
+ *			fix byte-swapped cdrom strings (again.. arghh!)
+ *			ignore INDEX bit when checking the ALTSTATUS reg
+ *  Version 3.15	add SINGLE_THREADED flag for use with dual-CMD i/f
+ *			ignore WRERR_STAT for non-write operations
+ *			added vlb_sync support for DC-2000A & others,
+ *			 (incl. some Promise chips), courtesy of Frank Gockel
+ *  Version 3.16	convert vlb_32bit and vlb_sync into runtime flags
+ *			add ioctls to get/set VLB flags (HDIO_[SG]ET_CHIPSET)
+ *			rename SINGLE_THREADED to SUPPORT_SERIALIZE,
+ *			add boot flag to "serialize" operation for CMD i/f
+ *			add optional support for DTC2278 interfaces,
+ *			 courtesy of andy@cercle.cts.com (Dyan Wile).
+ *			add boot flag to enable "dtc2278" probe
+ *			add probe to avoid EATA (SCSI) interfaces,
+ *			 courtesy of neuffer@goofy.zdv.uni-mainz.de.
+ *  Version 4.00	tidy up verify_area() calls - heiko@colossus.escape.de
+ *			add flag to ignore WRERR_STAT for some drives
+ *			 courtesy of David.H.West@um.cc.umich.edu
+ *			assembly syntax tweak to vlb_sync
+ *			removeable drive support from scuba@cs.tu-berlin.de
+ *			add transparent support for DiskManager-6.0x "Dynamic
+ *			 Disk Overlay" (DDO), most of this is in genhd.c
+ *			eliminate "multiple mode turned off" message at boot
+ *  Version 4.10	fix bug in ioctl for "hdparm -c3"
+ *			fix DM6:DDO support -- now works with LILO, fdisk, ...
+ *			don't treat some naughty WD drives as removeable
+ *  Version 4.11	updated DM6 support using info provided by OnTrack
+ *  Version 5.00	major overhaul, multmode setting fixed, vlb_sync fixed
+ *			added support for 3rd/4th/alternative IDE ports
+ *			created ide.h; ide-cd.c now compiles separate from ide.c
+ *			hopefully fixed infinite "unexpected_intr" from cdroms
+ *			zillions of other changes and restructuring
+ *			somehow reduced overall memory usage by several kB
+ *			probably slowed things down slightly, but worth it
+ *  Version 5.01	AT LAST!!  Finally understood why "unexpected_intr"
+ *			 was happening at various times/places:  whenever the
+ *			 ide-interface's ctl_port was used to "mask" the irq,
+ *			 it also would trigger an edge in the process of masking
+ *			 which would result in a self-inflicted interrupt!!
+ *			 (such a stupid way to build a hardware interrupt mask).
+ *			 This is now fixed (after a year of head-scratching).
+ *  Version 5.02	got rid of need for {enable,disable}_irq_list()
+ *  Version 5.03	tune-ups, comments, remove "busy wait" from drive resets
+ *			removed PROBE_FOR_IRQS option -- no longer needed
+ *			OOOPS!  fixed "bad access" bug for 2nd drive on an i/f
+ *  Version 5.04	changed "ira %d" to "irq %d" in DEBUG message
+ *			added more comments, cleaned up unexpected_intr()
+ *			OOOPS!  fixed null pointer problem in ide reset code
+ *			added autodetect for Triton chipset -- no effect yet
+ *  Version 5.05	OOOPS!  fixed bug in revalidate_disk()
+ *			OOOPS!  fixed bug in ide_do_request()
+ *			added ATAPI reset sequence for cdroms
+ *  Version 5.10	added Bus-Mastered DMA support for Triton Chipset
+ *			some (mostly) cosmetic changes
+ *  Version 5.11	added ht6560b support by malafoss@snakemail.hut.fi
+ *			reworked PCI scanning code
+ *			added automatic RZ1000 detection/support
+ *			added automatic PCI CMD640 detection/support
+ *			added option for VLB CMD640 support
+ *			tweaked probe to find cdrom on hdb with disks on hda,hdc
+ *  Version 5.12	some performance tuning
+ *			added message to alert user to bad /dev/hd[cd] entries
+ *			OOOPS!  fixed bug in atapi reset
+ *			driver now forces "serialize" again for all cmd640 chips
+ *			noticed REALLY_SLOW_IO had no effect, moved it to ide.c
+ *			made do_drive_cmd() into public ide_do_drive_cmd()
+ *  Version 5.13	fixed typo ('B'), thanks to houston@boyd.geog.mcgill.ca
+ *			fixed ht6560b support
+ *  Version 5.13b (sss)	fix problem in calling ide_cdrom_setup()
+ *			don't bother invalidating nonexistent partitions
+ *  Version 5.14	fixes to cmd640 support.. maybe it works now(?)
+ *			added & tested full EZ-DRIVE support -- don't use LILO!
+ *			don't enable 2nd CMD640 PCI port during init - conflict
+ *  Version 5.15	bug fix in init_cmd640_vlb()
+ *			bug fix in interrupt sharing code
+ *  Version 5.16	ugh.. fix "serialize" support, broken in 5.15
+ *			remove "Huh?" from cmd640 code
+ *			added qd6580 interface speed select from Colten Edwards
+ *  Version 5.17	kludge around bug in BIOS32 on Intel triton motherboards
+ *  Version 5.18	new CMD640 code, moved to cmd640.c, #include'd for now
+ *			new UMC8672 code, moved to umc8672.c, #include'd for now
+ *			disallow turning on DMA when h/w not capable of DMA
+ *  Version 5.19	fix potential infinite timeout on resets
+ *			extend reset poll into a general purpose polling scheme
+ *			add atapi tape drive support from Gadi Oxman
+ *			simplify exit from _intr routines -- no IDE_DO_REQUEST
+ *  Version 5.20	leave current rq on blkdev request list during I/O
+ *			generalized ide_do_drive_cmd() for tape/cdrom driver use
+ *  Version 5.21	fix nasty cdrom/tape bug (ide_preempt was messed up)
+ *  Version 5.22	fix ide_xlate_1024() to work with/without drive->id
+ *  Version 5.23	miscellaneous touch-ups
+ *  Version 5.24	fix #if's for SUPPORT_CMD640
+ *  Version 5.25	more touch-ups, fix cdrom resets, ...
+ *			cmd640.c now configs/compiles separate from ide.c
+ *  Version 5.26	keep_settings now maintains the using_dma flag
+ *			fix [EZD] remap message to only output at boot time
+ *			fix "bad /dev/ entry" message to say hdc, not hdc0
+ *			fix ide_xlate_1024() to respect user specified CHS
+ *			use CHS from partn table if it looks translated
+ *			re-merged flags chipset,vlb_32bit,vlb_sync into io_32bit
+ *			keep track of interface chipset type, when known
+ *			add generic PIO mode "tuneproc" mechanism
+ *			fix cmd640_vlb option
+ *			fix ht6560b support (was completely broken)
+ *			umc8672.c now configures/compiles separate from ide.c
+ *			move dtc2278 support to dtc2278.c
+ *			move ht6560b support to ht6560b.c
+ *			move qd6580  support to qd6580.c
+ *			add  ali14xx support in ali14xx.c
+ * Version 5.27		add [no]autotune parameters to help cmd640
+ *			move rz1000  support to rz1000.c
+ * Version 5.28		#include "ide_modes.h"
+ *			fix disallow_unmask: now per-interface "no_unmask" bit
+ *			force io_32bit to be the same on drive pairs of dtc2278
+ *			improved IDE tape error handling, and tape DMA support
+ *			bugfix in ide_do_drive_cmd() for cdroms + serialize
+ *
+ *  Some additional driver compile-time options are in ide.h
+ *
+ *  To do, in likely order of completion:
+ *	- add Promise DC4030VL support from peterd@pnd-pc.demon.co.uk
+ *	- modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
+*/
+
+#if defined (MACH) && !defined (LINUX_IDE_DEBUG)
+#undef DEBUG
+#endif
+
+#undef REALLY_SLOW_IO		/* most systems can safely undef this */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/major.h>
+#include <linux/blkdev.h>
+#include <linux/errno.h>
+#include <linux/hdreg.h>
+#include <linux/genhd.h>
+#include <linux/malloc.h>
+
+#include <asm/byteorder.h>
+#include <asm/irq.h>
+#include <asm/segment.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_PCI
+#include <linux/bios32.h>
+#include <linux/pci.h>
+#endif /* CONFIG_PCI */
+
+#include "ide.h"
+#include "ide_modes.h"
+
+static ide_hwgroup_t	*irq_to_hwgroup [NR_IRQS];
+static const byte	ide_hwif_to_major[MAX_HWIFS] = {IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR};
+
+static const unsigned short default_io_base[MAX_HWIFS] = {0x1f0, 0x170, 0x1e8, 0x168};
+static const byte	default_irqs[MAX_HWIFS]     = {14, 15, 11, 10};
+
+#if (DISK_RECOVERY_TIME > 0)
+/*
+ * For really screwy hardware (hey, at least it *can* be used with Linux)
+ * we can enforce a minimum delay time between successive operations.
+ */
+static unsigned long read_timer(void)
+{
+	unsigned long t, flags;
+	int i;
+
+	save_flags(flags);
+	cli();
+	t = jiffies * 11932;
+    	outb_p(0, 0x43);
+	i = inb_p(0x40);
+	i |= inb(0x40) << 8;
+	restore_flags(flags);
+	return (t - i);
+}
+
+static void set_recovery_timer (ide_hwif_t *hwif)
+{
+	hwif->last_time = read_timer();
+}
+#define SET_RECOVERY_TIMER(drive) set_recovery_timer (drive)
+
+#else
+
+#define SET_RECOVERY_TIMER(drive)
+
+#endif /* DISK_RECOVERY_TIME */
+
+/*
+ * init_ide_data() sets reasonable default values into all fields
+ * of all instances of the hwifs and drives, but only on the first call.
+ * Subsequent calls have no effect (they don't wipe out anything).
+ *
+ * This routine is normally called at driver initialization time,
+ * but may also be called MUCH earlier during kernel "command-line"
+ * parameter processing.  As such, we cannot depend on any other parts
+ * of the kernel (such as memory allocation) to be functioning yet.
+ *
+ * This is too bad, as otherwise we could dynamically allocate the
+ * ide_drive_t structs as needed, rather than always consuming memory
+ * for the max possible number (MAX_HWIFS * MAX_DRIVES) of them.
+ */
+#define MAGIC_COOKIE 0x12345678
+static void init_ide_data (void)
+{
+	byte *p;
+	unsigned int h, unit;
+	static unsigned long magic_cookie = MAGIC_COOKIE;
+
+	if (magic_cookie != MAGIC_COOKIE)
+		return;		/* already initialized */
+	magic_cookie = 0;
+
+	for (h = 0; h < NR_IRQS; ++h)
+		 irq_to_hwgroup[h] = NULL;
+
+	/* bulk initialize hwif & drive info with zeros */
+	p = ((byte *) ide_hwifs) + sizeof(ide_hwifs);
+	do {
+		*--p = 0;
+	} while (p > (byte *) ide_hwifs);
+
+	/* fill in any non-zero initial values */
+	for (h = 0; h < MAX_HWIFS; ++h) {
+		ide_hwif_t *hwif = &ide_hwifs[h];
+
+		hwif->index     = h;
+		hwif->noprobe	= (h > 1);
+		hwif->io_base	= default_io_base[h];
+		hwif->ctl_port	= hwif->io_base ? hwif->io_base+0x206 : 0x000;
+#ifdef CONFIG_BLK_DEV_HD
+		if (hwif->io_base == HD_DATA)
+			hwif->noprobe = 1; /* may be overriden by ide_setup() */
+#endif /* CONFIG_BLK_DEV_HD */
+		hwif->major	= ide_hwif_to_major[h];
+		hwif->name[0]	= 'i';
+		hwif->name[1]	= 'd';
+		hwif->name[2]	= 'e';
+		hwif->name[3]	= '0' + h;
+#ifdef CONFIG_BLK_DEV_IDETAPE
+		hwif->tape_drive = NULL;
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+		for (unit = 0; unit < MAX_DRIVES; ++unit) {
+			ide_drive_t *drive = &hwif->drives[unit];
+
+			drive->select.all		= (unit<<4)|0xa0;
+			drive->hwif			= hwif;
+			drive->ctl			= 0x08;
+			drive->ready_stat		= READY_STAT;
+			drive->bad_wstat		= BAD_W_STAT;
+			drive->special.b.recalibrate	= 1;
+			drive->special.b.set_geometry	= 1;
+			drive->name[0]			= 'h';
+			drive->name[1]			= 'd';
+			drive->name[2]			= 'a' + (h * MAX_DRIVES) + unit;
+		}
+	}
+}
+
+#if SUPPORT_VLB_SYNC
+/*
+ * Some localbus EIDE interfaces require a special access sequence
+ * when using 32-bit I/O instructions to transfer data.  We call this
+ * the "vlb_sync" sequence, which consists of three successive reads
+ * of the sector count register location, with interrupts disabled
+ * to ensure that the reads all happen together.
+ */
+static inline void do_vlb_sync (unsigned short port) {
+	(void) inb (port);
+	(void) inb (port);
+	(void) inb (port);
+}
+#endif /* SUPPORT_VLB_SYNC */
+
+/*
+ * This is used for most PIO data transfers *from* the IDE interface
+ */
+void ide_input_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
+{
+	unsigned short io_base  = HWIF(drive)->io_base;
+	unsigned short data_reg = io_base+IDE_DATA_OFFSET;
+	byte io_32bit = drive->io_32bit;
+
+	if (io_32bit) {
+#if SUPPORT_VLB_SYNC
+		if (io_32bit & 2) {
+			cli();
+			do_vlb_sync(io_base+IDE_NSECTOR_OFFSET);
+			insl(data_reg, buffer, wcount);
+			if (drive->unmask)
+				sti();
+		} else
+#endif /* SUPPORT_VLB_SYNC */
+			insl(data_reg, buffer, wcount);
+	} else
+		insw(data_reg, buffer, wcount<<1);
+}
+
+/*
+ * This is used for most PIO data transfers *to* the IDE interface
+ */
+void ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
+{
+	unsigned short io_base  = HWIF(drive)->io_base;
+	unsigned short data_reg = io_base+IDE_DATA_OFFSET;
+	byte io_32bit = drive->io_32bit;
+
+	if (io_32bit) {
+#if SUPPORT_VLB_SYNC
+		if (io_32bit & 2) {
+			cli();
+			do_vlb_sync(io_base+IDE_NSECTOR_OFFSET);
+			outsl(data_reg, buffer, wcount);
+			if (drive->unmask)
+				sti();
+		} else
+#endif /* SUPPORT_VLB_SYNC */
+			outsl(data_reg, buffer, wcount);
+	} else
+		outsw(data_reg, buffer, wcount<<1);
+}
+
+/*
+ * This should get invoked any time we exit the driver to
+ * wait for an interrupt response from a drive.  handler() points
+ * at the appropriate code to handle the next interrupt, and a
+ * timer is started to prevent us from waiting forever in case
+ * something goes wrong (see the timer_expiry() handler later on).
+ */
+void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler, unsigned int timeout)
+{
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+#ifdef DEBUG
+	if (hwgroup->handler != NULL) {
+		printk("%s: ide_set_handler: handler not null; old=%p, new=%p\n",
+			drive->name, hwgroup->handler, handler);
+	}
+#endif
+	hwgroup->handler       = handler;
+	hwgroup->timer.expires = jiffies + timeout;
+	add_timer(&(hwgroup->timer));
+}
+
+/*
+ * lba_capacity_is_ok() performs a sanity check on the claimed "lba_capacity"
+ * value for this drive (from its reported identification information).
+ *
+ * Returns:	1 if lba_capacity looks sensible
+ *		0 otherwise
+ */
+static int lba_capacity_is_ok (struct hd_driveid *id)
+{
+	unsigned long lba_sects   = id->lba_capacity;
+	unsigned long chs_sects   = id->cyls * id->heads * id->sectors;
+	unsigned long _10_percent = chs_sects / 10;
+
+	/* perform a rough sanity check on lba_sects:  within 10% is "okay" */
+	if ((lba_sects - chs_sects) < _10_percent)
+		return 1;	/* lba_capacity is good */
+
+	/* some drives have the word order reversed */
+	lba_sects = (lba_sects << 16) | (lba_sects >> 16);
+	if ((lba_sects - chs_sects) < _10_percent) {
+		id->lba_capacity = lba_sects;	/* fix it */
+		return 1;	/* lba_capacity is (now) good */
+	}
+	return 0;	/* lba_capacity value is bad */
+}
+
+/*
+ * current_capacity() returns the capacity (in sectors) of a drive
+ * according to its current geometry/LBA settings.
+ */
+static unsigned long current_capacity (ide_drive_t  *drive)
+{
+	struct hd_driveid *id = drive->id;
+	unsigned long capacity;
+
+	if (!drive->present)
+		return 0;
+	if (drive->media != ide_disk)
+		return 0x7fffffff;	/* cdrom or tape */
+	/* Determine capacity, and use LBA if the drive properly supports it */
+	if (id != NULL && (id->capability & 2) && lba_capacity_is_ok(id)) {
+		drive->select.b.lba = 1;
+		capacity = id->lba_capacity;
+	} else {
+		drive->select.b.lba = 0;
+		capacity = drive->cyl * drive->head * drive->sect;
+	}
+	return (capacity - drive->sect0);
+}
+
+/*
+ * ide_geninit() is called exactly *once* for each major, from genhd.c,
+ * at the beginning of the initial partition check for the drives.
+ */
+static void ide_geninit (struct gendisk *gd)
+{
+	unsigned int unit;
+	ide_hwif_t *hwif = gd->real_devices;
+
+	for (unit = 0; unit < gd->nr_real; ++unit) {
+		ide_drive_t *drive = &hwif->drives[unit];
+#ifdef CONFIG_BLK_DEV_IDECD
+		if (drive->present && drive->media == ide_cdrom)
+			ide_cdrom_setup(drive);
+#endif /* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+		if (drive->present && drive->media == ide_tape)
+			idetape_setup(drive);
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+		drive->part[0].nr_sects = current_capacity(drive);
+		if (!drive->present || drive->media != ide_disk) {
+			drive->part[0].start_sect = -1; /* skip partition check */
+		}
+	}
+	/*
+	 * The partition check in genhd.c needs this string to identify
+	 * our minor devices by name for display purposes.
+	 * Note that doing this will prevent us from working correctly
+	 * if ever called a second time for this major (never happens).
+	 */
+	gd->real_devices = hwif->drives[0].name;  /* name of first drive */
+}
+
+/*
+ * init_gendisk() (as opposed to ide_geninit) is called for each major device,
+ * after probing for drives, to allocate partition tables and other data
+ * structures needed for the routines in genhd.c.  ide_geninit() gets called
+ * somewhat later, during the partition check.
+ */
+static void init_gendisk (ide_hwif_t *hwif)
+{
+	struct gendisk *gd;
+	unsigned int unit, units, minors;
+	int *bs;
+
+	/* figure out maximum drive number on the interface */
+	for (units = MAX_DRIVES; units > 0; --units) {
+		if (hwif->drives[units-1].present)
+			break;
+	}
+	minors    = units * (1<<PARTN_BITS);
+	gd        = kmalloc (sizeof(struct gendisk), GFP_KERNEL);
+	gd->sizes = kmalloc (minors * sizeof(int), GFP_KERNEL);
+	gd->part  = kmalloc (minors * sizeof(struct hd_struct), GFP_KERNEL);
+	bs        = kmalloc (minors*sizeof(int), GFP_KERNEL);
+
+	/* cdroms and msdos f/s are examples of non-1024 blocksizes */
+	blksize_size[hwif->major] = bs;
+	for (unit = 0; unit < minors; ++unit)
+		*bs++ = BLOCK_SIZE;
+
+	for (unit = 0; unit < units; ++unit)
+		hwif->drives[unit].part = &gd->part[unit << PARTN_BITS];
+
+	gd->major	= hwif->major;		/* our major device number */
+	gd->major_name	= IDE_MAJOR_NAME;	/* treated special in genhd.c */
+	gd->minor_shift	= PARTN_BITS;		/* num bits for partitions */
+	gd->max_p	= 1<<PARTN_BITS;	/* 1 + max partitions / drive */
+	gd->max_nr	= units;		/* max num real drives */
+	gd->nr_real	= units;		/* current num real drives */
+	gd->init	= ide_geninit;		/* initialization function */
+	gd->real_devices= hwif;			/* ptr to internal data */
+
+	gd->next = gendisk_head;		/* link new major into list */
+	hwif->gd = gendisk_head = gd;
+}
+
+static void do_reset1 (ide_drive_t *, int);		/* needed below */
+
+#ifdef CONFIG_BLK_DEV_IDEATAPI
+/*
+ * atapi_reset_pollfunc() gets invoked to poll the interface for completion every 50ms
+ * during an atapi drive reset operation. If the drive has not yet responded,
+ * and we have not yet hit our maximum waiting time, then the timer is restarted
+ * for another 50ms.
+ */
+static void atapi_reset_pollfunc (ide_drive_t *drive)
+{
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	byte stat;
+
+	OUT_BYTE (drive->select.all, IDE_SELECT_REG);
+	udelay (10);
+
+	if (OK_STAT(stat=GET_STAT(), 0, BUSY_STAT)) {
+		printk("%s: ATAPI reset complete\n", drive->name);
+	} else {
+		if (jiffies < hwgroup->poll_timeout) {
+			ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20);
+			return;	/* continue polling */
+		}
+		hwgroup->poll_timeout = 0;	/* end of polling */
+		printk("%s: ATAPI reset timed-out, status=0x%02x\n", drive->name, stat);
+		do_reset1 (drive, 1);	/* do it the old fashioned way */
+	}
+	hwgroup->poll_timeout = 0;	/* done polling */
+}
+#endif /* CONFIG_BLK_DEV_IDEATAPI */
+
+/*
+ * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
+ * during an ide reset operation. If the drives have not yet responded,
+ * and we have not yet hit our maximum waiting time, then the timer is restarted
+ * for another 50ms.
+ */
+static void reset_pollfunc (ide_drive_t *drive)
+{
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	ide_hwif_t *hwif = HWIF(drive);
+	byte tmp;
+
+	if (!OK_STAT(tmp=GET_STAT(), 0, BUSY_STAT)) {
+		if (jiffies < hwgroup->poll_timeout) {
+			ide_set_handler (drive, &reset_pollfunc, HZ/20);
+			return;	/* continue polling */
+		}
+		printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
+	} else  {
+		printk("%s: reset: ", hwif->name);
+		if ((tmp = GET_ERR()) == 1)
+			printk("success\n");
+		else {
+			printk("master: ");
+			switch (tmp & 0x7f) {
+				case 1: printk("passed");
+					break;
+				case 2: printk("formatter device error");
+					break;
+				case 3: printk("sector buffer error");
+					break;
+				case 4: printk("ECC circuitry error");
+					break;
+				case 5: printk("controlling MPU error");
+					break;
+				default:printk("error (0x%02x?)", tmp);
+			}
+			if (tmp & 0x80)
+				printk("; slave: failed");
+			printk("\n");
+		}
+	}
+	hwgroup->poll_timeout = 0;	/* done polling */
+}
+
+/*
+ * do_reset1() attempts to recover a confused drive by resetting it.
+ * Unfortunately, resetting a disk drive actually resets all devices on
+ * the same interface, so it can really be thought of as resetting the
+ * interface rather than resetting the drive.
+ *
+ * ATAPI devices have their own reset mechanism which allows them to be
+ * individually reset without clobbering other devices on the same interface.
+ *
+ * Unfortunately, the IDE interface does not generate an interrupt to let
+ * us know when the reset operation has finished, so we must poll for this.
+ * Equally poor, though, is the fact that this may a very long time to complete,
+ * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
+ * we set a timer to poll at 50ms intervals.
+ */
+static void do_reset1 (ide_drive_t *drive, int  do_not_try_atapi)
+{
+	unsigned int unit;
+	unsigned long flags;
+	ide_hwif_t *hwif = HWIF(drive);
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+
+	save_flags(flags);
+	cli();		/* Why ? */
+
+#ifdef CONFIG_BLK_DEV_IDEATAPI
+	/* For an ATAPI device, first try an ATAPI SRST. */
+	if (drive->media != ide_disk) {
+		if (!do_not_try_atapi) {
+			if (!drive->keep_settings)
+				drive->unmask = 0;
+			OUT_BYTE (drive->select.all, IDE_SELECT_REG);
+			udelay (20);
+			OUT_BYTE (WIN_SRST, IDE_COMMAND_REG);
+			hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
+			ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20);
+			restore_flags (flags);
+			return;
+		}
+	}
+#endif /* CONFIG_BLK_DEV_IDEATAPI */
+
+	/*
+	 * First, reset any device state data we were maintaining
+	 * for any of the drives on this interface.
+	 */
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		ide_drive_t *rdrive = &hwif->drives[unit];
+		rdrive->special.all = 0;
+		rdrive->special.b.set_geometry = 1;
+		rdrive->special.b.recalibrate  = 1;
+		if (OK_TO_RESET_CONTROLLER)
+			rdrive->mult_count = 0;
+		if (!rdrive->keep_settings) {
+			rdrive->using_dma = 0;
+			rdrive->mult_req = 0;
+			rdrive->unmask = 0;
+		}
+		if (rdrive->mult_req != rdrive->mult_count)
+			rdrive->special.b.set_multmode = 1;
+	}
+
+#if OK_TO_RESET_CONTROLLER
+	/*
+	 * Note that we also set nIEN while resetting the device,
+	 * to mask unwanted interrupts from the interface during the reset.
+	 * However, due to the design of PC hardware, this will cause an
+	 * immediate interrupt due to the edge transition it produces.
+	 * This single interrupt gives us a "fast poll" for drives that
+	 * recover from reset very quickly, saving us the first 50ms wait time.
+	 */
+	OUT_BYTE(drive->ctl|6,IDE_CONTROL_REG);	/* set SRST and nIEN */
+	udelay(5);			/* more than enough time */
+	OUT_BYTE(drive->ctl|2,IDE_CONTROL_REG);	/* clear SRST, leave nIEN */
+	hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
+	ide_set_handler (drive, &reset_pollfunc, HZ/20);
+#endif	/* OK_TO_RESET_CONTROLLER */
+
+	restore_flags (flags);
+}
+
+/*
+ * ide_do_reset() is the entry point to the drive/interface reset code.
+ */
+void ide_do_reset (ide_drive_t *drive)
+{
+	do_reset1 (drive, 0);
+#ifdef CONFIG_BLK_DEV_IDETAPE
+	if (drive->media == ide_tape)
+		drive->tape.reset_issued=1;
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+}
+
+/*
+ * Clean up after success/failure of an explicit drive cmd
+ */
+void ide_end_drive_cmd (ide_drive_t *drive, byte stat, byte err)
+{
+	unsigned long flags;
+	struct request *rq = HWGROUP(drive)->rq;
+
+	if (rq->cmd == IDE_DRIVE_CMD) {
+		byte *args = (byte *) rq->buffer;
+		rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
+		if (args) {
+			args[0] = stat;
+			args[1] = err;
+			args[2] = IN_BYTE(IDE_NSECTOR_REG);
+		}
+	}
+	save_flags(flags);
+	cli();
+	blk_dev[MAJOR(rq->rq_dev)].current_request = rq->next;
+	HWGROUP(drive)->rq = NULL;
+	rq->rq_status = RQ_INACTIVE;
+	if (rq->sem != NULL)
+		up(rq->sem);
+	restore_flags(flags);
+}
+
+/*
+ * Error reporting, in human readable form (luxurious, but a memory hog).
+ */
+byte ide_dump_status (ide_drive_t *drive, const char *msg, byte stat)
+{
+	unsigned long flags;
+	byte err = 0;
+
+	save_flags (flags);
+	sti();
+	printk("%s: %s: status=0x%02x", drive->name, msg, stat);
+#if FANCY_STATUS_DUMPS
+	if (drive->media == ide_disk) {
+		printk(" { ");
+		if (stat & BUSY_STAT)
+			printk("Busy ");
+		else {
+			if (stat & READY_STAT)	printk("DriveReady ");
+			if (stat & WRERR_STAT)	printk("DeviceFault ");
+			if (stat & SEEK_STAT)	printk("SeekComplete ");
+			if (stat & DRQ_STAT)	printk("DataRequest ");
+			if (stat & ECC_STAT)	printk("CorrectedError ");
+			if (stat & INDEX_STAT)	printk("Index ");
+			if (stat & ERR_STAT)	printk("Error ");
+		}
+		printk("}");
+	}
+#endif	/* FANCY_STATUS_DUMPS */
+	printk("\n");
+	if ((stat & (BUSY_STAT|ERR_STAT)) == ERR_STAT) {
+		err = GET_ERR();
+		printk("%s: %s: error=0x%02x", drive->name, msg, err);
+#if FANCY_STATUS_DUMPS
+		if (drive->media == ide_disk) {
+			printk(" { ");
+			if (err & BBD_ERR)	printk("BadSector ");
+			if (err & ECC_ERR)	printk("UncorrectableError ");
+			if (err & ID_ERR)	printk("SectorIdNotFound ");
+			if (err & ABRT_ERR)	printk("DriveStatusError ");
+			if (err & TRK0_ERR)	printk("TrackZeroNotFound ");
+			if (err & MARK_ERR)	printk("AddrMarkNotFound ");
+			printk("}");
+			if (err & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
+				byte cur = IN_BYTE(IDE_SELECT_REG);
+				if (cur & 0x40) {	/* using LBA? */
+					printk(", LBAsect=%ld", (unsigned long)
+					 ((cur&0xf)<<24)
+					 |(IN_BYTE(IDE_HCYL_REG)<<16)
+					 |(IN_BYTE(IDE_LCYL_REG)<<8)
+					 | IN_BYTE(IDE_SECTOR_REG));
+				} else {
+					printk(", CHS=%d/%d/%d",
+					 (IN_BYTE(IDE_HCYL_REG)<<8) +
+					  IN_BYTE(IDE_LCYL_REG),
+					  cur & 0xf,
+					  IN_BYTE(IDE_SECTOR_REG));
+				}
+				if (HWGROUP(drive)->rq)
+					printk(", sector=%ld", HWGROUP(drive)->rq->sector);
+			}
+		}
+#endif	/* FANCY_STATUS_DUMPS */
+		printk("\n");
+	}
+	restore_flags (flags);
+	return err;
+}
+
+/*
+ * try_to_flush_leftover_data() is invoked in response to a drive
+ * unexpectedly having its DRQ_STAT bit set.  As an alternative to
+ * resetting the drive, this routine tries to clear the condition
+ * by read a sector's worth of data from the drive.  Of course,
+ * this may not help if the drive is *waiting* for data from *us*.
+ */
+static void try_to_flush_leftover_data (ide_drive_t *drive)
+{
+	int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
+
+	while (i > 0) {
+		unsigned long buffer[16];
+		unsigned int wcount = (i > 16) ? 16 : i;
+		i -= wcount;
+		ide_input_data (drive, buffer, wcount);
+	}
+}
+
+/*
+ * ide_error() takes action based on the error returned by the controller.
+ */
+void ide_error (ide_drive_t *drive, const char *msg, byte stat)
+{
+	struct request *rq;
+	byte err;
+
+	err = ide_dump_status(drive, msg, stat);
+	if ((rq = HWGROUP(drive)->rq) == NULL || drive == NULL)
+		return;
+	/* retry only "normal" I/O: */
+	if (rq->cmd == IDE_DRIVE_CMD || (rq->cmd != READ && rq->cmd != WRITE && drive->media == ide_disk))
+	{
+		rq->errors = 1;
+		ide_end_drive_cmd(drive, stat, err);
+		return;
+	}
+	if (stat & BUSY_STAT) {		/* other bits are useless when BUSY */
+		rq->errors |= ERROR_RESET;
+	} else {
+		if (drive->media == ide_disk && (stat & ERR_STAT)) {
+			/* err has different meaning on cdrom and tape */
+			if (err & (BBD_ERR | ECC_ERR))	/* retries won't help these */
+				rq->errors = ERROR_MAX;
+			else if (err & TRK0_ERR)	/* help it find track zero */
+				rq->errors |= ERROR_RECAL;
+		}
+		if ((stat & DRQ_STAT) && rq->cmd != WRITE)
+			try_to_flush_leftover_data(drive);
+	}
+	if (GET_STAT() & (BUSY_STAT|DRQ_STAT))
+		rq->errors |= ERROR_RESET;	/* Mmmm.. timing problem */
+
+	if (rq->errors >= ERROR_MAX) {
+#ifdef CONFIG_BLK_DEV_IDETAPE
+		if (drive->media == ide_tape) {
+			rq->errors = 0;
+			idetape_end_request(0, HWGROUP(drive));
+		}
+		else
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+ 		ide_end_request(0, HWGROUP(drive));
+	}
+	else {
+		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
+			++rq->errors;
+			ide_do_reset(drive);
+			return;
+		} else if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
+			drive->special.b.recalibrate = 1;
+		++rq->errors;
+	}
+}
+
+/*
+ * read_intr() is the handler for disk read/multread interrupts
+ */
+static void read_intr (ide_drive_t *drive)
+{
+	byte stat;
+	int i;
+	unsigned int msect, nsect;
+	struct request *rq;
+
+	if (!OK_STAT(stat=GET_STAT(),DATA_READY,BAD_R_STAT)) {
+		ide_error(drive, "read_intr", stat);
+		return;
+	}
+	msect = drive->mult_count;
+read_next:
+	rq = HWGROUP(drive)->rq;
+	if (msect) {
+		if ((nsect = rq->current_nr_sectors) > msect)
+			nsect = msect;
+		msect -= nsect;
+	} else
+		nsect = 1;
+	ide_input_data(drive, rq->buffer, nsect * SECTOR_WORDS);
+#ifdef DEBUG
+	printk("%s:  read: sectors(%ld-%ld), buffer=0x%08lx, remaining=%ld\n",
+		drive->name, rq->sector, rq->sector+nsect-1,
+		(unsigned long) rq->buffer+(nsect<<9), rq->nr_sectors-nsect);
+#endif
+	rq->sector += nsect;
+	rq->buffer += nsect<<9;
+	rq->errors = 0;
+	i = (rq->nr_sectors -= nsect);
+	if ((rq->current_nr_sectors -= nsect) <= 0)
+		ide_end_request(1, HWGROUP(drive));
+	if (i > 0) {
+		if (msect)
+			goto read_next;
+		ide_set_handler (drive, &read_intr, WAIT_CMD);
+	}
+}
+
+/*
+ * write_intr() is the handler for disk write interrupts
+ */
+static void write_intr (ide_drive_t *drive)
+{
+	byte stat;
+	int i;
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	struct request *rq = hwgroup->rq;
+
+	if (OK_STAT(stat=GET_STAT(),DRIVE_READY,drive->bad_wstat)) {
+#ifdef DEBUG
+		printk("%s: write: sector %ld, buffer=0x%08lx, remaining=%ld\n",
+			drive->name, rq->sector, (unsigned long) rq->buffer,
+			rq->nr_sectors-1);
+#endif
+		if ((rq->nr_sectors == 1) ^ ((stat & DRQ_STAT) != 0)) {
+			rq->sector++;
+			rq->buffer += 512;
+			rq->errors = 0;
+			i = --rq->nr_sectors;
+			--rq->current_nr_sectors;
+			if (rq->current_nr_sectors <= 0)
+				ide_end_request(1, hwgroup);
+			if (i > 0) {
+				ide_output_data (drive, rq->buffer, SECTOR_WORDS);
+				ide_set_handler (drive, &write_intr, WAIT_CMD);
+			}
+			return;
+		}
+	}
+	ide_error(drive, "write_intr", stat);
+}
+
+/*
+ * multwrite() transfers a block of one or more sectors of data to a drive
+ * as part of a disk multwrite operation.
+ */
+static void multwrite (ide_drive_t *drive)
+{
+	struct request *rq = &HWGROUP(drive)->wrq;
+	unsigned int mcount = drive->mult_count;
+
+	do {
+		unsigned int nsect = rq->current_nr_sectors;
+		if (nsect > mcount)
+			nsect = mcount;
+		mcount -= nsect;
+
+		ide_output_data(drive, rq->buffer, nsect<<7);
+#ifdef DEBUG
+		printk("%s: multwrite: sector %ld, buffer=0x%08lx, count=%d, remaining=%ld\n",
+			drive->name, rq->sector, (unsigned long) rq->buffer,
+			nsect, rq->nr_sectors - nsect);
+#endif
+		if ((rq->nr_sectors -= nsect) <= 0)
+			break;
+		if ((rq->current_nr_sectors -= nsect) == 0) {
+			if ((rq->bh = rq->bh->b_reqnext) != NULL) {
+				rq->current_nr_sectors = rq->bh->b_size>>9;
+				rq->buffer             = rq->bh->b_data;
+			} else {
+				panic("%s: buffer list corrupted\n", drive->name);
+				break;
+			}
+		} else {
+			rq->buffer += nsect << 9;
+		}
+	} while (mcount);
+}
+
+/*
+ * multwrite_intr() is the handler for disk multwrite interrupts
+ */
+static void multwrite_intr (ide_drive_t *drive)
+{
+	byte stat;
+	int i;
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	struct request *rq = &hwgroup->wrq;
+
+	if (OK_STAT(stat=GET_STAT(),DRIVE_READY,drive->bad_wstat)) {
+		if (stat & DRQ_STAT) {
+			if (rq->nr_sectors) {
+				multwrite(drive);
+				ide_set_handler (drive, &multwrite_intr, WAIT_CMD);
+				return;
+			}
+		} else {
+			if (!rq->nr_sectors) {	/* all done? */
+				rq = hwgroup->rq;
+				for (i = rq->nr_sectors; i > 0;){
+					i -= rq->current_nr_sectors;
+					ide_end_request(1, hwgroup);
+				}
+				return;
+			}
+		}
+	}
+	ide_error(drive, "multwrite_intr", stat);
+}
+
+/*
+ * Issue a simple drive command
+ * The drive must be selected beforehand.
+ */
+static void ide_cmd(ide_drive_t *drive, byte cmd, byte nsect, ide_handler_t *handler)
+{
+	ide_set_handler (drive, handler, WAIT_CMD);
+	OUT_BYTE(drive->ctl,IDE_CONTROL_REG);
+	OUT_BYTE(nsect,IDE_NSECTOR_REG);
+	OUT_BYTE(cmd,IDE_COMMAND_REG);
+}
+
+/*
+ * set_multmode_intr() is invoked on completion of a WIN_SETMULT cmd.
+ */
+static void set_multmode_intr (ide_drive_t *drive)
+{
+	byte stat = GET_STAT();
+
+	sti();
+	if (OK_STAT(stat,READY_STAT,BAD_STAT)) {
+		drive->mult_count = drive->mult_req;
+	} else {
+		drive->mult_req = drive->mult_count = 0;
+		drive->special.b.recalibrate = 1;
+		(void) ide_dump_status(drive, "set_multmode", stat);
+	}
+}
+
+/*
+ * set_geometry_intr() is invoked on completion of a WIN_SPECIFY cmd.
+ */
+static void set_geometry_intr (ide_drive_t *drive)
+{
+	byte stat = GET_STAT();
+
+	sti();
+	if (!OK_STAT(stat,READY_STAT,BAD_STAT))
+		ide_error(drive, "set_geometry_intr", stat);
+}
+
+/*
+ * recal_intr() is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
+ */
+static void recal_intr (ide_drive_t *drive)
+{
+	byte stat = GET_STAT();
+
+	sti();
+	if (!OK_STAT(stat,READY_STAT,BAD_STAT))
+		ide_error(drive, "recal_intr", stat);
+}
+
+/*
+ * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
+ */
+static void drive_cmd_intr (ide_drive_t *drive)
+{
+	byte stat = GET_STAT();
+
+	sti();
+	if (OK_STAT(stat,READY_STAT,BAD_STAT))
+		ide_end_drive_cmd (drive, stat, GET_ERR());
+	else
+		ide_error(drive, "drive_cmd", stat); /* calls ide_end_drive_cmd */
+}
+
+/*
+ * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
+ * commands to a drive.  It used to do much more, but has been scaled back.
+ */
+static inline void do_special (ide_drive_t *drive)
+{
+	special_t *s = &drive->special;
+next:
+#ifdef DEBUG
+	printk("%s: do_special: 0x%02x\n", drive->name, s->all);
+#endif
+	if (s->b.set_geometry) {
+		s->b.set_geometry = 0;
+		if (drive->media == ide_disk) {
+			OUT_BYTE(drive->sect,IDE_SECTOR_REG);
+			OUT_BYTE(drive->cyl,IDE_LCYL_REG);
+			OUT_BYTE(drive->cyl>>8,IDE_HCYL_REG);
+			OUT_BYTE(((drive->head-1)|drive->select.all)&0xBF,IDE_SELECT_REG);
+			ide_cmd(drive, WIN_SPECIFY, drive->sect, &set_geometry_intr);
+		}
+	} else if (s->b.recalibrate) {
+		s->b.recalibrate = 0;
+		if (drive->media == ide_disk) {
+			ide_cmd(drive, WIN_RESTORE, drive->sect, &recal_intr);
+		}
+	} else if (s->b.set_pio) {
+		ide_tuneproc_t *tuneproc = HWIF(drive)->tuneproc;
+		s->b.set_pio = 0;
+		if (tuneproc != NULL)
+			tuneproc(drive, drive->pio_req);
+		goto next;
+	} else if (s->b.set_multmode) {
+		s->b.set_multmode = 0;
+		if (drive->media == ide_disk) {
+			if (drive->id && drive->mult_req > drive->id->max_multsect)
+				drive->mult_req = drive->id->max_multsect;
+			ide_cmd(drive, WIN_SETMULT, drive->mult_req, &set_multmode_intr);
+		} else
+			drive->mult_req = 0;
+	} else if (s->all) {
+		s->all = 0;
+		printk("%s: bad special flag: 0x%02x\n", drive->name, s->all);
+	}
+}
+
+/*
+ * This routine busy-waits for the drive status to be not "busy".
+ * It then checks the status for all of the "good" bits and none
+ * of the "bad" bits, and if all is okay it returns 0.  All other
+ * cases return 1 after invoking ide_error() -- caller should just return.
+ *
+ * This routine should get fixed to not hog the cpu during extra long waits..
+ * That could be done by busy-waiting for the first jiffy or two, and then
+ * setting a timer to wake up at half second intervals thereafter,
+ * until timeout is achieved, before timing out.
+ */
+int ide_wait_stat (ide_drive_t *drive, byte good, byte bad, unsigned long timeout)
+{
+	byte stat;
+	unsigned long flags;
+
+test:
+	udelay(1);	/* spec allows drive 400ns to change "BUSY" */
+	if (OK_STAT((stat = GET_STAT()), good, bad))
+		return 0;	/* fast exit for most frequent case */
+	if (!(stat & BUSY_STAT)) {
+		ide_error(drive, "status error", stat);
+		return 1;
+	}
+
+	save_flags(flags);
+	sti();
+	timeout += jiffies;
+	do {
+		if (!((stat = GET_STAT()) & BUSY_STAT)) {
+			restore_flags(flags);
+			goto test;
+		}
+	} while (jiffies <= timeout);
+
+	restore_flags(flags);
+	ide_error(drive, "status timeout", GET_STAT());
+	return 1;
+}
+
+/*
+ * do_rw_disk() issues WIN_{MULT}READ and WIN_{MULT}WRITE commands to a disk,
+ * using LBA if supported, or CHS otherwise, to address sectors.  It also takes
+ * care of issuing special DRIVE_CMDs.
+ */
+static inline void do_rw_disk (ide_drive_t *drive, struct request *rq, unsigned long block)
+{
+	unsigned short io_base = HWIF(drive)->io_base;
+
+	OUT_BYTE(drive->ctl,IDE_CONTROL_REG);
+	OUT_BYTE(rq->nr_sectors,io_base+IDE_NSECTOR_OFFSET);
+	if (drive->select.b.lba) {
+#ifdef DEBUG
+		printk("%s: %sing: LBAsect=%ld, sectors=%ld, buffer=0x%08lx\n",
+			drive->name, (rq->cmd==READ)?"read":"writ",
+			block, rq->nr_sectors, (unsigned long) rq->buffer);
+#endif
+		OUT_BYTE(block,io_base+IDE_SECTOR_OFFSET);
+		OUT_BYTE(block>>=8,io_base+IDE_LCYL_OFFSET);
+		OUT_BYTE(block>>=8,io_base+IDE_HCYL_OFFSET);
+		OUT_BYTE(((block>>8)&0x0f)|drive->select.all,io_base+IDE_SELECT_OFFSET);
+	} else {
+		unsigned int sect,head,cyl,track;
+		track = block / drive->sect;
+		sect  = block % drive->sect + 1;
+		OUT_BYTE(sect,io_base+IDE_SECTOR_OFFSET);
+		head  = track % drive->head;
+		cyl   = track / drive->head;
+		OUT_BYTE(cyl,io_base+IDE_LCYL_OFFSET);
+		OUT_BYTE(cyl>>8,io_base+IDE_HCYL_OFFSET);
+		OUT_BYTE(head|drive->select.all,io_base+IDE_SELECT_OFFSET);
+#ifdef DEBUG
+		printk("%s: %sing: CHS=%d/%d/%d, sectors=%ld, buffer=0x%08lx\n",
+			drive->name, (rq->cmd==READ)?"read":"writ", cyl,
+			head, sect, rq->nr_sectors, (unsigned long) rq->buffer);
+#endif
+	}
+	if (rq->cmd == READ) {
+#ifdef CONFIG_BLK_DEV_TRITON
+		if (drive->using_dma && !(HWIF(drive)->dmaproc(ide_dma_read, drive)))
+			return;
+#endif /* CONFIG_BLK_DEV_TRITON */
+		ide_set_handler(drive, &read_intr, WAIT_CMD);
+		OUT_BYTE(drive->mult_count ? WIN_MULTREAD : WIN_READ, io_base+IDE_COMMAND_OFFSET);
+		return;
+	}
+	if (rq->cmd == WRITE) {
+#ifdef CONFIG_BLK_DEV_TRITON
+		if (drive->using_dma && !(HWIF(drive)->dmaproc(ide_dma_write, drive)))
+			return;
+#endif /* CONFIG_BLK_DEV_TRITON */
+		OUT_BYTE(drive->mult_count ? WIN_MULTWRITE : WIN_WRITE, io_base+IDE_COMMAND_OFFSET);
+		if (ide_wait_stat(drive, DATA_READY, drive->bad_wstat, WAIT_DRQ)) {
+			printk("%s: no DRQ after issuing %s\n", drive->name,
+				drive->mult_count ? "MULTWRITE" : "WRITE");
+			return;
+		}
+		if (!drive->unmask)
+			cli();
+		if (drive->mult_count) {
+			HWGROUP(drive)->wrq = *rq; /* scratchpad */
+			ide_set_handler (drive, &multwrite_intr, WAIT_CMD);
+			multwrite(drive);
+		} else {
+			ide_set_handler (drive, &write_intr, WAIT_CMD);
+			ide_output_data(drive, rq->buffer, SECTOR_WORDS);
+		}
+		return;
+	}
+	if (rq->cmd == IDE_DRIVE_CMD) {
+		byte *args = rq->buffer;
+		if (args) {
+#ifdef DEBUG
+			printk("%s: DRIVE_CMD cmd=0x%02x sc=0x%02x fr=0x%02x\n",
+			 drive->name, args[0], args[1], args[2]);
+#endif
+			OUT_BYTE(args[2],io_base+IDE_FEATURE_OFFSET);
+			ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
+			return;
+		} else {
+			/*
+			 * NULL is actually a valid way of waiting for
+			 * all current requests to be flushed from the queue.
+			 */
+#ifdef DEBUG
+			printk("%s: DRIVE_CMD (null)\n", drive->name);
+#endif
+			ide_end_drive_cmd(drive, GET_STAT(), GET_ERR());
+			return;
+		}
+	}
+	printk("%s: bad command: %d\n", drive->name, rq->cmd);
+	ide_end_request(0, HWGROUP(drive));
+}
+
+/*
+ * do_request() initiates handling of a new I/O request
+ */
+static inline void do_request (ide_hwif_t *hwif, struct request *rq)
+{
+	unsigned int minor, unit;
+	unsigned long block, blockend;
+	ide_drive_t *drive;
+
+	sti();
+#ifdef DEBUG
+	printk("%s: do_request: current=0x%08lx\n", hwif->name, (unsigned long) rq);
+#endif
+	minor = MINOR(rq->rq_dev);
+	unit = minor >> PARTN_BITS;
+	if (MAJOR(rq->rq_dev) != hwif->major || unit >= MAX_DRIVES) {
+		printk("%s: bad device number: %s\n",
+		       hwif->name, kdevname(rq->rq_dev));
+		goto kill_rq;
+	}
+	drive = &hwif->drives[unit];
+#ifdef DEBUG
+	if (rq->bh && !buffer_locked(rq->bh)) {
+		printk("%s: block not locked\n", drive->name);
+		goto kill_rq;
+	}
+#endif
+	block    = rq->sector;
+	blockend = block + rq->nr_sectors;
+	if ((blockend < block) || (blockend > drive->part[minor&PARTN_MASK].nr_sects)) {
+		printk("%s%c: bad access: block=%ld, count=%ld\n", drive->name,
+		 (minor&PARTN_MASK)?'0'+(minor&PARTN_MASK):' ', block, rq->nr_sectors);
+		goto kill_rq;
+	}
+	block += drive->part[minor&PARTN_MASK].start_sect + drive->sect0;
+#if FAKE_FDISK_FOR_EZDRIVE
+	if (block == 0 && drive->remap_0_to_1)
+		block = 1;  /* redirect MBR access to EZ-Drive partn table */
+#endif /* FAKE_FDISK_FOR_EZDRIVE */
+	((ide_hwgroup_t *)hwif->hwgroup)->drive = drive;
+#ifdef CONFIG_BLK_DEV_HT6560B
+	if (hwif->selectproc)
+		hwif->selectproc (drive);
+#endif /* CONFIG_BLK_DEV_HT6560B */
+#if (DISK_RECOVERY_TIME > 0)
+	while ((read_timer() - hwif->last_time) < DISK_RECOVERY_TIME);
+#endif
+
+#ifdef CONFIG_BLK_DEV_IDETAPE
+	POLL_HWIF_TAPE_DRIVE;	/* macro from ide-tape.h */
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+
+	OUT_BYTE(drive->select.all,IDE_SELECT_REG);
+	if (ide_wait_stat(drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
+		printk("%s: drive not ready for command\n", drive->name);
+		return;
+	}
+	
+	if (!drive->special.all) {
+#ifdef CONFIG_BLK_DEV_IDEATAPI
+		switch (drive->media) {
+			case ide_disk:
+				do_rw_disk (drive, rq, block);
+				return;
+#ifdef CONFIG_BLK_DEV_IDECD
+			case ide_cdrom:
+				ide_do_rw_cdrom (drive, block);
+				return;
+#endif /* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+			case ide_tape:
+				if (rq->cmd == IDE_DRIVE_CMD) {
+					byte *args = (byte *) rq->buffer;
+					OUT_BYTE(args[2],IDE_FEATURE_REG);
+					ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
+					return;
+				}
+				idetape_do_request (drive, rq, block);
+				return;
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+
+			default:
+				printk("%s: media type %d not supported\n",
+					drive->name, drive->media);
+				goto kill_rq;
+		}
+#else
+		do_rw_disk (drive, rq, block); /* simpler and faster */
+		return;
+#endif /* CONFIG_BLK_DEV_IDEATAPI */;
+	}
+	do_special(drive);
+	return;
+kill_rq:
+	ide_end_request(0, hwif->hwgroup);
+}
+
+/*
+ * The driver enables interrupts as much as possible.  In order to do this,
+ * (a) the device-interrupt is always masked before entry, and
+ * (b) the timeout-interrupt is always disabled before entry.
+ *
+ * If we enter here from, say irq14, and then start a new request for irq15,
+ * (possible with "serialize" option) then we cannot ensure that we exit
+ * before the irq15 hits us. So, we must be careful not to let this bother us.
+ *
+ * Interrupts are still masked (by default) whenever we are exchanging
+ * data/cmds with a drive, because some drives seem to have very poor
+ * tolerance for latency during I/O.  For devices which don't suffer from
+ * this problem (most don't), the unmask flag can be set using the "hdparm"
+ * utility, to permit other interrupts during data/cmd transfers.
+ */
+void ide_do_request (ide_hwgroup_t *hwgroup)
+{
+	cli();	/* paranoia */
+	if (hwgroup->handler != NULL) {
+		printk("%s: EEeekk!! handler not NULL in ide_do_request()\n", hwgroup->hwif->name);
+		return;
+	}
+	do {
+		ide_hwif_t *hwif = hwgroup->hwif;
+		struct request *rq;
+		if ((rq = hwgroup->rq) == NULL) {
+			do {
+				rq = blk_dev[hwif->major].current_request;
+				if (rq != NULL && rq->rq_status != RQ_INACTIVE)
+					goto got_rq;
+			} while ((hwif = hwif->next) != hwgroup->hwif);
+			return;		/* no work left for this hwgroup */
+		}
+	got_rq:	
+		do_request(hwgroup->hwif = hwif, hwgroup->rq = rq);
+		cli();
+	} while (hwgroup->handler == NULL);
+}
+
+/*
+ * do_hwgroup_request() invokes ide_do_request() after first masking
+ * all possible interrupts for the current hwgroup.  This prevents race
+ * conditions in the event that an unexpected interrupt occurs while
+ * we are in the driver.
+ *
+ * Note that when an interrupt is used to reenter the driver, the first level
+ * handler will already have masked the irq that triggered, but any other ones
+ * for the hwgroup will still be unmasked.  The driver tries to be careful
+ * about such things.
+ */
+static void do_hwgroup_request (ide_hwgroup_t *hwgroup)
+{
+	if (hwgroup->handler == NULL) {
+		ide_hwif_t *hgif = hwgroup->hwif;
+		ide_hwif_t *hwif = hgif;
+		do {
+			disable_irq(hwif->irq);
+		} while ((hwif = hwif->next) != hgif);
+		ide_do_request (hwgroup);
+		do {
+			enable_irq(hwif->irq);
+		} while ((hwif = hwif->next) != hgif);
+	}
+}
+
+static void do_ide0_request (void)	/* invoked with cli() */
+{
+	do_hwgroup_request (ide_hwifs[0].hwgroup);
+}
+
+static void do_ide1_request (void)	/* invoked with cli() */
+{
+	do_hwgroup_request (ide_hwifs[1].hwgroup);
+}
+
+static void do_ide2_request (void)	/* invoked with cli() */
+{
+	do_hwgroup_request (ide_hwifs[2].hwgroup);
+}
+
+static void do_ide3_request (void)	/* invoked with cli() */
+{
+	do_hwgroup_request (ide_hwifs[3].hwgroup);
+}
+
+static void timer_expiry (unsigned long data)
+{
+	ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
+	ide_drive_t   *drive   = hwgroup->drive;
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+
+	if (hwgroup->poll_timeout != 0) { /* polling in progress? */
+		ide_handler_t *handler = hwgroup->handler;
+		hwgroup->handler = NULL;
+		handler(drive);
+	} else if (hwgroup->handler == NULL) {	 /* not waiting for anything? */
+		sti(); /* drive must have responded just as the timer expired */
+		printk("%s: marginal timeout\n", drive->name);
+	} else {
+		hwgroup->handler = NULL;	/* abort the operation */
+		if (hwgroup->hwif->dmaproc)
+			(void) hwgroup->hwif->dmaproc (ide_dma_abort, drive);
+		ide_error(drive, "irq timeout", GET_STAT());
+	}
+	if (hwgroup->handler == NULL)
+		do_hwgroup_request (hwgroup);
+	restore_flags(flags);
+}
+
+/*
+ * There's nothing really useful we can do with an unexpected interrupt,
+ * other than reading the status register (to clear it), and logging it.
+ * There should be no way that an irq can happen before we're ready for it,
+ * so we needn't worry much about losing an "important" interrupt here.
+ *
+ * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
+ * drive enters "idle", "standby", or "sleep" mode, so if the status looks
+ * "good", we just ignore the interrupt completely.
+ *
+ * This routine assumes cli() is in effect when called.
+ *
+ * If an unexpected interrupt happens on irq15 while we are handling irq14
+ * and if the two interfaces are "serialized" (CMD640B), then it looks like
+ * we could screw up by interfering with a new request being set up for irq15.
+ *
+ * In reality, this is a non-issue.  The new command is not sent unless the
+ * drive is ready to accept one, in which case we know the drive is not
+ * trying to interrupt us.  And ide_set_handler() is always invoked before
+ * completing the issuance of any new drive command, so we will not be
+ * accidently invoked as a result of any valid command completion interrupt.
+ *
+ */
+static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
+{
+	byte stat;
+	unsigned int unit;
+	ide_hwif_t *hwif = hwgroup->hwif;
+
+	/*
+	 * handle the unexpected interrupt
+	 */
+	do {
+		if (hwif->irq == irq) {
+			for (unit = 0; unit < MAX_DRIVES; ++unit) {
+				ide_drive_t *drive = &hwif->drives[unit];
+				if (!drive->present)
+					continue;
+#ifdef CONFIG_BLK_DEV_HT6560B
+				if (hwif->selectproc)
+					hwif->selectproc (drive);
+#endif /* CONFIG_BLK_DEV_HT6560B */
+				if (!OK_STAT(stat=GET_STAT(), drive->ready_stat, BAD_STAT))
+					(void) ide_dump_status(drive, "unexpected_intr", stat);
+				if ((stat & DRQ_STAT))
+					try_to_flush_leftover_data(drive);
+			}
+		}
+	} while ((hwif = hwif->next) != hwgroup->hwif);
+#ifdef CONFIG_BLK_DEV_HT6560B
+	if (hwif->selectproc)
+		hwif->selectproc (hwgroup->drive);
+#endif /* CONFIG_BLK_DEV_HT6560B */
+}
+
+/*
+ * entry point for all interrupts, caller does cli() for us
+ */
+static void ide_intr (int irq, struct pt_regs *regs)
+{
+	ide_hwgroup_t  *hwgroup = irq_to_hwgroup[irq];
+	ide_handler_t  *handler;
+
+	if (irq == hwgroup->hwif->irq && (handler = hwgroup->handler) != NULL) {
+		ide_drive_t *drive = hwgroup->drive;
+		hwgroup->handler = NULL;
+		del_timer(&(hwgroup->timer));
+		if (drive->unmask)
+			sti();
+		handler(drive);
+		cli();	/* this is necessary, as next rq may be different irq */
+		if (hwgroup->handler == NULL) {
+			SET_RECOVERY_TIMER(HWIF(drive));
+			ide_do_request(hwgroup);
+		}
+	} else {
+		unexpected_intr(irq, hwgroup);
+	}
+	cli();
+}
+
+/*
+ * get_info_ptr() returns the (ide_drive_t *) for a given device number.
+ * It returns NULL if the given device number does not match any present drives.
+ */
+static ide_drive_t *get_info_ptr (kdev_t i_rdev)
+{
+	int		major = MAJOR(i_rdev);
+	unsigned int	h;
+
+	for (h = 0; h < MAX_HWIFS; ++h) {
+		ide_hwif_t  *hwif = &ide_hwifs[h];
+		if (hwif->present && major == hwif->major) {
+			unsigned unit = DEVICE_NR(i_rdev);
+			if (unit < MAX_DRIVES) {
+				ide_drive_t *drive = &hwif->drives[unit];
+				if (drive->present)
+					return drive;
+			} else if (major == IDE0_MAJOR && unit < 4) {
+				printk("ide: probable bad entry for /dev/hd%c\n", 'a'+unit);
+				printk("ide: to fix it, run:  /usr/src/linux/drivers/block/MAKEDEV.ide\n");
+			}
+			break;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * This function is intended to be used prior to invoking ide_do_drive_cmd().
+ */
+void ide_init_drive_cmd (struct request *rq)
+{
+	rq->buffer = NULL;
+	rq->cmd = IDE_DRIVE_CMD;
+	rq->sector = 0;
+	rq->nr_sectors = 0;
+	rq->current_nr_sectors = 0;
+	rq->sem = NULL;
+	rq->bh = NULL;
+	rq->bhtail = NULL;
+	rq->next = NULL;
+
+#if 0	/* these are done each time through ide_do_drive_cmd() */
+	rq->errors = 0;
+	rq->rq_status = RQ_ACTIVE;
+	rq->rq_dev = ????;
+#endif
+}
+
+/*
+ * This function issues a special IDE device request
+ * onto the request queue.
+ *
+ * If action is ide_wait, then then rq is queued at the end of
+ * the request queue, and the function sleeps until it has been
+ * processed.  This is for use when invoked from an ioctl handler.
+ *
+ * If action is ide_preempt, then the rq is queued at the head of
+ * the request queue, displacing the currently-being-processed
+ * request and this function returns immediately without waiting
+ * for the new rq to be completed.  This is VERY DANGEROUS, and is
+ * intended for careful use by the ATAPI tape/cdrom driver code.
+ *
+ * If action is ide_next, then the rq is queued immediately after
+ * the currently-being-processed-request (if any), and the function
+ * returns without waiting for the new rq to be completed.  As above,
+ * This is VERY DANGEROUS, and is intended for careful use by the
+ * ATAPI tape/cdrom driver code.
+ *
+ * If action is ide_end, then the rq is queued at the end of the
+ * request queue, and the function returns immediately without waiting
+ * for the new rq to be completed. This is again intended for careful
+ * use by the ATAPI tape/cdrom driver code. (Currently used by ide-tape.c,
+ * when operating in the pipelined operation mode).
+ */
+int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
+{
+	unsigned long flags;
+	unsigned int major = HWIF(drive)->major;
+	struct request *cur_rq;
+	struct blk_dev_struct *bdev = &blk_dev[major];
+	struct semaphore sem = MUTEX_LOCKED;
+
+	rq->errors = 0;
+	rq->rq_status = RQ_ACTIVE;
+	rq->rq_dev = MKDEV(major,(drive->select.b.unit)<<PARTN_BITS);
+	if (action == ide_wait)
+		rq->sem = &sem;
+
+	save_flags(flags);
+	cli();
+	cur_rq = bdev->current_request;
+
+	if (cur_rq == NULL || action == ide_preempt) {
+		rq->next = cur_rq;
+		bdev->current_request = rq;
+		if (action == ide_preempt) {
+			HWGROUP(drive)->rq = NULL;
+		} else
+		if (HWGROUP(drive)->rq == NULL) {  /* is this necessary (?) */
+			bdev->request_fn();
+			cli();
+		}
+	} else {
+		if (action == ide_wait || action == ide_end) {
+			while (cur_rq->next != NULL)	/* find end of list */
+				cur_rq = cur_rq->next;
+		}
+		rq->next = cur_rq->next;
+		cur_rq->next = rq;
+	}
+	if (action == ide_wait  && rq->rq_status != RQ_INACTIVE)
+		down(&sem);	/* wait for it to be serviced */
+	restore_flags(flags);
+	return rq->errors ? -EIO : 0;	/* return -EIO if errors */
+}
+
+static int ide_open(struct inode * inode, struct file * filp)
+{
+	ide_drive_t *drive;
+	unsigned long flags;
+
+	if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
+		return -ENODEV;
+	save_flags(flags);
+	cli();
+	while (drive->busy)
+		sleep_on(&drive->wqueue);
+	drive->usage++;
+	restore_flags(flags);
+#ifdef CONFIG_BLK_DEV_IDECD
+	if (drive->media == ide_cdrom)
+		return ide_cdrom_open (inode, filp, drive);
+#endif	/* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+	if (drive->media == ide_tape)
+		return idetape_blkdev_open (inode, filp, drive);
+#endif	/* CONFIG_BLK_DEV_IDETAPE */
+	if (drive->removeable) {
+		byte door_lock[] = {WIN_DOORLOCK,0,0,0};
+		struct request rq;
+		check_disk_change(inode->i_rdev);
+		ide_init_drive_cmd (&rq);
+		rq.buffer = door_lock;
+		/*
+		 * Ignore the return code from door_lock,
+		 * since the open() has already succeeded,
+		 * and the door_lock is irrelevant at this point.
+		 */
+		(void) ide_do_drive_cmd(drive, &rq, ide_wait);
+	}
+	return 0;
+}
+
+/*
+ * Releasing a block device means we sync() it, so that it can safely
+ * be forgotten about...
+ */
+static void ide_release(struct inode * inode, struct file * file)
+{
+	ide_drive_t *drive;
+
+	if ((drive = get_info_ptr(inode->i_rdev)) != NULL) {
+		sync_dev(inode->i_rdev);
+		drive->usage--;
+#ifdef CONFIG_BLK_DEV_IDECD
+		if (drive->media == ide_cdrom) {
+			ide_cdrom_release (inode, file, drive);
+			return;
+		}
+#endif	/* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+		if (drive->media == ide_tape) {
+			idetape_blkdev_release (inode, file, drive);
+			return;
+		}
+#endif	/* CONFIG_BLK_DEV_IDETAPE */
+		if (drive->removeable) {
+			byte door_unlock[] = {WIN_DOORUNLOCK,0,0,0};
+			struct request rq;
+			invalidate_buffers(inode->i_rdev);
+			ide_init_drive_cmd (&rq);
+			rq.buffer = door_unlock;
+			(void) ide_do_drive_cmd(drive, &rq, ide_wait);
+		}
+	}
+}
+
+/*
+ * This routine is called to flush all partitions and partition tables
+ * for a changed disk, and then re-read the new partition table.
+ * If we are revalidating a disk because of a media change, then we
+ * enter with usage == 0.  If we are using an ioctl, we automatically have
+ * usage == 1 (we need an open channel to use an ioctl :-), so this
+ * is our limit.
+ */
+static int revalidate_disk(kdev_t i_rdev)
+{
+	ide_drive_t *drive;
+	unsigned int p, major, minor;
+	long flags;
+
+	if ((drive = get_info_ptr(i_rdev)) == NULL)
+		return -ENODEV;
+
+	major = MAJOR(i_rdev);
+	minor = drive->select.b.unit << PARTN_BITS;
+	save_flags(flags);
+	cli();
+	if (drive->busy || (drive->usage > 1)) {
+		restore_flags(flags);
+		return -EBUSY;
+	};
+	drive->busy = 1;
+	restore_flags(flags);
+
+	for (p = 0; p < (1<<PARTN_BITS); ++p) {
+		if (drive->part[p].nr_sects > 0) {
+			kdev_t devp = MKDEV(major, minor+p);
+			sync_dev           (devp);
+			invalidate_inodes  (devp);
+			invalidate_buffers (devp);
+		}
+		drive->part[p].start_sect = 0;
+		drive->part[p].nr_sects   = 0;
+	};
+
+	drive->part[0].nr_sects = current_capacity(drive);
+	if (drive->media == ide_disk)
+		resetup_one_dev(HWIF(drive)->gd, drive->select.b.unit);
+
+	drive->busy = 0;
+	wake_up(&drive->wqueue);
+	return 0;
+}
+
+static int write_fs_long (unsigned long useraddr, long value)
+{
+	int err;
+
+	if (NULL == (long *)useraddr)
+		return -EINVAL;
+	if ((err = verify_area(VERIFY_WRITE, (long *)useraddr, sizeof(long))))
+		return err;
+	put_user((unsigned)value, (long *) useraddr);
+	return 0;
+}
+
+static int ide_ioctl (struct inode *inode, struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	struct hd_geometry *loc = (struct hd_geometry *) arg;
+	int err;
+	ide_drive_t *drive;
+	unsigned long flags;
+	struct request rq;
+
+	ide_init_drive_cmd (&rq);
+	if (!inode || !(inode->i_rdev))
+		return -EINVAL;
+	if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
+		return -ENODEV;
+	switch (cmd) {
+		case HDIO_GETGEO:
+			if (!loc || drive->media != ide_disk) return -EINVAL;
+			err = verify_area(VERIFY_WRITE, loc, sizeof(*loc));
+			if (err) return err;
+			put_user(drive->bios_head, (byte *) &loc->heads);
+			put_user(drive->bios_sect, (byte *) &loc->sectors);
+			put_user(drive->bios_cyl, (unsigned short *) &loc->cylinders);
+			put_user((unsigned)drive->part[MINOR(inode->i_rdev)&PARTN_MASK].start_sect,
+				(unsigned long *) &loc->start);
+			return 0;
+
+		case BLKFLSBUF:
+			if(!suser()) return -EACCES;
+			fsync_dev(inode->i_rdev);
+			invalidate_buffers(inode->i_rdev);
+			return 0;
+
+		case BLKRASET:
+			if(!suser()) return -EACCES;
+			if(arg > 0xff) return -EINVAL;
+			read_ahead[MAJOR(inode->i_rdev)] = arg;
+			return 0;
+
+		case BLKRAGET:
+			return write_fs_long(arg, read_ahead[MAJOR(inode->i_rdev)]);
+
+	 	case BLKGETSIZE:   /* Return device size */
+			return write_fs_long(arg, drive->part[MINOR(inode->i_rdev)&PARTN_MASK].nr_sects);
+		case BLKRRPART: /* Re-read partition tables */
+			return revalidate_disk(inode->i_rdev);
+
+		case HDIO_GET_KEEPSETTINGS:
+			return write_fs_long(arg, drive->keep_settings);
+
+		case HDIO_GET_UNMASKINTR:
+			return write_fs_long(arg, drive->unmask);
+
+		case HDIO_GET_DMA:
+			return write_fs_long(arg, drive->using_dma);
+
+		case HDIO_GET_32BIT:
+			return write_fs_long(arg, drive->io_32bit);
+
+		case HDIO_GET_MULTCOUNT:
+			return write_fs_long(arg, drive->mult_count);
+
+		case HDIO_GET_IDENTITY:
+			if (!arg || (MINOR(inode->i_rdev) & PARTN_MASK))
+				return -EINVAL;
+			if (drive->id == NULL)
+				return -ENOMSG;
+			err = verify_area(VERIFY_WRITE, (char *)arg, sizeof(*drive->id));
+			if (!err)
+				memcpy_tofs((char *)arg, (char *)drive->id, sizeof(*drive->id));
+			return err;
+
+			case HDIO_GET_NOWERR:
+			return write_fs_long(arg, drive->bad_wstat == BAD_R_STAT);
+
+		case HDIO_SET_DMA:
+#ifdef CONFIG_BLK_DEV_IDECD
+			if (drive->media == ide_cdrom)
+				return -EPERM;
+#endif /* CONFIG_BLK_DEV_IDECD */
+			if (!drive->id || !(drive->id->capability & 1) || !HWIF(drive)->dmaproc)
+				return -EPERM;
+		case HDIO_SET_KEEPSETTINGS:
+		case HDIO_SET_UNMASKINTR:
+		case HDIO_SET_NOWERR:
+			if (arg > 1)
+				return -EINVAL;
+		case HDIO_SET_32BIT:
+			if (!suser())
+				return -EACCES;
+			if ((MINOR(inode->i_rdev) & PARTN_MASK))
+				return -EINVAL;
+			save_flags(flags);
+			cli();
+			switch (cmd) {
+				case HDIO_SET_DMA:
+					if (!(HWIF(drive)->dmaproc)) {
+						restore_flags(flags);
+						return -EPERM;
+					}
+					drive->using_dma = arg;
+					break;
+				case HDIO_SET_KEEPSETTINGS:
+					drive->keep_settings = arg;
+					break;
+				case HDIO_SET_UNMASKINTR:
+					if (arg && HWIF(drive)->no_unmask) {
+						restore_flags(flags);
+						return -EPERM;
+					}
+					drive->unmask = arg;
+					break;
+				case HDIO_SET_NOWERR:
+					drive->bad_wstat = arg ? BAD_R_STAT : BAD_W_STAT;
+					break;
+				case HDIO_SET_32BIT:
+					if (arg > (1 + (SUPPORT_VLB_SYNC<<1)))
+						return -EINVAL;
+					drive->io_32bit = arg;
+#ifdef CONFIG_BLK_DEV_DTC2278
+					if (HWIF(drive)->chipset == ide_dtc2278)
+						HWIF(drive)->drives[!drive->select.b.unit].io_32bit = arg;
+#endif /* CONFIG_BLK_DEV_DTC2278 */
+					break;
+			}
+			restore_flags(flags);
+			return 0;
+
+		case HDIO_SET_MULTCOUNT:
+			if (!suser())
+				return -EACCES;
+			if (MINOR(inode->i_rdev) & PARTN_MASK)
+				return -EINVAL;
+			if (drive->id && arg > drive->id->max_multsect)
+				return -EINVAL;
+			save_flags(flags);
+			cli();
+			if (drive->special.b.set_multmode) {
+				restore_flags(flags);
+				return -EBUSY;
+			}
+			drive->mult_req = arg;
+			drive->special.b.set_multmode = 1;
+			restore_flags(flags);
+			(void) ide_do_drive_cmd (drive, &rq, ide_wait);
+			return (drive->mult_count == arg) ? 0 : -EIO;
+
+		case HDIO_DRIVE_CMD:
+		{
+			unsigned long args;
+
+			if (NULL == (long *) arg)
+				err = ide_do_drive_cmd(drive, &rq, ide_wait);
+			else {
+				if (!(err = verify_area(VERIFY_READ,(long *)arg,sizeof(long))))
+				{
+					args = get_user((long *)arg);
+					if (!(err = verify_area(VERIFY_WRITE,(long *)arg,sizeof(long)))) {
+						rq.buffer = (char *) &args;
+						err = ide_do_drive_cmd(drive, &rq, ide_wait);
+						put_user(args,(long *)arg);
+					}
+				}
+			}
+			return err;
+		}
+		case HDIO_SET_PIO_MODE:
+			if (!suser())
+				return -EACCES;
+			if (MINOR(inode->i_rdev) & PARTN_MASK)
+				return -EINVAL;
+			if (!HWIF(drive)->tuneproc)
+				return -ENOSYS;
+			save_flags(flags);
+			cli();
+			drive->pio_req = (int) arg;
+			drive->special.b.set_pio = 1;
+			restore_flags(flags);
+			return 0;
+
+		RO_IOCTLS(inode->i_rdev, arg);
+
+		default:
+#ifdef CONFIG_BLK_DEV_IDECD
+			if (drive->media == ide_cdrom)
+				return ide_cdrom_ioctl(drive, inode, file, cmd, arg);
+#endif /* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+			if (drive->media == ide_tape)
+				return idetape_blkdev_ioctl(drive, inode, file, cmd, arg);
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+			return -EPERM;
+	}
+}
+
+static int ide_check_media_change (kdev_t i_rdev)
+{
+	ide_drive_t *drive;
+
+	if ((drive = get_info_ptr(i_rdev)) == NULL)
+		return -ENODEV;
+#ifdef CONFIG_BLK_DEV_IDECD
+	if (drive->media == ide_cdrom)
+		return ide_cdrom_check_media_change (drive);
+#endif	/* CONFIG_BLK_DEV_IDECD */
+	if (drive->removeable) /* for disks */
+		return 1;	/* always assume it was changed */
+	return 0;
+}
+
+void ide_fixstring (byte *s, const int bytecount, const int byteswap)
+{
+	byte *p = s, *end = &s[bytecount & ~1]; /* bytecount must be even */
+
+	if (byteswap) {
+		/* convert from big-endian to host byte order */
+		for (p = end ; p != s;) {
+			unsigned short *pp = (unsigned short *) (p -= 2);
+			*pp = ntohs(*pp);
+		}
+	}
+
+	/* strip leading blanks */
+	while (s != end && *s == ' ')
+		++s;
+
+	/* compress internal blanks and strip trailing blanks */
+	while (s != end && *s) {
+		if (*s++ != ' ' || (s != end && *s && *s != ' '))
+			*p++ = *(s-1);
+	}
+
+	/* wipe out trailing garbage */
+	while (p != end)
+		*p++ = '\0';
+}
+
+static inline void do_identify (ide_drive_t *drive, byte cmd)
+{
+	int bswap;
+	struct hd_driveid *id;
+	unsigned long capacity, check;
+
+	id = drive->id = kmalloc (SECTOR_WORDS*4, GFP_KERNEL);
+	ide_input_data(drive, id, SECTOR_WORDS);	/* read 512 bytes of id info */
+	sti();
+
+	/*
+	 * EATA SCSI controllers do a hardware ATA emulation:  ignore them
+	 */
+	if ((id->model[0] == 'P' && id->model[1] == 'M')
+	 || (id->model[0] == 'S' && id->model[1] == 'K')) {
+		printk("%s: EATA SCSI HBA %.10s\n", drive->name, id->model);
+		drive->present = 0;
+		return;
+	}
+
+	/*
+	 *  WIN_IDENTIFY returns little-endian info,
+	 *  WIN_PIDENTIFY *usually* returns little-endian info.
+	 */
+	bswap = 1;
+	if (cmd == WIN_PIDENTIFY) {
+		if ((id->model[0] == 'N' && id->model[1] == 'E') /* NEC */
+		 || (id->model[0] == 'F' && id->model[1] == 'X') /* Mitsumi */
+		 || (id->model[0] == 'P' && id->model[1] == 'i'))/* Pioneer */
+			bswap = 0;	/* Vertos drives may still be weird */
+	}
+	ide_fixstring (id->model,     sizeof(id->model),     bswap);
+	ide_fixstring (id->fw_rev,    sizeof(id->fw_rev),    bswap);
+	ide_fixstring (id->serial_no, sizeof(id->serial_no), bswap);
+
+	/*
+	 * Check for an ATAPI device
+	 */
+
+	if (cmd == WIN_PIDENTIFY) {
+		byte type = (id->config >> 8) & 0x1f;
+		printk("%s: %s, ATAPI ", drive->name, id->model);
+		switch (type) {
+			case 0:		/* Early cdrom models used zero */
+			case 5:
+#ifdef CONFIG_BLK_DEV_IDECD
+				printk ("CDROM drive\n");
+				drive->media = ide_cdrom;
+ 				drive->present = 1;
+				drive->removeable = 1;
+				return;
+#else
+				printk ("CDROM ");
+				break;
+#endif /* CONFIG_BLK_DEV_IDECD */
+			case 1:
+#ifdef CONFIG_BLK_DEV_IDETAPE
+				printk ("TAPE drive");
+				if (idetape_identify_device (drive,id)) {
+					drive->media = ide_tape;
+					drive->present = 1;
+					drive->removeable = 1;
+					if (HWIF(drive)->dmaproc != NULL &&
+					    !HWIF(drive)->dmaproc(ide_dma_check, drive))
+						printk(", DMA");
+					printk("\n");
+				}
+				else {
+					drive->present = 0;
+					printk ("\nide-tape: the tape is not supported by this version of the driver\n");
+				}
+				return;
+#else
+				printk ("TAPE ");
+				break;
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+			default:
+				drive->present = 0;
+				printk("Type %d - Unknown device\n", type);
+				return;
+		}
+		drive->present = 0;
+		printk("- not supported by this kernel\n");
+		return;
+	}
+
+	/* check for removeable disks (eg. SYQUEST), ignore 'WD' drives */
+	if (id->config & (1<<7)) {	/* removeable disk ? */
+		if (id->model[0] != 'W' || id->model[1] != 'D')
+			drive->removeable = 1;
+	}
+
+	drive->media = ide_disk;
+	/* Extract geometry if we did not already have one for the drive */
+	if (!drive->present) {
+		drive->present = 1;
+		drive->cyl     = drive->bios_cyl  = id->cyls;
+		drive->head    = drive->bios_head = id->heads;
+		drive->sect    = drive->bios_sect = id->sectors;
+	}
+	/* Handle logical geometry translation by the drive */
+	if ((id->field_valid & 1) && id->cur_cyls && id->cur_heads
+	 && (id->cur_heads <= 16) && id->cur_sectors)
+	{
+		/*
+		 * Extract the physical drive geometry for our use.
+		 * Note that we purposely do *not* update the bios info.
+		 * This way, programs that use it (like fdisk) will
+		 * still have the same logical view as the BIOS does,
+		 * which keeps the partition table from being screwed.
+		 *
+		 * An exception to this is the cylinder count,
+		 * which we reexamine later on to correct for 1024 limitations.
+		 */
+		drive->cyl  = id->cur_cyls;
+		drive->head = id->cur_heads;
+		drive->sect = id->cur_sectors;
+
+		/* check for word-swapped "capacity" field in id information */
+		capacity = drive->cyl * drive->head * drive->sect;
+		check = (id->cur_capacity0 << 16) | id->cur_capacity1;
+		if (check == capacity) {	/* was it swapped? */
+			/* yes, bring it into little-endian order: */
+			id->cur_capacity0 = (capacity >>  0) & 0xffff;
+			id->cur_capacity1 = (capacity >> 16) & 0xffff;
+		}
+	}
+	/* Use physical geometry if what we have still makes no sense */
+	if ((!drive->head || drive->head > 16) && id->heads && id->heads <= 16) {
+		drive->cyl  = id->cyls;
+		drive->head = id->heads;
+		drive->sect = id->sectors;
+	}
+	/* Correct the number of cyls if the bios value is too small */
+	if (drive->sect == drive->bios_sect && drive->head == drive->bios_head) {
+		if (drive->cyl > drive->bios_cyl)
+			drive->bios_cyl = drive->cyl;
+	}
+
+	(void) current_capacity (drive); /* initialize LBA selection */
+
+	printk ("%s: %.40s, %ldMB w/%dKB Cache, %sCHS=%d/%d/%d",
+	 drive->name, id->model, current_capacity(drive)/2048L, id->buf_size/2,
+	 drive->select.b.lba ? "LBA, " : "",
+	 drive->bios_cyl, drive->bios_head, drive->bios_sect);
+
+	drive->mult_count = 0;
+	if (id->max_multsect) {
+		drive->mult_req = INITIAL_MULT_COUNT;
+		if (drive->mult_req > id->max_multsect)
+			drive->mult_req = id->max_multsect;
+		if (drive->mult_req || ((id->multsect_valid & 1) && id->multsect))
+			drive->special.b.set_multmode = 1;
+	}
+	if (HWIF(drive)->dmaproc != NULL) {	/* hwif supports DMA? */
+		if (!(HWIF(drive)->dmaproc(ide_dma_check, drive)))
+			printk(", DMA");
+	}
+	printk("\n");
+}
+
+/*
+ * Delay for *at least* 10ms.  As we don't know how much time is left
+ * until the next tick occurs, we wait an extra tick to be safe.
+ * This is used only during the probing/polling for drives at boot time.
+ */
+static void delay_10ms (void)
+{
+	unsigned long timer = jiffies + (HZ + 99)/100 + 1;
+	while (timer > jiffies);
+}
+
+/*
+ * try_to_identify() sends an ATA(PI) IDENTIFY request to a drive
+ * and waits for a response.  It also monitors irqs while this is
+ * happening, in hope of automatically determining which one is
+ * being used by the interface.
+ *
+ * Returns:	0  device was identified
+ *		1  device timed-out (no response to identify request)
+ *		2  device aborted the command (refused to identify itself)
+ */
+static int try_to_identify (ide_drive_t *drive, byte cmd)
+{
+	int hd_status, rc;
+	unsigned long timeout;
+	int irqs = 0;
+
+	if (!HWIF(drive)->irq) {		/* already got an IRQ? */
+		probe_irq_off(probe_irq_on());	/* clear dangling irqs */
+		irqs = probe_irq_on();		/* start monitoring irqs */
+		OUT_BYTE(drive->ctl,IDE_CONTROL_REG);	/* enable device irq */
+	}
+
+	delay_10ms();				/* take a deep breath */
+	if ((IN_BYTE(IDE_ALTSTATUS_REG) ^ IN_BYTE(IDE_STATUS_REG)) & ~INDEX_STAT) {
+		printk("%s: probing with STATUS instead of ALTSTATUS\n", drive->name);
+		hd_status = IDE_STATUS_REG;	/* ancient Seagate drives */
+	} else
+		hd_status = IDE_ALTSTATUS_REG;	/* use non-intrusive polling */
+
+	OUT_BYTE(cmd,IDE_COMMAND_REG);		/* ask drive for ID */
+	timeout = ((cmd == WIN_IDENTIFY) ? WAIT_WORSTCASE : WAIT_PIDENTIFY) / 2;
+	timeout += jiffies;
+	do {
+		if (jiffies > timeout) {
+			if (!HWIF(drive)->irq)
+				(void) probe_irq_off(irqs);
+			return 1;	/* drive timed-out */
+		}
+		delay_10ms();		/* give drive a breather */
+	} while (IN_BYTE(hd_status) & BUSY_STAT);
+
+	delay_10ms();		/* wait for IRQ and DRQ_STAT */
+	if (OK_STAT(GET_STAT(),DRQ_STAT,BAD_R_STAT)) {
+		cli();			/* some systems need this */
+		do_identify(drive, cmd); /* drive returned ID */
+		if (drive->present && drive->media != ide_tape) {
+			ide_tuneproc_t *tuneproc = HWIF(drive)->tuneproc;
+			if (tuneproc != NULL && drive->autotune == 1)
+				tuneproc(drive, 255);	/* auto-tune PIO mode */
+		}
+		rc = 0;			/* drive responded with ID */
+	} else
+		rc = 2;			/* drive refused ID */
+	if (!HWIF(drive)->irq) {
+		irqs = probe_irq_off(irqs);	/* get irq number */
+		if (irqs > 0)
+			HWIF(drive)->irq = irqs;
+		else				/* Mmmm.. multiple IRQs */
+			printk("%s: IRQ probe failed (%d)\n", drive->name, irqs);
+	}
+	return rc;
+}
+
+/*
+ * do_probe() has the difficult job of finding a drive if it exists,
+ * without getting hung up if it doesn't exist, without trampling on
+ * ethernet cards, and without leaving any IRQs dangling to haunt us later.
+ *
+ * If a drive is "known" to exist (from CMOS or kernel parameters),
+ * but does not respond right away, the probe will "hang in there"
+ * for the maximum wait time (about 30 seconds), otherwise it will
+ * exit much more quickly.
+ *
+ * Returns:	0  device was identified
+ *		1  device timed-out (no response to identify request)
+ *		2  device aborted the command (refused to identify itself)
+ *		3  bad status from device (possible for ATAPI drives)
+ *		4  probe was not attempted because failure was obvious
+ */
+static int do_probe (ide_drive_t *drive, byte cmd)
+{
+	int rc;
+#ifdef CONFIG_BLK_DEV_IDEATAPI
+	if (drive->present) {	/* avoid waiting for inappropriate probes */
+		if ((drive->media != ide_disk) && (cmd == WIN_IDENTIFY))
+			return 4;
+	}
+#endif	/* CONFIG_BLK_DEV_IDEATAPI */
+#ifdef DEBUG
+	printk("probing for %s: present=%d, media=%d, probetype=%s\n",
+		drive->name, drive->present, drive->media,
+		(cmd == WIN_IDENTIFY) ? "ATA" : "ATAPI");
+#endif
+#ifdef CONFIG_BLK_DEV_HT6560B
+	if (HWIF(drive)->selectproc)
+		HWIF(drive)->selectproc (drive);
+#endif /* CONFIG_BLK_DEV_HT6560B */
+	OUT_BYTE(drive->select.all,IDE_SELECT_REG);	/* select target drive */
+	delay_10ms();				/* wait for BUSY_STAT */
+	if (IN_BYTE(IDE_SELECT_REG) != drive->select.all && !drive->present) {
+		OUT_BYTE(0xa0,IDE_SELECT_REG);	/* exit with drive0 selected */
+		return 3;    /* no i/f present: avoid killing ethernet cards */
+	}
+
+	if (OK_STAT(GET_STAT(),READY_STAT,BUSY_STAT)
+	 || drive->present || cmd == WIN_PIDENTIFY)
+	{
+		if ((rc = try_to_identify(drive,cmd)))   /* send cmd and wait */
+			rc = try_to_identify(drive,cmd); /* failed: try again */
+		if (rc == 1)
+			printk("%s: no response (status = 0x%02x)\n", drive->name, GET_STAT());
+		(void) GET_STAT();		/* ensure drive irq is clear */
+	} else {
+		rc = 3;				/* not present or maybe ATAPI */
+	}
+	if (drive->select.b.unit != 0) {
+		OUT_BYTE(0xa0,IDE_SELECT_REG);	/* exit with drive0 selected */
+		delay_10ms();
+		(void) GET_STAT();		/* ensure drive irq is clear */
+	}
+	return rc;
+}
+
+/*
+ * probe_for_drive() tests for existance of a given drive using do_probe().
+ *
+ * Returns:	0  no device was found
+ *		1  device was found (note: drive->present might still be 0)
+ */
+static inline byte probe_for_drive (ide_drive_t *drive)
+{
+	if (drive->noprobe)			/* skip probing? */
+		return drive->present;
+	if (do_probe(drive, WIN_IDENTIFY) >= 2) { /* if !(success||timed-out) */
+#ifdef CONFIG_BLK_DEV_IDEATAPI
+		(void) do_probe(drive, WIN_PIDENTIFY); /* look for ATAPI device */
+#endif	/* CONFIG_BLK_DEV_IDEATAPI */
+	}
+	if (!drive->present)
+		return 0;			/* drive not found */
+	if (drive->id == NULL) {		/* identification failed? */
+		if (drive->media == ide_disk) {
+			printk ("%s: non-IDE drive, CHS=%d/%d/%d\n",
+			 drive->name, drive->cyl, drive->head, drive->sect);
+		}
+#ifdef CONFIG_BLK_DEV_IDECD
+		else if (drive->media == ide_cdrom) {
+			printk("%s: ATAPI cdrom (?)\n", drive->name);
+		}
+#endif	/* CONFIG_BLK_DEV_IDECD */
+		else {
+			drive->present = 0;	/* nuke it */
+			return 1;		/* drive was found */
+		}
+	}
+	if (drive->media == ide_disk && !drive->select.b.lba) {
+		if (!drive->head || drive->head > 16) {
+			printk("%s: INVALID GEOMETRY: %d PHYSICAL HEADS?\n",
+			 drive->name, drive->head);
+			drive->present = 0;
+		}
+	}
+	return 1;	/* drive was found */
+}
+
+/*
+ *  This routine only knows how to look for drive units 0 and 1
+ *  on an interface, so any setting of MAX_DRIVES > 2 won't work here.
+ */
+static void probe_for_drives (ide_hwif_t *hwif)
+{
+	unsigned int unit;
+
+	if (check_region(hwif->io_base,8) || check_region(hwif->ctl_port,1)) {
+		int msgout = 0;
+		for (unit = 0; unit < MAX_DRIVES; ++unit) {
+			ide_drive_t *drive = &hwif->drives[unit];
+			if (drive->present) {
+				drive->present = 0;
+				printk("%s: ERROR, PORTS ALREADY IN USE\n", drive->name);
+				msgout = 1;
+			}
+		}
+		if (!msgout)
+			printk("%s: ports already in use, skipping probe\n", hwif->name);
+	} else {
+		unsigned long flags;
+		save_flags(flags);
+
+#if (MAX_DRIVES > 2)
+		printk("%s: probing for first 2 of %d possible drives\n", hwif->name, MAX_DRIVES);
+#endif
+		sti();	/* needed for jiffies and irq probing */
+		/*
+		 * Second drive should only exist if first drive was found,
+		 * but a lot of cdrom drives seem to be configured as slave-only
+		 */
+		for (unit = 0; unit < 2; ++unit) { /* note the hardcoded '2' */
+			ide_drive_t *drive = &hwif->drives[unit];
+			(void) probe_for_drive (drive);
+		}
+		for (unit = 0; unit < MAX_DRIVES; ++unit) {
+			ide_drive_t *drive = &hwif->drives[unit];
+			if (drive->present) {
+				hwif->present = 1;
+				request_region(hwif->io_base,  8, hwif->name);
+				request_region(hwif->ctl_port, 1, hwif->name);
+				break;
+			}
+		}
+		restore_flags(flags);
+	}
+}
+
+/*
+ * stridx() returns the offset of c within s,
+ * or -1 if c is '\0' or not found within s.
+ */
+static int stridx (const char *s, char c)
+{
+	char *i = strchr(s, c);
+	return (i && c) ? i - s : -1;
+}
+
+/*
+ * match_parm() does parsing for ide_setup():
+ *
+ * 1. the first char of s must be '='.
+ * 2. if the remainder matches one of the supplied keywords,
+ *     the index (1 based) of the keyword is negated and returned.
+ * 3. if the remainder is a series of no more than max_vals numbers
+ *     separated by commas, the numbers are saved in vals[] and a
+ *     count of how many were saved is returned.  Base10 is assumed,
+ *     and base16 is allowed when prefixed with "0x".
+ * 4. otherwise, zero is returned.
+ */
+static int match_parm (char *s, const char *keywords[], int vals[], int max_vals)
+{
+	static const char *decimal = "0123456789";
+	static const char *hex = "0123456789abcdef";
+	int i, n;
+
+	if (*s++ == '=') {
+		/*
+		 * Try matching against the supplied keywords,
+		 * and return -(index+1) if we match one
+		 */
+		for (i = 0; *keywords != NULL; ++i) {
+			if (!strcmp(s, *keywords++))
+				return -(i+1);
+		}
+		/*
+		 * Look for a series of no more than "max_vals"
+		 * numeric values separated by commas, in base10,
+		 * or base16 when prefixed with "0x".
+		 * Return a count of how many were found.
+		 */
+		for (n = 0; (i = stridx(decimal, *s)) >= 0;) {
+			vals[n] = i;
+			while ((i = stridx(decimal, *++s)) >= 0)
+				vals[n] = (vals[n] * 10) + i;
+			if (*s == 'x' && !vals[n]) {
+				while ((i = stridx(hex, *++s)) >= 0)
+					vals[n] = (vals[n] * 0x10) + i;
+			}
+			if (++n == max_vals)
+				break;
+			if (*s == ',')
+				++s;
+		}
+		if (!*s)
+			return n;
+	}
+	return 0;	/* zero = nothing matched */
+}
+
+/*
+ * ide_setup() gets called VERY EARLY during initialization,
+ * to handle kernel "command line" strings beginning with "hdx="
+ * or "ide".  Here is the complete set currently supported:
+ *
+ * "hdx="  is recognized for all "x" from "a" to "h", such as "hdc".
+ * "idex=" is recognized for all "x" from "0" to "3", such as "ide1".
+ *
+ * "hdx=noprobe"	: drive may be present, but do not probe for it
+ * "hdx=nowerr"		: ignore the WRERR_STAT bit on this drive
+ * "hdx=cdrom"		: drive is present, and is a cdrom drive
+ * "hdx=cyl,head,sect"	: disk drive is present, with specified geometry
+ * "hdx=autotune"	: driver will attempt to tune interface speed
+ *				to the fastest PIO mode supported,
+ *				if possible for this drive only.
+ *				Not fully supported by all chipset types,
+ *				and quite likely to cause trouble with
+ *				older/odd IDE drives.
+ *
+ * "idex=noprobe"	: do not attempt to access/use this interface
+ * "idex=base"		: probe for an interface at the addr specified,
+ *				where "base" is usually 0x1f0 or 0x170
+ *				and "ctl" is assumed to be "base"+0x206
+ * "idex=base,ctl"	: specify both base and ctl
+ * "idex=base,ctl,irq"	: specify base, ctl, and irq number
+ * "idex=autotune"	: driver will attempt to tune interface speed
+ *				to the fastest PIO mode supported,
+ *				for all drives on this interface.
+ *				Not fully supported by all chipset types,
+ *				and quite likely to cause trouble with
+ *				older/odd IDE drives.
+ * "idex=noautotune"	: driver will NOT attempt to tune interface speed
+ *				This is the default for most chipsets,
+ *				except the cmd640.
+ *
+ * The following two are valid ONLY on ide0,
+ * and the defaults for the base,ctl ports must not be altered.
+ *
+ * "ide0=serialize"	: do not overlap operations on ide0 and ide1.
+ * "ide0=dtc2278"	: probe/support DTC2278 interface
+ * "ide0=ht6560b"	: probe/support HT6560B interface
+ * "ide0=cmd640_vlb"	: *REQUIRED* for VLB cards with the CMD640 chip
+ *			  (not for PCI -- automatically detected)
+ * "ide0=qd6580"	: probe/support qd6580 interface
+ * "ide0=ali14xx"	: probe/support ali14xx chipsets (ALI M1439, M1443, M1445)
+ * "ide0=umc8672"	: probe/support umc8672 chipsets
+ */
+void ide_setup (char *s)
+{
+	int i, vals[3];
+	ide_hwif_t *hwif;
+	ide_drive_t *drive;
+	unsigned int hw, unit;
+	const char max_drive = 'a' + ((MAX_HWIFS * MAX_DRIVES) - 1);
+	const char max_hwif  = '0' + (MAX_HWIFS - 1);
+
+	printk("ide_setup: %s", s);
+	init_ide_data ();
+
+	/*
+	 * Look for drive options:  "hdx="
+	 */
+	if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) {
+		const char *hd_words[] = {"noprobe", "nowerr", "cdrom", "serialize",
+						"autotune", "noautotune", NULL};
+		unit = s[2] - 'a';
+		hw   = unit / MAX_DRIVES;
+		unit = unit % MAX_DRIVES;
+		hwif = &ide_hwifs[hw];
+		drive = &hwif->drives[unit];
+		switch (match_parm(&s[3], hd_words, vals, 3)) {
+			case -1: /* "noprobe" */
+				drive->noprobe = 1;
+				goto done;
+			case -2: /* "nowerr" */
+				drive->bad_wstat = BAD_R_STAT;
+				hwif->noprobe = 0;
+				goto done;
+			case -3: /* "cdrom" */
+				drive->present = 1;
+				drive->media = ide_cdrom;
+				hwif->noprobe = 0;
+				goto done;
+			case -4: /* "serialize" */
+				printk(" -- USE \"ide%c=serialize\" INSTEAD", '0'+hw);
+				goto do_serialize;
+			case -5: /* "autotune" */
+				drive->autotune = 1;
+				goto done;
+			case -6: /* "noautotune" */
+				drive->autotune = 2;
+				goto done;
+			case 3: /* cyl,head,sect */
+				drive->media	= ide_disk;
+				drive->cyl	= drive->bios_cyl  = vals[0];
+				drive->head	= drive->bios_head = vals[1];
+				drive->sect	= drive->bios_sect = vals[2];
+				drive->present	= 1;
+				drive->forced_geom = 1;
+				hwif->noprobe = 0;
+				goto done;
+			default:
+				goto bad_option;
+		}
+	}
+	/*
+	 * Look for interface options:  "idex="
+	 */
+	if (s[0] == 'i' && s[1] == 'd' && s[2] == 'e' && s[3] >= '0' && s[3] <= max_hwif) {
+		/*
+		 * Be VERY CAREFUL changing this: note hardcoded indexes below
+		 */
+		const char *ide_words[] = {"noprobe", "serialize", "autotune", "noautotune",
+			"qd6580", "ht6560b", "cmd640_vlb", "dtc2278", "umc8672", "ali14xx", NULL};
+		hw = s[3] - '0';
+		hwif = &ide_hwifs[hw];
+		i = match_parm(&s[4], ide_words, vals, 3);
+
+		/*
+		 * Cryptic check to ensure chipset not already set for hwif:
+		 */
+		if (i != -1 && i != -2) {
+			if (hwif->chipset != ide_unknown)
+				goto bad_option;
+			if (i < 0 && ide_hwifs[1].chipset != ide_unknown)
+				goto bad_option;
+		}
+		/*
+		 * Interface keywords work only for ide0:
+		 */
+		if (i <= -6 && hw != 0)
+			goto bad_hwif;
+
+		switch (i) {
+#ifdef CONFIG_BLK_DEV_ALI14XX
+			case -10: /* "ali14xx" */
+			{
+				extern void init_ali14xx (void);
+				init_ali14xx();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_ALI14XX */
+#ifdef CONFIG_BLK_DEV_UMC8672
+			case -9: /* "umc8672" */
+			{
+				extern void init_umc8672 (void);
+				init_umc8672();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_UMC8672 */
+#ifdef CONFIG_BLK_DEV_DTC2278
+			case -8: /* "dtc2278" */
+			{
+				extern void init_dtc2278 (void);
+				init_dtc2278();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_DTC2278 */
+#ifdef CONFIG_BLK_DEV_CMD640
+			case -7: /* "cmd640_vlb" */
+			{
+				extern int cmd640_vlb; /* flag for cmd640.c */
+				cmd640_vlb = 1;
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_CMD640 */
+#ifdef CONFIG_BLK_DEV_HT6560B
+			case -6: /* "ht6560b" */
+			{
+				extern void init_ht6560b (void);
+				init_ht6560b();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_HT6560B */
+#if CONFIG_BLK_DEV_QD6580
+			case -5: /* "qd6580" (no secondary i/f) */
+			{
+				extern void init_qd6580 (void);
+				init_qd6580();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_QD6580 */
+			case -4: /* "noautotune" */
+				hwif->drives[0].autotune = 2;
+				hwif->drives[1].autotune = 2;
+				goto done;
+			case -3: /* "autotune" */
+				hwif->drives[0].autotune = 1;
+				hwif->drives[1].autotune = 1;
+				goto done;
+			case -2: /* "serialize" */
+			do_serialize:
+				if (hw > 1) goto bad_hwif;
+				ide_hwifs[0].serialized = 1;
+				goto done;
+
+			case -1: /* "noprobe" */
+				hwif->noprobe = 1;
+				goto done;
+
+			case 1:	/* base */
+				vals[1] = vals[0] + 0x206; /* default ctl */
+			case 2: /* base,ctl */
+				vals[2] = 0;	/* default irq = probe for it */
+			case 3: /* base,ctl,irq */
+				hwif->io_base  = vals[0];
+				hwif->ctl_port = vals[1];
+				hwif->irq      = vals[2];
+				hwif->noprobe  = 0;
+				hwif->chipset  = ide_generic;
+				goto done;
+
+			case 0: goto bad_option;
+			default:
+				printk(" -- SUPPORT NOT CONFIGURED IN THIS KERNEL\n");
+				return;
+		}
+	}
+bad_option:
+	printk(" -- BAD OPTION\n");
+	return;
+bad_hwif:
+	printk("-- NOT SUPPORTED ON ide%d", hw);
+done:
+	printk("\n");
+}
+
+/*
+ * This routine is called from the partition-table code in genhd.c
+ * to "convert" a drive to a logical geometry with fewer than 1024 cyls.
+ *
+ * The second parameter, "xparm", determines exactly how the translation 
+ * will be handled:
+ *		 0 = convert to CHS with fewer than 1024 cyls
+ *			using the same method as Ontrack DiskManager.
+ *		 1 = same as "0", plus offset everything by 63 sectors.
+ *		-1 = similar to "0", plus redirect sector 0 to sector 1.
+ *		>1 = convert to a CHS geometry with "xparm" heads.
+ *
+ * Returns 0 if the translation was not possible, if the device was not 
+ * an IDE disk drive, or if a geometry was "forced" on the commandline.
+ * Returns 1 if the geometry translation was successful.
+ */
+int ide_xlate_1024 (kdev_t i_rdev, int xparm, const char *msg)
+{
+	ide_drive_t *drive;
+	static const byte head_vals[] = {4, 8, 16, 32, 64, 128, 255, 0};
+	const byte *heads = head_vals;
+	unsigned long tracks;
+
+	if ((drive = get_info_ptr(i_rdev)) == NULL || drive->forced_geom)
+		return 0;
+
+	if (xparm > 1 && xparm <= drive->bios_head && drive->bios_sect == 63)
+		return 0;		/* we already have a translation */
+
+	printk("%s ", msg);
+
+	if (drive->id) {
+		drive->cyl  = drive->id->cyls;
+		drive->head = drive->id->heads;
+		drive->sect = drive->id->sectors;
+	}
+	drive->bios_cyl  = drive->cyl;
+	drive->bios_head = drive->head;
+	drive->bios_sect = drive->sect;
+	drive->special.b.set_geometry = 1;
+
+	tracks = drive->bios_cyl * drive->bios_head * drive->bios_sect / 63;
+	drive->bios_sect = 63;
+	if (xparm > 1) {
+		drive->bios_head = xparm;
+		drive->bios_cyl = tracks / drive->bios_head;
+	} else {
+		while (drive->bios_cyl >= 1024) {
+			drive->bios_head = *heads;
+			drive->bios_cyl = tracks / drive->bios_head;
+			if (0 == *++heads)
+				break;
+		}
+#if FAKE_FDISK_FOR_EZDRIVE
+		if (xparm == -1) {
+			drive->remap_0_to_1 = 1;
+			msg = "0->1";
+		} else
+#endif /* FAKE_FDISK_FOR_EZDRIVE */
+		if (xparm == 1) {
+			drive->sect0 = 63;
+			drive->bios_cyl = (tracks - 1) / drive->bios_head;
+			msg = "+63";
+		}
+		printk("[remap %s] ", msg);
+	}
+	drive->part[0].nr_sects = current_capacity(drive);
+	printk("[%d/%d/%d]", drive->bios_cyl, drive->bios_head, drive->bios_sect);
+	return 1;
+}
+
+/*
+ * We query CMOS about hard disks : it could be that we have a SCSI/ESDI/etc
+ * controller that is BIOS compatible with ST-506, and thus showing up in our
+ * BIOS table, but not register compatible, and therefore not present in CMOS.
+ *
+ * Furthermore, we will assume that our ST-506 drives <if any> are the primary
+ * drives in the system -- the ones reflected as drive 1 or 2.  The first
+ * drive is stored in the high nibble of CMOS byte 0x12, the second in the low
+ * nibble.  This will be either a 4 bit drive type or 0xf indicating use byte
+ * 0x19 for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.  A non-zero value
+ * means we have an AT controller hard disk for that drive.
+ *
+ * Of course, there is no guarantee that either drive is actually on the
+ * "primary" IDE interface, but we don't bother trying to sort that out here.
+ * If a drive is not actually on the primary interface, then these parameters
+ * will be ignored.  This results in the user having to supply the logical
+ * drive geometry as a boot parameter for each drive not on the primary i/f.
+ *
+ * The only "perfect" way to handle this would be to modify the setup.[cS] code
+ * to do BIOS calls Int13h/Fn08h and Int13h/Fn48h to get all of the drive info
+ * for us during initialization.  I have the necessary docs -- any takers?  -ml
+ */
+
+static void probe_cmos_for_drives (ide_hwif_t *hwif)
+{
+#ifdef __i386__
+	extern struct drive_info_struct drive_info;
+	byte cmos_disks, *BIOS = (byte *) &drive_info;
+	int unit;
+
+	outb_p(0x12,0x70);		/* specify CMOS address 0x12 */
+	cmos_disks = inb_p(0x71);	/* read the data from 0x12 */
+	/* Extract drive geometry from CMOS+BIOS if not already setup */
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		ide_drive_t *drive = &hwif->drives[unit];
+		if ((cmos_disks & (0xf0 >> (unit*4))) && !drive->present) {
+			drive->cyl   = drive->bios_cyl  = *(unsigned short *)BIOS;
+			drive->head  = drive->bios_head = *(BIOS+2);
+			drive->sect  = drive->bios_sect = *(BIOS+14);
+			drive->ctl   = *(BIOS+8);
+			drive->present = 1;
+		}
+		BIOS += 16;
+	}
+#endif
+}
+
+/*
+ * This routine sets up the irq for an ide interface, and creates a new
+ * hwgroup for the irq/hwif if none was previously assigned.
+ *
+ * The SA_INTERRUPT in sa_flags means ide_intr() is always entered with
+ * interrupts completely disabled.  This can be bad for interrupt latency,
+ * but anything else has led to problems on some machines.  We re-enable
+ * interrupts as much as we can safely do in most places.
+ */
+static int init_irq (ide_hwif_t *hwif)
+{
+	unsigned long flags;
+	int irq = hwif->irq;
+	ide_hwgroup_t *hwgroup = irq_to_hwgroup[irq];
+
+	save_flags(flags);
+	cli();
+
+	/*
+	 * Grab the irq if we don't already have it from a previous hwif
+	 */
+	if (hwgroup == NULL)  {
+		if (request_irq(irq, ide_intr, SA_INTERRUPT|SA_SAMPLE_RANDOM, hwif->name)) {
+			restore_flags(flags);
+			printk(" -- FAILED!");
+			return 1;
+		}
+	}
+	/*
+	 * Check for serialization with ide1.
+	 * This code depends on us having already taken care of ide1.
+	 */
+	if (hwif->serialized && hwif->name[3] == '0' && ide_hwifs[1].present)
+		hwgroup = ide_hwifs[1].hwgroup;
+	/*
+	 * If this is the first interface in a group,
+	 * then we need to create the hwgroup structure
+	 */
+	if (hwgroup == NULL) {
+		hwgroup = kmalloc (sizeof(ide_hwgroup_t), GFP_KERNEL);
+		hwgroup->hwif 	 = hwif->next = hwif;
+		hwgroup->rq      = NULL;
+		hwgroup->handler = NULL;
+		hwgroup->drive   = &hwif->drives[0];
+		hwgroup->poll_timeout = 0;
+		init_timer(&hwgroup->timer);
+		hwgroup->timer.function = &timer_expiry;
+		hwgroup->timer.data = (unsigned long) hwgroup;
+	} else {
+		hwif->next = hwgroup->hwif->next;
+		hwgroup->hwif->next = hwif;
+	}
+	hwif->hwgroup = hwgroup;
+	irq_to_hwgroup[irq] = hwgroup;
+
+	restore_flags(flags);	/* safe now that hwif->hwgroup is set up */
+
+	printk("%s at 0x%03x-0x%03x,0x%03x on irq %d", hwif->name,
+		hwif->io_base, hwif->io_base+7, hwif->ctl_port, irq);
+	if (hwgroup->hwif != hwif)
+		printk(" (serialized with %s)", hwgroup->hwif->name);
+	printk("\n");
+	return 0;
+}
+
+static struct file_operations ide_fops = {
+	NULL,			/* lseek - default */
+	block_read,		/* read - general block-dev read */
+	block_write,		/* write - general block-dev write */
+	NULL,			/* readdir - bad */
+	NULL,			/* select */
+	ide_ioctl,		/* ioctl */
+	NULL,			/* mmap */
+	ide_open,		/* open */
+	ide_release,		/* release */
+	block_fsync		/* fsync */
+	,NULL,			/* fasync */
+	ide_check_media_change,	/* check_media_change */
+	revalidate_disk		/* revalidate */
+};
+
+#ifdef CONFIG_PCI
+#if defined(CONFIG_BLK_DEV_RZ1000) || defined(CONFIG_BLK_DEV_TRITON)
+
+typedef void (ide_pci_init_proc_t)(byte, byte);
+
+/*
+ * ide_probe_pci() scans PCI for a specific vendor/device function,
+ * and invokes the supplied init routine for each instance detected.
+ */
+static void ide_probe_pci (unsigned short vendor, unsigned short device, ide_pci_init_proc_t *init, int func_adj)
+{
+	unsigned long flags;
+	unsigned index;
+	byte fn, bus;
+
+	save_flags(flags);
+	cli();
+	for (index = 0; !pcibios_find_device (vendor, device, index, &bus, &fn); ++index) {
+		init (bus, fn + func_adj);
+	}
+	restore_flags(flags);
+}
+
+#endif /* defined(CONFIG_BLK_DEV_RZ1000) || defined(CONFIG_BLK_DEV_TRITON) */
+#endif /* CONFIG_PCI */
+
+/*
+ * ide_init_pci() finds/initializes "known" PCI IDE interfaces
+ *
+ * This routine should ideally be using pcibios_find_class() to find
+ * all IDE interfaces, but that function causes some systems to "go weird".
+ */
+static void probe_for_hwifs (void)
+{
+#ifdef CONFIG_PCI
+	/*
+	 * Find/initialize PCI IDE interfaces
+	 */
+	if (pcibios_present()) {
+#ifdef CONFIG_BLK_DEV_RZ1000
+		ide_pci_init_proc_t init_rz1000;
+		ide_probe_pci (PCI_VENDOR_ID_PCTECH, PCI_DEVICE_ID_PCTECH_RZ1000, &init_rz1000, 0);
+#endif /* CONFIG_BLK_DEV_RZ1000 */
+#ifdef CONFIG_BLK_DEV_TRITON
+		/*
+		 * Apparently the BIOS32 services on Intel motherboards are
+		 * buggy and won't find the PCI_DEVICE_ID_INTEL_82371_1 for us.
+		 * So instead, we search for PCI_DEVICE_ID_INTEL_82371_0,
+		 * and then add 1.
+		 */
+		ide_probe_pci (PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371_0, &ide_init_triton, 1);
+#endif /* CONFIG_BLK_DEV_TRITON */
+	}
+#endif /* CONFIG_PCI */
+#ifdef CONFIG_BLK_DEV_CMD640
+	{
+		extern void ide_probe_for_cmd640x (void);
+		ide_probe_for_cmd640x();
+	}
+#endif
+}
+
+/*
+ * This is gets invoked once during initialization, to set *everything* up
+ */
+int ide_init (void)
+{
+	int h;
+
+	init_ide_data ();
+	/*
+	 * Probe for special "known" interface chipsets
+	 */
+	probe_for_hwifs ();
+
+	/*
+	 * Probe for drives in the usual way.. CMOS/BIOS, then poke at ports
+	 */
+	for (h = 0; h < MAX_HWIFS; ++h) {
+		ide_hwif_t *hwif = &ide_hwifs[h];
+		if (!hwif->noprobe) {
+			if (hwif->io_base == HD_DATA)
+				probe_cmos_for_drives (hwif);
+			probe_for_drives (hwif);
+		}
+		if (hwif->present) {
+			if (!hwif->irq) {
+				if (!(hwif->irq = default_irqs[h])) {
+					printk("%s: DISABLED, NO IRQ\n", hwif->name);
+					hwif->present = 0;
+					continue;
+				}
+			}
+#ifdef CONFIG_BLK_DEV_HD
+			if (hwif->irq == HD_IRQ && hwif->io_base != HD_DATA) {
+				printk("%s: CANNOT SHARE IRQ WITH OLD HARDDISK DRIVER (hd.c)\n", hwif->name);
+				hwif->present = 0;
+			}
+#endif /* CONFIG_BLK_DEV_HD */
+		}
+	}
+
+	/*
+	 * Now we try to set up irqs and major devices for what was found
+	 */
+	for (h = MAX_HWIFS-1; h >= 0; --h) {
+		void (*rfn)(void);
+		ide_hwif_t *hwif = &ide_hwifs[h];
+		if (!hwif->present)
+			continue;
+		hwif->present = 0; /* we set it back to 1 if all is ok below */
+		switch (hwif->major) {
+			case IDE0_MAJOR: rfn = &do_ide0_request; break;
+			case IDE1_MAJOR: rfn = &do_ide1_request; break;
+			case IDE2_MAJOR: rfn = &do_ide2_request; break;
+			case IDE3_MAJOR: rfn = &do_ide3_request; break;
+			default:
+				printk("%s: request_fn NOT DEFINED\n", hwif->name);
+				continue;
+		}
+		if (register_blkdev (hwif->major, hwif->name, &ide_fops)) {
+			printk("%s: UNABLE TO GET MAJOR NUMBER %d\n", hwif->name, hwif->major);
+		} else if (init_irq (hwif)) {
+			printk("%s: UNABLE TO GET IRQ %d\n", hwif->name, hwif->irq);
+			(void) unregister_blkdev (hwif->major, hwif->name);
+		} else {
+			init_gendisk(hwif);
+			blk_dev[hwif->major].request_fn = rfn;
+			read_ahead[hwif->major] = 8;	/* (4kB) */
+			hwif->present = 1;	/* success */
+		}
+	}
+
+#ifdef CONFIG_BLK_DEV_IDETAPE
+	idetape_register_chrdev();	/* Register character device interface to the ide tape */
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+	
+	return 0;
+}