patch-2.3.99-pre1 linux/drivers/ide/ide.c

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diff -u --recursive --new-file v2.3.51/linux/drivers/ide/ide.c linux/drivers/ide/ide.c
@@ -0,0 +1,3639 @@
+/*
+ *  linux/drivers/block/ide.c		Version 6.30	Dec 28, 1999
+ *
+ *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
+ */
+
+/*
+ *  Mostly written by Mark Lord  <mlord@pobox.com>
+ *                and Gadi Oxman <gadio@netvision.net.il>
+ *
+ *  See linux/MAINTAINERS for address of current maintainer.
+ *
+ * This is the multiple IDE interface driver, as evolved from hd.c.
+ * It supports up to MAX_HWIFS 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:    ide0, port 0x1f0; major=3;  hda is minor=0; hdb is minor=64
+ * Secondary:  ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
+ * Tertiary:   ide2, port 0x???; major=33; hde is minor=0; hdf is minor=64
+ * Quaternary: ide3, port 0x???; major=34; hdg is minor=0; hdh is minor=64
+ * ...
+ *
+ *  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@pobox.com).
+ *
+ *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
+ *
+ *	Mark Lord	(mlord@pobox.com)		(IDE Perf.Pkg)
+ *	Delman Lee	(delman@ieee.org)		("Mr. atdisk2")
+ *	Scott Snyder	(snyder@fnald0.fnal.gov)	(ATAPI IDE cd-rom)
+ *
+ *  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 5.50		allow values as small as 20 for idebus=
+ * Version 5.51		force non io_32bit in drive_cmd_intr()
+ *			change delay_10ms() to delay_50ms() to fix problems
+ * Version 5.52		fix incorrect invalidation of removable devices
+ *			add "hdx=slow" command line option
+ * Version 5.60		start to modularize the driver; the disk and ATAPI
+ *			 drivers can be compiled as loadable modules.
+ *			move IDE probe code to ide-probe.c
+ *			move IDE disk code to ide-disk.c
+ *			add support for generic IDE device subdrivers
+ *			add m68k code from Geert Uytterhoeven
+ *			probe all interfaces by default
+ *			add ioctl to (re)probe an interface
+ * Version 6.00		use per device request queues
+ *			attempt to optimize shared hwgroup performance
+ *			add ioctl to manually adjust bandwidth algorithms
+ *			add kerneld support for the probe module
+ *			fix bug in ide_error()
+ *			fix bug in the first ide_get_lock() call for Atari
+ *			don't flush leftover data for ATAPI devices
+ * Version 6.01		clear hwgroup->active while the hwgroup sleeps
+ *			support HDIO_GETGEO for floppies
+ * Version 6.02		fix ide_ack_intr() call
+ *			check partition table on floppies
+ * Version 6.03		handle bad status bit sequencing in ide_wait_stat()
+ * Version 6.10		deleted old entries from this list of updates
+ *			replaced triton.c with ide-dma.c generic PCI DMA
+ *			added support for BIOS-enabled UltraDMA
+ *			rename all "promise" things to "pdc4030"
+ *			fix EZ-DRIVE handling on small disks
+ * Version 6.11		fix probe error in ide_scan_devices()
+ *			fix ancient "jiffies" polling bugs
+ *			mask all hwgroup interrupts on each irq entry
+ * Version 6.12		integrate ioctl and proc interfaces
+ *			fix parsing of "idex=" command line parameter
+ * Version 6.13		add support for ide4/ide5 courtesy rjones@orchestream.com
+ * Version 6.14		fixed IRQ sharing among PCI devices
+ * Version 6.15		added SMP awareness to IDE drivers
+ * Version 6.16		fixed various bugs; even more SMP friendly
+ * Version 6.17		fix for newest EZ-Drive problem
+ * Version 6.18		default unpartitioned-disk translation now "BIOS LBA"
+ * Version 6.19		Re-design for a UNIFORM driver for all platforms,
+ *			  model based on suggestions from Russell King and
+ *			  Geert Uytterhoeven
+ *			Promise DC4030VL now supported.
+ *			add support for ide6/ide7
+ *			delay_50ms() changed to ide_delay_50ms() and exported.
+ * Version 6.20		Added/Fixed Generic ATA-66 support and hwif detection.
+ *			Added hdx=flash to allow for second flash disk
+ *			  detection w/o the hang loop.
+ *			Added support for ide8/ide9
+ *			Added idex=ata66 for the quirky chipsets that are
+ *			  ATA-66 compliant, but have yet to determine a method
+ *			  of verification of the 80c cable presence.
+ *			  Specifically Promise's PDC20262 chipset.
+ * Version 6.21		Fixing/Fixed SMP spinlock issue with insight from an old
+ *			  hat that clarified original low level driver design.
+ * Version 6.30		Added SMP support; fixed multmode issues.  -ml
+ *
+ *  Some additional driver compile-time options are in ./include/linux/ide.h
+ *
+ *  To do, in likely order of completion:
+ *	- modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
+ *
+ */
+
+#define	REVISION	"Revision: 6.30"
+#define	VERSION		"Id: ide.c 6.30 1999/12/28"
+
+#undef REALLY_SLOW_IO		/* most systems can safely undef this */
+
+#define _IDE_C			/* Tell ide.h it's really us */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/genhd.h>
+#include <linux/blkpg.h>
+#include <linux/malloc.h>
+#ifndef MODULE
+#include <linux/init.h>
+#endif /* MODULE */
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/ide.h>
+#include <linux/devfs_fs_kernel.h>
+
+#include <asm/byteorder.h>
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+
+#include "ide_modes.h"
+
+#ifdef CONFIG_KMOD
+#include <linux/kmod.h>
+#endif /* CONFIG_KMOD */
+
+#ifdef CONFIG_BLK_DEV_VIA82CXXX
+extern byte fifoconfig;		/* defined in via82cxxx.c used by ide_setup() */
+#endif /* CONFIG_BLK_DEV_VIA82CXXX */
+
+static const byte ide_hwif_to_major[] = { IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR, IDE4_MAJOR, IDE5_MAJOR, IDE6_MAJOR, IDE7_MAJOR, IDE8_MAJOR, IDE9_MAJOR };
+
+static int	idebus_parameter = 0; /* holds the "idebus=" parameter */
+static int	system_bus_speed = 0; /* holds what we think is VESA/PCI bus speed */
+static int	initializing;     /* set while initializing built-in drivers */
+
+#ifdef CONFIG_BLK_DEV_IDEPCI
+static int	ide_scan_direction = 0;	/* THIS was formerly 2.2.x pci=reverse */
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+
+#if defined(__mc68000__) || defined(CONFIG_APUS)
+/*
+ * ide_lock is used by the Atari code to obtain access to the IDE interrupt,
+ * which is shared between several drivers.
+ */
+static int	ide_lock = 0;
+#endif /* __mc68000__ || CONFIG_APUS */
+
+/*
+ * ide_modules keeps track of the available IDE chipset/probe/driver modules.
+ */
+ide_module_t *ide_modules	= NULL;
+ide_module_t *ide_probe		= NULL;
+
+/*
+ * This is declared extern in ide.h, for access by other IDE modules:
+ */
+ide_hwif_t	ide_hwifs[MAX_HWIFS];	/* master data repository */
+
+#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);	/* local CPU only */
+	__cli();		/* local CPU only */
+	t = jiffies * 11932;
+    	outb_p(0, 0x43);
+	i = inb_p(0x40);
+	i |= inb(0x40) << 8;
+	__restore_flags(flags);	/* local CPU only */
+	return (t - i);
+}
+#endif /* DISK_RECOVERY_TIME */
+
+static inline void set_recovery_timer (ide_hwif_t *hwif)
+{
+#if (DISK_RECOVERY_TIME > 0)
+	hwif->last_time = read_timer();
+#endif /* DISK_RECOVERY_TIME */
+}
+
+/*
+ * Do not even *think* about calling this!
+ */
+static void init_hwif_data (unsigned int index)
+{
+	unsigned int unit;
+	hw_regs_t hw;
+	ide_hwif_t *hwif = &ide_hwifs[index];
+
+	/* bulk initialize hwif & drive info with zeros */
+	memset(hwif, 0, sizeof(ide_hwif_t));
+	memset(&hw, 0, sizeof(hw_regs_t));
+
+	/* fill in any non-zero initial values */
+	hwif->index     = index;
+	ide_init_hwif_ports(&hw, ide_default_io_base(index), 0, &hwif->irq);
+	memcpy(&hwif->hw, &hw, sizeof(hw));
+	memcpy(hwif->io_ports, hw.io_ports, sizeof(hw.io_ports));
+	hwif->noprobe	= !hwif->io_ports[IDE_DATA_OFFSET];
+#ifdef CONFIG_BLK_DEV_HD
+	if (hwif->io_ports[IDE_DATA_OFFSET] == HD_DATA)
+		hwif->noprobe = 1; /* may be overridden by ide_setup() */
+#endif /* CONFIG_BLK_DEV_HD */
+	hwif->major	= ide_hwif_to_major[index];
+	hwif->name[0]	= 'i';
+	hwif->name[1]	= 'd';
+	hwif->name[2]	= 'e';
+	hwif->name[3]	= '0' + index;
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		ide_drive_t *drive = &hwif->drives[unit];
+
+		drive->media			= ide_disk;
+		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' + (index * MAX_DRIVES) + unit;
+		init_waitqueue_head(&drive->wqueue);
+	}
+}
+
+/*
+ * 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 init_ide_data (void)
+{
+	unsigned int index;
+	static unsigned long magic_cookie = MAGIC_COOKIE;
+
+	if (magic_cookie != MAGIC_COOKIE)
+		return;		/* already initialized */
+	magic_cookie = 0;
+
+	/* Initialise all interface structures */
+	for (index = 0; index < MAX_HWIFS; ++index)
+		init_hwif_data(index);
+
+	/* Add default hw interfaces */
+	ide_init_default_hwifs();
+
+	idebus_parameter = 0;
+	system_bus_speed = 0;
+}
+
+/*
+ * CompactFlash cards and their brethern pretend to be removable hard disks, except:
+ *	(1) they never have a slave unit, and
+ *	(2) they don't have doorlock mechanisms.
+ * This test catches them, and is invoked elsewhere when setting appropriate config bits.
+ *
+ * FIXME: This treatment is probably applicable for *all* PCMCIA (PC CARD) devices,
+ * so in linux 2.3.x we should change this to just treat all PCMCIA drives this way,
+ * and get rid of the model-name tests below (too big of an interface change for 2.2.x).
+ * At that time, we might also consider parameterizing the timeouts and retries,
+ * since these are MUCH faster than mechanical drives.	-M.Lord
+ */
+int drive_is_flashcard (ide_drive_t *drive)
+{
+	struct hd_driveid *id = drive->id;
+
+	if (drive->removable && id != NULL) {
+		if (id->config == 0x848a) return 1;	/* CompactFlash */
+		if (!strncmp(id->model, "KODAK ATA_FLASH", 15)	/* Kodak */
+		 || !strncmp(id->model, "Hitachi CV", 10)	/* Hitachi */
+		 || !strncmp(id->model, "SunDisk SDCFB", 13)	/* SunDisk */
+		 || !strncmp(id->model, "HAGIWARA HPC", 12)	/* Hagiwara */
+		 || !strncmp(id->model, "ATA_FLASH", 9))	/* Simple Tech */
+		{
+			return 1;	/* yes, it is a flash memory card */
+		}
+	}
+	return 0;	/* no, it is not a flash memory card */
+}
+
+/*
+ * ide_system_bus_speed() returns what we think is the system VESA/PCI
+ * bus speed (in MHz).  This is used for calculating interface PIO timings.
+ * The default is 40 for known PCI systems, 50 otherwise.
+ * The "idebus=xx" parameter can be used to override this value.
+ * The actual value to be used is computed/displayed the first time through.
+ */
+int ide_system_bus_speed (void)
+{
+	if (!system_bus_speed) {
+		if (idebus_parameter)
+			system_bus_speed = idebus_parameter;	/* user supplied value */
+#ifdef CONFIG_PCI
+		else if (pci_present())
+			system_bus_speed = 40;	/* safe default value for PCI */
+#endif /* CONFIG_PCI */
+		else
+			system_bus_speed = 50;	/* safe default value for VESA and PCI */
+		printk("ide: Assuming %dMHz system bus speed for PIO modes%s\n", system_bus_speed,
+			idebus_parameter ? "" : "; override with idebus=xx");
+	}
+	return system_bus_speed;
+}
+
+#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 (ide_ioreg_t 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)
+{
+	byte io_32bit = drive->io_32bit;
+
+	if (io_32bit) {
+#if SUPPORT_VLB_SYNC
+		if (io_32bit & 2) {
+			unsigned long flags;
+			__save_flags(flags);	/* local CPU only */
+			__cli();		/* local CPU only */
+			do_vlb_sync(IDE_NSECTOR_REG);
+			insl(IDE_DATA_REG, buffer, wcount);
+			__restore_flags(flags);	/* local CPU only */
+		} else
+#endif /* SUPPORT_VLB_SYNC */
+			insl(IDE_DATA_REG, buffer, wcount);
+	} else {
+#if SUPPORT_SLOW_DATA_PORTS
+		if (drive->slow) {
+			unsigned short *ptr = (unsigned short *) buffer;
+			while (wcount--) {
+				*ptr++ = inw_p(IDE_DATA_REG);
+				*ptr++ = inw_p(IDE_DATA_REG);
+			}
+		} else
+#endif /* SUPPORT_SLOW_DATA_PORTS */
+			insw(IDE_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)
+{
+	byte io_32bit = drive->io_32bit;
+
+	if (io_32bit) {
+#if SUPPORT_VLB_SYNC
+		if (io_32bit & 2) {
+			unsigned long flags;
+			__save_flags(flags);	/* local CPU only */
+			__cli();		/* local CPU only */
+			do_vlb_sync(IDE_NSECTOR_REG);
+			outsl(IDE_DATA_REG, buffer, wcount);
+			__restore_flags(flags);	/* local CPU only */
+		} else
+#endif /* SUPPORT_VLB_SYNC */
+			outsl(IDE_DATA_REG, buffer, wcount);
+	} else {
+#if SUPPORT_SLOW_DATA_PORTS
+		if (drive->slow) {
+			unsigned short *ptr = (unsigned short *) buffer;
+			while (wcount--) {
+				outw_p(*ptr++, IDE_DATA_REG);
+				outw_p(*ptr++, IDE_DATA_REG);
+			}
+		} else
+#endif /* SUPPORT_SLOW_DATA_PORTS */
+			outsw(IDE_DATA_REG, buffer, wcount<<1);
+	}
+}
+
+/*
+ * The following routines are mainly used by the ATAPI drivers.
+ *
+ * These routines will round up any request for an odd number of bytes,
+ * so if an odd bytecount is specified, be sure that there's at least one
+ * extra byte allocated for the buffer.
+ */
+void atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
+{
+	++bytecount;
+#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
+	if (MACH_IS_ATARI || MACH_IS_Q40) {
+		/* Atari has a byte-swapped IDE interface */
+		insw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
+		return;
+	}
+#endif /* CONFIG_ATARI */
+	ide_input_data (drive, buffer, bytecount / 4);
+	if ((bytecount & 0x03) >= 2)
+		insw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
+}
+
+void atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
+{
+	++bytecount;
+#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
+	if (MACH_IS_ATARI || MACH_IS_Q40) {
+		/* Atari has a byte-swapped IDE interface */
+		outsw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
+		return;
+	}
+#endif /* CONFIG_ATARI */
+	ide_output_data (drive, buffer, bytecount / 4);
+	if ((bytecount & 0x03) >= 2)
+		outsw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
+}
+
+/*
+ * Needed for PCI irq sharing
+ */
+static inline int drive_is_ready (ide_drive_t *drive)
+{
+	if (drive->waiting_for_dma)
+		return HWIF(drive)->dmaproc(ide_dma_test_irq, drive);
+#if 0
+	udelay(1);	/* need to guarantee 400ns since last command was issued */
+#endif
+	if (GET_STAT() & BUSY_STAT)	/* Note: this may clear a pending IRQ!! */
+		return 0;	/* drive busy:  definitely not interrupting */
+	return 1;		/* drive ready: *might* be interrupting */
+}
+
+/*
+ * This is our end_request replacement function.
+ */
+void ide_end_request (byte uptodate, ide_hwgroup_t *hwgroup)
+{
+	struct request *rq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&io_request_lock, flags);
+	rq = hwgroup->rq;
+
+	if (!end_that_request_first(rq, uptodate, hwgroup->drive->name)) {
+		add_blkdev_randomness(MAJOR(rq->rq_dev));
+		blkdev_dequeue_request(rq);
+        	hwgroup->rq = NULL;
+		end_that_request_last(rq);
+	}
+	spin_unlock_irqrestore(&io_request_lock, flags);
+}
+
+/*
+ * 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 ide_timer_expiry() handler later on).
+ */
+void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
+		      unsigned int timeout, ide_expiry_t *expiry)
+{
+	unsigned long flags;
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+
+	spin_lock_irqsave(&io_request_lock, flags);
+	if (hwgroup->handler != NULL) {
+		printk("%s: ide_set_handler: handler not null; old=%p, new=%p\n",
+			drive->name, hwgroup->handler, handler);
+	}
+	hwgroup->handler	= handler;
+	hwgroup->expiry		= expiry;
+	hwgroup->timer.expires	= jiffies + timeout;
+	add_timer(&hwgroup->timer);
+	spin_unlock_irqrestore(&io_request_lock, flags);
+}
+
+/*
+ * current_capacity() returns the capacity (in sectors) of a drive
+ * according to its current geometry/LBA settings.
+ */
+unsigned long current_capacity (ide_drive_t *drive)
+{
+	if (!drive->present)
+		return 0;
+	if (drive->driver != NULL)
+		return DRIVER(drive)->capacity(drive);
+	return 0;
+}
+
+extern struct block_device_operations ide_fops[];
+/*
+ * ide_geninit() is called exactly *once* for each interface.
+ */
+void ide_geninit (ide_hwif_t *hwif)
+{
+	unsigned int unit;
+	struct gendisk *gd = hwif->gd;
+
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		ide_drive_t *drive = &hwif->drives[unit];
+
+		if (!drive->present)
+			continue;
+		if (drive->media!=ide_disk && drive->media!=ide_floppy)
+			continue;
+		register_disk(gd,MKDEV(hwif->major,unit<<PARTN_BITS),
+#ifdef CONFIG_BLK_DEV_ISAPNP
+			(drive->forced_geom && drive->noprobe) ? 1 :
+#endif /* CONFIG_BLK_DEV_ISAPNP */
+			1<<PARTN_BITS, ide_fops,
+			current_capacity(drive));
+	}
+}
+
+static ide_startstop_t do_reset1 (ide_drive_t *, int);		/* needed below */
+
+/*
+ * 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 ide_startstop_t atapi_reset_pollfunc (ide_drive_t *drive)
+{
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	byte stat;
+
+	SELECT_DRIVE(HWIF(drive),drive);
+	udelay (10);
+
+	if (OK_STAT(stat=GET_STAT(), 0, BUSY_STAT)) {
+		printk("%s: ATAPI reset complete\n", drive->name);
+	} else {
+		if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
+			ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20, NULL);
+			return ide_started;	/* continue polling */
+		}
+		hwgroup->poll_timeout = 0;	/* end of polling */
+		printk("%s: ATAPI reset timed-out, status=0x%02x\n", drive->name, stat);
+		return do_reset1 (drive, 1);	/* do it the old fashioned way */
+	}
+	hwgroup->poll_timeout = 0;	/* done polling */
+	return ide_stopped;
+}
+
+/*
+ * 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 ide_startstop_t 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 (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
+			ide_set_handler (drive, &reset_pollfunc, HZ/20, NULL);
+			return ide_started;	/* 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 {
+#if FANCY_STATUS_DUMPS
+			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");
+#else
+			printk("failed\n");
+#endif /* FANCY_STATUS_DUMPS */
+		}
+	}
+	hwgroup->poll_timeout = 0;	/* done polling */
+	return ide_stopped;
+}
+
+static void pre_reset (ide_drive_t *drive)
+{
+	if (drive->driver != NULL)
+		DRIVER(drive)->pre_reset(drive);
+
+	if (!drive->keep_settings) {
+		if (drive->using_dma) {
+			(void) HWIF(drive)->dmaproc(ide_dma_off, drive);
+		} else {
+			drive->unmask = 0;
+			drive->io_32bit = 0;
+		}
+	}
+}
+
+/*
+ * 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 ide_startstop_t 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);	/* local CPU only */
+	__cli();		/* local CPU only */
+
+	/* For an ATAPI device, first try an ATAPI SRST. */
+	if (drive->media != ide_disk && !do_not_try_atapi) {
+		pre_reset(drive);
+		SELECT_DRIVE(hwif,drive);
+		udelay (20);
+		OUT_BYTE (WIN_SRST, IDE_COMMAND_REG);
+		hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
+		ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20, NULL);
+		__restore_flags (flags);	/* local CPU only */
+		return ide_started;
+	}
+
+	/*
+	 * First, reset any device state data we were maintaining
+	 * for any of the drives on this interface.
+	 */
+	for (unit = 0; unit < MAX_DRIVES; ++unit)
+		pre_reset(&hwif->drives[unit]);
+
+#if OK_TO_RESET_CONTROLLER
+	if (!IDE_CONTROL_REG) {
+		__restore_flags(flags);
+		return ide_stopped;
+	}
+	/*
+	 * 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(10);			/* more than enough time */
+	OUT_BYTE(drive->ctl|2,IDE_CONTROL_REG);	/* clear SRST, leave nIEN */
+	udelay(10);			/* more than enough time */
+	hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
+	ide_set_handler (drive, &reset_pollfunc, HZ/20, NULL);
+
+	/*
+	 * Some weird controller like resetting themselves to a strange
+	 * state when the disks are reset this way. At least, the Winbond
+	 * 553 documentation says that
+	 */
+	if (hwif->resetproc != NULL)
+		hwif->resetproc(drive);
+
+#endif	/* OK_TO_RESET_CONTROLLER */
+
+	__restore_flags (flags);	/* local CPU only */
+	return ide_started;
+}
+
+/*
+ * ide_do_reset() is the entry point to the drive/interface reset code.
+ */
+ide_startstop_t ide_do_reset (ide_drive_t *drive)
+{
+	return do_reset1 (drive, 0);
+}
+
+/*
+ * 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);
+		}
+	}
+	spin_lock_irqsave(&io_request_lock, flags);
+	blkdev_dequeue_request(rq);
+	HWGROUP(drive)->rq = NULL;
+	rq->rq_status = RQ_INACTIVE;
+	spin_unlock_irqrestore(&io_request_lock, flags);
+	if (rq->sem != NULL)
+		up(rq->sem);	/* inform originator that rq has been serviced */
+}
+
+/*
+ * 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);	/* local CPU only */
+	ide__sti();		/* local CPU only */
+	printk("%s: %s: status=0x%02x", drive->name, msg, stat);
+#if FANCY_STATUS_DUMPS
+	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 & ABRT_ERR)	printk("DriveStatusError ");
+			if (err & ICRC_ERR)	printk((err & ABRT_ERR) ? "BadCRC " : "BadSector ");
+			if (err & ECC_ERR)	printk("UncorrectableError ");
+			if (err & ID_ERR)	printk("SectorIdNotFound ");
+			if (err & TRK0_ERR)	printk("TrackZeroNotFound ");
+			if (err & MARK_ERR)	printk("AddrMarkNotFound ");
+			printk("}");
+			if ((err & (BBD_ERR | ABRT_ERR)) == BBD_ERR || (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);	/* local CPU only */
+	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;
+
+	if (drive->media != ide_disk)
+		return;
+	while (i > 0) {
+		u32 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 drive.
+ */
+ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, byte stat)
+{
+	struct request *rq;
+	byte err;
+
+	err = ide_dump_status(drive, msg, stat);
+	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
+		return ide_stopped;
+	/* retry only "normal" I/O: */
+	if (rq->cmd == IDE_DRIVE_CMD) {
+		rq->errors = 1;
+		ide_end_drive_cmd(drive, stat, err);
+		return ide_stopped;
+	}
+	if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) { /* 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 == ABRT_ERR) {
+				if (drive->select.b.lba && IN_BYTE(IDE_COMMAND_REG) == WIN_SPECIFY)
+					return ide_stopped; /* some newer drives don't support WIN_SPECIFY */
+			} else if ((err & (ABRT_ERR | ICRC_ERR)) == (ABRT_ERR | ICRC_ERR))
+				; /* UDMA crc error -- just retry the operation */
+			else 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))
+		OUT_BYTE(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);	/* force an abort */
+
+	if (rq->errors >= ERROR_MAX) {
+		if (drive->driver != NULL)
+			DRIVER(drive)->end_request(0, HWGROUP(drive));
+		else
+	 		ide_end_request(0, HWGROUP(drive));
+	} else {
+		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
+			++rq->errors;
+			return ide_do_reset(drive);
+		}
+		if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
+			drive->special.b.recalibrate = 1;
+		++rq->errors;
+	}
+	return ide_stopped;
+}
+
+/*
+ * Issue a simple drive command
+ * The drive must be selected beforehand.
+ */
+void ide_cmd (ide_drive_t *drive, byte cmd, byte nsect, ide_handler_t *handler)
+{
+	ide_set_handler (drive, handler, WAIT_CMD, NULL);
+	if (IDE_CONTROL_REG)
+		OUT_BYTE(drive->ctl,IDE_CONTROL_REG);	/* clear nIEN */
+	OUT_BYTE(nsect,IDE_NSECTOR_REG);
+	OUT_BYTE(cmd,IDE_COMMAND_REG);
+}
+
+/*
+ * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
+ */
+static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
+{
+	struct request *rq = HWGROUP(drive)->rq;
+	byte *args = (byte *) rq->buffer;
+	byte stat = GET_STAT();
+	int retries = 10;
+
+	ide__sti();	/* local CPU only */
+	if ((stat & DRQ_STAT) && args && args[3]) {
+		byte io_32bit = drive->io_32bit;
+		drive->io_32bit = 0;
+		ide_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
+		drive->io_32bit = io_32bit;
+		while (((stat = GET_STAT()) & BUSY_STAT) && retries--)
+			udelay(100);
+	}
+
+	if (!OK_STAT(stat, READY_STAT, BAD_STAT))
+		return ide_error(drive, "drive_cmd", stat); /* calls ide_end_drive_cmd */
+	ide_end_drive_cmd (drive, stat, GET_ERR());
+	return ide_stopped;
+}
+
+/*
+ * 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 ide_startstop_t do_special (ide_drive_t *drive)
+{
+	special_t *s = &drive->special;
+
+#ifdef DEBUG
+	printk("%s: do_special: 0x%02x\n", drive->name, s->all);
+#endif
+	if (s->b.set_tune) {
+		ide_tuneproc_t *tuneproc = HWIF(drive)->tuneproc;
+		s->b.set_tune = 0;
+		if (tuneproc != NULL)
+			tuneproc(drive, drive->tune_req);
+	} else if (drive->driver != NULL) {
+		return DRIVER(drive)->special(drive);
+	} else if (s->all) {
+		printk("%s: bad special flag: 0x%02x\n", drive->name, s->all);
+		s->all = 0;
+	}
+	return ide_stopped;
+}
+
+/*
+ * 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_startstop_t *startstop, ide_drive_t *drive, byte good, byte bad, unsigned long timeout) {
+	byte stat;
+	int i;
+	unsigned long flags;
+ 
+	udelay(1);	/* spec allows drive 400ns to assert "BUSY" */
+	if ((stat = GET_STAT()) & BUSY_STAT) {
+		__save_flags(flags);	/* local CPU only */
+		ide__sti();		/* local CPU only */
+		timeout += jiffies;
+		while ((stat = GET_STAT()) & BUSY_STAT) {
+			if (0 < (signed long)(jiffies - timeout)) {
+				__restore_flags(flags);	/* local CPU only */
+				*startstop = ide_error(drive, "status timeout", stat);
+				return 1;
+			}
+		}
+		__restore_flags(flags);	/* local CPU only */
+	}
+	/*
+	 * Allow status to settle, then read it again.
+	 * A few rare drives vastly violate the 400ns spec here,
+	 * so we'll wait up to 10usec for a "good" status
+	 * rather than expensively fail things immediately.
+	 * This fix courtesy of Matthew Faupel & Niccolo Rigacci.
+	 */
+	for (i = 0; i < 10; i++) {
+		udelay(1);
+		if (OK_STAT((stat = GET_STAT()), good, bad))
+			return 0;
+	}
+	*startstop = ide_error(drive, "status error", stat);
+	return 1;
+}
+
+/*
+ * execute_drive_cmd() issues a special drive command,
+ * usually initiated by ioctl() from the external hdparm program.
+ */
+static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq)
+{
+	byte *args = rq->buffer;
+	if (args) {
+#ifdef DEBUG
+		printk("%s: DRIVE_CMD cmd=0x%02x sc=0x%02x fr=0x%02x xx=0x%02x\n",
+		 drive->name, args[0], args[1], args[2], args[3]);
+#endif
+		if (args[0] == WIN_SMART) {
+			OUT_BYTE(0x4f, IDE_LCYL_REG);
+			OUT_BYTE(0xc2, IDE_HCYL_REG);
+			OUT_BYTE(args[2],IDE_FEATURE_REG);
+			OUT_BYTE(args[1],IDE_SECTOR_REG);
+			ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
+			return ide_started;
+		}
+		OUT_BYTE(args[2],IDE_FEATURE_REG);
+		ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
+		return ide_started;
+	} 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 ide_stopped;
+	}
+}
+
+/*
+ * start_request() initiates handling of a new I/O request
+ */
+static ide_startstop_t start_request (ide_drive_t *drive)
+{
+	ide_startstop_t startstop;
+	unsigned long block, blockend;
+	struct request *rq = blkdev_entry_next_request(&drive->queue.queue_head);
+	unsigned int minor = MINOR(rq->rq_dev), unit = minor >> PARTN_BITS;
+	ide_hwif_t *hwif = HWIF(drive);
+
+#ifdef DEBUG
+	printk("%s: start_request: current=0x%08lx\n", hwif->name, (unsigned long) rq);
+#endif
+	if (unit >= MAX_DRIVES) {
+		printk("%s: bad device number: %s\n", hwif->name, kdevname(rq->rq_dev));
+		goto kill_rq;
+	}
+#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 0
+	if ((rq->cmd == READ || rq->cmd == WRITE) &&
+	    (drive->media == ide_disk || drive->media == ide_floppy))
+#endif
+	{
+		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;
+	}
+	/* Yecch - this will shift the entire interval,
+	   possibly killing some innocent following sector */
+	if (block == 0 && drive->remap_0_to_1 == 1)
+		block = 1;  /* redirect MBR access to EZ-Drive partn table */
+
+#if (DISK_RECOVERY_TIME > 0)
+	while ((read_timer() - hwif->last_time) < DISK_RECOVERY_TIME);
+#endif
+
+	SELECT_DRIVE(hwif, drive);
+	if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
+		printk("%s: drive not ready for command\n", drive->name);
+		return startstop;
+	}
+	if (!drive->special.all) {
+		if (rq->cmd == IDE_DRIVE_CMD) {
+			return execute_drive_cmd(drive, rq);
+		}
+		if (drive->driver != NULL) {
+			return (DRIVER(drive)->do_request(drive, rq, block));
+		}
+		printk("%s: media type %d not supported\n", drive->name, drive->media);
+		goto kill_rq;
+	}
+	return do_special(drive);
+kill_rq:
+	if (drive->driver != NULL)
+		DRIVER(drive)->end_request(0, HWGROUP(drive));
+	else
+		ide_end_request(0, HWGROUP(drive));
+	return ide_stopped;
+}
+
+/*
+ * ide_stall_queue() can be used by a drive to give excess bandwidth back
+ * to the hwgroup by sleeping for timeout jiffies.
+ */
+void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
+{
+	if (timeout > WAIT_WORSTCASE)
+		timeout = WAIT_WORSTCASE;
+	drive->sleep = timeout + jiffies;
+}
+
+#define WAKEUP(drive)	((drive)->service_start + 2 * (drive)->service_time)
+
+/*
+ * choose_drive() selects the next drive which will be serviced.
+ */
+static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
+{
+	ide_drive_t *drive, *best;
+
+repeat:	
+	best = NULL;
+	drive = hwgroup->drive;
+	do {
+		if (!list_empty(&drive->queue.queue_head) && (!drive->sleep || 0 <= (signed long)(jiffies - drive->sleep))) {
+			if (!best
+			 || (drive->sleep && (!best->sleep || 0 < (signed long)(best->sleep - drive->sleep)))
+			 || (!best->sleep && 0 < (signed long)(WAKEUP(best) - WAKEUP(drive))))
+			{
+				if( !drive->queue.plugged )
+					best = drive;
+			}
+		}
+	} while ((drive = drive->next) != hwgroup->drive);
+	if (best && best->nice1 && !best->sleep && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
+		long t = (signed long)(WAKEUP(best) - jiffies);
+		if (t >= WAIT_MIN_SLEEP) {
+			/*
+			 * We *may* have some time to spare, but first let's see if
+			 * someone can potentially benefit from our nice mood today..
+			 */
+			drive = best->next;
+			do {
+				if (!drive->sleep
+				 && 0 < (signed long)(WAKEUP(drive) - (jiffies - best->service_time))
+				 && 0 < (signed long)((jiffies + t) - WAKEUP(drive)))
+				{
+					ide_stall_queue(best, IDE_MIN(t, 10 * WAIT_MIN_SLEEP));
+					goto repeat;
+				}
+			} while ((drive = drive->next) != best);
+		}
+	}
+	return best;
+}
+
+/*
+ * Issue a new request to a drive from hwgroup
+ * Caller must have already done spin_lock_irqsave(&io_request_lock, ..);
+ *
+ * A hwgroup is a serialized group of IDE interfaces.  Usually there is
+ * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
+ * may have both interfaces in a single hwgroup to "serialize" access.
+ * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
+ * together into one hwgroup for serialized access.
+ *
+ * Note also that several hwgroups can end up sharing a single IRQ,
+ * possibly along with many other devices.  This is especially common in
+ * PCI-based systems with off-board IDE controller cards.
+ *
+ * The IDE driver uses the single global io_request_lock spinlock to protect
+ * access to the request queues, and to protect the hwgroup->busy flag.
+ *
+ * The first thread into the driver for a particular hwgroup sets the
+ * hwgroup->busy flag to indicate that this hwgroup is now active,
+ * and then initiates processing of the top request from the request queue.
+ *
+ * Other threads attempting entry notice the busy setting, and will simply
+ * queue their new requests and exit immediately.  Note that hwgroup->busy
+ * remains set even when the driver is merely awaiting the next interrupt.
+ * Thus, the meaning is "this hwgroup is busy processing a request".
+ *
+ * When processing of a request completes, the completing thread or IRQ-handler
+ * will start the next request from the queue.  If no more work remains,
+ * the driver will clear the hwgroup->busy flag and exit.
+ *
+ * The io_request_lock (spinlock) is used to protect all access to the
+ * hwgroup->busy flag, but is otherwise not needed for most processing in
+ * the driver.  This makes the driver much more friendlier to shared IRQs
+ * than previous designs, while remaining 100% (?) SMP safe and capable.
+ */
+static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
+{
+	ide_drive_t	*drive;
+	ide_hwif_t	*hwif;
+	ide_startstop_t	startstop;
+
+	ide_get_lock(&ide_lock, ide_intr, hwgroup);	/* for atari only: POSSIBLY BROKEN HERE(?) */
+
+	__cli();	/* necessary paranoia: ensure IRQs are masked on local CPU */
+
+	while (!hwgroup->busy) {
+		hwgroup->busy = 1;
+		drive = choose_drive(hwgroup);
+		if (drive == NULL) {
+			unsigned long sleep = 0;
+			hwgroup->rq = NULL;
+			drive = hwgroup->drive;
+			do {
+				if (drive->sleep && (!sleep || 0 < (signed long)(sleep - drive->sleep)))
+					sleep = drive->sleep;
+			} while ((drive = drive->next) != hwgroup->drive);
+			if (sleep) {
+				/*
+				 * Take a short snooze, and then wake up this hwgroup again.
+				 * This gives other hwgroups on the same a chance to
+				 * play fairly with us, just in case there are big differences
+				 * in relative throughputs.. don't want to hog the cpu too much.
+				 */
+				if (0 < (signed long)(jiffies + WAIT_MIN_SLEEP - sleep)) 
+					sleep = jiffies + WAIT_MIN_SLEEP;
+#if 1
+				if (hwgroup->timer.next || hwgroup->timer.prev)
+					printk("ide_set_handler: timer already active\n");
+#endif
+				hwgroup->sleeping = 1;	/* so that ide_timer_expiry knows what to do */
+				mod_timer(&hwgroup->timer, sleep);
+				/* we purposely leave hwgroup->busy==1 while sleeping */
+			} else {
+				/* Ugly, but how can we sleep for the lock otherwise? perhaps from tq_scheduler? */
+				ide_release_lock(&ide_lock);	/* for atari only */
+				hwgroup->busy = 0;
+			}
+			return;		/* no more work for this hwgroup (for now) */
+		}
+		hwif = HWIF(drive);
+		if (hwgroup->hwif->sharing_irq && hwif != hwgroup->hwif && hwif->io_ports[IDE_CONTROL_OFFSET]) {
+			/* set nIEN for previous hwif */
+			OUT_BYTE(hwgroup->drive->ctl|2, hwgroup->hwif->io_ports[IDE_CONTROL_OFFSET]);
+		}
+		hwgroup->hwif = hwif;
+		hwgroup->drive = drive;
+		drive->sleep = 0;
+		drive->service_start = jiffies;
+
+		if ( drive->queue.plugged )	/* paranoia */
+			printk("%s: Huh? nuking plugged queue\n", drive->name);
+		hwgroup->rq = blkdev_entry_next_request(&drive->queue.queue_head);
+		/*
+		 * Some systems have trouble with IDE IRQs arriving while
+		 * the driver is still setting things up.  So, here we disable
+		 * the IRQ used by this interface while the request is being started.
+		 * This may look bad at first, but pretty much the same thing
+		 * happens anyway when any interrupt comes in, IDE or otherwise
+		 *  -- the kernel masks the IRQ while it is being handled.
+		 */
+		if (hwif->irq != masked_irq)
+			disable_irq_nosync(hwif->irq);
+		spin_unlock(&io_request_lock);
+		ide__sti();	/* allow other IRQs while we start this request */
+		startstop = start_request(drive);
+		spin_lock_irq(&io_request_lock);
+		if (hwif->irq != masked_irq)
+			enable_irq(hwif->irq);
+		if (startstop == ide_stopped)
+			hwgroup->busy = 0;
+	}
+}
+
+/*
+ * ide_get_queue() returns the queue which corresponds to a given device.
+ */
+request_queue_t *ide_get_queue (kdev_t dev)
+{
+	ide_hwif_t *hwif = (ide_hwif_t *)blk_dev[MAJOR(dev)].data;
+
+	return &hwif->drives[DEVICE_NR(dev) & 1].queue;
+}
+
+void do_ide0_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[0].hwgroup, 0);
+}
+
+#if MAX_HWIFS > 1
+void do_ide1_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[1].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 1 */
+
+#if MAX_HWIFS > 2
+void do_ide2_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[2].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 2 */
+
+#if MAX_HWIFS > 3
+void do_ide3_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[3].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 3 */
+
+#if MAX_HWIFS > 4
+void do_ide4_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[4].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 4 */
+
+#if MAX_HWIFS > 5
+void do_ide5_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[5].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 5 */
+
+#if MAX_HWIFS > 6
+void do_ide6_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[6].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 6 */
+
+#if MAX_HWIFS > 7
+void do_ide7_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[7].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 7 */
+
+#if MAX_HWIFS > 8
+void do_ide8_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[8].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 8 */
+
+#if MAX_HWIFS > 9
+void do_ide9_request (request_queue_t *q)
+{
+	ide_do_request (ide_hwifs[9].hwgroup, 0);
+}
+#endif /* MAX_HWIFS > 9 */
+
+/*
+ * ide_timer_expiry() is our timeout function for all drive operations.
+ * But note that it can also be invoked as a result of a "sleep" operation
+ * triggered by the mod_timer() call in ide_do_request.
+ */
+void ide_timer_expiry (unsigned long data)
+{
+	ide_hwgroup_t	*hwgroup = (ide_hwgroup_t *) data;
+	ide_handler_t	*handler;
+	ide_expiry_t	*expiry;
+ 	unsigned long	flags;
+	unsigned long	wait;
+
+	spin_lock_irqsave(&io_request_lock, flags);
+	del_timer(&hwgroup->timer);
+
+	if ((handler = hwgroup->handler) == NULL) {
+		/*
+		 * Either a marginal timeout occured
+		 * (got the interrupt just as timer expired),
+		 * or we were "sleeping" to give other devices a chance.
+		 * Either way, we don't really want to complain about anything.
+		 */
+		if (hwgroup->sleeping) {
+			hwgroup->sleeping = 0;
+			hwgroup->busy = 0;
+		}
+	} else {
+		ide_drive_t *drive = hwgroup->drive;
+		if (!drive) {
+			printk("ide_timer_expiry: hwgroup->drive was NULL\n");
+			hwgroup->handler = NULL;
+		} else {
+			ide_hwif_t *hwif;
+			ide_startstop_t startstop;
+			if (!hwgroup->busy) {
+				hwgroup->busy = 1;	/* paranoia */
+				printk("%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
+			}
+			if ((expiry = hwgroup->expiry) != NULL) {
+				/* continue */
+				if ((wait = expiry(drive)) != 0) {
+					/* reset timer */
+					hwgroup->timer.expires  = jiffies + wait;
+					add_timer(&hwgroup->timer);
+					spin_unlock_irqrestore(&io_request_lock, flags);
+					return;
+				}
+			}
+			hwgroup->handler = NULL;
+			/*
+			 * We need to simulate a real interrupt when invoking
+			 * the handler() function, which means we need to globally
+			 * mask the specific IRQ:
+			 */
+			spin_unlock(&io_request_lock);
+			hwif  = HWIF(drive);
+			disable_irq(hwif->irq);	/* disable_irq_nosync ?? */
+			__cli();	/* local CPU only, as if we were handling an interrupt */
+			if (hwgroup->poll_timeout != 0) {
+				startstop = handler(drive);
+			} else if (drive_is_ready(drive)) {
+				if (drive->waiting_for_dma)
+					(void) hwgroup->hwif->dmaproc(ide_dma_lostirq, drive);
+				(void)ide_ack_intr(hwif);
+				printk("%s: lost interrupt\n", drive->name);
+				startstop = handler(drive);
+			} else {
+				if (drive->waiting_for_dma) {
+					(void) hwgroup->hwif->dmaproc(ide_dma_end, drive);
+					printk("%s: timeout waiting for DMA\n", drive->name);
+					(void) hwgroup->hwif->dmaproc(ide_dma_timeout, drive);
+				}
+				startstop = ide_error(drive, "irq timeout", GET_STAT());
+			}
+			set_recovery_timer(hwif);
+			drive->service_time = jiffies - drive->service_start;
+			enable_irq(hwif->irq);
+			spin_lock_irq(&io_request_lock);
+			if (startstop == ide_stopped)
+				hwgroup->busy = 0;
+		}
+	}
+	ide_do_request(hwgroup, 0);
+	spin_unlock_irqrestore(&io_request_lock, 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" (CMD640), 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;
+	ide_hwif_t *hwif = hwgroup->hwif;
+
+	/*
+	 * handle the unexpected interrupt
+	 */
+	do {
+		if (hwif->irq == irq) {
+			stat = IN_BYTE(hwif->io_ports[IDE_STATUS_OFFSET]);
+			if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
+				/* Try to not flood the console with msgs */
+				static unsigned long last_msgtime = 0, count = 0;
+				++count;
+				if (0 < (signed long)(jiffies - (last_msgtime + HZ))) {
+					last_msgtime = jiffies;
+					printk("%s%s: unexpected interrupt, status=0x%02x, count=%ld\n",
+					 hwif->name, (hwif->next == hwgroup->hwif) ? "" : "(?)", stat, count);
+				}
+			}
+		}
+	} while ((hwif = hwif->next) != hwgroup->hwif);
+}
+
+/*
+ * entry point for all interrupts, caller does __cli() for us
+ */
+void ide_intr (int irq, void *dev_id, struct pt_regs *regs)
+{
+	unsigned long flags;
+	ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
+	ide_hwif_t *hwif;
+	ide_drive_t *drive;
+	ide_handler_t *handler;
+	ide_startstop_t startstop;
+
+	spin_lock_irqsave(&io_request_lock, flags);
+	hwif = hwgroup->hwif;
+
+	if (!ide_ack_intr(hwif)) {
+		spin_unlock_irqrestore(&io_request_lock, flags);
+		return;
+	}
+
+	if ((handler = hwgroup->handler) == NULL || hwgroup->poll_timeout != 0) {
+		/*
+		 * Not expecting an interrupt from this drive.
+		 * That means this could be:
+		 *	(1) an interrupt from another PCI device
+		 *	sharing the same PCI INT# as us.
+		 * or	(2) a drive just entered sleep or standby mode,
+		 *	and is interrupting to let us know.
+		 * or	(3) a spurious interrupt of unknown origin.
+		 *
+		 * For PCI, we cannot tell the difference,
+		 * so in that case we just ignore it and hope it goes away.
+		 */
+#ifdef CONFIG_BLK_DEV_IDEPCI
+		if (IDE_PCI_DEVID_EQ(hwif->pci_devid, IDE_PCI_DEVID_NULL))
+#endif	/* CONFIG_BLK_DEV_IDEPCI */
+		{
+			/*
+			 * Probably not a shared PCI interrupt,
+			 * so we can safely try to do something about it:
+			 */
+			unexpected_intr(irq, hwgroup);
+#ifdef CONFIG_BLK_DEV_IDEPCI
+		} else {
+			/*
+			 * Whack the status register, just in case we have a leftover pending IRQ.
+			 */
+			(void) IN_BYTE(hwif->io_ports[IDE_STATUS_OFFSET]);
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+		}
+		spin_unlock_irqrestore(&io_request_lock, flags);
+		return;
+	}
+	drive = hwgroup->drive;
+	if (!drive) {
+		/*
+		 * This should NEVER happen, and there isn't much we could do about it here.
+		 */
+		spin_unlock_irqrestore(&io_request_lock, flags);
+		return;
+	}
+	if (!drive_is_ready(drive)) {
+		/*
+		 * This happens regularly when we share a PCI IRQ with another device.
+		 * Unfortunately, it can also happen with some buggy drives that trigger
+		 * the IRQ before their status register is up to date.  Hopefully we have
+		 * enough advance overhead that the latter isn't a problem.
+		 */
+		spin_unlock_irqrestore(&io_request_lock, flags);
+		return;
+	}
+	if (!hwgroup->busy) {
+		hwgroup->busy = 1;	/* paranoia */
+		printk("%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
+	}
+	hwgroup->handler = NULL;
+	del_timer(&hwgroup->timer);
+	spin_unlock(&io_request_lock);
+
+	if (drive->unmask)
+		ide__sti();	/* local CPU only */
+	startstop = handler(drive);		/* service this interrupt, may set handler for next interrupt */
+	spin_lock_irq(&io_request_lock);
+
+	/*
+	 * Note that handler() may have set things up for another
+	 * interrupt to occur soon, but it cannot happen until
+	 * we exit from this routine, because it will be the
+	 * same irq as is currently being serviced here, and Linux
+	 * won't allow another of the same (on any CPU) until we return.
+	 */
+	set_recovery_timer(HWIF(drive));
+	drive->service_time = jiffies - drive->service_start;
+	if (startstop == ide_stopped) {
+		if (hwgroup->handler == NULL) {	/* paranoia */
+			hwgroup->busy = 0;
+			ide_do_request(hwgroup, hwif->irq);
+		} else {
+			printk("%s: ide_intr: huh? expected NULL handler on exit\n", drive->name);
+		}
+	}
+	spin_unlock_irqrestore(&io_request_lock, flags);
+}
+
+/*
+ * 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.
+ */
+ide_drive_t *get_info_ptr (kdev_t i_rdev)
+{
+	int		major = MAJOR(i_rdev);
+#if 0
+	int		minor = MINOR(i_rdev) & PARTN_MASK;
+#endif
+	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 0
+				if ((drive->present) && (drive->part[minor].nr_sects))
+#else
+				if (drive->present)
+#endif
+					return drive;
+			}
+			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->q = NULL;
+}
+
+/*
+ * This function issues a special IDE device request
+ * onto the request queue.
+ *
+ * If action is ide_wait, then the 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.
+ */
+int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
+{
+	unsigned long flags;
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	unsigned int major = HWIF(drive)->major;
+	struct list_head * queue_head;
+	DECLARE_MUTEX_LOCKED(sem);
+
+#ifdef CONFIG_BLK_DEV_PDC4030
+	if (HWIF(drive)->chipset == ide_pdc4030 && rq->buffer != NULL)
+		return -ENOSYS;  /* special drive cmds not supported */
+#endif
+	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;
+	spin_lock_irqsave(&io_request_lock, flags);
+	queue_head = &drive->queue.queue_head;
+	if (list_empty(queue_head) || action == ide_preempt) {
+		if (action == ide_preempt)
+			hwgroup->rq = NULL;
+	} else {
+		if (action == ide_wait || action == ide_end) {
+			queue_head = queue_head->prev;
+		} else
+			queue_head = queue_head->next;
+	}
+	list_add(&rq->queue, queue_head);
+	ide_do_request(hwgroup, 0);
+	spin_unlock_irqrestore(&io_request_lock, flags);
+	if (action == ide_wait) {
+		down(&sem);			/* wait for it to be serviced */
+		return rq->errors ? -EIO : 0;	/* return -EIO if errors */
+	}
+	return 0;
+
+}
+
+/*
+ * 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.
+ */
+int ide_revalidate_disk (kdev_t i_rdev)
+{
+	ide_drive_t *drive;
+	ide_hwgroup_t *hwgroup;
+	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;
+	hwgroup = HWGROUP(drive);
+	spin_lock_irqsave(&io_request_lock, flags);
+	if (drive->busy || (drive->usage > 1)) {
+		spin_unlock_irqrestore(&io_request_lock, flags);
+		return -EBUSY;
+	};
+	drive->busy = 1;
+	MOD_INC_USE_COUNT;
+	spin_unlock_irqrestore(&io_request_lock, flags);
+
+	for (p = 0; p < (1<<PARTN_BITS); ++p) {
+		if (drive->part[p].nr_sects > 0) {
+			kdev_t devp = MKDEV(major, minor+p);
+			struct super_block * sb = get_super(devp);
+			fsync_dev          (devp);
+			if (sb)
+				invalidate_inodes(sb);
+			invalidate_buffers (devp);
+			set_blocksize(devp, 1024);
+		}
+		drive->part[p].start_sect = 0;
+		drive->part[p].nr_sects   = 0;
+	};
+
+	grok_partitions(HWIF(drive)->gd, drive->select.b.unit,
+			(drive->media != ide_disk &&
+			 drive->media != ide_floppy) ? 1 : 1<<PARTN_BITS,
+				current_capacity(drive));
+
+	drive->busy = 0;
+	wake_up(&drive->wqueue);
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+static void revalidate_drives (void)
+{
+	ide_hwif_t *hwif;
+	ide_drive_t *drive;
+	int index, unit;
+
+	for (index = 0; index < MAX_HWIFS; ++index) {
+		hwif = &ide_hwifs[index];
+		for (unit = 0; unit < MAX_DRIVES; ++unit) {
+			drive = &ide_hwifs[index].drives[unit];
+			if (drive->revalidate) {
+				drive->revalidate = 0;
+				if (!initializing)
+					(void) ide_revalidate_disk(MKDEV(hwif->major, unit<<PARTN_BITS));
+			}
+		}
+	}
+}
+
+static void ide_probe_module (void)
+{
+	if (!ide_probe) {
+#ifdef CONFIG_KMOD
+		(void) request_module("ide-probe-mod");
+#endif /* CONFIG_KMOD */
+	} else {
+		(void) ide_probe->init();
+	}
+	revalidate_drives();
+}
+
+static void ide_driver_module (void)
+{
+	int index;
+	ide_module_t *module = ide_modules;
+
+	for (index = 0; index < MAX_HWIFS; ++index)
+		if (ide_hwifs[index].present)
+			goto search;
+	ide_probe_module();
+search:
+	while (module) {
+		(void) module->init();
+		module = module->next;
+	}
+	revalidate_drives();
+}
+
+static int ide_open (struct inode * inode, struct file * filp)
+{
+	ide_drive_t *drive;
+	int rc;
+
+	if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
+		return -ENXIO;
+	MOD_INC_USE_COUNT;
+	if (drive->driver == NULL)
+		ide_driver_module();
+#ifdef CONFIG_KMOD
+	if (drive->driver == NULL) {
+		if (drive->media == ide_disk)
+			(void) request_module("ide-disk");
+		if (drive->media == ide_cdrom)
+			(void) request_module("ide-cd");
+		if (drive->media == ide_tape)
+			(void) request_module("ide-tape");
+		if (drive->media == ide_floppy)
+			(void) request_module("ide-floppy");
+	}
+#endif /* CONFIG_KMOD */
+	while (drive->busy)
+		sleep_on(&drive->wqueue);
+	drive->usage++;
+	if (drive->driver != NULL) {
+		if ((rc = DRIVER(drive)->open(inode, filp, drive)))
+			MOD_DEC_USE_COUNT;
+		return rc;
+	}
+	printk ("%s: driver not present\n", drive->name);
+	drive->usage--;
+	MOD_DEC_USE_COUNT;
+	return -ENXIO;
+}
+
+/*
+ * Releasing a block device means we sync() it, so that it can safely
+ * be forgotten about...
+ */
+static int ide_release (struct inode * inode, struct file * file)
+{
+	ide_drive_t *drive;
+
+	if ((drive = get_info_ptr(inode->i_rdev)) != NULL) {
+		drive->usage--;
+		if (drive->driver != NULL)
+			DRIVER(drive)->release(inode, file, drive);
+		MOD_DEC_USE_COUNT;
+	}
+	return 0;
+}
+
+int ide_replace_subdriver (ide_drive_t *drive, const char *driver)
+{
+	if (!drive->present || drive->busy || drive->usage)
+		goto abort;
+	if (drive->driver != NULL && DRIVER(drive)->cleanup(drive))
+		goto abort;
+	strncpy(drive->driver_req, driver, 9);
+	ide_driver_module();
+	drive->driver_req[0] = 0;
+	ide_driver_module();
+	if (DRIVER(drive) && !strcmp(DRIVER(drive)->name, driver))
+		return 0;
+abort:
+	return 1;
+}
+
+#ifdef CONFIG_PROC_FS
+ide_proc_entry_t generic_subdriver_entries[] = {
+	{ "capacity",	S_IFREG|S_IRUGO,	proc_ide_read_capacity,	NULL },
+	{ NULL, 0, NULL, NULL }
+};
+#endif
+
+/*
+ * Note that we only release the standard ports,
+ * and do not even try to handle any extra ports
+ * allocated for weird IDE interface chipsets.
+ */
+void hwif_unregister (ide_hwif_t *hwif)
+{
+	if (hwif->straight8) {
+		ide_release_region(hwif->io_ports[IDE_DATA_OFFSET], 8);
+		goto jump_eight;
+	}
+	if (hwif->io_ports[IDE_DATA_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_DATA_OFFSET], 1);
+	if (hwif->io_ports[IDE_ERROR_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_ERROR_OFFSET], 1);
+	if (hwif->io_ports[IDE_NSECTOR_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_NSECTOR_OFFSET], 1);
+	if (hwif->io_ports[IDE_SECTOR_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_SECTOR_OFFSET], 1);
+	if (hwif->io_ports[IDE_LCYL_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_LCYL_OFFSET], 1);
+	if (hwif->io_ports[IDE_HCYL_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_HCYL_OFFSET], 1);
+	if (hwif->io_ports[IDE_SELECT_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_SELECT_OFFSET], 1);
+	if (hwif->io_ports[IDE_STATUS_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_STATUS_OFFSET], 1);
+jump_eight:
+	if (hwif->io_ports[IDE_CONTROL_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_CONTROL_OFFSET], 1);
+	if (hwif->io_ports[IDE_IRQ_OFFSET])
+		ide_release_region(hwif->io_ports[IDE_IRQ_OFFSET], 1);
+}
+
+void ide_unregister (unsigned int index)
+{
+	struct gendisk *gd, **gdp;
+	ide_drive_t *drive, *d;
+	ide_hwif_t *hwif, *g;
+	ide_hwgroup_t *hwgroup;
+	int irq_count = 0, unit, i;
+	unsigned long flags;
+	unsigned int p, minor;
+	ide_hwif_t old_hwif;
+
+	if (index >= MAX_HWIFS)
+		return;
+	save_flags(flags);	/* all CPUs */
+	cli();			/* all CPUs */
+	hwif = &ide_hwifs[index];
+	if (!hwif->present)
+		goto abort;
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		drive = &hwif->drives[unit];
+		if (!drive->present)
+			continue;
+		if (drive->busy || drive->usage)
+			goto abort;
+		if (drive->driver != NULL && DRIVER(drive)->cleanup(drive))
+			goto abort;
+	}
+	hwif->present = 0;
+	
+	/*
+	 * All clear?  Then blow away the buffer cache
+	 */
+	sti();
+	for (unit = 0; unit < MAX_DRIVES; ++unit) {
+		drive = &hwif->drives[unit];
+		if (!drive->present)
+			continue;
+		minor = drive->select.b.unit << PARTN_BITS;
+		for (p = 0; p < (1<<PARTN_BITS); ++p) {
+			if (drive->part[p].nr_sects > 0) {
+				kdev_t devp = MKDEV(hwif->major, minor+p);
+				struct super_block * sb = get_super(devp);
+				if (sb) invalidate_inodes(sb);
+				invalidate_buffers (devp);
+			}
+		}
+#ifdef CONFIG_PROC_FS
+		destroy_proc_ide_drives(hwif);
+#endif
+	}
+	cli();
+	hwgroup = hwif->hwgroup;
+
+	/*
+	 * free the irq if we were the only hwif using it
+	 */
+	g = hwgroup->hwif;
+	do {
+		if (g->irq == hwif->irq)
+			++irq_count;
+		g = g->next;
+	} while (g != hwgroup->hwif);
+	if (irq_count == 1)
+		free_irq(hwif->irq, hwgroup);
+
+	/*
+	 * Note that we only release the standard ports,
+	 * and do not even try to handle any extra ports
+	 * allocated for weird IDE interface chipsets.
+	 */
+	hwif_unregister(hwif);
+
+	/*
+	 * Remove us from the hwgroup, and free
+	 * the hwgroup if we were the only member
+	 */
+	d = hwgroup->drive;
+	for (i = 0; i < MAX_DRIVES; ++i) {
+		drive = &hwif->drives[i];
+		if (drive->de) {
+			devfs_unregister (drive->de);
+			drive->de = NULL;
+		}
+		if (!drive->present)
+			continue;
+		while (hwgroup->drive->next != drive)
+			hwgroup->drive = hwgroup->drive->next;
+		hwgroup->drive->next = drive->next;
+		if (hwgroup->drive == drive)
+			hwgroup->drive = NULL;
+		if (drive->id != NULL) {
+			kfree(drive->id);
+			drive->id = NULL;
+		}
+		drive->present = 0;
+	}
+	if (d->present)
+		hwgroup->drive = d;
+	while (hwgroup->hwif->next != hwif)
+		hwgroup->hwif = hwgroup->hwif->next;
+	hwgroup->hwif->next = hwif->next;
+	if (hwgroup->hwif == hwif)
+		kfree(hwgroup);
+	else
+		hwgroup->hwif = HWIF(hwgroup->drive);
+
+#ifdef CONFIG_BLK_DEV_IDEDMA
+	if (hwif->dma_base)
+		(void) ide_release_dma(hwif);
+#endif /* CONFIG_BLK_DEV_IDEDMA */
+
+	/*
+	 * Remove us from the kernel's knowledge
+	 */
+	unregister_blkdev(hwif->major, hwif->name);
+	kfree(blksize_size[hwif->major]);
+	kfree(max_sectors[hwif->major]);
+	kfree(max_readahead[hwif->major]);
+	blk_cleanup_queue(BLK_DEFAULT_QUEUE(hwif->major));
+	blk_dev[hwif->major].data = NULL;
+	blk_dev[hwif->major].queue = NULL;
+	blksize_size[hwif->major] = NULL;
+	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
+		if (*gdp == hwif->gd)
+			break;
+	if (*gdp == NULL)
+		printk("gd not in disk chain!\n");
+	else {
+		gd = *gdp; *gdp = gd->next;
+		kfree(gd->sizes);
+		kfree(gd->part);
+		if (gd->de_arr)
+			kfree (gd->de_arr);
+		if (gd->flags)
+			kfree (gd->flags);
+		kfree(gd);
+	}
+	old_hwif		= *hwif;
+	init_hwif_data (index);	/* restore hwif data to pristine status */
+	hwif->hwgroup		= old_hwif.hwgroup;
+	hwif->tuneproc		= old_hwif.tuneproc;
+	hwif->selectproc	= old_hwif.selectproc;
+	hwif->resetproc		= old_hwif.resetproc;
+	hwif->dmaproc		= old_hwif.dmaproc;
+	hwif->dma_base		= old_hwif.dma_base;
+	hwif->dma_extra		= old_hwif.dma_extra;
+	hwif->config_data	= old_hwif.config_data;
+	hwif->select_data	= old_hwif.select_data;
+	hwif->proc		= old_hwif.proc;
+	hwif->irq		= old_hwif.irq;
+	hwif->major		= old_hwif.major;
+	hwif->chipset		= old_hwif.chipset;
+	hwif->autodma		= old_hwif.autodma;
+	hwif->udma_four		= old_hwif.udma_four;
+#ifdef CONFIG_BLK_DEV_IDEPCI
+	hwif->pci_dev		= old_hwif.pci_dev;
+	hwif->pci_devid		= old_hwif.pci_devid;
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+	hwif->straight8		= old_hwif.straight8;
+
+abort:
+	restore_flags(flags);	/* all CPUs */
+}
+
+/*
+ * Setup hw_regs_t structure described by parameters.  You
+ * may set up the hw structure yourself OR use this routine to
+ * do it for you.
+ */
+void ide_setup_ports (	hw_regs_t *hw,
+			ide_ioreg_t base, int *offsets,
+			ide_ioreg_t ctrl, ide_ioreg_t intr,
+			ide_ack_intr_t *ack_intr, int irq)
+{
+	int i;
+
+	for (i = 0; i < IDE_NR_PORTS; i++) {
+		if (offsets[i] == -1) {
+			switch(i) {
+				case IDE_CONTROL_OFFSET:
+					hw->io_ports[i] = ctrl;
+					break;
+				case IDE_IRQ_OFFSET:
+					hw->io_ports[i] = intr;
+					break;
+				default:
+					hw->io_ports[i] = 0;
+					break;
+			}
+		} else {
+			hw->io_ports[i] = base + offsets[i];
+		}
+	}
+	hw->irq = irq;
+	hw->dma = NO_DMA;
+	hw->ack_intr = ack_intr;
+}
+
+/*
+ * Register an IDE interface, specifing exactly the registers etc
+ * Set init=1 iff calling before probes have taken place.
+ */
+int ide_register_hw (hw_regs_t *hw, ide_hwif_t **hwifp)
+{
+	int index, retry = 1;
+	ide_hwif_t *hwif;
+
+	do {
+		for (index = 0; index < MAX_HWIFS; ++index) {
+			hwif = &ide_hwifs[index];
+			if (hwif->hw.io_ports[IDE_DATA_OFFSET] == hw->io_ports[IDE_DATA_OFFSET])
+				goto found;
+		}
+		for (index = 0; index < MAX_HWIFS; ++index) {
+			hwif = &ide_hwifs[index];
+			if ((!hwif->present && !hwif->mate && !initializing) ||
+			    (!hwif->hw.io_ports[IDE_DATA_OFFSET] && initializing))
+				goto found;
+		}
+		for (index = 0; index < MAX_HWIFS; index++)
+			ide_unregister(index);
+	} while (retry--);
+	return -1;
+found:
+	if (hwif->present)
+		ide_unregister(index);
+	if (hwif->present)
+		return -1;
+	memcpy(&hwif->hw, hw, sizeof(*hw));
+	memcpy(hwif->io_ports, hwif->hw.io_ports, sizeof(hwif->hw.io_ports));
+	hwif->irq = hw->irq;
+	hwif->noprobe = 0;
+
+	if (!initializing) {
+		ide_probe_module();
+#ifdef CONFIG_PROC_FS
+		create_proc_ide_interfaces();
+#endif
+		ide_driver_module();
+	}
+
+	if (hwifp)
+		*hwifp = hwif;
+
+	return (initializing || hwif->present) ? index : -1;
+}
+
+/*
+ * Compatability function with existing drivers.  If you want
+ * something different, use the function above.
+ */
+int ide_register (int arg1, int arg2, int irq)
+{
+	hw_regs_t hw;
+	ide_init_hwif_ports(&hw, (ide_ioreg_t) arg1, (ide_ioreg_t) arg2, NULL);
+	hw.irq = irq;
+	return ide_register_hw(&hw, NULL);
+}
+
+void ide_add_setting (ide_drive_t *drive, const char *name, int rw, int read_ioctl, int write_ioctl, int data_type, int min, int max, int mul_factor, int div_factor, void *data, ide_procset_t *set)
+{
+	ide_settings_t **p = (ide_settings_t **) &drive->settings, *setting = NULL;
+
+	while ((*p) && strcmp((*p)->name, name) < 0)
+		p = &((*p)->next);
+	if ((setting = kmalloc(sizeof(*setting), GFP_KERNEL)) == NULL)
+		goto abort;
+	memset(setting, 0, sizeof(*setting));
+	if ((setting->name = kmalloc(strlen(name) + 1, GFP_KERNEL)) == NULL)
+		goto abort;
+	strcpy(setting->name, name);		setting->rw = rw;
+	setting->read_ioctl = read_ioctl;	setting->write_ioctl = write_ioctl;
+	setting->data_type = data_type;		setting->min = min;
+	setting->max = max;			setting->mul_factor = mul_factor;
+	setting->div_factor = div_factor;	setting->data = data;
+	setting->set = set;			setting->next = *p;
+	if (drive->driver)
+		setting->auto_remove = 1;
+	*p = setting;
+	return;
+abort:
+	if (setting)
+		kfree(setting);
+}
+
+void ide_remove_setting (ide_drive_t *drive, char *name)
+{
+	ide_settings_t **p = (ide_settings_t **) &drive->settings, *setting;
+
+	while ((*p) && strcmp((*p)->name, name))
+		p = &((*p)->next);
+	if ((setting = (*p)) == NULL)
+		return;
+	(*p) = setting->next;
+	kfree(setting->name);
+	kfree(setting);
+}
+
+static ide_settings_t *ide_find_setting_by_ioctl (ide_drive_t *drive, int cmd)
+{
+	ide_settings_t *setting = drive->settings;
+
+	while (setting) {
+		if (setting->read_ioctl == cmd || setting->write_ioctl == cmd)
+			break;
+		setting = setting->next;
+	}
+	return setting;
+}
+
+ide_settings_t *ide_find_setting_by_name (ide_drive_t *drive, char *name)
+{
+	ide_settings_t *setting = drive->settings;
+
+	while (setting) {
+		if (strcmp(setting->name, name) == 0)
+			break;
+		setting = setting->next;
+	}
+	return setting;
+}
+
+static void auto_remove_settings (ide_drive_t *drive)
+{
+	ide_settings_t *setting;
+repeat:
+	setting = drive->settings;
+	while (setting) {
+		if (setting->auto_remove) {
+			ide_remove_setting(drive, setting->name);
+			goto repeat;
+		}
+		setting = setting->next;
+	}
+}
+
+int ide_read_setting (ide_drive_t *drive, ide_settings_t *setting)
+{
+	int		val = -EINVAL;
+	unsigned long	flags;
+
+	if ((setting->rw & SETTING_READ)) {
+		spin_lock_irqsave(&io_request_lock, flags);
+		switch(setting->data_type) {
+			case TYPE_BYTE:
+				val = *((u8 *) setting->data);
+				break;
+			case TYPE_SHORT:
+				val = *((u16 *) setting->data);
+				break;
+			case TYPE_INT:
+			case TYPE_INTA:
+				val = *((u32 *) setting->data);
+				break;
+		}
+		spin_unlock_irqrestore(&io_request_lock, flags);
+	}
+	return val;
+}
+
+int ide_spin_wait_hwgroup (ide_drive_t *drive, unsigned long *flags)
+{
+	ide_hwgroup_t *hwgroup = HWGROUP(drive);
+	unsigned long timeout = jiffies + (3 * HZ);
+
+	spin_lock_irqsave(&io_request_lock, *flags);
+	while (hwgroup->busy) {
+		unsigned long lflags;
+		spin_unlock_irqrestore(&io_request_lock, *flags);
+		__save_flags(lflags);	/* local CPU only */
+		__sti();		/* local CPU only; needed for jiffies */
+		if (0 < (signed long)(jiffies - timeout)) {
+			__restore_flags(lflags);	/* local CPU only */
+			printk("%s: channel busy\n", drive->name);
+			return -EBUSY;
+		}
+		__restore_flags(lflags);	/* local CPU only */
+		spin_lock_irqsave(&io_request_lock, *flags);
+	}
+	return 0;
+}
+
+/*
+ * FIXME:  This should be changed to enqueue a special request
+ * to the driver to change settings, and then wait on a sema for completion.
+ * The current scheme of polling is kludgey, though safe enough.
+ */
+int ide_write_setting (ide_drive_t *drive, ide_settings_t *setting, int val)
+{
+	unsigned long flags;
+	int i;
+	u32 *p;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+	if (!(setting->rw & SETTING_WRITE))
+		return -EPERM;
+	if (val < setting->min || val > setting->max)
+		return -EINVAL;
+	if (setting->set)
+		return setting->set(drive, val);
+	if (ide_spin_wait_hwgroup(drive, &flags))
+		return -EBUSY;
+	switch (setting->data_type) {
+		case TYPE_BYTE:
+			*((u8 *) setting->data) = val;
+			break;
+		case TYPE_SHORT:
+			*((u16 *) setting->data) = val;
+			break;
+		case TYPE_INT:
+			*((u32 *) setting->data) = val;
+			break;
+		case TYPE_INTA:
+			p = (u32 *) setting->data;
+			for (i = 0; i < 1 << PARTN_BITS; i++, p++)
+				*p = val;
+			break;
+	}
+	spin_unlock_irqrestore(&io_request_lock, flags);
+	return 0;
+}
+
+static int set_io_32bit(ide_drive_t *drive, int arg)
+{
+	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 */
+	return 0;
+}
+
+static int set_using_dma (ide_drive_t *drive, int arg)
+{
+	if (!drive->driver || !DRIVER(drive)->supports_dma)
+		return -EPERM;
+	if (!drive->id || !(drive->id->capability & 1) || !HWIF(drive)->dmaproc)
+		return -EPERM;
+	if (HWIF(drive)->dmaproc(arg ? ide_dma_on : ide_dma_off, drive))
+		return -EIO;
+	return 0;
+}
+
+static int set_pio_mode (ide_drive_t *drive, int arg)
+{
+	struct request rq;
+
+	if (!HWIF(drive)->tuneproc)
+		return -ENOSYS;
+	if (drive->special.b.set_tune)
+		return -EBUSY;
+	ide_init_drive_cmd(&rq);
+	drive->tune_req = (byte) arg;
+	drive->special.b.set_tune = 1;
+	(void) ide_do_drive_cmd (drive, &rq, ide_wait);
+	return 0;
+}
+
+void ide_add_generic_settings (ide_drive_t *drive)
+{
+/*
+ *			drive	setting name		read/write access				read ioctl		write ioctl		data type	min	max				mul_factor	div_factor	data pointer			set function
+ */
+	ide_add_setting(drive,	"io_32bit",		drive->no_io_32bit ? SETTING_READ : SETTING_RW,	HDIO_GET_32BIT,		HDIO_SET_32BIT,		TYPE_BYTE,	0,	1 + (SUPPORT_VLB_SYNC << 1),	1,		1,		&drive->io_32bit,		set_io_32bit);
+	ide_add_setting(drive,	"keepsettings",		SETTING_RW,					HDIO_GET_KEEPSETTINGS,	HDIO_SET_KEEPSETTINGS,	TYPE_BYTE,	0,	1,				1,		1,		&drive->keep_settings,		NULL);
+	ide_add_setting(drive,	"nice1",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	1,				1,		1,		&drive->nice1,			NULL);
+	ide_add_setting(drive,	"pio_mode",		SETTING_WRITE,					-1,			HDIO_SET_PIO_MODE,	TYPE_BYTE,	0,	255,				1,		1,		NULL,				set_pio_mode);
+	ide_add_setting(drive,	"slow",			SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	1,				1,		1,		&drive->slow,			NULL);
+	ide_add_setting(drive,	"unmaskirq",		drive->no_unmask ? SETTING_READ : SETTING_RW,	HDIO_GET_UNMASKINTR,	HDIO_SET_UNMASKINTR,	TYPE_BYTE,	0,	1,				1,		1,		&drive->unmask,			NULL);
+	ide_add_setting(drive,	"using_dma",		SETTING_RW,					HDIO_GET_DMA,		HDIO_SET_DMA,		TYPE_BYTE,	0,	1,				1,		1,		&drive->using_dma,		set_using_dma);
+	ide_add_setting(drive,	"ide_scsi",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	1,				1,		1,		&drive->scsi,			NULL);
+}
+
+int ide_wait_cmd (ide_drive_t *drive, int cmd, int nsect, int feature, int sectors, byte *buf)
+{
+	struct request rq;
+	byte buffer[4];
+
+	if (!buf)
+		buf = buffer;
+	memset(buf, 0, 4 + SECTOR_WORDS * 4 * sectors);
+	ide_init_drive_cmd(&rq);
+	rq.buffer = buf;
+	*buf++ = cmd;
+	*buf++ = nsect;
+	*buf++ = feature;
+	*buf++ = sectors;
+	return ide_do_drive_cmd(drive, &rq, ide_wait);
+}
+
+/*
+ * Delay for *at least* 50ms.  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.
+ *
+ * However, its usefullness may be needed in other places, thus we export it now.
+ * The future may change this to a millisecond setable delay.
+ */
+void ide_delay_50ms (void)
+{
+	unsigned long timeout = jiffies + ((HZ + 19)/20) + 1;
+	while (0 < (signed long)(timeout - jiffies));
+}
+
+static int ide_ioctl (struct inode *inode, struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	int err = 0, major, minor;
+	ide_drive_t *drive;
+	struct request rq;
+	kdev_t dev;
+	ide_settings_t *setting;
+
+	if (!inode || !(dev = inode->i_rdev))
+		return -EINVAL;
+	major = MAJOR(dev); minor = MINOR(dev);
+	if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
+		return -ENODEV;
+
+	if ((setting = ide_find_setting_by_ioctl(drive, cmd)) != NULL) {
+		if (cmd == setting->read_ioctl) {
+			err = ide_read_setting(drive, setting);
+			return err >= 0 ? put_user(err, (long *) arg) : err;
+		} else {
+			if ((MINOR(inode->i_rdev) & PARTN_MASK))
+				return -EINVAL;
+			return ide_write_setting(drive, setting, arg);
+		}
+	}
+
+	ide_init_drive_cmd (&rq);
+	switch (cmd) {
+		case HDIO_GETGEO:
+		{
+			struct hd_geometry *loc = (struct hd_geometry *) arg;
+			unsigned short bios_cyl = drive->bios_cyl; /* truncate */
+			if (!loc || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
+			if (put_user(drive->bios_head, (byte *) &loc->heads)) return -EFAULT;
+			if (put_user(drive->bios_sect, (byte *) &loc->sectors)) return -EFAULT;
+			if (put_user(bios_cyl, (unsigned short *) &loc->cylinders)) return -EFAULT;
+			if (put_user((unsigned)drive->part[MINOR(inode->i_rdev)&PARTN_MASK].start_sect,
+				(unsigned long *) &loc->start)) return -EFAULT;
+			return 0;
+		}
+
+	 	case BLKGETSIZE:   /* Return device size */
+			return put_user(drive->part[MINOR(inode->i_rdev)&PARTN_MASK].nr_sects, (long *) arg);
+
+		case BLKRRPART: /* Re-read partition tables */
+			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+			return ide_revalidate_disk(inode->i_rdev);
+
+		case HDIO_OBSOLETE_IDENTITY:
+		case HDIO_GET_IDENTITY:
+			if (MINOR(inode->i_rdev) & PARTN_MASK)
+				return -EINVAL;
+			if (drive->id == NULL)
+				return -ENOMSG;
+			if (copy_to_user((char *)arg, (char *)drive->id, (cmd == HDIO_GET_IDENTITY) ? sizeof(*drive->id) : 142))
+				return -EFAULT;
+			return 0;
+
+		case HDIO_GET_NICE:
+			return put_user(drive->dsc_overlap	<<	IDE_NICE_DSC_OVERLAP	|
+					drive->atapi_overlap	<<	IDE_NICE_ATAPI_OVERLAP	|
+					drive->nice0		<< 	IDE_NICE_0		|
+					drive->nice1		<<	IDE_NICE_1		|
+					drive->nice2		<<	IDE_NICE_2,
+					(long *) arg);
+		case HDIO_DRIVE_CMD:
+		{
+			byte args[4], *argbuf = args;
+			int argsize = 4;
+			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+			if (NULL == (void *) arg)
+				return ide_do_drive_cmd(drive, &rq, ide_wait);
+			if (copy_from_user(args, (void *)arg, 4))
+				return -EFAULT;
+			if (args[3]) {
+				argsize = 4 + (SECTOR_WORDS * 4 * args[3]);
+				argbuf = kmalloc(argsize, GFP_KERNEL);
+				if (argbuf == NULL)
+					return -ENOMEM;
+				memcpy(argbuf, args, 4);
+			}
+			if (ide_ata66_check(drive, args[0], args[1], args[2]))
+				goto abort;
+
+			err = ide_wait_cmd(drive, args[0], args[1], args[2], args[3], argbuf);
+
+			if (!err && set_transfer(drive, args[0], args[1], args[2])) {
+#if 0
+				/* active-retuning-calls future */
+				if (HWIF(drive)->tune2proc)
+					HWIF(drive)->tune2proc(drive, args[1]);
+#endif
+				ide_driveid_update(drive);
+			}
+		abort:
+			if (copy_to_user((void *)arg, argbuf, argsize))
+				err = -EFAULT;
+			if (argsize > 4)
+				kfree(argbuf);
+			return err;
+		}
+
+		case HDIO_SCAN_HWIF:
+		{
+			int args[3];
+			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+			if (copy_from_user(args, (void *)arg, 3 * sizeof(int)))
+				return -EFAULT;
+			if (ide_register(args[0], args[1], args[2]) == -1)
+				return -EIO;
+			return 0;
+		}
+	        case HDIO_UNREGISTER_HWIF:
+			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+			/* should I check here for arg > MAX_HWIFS, or
+			   just let ide_unregister fail silently? -- shaver */
+			ide_unregister(arg);
+			return 0;
+		case HDIO_SET_NICE:
+			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
+			if (drive->driver == NULL)
+				return -EPERM;
+			if (arg != (arg & ((1 << IDE_NICE_DSC_OVERLAP) | (1 << IDE_NICE_1))))
+				return -EPERM;
+			drive->dsc_overlap = (arg >> IDE_NICE_DSC_OVERLAP) & 1;
+			if (drive->dsc_overlap && !DRIVER(drive)->supports_dsc_overlap) {
+				drive->dsc_overlap = 0;
+				return -EPERM;
+			}
+			drive->nice1 = (arg >> IDE_NICE_1) & 1;
+			return 0;
+
+		case BLKROSET:
+		case BLKROGET:
+		case BLKFLSBUF:
+		case BLKSSZGET:
+		case BLKPG:
+		case BLKELVGET:
+		case BLKELVSET:
+			return blk_ioctl(inode->i_rdev, cmd, arg);
+
+		default:
+			if (drive->driver != NULL)
+				return DRIVER(drive)->ioctl(drive, inode, file, cmd, arg);
+			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;
+	if (drive->driver != NULL)
+		return DRIVER(drive)->media_change(drive);
+	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';
+}
+
+/*
+ * stridx() returns the offset of c within s,
+ * or -1 if c is '\0' or not found within s.
+ */
+static int __init 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 __init 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
+		 */
+		if (keywords != NULL) {
+			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 == ';')
+				++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=none"		: drive is NOT present, ignore cmos and do not probe
+ * "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=noremap"	: do not remap 0->1 even though EZD was detected
+ * "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.
+ *
+ * "hdx=slow"		: insert a huge pause after each access to the data
+ *				port. Should be used only as a last resort.
+ *
+ * "hdx=swapdata"	: when the drive is a disk, byte swap all data
+ * "hdx=bswap"		: same as above..........
+ * "hdxlun=xx"          : set the drive last logical unit.
+ * "hdx=flash"		: allows for more than one ata_flash disk to be
+ *				registered. In most cases, only one device
+ *				will be present.
+ * "hdx=scsi"		: the return of the ide-scsi flag, this is useful for
+ *				allowwing ide-floppy, ide-tape, and ide-cdrom|writers
+ *				to use ide-scsi emulation on a device specific option.
+ * "idebus=xx"		: inform IDE driver of VESA/PCI bus speed in MHz,
+ *				where "xx" is between 20 and 66 inclusive,
+ *				used when tuning chipset PIO modes.
+ *				For PCI bus, 25 is correct for a P75 system,
+ *				30 is correct for P90,P120,P180 systems,
+ *				and 33 is used for P100,P133,P166 systems.
+ *				If in doubt, use idebus=33 for PCI.
+ *				As for VLB, it is safest to not specify it.
+ *
+ * "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.
+ * "idex=serialize"	: do not overlap operations on idex and ide(x^1)
+ * "idex=four"		: four drives on idex and ide(x^1) share same ports
+ * "idex=reset"		: reset interface before first use
+ * "idex=dma"		: enable DMA by default on both drives if possible
+ * "idex=ata66"		: informs the interface that it has an 80c cable
+ *				for chipsets that are ATA-66 capable, but
+ *				the ablity to bit test for detection is
+ *				currently unknown.
+ * "ide=reverse"	: Formerly called to pci sub-system, but now local.
+ *
+ * "splitfifo=betweenChan"
+ *			: FIFO Configuration of VIA 82c586(<nothing>,"A"or"B").
+ *                                 --see what follows...
+ * "splitfifo=betweenChan,thresholdprim,thresholdsec"
+ *			: FIFO Configuration of VIA 82c586(<nothing>,"A" or "B").
+ *				betweenChan = 1(all FIFO's to primary channel)
+ *                                          , 2(all FIFO's to secondary channel)
+ *                                          , 3 or 4(evenly shared between them).
+ *				note: without FIFO, a channel is (u)dma disabled!
+ *				thresholdprim = 4, 3, 2 or 1
+ *						(standing for 1, 3/4, 1/2, 1/4).
+ *                                    Sets the threshold of FIFO to begin dma
+ *                                    transfer on the primary channel.
+ *				thresholdsec = cf upper, but for secondary channel.
+ *
+ * The following are valid ONLY on ide0, (except dc4030)
+ * and the defaults for the base,ctl ports must not be altered.
+ *
+ * "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
+ * "idex=dc4030"	: probe/support Promise DC4030VL interface
+ * "ide=doubler"	: probe/support IDE doublers on Amiga
+ */
+int __init 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 ();
+
+#ifdef CONFIG_BLK_DEV_IDEDOUBLER
+	if (!strcmp(s, "ide=doubler")) {
+		extern int ide_doubler;
+
+		printk(" : Enabled support for IDE doublers\n");
+		ide_doubler = 1;
+		return 0;
+	}
+#endif /* CONFIG_BLK_DEV_IDEDOUBLER */
+
+#ifdef CONFIG_BLK_DEV_IDEPCI
+	if (!strcmp(s, "ide=reverse")) {
+		ide_scan_direction = 1;
+		printk(" : Enabled support for IDE inverse scan order.\n");
+		return 0;
+	}
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+
+	/*
+	 * Look for drive options:  "hdx="
+	 */
+	if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) {
+		const char *hd_words[] = {"none", "noprobe", "nowerr", "cdrom",
+				"serialize", "autotune", "noautotune",
+				"slow", "swapdata", "bswap", "flash",
+				"remap", "noremap", "scsi", NULL};
+		unit = s[2] - 'a';
+		hw   = unit / MAX_DRIVES;
+		unit = unit % MAX_DRIVES;
+		hwif = &ide_hwifs[hw];
+		drive = &hwif->drives[unit];
+		if (strncmp(s + 4, "ide-", 4) == 0) {
+			strncpy(drive->driver_req, s + 4, 9);
+			goto done;
+		}
+		/*
+		 * Look for last lun option:  "hdxlun="
+		 */
+		if (s[3] == 'l' && s[4] == 'u' && s[5] == 'n') {
+			if (match_parm(&s[6], NULL, vals, 1) != 1)
+				goto bad_option;
+			if (vals[0] >= 0 && vals[0] <= 7) {
+				drive->last_lun = vals[0];
+				drive->forced_lun = 1;
+			} else
+				printk(" -- BAD LAST LUN! Expected value from 0 to 7");
+			goto done;
+		}
+		switch (match_parm(&s[3], hd_words, vals, 3)) {
+			case -1: /* "none" */
+				drive->nobios = 1;  /* drop into "noprobe" */
+			case -2: /* "noprobe" */
+				drive->noprobe = 1;
+				goto done;
+			case -3: /* "nowerr" */
+				drive->bad_wstat = BAD_R_STAT;
+				hwif->noprobe = 0;
+				goto done;
+			case -4: /* "cdrom" */
+				drive->present = 1;
+				drive->media = ide_cdrom;
+				hwif->noprobe = 0;
+				goto done;
+			case -5: /* "serialize" */
+				printk(" -- USE \"ide%d=serialize\" INSTEAD", hw);
+				goto do_serialize;
+			case -6: /* "autotune" */
+				drive->autotune = 1;
+				goto done;
+			case -7: /* "noautotune" */
+				drive->autotune = 2;
+				goto done;
+			case -8: /* "slow" */
+				drive->slow = 1;
+				goto done;
+			case -9: /* "swapdata" or "bswap" */
+			case -10:
+				drive->bswap = 1;
+				goto done;
+			case -11: /* "flash" */
+				drive->ata_flash = 1;
+				goto done;
+			case -12: /* "remap" */
+				drive->remap_0_to_1 = 1;
+				goto done;
+			case -13: /* "noremap" */
+				drive->remap_0_to_1 = 2;
+				goto done;
+			case -14: /* "scsi" */
+#if defined(CONFIG_BLK_DEV_IDESCSI) && defined(CONFIG_SCSI)
+				drive->scsi = 1;
+				goto done;
+#else
+				drive->scsi = 0;
+				goto bad_option;
+#endif /* defined(CONFIG_BLK_DEV_IDESCSI) && defined(CONFIG_SCSI) */
+			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;
+		}
+	}
+
+#if defined(CONFIG_BLK_DEV_VIA82CXXX)
+	/*
+	 *  Look for drive option "splitfifo=..."
+	 */
+
+	if (s[0] == 's' && s[1] == 'p' && s[2] == 'l' &&
+	    s[3] == 'i' && s[4] == 't' && s[5] == 'f' &&
+	    s[6] == 'i' && s[7] == 'f' && s[8] == 'o') {
+		byte tmp = 0x3a;		/* default config byte */
+
+		i = match_parm(&s[9], NULL, vals, 3);
+		switch(i) {
+		case 3:	
+			tmp &= 0xf0;
+			if ((vals[1] > 0) && (vals[1] < 5)) {
+				/* sets threshold for primary Channel: */
+				byte x = 4 - vals[1];
+				tmp |= (x << 2);
+			}
+			else
+				goto bad_option;
+			if ((vals[2] > 0) && (vals[2] < 5)) {
+				/* sets threshold for secondary Channel: */
+				byte x = 4 - vals[2];
+				tmp |= x;
+			}
+			else
+				goto bad_option;
+		case 1:
+			/* set the FIFO config between channels to 0: */
+			tmp &= 0x9f;
+			/* set the needed FIFO config between channels: */
+			if (vals[0] == 1)	/* primary fifo only */
+				tmp |= 0x10;
+			else if (vals[0] == 2)	/* secondary fifo only */
+				tmp |= 0x70;
+			else if (vals[0] == 4)	/* other shared fifo config */
+				tmp |= 0x50;
+			else if (vals[0] == 3)	/* default config */
+				tmp |= 0x30;
+			else
+				goto bad_option;
+			break;
+		default:
+			goto bad_option;
+		}
+		/* set the found option in fifoconfig */
+		fifoconfig = tmp;		
+		goto done;
+	}
+#endif  /* defined(CONFIG_BLK_DEV_VIA82CXXX) */
+
+	if (s[0] != 'i' || s[1] != 'd' || s[2] != 'e')
+		goto bad_option;
+	/*
+	 * Look for bus speed option:  "idebus="
+	 */
+	if (s[3] == 'b' && s[4] == 'u' && s[5] == 's') {
+		if (match_parm(&s[6], NULL, vals, 1) != 1)
+			goto bad_option;
+		if (vals[0] >= 20 && vals[0] <= 66) {
+			idebus_parameter = vals[0];
+		} else
+			printk(" -- BAD BUS SPEED! Expected value from 20 to 66");
+		goto done;
+	}
+	/*
+	 * Look for interface options:  "idex="
+	 */
+	if (s[3] >= '0' && s[3] <= max_hwif) {
+		/*
+		 * Be VERY CAREFUL changing this: note hardcoded indexes below
+		 * -8,-9,-10 : are reserved for future idex calls to ease the hardcoding.
+		 */
+		const char *ide_words[] = {
+			"noprobe", "serialize", "autotune", "noautotune", "reset", "dma", "ata66",
+			"minus8", "minus9", "minus10",
+			"four", "qd6580", "ht6560b", "cmd640_vlb", "dtc2278", "umc8672", "ali14xx", "dc4030", 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 > 0 || i <= -11) {			/* is parameter a chipset name? */
+			if (hwif->chipset != ide_unknown)
+				goto bad_option;	/* chipset already specified */
+			if (i <= -11 && i != -18 && hw != 0)
+				goto bad_hwif;		/* chipset drivers are for "ide0=" only */
+			if (i <= -11 && i != -18 && ide_hwifs[hw+1].chipset != ide_unknown)
+				goto bad_option;	/* chipset for 2nd port already specified */
+			printk("\n");
+		}
+
+		switch (i) {
+#ifdef CONFIG_BLK_DEV_PDC4030
+			case -18: /* "dc4030" */
+			{
+				extern void init_pdc4030(void);
+				init_pdc4030();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_PDC4030 */
+#ifdef CONFIG_BLK_DEV_ALI14XX
+			case -17: /* "ali14xx" */
+			{
+				extern void init_ali14xx (void);
+				init_ali14xx();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_ALI14XX */
+#ifdef CONFIG_BLK_DEV_UMC8672
+			case -16: /* "umc8672" */
+			{
+				extern void init_umc8672 (void);
+				init_umc8672();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_UMC8672 */
+#ifdef CONFIG_BLK_DEV_DTC2278
+			case -15: /* "dtc2278" */
+			{
+				extern void init_dtc2278 (void);
+				init_dtc2278();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_DTC2278 */
+#ifdef CONFIG_BLK_DEV_CMD640
+			case -14: /* "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 -13: /* "ht6560b" */
+			{
+				extern void init_ht6560b (void);
+				init_ht6560b();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_HT6560B */
+#if CONFIG_BLK_DEV_QD6580
+			case -12: /* "qd6580" */
+			{
+				extern void init_qd6580 (void);
+				init_qd6580();
+				goto done;
+			}
+#endif /* CONFIG_BLK_DEV_QD6580 */
+#ifdef CONFIG_BLK_DEV_4DRIVES
+			case -11: /* "four" drives on one set of ports */
+			{
+				ide_hwif_t *mate = &ide_hwifs[hw^1];
+				mate->drives[0].select.all ^= 0x20;
+				mate->drives[1].select.all ^= 0x20;
+				hwif->chipset = mate->chipset = ide_4drives;
+				mate->irq = hwif->irq;
+				memcpy(mate->io_ports, hwif->io_ports, sizeof(hwif->io_ports));
+				goto do_serialize;
+			}
+#endif /* CONFIG_BLK_DEV_4DRIVES */
+			case -10: /* minus10 */
+			case -9: /* minus9 */
+			case -8: /* minus8 */
+				goto bad_option;
+			case -7: /* ata66 */
+#ifdef CONFIG_BLK_DEV_IDEPCI
+				hwif->udma_four = 1;
+				goto done;
+#else /* !CONFIG_BLK_DEV_IDEPCI */
+				hwif->udma_four = 0;
+				goto bad_hwif;
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+			case -6: /* dma */
+				hwif->autodma = 1;
+				goto done;
+			case -5: /* "reset" */
+				hwif->reset = 1;
+				goto done;
+			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:
+				hwif->mate = &ide_hwifs[hw^1];
+				hwif->mate->mate = hwif;
+				hwif->serialized = hwif->mate->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->hw.irq = vals[2];
+				ide_init_hwif_ports(&hwif->hw, (ide_ioreg_t) vals[0], (ide_ioreg_t) vals[1], &hwif->irq);
+				memcpy(hwif->io_ports, hwif->hw.io_ports, sizeof(hwif->io_ports));
+				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 0;
+		}
+	}
+bad_option:
+	printk(" -- BAD OPTION\n");
+	return 0;
+bad_hwif:
+	printk("-- NOT SUPPORTED ON ide%d", hw);
+done:
+	printk("\n");
+	return 0;
+}
+
+/*
+ * probe_for_hwifs() finds/initializes "known" IDE interfaces
+ */
+static void __init probe_for_hwifs (void)
+{
+#ifdef CONFIG_PCI
+	if (pci_present())
+	{
+#ifdef CONFIG_BLK_DEV_IDEPCI
+		ide_scan_pcibus(ide_scan_direction);
+#else
+#ifdef CONFIG_BLK_DEV_RZ1000
+		{
+			extern void ide_probe_for_rz100x(void);
+			ide_probe_for_rz100x();
+		}
+#endif /* CONFIG_BLK_DEV_RZ1000 */
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+	}
+#endif /* CONFIG_PCI */
+
+#ifdef CONFIG_BLK_DEV_CMD640
+	{
+		extern void ide_probe_for_cmd640x(void);
+		ide_probe_for_cmd640x();
+	}
+#endif /* CONFIG_BLK_DEV_CMD640 */
+#ifdef CONFIG_BLK_DEV_PDC4030
+	{
+		extern int ide_probe_for_pdc4030(void);
+		(void) ide_probe_for_pdc4030();
+	}
+#endif /* CONFIG_BLK_DEV_PDC4030 */
+#ifdef CONFIG_BLK_DEV_IDE_PMAC
+	{
+		extern void pmac_ide_probe(void);
+		pmac_ide_probe();
+	}
+#endif /* CONFIG_BLK_DEV_IDE_PMAC */
+#ifdef CONFIG_BLK_DEV_IDE_ICSIDE
+	{
+		extern void icside_init(void);
+		icside_init();
+	}
+#endif /* CONFIG_BLK_DEV_IDE_ICSIDE */
+#ifdef CONFIG_BLK_DEV_IDE_RAPIDE
+	{
+		extern void rapide_init(void);
+		rapide_init();
+	}
+#endif /* CONFIG_BLK_DEV_IDE_RAPIDE */
+#ifdef CONFIG_BLK_DEV_GAYLE
+	{
+		extern void gayle_init(void);
+		gayle_init();
+	}
+#endif /* CONFIG_BLK_DEV_GAYLE */
+#ifdef CONFIG_BLK_DEV_FALCON_IDE
+	{
+		extern void falconide_init(void);
+		falconide_init();
+	}
+#endif /* CONFIG_BLK_DEV_FALCON_IDE */
+#ifdef CONFIG_BLK_DEV_MAC_IDE
+	{
+		extern void macide_init(void);
+		macide_init();
+	}
+#endif /* CONFIG_BLK_DEV_MAC_IDE */
+#ifdef CONFIG_BLK_DEV_BUDDHA
+	{
+		extern void buddha_init(void);
+		buddha_init();
+	}
+#endif /* CONFIG_BLK_DEV_BUDDHA */
+#if defined(CONFIG_BLK_DEV_ISAPNP) && defined(CONFIG_ISAPNP)
+	{
+		extern void pnpide_init(int enable);
+		pnpide_init(1);
+	}
+#endif /* CONFIG_BLK_DEV_ISAPNP */
+}
+
+void __init ide_init_builtin_drivers (void)
+{
+	/*
+	 * Probe for special PCI and other "known" interface chipsets
+	 */
+	probe_for_hwifs ();
+
+#ifdef CONFIG_BLK_DEV_IDE
+#if defined(__mc68000__) || defined(CONFIG_APUS)
+	if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET]) {
+		ide_get_lock(&ide_lock, NULL, NULL);	/* for atari only */
+		disable_irq(ide_hwifs[0].irq);	/* disable_irq_nosync ?? */
+	}
+#endif /* __mc68000__ || CONFIG_APUS */
+
+	(void) ideprobe_init();
+
+#if defined(__mc68000__) || defined(CONFIG_APUS)
+	if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET]) {
+		enable_irq(ide_hwifs[0].irq);
+		ide_release_lock(&ide_lock);	/* for atari only */
+	}
+#endif /* __mc68000__ || CONFIG_APUS */
+#endif /* CONFIG_BLK_DEV_IDE */
+
+#ifdef CONFIG_PROC_FS
+	proc_ide_create();
+#endif
+
+	/*
+	 * Attempt to match drivers for the available drives
+	 */
+#ifdef CONFIG_BLK_DEV_IDEDISK
+	(void) idedisk_init();
+#endif /* CONFIG_BLK_DEV_IDEDISK */
+#ifdef CONFIG_BLK_DEV_IDECD
+	(void) ide_cdrom_init();
+#endif /* CONFIG_BLK_DEV_IDECD */
+#ifdef CONFIG_BLK_DEV_IDETAPE
+	(void) idetape_init();
+#endif /* CONFIG_BLK_DEV_IDETAPE */
+#ifdef CONFIG_BLK_DEV_IDEFLOPPY
+	(void) idefloppy_init();
+#endif /* CONFIG_BLK_DEV_IDEFLOPPY */
+#ifdef CONFIG_BLK_DEV_IDESCSI
+ #ifdef CONFIG_SCSI
+	(void) idescsi_init();
+ #else
+    #warning ide scsi-emulation selected but no SCSI-subsystem in kernel
+ #endif
+#endif /* CONFIG_BLK_DEV_IDESCSI */
+}
+
+static int default_cleanup (ide_drive_t *drive)
+{
+	return ide_unregister_subdriver(drive);
+}
+
+static ide_startstop_t default_do_request(ide_drive_t *drive, struct request *rq, unsigned long block)
+{
+	ide_end_request(0, HWGROUP(drive));
+	return ide_stopped;
+}
+ 
+static void default_end_request (byte uptodate, ide_hwgroup_t *hwgroup)
+{
+	ide_end_request(uptodate, hwgroup);
+}
+  
+static int default_ioctl (ide_drive_t *drive, struct inode *inode, struct file *file,
+			  unsigned int cmd, unsigned long arg)
+{
+	return -EIO;
+}
+
+static int default_open (struct inode *inode, struct file *filp, ide_drive_t *drive)
+{
+	drive->usage--;
+	return -EIO;
+}
+
+static void default_release (struct inode *inode, struct file *filp, ide_drive_t *drive)
+{
+}
+
+static int default_check_media_change (ide_drive_t *drive)
+{
+	return 1;
+}
+
+static void default_pre_reset (ide_drive_t *drive)
+{
+}
+
+static unsigned long default_capacity (ide_drive_t *drive)
+{
+	return 0x7fffffff;	/* cdrom or tape */
+}
+
+static ide_startstop_t default_special (ide_drive_t *drive)
+{
+	special_t *s = &drive->special;
+
+	s->all = 0;
+	drive->mult_req = 0;
+	return ide_stopped;
+}
+
+static void setup_driver_defaults (ide_drive_t *drive)
+{
+	ide_driver_t *d = drive->driver;
+
+	if (d->cleanup == NULL)		d->cleanup = default_cleanup;
+	if (d->do_request == NULL)	d->do_request = default_do_request;
+	if (d->end_request == NULL)	d->end_request = default_end_request;
+	if (d->ioctl == NULL)		d->ioctl = default_ioctl;
+	if (d->open == NULL)		d->open = default_open;
+	if (d->release == NULL)		d->release = default_release;
+	if (d->media_change == NULL)	d->media_change = default_check_media_change;
+	if (d->pre_reset == NULL)	d->pre_reset = default_pre_reset;
+	if (d->capacity == NULL)	d->capacity = default_capacity;
+	if (d->special == NULL)		d->special = default_special;
+}
+
+ide_drive_t *ide_scan_devices (byte media, const char *name, ide_driver_t *driver, int n)
+{
+	unsigned int unit, index, i;
+
+	for (index = 0, i = 0; index < MAX_HWIFS; ++index) {
+		ide_hwif_t *hwif = &ide_hwifs[index];
+		if (!hwif->present)
+			continue;
+		for (unit = 0; unit < MAX_DRIVES; ++unit) {
+			ide_drive_t *drive = &hwif->drives[unit];
+			char *req = drive->driver_req;
+			if (*req && !strstr(name, req))
+				continue;
+			if (drive->present && drive->media == media && drive->driver == driver && ++i > n)
+				return drive;
+		}
+	}
+	return NULL;
+}
+
+int ide_register_subdriver (ide_drive_t *drive, ide_driver_t *driver, int version)
+{
+	unsigned long flags;
+	
+	save_flags(flags);		/* all CPUs */
+	cli();				/* all CPUs */
+	if (version != IDE_SUBDRIVER_VERSION || !drive->present || drive->driver != NULL || drive->busy || drive->usage) {
+		restore_flags(flags);	/* all CPUs */
+		return 1;
+	}
+	drive->driver = driver;
+	setup_driver_defaults(drive);
+	restore_flags(flags);		/* all CPUs */
+	if (drive->autotune != 2) {
+		if (driver->supports_dma && HWIF(drive)->dmaproc != NULL) {
+			/*
+			 * Force DMAing for the beginning of the check.
+			 * Some chipsets appear to do interesting things,
+			 * if not checked and cleared.
+			 *   PARANOIA!!!
+			 */
+			(void) (HWIF(drive)->dmaproc(ide_dma_off_quietly, drive));
+			(void) (HWIF(drive)->dmaproc(ide_dma_check, drive));
+		}
+		drive->dsc_overlap = (drive->next != drive && driver->supports_dsc_overlap);
+		drive->nice1 = 1;
+	}
+	drive->revalidate = 1;
+#ifdef CONFIG_PROC_FS
+	ide_add_proc_entries(drive->proc, generic_subdriver_entries, drive);
+	ide_add_proc_entries(drive->proc, driver->proc, drive);
+#endif
+	return 0;
+}
+
+int ide_unregister_subdriver (ide_drive_t *drive)
+{
+	unsigned long flags;
+	
+	save_flags(flags);		/* all CPUs */
+	cli();				/* all CPUs */
+	if (drive->usage || drive->busy || drive->driver == NULL || DRIVER(drive)->busy) {
+		restore_flags(flags);	/* all CPUs */
+		return 1;
+	}
+#if defined(CONFIG_BLK_DEV_ISAPNP) && defined(CONFIG_ISAPNP) && defined(MODULE)
+	pnpide_init(0);
+#endif /* CONFIG_BLK_DEV_ISAPNP */
+#ifdef CONFIG_PROC_FS
+	ide_remove_proc_entries(drive->proc, DRIVER(drive)->proc);
+	ide_remove_proc_entries(drive->proc, generic_subdriver_entries);
+#endif
+	auto_remove_settings(drive);
+	drive->driver = NULL;
+	restore_flags(flags);		/* all CPUs */
+	return 0;
+}
+
+int ide_register_module (ide_module_t *module)
+{
+	ide_module_t *p = ide_modules;
+
+	while (p) {
+		if (p == module)
+			return 1;
+		p = p->next;
+	}
+	module->next = ide_modules;
+	ide_modules = module;
+	revalidate_drives();
+	return 0;
+}
+
+void ide_unregister_module (ide_module_t *module)
+{
+	ide_module_t **p;
+
+	for (p = &ide_modules; (*p) && (*p) != module; p = &((*p)->next));
+	if (*p)
+		*p = (*p)->next;
+}
+
+struct block_device_operations ide_fops[] = {{
+	open:			ide_open,
+	release:		ide_release,
+	ioctl:			ide_ioctl,
+	check_media_change:	ide_check_media_change,
+	revalidate:		ide_revalidate_disk
+}};
+
+EXPORT_SYMBOL(ide_hwifs);
+EXPORT_SYMBOL(ide_register_module);
+EXPORT_SYMBOL(ide_unregister_module);
+EXPORT_SYMBOL(ide_spin_wait_hwgroup);
+
+/*
+ * Probe module
+ */
+devfs_handle_t ide_devfs_handle = NULL;
+
+EXPORT_SYMBOL(ide_probe);
+EXPORT_SYMBOL(drive_is_flashcard);
+EXPORT_SYMBOL(ide_timer_expiry);
+EXPORT_SYMBOL(ide_intr);
+EXPORT_SYMBOL(ide_fops);
+EXPORT_SYMBOL(ide_get_queue);
+EXPORT_SYMBOL(do_ide0_request);
+EXPORT_SYMBOL(ide_add_generic_settings);
+EXPORT_SYMBOL(ide_devfs_handle);
+#if MAX_HWIFS > 1
+EXPORT_SYMBOL(do_ide1_request);
+#endif /* MAX_HWIFS > 1 */
+#if MAX_HWIFS > 2
+EXPORT_SYMBOL(do_ide2_request);
+#endif /* MAX_HWIFS > 2 */
+#if MAX_HWIFS > 3
+EXPORT_SYMBOL(do_ide3_request);
+#endif /* MAX_HWIFS > 3 */
+#if MAX_HWIFS > 4
+EXPORT_SYMBOL(do_ide4_request);
+#endif /* MAX_HWIFS > 4 */
+#if MAX_HWIFS > 5
+EXPORT_SYMBOL(do_ide5_request);
+#endif /* MAX_HWIFS > 5 */
+#if MAX_HWIFS > 6
+EXPORT_SYMBOL(do_ide6_request);
+#endif /* MAX_HWIFS > 6 */
+#if MAX_HWIFS > 7
+EXPORT_SYMBOL(do_ide7_request);
+#endif /* MAX_HWIFS > 7 */
+#if MAX_HWIFS > 8
+EXPORT_SYMBOL(do_ide8_request);
+#endif /* MAX_HWIFS > 8 */
+#if MAX_HWIFS > 9
+EXPORT_SYMBOL(do_ide9_request);
+#endif /* MAX_HWIFS > 9 */
+
+/*
+ * Driver module
+ */
+EXPORT_SYMBOL(ide_scan_devices);
+EXPORT_SYMBOL(ide_register_subdriver);
+EXPORT_SYMBOL(ide_unregister_subdriver);
+EXPORT_SYMBOL(ide_replace_subdriver);
+EXPORT_SYMBOL(ide_input_data);
+EXPORT_SYMBOL(ide_output_data);
+EXPORT_SYMBOL(atapi_input_bytes);
+EXPORT_SYMBOL(atapi_output_bytes);
+EXPORT_SYMBOL(ide_set_handler);
+EXPORT_SYMBOL(ide_dump_status);
+EXPORT_SYMBOL(ide_error);
+EXPORT_SYMBOL(ide_fixstring);
+EXPORT_SYMBOL(ide_wait_stat);
+EXPORT_SYMBOL(ide_do_reset);
+EXPORT_SYMBOL(ide_init_drive_cmd);
+EXPORT_SYMBOL(ide_do_drive_cmd);
+EXPORT_SYMBOL(ide_end_drive_cmd);
+EXPORT_SYMBOL(ide_end_request);
+EXPORT_SYMBOL(ide_revalidate_disk);
+EXPORT_SYMBOL(ide_cmd);
+EXPORT_SYMBOL(ide_wait_cmd);
+EXPORT_SYMBOL(ide_delay_50ms);
+EXPORT_SYMBOL(ide_stall_queue);
+#ifdef CONFIG_PROC_FS
+EXPORT_SYMBOL(ide_add_proc_entries);
+EXPORT_SYMBOL(ide_remove_proc_entries);
+EXPORT_SYMBOL(proc_ide_read_geometry);
+EXPORT_SYMBOL(create_proc_ide_interfaces);
+#endif
+EXPORT_SYMBOL(ide_add_setting);
+EXPORT_SYMBOL(ide_remove_setting);
+
+EXPORT_SYMBOL(ide_register_hw);
+EXPORT_SYMBOL(ide_register);
+EXPORT_SYMBOL(ide_unregister);
+EXPORT_SYMBOL(ide_setup_ports);
+EXPORT_SYMBOL(hwif_unregister);
+EXPORT_SYMBOL(get_info_ptr);
+EXPORT_SYMBOL(current_capacity);
+
+/*
+ * This is gets invoked once during initialization, to set *everything* up
+ */
+int __init ide_init (void)
+{
+	static char banner_printed = 0;
+	int i;
+
+	if (!banner_printed) {
+		printk(KERN_INFO "Uniform Multi-Platform E-IDE driver " REVISION "\n");
+		ide_devfs_handle = devfs_mk_dir (NULL, "ide", 3, NULL);
+		(void) ide_system_bus_speed();
+		banner_printed = 1;
+	}
+
+	init_ide_data ();
+
+	initializing = 1;
+	ide_init_builtin_drivers();
+	initializing = 0;
+
+	for (i = 0; i < MAX_HWIFS; ++i) {
+		ide_hwif_t  *hwif = &ide_hwifs[i];
+		if (hwif->present)
+			ide_geninit(hwif);
+	}
+
+	return 0;
+}
+
+static void __init parse_options (char *line)
+{
+	char *next = line;
+
+	if (line == NULL || !*line)
+		return;
+	while ((line = next) != NULL) {
+ 		if ((next = strchr(line,' ')) != NULL)
+			*next++ = 0;
+		if (!strncmp(line,"ide",3) ||
+		    !strncmp(line,"idebus",6) ||
+#ifdef CONFIG_BLK_DEV_VIA82CXXX
+		    !strncmp(line,"splitfifo",9) ||
+#endif /* CONFIG_BLK_DEV_VIA82CXXX */
+		    !strncmp(line,"hdxlun",6) ||
+		    (!strncmp(line,"hd",2) && line[2] != '='))
+			(void) ide_setup(line);
+	}
+}
+
+#ifdef MODULE
+char *options = NULL;
+MODULE_PARM(options,"s");
+
+int init_module (void)
+{
+	parse_options(options);
+	return ide_init();
+}
+
+void cleanup_module (void)
+{
+	int index;
+
+	for (index = 0; index < MAX_HWIFS; ++index)
+		ide_unregister(index);
+
+#ifdef CONFIG_PROC_FS
+	proc_ide_destroy();
+#endif
+	devfs_unregister (ide_devfs_handle);
+}
+
+#else /* !MODULE */
+
+static int parse_ide_setup (char *line)
+{
+	parse_options(line);
+	return 0;
+}
+__setup("", parse_ide_setup);
+
+#endif /* MODULE */

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TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)