/*
 *  linux/drivers/ide/ide.c             Version 7.00beta3       Apr 22 2003
 *
 *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
 */

/*
 *  Mostly written by Mark Lord  <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 *  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
 * Version 6.31         Debug Share INTR's and request queue streaming
 *                      Native ATA-100 support
 *                      Prep for Cascades Project
 * Version 7.00alpha    First named revision of ide rearrange
 * Version 7.00beta     (2.4 backport)
 *
 *  Some additional driver compile-time options are in ./include/linux/ide.h
 *
 */

#define REVISION        "Revision: 7.00beta4-2.4"
#define VERSION         "Id: ide.c 7.00b4 20030520"

#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/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/completion.h>
#include <linux/reboot.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"

#include <linux/kmod.h>

/* default maximum number of failures */
#define IDE_DEFAULT_MAX_FAILURES        1

static const u8 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;    /* holds the "idebus=" parameter */
static int system_bus_speed;    /* holds what we think is VESA/PCI bus speed */
static int initializing;        /* set while initializing built-in drivers */

static int ide_scan_direction;  /* THIS was formerly 2.2.x pci=reverse */

#ifdef CONFIG_IDEDMA_AUTO
int noautodma = 0;
#else
int noautodma = 1;
#endif

EXPORT_SYMBOL(noautodma);


/*
 * ide_modules keeps track of the available IDE chipset/probe/driver modules.
 */
ide_module_t *ide_chipsets;
ide_module_t *ide_modules;
ide_module_t *ide_probe;

/*
 * This is declared extern in ide.h, for access by other IDE modules:
 */
ide_hwif_t ide_hwifs[MAX_HWIFS];        /* master data repository */

EXPORT_SYMBOL(ide_hwifs);

ide_devices_t *idedisk;
ide_devices_t *idecd;
ide_devices_t *idefloppy;
ide_devices_t *idetape;
ide_devices_t *idescsi;

EXPORT_SYMBOL(idedisk);
EXPORT_SYMBOL(idecd);
EXPORT_SYMBOL(idefloppy);
EXPORT_SYMBOL(idetape);
EXPORT_SYMBOL(idescsi);

extern ide_driver_t idedefault_driver;
static void setup_driver_defaults (ide_drive_t *drive);

/*
 * 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;
        hwif->bus_state = BUSSTATE_ON;
        hwif->reset_poll= NULL;
        hwif->pre_reset = NULL;

        hwif->atapi_dma = 0;            /* disable all atapi dma */ 
        hwif->ultra_mask = 0x80;        /* disable all ultra */
        hwif->mwdma_mask = 0x80;        /* disable all mwdma */
        hwif->swdma_mask = 0x80;        /* disable all swdma */
        hwif->sata = 0;                 /* assume PATA */

        default_hwif_iops(hwif);
        default_hwif_transport(hwif);
        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;
                drive->max_failures             = IDE_DEFAULT_MAX_FAILURES;
                drive->using_dma                = 0;
                drive->is_flash                 = 0;
                drive->driver                   = &idedefault_driver;
                setup_driver_defaults(drive);
                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.
 *
 * FIXME: We should stuff the setup data into __init and copy the
 * relevant hwifs/allocate them properly during boot.
 */
#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;
}

/*
 * 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) {
                        /* user supplied value */
                        system_bus_speed = idebus_parameter;
                } else if (pci_present()) {
                        /* safe default value for PCI */
                        system_bus_speed = 33;
                } else {
                        /* safe default value for VESA and PCI */
                        system_bus_speed = 50;
                }
                printk(KERN_INFO "ide: Assuming %dMHz system bus speed "
                        "for PIO modes%s\n", system_bus_speed,
                        idebus_parameter ? "" : "; override with idebus=xx");
        }
        return system_bus_speed;
}

/*
 * 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;
        return DRIVER(drive)->capacity(drive);
}

EXPORT_SYMBOL(current_capacity);

static inline u32 read_24 (ide_drive_t *drive)
{
        return  (HWIF(drive)->INB(IDE_HCYL_REG)<<16) |
                (HWIF(drive)->INB(IDE_LCYL_REG)<<8) |
                 HWIF(drive)->INB(IDE_SECTOR_REG);
}

/*
 * Error reporting, in human readable form (luxurious, but a memory hog).
 */
u8 ide_dump_status (ide_drive_t *drive, const char *msg, u8 stat)
{
        ide_hwif_t *hwif = HWIF(drive);
        unsigned long flags;
        u8 err = 0;

        local_irq_set(flags);
        printk(KERN_WARNING "%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 = hwif->INB(IDE_ERROR_REG);
                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("Bad%s ", (err & ABRT_ERR) ? "CRC" : "Sector");
                        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))) {
                                if ((drive->id->command_set_2 & 0x0400) &&
                                    (drive->id->cfs_enable_2 & 0x0400) &&
                                    (drive->addressing == 1)) {
                                        u64 sectors = 0;
                                        u32 high = 0;
                                        u32 low = read_24(drive);
                                        hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
                                        high = read_24(drive);

                                        sectors = ((u64)high << 24) | low;
                                        printk(", LBAsect=%llu, high=%d, low=%d",
                                               (u64) sectors,
                                               high, low);
                                } else {
                                        u8 cur = hwif->INB(IDE_SELECT_REG);
                                        if (cur & 0x40) {       /* using LBA? */
                                                printk(", LBAsect=%ld", (unsigned long)
                                                 ((cur&0xf)<<24)
                                                 |(hwif->INB(IDE_HCYL_REG)<<16)
                                                 |(hwif->INB(IDE_LCYL_REG)<<8)
                                                 | hwif->INB(IDE_SECTOR_REG));
                                        } else {
                                                printk(", CHS=%d/%d/%d",
                                                 (hwif->INB(IDE_HCYL_REG)<<8) +
                                                  hwif->INB(IDE_LCYL_REG),
                                                  cur & 0xf,
                                                  hwif->INB(IDE_SECTOR_REG));
                                        }
                                }
                                if (HWGROUP(drive) && HWGROUP(drive)->rq)
                                        printk(", sector=%ld", HWGROUP(drive)->rq->sector);
                        }
                }
#endif  /* FANCY_STATUS_DUMPS */
                printk("\n");
        }
        local_irq_restore(flags);
        return err;
}

EXPORT_SYMBOL(ide_dump_status);


/*
 * 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;
        unsigned long flags;

        if ((drive = ide_info_ptr(i_rdev, 0)) == 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);
                        invalidate_device(devp, 1);
                }
                drive->part[p].start_sect = 0;
                drive->part[p].nr_sects   = 0;
        };

        if (DRIVER(drive)->revalidate)
                DRIVER(drive)->revalidate(drive);

        drive->busy = 0;
        wake_up(&drive->wqueue);
        MOD_DEC_USE_COUNT;
        return 0;
}

EXPORT_SYMBOL(ide_revalidate_disk);

static void revalidate_drives (int revaldiate)
{
        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) && (revaldiate))
                                        (void) ide_revalidate_disk(MKDEV(hwif->major, unit<<PARTN_BITS));
                        }
                }
        }
}

void ide_probe_module (int revaldiate)
{
        if (!ide_probe) {
#if  defined(CONFIG_BLK_DEV_IDE_MODULE)
                (void) request_module("ide-probe-mod");
#endif
        } else {
                (void) ide_probe->init();
        }
        revalidate_drives(revaldiate);
}

EXPORT_SYMBOL(ide_probe_module);

void ide_driver_module (int revaldiate)
{
        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(revaldiate);
search:
        while (module) {
                (void) module->init();
                module = module->next;
        }
        revalidate_drives(revaldiate);
}

EXPORT_SYMBOL(ide_driver_module);

static int ide_open (struct inode * inode, struct file * filp)
{
        ide_drive_t *drive;
        int force = 1/*FIXME 0*/;
        
        if(capable(CAP_SYS_ADMIN) && (filp->f_flags & O_NDELAY))
                force = 1;

        if ((drive = ide_info_ptr(inode->i_rdev, force)) == NULL)
                return -ENXIO;
        
        /*
         *      If the device is present make sure that we attach any
         *      needed driver
         */     

        if (drive->present)
        {
                if (drive->driver == &idedefault_driver)
                        ide_driver_module(1);
                if (drive->driver == &idedefault_driver) {
                        if (drive->media == ide_disk)
                                (void) request_module("ide-disk");
                        if (drive->scsi)
                                (void) request_module("ide-scsi");
                        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");
                }
        
                /* The locking here isnt enough, but this is hard to fix
                   in the 2.4 cases */
                while (drive->busy)
                        sleep_on(&drive->wqueue);
        }
        
        /*
         *      Now do the actual open
         */
         
        drive->usage++;
        if (!drive->dead || force)
                return DRIVER(drive)->open(inode, filp, drive);
        printk(KERN_WARNING "%s: driver not present\n", drive->name);
        drive->usage--;
        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 = ide_info_ptr(inode->i_rdev, 1)) != NULL) {
                drive->usage--;
                DRIVER(drive)->release(inode, file, drive);
        }
        return 0;
}

#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


#define hwif_release_region(addr, num) \
        ((hwif->mmio) ? release_mem_region((addr),(num)) : release_region((addr),(num)))

/*
 * 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)
{
        u32 i = 0;

        if (hwif->mmio == 2)
                return;
        if (hwif->io_ports[IDE_CONTROL_OFFSET])
                hwif_release_region(hwif->io_ports[IDE_CONTROL_OFFSET], 1);
#if defined(CONFIG_AMIGA) || defined(CONFIG_MAC)
        if (hwif->io_ports[IDE_IRQ_OFFSET])
                hwif_release_region(hwif->io_ports[IDE_IRQ_OFFSET], 1);
#endif /* (CONFIG_AMIGA) || (CONFIG_MAC) */

        if (hwif->straight8) {
                hwif_release_region(hwif->io_ports[IDE_DATA_OFFSET], 8);
                return;
        }
        for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++) {
                if (hwif->io_ports[i]) {
                        hwif_release_region(hwif->io_ports[i], 1);
                }
        }
}

EXPORT_SYMBOL(hwif_unregister);

extern void init_hwif_data(unsigned int index);

/**
 *      ide_prepare_tristate    -       prepare interface for warm unplug
 *      @drive: drive on this hwif we are using
 *
 *      Prepares a drive for shutdown after a bus tristate. The
 *      drives must be quiescent and the only user the calling ioctl
 */
 
static int ide_prepare_tristate(ide_drive_t *our_drive)
{
        ide_drive_t *drive;
        int unit;
        unsigned long flags;
        int minor;
        int p;
        int i;
        ide_hwif_t *hwif = HWIF(our_drive);
                
        if(our_drive->busy)
                printk("HUH? We are busy.\n");
                
        if (!hwif->present)
                BUG();
        spin_lock_irqsave(&io_request_lock, flags);
        
        /* Abort if anything is busy */
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present)
                        continue;
                if (drive == our_drive && drive->usage != 1)
                        goto abort;
                if (drive != our_drive && drive->usage)
                        goto abort;
                if (drive->busy)
                        goto abort;
        }
        /* Commit to shutdown sequence */
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present)
                        continue;
                if (drive != our_drive && DRIVER(drive)->shutdown(drive))
                        goto abort;
        }
        /* We hold the lock here.. which is important as we need to play
           with usage counts beyond the scenes */
           
        our_drive->usage--;
        i = DRIVER(our_drive)->shutdown(our_drive);
        if(i)
                goto abort_fix;
        /* Drive shutdown sequence done */
        /* Prevent new opens ?? */
        spin_unlock_irqrestore(&io_request_lock, flags);
        /*
         * Flush kernel side caches, and dump the /proc files
         */
        spin_unlock_irqrestore(&io_request_lock, flags);
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present)
                        continue;
                DRIVER(drive)->cleanup(drive);
                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);
                                invalidate_device(devp, 0);
                        }
                }
#ifdef CONFIG_PROC_FS
                destroy_proc_ide_drives(hwif);
#endif
        }
        spin_lock_irqsave(&io_request_lock, flags);
        our_drive->usage++;
        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;
                if (drive->id != NULL) {
                        kfree(drive->id);
                        drive->id = NULL;
                }
                drive->present = 0;
                /* Safe to clear now */
                drive->dead = 0;
        }
        spin_unlock_irqrestore(&io_request_lock, flags);
        return 0;

abort_fix:
        our_drive->usage++;
abort:
        spin_unlock_irqrestore(&io_request_lock, flags);
        return -EBUSY;
}


/**
 *      ide_resume_hwif         -       return a hwif to active mode
 *      @hwif: interface to resume
 *      
 *      Restore a dead interface from tristate back to normality. At this
 *      point the hardware driver busproc has reconnected the bus, but
 *      nothing else has happened
 */
 
static int ide_resume_hwif(ide_drive_t *our_drive)
{
        ide_hwif_t *hwif = HWIF(our_drive);
        int err = ide_wait_hwif_ready(hwif);
        int irqd;
        int present = 0;
        int unit;
                
        if(err)
        {
                printk(KERN_ERR "%s: drives not ready.\n", our_drive->name);
                return err;
        }
                
        /* The drives are now taking commands */
        
        irqd = hwif->irq;
        if(irqd)
                disable_irq(irqd);
                
        /* Identify and probe the drives */
        
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];
                drive->dn = ((hwif->channel ? 2 : 0) + unit);
                drive->usage = 0;
                drive->busy = 0;
                hwif->drives[unit].dn = ((hwif->channel ? 2 : 0) + unit);
                (void) ide_probe_for_drive(drive);
                if (drive->present)
                        present = 1;
        }
        ide_probe_reset(hwif);
        if(irqd)
                enable_irq(irqd);
        
        if(present)
                printk(KERN_INFO "ide: drives found on hot-added interface.\n");
                        
        /*
         *      Set up the drive modes (Even if we didnt swap drives
         *      we may have lost settings when we disconnected the bus)
         */
         
        ide_tune_drives(hwif);
        if(present)
                hwif->present = 1;
                
        /*
         *      Reattach the devices to drivers
         */
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];
                if(drive->present && !drive->dead)
                        ide_attach_drive(drive);
        }
        our_drive->usage++;
        return 0;
}

int ide_unregister (unsigned int index)
{
        struct gendisk *gd;
        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)
                BUG();
                
        spin_lock_irqsave(&io_request_lock, flags);
        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 (DRIVER(drive)->shutdown(drive))
                        goto abort;
        }
        hwif->present = 0;
        
        /*
         * All clear?  Then blow away the buffer cache
         */
        spin_unlock_irqrestore(&io_request_lock, flags);
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present)
                        continue;
                DRIVER(drive)->cleanup(drive);
                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);
                                invalidate_device(devp, 0);
                        }
                }
#ifdef CONFIG_PROC_FS
                destroy_proc_ide_drives(hwif);
#endif
        }

        spin_lock_irqsave(&io_request_lock, flags);
        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;
                blk_cleanup_queue(&drive->queue);
        }
        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);

#if !defined(CONFIG_DMA_NONPCI)
        if (hwif->dma_base) {
                (void) ide_release_dma(hwif);

                hwif->dma_base = 0;
                hwif->dma_master = 0;
                hwif->dma_command = 0;
                hwif->dma_vendor1 = 0;
                hwif->dma_status = 0;
                hwif->dma_vendor3 = 0;
                hwif->dma_prdtable = 0;
        }
#endif /* !(CONFIG_DMA_NONPCI) */

        /*
         * 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_dev[hwif->major].data = NULL;
        blk_dev[hwif->major].queue = NULL;
        blksize_size[hwif->major] = NULL;
        gd = hwif->gd;
        if (gd) {
                del_gendisk(gd);
                kfree(gd->sizes);
                kfree(gd->part);
                if (gd->de_arr)
                        kfree(gd->de_arr);
                if (gd->flags)
                        kfree(gd->flags);
                kfree(gd);
                hwif->gd = NULL;
        }

        old_hwif                        = *hwif;
        init_hwif_data(index);  /* restore hwif data to pristine status */
        hwif->hwgroup                   = old_hwif.hwgroup;

        hwif->proc                      = old_hwif.proc;

        hwif->major                     = old_hwif.major;
//      hwif->index                     = old_hwif.index;
//      hwif->channel                   = old_hwif.channel;
        hwif->straight8                 = old_hwif.straight8;
        hwif->bus_state                 = old_hwif.bus_state;

        hwif->atapi_dma                 = old_hwif.atapi_dma;
        hwif->ultra_mask                = old_hwif.ultra_mask;
        hwif->mwdma_mask                = old_hwif.mwdma_mask;
        hwif->swdma_mask                = old_hwif.swdma_mask;

        hwif->chipset                   = old_hwif.chipset;
        hwif->hold                      = old_hwif.hold;

#ifdef CONFIG_BLK_DEV_IDEPCI
        hwif->pci_dev                   = old_hwif.pci_dev;
        hwif->cds                       = old_hwif.cds;
#endif /* CONFIG_BLK_DEV_IDEPCI */

#if 0

        hwif->hwifops                   = old_hwif.hwifops;
#else
        hwif->identify                  = old_hwif.identify;
        hwif->tuneproc                  = old_hwif.tuneproc;
        hwif->speedproc                 = old_hwif.speedproc;
        hwif->selectproc                = old_hwif.selectproc;
        hwif->reset_poll                = old_hwif.reset_poll;
        hwif->pre_reset                 = old_hwif.pre_reset;
        hwif->resetproc                 = old_hwif.resetproc;
        hwif->intrproc                  = old_hwif.intrproc;
        hwif->maskproc                  = old_hwif.maskproc;
        hwif->quirkproc                 = old_hwif.quirkproc;
        hwif->busproc                   = old_hwif.busproc;
#endif

#if 0
        hwif->pioops                    = old_hwif.pioops;
#else
        hwif->ata_input_data            = old_hwif.ata_input_data;
        hwif->ata_output_data           = old_hwif.ata_output_data;
        hwif->atapi_input_bytes         = old_hwif.atapi_input_bytes;
        hwif->atapi_output_bytes        = old_hwif.atapi_output_bytes;
#endif

#if 0
        hwif->dmaops                    = old_hwif.dmaops;
#else
        hwif->ide_dma_read              = old_hwif.ide_dma_read;
        hwif->ide_dma_write             = old_hwif.ide_dma_write;
        hwif->ide_dma_begin             = old_hwif.ide_dma_begin;
        hwif->ide_dma_end               = old_hwif.ide_dma_end;
        hwif->ide_dma_check             = old_hwif.ide_dma_check;
        hwif->ide_dma_on                = old_hwif.ide_dma_on;
        hwif->ide_dma_off               = old_hwif.ide_dma_off;
        hwif->ide_dma_off_quietly       = old_hwif.ide_dma_off_quietly;
        hwif->ide_dma_test_irq          = old_hwif.ide_dma_test_irq;
        hwif->ide_dma_host_on           = old_hwif.ide_dma_host_on;
        hwif->ide_dma_host_off          = old_hwif.ide_dma_host_off;
        hwif->ide_dma_bad_drive         = old_hwif.ide_dma_bad_drive;
        hwif->ide_dma_good_drive        = old_hwif.ide_dma_good_drive;
        hwif->ide_dma_count             = old_hwif.ide_dma_count;
        hwif->ide_dma_verbose           = old_hwif.ide_dma_verbose;
        hwif->ide_dma_retune            = old_hwif.ide_dma_retune;
        hwif->ide_dma_lostirq           = old_hwif.ide_dma_lostirq;
        hwif->ide_dma_timeout           = old_hwif.ide_dma_timeout;
#endif

#if 0
        hwif->iops                      = old_hwif.iops;
#else
        hwif->OUTB              = old_hwif.OUTB;
        hwif->OUTBSYNC          = old_hwif.OUTBSYNC;
        hwif->OUTW              = old_hwif.OUTW;
        hwif->OUTL              = old_hwif.OUTL;
        hwif->OUTSW             = old_hwif.OUTSW;
        hwif->OUTSL             = old_hwif.OUTSL;

        hwif->INB               = old_hwif.INB;
        hwif->INW               = old_hwif.INW;
        hwif->INL               = old_hwif.INL;
        hwif->INSW              = old_hwif.INSW;
        hwif->INSL              = old_hwif.INSL;
#endif

        hwif->mmio                      = old_hwif.mmio;
        hwif->rqsize                    = old_hwif.rqsize;
        hwif->addressing                = old_hwif.addressing;
#ifndef CONFIG_BLK_DEV_IDECS
        hwif->irq                       = old_hwif.irq;
#endif /* CONFIG_BLK_DEV_IDECS */
        hwif->initializing              = old_hwif.initializing;

        hwif->dma_base                  = old_hwif.dma_base;
        hwif->dma_master                = old_hwif.dma_master;
        hwif->dma_command               = old_hwif.dma_command;
        hwif->dma_vendor1               = old_hwif.dma_vendor1;
        hwif->dma_status                = old_hwif.dma_status;
        hwif->dma_vendor3               = old_hwif.dma_vendor3;
        hwif->dma_prdtable              = old_hwif.dma_prdtable;

        hwif->dma_extra                 = old_hwif.dma_extra;
        hwif->config_data               = old_hwif.config_data;
        hwif->select_data               = old_hwif.select_data;
        hwif->autodma                   = old_hwif.autodma;
        hwif->udma_four                 = old_hwif.udma_four;
        hwif->no_dsc                    = old_hwif.no_dsc;

        hwif->hwif_data                 = old_hwif.hwif_data;
        spin_unlock_irqrestore(&io_request_lock, flags);
        return 0;

abort:
        spin_unlock_irqrestore(&io_request_lock, flags);
        return 1;
        
}

EXPORT_SYMBOL(ide_unregister);

/*
 * 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,
/*
 *                      ide_io_ops_t *iops,
 */
                        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;
#if defined(CONFIG_AMIGA) || defined(CONFIG_MAC)
                                case IDE_IRQ_OFFSET:
                                        hw->io_ports[i] = intr;
                                        break;
#endif /* (CONFIG_AMIGA) || (CONFIG_MAC) */
                                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;
/*
 *      hw->iops = iops;
 */
}

EXPORT_SYMBOL(ide_setup_ports);

/*
 * 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->hold && ((!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);
        else if (!hwif->hold)
                init_hwif_data(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;
        hwif->chipset = hw->chipset;

        if (!initializing) {
                ide_probe_module(1);
#ifdef CONFIG_PROC_FS
                create_proc_ide_interfaces();
#endif
                ide_driver_module(1);
        }

        if (hwifp)
                *hwifp = hwif;

        return (initializing || hwif->present) ? index : -1;
}

EXPORT_SYMBOL(ide_register_hw);

/*
 * 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);
}

EXPORT_SYMBOL(ide_register);


/*
 *      Locks for IDE setting functionality
 */

DECLARE_MUTEX(ide_setting_sem);
EXPORT_SYMBOL(ide_setting_sem);

/**
 *      ide_add_setting -       add an ide setting option
 *      @drive: drive to use
 *      @name: setting name
 *      @rw: true if the function is read write
 *      @read_ioctl: function to call on read
 *      @write_ioctl: function to call on write
 *      @data_type: type of data
 *      @min: range minimum
 *      @max: range maximum
 *      @mul_factor: multiplication scale
 *      @div_factor: divison scale
 *      @data: private data field
 *      @set: setting
 *
 *      Removes the setting named from the device if it is present.
 *      The function takes the settings_lock to protect against 
 *      parallel changes. This function must not be called from IRQ
 *      context. Returns 0 on success or -1 on failure.
 *
 *      BUGS: This code is seriously over-engineered. There is also
 *      magic about how the driver specific features are setup. If
 *      a driver is attached we assume the driver settings are auto
 *      remove.
 */
 
int 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;

        down(&ide_setting_sem);
        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 != &idedefault_driver)
                setting->auto_remove = 1;
        *p = setting;
        up(&ide_setting_sem);
        return 0;
abort:
        up(&ide_setting_sem);
        if (setting)
                kfree(setting);
        return -1;
}

EXPORT_SYMBOL(ide_add_setting);

/**
 *      __ide_remove_setting    -       remove an ide setting option
 *      @drive: drive to use
 *      @name: setting name
 *
 *      Removes the setting named from the device if it is present.
 *      The caller must hold the setting semaphore.
 */
 
static void __ide_remove_setting (ide_drive_t *drive, char *name)
{
        ide_settings_t **p, *setting;

        p = (ide_settings_t **) &drive->settings;

        while ((*p) && strcmp((*p)->name, name))
                p = &((*p)->next);
        if ((setting = (*p)) == NULL)
                return;

        (*p) = setting->next;
        
        kfree(setting->name);
        kfree(setting);
}

/**
 *      ide_remove_setting      -       remove an ide setting option
 *      @drive: drive to use
 *      @name: setting name
 *
 *      Removes the setting named from the device if it is present.
 *      The function takes the settings_lock to protect against 
 *      parallel changes. This function must not be called from IRQ
 *      context.
 */
 
void ide_remove_setting (ide_drive_t *drive, char *name)
{
        down(&ide_setting_sem);
        __ide_remove_setting(drive, name);
        up(&ide_setting_sem);
}

EXPORT_SYMBOL(ide_remove_setting);

/**
 *      ide_find_setting_by_ioctl       -       find a drive specific ioctl
 *      @drive: drive to scan
 *      @cmd: ioctl command to handle
 *
 *      Scan's the device setting table for a matching entry and returns
 *      this or NULL if no entry is found. The caller must hold the
 *      setting semaphore
 */
 
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_find_setting_by_name        -       find a drive specific setting
 *      @drive: drive to scan
 *      @name: setting name
 *
 *      Scan's the device setting table for a matching entry and returns
 *      this or NULL if no entry is found. The caller must hold the
 *      setting semaphore
 */
 
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;
}

/**
 *      auto_remove_settings    -       remove driver specific settings
 *      @drive: drive
 *
 *      Automatically remove all the driver specific settings for this
 *      drive. This function may sleep and must not be called from IRQ
 *      context. Caller must hold the setting lock.
 */
 
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;
        }
}

/**
 *      ide_read_setting        -       read an IDE setting
 *      @drive: drive to read from
 *      @setting: drive setting
 *
 *      Read a drive setting and return the value. The caller
 *      must hold the ide_setting_sem when making this call.
 *
 *      BUGS: the data return and error are the same return value
 *      so an error -EINVAL and true return of the same value cannot
 *      be told apart
 */
 
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)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        unsigned long timeout = jiffies + (3 * HZ);

        spin_lock_irq(&io_request_lock);

        while (hwgroup->busy) {
                unsigned long lflags;
                spin_unlock_irq(&io_request_lock);
                local_irq_set(lflags);
                if (time_after(jiffies, timeout)) {
                        local_irq_restore(lflags);
                        printk(KERN_ERR "%s: channel busy\n", drive->name);
                        return -EBUSY;
                }
                local_irq_restore(lflags);
                spin_lock_irq(&io_request_lock);
        }
        return 0;
}

EXPORT_SYMBOL(ide_spin_wait_hwgroup);

/**
 *      ide_write_setting       -       read an IDE setting
 *      @drive: drive to read from
 *      @setting: drive setting
 *      @val: value
 *
 *      Write a drive setting if it is possible. The caller
 *      must hold the ide_setting_sem when making this call.
 *
 *      BUGS: the data return and error are the same return value
 *      so an error -EINVAL and true return of the same value cannot
 *      be told apart
 *
 *      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 kludgy, though safe enough.
 */
int ide_write_setting (ide_drive_t *drive, ide_settings_t *setting, int val)
{
        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))
                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_irq(&io_request_lock);
        return 0;
}

EXPORT_SYMBOL(ide_write_setting);

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 (!DRIVER(drive)->supports_dma)
                return -EPERM;
        if (!(drive->id->capability & 1))
                return -EPERM;
        if (HWIF(drive)->ide_dma_check == NULL)
                return -EPERM;
        if (HWIF(drive)->ide_dma_check(drive) != 0)
                return -EIO;
        if (arg) {
                if (HWIF(drive)->ide_dma_check(drive) != 0)
                        return -EIO;
                if (HWIF(drive)->ide_dma_on(drive)) return -EIO;
        } else {
                if (HWIF(drive)->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 = (u8) arg;
        drive->special.b.set_tune = 1;
        (void) ide_do_drive_cmd(drive, &rq, ide_wait);
        return 0;
}

static int set_xfer_rate (ide_drive_t *drive, int arg)
{
        int err = ide_wait_cmd(drive,
                        WIN_SETFEATURES, (u8) arg,
                        SETFEATURES_XFER, 0, NULL);

        if (!err && arg) {
                ide_set_xfer_rate(drive, (u8) arg);
                ide_driveid_update(drive);
        }
        return err;
}

int ide_atapi_to_scsi (ide_drive_t *drive, int arg)
{
        if (drive->media == ide_disk) {
                drive->scsi = 0;
                return 0;
        }
        if (DRIVER(drive)->cleanup(drive)) {
                drive->scsi = 0;
                return 0;
        }
        drive->scsi = (u8) arg;
        ide_attach_drive(drive);
        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,  "init_speed",           SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      70,                             1,              1,              &drive->init_speed,             NULL);
        ide_add_setting(drive,  "current_speed",        SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      70,                             1,              1,              &drive->current_speed,          set_xfer_rate);
        ide_add_setting(drive,  "number",               SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      3,                              1,              1,              &drive->dn,                     NULL);
#if 0
        /* Experimental, but this needs the setting/register locking rewritten to be used */    
        if (drive->media != ide_disk)
                ide_add_setting(drive,  "ide-scsi",             SETTING_RW,                                     -1,             HDIO_SET_IDE_SCSI,              TYPE_BYTE,      0,      1,                              1,              1,              &drive->scsi,                   ide_atapi_to_scsi);
#endif          
}

EXPORT_SYMBOL_GPL(ide_add_generic_settings);

/*
 * 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)
{
#ifndef CONFIG_BLK_DEV_IDECS
        mdelay(50);
#else
        __set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout(1+HZ/20);
#endif /* CONFIG_BLK_DEV_IDECS */
}

EXPORT_SYMBOL(ide_delay_50ms);

int system_bus_clock (void)
{
        return((int) ((!system_bus_speed) ? ide_system_bus_speed() : system_bus_speed ));
}

EXPORT_SYMBOL(system_bus_clock);

int ide_replace_subdriver (ide_drive_t *drive, const char *driver)
{
        if (!drive->present || drive->busy || drive->usage || drive->dead)
                goto abort;
        if (DRIVER(drive)->cleanup(drive))
                goto abort;
        strncpy(drive->driver_req, driver, 9);
        ide_driver_module(0);
        drive->driver_req[0] = 0;
        ide_driver_module(0);
        if (!strcmp(DRIVER(drive)->name, driver))
                return 0;
abort:
        return 1;
}

EXPORT_SYMBOL(ide_replace_subdriver);

int ide_attach_drive (ide_drive_t *drive)
{
        /* Someone unplugged the device on us */
        if(drive->dead)
                return 1;
                
#ifdef CONFIG_BLK_DEV_IDESCSI
        if (drive->scsi) {
                extern int idescsi_attach(ide_drive_t *drive);
                if (idescsi_attach(drive))
                        return 0;
        }
#endif /* CONFIG_BLK_DEV_IDESCSI */

        switch (drive->media) {
#ifdef CONFIG_BLK_DEV_IDECD
                case ide_cdrom:
                {
                        extern int ide_cdrom_attach(ide_drive_t *drive);
                        if (ide_cdrom_attach(drive))
                                return 1;
                        break;
                }
#endif /* CONFIG_BLK_DEV_IDECD */
#ifdef CONFIG_BLK_DEV_IDEDISK
                case ide_disk:
                {
                        extern int idedisk_attach(ide_drive_t *drive);
                        if (idedisk_attach(drive))
                                return 1;
                        break;
                }
#endif /* CONFIG_BLK_DEV_IDEDISK */
#ifdef CONFIG_BLK_DEV_IDEFLOPPY
                case ide_floppy:
                {
                        extern int idefloppy_attach(ide_drive_t *drive);
                        if (idefloppy_attach(drive))
                                return 1;
                        break;
                }
#endif /* CONFIG_BLK_DEV_IDEFLOPPY */
#ifdef CONFIG_BLK_DEV_IDETAPE
                case ide_tape:
                {
                        extern int idetape_attach(ide_drive_t *drive);
                        if (idetape_attach(drive))
                                return 1;
                        break;
                }
#endif /* CONFIG_BLK_DEV_IDETAPE */
                default:
                {
                        extern int idedefault_attach(ide_drive_t *drive);
                        if(idedefault_attach(drive))
                                printk(KERN_CRIT "ide: failed to attach default driver.\n");
                        return 1;
                }
        }
        return 0;
}

EXPORT_SYMBOL(ide_attach_drive);

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;
        int force = 0;
        
        if (!inode || !(dev = inode->i_rdev))
                return -EINVAL;
                
        switch(cmd)
        {
                case HDIO_GET_BUSSTATE:
                case HDIO_SET_BUSSTATE:
                case HDIO_SCAN_HWIF:
                case HDIO_UNREGISTER_HWIF:
                        force = 1;
        }
        
        major = MAJOR(dev); minor = MINOR(dev);
        if ((drive = ide_info_ptr(inode->i_rdev, force)) == NULL)
                return -ENODEV;

        down(&ide_setting_sem);
        if ((setting = ide_find_setting_by_ioctl(drive, cmd)) != NULL) {
                if (cmd == setting->read_ioctl) {
                        err = ide_read_setting(drive, setting);
                        up(&ide_setting_sem);
                        return err >= 0 ? put_user(err, (long *) arg) : err;
                } else {
                        if ((MINOR(inode->i_rdev) & PARTN_MASK))
                                err = -EINVAL;
                        else 
                                err = ide_write_setting(drive, setting, arg);
                        up(&ide_setting_sem);
                        return err;
                }
        }
        up(&ide_setting_sem);

        ide_init_drive_cmd (&rq);
        switch (cmd) {
                case HDIO_GETGEO:
                {
                        struct hd_geometry *loc = (struct hd_geometry *) arg;
                        u16 bios_cyl = drive->bios_cyl; /* truncate */
                        if (!loc || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
                        if (put_user(drive->bios_head, (u8 *) &loc->heads)) return -EFAULT;
                        if (put_user(drive->bios_sect, (u8 *) &loc->sectors)) return -EFAULT;
                        if (put_user(bios_cyl, (u16 *) &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 HDIO_GETGEO_BIG:
                {
                        struct hd_big_geometry *loc = (struct hd_big_geometry *) arg;
                        if (!loc || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
                        if (put_user(drive->bios_head, (u8 *) &loc->heads)) return -EFAULT;
                        if (put_user(drive->bios_sect, (u8 *) &loc->sectors)) return -EFAULT;
                        if (put_user(drive->bios_cyl, (unsigned int *) &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 HDIO_GETGEO_BIG_RAW:
                {
                        struct hd_big_geometry *loc = (struct hd_big_geometry *) arg;
                        if (!loc || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
                        if (put_user(drive->head, (u8 *) &loc->heads)) return -EFAULT;
                        if (put_user(drive->sect, (u8 *) &loc->sectors)) return -EFAULT;
                        if (put_user(drive->cyl, (unsigned int *) &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, (unsigned long *) arg);
                case BLKGETSIZE64:
                        return put_user((u64)drive->part[MINOR(inode->i_rdev)&PARTN_MASK].nr_sects << 9, (u64 *) 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_read == 0)
                                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);

#ifdef CONFIG_IDE_TASK_IOCTL
                case HDIO_DRIVE_TASKFILE:
                        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
                                return -EACCES;
                        switch(drive->media) {
                                case ide_disk:
                                        return ide_taskfile_ioctl(drive, inode, file, cmd, arg);
#ifdef CONFIG_PKT_TASK_IOCTL
                                case ide_cdrom:
                                case ide_tape:
                                case ide_floppy:
                                        return pkt_taskfile_ioctl(drive, inode, file, cmd, arg);
#endif /* CONFIG_PKT_TASK_IOCTL */
                                default:
                                        return -ENOMSG;
                        }
#endif /* CONFIG_IDE_TASK_IOCTL */

                case HDIO_DRIVE_CMD:
                        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
                                return -EACCES;
                        return ide_cmd_ioctl(drive, inode, file, cmd, arg);

                case HDIO_DRIVE_TASK:
                        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
                                return -EACCES;
                        return ide_task_ioctl(drive, inode, file, cmd, arg);

                case HDIO_SCAN_HWIF:
                {
                        int args[3];
                        if (!capable(CAP_SYS_RAWIO)) 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_RAWIO)) return -EACCES;
                        /* (arg > MAX_HWIFS) checked in function */
                        ide_unregister(arg);
                        return 0;
                case HDIO_SET_NICE:
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        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 HDIO_DRIVE_RESET:
                {
                        unsigned long flags;
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        
                        /*
                         *      Abort the current command on the
                         *      group if there is one, taking
                         *      care not to allow anything else
                         *      to be queued and to die on the
                         *      spot if we miss one somehow
                         */

                        spin_lock_irqsave(&io_request_lock, flags);
                        
                        DRIVER(drive)->abort(drive, "drive reset");
                        if(HWGROUP(drive)->handler)
                                BUG();
                                
                        /* Ensure nothing gets queued after we
                           drop the lock. Reset will clear the busy */
                           
                        HWGROUP(drive)->busy = 1;
                        spin_unlock_irqrestore(&io_request_lock, flags);

                        (void) ide_do_reset(drive);
                        if (drive->suspend_reset) {
/*
 *                              APM WAKE UP todo !!
 *                              int nogoodpower = 1;
 *                              while(nogoodpower) {
 *                                      check_power1() or check_power2()
 *                                      nogoodpower = 0;
 *                              } 
 *                              HWIF(drive)->multiproc(drive);
 */
                                return ide_revalidate_disk(inode->i_rdev);
                        }
                        return 0;
                }
                case BLKROSET:
                case BLKROGET:
                case BLKFLSBUF:
                case BLKSSZGET:
                case BLKPG:
                case BLKELVGET:
                case BLKELVSET:
                case BLKBSZGET:
                case BLKBSZSET:
                        return blk_ioctl(inode->i_rdev, cmd, arg);

                case HDIO_GET_BUSSTATE:
                        if (!capable(CAP_SYS_ADMIN))
                                return -EACCES;
                        if (put_user(HWIF(drive)->bus_state, (long *)arg))
                                return -EFAULT;
                        return 0;

                case HDIO_SET_BUSSTATE:
                {
                        ide_hwif_t *hwif =  HWIF(drive);
                        
                        if (!capable(CAP_SYS_ADMIN))
                                return -EACCES;
#ifdef OLD_STUFF
                        if (hwif->busproc)
                                return HWIF(drive)->busproc(drive, (int)arg);
                        return -EOPNOTSUPP;
#else
                        if(hwif->bus_state == arg)
                                return 0;
                                
                        if(hwif->bus_state == BUSSTATE_ON)
                        {
                                /* "drive" may vanish beyond here */
                                if((err = ide_prepare_tristate(drive)) != 0)
                                        return err;
                                hwif->bus_state = arg;
                        }
                        if (hwif->busproc)
                        {
                                err = hwif->busproc(drive, (int)arg);
                                if(err)
                                        return err;
                        }
                        if(arg != BUSSTATE_OFF)
                        {
                                err = ide_resume_hwif(drive);
                                hwif->bus_state = arg;
                                if(err)
                                        return err;
                        }
                        return 0;
#endif                  
                }                               

                default:
                        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 = ide_info_ptr(i_rdev, 0)) == NULL)
                return -ENODEV;
        return DRIVER(drive)->media_change(drive);
}

/*
 * 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.
 *
 * 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=qd65xx"        : probe/support qd65xx 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);

        
        if (strncmp(s,"hd",2) == 0 && s[2] == '=')      /* hd= is for hd.c   */
                return 0;                               /* driver and not us */

        if (strncmp(s,"ide",3) &&
            strncmp(s,"idebus",6) &&
            strncmp(s,"hd",2))          /* hdx= & hdxlun= */
                return 0;

        printk(KERN_INFO "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 1;
        }
#endif /* CONFIG_BLK_DEV_IDEDOUBLER */

        if (!strcmp(s, "ide=nodma")) {
                printk(" : Prevented DMA\n");
                noautodma = 1;
                return 1;
        }

#ifdef CONFIG_BLK_DEV_IDEPCI
        if (!strcmp(s, "ide=reverse")) {
                ide_scan_direction = 1;
                printk(" : Enabled support for IDE inverse scan order.\n");
                return 1;
        }
#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" */
                                drive->scsi = 1;
                                goto done;
                        case 3: /* cyl,head,sect */
                                drive->media    = ide_disk;
                                drive->cyl      = drive->bios_cyl  = vals[0];
                                drive->head     = drive->bios_head = vals[1];
                                drive->sect     = drive->bios_sect = vals[2];
                                drive->present  = 1;
                                drive->forced_geom = 1;
                                hwif->noprobe = 0;
                                goto done;
                        default:
                                goto bad_option;
                }
        }

        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", "qd65xx", "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 void init_cmd640_vlb (void);
                                init_cmd640_vlb();
                                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_QD65XX
                        case -12: /* "qd65xx" */
                        {
                                extern void init_qd65xx (void);
                                init_qd65xx();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_QD65XX */
#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 1;
                }
        }
bad_option:
        printk(" -- BAD OPTION\n");
        return 1;
bad_hwif:
        printk("-- NOT SUPPORTED ON ide%d", hw);
done:
        printk("\n");
        return 1;
}

/*
 *      Legacy interface registration
 */
#define NUM_DRIVER              32

/*
 *      Yes this is moronically simple, but why not - it works!
 */

static __initdata ide_driver_call ide_scan[NUM_DRIVER];
static int drivers_run = 0;

void __init ide_register_driver(ide_driver_call scan)
{
        static int ide_scans = 0;
        if(ide_scans == NUM_DRIVER)
                panic("Too many IDE drivers");
        ide_scan[ide_scans++]=scan;
        if(drivers_run)
        {
                printk(KERN_ERR "ide: late registration of driver.\n");
                scan();
        }
}

EXPORT_SYMBOL(ide_register_driver);

static void __init ide_scan_drivers(void)
{
        int i = 0;
        while(ide_scan[i])
        {
                (ide_scan[i])();
                i++;
        }
        drivers_run = 1;
}

/*
 * probe_for_hwifs() finds/initializes "known" IDE interfaces
 */
static void __init probe_for_hwifs (void)
{
#ifdef CONFIG_BLK_DEV_IDEPCI
        if (pci_present())
        {
                ide_scan_pcibus(ide_scan_direction);
        }
#endif /* CONFIG_BLK_DEV_IDEPCI */
        ide_scan_drivers();

        /*
         *      Unconverted drivers
         */     
#ifdef CONFIG_ETRAX_IDE
        {
                extern void init_e100_ide(void);
                init_e100_ide();
        }
#endif /* CONFIG_ETRAX_IDE */
#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_SIBYTE
        {
                extern void sibyte_ide_probe(void);
                sibyte_ide_probe();
        }
#endif /* CONFIG_BLK_DEV_IDE_SIBYTE */
#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_CPCI405_IDE
        {
                extern void cpci405ide_init(void);
                cpci405ide_init();
        }
#endif /* CONFIG_BLK_DEV_CPCI405_IDE */
#ifdef CONFIG_BLK_DEV_Q40IDE
        {
                extern void q40ide_init(void);
                q40ide_init();
        }
#endif /* CONFIG_BLK_DEV_Q40IDE */
#ifdef CONFIG_BLK_DEV_BUDDHA
        {
                extern void buddha_init(void);
                buddha_init();
        }
#endif /* CONFIG_BLK_DEV_BUDDHA */
}

void __init ide_init_builtin_subdrivers (void)
{
        idedefault_init();
#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 */
}

#ifndef CLASSIC_BUILTINS_METHOD
#  ifndef DIRECT_HWIF_PROBE_ATTACH_METHOD
#    ifdef FAKE_CLASSIC_ATTACH_METHOD
/*
 * Attempt to match drivers for the available drives
 */
void ide_attach_devices (void)
{
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        int i, unit;

        for (i = 0; i < MAX_HWIFS; i++) {
                hwif = &ide_hwifs[i];
                if (!hwif->present)
                        continue;
                for (unit = 0; unit < MAX_DRIVES; ++unit) {
                        drive = &hwif->drives[unit];
                        if (drive->present && !drive->dead)
                                ide_attach_drive(drive);
                }
        }
}
#    endif /* FAKE_CLASSIC_ATTACH_METHOD */
#  endif /* DIRECT_HWIF_PROBE_ATTACH_METHOD */
#endif /* CLASSIC_BUILTINS_METHOD */

void __init ide_init_builtin_drivers (void)
{
        /*
         * Attach null driver
         */
        idedefault_init();
        /*
         * Probe for special PCI and other "known" interface chipsets
         */
        probe_for_hwifs ();

#ifdef CONFIG_BLK_DEV_IDE
        if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET])
                ide_get_lock(NULL, NULL); /* for atari only */

        (void) ideprobe_init();

        if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET])
                ide_release_lock();     /* for atari only */
#endif /* CONFIG_BLK_DEV_IDE */

#ifdef CONFIG_PROC_FS
        proc_ide_create();
#endif

#ifdef CLASSIC_BUILTINS_METHOD
        ide_init_builtin_subdrivers();
#else /* ! CLASSIC_BUILTINS_METHOD */
#  ifndef DIRECT_HWIF_PROBE_ATTACH_METHOD
#    ifdef FAKE_CLASSIC_ATTACH_METHOD
        ide_attach_devices();
#    endif /* FAKE_CLASSIC_ATTACH_METHOD */
#  endif /* DIRECT_HWIF_PROBE_ATTACH_METHOD */
#endif /* CLASSIC_BUILTINS_METHOD */
}

/*
 *      Actually unregister the subdriver. Called with the
 *      request lock dropped.
 */
 
static int default_cleanup (ide_drive_t *drive)
{
        return ide_unregister_subdriver(drive);
}

/*
 *      Check if we can unregister the subdriver. Called with the
 *      request lock held.
 */
 
static int default_shutdown(ide_drive_t *drive)
{
        if (drive->usage || drive->busy || DRIVER(drive)->busy) {
                return 1;
        }
        drive->dead = 1;
        return 0;
}

static int default_standby (ide_drive_t *drive)
{
        return 0;
}

static int default_suspend (ide_drive_t *drive)
{
        return 0;
}

static int default_resume (ide_drive_t *drive)
{
        return 0;
}

static int default_flushcache (ide_drive_t *drive)
{
        return 0;
}

static ide_startstop_t default_do_request (ide_drive_t *drive, struct request *rq, unsigned long block)
{
        ide_end_request(drive, 0);
        return ide_stopped;
}

static int default_end_request (ide_drive_t *drive, int uptodate)
{
        return ide_end_request(drive, uptodate);
}

static u8 default_sense (ide_drive_t *drive, const char *msg, u8 stat)
{
        return ide_dump_status(drive, msg, stat);
}

static ide_startstop_t default_error (ide_drive_t *drive, const char *msg, u8 stat)
{
        return ide_error(drive, msg, stat);
}

static ide_startstop_t default_abort (ide_drive_t *drive, const char *msg)
{
        return ide_abort(drive, msg);
}

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;
}

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 int default_init (void)
{
        return 0;
}

static int default_attach (ide_drive_t *drive)
{
        printk(KERN_ERR "%s: does not support hotswap of device class !\n",
                drive->name);

        return 0;
}

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->shutdown == NULL)        d->shutdown = default_shutdown;
        if (d->standby == NULL)         d->standby = default_standby;
        if (d->suspend == NULL)         d->suspend = default_suspend;
        if (d->resume == NULL)          d->resume = default_resume;
        if (d->flushcache == NULL)      d->flushcache = default_flushcache;
        if (d->do_request == NULL)      d->do_request = default_do_request;
        if (d->end_request == NULL)     d->end_request = default_end_request;
        if (d->sense == NULL)           d->sense = default_sense;
        if (d->error == NULL)           d->error = default_error;
        if (d->error == NULL)           d->abort = default_abort;
        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;
        if (d->init == NULL)            d->init = default_init;
        if (d->attach == NULL)          d->attach = default_attach;
}

ide_drive_t *ide_scan_devices (u8 media, const char *name, ide_driver_t *driver, int n)
{
        unsigned int unit, index, i;
        
        if(driver == NULL)      /* No driver is actually &idedefault_driver */
                driver = &idedefault_driver;

        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;
}

EXPORT_SYMBOL(ide_scan_devices);

int ide_register_subdriver (ide_drive_t *drive, ide_driver_t *driver, int version)
{
        unsigned long flags;
        
        BUG_ON(drive->driver == NULL);
        
        spin_lock_irqsave(&io_request_lock, flags);
        if (version != IDE_SUBDRIVER_VERSION || !drive->present ||
            drive->driver != &idedefault_driver || drive->busy || drive->usage) {
                spin_unlock_irqrestore(&io_request_lock, flags);
                return 1;
        }
        drive->driver = driver;
        setup_driver_defaults(drive);
        printk("%s: attached %s driver.\n", drive->name, driver->name);
        spin_unlock_irqrestore(&io_request_lock, flags);
        if (drive->autotune != 2) {
                /* DMA timings and setup moved to ide-probe.c */
                if (!driver->supports_dma && HWIF(drive)->ide_dma_off_quietly)
//                      HWIF(drive)->ide_dma_off_quietly(drive);
                        HWIF(drive)->ide_dma_off(drive);
                drive->dsc_overlap = (drive->next != drive && driver->supports_dsc_overlap);
                drive->nice1 = 1;
        }
        drive->revalidate = 1;
        drive->suspend_reset = 0;
#ifdef CONFIG_PROC_FS
        if (drive->driver != &idedefault_driver) {
                ide_add_proc_entries(drive->proc, generic_subdriver_entries, drive);
                ide_add_proc_entries(drive->proc, driver->proc, drive);
        }
#endif
        return 0;
}

EXPORT_SYMBOL(ide_register_subdriver);

int ide_unregister_subdriver (ide_drive_t *drive)
{
        unsigned long flags;

        down(&ide_setting_sem); 
        spin_lock_irqsave(&io_request_lock, flags);
        if (drive->usage || drive->busy || DRIVER(drive)->busy) {
                spin_unlock_irqrestore(&io_request_lock, flags);
                up(&ide_setting_sem);
                return 1;
        }
#ifdef CONFIG_PROC_FS
        ide_remove_proc_entries(drive->proc, DRIVER(drive)->proc);
        ide_remove_proc_entries(drive->proc, generic_subdriver_entries);
#endif
        drive->driver = &idedefault_driver;
        setup_driver_defaults(drive);
        auto_remove_settings(drive);
        spin_unlock_irqrestore(&io_request_lock, flags);
        up(&ide_setting_sem);
        return 0;
}

EXPORT_SYMBOL(ide_unregister_subdriver);

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(1);
        return 0;
}

EXPORT_SYMBOL(ide_register_module);

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;
}

EXPORT_SYMBOL(ide_unregister_module);

struct block_device_operations ide_fops[] = {{
        owner:                  THIS_MODULE,
        open:                   ide_open,
        release:                ide_release,
        ioctl:                  ide_ioctl,
        check_media_change:     ide_check_media_change,
        revalidate:             ide_revalidate_disk
}};

EXPORT_SYMBOL(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));
        }
}

EXPORT_SYMBOL(ide_geninit);


/*
 * Probe module
 */
devfs_handle_t ide_devfs_handle;

EXPORT_SYMBOL(ide_probe);
EXPORT_SYMBOL(ide_devfs_handle);

static int ide_notify_reboot (struct notifier_block *this, unsigned long event, void *x)
{
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        int i, unit;

        switch (event) {
                case SYS_HALT:
                case SYS_POWER_OFF:
                case SYS_RESTART:
                        break;
                default:
                        return NOTIFY_DONE;
        }

        printk(KERN_INFO "flushing ide devices: ");

        for (i = 0; i < MAX_HWIFS; i++) {
                hwif = &ide_hwifs[i];
                if (!hwif->present)
                        continue;
                for (unit = 0; unit < MAX_DRIVES; ++unit) {
                        drive = &hwif->drives[unit];
                        if (!drive->present)
                                continue;

                        /* set the drive to standby */
                        printk("%s ", drive->name);
#ifdef  CONFIG_ALPHA
                        /* On Alpha, halt(8) doesn't actually turn the machine
                           off, it puts you into the sort of firmware monitor.
                           Typically, it's used to boot another kernel image,
                           so it's not much different from reboot(8).