Import 2.1.122

[davej-history.git] / drivers / block / ide.c

/*
 *  linux/drivers/block/ide.c   Version 6.18  August 16, 1998
 *
 *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
 */

/*
 *  Maintained by Mark Lord  <mlord@pobox.com>
 *            and Gadi Oxman <gadio@netvision.net.il>
 *
 * 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@mipg.upenn.edu)         ("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"
 *
 *  Some additional driver compile-time options are in ide.h
 *
 *  To do, in likely order of completion:
 *      - modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
*/

#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/malloc.h>
#include <linux/pci.h>
#include <linux/delay.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/bitops.h>

#include "ide.h"
#include "ide_modes.h"

#ifdef CONFIG_KMOD
#include <linux/kmod.h>
#endif /* CONFIG_KMOD */

static const byte       ide_hwif_to_major[] = {IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR, IDE4_MAJOR, IDE5_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 */

/*
 * ide_lock is used by the Atari code to obtain access to the IDE interrupt,
 * which is shared between several drivers.
 */
static int      ide_lock = 0;

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

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

#if (DISK_RECOVERY_TIME > 0)
/*
 * For really screwy hardware (hey, at least it *can* be used with Linux)
 * we can enforce a minimum delay time between successive operations.
 */
static unsigned long read_timer(void)
{
        unsigned long t, flags;
        int i;

        __save_flags(flags);    /* local CPU only */
        __cli();                /* local CPU only */
        t = jiffies * 11932;
        outb_p(0, 0x43);
        i = inb_p(0x40);
        i |= inb(0x40) << 8;
        __restore_flags(flags); /* local CPU only */
        return (t - i);
}
#endif /* DISK_RECOVERY_TIME */

static inline void set_recovery_timer (ide_hwif_t *hwif)
{
#if (DISK_RECOVERY_TIME > 0)
        hwif->last_time = read_timer();
#endif /* DISK_RECOVERY_TIME */
}

/*
 * Do not even *think* about calling this!
 */
static void init_hwif_data (unsigned int index)
{
        unsigned int unit;
        ide_hwif_t *hwif = &ide_hwifs[index];

        /* bulk initialize hwif & drive info with zeros */
        memset(hwif, 0, sizeof(ide_hwif_t));

        /* fill in any non-zero initial values */
        hwif->index     = index;
        ide_init_hwif_ports(hwif->io_ports, ide_default_io_base(index), &hwif->irq);
        hwif->noprobe   = !hwif->io_ports[IDE_DATA_OFFSET];
#ifdef CONFIG_BLK_DEV_HD
        if (hwif->io_ports[IDE_DATA_OFFSET] == HD_DATA)
                hwif->noprobe = 1; /* may be overridden by ide_setup() */
#endif /* CONFIG_BLK_DEV_HD */
        hwif->major     = ide_hwif_to_major[index];
        hwif->name[0]   = 'i';
        hwif->name[1]   = 'd';
        hwif->name[2]   = 'e';
        hwif->name[3]   = '0' + index;
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];

                drive->media                    = ide_disk;
                drive->select.all               = (unit<<4)|0xa0;
                drive->hwif                     = hwif;
                drive->ctl                      = 0x08;
                drive->ready_stat               = READY_STAT;
                drive->bad_wstat                = BAD_W_STAT;
                drive->special.b.recalibrate    = 1;
                drive->special.b.set_geometry   = 1;
                drive->name[0]                  = 'h';
                drive->name[1]                  = 'd';
                drive->name[2]                  = 'a' + (index * MAX_DRIVES) + unit;
        }
}

/*
 * init_ide_data() sets reasonable default values into all fields
 * of all instances of the hwifs and drives, but only on the first call.
 * Subsequent calls have no effect (they don't wipe out anything).
 *
 * This routine is normally called at driver initialization time,
 * but may also be called MUCH earlier during kernel "command-line"
 * parameter processing.  As such, we cannot depend on any other parts
 * of the kernel (such as memory allocation) to be functioning yet.
 *
 * This is too bad, as otherwise we could dynamically allocate the
 * ide_drive_t structs as needed, rather than always consuming memory
 * for the max possible number (MAX_HWIFS * MAX_DRIVES) of them.
 */
#define MAGIC_COOKIE 0x12345678
static void init_ide_data (void)
{
        unsigned int index;
        static unsigned long magic_cookie = MAGIC_COOKIE;

        if (magic_cookie != MAGIC_COOKIE)
                return;         /* already initialized */
        magic_cookie = 0;

        for (index = 0; index < MAX_HWIFS; ++index)
                init_hwif_data(index);

        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)
                        system_bus_speed = idebus_parameter;    /* user supplied value */
#ifdef CONFIG_PCI
                else if (pci_present())
                        system_bus_speed = 40;  /* safe default value for PCI */
#endif /* CONFIG_PCI */
                else
                        system_bus_speed = 50;  /* safe default value for VESA and PCI */
                printk("ide: Assuming %dMHz system bus speed for PIO modes%s\n", system_bus_speed,
                        idebus_parameter ? "" : "; override with idebus=xx");
        }
        return system_bus_speed;
}

#if SUPPORT_VLB_SYNC
/*
 * Some localbus EIDE interfaces require a special access sequence
 * when using 32-bit I/O instructions to transfer data.  We call this
 * the "vlb_sync" sequence, which consists of three successive reads
 * of the sector count register location, with interrupts disabled
 * to ensure that the reads all happen together.
 */
static inline void do_vlb_sync (ide_ioreg_t port) {
        (void) inb (port);
        (void) inb (port);
        (void) inb (port);
}
#endif /* SUPPORT_VLB_SYNC */

/*
 * This is used for most PIO data transfers *from* the IDE interface
 */
void ide_input_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
        byte io_32bit = drive->io_32bit;

        if (io_32bit) {
#if SUPPORT_VLB_SYNC
                if (io_32bit & 2) {
                        unsigned long flags;
                        __save_flags(flags);    /* local CPU only */
                        __cli();                /* local CPU only */
                        do_vlb_sync(IDE_NSECTOR_REG);
                        insl(IDE_DATA_REG, buffer, wcount);
                        __restore_flags(flags); /* local CPU only */
                } else
#endif /* SUPPORT_VLB_SYNC */
                        insl(IDE_DATA_REG, buffer, wcount);
        } else {
#if SUPPORT_SLOW_DATA_PORTS
                if (drive->slow) {
                        unsigned short *ptr = (unsigned short *) buffer;
                        while (wcount--) {
                                *ptr++ = inw_p(IDE_DATA_REG);
                                *ptr++ = inw_p(IDE_DATA_REG);
                        }
                } else
#endif /* SUPPORT_SLOW_DATA_PORTS */
                        insw(IDE_DATA_REG, buffer, wcount<<1);
        }
}

/*
 * This is used for most PIO data transfers *to* the IDE interface
 */
void ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
        byte io_32bit = drive->io_32bit;

        if (io_32bit) {
#if SUPPORT_VLB_SYNC
                if (io_32bit & 2) {
                        unsigned long flags;
                        __save_flags(flags);    /* local CPU only */
                        __cli();                /* local CPU only */
                        do_vlb_sync(IDE_NSECTOR_REG);
                        outsl(IDE_DATA_REG, buffer, wcount);
                        __restore_flags(flags); /* local CPU only */
                } else
#endif /* SUPPORT_VLB_SYNC */
                        outsl(IDE_DATA_REG, buffer, wcount);
        } else {
#if SUPPORT_SLOW_DATA_PORTS
                if (drive->slow) {
                        unsigned short *ptr = (unsigned short *) buffer;
                        while (wcount--) {
                                outw_p(*ptr++, IDE_DATA_REG);
                                outw_p(*ptr++, IDE_DATA_REG);
                        }
                } else
#endif /* SUPPORT_SLOW_DATA_PORTS */
                        outsw(IDE_DATA_REG, buffer, wcount<<1);
        }
}

/*
 * The following routines are mainly used by the ATAPI drivers.
 *
 * These routines will round up any request for an odd number of bytes,
 * so if an odd bytecount is specified, be sure that there's at least one
 * extra byte allocated for the buffer.
 */
void atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
        ++bytecount;
#ifdef CONFIG_ATARI
        if (MACH_IS_ATARI) {
                /* Atari has a byte-swapped IDE interface */
                insw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
                return;
        }
#endif /* CONFIG_ATARI */
        ide_input_data (drive, buffer, bytecount / 4);
        if ((bytecount & 0x03) >= 2)
                insw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

void atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
        ++bytecount;
#ifdef CONFIG_ATARI
        if (MACH_IS_ATARI) {
                /* Atari has a byte-swapped IDE interface */
                outsw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
                return;
        }
#endif /* CONFIG_ATARI */
        ide_output_data (drive, buffer, bytecount / 4);
        if ((bytecount & 0x03) >= 2)
                outsw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

/*
 * Needed for PCI irq sharing
 */
static inline int drive_is_ready (ide_drive_t *drive)
{
        if (drive->waiting_for_dma)
                return HWIF(drive)->dmaproc(ide_dma_test_irq, drive);
#if 0
        udelay(1);      /* need to guarantee 400ns since last command was issued */
#endif
        if (GET_STAT() & BUSY_STAT)
                return 0;       /* drive busy:  definitely not interrupting */
        return 1;               /* drive ready: *might* be interrupting */
}

/*
 * This is our end_request replacement function.
 */
void ide_end_request(byte uptodate, ide_hwgroup_t *hwgroup)
{
        struct request *rq;
        unsigned long flags;

        spin_lock_irqsave(&io_request_lock, flags);
        rq = hwgroup->rq;

        if (!end_that_request_first(rq, uptodate, hwgroup->drive->name)) {
                add_blkdev_randomness(MAJOR(rq->rq_dev));
                hwgroup->drive->queue = rq->next;
                blk_dev[MAJOR(rq->rq_dev)].current_request = NULL;
                hwgroup->rq = NULL;
                end_that_request_last(rq);
        }
        spin_unlock_irqrestore(&io_request_lock, flags);
}

/*
 * This should get invoked any time we exit the driver to
 * wait for an interrupt response from a drive.  handler() points
 * at the appropriate code to handle the next interrupt, and a
 * timer is started to prevent us from waiting forever in case
 * something goes wrong (see the ide_timer_expiry() handler later on).
 */
void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler, unsigned int timeout)
{
        unsigned long flags;
        ide_hwgroup_t *hwgroup = HWGROUP(drive);

        spin_lock_irqsave(&hwgroup->spinlock, flags);
#ifdef DEBUG
        if (hwgroup->handler != NULL) {
                printk("%s: ide_set_handler: handler not null; old=%p, new=%p\n",
                        drive->name, hwgroup->handler, handler);
        }
#endif
        hwgroup->handler       = handler;
        hwgroup->timer.expires = jiffies + timeout;
        add_timer(&(hwgroup->timer));
        spin_unlock_irqrestore(&hwgroup->spinlock, flags);
}

/*
 * current_capacity() returns the capacity (in sectors) of a drive
 * according to its current geometry/LBA settings.
 */
static unsigned long current_capacity (ide_drive_t *drive)
{
        if (!drive->present)
                return 0;
        if (drive->driver != NULL)
                return DRIVER(drive)->capacity(drive);
        return 0;
}

/*
 * ide_geninit() is called exactly *once* for each major, from genhd.c,
 * at the beginning of the initial partition check for the drives.
 */
void ide_geninit (struct gendisk *gd)
{
        unsigned int unit;
        ide_hwif_t *hwif = gd->real_devices;

        for (unit = 0; unit < gd->nr_real; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];

                drive->part[0].nr_sects = current_capacity(drive);
                if (!drive->present || (drive->media != ide_disk && drive->media != ide_floppy) ||
                    drive->driver == NULL || !drive->part[0].nr_sects)
                        drive->part[0].start_sect = -1; /* skip partition check */
        }
}

static void do_reset1 (ide_drive_t *, int);             /* needed below */

/*
 * atapi_reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an atapi drive reset operation. If the drive has not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static void atapi_reset_pollfunc (ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        byte stat;

        SELECT_DRIVE(HWIF(drive),drive);
        udelay (10);

        if (OK_STAT(stat=GET_STAT(), 0, BUSY_STAT)) {
                printk("%s: ATAPI reset complete\n", drive->name);
        } else {
                if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
                        ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20);
                        return; /* continue polling */
                }
                hwgroup->poll_timeout = 0;      /* end of polling */
                printk("%s: ATAPI reset timed-out, status=0x%02x\n", drive->name, stat);
                do_reset1 (drive, 1);   /* do it the old fashioned way */
                return;
        }
        hwgroup->poll_timeout = 0;      /* done polling */
}

/*
 * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an ide reset operation. If the drives have not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static void reset_pollfunc (ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        ide_hwif_t *hwif = HWIF(drive);
        byte tmp;

        if (!OK_STAT(tmp=GET_STAT(), 0, BUSY_STAT)) {
                if (0 < (signed long)(hwgroup->poll_timeout - jiffies)) {
                        ide_set_handler (drive, &reset_pollfunc, HZ/20);
                        return; /* continue polling */
                }
                printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
        } else  {
                printk("%s: reset: ", hwif->name);
                if ((tmp = GET_ERR()) == 1)
                        printk("success\n");
                else {
#if FANCY_STATUS_DUMPS
                        printk("master: ");
                        switch (tmp & 0x7f) {
                                case 1: printk("passed");
                                        break;
                                case 2: printk("formatter device error");
                                        break;
                                case 3: printk("sector buffer error");
                                        break;
                                case 4: printk("ECC circuitry error");
                                        break;
                                case 5: printk("controlling MPU error");
                                        break;
                                default:printk("error (0x%02x?)", tmp);
                        }
                        if (tmp & 0x80)
                                printk("; slave: failed");
                        printk("\n");
#else
                        printk("failed\n");
#endif /* FANCY_STATUS_DUMPS */
                }
        }
        hwgroup->poll_timeout = 0;      /* done polling */
}

static void pre_reset (ide_drive_t *drive)
{
        if (!drive->keep_settings) {
                drive->unmask = 0;
                drive->io_32bit = 0;
                if (drive->using_dma)
                        (void) HWIF(drive)->dmaproc(ide_dma_off, drive);
        }
        if (drive->driver != NULL)
                DRIVER(drive)->pre_reset(drive);
}

/*
 * do_reset1() attempts to recover a confused drive by resetting it.
 * Unfortunately, resetting a disk drive actually resets all devices on
 * the same interface, so it can really be thought of as resetting the
 * interface rather than resetting the drive.
 *
 * ATAPI devices have their own reset mechanism which allows them to be
 * individually reset without clobbering other devices on the same interface.
 *
 * Unfortunately, the IDE interface does not generate an interrupt to let
 * us know when the reset operation has finished, so we must poll for this.
 * Equally poor, though, is the fact that this may a very long time to complete,
 * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
 * we set a timer to poll at 50ms intervals.
 */
static void do_reset1 (ide_drive_t *drive, int  do_not_try_atapi)
{
        unsigned int unit;
        unsigned long flags;
        ide_hwif_t *hwif = HWIF(drive);
        ide_hwgroup_t *hwgroup = HWGROUP(drive);

        __save_flags(flags);    /* local CPU only */
        __cli();                /* local CPU only */

        /* For an ATAPI device, first try an ATAPI SRST. */
        if (drive->media != ide_disk && !do_not_try_atapi) {
                pre_reset(drive);
                SELECT_DRIVE(hwif,drive);
                udelay (20);
                OUT_BYTE (WIN_SRST, IDE_COMMAND_REG);
                hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
                ide_set_handler (drive, &atapi_reset_pollfunc, HZ/20);
                __restore_flags (flags);        /* local CPU only */
                return;
        }

        /*
         * First, reset any device state data we were maintaining
         * for any of the drives on this interface.
         */
        for (unit = 0; unit < MAX_DRIVES; ++unit)
                pre_reset(&hwif->drives[unit]);

#if OK_TO_RESET_CONTROLLER
        /*
         * Note that we also set nIEN while resetting the device,
         * to mask unwanted interrupts from the interface during the reset.
         * However, due to the design of PC hardware, this will cause an
         * immediate interrupt due to the edge transition it produces.
         * This single interrupt gives us a "fast poll" for drives that
         * recover from reset very quickly, saving us the first 50ms wait time.
         */
        OUT_BYTE(drive->ctl|6,IDE_CONTROL_REG); /* set SRST and nIEN */
        udelay(10);                     /* more than enough time */
        OUT_BYTE(drive->ctl|2,IDE_CONTROL_REG); /* clear SRST, leave nIEN */
        udelay(10);                     /* more than enough time */
        hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
        ide_set_handler (drive, &reset_pollfunc, HZ/20);
#endif  /* OK_TO_RESET_CONTROLLER */

        __restore_flags (flags);        /* local CPU only */
}

/*
 * ide_do_reset() is the entry point to the drive/interface reset code.
 */
void ide_do_reset (ide_drive_t *drive)
{
        do_reset1 (drive, 0);
}

/*
 * Clean up after success/failure of an explicit drive cmd
 */
void ide_end_drive_cmd (ide_drive_t *drive, byte stat, byte err)
{
        unsigned long flags;
        struct request *rq = HWGROUP(drive)->rq;

        if (rq->cmd == IDE_DRIVE_CMD) {
                byte *args = (byte *) rq->buffer;
                rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
                if (args) {
                        args[0] = stat;
                        args[1] = err;
                        args[2] = IN_BYTE(IDE_NSECTOR_REG);
                }
        }
        spin_lock_irqsave(&io_request_lock, flags);
        drive->queue = rq->next;
        blk_dev[MAJOR(rq->rq_dev)].current_request = NULL;
        HWGROUP(drive)->rq = NULL;
        rq->rq_status = RQ_INACTIVE;
        spin_unlock_irqrestore(&io_request_lock, flags);
        save_flags(flags);      /* all CPUs; overkill? */
        cli();                  /* all CPUs; overkill? */
        if (rq->sem != NULL)
                up(rq->sem);    /* inform originator that rq has been serviced */
        restore_flags(flags);   /* all CPUs; overkill? */
}

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

        __save_flags (flags);   /* local CPU only */
        ide__sti();             /* local CPU only */
        printk("%s: %s: status=0x%02x", drive->name, msg, stat);
#if FANCY_STATUS_DUMPS
        printk(" { ");
        if (stat & BUSY_STAT)
                printk("Busy ");
        else {
                if (stat & READY_STAT)  printk("DriveReady ");
                if (stat & WRERR_STAT)  printk("DeviceFault ");
                if (stat & SEEK_STAT)   printk("SeekComplete ");
                if (stat & DRQ_STAT)    printk("DataRequest ");
                if (stat & ECC_STAT)    printk("CorrectedError ");
                if (stat & INDEX_STAT)  printk("Index ");
                if (stat & ERR_STAT)    printk("Error ");
        }
        printk("}");
#endif  /* FANCY_STATUS_DUMPS */
        printk("\n");
        if ((stat & (BUSY_STAT|ERR_STAT)) == ERR_STAT) {
                err = GET_ERR();
                printk("%s: %s: error=0x%02x", drive->name, msg, err);
#if FANCY_STATUS_DUMPS
                if (drive->media == ide_disk) {
                        printk(" { ");
                        if (err & ABRT_ERR)     printk("DriveStatusError ");
                        if (err & ICRC_ERR)     printk((err & ABRT_ERR) ? "BadCRC " : "BadSector ");
                        if (err & ECC_ERR)      printk("UncorrectableError ");
                        if (err & ID_ERR)       printk("SectorIdNotFound ");
                        if (err & TRK0_ERR)     printk("TrackZeroNotFound ");
                        if (err & MARK_ERR)     printk("AddrMarkNotFound ");
                        printk("}");
                        if ((err & (BBD_ERR | ABRT_ERR)) == BBD_ERR || (err & (ECC_ERR|ID_ERR|MARK_ERR))) {
                                byte cur = IN_BYTE(IDE_SELECT_REG);
                                if (cur & 0x40) {       /* using LBA? */
                                        printk(", LBAsect=%ld", (unsigned long)
                                         ((cur&0xf)<<24)
                                         |(IN_BYTE(IDE_HCYL_REG)<<16)
                                         |(IN_BYTE(IDE_LCYL_REG)<<8)
                                         | IN_BYTE(IDE_SECTOR_REG));
                                } else {
                                        printk(", CHS=%d/%d/%d",
                                         (IN_BYTE(IDE_HCYL_REG)<<8) +
                                          IN_BYTE(IDE_LCYL_REG),
                                          cur & 0xf,
                                          IN_BYTE(IDE_SECTOR_REG));
                                }
                                if (HWGROUP(drive)->rq)
                                        printk(", sector=%ld", HWGROUP(drive)->rq->sector);
                        }
                }
#endif  /* FANCY_STATUS_DUMPS */
                printk("\n");
        }
        __restore_flags (flags);        /* local CPU only */
        return err;
}

/*
 * try_to_flush_leftover_data() is invoked in response to a drive
 * unexpectedly having its DRQ_STAT bit set.  As an alternative to
 * resetting the drive, this routine tries to clear the condition
 * by read a sector's worth of data from the drive.  Of course,
 * this may not help if the drive is *waiting* for data from *us*.
 */
static void try_to_flush_leftover_data (ide_drive_t *drive)
{
        int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;

        if (drive->media != ide_disk)
                return;
        while (i > 0) {
                unsigned long buffer[16];
                unsigned int wcount = (i > 16) ? 16 : i;
                i -= wcount;
                ide_input_data (drive, buffer, wcount);
        }
}

/*
 * ide_error() takes action based on the error returned by the drive.
 */
void ide_error (ide_drive_t *drive, const char *msg, byte stat)
{
        struct request *rq;
        byte err;

        err = ide_dump_status(drive, msg, stat);
        if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
                return;
        /* retry only "normal" I/O: */
        if (rq->cmd == IDE_DRIVE_CMD) {
                rq->errors = 1;
                ide_end_drive_cmd(drive, stat, err);
                return;
        }
        if (stat & BUSY_STAT) {         /* other bits are useless when BUSY */
                rq->errors |= ERROR_RESET;
        } else {
                if (drive->media == ide_disk && (stat & ERR_STAT)) {
                        /* err has different meaning on cdrom and tape */
                        if (err == ABRT_ERR) {
                                if (drive->select.b.lba && IN_BYTE(IDE_COMMAND_REG) == WIN_SPECIFY)
                                        return; /* some newer drives don't support WIN_SPECIFY */
                        } else if ((err & (ABRT_ERR | ICRC_ERR)) == (ABRT_ERR | ICRC_ERR))
                                ; /* UDMA crc error -- just retry the operation */
                        else if (err & (BBD_ERR | ECC_ERR))     /* retries won't help these */
                                rq->errors = ERROR_MAX;
                        else if (err & TRK0_ERR)        /* help it find track zero */
                                rq->errors |= ERROR_RECAL;
                }
                if ((stat & DRQ_STAT) && rq->cmd != WRITE)
                        try_to_flush_leftover_data(drive);
        }
        if (GET_STAT() & (BUSY_STAT|DRQ_STAT))
                rq->errors |= ERROR_RESET;      /* Mmmm.. timing problem */

        if (rq->errors >= ERROR_MAX) {
                if (drive->driver != NULL)
                        DRIVER(drive)->end_request(0, HWGROUP(drive));
                else
                        ide_end_request(0, HWGROUP(drive));
        } else {
                if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
                        ++rq->errors;
                        ide_do_reset(drive);
                        return;
                } else if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
                        drive->special.b.recalibrate = 1;
                ++rq->errors;
        }
}

/*
 * Issue a simple drive command
 * The drive must be selected beforehand.
 */
void ide_cmd(ide_drive_t *drive, byte cmd, byte nsect, ide_handler_t *handler)
{
        ide_set_handler (drive, handler, WAIT_CMD);
        OUT_BYTE(drive->ctl,IDE_CONTROL_REG);   /* clear nIEN */
        OUT_BYTE(nsect,IDE_NSECTOR_REG);
        OUT_BYTE(cmd,IDE_COMMAND_REG);
}

/*
 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
 */
static void drive_cmd_intr (ide_drive_t *drive)
{
        struct request *rq = HWGROUP(drive)->rq;
        byte *args = (byte *) rq->buffer;
        byte stat = GET_STAT();
        int retries = 10;

        ide__sti();     /* local CPU only */
        if ((stat & DRQ_STAT) && args && args[3]) {
                byte io_32bit = drive->io_32bit;
                drive->io_32bit = 0;
                ide_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
                drive->io_32bit = io_32bit;
                while (((stat = GET_STAT()) & BUSY_STAT) && retries--)
                        udelay(100);
        }

        if (OK_STAT(stat, READY_STAT, BAD_STAT))
                ide_end_drive_cmd (drive, stat, GET_ERR());
        else
                ide_error(drive, "drive_cmd", stat); /* calls ide_end_drive_cmd */
}

/*
 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
 * commands to a drive.  It used to do much more, but has been scaled back.
 */
static inline void do_special (ide_drive_t *drive)
{
        special_t *s = &drive->special;

#ifdef DEBUG
        printk("%s: do_special: 0x%02x\n", drive->name, s->all);
#endif
        if (s->b.set_tune) {
                ide_tuneproc_t *tuneproc = HWIF(drive)->tuneproc;
                s->b.set_tune = 0;
                if (tuneproc != NULL)
                        tuneproc(drive, drive->tune_req);
        } else if (drive->driver != NULL) {
                DRIVER(drive)->special(drive);
        } else if (s->all) {
                printk("%s: bad special flag: 0x%02x\n", drive->name, s->all);
                s->all = 0;
        }
}

/*
 * This routine busy-waits for the drive status to be not "busy".
 * It then checks the status for all of the "good" bits and none
 * of the "bad" bits, and if all is okay it returns 0.  All other
 * cases return 1 after invoking ide_error() -- caller should just return.
 *
 * This routine should get fixed to not hog the cpu during extra long waits..
 * That could be done by busy-waiting for the first jiffy or two, and then
 * setting a timer to wake up at half second intervals thereafter,
 * until timeout is achieved, before timing out.
 */
int ide_wait_stat (ide_drive_t *drive, byte good, byte bad, unsigned long timeout)
{
        byte stat;
        unsigned long flags;

        udelay(1);      /* spec allows drive 400ns to assert "BUSY" */
        if ((stat = GET_STAT()) & BUSY_STAT) {
                __save_flags(flags);    /* local CPU only */
                ide__sti();             /* local CPU only */
                timeout += jiffies;
                while ((stat = GET_STAT()) & BUSY_STAT) {
                        if (0 < (signed long)(jiffies - timeout)) {
                                __restore_flags(flags); /* local CPU only */
                                ide_error(drive, "status timeout", stat);
                                return 1;
                        }
                }
                __restore_flags(flags); /* local CPU only */
        }
        udelay(1);      /* allow status to settle, then read it again */
        if (OK_STAT((stat = GET_STAT()), good, bad))
                return 0;
        ide_error(drive, "status error", stat);
        return 1;
}

/*
 * execute_drive_cmd() issues a special drive command,
 * usually initiated by ioctl() from the external hdparm program.
 */
static void execute_drive_cmd (ide_drive_t *drive, struct request *rq)
{
        byte *args = rq->buffer;
        if (args) {
#ifdef DEBUG
                printk("%s: DRIVE_CMD cmd=0x%02x sc=0x%02x fr=0x%02x xx=0x%02x\n",
                 drive->name, args[0], args[1], args[2], args[3]);
#endif
                if (args[0] == WIN_SMART) {
                        OUT_BYTE(0x4f, IDE_LCYL_REG);
                        OUT_BYTE(0xc2, IDE_HCYL_REG);
                }
                OUT_BYTE(args[2],IDE_FEATURE_REG);
                ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
                return;
        } else {
                /*
                 * NULL is actually a valid way of waiting for
                 * all current requests to be flushed from the queue.
                 */
#ifdef DEBUG
                printk("%s: DRIVE_CMD (null)\n", drive->name);
#endif
                ide_end_drive_cmd(drive, GET_STAT(), GET_ERR());
                return;
        }
}

/*
 * start_request() initiates handling of a new I/O request
 */
static inline void start_request (ide_drive_t *drive)
{
        unsigned long block, blockend;
        struct request *rq = drive->queue;
        unsigned int minor = MINOR(rq->rq_dev), unit = minor >> PARTN_BITS;
        ide_hwif_t *hwif = HWIF(drive);

        ide__sti();     /* local CPU only */
#ifdef DEBUG
        printk("%s: start_request: current=0x%08lx\n", hwif->name, (unsigned long) rq);
#endif
        if (unit >= MAX_DRIVES) {
                printk("%s: bad device number: %s\n", hwif->name, kdevname(rq->rq_dev));
                goto kill_rq;
        }
#ifdef DEBUG
        if (rq->bh && !buffer_locked(rq->bh)) {
                printk("%s: block not locked\n", drive->name);
                goto kill_rq;
        }
#endif
        block    = rq->sector;
        blockend = block + rq->nr_sectors;
        if ((blockend < block) || (blockend > drive->part[minor&PARTN_MASK].nr_sects)) {
                printk("%s%c: bad access: block=%ld, count=%ld\n", drive->name,
                 (minor&PARTN_MASK)?'0'+(minor&PARTN_MASK):' ', block, rq->nr_sectors);
                goto kill_rq;
        }
        block += drive->part[minor&PARTN_MASK].start_sect + drive->sect0;
#if FAKE_FDISK_FOR_EZDRIVE
        if (block == 0 && drive->remap_0_to_1)
                block = 1;  /* redirect MBR access to EZ-Drive partn table */
#endif /* FAKE_FDISK_FOR_EZDRIVE */
#if (DISK_RECOVERY_TIME > 0)
        while ((read_timer() - hwif->last_time) < DISK_RECOVERY_TIME);
#endif
        SELECT_DRIVE(hwif, drive);
        if (ide_wait_stat(drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
                printk("%s: drive not ready for command\n", drive->name);
                return;
        }
        if (!drive->special.all) {
                if (rq->cmd == IDE_DRIVE_CMD) {
                        execute_drive_cmd(drive, rq);
                        return;
                }
                if (drive->driver != NULL) {
                        DRIVER(drive)->do_request(drive, rq, block);
                        return;
                }
                printk("%s: media type %d not supported\n", drive->name, drive->media);
                goto kill_rq;
        }
        do_special(drive);
        return;
kill_rq:
        if (drive->driver != NULL)
                DRIVER(drive)->end_request(0, HWGROUP(drive));
        else
                ide_end_request(0, HWGROUP(drive));
}

/*
 * ide_stall_queue() can be used by a drive to give excess bandwidth back
 * to the hwgroup by sleeping for timeout jiffies.
 */
void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
{
        if (timeout > WAIT_WORSTCASE)
                timeout = WAIT_WORSTCASE;
        drive->sleep = timeout + jiffies;
}

#define WAKEUP(drive)   ((drive)->service_start + 2 * (drive)->service_time)

/*
 * choose_drive() selects the next drive which will be serviced.
 */
static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
{
        ide_drive_t *drive, *best;

repeat: 
        best = NULL;
        drive = hwgroup->drive;
        do {
                if (drive->queue && (!drive->sleep || 0 <= (signed long)(jiffies - drive->sleep))) {
                        if (!best
                         || (drive->sleep && (!best->sleep || 0 < (signed long)(best->sleep - drive->sleep)))
                         || (!best->sleep && 0 < (signed long)(WAKEUP(best) - WAKEUP(drive))))
                        {
                                struct blk_dev_struct *bdev = &blk_dev[HWIF(drive)->major];
                                if (bdev->current_request != &bdev->plug)
                                        best = drive;
                        }
                }
        } while ((drive = drive->next) != hwgroup->drive);
        if (best && best->nice1 && !best->sleep && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
                long t = (signed long)(WAKEUP(best) - jiffies);
                if (t >= WAIT_MIN_SLEEP) {
                        /*
                         * We *may* have some time to spare, but first let's see if
                         * someone can potentially benefit from our nice mood today..
                         */
                        drive = best->next;
                        do {
                                if (!drive->sleep
                                 && 0 < (signed long)(WAKEUP(drive) - (jiffies - best->service_time))
                                 && 0 < (signed long)((jiffies + t) - WAKEUP(drive)))
                                {
                                        ide_stall_queue(best, IDE_MIN(t, 10 * WAIT_MIN_SLEEP));
                                        goto repeat;
                                }
                        } while ((drive = drive->next) != best);
                }
        }
        return best;
}

/*
 * Caller must have already acquired spinlock using *spinflags 
 */
static void ide_do_request (ide_hwgroup_t *hwgroup, unsigned long *hwgroup_flags, int masked_irq)
{
        struct blk_dev_struct *bdev;
        ide_drive_t     *drive;
        ide_hwif_t      *hwif;
        unsigned long   io_flags;

        hwgroup->busy = 1;
        while (hwgroup->handler == NULL) {
                spin_lock_irqsave(&io_request_lock, io_flags);
                drive = choose_drive(hwgroup);
                if (drive == NULL) {
                        unsigned long sleep = 0;

                        hwgroup->rq = NULL;
                        drive = hwgroup->drive;
                        do {
                                bdev = &blk_dev[HWIF(drive)->major];
                                if (bdev->current_request != &bdev->plug)       /* FIXME: this will do for now */
                                        bdev->current_request = NULL;           /* (broken since patch-2.1.15) */
                                if (drive->sleep && (!sleep || 0 < (signed long)(sleep - drive->sleep)))
                                        sleep = drive->sleep;
                        } while ((drive = drive->next) != hwgroup->drive);
                        spin_unlock_irqrestore(&io_request_lock, io_flags);
                        if (sleep) {
                                if (0 < (signed long)(jiffies + WAIT_MIN_SLEEP - sleep)) 
                                        sleep = jiffies + WAIT_MIN_SLEEP;
#if 1
                                if (hwgroup->timer.next || hwgroup->timer.prev)
                                        printk("ide_set_handler: timer already active\n");
#endif
                                mod_timer(&hwgroup->timer, sleep);
                        } else {
                                /* Ugly, but how can we sleep for the lock otherwise? perhaps from tq_scheduler? */
                                ide_release_lock(&ide_lock);    /* for atari only */
                        }
                        hwgroup->busy = 0;
                        return;
                }
                hwif = HWIF(drive);
                if (hwgroup->hwif->sharing_irq && hwif != hwgroup->hwif) /* set nIEN for previous hwif */
                        OUT_BYTE(hwgroup->drive->ctl|2, hwgroup->hwif->io_ports[IDE_CONTROL_OFFSET]);
                hwgroup->hwif = hwif;
                hwgroup->drive = drive;
                drive->sleep = 0;
                drive->service_start = jiffies;

                bdev = &blk_dev[hwif->major];
                if (bdev->current_request == &bdev->plug)       /* FIXME: paranoia */
                        printk("%s: Huh? nuking plugged queue\n", drive->name);
                bdev->current_request = hwgroup->rq = drive->queue;
                spin_unlock_irqrestore(&io_request_lock, io_flags);

                if (hwif->irq != masked_irq)
                        disable_irq(hwif->irq);
                spin_unlock_irqrestore(&hwgroup->spinlock, *hwgroup_flags);
                start_request(drive);
                spin_lock_irqsave(&hwgroup->spinlock, *hwgroup_flags);
                if (hwif->irq != masked_irq)
                        enable_irq(hwif->irq);
        }
}

/*
 * ide_get_queue() returns the queue which corresponds to a given device.
 */
struct request **ide_get_queue (kdev_t dev)
{
        ide_hwif_t *hwif = (ide_hwif_t *)blk_dev[MAJOR(dev)].data;

        return &hwif->drives[DEVICE_NR(dev) & 1].queue;
}

/*
 * do_hwgroup_request() invokes ide_do_request() after claiming hwgroup->busy.
 */
static void do_hwgroup_request (ide_hwgroup_t *hwgroup)
{
        unsigned long flags;

        spin_lock_irqsave(&hwgroup->spinlock, flags);
        if (hwgroup->busy) {
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                return;
        }
        del_timer(&hwgroup->timer);
        ide_get_lock(&ide_lock, ide_intr, hwgroup);     /* for atari only */
        ide_do_request(hwgroup, &flags, 0);
        spin_unlock_irqrestore(&hwgroup->spinlock, flags);
}

/*
 * ll_rw_blk.c invokes our do_idex_request() function
 * with the io_request_spinlock already grabbed.
 * Since we need to do our own spinlock's internally,
 * on paths that don't necessarily originate through the
 * do_idex_request() path, we have to undo the spinlock on entry,
 * and restore it again on exit.
 * Fortunately, this is mostly a nop for non-SMP kernels.
 */
static inline void unlock_do_hwgroup_request (ide_hwgroup_t *hwgroup)
{
        spin_unlock(&io_request_lock);
        do_hwgroup_request (hwgroup);
        spin_lock_irq(&io_request_lock);
}

void do_ide0_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[0].hwgroup);
}

#if MAX_HWIFS > 1
void do_ide1_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[1].hwgroup);
}
#endif /* MAX_HWIFS > 1 */

#if MAX_HWIFS > 2
void do_ide2_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[2].hwgroup);
}
#endif /* MAX_HWIFS > 2 */

#if MAX_HWIFS > 3
void do_ide3_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[3].hwgroup);
}
#endif /* MAX_HWIFS > 3 */

#if MAX_HWIFS > 4
void do_ide4_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[4].hwgroup);
}
#endif /* MAX_HWIFS > 4 */

#if MAX_HWIFS > 5
void do_ide5_request (void)
{
        unlock_do_hwgroup_request (ide_hwifs[5].hwgroup);
}
#endif /* MAX_HWIFS > 5 */

static void start_next_request (ide_hwgroup_t *hwgroup, int masked_irq)
{
        unsigned long   flags;
        ide_drive_t     *drive;

        spin_lock_irqsave(&hwgroup->spinlock, flags);
        if (hwgroup->handler != NULL) {
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                return;
        }
        drive = hwgroup->drive;
        set_recovery_timer(HWIF(drive));
        drive->service_time = jiffies - drive->service_start;
        ide_do_request(hwgroup, &flags, masked_irq);
        spin_unlock_irqrestore(&hwgroup->spinlock, flags);
}

void ide_timer_expiry (unsigned long data)
{
        ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
        ide_drive_t   *drive;
        ide_handler_t *handler;
        unsigned long flags;

        spin_lock_irqsave(&hwgroup->spinlock, flags);
        drive = hwgroup->drive;
        if ((handler = hwgroup->handler) == NULL) {
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                do_hwgroup_request(hwgroup);
                return;
        }
        hwgroup->busy = 1;      /* should already be "1" */
        hwgroup->handler = NULL;
        del_timer(&hwgroup->timer);     /* Is this needed?? */
        if (hwgroup->poll_timeout != 0) {       /* polling in progress? */
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                handler(drive);
        } else if (drive_is_ready(drive)) {
                printk("%s: lost interrupt\n", drive->name);
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                handler(drive);
        } else {
                if (drive->waiting_for_dma) {
                        (void) hwgroup->hwif->dmaproc(ide_dma_end, drive);
                        printk("%s: timeout waiting for DMA\n", drive->name);
        /*
         *  need something here for HX PIIX3 UDMA and HPT343.......AMH
         *  irq timeout: status=0x58 { DriveReady SeekComplete DataRequest }
         */
                }
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                ide_error(drive, "irq timeout", GET_STAT());
        }
        start_next_request(hwgroup, 0);
}

/*
 * There's nothing really useful we can do with an unexpected interrupt,
 * other than reading the status register (to clear it), and logging it.
 * There should be no way that an irq can happen before we're ready for it,
 * so we needn't worry much about losing an "important" interrupt here.
 *
 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
 * drive enters "idle", "standby", or "sleep" mode, so if the status looks
 * "good", we just ignore the interrupt completely.
 *
 * This routine assumes __cli() is in effect when called.
 *
 * If an unexpected interrupt happens on irq15 while we are handling irq14
 * and if the two interfaces are "serialized" (CMD640), then it looks like
 * we could screw up by interfering with a new request being set up for irq15.
 *
 * In reality, this is a non-issue.  The new command is not sent unless the
 * drive is ready to accept one, in which case we know the drive is not
 * trying to interrupt us.  And ide_set_handler() is always invoked before
 * completing the issuance of any new drive command, so we will not be
 * accidently invoked as a result of any valid command completion interrupt.
 *
 */
static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
{
        byte stat;
        ide_hwif_t *hwif = hwgroup->hwif;

        /*
         * handle the unexpected interrupt
         */
        do {
                if (hwif->irq == irq) {
                        stat = IN_BYTE(hwif->io_ports[IDE_STATUS_OFFSET]);
                        if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
                                /* Try to not flood the console with msgs */
                                static unsigned long last_msgtime = 0, count = 0;
                                ++count;
                                if (0 < (signed long)(jiffies - (last_msgtime + HZ))) {
                                        last_msgtime = jiffies;
                                        printk("%s%s: unexpected interrupt, status=0x%02x, count=%ld\n",
                                         hwif->name, (hwif->next == hwgroup->hwif) ? "" : "(?)", stat, count);
                                }
                        }
                }
        } while ((hwif = hwif->next) != hwgroup->hwif);
}
/*
 * entry point for all interrupts, caller does __cli() for us
 */
void ide_intr (int irq, void *dev_id, struct pt_regs *regs)
{
        unsigned long flags;
        ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        ide_handler_t *handler;

        __cli();        /* local CPU only */
        spin_lock_irqsave(&hwgroup->spinlock, flags);
        hwif = hwgroup->hwif;
        if ((handler = hwgroup->handler) == NULL || hwgroup->poll_timeout != 0) {
                /*
                 * Not expecting an interrupt from this drive.
                 * That means this could be:
                 *      (1) an interrupt from another PCI device
                 *      sharing the same PCI INT# as us.
                 * or   (2) a drive just entered sleep or standby mode,
                 *      and is interrupting to let us know.
                 * or   (3) a spurious interrupt of unknown origin.
                 *
                 * For PCI, we cannot tell the difference,
                 * so in that case we just ignore it and hope it goes away.
                 */
#ifdef CONFIG_BLK_DEV_IDEPCI
                if (IDE_PCI_DEVID_EQ(hwif->pci_devid, IDE_PCI_DEVID_NULL))
#endif  /* CONFIG_BLK_DEV_IDEPCI */
                {
                        /*
                         * Probably not a shared PCI interrupt,
                         * so we can safely try to do something about it:
                         */
                        (void)ide_ack_intr(hwif->io_ports[IDE_STATUS_OFFSET], hwif->io_ports[IDE_IRQ_OFFSET]);
                        unexpected_intr(irq, hwgroup);
                }
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                return;
        }
        drive = hwgroup->drive;
        if (!drive || !drive_is_ready(drive)) {
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                return;
        }
        hwgroup->handler = NULL;
        (void)ide_ack_intr(hwif->io_ports[IDE_STATUS_OFFSET], hwif->io_ports[IDE_IRQ_OFFSET]);
        del_timer(&(hwgroup->timer));
        spin_unlock_irqrestore(&hwgroup->spinlock, flags);
        if (drive->unmask)
                ide__sti();     /* local CPU only */
        handler(drive);         /* service this interrupt, may set handler for next interrupt */
        /*
         * Note that handler() may have set things up for another
         * interrupt to occur soon, but it cannot happen until
         * we exit from this routine, because it will be the
         * same irq as is currently being serviced here,
         * and Linux won't allow another (on any CPU) until we return.
         */
        start_next_request(hwgroup, hwif->irq);
}

/*
 * get_info_ptr() returns the (ide_drive_t *) for a given device number.
 * It returns NULL if the given device number does not match any present drives.
 */
static ide_drive_t *get_info_ptr (kdev_t i_rdev)
{
        int             major = MAJOR(i_rdev);
        unsigned int    h;

        for (h = 0; h < MAX_HWIFS; ++h) {
                ide_hwif_t  *hwif = &ide_hwifs[h];
                if (hwif->present && major == hwif->major) {
                        unsigned unit = DEVICE_NR(i_rdev);
                        if (unit < MAX_DRIVES) {
                                ide_drive_t *drive = &hwif->drives[unit];
                                if (drive->present)
                                        return drive;
                        }
                        break;
                }
        }
        return NULL;
}

/*
 * This function is intended to be used prior to invoking ide_do_drive_cmd().
 */
void ide_init_drive_cmd (struct request *rq)
{
        rq->buffer = NULL;
        rq->cmd = IDE_DRIVE_CMD;
        rq->sector = 0;
        rq->nr_sectors = 0;
        rq->current_nr_sectors = 0;
        rq->sem = NULL;
        rq->bh = NULL;
        rq->bhtail = NULL;
        rq->next = NULL;
}

/*
 * This function issues a special IDE device request
 * onto the request queue.
 *
 * If action is ide_wait, then then rq is queued at the end of
 * the request queue, and the function sleeps until it has been
 * processed.  This is for use when invoked from an ioctl handler.
 *
 * If action is ide_preempt, then the rq is queued at the head of
 * the request queue, displacing the currently-being-processed
 * request and this function returns immediately without waiting
 * for the new rq to be completed.  This is VERY DANGEROUS, and is
 * intended for careful use by the ATAPI tape/cdrom driver code.
 *
 * If action is ide_next, then the rq is queued immediately after
 * the currently-being-processed-request (if any), and the function
 * returns without waiting for the new rq to be completed.  As above,
 * This is VERY DANGEROUS, and is intended for careful use by the
 * ATAPI tape/cdrom driver code.
 *
 * If action is ide_end, then the rq is queued at the end of the
 * request queue, and the function returns immediately without waiting
 * for the new rq to be completed. This is again intended for careful
 * use by the ATAPI tape/cdrom driver code.
 */
int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
{
        unsigned long flags;
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        unsigned int major = HWIF(drive)->major;
        struct request *cur_rq;
        struct semaphore sem = MUTEX_LOCKED;

        if (IS_PDC4030_DRIVE && rq->buffer != NULL)
                return -ENOSYS;  /* special drive cmds not supported */
        rq->errors = 0;
        rq->rq_status = RQ_ACTIVE;
        rq->rq_dev = MKDEV(major,(drive->select.b.unit)<<PARTN_BITS);
        if (action == ide_wait)
                rq->sem = &sem;

        spin_lock_irqsave(&io_request_lock, flags);
        cur_rq = drive->queue;
        if (cur_rq == NULL || action == ide_preempt) {
                rq->next = cur_rq;
                drive->queue = rq;
                if (action == ide_preempt)
                        hwgroup->rq = NULL;
        } else {
                if (action == ide_wait || action == ide_end) {
                        while (cur_rq->next != NULL)    /* find end of list */
                                cur_rq = cur_rq->next;
                }
                rq->next = cur_rq->next;
                cur_rq->next = rq;
        }
        spin_unlock_irqrestore(&io_request_lock, flags);
        do_hwgroup_request(hwgroup);
        save_flags(flags);      /* all CPUs; overkill? */
        cli();                  /* all CPUs; overkill? */
        if (action == ide_wait && rq->rq_status != RQ_INACTIVE)
                down(&sem);     /* wait for it to be serviced */
        restore_flags(flags);   /* all CPUs; overkill? */
        return rq->errors ? -EIO : 0;   /* return -EIO if errors */
}

/*
 * This routine is called to flush all partitions and partition tables
 * for a changed disk, and then re-read the new partition table.
 * If we are revalidating a disk because of a media change, then we
 * enter with usage == 0.  If we are using an ioctl, we automatically have
 * usage == 1 (we need an open channel to use an ioctl :-), so this
 * is our limit.
 */
int ide_revalidate_disk(kdev_t i_rdev)
{
        ide_drive_t *drive;
        ide_hwgroup_t *hwgroup;
        unsigned int p, major, minor;
        long flags;

        if ((drive = get_info_ptr(i_rdev)) == NULL)
                return -ENODEV;
        major = MAJOR(i_rdev);
        minor = drive->select.b.unit << PARTN_BITS;
        hwgroup = HWGROUP(drive);
        spin_lock_irqsave(&hwgroup->spinlock, flags);
        if (drive->busy || (drive->usage > 1)) {
                spin_unlock_irqrestore(&hwgroup->spinlock, flags);
                return -EBUSY;
        };
        drive->busy = 1;
        MOD_INC_USE_COUNT;
        spin_unlock_irqrestore(&hwgroup->spinlock, flags);

        for (p = 0; p < (1<<PARTN_BITS); ++p) {
                if (drive->part[p].nr_sects > 0) {
                        kdev_t devp = MKDEV(major, minor+p);
                        struct super_block * sb = get_super(devp);
                        fsync_dev          (devp);
                        if (sb)
                                invalidate_inodes(sb);
                        invalidate_buffers (devp);
                        set_blocksize(devp, 1024);
                }
                drive->part[p].start_sect = 0;
                drive->part[p].nr_sects   = 0;
        };

        drive->part[0].nr_sects = current_capacity(drive);
        if ((drive->media != ide_disk && drive->media != ide_floppy) ||
             drive->driver == NULL || !drive->part[0].nr_sects)
                drive->part[0].start_sect = -1;
        resetup_one_dev(HWIF(drive)->gd, drive->select.b.unit);

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

static void revalidate_drives (void)
{
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        int index, unit;

        for (index = 0; index < MAX_HWIFS; ++index) {
                hwif = &ide_hwifs[index];
                for (unit = 0; unit < MAX_DRIVES; ++unit) {
                        drive = &ide_hwifs[index].drives[unit];
                        if (drive->revalidate) {
                                drive->revalidate = 0;
                                if (!initializing)
                                        (void) ide_revalidate_disk(MKDEV(hwif->major, unit<<PARTN_BITS));
                        }
                }
        }
}

static void ide_init_module (int type)
{
        int found = 0;
        ide_module_t *module = ide_modules;
        
        while (module) {
                if (module->type == type) {
                        found = 1;
                        (void) module->init();
                }
                module = module->next;
        }
        revalidate_drives();
#ifdef CONFIG_KMOD
        if (!found && type == IDE_PROBE_MODULE)
                (void) request_module("ide-probe");
#endif /* CONFIG_KMOD */
}

static int ide_open(struct inode * inode, struct file * filp)
{
        ide_drive_t *drive;
        int rc;

        if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
                return -ENXIO;
        MOD_INC_USE_COUNT;
        if (drive->driver == NULL)
                ide_init_module(IDE_DRIVER_MODULE);
#ifdef CONFIG_KMOD
        if (drive->driver == NULL) {
                if (drive->media == ide_disk)
                        (void) request_module("ide-disk");
                if (drive->media == ide_cdrom)
                        (void) request_module("ide-cd");
                if (drive->media == ide_tape)
                        (void) request_module("ide-tape");
                if (drive->media == ide_floppy)
                        (void) request_module("ide-floppy");
        }
#endif /* CONFIG_KMOD */
        while (drive->busy)
                sleep_on(&drive->wqueue);
        drive->usage++;
        if (drive->driver != NULL) {
                if ((rc = DRIVER(drive)->open(inode, filp, drive)))
                        MOD_DEC_USE_COUNT;
                return rc;
        }
        printk ("%s: driver not present\n", drive->name);
        drive->usage--;
        MOD_DEC_USE_COUNT;
        return -ENXIO;
}

/*
 * Releasing a block device means we sync() it, so that it can safely
 * be forgotten about...
 */
static int ide_release(struct inode * inode, struct file * file)
{
        ide_drive_t *drive;

        if ((drive = get_info_ptr(inode->i_rdev)) != NULL) {
                fsync_dev(inode->i_rdev);
                drive->usage--;
                if (drive->driver != NULL)
                        DRIVER(drive)->release(inode, file, drive);
                MOD_DEC_USE_COUNT;
        }
        return 0;
}

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

void ide_unregister (unsigned int index)
{
        struct gendisk *gd, **gdp;
        ide_drive_t *drive, *d;
        ide_hwif_t *hwif, *g;
        ide_hwgroup_t *hwgroup;
        int irq_count = 0, unit, i;
        unsigned long flags;

        if (index >= MAX_HWIFS)
                return;
        save_flags(flags);      /* all CPUs */
        cli();                  /* all CPUs */
        hwif = &ide_hwifs[index];
        if (!hwif->present)
                goto abort;
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present)
                        continue;
                if (drive->busy || drive->usage)
                        goto abort;
                if (drive->driver != NULL && DRIVER(drive)->cleanup(drive))
                        goto abort;
        }
        hwif->present = 0;
        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.
         */
        ide_release_region(hwif->io_ports[IDE_DATA_OFFSET], 8);
        ide_release_region(hwif->io_ports[IDE_CONTROL_OFFSET], 1);

        /*
         * 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->present)
                        continue;
                while (hwgroup->drive->next != drive)
                        hwgroup->drive = hwgroup->drive->next;
                hwgroup->drive->next = drive->next;
                if (hwgroup->drive == drive)
                        hwgroup->drive = NULL;
                if (drive->id != NULL) {
                        kfree(drive->id);
                        drive->id = NULL;
                }
                drive->present = 0;
        }
        if (d->present)
                hwgroup->drive = d;
        while (hwgroup->hwif->next != hwif)
                hwgroup->hwif = hwgroup->hwif->next;
        hwgroup->hwif->next = hwif->next;
        if (hwgroup->hwif == hwif)
                kfree(hwgroup);
        else
                hwgroup->hwif = HWIF(hwgroup->drive);

        /*
         * 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].request_fn = NULL;
        blk_dev[hwif->major].data = NULL;
        blk_dev[hwif->major].queue = NULL;
        blksize_size[hwif->major] = NULL;
        for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
                if (*gdp == hwif->gd)
                        break;
        if (*gdp == NULL)
                printk("gd not in disk chain!\n");
        else {
                gd = *gdp; *gdp = gd->next;
                kfree(gd->sizes);
                kfree(gd->part);
                kfree(gd);
        }
        init_hwif_data (index); /* restore hwif data to pristine status */
abort:
        restore_flags(flags);   /* all CPUs */
}

int ide_register (int arg1, int arg2, int irq)
{
        int index, retry = 1;
        ide_hwif_t *hwif;
        ide_ioreg_t data_port = (ide_ioreg_t) arg1, ctl_port = (ide_ioreg_t) arg2;

        do {
                for (index = 0; index < MAX_HWIFS; ++index) {
                        hwif = &ide_hwifs[index];
                        if (hwif->io_ports[IDE_DATA_OFFSET] == data_port)
                                goto found;
                }
                for (index = 0; index < MAX_HWIFS; ++index) {
                        hwif = &ide_hwifs[index];
                        if (!hwif->present)
                                goto found;
                }
                for (index = 0; index < MAX_HWIFS; index++)
                        ide_unregister(index);
        } while (retry--);
        return -1;
found:
        if (hwif->present)
                ide_unregister(index);
        if (hwif->present)
                return -1;
        ide_init_hwif_ports(hwif->io_ports, data_port, &hwif->irq);
        if (ctl_port)
                hwif->io_ports[IDE_CONTROL_OFFSET] = ctl_port;
        hwif->irq = irq;
        hwif->noprobe = 0;
        ide_init_module(IDE_PROBE_MODULE);
        ide_init_module(IDE_DRIVER_MODULE);
        return hwif->present ? index : -1;
}

void ide_add_setting(ide_drive_t *drive, const char *name, int rw, int read_ioctl, int write_ioctl, int data_type, int min, int max, int mul_factor, int div_factor, void *data, ide_procset_t *set)
{
        ide_settings_t **p = (ide_settings_t **) &drive->settings, *setting = NULL;

        while ((*p) && strcmp((*p)->name, name) < 0)
                p = &((*p)->next);
        if ((setting = kmalloc(sizeof(*setting), GFP_KERNEL)) == NULL)
                goto abort;
        memset(setting, 0, sizeof(*setting));
        if ((setting->name = kmalloc(strlen(name) + 1, GFP_KERNEL)) == NULL)
                goto abort;
        strcpy(setting->name, name);            setting->rw = rw;
        setting->read_ioctl = read_ioctl;       setting->write_ioctl = write_ioctl;
        setting->data_type = data_type;         setting->min = min;
        setting->max = max;                     setting->mul_factor = mul_factor;
        setting->div_factor = div_factor;       setting->data = data;
        setting->set = set;                     setting->next = *p;
        if (drive->driver)
                setting->auto_remove = 1;
        *p = setting;
        return;
abort:
        if (setting)
                kfree(setting);
}

void ide_remove_setting(ide_drive_t *drive, char *name)
{
        ide_settings_t **p = (ide_settings_t **) &drive->settings, *setting;

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

static ide_settings_t *ide_find_setting_by_ioctl(ide_drive_t *drive, int cmd)
{
        ide_settings_t *setting = drive->settings;

        while (setting) {
                if (setting->read_ioctl == cmd || setting->write_ioctl == cmd)
                        break;
                setting = setting->next;
        }
        return setting;
}

ide_settings_t *ide_find_setting_by_name(ide_drive_t *drive, char *name)
{
        ide_settings_t *setting = drive->settings;

        while (setting) {
                if (strcmp(setting->name, name) == 0)
                        break;
                setting = setting->next;
        }
        return setting;
}

static void auto_remove_settings(ide_drive_t *drive)
{
        ide_settings_t *setting;
repeat:
        setting = drive->settings;
        while (setting) {
                if (setting->auto_remove) {
                        ide_remove_setting(drive, setting->name);
                        goto repeat;
                }
                setting = setting->next;
        }
}

int ide_read_setting(ide_drive_t *drive, ide_settings_t *setting)
{
        int             val = -EINVAL;
        unsigned long   flags;

        if ((setting->rw & SETTING_READ)) {
                spin_lock_irqsave(&HWGROUP(drive)->spinlock, 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(&HWGROUP(drive)->spinlock, flags);
        }
        return val;
}

int ide_spin_wait_hwgroup (ide_drive_t *drive, unsigned long *flags)
{
        ide_hwgroup_t *hwgroup = HWGROUP(drive);
        unsigned long timeout = jiffies + (3 * HZ);

        spin_lock_irqsave(&hwgroup->spinlock, *flags);
        while (hwgroup->busy) {
                spin_unlock_irqrestore(&hwgroup->spinlock, *flags);
                __sti();        /* local CPU only; needed for jiffies */
                if (0 < (signed long)(jiffies - timeout)) {
                        printk("%s: channel busy\n", drive->name);
                        return -EBUSY;
                }
                spin_lock_irqsave(&hwgroup->spinlock, *flags);
        }
        return 0;
}

int ide_write_setting(ide_drive_t *drive, ide_settings_t *setting, int val)
{
        unsigned long flags;
        int i;
        u32 *p;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!(setting->rw & SETTING_WRITE))
                return -EPERM;
        if (val < setting->min || val > setting->max)
                return -EINVAL;
        if (setting->set)
                return setting->set(drive, val);
        if (ide_spin_wait_hwgroup(drive, &flags))
                return -EBUSY;
        switch (setting->data_type) {
                case TYPE_BYTE:
                        *((u8 *) setting->data) = val;
                        break;
                case TYPE_SHORT:
                        *((u16 *) setting->data) = val;
                        break;
                case TYPE_INT:
                        *((u32 *) setting->data) = val;
                        break;
                case TYPE_INTA:
                        p = (u32 *) setting->data;
                        for (i = 0; i < 1 << PARTN_BITS; i++, p++)
                                *p = val;
                        break;
        }
        spin_unlock_irqrestore(&HWGROUP(drive)->spinlock, flags);
        return 0;
}

static int set_io_32bit(ide_drive_t *drive, int arg)
{
        drive->io_32bit = arg;
#ifdef CONFIG_BLK_DEV_DTC2278
        if (HWIF(drive)->chipset == ide_dtc2278)
                HWIF(drive)->drives[!drive->select.b.unit].io_32bit = arg;
#endif /* CONFIG_BLK_DEV_DTC2278 */
        return 0;
}

static int set_using_dma(ide_drive_t *drive, int arg)
{
        if (!drive->driver || !DRIVER(drive)->supports_dma)
                return -EPERM;
        if (!drive->id || !(drive->id->capability & 1) || !HWIF(drive)->dmaproc)
                return -EPERM;
        if (HWIF(drive)->dmaproc(arg ? ide_dma_on : ide_dma_off, drive))
                return -EIO;
        return 0;
}

static int set_pio_mode(ide_drive_t *drive, int arg)
{
        struct request rq;

        if (!HWIF(drive)->tuneproc)
                return -ENOSYS;
        if (drive->special.b.set_tune)
                return -EBUSY;
        ide_init_drive_cmd(&rq);
        drive->tune_req = (byte) arg;
        drive->special.b.set_tune = 1;
        (void) ide_do_drive_cmd (drive, &rq, ide_wait);
        return 0;
}

void ide_add_generic_settings(ide_drive_t *drive)
{
/*
 *                      drive   setting name            read/write access                               read ioctl              write ioctl             data type       min     max                             mul_factor      div_factor      data pointer                    set function
 */
        ide_add_setting(drive,  "io_32bit",             drive->no_io_32bit ? SETTING_READ : SETTING_RW, HDIO_GET_32BIT,         HDIO_SET_32BIT,         TYPE_BYTE,      0,      1 + (SUPPORT_VLB_SYNC << 1),    1,              1,              &drive->io_32bit,               set_io_32bit);
        ide_add_setting(drive,  "keepsettings",         SETTING_RW,                                     HDIO_GET_KEEPSETTINGS,  HDIO_SET_KEEPSETTINGS,  TYPE_BYTE,      0,      1,                              1,              1,              &drive->keep_settings,          NULL);
        ide_add_setting(drive,  "nice1",                SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      1,                              1,              1,              &drive->nice1,                  NULL);
        ide_add_setting(drive,  "pio_mode",             SETTING_WRITE,                                  -1,                     HDIO_SET_PIO_MODE,      TYPE_BYTE,      0,      255,                            1,              1,              NULL,                           set_pio_mode);
        ide_add_setting(drive,  "slow",                 SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      1,                              1,              1,              &drive->slow,                   NULL);
        ide_add_setting(drive,  "unmaskirq",            drive->no_unmask ? SETTING_READ : SETTING_RW,   HDIO_GET_UNMASKINTR,    HDIO_SET_UNMASKINTR,    TYPE_BYTE,      0,      1,                              1,              1,              &drive->unmask,                 NULL);
        ide_add_setting(drive,  "using_dma",            SETTING_RW,                                     HDIO_GET_DMA,           HDIO_SET_DMA,           TYPE_BYTE,      0,      1,                              1,              1,              &drive->using_dma,              set_using_dma);
}

int ide_wait_cmd (ide_drive_t *drive, int cmd, int nsect, int feature, int sectors, byte *buf)
{
        struct request rq;
        byte buffer[4];

        if (!buf)
                buf = buffer;
        memset(buf, 0, 4 + SECTOR_WORDS * 4 * sectors);
        ide_init_drive_cmd(&rq);
        rq.buffer = buf;
        *buf++ = cmd;
        *buf++ = nsect;
        *buf++ = feature;
        *buf++ = sectors;
        return ide_do_drive_cmd(drive, &rq, ide_wait);
}

static int ide_ioctl (struct inode *inode, struct file *file,
                        unsigned int cmd, unsigned long arg)
{
        int err, major, minor;
        ide_drive_t *drive;
        struct request rq;
        kdev_t dev;
        ide_settings_t *setting;

        if (!inode || !(dev = inode->i_rdev))
                return -EINVAL;
        major = MAJOR(dev); minor = MINOR(dev);
        if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
                return -ENODEV;

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

        ide_init_drive_cmd (&rq);
        switch (cmd) {
                case HDIO_GETGEO:
                {
                        struct hd_geometry *loc = (struct hd_geometry *) arg;
                        if (!loc || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
                        if (put_user(drive->bios_head, (byte *) &loc->heads)) return -EFAULT;
                        if (put_user(drive->bios_sect, (byte *) &loc->sectors)) return -EFAULT;
                        if (put_user(drive->bios_cyl, (unsigned short *) &loc->cylinders)) return -EFAULT;
                        if (put_user((unsigned)drive->part[MINOR(inode->i_rdev)&PARTN_MASK].start_sect,
                                (unsigned long *) &loc->start)) return -EFAULT;
                        return 0;
                }
                case BLKFLSBUF:
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        fsync_dev(inode->i_rdev);
                        invalidate_buffers(inode->i_rdev);
                        return 0;

                case BLKGETSIZE:   /* Return device size */
                        return put_user(drive->part[MINOR(inode->i_rdev)&PARTN_MASK].nr_sects, (long *) arg);

                case BLKRRPART: /* Re-read partition tables */
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        return ide_revalidate_disk(inode->i_rdev);

                case HDIO_OBSOLETE_IDENTITY:
                case HDIO_GET_IDENTITY:
                        if (MINOR(inode->i_rdev) & PARTN_MASK)
                                return -EINVAL;
                        if (drive->id == NULL)
                                return -ENOMSG;
                        if (copy_to_user((char *)arg, (char *)drive->id, (cmd == HDIO_GET_IDENTITY) ? sizeof(*drive->id) : 142))
                                return -EFAULT;
                        return 0;

                case HDIO_GET_NICE:
                        return put_user(drive->dsc_overlap      <<      IDE_NICE_DSC_OVERLAP    |
                                        drive->atapi_overlap    <<      IDE_NICE_ATAPI_OVERLAP  |
                                        drive->nice0            <<      IDE_NICE_0              |
                                        drive->nice1            <<      IDE_NICE_1              |
                                        drive->nice2            <<      IDE_NICE_2,
                                        (long *) arg);
                case HDIO_DRIVE_CMD:
                {
                        byte args[4], *argbuf = args;
                        int argsize = 4;
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        if (NULL == (void *) arg)
                                return ide_do_drive_cmd(drive, &rq, ide_wait);
                        if (copy_from_user(args, (void *)arg, 4))
                                return -EFAULT;
                        if (args[3]) {
                                argsize = 4 + (SECTOR_WORDS * 4 * args[3]);
                                argbuf = kmalloc(argsize, GFP_KERNEL);
                                if (argbuf == NULL)
                                        return -ENOMEM;
                                memcpy(argbuf, args, 4);
                        }
                        err = ide_wait_cmd(drive, args[0], args[1], args[2], args[3], argbuf);
                        if (copy_to_user((void *)arg, argbuf, argsize))
                                err = -EFAULT;
                        if (argsize > 4)
                                kfree(argbuf);
                        return err;
                }

                case HDIO_SCAN_HWIF:
                {
                        int args[3];
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        if (copy_from_user(args, (void *)arg, 3 * sizeof(int)))
                                return -EFAULT;
                        if (ide_register(args[0], args[1], args[2]) == -1)
                                return -EIO;
                        return 0;
                }
                case HDIO_SET_NICE:
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        if (drive->driver == NULL)
                                return -EPERM;
                        if (arg != (arg & ((1 << IDE_NICE_DSC_OVERLAP) | (1 << IDE_NICE_1))))
                                return -EPERM;
                        drive->dsc_overlap = (arg >> IDE_NICE_DSC_OVERLAP) & 1;
                        if (drive->dsc_overlap && !DRIVER(drive)->supports_dsc_overlap) {
                                drive->dsc_overlap = 0;
                                return -EPERM;
                        }
                        drive->nice1 = (arg >> IDE_NICE_1) & 1;
                        return 0;

                RO_IOCTLS(inode->i_rdev, arg);

                default:
                        if (drive->driver != NULL)
                                return DRIVER(drive)->ioctl(drive, inode, file, cmd, arg);
                        return -EPERM;
        }
}

static int ide_check_media_change (kdev_t i_rdev)
{
        ide_drive_t *drive;

        if ((drive = get_info_ptr(i_rdev)) == NULL)
                return -ENODEV;
        if (drive->driver != NULL)
                return DRIVER(drive)->media_change(drive);
        return 0;
}

void ide_fixstring (byte *s, const int bytecount, const int byteswap)
{
        byte *p = s, *end = &s[bytecount & ~1]; /* bytecount must be even */

        if (byteswap) {
                /* convert from big-endian to host byte order */
                for (p = end ; p != s;) {
                        unsigned short *pp = (unsigned short *) (p -= 2);
                        *pp = ntohs(*pp);
                }
        }

        /* strip leading blanks */
        while (s != end && *s == ' ')
                ++s;

        /* compress internal blanks and strip trailing blanks */
        while (s != end && *s) {
                if (*s++ != ' ' || (s != end && *s && *s != ' '))
                        *p++ = *(s-1);
        }

        /* wipe out trailing garbage */
        while (p != end)
                *p++ = '\0';
}

/*
 * stridx() returns the offset of c within s,
 * or -1 if c is '\0' or not found within s.
 */
__initfunc(static int stridx (const char *s, char c))
{
        char *i = strchr(s, c);
        return (i && c) ? i - s : -1;
}

/*
 * match_parm() does parsing for ide_setup():
 *
 * 1. the first char of s must be '='.
 * 2. if the remainder matches one of the supplied keywords,
 *     the index (1 based) of the keyword is negated and returned.
 * 3. if the remainder is a series of no more than max_vals numbers
 *     separated by commas, the numbers are saved in vals[] and a
 *     count of how many were saved is returned.  Base10 is assumed,
 *     and base16 is allowed when prefixed with "0x".
 * 4. otherwise, zero is returned.
 */
__initfunc(static int match_parm (char *s, const char *keywords[], int vals[], int max_vals))
{
        static const char *decimal = "0123456789";
        static const char *hex = "0123456789abcdef";
        int i, n;

        if (*s++ == '=') {
                /*
                 * Try matching against the supplied keywords,
                 * and return -(index+1) if we match one
                 */
                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=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.
 *
 * "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
 *
 * The following are valid ONLY on ide0,
 * and the defaults for the base,ctl ports must not be altered.
 *
 * "ide0=dtc2278"       : probe/support DTC2278 interface
 * "ide0=ht6560b"       : probe/support HT6560B interface
 * "ide0=cmd640_vlb"    : *REQUIRED* for VLB cards with the CMD640 chip
 *                        (not for PCI -- automatically detected)
 * "ide0=qd6580"        : probe/support qd6580 interface
 * "ide0=ali14xx"       : probe/support ali14xx chipsets (ALI M1439, M1443, M1445)
 * "ide0=umc8672"       : probe/support umc8672 chipsets
 */
__initfunc(void ide_setup (char *s))
{
        int i, vals[3];
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        unsigned int hw, unit;
        const char max_drive = 'a' + ((MAX_HWIFS * MAX_DRIVES) - 1);
        const char max_hwif  = '0' + (MAX_HWIFS - 1);

        printk("ide_setup: %s", s);
        init_ide_data ();

        /*
         * Look for drive options:  "hdx="
         */
        if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) {
                const char *hd_words[] = {"none", "noprobe", "nowerr", "cdrom",
                                "serialize", "autotune", "noautotune",
                                "slow", "swapdata", NULL};
                unit = s[2] - 'a';
                hw   = unit / MAX_DRIVES;
                unit = unit % MAX_DRIVES;
                hwif = &ide_hwifs[hw];
                drive = &hwif->drives[unit];
                switch (match_parm(&s[3], hd_words, vals, 3)) {
                        case -1: /* "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 */
                                drive->bswap = 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
                 */
                const char *ide_words[] = {"noprobe", "serialize", "autotune", "noautotune", "reset", "dma", "four",
                        "qd6580", "ht6560b", "cmd640_vlb", "dtc2278", "umc8672", "ali14xx", "dc4030", NULL};
                hw = s[3] - '0';
                hwif = &ide_hwifs[hw];
                i = match_parm(&s[4], ide_words, vals, 3);

                /*
                 * Cryptic check to ensure chipset not already set for hwif:
                 */
                if (i > 0 || i <= -7) {                 /* is parameter a chipset name? */
                        if (hwif->chipset != ide_unknown)
                                goto bad_option;        /* chipset already specified */
                        if (i <= -7 && hw != 0)
                                goto bad_hwif;          /* chipset drivers are for "ide0=" only */
                        if (i <= -7 && 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 -14: /* "dc4030" */
                        {
                                extern void setup_pdc4030(ide_hwif_t *);
                                setup_pdc4030(hwif);
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_PDC4030 */
#ifdef CONFIG_BLK_DEV_ALI14XX
                        case -13: /* "ali14xx" */
                        {
                                extern void init_ali14xx (void);
                                init_ali14xx();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_ALI14XX */
#ifdef CONFIG_BLK_DEV_UMC8672
                        case -12: /* "umc8672" */
                        {
                                extern void init_umc8672 (void);
                                init_umc8672();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_UMC8672 */
#ifdef CONFIG_BLK_DEV_DTC2278
                        case -11: /* "dtc2278" */
                        {
                                extern void init_dtc2278 (void);
                                init_dtc2278();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_DTC2278 */
#ifdef CONFIG_BLK_DEV_CMD640
                        case -10: /* "cmd640_vlb" */
                        {
                                extern int cmd640_vlb; /* flag for cmd640.c */
                                cmd640_vlb = 1;
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_CMD640 */
#ifdef CONFIG_BLK_DEV_HT6560B
                        case -9: /* "ht6560b" */
                        {
                                extern void init_ht6560b (void);
                                init_ht6560b();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_HT6560B */
#if CONFIG_BLK_DEV_QD6580
                        case -8: /* "qd6580" */
                        {
                                extern void init_qd6580 (void);
                                init_qd6580();
                                goto done;
                        }
#endif /* CONFIG_BLK_DEV_QD6580 */
#ifdef CONFIG_BLK_DEV_4DRIVES
                        case -7: /* "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 -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 */
                                ide_init_hwif_ports(hwif->io_ports, (ide_ioreg_t) vals[0], &hwif->irq);
                                hwif->io_ports[IDE_CONTROL_OFFSET] = (ide_ioreg_t) vals[1];
                                hwif->irq      = vals[2];
                                hwif->noprobe  = 0;
                                hwif->chipset  = ide_generic;
                                goto done;

                        case 0: goto bad_option;
                        default:
                                printk(" -- SUPPORT NOT CONFIGURED IN THIS KERNEL\n");
                                return;
                }
        }
bad_option:
        printk(" -- BAD OPTION\n");
        return;
bad_hwif:
        printk("-- NOT SUPPORTED ON ide%d", hw);
done:
        printk("\n");
}

/*
 * This routine is called from the partition-table code in genhd.c
 * to "convert" a drive to a logical geometry with fewer than 1024 cyls.
 *
 * The second parameter, "xparm", determines exactly how the translation 
 * will be handled:
 *               0 = convert to CHS with fewer than 1024 cyls
 *                      using the same method as Ontrack DiskManager.
 *               1 = same as "0", plus offset everything by 63 sectors.
 *              -1 = similar to "0", plus redirect sector 0 to sector 1.
 *              >1 = convert to a CHS geometry with "xparm" heads.
 *
 * Returns 0 if the translation was not possible, if the device was not 
 * an IDE disk drive, or if a geometry was "forced" on the commandline.
 * Returns 1 if the geometry translation was successful.
 */
int ide_xlate_1024 (kdev_t i_rdev, int xparm, const char *msg)
{
        ide_drive_t *drive;
        static const byte head_vals[] = {4, 8, 16, 32, 64, 128, 255, 0};
        const byte *heads = head_vals;
        unsigned long tracks;

        if ((drive = get_info_ptr(i_rdev)) == NULL || drive->forced_geom)
                return 0;

        if (xparm > 1 && xparm <= drive->bios_head && drive->bios_sect == 63)
                return 0;               /* we already have a translation */

        printk("%s ", msg);

        if (xparm < 0 && (drive->bios_cyl * drive->bios_head * drive->bios_sect) < (1024 * 16 * 63))
                return 0;               /* small disk: no translation needed */

        if (drive->id) {
                drive->cyl  = drive->id->cyls;
                drive->head = drive->id->heads;
                drive->sect = drive->id->sectors;
        }
        drive->bios_cyl  = drive->cyl;
        drive->bios_head = drive->head;
        drive->bios_sect = drive->sect;
        drive->special.b.set_geometry = 1;

        tracks = drive->bios_cyl * drive->bios_head * drive->bios_sect / 63;
        drive->bios_sect = 63;
        if (xparm > 1) {
                drive->bios_head = xparm;
                drive->bios_cyl = tracks / drive->bios_head;
        } else {
                while (drive->bios_cyl >= 1024) {
                        drive->bios_head = *heads;
                        drive->bios_cyl = tracks / drive->bios_head;
                        if (0 == *++heads)
                                break;
                }
#if FAKE_FDISK_FOR_EZDRIVE
                if (xparm == -1) {
                        drive->remap_0_to_1 = 1;
                        printk("[remap 0->1] ");
                } else
#endif /* FAKE_FDISK_FOR_EZDRIVE */
                if (xparm == 1) {
                        drive->sect0 = 63;
                        drive->bios_cyl = (tracks - 1) / drive->bios_head;
                        printk("[remap +63] ");
                }
        }
        drive->part[0].nr_sects = current_capacity(drive);
        printk("[%d/%d/%d]", drive->bios_cyl, drive->bios_head, drive->bios_sect);
        return 1;
}

/*
 * probe_for_hwifs() finds/initializes "known" IDE interfaces
 */
__initfunc(static void probe_for_hwifs (void))
{
#ifdef CONFIG_PCI
        if (pci_present())
        {
#ifdef CONFIG_BLK_DEV_IDEPCI
                ide_scan_pcibus();
#else
#ifdef CONFIG_BLK_DEV_RZ1000
                {
                        extern void ide_probe_for_rz100x(void);
                        ide_probe_for_rz100x();
                }
#endif /* CONFIG_BLK_DEV_RZ1000 */
#endif /* CONFIG_BLK_DEV_IDEPCI */
        }
#endif /* CONFIG_PCI */

#ifdef CONFIG_BLK_DEV_CMD640
        {
                extern void ide_probe_for_cmd640x(void);
                ide_probe_for_cmd640x();
        }
#endif /* CONFIG_BLK_DEV_CMD640 */
#ifdef CONFIG_BLK_DEV_PDC4030
        {
                extern int init_pdc4030(void);
                (void) init_pdc4030();
        }
#endif /* CONFIG_BLK_DEV_PDC4030 */
#ifdef CONFIG_BLK_DEV_IDE_PMAC
        {
                extern void pmac_ide_probe(void);
                pmac_ide_probe();
        }
#endif /* CONFIG_BLK_DEV_IDE_PMAC */
}

__initfunc(void ide_init_builtin_drivers (void))
{
        /*
         * Probe for special PCI and other "known" interface chipsets
         */
        probe_for_hwifs ();

#ifdef CONFIG_BLK_DEV_IDE
#if defined(__mc68000__) || defined(CONFIG_APUS)
        if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET]) {
                ide_get_lock(&ide_lock, NULL, NULL);    /* for atari only */
                disable_irq(ide_hwifs[0].irq);
        }
#endif /* __mc68000__ || CONFIG_APUS */

        (void) ideprobe_init();

#if defined(__mc68000__) || defined(CONFIG_APUS)
        if (ide_hwifs[0].io_ports[IDE_DATA_OFFSET]) {
                enable_irq(ide_hwifs[0].irq);
                ide_release_lock(&ide_lock);    /* for atari only */
        }
#endif /* __mc68000__ || CONFIG_APUS */
#endif /* CONFIG_BLK_DEV_IDE */

#ifdef CONFIG_PROC_FS
        proc_ide_create();
#endif

        /*
         * Attempt to match drivers for the available drives
         */
#ifdef CONFIG_BLK_DEV_IDEDISK
        (void) idedisk_init();
#endif /* CONFIG_BLK_DEV_IDEDISK */
#ifdef CONFIG_BLK_DEV_IDECD
        (void) ide_cdrom_init();
#endif /* CONFIG_BLK_DEV_IDECD */
#ifdef CONFIG_BLK_DEV_IDETAPE
        (void) idetape_init();
#endif /* CONFIG_BLK_DEV_IDETAPE */
#ifdef CONFIG_BLK_DEV_IDEFLOPPY
        (void) idefloppy_init();
#endif /* CONFIG_BLK_DEV_IDEFLOPPY */
#ifdef CONFIG_BLK_DEV_IDESCSI
        (void) idescsi_init();
#endif /* CONFIG_BLK_DEV_IDESCSI */
}

static int default_cleanup (ide_drive_t *drive)
{
        return ide_unregister_subdriver(drive);
}

static void default_do_request(ide_drive_t *drive, struct request *rq, unsigned long block)
{
        ide_end_request(0, HWGROUP(drive));
}
 
static void default_end_request (byte uptodate, ide_hwgroup_t *hwgroup)
{
        ide_end_request(uptodate, hwgroup);
}
  
static int default_ioctl (ide_drive_t *drive, struct inode *inode, struct file *file,
                          unsigned int cmd, unsigned long arg)
{
        return -EIO;
}

static int default_open (struct inode *inode, struct file *filp, ide_drive_t *drive)
{
        drive->usage--;
        return -EIO;
}

static void default_release (struct inode *inode, struct file *filp, ide_drive_t *drive)
{
}

static int default_check_media_change (ide_drive_t *drive)
{
        return 1;
}

static void default_pre_reset (ide_drive_t *drive)
{
}

static unsigned long default_capacity (ide_drive_t *drive)
{
        return 0x7fffffff;      /* cdrom or tape */
}

static void default_special (ide_drive_t *drive)
{
        special_t *s = &drive->special;

        s->all = 0;
        drive->mult_req = 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->do_request == NULL)      d->do_request = default_do_request;
        if (d->end_request == NULL)     d->end_request = default_end_request;
        if (d->ioctl == NULL)           d->ioctl = default_ioctl;
        if (d->open == NULL)            d->open = default_open;
        if (d->release == NULL)         d->release = default_release;
        if (d->media_change == NULL)    d->media_change = default_check_media_change;
        if (d->pre_reset == NULL)       d->pre_reset = default_pre_reset;
        if (d->capacity == NULL)        d->capacity = default_capacity;
        if (d->special == NULL)         d->special = default_special;
}

ide_drive_t *ide_scan_devices (byte media, const char *name, ide_driver_t *driver, int n)
{
        unsigned int unit, index, i;

        for (index = 0; index < MAX_HWIFS; ++index)
                if (ide_hwifs[index].present) goto search;
        ide_init_module(IDE_PROBE_MODULE);
search:
        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;
}

#ifdef CONFIG_PROC_FS
static ide_proc_entry_t generic_subdriver_entries[] = {
        { "capacity",   S_IFREG|S_IRUGO,        proc_ide_read_capacity, NULL },
        { NULL, 0, NULL, NULL }
};
#endif

int ide_register_subdriver (ide_drive_t *drive, ide_driver_t *driver, int version)
{
        unsigned long flags;
        
        save_flags(flags);              /* all CPUs */
        cli();                          /* all CPUs */
        if (version != IDE_SUBDRIVER_VERSION || !drive->present || drive->driver != NULL || drive->busy || drive->usage) {
                restore_flags(flags);   /* all CPUs */
                return 1;
        }
        drive->driver = driver;
        setup_driver_defaults(drive);
        restore_flags(flags);           /* all CPUs */
        if (drive->autotune != 2) {
                if (driver->supports_dma && HWIF(drive)->dmaproc != NULL)
                        (void) (HWIF(drive)->dmaproc(ide_dma_check, drive));
                drive->dsc_overlap = (drive->next != drive && driver->supports_dsc_overlap);
                drive->nice1 = 1;
        }
        drive->revalidate = 1;
#ifdef CONFIG_PROC_FS
        ide_add_proc_entries(drive->proc, generic_subdriver_entries, drive);
        ide_add_proc_entries(drive->proc, driver->proc, drive);
#endif
        return 0;
}

int ide_unregister_subdriver (ide_drive_t *drive)
{
        unsigned long flags;
        
        save_flags(flags);              /* all CPUs */
        cli();                          /* all CPUs */
        if (drive->usage || drive->busy || drive->driver == NULL || DRIVER(drive)->busy) {
                restore_flags(flags);   /* all CPUs */
                return 1;
        }
#ifdef CONFIG_PROC_FS
        ide_remove_proc_entries(drive->proc, DRIVER(drive)->proc);
        ide_remove_proc_entries(drive->proc, generic_subdriver_entries);
#endif
        auto_remove_settings(drive);
        drive->driver = NULL;
        restore_flags(flags);           /* all CPUs */
        return 0;
}

int ide_register_module (ide_module_t *module)
{
        ide_module_t *p = ide_modules;

        while (p) {
                if (p == module)
                        return 1;
                p = p->next;
        }
        module->next = ide_modules;
        ide_modules = module;
        revalidate_drives();
        return 0;
}

void ide_unregister_module (ide_module_t *module)
{
        ide_module_t **p;

        for (p = &ide_modules; (*p) && (*p) != module; p = &((*p)->next));
        if (*p)
                *p = (*p)->next;
}

struct file_operations ide_fops[] = {{
        NULL,                   /* lseek - default */
        block_read,             /* read - general block-dev read */
        block_write,            /* write - general block-dev write */
        NULL,                   /* readdir - bad */
        NULL,                   /* poll */
        ide_ioctl,              /* ioctl */
        NULL,                   /* mmap */
        ide_open,               /* open */
        NULL,                   /* flush */
        ide_release,            /* release */
        block_fsync,            /* fsync */
        NULL,                   /* fasync */
        ide_check_media_change, /* check_media_change */
        ide_revalidate_disk     /* revalidate */
}};

EXPORT_SYMBOL(ide_hwifs);
EXPORT_SYMBOL(ide_register_module);
EXPORT_SYMBOL(ide_unregister_module);
EXPORT_SYMBOL(ide_spin_wait_hwgroup);

/*
 * Probe module
 */
EXPORT_SYMBOL(ide_timer_expiry);
EXPORT_SYMBOL(ide_intr);
EXPORT_SYMBOL(ide_geninit);
EXPORT_SYMBOL(ide_fops);
EXPORT_SYMBOL(ide_get_queue);
EXPORT_SYMBOL(do_ide0_request);
EXPORT_SYMBOL(ide_add_generic_settings);
#if MAX_HWIFS > 1
EXPORT_SYMBOL(do_ide1_request);
#endif /* MAX_HWIFS > 1 */
#if MAX_HWIFS > 2
EXPORT_SYMBOL(do_ide2_request);
#endif /* MAX_HWIFS > 2 */
#if MAX_HWIFS > 3
EXPORT_SYMBOL(do_ide3_request);
#endif /* MAX_HWIFS > 3 */
#if MAX_HWIFS > 4
EXPORT_SYMBOL(do_ide4_request);
#endif /* MAX_HWIFS > 4 */
#if MAX_HWIFS > 5
EXPORT_SYMBOL(do_ide5_request);
#endif /* MAX_HWIFS > 5 */

/*
 * Driver module
 */
EXPORT_SYMBOL(ide_scan_devices);
EXPORT_SYMBOL(ide_register_subdriver);
EXPORT_SYMBOL(ide_unregister_subdriver);
EXPORT_SYMBOL(ide_input_data);
EXPORT_SYMBOL(ide_output_data);
EXPORT_SYMBOL(atapi_input_bytes);
EXPORT_SYMBOL(atapi_output_bytes);
EXPORT_SYMBOL(ide_set_handler);
EXPORT_SYMBOL(ide_dump_status);
EXPORT_SYMBOL(ide_error);
EXPORT_SYMBOL(ide_fixstring);
EXPORT_SYMBOL(ide_wait_stat);
EXPORT_SYMBOL(ide_do_reset);
EXPORT_SYMBOL(ide_init_drive_cmd);
EXPORT_SYMBOL(ide_do_drive_cmd);
EXPORT_SYMBOL(ide_end_drive_cmd);
EXPORT_SYMBOL(ide_end_request);
EXPORT_SYMBOL(ide_revalidate_disk);
EXPORT_SYMBOL(ide_cmd);
EXPORT_SYMBOL(ide_wait_cmd);
EXPORT_SYMBOL(ide_stall_queue);
#ifdef CONFIG_PROC_FS
EXPORT_SYMBOL(ide_add_proc_entries);
EXPORT_SYMBOL(ide_remove_proc_entries);
EXPORT_SYMBOL(proc_ide_read_geometry);
#endif
EXPORT_SYMBOL(ide_add_setting);
EXPORT_SYMBOL(ide_remove_setting);

EXPORT_SYMBOL(ide_register);
EXPORT_SYMBOL(ide_unregister);

/*
 * This is gets invoked once during initialization, to set *everything* up
 */
__initfunc(int ide_init (void))
{
        init_ide_data ();

        initializing = 1;
        ide_init_builtin_drivers();
        initializing = 0;

        return 0;
}

#ifdef MODULE
char *options = NULL;
MODULE_PARM(options,"s");

__initfunc(static void parse_options (char *line))
{
        char *next = line;

        if (line == NULL || !*line)
                return;
        while ((line = next) != NULL) {
                if ((next = strchr(line,' ')) != NULL)
                        *next++ = 0;
                if (!strncmp(line,"ide",3) || (!strncmp(line,"hd",2) && line[2] != '='))
                        ide_setup(line);
        }
}

int init_module (void)
{
        parse_options(options);
        return ide_init();
}

void cleanup_module (void)
{
        int index;

        for (index = 0; index < MAX_HWIFS; ++index)
                ide_unregister(index);
#ifdef CONFIG_PROC_FS
        proc_ide_destroy();
#endif
}
#endif /* MODULE */