Merge branch 'master'

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / ide / ide.c

/*
 *  linux/drivers/ide/ide.c             Version 7.00beta2       Mar 05 2003
 *
 *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
 */

/*
 *  Mostly written by Mark Lord  <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 *  See linux/MAINTAINERS for address of current maintainer.
 *
 * This is the multiple IDE interface driver, as evolved from hd.c.
 * It supports up to MAX_HWIFS IDE interfaces, on one or more IRQs
 *   (usually 14 & 15).
 * There can be up to two drives per interface, as per the ATA-2 spec.
 *
 * Primary:    ide0, port 0x1f0; major=3;  hda is minor=0; hdb is minor=64
 * Secondary:  ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
 * Tertiary:   ide2, port 0x???; major=33; hde is minor=0; hdf is minor=64
 * Quaternary: ide3, port 0x???; major=34; hdg is minor=0; hdh is minor=64
 * ...
 *
 *  From hd.c:
 *  |
 *  | It traverses the request-list, using interrupts to jump between functions.
 *  | As nearly all functions can be called within interrupts, we may not sleep.
 *  | Special care is recommended.  Have Fun!
 *  |
 *  | modified by Drew Eckhardt to check nr of hd's from the CMOS.
 *  |
 *  | Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
 *  | in the early extended-partition checks and added DM partitions.
 *  |
 *  | Early work on error handling by Mika Liljeberg (liljeber@cs.Helsinki.FI).
 *  |
 *  | IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
 *  | and general streamlining by Mark Lord (mlord@pobox.com).
 *
 *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
 *
 *      Mark Lord       (mlord@pobox.com)               (IDE Perf.Pkg)
 *      Delman Lee      (delman@ieee.org)               ("Mr. atdisk2")
 *      Scott Snyder    (snyder@fnald0.fnal.gov)        (ATAPI IDE cd-rom)
 *
 *  This was a rewrite of just about everything from hd.c, though some original
 *  code is still sprinkled about.  Think of it as a major evolution, with
 *  inspiration from lots of linux users, esp.  hamish@zot.apana.org.au
 *
 *  Version 1.0 ALPHA   initial code, primary i/f working okay
 *  Version 1.3 BETA    dual i/f on shared irq tested & working!
 *  Version 1.4 BETA    added auto probing for irq(s)
 *  Version 1.5 BETA    added ALPHA (untested) support for IDE cd-roms,
 *  ...
 * Version 5.50         allow values as small as 20 for idebus=
 * Version 5.51         force non io_32bit in drive_cmd_intr()
 *                      change delay_10ms() to delay_50ms() to fix problems
 * Version 5.52         fix incorrect invalidation of removable devices
 *                      add "hdx=slow" command line option
 * Version 5.60         start to modularize the driver; the disk and ATAPI
 *                       drivers can be compiled as loadable modules.
 *                      move IDE probe code to ide-probe.c
 *                      move IDE disk code to ide-disk.c
 *                      add support for generic IDE device subdrivers
 *                      add m68k code from Geert Uytterhoeven
 *                      probe all interfaces by default
 *                      add ioctl to (re)probe an interface
 * Version 6.00         use per device request queues
 *                      attempt to optimize shared hwgroup performance
 *                      add ioctl to manually adjust bandwidth algorithms
 *                      add kerneld support for the probe module
 *                      fix bug in ide_error()
 *                      fix bug in the first ide_get_lock() call for Atari
 *                      don't flush leftover data for ATAPI devices
 * Version 6.01         clear hwgroup->active while the hwgroup sleeps
 *                      support HDIO_GETGEO for floppies
 * Version 6.02         fix ide_ack_intr() call
 *                      check partition table on floppies
 * Version 6.03         handle bad status bit sequencing in ide_wait_stat()
 * Version 6.10         deleted old entries from this list of updates
 *                      replaced triton.c with ide-dma.c generic PCI DMA
 *                      added support for BIOS-enabled UltraDMA
 *                      rename all "promise" things to "pdc4030"
 *                      fix EZ-DRIVE handling on small disks
 * Version 6.11         fix probe error in ide_scan_devices()
 *                      fix ancient "jiffies" polling bugs
 *                      mask all hwgroup interrupts on each irq entry
 * Version 6.12         integrate ioctl and proc interfaces
 *                      fix parsing of "idex=" command line parameter
 * Version 6.13         add support for ide4/ide5 courtesy rjones@orchestream.com
 * Version 6.14         fixed IRQ sharing among PCI devices
 * Version 6.15         added SMP awareness to IDE drivers
 * Version 6.16         fixed various bugs; even more SMP friendly
 * Version 6.17         fix for newest EZ-Drive problem
 * Version 6.18         default unpartitioned-disk translation now "BIOS LBA"
 * Version 6.19         Re-design for a UNIFORM driver for all platforms,
 *                        model based on suggestions from Russell King and
 *                        Geert Uytterhoeven
 *                      Promise DC4030VL now supported.
 *                      add support for ide6/ide7
 *                      delay_50ms() changed to ide_delay_50ms() and exported.
 * Version 6.20         Added/Fixed Generic ATA-66 support and hwif detection.
 *                      Added hdx=flash to allow for second flash disk
 *                        detection w/o the hang loop.
 *                      Added support for ide8/ide9
 *                      Added idex=ata66 for the quirky chipsets that are
 *                        ATA-66 compliant, but have yet to determine a method
 *                        of verification of the 80c cable presence.
 *                        Specifically Promise's PDC20262 chipset.
 * Version 6.21         Fixing/Fixed SMP spinlock issue with insight from an old
 *                        hat that clarified original low level driver design.
 * Version 6.30         Added SMP support; fixed multmode issues.  -ml
 * Version 6.31         Debug Share INTR's and request queue streaming
 *                      Native ATA-100 support
 *                      Prep for Cascades Project
 * Version 7.00alpha    First named revision of ide rearrange
 *
 *  Some additional driver compile-time options are in ./include/linux/ide.h
 *
 *  To do, in likely order of completion:
 *      - modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
 *
 */

#define REVISION        "Revision: 7.00alpha2"
#define VERSION         "Id: ide.c 7.00a2 20020906"

#undef REALLY_SLOW_IO           /* most systems can safely undef this */

#define _IDE_C                  /* Tell ide.h it's really us */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/completion.h>
#include <linux/reboot.h>
#include <linux/cdrom.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/bitops.h>

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


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

static const u8 ide_hwif_to_major[] = { IDE0_MAJOR, IDE1_MAJOR,
                                        IDE2_MAJOR, IDE3_MAJOR,
                                        IDE4_MAJOR, IDE5_MAJOR,
                                        IDE6_MAJOR, IDE7_MAJOR,
                                        IDE8_MAJOR, IDE9_MAJOR };

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

DECLARE_MUTEX(ide_cfg_sem);
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);

#ifdef CONFIG_BLK_DEV_IDEPCI
static int ide_scan_direction; /* THIS was formerly 2.2.x pci=reverse */
#endif

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

EXPORT_SYMBOL(noautodma);

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

EXPORT_SYMBOL(ide_hwifs);

/*
 * Do not even *think* about calling this!
 */
static void init_hwif_data(ide_hwif_t *hwif, unsigned int index)
{
        unsigned int unit;

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

        /* fill in any non-zero initial values */
        hwif->index     = index;
        hwif->major     = ide_hwif_to_major[index];

        hwif->name[0]   = 'i';
        hwif->name[1]   = 'd';
        hwif->name[2]   = 'e';
        hwif->name[3]   = '0' + index;

        hwif->bus_state = BUSSTATE_ON;

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

        sema_init(&hwif->gendev_rel_sem, 0);

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

                drive->media                    = ide_disk;
                drive->select.all               = (unit<<4)|0xa0;
                drive->hwif                     = hwif;
                drive->ctl                      = 0x08;
                drive->ready_stat               = READY_STAT;
                drive->bad_wstat                = BAD_W_STAT;
                drive->special.b.recalibrate    = 1;
                drive->special.b.set_geometry   = 1;
                drive->name[0]                  = 'h';
                drive->name[1]                  = 'd';
                drive->name[2]                  = 'a' + (index * MAX_DRIVES) + unit;
                drive->max_failures             = IDE_DEFAULT_MAX_FAILURES;
                drive->using_dma                = 0;
                drive->is_flash                 = 0;
                drive->vdma                     = 0;
                INIT_LIST_HEAD(&drive->list);
                sema_init(&drive->gendev_rel_sem, 0);
        }
}

static void init_hwif_default(ide_hwif_t *hwif, unsigned int index)
{
        hw_regs_t hw;

        memset(&hw, 0, sizeof(hw_regs_t));

        ide_init_hwif_ports(&hw, ide_default_io_base(index), 0, &hwif->irq);

        memcpy(&hwif->hw, &hw, sizeof(hw));
        memcpy(hwif->io_ports, hw.io_ports, sizeof(hw.io_ports));

        hwif->noprobe = !hwif->io_ports[IDE_DATA_OFFSET];
#ifdef CONFIG_BLK_DEV_HD
        if (hwif->io_ports[IDE_DATA_OFFSET] == HD_DATA)
                hwif->noprobe = 1;      /* may be overridden by ide_setup() */
#endif
}

extern void ide_arm_init(void);

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

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

        /* Initialise all interface structures */
        for (index = 0; index < MAX_HWIFS; ++index) {
                hwif = &ide_hwifs[index];
                init_hwif_data(hwif, index);
                init_hwif_default(hwif, index);
#if !defined(CONFIG_PPC32) || !defined(CONFIG_PCI)
                hwif->irq = hwif->hw.irq =
                        ide_init_default_irq(hwif->io_ports[IDE_DATA_OFFSET]);
#endif
        }
#ifdef CONFIG_IDE_ARM
        initializing = 1;
        ide_arm_init();
        initializing = 0;
#endif
}

/**
 *      ide_system_bus_speed    -       guess bus speed
 *
 *      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. Drivers should only use this as a last resort.
 *
 *      Returns a guessed speed in MHz.
 */

static int ide_system_bus_speed(void)
{
#ifdef CONFIG_PCI
        static struct pci_device_id pci_default[] = {
                { PCI_DEVICE(PCI_ANY_ID, PCI_ANY_ID) },
                { }
        };
#else
#define pci_default 0
#endif /* CONFIG_PCI */

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

#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_ide_root;
#endif

static struct resource* hwif_request_region(ide_hwif_t *hwif,
                                            unsigned long addr, int num)
{
        struct resource *res = request_region(addr, num, hwif->name);

        if (!res)
                printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.\n",
                                hwif->name, addr, addr+num-1);
        return res;
}

/**
 *      ide_hwif_request_regions - request resources for IDE
 *      @hwif: interface to use
 *
 *      Requests all the needed resources for an interface.
 *      Right now core IDE code does this work which is deeply wrong.
 *      MMIO leaves it to the controller driver,
 *      PIO will migrate this way over time.
 */

int ide_hwif_request_regions(ide_hwif_t *hwif)
{
        unsigned long addr;
        unsigned int i;

        if (hwif->mmio == 2)
                return 0;
        BUG_ON(hwif->mmio == 1);
        addr = hwif->io_ports[IDE_CONTROL_OFFSET];
        if (addr && !hwif_request_region(hwif, addr, 1))
                goto control_region_busy;
        hwif->straight8 = 0;
        addr = hwif->io_ports[IDE_DATA_OFFSET];
        if ((addr | 7) == hwif->io_ports[IDE_STATUS_OFFSET]) {
                if (!hwif_request_region(hwif, addr, 8))
                        goto data_region_busy;
                hwif->straight8 = 1;
                return 0;
        }
        for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++) {
                addr = hwif->io_ports[i];
                if (!hwif_request_region(hwif, addr, 1)) {
                        while (--i)
                                release_region(addr, 1);
                        goto data_region_busy;
                }
        }
        return 0;

data_region_busy:
        addr = hwif->io_ports[IDE_CONTROL_OFFSET];
        if (addr)
                release_region(addr, 1);
control_region_busy:
        /* If any errors are return, we drop the hwif interface. */
        return -EBUSY;
}

/**
 *      ide_hwif_release_regions - free IDE resources
 *
 *      Note that we only release the standard ports,
 *      and do not even try to handle any extra ports
 *      allocated for weird IDE interface chipsets.
 *
 *      Note also that we don't yet handle mmio resources here. More
 *      importantly our caller should be doing this so we need to 
 *      restructure this as a helper function for drivers.
 */

void ide_hwif_release_regions(ide_hwif_t *hwif)
{
        u32 i = 0;

        if (hwif->mmio == 2)
                return;
        if (hwif->io_ports[IDE_CONTROL_OFFSET])
                release_region(hwif->io_ports[IDE_CONTROL_OFFSET], 1);
        if (hwif->straight8) {
                release_region(hwif->io_ports[IDE_DATA_OFFSET], 8);
                return;
        }
        for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++)
                if (hwif->io_ports[i])
                        release_region(hwif->io_ports[i], 1);
}

/**
 *      ide_hwif_restore        -       restore hwif to template
 *      @hwif: hwif to update
 *      @tmp_hwif: template
 *
 *      Restore hwif to a previous state by copying most settngs
 *      from the template.
 */

static void ide_hwif_restore(ide_hwif_t *hwif, ide_hwif_t *tmp_hwif)
{
        hwif->hwgroup                   = tmp_hwif->hwgroup;

        hwif->gendev.parent             = tmp_hwif->gendev.parent;

        hwif->proc                      = tmp_hwif->proc;

        hwif->major                     = tmp_hwif->major;
        hwif->straight8                 = tmp_hwif->straight8;
        hwif->bus_state                 = tmp_hwif->bus_state;

        hwif->atapi_dma                 = tmp_hwif->atapi_dma;
        hwif->ultra_mask                = tmp_hwif->ultra_mask;
        hwif->mwdma_mask                = tmp_hwif->mwdma_mask;
        hwif->swdma_mask                = tmp_hwif->swdma_mask;

        hwif->chipset                   = tmp_hwif->chipset;
        hwif->hold                      = tmp_hwif->hold;

#ifdef CONFIG_BLK_DEV_IDEPCI
        hwif->pci_dev                   = tmp_hwif->pci_dev;
        hwif->cds                       = tmp_hwif->cds;
#endif

        hwif->tuneproc                  = tmp_hwif->tuneproc;
        hwif->speedproc                 = tmp_hwif->speedproc;
        hwif->selectproc                = tmp_hwif->selectproc;
        hwif->reset_poll                = tmp_hwif->reset_poll;
        hwif->pre_reset                 = tmp_hwif->pre_reset;
        hwif->resetproc                 = tmp_hwif->resetproc;
        hwif->intrproc                  = tmp_hwif->intrproc;
        hwif->maskproc                  = tmp_hwif->maskproc;
        hwif->quirkproc                 = tmp_hwif->quirkproc;
        hwif->busproc                   = tmp_hwif->busproc;

        hwif->ata_input_data            = tmp_hwif->ata_input_data;
        hwif->ata_output_data           = tmp_hwif->ata_output_data;
        hwif->atapi_input_bytes         = tmp_hwif->atapi_input_bytes;
        hwif->atapi_output_bytes        = tmp_hwif->atapi_output_bytes;

        hwif->dma_setup                 = tmp_hwif->dma_setup;
        hwif->dma_exec_cmd              = tmp_hwif->dma_exec_cmd;
        hwif->dma_start                 = tmp_hwif->dma_start;
        hwif->ide_dma_end               = tmp_hwif->ide_dma_end;
        hwif->ide_dma_check             = tmp_hwif->ide_dma_check;
        hwif->ide_dma_on                = tmp_hwif->ide_dma_on;
        hwif->ide_dma_off_quietly       = tmp_hwif->ide_dma_off_quietly;
        hwif->ide_dma_test_irq          = tmp_hwif->ide_dma_test_irq;
        hwif->ide_dma_host_on           = tmp_hwif->ide_dma_host_on;
        hwif->ide_dma_host_off          = tmp_hwif->ide_dma_host_off;
        hwif->ide_dma_lostirq           = tmp_hwif->ide_dma_lostirq;
        hwif->ide_dma_timeout           = tmp_hwif->ide_dma_timeout;

        hwif->OUTB                      = tmp_hwif->OUTB;
        hwif->OUTBSYNC                  = tmp_hwif->OUTBSYNC;
        hwif->OUTW                      = tmp_hwif->OUTW;
        hwif->OUTL                      = tmp_hwif->OUTL;
        hwif->OUTSW                     = tmp_hwif->OUTSW;
        hwif->OUTSL                     = tmp_hwif->OUTSL;

        hwif->INB                       = tmp_hwif->INB;
        hwif->INW                       = tmp_hwif->INW;
        hwif->INL                       = tmp_hwif->INL;
        hwif->INSW                      = tmp_hwif->INSW;
        hwif->INSL                      = tmp_hwif->INSL;

        hwif->sg_max_nents              = tmp_hwif->sg_max_nents;

        hwif->mmio                      = tmp_hwif->mmio;
        hwif->rqsize                    = tmp_hwif->rqsize;
        hwif->no_lba48                  = tmp_hwif->no_lba48;

#ifndef CONFIG_BLK_DEV_IDECS
        hwif->irq                       = tmp_hwif->irq;
#endif

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

        hwif->dma_extra                 = tmp_hwif->dma_extra;
        hwif->config_data               = tmp_hwif->config_data;
        hwif->select_data               = tmp_hwif->select_data;
        hwif->autodma                   = tmp_hwif->autodma;
        hwif->udma_four                 = tmp_hwif->udma_four;
        hwif->no_dsc                    = tmp_hwif->no_dsc;

        hwif->hwif_data                 = tmp_hwif->hwif_data;
}

/**
 *      ide_unregister          -       free an ide interface
 *      @index: index of interface (will change soon to a pointer)
 *
 *      Perform the final unregister of an IDE interface. At the moment
 *      we don't refcount interfaces so this will also get split up.
 *
 *      Locking:
 *      The caller must not hold the IDE locks
 *      The drive present/vanishing is not yet properly locked
 *      Take care with the callbacks. These have been split to avoid
 *      deadlocking the IDE layer. The shutdown callback is called
 *      before we take the lock and free resources. It is up to the
 *      caller to be sure there is no pending I/O here, and that
 *      the interfce will not be reopened (present/vanishing locking
 *      isnt yet done btw). After we commit to the final kill we
 *      call the cleanup callback with the ide locks held.
 *
 *      Unregister restores the hwif structures to the default state.
 *      This is raving bonkers.
 */

void ide_unregister(unsigned int index)
{
        ide_drive_t *drive;
        ide_hwif_t *hwif, *g;
        static ide_hwif_t tmp_hwif; /* protected by ide_cfg_sem */
        ide_hwgroup_t *hwgroup;
        int irq_count = 0, unit;

        BUG_ON(index >= MAX_HWIFS);

        BUG_ON(in_interrupt());
        BUG_ON(irqs_disabled());
        down(&ide_cfg_sem);
        spin_lock_irq(&ide_lock);
        hwif = &ide_hwifs[index];
        if (!hwif->present)
                goto abort;
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                drive = &hwif->drives[unit];
                if (!drive->present) {
                        if (drive->devfs_name[0] != '\0') {
                                devfs_remove(drive->devfs_name);
                                drive->devfs_name[0] = '\0';
                        }
                        continue;
                }
                spin_unlock_irq(&ide_lock);
                device_unregister(&drive->gendev);
                down(&drive->gendev_rel_sem);
                spin_lock_irq(&ide_lock);
        }
        hwif->present = 0;

        spin_unlock_irq(&ide_lock);

        destroy_proc_ide_interface(hwif);

        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);

        spin_lock_irq(&ide_lock);
        /*
         * 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_hwif_release_regions(hwif);

        /*
         * Remove us from the hwgroup, and free
         * the hwgroup if we were the only member
         */
        if (hwif->next == hwif) {
                BUG_ON(hwgroup->hwif != hwif);
                kfree(hwgroup);
        } else {
                /* There is another interface in hwgroup.
                 * Unlink us, and set hwgroup->drive and ->hwif to
                 * something sane.
                 */
                g = hwgroup->hwif;
                while (g->next != hwif)
                        g = g->next;
                g->next = hwif->next;
                if (hwgroup->hwif == hwif) {
                        /* Chose a random hwif for hwgroup->hwif.
                         * It's guaranteed that there are no drives
                         * left in the hwgroup.
                         */
                        BUG_ON(hwgroup->drive != NULL);
                        hwgroup->hwif = g;
                }
                BUG_ON(hwgroup->hwif == hwif);
        }

        /* More messed up locking ... */
        spin_unlock_irq(&ide_lock);
        device_unregister(&hwif->gendev);
        down(&hwif->gendev_rel_sem);

        /*
         * Remove us from the kernel's knowledge
         */
        blk_unregister_region(MKDEV(hwif->major, 0), MAX_DRIVES<<PARTN_BITS);
        kfree(hwif->sg_table);
        unregister_blkdev(hwif->major, hwif->name);
        spin_lock_irq(&ide_lock);

        if (hwif->dma_base) {
                (void) ide_release_dma(hwif);

                hwif->dma_base = 0;
                hwif->dma_master = 0;
                hwif->dma_command = 0;
                hwif->dma_vendor1 = 0;
                hwif->dma_status = 0;
                hwif->dma_vendor3 = 0;
                hwif->dma_prdtable = 0;
        }

        /* copy original settings */
        tmp_hwif = *hwif;

        /* restore hwif data to pristine status */
        init_hwif_data(hwif, index);
        init_hwif_default(hwif, index);

        ide_hwif_restore(hwif, &tmp_hwif);

abort:
        spin_unlock_irq(&ide_lock);
        up(&ide_cfg_sem);
}

EXPORT_SYMBOL(ide_unregister);


/**
 *      ide_setup_ports         -       set up IDE interface ports
 *      @hw: register descriptions
 *      @base: base register
 *      @offsets: table of register offsets
 *      @ctrl: control register
 *      @ack_irq: IRQ ack
 *      @irq: interrupt lie
 *
 *      Setup hw_regs_t structure described by parameters.  You
 *      may set up the hw structure yourself OR use this routine to
 *      do it for you. This is basically a helper
 *
 */
 
void ide_setup_ports (  hw_regs_t *hw,
                        unsigned long base, int *offsets,
                        unsigned long ctrl, unsigned long intr,
                        ide_ack_intr_t *ack_intr,
/*
 *                      ide_io_ops_t *iops,
 */
                        int irq)
{
        int i;

        for (i = 0; i < IDE_NR_PORTS; i++) {
                if (offsets[i] == -1) {
                        switch(i) {
                                case IDE_CONTROL_OFFSET:
                                        hw->io_ports[i] = ctrl;
                                        break;
#if defined(CONFIG_AMIGA) || defined(CONFIG_MAC)
                                case IDE_IRQ_OFFSET:
                                        hw->io_ports[i] = intr;
                                        break;
#endif /* (CONFIG_AMIGA) || (CONFIG_MAC) */
                                default:
                                        hw->io_ports[i] = 0;
                                        break;
                        }
                } else {
                        hw->io_ports[i] = base + offsets[i];
                }
        }
        hw->irq = irq;
        hw->dma = NO_DMA;
        hw->ack_intr = ack_intr;
/*
 *      hw->iops = iops;
 */
}

/**
 *      ide_register_hw_with_fixup      -       register IDE interface
 *      @hw: hardware registers
 *      @hwifp: pointer to returned hwif
 *      @fixup: fixup function
 *
 *      Register an IDE interface, specifying exactly the registers etc.
 *      Set init=1 iff calling before probes have taken place.
 *
 *      Returns -1 on error.
 */

int ide_register_hw_with_fixup(hw_regs_t *hw, ide_hwif_t **hwifp, void(*fixup)(ide_hwif_t *hwif))
{
        int index, retry = 1;
        ide_hwif_t *hwif;

        do {
                for (index = 0; index < MAX_HWIFS; ++index) {
                        hwif = &ide_hwifs[index];
                        if (hwif->hw.io_ports[IDE_DATA_OFFSET] == hw->io_ports[IDE_DATA_OFFSET])
                                goto found;
                }
                for (index = 0; index < MAX_HWIFS; ++index) {
                        hwif = &ide_hwifs[index];
                        if (hwif->hold)
                                continue;
                        if ((!hwif->present && !hwif->mate && !initializing) ||
                            (!hwif->hw.io_ports[IDE_DATA_OFFSET] && initializing))
                                goto found;
                }
                for (index = 0; index < MAX_HWIFS; index++)
                        ide_unregister(index);
        } while (retry--);
        return -1;
found:
        if (hwif->present)
                ide_unregister(index);
        else if (!hwif->hold) {
                init_hwif_data(hwif, index);
                init_hwif_default(hwif, index);
        }
        if (hwif->present)
                return -1;
        memcpy(&hwif->hw, hw, sizeof(*hw));
        memcpy(hwif->io_ports, hwif->hw.io_ports, sizeof(hwif->hw.io_ports));
        hwif->irq = hw->irq;
        hwif->noprobe = 0;
        hwif->chipset = hw->chipset;
        hwif->gendev.parent = hw->dev;

        if (!initializing) {
                probe_hwif_init_with_fixup(hwif, fixup);
                create_proc_ide_interfaces();
        }

        if (hwifp)
                *hwifp = hwif;

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

EXPORT_SYMBOL(ide_register_hw_with_fixup);

int ide_register_hw(hw_regs_t *hw, ide_hwif_t **hwifp)
{
        return ide_register_hw_with_fixup(hw, hwifp, NULL);
}

EXPORT_SYMBOL(ide_register_hw);

/*
 *      Locks for IDE setting functionality
 */

DECLARE_MUTEX(ide_setting_sem);

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

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

        down(&ide_setting_sem);
        while ((*p) && strcmp((*p)->name, name) < 0)
                p = &((*p)->next);
        if ((setting = kzalloc(sizeof(*setting), GFP_KERNEL)) == NULL)
                goto abort;
        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 (auto_remove)
                setting->auto_remove = 1;
        *p = setting;
        up(&ide_setting_sem);
        return 0;
abort:
        up(&ide_setting_sem);
        kfree(setting);
        return -1;
}

int ide_add_setting(ide_drive_t *drive, const char *name, int rw, int read_ioctl, int write_ioctl, int data_type, int min, int max, int mul_factor, int div_factor, void *data, ide_procset_t *set)
{
        return __ide_add_setting(drive, name, rw, read_ioctl, write_ioctl, data_type, min, max, mul_factor, div_factor, data, set, 1);
}

EXPORT_SYMBOL(ide_add_setting);

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

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

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

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

/**
 *      ide_find_setting_by_ioctl       -       find a drive specific ioctl
 *      @drive: drive to scan
 *      @cmd: ioctl command to handle
 *
 *      Scan's the device setting table for a matching entry and returns
 *      this or NULL if no entry is found. The caller must hold the
 *      setting semaphore
 */
 
static ide_settings_t *ide_find_setting_by_ioctl (ide_drive_t *drive, int cmd)
{
        ide_settings_t *setting = drive->settings;

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

/**
 *      ide_find_setting_by_name        -       find a drive specific setting
 *      @drive: drive to scan
 *      @name: setting name
 *
 *      Scan's the device setting table for a matching entry and returns
 *      this or NULL if no entry is found. The caller must hold the
 *      setting semaphore
 */
 
ide_settings_t *ide_find_setting_by_name (ide_drive_t *drive, char *name)
{
        ide_settings_t *setting = drive->settings;

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

/**
 *      auto_remove_settings    -       remove driver specific settings
 *      @drive: drive
 *
 *      Automatically remove all the driver specific settings for this
 *      drive. This function may sleep and must not be called from IRQ
 *      context. The caller must hold ide_setting_sem.
 */
 
static void auto_remove_settings (ide_drive_t *drive)
{
        ide_settings_t *setting;
repeat:
        setting = drive->settings;
        while (setting) {
                if (setting->auto_remove) {
                        __ide_remove_setting(drive, setting->name);
                        goto repeat;
                }
                setting = setting->next;
        }
}

/**
 *      ide_read_setting        -       read an IDE setting
 *      @drive: drive to read from
 *      @setting: drive setting
 *
 *      Read a drive setting and return the value. The caller
 *      must hold the ide_setting_sem when making this call.
 *
 *      BUGS: the data return and error are the same return value
 *      so an error -EINVAL and true return of the same value cannot
 *      be told apart
 */
 
int ide_read_setting (ide_drive_t *drive, ide_settings_t *setting)
{
        int             val = -EINVAL;
        unsigned long   flags;

        if ((setting->rw & SETTING_READ)) {
                spin_lock_irqsave(&ide_lock, flags);
                switch(setting->data_type) {
                        case TYPE_BYTE:
                                val = *((u8 *) setting->data);
                                break;
                        case TYPE_SHORT:
                                val = *((u16 *) setting->data);
                                break;
                        case TYPE_INT:
                        case TYPE_INTA:
                                val = *((u32 *) setting->data);
                                break;
                }
                spin_unlock_irqrestore(&ide_lock, flags);
        }
        return val;
}

/**
 *      ide_spin_wait_hwgroup   -       wait for group
 *      @drive: drive in the group
 *
 *      Wait for an IDE device group to go non busy and then return
 *      holding the ide_lock which guards the hwgroup->busy status
 *      and right to use it.
 */

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

        spin_lock_irq(&ide_lock);

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

EXPORT_SYMBOL(ide_spin_wait_hwgroup);

/**
 *      ide_write_setting       -       read an IDE setting
 *      @drive: drive to read from
 *      @setting: drive setting
 *      @val: value
 *
 *      Write a drive setting if it is possible. The caller
 *      must hold the ide_setting_sem when making this call.
 *
 *      BUGS: the data return and error are the same return value
 *      so an error -EINVAL and true return of the same value cannot
 *      be told apart
 *
 *      FIXME:  This should be changed to enqueue a special request
 *      to the driver to change settings, and then wait on a sema for completion.
 *      The current scheme of polling is kludgy, though safe enough.
 */

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

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!(setting->rw & SETTING_WRITE))
                return -EPERM;
        if (val < setting->min || val > setting->max)
                return -EINVAL;
        if (setting->set)
                return setting->set(drive, val);
        if (ide_spin_wait_hwgroup(drive))
                return -EBUSY;
        switch (setting->data_type) {
                case TYPE_BYTE:
                        *((u8 *) setting->data) = val;
                        break;
                case TYPE_SHORT:
                        *((u16 *) setting->data) = val;
                        break;
                case TYPE_INT:
                        *((u32 *) setting->data) = val;
                        break;
                case TYPE_INTA:
                        p = (u32 *) setting->data;
                        for (i = 0; i < 1 << PARTN_BITS; i++, p++)
                                *p = val;
                        break;
        }
        spin_unlock_irq(&ide_lock);
        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)
{
#ifdef CONFIG_BLK_DEV_IDEDMA
        if (!drive->id || !(drive->id->capability & 1))
                return -EPERM;
        if (HWIF(drive)->ide_dma_check == NULL)
                return -EPERM;
        if (arg) {
                if (HWIF(drive)->ide_dma_check(drive)) return -EIO;
                if (HWIF(drive)->ide_dma_on(drive)) return -EIO;
        } else {
                if (__ide_dma_off(drive))
                        return -EIO;
        }
        return 0;
#else
        return -EPERM;
#endif
}

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

        if (!HWIF(drive)->tuneproc)
                return -ENOSYS;
        if (drive->special.b.set_tune)
                return -EBUSY;
        ide_init_drive_cmd(&rq);
        drive->tune_req = (u8) arg;
        drive->special.b.set_tune = 1;
        (void) ide_do_drive_cmd(drive, &rq, ide_wait);
        return 0;
}

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

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

/**
 *      ide_add_generic_settings        -       generic ide settings
 *      @drive: drive being configured
 *
 *      Add the generic parts of the system settings to the /proc files and
 *      ioctls for this IDE device. The caller must not be holding the
 *      ide_setting_sem.
 */

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,   0);
        __ide_add_setting(drive,        "keepsettings",         SETTING_RW,                                     HDIO_GET_KEEPSETTINGS,  HDIO_SET_KEEPSETTINGS,  TYPE_BYTE,      0,      1,                              1,              1,              &drive->keep_settings,          NULL,           0);
        __ide_add_setting(drive,        "nice1",                SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      1,                              1,              1,              &drive->nice1,                  NULL,           0);
        __ide_add_setting(drive,        "pio_mode",             SETTING_WRITE,                                  -1,                     HDIO_SET_PIO_MODE,      TYPE_BYTE,      0,      255,                            1,              1,              NULL,                           set_pio_mode,   0);
        __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,           0);
        __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,  0);
        __ide_add_setting(drive,        "init_speed",           SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      70,                             1,              1,              &drive->init_speed,             NULL,           0);
        __ide_add_setting(drive,        "current_speed",        SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      70,                             1,              1,              &drive->current_speed,          set_xfer_rate,  0);
        __ide_add_setting(drive,        "number",               SETTING_RW,                                     -1,                     -1,                     TYPE_BYTE,      0,      3,                              1,              1,              &drive->dn,                     NULL,           0);
}

/**
 *      system_bus_clock        -       clock guess
 *
 *      External version of the bus clock guess used by very old IDE drivers
 *      for things like VLB timings. Should not be used.
 */

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

EXPORT_SYMBOL(system_bus_clock);

static int generic_ide_suspend(struct device *dev, pm_message_t state)
{
        ide_drive_t *drive = dev->driver_data;
        struct request rq;
        struct request_pm_state rqpm;
        ide_task_t args;

        memset(&rq, 0, sizeof(rq));
        memset(&rqpm, 0, sizeof(rqpm));
        memset(&args, 0, sizeof(args));
        rq.flags = REQ_PM_SUSPEND;
        rq.special = &args;
        rq.pm = &rqpm;
        rqpm.pm_step = ide_pm_state_start_suspend;
        rqpm.pm_state = state.event;

        return ide_do_drive_cmd(drive, &rq, ide_wait);
}

static int generic_ide_resume(struct device *dev)
{
        ide_drive_t *drive = dev->driver_data;
        struct request rq;
        struct request_pm_state rqpm;
        ide_task_t args;

        memset(&rq, 0, sizeof(rq));
        memset(&rqpm, 0, sizeof(rqpm));
        memset(&args, 0, sizeof(args));
        rq.flags = REQ_PM_RESUME;
        rq.special = &args;
        rq.pm = &rqpm;
        rqpm.pm_step = ide_pm_state_start_resume;
        rqpm.pm_state = PM_EVENT_ON;

        return ide_do_drive_cmd(drive, &rq, ide_head_wait);
}

int generic_ide_ioctl(ide_drive_t *drive, struct file *file, struct block_device *bdev,
                        unsigned int cmd, unsigned long arg)
{
        ide_settings_t *setting;
        ide_driver_t *drv;
        int err = 0;
        void __user *p = (void __user *)arg;

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

        switch (cmd) {
                case HDIO_GETGEO:
                {
                        struct hd_geometry geom;
                        if (!p || (drive->media != ide_disk && drive->media != ide_floppy)) return -EINVAL;
                        geom.heads = drive->bios_head;
                        geom.sectors = drive->bios_sect;
                        geom.cylinders = (u16)drive->bios_cyl; /* truncate */
                        geom.start = get_start_sect(bdev);
                        if (copy_to_user(p, &geom, sizeof(struct hd_geometry)))
                                return -EFAULT;
                        return 0;
                }

                case HDIO_OBSOLETE_IDENTITY:
                case HDIO_GET_IDENTITY:
                        if (bdev != bdev->bd_contains)
                                return -EINVAL;
                        if (drive->id_read == 0)
                                return -ENOMSG;
                        if (copy_to_user(p, 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 __user *) arg);

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

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

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

                case HDIO_SCAN_HWIF:
                {
                        hw_regs_t hw;
                        int args[3];
                        if (!capable(CAP_SYS_RAWIO)) return -EACCES;
                        if (copy_from_user(args, p, 3 * sizeof(int)))
                                return -EFAULT;
                        memset(&hw, 0, sizeof(hw));
                        ide_init_hwif_ports(&hw, (unsigned long) args[0],
                                            (unsigned long) args[1], NULL);
                        hw.irq = args[2];
                        if (ide_register_hw(&hw, NULL) == -1)
                                return -EIO;
                        return 0;
                }
                case HDIO_UNREGISTER_HWIF:
                        if (!capable(CAP_SYS_RAWIO)) return -EACCES;
                        /* (arg > MAX_HWIFS) checked in function */
                        ide_unregister(arg);
                        return 0;
                case HDIO_SET_NICE:
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        if (arg != (arg & ((1 << IDE_NICE_DSC_OVERLAP) | (1 << IDE_NICE_1))))
                                return -EPERM;
                        drive->dsc_overlap = (arg >> IDE_NICE_DSC_OVERLAP) & 1;
                        drv = *(ide_driver_t **)bdev->bd_disk->private_data;
                        if (drive->dsc_overlap && !drv->supports_dsc_overlap) {
                                drive->dsc_overlap = 0;
                                return -EPERM;
                        }
                        drive->nice1 = (arg >> IDE_NICE_1) & 1;
                        return 0;
                case HDIO_DRIVE_RESET:
                {
                        unsigned long flags;
                        if (!capable(CAP_SYS_ADMIN)) return -EACCES;
                        
                        /*
                         *      Abort the current command on the
                         *      group if there is one, taking
                         *      care not to allow anything else
                         *      to be queued and to die on the
                         *      spot if we miss one somehow
                         */

                        spin_lock_irqsave(&ide_lock, flags);

                        ide_abort(drive, "drive reset");

                        if(HWGROUP(drive)->handler)
                                BUG();
                                
                        /* Ensure nothing gets queued after we
                           drop the lock. Reset will clear the busy */
                   
                        HWGROUP(drive)->busy = 1;
                        spin_unlock_irqrestore(&ide_lock, flags);
                        (void) ide_do_reset(drive);

                        return 0;
                }

                case CDROMEJECT:
                case CDROMCLOSETRAY:
                        return scsi_cmd_ioctl(file, bdev->bd_disk, cmd, p);

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

                case HDIO_SET_BUSSTATE:
                        if (!capable(CAP_SYS_ADMIN))
                                return -EACCES;
                        if (HWIF(drive)->busproc)
                                return HWIF(drive)->busproc(drive, (int)arg);
                        return -EOPNOTSUPP;
                default:
                        return -EINVAL;
        }
}

EXPORT_SYMBOL(generic_ide_ioctl);

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

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

        if (*s++ == '=') {
                /*
                 * Try matching against the supplied keywords,
                 * and return -(index+1) if we match one
                 */
                if (keywords != NULL) {
                        for (i = 0; *keywords != NULL; ++i) {
                                if (!strcmp(s, *keywords++))
                                        return -(i+1);
                        }
                }
                /*
                 * Look for a series of no more than "max_vals"
                 * numeric values separated by commas, in base10,
                 * or base16 when prefixed with "0x".
                 * Return a count of how many were found.
                 */
                for (n = 0; (i = stridx(decimal, *s)) >= 0;) {
                        vals[n] = i;
                        while ((i = stridx(decimal, *++s)) >= 0)
                                vals[n] = (vals[n] * 10) + i;
                        if (*s == 'x' && !vals[n]) {
                                while ((i = stridx(hex, *++s)) >= 0)
                                        vals[n] = (vals[n] * 0x10) + i;
                        }
                        if (++n == max_vals)
                                break;
                        if (*s == ',' || *s == ';')
                                ++s;
                }
                if (!*s)
                        return n;
        }
        return 0;       /* zero = nothing matched */
}

#ifdef CONFIG_BLK_DEV_ALI14XX
static int __initdata probe_ali14xx;
extern int ali14xx_init(void);
#endif
#ifdef CONFIG_BLK_DEV_UMC8672
static int __initdata probe_umc8672;
extern int umc8672_init(void);
#endif
#ifdef CONFIG_BLK_DEV_DTC2278
static int __initdata probe_dtc2278;
extern int dtc2278_init(void);
#endif
#ifdef CONFIG_BLK_DEV_HT6560B
static int __initdata probe_ht6560b;
extern int ht6560b_init(void);
#endif
#ifdef CONFIG_BLK_DEV_QD65XX
static int __initdata probe_qd65xx;
extern int qd65xx_init(void);
#endif

static int __initdata is_chipset_set[MAX_HWIFS];

/*
 * ide_setup() gets called VERY EARLY during initialization,
 * to handle kernel "command line" strings beginning with "hdx=" or "ide".
 *
 * Remember to update Documentation/ide.txt if you change something here.
 */
static int __init ide_setup(char *s)
{
        int i, vals[3];
        ide_hwif_t *hwif;
        ide_drive_t *drive;
        unsigned int hw, unit;
        const char max_drive = 'a' + ((MAX_HWIFS * MAX_DRIVES) - 1);
        const char max_hwif  = '0' + (MAX_HWIFS - 1);

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

        if (strncmp(s,"ide",3) && strncmp(s,"idebus",6) && strncmp(s,"hd",2))
                return 0;

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

#ifdef CONFIG_BLK_DEV_IDEDOUBLER
        if (!strcmp(s, "ide=doubler")) {
                extern int ide_doubler;

                printk(" : Enabled support for IDE doublers\n");
                ide_doubler = 1;
                return 1;
        }
#endif /* CONFIG_BLK_DEV_IDEDOUBLER */

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

#ifdef CONFIG_BLK_DEV_IDEPCI
        if (!strcmp(s, "ide=reverse")) {
                ide_scan_direction = 1;
                printk(" : Enabled support for IDE inverse scan order.\n");
                return 1;
        }
#endif /* CONFIG_BLK_DEV_IDEPCI */

        /*
         * Look for drive options:  "hdx="
         */
        if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) {
                const char *hd_words[] = {
                        "none", "noprobe", "nowerr", "cdrom", "serialize",
                        "autotune", "noautotune", "minus8", "swapdata", "bswap",
                        "minus11", "remap", "remap63", "scsi", NULL };
                unit = s[2] - 'a';
                hw   = unit / MAX_DRIVES;
                unit = unit % MAX_DRIVES;
                hwif = &ide_hwifs[hw];
                drive = &hwif->drives[unit];
                if (strncmp(s + 4, "ide-", 4) == 0) {
                        strlcpy(drive->driver_req, s + 4, sizeof(drive->driver_req));
                        goto done;
                }
                switch (match_parm(&s[3], hd_words, vals, 3)) {
                        case -1: /* "none" */
                        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;
                                /* an ATAPI device ignores DRDY */
                                drive->ready_stat = 0;
                                hwif->noprobe = 0;
                                goto done;
                        case -5: /* "serialize" */
                                printk(" -- USE \"ide%d=serialize\" INSTEAD", hw);
                                goto do_serialize;
                        case -6: /* "autotune" */
                                drive->autotune = IDE_TUNE_AUTO;
                                goto obsolete_option;
                        case -7: /* "noautotune" */
                                drive->autotune = IDE_TUNE_NOAUTO;
                                goto obsolete_option;
                        case -9: /* "swapdata" */
                        case -10: /* "bswap" */
                                drive->bswap = 1;
                                goto done;
                        case -12: /* "remap" */
                                drive->remap_0_to_1 = 1;
                                goto done;
                        case -13: /* "remap63" */
                                drive->sect0 = 63;
                                goto done;
                        case -14: /* "scsi" */
                                drive->scsi = 1;
                                goto done;
                        case 3: /* cyl,head,sect */
                                drive->media    = ide_disk;
                                drive->ready_stat = READY_STAT;
                                drive->cyl      = drive->bios_cyl  = vals[0];
                                drive->head     = drive->bios_head = vals[1];
                                drive->sect     = drive->bios_sect = vals[2];
                                drive->present  = 1;
                                drive->forced_geom = 1;
                                hwif->noprobe = 0;
                                goto done;
                        default:
                                goto bad_option;
                }
        }

        if (s[0] != 'i' || s[1] != 'd' || s[2] != 'e')
                goto bad_option;
        /*
         * Look for bus speed option:  "idebus="
         */
        if (s[3] == 'b' && s[4] == 'u' && s[5] == 's') {
                if (match_parm(&s[6], NULL, vals, 1) != 1)
                        goto bad_option;
                if (vals[0] >= 20 && vals[0] <= 66) {
                        idebus_parameter = vals[0];
                } else
                        printk(" -- BAD BUS SPEED! Expected value from 20 to 66");
                goto done;
        }
        /*
         * Look for interface options:  "idex="
         */
        if (s[3] >= '0' && s[3] <= max_hwif) {
                /*
                 * Be VERY CAREFUL changing this: note hardcoded indexes below
                 * (-8, -9, -10) are reserved to ease the hardcoding.
                 */
                static const char *ide_words[] = {
                        "noprobe", "serialize", "autotune", "noautotune", 
                        "reset", "dma", "ata66", "minus8", "minus9",
                        "minus10", "four", "qd65xx", "ht6560b", "cmd640_vlb",
                        "dtc2278", "umc8672", "ali14xx", NULL };
                hw = s[3] - '0';
                hwif = &ide_hwifs[hw];
                i = match_parm(&s[4], ide_words, vals, 3);

                /*
                 * Cryptic check to ensure chipset not already set for hwif.
                 * Note: we can't depend on hwif->chipset here.
                 */
                if ((i >= -18 && i <= -11) || (i > 0 && i <= 3)) {
                        /* chipset already specified */
                        if (is_chipset_set[hw])
                                goto bad_option;
                        if (i > -18 && i <= -11) {
                                /* these drivers are for "ide0=" only */
                                if (hw != 0)
                                        goto bad_hwif;
                                /* chipset already specified for 2nd port */
                                if (is_chipset_set[hw+1])
                                        goto bad_option;
                        }
                        is_chipset_set[hw] = 1;
                        printk("\n");
                }

                switch (i) {
#ifdef CONFIG_BLK_DEV_ALI14XX
                        case -17: /* "ali14xx" */
                                probe_ali14xx = 1;
                                goto done;
#endif
#ifdef CONFIG_BLK_DEV_UMC8672
                        case -16: /* "umc8672" */
                                probe_umc8672 = 1;
                                goto done;
#endif
#ifdef CONFIG_BLK_DEV_DTC2278
                        case -15: /* "dtc2278" */
                                probe_dtc2278 = 1;
                                goto done;
#endif
#ifdef CONFIG_BLK_DEV_CMD640
                        case -14: /* "cmd640_vlb" */
                        {
                                extern int cmd640_vlb; /* flag for cmd640.c */
                                cmd640_vlb = 1;
                                goto done;
                        }
#endif
#ifdef CONFIG_BLK_DEV_HT6560B
                        case -13: /* "ht6560b" */
                                probe_ht6560b = 1;
                                goto done;
#endif
#ifdef CONFIG_BLK_DEV_QD65XX
                        case -12: /* "qd65xx" */
                                probe_qd65xx = 1;
                                goto done;
#endif
#ifdef CONFIG_BLK_DEV_4DRIVES
                        case -11: /* "four" drives on one set of ports */
                        {
                                ide_hwif_t *mate = &ide_hwifs[hw^1];
                                mate->drives[0].select.all ^= 0x20;
                                mate->drives[1].select.all ^= 0x20;
                                hwif->chipset = mate->chipset = ide_4drives;
                                mate->irq = hwif->irq;
                                memcpy(mate->io_ports, hwif->io_ports, sizeof(hwif->io_ports));
                                goto do_serialize;
                        }
#endif /* CONFIG_BLK_DEV_4DRIVES */
                        case -10: /* minus10 */
                        case -9: /* minus9 */
                        case -8: /* minus8 */
                                goto bad_option;
                        case -7: /* ata66 */
#ifdef CONFIG_BLK_DEV_IDEPCI
                                hwif->udma_four = 1;
                                goto obsolete_option;
#else
                                goto bad_hwif;
#endif
                        case -6: /* dma */
                                hwif->autodma = 1;
                                goto obsolete_option;
                        case -5: /* "reset" */
                                hwif->reset = 1;
                                goto obsolete_option;
                        case -4: /* "noautotune" */
                                hwif->drives[0].autotune = IDE_TUNE_NOAUTO;
                                hwif->drives[1].autotune = IDE_TUNE_NOAUTO;
                                goto obsolete_option;
                        case -3: /* "autotune" */
                                hwif->drives[0].autotune = IDE_TUNE_AUTO;
                                hwif->drives[1].autotune = IDE_TUNE_AUTO;
                                goto obsolete_option;
                        case -2: /* "serialize" */
                        do_serialize:
                                hwif->mate = &ide_hwifs[hw^1];
                                hwif->mate->mate = hwif;
                                hwif->serialized = hwif->mate->serialized = 1;
                                goto obsolete_option;

                        case -1: /* "noprobe" */
                                hwif->noprobe = 1;
                                goto done;

                        case 1: /* base */
                                vals[1] = vals[0] + 0x206; /* default ctl */
                        case 2: /* base,ctl */
                                vals[2] = 0;    /* default irq = probe for it */
                        case 3: /* base,ctl,irq */
                                hwif->hw.irq = vals[2];
                                ide_init_hwif_ports(&hwif->hw, (unsigned long) vals[0], (unsigned long) vals[1], &hwif->irq);
                                memcpy(hwif->io_ports, hwif->hw.io_ports, sizeof(hwif->io_ports));
                                hwif->irq      = vals[2];
                                hwif->noprobe  = 0;
                                hwif->chipset  = ide_forced;
                                goto obsolete_option;

                        case 0: goto bad_option;
                        default:
                                printk(" -- SUPPORT NOT CONFIGURED IN THIS KERNEL\n");
                                return 1;
                }
        }
bad_option:
        printk(" -- BAD OPTION\n");
        return 1;
obsolete_option:
        printk(" -- OBSOLETE OPTION, WILL BE REMOVED SOON!\n");
        return 1;
bad_hwif:
        printk("-- NOT SUPPORTED ON ide%d", hw);
done:
        printk("\n");
        return 1;
}

extern void pnpide_init(void);
extern void h8300_ide_init(void);

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

#ifdef CONFIG_ETRAX_IDE
        {
                extern void init_e100_ide(void);
                init_e100_ide();
        }
#endif /* CONFIG_ETRAX_IDE */
#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_IDE_PMAC
        {
                extern void pmac_ide_probe(void);
                pmac_ide_probe();
        }
#endif /* CONFIG_BLK_DEV_IDE_PMAC */
#ifdef CONFIG_BLK_DEV_GAYLE
        {
                extern void gayle_init(void);
                gayle_init();
        }
#endif /* CONFIG_BLK_DEV_GAYLE */
#ifdef CONFIG_BLK_DEV_FALCON_IDE
        {
                extern void falconide_init(void);
                falconide_init();
        }
#endif /* CONFIG_BLK_DEV_FALCON_IDE */
#ifdef CONFIG_BLK_DEV_MAC_IDE
        {
                extern void macide_init(void);
                macide_init();
        }
#endif /* CONFIG_BLK_DEV_MAC_IDE */
#ifdef CONFIG_BLK_DEV_Q40IDE
        {
                extern void q40ide_init(void);
                q40ide_init();
        }
#endif /* CONFIG_BLK_DEV_Q40IDE */
#ifdef CONFIG_BLK_DEV_BUDDHA
        {
                extern void buddha_init(void);
                buddha_init();
        }
#endif /* CONFIG_BLK_DEV_BUDDHA */
#ifdef CONFIG_BLK_DEV_IDEPNP
        pnpide_init();
#endif
#ifdef CONFIG_H8300
        h8300_ide_init();
#endif
}

void ide_register_subdriver(ide_drive_t *drive, ide_driver_t *driver)
{
#ifdef CONFIG_PROC_FS
        ide_add_proc_entries(drive->proc, driver->proc, drive);
#endif
}

EXPORT_SYMBOL(ide_register_subdriver);

/**
 *      ide_unregister_subdriver        -       disconnect drive from driver
 *      @drive: drive to unplug
 *      @driver: driver
 *
 *      Disconnect a drive from the driver it was attached to and then
 *      clean up the various proc files and other objects attached to it.
 *
 *      Takes ide_setting_sem and ide_lock.
 *      Caller must hold none of the locks.
 */

void ide_unregister_subdriver(ide_drive_t *drive, ide_driver_t *driver)
{
        unsigned long flags;
        
        down(&ide_setting_sem);
        spin_lock_irqsave(&ide_lock, flags);
#ifdef CONFIG_PROC_FS
        ide_remove_proc_entries(drive->proc, driver->proc);
#endif
        auto_remove_settings(drive);
        spin_unlock_irqrestore(&ide_lock, flags);
        up(&ide_setting_sem);
}

EXPORT_SYMBOL(ide_unregister_subdriver);

/*
 * Probe module
 */

EXPORT_SYMBOL(ide_lock);

static int ide_bus_match(struct device *dev, struct device_driver *drv)
{
        return 1;
}

struct bus_type ide_bus_type = {
        .name           = "ide",
        .match          = ide_bus_match,
        .suspend        = generic_ide_suspend,
        .resume         = generic_ide_resume,
};

EXPORT_SYMBOL_GPL(ide_bus_type);

/*
 * This is gets invoked once during initialization, to set *everything* up
 */
static int __init ide_init(void)
{
        printk(KERN_INFO "Uniform Multi-Platform E-IDE driver " REVISION "\n");
        devfs_mk_dir("ide");
        system_bus_speed = ide_system_bus_speed();

        bus_register(&ide_bus_type);

        init_ide_data();

#ifdef CONFIG_PROC_FS
        proc_ide_root = proc_mkdir("ide", NULL);
#endif

#ifdef CONFIG_BLK_DEV_ALI14XX
        if (probe_ali14xx)
                (void)ali14xx_init();
#endif
#ifdef CONFIG_BLK_DEV_UMC8672
        if (probe_umc8672)
                (void)umc8672_init();
#endif
#ifdef CONFIG_BLK_DEV_DTC2278
        if (probe_dtc2278)
                (void)dtc2278_init();
#endif
#ifdef CONFIG_BLK_DEV_HT6560B
        if (probe_ht6560b)
                (void)ht6560b_init();
#endif
#ifdef CONFIG_BLK_DEV_QD65XX
        if (probe_qd65xx)
                (void)qd65xx_init();
#endif

        initializing = 1;
        /* Probe for special PCI and other "known" interface chipsets. */
        probe_for_hwifs();
        initializing = 0;

#ifdef CONFIG_PROC_FS
        proc_ide_create();
#endif
        return 0;
}

#ifdef MODULE
static char *options = NULL;
module_param(options, charp, 0);
MODULE_LICENSE("GPL");

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

        if (line == NULL || !*line)
                return;
        while ((line = next) != NULL) {
                if ((next = strchr(line,' ')) != NULL)
                        *next++ = 0;
                if (!ide_setup(line))
                        printk (KERN_INFO "Unknown option '%s'\n", 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
        devfs_remove("ide");

        bus_unregister(&ide_bus_type);
}

#else /* !MODULE */

__setup("", ide_setup);

module_init(ide_init);

#endif /* MODULE */