ide: add "noacpi" / "acpigtf" / "acpionboot" parameters

[deliverable/linux.git] / drivers / ide / ide.c

/*
 *  Copyright (C) 1994-1998         Linus Torvalds & authors (see below)
 *  Copyrifht (C) 2003-2005, 2007   Bartlomiej Zolnierkiewicz
 */

/*
 *  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.
 *
 * ...
 *
 *  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
 */

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

#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/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

struct class *ide_port_class;

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 */

DEFINE_MUTEX(ide_cfg_mtx);
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);

int noautodma = 0;

ide_hwif_t ide_hwifs[MAX_HWIFS];        /* master data repository */

static void ide_port_init_devices_data(ide_hwif_t *);

/*
 * Do not even *think* about calling this!
 */
void ide_init_port_data(ide_hwif_t *hwif, unsigned int 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;
        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;

        init_completion(&hwif->gendev_rel_comp);

        default_hwif_iops(hwif);
        default_hwif_transport(hwif);

        ide_port_init_devices_data(hwif);
}
EXPORT_SYMBOL_GPL(ide_init_port_data);

static void ide_port_init_devices_data(ide_hwif_t *hwif)
{
        int unit;

        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];
                u8 j = (hwif->index * MAX_DRIVES) + unit;

                memset(drive, 0, sizeof(*drive));

                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' + j;
                drive->max_failures             = IDE_DEFAULT_MAX_FAILURES;

                INIT_LIST_HEAD(&drive->list);
                init_completion(&drive->gendev_rel_comp);
        }
}

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

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

        /* Initialise all interface structures */
        for (index = 0; index < MAX_HWIFS; ++index) {
                ide_hwif_t *hwif = &ide_hwifs[index];

                ide_init_port_data(hwif, index);
        }
}

/**
 *      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 */

        /* user supplied value */
        if (idebus_parameter)
                return idebus_parameter;

        /* safe default value for PCI or VESA and PCI*/
        return pci_dev_present(pci_default) ? 33 : 50;
}

void ide_remove_port_from_hwgroup(ide_hwif_t *hwif)
{
        ide_hwgroup_t *hwgroup = hwif->hwgroup;

        spin_lock_irq(&ide_lock);
        /*
         * 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.
                 */
                ide_hwif_t *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);
        }
        spin_unlock_irq(&ide_lock);
}

/* Called with ide_lock held. */
static void __ide_port_unregister_devices(ide_hwif_t *hwif)
{
        int i;

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

                if (drive->present) {
                        spin_unlock_irq(&ide_lock);
                        device_unregister(&drive->gendev);
                        wait_for_completion(&drive->gendev_rel_comp);
                        spin_lock_irq(&ide_lock);
                }
        }
}

void ide_port_unregister_devices(ide_hwif_t *hwif)
{
        mutex_lock(&ide_cfg_mtx);
        spin_lock_irq(&ide_lock);
        __ide_port_unregister_devices(hwif);
        hwif->present = 0;
        ide_port_init_devices_data(hwif);
        spin_unlock_irq(&ide_lock);
        mutex_unlock(&ide_cfg_mtx);
}
EXPORT_SYMBOL_GPL(ide_port_unregister_devices);

/**
 *      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 interface will not be reopened (present/vanishing locking
 *      isn't 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_hwif_t *hwif, *g;
        ide_hwgroup_t *hwgroup;
        int irq_count = 0;

        BUG_ON(index >= MAX_HWIFS);

        BUG_ON(in_interrupt());
        BUG_ON(irqs_disabled());
        mutex_lock(&ide_cfg_mtx);
        spin_lock_irq(&ide_lock);
        hwif = &ide_hwifs[index];
        if (!hwif->present)
                goto abort;
        __ide_port_unregister_devices(hwif);
        hwif->present = 0;

        spin_unlock_irq(&ide_lock);

        ide_proc_unregister_port(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);

        ide_remove_port_from_hwgroup(hwif);

        device_unregister(hwif->portdev);
        device_unregister(&hwif->gendev);
        wait_for_completion(&hwif->gendev_rel_comp);

        /*
         * 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)
                ide_release_dma_engine(hwif);

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

abort:
        spin_unlock_irq(&ide_lock);
        mutex_unlock(&ide_cfg_mtx);
}

EXPORT_SYMBOL(ide_unregister);

void ide_init_port_hw(ide_hwif_t *hwif, hw_regs_t *hw)
{
        memcpy(hwif->io_ports, hw->io_ports, sizeof(hwif->io_ports));
        hwif->irq = hw->irq;
        hwif->chipset = hw->chipset;
        hwif->gendev.parent = hw->dev;
        hwif->ack_intr = hw->ack_intr;
}
EXPORT_SYMBOL_GPL(ide_init_port_hw);

/*
 *      Locks for IDE setting functionality
 */

DEFINE_MUTEX(ide_setting_mtx);

EXPORT_SYMBOL_GPL(ide_setting_mtx);

/**
 *      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);

int set_io_32bit(ide_drive_t *drive, int arg)
{
        if (drive->no_io_32bit)
                return -EPERM;

        if (arg < 0 || arg > 1 + (SUPPORT_VLB_SYNC << 1))
                return -EINVAL;

        if (ide_spin_wait_hwgroup(drive))
                return -EBUSY;

        drive->io_32bit = arg;

        spin_unlock_irq(&ide_lock);

        return 0;
}

static int set_ksettings(ide_drive_t *drive, int arg)
{
        if (arg < 0 || arg > 1)
                return -EINVAL;

        if (ide_spin_wait_hwgroup(drive))
                return -EBUSY;
        drive->keep_settings = arg;
        spin_unlock_irq(&ide_lock);

        return 0;
}

int set_using_dma(ide_drive_t *drive, int arg)
{
#ifdef CONFIG_BLK_DEV_IDEDMA
        ide_hwif_t *hwif = drive->hwif;
        int err = -EPERM;

        if (arg < 0 || arg > 1)
                return -EINVAL;

        if (!drive->id || !(drive->id->capability & 1))
                goto out;

        if (hwif->dma_ops == NULL)
                goto out;

        err = -EBUSY;
        if (ide_spin_wait_hwgroup(drive))
                goto out;
        /*
         * set ->busy flag, unlock and let it ride
         */
        hwif->hwgroup->busy = 1;
        spin_unlock_irq(&ide_lock);

        err = 0;

        if (arg) {
                if (ide_set_dma(drive))
                        err = -EIO;
        } else
                ide_dma_off(drive);

        /*
         * lock, clear ->busy flag and unlock before leaving
         */
        spin_lock_irq(&ide_lock);
        hwif->hwgroup->busy = 0;
        spin_unlock_irq(&ide_lock);
out:
        return err;
#else
        if (arg < 0 || arg > 1)
                return -EINVAL;

        return -EPERM;
#endif
}

int set_pio_mode(ide_drive_t *drive, int arg)
{
        struct request rq;
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_port_ops *port_ops = hwif->port_ops;

        if (arg < 0 || arg > 255)
                return -EINVAL;

        if (port_ops == NULL || port_ops->set_pio_mode == NULL ||
            (hwif->host_flags & IDE_HFLAG_NO_SET_MODE))
                return -ENOSYS;

        if (drive->special.b.set_tune)
                return -EBUSY;

        ide_init_drive_cmd(&rq);
        rq.cmd_type = REQ_TYPE_ATA_TASKFILE;

        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_unmaskirq(ide_drive_t *drive, int arg)
{
        if (drive->no_unmask)
                return -EPERM;

        if (arg < 0 || arg > 1)
                return -EINVAL;

        if (ide_spin_wait_hwgroup(drive))
                return -EBUSY;
        drive->unmask = arg;
        spin_unlock_irq(&ide_lock);

        return 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 system_bus_speed;
}

EXPORT_SYMBOL(system_bus_clock);

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

        /* Call ACPI _GTM only once */
        if (!(drive->dn % 2))
                ide_acpi_get_timing(hwif);

        memset(&rq, 0, sizeof(rq));
        memset(&rqpm, 0, sizeof(rqpm));
        memset(&args, 0, sizeof(args));
        rq.cmd_type = REQ_TYPE_PM_SUSPEND;
        rq.special = &args;
        rq.data = &rqpm;
        rqpm.pm_step = ide_pm_state_start_suspend;
        if (mesg.event == PM_EVENT_PRETHAW)
                mesg.event = PM_EVENT_FREEZE;
        rqpm.pm_state = mesg.event;

        ret = ide_do_drive_cmd(drive, &rq, ide_wait);
        /* only call ACPI _PS3 after both drivers are suspended */
        if (!ret && (((drive->dn % 2) && hwif->drives[0].present
                 && hwif->drives[1].present)
                 || !hwif->drives[0].present
                 || !hwif->drives[1].present))
                ide_acpi_set_state(hwif, 0);
        return ret;
}

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

        /* Call ACPI _STM only once */
        if (!(drive->dn % 2)) {
                ide_acpi_set_state(hwif, 1);
                ide_acpi_push_timing(hwif);
        }

        ide_acpi_exec_tfs(drive);

        memset(&rq, 0, sizeof(rq));
        memset(&rqpm, 0, sizeof(rqpm));
        memset(&args, 0, sizeof(args));
        rq.cmd_type = REQ_TYPE_PM_RESUME;
        rq.special = &args;
        rq.data = &rqpm;
        rqpm.pm_step = ide_pm_state_start_resume;
        rqpm.pm_state = PM_EVENT_ON;

        err = ide_do_drive_cmd(drive, &rq, ide_head_wait);

        if (err == 0 && dev->driver) {
                ide_driver_t *drv = to_ide_driver(dev->driver);

                if (drv->resume)
                        drv->resume(drive);
        }

        return err;
}

int generic_ide_ioctl(ide_drive_t *drive, struct file *file, struct block_device *bdev,
                        unsigned int cmd, unsigned long arg)
{
        unsigned long flags;
        ide_driver_t *drv;
        void __user *p = (void __user *)arg;
        int err = 0, (*setfunc)(ide_drive_t *, int);
        u8 *val;

        switch (cmd) {
        case HDIO_GET_32BIT:        val = &drive->io_32bit;      goto read_val;
        case HDIO_GET_KEEPSETTINGS: val = &drive->keep_settings; goto read_val;
        case HDIO_GET_UNMASKINTR:   val = &drive->unmask;        goto read_val;
        case HDIO_GET_DMA:          val = &drive->using_dma;     goto read_val;
        case HDIO_SET_32BIT:        setfunc = set_io_32bit;      goto set_val;
        case HDIO_SET_KEEPSETTINGS: setfunc = set_ksettings;     goto set_val;
        case HDIO_SET_PIO_MODE:     setfunc = set_pio_mode;      goto set_val;
        case HDIO_SET_UNMASKINTR:   setfunc = set_unmaskirq;     goto set_val;
        case HDIO_SET_DMA:          setfunc = set_using_dma;     goto set_val;
        }

        switch (cmd) {
                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->nice1 << IDE_NICE_1,
                                        (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_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:
                        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);

                        if (HWGROUP(drive)->resetting) {
                                spin_unlock_irqrestore(&ide_lock, flags);
                                return -EBUSY;
                        }

                        ide_abort(drive, "drive reset");

                        BUG_ON(HWGROUP(drive)->handler);

                        /* 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 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;
                        return -EOPNOTSUPP;
                default:
                        return -EINVAL;
        }

read_val:
        mutex_lock(&ide_setting_mtx);
        spin_lock_irqsave(&ide_lock, flags);
        err = *val;
        spin_unlock_irqrestore(&ide_lock, flags);
        mutex_unlock(&ide_setting_mtx);
        return err >= 0 ? put_user(err, (long __user *)arg) : err;

set_val:
        if (bdev != bdev->bd_contains)
                err = -EINVAL;
        else {
                if (!capable(CAP_SYS_ADMIN))
                        err = -EACCES;
                else {
                        mutex_lock(&ide_setting_mtx);
                        err = setfunc(drive, arg);
                        mutex_unlock(&ide_setting_mtx);
                }
        }
        return err;
}

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 */
}

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

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

#ifdef CONFIG_BLK_DEV_IDEACPI
        if (!strcmp(s, "ide=noacpi")) {
                //printk(" : Disable IDE ACPI support.\n");
                ide_noacpi = 1;
                goto obsolete_option;
        }
        if (!strcmp(s, "ide=acpigtf")) {
                //printk(" : Enable IDE ACPI _GTF support.\n");
                ide_acpigtf = 1;
                goto obsolete_option;
        }
        if (!strcmp(s, "ide=acpionboot")) {
                //printk(" : Call IDE ACPI methods on boot.\n");
                ide_acpionboot = 1;
                goto obsolete_option;
        }
#endif /* CONFIG_BLK_DEV_IDEACPI */

        /*
         * 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", "nodma",
                        "-6", "-7", "-8", "-9", "-10",
                        "noflush", "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 obsolete_option;
                }
                switch (match_parm(&s[3], hd_words, vals, 3)) {
                        case -1: /* "none" */
                        case -2: /* "noprobe" */
                                drive->noprobe = 1;
                                goto obsolete_option;
                        case -3: /* "nowerr" */
                                drive->bad_wstat = BAD_R_STAT;
                                goto obsolete_option;
                        case -4: /* "cdrom" */
                                drive->present = 1;
                                drive->media = ide_cdrom;
                                /* an ATAPI device ignores DRDY */
                                drive->ready_stat = 0;
                                goto obsolete_option;
                        case -5: /* nodma */
                                drive->nodma = 1;
                                goto obsolete_option;
                        case -11: /* noflush */
                                drive->noflush = 1;
                                goto obsolete_option;
                        case -12: /* "remap" */
                                drive->remap_0_to_1 = 1;
                                goto obsolete_option;
                        case -13: /* "remap63" */
                                drive->sect0 = 63;
                                goto obsolete_option;
                        case -14: /* "scsi" */
                                drive->scsi = 1;
                                goto obsolete_option;
                        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;
                                goto obsolete_option;
                        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 obsolete_option;
        }

bad_option:
        printk(" -- BAD OPTION\n");
        return 1;
obsolete_option:
        printk(" -- OBSOLETE OPTION, WILL BE REMOVED SOON!\n");
        return 1;
}

EXPORT_SYMBOL(ide_lock);

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

static char *media_string(ide_drive_t *drive)
{
        switch (drive->media) {
        case ide_disk:
                return "disk";
        case ide_cdrom:
                return "cdrom";
        case ide_tape:
                return "tape";
        case ide_floppy:
                return "floppy";
        case ide_optical:
                return "optical";
        default:
                return "UNKNOWN";
        }
}

static ssize_t media_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "%s\n", media_string(drive));
}

static ssize_t drivename_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "%s\n", drive->name);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "ide:m-%s\n", media_string(drive));
}

static ssize_t model_show(struct device *dev, struct device_attribute *attr,
                          char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "%s\n", drive->id->model);
}

static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "%s\n", drive->id->fw_rev);
}

static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
                           char *buf)
{
        ide_drive_t *drive = to_ide_device(dev);
        return sprintf(buf, "%s\n", drive->id->serial_no);
}

static struct device_attribute ide_dev_attrs[] = {
        __ATTR_RO(media),
        __ATTR_RO(drivename),
        __ATTR_RO(modalias),
        __ATTR_RO(model),
        __ATTR_RO(firmware),
        __ATTR(serial, 0400, serial_show, NULL),
        __ATTR_NULL
};

static int ide_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        ide_drive_t *drive = to_ide_device(dev);

        add_uevent_var(env, "MEDIA=%s", media_string(drive));
        add_uevent_var(env, "DRIVENAME=%s", drive->name);
        add_uevent_var(env, "MODALIAS=ide:m-%s", media_string(drive));
        return 0;
}

static int generic_ide_probe(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        ide_driver_t *drv = to_ide_driver(dev->driver);

        return drv->probe ? drv->probe(drive) : -ENODEV;
}

static int generic_ide_remove(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        ide_driver_t *drv = to_ide_driver(dev->driver);

        if (drv->remove)
                drv->remove(drive);

        return 0;
}

static void generic_ide_shutdown(struct device *dev)
{
        ide_drive_t *drive = to_ide_device(dev);
        ide_driver_t *drv = to_ide_driver(dev->driver);

        if (dev->driver && drv->shutdown)
                drv->shutdown(drive);
}

struct bus_type ide_bus_type = {
        .name           = "ide",
        .match          = ide_bus_match,
        .uevent         = ide_uevent,
        .probe          = generic_ide_probe,
        .remove         = generic_ide_remove,
        .shutdown       = generic_ide_shutdown,
        .dev_attrs      = ide_dev_attrs,
        .suspend        = generic_ide_suspend,
        .resume         = generic_ide_resume,
};

EXPORT_SYMBOL_GPL(ide_bus_type);

static void ide_port_class_release(struct device *portdev)
{
        ide_hwif_t *hwif = dev_get_drvdata(portdev);

        put_device(&hwif->gendev);
}

int ide_vlb_clk;
EXPORT_SYMBOL_GPL(ide_vlb_clk);

module_param_named(vlb_clock, ide_vlb_clk, int, 0);
MODULE_PARM_DESC(vlb_clock, "VLB clock frequency (in MHz)");

int ide_pci_clk;
EXPORT_SYMBOL_GPL(ide_pci_clk);

module_param_named(pci_clock, ide_pci_clk, int, 0);
MODULE_PARM_DESC(pci_clock, "PCI bus clock frequency (in MHz)");

static int ide_set_dev_param_mask(const char *s, struct kernel_param *kp)
{
        int a, b, i, j = 1;
        unsigned int *dev_param_mask = (unsigned int *)kp->arg;

        if (sscanf(s, "%d.%d:%d", &a, &b, &j) != 3 &&
            sscanf(s, "%d.%d", &a, &b) != 2)
                return -EINVAL;

        i = a * MAX_DRIVES + b;

        if (i >= MAX_HWIFS * MAX_DRIVES || j < 0 || j > 1)
                return -EINVAL;

        if (j)
                *dev_param_mask |= (1 << i);
        else
                *dev_param_mask &= (1 << i);

        return 0;
}

static unsigned int ide_nodma;

module_param_call(nodma, ide_set_dev_param_mask, NULL, &ide_nodma, 0);
MODULE_PARM_DESC(nodma, "disallow DMA for a device");

static unsigned int ide_noflush;

module_param_call(noflush, ide_set_dev_param_mask, NULL, &ide_noflush, 0);
MODULE_PARM_DESC(noflush, "disable flush requests for a device");

static unsigned int ide_noprobe;

module_param_call(noprobe, ide_set_dev_param_mask, NULL, &ide_noprobe, 0);
MODULE_PARM_DESC(noprobe, "skip probing for a device");

static unsigned int ide_nowerr;

module_param_call(nowerr, ide_set_dev_param_mask, NULL, &ide_nowerr, 0);
MODULE_PARM_DESC(nowerr, "ignore the WRERR_STAT bit for a device");

static unsigned int ide_cdroms;

module_param_call(cdrom, ide_set_dev_param_mask, NULL, &ide_cdroms, 0);
MODULE_PARM_DESC(cdrom, "force device as a CD-ROM");

struct chs_geom {
        unsigned int    cyl;
        u8              head;
        u8              sect;
};

static unsigned int ide_disks;
static struct chs_geom ide_disks_chs[MAX_HWIFS * MAX_DRIVES];

static int ide_set_disk_chs(const char *str, struct kernel_param *kp)
{
        int a, b, c = 0, h = 0, s = 0, i, j = 1;

        if (sscanf(str, "%d.%d:%d,%d,%d", &a, &b, &c, &h, &s) != 5 &&
            sscanf(str, "%d.%d:%d", &a, &b, &j) != 3)
                return -EINVAL;

        i = a * MAX_DRIVES + b;

        if (i >= MAX_HWIFS * MAX_DRIVES || j < 0 || j > 1)
                return -EINVAL;

        if (c > INT_MAX || h > 255 || s > 255)
                return -EINVAL;

        if (j)
                ide_disks |= (1 << i);
        else
                ide_disks &= (1 << i);

        ide_disks_chs[i].cyl  = c;
        ide_disks_chs[i].head = h;
        ide_disks_chs[i].sect = s;

        return 0;
}

module_param_call(chs, ide_set_disk_chs, NULL, NULL, 0);
MODULE_PARM_DESC(chs, "force device as a disk (using CHS)");

static void ide_dev_apply_params(ide_drive_t *drive)
{
        int i = drive->hwif->index * MAX_DRIVES + drive->select.b.unit;

        if (ide_nodma & (1 << i)) {
                printk(KERN_INFO "ide: disallowing DMA for %s\n", drive->name);
                drive->nodma = 1;
        }
        if (ide_noflush & (1 << i)) {
                printk(KERN_INFO "ide: disabling flush requests for %s\n",
                                 drive->name);
                drive->noflush = 1;
        }
        if (ide_noprobe & (1 << i)) {
                printk(KERN_INFO "ide: skipping probe for %s\n", drive->name);
                drive->noprobe = 1;
        }
        if (ide_nowerr & (1 << i)) {
                printk(KERN_INFO "ide: ignoring the WRERR_STAT bit for %s\n",
                                 drive->name);
                drive->bad_wstat = BAD_R_STAT;
        }
        if (ide_cdroms & (1 << i)) {
                printk(KERN_INFO "ide: forcing %s as a CD-ROM\n", drive->name);
                drive->present = 1;
                drive->media = ide_cdrom;
                /* an ATAPI device ignores DRDY */
                drive->ready_stat = 0;
        }
        if (ide_disks & (1 << i)) {
                drive->cyl  = drive->bios_cyl  = ide_disks_chs[i].cyl;
                drive->head = drive->bios_head = ide_disks_chs[i].head;
                drive->sect = drive->bios_sect = ide_disks_chs[i].sect;
                drive->forced_geom = 1;
                printk(KERN_INFO "ide: forcing %s as a disk (%d/%d/%d)\n",
                                 drive->name,
                                 drive->cyl, drive->head, drive->sect);
                drive->present = 1;
                drive->media = ide_disk;
                drive->ready_stat = READY_STAT;
        }
}

static unsigned int ide_ignore_cable;

static int ide_set_ignore_cable(const char *s, struct kernel_param *kp)
{
        int i, j = 1;

        if (sscanf(s, "%d:%d", &i, &j) != 2 && sscanf(s, "%d", &i) != 1)
                return -EINVAL;

        if (i >= MAX_HWIFS || j < 0 || j > 1)
                return -EINVAL;

        if (j)
                ide_ignore_cable |= (1 << i);
        else
                ide_ignore_cable &= (1 << i);

        return 0;
}

module_param_call(ignore_cable, ide_set_ignore_cable, NULL, NULL, 0);
MODULE_PARM_DESC(ignore_cable, "ignore cable detection");

void ide_port_apply_params(ide_hwif_t *hwif)
{
        int i;

        if (ide_ignore_cable & (1 << hwif->index)) {
                printk(KERN_INFO "ide: ignoring cable detection for %s\n",
                                 hwif->name);
                hwif->cbl = ATA_CBL_PATA40_SHORT;
        }

        for (i = 0; i < MAX_DRIVES; i++)
                ide_dev_apply_params(&hwif->drives[i]);
}

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

        printk(KERN_INFO "Uniform Multi-Platform E-IDE driver\n");
        system_bus_speed = ide_system_bus_speed();

        printk(KERN_INFO "ide: Assuming %dMHz system bus speed "
                         "for PIO modes%s\n", system_bus_speed,
                        idebus_parameter ? "" : "; override with idebus=xx");

        ret = bus_register(&ide_bus_type);
        if (ret < 0) {
                printk(KERN_WARNING "IDE: bus_register error: %d\n", ret);
                return ret;
        }

        ide_port_class = class_create(THIS_MODULE, "ide_port");
        if (IS_ERR(ide_port_class)) {
                ret = PTR_ERR(ide_port_class);
                goto out_port_class;
        }
        ide_port_class->dev_release = ide_port_class_release;

        init_ide_data();

        proc_ide_create();

        return 0;

out_port_class:
        bus_unregister(&ide_bus_type);

        return ret;
}

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

void __exit cleanup_module (void)
{
        int index;

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

        proc_ide_destroy();

        class_destroy(ide_port_class);

        bus_unregister(&ide_bus_type);
}

#else /* !MODULE */

__setup("", ide_setup);

module_init(ide_init);

#endif /* MODULE */