Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6

[linux-2.6] / drivers / ide / ide-probe.c

/*
 *  Copyright (C) 1994-1998   Linus Torvalds & authors (see below)
 *  Copyright (C) 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 IDE probe module, as evolved from hd.c and ide.c.
 *
 * -- increase WAIT_PIDENTIFY to avoid CD-ROM locking at boot
 *       by Andrea Arcangeli
 */

#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/slab.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/spinlock.h>
#include <linux/kmod.h>
#include <linux/pci.h>
#include <linux/scatterlist.h>

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

/**
 *      generic_id              -       add a generic drive id
 *      @drive: drive to make an ID block for
 *      
 *      Add a fake id field to the drive we are passed. This allows
 *      use to skip a ton of NULL checks (which people always miss) 
 *      and make drive properties unconditional outside of this file
 */
 
static void generic_id(ide_drive_t *drive)
{
        u16 *id = drive->id;

        id[ATA_ID_CUR_CYLS]     = id[ATA_ID_CYLS]       = drive->cyl;
        id[ATA_ID_CUR_HEADS]    = id[ATA_ID_HEADS]      = drive->head;
        id[ATA_ID_CUR_SECTORS]  = id[ATA_ID_SECTORS]    = drive->sect;
}

static void ide_disk_init_chs(ide_drive_t *drive)
{
        u16 *id = drive->id;

        /* Extract geometry if we did not already have one for the drive */
        if (!drive->cyl || !drive->head || !drive->sect) {
                drive->cyl  = drive->bios_cyl  = id[ATA_ID_CYLS];
                drive->head = drive->bios_head = id[ATA_ID_HEADS];
                drive->sect = drive->bios_sect = id[ATA_ID_SECTORS];
        }

        /* Handle logical geometry translation by the drive */
        if (ata_id_current_chs_valid(id)) {
                drive->cyl  = id[ATA_ID_CUR_CYLS];
                drive->head = id[ATA_ID_CUR_HEADS];
                drive->sect = id[ATA_ID_CUR_SECTORS];
        }

        /* Use physical geometry if what we have still makes no sense */
        if (drive->head > 16 && id[ATA_ID_HEADS] && id[ATA_ID_HEADS] <= 16) {
                drive->cyl  = id[ATA_ID_CYLS];
                drive->head = id[ATA_ID_HEADS];
                drive->sect = id[ATA_ID_SECTORS];
        }
}

static void ide_disk_init_mult_count(ide_drive_t *drive)
{
        u16 *id = drive->id;
        u8 max_multsect = id[ATA_ID_MAX_MULTSECT] & 0xff;

        if (max_multsect) {
                if ((max_multsect / 2) > 1)
                        id[ATA_ID_MULTSECT] = max_multsect | 0x100;
                else
                        id[ATA_ID_MULTSECT] &= ~0x1ff;

                drive->mult_req = id[ATA_ID_MULTSECT] & 0xff;

                if (drive->mult_req)
                        drive->special.b.set_multmode = 1;
        }
}

/**
 *      do_identify     -       identify a drive
 *      @drive: drive to identify 
 *      @cmd: command used
 *
 *      Called when we have issued a drive identify command to
 *      read and parse the results. This function is run with
 *      interrupts disabled. 
 */
 
static inline void do_identify (ide_drive_t *drive, u8 cmd)
{
        ide_hwif_t *hwif = HWIF(drive);
        u16 *id = drive->id;
        char *m = (char *)&id[ATA_ID_PROD];
        int bswap = 1, is_cfa;

        /* read 512 bytes of id info */
        hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);

        drive->dev_flags |= IDE_DFLAG_ID_READ;

        local_irq_enable();
#ifdef DEBUG
        printk(KERN_INFO "%s: dumping identify data\n", drive->name);
        ide_dump_identify((u8 *)id);
#endif
        ide_fix_driveid(id);

        /*
         *  ATA_CMD_ID_ATA returns little-endian info,
         *  ATA_CMD_ID_ATAPI *usually* returns little-endian info.
         */
        if (cmd == ATA_CMD_ID_ATAPI) {
                if ((m[0] == 'N' && m[1] == 'E') ||  /* NEC */
                    (m[0] == 'F' && m[1] == 'X') ||  /* Mitsumi */
                    (m[0] == 'P' && m[1] == 'i'))    /* Pioneer */
                        /* Vertos drives may still be weird */
                        bswap ^= 1;
        }

        ide_fixstring(m, ATA_ID_PROD_LEN, bswap);
        ide_fixstring((char *)&id[ATA_ID_FW_REV], ATA_ID_FW_REV_LEN, bswap);
        ide_fixstring((char *)&id[ATA_ID_SERNO], ATA_ID_SERNO_LEN, bswap);

        /* we depend on this a lot! */
        m[ATA_ID_PROD_LEN - 1] = '\0';

        if (strstr(m, "E X A B Y T E N E S T"))
                goto err_misc;

        printk(KERN_INFO "%s: %s, ", drive->name, m);

        drive->dev_flags |= IDE_DFLAG_PRESENT;
        drive->dev_flags &= ~IDE_DFLAG_DEAD;

        /*
         * Check for an ATAPI device
         */
        if (cmd == ATA_CMD_ID_ATAPI) {
                u8 type = (id[ATA_ID_CONFIG] >> 8) & 0x1f;

                printk(KERN_CONT "ATAPI ");
                switch (type) {
                        case ide_floppy:
                                if (!strstr(m, "CD-ROM")) {
                                        if (!strstr(m, "oppy") &&
                                            !strstr(m, "poyp") &&
                                            !strstr(m, "ZIP"))
                                                printk(KERN_CONT "cdrom or floppy?, assuming ");
                                        if (drive->media != ide_cdrom) {
                                                printk(KERN_CONT "FLOPPY");
                                                drive->dev_flags |= IDE_DFLAG_REMOVABLE;
                                                break;
                                        }
                                }
                                /* Early cdrom models used zero */
                                type = ide_cdrom;
                        case ide_cdrom:
                                drive->dev_flags |= IDE_DFLAG_REMOVABLE;
#ifdef CONFIG_PPC
                                /* kludge for Apple PowerBook internal zip */
                                if (!strstr(m, "CD-ROM") && strstr(m, "ZIP")) {
                                        printk(KERN_CONT "FLOPPY");
                                        type = ide_floppy;
                                        break;
                                }
#endif
                                printk(KERN_CONT "CD/DVD-ROM");
                                break;
                        case ide_tape:
                                printk(KERN_CONT "TAPE");
                                break;
                        case ide_optical:
                                printk(KERN_CONT "OPTICAL");
                                drive->dev_flags |= IDE_DFLAG_REMOVABLE;
                                break;
                        default:
                                printk(KERN_CONT "UNKNOWN (type %d)", type);
                                break;
                }
                printk(KERN_CONT " drive\n");
                drive->media = type;
                /* an ATAPI device ignores DRDY */
                drive->ready_stat = 0;
                if (ata_id_cdb_intr(id))
                        drive->atapi_flags |= IDE_AFLAG_DRQ_INTERRUPT;
                drive->dev_flags |= IDE_DFLAG_DOORLOCKING;
                /* we don't do head unloading on ATAPI devices */
                drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
                return;
        }

        /*
         * Not an ATAPI device: looks like a "regular" hard disk
         */

        is_cfa = ata_id_is_cfa(id);

        /* CF devices are *not* removable in Linux definition of the term */
        if (is_cfa == 0 && (id[ATA_ID_CONFIG] & (1 << 7)))
                drive->dev_flags |= IDE_DFLAG_REMOVABLE;

        drive->media = ide_disk;

        if (!ata_id_has_unload(drive->id))
                drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;

        printk(KERN_CONT "%s DISK drive\n", is_cfa ? "CFA" : "ATA");

        return;

err_misc:
        kfree(id);
        drive->dev_flags &= ~IDE_DFLAG_PRESENT;
        return;
}

/**
 *      actual_try_to_identify  -       send ata/atapi identify
 *      @drive: drive to identify
 *      @cmd: command to use
 *
 *      try_to_identify() sends an ATA(PI) IDENTIFY request to a drive
 *      and waits for a response.  It also monitors irqs while this is
 *      happening, in hope of automatically determining which one is
 *      being used by the interface.
 *
 *      Returns:        0  device was identified
 *                      1  device timed-out (no response to identify request)
 *                      2  device aborted the command (refused to identify itself)
 */

static int actual_try_to_identify (ide_drive_t *drive, u8 cmd)
{
        ide_hwif_t *hwif = HWIF(drive);
        struct ide_io_ports *io_ports = &hwif->io_ports;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        int use_altstatus = 0, rc;
        unsigned long timeout;
        u8 s = 0, a = 0;

        /* take a deep breath */
        msleep(50);

        if (io_ports->ctl_addr &&
            (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) {
                a = tp_ops->read_altstatus(hwif);
                s = tp_ops->read_status(hwif);
                if ((a ^ s) & ~ATA_IDX)
                        /* ancient Seagate drives, broken interfaces */
                        printk(KERN_INFO "%s: probing with STATUS(0x%02x) "
                                         "instead of ALTSTATUS(0x%02x)\n",
                                         drive->name, s, a);
                else
                        /* use non-intrusive polling */
                        use_altstatus = 1;
        }

        /* set features register for atapi
         * identify command to be sure of reply
         */
        if (cmd == ATA_CMD_ID_ATAPI) {
                ide_task_t task;

                memset(&task, 0, sizeof(task));
                /* disable DMA & overlap */
                task.tf_flags = IDE_TFLAG_OUT_FEATURE;

                tp_ops->tf_load(drive, &task);
        }

        /* ask drive for ID */
        tp_ops->exec_command(hwif, cmd);

        timeout = ((cmd == ATA_CMD_ID_ATA) ? WAIT_WORSTCASE : WAIT_PIDENTIFY) / 2;

        if (ide_busy_sleep(hwif, timeout, use_altstatus))
                return 1;

        /* wait for IRQ and ATA_DRQ */
        msleep(50);
        s = tp_ops->read_status(hwif);

        if (OK_STAT(s, ATA_DRQ, BAD_R_STAT)) {
                unsigned long flags;

                /* local CPU only; some systems need this */
                local_irq_save(flags);
                /* drive returned ID */
                do_identify(drive, cmd);
                /* drive responded with ID */
                rc = 0;
                /* clear drive IRQ */
                (void)tp_ops->read_status(hwif);
                local_irq_restore(flags);
        } else {
                /* drive refused ID */
                rc = 2;
        }
        return rc;
}

/**
 *      try_to_identify -       try to identify a drive
 *      @drive: drive to probe
 *      @cmd: command to use
 *
 *      Issue the identify command and then do IRQ probing to
 *      complete the identification when needed by finding the
 *      IRQ the drive is attached to
 */
 
static int try_to_identify (ide_drive_t *drive, u8 cmd)
{
        ide_hwif_t *hwif = HWIF(drive);
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        int retval;
        int autoprobe = 0;
        unsigned long cookie = 0;

        /*
         * Disable device irq unless we need to
         * probe for it. Otherwise we'll get spurious
         * interrupts during the identify-phase that
         * the irq handler isn't expecting.
         */
        if (hwif->io_ports.ctl_addr) {
                if (!hwif->irq) {
                        autoprobe = 1;
                        cookie = probe_irq_on();
                }
                tp_ops->set_irq(hwif, autoprobe);
        }

        retval = actual_try_to_identify(drive, cmd);

        if (autoprobe) {
                int irq;

                tp_ops->set_irq(hwif, 0);
                /* clear drive IRQ */
                (void)tp_ops->read_status(hwif);
                udelay(5);
                irq = probe_irq_off(cookie);
                if (!hwif->irq) {
                        if (irq > 0) {
                                hwif->irq = irq;
                        } else {
                                /* Mmmm.. multiple IRQs..
                                 * don't know which was ours
                                 */
                                printk(KERN_ERR "%s: IRQ probe failed (0x%lx)\n",
                                        drive->name, cookie);
                        }
                }
        }
        return retval;
}

int ide_busy_sleep(ide_hwif_t *hwif, unsigned long timeout, int altstatus)
{
        u8 stat;

        timeout += jiffies;

        do {
                msleep(50);     /* give drive a breather */
                stat = altstatus ? hwif->tp_ops->read_altstatus(hwif)
                                 : hwif->tp_ops->read_status(hwif);
                if ((stat & ATA_BUSY) == 0)
                        return 0;
        } while (time_before(jiffies, timeout));

        return 1;       /* drive timed-out */
}

static u8 ide_read_device(ide_drive_t *drive)
{
        ide_task_t task;

        memset(&task, 0, sizeof(task));
        task.tf_flags = IDE_TFLAG_IN_DEVICE;

        drive->hwif->tp_ops->tf_read(drive, &task);

        return task.tf.device;
}

/**
 *      do_probe                -       probe an IDE device
 *      @drive: drive to probe
 *      @cmd: command to use
 *
 *      do_probe() has the difficult job of finding a drive if it exists,
 *      without getting hung up if it doesn't exist, without trampling on
 *      ethernet cards, and without leaving any IRQs dangling to haunt us later.
 *
 *      If a drive is "known" to exist (from CMOS or kernel parameters),
 *      but does not respond right away, the probe will "hang in there"
 *      for the maximum wait time (about 30 seconds), otherwise it will
 *      exit much more quickly.
 *
 * Returns:     0  device was identified
 *              1  device timed-out (no response to identify request)
 *              2  device aborted the command (refused to identify itself)
 *              3  bad status from device (possible for ATAPI drives)
 *              4  probe was not attempted because failure was obvious
 */

static int do_probe (ide_drive_t *drive, u8 cmd)
{
        ide_hwif_t *hwif = HWIF(drive);
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        int rc;
        u8 present = !!(drive->dev_flags & IDE_DFLAG_PRESENT), stat;

        /* avoid waiting for inappropriate probes */
        if (present && drive->media != ide_disk && cmd == ATA_CMD_ID_ATA)
                return 4;

#ifdef DEBUG
        printk(KERN_INFO "probing for %s: present=%d, media=%d, probetype=%s\n",
                drive->name, present, drive->media,
                (cmd == ATA_CMD_ID_ATA) ? "ATA" : "ATAPI");
#endif

        /* needed for some systems
         * (e.g. crw9624 as drive0 with disk as slave)
         */
        msleep(50);
        SELECT_DRIVE(drive);
        msleep(50);

        if (ide_read_device(drive) != drive->select && present == 0) {
                if (drive->dn & 1) {
                        /* exit with drive0 selected */
                        SELECT_DRIVE(&hwif->drives[0]);
                        /* allow ATA_BUSY to assert & clear */
                        msleep(50);
                }
                /* no i/f present: mmm.. this should be a 4 -ml */
                return 3;
        }

        stat = tp_ops->read_status(hwif);

        if (OK_STAT(stat, ATA_DRDY, ATA_BUSY) ||
            present || cmd == ATA_CMD_ID_ATAPI) {
                /* send cmd and wait */
                if ((rc = try_to_identify(drive, cmd))) {
                        /* failed: try again */
                        rc = try_to_identify(drive,cmd);
                }

                stat = tp_ops->read_status(hwif);

                if (stat == (ATA_BUSY | ATA_DRDY))
                        return 4;

                if (rc == 1 && cmd == ATA_CMD_ID_ATAPI) {
                        printk(KERN_ERR "%s: no response (status = 0x%02x), "
                                        "resetting drive\n", drive->name, stat);
                        msleep(50);
                        SELECT_DRIVE(drive);
                        msleep(50);
                        tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
                        (void)ide_busy_sleep(hwif, WAIT_WORSTCASE, 0);
                        rc = try_to_identify(drive, cmd);
                }

                /* ensure drive IRQ is clear */
                stat = tp_ops->read_status(hwif);

                if (rc == 1)
                        printk(KERN_ERR "%s: no response (status = 0x%02x)\n",
                                        drive->name, stat);
        } else {
                /* not present or maybe ATAPI */
                rc = 3;
        }
        if (drive->dn & 1) {
                /* exit with drive0 selected */
                SELECT_DRIVE(&hwif->drives[0]);
                msleep(50);
                /* ensure drive irq is clear */
                (void)tp_ops->read_status(hwif);
        }
        return rc;
}

/*
 *
 */
static void enable_nest (ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        u8 stat;

        printk(KERN_INFO "%s: enabling %s -- ",
                hwif->name, (char *)&drive->id[ATA_ID_PROD]);

        SELECT_DRIVE(drive);
        msleep(50);
        tp_ops->exec_command(hwif, ATA_EXABYTE_ENABLE_NEST);

        if (ide_busy_sleep(hwif, WAIT_WORSTCASE, 0)) {
                printk(KERN_CONT "failed (timeout)\n");
                return;
        }

        msleep(50);

        stat = tp_ops->read_status(hwif);

        if (!OK_STAT(stat, 0, BAD_STAT))
                printk(KERN_CONT "failed (status = 0x%02x)\n", stat);
        else
                printk(KERN_CONT "success\n");
}

/**
 *      probe_for_drives        -       upper level drive probe
 *      @drive: drive to probe for
 *
 *      probe_for_drive() tests for existence of a given drive using do_probe()
 *      and presents things to the user as needed.
 *
 *      Returns:        0  no device was found
 *                      1  device was found
 *                         (note: IDE_DFLAG_PRESENT might still be not set)
 */
 
static inline u8 probe_for_drive (ide_drive_t *drive)
{
        char *m;

        /*
         *      In order to keep things simple we have an id
         *      block for all drives at all times. If the device
         *      is pre ATA or refuses ATA/ATAPI identify we
         *      will add faked data to this.
         *
         *      Also note that 0 everywhere means "can't do X"
         */
 
        drive->dev_flags &= ~IDE_DFLAG_ID_READ;

        drive->id = kzalloc(SECTOR_SIZE, GFP_KERNEL);
        if (drive->id == NULL) {
                printk(KERN_ERR "ide: out of memory for id data.\n");
                return 0;
        }

        m = (char *)&drive->id[ATA_ID_PROD];
        strcpy(m, "UNKNOWN");

        /* skip probing? */
        if ((drive->dev_flags & IDE_DFLAG_NOPROBE) == 0) {
retry:
                /* if !(success||timed-out) */
                if (do_probe(drive, ATA_CMD_ID_ATA) >= 2)
                        /* look for ATAPI device */
                        (void)do_probe(drive, ATA_CMD_ID_ATAPI);

                if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
                        /* drive not found */
                        return 0;

                if (strstr(m, "E X A B Y T E N E S T")) {
                        enable_nest(drive);
                        goto retry;
                }

                /* identification failed? */
                if ((drive->dev_flags & IDE_DFLAG_ID_READ) == 0) {
                        if (drive->media == ide_disk) {
                                printk(KERN_INFO "%s: non-IDE drive, CHS=%d/%d/%d\n",
                                        drive->name, drive->cyl,
                                        drive->head, drive->sect);
                        } else if (drive->media == ide_cdrom) {
                                printk(KERN_INFO "%s: ATAPI cdrom (?)\n", drive->name);
                        } else {
                                /* nuke it */
                                printk(KERN_WARNING "%s: Unknown device on bus refused identification. Ignoring.\n", drive->name);
                                drive->dev_flags &= ~IDE_DFLAG_PRESENT;
                        }
                }
                /* drive was found */
        }

        if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
                return 0;

        /* The drive wasn't being helpful. Add generic info only */
        if ((drive->dev_flags & IDE_DFLAG_ID_READ) == 0) {
                generic_id(drive);
                return 1;
        }

        if (drive->media == ide_disk) {
                ide_disk_init_chs(drive);
                ide_disk_init_mult_count(drive);
        }

        return !!(drive->dev_flags & IDE_DFLAG_PRESENT);
}

static void hwif_release_dev(struct device *dev)
{
        ide_hwif_t *hwif = container_of(dev, ide_hwif_t, gendev);

        complete(&hwif->gendev_rel_comp);
}

static int ide_register_port(ide_hwif_t *hwif)
{
        int ret;

        /* register with global device tree */
        strlcpy(hwif->gendev.bus_id,hwif->name,BUS_ID_SIZE);
        hwif->gendev.driver_data = hwif;
        if (hwif->gendev.parent == NULL) {
                if (hwif->dev)
                        hwif->gendev.parent = hwif->dev;
                else
                        /* Would like to do = &device_legacy */
                        hwif->gendev.parent = NULL;
        }
        hwif->gendev.release = hwif_release_dev;
        ret = device_register(&hwif->gendev);
        if (ret < 0) {
                printk(KERN_WARNING "IDE: %s: device_register error: %d\n",
                        __func__, ret);
                goto out;
        }

        hwif->portdev = device_create(ide_port_class, &hwif->gendev,
                                      MKDEV(0, 0), hwif, hwif->name);
        if (IS_ERR(hwif->portdev)) {
                ret = PTR_ERR(hwif->portdev);
                device_unregister(&hwif->gendev);
        }
out:
        return ret;
}

/**
 *      ide_port_wait_ready     -       wait for port to become ready
 *      @hwif: IDE port
 *
 *      This is needed on some PPCs and a bunch of BIOS-less embedded
 *      platforms.  Typical cases are:
 *
 *      - The firmware hard reset the disk before booting the kernel,
 *        the drive is still doing it's poweron-reset sequence, that
 *        can take up to 30 seconds.
 *
 *      - The firmware does nothing (or no firmware), the device is
 *        still in POST state (same as above actually).
 *
 *      - Some CD/DVD/Writer combo drives tend to drive the bus during
 *        their reset sequence even when they are non-selected slave
 *        devices, thus preventing discovery of the main HD.
 *
 *      Doing this wait-for-non-busy should not harm any existing
 *      configuration and fix some issues like the above.
 *
 *      BenH.
 *
 *      Returns 0 on success, error code (< 0) otherwise.
 */

static int ide_port_wait_ready(ide_hwif_t *hwif)
{
        int unit, rc;

        printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name);

        /* Let HW settle down a bit from whatever init state we
         * come from */
        mdelay(2);

        /* Wait for BSY bit to go away, spec timeout is 30 seconds,
         * I know of at least one disk who takes 31 seconds, I use 35
         * here to be safe
         */
        rc = ide_wait_not_busy(hwif, 35000);
        if (rc)
                return rc;

        /* Now make sure both master & slave are ready */
        for (unit = 0; unit < MAX_DRIVES; unit++) {
                ide_drive_t *drive = &hwif->drives[unit];

                /* Ignore disks that we will not probe for later. */
                if ((drive->dev_flags & IDE_DFLAG_NOPROBE) == 0 ||
                    (drive->dev_flags & IDE_DFLAG_PRESENT)) {
                        SELECT_DRIVE(drive);
                        hwif->tp_ops->set_irq(hwif, 1);
                        mdelay(2);
                        rc = ide_wait_not_busy(hwif, 35000);
                        if (rc)
                                goto out;
                } else
                        printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n",
                                          drive->name);
        }
out:
        /* Exit function with master reselected (let's be sane) */
        if (unit)
                SELECT_DRIVE(&hwif->drives[0]);

        return rc;
}

/**
 *      ide_undecoded_slave     -       look for bad CF adapters
 *      @dev1: slave device
 *
 *      Analyse the drives on the interface and attempt to decide if we
 *      have the same drive viewed twice. This occurs with crap CF adapters
 *      and PCMCIA sometimes.
 */

void ide_undecoded_slave(ide_drive_t *dev1)
{
        ide_drive_t *dev0 = &dev1->hwif->drives[0];

        if ((dev1->dn & 1) == 0 || (dev0->dev_flags & IDE_DFLAG_PRESENT) == 0)
                return;

        /* If the models don't match they are not the same product */
        if (strcmp((char *)&dev0->id[ATA_ID_PROD],
                   (char *)&dev1->id[ATA_ID_PROD]))
                return;

        /* Serial numbers do not match */
        if (strncmp((char *)&dev0->id[ATA_ID_SERNO],
                    (char *)&dev1->id[ATA_ID_SERNO], ATA_ID_SERNO_LEN))
                return;

        /* No serial number, thankfully very rare for CF */
        if (*(char *)&dev0->id[ATA_ID_SERNO] == 0)
                return;

        /* Appears to be an IDE flash adapter with decode bugs */
        printk(KERN_WARNING "ide-probe: ignoring undecoded slave\n");

        dev1->dev_flags &= ~IDE_DFLAG_PRESENT;
}

EXPORT_SYMBOL_GPL(ide_undecoded_slave);

static int ide_probe_port(ide_hwif_t *hwif)
{
        unsigned long flags;
        unsigned int irqd;
        int unit, rc = -ENODEV;

        BUG_ON(hwif->present);

        if ((hwif->drives[0].dev_flags & IDE_DFLAG_NOPROBE) &&
            (hwif->drives[1].dev_flags & IDE_DFLAG_NOPROBE))
                return -EACCES;

        /*
         * We must always disable IRQ, as probe_for_drive will assert IRQ, but
         * we'll install our IRQ driver much later...
         */
        irqd = hwif->irq;
        if (irqd)
                disable_irq(hwif->irq);

        local_irq_set(flags);

        if (ide_port_wait_ready(hwif) == -EBUSY)
                printk(KERN_DEBUG "%s: Wait for ready failed before probe !\n", hwif->name);

        /*
         * Second drive should only exist if first drive was found,
         * but a lot of cdrom drives are configured as single slaves.
         */
        for (unit = 0; unit < MAX_DRIVES; ++unit) {
                ide_drive_t *drive = &hwif->drives[unit];

                (void) probe_for_drive(drive);
                if (drive->dev_flags & IDE_DFLAG_PRESENT)
                        rc = 0;
        }

        local_irq_restore(flags);

        /*
         * Use cached IRQ number. It might be (and is...) changed by probe
         * code above
         */
        if (irqd)
                enable_irq(irqd);

        return rc;
}

static void ide_port_tune_devices(ide_hwif_t *hwif)
{
        const struct ide_port_ops *port_ops = hwif->port_ops;
        int unit;

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

                if (drive->dev_flags & IDE_DFLAG_PRESENT) {
                        if (port_ops && port_ops->quirkproc)
                                port_ops->quirkproc(drive);
                }
        }

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

                if (drive->dev_flags & IDE_DFLAG_PRESENT) {
                        ide_set_max_pio(drive);

                        drive->dev_flags |= IDE_DFLAG_NICE1;

                        if (hwif->dma_ops)
                                ide_set_dma(drive);
                }
        }

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

                if ((hwif->host_flags & IDE_HFLAG_NO_IO_32BIT) ||
                    drive->id[ATA_ID_DWORD_IO])
                        drive->dev_flags |= IDE_DFLAG_NO_IO_32BIT;
                else
                        drive->dev_flags &= ~IDE_DFLAG_NO_IO_32BIT;
        }
}

/*
 * save_match() is used to simplify logic in init_irq() below.
 *
 * A loophole here is that we may not know about a particular
 * hwif's irq until after that hwif is actually probed/initialized..
 * This could be a problem for the case where an hwif is on a
 * dual interface that requires serialization (eg. cmd640) and another
 * hwif using one of the same irqs is initialized beforehand.
 *
 * This routine detects and reports such situations, but does not fix them.
 */
static void save_match(ide_hwif_t *hwif, ide_hwif_t *new, ide_hwif_t **match)
{
        ide_hwif_t *m = *match;

        if (m && m->hwgroup && m->hwgroup != new->hwgroup) {
                if (!new->hwgroup)
                        return;
                printk(KERN_WARNING "%s: potential IRQ problem with %s and %s\n",
                        hwif->name, new->name, m->name);
        }
        if (!m || m->irq != hwif->irq) /* don't undo a prior perfect match */
                *match = new;
}

/*
 * init request queue
 */
static int ide_init_queue(ide_drive_t *drive)
{
        struct request_queue *q;
        ide_hwif_t *hwif = HWIF(drive);
        int max_sectors = 256;
        int max_sg_entries = PRD_ENTRIES;

        /*
         *      Our default set up assumes the normal IDE case,
         *      that is 64K segmenting, standard PRD setup
         *      and LBA28. Some drivers then impose their own
         *      limits and LBA48 we could raise it but as yet
         *      do not.
         */

        q = blk_init_queue_node(do_ide_request, &ide_lock, hwif_to_node(hwif));
        if (!q)
                return 1;

        q->queuedata = drive;
        blk_queue_segment_boundary(q, 0xffff);

        if (hwif->rqsize < max_sectors)
                max_sectors = hwif->rqsize;
        blk_queue_max_sectors(q, max_sectors);

#ifdef CONFIG_PCI
        /* When we have an IOMMU, we may have a problem where pci_map_sg()
         * creates segments that don't completely match our boundary
         * requirements and thus need to be broken up again. Because it
         * doesn't align properly either, we may actually have to break up
         * to more segments than what was we got in the first place, a max
         * worst case is twice as many.
         * This will be fixed once we teach pci_map_sg() about our boundary
         * requirements, hopefully soon. *FIXME*
         */
        if (!PCI_DMA_BUS_IS_PHYS)
                max_sg_entries >>= 1;
#endif /* CONFIG_PCI */

        blk_queue_max_hw_segments(q, max_sg_entries);
        blk_queue_max_phys_segments(q, max_sg_entries);

        /* assign drive queue */
        drive->queue = q;

        /* needs drive->queue to be set */
        ide_toggle_bounce(drive, 1);

        return 0;
}

static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

        spin_lock_irq(&ide_lock);
        if (!hwgroup->drive) {
                /* first drive for hwgroup. */
                drive->next = drive;
                hwgroup->drive = drive;
                hwgroup->hwif = HWIF(hwgroup->drive);
        } else {
                drive->next = hwgroup->drive->next;
                hwgroup->drive->next = drive;
        }
        spin_unlock_irq(&ide_lock);
}

/*
 * For any present drive:
 * - allocate the block device queue
 * - link drive into the hwgroup
 */
static int ide_port_setup_devices(ide_hwif_t *hwif)
{
        int i, j = 0;

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

                if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
                        continue;

                if (ide_init_queue(drive)) {
                        printk(KERN_ERR "ide: failed to init %s\n",
                                        drive->name);
                        kfree(drive->id);
                        drive->id = NULL;
                        drive->dev_flags &= ~IDE_DFLAG_PRESENT;
                        continue;
                }

                j++;

                ide_add_drive_to_hwgroup(drive);
        }
        mutex_unlock(&ide_cfg_mtx);

        return j;
}

static ide_hwif_t *ide_ports[MAX_HWIFS];

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

        ide_ports[hwif->index] = NULL;

        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);
}

/*
 * This routine sets up the irq for an ide interface, and creates a new
 * hwgroup for the irq/hwif if none was previously assigned.
 *
 * Much of the code is for correctly detecting/handling irq sharing
 * and irq serialization situations.  This is somewhat complex because
 * it handles static as well as dynamic (PCMCIA) IDE interfaces.
 */
static int init_irq (ide_hwif_t *hwif)
{
        struct ide_io_ports *io_ports = &hwif->io_ports;
        unsigned int index;
        ide_hwgroup_t *hwgroup;
        ide_hwif_t *match = NULL;

        mutex_lock(&ide_cfg_mtx);
        hwif->hwgroup = NULL;

        /*
         * Group up with any other hwifs that share our irq(s).
         */
        for (index = 0; index < MAX_HWIFS; index++) {
                ide_hwif_t *h = ide_ports[index];

                if (h && h->hwgroup) {  /* scan only initialized ports */
                        if (hwif->irq == h->irq) {
                                hwif->sharing_irq = h->sharing_irq = 1;
                                if (hwif->chipset != ide_pci ||
                                    h->chipset != ide_pci) {
                                        save_match(hwif, h, &match);
                                }
                        }
                        if (hwif->serialized) {
                                if (hwif->mate && hwif->mate->irq == h->irq)
                                        save_match(hwif, h, &match);
                        }
                        if (h->serialized) {
                                if (h->mate && hwif->irq == h->mate->irq)
                                        save_match(hwif, h, &match);
                        }
                }
        }

        /*
         * If we are still without a hwgroup, then form a new one
         */
        if (match) {
                hwgroup = match->hwgroup;
                hwif->hwgroup = hwgroup;
                /*
                 * Link us into the hwgroup.
                 * This must be done early, do ensure that unexpected_intr
                 * can find the hwif and prevent irq storms.
                 * No drives are attached to the new hwif, choose_drive
                 * can't do anything stupid (yet).
                 * Add ourself as the 2nd entry to the hwgroup->hwif
                 * linked list, the first entry is the hwif that owns
                 * hwgroup->handler - do not change that.
                 */
                spin_lock_irq(&ide_lock);
                hwif->next = hwgroup->hwif->next;
                hwgroup->hwif->next = hwif;
                BUG_ON(hwif->next == hwif);
                spin_unlock_irq(&ide_lock);
        } else {
                hwgroup = kmalloc_node(sizeof(*hwgroup), GFP_KERNEL|__GFP_ZERO,
                                       hwif_to_node(hwif));
                if (hwgroup == NULL)
                        goto out_up;

                hwif->hwgroup = hwgroup;
                hwgroup->hwif = hwif->next = hwif;

                init_timer(&hwgroup->timer);
                hwgroup->timer.function = &ide_timer_expiry;
                hwgroup->timer.data = (unsigned long) hwgroup;
        }

        ide_ports[hwif->index] = hwif;

        /*
         * Allocate the irq, if not already obtained for another hwif
         */
        if (!match || match->irq != hwif->irq) {
                int sa = 0;
#if defined(__mc68000__)
                sa = IRQF_SHARED;
#endif /* __mc68000__ */

                if (hwif->chipset == ide_pci || hwif->chipset == ide_cmd646 ||
                    hwif->chipset == ide_ali14xx)
                        sa = IRQF_SHARED;

                if (io_ports->ctl_addr)
                        hwif->tp_ops->set_irq(hwif, 1);

                if (request_irq(hwif->irq,&ide_intr,sa,hwif->name,hwgroup))
                        goto out_unlink;
        }

        if (!hwif->rqsize) {
                if ((hwif->host_flags & IDE_HFLAG_NO_LBA48) ||
                    (hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA))
                        hwif->rqsize = 256;
                else
                        hwif->rqsize = 65536;
        }

#if !defined(__mc68000__)
        printk(KERN_INFO "%s at 0x%03lx-0x%03lx,0x%03lx on irq %d", hwif->name,
                io_ports->data_addr, io_ports->status_addr,
                io_ports->ctl_addr, hwif->irq);
#else
        printk(KERN_INFO "%s at 0x%08lx on irq %d", hwif->name,
                io_ports->data_addr, hwif->irq);
#endif /* __mc68000__ */
        if (match)
                printk(KERN_CONT " (%sed with %s)",
                        hwif->sharing_irq ? "shar" : "serializ", match->name);
        printk(KERN_CONT "\n");

        mutex_unlock(&ide_cfg_mtx);
        return 0;
out_unlink:
        ide_remove_port_from_hwgroup(hwif);
out_up:
        mutex_unlock(&ide_cfg_mtx);
        return 1;
}

static int ata_lock(dev_t dev, void *data)
{
        /* FIXME: we want to pin hwif down */
        return 0;
}

static struct kobject *ata_probe(dev_t dev, int *part, void *data)
{
        ide_hwif_t *hwif = data;
        int unit = *part >> PARTN_BITS;
        ide_drive_t *drive = &hwif->drives[unit];

        if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
                return NULL;

        if (drive->media == ide_disk)
                request_module("ide-disk");
        if (drive->dev_flags & IDE_DFLAG_SCSI)
                request_module("ide-scsi");
        if (drive->media == ide_cdrom || drive->media == ide_optical)
                request_module("ide-cd");
        if (drive->media == ide_tape)
                request_module("ide-tape");
        if (drive->media == ide_floppy)
                request_module("ide-floppy");

        return NULL;
}

static struct kobject *exact_match(dev_t dev, int *part, void *data)
{
        struct gendisk *p = data;
        *part &= (1 << PARTN_BITS) - 1;
        return &disk_to_dev(p)->kobj;
}

static int exact_lock(dev_t dev, void *data)
{
        struct gendisk *p = data;

        if (!get_disk(p))
                return -1;
        return 0;
}

void ide_register_region(struct gendisk *disk)
{
        blk_register_region(MKDEV(disk->major, disk->first_minor),
                            disk->minors, NULL, exact_match, exact_lock, disk);
}

EXPORT_SYMBOL_GPL(ide_register_region);

void ide_unregister_region(struct gendisk *disk)
{
        blk_unregister_region(MKDEV(disk->major, disk->first_minor),
                              disk->minors);
}

EXPORT_SYMBOL_GPL(ide_unregister_region);

void ide_init_disk(struct gendisk *disk, ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned int unit = drive->dn & 1;

        disk->major = hwif->major;
        disk->first_minor = unit << PARTN_BITS;
        sprintf(disk->disk_name, "hd%c", 'a' + hwif->index * MAX_DRIVES + unit);
        disk->queue = drive->queue;
}

EXPORT_SYMBOL_GPL(ide_init_disk);

static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
{
        ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

        if (drive == drive->next) {
                /* special case: last drive from hwgroup. */
                BUG_ON(hwgroup->drive != drive);
                hwgroup->drive = NULL;
        } else {
                ide_drive_t *walk;

                walk = hwgroup->drive;
                while (walk->next != drive)
                        walk = walk->next;
                walk->next = drive->next;
                if (hwgroup->drive == drive) {
                        hwgroup->drive = drive->next;
                        hwgroup->hwif = hwgroup->drive->hwif;
                }
        }
        BUG_ON(hwgroup->drive == drive);
}

static void drive_release_dev (struct device *dev)
{
        ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);

        ide_proc_unregister_device(drive);

        spin_lock_irq(&ide_lock);
        ide_remove_drive_from_hwgroup(drive);
        kfree(drive->id);
        drive->id = NULL;
        drive->dev_flags &= ~IDE_DFLAG_PRESENT;
        /* Messed up locking ... */
        spin_unlock_irq(&ide_lock);
        blk_cleanup_queue(drive->queue);
        spin_lock_irq(&ide_lock);
        drive->queue = NULL;
        spin_unlock_irq(&ide_lock);

        complete(&drive->gendev_rel_comp);
}

static int hwif_init(ide_hwif_t *hwif)
{
        int old_irq;

        if (!hwif->irq) {
                hwif->irq = __ide_default_irq(hwif->io_ports.data_addr);
                if (!hwif->irq) {
                        printk(KERN_ERR "%s: disabled, no IRQ\n", hwif->name);
                        return 0;
                }
        }

        if (register_blkdev(hwif->major, hwif->name))
                return 0;

        if (!hwif->sg_max_nents)
                hwif->sg_max_nents = PRD_ENTRIES;

        hwif->sg_table = kmalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,
                                 GFP_KERNEL);
        if (!hwif->sg_table) {
                printk(KERN_ERR "%s: unable to allocate SG table.\n", hwif->name);
                goto out;
        }

        sg_init_table(hwif->sg_table, hwif->sg_max_nents);
        
        if (init_irq(hwif) == 0)
                goto done;

        old_irq = hwif->irq;
        /*
         *      It failed to initialise. Find the default IRQ for 
         *      this port and try that.
         */
        hwif->irq = __ide_default_irq(hwif->io_ports.data_addr);
        if (!hwif->irq) {
                printk(KERN_ERR "%s: disabled, unable to get IRQ %d\n",
                        hwif->name, old_irq);
                goto out;
        }
        if (init_irq(hwif)) {
                printk(KERN_ERR "%s: probed IRQ %d and default IRQ %d failed\n",
                        hwif->name, old_irq, hwif->irq);
                goto out;
        }
        printk(KERN_WARNING "%s: probed IRQ %d failed, using default\n",
                hwif->name, hwif->irq);

done:
        blk_register_region(MKDEV(hwif->major, 0), MAX_DRIVES << PARTN_BITS,
                            THIS_MODULE, ata_probe, ata_lock, hwif);
        return 1;

out:
        unregister_blkdev(hwif->major, hwif->name);
        return 0;
}

static void hwif_register_devices(ide_hwif_t *hwif)
{
        unsigned int i;

        for (i = 0; i < MAX_DRIVES; i++) {
                ide_drive_t *drive = &hwif->drives[i];
                struct device *dev = &drive->gendev;
                int ret;

                if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)
                        continue;

                snprintf(dev->bus_id, BUS_ID_SIZE, "%u.%u", hwif->index, i);
                dev->parent = &hwif->gendev;
                dev->bus = &ide_bus_type;
                dev->driver_data = drive;
                dev->release = drive_release_dev;

                ret = device_register(dev);
                if (ret < 0)
                        printk(KERN_WARNING "IDE: %s: device_register error: "
                                            "%d\n", __func__, ret);
        }
}

static void ide_port_init_devices(ide_hwif_t *hwif)
{
        const struct ide_port_ops *port_ops = hwif->port_ops;
        int i;

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

                drive->dn = i + hwif->channel * 2;

                if (hwif->host_flags & IDE_HFLAG_IO_32BIT)
                        drive->io_32bit = 1;
                if (hwif->host_flags & IDE_HFLAG_UNMASK_IRQS)
                        drive->dev_flags |= IDE_DFLAG_UNMASK;
                if (hwif->host_flags & IDE_HFLAG_NO_UNMASK_IRQS)
                        drive->dev_flags |= IDE_DFLAG_NO_UNMASK;

                if (port_ops && port_ops->init_dev)
                        port_ops->init_dev(drive);
        }
}

static void ide_init_port(ide_hwif_t *hwif, unsigned int port,
                          const struct ide_port_info *d)
{
        hwif->channel = port;

        if (d->chipset)
                hwif->chipset = d->chipset;

        if (d->init_iops)
                d->init_iops(hwif);

        if ((!hwif->irq && (d->host_flags & IDE_HFLAG_LEGACY_IRQS)) ||
            (d->host_flags & IDE_HFLAG_FORCE_LEGACY_IRQS))
                hwif->irq = port ? 15 : 14;

        /* ->host_flags may be set by ->init_iops (or even earlier...) */
        hwif->host_flags |= d->host_flags;
        hwif->pio_mask = d->pio_mask;

        if (d->tp_ops)
                hwif->tp_ops = d->tp_ops;

        /* ->set_pio_mode for DTC2278 is currently limited to port 0 */
        if (hwif->chipset != ide_dtc2278 || hwif->channel == 0)
                hwif->port_ops = d->port_ops;

        hwif->swdma_mask = d->swdma_mask;
        hwif->mwdma_mask = d->mwdma_mask;
        hwif->ultra_mask = d->udma_mask;

        if ((d->host_flags & IDE_HFLAG_NO_DMA) == 0) {
                int rc;

                if (d->init_dma)
                        rc = d->init_dma(hwif, d);
                else
                        rc = ide_hwif_setup_dma(hwif, d);

                if (rc < 0) {
                        printk(KERN_INFO "%s: DMA disabled\n", hwif->name);
                        hwif->dma_base = 0;
                        hwif->swdma_mask = 0;
                        hwif->mwdma_mask = 0;
                        hwif->ultra_mask = 0;
                } else if (d->dma_ops)
                        hwif->dma_ops = d->dma_ops;
        }

        if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||
            ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base)) {
                if (hwif->mate)
                        hwif->mate->serialized = hwif->serialized = 1;
        }

        if (d->host_flags & IDE_HFLAG_RQSIZE_256)
                hwif->rqsize = 256;

        /* call chipset specific routine for each enabled port */
        if (d->init_hwif)
                d->init_hwif(hwif);
}

static void ide_port_cable_detect(ide_hwif_t *hwif)
{
        const struct ide_port_ops *port_ops = hwif->port_ops;

        if (port_ops && port_ops->cable_detect && (hwif->ultra_mask & 0x78)) {
                if (hwif->cbl != ATA_CBL_PATA40_SHORT)
                        hwif->cbl = port_ops->cable_detect(hwif);
        }
}

static ssize_t store_delete_devices(struct device *portdev,
                                    struct device_attribute *attr,
                                    const char *buf, size_t n)
{
        ide_hwif_t *hwif = dev_get_drvdata(portdev);

        if (strncmp(buf, "1", n))
                return -EINVAL;

        ide_port_unregister_devices(hwif);

        return n;
};

static DEVICE_ATTR(delete_devices, S_IWUSR, NULL, store_delete_devices);

static ssize_t store_scan(struct device *portdev,
                          struct device_attribute *attr,
                          const char *buf, size_t n)
{
        ide_hwif_t *hwif = dev_get_drvdata(portdev);

        if (strncmp(buf, "1", n))
                return -EINVAL;

        ide_port_unregister_devices(hwif);
        ide_port_scan(hwif);

        return n;
};

static DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);

static struct device_attribute *ide_port_attrs[] = {
        &dev_attr_delete_devices,
        &dev_attr_scan,
        NULL
};

static int ide_sysfs_register_port(ide_hwif_t *hwif)
{
        int i, uninitialized_var(rc);

        for (i = 0; ide_port_attrs[i]; i++) {
                rc = device_create_file(hwif->portdev, ide_port_attrs[i]);
                if (rc)
                        break;
        }

        return rc;
}

static unsigned int ide_indexes;

/**
 *      ide_find_port_slot      -       find free port slot
 *      @d: IDE port info
 *
 *      Return the new port slot index or -ENOENT if we are out of free slots.
 */

static int ide_find_port_slot(const struct ide_port_info *d)
{
        int idx = -ENOENT;
        u8 bootable = (d && (d->host_flags & IDE_HFLAG_NON_BOOTABLE)) ? 0 : 1;
        u8 i = (d && (d->host_flags & IDE_HFLAG_QD_2ND_PORT)) ? 1 : 0;;

        /*
         * Claim an unassigned slot.
         *
         * Give preference to claiming other slots before claiming ide0/ide1,
         * just in case there's another interface yet-to-be-scanned
         * which uses ports 0x1f0/0x170 (the ide0/ide1 defaults).
         *
         * Unless there is a bootable card that does not use the standard
         * ports 0x1f0/0x170 (the ide0/ide1 defaults).
         */
        mutex_lock(&ide_cfg_mtx);
        if (bootable) {
                if ((ide_indexes | i) != (1 << MAX_HWIFS) - 1)
                        idx = ffz(ide_indexes | i);
        } else {
                if ((ide_indexes | 3) != (1 << MAX_HWIFS) - 1)
                        idx = ffz(ide_indexes | 3);
                else if ((ide_indexes & 3) != 3)
                        idx = ffz(ide_indexes);
        }
        if (idx >= 0)
                ide_indexes |= (1 << idx);
        mutex_unlock(&ide_cfg_mtx);

        return idx;
}

static void ide_free_port_slot(int idx)
{
        mutex_lock(&ide_cfg_mtx);
        ide_indexes &= ~(1 << idx);
        mutex_unlock(&ide_cfg_mtx);
}

struct ide_host *ide_host_alloc(const struct ide_port_info *d, hw_regs_t **hws)
{
        struct ide_host *host;
        int i;

        host = kzalloc(sizeof(*host), GFP_KERNEL);
        if (host == NULL)
                return NULL;

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                ide_hwif_t *hwif;
                int idx;

                if (hws[i] == NULL)
                        continue;

                hwif = kzalloc(sizeof(*hwif), GFP_KERNEL);
                if (hwif == NULL)
                        continue;

                idx = ide_find_port_slot(d);
                if (idx < 0) {
                        printk(KERN_ERR "%s: no free slot for interface\n",
                                        d ? d->name : "ide");
                        kfree(hwif);
                        continue;
                }

                ide_init_port_data(hwif, idx);

                hwif->host = host;

                host->ports[i] = hwif;
                host->n_ports++;
        }

        if (host->n_ports == 0) {
                kfree(host);
                return NULL;
        }

        if (hws[0])
                host->dev[0] = hws[0]->dev;

        if (d) {
                host->init_chipset = d->init_chipset;
                host->host_flags = d->host_flags;
        }

        return host;
}
EXPORT_SYMBOL_GPL(ide_host_alloc);

int ide_host_register(struct ide_host *host, const struct ide_port_info *d,
                      hw_regs_t **hws)
{
        ide_hwif_t *hwif, *mate = NULL;
        int i, j = 0;

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL) {
                        mate = NULL;
                        continue;
                }

                ide_init_port_hw(hwif, hws[i]);
                ide_port_apply_params(hwif);

                if (d == NULL) {
                        mate = NULL;
                } else {
                        if ((i & 1) && mate) {
                                hwif->mate = mate;
                                mate->mate = hwif;
                        }

                        mate = (i & 1) ? NULL : hwif;

                        ide_init_port(hwif, i & 1, d);
                        ide_port_cable_detect(hwif);
                }

                ide_port_init_devices(hwif);
        }

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL)
                        continue;

                if (ide_probe_port(hwif) == 0)
                        hwif->present = 1;

                if (hwif->chipset != ide_4drives || !hwif->mate ||
                    !hwif->mate->present)
                        ide_register_port(hwif);

                if (hwif->present)
                        ide_port_tune_devices(hwif);
        }

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL)
                        continue;

                if (hwif_init(hwif) == 0) {
                        printk(KERN_INFO "%s: failed to initialize IDE "
                                         "interface\n", hwif->name);
                        hwif->present = 0;
                        continue;
                }

                if (hwif->present)
                        if (ide_port_setup_devices(hwif) == 0) {
                                hwif->present = 0;
                                continue;
                        }

                j++;

                ide_acpi_init(hwif);

                if (hwif->present)
                        ide_acpi_port_init_devices(hwif);
        }

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL)
                        continue;

                if (hwif->chipset == ide_unknown)
                        hwif->chipset = ide_generic;

                if (hwif->present)
                        hwif_register_devices(hwif);
        }

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL)
                        continue;

                ide_sysfs_register_port(hwif);
                ide_proc_register_port(hwif);

                if (hwif->present)
                        ide_proc_port_register_devices(hwif);
        }

        return j ? 0 : -1;
}
EXPORT_SYMBOL_GPL(ide_host_register);

int ide_host_add(const struct ide_port_info *d, hw_regs_t **hws,
                 struct ide_host **hostp)
{
        struct ide_host *host;
        int rc;

        host = ide_host_alloc(d, hws);
        if (host == NULL)
                return -ENOMEM;

        rc = ide_host_register(host, d, hws);
        if (rc) {
                ide_host_free(host);
                return rc;
        }

        if (hostp)
                *hostp = host;

        return 0;
}
EXPORT_SYMBOL_GPL(ide_host_add);

void ide_host_free(struct ide_host *host)
{
        ide_hwif_t *hwif;
        int i;

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                hwif = host->ports[i];

                if (hwif == NULL)
                        continue;

                ide_free_port_slot(hwif->index);
                kfree(hwif);
        }

        kfree(host);
}
EXPORT_SYMBOL_GPL(ide_host_free);

void ide_host_remove(struct ide_host *host)
{
        int i;

        for (i = 0; i < MAX_HOST_PORTS; i++) {
                if (host->ports[i])
                        ide_unregister(host->ports[i]);
        }

        ide_host_free(host);
}
EXPORT_SYMBOL_GPL(ide_host_remove);

void ide_port_scan(ide_hwif_t *hwif)
{
        ide_port_apply_params(hwif);
        ide_port_cable_detect(hwif);
        ide_port_init_devices(hwif);

        if (ide_probe_port(hwif) < 0)
                return;

        hwif->present = 1;

        ide_port_tune_devices(hwif);
        ide_acpi_port_init_devices(hwif);
        ide_port_setup_devices(hwif);
        hwif_register_devices(hwif);
        ide_proc_port_register_devices(hwif);
}
EXPORT_SYMBOL_GPL(ide_port_scan);

static void ide_legacy_init_one(hw_regs_t **hws, hw_regs_t *hw,
                                u8 port_no, const struct ide_port_info *d,
                                unsigned long config)
{
        unsigned long base, ctl;
        int irq;

        if (port_no == 0) {
                base = 0x1f0;
                ctl  = 0x3f6;
                irq  = 14;
        } else {
                base = 0x170;
                ctl  = 0x376;
                irq  = 15;
        }

        if (!request_region(base, 8, d->name)) {
                printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.\n",
                                d->name, base, base + 7);
                return;
        }

        if (!request_region(ctl, 1, d->name)) {
                printk(KERN_ERR "%s: I/O resource 0x%lX not free.\n",
                                d->name, ctl);
                release_region(base, 8);
                return;
        }

        ide_std_init_ports(hw, base, ctl);
        hw->irq = irq;
        hw->chipset = d->chipset;
        hw->config = config;

        hws[port_no] = hw;
}

int ide_legacy_device_add(const struct ide_port_info *d, unsigned long config)
{
        hw_regs_t hw[2], *hws[] = { NULL, NULL, NULL, NULL };

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

        if ((d->host_flags & IDE_HFLAG_QD_2ND_PORT) == 0)
                ide_legacy_init_one(hws, &hw[0], 0, d, config);
        ide_legacy_init_one(hws, &hw[1], 1, d, config);

        if (hws[0] == NULL && hws[1] == NULL &&
            (d->host_flags & IDE_HFLAG_SINGLE))
                return -ENOENT;

        return ide_host_add(d, hws, NULL);
}
EXPORT_SYMBOL_GPL(ide_legacy_device_add);