ide-probe.c

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

/*
 *  Mostly written by Mark Lord <[email protected]>
 *                and Gadi Oxman <[email protected]>
 *                and Andre Hedrick <[email protected]>
 *
 *  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>

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_flags |= IDE_SFLAG_SET_MULTMODE;
    }
}

static void ide_classify_ata_dev(ide_drive_t *drive)
{
    u16 *id = drive->id;
    char *m = (char *)&id[ATA_ID_PROD];
    int 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_INFO "%s: %s, %s DISK drive\n", drive->name, m,
        is_cfa ? "CFA" : "ATA");
}

static void ide_classify_atapi_dev(ide_drive_t *drive)
{
    u16 *id = drive->id;
    char *m = (char *)&id[ATA_ID_PROD];
    u8 type = (id[ATA_ID_CONFIG] >> 8) & 0x1f;

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

static void do_identify(ide_drive_t *drive, u8 cmd, u16 *id)
{
    ide_hwif_t *hwif = drive->hwif;
    char *m = (char *)&id[ATA_ID_PROD];
    unsigned long flags;
    int bswap = 1;

    /* local CPU only; some systems need this */
    local_irq_save(flags);
    /* read 512 bytes of id info */
    hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);
    local_irq_restore(flags);

    drive->dev_flags |= IDE_DFLAG_ID_READ;
#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"))
        drive->dev_flags &= ~IDE_DFLAG_PRESENT;
    else
        drive->dev_flags |= IDE_DFLAG_PRESENT;
}

int ide_dev_read_id(ide_drive_t *drive, u8 cmd, u16 *id, int irq_ctx)
{
    ide_hwif_t *hwif = drive->hwif;
    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;

    /*
     * Disable device IRQ.  Otherwise we'll get spurious interrupts
     * during the identify phase that the IRQ handler isn't expecting.
     */
    if (io_ports->ctl_addr)
        tp_ops->write_devctl(hwif, ATA_NIEN | ATA_DEVCTL_OBS);

    /* take a deep breath */
    if (irq_ctx)
        mdelay(50);
    else
        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) {
        struct ide_taskfile tf;

        memset(&tf, 0, sizeof(tf));
        /* disable DMA & overlap */
        tp_ops->tf_load(drive, &tf, IDE_VALID_FEATURE);
    }

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

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

    /* wait for IRQ and ATA_DRQ */
    if (irq_ctx) {
        rc = __ide_wait_stat(drive, ATA_DRQ, BAD_R_STAT, timeout, &s);
        if (rc)
            return 1;
    } else {
        rc = ide_busy_sleep(drive, timeout, use_altstatus);
        if (rc)
            return 1;

        msleep(50);
        s = tp_ops->read_status(hwif);
    }

    if (OK_STAT(s, ATA_DRQ, BAD_R_STAT)) {
        /* drive returned ID */
        do_identify(drive, cmd, id);
        /* drive responded with ID */
        rc = 0;
        /* clear drive IRQ */
        (void)tp_ops->read_status(hwif);
    } else {
        /* drive refused ID */
        rc = 2;
    }
    return rc;
}

int ide_busy_sleep(ide_drive_t *drive, unsigned long timeout, int altstatus)
{
    ide_hwif_t *hwif = drive->hwif;
    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));

    printk(KERN_ERR "%s: timeout in %s\n", drive->name, __func__);

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

static u8 ide_read_device(ide_drive_t *drive)
{
    struct ide_taskfile tf;

    drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_DEVICE);

    return tf.device;
}

static int do_probe (ide_drive_t *drive, u8 cmd)
{
    ide_hwif_t *hwif = drive->hwif;
    const struct ide_tp_ops *tp_ops = hwif->tp_ops;
    u16 *id = drive->id;
    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);
    tp_ops->dev_select(drive);
    msleep(50);

    if (ide_read_device(drive) != drive->select && present == 0) {
        if (drive->dn & 1) {
            /* exit with drive0 selected */
            tp_ops->dev_select(hwif->devices[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) {
        rc = ide_dev_read_id(drive, cmd, id, 0);
        if (rc)
            /* failed: try again */
            rc = ide_dev_read_id(drive, cmd, id, 0);

        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);
            tp_ops->dev_select(drive);
            msleep(50);
            tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
            (void)ide_busy_sleep(drive, WAIT_WORSTCASE, 0);
            rc = ide_dev_read_id(drive, cmd, id, 0);
        }

        /* 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 */
        tp_ops->dev_select(hwif->devices[0]);
        msleep(50);
        /* ensure drive irq is clear */
        (void)tp_ops->read_status(hwif);
    }
    return rc;
}

static u8 probe_for_drive(ide_drive_t *drive)
{
    char *m;
    int rc;
    u8 cmd;

    drive->dev_flags &= ~IDE_DFLAG_ID_READ;

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

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

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

        /* 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;
            }
        } else {
            if (cmd == ATA_CMD_ID_ATAPI)
                ide_classify_atapi_dev(drive);
            else
                ide_classify_ata_dev(drive);
        }
    }

    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 1;
}

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 */
    dev_set_name(&hwif->gendev, hwif->name);
    dev_set_drvdata(&hwif->gendev, hwif);
    if (hwif->gendev.parent == NULL)
        hwif->gendev.parent = hwif->dev;
    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;
}

static int ide_port_wait_ready(ide_hwif_t *hwif)
{
    const struct ide_tp_ops *tp_ops = hwif->tp_ops;
    ide_drive_t *drive;
    int i, 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 */
    ide_port_for_each_dev(i, drive, hwif) {
        /* Ignore disks that we will not probe for later. */
        if ((drive->dev_flags & IDE_DFLAG_NOPROBE) == 0 ||
            (drive->dev_flags & IDE_DFLAG_PRESENT)) {
            tp_ops->dev_select(drive);
            tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);
            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 (i)
        tp_ops->dev_select(hwif->devices[0]);

    return rc;
}

void ide_undecoded_slave(ide_drive_t *dev1)
{
    ide_drive_t *dev0 = dev1->hwif->devices[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)
{
    ide_drive_t *drive;
    unsigned int irqd;
    int i, rc = -ENODEV;

    BUG_ON(hwif->present);

    if ((hwif->devices[0]->dev_flags & IDE_DFLAG_NOPROBE) &&
        (hwif->devices[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);

    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.
     */
    ide_port_for_each_dev(i, drive, hwif) {
        (void) probe_for_drive(drive);
        if (drive->dev_flags & IDE_DFLAG_PRESENT)
            rc = 0;
    }

    /*
     * 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;
    ide_drive_t *drive;
    int i;

    ide_port_for_each_present_dev(i, drive, hwif) {
        ide_check_nien_quirk_list(drive);

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

    ide_port_for_each_present_dev(i, drive, hwif) {
        ide_set_max_pio(drive);

        drive->dev_flags |= IDE_DFLAG_NICE1;

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

/*
 * init request queue
 */
static int ide_init_queue(ide_drive_t *drive)
{
    struct request_queue *q;
    ide_hwif_t *hwif = drive->hwif;
    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, NULL, 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_hw_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_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 DEFINE_MUTEX(ide_cfg_mtx);

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

    mutex_lock(&ide_cfg_mtx);
    ide_port_for_each_present_dev(i, drive, hwif) {
        if (ide_init_queue(drive)) {
            printk(KERN_ERR "ide: failed to init %s\n",
                    drive->name);
            drive->dev_flags &= ~IDE_DFLAG_PRESENT;
            continue;
        }

        j++;
    }
    mutex_unlock(&ide_cfg_mtx);

    return j;
}

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

    ide_host_for_each_port(i, hwif, host) {
        if (hwif == NULL)
            continue;

        /* clear any pending IRQs */
        hwif->tp_ops->read_status(hwif);

        /* unmask IRQs */
        if (hwif->io_ports.ctl_addr)
            hwif->tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);
    }
}

/*
 * This routine sets up the IRQ for an IDE interface.
 */
static int init_irq (ide_hwif_t *hwif)
{
    struct ide_io_ports *io_ports = &hwif->io_ports;
    struct ide_host *host = hwif->host;
    irq_handler_t irq_handler = host->irq_handler;
    int sa = host->irq_flags;

    if (irq_handler == NULL)
        irq_handler = ide_intr;

    if (request_irq(hwif->irq, irq_handler, sa, hwif->name, hwif))
        goto out_up;

#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 (hwif->host->host_flags & IDE_HFLAG_SERIALIZE)
        printk(KERN_CONT " (serialized)");
    printk(KERN_CONT "\n");

    return 0;
out_up:
    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->devices[unit];

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

    if (drive->media == ide_disk)
        request_module("ide-disk");
    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 drive_release_dev (struct device *dev)
{
    ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);

    ide_proc_unregister_device(drive);

    blk_cleanup_queue(drive->queue);
    drive->queue = NULL;

    drive->dev_flags &= ~IDE_DFLAG_PRESENT;

    complete(&drive->gendev_rel_comp);
}

static int hwif_init(ide_hwif_t *hwif)
{
    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)) {
        printk(KERN_ERR "%s: disabled, unable to get IRQ %d\n",
            hwif->name, hwif->irq);
        goto out;
    }

    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)
{
    ide_drive_t *drive;
    unsigned int i;

    ide_port_for_each_present_dev(i, drive, hwif) {
        struct device *dev = &drive->gendev;
        int ret;

        dev_set_name(dev, "%u.%u", hwif->index, i);
        dev_set_drvdata(dev, drive);
        dev->parent = &hwif->gendev;
        dev->bus = &ide_bus_type;
        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;
    ide_drive_t *drive;
    int i;

    ide_port_for_each_dev(i, drive, hwif) {
        drive->dn = i + hwif->channel * 2;

        if (hwif->host_flags & IDE_HFLAG_IO_32BIT)
            drive->io_32bit = 1;
        if (hwif->host_flags & IDE_HFLAG_NO_IO_32BIT)
            drive->dev_flags |= IDE_DFLAG_NO_IO_32BIT;
        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;

        drive->pio_mode = XFER_PIO_0;

        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;

    hwif->chipset = d->chipset ? d->chipset : ide_pci;

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

    /* ->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->host_flags & IDE_HFLAG_DTC2278) == 0 || 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;

        hwif->dma_ops = d->dma_ops;

        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_ops = NULL;
            hwif->dma_base = 0;
            hwif->swdma_mask = 0;
            hwif->mwdma_mask = 0;
            hwif->ultra_mask = 0;
        }
    }

    if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||
        ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base))
        hwif->host->host_flags |= IDE_HFLAG_SERIALIZE;

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

    /* 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 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 void ide_port_init_devices_data(ide_hwif_t *hwif)
{
    ide_drive_t *drive;
    int i;

    ide_port_for_each_dev(i, drive, hwif) {
        u8 j = (hwif->index * MAX_DRIVES) + i;
        u16 *saved_id = drive->id;

        memset(drive, 0, sizeof(*drive));
        memset(saved_id, 0, SECTOR_SIZE);
        drive->id = saved_id;

        drive->media            = ide_disk;
        drive->select           = (i << 4) | ATA_DEVICE_OBS;
        drive->hwif         = hwif;
        drive->ready_stat       = ATA_DRDY;
        drive->bad_wstat        = BAD_W_STAT;
        drive->special_flags        = IDE_SFLAG_RECALIBRATE |
                          IDE_SFLAG_SET_GEOMETRY;
        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);
    }
}

static void ide_init_port_data(ide_hwif_t *hwif, unsigned int index)
{
    /* 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;

    spin_lock_init(&hwif->lock);

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

    init_completion(&hwif->gendev_rel_comp);

    hwif->tp_ops = &default_tp_ops;

    ide_port_init_devices_data(hwif);
}

static void ide_init_port_hw(ide_hwif_t *hwif, struct ide_hw *hw)
{
    memcpy(&hwif->io_ports, &hw->io_ports, sizeof(hwif->io_ports));
    hwif->irq = hw->irq;
    hwif->dev = hw->dev;
    hwif->gendev.parent = hw->parent ? hw->parent : hw->dev;
    hwif->config_data = hw->config;
}

static unsigned int ide_indexes;

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);
}

static void ide_port_free_devices(ide_hwif_t *hwif)
{
    ide_drive_t *drive;
    int i;

    ide_port_for_each_dev(i, drive, hwif) {
        kfree(drive->id);
        kfree(drive);
    }
}

static int ide_port_alloc_devices(ide_hwif_t *hwif, int node)
{
    int i;

    for (i = 0; i < MAX_DRIVES; i++) {
        ide_drive_t *drive;

        drive = kzalloc_node(sizeof(*drive), GFP_KERNEL, node);
        if (drive == NULL)
            goto out_nomem;

        /*
         * 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->id = kzalloc_node(SECTOR_SIZE, GFP_KERNEL, node);
        if (drive->id == NULL)
            goto out_nomem;

        hwif->devices[i] = drive;
    }
    return 0;

out_nomem:
    ide_port_free_devices(hwif);
    return -ENOMEM;
}

struct ide_host *ide_host_alloc(const struct ide_port_info *d,
                struct ide_hw **hws, unsigned int n_ports)
{
    struct ide_host *host;
    struct device *dev = hws[0] ? hws[0]->dev : NULL;
    int node = dev ? dev_to_node(dev) : -1;
    int i;

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

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

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

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

        if (ide_port_alloc_devices(hwif, node) < 0) {
            kfree(hwif);
            continue;
        }

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

    host->dev[0] = dev;

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

    return host;
}
EXPORT_SYMBOL_GPL(ide_host_alloc);

static void ide_port_free(ide_hwif_t *hwif)
{
    ide_port_free_devices(hwif);
    ide_free_port_slot(hwif->index);
    kfree(hwif);
}

static void ide_disable_port(ide_hwif_t *hwif)
{
    struct ide_host *host = hwif->host;
    int i;

    printk(KERN_INFO "%s: disabling port\n", hwif->name);

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

    ide_port_free(hwif);
}

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

    ide_host_for_each_port(i, hwif, host) {
        if (hwif == NULL) {
            mate = NULL;
            continue;
        }

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

        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);

        hwif->port_flags |= IDE_PFLAG_PROBING;

        ide_port_init_devices(hwif);
    }

    ide_host_for_each_port(i, hwif, host) {
        if (hwif == NULL)
            continue;

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

        hwif->port_flags &= ~IDE_PFLAG_PROBING;

        if ((hwif->host_flags & IDE_HFLAG_4DRIVES) == 0 ||
            hwif->mate == NULL || hwif->mate->present == 0) {
            if (ide_register_port(hwif)) {
                ide_disable_port(hwif);
                continue;
            }
        }

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

    ide_host_enable_irqs(host);

    ide_host_for_each_port(i, hwif, host) {
        if (hwif == NULL)
            continue;

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

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

        j++;

        ide_acpi_init_port(hwif);

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

    ide_host_for_each_port(i, hwif, host) {
        if (hwif == NULL)
            continue;

        ide_sysfs_register_port(hwif);
        ide_proc_register_port(hwif);

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

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

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

    host = ide_host_alloc(d, hws, n_ports);
    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);

static void __ide_port_unregister_devices(ide_hwif_t *hwif)
{
    ide_drive_t *drive;
    int i;

    ide_port_for_each_present_dev(i, drive, hwif) {
        device_unregister(&drive->gendev);
        wait_for_completion(&drive->gendev_rel_comp);
    }
}

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

static void ide_unregister(ide_hwif_t *hwif)
{
    BUG_ON(in_interrupt());
    BUG_ON(irqs_disabled());

    mutex_lock(&ide_cfg_mtx);

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

    ide_proc_unregister_port(hwif);

    free_irq(hwif->irq, 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);

    ide_release_dma_engine(hwif);

    mutex_unlock(&ide_cfg_mtx);
}

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

    ide_host_for_each_port(i, hwif, host) {
        if (hwif)
            ide_port_free(hwif);
    }

    kfree(host);
}
EXPORT_SYMBOL_GPL(ide_host_free);

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

    ide_host_for_each_port(i, hwif, host) {
        if (hwif)
            ide_unregister(hwif);
    }

    ide_host_free(host);
}
EXPORT_SYMBOL_GPL(ide_host_remove);

void ide_port_scan(ide_hwif_t *hwif)
{
    int rc;

    ide_port_apply_params(hwif);
    ide_port_cable_detect(hwif);

    hwif->port_flags |= IDE_PFLAG_PROBING;

    ide_port_init_devices(hwif);

    rc = ide_probe_port(hwif);

    hwif->port_flags &= ~IDE_PFLAG_PROBING;

    if (rc < 0)
        return;

    hwif->present = 1;

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