irq: make irqs in kernel stat use per_cpu_dyn_array

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

/*
 *  Copyright (C) 1994-1998        Linus Torvalds & authors (see below)
 *  Copyright (C) 1998-2002        Linux ATA Development
 *                                    Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2003             Red Hat <alan@redhat.com>
 *  Copyright (C) 2003-2005, 2007  Bartlomiej Zolnierkiewicz
 */

/*
 *  Mostly written by Mark Lord <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 * This is the IDE/ATA disk driver, as evolved from hd.c and ide.c.
 */

#define IDEDISK_VERSION "1.18"

#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/mutex.h>
#include <linux/leds.h>
#include <linux/ide.h>
#include <linux/hdreg.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/div64.h>

#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
#define IDE_DISK_MINORS         (1 << PARTN_BITS)
#else
#define IDE_DISK_MINORS         0
#endif

#include "ide-disk.h"

static DEFINE_MUTEX(idedisk_ref_mutex);

#define to_ide_disk(obj) container_of(obj, struct ide_disk_obj, kref)

static void ide_disk_release(struct kref *);

static struct ide_disk_obj *ide_disk_get(struct gendisk *disk)
{
        struct ide_disk_obj *idkp = NULL;

        mutex_lock(&idedisk_ref_mutex);
        idkp = ide_disk_g(disk);
        if (idkp) {
                if (ide_device_get(idkp->drive))
                        idkp = NULL;
                else
                        kref_get(&idkp->kref);
        }
        mutex_unlock(&idedisk_ref_mutex);
        return idkp;
}

static void ide_disk_put(struct ide_disk_obj *idkp)
{
        ide_drive_t *drive = idkp->drive;

        mutex_lock(&idedisk_ref_mutex);
        kref_put(&idkp->kref, ide_disk_release);
        ide_device_put(drive);
        mutex_unlock(&idedisk_ref_mutex);
}

static const u8 ide_rw_cmds[] = {
        ATA_CMD_READ_MULTI,
        ATA_CMD_WRITE_MULTI,
        ATA_CMD_READ_MULTI_EXT,
        ATA_CMD_WRITE_MULTI_EXT,
        ATA_CMD_PIO_READ,
        ATA_CMD_PIO_WRITE,
        ATA_CMD_PIO_READ_EXT,
        ATA_CMD_PIO_WRITE_EXT,
        ATA_CMD_READ,
        ATA_CMD_WRITE,
        ATA_CMD_READ_EXT,
        ATA_CMD_WRITE_EXT,
};

static const u8 ide_data_phases[] = {
        TASKFILE_MULTI_IN,
        TASKFILE_MULTI_OUT,
        TASKFILE_IN,
        TASKFILE_OUT,
        TASKFILE_IN_DMA,
        TASKFILE_OUT_DMA,
};

static void ide_tf_set_cmd(ide_drive_t *drive, ide_task_t *task, u8 dma)
{
        u8 index, lba48, write;

        lba48 = (task->tf_flags & IDE_TFLAG_LBA48) ? 2 : 0;
        write = (task->tf_flags & IDE_TFLAG_WRITE) ? 1 : 0;

        if (dma)
                index = 8;
        else
                index = drive->mult_count ? 0 : 4;

        task->tf.command = ide_rw_cmds[index + lba48 + write];

        if (dma)
                index = 8; /* fixup index */

        task->data_phase = ide_data_phases[index / 2 + write];
}

/*
 * __ide_do_rw_disk() issues READ and WRITE commands to a disk,
 * using LBA if supported, or CHS otherwise, to address sectors.
 */
static ide_startstop_t __ide_do_rw_disk(ide_drive_t *drive, struct request *rq,
                                        sector_t block)
{
        ide_hwif_t *hwif        = HWIF(drive);
        u16 nsectors            = (u16)rq->nr_sectors;
        u8 lba48                = !!(drive->dev_flags & IDE_DFLAG_LBA48);
        u8 dma                  = !!(drive->dev_flags & IDE_DFLAG_USING_DMA);
        ide_task_t              task;
        struct ide_taskfile     *tf = &task.tf;
        ide_startstop_t         rc;

        if ((hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA) && lba48 && dma) {
                if (block + rq->nr_sectors > 1ULL << 28)
                        dma = 0;
                else
                        lba48 = 0;
        }

        if (!dma) {
                ide_init_sg_cmd(drive, rq);
                ide_map_sg(drive, rq);
        }

        memset(&task, 0, sizeof(task));
        task.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;

        if (drive->dev_flags & IDE_DFLAG_LBA) {
                if (lba48) {
                        pr_debug("%s: LBA=0x%012llx\n", drive->name,
                                        (unsigned long long)block);

                        tf->hob_nsect = (nsectors >> 8) & 0xff;
                        tf->hob_lbal  = (u8)(block >> 24);
                        if (sizeof(block) != 4) {
                                tf->hob_lbam = (u8)((u64)block >> 32);
                                tf->hob_lbah = (u8)((u64)block >> 40);
                        }

                        tf->nsect  = nsectors & 0xff;
                        tf->lbal   = (u8) block;
                        tf->lbam   = (u8)(block >>  8);
                        tf->lbah   = (u8)(block >> 16);

                        task.tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_HOB);
                } else {
                        tf->nsect  = nsectors & 0xff;
                        tf->lbal   = block;
                        tf->lbam   = block >>= 8;
                        tf->lbah   = block >>= 8;
                        tf->device = (block >> 8) & 0xf;
                }

                tf->device |= ATA_LBA;
        } else {
                unsigned int sect, head, cyl, track;

                track = (int)block / drive->sect;
                sect  = (int)block % drive->sect + 1;
                head  = track % drive->head;
                cyl   = track / drive->head;

                pr_debug("%s: CHS=%u/%u/%u\n", drive->name, cyl, head, sect);

                tf->nsect  = nsectors & 0xff;
                tf->lbal   = sect;
                tf->lbam   = cyl;
                tf->lbah   = cyl >> 8;
                tf->device = head;
        }

        if (rq_data_dir(rq))
                task.tf_flags |= IDE_TFLAG_WRITE;

        ide_tf_set_cmd(drive, &task, dma);
        if (!dma)
                hwif->data_phase = task.data_phase;
        task.rq = rq;

        rc = do_rw_taskfile(drive, &task);

        if (rc == ide_stopped && dma) {
                /* fallback to PIO */
                task.tf_flags |= IDE_TFLAG_DMA_PIO_FALLBACK;
                ide_tf_set_cmd(drive, &task, 0);
                hwif->data_phase = task.data_phase;
                ide_init_sg_cmd(drive, rq);
                rc = do_rw_taskfile(drive, &task);
        }

        return rc;
}

/*
 * 268435455  == 137439 MB or 28bit limit
 * 320173056  == 163929 MB or 48bit addressing
 * 1073741822 == 549756 MB or 48bit addressing fake drive
 */

static ide_startstop_t ide_do_rw_disk(ide_drive_t *drive, struct request *rq,
                                      sector_t block)
{
        ide_hwif_t *hwif = HWIF(drive);

        BUG_ON(drive->dev_flags & IDE_DFLAG_BLOCKED);

        if (!blk_fs_request(rq)) {
                blk_dump_rq_flags(rq, "ide_do_rw_disk - bad command");
                ide_end_request(drive, 0, 0);
                return ide_stopped;
        }

        ledtrig_ide_activity();

        pr_debug("%s: %sing: block=%llu, sectors=%lu, buffer=0x%08lx\n",
                 drive->name, rq_data_dir(rq) == READ ? "read" : "writ",
                 (unsigned long long)block, rq->nr_sectors,
                 (unsigned long)rq->buffer);

        if (hwif->rw_disk)
                hwif->rw_disk(drive, rq);

        return __ide_do_rw_disk(drive, rq, block);
}

/*
 * Queries for true maximum capacity of the drive.
 * Returns maximum LBA address (> 0) of the drive, 0 if failed.
 */
static u64 idedisk_read_native_max_address(ide_drive_t *drive, int lba48)
{
        ide_task_t args;
        struct ide_taskfile *tf = &args.tf;
        u64 addr = 0;

        /* Create IDE/ATA command request structure */
        memset(&args, 0, sizeof(ide_task_t));
        if (lba48)
                tf->command = ATA_CMD_READ_NATIVE_MAX_EXT;
        else
                tf->command = ATA_CMD_READ_NATIVE_MAX;
        tf->device  = ATA_LBA;
        args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
        if (lba48)
                args.tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_HOB);
        /* submit command request */
        ide_no_data_taskfile(drive, &args);

        /* if OK, compute maximum address value */
        if ((tf->status & 0x01) == 0)
                addr = ide_get_lba_addr(tf, lba48) + 1;

        return addr;
}

/*
 * Sets maximum virtual LBA address of the drive.
 * Returns new maximum virtual LBA address (> 0) or 0 on failure.
 */
static u64 idedisk_set_max_address(ide_drive_t *drive, u64 addr_req, int lba48)
{
        ide_task_t args;
        struct ide_taskfile *tf = &args.tf;
        u64 addr_set = 0;

        addr_req--;
        /* Create IDE/ATA command request structure */
        memset(&args, 0, sizeof(ide_task_t));
        tf->lbal     = (addr_req >>  0) & 0xff;
        tf->lbam     = (addr_req >>= 8) & 0xff;
        tf->lbah     = (addr_req >>= 8) & 0xff;
        if (lba48) {
                tf->hob_lbal = (addr_req >>= 8) & 0xff;
                tf->hob_lbam = (addr_req >>= 8) & 0xff;
                tf->hob_lbah = (addr_req >>= 8) & 0xff;
                tf->command  = ATA_CMD_SET_MAX_EXT;
        } else {
                tf->device   = (addr_req >>= 8) & 0x0f;
                tf->command  = ATA_CMD_SET_MAX;
        }
        tf->device |= ATA_LBA;
        args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
        if (lba48)
                args.tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_HOB);
        /* submit command request */
        ide_no_data_taskfile(drive, &args);
        /* if OK, compute maximum address value */
        if ((tf->status & 0x01) == 0)
                addr_set = ide_get_lba_addr(tf, lba48) + 1;

        return addr_set;
}

static unsigned long long sectors_to_MB(unsigned long long n)
{
        n <<= 9;                /* make it bytes */
        do_div(n, 1000000);     /* make it MB */
        return n;
}

/*
 * Some disks report total number of sectors instead of
 * maximum sector address.  We list them here.
 */
static const struct drive_list_entry hpa_list[] = {
        { "ST340823A",  NULL },
        { "ST320413A",  NULL },
        { "ST310211A",  NULL },
        { NULL,         NULL }
};

static void idedisk_check_hpa(ide_drive_t *drive)
{
        unsigned long long capacity, set_max;
        int lba48 = ata_id_lba48_enabled(drive->id);

        capacity = drive->capacity64;

        set_max = idedisk_read_native_max_address(drive, lba48);

        if (ide_in_drive_list(drive->id, hpa_list)) {
                /*
                 * Since we are inclusive wrt to firmware revisions do this
                 * extra check and apply the workaround only when needed.
                 */
                if (set_max == capacity + 1)
                        set_max--;
        }

        if (set_max <= capacity)
                return;

        printk(KERN_INFO "%s: Host Protected Area detected.\n"
                         "\tcurrent capacity is %llu sectors (%llu MB)\n"
                         "\tnative  capacity is %llu sectors (%llu MB)\n",
                         drive->name,
                         capacity, sectors_to_MB(capacity),
                         set_max, sectors_to_MB(set_max));

        set_max = idedisk_set_max_address(drive, set_max, lba48);

        if (set_max) {
                drive->capacity64 = set_max;
                printk(KERN_INFO "%s: Host Protected Area disabled.\n",
                                 drive->name);
        }
}

static void init_idedisk_capacity(ide_drive_t *drive)
{
        u16 *id = drive->id;
        int lba;

        if (ata_id_lba48_enabled(id)) {
                /* drive speaks 48-bit LBA */
                lba = 1;
                drive->capacity64 = ata_id_u64(id, ATA_ID_LBA_CAPACITY_2);
        } else if (ata_id_has_lba(id) && ata_id_is_lba_capacity_ok(id)) {
                /* drive speaks 28-bit LBA */
                lba = 1;
                drive->capacity64 = ata_id_u32(id, ATA_ID_LBA_CAPACITY);
        } else {
                /* drive speaks boring old 28-bit CHS */
                lba = 0;
                drive->capacity64 = drive->cyl * drive->head * drive->sect;
        }

        if (lba) {
                drive->dev_flags |= IDE_DFLAG_LBA;

                /*
                * If this device supports the Host Protected Area feature set,
                * then we may need to change our opinion about its capacity.
                */
                if (ata_id_hpa_enabled(id))
                        idedisk_check_hpa(drive);
        }
}

sector_t ide_disk_capacity(ide_drive_t *drive)
{
        return drive->capacity64;
}

static void idedisk_prepare_flush(struct request_queue *q, struct request *rq)
{
        ide_drive_t *drive = q->queuedata;
        ide_task_t *task = kmalloc(sizeof(*task), GFP_ATOMIC);

        /* FIXME: map struct ide_taskfile on rq->cmd[] */
        BUG_ON(task == NULL);

        memset(task, 0, sizeof(*task));
        if (ata_id_flush_ext_enabled(drive->id) &&
            (drive->capacity64 >= (1UL << 28)))
                task->tf.command = ATA_CMD_FLUSH_EXT;
        else
                task->tf.command = ATA_CMD_FLUSH;
        task->tf_flags   = IDE_TFLAG_OUT_TF | IDE_TFLAG_OUT_DEVICE |
                           IDE_TFLAG_DYN;
        task->data_phase = TASKFILE_NO_DATA;

        rq->cmd_type = REQ_TYPE_ATA_TASKFILE;
        rq->cmd_flags |= REQ_SOFTBARRIER;
        rq->special = task;
}

ide_devset_get(multcount, mult_count);

/*
 * This is tightly woven into the driver->do_special can not touch.
 * DON'T do it again until a total personality rewrite is committed.
 */
static int set_multcount(ide_drive_t *drive, int arg)
{
        struct request *rq;
        int error;

        if (arg < 0 || arg > (drive->id[ATA_ID_MAX_MULTSECT] & 0xff))
                return -EINVAL;

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

        rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
        rq->cmd_type = REQ_TYPE_ATA_TASKFILE;

        drive->mult_req = arg;
        drive->special.b.set_multmode = 1;
        error = blk_execute_rq(drive->queue, NULL, rq, 0);
        blk_put_request(rq);

        return (drive->mult_count == arg) ? 0 : -EIO;
}

ide_devset_get_flag(nowerr, IDE_DFLAG_NOWERR);

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

        if (arg)
                drive->dev_flags |= IDE_DFLAG_NOWERR;
        else
                drive->dev_flags &= ~IDE_DFLAG_NOWERR;

        drive->bad_wstat = arg ? BAD_R_STAT : BAD_W_STAT;

        return 0;
}

static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect)
{
        ide_task_t task;

        memset(&task, 0, sizeof(task));
        task.tf.feature = feature;
        task.tf.nsect   = nsect;
        task.tf.command = ATA_CMD_SET_FEATURES;
        task.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;

        return ide_no_data_taskfile(drive, &task);
}

static void update_ordered(ide_drive_t *drive)
{
        u16 *id = drive->id;
        unsigned ordered = QUEUE_ORDERED_NONE;
        prepare_flush_fn *prep_fn = NULL;

        if (drive->dev_flags & IDE_DFLAG_WCACHE) {
                unsigned long long capacity;
                int barrier;
                /*
                 * We must avoid issuing commands a drive does not
                 * understand or we may crash it. We check flush cache
                 * is supported. We also check we have the LBA48 flush
                 * cache if the drive capacity is too large. By this
                 * time we have trimmed the drive capacity if LBA48 is
                 * not available so we don't need to recheck that.
                 */
                capacity = ide_disk_capacity(drive);
                barrier = ata_id_flush_enabled(id) &&
                        (drive->dev_flags & IDE_DFLAG_NOFLUSH) == 0 &&
                        ((drive->dev_flags & IDE_DFLAG_LBA48) == 0 ||
                         capacity <= (1ULL << 28) ||
                         ata_id_flush_ext_enabled(id));

                printk(KERN_INFO "%s: cache flushes %ssupported\n",
                       drive->name, barrier ? "" : "not ");

                if (barrier) {
                        ordered = QUEUE_ORDERED_DRAIN_FLUSH;
                        prep_fn = idedisk_prepare_flush;
                }
        } else
                ordered = QUEUE_ORDERED_DRAIN;

        blk_queue_ordered(drive->queue, ordered, prep_fn);
}

ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);

static int set_wcache(ide_drive_t *drive, int arg)
{
        int err = 1;

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

        if (ata_id_flush_enabled(drive->id)) {
                err = ide_do_setfeature(drive,
                        arg ? SETFEATURES_WC_ON : SETFEATURES_WC_OFF, 0);
                if (err == 0) {
                        if (arg)
                                drive->dev_flags |= IDE_DFLAG_WCACHE;
                        else
                                drive->dev_flags &= ~IDE_DFLAG_WCACHE;
                }
        }

        update_ordered(drive);

        return err;
}

static int do_idedisk_flushcache(ide_drive_t *drive)
{
        ide_task_t args;

        memset(&args, 0, sizeof(ide_task_t));
        if (ata_id_flush_ext_enabled(drive->id))
                args.tf.command = ATA_CMD_FLUSH_EXT;
        else
                args.tf.command = ATA_CMD_FLUSH;
        args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
        return ide_no_data_taskfile(drive, &args);
}

ide_devset_get(acoustic, acoustic);

static int set_acoustic(ide_drive_t *drive, int arg)
{
        if (arg < 0 || arg > 254)
                return -EINVAL;

        ide_do_setfeature(drive,
                arg ? SETFEATURES_AAM_ON : SETFEATURES_AAM_OFF, arg);

        drive->acoustic = arg;

        return 0;
}

ide_devset_get_flag(addressing, IDE_DFLAG_LBA48);

/*
 * drive->addressing:
 *      0: 28-bit
 *      1: 48-bit
 *      2: 48-bit capable doing 28-bit
 */
static int set_addressing(ide_drive_t *drive, int arg)
{
        if (arg < 0 || arg > 2)
                return -EINVAL;

        if (arg && ((drive->hwif->host_flags & IDE_HFLAG_NO_LBA48) ||
            ata_id_lba48_enabled(drive->id) == 0))
                return -EIO;

        if (arg == 2)
                arg = 0;

        if (arg)
                drive->dev_flags |= IDE_DFLAG_LBA48;
        else
                drive->dev_flags &= ~IDE_DFLAG_LBA48;

        return 0;
}

ide_ext_devset_rw(acoustic, acoustic);
ide_ext_devset_rw(address, addressing);
ide_ext_devset_rw(multcount, multcount);
ide_ext_devset_rw(wcache, wcache);

ide_ext_devset_rw_sync(nowerr, nowerr);

static void idedisk_setup(ide_drive_t *drive)
{
        struct ide_disk_obj *idkp = drive->driver_data;
        ide_hwif_t *hwif = drive->hwif;
        u16 *id = drive->id;
        char *m = (char *)&id[ATA_ID_PROD];
        unsigned long long capacity;

        ide_proc_register_driver(drive, idkp->driver);

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

        if (drive->dev_flags & IDE_DFLAG_REMOVABLE) {
                /*
                 * Removable disks (eg. SYQUEST); ignore 'WD' drives
                 */
                if (m[0] != 'W' || m[1] != 'D')
                        drive->dev_flags |= IDE_DFLAG_DOORLOCKING;
        }

        (void)set_addressing(drive, 1);

        if (drive->dev_flags & IDE_DFLAG_LBA48) {
                int max_s = 2048;

                if (max_s > hwif->rqsize)
                        max_s = hwif->rqsize;

                blk_queue_max_sectors(drive->queue, max_s);
        }

        printk(KERN_INFO "%s: max request size: %dKiB\n", drive->name,
                         drive->queue->max_sectors / 2);

        /* calculate drive capacity, and select LBA if possible */
        init_idedisk_capacity(drive);

        /* limit drive capacity to 137GB if LBA48 cannot be used */
        if ((drive->dev_flags & IDE_DFLAG_LBA48) == 0 &&
            drive->capacity64 > 1ULL << 28) {
                printk(KERN_WARNING "%s: cannot use LBA48 - full capacity "
                       "%llu sectors (%llu MB)\n",
                       drive->name, (unsigned long long)drive->capacity64,
                       sectors_to_MB(drive->capacity64));
                drive->capacity64 = 1ULL << 28;
        }

        if ((hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA) &&
            (drive->dev_flags & IDE_DFLAG_LBA48)) {
                if (drive->capacity64 > 1ULL << 28) {
                        printk(KERN_INFO "%s: cannot use LBA48 DMA - PIO mode"
                                         " will be used for accessing sectors "
                                         "> %u\n", drive->name, 1 << 28);
                } else
                        drive->dev_flags &= ~IDE_DFLAG_LBA48;
        }

        /*
         * if possible, give fdisk access to more of the drive,
         * by correcting bios_cyls:
         */
        capacity = ide_disk_capacity(drive);

        if ((drive->dev_flags & IDE_DFLAG_FORCED_GEOM) == 0) {
                if (ata_id_lba48_enabled(drive->id)) {
                        /* compatibility */
                        drive->bios_sect = 63;
                        drive->bios_head = 255;
                }

                if (drive->bios_sect && drive->bios_head) {
                        unsigned int cap0 = capacity; /* truncate to 32 bits */
                        unsigned int cylsz, cyl;

                        if (cap0 != capacity)
                                drive->bios_cyl = 65535;
                        else {
                                cylsz = drive->bios_sect * drive->bios_head;
                                cyl = cap0 / cylsz;
                                if (cyl > 65535)
                                        cyl = 65535;
                                if (cyl > drive->bios_cyl)
                                        drive->bios_cyl = cyl;
                        }
                }
        }
        printk(KERN_INFO "%s: %llu sectors (%llu MB)",
                         drive->name, capacity, sectors_to_MB(capacity));

        /* Only print cache size when it was specified */
        if (id[ATA_ID_BUF_SIZE])
                printk(KERN_CONT " w/%dKiB Cache", id[ATA_ID_BUF_SIZE] / 2);

        printk(KERN_CONT ", CHS=%d/%d/%d\n",
                         drive->bios_cyl, drive->bios_head, drive->bios_sect);

        /* write cache enabled? */
        if ((id[ATA_ID_CSFO] & 1) || ata_id_wcache_enabled(id))
                drive->dev_flags |= IDE_DFLAG_WCACHE;

        set_wcache(drive, 1);
}

static void ide_cacheflush_p(ide_drive_t *drive)
{
        if (ata_id_flush_enabled(drive->id) == 0 ||
            (drive->dev_flags & IDE_DFLAG_WCACHE) == 0)
                return;

        if (do_idedisk_flushcache(drive))
                printk(KERN_INFO "%s: wcache flush failed!\n", drive->name);
}

static void ide_disk_remove(ide_drive_t *drive)
{
        struct ide_disk_obj *idkp = drive->driver_data;
        struct gendisk *g = idkp->disk;

        ide_proc_unregister_driver(drive, idkp->driver);

        del_gendisk(g);

        ide_cacheflush_p(drive);

        ide_disk_put(idkp);
}

static void ide_disk_release(struct kref *kref)
{
        struct ide_disk_obj *idkp = to_ide_disk(kref);
        ide_drive_t *drive = idkp->drive;
        struct gendisk *g = idkp->disk;

        drive->driver_data = NULL;
        g->private_data = NULL;
        put_disk(g);
        kfree(idkp);
}

static int ide_disk_probe(ide_drive_t *drive);

/*
 * On HPA drives the capacity needs to be
 * reinitilized on resume otherwise the disk
 * can not be used and a hard reset is required
 */
static void ide_disk_resume(ide_drive_t *drive)
{
        if (ata_id_hpa_enabled(drive->id))
                init_idedisk_capacity(drive);
}

static void ide_device_shutdown(ide_drive_t *drive)
{
#ifdef  CONFIG_ALPHA
        /* On Alpha, halt(8) doesn't actually turn the machine off,
           it puts you into the sort of firmware monitor. Typically,
           it's used to boot another kernel image, so it's not much
           different from reboot(8). Therefore, we don't need to
           spin down the disk in this case, especially since Alpha
           firmware doesn't handle disks in standby mode properly.
           On the other hand, it's reasonably safe to turn the power
           off when the shutdown process reaches the firmware prompt,
           as the firmware initialization takes rather long time -
           at least 10 seconds, which should be sufficient for
           the disk to expire its write cache. */
        if (system_state != SYSTEM_POWER_OFF) {
#else
        if (system_state == SYSTEM_RESTART) {
#endif
                ide_cacheflush_p(drive);
                return;
        }

        printk(KERN_INFO "Shutdown: %s\n", drive->name);

        drive->gendev.bus->suspend(&drive->gendev, PMSG_SUSPEND);
}

static ide_driver_t idedisk_driver = {
        .gen_driver = {
                .owner          = THIS_MODULE,
                .name           = "ide-disk",
                .bus            = &ide_bus_type,
        },
        .probe                  = ide_disk_probe,
        .remove                 = ide_disk_remove,
        .resume                 = ide_disk_resume,
        .shutdown               = ide_device_shutdown,
        .version                = IDEDISK_VERSION,
        .do_request             = ide_do_rw_disk,
        .end_request            = ide_end_request,
        .error                  = __ide_error,
#ifdef CONFIG_IDE_PROC_FS
        .proc                   = ide_disk_proc,
        .settings               = ide_disk_settings,
#endif
};

static int idedisk_set_doorlock(ide_drive_t *drive, int on)
{
        ide_task_t task;

        memset(&task, 0, sizeof(task));
        task.tf.command = on ? ATA_CMD_MEDIA_LOCK : ATA_CMD_MEDIA_UNLOCK;
        task.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;

        return ide_no_data_taskfile(drive, &task);
}

static int idedisk_open(struct inode *inode, struct file *filp)
{
        struct gendisk *disk = inode->i_bdev->bd_disk;
        struct ide_disk_obj *idkp;
        ide_drive_t *drive;

        idkp = ide_disk_get(disk);
        if (idkp == NULL)
                return -ENXIO;

        drive = idkp->drive;

        idkp->openers++;

        if ((drive->dev_flags & IDE_DFLAG_REMOVABLE) && idkp->openers == 1) {
                check_disk_change(inode->i_bdev);
                /*
                 * Ignore the return code from door_lock,
                 * since the open() has already succeeded,
                 * and the door_lock is irrelevant at this point.
                 */
                if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) &&
                    idedisk_set_doorlock(drive, 1))
                        drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
        }
        return 0;
}

static int idedisk_release(struct inode *inode, struct file *filp)
{
        struct gendisk *disk = inode->i_bdev->bd_disk;
        struct ide_disk_obj *idkp = ide_disk_g(disk);
        ide_drive_t *drive = idkp->drive;

        if (idkp->openers == 1)
                ide_cacheflush_p(drive);

        if ((drive->dev_flags & IDE_DFLAG_REMOVABLE) && idkp->openers == 1) {
                if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) &&
                    idedisk_set_doorlock(drive, 0))
                        drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
        }

        idkp->openers--;

        ide_disk_put(idkp);

        return 0;
}

static int idedisk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
        struct ide_disk_obj *idkp = ide_disk_g(bdev->bd_disk);
        ide_drive_t *drive = idkp->drive;

        geo->heads = drive->bios_head;
        geo->sectors = drive->bios_sect;
        geo->cylinders = (u16)drive->bios_cyl; /* truncate */
        return 0;
}

static int idedisk_media_changed(struct gendisk *disk)
{
        struct ide_disk_obj *idkp = ide_disk_g(disk);
        ide_drive_t *drive = idkp->drive;

        /* do not scan partitions twice if this is a removable device */
        if (drive->dev_flags & IDE_DFLAG_ATTACH) {
                drive->dev_flags &= ~IDE_DFLAG_ATTACH;
                return 0;
        }

        /* if removable, always assume it was changed */
        return !!(drive->dev_flags & IDE_DFLAG_REMOVABLE);
}

static int idedisk_revalidate_disk(struct gendisk *disk)
{
        struct ide_disk_obj *idkp = ide_disk_g(disk);
        set_capacity(disk, ide_disk_capacity(idkp->drive));
        return 0;
}

static struct block_device_operations idedisk_ops = {
        .owner                  = THIS_MODULE,
        .open                   = idedisk_open,
        .release                = idedisk_release,
        .ioctl                  = ide_disk_ioctl,
        .getgeo                 = idedisk_getgeo,
        .media_changed          = idedisk_media_changed,
        .revalidate_disk        = idedisk_revalidate_disk
};

MODULE_DESCRIPTION("ATA DISK Driver");

static int ide_disk_probe(ide_drive_t *drive)
{
        struct ide_disk_obj *idkp;
        struct gendisk *g;

        /* strstr("foo", "") is non-NULL */
        if (!strstr("ide-disk", drive->driver_req))
                goto failed;

        if (drive->media != ide_disk)
                goto failed;

        idkp = kzalloc(sizeof(*idkp), GFP_KERNEL);
        if (!idkp)
                goto failed;

        g = alloc_disk_node(IDE_DISK_MINORS, hwif_to_node(drive->hwif));
        if (!g)
                goto out_free_idkp;

        ide_init_disk(g, drive);

        kref_init(&idkp->kref);

        idkp->drive = drive;
        idkp->driver = &idedisk_driver;
        idkp->disk = g;

        g->private_data = &idkp->driver;

        drive->driver_data = idkp;

        idedisk_setup(drive);
        if ((drive->dev_flags & IDE_DFLAG_LBA) == 0 &&
            (drive->head == 0 || drive->head > 16)) {
                printk(KERN_ERR "%s: INVALID GEOMETRY: %d PHYSICAL HEADS?\n",
                        drive->name, drive->head);
                drive->dev_flags &= ~IDE_DFLAG_ATTACH;
        } else
                drive->dev_flags |= IDE_DFLAG_ATTACH;

        g->minors = IDE_DISK_MINORS;
        g->driverfs_dev = &drive->gendev;
        g->flags |= GENHD_FL_EXT_DEVT;
        if (drive->dev_flags & IDE_DFLAG_REMOVABLE)
                g->flags = GENHD_FL_REMOVABLE;
        set_capacity(g, ide_disk_capacity(drive));
        g->fops = &idedisk_ops;
        add_disk(g);
        return 0;

out_free_idkp:
        kfree(idkp);
failed:
        return -ENODEV;
}

static void __exit idedisk_exit(void)
{
        driver_unregister(&idedisk_driver.gen_driver);
}

static int __init idedisk_init(void)
{
        return driver_register(&idedisk_driver.gen_driver);
}

MODULE_ALIAS("ide:*m-disk*");
MODULE_ALIAS("ide-disk");
module_init(idedisk_init);
module_exit(idedisk_exit);
MODULE_LICENSE("GPL");