Merge branch 'bjorn-cleanups' into release

[mirror_ubuntu-zesty-kernel.git] / drivers / ide / ide-iops.c

/*
 *  Copyright (C) 2000-2002     Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2003          Red Hat
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/bitops.h>
#include <linux/nmi.h>

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

/*
 *      Conventional PIO operations for ATA devices
 */

static u8 ide_inb (unsigned long port)
{
        return (u8) inb(port);
}

static void ide_outb (u8 val, unsigned long port)
{
        outb(val, port);
}

/*
 *      MMIO operations, typically used for SATA controllers
 */

static u8 ide_mm_inb (unsigned long port)
{
        return (u8) readb((void __iomem *) port);
}

static void ide_mm_outb (u8 value, unsigned long port)
{
        writeb(value, (void __iomem *) port);
}

void SELECT_DRIVE (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_port_ops *port_ops = hwif->port_ops;
        ide_task_t task;

        if (port_ops && port_ops->selectproc)
                port_ops->selectproc(drive);

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

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

void SELECT_MASK(ide_drive_t *drive, int mask)
{
        const struct ide_port_ops *port_ops = drive->hwif->port_ops;

        if (port_ops && port_ops->maskproc)
                port_ops->maskproc(drive, mask);
}

void ide_exec_command(ide_hwif_t *hwif, u8 cmd)
{
        if (hwif->host_flags & IDE_HFLAG_MMIO)
                writeb(cmd, (void __iomem *)hwif->io_ports.command_addr);
        else
                outb(cmd, hwif->io_ports.command_addr);
}
EXPORT_SYMBOL_GPL(ide_exec_command);

u8 ide_read_status(ide_hwif_t *hwif)
{
        if (hwif->host_flags & IDE_HFLAG_MMIO)
                return readb((void __iomem *)hwif->io_ports.status_addr);
        else
                return inb(hwif->io_ports.status_addr);
}
EXPORT_SYMBOL_GPL(ide_read_status);

u8 ide_read_altstatus(ide_hwif_t *hwif)
{
        if (hwif->host_flags & IDE_HFLAG_MMIO)
                return readb((void __iomem *)hwif->io_ports.ctl_addr);
        else
                return inb(hwif->io_ports.ctl_addr);
}
EXPORT_SYMBOL_GPL(ide_read_altstatus);

void ide_set_irq(ide_hwif_t *hwif, int on)
{
        u8 ctl = ATA_DEVCTL_OBS;

        if (on == 4) { /* hack for SRST */
                ctl |= 4;
                on &= ~4;
        }

        ctl |= on ? 0 : 2;

        if (hwif->host_flags & IDE_HFLAG_MMIO)
                writeb(ctl, (void __iomem *)hwif->io_ports.ctl_addr);
        else
                outb(ctl, hwif->io_ports.ctl_addr);
}
EXPORT_SYMBOL_GPL(ide_set_irq);

void ide_tf_load(ide_drive_t *drive, ide_task_t *task)
{
        ide_hwif_t *hwif = drive->hwif;
        struct ide_io_ports *io_ports = &hwif->io_ports;
        struct ide_taskfile *tf = &task->tf;
        void (*tf_outb)(u8 addr, unsigned long port);
        u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;
        u8 HIHI = (task->tf_flags & IDE_TFLAG_LBA48) ? 0xE0 : 0xEF;

        if (mmio)
                tf_outb = ide_mm_outb;
        else
                tf_outb = ide_outb;

        if (task->tf_flags & IDE_TFLAG_FLAGGED)
                HIHI = 0xFF;

        if (task->tf_flags & IDE_TFLAG_OUT_DATA) {
                u16 data = (tf->hob_data << 8) | tf->data;

                if (mmio)
                        writew(data, (void __iomem *)io_ports->data_addr);
                else
                        outw(data, io_ports->data_addr);
        }

        if (task->tf_flags & IDE_TFLAG_OUT_HOB_FEATURE)
                tf_outb(tf->hob_feature, io_ports->feature_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_HOB_NSECT)
                tf_outb(tf->hob_nsect, io_ports->nsect_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_HOB_LBAL)
                tf_outb(tf->hob_lbal, io_ports->lbal_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_HOB_LBAM)
                tf_outb(tf->hob_lbam, io_ports->lbam_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_HOB_LBAH)
                tf_outb(tf->hob_lbah, io_ports->lbah_addr);

        if (task->tf_flags & IDE_TFLAG_OUT_FEATURE)
                tf_outb(tf->feature, io_ports->feature_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_NSECT)
                tf_outb(tf->nsect, io_ports->nsect_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_LBAL)
                tf_outb(tf->lbal, io_ports->lbal_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_LBAM)
                tf_outb(tf->lbam, io_ports->lbam_addr);
        if (task->tf_flags & IDE_TFLAG_OUT_LBAH)
                tf_outb(tf->lbah, io_ports->lbah_addr);

        if (task->tf_flags & IDE_TFLAG_OUT_DEVICE)
                tf_outb((tf->device & HIHI) | drive->select,
                         io_ports->device_addr);
}
EXPORT_SYMBOL_GPL(ide_tf_load);

void ide_tf_read(ide_drive_t *drive, ide_task_t *task)
{
        ide_hwif_t *hwif = drive->hwif;
        struct ide_io_ports *io_ports = &hwif->io_ports;
        struct ide_taskfile *tf = &task->tf;
        void (*tf_outb)(u8 addr, unsigned long port);
        u8 (*tf_inb)(unsigned long port);
        u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;

        if (mmio) {
                tf_outb = ide_mm_outb;
                tf_inb  = ide_mm_inb;
        } else {
                tf_outb = ide_outb;
                tf_inb  = ide_inb;
        }

        if (task->tf_flags & IDE_TFLAG_IN_DATA) {
                u16 data;

                if (mmio)
                        data = readw((void __iomem *)io_ports->data_addr);
                else
                        data = inw(io_ports->data_addr);

                tf->data = data & 0xff;
                tf->hob_data = (data >> 8) & 0xff;
        }

        /* be sure we're looking at the low order bits */
        tf_outb(ATA_DEVCTL_OBS & ~0x80, io_ports->ctl_addr);

        if (task->tf_flags & IDE_TFLAG_IN_FEATURE)
                tf->feature = tf_inb(io_ports->feature_addr);
        if (task->tf_flags & IDE_TFLAG_IN_NSECT)
                tf->nsect  = tf_inb(io_ports->nsect_addr);
        if (task->tf_flags & IDE_TFLAG_IN_LBAL)
                tf->lbal   = tf_inb(io_ports->lbal_addr);
        if (task->tf_flags & IDE_TFLAG_IN_LBAM)
                tf->lbam   = tf_inb(io_ports->lbam_addr);
        if (task->tf_flags & IDE_TFLAG_IN_LBAH)
                tf->lbah   = tf_inb(io_ports->lbah_addr);
        if (task->tf_flags & IDE_TFLAG_IN_DEVICE)
                tf->device = tf_inb(io_ports->device_addr);

        if (task->tf_flags & IDE_TFLAG_LBA48) {
                tf_outb(ATA_DEVCTL_OBS | 0x80, io_ports->ctl_addr);

                if (task->tf_flags & IDE_TFLAG_IN_HOB_FEATURE)
                        tf->hob_feature = tf_inb(io_ports->feature_addr);
                if (task->tf_flags & IDE_TFLAG_IN_HOB_NSECT)
                        tf->hob_nsect   = tf_inb(io_ports->nsect_addr);
                if (task->tf_flags & IDE_TFLAG_IN_HOB_LBAL)
                        tf->hob_lbal    = tf_inb(io_ports->lbal_addr);
                if (task->tf_flags & IDE_TFLAG_IN_HOB_LBAM)
                        tf->hob_lbam    = tf_inb(io_ports->lbam_addr);
                if (task->tf_flags & IDE_TFLAG_IN_HOB_LBAH)
                        tf->hob_lbah    = tf_inb(io_ports->lbah_addr);
        }
}
EXPORT_SYMBOL_GPL(ide_tf_read);

/*
 * Some localbus EIDE interfaces require a special access sequence
 * when using 32-bit I/O instructions to transfer data.  We call this
 * the "vlb_sync" sequence, which consists of three successive reads
 * of the sector count register location, with interrupts disabled
 * to ensure that the reads all happen together.
 */
static void ata_vlb_sync(unsigned long port)
{
        (void)inb(port);
        (void)inb(port);
        (void)inb(port);
}

/*
 * This is used for most PIO data transfers *from* the IDE interface
 *
 * These routines will round up any request for an odd number of bytes,
 * so if an odd len is specified, be sure that there's at least one
 * extra byte allocated for the buffer.
 */
void ide_input_data(ide_drive_t *drive, struct request *rq, void *buf,
                    unsigned int len)
{
        ide_hwif_t *hwif = drive->hwif;
        struct ide_io_ports *io_ports = &hwif->io_ports;
        unsigned long data_addr = io_ports->data_addr;
        u8 io_32bit = drive->io_32bit;
        u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;

        len++;

        if (io_32bit) {
                unsigned long uninitialized_var(flags);

                if ((io_32bit & 2) && !mmio) {
                        local_irq_save(flags);
                        ata_vlb_sync(io_ports->nsect_addr);
                }

                if (mmio)
                        __ide_mm_insl((void __iomem *)data_addr, buf, len / 4);
                else
                        insl(data_addr, buf, len / 4);

                if ((io_32bit & 2) && !mmio)
                        local_irq_restore(flags);

                if ((len & 3) >= 2) {
                        if (mmio)
                                __ide_mm_insw((void __iomem *)data_addr,
                                                (u8 *)buf + (len & ~3), 1);
                        else
                                insw(data_addr, (u8 *)buf + (len & ~3), 1);
                }
        } else {
                if (mmio)
                        __ide_mm_insw((void __iomem *)data_addr, buf, len / 2);
                else
                        insw(data_addr, buf, len / 2);
        }
}
EXPORT_SYMBOL_GPL(ide_input_data);

/*
 * This is used for most PIO data transfers *to* the IDE interface
 */
void ide_output_data(ide_drive_t *drive, struct request *rq, void *buf,
                     unsigned int len)
{
        ide_hwif_t *hwif = drive->hwif;
        struct ide_io_ports *io_ports = &hwif->io_ports;
        unsigned long data_addr = io_ports->data_addr;
        u8 io_32bit = drive->io_32bit;
        u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;

        len++;

        if (io_32bit) {
                unsigned long uninitialized_var(flags);

                if ((io_32bit & 2) && !mmio) {
                        local_irq_save(flags);
                        ata_vlb_sync(io_ports->nsect_addr);
                }

                if (mmio)
                        __ide_mm_outsl((void __iomem *)data_addr, buf, len / 4);
                else
                        outsl(data_addr, buf, len / 4);

                if ((io_32bit & 2) && !mmio)
                        local_irq_restore(flags);

                if ((len & 3) >= 2) {
                        if (mmio)
                                __ide_mm_outsw((void __iomem *)data_addr,
                                                 (u8 *)buf + (len & ~3), 1);
                        else
                                outsw(data_addr, (u8 *)buf + (len & ~3), 1);
                }
        } else {
                if (mmio)
                        __ide_mm_outsw((void __iomem *)data_addr, buf, len / 2);
                else
                        outsw(data_addr, buf, len / 2);
        }
}
EXPORT_SYMBOL_GPL(ide_output_data);

u8 ide_read_error(ide_drive_t *drive)
{
        ide_task_t task;

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

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

        return task.tf.error;
}
EXPORT_SYMBOL_GPL(ide_read_error);

void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
{
        ide_task_t task;

        memset(&task, 0, sizeof(task));
        task.tf_flags = IDE_TFLAG_IN_LBAH | IDE_TFLAG_IN_LBAM |
                        IDE_TFLAG_IN_NSECT;

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

        *bcount = (task.tf.lbah << 8) | task.tf.lbam;
        *ireason = task.tf.nsect & 3;
}
EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);

const struct ide_tp_ops default_tp_ops = {
        .exec_command           = ide_exec_command,
        .read_status            = ide_read_status,
        .read_altstatus         = ide_read_altstatus,

        .set_irq                = ide_set_irq,

        .tf_load                = ide_tf_load,
        .tf_read                = ide_tf_read,

        .input_data             = ide_input_data,
        .output_data            = ide_output_data,
};

void ide_fix_driveid(u16 *id)
{
#ifndef __LITTLE_ENDIAN
# ifdef __BIG_ENDIAN
        int i;

        for (i = 0; i < 256; i++)
                id[i] = __le16_to_cpu(id[i]);
# else
#  error "Please fix <asm/byteorder.h>"
# endif
#endif
}

/*
 * ide_fixstring() cleans up and (optionally) byte-swaps a text string,
 * removing leading/trailing blanks and compressing internal blanks.
 * It is primarily used to tidy up the model name/number fields as
 * returned by the ATA_CMD_ID_ATA[PI] commands.
 */

void ide_fixstring (u8 *s, const int bytecount, const int byteswap)
{
        u8 *p, *end = &s[bytecount & ~1]; /* bytecount must be even */

        if (byteswap) {
                /* convert from big-endian to host byte order */
                for (p = s ; p != end ; p += 2)
                        be16_to_cpus((u16 *) p);
        }

        /* strip leading blanks */
        p = s;
        while (s != end && *s == ' ')
                ++s;
        /* compress internal blanks and strip trailing blanks */
        while (s != end && *s) {
                if (*s++ != ' ' || (s != end && *s && *s != ' '))
                        *p++ = *(s-1);
        }
        /* wipe out trailing garbage */
        while (p != end)
                *p++ = '\0';
}

EXPORT_SYMBOL(ide_fixstring);

/*
 * Needed for PCI irq sharing
 */
int drive_is_ready (ide_drive_t *drive)
{
        ide_hwif_t *hwif        = drive->hwif;
        u8 stat                 = 0;

        if (drive->waiting_for_dma)
                return hwif->dma_ops->dma_test_irq(drive);

        /*
         * We do a passive status test under shared PCI interrupts on
         * cards that truly share the ATA side interrupt, but may also share
         * an interrupt with another pci card/device.  We make no assumptions
         * about possible isa-pnp and pci-pnp issues yet.
         */
        if (hwif->io_ports.ctl_addr &&
            (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
                stat = hwif->tp_ops->read_altstatus(hwif);
        else
                /* Note: this may clear a pending IRQ!! */
                stat = hwif->tp_ops->read_status(hwif);

        if (stat & ATA_BUSY)
                /* drive busy:  definitely not interrupting */
                return 0;

        /* drive ready: *might* be interrupting */
        return 1;
}

EXPORT_SYMBOL(drive_is_ready);

/*
 * This routine busy-waits for the drive status to be not "busy".
 * It then checks the status for all of the "good" bits and none
 * of the "bad" bits, and if all is okay it returns 0.  All other
 * cases return error -- caller may then invoke ide_error().
 *
 * This routine should get fixed to not hog the cpu during extra long waits..
 * That could be done by busy-waiting for the first jiffy or two, and then
 * setting a timer to wake up at half second intervals thereafter,
 * until timeout is achieved, before timing out.
 */
static int __ide_wait_stat(ide_drive_t *drive, u8 good, u8 bad, unsigned long timeout, u8 *rstat)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        unsigned long flags;
        int i;
        u8 stat;

        udelay(1);      /* spec allows drive 400ns to assert "BUSY" */
        stat = tp_ops->read_status(hwif);

        if (stat & ATA_BUSY) {
                local_save_flags(flags);
                local_irq_enable_in_hardirq();
                timeout += jiffies;
                while ((stat = tp_ops->read_status(hwif)) & ATA_BUSY) {
                        if (time_after(jiffies, timeout)) {
                                /*
                                 * One last read after the timeout in case
                                 * heavy interrupt load made us not make any
                                 * progress during the timeout..
                                 */
                                stat = tp_ops->read_status(hwif);
                                if ((stat & ATA_BUSY) == 0)
                                        break;

                                local_irq_restore(flags);
                                *rstat = stat;
                                return -EBUSY;
                        }
                }
                local_irq_restore(flags);
        }
        /*
         * Allow status to settle, then read it again.
         * A few rare drives vastly violate the 400ns spec here,
         * so we'll wait up to 10usec for a "good" status
         * rather than expensively fail things immediately.
         * This fix courtesy of Matthew Faupel & Niccolo Rigacci.
         */
        for (i = 0; i < 10; i++) {
                udelay(1);
                stat = tp_ops->read_status(hwif);

                if (OK_STAT(stat, good, bad)) {
                        *rstat = stat;
                        return 0;
                }
        }
        *rstat = stat;
        return -EFAULT;
}

/*
 * In case of error returns error value after doing "*startstop = ide_error()".
 * The caller should return the updated value of "startstop" in this case,
 * "startstop" is unchanged when the function returns 0.
 */
int ide_wait_stat(ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 bad, unsigned long timeout)
{
        int err;
        u8 stat;

        /* bail early if we've exceeded max_failures */
        if (drive->max_failures && (drive->failures > drive->max_failures)) {
                *startstop = ide_stopped;
                return 1;
        }

        err = __ide_wait_stat(drive, good, bad, timeout, &stat);

        if (err) {
                char *s = (err == -EBUSY) ? "status timeout" : "status error";
                *startstop = ide_error(drive, s, stat);
        }

        return err;
}

EXPORT_SYMBOL(ide_wait_stat);

/**
 *      ide_in_drive_list       -       look for drive in black/white list
 *      @id: drive identifier
 *      @table: list to inspect
 *
 *      Look for a drive in the blacklist and the whitelist tables
 *      Returns 1 if the drive is found in the table.
 */

int ide_in_drive_list(u16 *id, const struct drive_list_entry *table)
{
        for ( ; table->id_model; table++)
                if ((!strcmp(table->id_model, (char *)&id[ATA_ID_PROD])) &&
                    (!table->id_firmware ||
                     strstr((char *)&id[ATA_ID_FW_REV], table->id_firmware)))
                        return 1;
        return 0;
}

EXPORT_SYMBOL_GPL(ide_in_drive_list);

/*
 * Early UDMA66 devices don't set bit14 to 1, only bit13 is valid.
 * We list them here and depend on the device side cable detection for them.
 *
 * Some optical devices with the buggy firmwares have the same problem.
 */
static const struct drive_list_entry ivb_list[] = {
        { "QUANTUM FIREBALLlct10 05"    , "A03.0900"    },
        { "TSSTcorp CDDVDW SH-S202J"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202J"    , "SB01"        },
        { "TSSTcorp CDDVDW SH-S202N"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202N"    , "SB01"        },
        { "TSSTcorp CDDVDW SH-S202H"    , "SB00"        },
        { "TSSTcorp CDDVDW SH-S202H"    , "SB01"        },
        { "SAMSUNG SP0822N"             , "WA100-10"    },
        { NULL                          , NULL          }
};

/*
 *  All hosts that use the 80c ribbon must use!
 *  The name is derived from upper byte of word 93 and the 80c ribbon.
 */
u8 eighty_ninty_three (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        u16 *id = drive->id;
        int ivb = ide_in_drive_list(id, ivb_list);

        if (hwif->cbl == ATA_CBL_PATA40_SHORT)
                return 1;

        if (ivb)
                printk(KERN_DEBUG "%s: skipping word 93 validity check\n",
                                  drive->name);

        if (ata_id_is_sata(id) && !ivb)
                return 1;

        if (hwif->cbl != ATA_CBL_PATA80 && !ivb)
                goto no_80w;

        /*
         * FIXME:
         * - change master/slave IDENTIFY order
         * - force bit13 (80c cable present) check also for !ivb devices
         *   (unless the slave device is pre-ATA3)
         */
        if ((id[ATA_ID_HW_CONFIG] & 0x4000) ||
            (ivb && (id[ATA_ID_HW_CONFIG] & 0x2000)))
                return 1;

no_80w:
        if (drive->dev_flags & IDE_DFLAG_UDMA33_WARNED)
                return 0;

        printk(KERN_WARNING "%s: %s side 80-wire cable detection failed, "
                            "limiting max speed to UDMA33\n",
                            drive->name,
                            hwif->cbl == ATA_CBL_PATA80 ? "drive" : "host");

        drive->dev_flags |= IDE_DFLAG_UDMA33_WARNED;

        return 0;
}

int ide_driveid_update(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        u16 *id;
        unsigned long flags;
        u8 stat;

        /*
         * Re-read drive->id for possible DMA mode
         * change (copied from ide-probe.c)
         */

        SELECT_MASK(drive, 1);
        tp_ops->set_irq(hwif, 0);
        msleep(50);
        tp_ops->exec_command(hwif, ATA_CMD_ID_ATA);

        if (ide_busy_sleep(hwif, WAIT_WORSTCASE, 1)) {
                SELECT_MASK(drive, 0);
                return 0;
        }

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

        if (!OK_STAT(stat, ATA_DRQ, BAD_R_STAT)) {
                SELECT_MASK(drive, 0);
                printk("%s: CHECK for good STATUS\n", drive->name);
                return 0;
        }
        local_irq_save(flags);
        SELECT_MASK(drive, 0);
        id = kmalloc(SECTOR_SIZE, GFP_ATOMIC);
        if (!id) {
                local_irq_restore(flags);
                return 0;
        }
        tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);
        (void)tp_ops->read_status(hwif);        /* clear drive IRQ */
        local_irq_enable();
        local_irq_restore(flags);
        ide_fix_driveid(id);

        drive->id[ATA_ID_UDMA_MODES]  = id[ATA_ID_UDMA_MODES];
        drive->id[ATA_ID_MWDMA_MODES] = id[ATA_ID_MWDMA_MODES];
        drive->id[ATA_ID_SWDMA_MODES] = id[ATA_ID_SWDMA_MODES];
        /* anything more ? */

        kfree(id);

        if ((drive->dev_flags & IDE_DFLAG_USING_DMA) && ide_id_dma_bug(drive))
                ide_dma_off(drive);

        return 1;
}

int ide_config_drive_speed(ide_drive_t *drive, u8 speed)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        u16 *id = drive->id, i;
        int error = 0;
        u8 stat;
        ide_task_t task;

#ifdef CONFIG_BLK_DEV_IDEDMA
        if (hwif->dma_ops)      /* check if host supports DMA */
                hwif->dma_ops->dma_host_set(drive, 0);
#endif

        /* Skip setting PIO flow-control modes on pre-EIDE drives */
        if ((speed & 0xf8) == XFER_PIO_0 && ata_id_has_iordy(drive->id) == 0)
                goto skip;

        /*
         * Don't use ide_wait_cmd here - it will
         * attempt to set_geometry and recalibrate,
         * but for some reason these don't work at
         * this point (lost interrupt).
         */
        /*
         * Select the drive, and issue the SETFEATURES command
         */
        disable_irq_nosync(hwif->irq);
        
        /*
         *      FIXME: we race against the running IRQ here if
         *      this is called from non IRQ context. If we use
         *      disable_irq() we hang on the error path. Work
         *      is needed.
         */
         
        udelay(1);
        SELECT_DRIVE(drive);
        SELECT_MASK(drive, 1);
        udelay(1);
        tp_ops->set_irq(hwif, 0);

        memset(&task, 0, sizeof(task));
        task.tf_flags = IDE_TFLAG_OUT_FEATURE | IDE_TFLAG_OUT_NSECT;
        task.tf.feature = SETFEATURES_XFER;
        task.tf.nsect   = speed;

        tp_ops->tf_load(drive, &task);

        tp_ops->exec_command(hwif, ATA_CMD_SET_FEATURES);

        if (drive->quirk_list == 2)
                tp_ops->set_irq(hwif, 1);

        error = __ide_wait_stat(drive, drive->ready_stat,
                                ATA_BUSY | ATA_DRQ | ATA_ERR,
                                WAIT_CMD, &stat);

        SELECT_MASK(drive, 0);

        enable_irq(hwif->irq);

        if (error) {
                (void) ide_dump_status(drive, "set_drive_speed_status", stat);
                return error;
        }

        id[ATA_ID_UDMA_MODES]  &= ~0xFF00;
        id[ATA_ID_MWDMA_MODES] &= ~0x0F00;
        id[ATA_ID_SWDMA_MODES] &= ~0x0F00;

 skip:
#ifdef CONFIG_BLK_DEV_IDEDMA
        if (speed >= XFER_SW_DMA_0 && (drive->dev_flags & IDE_DFLAG_USING_DMA))
                hwif->dma_ops->dma_host_set(drive, 1);
        else if (hwif->dma_ops) /* check if host supports DMA */
                ide_dma_off_quietly(drive);
#endif

        if (speed >= XFER_UDMA_0) {
                i = 1 << (speed - XFER_UDMA_0);
                id[ATA_ID_UDMA_MODES] |= (i << 8 | i);
        } else if (speed >= XFER_MW_DMA_0) {
                i = 1 << (speed - XFER_MW_DMA_0);
                id[ATA_ID_MWDMA_MODES] |= (i << 8 | i);
        } else if (speed >= XFER_SW_DMA_0) {
                i = 1 << (speed - XFER_SW_DMA_0);
                id[ATA_ID_SWDMA_MODES] |= (i << 8 | i);
        }

        if (!drive->init_speed)
                drive->init_speed = speed;
        drive->current_speed = speed;
        return error;
}

/*
 * This should get invoked any time we exit the driver to
 * wait for an interrupt response from a drive.  handler() points
 * at the appropriate code to handle the next interrupt, and a
 * timer is started to prevent us from waiting forever in case
 * something goes wrong (see the ide_timer_expiry() handler later on).
 *
 * See also ide_execute_command
 */
static void __ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
                      unsigned int timeout, ide_expiry_t *expiry)
{
        ide_hwif_t *hwif = drive->hwif;

        BUG_ON(hwif->handler);
        hwif->handler           = handler;
        hwif->expiry            = expiry;
        hwif->timer.expires     = jiffies + timeout;
        hwif->req_gen_timer     = hwif->req_gen;
        add_timer(&hwif->timer);
}

void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
                      unsigned int timeout, ide_expiry_t *expiry)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;

        spin_lock_irqsave(&hwif->lock, flags);
        __ide_set_handler(drive, handler, timeout, expiry);
        spin_unlock_irqrestore(&hwif->lock, flags);
}

EXPORT_SYMBOL(ide_set_handler);
 
/**
 *      ide_execute_command     -       execute an IDE command
 *      @drive: IDE drive to issue the command against
 *      @command: command byte to write
 *      @handler: handler for next phase
 *      @timeout: timeout for command
 *      @expiry:  handler to run on timeout
 *
 *      Helper function to issue an IDE command. This handles the
 *      atomicity requirements, command timing and ensures that the 
 *      handler and IRQ setup do not race. All IDE command kick off
 *      should go via this function or do equivalent locking.
 */

void ide_execute_command(ide_drive_t *drive, u8 cmd, ide_handler_t *handler,
                         unsigned timeout, ide_expiry_t *expiry)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;

        spin_lock_irqsave(&hwif->lock, flags);
        __ide_set_handler(drive, handler, timeout, expiry);
        hwif->tp_ops->exec_command(hwif, cmd);
        /*
         * Drive takes 400nS to respond, we must avoid the IRQ being
         * serviced before that.
         *
         * FIXME: we could skip this delay with care on non shared devices
         */
        ndelay(400);
        spin_unlock_irqrestore(&hwif->lock, flags);
}
EXPORT_SYMBOL(ide_execute_command);

void ide_execute_pkt_cmd(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;

        spin_lock_irqsave(&hwif->lock, flags);
        hwif->tp_ops->exec_command(hwif, ATA_CMD_PACKET);
        ndelay(400);
        spin_unlock_irqrestore(&hwif->lock, flags);
}
EXPORT_SYMBOL_GPL(ide_execute_pkt_cmd);

static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
{
        struct request *rq = drive->hwif->rq;

        if (rq && blk_special_request(rq) && rq->cmd[0] == REQ_DRIVE_RESET)
                ide_end_request(drive, err ? err : 1, 0);
}

/* needed below */
static ide_startstop_t do_reset1 (ide_drive_t *, int);

/*
 * atapi_reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an atapi drive reset operation. If the drive has not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t atapi_reset_pollfunc (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        u8 stat;

        SELECT_DRIVE(drive);
        udelay (10);
        stat = hwif->tp_ops->read_status(hwif);

        if (OK_STAT(stat, 0, ATA_BUSY))
                printk("%s: ATAPI reset complete\n", drive->name);
        else {
                if (time_before(jiffies, hwif->poll_timeout)) {
                        ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
                        /* continue polling */
                        return ide_started;
                }
                /* end of polling */
                hwif->polling = 0;
                printk("%s: ATAPI reset timed-out, status=0x%02x\n",
                                drive->name, stat);
                /* do it the old fashioned way */
                return do_reset1(drive, 1);
        }
        /* done polling */
        hwif->polling = 0;
        ide_complete_drive_reset(drive, 0);
        return ide_stopped;
}

static void ide_reset_report_error(ide_hwif_t *hwif, u8 err)
{
        static const char *err_master_vals[] =
                { NULL, "passed", "formatter device error",
                  "sector buffer error", "ECC circuitry error",
                  "controlling MPU error" };

        u8 err_master = err & 0x7f;

        printk(KERN_ERR "%s: reset: master: ", hwif->name);
        if (err_master && err_master < 6)
                printk(KERN_CONT "%s", err_master_vals[err_master]);
        else
                printk(KERN_CONT "error (0x%02x?)", err);
        if (err & 0x80)
                printk(KERN_CONT "; slave: failed");
        printk(KERN_CONT "\n");
}

/*
 * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an ide reset operation. If the drives have not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t reset_pollfunc (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_port_ops *port_ops = hwif->port_ops;
        u8 tmp;
        int err = 0;

        if (port_ops && port_ops->reset_poll) {
                err = port_ops->reset_poll(drive);
                if (err) {
                        printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
                                hwif->name, drive->name);
                        goto out;
                }
        }

        tmp = hwif->tp_ops->read_status(hwif);

        if (!OK_STAT(tmp, 0, ATA_BUSY)) {
                if (time_before(jiffies, hwif->poll_timeout)) {
                        ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);
                        /* continue polling */
                        return ide_started;
                }
                printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
                drive->failures++;
                err = -EIO;
        } else  {
                tmp = ide_read_error(drive);

                if (tmp == 1) {
                        printk(KERN_INFO "%s: reset: success\n", hwif->name);
                        drive->failures = 0;
                } else {
                        ide_reset_report_error(hwif, tmp);
                        drive->failures++;
                        err = -EIO;
                }
        }
out:
        hwif->polling = 0;      /* done polling */
        ide_complete_drive_reset(drive, err);
        return ide_stopped;
}

static void ide_disk_pre_reset(ide_drive_t *drive)
{
        int legacy = (drive->id[ATA_ID_CFS_ENABLE_2] & 0x0400) ? 0 : 1;

        drive->special.all = 0;
        drive->special.b.set_geometry = legacy;
        drive->special.b.recalibrate  = legacy;

        drive->mult_count = 0;
        drive->dev_flags &= ~IDE_DFLAG_PARKED;

        if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0 &&
            (drive->dev_flags & IDE_DFLAG_USING_DMA) == 0)
                drive->mult_req = 0;

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

static void pre_reset(ide_drive_t *drive)
{
        const struct ide_port_ops *port_ops = drive->hwif->port_ops;

        if (drive->media == ide_disk)
                ide_disk_pre_reset(drive);
        else
                drive->dev_flags |= IDE_DFLAG_POST_RESET;

        if (drive->dev_flags & IDE_DFLAG_USING_DMA) {
                if (drive->crc_count)
                        ide_check_dma_crc(drive);
                else
                        ide_dma_off(drive);
        }

        if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0) {
                if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0) {
                        drive->dev_flags &= ~IDE_DFLAG_UNMASK;
                        drive->io_32bit = 0;
                }
                return;
        }

        if (port_ops && port_ops->pre_reset)
                port_ops->pre_reset(drive);

        if (drive->current_speed != 0xff)
                drive->desired_speed = drive->current_speed;
        drive->current_speed = 0xff;
}

/*
 * do_reset1() attempts to recover a confused drive by resetting it.
 * Unfortunately, resetting a disk drive actually resets all devices on
 * the same interface, so it can really be thought of as resetting the
 * interface rather than resetting the drive.
 *
 * ATAPI devices have their own reset mechanism which allows them to be
 * individually reset without clobbering other devices on the same interface.
 *
 * Unfortunately, the IDE interface does not generate an interrupt to let
 * us know when the reset operation has finished, so we must poll for this.
 * Equally poor, though, is the fact that this may a very long time to complete,
 * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
 * we set a timer to poll at 50ms intervals.
 */
static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)
{
        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;
        const struct ide_port_ops *port_ops;
        ide_drive_t *tdrive;
        unsigned long flags, timeout;
        int i;
        DEFINE_WAIT(wait);

        spin_lock_irqsave(&hwif->lock, flags);

        /* We must not reset with running handlers */
        BUG_ON(hwif->handler != NULL);

        /* For an ATAPI device, first try an ATAPI SRST. */
        if (drive->media != ide_disk && !do_not_try_atapi) {
                pre_reset(drive);
                SELECT_DRIVE(drive);
                udelay (20);
                tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
                ndelay(400);
                hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
                hwif->polling = 1;
                __ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
                spin_unlock_irqrestore(&hwif->lock, flags);
                return ide_started;
        }

        /* We must not disturb devices in the IDE_DFLAG_PARKED state. */
        do {
                unsigned long now;

                prepare_to_wait(&ide_park_wq, &wait, TASK_UNINTERRUPTIBLE);
                timeout = jiffies;
                ide_port_for_each_dev(i, tdrive, hwif) {
                        if (tdrive->dev_flags & IDE_DFLAG_PRESENT &&
                            tdrive->dev_flags & IDE_DFLAG_PARKED &&
                            time_after(tdrive->sleep, timeout))
                                timeout = tdrive->sleep;
                }

                now = jiffies;
                if (time_before_eq(timeout, now))
                        break;

                spin_unlock_irqrestore(&hwif->lock, flags);
                timeout = schedule_timeout_uninterruptible(timeout - now);
                spin_lock_irqsave(&hwif->lock, flags);
        } while (timeout);
        finish_wait(&ide_park_wq, &wait);

        /*
         * First, reset any device state data we were maintaining
         * for any of the drives on this interface.
         */
        ide_port_for_each_dev(i, tdrive, hwif)
                pre_reset(tdrive);

        if (io_ports->ctl_addr == 0) {
                spin_unlock_irqrestore(&hwif->lock, flags);
                ide_complete_drive_reset(drive, -ENXIO);
                return ide_stopped;
        }

        /*
         * Note that we also set nIEN while resetting the device,
         * to mask unwanted interrupts from the interface during the reset.
         * However, due to the design of PC hardware, this will cause an
         * immediate interrupt due to the edge transition it produces.
         * This single interrupt gives us a "fast poll" for drives that
         * recover from reset very quickly, saving us the first 50ms wait time.
         *
         * TODO: add ->softreset method and stop abusing ->set_irq
         */
        /* set SRST and nIEN */
        tp_ops->set_irq(hwif, 4);
        /* more than enough time */
        udelay(10);
        /* clear SRST, leave nIEN (unless device is on the quirk list) */
        tp_ops->set_irq(hwif, drive->quirk_list == 2);
        /* more than enough time */
        udelay(10);
        hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
        hwif->polling = 1;
        __ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);

        /*
         * Some weird controller like resetting themselves to a strange
         * state when the disks are reset this way. At least, the Winbond
         * 553 documentation says that
         */
        port_ops = hwif->port_ops;
        if (port_ops && port_ops->resetproc)
                port_ops->resetproc(drive);

        spin_unlock_irqrestore(&hwif->lock, flags);
        return ide_started;
}

/*
 * ide_do_reset() is the entry point to the drive/interface reset code.
 */

ide_startstop_t ide_do_reset (ide_drive_t *drive)
{
        return do_reset1(drive, 0);
}

EXPORT_SYMBOL(ide_do_reset);

/*
 * ide_wait_not_busy() waits for the currently selected device on the hwif
 * to report a non-busy status, see comments in ide_probe_port().
 */
int ide_wait_not_busy(ide_hwif_t *hwif, unsigned long timeout)
{
        u8 stat = 0;

        while(timeout--) {
                /*
                 * Turn this into a schedule() sleep once I'm sure
                 * about locking issues (2.5 work ?).
                 */
                mdelay(1);
                stat = hwif->tp_ops->read_status(hwif);
                if ((stat & ATA_BUSY) == 0)
                        return 0;
                /*
                 * Assume a value of 0xff means nothing is connected to
                 * the interface and it doesn't implement the pull-down
                 * resistor on D7.
                 */
                if (stat == 0xff)
                        return -ENODEV;
                touch_softlockup_watchdog();
                touch_nmi_watchdog();
        }
        return -EBUSY;
}