sched: make early bootup sched_clock() use safer

[wrt350n-kernel.git] / drivers / ide / ide-iops.c

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

#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/hdreg.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 u16 ide_inw (unsigned long port)
{
        return (u16) inw(port);
}

static void ide_insw (unsigned long port, void *addr, u32 count)
{
        insw(port, addr, count);
}

static void ide_insl (unsigned long port, void *addr, u32 count)
{
        insl(port, addr, count);
}

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

static void ide_outbsync (ide_drive_t *drive, u8 addr, unsigned long port)
{
        outb(addr, port);
}

static void ide_outw (u16 val, unsigned long port)
{
        outw(val, port);
}

static void ide_outsw (unsigned long port, void *addr, u32 count)
{
        outsw(port, addr, count);
}

static void ide_outsl (unsigned long port, void *addr, u32 count)
{
        outsl(port, addr, count);
}

void default_hwif_iops (ide_hwif_t *hwif)
{
        hwif->OUTB      = ide_outb;
        hwif->OUTBSYNC  = ide_outbsync;
        hwif->OUTW      = ide_outw;
        hwif->OUTSW     = ide_outsw;
        hwif->OUTSL     = ide_outsl;
        hwif->INB       = ide_inb;
        hwif->INW       = ide_inw;
        hwif->INSW      = ide_insw;
        hwif->INSL      = ide_insl;
}

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

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

static u16 ide_mm_inw (unsigned long port)
{
        return (u16) readw((void __iomem *) port);
}

static void ide_mm_insw (unsigned long port, void *addr, u32 count)
{
        __ide_mm_insw((void __iomem *) port, addr, count);
}

static void ide_mm_insl (unsigned long port, void *addr, u32 count)
{
        __ide_mm_insl((void __iomem *) port, addr, count);
}

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

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

static void ide_mm_outw (u16 value, unsigned long port)
{
        writew(value, (void __iomem *) port);
}

static void ide_mm_outsw (unsigned long port, void *addr, u32 count)
{
        __ide_mm_outsw((void __iomem *) port, addr, count);
}

static void ide_mm_outsl (unsigned long port, void *addr, u32 count)
{
        __ide_mm_outsl((void __iomem *) port, addr, count);
}

void default_hwif_mmiops (ide_hwif_t *hwif)
{
        hwif->OUTB      = ide_mm_outb;
        /* Most systems will need to override OUTBSYNC, alas however
           this one is controller specific! */
        hwif->OUTBSYNC  = ide_mm_outbsync;
        hwif->OUTW      = ide_mm_outw;
        hwif->OUTSW     = ide_mm_outsw;
        hwif->OUTSL     = ide_mm_outsl;
        hwif->INB       = ide_mm_inb;
        hwif->INW       = ide_mm_inw;
        hwif->INSW      = ide_mm_insw;
        hwif->INSL      = ide_mm_insl;
}

EXPORT_SYMBOL(default_hwif_mmiops);

void SELECT_DRIVE (ide_drive_t *drive)
{
        if (HWIF(drive)->selectproc)
                HWIF(drive)->selectproc(drive);
        HWIF(drive)->OUTB(drive->select.all, IDE_SELECT_REG);
}

void SELECT_MASK (ide_drive_t *drive, int mask)
{
        if (HWIF(drive)->maskproc)
                HWIF(drive)->maskproc(drive, mask);
}

/*
 * 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(ide_drive_t *drive, unsigned long port)
{
        (void) HWIF(drive)->INB(port);
        (void) HWIF(drive)->INB(port);
        (void) HWIF(drive)->INB(port);
}

/*
 * This is used for most PIO data transfers *from* the IDE interface
 */
static void ata_input_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
        ide_hwif_t *hwif        = HWIF(drive);
        u8 io_32bit             = drive->io_32bit;

        if (io_32bit) {
                if (io_32bit & 2) {
                        unsigned long flags;
                        local_irq_save(flags);
                        ata_vlb_sync(drive, IDE_NSECTOR_REG);
                        hwif->INSL(IDE_DATA_REG, buffer, wcount);
                        local_irq_restore(flags);
                } else
                        hwif->INSL(IDE_DATA_REG, buffer, wcount);
        } else {
                hwif->INSW(IDE_DATA_REG, buffer, wcount<<1);
        }
}

/*
 * This is used for most PIO data transfers *to* the IDE interface
 */
static void ata_output_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
        ide_hwif_t *hwif        = HWIF(drive);
        u8 io_32bit             = drive->io_32bit;

        if (io_32bit) {
                if (io_32bit & 2) {
                        unsigned long flags;
                        local_irq_save(flags);
                        ata_vlb_sync(drive, IDE_NSECTOR_REG);
                        hwif->OUTSL(IDE_DATA_REG, buffer, wcount);
                        local_irq_restore(flags);
                } else
                        hwif->OUTSL(IDE_DATA_REG, buffer, wcount);
        } else {
                hwif->OUTSW(IDE_DATA_REG, buffer, wcount<<1);
        }
}

/*
 * The following routines are mainly used by the ATAPI drivers.
 *
 * These routines will round up any request for an odd number of bytes,
 * so if an odd bytecount is specified, be sure that there's at least one
 * extra byte allocated for the buffer.
 */

static void atapi_input_bytes(ide_drive_t *drive, void *buffer, u32 bytecount)
{
        ide_hwif_t *hwif = HWIF(drive);

        ++bytecount;
#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
        if (MACH_IS_ATARI || MACH_IS_Q40) {
                /* Atari has a byte-swapped IDE interface */
                insw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
                return;
        }
#endif /* CONFIG_ATARI || CONFIG_Q40 */
        hwif->ata_input_data(drive, buffer, bytecount / 4);
        if ((bytecount & 0x03) >= 2)
                hwif->INSW(IDE_DATA_REG, ((u8 *)buffer)+(bytecount & ~0x03), 1);
}

static void atapi_output_bytes(ide_drive_t *drive, void *buffer, u32 bytecount)
{
        ide_hwif_t *hwif = HWIF(drive);

        ++bytecount;
#if defined(CONFIG_ATARI) || defined(CONFIG_Q40)
        if (MACH_IS_ATARI || MACH_IS_Q40) {
                /* Atari has a byte-swapped IDE interface */
                outsw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
                return;
        }
#endif /* CONFIG_ATARI || CONFIG_Q40 */
        hwif->ata_output_data(drive, buffer, bytecount / 4);
        if ((bytecount & 0x03) >= 2)
                hwif->OUTSW(IDE_DATA_REG, ((u8*)buffer)+(bytecount & ~0x03), 1);
}

void default_hwif_transport(ide_hwif_t *hwif)
{
        hwif->ata_input_data            = ata_input_data;
        hwif->ata_output_data           = ata_output_data;
        hwif->atapi_input_bytes         = atapi_input_bytes;
        hwif->atapi_output_bytes        = atapi_output_bytes;
}

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

        id->config         = __le16_to_cpu(id->config);
        id->cyls           = __le16_to_cpu(id->cyls);
        id->reserved2      = __le16_to_cpu(id->reserved2);
        id->heads          = __le16_to_cpu(id->heads);
        id->track_bytes    = __le16_to_cpu(id->track_bytes);
        id->sector_bytes   = __le16_to_cpu(id->sector_bytes);
        id->sectors        = __le16_to_cpu(id->sectors);
        id->vendor0        = __le16_to_cpu(id->vendor0);
        id->vendor1        = __le16_to_cpu(id->vendor1);
        id->vendor2        = __le16_to_cpu(id->vendor2);
        stringcast = (u16 *)&id->serial_no[0];
        for (i = 0; i < (20/2); i++)
                stringcast[i] = __le16_to_cpu(stringcast[i]);
        id->buf_type       = __le16_to_cpu(id->buf_type);
        id->buf_size       = __le16_to_cpu(id->buf_size);
        id->ecc_bytes      = __le16_to_cpu(id->ecc_bytes);
        stringcast = (u16 *)&id->fw_rev[0];
        for (i = 0; i < (8/2); i++)
                stringcast[i] = __le16_to_cpu(stringcast[i]);
        stringcast = (u16 *)&id->model[0];
        for (i = 0; i < (40/2); i++)
                stringcast[i] = __le16_to_cpu(stringcast[i]);
        id->dword_io       = __le16_to_cpu(id->dword_io);
        id->reserved50     = __le16_to_cpu(id->reserved50);
        id->field_valid    = __le16_to_cpu(id->field_valid);
        id->cur_cyls       = __le16_to_cpu(id->cur_cyls);
        id->cur_heads      = __le16_to_cpu(id->cur_heads);
        id->cur_sectors    = __le16_to_cpu(id->cur_sectors);
        id->cur_capacity0  = __le16_to_cpu(id->cur_capacity0);
        id->cur_capacity1  = __le16_to_cpu(id->cur_capacity1);
        id->lba_capacity   = __le32_to_cpu(id->lba_capacity);
        id->dma_1word      = __le16_to_cpu(id->dma_1word);
        id->dma_mword      = __le16_to_cpu(id->dma_mword);
        id->eide_pio_modes = __le16_to_cpu(id->eide_pio_modes);
        id->eide_dma_min   = __le16_to_cpu(id->eide_dma_min);
        id->eide_dma_time  = __le16_to_cpu(id->eide_dma_time);
        id->eide_pio       = __le16_to_cpu(id->eide_pio);
        id->eide_pio_iordy = __le16_to_cpu(id->eide_pio_iordy);
        for (i = 0; i < 2; ++i)
                id->words69_70[i] = __le16_to_cpu(id->words69_70[i]);
        for (i = 0; i < 4; ++i)
                id->words71_74[i] = __le16_to_cpu(id->words71_74[i]);
        id->queue_depth    = __le16_to_cpu(id->queue_depth);
        for (i = 0; i < 4; ++i)
                id->words76_79[i] = __le16_to_cpu(id->words76_79[i]);
        id->major_rev_num  = __le16_to_cpu(id->major_rev_num);
        id->minor_rev_num  = __le16_to_cpu(id->minor_rev_num);
        id->command_set_1  = __le16_to_cpu(id->command_set_1);
        id->command_set_2  = __le16_to_cpu(id->command_set_2);
        id->cfsse          = __le16_to_cpu(id->cfsse);
        id->cfs_enable_1   = __le16_to_cpu(id->cfs_enable_1);
        id->cfs_enable_2   = __le16_to_cpu(id->cfs_enable_2);
        id->csf_default    = __le16_to_cpu(id->csf_default);
        id->dma_ultra      = __le16_to_cpu(id->dma_ultra);
        id->trseuc         = __le16_to_cpu(id->trseuc);
        id->trsEuc         = __le16_to_cpu(id->trsEuc);
        id->CurAPMvalues   = __le16_to_cpu(id->CurAPMvalues);
        id->mprc           = __le16_to_cpu(id->mprc);
        id->hw_config      = __le16_to_cpu(id->hw_config);
        id->acoustic       = __le16_to_cpu(id->acoustic);
        id->msrqs          = __le16_to_cpu(id->msrqs);
        id->sxfert         = __le16_to_cpu(id->sxfert);
        id->sal            = __le16_to_cpu(id->sal);
        id->spg            = __le32_to_cpu(id->spg);
        id->lba_capacity_2 = __le64_to_cpu(id->lba_capacity_2);
        for (i = 0; i < 22; i++)
                id->words104_125[i]   = __le16_to_cpu(id->words104_125[i]);
        id->last_lun       = __le16_to_cpu(id->last_lun);
        id->word127        = __le16_to_cpu(id->word127);
        id->dlf            = __le16_to_cpu(id->dlf);
        id->csfo           = __le16_to_cpu(id->csfo);
        for (i = 0; i < 26; i++)
                id->words130_155[i] = __le16_to_cpu(id->words130_155[i]);
        id->word156        = __le16_to_cpu(id->word156);
        for (i = 0; i < 3; i++)
                id->words157_159[i] = __le16_to_cpu(id->words157_159[i]);
        id->cfa_power      = __le16_to_cpu(id->cfa_power);
        for (i = 0; i < 14; i++)
                id->words161_175[i] = __le16_to_cpu(id->words161_175[i]);
        for (i = 0; i < 31; i++)
                id->words176_205[i] = __le16_to_cpu(id->words176_205[i]);
        for (i = 0; i < 48; i++)
                id->words206_254[i] = __le16_to_cpu(id->words206_254[i]);
        id->integrity_word  = __le16_to_cpu(id->integrity_word);
# 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 WIN_[P]IDENTIFY commands.
 */

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

        if (byteswap) {
                /* convert from big-endian to host byte order */
                for (p = end ; p != s;) {
                        unsigned short *pp = (unsigned short *) (p -= 2);
                        *pp = ntohs(*pp);
                }
        }
        /* strip leading blanks */
        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        = HWIF(drive);
        u8 stat                 = 0;

        if (drive->waiting_for_dma)
                return hwif->ide_dma_test_irq(drive);

#if 0
        /* need to guarantee 400ns since last command was issued */
        udelay(1);
#endif

        /*
         * 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 (IDE_CONTROL_REG)
                stat = ide_read_altstatus(drive);
        else
                /* Note: this may clear a pending IRQ!! */
                stat = ide_read_status(drive);

        if (stat & BUSY_STAT)
                /* 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)
{
        unsigned long flags;
        int i;
        u8 stat;

        udelay(1);      /* spec allows drive 400ns to assert "BUSY" */
        stat = ide_read_status(drive);

        if (stat & BUSY_STAT) {
                local_irq_set(flags);
                timeout += jiffies;
                while ((stat = ide_read_status(drive)) & BUSY_STAT) {
                        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 = ide_read_status(drive);
                                if (!(stat & BUSY_STAT))
                                        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 = ide_read_status(drive);

                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
 *      @drive_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(struct hd_driveid *id, const struct drive_list_entry *drive_table)
{
        for ( ; drive_table->id_model; drive_table++)
                if ((!strcmp(drive_table->id_model, id->model)) &&
                    (!drive_table->id_firmware ||
                     strstr(id->fw_rev, drive_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"        },
        { 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;
        struct hd_driveid *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 (ide_dev_is_sata(id) && !ivb)
                return 1;

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

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

no_80w:
        if (drive->udma33_warned == 1)
                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->udma33_warned = 1;

        return 0;
}

int ide_driveid_update(ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct hd_driveid *id;
        unsigned long timeout, flags;
        u8 stat;

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

        SELECT_MASK(drive, 1);
        ide_set_irq(drive, 1);
        msleep(50);
        hwif->OUTB(WIN_IDENTIFY, IDE_COMMAND_REG);
        timeout = jiffies + WAIT_WORSTCASE;
        do {
                if (time_after(jiffies, timeout)) {
                        SELECT_MASK(drive, 0);
                        return 0;       /* drive timed-out */
                }

                msleep(50);     /* give drive a breather */
                stat = ide_read_altstatus(drive);
        } while (stat & BUSY_STAT);

        msleep(50);     /* wait for IRQ and DRQ_STAT */
        stat = ide_read_status(drive);

        if (!OK_STAT(stat, DRQ_STAT, 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_WORDS*4, GFP_ATOMIC);
        if (!id) {
                local_irq_restore(flags);
                return 0;
        }
        ata_input_data(drive, id, SECTOR_WORDS);
        (void)ide_read_status(drive);   /* clear drive IRQ */
        local_irq_enable();
        local_irq_restore(flags);
        ide_fix_driveid(id);
        if (id) {
                drive->id->dma_ultra = id->dma_ultra;
                drive->id->dma_mword = id->dma_mword;
                drive->id->dma_1word = id->dma_1word;
                /* anything more ? */
                kfree(id);

                if (drive->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;
        int error = 0;
        u8 stat;

//      while (HWGROUP(drive)->busy)
//              msleep(50);

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

        /* Skip setting PIO flow-control modes on pre-EIDE drives */
        if ((speed & 0xf8) == XFER_PIO_0 && !(drive->id->capability & 0x08))
                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, 0);
        udelay(1);
        ide_set_irq(drive, 0);
        hwif->OUTB(speed, IDE_NSECTOR_REG);
        hwif->OUTB(SETFEATURES_XFER, IDE_FEATURE_REG);
        hwif->OUTBSYNC(drive, WIN_SETFEATURES, IDE_COMMAND_REG);
        if (drive->quirk_list == 2)
                ide_set_irq(drive, 1);

        error = __ide_wait_stat(drive, drive->ready_stat,
                                BUSY_STAT|DRQ_STAT|ERR_STAT,
                                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;
        }

        drive->id->dma_ultra &= ~0xFF00;
        drive->id->dma_mword &= ~0x0F00;
        drive->id->dma_1word &= ~0x0F00;

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

        switch(speed) {
                case XFER_UDMA_7:   drive->id->dma_ultra |= 0x8080; break;
                case XFER_UDMA_6:   drive->id->dma_ultra |= 0x4040; break;
                case XFER_UDMA_5:   drive->id->dma_ultra |= 0x2020; break;
                case XFER_UDMA_4:   drive->id->dma_ultra |= 0x1010; break;
                case XFER_UDMA_3:   drive->id->dma_ultra |= 0x0808; break;
                case XFER_UDMA_2:   drive->id->dma_ultra |= 0x0404; break;
                case XFER_UDMA_1:   drive->id->dma_ultra |= 0x0202; break;
                case XFER_UDMA_0:   drive->id->dma_ultra |= 0x0101; break;
                case XFER_MW_DMA_2: drive->id->dma_mword |= 0x0404; break;
                case XFER_MW_DMA_1: drive->id->dma_mword |= 0x0202; break;
                case XFER_MW_DMA_0: drive->id->dma_mword |= 0x0101; break;
                case XFER_SW_DMA_2: drive->id->dma_1word |= 0x0404; break;
                case XFER_SW_DMA_1: drive->id->dma_1word |= 0x0202; break;
                case XFER_SW_DMA_0: drive->id->dma_1word |= 0x0101; break;
                default: break;
        }
        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_hwgroup_t *hwgroup = HWGROUP(drive);

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

void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
                      unsigned int timeout, ide_expiry_t *expiry)
{
        unsigned long flags;
        spin_lock_irqsave(&ide_lock, flags);
        __ide_set_handler(drive, handler, timeout, expiry);
        spin_unlock_irqrestore(&ide_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)
{
        unsigned long flags;
        ide_hwif_t *hwif = HWIF(drive);

        spin_lock_irqsave(&ide_lock, flags);
        __ide_set_handler(drive, handler, timeout, expiry);
        hwif->OUTBSYNC(drive, cmd, IDE_COMMAND_REG);
        /*
         * 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(&ide_lock, flags);
}

EXPORT_SYMBOL(ide_execute_command);


/* 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_hwgroup_t *hwgroup  = HWGROUP(drive);
        u8 stat;

        SELECT_DRIVE(drive);
        udelay (10);
        stat = ide_read_status(drive);

        if (OK_STAT(stat, 0, BUSY_STAT))
                printk("%s: ATAPI reset complete\n", drive->name);
        else {
                if (time_before(jiffies, hwgroup->poll_timeout)) {
                        ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
                        /* continue polling */
                        return ide_started;
                }
                /* end of polling */
                hwgroup->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 */
        hwgroup->polling = 0;
        hwgroup->resetting = 0;
        return ide_stopped;
}

/*
 * 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_hwgroup_t *hwgroup  = HWGROUP(drive);
        ide_hwif_t *hwif        = HWIF(drive);
        u8 tmp;

        if (hwif->reset_poll != NULL) {
                if (hwif->reset_poll(drive)) {
                        printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
                                hwif->name, drive->name);
                        return ide_stopped;
                }
        }

        tmp = ide_read_status(drive);

        if (!OK_STAT(tmp, 0, BUSY_STAT)) {
                if (time_before(jiffies, hwgroup->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++;
        } else  {
                printk("%s: reset: ", hwif->name);
                tmp = ide_read_error(drive);

                if (tmp == 1) {
                        printk("success\n");
                        drive->failures = 0;
                } else {
                        drive->failures++;
                        printk("master: ");
                        switch (tmp & 0x7f) {
                                case 1: printk("passed");
                                        break;
                                case 2: printk("formatter device error");
                                        break;
                                case 3: printk("sector buffer error");
                                        break;
                                case 4: printk("ECC circuitry error");
                                        break;
                                case 5: printk("controlling MPU error");
                                        break;
                                default:printk("error (0x%02x?)", tmp);
                        }
                        if (tmp & 0x80)
                                printk("; slave: failed");
                        printk("\n");
                }
        }
        hwgroup->polling = 0;   /* done polling */
        hwgroup->resetting = 0; /* done reset attempt */
        return ide_stopped;
}

static void ide_disk_pre_reset(ide_drive_t *drive)
{
        int legacy = (drive->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;
        if (!drive->keep_settings && !drive->using_dma)
                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)
{
        if (drive->media == ide_disk)
                ide_disk_pre_reset(drive);
        else
                drive->post_reset = 1;

        if (drive->using_dma) {
                if (drive->crc_count)
                        ide_check_dma_crc(drive);
                else
                        ide_dma_off(drive);
        }

        if (!drive->keep_settings) {
                if (!drive->using_dma) {
                        drive->unmask = 0;
                        drive->io_32bit = 0;
                }
                return;
        }

        if (HWIF(drive)->pre_reset != NULL)
                HWIF(drive)->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)
{
        unsigned int unit;
        unsigned long flags;
        ide_hwif_t *hwif;
        ide_hwgroup_t *hwgroup;
        
        spin_lock_irqsave(&ide_lock, flags);
        hwif = HWIF(drive);
        hwgroup = HWGROUP(drive);

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

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

        /*
         * First, reset any device state data we were maintaining
         * for any of the drives on this interface.
         */
        for (unit = 0; unit < MAX_DRIVES; ++unit)
                pre_reset(&hwif->drives[unit]);

        if (!IDE_CONTROL_REG) {
                spin_unlock_irqrestore(&ide_lock, flags);
                return ide_stopped;
        }

        hwgroup->resetting = 1;
        /*
         * 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.
         */
        /* set SRST and nIEN */
        hwif->OUTBSYNC(drive, drive->ctl|6,IDE_CONTROL_REG);
        /* more than enough time */
        udelay(10);
        if (drive->quirk_list == 2) {
                /* clear SRST and nIEN */
                hwif->OUTBSYNC(drive, drive->ctl, IDE_CONTROL_REG);
        } else {
                /* clear SRST, leave nIEN */
                hwif->OUTBSYNC(drive, drive->ctl|2, IDE_CONTROL_REG);
        }
        /* more than enough time */
        udelay(10);
        hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
        hwgroup->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
         */
        if (hwif->resetproc)
                hwif->resetproc(drive);

        spin_unlock_irqrestore(&ide_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->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
                if ((stat & BUSY_STAT) == 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;
}

EXPORT_SYMBOL_GPL(ide_wait_not_busy);