Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git

[mirror_ubuntu-bionic-kernel.git] / drivers / ide / ide-taskfile.c

/*
 * linux/drivers/ide/ide-taskfile.c     Version 0.38    March 05, 2003
 *
 *  Copyright (C) 2000-2002     Michael Cornwell <cornwell@acm.org>
 *  Copyright (C) 2000-2002     Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2001-2002     Klaus Smolin
 *                                      IBM Storage Technology Division
 *  Copyright (C) 2003-2004     Bartlomiej Zolnierkiewicz
 *
 *  The big the bad and the ugly.
 *
 *  Problems to be fixed because of BH interface or the lack therefore.
 *
 *  Fill me in stupid !!!
 *
 *  HOST:
 *      General refers to the Controller and Driver "pair".
 *  DATA HANDLER:
 *      Under the context of Linux it generally refers to an interrupt handler.
 *      However, it correctly describes the 'HOST'
 *  DATA BLOCK:
 *      The amount of data needed to be transfered as predefined in the
 *      setup of the device.
 *  STORAGE ATOMIC:
 *      The 'DATA BLOCK' associated to the 'DATA HANDLER', and can be as
 *      small as a single sector or as large as the entire command block
 *      request.
 */

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

#define DEBUG_TASKFILE  0       /* unset when fixed */

static void ata_bswap_data (void *buffer, int wcount)
{
        u16 *p = buffer;

        while (wcount--) {
                *p = *p << 8 | *p >> 8; p++;
                *p = *p << 8 | *p >> 8; p++;
        }
}

static void taskfile_input_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
        HWIF(drive)->ata_input_data(drive, buffer, wcount);
        if (drive->bswap)
                ata_bswap_data(buffer, wcount);
}

static void taskfile_output_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
        if (drive->bswap) {
                ata_bswap_data(buffer, wcount);
                HWIF(drive)->ata_output_data(drive, buffer, wcount);
                ata_bswap_data(buffer, wcount);
        } else {
                HWIF(drive)->ata_output_data(drive, buffer, wcount);
        }
}

int taskfile_lib_get_identify (ide_drive_t *drive, u8 *buf)
{
        ide_task_t args;
        memset(&args, 0, sizeof(ide_task_t));
        args.tfRegister[IDE_NSECTOR_OFFSET]     = 0x01;
        if (drive->media == ide_disk)
                args.tfRegister[IDE_COMMAND_OFFSET]     = WIN_IDENTIFY;
        else
                args.tfRegister[IDE_COMMAND_OFFSET]     = WIN_PIDENTIFY;
        args.command_type = IDE_DRIVE_TASK_IN;
        args.data_phase   = TASKFILE_IN;
        args.handler      = &task_in_intr;
        return ide_raw_taskfile(drive, &args, buf);
}

ide_startstop_t do_rw_taskfile (ide_drive_t *drive, ide_task_t *task)
{
        ide_hwif_t *hwif        = HWIF(drive);
        task_struct_t *taskfile = (task_struct_t *) task->tfRegister;
        hob_struct_t *hobfile   = (hob_struct_t *) task->hobRegister;
        u8 HIHI                 = (drive->addressing == 1) ? 0xE0 : 0xEF;

        /* ALL Command Block Executions SHALL clear nIEN, unless otherwise */
        if (IDE_CONTROL_REG) {
                /* clear nIEN */
                hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
        }
        SELECT_MASK(drive, 0);

        if (drive->addressing == 1) {
                hwif->OUTB(hobfile->feature, IDE_FEATURE_REG);
                hwif->OUTB(hobfile->sector_count, IDE_NSECTOR_REG);
                hwif->OUTB(hobfile->sector_number, IDE_SECTOR_REG);
                hwif->OUTB(hobfile->low_cylinder, IDE_LCYL_REG);
                hwif->OUTB(hobfile->high_cylinder, IDE_HCYL_REG);
        }

        hwif->OUTB(taskfile->feature, IDE_FEATURE_REG);
        hwif->OUTB(taskfile->sector_count, IDE_NSECTOR_REG);
        hwif->OUTB(taskfile->sector_number, IDE_SECTOR_REG);
        hwif->OUTB(taskfile->low_cylinder, IDE_LCYL_REG);
        hwif->OUTB(taskfile->high_cylinder, IDE_HCYL_REG);

        hwif->OUTB((taskfile->device_head & HIHI) | drive->select.all, IDE_SELECT_REG);

        if (task->handler != NULL) {
                if (task->prehandler != NULL) {
                        hwif->OUTBSYNC(drive, taskfile->command, IDE_COMMAND_REG);
                        ndelay(400);    /* FIXME */
                        return task->prehandler(drive, task->rq);
                }
                ide_execute_command(drive, taskfile->command, task->handler, WAIT_WORSTCASE, NULL);
                return ide_started;
        }

        if (!drive->using_dma)
                return ide_stopped;

        switch (taskfile->command) {
                case WIN_WRITEDMA_ONCE:
                case WIN_WRITEDMA:
                case WIN_WRITEDMA_EXT:
                case WIN_READDMA_ONCE:
                case WIN_READDMA:
                case WIN_READDMA_EXT:
                case WIN_IDENTIFY_DMA:
                        if (!hwif->dma_setup(drive)) {
                                hwif->dma_exec_cmd(drive, taskfile->command);
                                hwif->dma_start(drive);
                                return ide_started;
                        }
                        break;
                default:
                        if (task->handler == NULL)
                                return ide_stopped;
        }

        return ide_stopped;
}

/*
 * set_multmode_intr() is invoked on completion of a WIN_SETMULT cmd.
 */
ide_startstop_t set_multmode_intr (ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        u8 stat;

        if (OK_STAT(stat = hwif->INB(IDE_STATUS_REG),READY_STAT,BAD_STAT)) {
                drive->mult_count = drive->mult_req;
        } else {
                drive->mult_req = drive->mult_count = 0;
                drive->special.b.recalibrate = 1;
                (void) ide_dump_status(drive, "set_multmode", stat);
        }
        return ide_stopped;
}

/*
 * set_geometry_intr() is invoked on completion of a WIN_SPECIFY cmd.
 */
ide_startstop_t set_geometry_intr (ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        int retries = 5;
        u8 stat;

        while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
                udelay(10);

        if (OK_STAT(stat, READY_STAT, BAD_STAT))
                return ide_stopped;

        if (stat & (ERR_STAT|DRQ_STAT))
                return ide_error(drive, "set_geometry_intr", stat);

        if (HWGROUP(drive)->handler != NULL)
                BUG();
        ide_set_handler(drive, &set_geometry_intr, WAIT_WORSTCASE, NULL);
        return ide_started;
}

/*
 * recal_intr() is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
 */
ide_startstop_t recal_intr (ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        u8 stat;

        if (!OK_STAT(stat = hwif->INB(IDE_STATUS_REG), READY_STAT, BAD_STAT))
                return ide_error(drive, "recal_intr", stat);
        return ide_stopped;
}

/*
 * Handler for commands without a data phase
 */
ide_startstop_t task_no_data_intr (ide_drive_t *drive)
{
        ide_task_t *args        = HWGROUP(drive)->rq->special;
        ide_hwif_t *hwif        = HWIF(drive);
        u8 stat;

        local_irq_enable();
        if (!OK_STAT(stat = hwif->INB(IDE_STATUS_REG),READY_STAT,BAD_STAT)) {
                return ide_error(drive, "task_no_data_intr", stat);
                /* calls ide_end_drive_cmd */
        }
        if (args)
                ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));

        return ide_stopped;
}

EXPORT_SYMBOL(task_no_data_intr);

static u8 wait_drive_not_busy(ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        int retries = 100;
        u8 stat;

        /*
         * Last sector was transfered, wait until drive is ready.
         * This can take up to 10 usec, but we will wait max 1 ms
         * (drive_cmd_intr() waits that long).
         */
        while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
                udelay(10);

        if (!retries)
                printk(KERN_ERR "%s: drive still BUSY!\n", drive->name);

        return stat;
}

static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
{
        ide_hwif_t *hwif = drive->hwif;
        struct scatterlist *sg = hwif->sg_table;
        struct page *page;
#ifdef CONFIG_HIGHMEM
        unsigned long flags;
#endif
        unsigned int offset;
        u8 *buf;

        page = sg[hwif->cursg].page;
        offset = sg[hwif->cursg].offset + hwif->cursg_ofs * SECTOR_SIZE;

        /* get the current page and offset */
        page = nth_page(page, (offset >> PAGE_SHIFT));
        offset %= PAGE_SIZE;

#ifdef CONFIG_HIGHMEM
        local_irq_save(flags);
#endif
        buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset;

        hwif->nleft--;
        hwif->cursg_ofs++;

        if ((hwif->cursg_ofs * SECTOR_SIZE) == sg[hwif->cursg].length) {
                hwif->cursg++;
                hwif->cursg_ofs = 0;
        }

        /* do the actual data transfer */
        if (write)
                taskfile_output_data(drive, buf, SECTOR_WORDS);
        else
                taskfile_input_data(drive, buf, SECTOR_WORDS);

        kunmap_atomic(buf, KM_BIO_SRC_IRQ);
#ifdef CONFIG_HIGHMEM
        local_irq_restore(flags);
#endif
}

static void ide_pio_multi(ide_drive_t *drive, unsigned int write)
{
        unsigned int nsect;

        nsect = min_t(unsigned int, drive->hwif->nleft, drive->mult_count);
        while (nsect--)
                ide_pio_sector(drive, write);
}

static inline void ide_pio_datablock(ide_drive_t *drive, struct request *rq,
                                     unsigned int write)
{
        if (rq->bio)    /* fs request */
                rq->errors = 0;

        switch (drive->hwif->data_phase) {
        case TASKFILE_MULTI_IN:
        case TASKFILE_MULTI_OUT:
                ide_pio_multi(drive, write);
                break;
        default:
                ide_pio_sector(drive, write);
                break;
        }
}

static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
                                  const char *s, u8 stat)
{
        if (rq->bio) {
                ide_hwif_t *hwif = drive->hwif;
                int sectors = hwif->nsect - hwif->nleft;

                switch (hwif->data_phase) {
                case TASKFILE_IN:
                        if (hwif->nleft)
                                break;
                        /* fall through */
                case TASKFILE_OUT:
                        sectors--;
                        break;
                case TASKFILE_MULTI_IN:
                        if (hwif->nleft)
                                break;
                        /* fall through */
                case TASKFILE_MULTI_OUT:
                        sectors -= drive->mult_count;
                default:
                        break;
                }

                if (sectors > 0) {
                        ide_driver_t *drv;

                        drv = *(ide_driver_t **)rq->rq_disk->private_data;
                        drv->end_request(drive, 1, sectors);
                }
        }
        return ide_error(drive, s, stat);
}

static void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
{
        if (rq->flags & REQ_DRIVE_TASKFILE) {
                ide_task_t *task = rq->special;

                if (task->tf_out_flags.all) {
                        u8 err = drive->hwif->INB(IDE_ERROR_REG);
                        ide_end_drive_cmd(drive, stat, err);
                        return;
                }
        }

        ide_end_request(drive, 1, rq->hard_nr_sectors);
}

/*
 * Handler for command with PIO data-in phase (Read/Read Multiple).
 */
ide_startstop_t task_in_intr (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq = HWGROUP(drive)->rq;
        u8 stat = hwif->INB(IDE_STATUS_REG);

        /* new way for dealing with premature shared PCI interrupts */
        if (!OK_STAT(stat, DATA_READY, BAD_R_STAT)) {
                if (stat & (ERR_STAT | DRQ_STAT))
                        return task_error(drive, rq, __FUNCTION__, stat);
                /* No data yet, so wait for another IRQ. */
                ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);
                return ide_started;
        }

        ide_pio_datablock(drive, rq, 0);

        /* If it was the last datablock check status and finish transfer. */
        if (!hwif->nleft) {
                stat = wait_drive_not_busy(drive);
                if (!OK_STAT(stat, 0, BAD_R_STAT))
                        return task_error(drive, rq, __FUNCTION__, stat);
                task_end_request(drive, rq, stat);
                return ide_stopped;
        }

        /* Still data left to transfer. */
        ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);

        return ide_started;
}
EXPORT_SYMBOL(task_in_intr);

/*
 * Handler for command with PIO data-out phase (Write/Write Multiple).
 */
static ide_startstop_t task_out_intr (ide_drive_t *drive)
{
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq = HWGROUP(drive)->rq;
        u8 stat = hwif->INB(IDE_STATUS_REG);

        if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))
                return task_error(drive, rq, __FUNCTION__, stat);

        /* Deal with unexpected ATA data phase. */
        if (((stat & DRQ_STAT) == 0) ^ !hwif->nleft)
                return task_error(drive, rq, __FUNCTION__, stat);

        if (!hwif->nleft) {
                task_end_request(drive, rq, stat);
                return ide_stopped;
        }

        /* Still data left to transfer. */
        ide_pio_datablock(drive, rq, 1);
        ide_set_handler(drive, &task_out_intr, WAIT_WORSTCASE, NULL);

        return ide_started;
}

ide_startstop_t pre_task_out_intr (ide_drive_t *drive, struct request *rq)
{
        ide_startstop_t startstop;

        if (ide_wait_stat(&startstop, drive, DATA_READY,
                          drive->bad_wstat, WAIT_DRQ)) {
                printk(KERN_ERR "%s: no DRQ after issuing %sWRITE%s\n",
                                drive->name,
                                drive->hwif->data_phase ? "MULT" : "",
                                drive->addressing ? "_EXT" : "");
                return startstop;
        }

        if (!drive->unmask)
                local_irq_disable();

        ide_set_handler(drive, &task_out_intr, WAIT_WORSTCASE, NULL);
        ide_pio_datablock(drive, rq, 1);

        return ide_started;
}
EXPORT_SYMBOL(pre_task_out_intr);

static int ide_diag_taskfile(ide_drive_t *drive, ide_task_t *args, unsigned long data_size, u8 *buf)
{
        struct request rq;

        memset(&rq, 0, sizeof(rq));
        rq.flags = REQ_DRIVE_TASKFILE;
        rq.buffer = buf;

        /*
         * (ks) We transfer currently only whole sectors.
         * This is suffient for now.  But, it would be great,
         * if we would find a solution to transfer any size.
         * To support special commands like READ LONG.
         */
        if (args->command_type != IDE_DRIVE_TASK_NO_DATA) {
                if (data_size == 0)
                        rq.nr_sectors = (args->hobRegister[IDE_NSECTOR_OFFSET] << 8) | args->tfRegister[IDE_NSECTOR_OFFSET];
                else
                        rq.nr_sectors = data_size / SECTOR_SIZE;

                if (!rq.nr_sectors) {
                        printk(KERN_ERR "%s: in/out command without data\n",
                                        drive->name);
                        return -EFAULT;
                }

                rq.hard_nr_sectors = rq.nr_sectors;
                rq.hard_cur_sectors = rq.current_nr_sectors = rq.nr_sectors;

                if (args->command_type == IDE_DRIVE_TASK_RAW_WRITE)
                        rq.flags |= REQ_RW;
        }

        rq.special = args;
        args->rq = &rq;
        return ide_do_drive_cmd(drive, &rq, ide_wait);
}

int ide_raw_taskfile (ide_drive_t *drive, ide_task_t *args, u8 *buf)
{
        return ide_diag_taskfile(drive, args, 0, buf);
}

EXPORT_SYMBOL(ide_raw_taskfile);

int ide_taskfile_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
{
        ide_task_request_t      *req_task;
        ide_task_t              args;
        u8 *outbuf              = NULL;
        u8 *inbuf               = NULL;
        task_ioreg_t *argsptr   = args.tfRegister;
        task_ioreg_t *hobsptr   = args.hobRegister;
        int err                 = 0;
        int tasksize            = sizeof(struct ide_task_request_s);
        int taskin              = 0;
        int taskout             = 0;
        u8 io_32bit             = drive->io_32bit;
        char __user *buf = (char __user *)arg;

//      printk("IDE Taskfile ...\n");

        req_task = kzalloc(tasksize, GFP_KERNEL);
        if (req_task == NULL) return -ENOMEM;
        if (copy_from_user(req_task, buf, tasksize)) {
                kfree(req_task);
                return -EFAULT;
        }

        taskout = (int) req_task->out_size;
        taskin  = (int) req_task->in_size;

        if (taskout) {
                int outtotal = tasksize;
                outbuf = kzalloc(taskout, GFP_KERNEL);
                if (outbuf == NULL) {
                        err = -ENOMEM;
                        goto abort;
                }
                if (copy_from_user(outbuf, buf + outtotal, taskout)) {
                        err = -EFAULT;
                        goto abort;
                }
        }

        if (taskin) {
                int intotal = tasksize + taskout;
                inbuf = kzalloc(taskin, GFP_KERNEL);
                if (inbuf == NULL) {
                        err = -ENOMEM;
                        goto abort;
                }
                if (copy_from_user(inbuf, buf + intotal, taskin)) {
                        err = -EFAULT;
                        goto abort;
                }
        }

        memset(&args, 0, sizeof(ide_task_t));
        memcpy(argsptr, req_task->io_ports, HDIO_DRIVE_TASK_HDR_SIZE);
        memcpy(hobsptr, req_task->hob_ports, HDIO_DRIVE_HOB_HDR_SIZE);

        args.tf_in_flags  = req_task->in_flags;
        args.tf_out_flags = req_task->out_flags;
        args.data_phase   = req_task->data_phase;
        args.command_type = req_task->req_cmd;

        drive->io_32bit = 0;
        switch(req_task->data_phase) {
                case TASKFILE_OUT_DMAQ:
                case TASKFILE_OUT_DMA:
                        err = ide_diag_taskfile(drive, &args, taskout, outbuf);
                        break;
                case TASKFILE_IN_DMAQ:
                case TASKFILE_IN_DMA:
                        err = ide_diag_taskfile(drive, &args, taskin, inbuf);
                        break;
                case TASKFILE_MULTI_OUT:
                        if (!drive->mult_count) {
                                /* (hs): give up if multcount is not set */
                                printk(KERN_ERR "%s: %s Multimode Write " \
                                        "multcount is not set\n",
                                        drive->name, __FUNCTION__);
                                err = -EPERM;
                                goto abort;
                        }
                        /* fall through */
                case TASKFILE_OUT:
                        args.prehandler = &pre_task_out_intr;
                        args.handler = &task_out_intr;
                        err = ide_diag_taskfile(drive, &args, taskout, outbuf);
                        break;
                case TASKFILE_MULTI_IN:
                        if (!drive->mult_count) {
                                /* (hs): give up if multcount is not set */
                                printk(KERN_ERR "%s: %s Multimode Read failure " \
                                        "multcount is not set\n",
                                        drive->name, __FUNCTION__);
                                err = -EPERM;
                                goto abort;
                        }
                        /* fall through */
                case TASKFILE_IN:
                        args.handler = &task_in_intr;
                        err = ide_diag_taskfile(drive, &args, taskin, inbuf);
                        break;
                case TASKFILE_NO_DATA:
                        args.handler = &task_no_data_intr;
                        err = ide_diag_taskfile(drive, &args, 0, NULL);
                        break;
                default:
                        err = -EFAULT;
                        goto abort;
        }

        memcpy(req_task->io_ports, &(args.tfRegister), HDIO_DRIVE_TASK_HDR_SIZE);
        memcpy(req_task->hob_ports, &(args.hobRegister), HDIO_DRIVE_HOB_HDR_SIZE);
        req_task->in_flags  = args.tf_in_flags;
        req_task->out_flags = args.tf_out_flags;

        if (copy_to_user(buf, req_task, tasksize)) {
                err = -EFAULT;
                goto abort;
        }
        if (taskout) {
                int outtotal = tasksize;
                if (copy_to_user(buf + outtotal, outbuf, taskout)) {
                        err = -EFAULT;
                        goto abort;
                }
        }
        if (taskin) {
                int intotal = tasksize + taskout;
                if (copy_to_user(buf + intotal, inbuf, taskin)) {
                        err = -EFAULT;
                        goto abort;
                }
        }
abort:
        kfree(req_task);
        kfree(outbuf);
        kfree(inbuf);

//      printk("IDE Taskfile ioctl ended. rc = %i\n", err);

        drive->io_32bit = io_32bit;

        return err;
}

int ide_wait_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, u8 feature, u8 sectors, u8 *buf)
{
        struct request rq;
        u8 buffer[4];

        if (!buf)
                buf = buffer;
        memset(buf, 0, 4 + SECTOR_WORDS * 4 * sectors);
        ide_init_drive_cmd(&rq);
        rq.buffer = buf;
        *buf++ = cmd;
        *buf++ = nsect;
        *buf++ = feature;
        *buf++ = sectors;
        return ide_do_drive_cmd(drive, &rq, ide_wait);
}

/*
 * FIXME : this needs to map into at taskfile. <andre@linux-ide.org>
 */
int ide_cmd_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
{
        int err = 0;
        u8 args[4], *argbuf = args;
        u8 xfer_rate = 0;
        int argsize = 4;
        ide_task_t tfargs;

        if (NULL == (void *) arg) {
                struct request rq;
                ide_init_drive_cmd(&rq);
                return ide_do_drive_cmd(drive, &rq, ide_wait);
        }

        if (copy_from_user(args, (void __user *)arg, 4))
                return -EFAULT;

        memset(&tfargs, 0, sizeof(ide_task_t));
        tfargs.tfRegister[IDE_FEATURE_OFFSET] = args[2];
        tfargs.tfRegister[IDE_NSECTOR_OFFSET] = args[3];
        tfargs.tfRegister[IDE_SECTOR_OFFSET]  = args[1];
        tfargs.tfRegister[IDE_LCYL_OFFSET]    = 0x00;
        tfargs.tfRegister[IDE_HCYL_OFFSET]    = 0x00;
        tfargs.tfRegister[IDE_SELECT_OFFSET]  = 0x00;
        tfargs.tfRegister[IDE_COMMAND_OFFSET] = args[0];

        if (args[3]) {
                argsize = 4 + (SECTOR_WORDS * 4 * args[3]);
                argbuf = kzalloc(argsize, GFP_KERNEL);
                if (argbuf == NULL)
                        return -ENOMEM;
        }
        if (set_transfer(drive, &tfargs)) {
                xfer_rate = args[1];
                if (ide_ata66_check(drive, &tfargs))
                        goto abort;
        }

        err = ide_wait_cmd(drive, args[0], args[1], args[2], args[3], argbuf);

        if (!err && xfer_rate) {
                /* active-retuning-calls future */
                ide_set_xfer_rate(drive, xfer_rate);
                ide_driveid_update(drive);
        }
abort:
        if (copy_to_user((void __user *)arg, argbuf, argsize))
                err = -EFAULT;
        if (argsize > 4)
                kfree(argbuf);
        return err;
}

static int ide_wait_cmd_task(ide_drive_t *drive, u8 *buf)
{
        struct request rq;

        ide_init_drive_cmd(&rq);
        rq.flags = REQ_DRIVE_TASK;
        rq.buffer = buf;
        return ide_do_drive_cmd(drive, &rq, ide_wait);
}

/*
 * FIXME : this needs to map into at taskfile. <andre@linux-ide.org>
 */
int ide_task_ioctl (ide_drive_t *drive, unsigned int cmd, unsigned long arg)
{
        void __user *p = (void __user *)arg;
        int err = 0;
        u8 args[7], *argbuf = args;
        int argsize = 7;

        if (copy_from_user(args, p, 7))
                return -EFAULT;
        err = ide_wait_cmd_task(drive, argbuf);
        if (copy_to_user(p, argbuf, argsize))
                err = -EFAULT;
        return err;
}

/*
 * NOTICE: This is additions from IBM to provide a discrete interface,
 * for selective taskregister access operations.  Nice JOB Klaus!!!
 * Glad to be able to work and co-develop this with you and IBM.
 */
ide_startstop_t flagged_taskfile (ide_drive_t *drive, ide_task_t *task)
{
        ide_hwif_t *hwif        = HWIF(drive);
        task_struct_t *taskfile = (task_struct_t *) task->tfRegister;
        hob_struct_t *hobfile   = (hob_struct_t *) task->hobRegister;
#if DEBUG_TASKFILE
        u8 status;
#endif

        if (task->data_phase == TASKFILE_MULTI_IN ||
            task->data_phase == TASKFILE_MULTI_OUT) {
                if (!drive->mult_count) {
                        printk(KERN_ERR "%s: multimode not set!\n", drive->name);
                        return ide_stopped;
                }
        }

        /*
         * (ks) Check taskfile in/out flags.
         * If set, then execute as it is defined.
         * If not set, then define default settings.
         * The default values are:
         *      write and read all taskfile registers (except data) 
         *      write and read the hob registers (sector,nsector,lcyl,hcyl)
         */
        if (task->tf_out_flags.all == 0) {
                task->tf_out_flags.all = IDE_TASKFILE_STD_OUT_FLAGS;
                if (drive->addressing == 1)
                        task->tf_out_flags.all |= (IDE_HOB_STD_OUT_FLAGS << 8);
        }

        if (task->tf_in_flags.all == 0) {
                task->tf_in_flags.all = IDE_TASKFILE_STD_IN_FLAGS;
                if (drive->addressing == 1)
                        task->tf_in_flags.all |= (IDE_HOB_STD_IN_FLAGS  << 8);
        }

        /* ALL Command Block Executions SHALL clear nIEN, unless otherwise */
        if (IDE_CONTROL_REG)
                /* clear nIEN */
                hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
        SELECT_MASK(drive, 0);

#if DEBUG_TASKFILE
        status = hwif->INB(IDE_STATUS_REG);
        if (status & 0x80) {
                printk("flagged_taskfile -> Bad status. Status = %02x. wait 100 usec ...\n", status);
                udelay(100);
                status = hwif->INB(IDE_STATUS_REG);
                printk("flagged_taskfile -> Status = %02x\n", status);
        }
#endif

        if (task->tf_out_flags.b.data) {
                u16 data =  taskfile->data + (hobfile->data << 8);
                hwif->OUTW(data, IDE_DATA_REG);
        }

        /* (ks) send hob registers first */
        if (task->tf_out_flags.b.nsector_hob)
                hwif->OUTB(hobfile->sector_count, IDE_NSECTOR_REG);
        if (task->tf_out_flags.b.sector_hob)
                hwif->OUTB(hobfile->sector_number, IDE_SECTOR_REG);
        if (task->tf_out_flags.b.lcyl_hob)
                hwif->OUTB(hobfile->low_cylinder, IDE_LCYL_REG);
        if (task->tf_out_flags.b.hcyl_hob)
                hwif->OUTB(hobfile->high_cylinder, IDE_HCYL_REG);

        /* (ks) Send now the standard registers */
        if (task->tf_out_flags.b.error_feature)
                hwif->OUTB(taskfile->feature, IDE_FEATURE_REG);
        /* refers to number of sectors to transfer */
        if (task->tf_out_flags.b.nsector)
                hwif->OUTB(taskfile->sector_count, IDE_NSECTOR_REG);
        /* refers to sector offset or start sector */
        if (task->tf_out_flags.b.sector)
                hwif->OUTB(taskfile->sector_number, IDE_SECTOR_REG);
        if (task->tf_out_flags.b.lcyl)
                hwif->OUTB(taskfile->low_cylinder, IDE_LCYL_REG);
        if (task->tf_out_flags.b.hcyl)
                hwif->OUTB(taskfile->high_cylinder, IDE_HCYL_REG);

        /*
         * (ks) In the flagged taskfile approch, we will use all specified
         * registers and the register value will not be changed, except the
         * select bit (master/slave) in the drive_head register. We must make
         * sure that the desired drive is selected.
         */
        hwif->OUTB(taskfile->device_head | drive->select.all, IDE_SELECT_REG);
        switch(task->data_phase) {

                case TASKFILE_OUT_DMAQ:
                case TASKFILE_OUT_DMA:
                case TASKFILE_IN_DMAQ:
                case TASKFILE_IN_DMA:
                        hwif->dma_setup(drive);
                        hwif->dma_exec_cmd(drive, taskfile->command);
                        hwif->dma_start(drive);
                        break;

                default:
                        if (task->handler == NULL)
                                return ide_stopped;

                        /* Issue the command */
                        if (task->prehandler) {
                                hwif->OUTBSYNC(drive, taskfile->command, IDE_COMMAND_REG);
                                ndelay(400);    /* FIXME */
                                return task->prehandler(drive, task->rq);
                        }
                        ide_execute_command(drive, taskfile->command, task->handler, WAIT_WORSTCASE, NULL);
        }

        return ide_started;
}