nilfs2: fix oopses with doubly mounted snapshots

[linux-2.6/mini2440.git] / drivers / ide / ide-eh.c

#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/delay.h>

static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
                                     u8 stat, u8 err)
{
        ide_hwif_t *hwif = drive->hwif;

        if ((stat & ATA_BUSY) ||
            ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
                /* other bits are useless when BUSY */
                rq->errors |= ERROR_RESET;
        } else if (stat & ATA_ERR) {
                /* err has different meaning on cdrom and tape */
                if (err == ATA_ABORTED) {
                        if ((drive->dev_flags & IDE_DFLAG_LBA) &&
                            /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */
                            hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS)
                                return ide_stopped;
                } else if ((err & BAD_CRC) == BAD_CRC) {
                        /* UDMA crc error, just retry the operation */
                        drive->crc_count++;
                } else if (err & (ATA_BBK | ATA_UNC)) {
                        /* retries won't help these */
                        rq->errors = ERROR_MAX;
                } else if (err & ATA_TRK0NF) {
                        /* help it find track zero */
                        rq->errors |= ERROR_RECAL;
                }
        }

        if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ &&
            (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) {
                int nsect = drive->mult_count ? drive->mult_count : 1;

                ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
        }

        if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
                ide_kill_rq(drive, rq);
                return ide_stopped;
        }

        if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
                rq->errors |= ERROR_RESET;

        if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
                ++rq->errors;
                return ide_do_reset(drive);
        }

        if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
                drive->special_flags |= IDE_SFLAG_RECALIBRATE;

        ++rq->errors;

        return ide_stopped;
}

static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
                                       u8 stat, u8 err)
{
        ide_hwif_t *hwif = drive->hwif;

        if ((stat & ATA_BUSY) ||
            ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
                /* other bits are useless when BUSY */
                rq->errors |= ERROR_RESET;
        } else {
                /* add decoding error stuff */
        }

        if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
                /* force an abort */
                hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);

        if (rq->errors >= ERROR_MAX) {
                ide_kill_rq(drive, rq);
        } else {
                if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
                        ++rq->errors;
                        return ide_do_reset(drive);
                }
                ++rq->errors;
        }

        return ide_stopped;
}

static ide_startstop_t __ide_error(ide_drive_t *drive, struct request *rq,
                                   u8 stat, u8 err)
{
        if (drive->media == ide_disk)
                return ide_ata_error(drive, rq, stat, err);
        return ide_atapi_error(drive, rq, stat, err);
}

/**
 *      ide_error       -       handle an error on the IDE
 *      @drive: drive the error occurred on
 *      @msg: message to report
 *      @stat: status bits
 *
 *      ide_error() takes action based on the error returned by the drive.
 *      For normal I/O that may well include retries. We deal with
 *      both new-style (taskfile) and old style command handling here.
 *      In the case of taskfile command handling there is work left to
 *      do
 */

ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
{
        struct request *rq;
        u8 err;

        err = ide_dump_status(drive, msg, stat);

        rq = drive->hwif->rq;
        if (rq == NULL)
                return ide_stopped;

        /* retry only "normal" I/O: */
        if (!blk_fs_request(rq)) {
                if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
                        struct ide_cmd *cmd = rq->special;

                        if (cmd)
                                ide_complete_cmd(drive, cmd, stat, err);
                } else if (blk_pm_request(rq)) {
                        rq->errors = 1;
                        ide_complete_pm_rq(drive, rq);
                        return ide_stopped;
                }
                rq->errors = err;
                ide_complete_rq(drive, err ? -EIO : 0, blk_rq_bytes(rq));
                return ide_stopped;
        }

        return __ide_error(drive, rq, stat, err);
}
EXPORT_SYMBOL_GPL(ide_error);

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) {
                if (err <= 0 && rq->errors == 0)
                        rq->errors = -EIO;
                ide_complete_rq(drive, err ? err : 0, blk_rq_bytes(rq));
        }
}

/* 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;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        u8 stat;

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

        if (OK_STAT(stat, 0, ATA_BUSY))
                printk(KERN_INFO "%s: ATAPI reset complete\n", drive->name);
        else {
                if (time_before(jiffies, hwif->poll_timeout)) {
                        ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20);
                        /* continue polling */
                        return ide_started;
                }
                /* end of polling */
                hwif->polling = 0;
                printk(KERN_ERR "%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);
                        /* continue polling */
                        return ide_started;
                }
                printk(KERN_ERR "%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_flags =
                legacy ? (IDE_SFLAG_SET_GEOMETRY | IDE_SFLAG_RECALIBRATE) : 0;

        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_flags |= IDE_SFLAG_SET_MULTMODE;
}

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);
                tp_ops->dev_select(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);
                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_present_dev(i, tdrive, hwif) {
                        if ((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.
         */
        /* set SRST and nIEN */
        tp_ops->write_devctl(hwif, ATA_SRST | ATA_NIEN | ATA_DEVCTL_OBS);
        /* more than enough time */
        udelay(10);
        /* clear SRST, leave nIEN (unless device is on the quirk list) */
        tp_ops->write_devctl(hwif,
                ((drive->dev_flags & IDE_DFLAG_NIEN_QUIRK) ? 0 : ATA_NIEN) |
                 ATA_DEVCTL_OBS);
        /* more than enough time */
        udelay(10);
        hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
        hwif->polling = 1;
        __ide_set_handler(drive, &reset_pollfunc, HZ/20);

        /*
         * 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);