#include <linux/kernel.h>
  #include <linux/export.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 (rq->cmd_type != REQ_TYPE_FS) {
  		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 && rq->cmd_type == REQ_TYPE_SPECIAL &&
  	    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
  ", 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
  ",
  			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 "
  ");
  }
  
  /*
   * 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.
  ",
  				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
  ",
  			hwif->name, tmp);
  		drive->failures++;
  		err = -EIO;
  	} else  {
  		tmp = ide_read_error(drive);
  
  		if (tmp == 1) {
  			printk(KERN_INFO "%s: reset: success
  ", 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);