/*

   *  Copyright (C) 1994-1998   Linus Torvalds & authors (see below)
   *  Copyright (C) 2005, 2007  Bartlomiej Zolnierkiewicz

   */
  
  /*
   *  Mostly written by Mark Lord <mlord@pobox.com>
   *                and Gadi Oxman <gadio@netvision.net.il>
   *                and Andre Hedrick <andre@linux-ide.org>
   *
   *  See linux/MAINTAINERS for address of current maintainer.
   *
   * This is the IDE probe module, as evolved from hd.c and ide.c.
   *

   * -- increase WAIT_PIDENTIFY to avoid CD-ROM locking at boot
   *	 by Andrea Arcangeli

   */

  #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/slab.h>
  #include <linux/delay.h>
  #include <linux/ide.h>
  #include <linux/spinlock.h>
  #include <linux/kmod.h>
  #include <linux/pci.h>

  #include <linux/scatterlist.h>

  
  #include <asm/byteorder.h>
  #include <asm/irq.h>
  #include <asm/uaccess.h>
  #include <asm/io.h>
  
  /**
   *	generic_id		-	add a generic drive id
   *	@drive:	drive to make an ID block for
   *	
   *	Add a fake id field to the drive we are passed. This allows
   *	use to skip a ton of NULL checks (which people always miss) 
   *	and make drive properties unconditional outside of this file
   */
   
  static void generic_id(ide_drive_t *drive)
  {

  	u16 *id = drive->id;
  
  	id[ATA_ID_CUR_CYLS]	= id[ATA_ID_CYLS]	= drive->cyl;
  	id[ATA_ID_CUR_HEADS]	= id[ATA_ID_HEADS]	= drive->head;
  	id[ATA_ID_CUR_SECTORS]	= id[ATA_ID_SECTORS]	= drive->sect;

  }
  
  static void ide_disk_init_chs(ide_drive_t *drive)
  {

  	u16 *id = drive->id;

  
  	/* Extract geometry if we did not already have one for the drive */
  	if (!drive->cyl || !drive->head || !drive->sect) {

  		drive->cyl  = drive->bios_cyl  = id[ATA_ID_CYLS];
  		drive->head = drive->bios_head = id[ATA_ID_HEADS];
  		drive->sect = drive->bios_sect = id[ATA_ID_SECTORS];

  	}
  
  	/* Handle logical geometry translation by the drive */

  	if (ata_id_current_chs_valid(id)) {

  		drive->cyl  = id[ATA_ID_CUR_CYLS];
  		drive->head = id[ATA_ID_CUR_HEADS];
  		drive->sect = id[ATA_ID_CUR_SECTORS];

  	}
  
  	/* Use physical geometry if what we have still makes no sense */

  	if (drive->head > 16 && id[ATA_ID_HEADS] && id[ATA_ID_HEADS] <= 16) {
  		drive->cyl  = id[ATA_ID_CYLS];
  		drive->head = id[ATA_ID_HEADS];
  		drive->sect = id[ATA_ID_SECTORS];

  	}
  }
  
  static void ide_disk_init_mult_count(ide_drive_t *drive)
  {

  	u16 *id = drive->id;
  	u8 max_multsect = id[ATA_ID_MAX_MULTSECT] & 0xff;

  	if (max_multsect) {

  		if ((max_multsect / 2) > 1)
  			id[ATA_ID_MULTSECT] = max_multsect | 0x100;
  		else
  			id[ATA_ID_MULTSECT] &= ~0x1ff;
  
  		drive->mult_req = id[ATA_ID_MULTSECT] & 0xff;

  
  		if (drive->mult_req)

  			drive->special_flags |= IDE_SFLAG_SET_MULTMODE;

  	}
  }

  static void ide_classify_ata_dev(ide_drive_t *drive)
  {
  	u16 *id = drive->id;
  	char *m = (char *)&id[ATA_ID_PROD];
  	int is_cfa = ata_id_is_cfa(id);
  
  	/* CF devices are *not* removable in Linux definition of the term */
  	if (is_cfa == 0 && (id[ATA_ID_CONFIG] & (1 << 7)))
  		drive->dev_flags |= IDE_DFLAG_REMOVABLE;
  
  	drive->media = ide_disk;
  
  	if (!ata_id_has_unload(drive->id))
  		drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
  
  	printk(KERN_INFO "%s: %s, %s DISK drive
  ", drive->name, m,
  		is_cfa ? "CFA" : "ATA");
  }
  
  static void ide_classify_atapi_dev(ide_drive_t *drive)
  {
  	u16 *id = drive->id;
  	char *m = (char *)&id[ATA_ID_PROD];
  	u8 type = (id[ATA_ID_CONFIG] >> 8) & 0x1f;
  
  	printk(KERN_INFO "%s: %s, ATAPI ", drive->name, m);
  	switch (type) {
  	case ide_floppy:
  		if (!strstr(m, "CD-ROM")) {
  			if (!strstr(m, "oppy") &&
  			    !strstr(m, "poyp") &&
  			    !strstr(m, "ZIP"))
  				printk(KERN_CONT "cdrom or floppy?, assuming ");
  			if (drive->media != ide_cdrom) {
  				printk(KERN_CONT "FLOPPY");
  				drive->dev_flags |= IDE_DFLAG_REMOVABLE;
  				break;
  			}
  		}
  		/* Early cdrom models used zero */
  		type = ide_cdrom;
  	case ide_cdrom:
  		drive->dev_flags |= IDE_DFLAG_REMOVABLE;
  #ifdef CONFIG_PPC
  		/* kludge for Apple PowerBook internal zip */
  		if (!strstr(m, "CD-ROM") && strstr(m, "ZIP")) {
  			printk(KERN_CONT "FLOPPY");
  			type = ide_floppy;
  			break;
  		}
  #endif
  		printk(KERN_CONT "CD/DVD-ROM");
  		break;
  	case ide_tape:
  		printk(KERN_CONT "TAPE");
  		break;
  	case ide_optical:
  		printk(KERN_CONT "OPTICAL");
  		drive->dev_flags |= IDE_DFLAG_REMOVABLE;
  		break;
  	default:
  		printk(KERN_CONT "UNKNOWN (type %d)", type);
  		break;
  	}
  
  	printk(KERN_CONT " drive
  ");
  	drive->media = type;
  	/* an ATAPI device ignores DRDY */
  	drive->ready_stat = 0;
  	if (ata_id_cdb_intr(id))
  		drive->atapi_flags |= IDE_AFLAG_DRQ_INTERRUPT;
  	drive->dev_flags |= IDE_DFLAG_DOORLOCKING;
  	/* we don't do head unloading on ATAPI devices */
  	drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
  }

  /**

   *	do_identify	-	identify a drive
   *	@drive: drive to identify 
   *	@cmd: command used

   *	@id: buffer for IDENTIFY data

   *
   *	Called when we have issued a drive identify command to
   *	read and parse the results. This function is run with
   *	interrupts disabled. 
   */

  static void do_identify(ide_drive_t *drive, u8 cmd, u16 *id)

  {

  	ide_hwif_t *hwif = drive->hwif;

  	char *m = (char *)&id[ATA_ID_PROD];

  	unsigned long flags;

  	int bswap = 1;

  	/* local CPU only; some systems need this */
  	local_irq_save(flags);

  	/* read 512 bytes of id info */

  	hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);

  	local_irq_restore(flags);

  	drive->dev_flags |= IDE_DFLAG_ID_READ;

  #ifdef DEBUG
  	printk(KERN_INFO "%s: dumping identify data
  ", drive->name);
  	ide_dump_identify((u8 *)id);
  #endif

  	ide_fix_driveid(id);

  	/*

  	 *  ATA_CMD_ID_ATA returns little-endian info,
  	 *  ATA_CMD_ID_ATAPI *usually* returns little-endian info.

  	 */

  	if (cmd == ATA_CMD_ID_ATAPI) {

  		if ((m[0] == 'N' && m[1] == 'E') ||  /* NEC */
  		    (m[0] == 'F' && m[1] == 'X') ||  /* Mitsumi */
  		    (m[0] == 'P' && m[1] == 'i'))    /* Pioneer */

  			/* Vertos drives may still be weird */

  			bswap ^= 1;

  	}

  
  	ide_fixstring(m, ATA_ID_PROD_LEN, bswap);
  	ide_fixstring((char *)&id[ATA_ID_FW_REV], ATA_ID_FW_REV_LEN, bswap);
  	ide_fixstring((char *)&id[ATA_ID_SERNO], ATA_ID_SERNO_LEN, bswap);

  	/* we depend on this a lot! */

  	m[ATA_ID_PROD_LEN - 1] = '\0';

  	if (strstr(m, "E X A B Y T E N E S T"))

  		drive->dev_flags &= ~IDE_DFLAG_PRESENT;
  	else
  		drive->dev_flags |= IDE_DFLAG_PRESENT;

  }
  
  /**

   *	ide_dev_read_id	-	send ATA/ATAPI IDENTIFY command

   *	@drive: drive to identify
   *	@cmd: command to use

   *	@id: buffer for IDENTIFY data

   *	@irq_ctx: flag set when called from the IRQ context

   *

   *	Sends an ATA(PI) IDENTIFY request to a drive and waits for a response.

   *
   *	Returns:	0  device was identified
   *			1  device timed-out (no response to identify request)
   *			2  device aborted the command (refused to identify itself)
   */

  int ide_dev_read_id(ide_drive_t *drive, u8 cmd, u16 *id, int irq_ctx)

  {

  	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;

  	int use_altstatus = 0, rc;

  	unsigned long timeout;
  	u8 s = 0, a = 0;

  	/*
  	 * Disable device IRQ.  Otherwise we'll get spurious interrupts
  	 * during the identify phase that the IRQ handler isn't expecting.
  	 */
  	if (io_ports->ctl_addr)

  		tp_ops->write_devctl(hwif, ATA_NIEN | ATA_DEVCTL_OBS);

  	/* take a deep breath */

  	if (irq_ctx)
  		mdelay(50);
  	else
  		msleep(50);

  	if (io_ports->ctl_addr &&
  	    (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) {

  		a = tp_ops->read_altstatus(hwif);
  		s = tp_ops->read_status(hwif);

  		if ((a ^ s) & ~ATA_IDX)

  			/* ancient Seagate drives, broken interfaces */

  			printk(KERN_INFO "%s: probing with STATUS(0x%02x) "
  					 "instead of ALTSTATUS(0x%02x)
  ",
  					 drive->name, s, a);
  		else

  			/* use non-intrusive polling */

  			use_altstatus = 1;
  	}

  
  	/* set features register for atapi
  	 * identify command to be sure of reply
  	 */

  	if (cmd == ATA_CMD_ID_ATAPI) {

  		struct ide_taskfile tf;

  		memset(&tf, 0, sizeof(tf));

  		/* disable DMA & overlap */

  		tp_ops->tf_load(drive, &tf, IDE_VALID_FEATURE);

  	}

  
  	/* ask drive for ID */

  	tp_ops->exec_command(hwif, cmd);

  	timeout = ((cmd == ATA_CMD_ID_ATA) ? WAIT_WORSTCASE : WAIT_PIDENTIFY) / 2;

  	/* wait for IRQ and ATA_DRQ */

  	if (irq_ctx) {
  		rc = __ide_wait_stat(drive, ATA_DRQ, BAD_R_STAT, timeout, &s);
  		if (rc)
  			return 1;
  	} else {
  		rc = ide_busy_sleep(drive, timeout, use_altstatus);
  		if (rc)
  			return 1;
  
  		msleep(50);
  		s = tp_ops->read_status(hwif);
  	}

  	if (OK_STAT(s, ATA_DRQ, BAD_R_STAT)) {

  		/* drive returned ID */

  		do_identify(drive, cmd, id);

  		/* drive responded with ID */
  		rc = 0;
  		/* clear drive IRQ */

  		(void)tp_ops->read_status(hwif);

  	} else {
  		/* drive refused ID */
  		rc = 2;
  	}
  	return rc;
  }

  int ide_busy_sleep(ide_drive_t *drive, unsigned long timeout, int altstatus)

  {

  	ide_hwif_t *hwif = drive->hwif;

  	u8 stat;

  	timeout += jiffies;

  	do {

  		msleep(50);	/* give drive a breather */
  		stat = altstatus ? hwif->tp_ops->read_altstatus(hwif)
  				 : hwif->tp_ops->read_status(hwif);

  		if ((stat & ATA_BUSY) == 0)

  			return 0;
  	} while (time_before(jiffies, timeout));

  	printk(KERN_ERR "%s: timeout in %s
  ", drive->name, __func__);

  	return 1;	/* drive timed-out */

  }

  static u8 ide_read_device(ide_drive_t *drive)
  {

  	struct ide_taskfile tf;

  	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_DEVICE);

  	return tf.device;

  }

  /**
   *	do_probe		-	probe an IDE device
   *	@drive: drive to probe
   *	@cmd: command to use
   *
   *	do_probe() has the difficult job of finding a drive if it exists,
   *	without getting hung up if it doesn't exist, without trampling on
   *	ethernet cards, and without leaving any IRQs dangling to haunt us later.
   *
   *	If a drive is "known" to exist (from CMOS or kernel parameters),
   *	but does not respond right away, the probe will "hang in there"
   *	for the maximum wait time (about 30 seconds), otherwise it will
   *	exit much more quickly.
   *
   * Returns:	0  device was identified
   *		1  device timed-out (no response to identify request)
   *		2  device aborted the command (refused to identify itself)
   *		3  bad status from device (possible for ATAPI drives)
   *		4  probe was not attempted because failure was obvious
   */
  
  static int do_probe (ide_drive_t *drive, u8 cmd)
  {

  	ide_hwif_t *hwif = drive->hwif;

  	const struct ide_tp_ops *tp_ops = hwif->tp_ops;

  	u16 *id = drive->id;

  	int rc;

  	u8 present = !!(drive->dev_flags & IDE_DFLAG_PRESENT), stat;
  
  	/* avoid waiting for inappropriate probes */
  	if (present && drive->media != ide_disk && cmd == ATA_CMD_ID_ATA)
  		return 4;

  #ifdef DEBUG

  	printk(KERN_INFO "probing for %s: present=%d, media=%d, probetype=%s
  ",

  		drive->name, present, drive->media,

  		(cmd == ATA_CMD_ID_ATA) ? "ATA" : "ATAPI");

  #endif
  
  	/* needed for some systems
  	 * (e.g. crw9624 as drive0 with disk as slave)
  	 */
  	msleep(50);

  	tp_ops->dev_select(drive);

  	msleep(50);

  	if (ide_read_device(drive) != drive->select && present == 0) {

  		if (drive->dn & 1) {

  			/* exit with drive0 selected */

  			tp_ops->dev_select(hwif->devices[0]);

  			/* allow ATA_BUSY to assert & clear */

  			msleep(50);
  		}
  		/* no i/f present: mmm.. this should be a 4 -ml */
  		return 3;
  	}

  	stat = tp_ops->read_status(hwif);

  	if (OK_STAT(stat, ATA_DRDY, ATA_BUSY) ||

  	    present || cmd == ATA_CMD_ID_ATAPI) {

  		rc = ide_dev_read_id(drive, cmd, id, 0);

  		if (rc)

  			/* failed: try again */

  			rc = ide_dev_read_id(drive, cmd, id, 0);

  		stat = tp_ops->read_status(hwif);

  		if (stat == (ATA_BUSY | ATA_DRDY))

  			return 4;

  		if (rc == 1 && cmd == ATA_CMD_ID_ATAPI) {

  			printk(KERN_ERR "%s: no response (status = 0x%02x), "
  					"resetting drive
  ", drive->name, stat);

  			msleep(50);

  			tp_ops->dev_select(drive);

  			msleep(50);

  			tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);

  			(void)ide_busy_sleep(drive, WAIT_WORSTCASE, 0);

  			rc = ide_dev_read_id(drive, cmd, id, 0);

  		}

  
  		/* ensure drive IRQ is clear */

  		stat = tp_ops->read_status(hwif);

  		if (rc == 1)

  			printk(KERN_ERR "%s: no response (status = 0x%02x)
  ",
  					drive->name, stat);

  	} else {
  		/* not present or maybe ATAPI */
  		rc = 3;
  	}

  	if (drive->dn & 1) {

  		/* exit with drive0 selected */

  		tp_ops->dev_select(hwif->devices[0]);

  		msleep(50);
  		/* ensure drive irq is clear */

  		(void)tp_ops->read_status(hwif);

  	}
  	return rc;
  }

  /**
   *	probe_for_drives	-	upper level drive probe
   *	@drive: drive to probe for
   *
   *	probe_for_drive() tests for existence of a given drive using do_probe()
   *	and presents things to the user as needed.
   *
   *	Returns:	0  no device was found

   *			1  device was found
   *			   (note: IDE_DFLAG_PRESENT might still be not set)

   */

  
  static u8 probe_for_drive(ide_drive_t *drive)

  {

  	char *m;

  	int rc;
  	u8 cmd;

  	drive->dev_flags &= ~IDE_DFLAG_ID_READ;

  	m = (char *)&drive->id[ATA_ID_PROD];
  	strcpy(m, "UNKNOWN");

  	/* skip probing? */

  	if ((drive->dev_flags & IDE_DFLAG_NOPROBE) == 0) {

  		/* if !(success||timed-out) */

  		cmd = ATA_CMD_ID_ATA;
  		rc = do_probe(drive, cmd);
  		if (rc >= 2) {

  			/* look for ATAPI device */

  			cmd = ATA_CMD_ID_ATAPI;
  			rc = do_probe(drive, cmd);
  		}

  		if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)

  			return 0;

  		/* identification failed? */

  		if ((drive->dev_flags & IDE_DFLAG_ID_READ) == 0) {

  			if (drive->media == ide_disk) {
  				printk(KERN_INFO "%s: non-IDE drive, CHS=%d/%d/%d
  ",
  					drive->name, drive->cyl,
  					drive->head, drive->sect);
  			} else if (drive->media == ide_cdrom) {
  				printk(KERN_INFO "%s: ATAPI cdrom (?)
  ", drive->name);
  			} else {
  				/* nuke it */
  				printk(KERN_WARNING "%s: Unknown device on bus refused identification. Ignoring.
  ", drive->name);

  				drive->dev_flags &= ~IDE_DFLAG_PRESENT;

  			}

  		} else {
  			if (cmd == ATA_CMD_ID_ATAPI)
  				ide_classify_atapi_dev(drive);
  			else
  				ide_classify_ata_dev(drive);

  		}

  	}

  
  	if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)

  		return 0;

  	/* The drive wasn't being helpful. Add generic info only */

  	if ((drive->dev_flags & IDE_DFLAG_ID_READ) == 0) {

  		generic_id(drive);
  		return 1;
  	}
  
  	if (drive->media == ide_disk) {
  		ide_disk_init_chs(drive);
  		ide_disk_init_mult_count(drive);
  	}

  	return 1;

  }

  static void hwif_release_dev(struct device *dev)

  {
  	ide_hwif_t *hwif = container_of(dev, ide_hwif_t, gendev);

  	complete(&hwif->gendev_rel_comp);

  }

  static int ide_register_port(ide_hwif_t *hwif)

  {

  	int ret;

  	/* register with global device tree */

  	dev_set_name(&hwif->gendev, hwif->name);

  	dev_set_drvdata(&hwif->gendev, hwif);

  	if (hwif->gendev.parent == NULL)
  		hwif->gendev.parent = hwif->dev;

  	hwif->gendev.release = hwif_release_dev;

  	ret = device_register(&hwif->gendev);

  	if (ret < 0) {

  		printk(KERN_WARNING "IDE: %s: device_register error: %d
  ",

  			__func__, ret);

  		goto out;
  	}

  	hwif->portdev = device_create(ide_port_class, &hwif->gendev,
  				      MKDEV(0, 0), hwif, hwif->name);

  	if (IS_ERR(hwif->portdev)) {
  		ret = PTR_ERR(hwif->portdev);
  		device_unregister(&hwif->gendev);
  	}

  out:
  	return ret;

  }

  /**
   *	ide_port_wait_ready	-	wait for port to become ready
   *	@hwif: IDE port
   *
   *	This is needed on some PPCs and a bunch of BIOS-less embedded
   *	platforms.  Typical cases are:
   *
   *	- The firmware hard reset the disk before booting the kernel,
   *	  the drive is still doing it's poweron-reset sequence, that
   *	  can take up to 30 seconds.
   *
   *	- The firmware does nothing (or no firmware), the device is
   *	  still in POST state (same as above actually).
   *
   *	- Some CD/DVD/Writer combo drives tend to drive the bus during
   *	  their reset sequence even when they are non-selected slave
   *	  devices, thus preventing discovery of the main HD.
   *
   *	Doing this wait-for-non-busy should not harm any existing
   *	configuration and fix some issues like the above.
   *
   *	BenH.
   *
   *	Returns 0 on success, error code (< 0) otherwise.
   */
  
  static int ide_port_wait_ready(ide_hwif_t *hwif)

  {

  	const struct ide_tp_ops *tp_ops = hwif->tp_ops;

  	ide_drive_t *drive;
  	int i, rc;

  
  	printk(KERN_DEBUG "Probing IDE interface %s...
  ", hwif->name);
  
  	/* Let HW settle down a bit from whatever init state we
  	 * come from */
  	mdelay(2);
  
  	/* Wait for BSY bit to go away, spec timeout is 30 seconds,
  	 * I know of at least one disk who takes 31 seconds, I use 35
  	 * here to be safe
  	 */
  	rc = ide_wait_not_busy(hwif, 35000);
  	if (rc)
  		return rc;
  
  	/* Now make sure both master & slave are ready */

  	ide_port_for_each_dev(i, drive, hwif) {

  		/* Ignore disks that we will not probe for later. */

  		if ((drive->dev_flags & IDE_DFLAG_NOPROBE) == 0 ||
  		    (drive->dev_flags & IDE_DFLAG_PRESENT)) {

  			tp_ops->dev_select(drive);
  			tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);

  			mdelay(2);
  			rc = ide_wait_not_busy(hwif, 35000);
  			if (rc)
  				goto out;
  		} else
  			printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped
  ",
  					  drive->name);
  	}
  out:

  	/* Exit function with master reselected (let's be sane) */

  	if (i)

  		tp_ops->dev_select(hwif->devices[0]);

  	return rc;
  }
  
  /**
   *	ide_undecoded_slave	-	look for bad CF adapters

   *	@dev1: slave device

   *
   *	Analyse the drives on the interface and attempt to decide if we
   *	have the same drive viewed twice. This occurs with crap CF adapters
   *	and PCMCIA sometimes.
   */

  void ide_undecoded_slave(ide_drive_t *dev1)

  {

  	ide_drive_t *dev0 = dev1->hwif->devices[0];

  	if ((dev1->dn & 1) == 0 || (dev0->dev_flags & IDE_DFLAG_PRESENT) == 0)

  		return;
  
  	/* If the models don't match they are not the same product */

  	if (strcmp((char *)&dev0->id[ATA_ID_PROD],
  		   (char *)&dev1->id[ATA_ID_PROD]))

  		return;
  
  	/* Serial numbers do not match */

  	if (strncmp((char *)&dev0->id[ATA_ID_SERNO],
  		    (char *)&dev1->id[ATA_ID_SERNO], ATA_ID_SERNO_LEN))

  		return;
  
  	/* No serial number, thankfully very rare for CF */

  	if (*(char *)&dev0->id[ATA_ID_SERNO] == 0)

  		return;
  
  	/* Appears to be an IDE flash adapter with decode bugs */
  	printk(KERN_WARNING "ide-probe: ignoring undecoded slave
  ");

  	dev1->dev_flags &= ~IDE_DFLAG_PRESENT;

  }
  
  EXPORT_SYMBOL_GPL(ide_undecoded_slave);

  static int ide_probe_port(ide_hwif_t *hwif)

  {

  	ide_drive_t *drive;

  	unsigned int irqd;

  	int i, rc = -ENODEV;

  
  	BUG_ON(hwif->present);

  	if ((hwif->devices[0]->dev_flags & IDE_DFLAG_NOPROBE) &&
  	    (hwif->devices[1]->dev_flags & IDE_DFLAG_NOPROBE))

  		return -EACCES;

  	/*
  	 * We must always disable IRQ, as probe_for_drive will assert IRQ, but
  	 * we'll install our IRQ driver much later...
  	 */
  	irqd = hwif->irq;
  	if (irqd)
  		disable_irq(hwif->irq);

  	if (ide_port_wait_ready(hwif) == -EBUSY)
  		printk(KERN_DEBUG "%s: Wait for ready failed before probe !
  ", hwif->name);

  
  	/*

  	 * Second drive should only exist if first drive was found,
  	 * but a lot of cdrom drives are configured as single slaves.

  	 */

  	ide_port_for_each_dev(i, drive, hwif) {

  		(void) probe_for_drive(drive);

  		if (drive->dev_flags & IDE_DFLAG_PRESENT)

  			rc = 0;

  	}

  	/*
  	 * Use cached IRQ number. It might be (and is...) changed by probe
  	 * code above
  	 */
  	if (irqd)
  		enable_irq(irqd);

  	return rc;

  }
  
  static void ide_port_tune_devices(ide_hwif_t *hwif)
  {

  	const struct ide_port_ops *port_ops = hwif->port_ops;

  	ide_drive_t *drive;
  	int i;

  	ide_port_for_each_present_dev(i, drive, hwif) {

  		ide_check_nien_quirk_list(drive);

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

  	}

  	ide_port_for_each_present_dev(i, drive, hwif) {
  		ide_set_max_pio(drive);

  		drive->dev_flags |= IDE_DFLAG_NICE1;

  		if (hwif->dma_ops)
  			ide_set_dma(drive);

  	}
  }

  /*

   * init request queue
   */
  static int ide_init_queue(ide_drive_t *drive)
  {

  	struct request_queue *q;

  	ide_hwif_t *hwif = drive->hwif;

  	int max_sectors = 256;
  	int max_sg_entries = PRD_ENTRIES;
  
  	/*
  	 *	Our default set up assumes the normal IDE case,
  	 *	that is 64K segmenting, standard PRD setup
  	 *	and LBA28. Some drivers then impose their own
  	 *	limits and LBA48 we could raise it but as yet
  	 *	do not.
  	 */

  	q = blk_init_queue_node(do_ide_request, NULL, hwif_to_node(hwif));

  	if (!q)
  		return 1;
  
  	q->queuedata = drive;
  	blk_queue_segment_boundary(q, 0xffff);

  	if (hwif->rqsize < max_sectors)
  		max_sectors = hwif->rqsize;

  	blk_queue_max_hw_sectors(q, max_sectors);

  
  #ifdef CONFIG_PCI
  	/* When we have an IOMMU, we may have a problem where pci_map_sg()
  	 * creates segments that don't completely match our boundary
  	 * requirements and thus need to be broken up again. Because it
  	 * doesn't align properly either, we may actually have to break up
  	 * to more segments than what was we got in the first place, a max
  	 * worst case is twice as many.
  	 * This will be fixed once we teach pci_map_sg() about our boundary
  	 * requirements, hopefully soon. *FIXME*
  	 */
  	if (!PCI_DMA_BUS_IS_PHYS)
  		max_sg_entries >>= 1;
  #endif /* CONFIG_PCI */

  	blk_queue_max_segments(q, max_sg_entries);

  
  	/* assign drive queue */
  	drive->queue = q;
  
  	/* needs drive->queue to be set */
  	ide_toggle_bounce(drive, 1);

  	return 0;
  }

  static DEFINE_MUTEX(ide_cfg_mtx);

  /*

   * For any present drive:
   * - allocate the block device queue

   */

  static int ide_port_setup_devices(ide_hwif_t *hwif)

  {

  	ide_drive_t *drive;

  	int i, j = 0;

  	mutex_lock(&ide_cfg_mtx);

  	ide_port_for_each_present_dev(i, drive, hwif) {

  		if (ide_init_queue(drive)) {
  			printk(KERN_ERR "ide: failed to init %s
  ",
  					drive->name);

  			drive->dev_flags &= ~IDE_DFLAG_PRESENT;

  			continue;
  		}

  		j++;

  	}

  	mutex_unlock(&ide_cfg_mtx);

  
  	return j;

  }

  static void ide_host_enable_irqs(struct ide_host *host)
  {
  	ide_hwif_t *hwif;
  	int i;
  
  	ide_host_for_each_port(i, hwif, host) {
  		if (hwif == NULL)
  			continue;
  
  		/* clear any pending IRQs */
  		hwif->tp_ops->read_status(hwif);
  
  		/* unmask IRQs */
  		if (hwif->io_ports.ctl_addr)
  			hwif->tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);
  	}
  }

  /*

   * This routine sets up the IRQ for an IDE interface.

   */
  static int init_irq (ide_hwif_t *hwif)
  {

  	struct ide_io_ports *io_ports = &hwif->io_ports;

  	struct ide_host *host = hwif->host;
  	irq_handler_t irq_handler = host->irq_handler;
  	int sa = host->irq_flags;

  	if (irq_handler == NULL)
  		irq_handler = ide_intr;

  	if (request_irq(hwif->irq, irq_handler, sa, hwif->name, hwif))

  		goto out_up;

  #if !defined(__mc68000__)

  	printk(KERN_INFO "%s at 0x%03lx-0x%03lx,0x%03lx on irq %d", hwif->name,

  		io_ports->data_addr, io_ports->status_addr,
  		io_ports->ctl_addr, hwif->irq);

  #else

  	printk(KERN_INFO "%s at 0x%08lx on irq %d", hwif->name,

  		io_ports->data_addr, hwif->irq);

  #endif /* __mc68000__ */

  	if (hwif->host->host_flags & IDE_HFLAG_SERIALIZE)
  		printk(KERN_CONT " (serialized)");

  	printk(KERN_CONT "
  ");

  	return 0;

  out_up:

  	return 1;
  }
  
  static int ata_lock(dev_t dev, void *data)
  {
  	/* FIXME: we want to pin hwif down */
  	return 0;
  }
  
  static struct kobject *ata_probe(dev_t dev, int *part, void *data)
  {
  	ide_hwif_t *hwif = data;
  	int unit = *part >> PARTN_BITS;

  	ide_drive_t *drive = hwif->devices[unit];

  
  	if ((drive->dev_flags & IDE_DFLAG_PRESENT) == 0)

  		return NULL;
  
  	if (drive->media == ide_disk)
  		request_module("ide-disk");

  	if (drive->media == ide_cdrom || drive->media == ide_optical)
  		request_module("ide-cd");
  	if (drive->media == ide_tape)
  		request_module("ide-tape");
  	if (drive->media == ide_floppy)
  		request_module("ide-floppy");
  
  	return NULL;
  }
  
  static struct kobject *exact_match(dev_t dev, int *part, void *data)
  {
  	struct gendisk *p = data;
  	*part &= (1 << PARTN_BITS) - 1;

  	return &disk_to_dev(p)->kobj;

  }
  
  static int exact_lock(dev_t dev, void *data)
  {
  	struct gendisk *p = data;
  
  	if (!get_disk(p))
  		return -1;
  	return 0;
  }
  
  void ide_register_region(struct gendisk *disk)
  {
  	blk_register_region(MKDEV(disk->major, disk->first_minor),
  			    disk->minors, NULL, exact_match, exact_lock, disk);
  }
  
  EXPORT_SYMBOL_GPL(ide_register_region);
  
  void ide_unregister_region(struct gendisk *disk)
  {
  	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
  			      disk->minors);
  }
  
  EXPORT_SYMBOL_GPL(ide_unregister_region);
  
  void ide_init_disk(struct gendisk *disk, ide_drive_t *drive)
  {
  	ide_hwif_t *hwif = drive->hwif;

  	unsigned int unit = drive->dn & 1;

  
  	disk->major = hwif->major;
  	disk->first_minor = unit << PARTN_BITS;
  	sprintf(disk->disk_name, "hd%c", 'a' + hwif->index * MAX_DRIVES + unit);
  	disk->queue = drive->queue;
  }
  
  EXPORT_SYMBOL_GPL(ide_init_disk);
  
  static void drive_release_dev (struct device *dev)
  {
  	ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);

  	ide_proc_unregister_device(drive);

  	blk_cleanup_queue(drive->queue);
  	drive->queue = NULL;

  	drive->dev_flags &= ~IDE_DFLAG_PRESENT;

  	complete(&drive->gendev_rel_comp);

  }

  static int hwif_init(ide_hwif_t *hwif)
  {

  	if (!hwif->irq) {

  		printk(KERN_ERR "%s: disabled, no IRQ
  ", hwif->name);
  		return 0;

  	}

  	if (register_blkdev(hwif->major, hwif->name))
  		return 0;
  
  	if (!hwif->sg_max_nents)
  		hwif->sg_max_nents = PRD_ENTRIES;

  	hwif->sg_table = kmalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,

  				 GFP_KERNEL);
  	if (!hwif->sg_table) {
  		printk(KERN_ERR "%s: unable to allocate SG table.
  ", hwif->name);
  		goto out;
  	}

  
  	sg_init_table(hwif->sg_table, hwif->sg_max_nents);

  	if (init_irq(hwif)) {

  		printk(KERN_ERR "%s: disabled, unable to get IRQ %d
  ",
  			hwif->name, hwif->irq);

  		goto out;
  	}

  	blk_register_region(MKDEV(hwif->major, 0), MAX_DRIVES << PARTN_BITS,
  			    THIS_MODULE, ata_probe, ata_lock, hwif);

  	return 1;
  
  out:
  	unregister_blkdev(hwif->major, hwif->name);
  	return 0;
  }

  static void hwif_register_devices(ide_hwif_t *hwif)
  {

  	ide_drive_t *drive;

  	unsigned int i;

  	ide_port_for_each_present_dev(i, drive, hwif) {

  		struct device *dev = &drive->gendev;
  		int ret;

  		dev_set_name(dev, "%u.%u", hwif->index, i);

  		dev_set_drvdata(dev, drive);

  		dev->parent = &hwif->gendev;
  		dev->bus = &ide_bus_type;

  		dev->release = drive_release_dev;
  
  		ret = device_register(dev);
  		if (ret < 0)
  			printk(KERN_WARNING "IDE: %s: device_register error: "
  					    "%d
  ", __func__, ret);

  	}
  }

  static void ide_port_init_devices(ide_hwif_t *hwif)
  {

  	const struct ide_port_ops *port_ops = hwif->port_ops;

  	ide_drive_t *drive;

  	int i;

  	ide_port_for_each_dev(i, drive, hwif) {

  		drive->dn = i + hwif->channel * 2;

  		if (hwif->host_flags & IDE_HFLAG_IO_32BIT)
  			drive->io_32bit = 1;

  		if (hwif->host_flags & IDE_HFLAG_NO_IO_32BIT)
  			drive->dev_flags |= IDE_DFLAG_NO_IO_32BIT;

  		if (hwif->host_flags & IDE_HFLAG_UNMASK_IRQS)

  			drive->dev_flags |= IDE_DFLAG_UNMASK;

  		if (hwif->host_flags & IDE_HFLAG_NO_UNMASK_IRQS)

  			drive->dev_flags |= IDE_DFLAG_NO_UNMASK;

  		drive->pio_mode = XFER_PIO_0;

  		if (port_ops && port_ops->init_dev)
  			port_ops->init_dev(drive);
  	}

  }

  static void ide_init_port(ide_hwif_t *hwif, unsigned int port,
  			  const struct ide_port_info *d)

  {

  	hwif->channel = port;

  	hwif->chipset = d->chipset ? d->chipset : ide_pci;

  
  	if (d->init_iops)
  		d->init_iops(hwif);

  	/* ->host_flags may be set by ->init_iops (or even earlier...) */
  	hwif->host_flags |= d->host_flags;

  	hwif->pio_mask = d->pio_mask;

  	if (d->tp_ops)
  		hwif->tp_ops = d->tp_ops;

  	/* ->set_pio_mode for DTC2278 is currently limited to port 0 */

  	if ((hwif->host_flags & IDE_HFLAG_DTC2278) == 0 || hwif->channel == 0)

  		hwif->port_ops = d->port_ops;

  	hwif->swdma_mask = d->swdma_mask;
  	hwif->mwdma_mask = d->mwdma_mask;
  	hwif->ultra_mask = d->udma_mask;

  	if ((d->host_flags & IDE_HFLAG_NO_DMA) == 0) {
  		int rc;

  		hwif->dma_ops = d->dma_ops;

  		if (d->init_dma)
  			rc = d->init_dma(hwif, d);
  		else
  			rc = ide_hwif_setup_dma(hwif, d);
  
  		if (rc < 0) {
  			printk(KERN_INFO "%s: DMA disabled
  ", hwif->name);

  
  			hwif->dma_ops = NULL;

  			hwif->dma_base = 0;

  			hwif->swdma_mask = 0;
  			hwif->mwdma_mask = 0;
  			hwif->ultra_mask = 0;

  		}

  	}

  	if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||

  	    ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base))
  		hwif->host->host_flags |= IDE_HFLAG_SERIALIZE;

  	if (d->max_sectors)
  		hwif->rqsize = d->max_sectors;

  	else {
  		if ((hwif->host_flags & IDE_HFLAG_NO_LBA48) ||
  		    (hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA))
  			hwif->rqsize = 256;
  		else
  			hwif->rqsize = 65536;
  	}

  
  	/* call chipset specific routine for each enabled port */
  	if (d->init_hwif)
  		d->init_hwif(hwif);

  }

  static void ide_port_cable_detect(ide_hwif_t *hwif)
  {

  	const struct ide_port_ops *port_ops = hwif->port_ops;
  
  	if (port_ops && port_ops->cable_detect && (hwif->ultra_mask & 0x78)) {

  		if (hwif->cbl != ATA_CBL_PATA40_SHORT)

  			hwif->cbl = port_ops->cable_detect(hwif);

  	}

  }

  static const u8 ide_hwif_to_major[] =
  	{ IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR, IDE4_MAJOR,
  	  IDE5_MAJOR, IDE6_MAJOR, IDE7_MAJOR, IDE8_MAJOR, IDE9_MAJOR };
  
  static void ide_port_init_devices_data(ide_hwif_t *hwif)
  {

  	ide_drive_t *drive;
  	int i;

  	ide_port_for_each_dev(i, drive, hwif) {
  		u8 j = (hwif->index * MAX_DRIVES) + i;

  		u16 *saved_id = drive->id;

  
  		memset(drive, 0, sizeof(*drive));

  		memset(saved_id, 0, SECTOR_SIZE);
  		drive->id = saved_id;

  
  		drive->media			= ide_disk;

  		drive->select			= (i << 4) | ATA_DEVICE_OBS;

  		drive->hwif			= hwif;
  		drive->ready_stat		= ATA_DRDY;
  		drive->bad_wstat		= BAD_W_STAT;

  		drive->special_flags		= IDE_SFLAG_RECALIBRATE |
  						  IDE_SFLAG_SET_GEOMETRY;

  		drive->name[0]			= 'h';
  		drive->name[1]			= 'd';
  		drive->name[2]			= 'a' + j;
  		drive->max_failures		= IDE_DEFAULT_MAX_FAILURES;
  
  		INIT_LIST_HEAD(&drive->list);
  		init_completion(&drive->gendev_rel_comp);
  	}
  }
  
  static void ide_init_port_data(ide_hwif_t *hwif, unsigned int index)
  {

  	/* fill in any non-zero initial values */
  	hwif->index	= index;
  	hwif->major	= ide_hwif_to_major[index];
  
  	hwif->name[0]	= 'i';
  	hwif->name[1]	= 'd';
  	hwif->name[2]	= 'e';
  	hwif->name[3]	= '0' + index;

  	spin_lock_init(&hwif->lock);
  
  	init_timer(&hwif->timer);
  	hwif->timer.function = &ide_timer_expiry;
  	hwif->timer.data = (unsigned long)hwif;

  	init_completion(&hwif->gendev_rel_comp);
  
  	hwif->tp_ops = &default_tp_ops;
  
  	ide_port_init_devices_data(hwif);
  }

  static void ide_init_port_hw(ide_hwif_t *hwif, struct ide_hw *hw)

  {
  	memcpy(&hwif->io_ports, &hw->io_ports, sizeof(hwif->io_ports));
  	hwif->irq = hw->irq;

  	hwif->dev = hw->dev;
  	hwif->gendev.parent = hw->parent ? hw->parent : hw->dev;

  	hwif->config_data = hw->config;
  }

  static unsigned int ide_indexes;

  /**

   *	ide_find_port_slot	-	find free port slot

   *	@d: IDE port info
   *

   *	Return the new port slot index or -ENOENT if we are out of free slots.

   */

  static int ide_find_port_slot(const struct ide_port_info *d)

  {

  	int idx = -ENOENT;

  	u8 bootable = (d && (d->host_flags & IDE_HFLAG_NON_BOOTABLE)) ? 0 : 1;

  	u8 i = (d && (d->host_flags & IDE_HFLAG_QD_2ND_PORT)) ? 1 : 0;

  
  	/*
  	 * Claim an unassigned slot.
  	 *
  	 * Give preference to claiming other slots before claiming ide0/ide1,
  	 * just in case there's another interface yet-to-be-scanned
  	 * which uses ports 0x1f0/0x170 (the ide0/ide1 defaults).
  	 *
  	 * Unless there is a bootable card that does not use the standard
  	 * ports 0x1f0/0x170 (the ide0/ide1 defaults).
  	 */

  	mutex_lock(&ide_cfg_mtx);

  	if (bootable) {
  		if ((ide_indexes | i) != (1 << MAX_HWIFS) - 1)
  			idx = ffz(ide_indexes | i);

  	} else {

  		if ((ide_indexes | 3) != (1 << MAX_HWIFS) - 1)
  			idx = ffz(ide_indexes | 3);
  		else if ((ide_indexes & 3) != 3)
  			idx = ffz(ide_indexes);

  	}

  	if (idx >= 0)
  		ide_indexes |= (1 << idx);
  	mutex_unlock(&ide_cfg_mtx);

  	return idx;
  }

  static void ide_free_port_slot(int idx)
  {
  	mutex_lock(&ide_cfg_mtx);
  	ide_indexes &= ~(1 << idx);
  	mutex_unlock(&ide_cfg_mtx);

  }

  static void ide_port_free_devices(ide_hwif_t *hwif)
  {

  	ide_drive_t *drive;

  	int i;

  	ide_port_for_each_dev(i, drive, hwif) {
  		kfree(drive->id);

  		kfree(drive);

  	}

  }
  
  static int ide_port_alloc_devices(ide_hwif_t *hwif, int node)
  {
  	int i;
  
  	for (i = 0; i < MAX_DRIVES; i++) {
  		ide_drive_t *drive;
  
  		drive = kzalloc_node(sizeof(*drive), GFP_KERNEL, node);
  		if (drive == NULL)
  			goto out_nomem;

  		/*
  		 * In order to keep things simple we have an id
  		 * block for all drives at all times. If the device
  		 * is pre ATA or refuses ATA/ATAPI identify we
  		 * will add faked data to this.
  		 *
  		 * Also note that 0 everywhere means "can't do X"
  		 */
  		drive->id = kzalloc_node(SECTOR_SIZE, GFP_KERNEL, node);
  		if (drive->id == NULL)
  			goto out_nomem;

  		hwif->devices[i] = drive;
  	}
  	return 0;
  
  out_nomem:
  	ide_port_free_devices(hwif);
  	return -ENOMEM;
  }

  struct ide_host *ide_host_alloc(const struct ide_port_info *d,
  				struct ide_hw **hws, unsigned int n_ports)

  {
  	struct ide_host *host;

  	struct device *dev = hws[0] ? hws[0]->dev : NULL;
  	int node = dev ? dev_to_node(dev) : -1;

  	int i;

  	host = kzalloc_node(sizeof(*host), GFP_KERNEL, node);

  	if (host == NULL)
  		return NULL;

  	for (i = 0; i < n_ports; i++) {

  		ide_hwif_t *hwif;

  		int idx;

  
  		if (hws[i] == NULL)
  			continue;

  		hwif = kzalloc_node(sizeof(*hwif), GFP_KERNEL, node);

  		if (hwif == NULL)
  			continue;

  		if (ide_port_alloc_devices(hwif, node) < 0) {
  			kfree(hwif);
  			continue;
  		}

  		idx = ide_find_port_slot(d);
  		if (idx < 0) {
  			printk(KERN_ERR "%s: no free slot for interface
  ",
  					d ? d->name : "ide");

  			ide_port_free_devices(hwif);

  			kfree(hwif);

  			continue;

  		}

  		ide_init_port_data(hwif, idx);

  		hwif->host = host;

  		host->ports[i] = hwif;
  		host->n_ports++;

  	}
  
  	if (host->n_ports == 0) {
  		kfree(host);
  		return NULL;
  	}

  	host->dev[0] = dev;

  	if (d) {
  		host->init_chipset = d->init_chipset;

  		host->get_lock     = d->get_lock;
  		host->release_lock = d->release_lock;

  		host->host_flags = d->host_flags;

  		host->irq_flags = d->irq_flags;

  	}

  	return host;
  }

  EXPORT_SYMBOL_GPL(ide_host_alloc);

  static void ide_port_free(ide_hwif_t *hwif)
  {
  	ide_port_free_devices(hwif);
  	ide_free_port_slot(hwif->index);
  	kfree(hwif);
  }
  
  static void ide_disable_port(ide_hwif_t *hwif)
  {
  	struct ide_host *host = hwif->host;
  	int i;
  
  	printk(KERN_INFO "%s: disabling port
  ", hwif->name);
  
  	for (i = 0; i < MAX_HOST_PORTS; i++) {
  		if (host->ports[i] == hwif) {
  			host->ports[i] = NULL;
  			host->n_ports--;
  		}
  	}
  
  	ide_port_free(hwif);
  }

  int ide_host_register(struct ide_host *host, const struct ide_port_info *d,

  		      struct ide_hw **hws)

  {
  	ide_hwif_t *hwif, *mate = NULL;

  	int i, j = 0;

  	ide_host_for_each_port(i, hwif, host) {

  		if (hwif == NULL) {

  			mate = NULL;
  			continue;
  		}

  		ide_init_port_hw(hwif, hws[i]);

  		ide_port_apply_params(hwif);

  		if ((i & 1) && mate) {
  			hwif->mate = mate;
  			mate->mate = hwif;

  		}

  		mate = (i & 1) ? NULL : hwif;
  
  		ide_init_port(hwif, i & 1, d);
  		ide_port_cable_detect(hwif);

  
  		hwif->port_flags |= IDE_PFLAG_PROBING;

  		ide_port_init_devices(hwif);

  	}

  	ide_host_for_each_port(i, hwif, host) {

  		if (hwif == NULL)
  			continue;

  		if (ide_probe_port(hwif) == 0)
  			hwif->present = 1;

  		hwif->port_flags &= ~IDE_PFLAG_PROBING;

  		if ((hwif->host_flags & IDE_HFLAG_4DRIVES) == 0 ||
  		    hwif->mate == NULL || hwif->mate->present == 0) {

  			if (ide_register_port(hwif)) {
  				ide_disable_port(hwif);
  				continue;
  			}
  		}

  		if (hwif->present)
  			ide_port_tune_devices(hwif);

  	}

  	ide_host_enable_irqs(host);

  	ide_host_for_each_port(i, hwif, host) {

  		if (hwif == NULL)
  			continue;

  
  		if (hwif_init(hwif) == 0) {
  			printk(KERN_INFO "%s: failed to initialize IDE "
  					 "interface
  ", hwif->name);

  			device_unregister(&hwif->gendev);
  			ide_disable_port(hwif);

  			continue;
  		}

  		if (hwif->present)

  			if (ide_port_setup_devices(hwif) == 0) {
  				hwif->present = 0;
  				continue;
  			}
  
  		j++;

  		ide_acpi_init_port(hwif);

  
  		if (hwif->present)
  			ide_acpi_port_init_devices(hwif);

  	}

  	ide_host_for_each_port(i, hwif, host) {

  		if (hwif == NULL)
  			continue;

  		ide_sysfs_register_port(hwif);
  		ide_proc_register_port(hwif);

  		if (hwif->present) {

  			ide_proc_port_register_devices(hwif);

  			hwif_register_devices(hwif);
  		}

  	}

  	return j ? 0 : -1;

  }

  EXPORT_SYMBOL_GPL(ide_host_register);

  int ide_host_add(const struct ide_port_info *d, struct ide_hw **hws,

  		 unsigned int n_ports, struct ide_host **hostp)

  {
  	struct ide_host *host;

  	int rc;

  	host = ide_host_alloc(d, hws, n_ports);

  	if (host == NULL)
  		return -ENOMEM;

  	rc = ide_host_register(host, d, hws);
  	if (rc) {
  		ide_host_free(host);
  		return rc;
  	}

  
  	if (hostp)
  		*hostp = host;
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ide_host_add);

  static void __ide_port_unregister_devices(ide_hwif_t *hwif)
  {

  	ide_drive_t *drive;

  	int i;

  	ide_port_for_each_present_dev(i, drive, hwif) {
  		device_unregister(&drive->gendev);
  		wait_for_completion(&drive->gendev_rel_comp);

  	}
  }
  
  void ide_port_unregister_devices(ide_hwif_t *hwif)
  {
  	mutex_lock(&ide_cfg_mtx);
  	__ide_port_unregister_devices(hwif);
  	hwif->present = 0;
  	ide_port_init_devices_data(hwif);
  	mutex_unlock(&ide_cfg_mtx);
  }
  EXPORT_SYMBOL_GPL(ide_port_unregister_devices);
  
  /**
   *	ide_unregister		-	free an IDE interface
   *	@hwif: IDE interface
   *
   *	Perform the final unregister of an IDE interface.
   *
   *	Locking:
   *	The caller must not hold the IDE locks.
   *
   *	It is up to the caller to be sure there is no pending I/O here,
   *	and that the interface will not be reopened (present/vanishing
   *	locking isn't yet done BTW).
   */
  
  static void ide_unregister(ide_hwif_t *hwif)
  {
  	BUG_ON(in_interrupt());
  	BUG_ON(irqs_disabled());
  
  	mutex_lock(&ide_cfg_mtx);
  
  	if (hwif->present) {
  		__ide_port_unregister_devices(hwif);
  		hwif->present = 0;
  	}
  
  	ide_proc_unregister_port(hwif);
  
  	free_irq(hwif->irq, hwif);
  
  	device_unregister(hwif->portdev);
  	device_unregister(&hwif->gendev);
  	wait_for_completion(&hwif->gendev_rel_comp);
  
  	/*
  	 * Remove us from the kernel's knowledge
  	 */
  	blk_unregister_region(MKDEV(hwif->major, 0), MAX_DRIVES<<PARTN_BITS);
  	kfree(hwif->sg_table);
  	unregister_blkdev(hwif->major, hwif->name);
  
  	ide_release_dma_engine(hwif);
  
  	mutex_unlock(&ide_cfg_mtx);
  }

  void ide_host_free(struct ide_host *host)

  {

  	ide_hwif_t *hwif;

  	int i;

  	ide_host_for_each_port(i, hwif, host) {

  		if (hwif)
  			ide_port_free(hwif);

  	}

  	kfree(host);

  }

  EXPORT_SYMBOL_GPL(ide_host_free);
  
  void ide_host_remove(struct ide_host *host)
  {

  	ide_hwif_t *hwif;

  	int i;

  	ide_host_for_each_port(i, hwif, host) {
  		if (hwif)
  			ide_unregister(hwif);

  	}
  
  	ide_host_free(host);
  }

  EXPORT_SYMBOL_GPL(ide_host_remove);

  
  void ide_port_scan(ide_hwif_t *hwif)
  {

  	int rc;

  	ide_port_apply_params(hwif);

  	ide_port_cable_detect(hwif);

  
  	hwif->port_flags |= IDE_PFLAG_PROBING;

  	ide_port_init_devices(hwif);

  	rc = ide_probe_port(hwif);
  
  	hwif->port_flags &= ~IDE_PFLAG_PROBING;
  
  	if (rc < 0)

  		return;
  
  	hwif->present = 1;
  
  	ide_port_tune_devices(hwif);

  	ide_port_setup_devices(hwif);

  	ide_acpi_port_init_devices(hwif);

  	hwif_register_devices(hwif);
  	ide_proc_port_register_devices(hwif);
  }
  EXPORT_SYMBOL_GPL(ide_port_scan);