WSL2-Linux-Kernel/drivers/ide/ide-probe.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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 <linux/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\n", 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;
		fallthrough;
	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\n");
	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\n", 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_SENSE)
			/* ancient Seagate drives, broken interfaces */
			printk(KERN_INFO "%s: probing with STATUS(0x%02x) "
					 "instead of ALTSTATUS(0x%02x)\n",
					 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\n", 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\n",
		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\n", 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)\n",
					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\n",
					drive->name, drive->cyl,
					drive->head, drive->sect);
			} else if (drive->media == ide_cdrom) {
				printk(KERN_INFO "%s: ATAPI cdrom (?)\n", drive->name);
			} else {
				/* nuke it */
				printk(KERN_WARNING "%s: Unknown device on bus refused identification. Ignoring.\n", 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, "%s", 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\n",
			__func__, ret);
		goto out;
	}

	hwif->portdev = device_create(ide_port_class, &hwif->gendev,
				      MKDEV(0, 0), hwif, "%s", 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...\n", 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\n",
					  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\n");

	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 !\n", 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);
	}
}

static void ide_initialize_rq(struct request *rq)
{
	struct ide_request *req = blk_mq_rq_to_pdu(rq);

	req->special = NULL;
	scsi_req_init(&req->sreq);
	req->sreq.sense = req->sense;
}

static const struct blk_mq_ops ide_mq_ops = {
	.queue_rq		= ide_queue_rq,
	.initialize_rq_fn	= ide_initialize_rq,
};

/*
 * 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;
	struct blk_mq_tag_set *set;

	/*
	 *	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.
	 */

	set = &drive->tag_set;
	set->ops = &ide_mq_ops;
	set->nr_hw_queues = 1;
	set->queue_depth = 32;
	set->reserved_tags = 1;
	set->cmd_size = sizeof(struct ide_request);
	set->numa_node = hwif_to_node(hwif);
	set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
	if (blk_mq_alloc_tag_set(set))
		return 1;

	q = blk_mq_init_queue(set);
	if (IS_ERR(q)) {
		blk_mq_free_tag_set(set);
		return 1;
	}

	blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q);

	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*
	 */
	max_sg_entries >>= 1;
#endif /* CONFIG_PCI */

	blk_queue_max_segments(q, max_sg_entries);

	/* assign drive queue */
	drive->queue = q;

	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\n",
					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 (!host->get_lock)
		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 "\n");

	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_and_module(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);

	if (drive->sense_rq)
		blk_mq_free_request(drive->sense_rq);

	blk_cleanup_queue(drive->queue);
	drive->queue = NULL;
	blk_mq_free_tag_set(&drive->tag_set);

	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\n", 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_array(hwif->sg_max_nents,
				       sizeof(struct scatterlist),
				       GFP_KERNEL);
	if (!hwif->sg_table) {
		printk(KERN_ERR "%s: unable to allocate SG table.\n", 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\n",
			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\n", __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\n", 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);
	}
}

/*
 * Deferred request list insertion handler
 */
static void drive_rq_insert_work(struct work_struct *work)
{
	ide_drive_t *drive = container_of(work, ide_drive_t, rq_work);
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq;
	blk_status_t ret;
	LIST_HEAD(list);

	blk_mq_quiesce_queue(drive->queue);

	ret = BLK_STS_OK;
	spin_lock_irq(&hwif->lock);
	while (!list_empty(&drive->rq_list)) {
		rq = list_first_entry(&drive->rq_list, struct request, queuelist);
		list_del_init(&rq->queuelist);

		spin_unlock_irq(&hwif->lock);
		ret = ide_issue_rq(drive, rq, true);
		spin_lock_irq(&hwif->lock);
	}
	spin_unlock_irq(&hwif->lock);

	blk_mq_unquiesce_queue(drive->queue);

	if (ret != BLK_STS_OK)
		kblockd_schedule_work(&drive->rq_work);
}

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);

		INIT_WORK(&drive->rq_work, drive_rq_insert_work);
		INIT_LIST_HEAD(&drive->rq_list);
	}
}

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);

	timer_setup(&hwif->timer, ide_timer_expiry, 0);

	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)
{
	ide_drive_t *drive;
	int i;

	for (i = 0; i < MAX_DRIVES; i++) {
		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_free_drive;

		hwif->devices[i] = drive;
	}
	return 0;

out_free_drive:
	kfree(drive);
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\n",
					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\n", 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;

	pr_warn("legacy IDE will be removed in 2021, please switch to libata\n"
		"Report any missing HW support to linux-ide@vger.kernel.org\n");

	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\n", hwif->name);
			device_unregister(hwif->portdev);
			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);

	if (!hwif->host->get_lock)
		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);