drivers/block/hd.c - kernel/msm-4.9 - Gitiles

 /*
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  * This is the low-level hd interrupt support. It traverses the
  * request-list, using interrupts to jump between functions. As
  * all the functions are called within interrupts, we may not
  * sleep. Special care is recommended.
  *
  *  modified by Drew Eckhardt to check nr of hd's from the CMOS.
  *
  *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
  *  in the early extended-partition checks and added DM partitions
  *
  *  IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
  *  and general streamlining by Mark Lord.
  *
  *  Removed 99% of above. Use Mark's ide driver for those options.
  *  This is now a lightweight ST-506 driver. (Paul Gortmaker)
  *
  *  Modified 1995 Russell King for ARM processor.
  *
  *  Bugfix: max_sectors must be <= 255 or the wheels tend to come
  *  off in a hurry once you queue things up - Paul G. 02/2001
  */

 /* Uncomment the following if you want verbose error reports. */
 /* #define VERBOSE_ERRORS */

 #include <linux/blkdev.h>
 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/interrupt.h>
 #include <linux/timer.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
 #include <linux/genhd.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/blkpg.h>
 #include <linux/ata.h>
 #include <linux/hdreg.h>

 #define HD_IRQ 14

 #define REALLY_SLOW_IO
 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>

 #ifdef __arm__
 #undef  HD_IRQ
 #endif
 #include <asm/irq.h>
 #ifdef __arm__
 #define HD_IRQ IRQ_HARDDISK
 #endif

 /* Hd controller regster ports */

 #define HD_DATA		0x1f0		/* _CTL when writing */
 #define HD_ERROR	0x1f1		/* see err-bits */
 #define HD_NSECTOR	0x1f2		/* nr of sectors to read/write */
 #define HD_SECTOR	0x1f3		/* starting sector */
 #define HD_LCYL		0x1f4		/* starting cylinder */
 #define HD_HCYL		0x1f5		/* high byte of starting cyl */
 #define HD_CURRENT	0x1f6		/* 101dhhhh , d=drive, hhhh=head */
 #define HD_STATUS	0x1f7		/* see status-bits */
 #define HD_FEATURE	HD_ERROR	/* same io address, read=error, write=feature */
 #define HD_PRECOMP	HD_FEATURE	/* obsolete use of this port - predates IDE */
 #define HD_COMMAND	HD_STATUS	/* same io address, read=status, write=cmd */

 #define HD_CMD		0x3f6		/* used for resets */
 #define HD_ALTSTATUS	0x3f6		/* same as HD_STATUS but doesn't clear irq */

 /* Bits of HD_STATUS */
 #define ERR_STAT		0x01
 #define INDEX_STAT		0x02
 #define ECC_STAT		0x04	/* Corrected error */
 #define DRQ_STAT		0x08
 #define SEEK_STAT		0x10
 #define SERVICE_STAT		SEEK_STAT
 #define WRERR_STAT		0x20
 #define READY_STAT		0x40
 #define BUSY_STAT		0x80

 /* Bits for HD_ERROR */
 #define MARK_ERR		0x01	/* Bad address mark */
 #define TRK0_ERR		0x02	/* couldn't find track 0 */
 #define ABRT_ERR		0x04	/* Command aborted */
 #define MCR_ERR			0x08	/* media change request */
 #define ID_ERR			0x10	/* ID field not found */
 #define MC_ERR			0x20	/* media changed */
 #define ECC_ERR			0x40	/* Uncorrectable ECC error */
 #define BBD_ERR			0x80	/* pre-EIDE meaning:  block marked bad */
 #define ICRC_ERR		0x80	/* new meaning:  CRC error during transfer */

 static DEFINE_SPINLOCK(hd_lock);
 static struct request_queue *hd_queue;

 #define MAJOR_NR HD_MAJOR
 #define QUEUE (hd_queue)
 #define CURRENT elv_next_request(hd_queue)

 #define TIMEOUT_VALUE	(6*HZ)
 #define	HD_DELAY	0

 #define MAX_ERRORS     16	/* Max read/write errors/sector */
 #define RESET_FREQ      8	/* Reset controller every 8th retry */
 #define RECAL_FREQ      4	/* Recalibrate every 4th retry */
 #define MAX_HD		2

 #define STAT_OK		(READY_STAT|SEEK_STAT)
 #define OK_STATUS(s)	(((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)

 static void recal_intr(void);
 static void bad_rw_intr(void);

 static int reset;
 static int hd_error;

 /*
  *  This struct defines the HD's and their types.
  */
 struct hd_i_struct {
 	unsigned int head, sect, cyl, wpcom, lzone, ctl;
 	int unit;
 	int recalibrate;
 	int special_op;
 };

 #ifdef HD_TYPE
 static struct hd_i_struct hd_info[] = { HD_TYPE };
 static int NR_HD = ARRAY_SIZE(hd_info);
 #else
 static struct hd_i_struct hd_info[MAX_HD];
 static int NR_HD;
 #endif

 static struct gendisk *hd_gendisk[MAX_HD];

 static struct timer_list device_timer;

 #define TIMEOUT_VALUE (6*HZ)

 #define SET_TIMER							\
 	do {								\
 		mod_timer(&device_timer, jiffies + TIMEOUT_VALUE);	\
 	} while (0)

 static void (*do_hd)(void) = NULL;
 #define SET_HANDLER(x) \
 if ((do_hd = (x)) != NULL) \
 	SET_TIMER; \
 else \
 	del_timer(&device_timer);


 #if (HD_DELAY > 0)

 #include <asm/i8253.h>

 unsigned long last_req;

 unsigned long read_timer(void)
 {
 	unsigned long t, flags;
 	int i;

 	spin_lock_irqsave(&i8253_lock, flags);
 	t = jiffies * 11932;
 	outb_p(0, 0x43);
 	i = inb_p(0x40);
 	i |= inb(0x40) << 8;
 	spin_unlock_irqrestore(&i8253_lock, flags);
 	return(t - i);
 }
 #endif

 static void __init hd_setup(char *str, int *ints)
 {
 	int hdind = 0;

 	if (ints[0] != 3)
 		return;
 	if (hd_info[0].head != 0)
 		hdind = 1;
 	hd_info[hdind].head = ints[2];
 	hd_info[hdind].sect = ints[3];
 	hd_info[hdind].cyl = ints[1];
 	hd_info[hdind].wpcom = 0;
 	hd_info[hdind].lzone = ints[1];
 	hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
 	NR_HD = hdind+1;
 }

 static void dump_status(const char *msg, unsigned int stat)
 {
 	char *name = "hd?";
 	if (CURRENT)
 		name = CURRENT->rq_disk->disk_name;

 #ifdef VERBOSE_ERRORS
 	printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
 	if (stat & BUSY_STAT)	printk("Busy ");
 	if (stat & READY_STAT)	printk("DriveReady ");
 	if (stat & WRERR_STAT)	printk("WriteFault ");
 	if (stat & SEEK_STAT)	printk("SeekComplete ");
 	if (stat & DRQ_STAT)	printk("DataRequest ");
 	if (stat & ECC_STAT)	printk("CorrectedError ");
 	if (stat & INDEX_STAT)	printk("Index ");
 	if (stat & ERR_STAT)	printk("Error ");
 	printk("}\n");
 	if ((stat & ERR_STAT) == 0) {
 		hd_error = 0;
 	} else {
 		hd_error = inb(HD_ERROR);
 		printk("%s: %s: error=0x%02x { ", name, msg, hd_error & 0xff);
 		if (hd_error & BBD_ERR)		printk("BadSector ");
 		if (hd_error & ECC_ERR)		printk("UncorrectableError ");
 		if (hd_error & ID_ERR)		printk("SectorIdNotFound ");
 		if (hd_error & ABRT_ERR)	printk("DriveStatusError ");
 		if (hd_error & TRK0_ERR)	printk("TrackZeroNotFound ");
 		if (hd_error & MARK_ERR)	printk("AddrMarkNotFound ");
 		printk("}");
 		if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
 			printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
 				inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
 			if (CURRENT)
 				printk(", sector=%ld", CURRENT->sector);
 		}
 		printk("\n");
 	}
 #else
 	printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
 	if ((stat & ERR_STAT) == 0) {
 		hd_error = 0;
 	} else {
 		hd_error = inb(HD_ERROR);
 		printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
 	}
 #endif
 }

 static void check_status(void)
 {
 	int i = inb_p(HD_STATUS);

 	if (!OK_STATUS(i)) {
 		dump_status("check_status", i);
 		bad_rw_intr();
 	}
 }

 static int controller_busy(void)
 {
 	int retries = 100000;
 	unsigned char status;

 	do {
 		status = inb_p(HD_STATUS);
 	} while ((status & BUSY_STAT) && --retries);
 	return status;
 }

 static int status_ok(void)
 {
 	unsigned char status = inb_p(HD_STATUS);

 	if (status & BUSY_STAT)
 		return 1;	/* Ancient, but does it make sense??? */
 	if (status & WRERR_STAT)
 		return 0;
 	if (!(status & READY_STAT))
 		return 0;
 	if (!(status & SEEK_STAT))
 		return 0;
 	return 1;
 }

 static int controller_ready(unsigned int drive, unsigned int head)
 {
 	int retry = 100;

 	do {
 		if (controller_busy() & BUSY_STAT)
 			return 0;
 		outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
 		if (status_ok())
 			return 1;
 	} while (--retry);
 	return 0;
 }

 static void hd_out(struct hd_i_struct *disk,
 		   unsigned int nsect,
 		   unsigned int sect,
 		   unsigned int head,
 		   unsigned int cyl,
 		   unsigned int cmd,
 		   void (*intr_addr)(void))
 {
 	unsigned short port;

 #if (HD_DELAY > 0)
 	while (read_timer() - last_req < HD_DELAY)
 		/* nothing */;
 #endif
 	if (reset)
 		return;
 	if (!controller_ready(disk->unit, head)) {
 		reset = 1;
 		return;
 	}
 	SET_HANDLER(intr_addr);
 	outb_p(disk->ctl, HD_CMD);
 	port = HD_DATA;
 	outb_p(disk->wpcom >> 2, ++port);
 	outb_p(nsect, ++port);
 	outb_p(sect, ++port);
 	outb_p(cyl, ++port);
 	outb_p(cyl >> 8, ++port);
 	outb_p(0xA0 | (disk->unit << 4) | head, ++port);
 	outb_p(cmd, ++port);
 }

 static void hd_request (void);

 static int drive_busy(void)
 {
 	unsigned int i;
 	unsigned char c;

 	for (i = 0; i < 500000 ; i++) {
 		c = inb_p(HD_STATUS);
 		if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
 			return 0;
 	}
 	dump_status("reset timed out", c);
 	return 1;
 }

 static void reset_controller(void)
 {
 	int	i;

 	outb_p(4, HD_CMD);
 	for (i = 0; i < 1000; i++) barrier();
 	outb_p(hd_info[0].ctl & 0x0f, HD_CMD);
 	for (i = 0; i < 1000; i++) barrier();
 	if (drive_busy())
 		printk("hd: controller still busy\n");
 	else if ((hd_error = inb(HD_ERROR)) != 1)
 		printk("hd: controller reset failed: %02x\n", hd_error);
 }

 static void reset_hd(void)
 {
 	static int i;

 repeat:
 	if (reset) {
 		reset = 0;
 		i = -1;
 		reset_controller();
 	} else {
 		check_status();
 		if (reset)
 			goto repeat;
 	}
 	if (++i < NR_HD) {
 		struct hd_i_struct *disk = &hd_info[i];
 		disk->special_op = disk->recalibrate = 1;
 		hd_out(disk, disk->sect, disk->sect, disk->head-1,
 			disk->cyl, ATA_CMD_INIT_DEV_PARAMS, &reset_hd);
 		if (reset)
 			goto repeat;
 	} else
 		hd_request();
 }

 /*
  * Ok, don't know what to do with the unexpected interrupts: on some machines
  * doing a reset and a retry seems to result in an eternal loop. Right now I
  * ignore it, and just set the timeout.
  *
  * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
  * drive enters "idle", "standby", or "sleep" mode, so if the status looks
  * "good", we just ignore the interrupt completely.
  */
 static void unexpected_hd_interrupt(void)
 {
 	unsigned int stat = inb_p(HD_STATUS);

 	if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
 		dump_status("unexpected interrupt", stat);
 		SET_TIMER;
 	}
 }

 /*
  * bad_rw_intr() now tries to be a bit smarter and does things
  * according to the error returned by the controller.
  * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
  */
 static void bad_rw_intr(void)
 {
 	struct request *req = CURRENT;
 	if (req != NULL) {
 		struct hd_i_struct *disk = req->rq_disk->private_data;
 		if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
 			end_request(req, 0);
 			disk->special_op = disk->recalibrate = 1;
 		} else if (req->errors % RESET_FREQ == 0)
 			reset = 1;
 		else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0)
 			disk->special_op = disk->recalibrate = 1;
 		/* Otherwise just retry */
 	}
 }

 static inline int wait_DRQ(void)
 {
 	int retries;
 	int stat;

 	for (retries = 0; retries < 100000; retries++) {
 		stat = inb_p(HD_STATUS);
 		if (stat & DRQ_STAT)
 			return 0;
 	}
 	dump_status("wait_DRQ", stat);
 	return -1;
 }

 static void read_intr(void)
 {
 	struct request *req;
 	int i, retries = 100000;

 	do {
 		i = (unsigned) inb_p(HD_STATUS);
 		if (i & BUSY_STAT)
 			continue;
 		if (!OK_STATUS(i))
 			break;
 		if (i & DRQ_STAT)
 			goto ok_to_read;
 	} while (--retries > 0);
 	dump_status("read_intr", i);
 	bad_rw_intr();
 	hd_request();
 	return;
 ok_to_read:
 	req = CURRENT;
 	insw(HD_DATA, req->buffer, 256);
 	req->sector++;
 	req->buffer += 512;
 	req->errors = 0;
 	i = --req->nr_sectors;
 	--req->current_nr_sectors;
 #ifdef DEBUG
 	printk("%s: read: sector %ld, remaining = %ld, buffer=%p\n",
 		req->rq_disk->disk_name, req->sector, req->nr_sectors,
 		req->buffer+512);
 #endif
 	if (req->current_nr_sectors <= 0)
 		end_request(req, 1);
 	if (i > 0) {
 		SET_HANDLER(&read_intr);
 		return;
 	}
 	(void) inb_p(HD_STATUS);
 #if (HD_DELAY > 0)
 	last_req = read_timer();
 #endif
 	if (elv_next_request(QUEUE))
 		hd_request();
 	return;
 }

 static void write_intr(void)
 {
 	struct request *req = CURRENT;
 	int i;
 	int retries = 100000;

 	do {
 		i = (unsigned) inb_p(HD_STATUS);
 		if (i & BUSY_STAT)
 			continue;
 		if (!OK_STATUS(i))
 			break;
 		if ((req->nr_sectors <= 1) || (i & DRQ_STAT))
 			goto ok_to_write;
 	} while (--retries > 0);
 	dump_status("write_intr", i);
 	bad_rw_intr();
 	hd_request();
 	return;
 ok_to_write:
 	req->sector++;
 	i = --req->nr_sectors;
 	--req->current_nr_sectors;
 	req->buffer += 512;
 	if (!i || (req->bio && req->current_nr_sectors <= 0))
 		end_request(req, 1);
 	if (i > 0) {
 		SET_HANDLER(&write_intr);
 		outsw(HD_DATA, req->buffer, 256);
 		local_irq_enable();
 	} else {
 #if (HD_DELAY > 0)
 		last_req = read_timer();
 #endif
 		hd_request();
 	}
 	return;
 }

 static void recal_intr(void)
 {
 	check_status();
 #if (HD_DELAY > 0)
 	last_req = read_timer();
 #endif
 	hd_request();
 }

 /*
  * This is another of the error-routines I don't know what to do with. The
  * best idea seems to just set reset, and start all over again.
  */
 static void hd_times_out(unsigned long dummy)
 {
 	char *name;

 	do_hd = NULL;

 	if (!CURRENT)
 		return;

 	disable_irq(HD_IRQ);
 	local_irq_enable();
 	reset = 1;
 	name = CURRENT->rq_disk->disk_name;
 	printk("%s: timeout\n", name);
 	if (++CURRENT->errors >= MAX_ERRORS) {
 #ifdef DEBUG
 		printk("%s: too many errors\n", name);
 #endif
 		end_request(CURRENT, 0);
 	}
 	local_irq_disable();
 	hd_request();
 	enable_irq(HD_IRQ);
 }

 static int do_special_op(struct hd_i_struct *disk, struct request *req)
 {
 	if (disk->recalibrate) {
 		disk->recalibrate = 0;
 		hd_out(disk, disk->sect, 0, 0, 0, ATA_CMD_RESTORE, &recal_intr);
 		return reset;
 	}
 	if (disk->head > 16) {
 		printk("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
 		end_request(req, 0);
 	}
 	disk->special_op = 0;
 	return 1;
 }

 /*
  * The driver enables interrupts as much as possible.  In order to do this,
  * (a) the device-interrupt is disabled before entering hd_request(),
  * and (b) the timeout-interrupt is disabled before the sti().
  *
  * Interrupts are still masked (by default) whenever we are exchanging
  * data/cmds with a drive, because some drives seem to have very poor
  * tolerance for latency during I/O. The IDE driver has support to unmask
  * interrupts for non-broken hardware, so use that driver if required.
  */
 static void hd_request(void)
 {
 	unsigned int block, nsect, sec, track, head, cyl;
 	struct hd_i_struct *disk;
 	struct request *req;

 	if (do_hd)
 		return;
 repeat:
 	del_timer(&device_timer);
 	local_irq_enable();

 	req = CURRENT;
 	if (!req) {
 		do_hd = NULL;
 		return;
 	}

 	if (reset) {
 		local_irq_disable();
 		reset_hd();
 		return;
 	}
 	disk = req->rq_disk->private_data;
 	block = req->sector;
 	nsect = req->nr_sectors;
 	if (block >= get_capacity(req->rq_disk) ||
 	    ((block+nsect) > get_capacity(req->rq_disk))) {
 		printk("%s: bad access: block=%d, count=%d\n",
 			req->rq_disk->disk_name, block, nsect);
 		end_request(req, 0);
 		goto repeat;
 	}

 	if (disk->special_op) {
 		if (do_special_op(disk, req))
 			goto repeat;
 		return;
 	}
 	sec   = block % disk->sect + 1;
 	track = block / disk->sect;
 	head  = track % disk->head;
 	cyl   = track / disk->head;
 #ifdef DEBUG
 	printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
 		req->rq_disk->disk_name,
 		req_data_dir(req) == READ ? "read" : "writ",
 		cyl, head, sec, nsect, req->buffer);
 #endif
 	if (blk_fs_request(req)) {
 		switch (rq_data_dir(req)) {
 		case READ:
 			hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
 				&read_intr);
 			if (reset)
 				goto repeat;
 			break;
 		case WRITE:
 			hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
 				&write_intr);
 			if (reset)
 				goto repeat;
 			if (wait_DRQ()) {
 				bad_rw_intr();
 				goto repeat;
 			}
 			outsw(HD_DATA, req->buffer, 256);
 			break;
 		default:
 			printk("unknown hd-command\n");
 			end_request(req, 0);
 			break;
 		}
 	}
 }

 static void do_hd_request(struct request_queue *q)
 {
 	disable_irq(HD_IRQ);
 	hd_request();
 	enable_irq(HD_IRQ);
 }

 static int hd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
 	struct hd_i_struct *disk = bdev->bd_disk->private_data;

 	geo->heads = disk->head;
 	geo->sectors = disk->sect;
 	geo->cylinders = disk->cyl;
 	return 0;
 }

 /*
  * Releasing a block device means we sync() it, so that it can safely
  * be forgotten about...
  */

 static irqreturn_t hd_interrupt(int irq, void *dev_id)
 {
 	void (*handler)(void) = do_hd;

 	do_hd = NULL;
 	del_timer(&device_timer);
 	if (!handler)
 		handler = unexpected_hd_interrupt;
 	handler();
 	local_irq_enable();
 	return IRQ_HANDLED;
 }

 static struct block_device_operations hd_fops = {
 	.getgeo =	hd_getgeo,
 };

 /*
  * This is the hard disk IRQ description. The IRQF_DISABLED in sa_flags
  * means we run the IRQ-handler with interrupts disabled:  this is bad for
  * interrupt latency, but anything else has led to problems on some
  * machines.
  *
  * We enable interrupts in some of the routines after making sure it's
  * safe.
  */

 static int __init hd_init(void)
 {
 	int drive;

 	if (register_blkdev(MAJOR_NR, "hd"))
 		return -1;

 	hd_queue = blk_init_queue(do_hd_request, &hd_lock);
 	if (!hd_queue) {
 		unregister_blkdev(MAJOR_NR, "hd");
 		return -ENOMEM;
 	}

 	blk_queue_max_sectors(hd_queue, 255);
 	init_timer(&device_timer);
 	device_timer.function = hd_times_out;
 	blk_queue_hardsect_size(hd_queue, 512);

 	if (!NR_HD) {
 		/*
 		 * We don't know anything about the drive.  This means
 		 * that you *MUST* specify the drive parameters to the
 		 * kernel yourself.
 		 *
 		 * If we were on an i386, we used to read this info from
 		 * the BIOS or CMOS.  This doesn't work all that well,
 		 * since this assumes that this is a primary or secondary
 		 * drive, and if we're using this legacy driver, it's
 		 * probably an auxilliary controller added to recover
 		 * legacy data off an ST-506 drive.  Either way, it's
 		 * definitely safest to have the user explicitly specify
 		 * the information.
 		 */
 		printk("hd: no drives specified - use hd=cyl,head,sectors"
 			" on kernel command line\n");
 		goto out;
 	}

 	for (drive = 0 ; drive < NR_HD ; drive++) {
 		struct gendisk *disk = alloc_disk(64);
 		struct hd_i_struct *p = &hd_info[drive];
 		if (!disk)
 			goto Enomem;
 		disk->major = MAJOR_NR;
 		disk->first_minor = drive << 6;
 		disk->fops = &hd_fops;
 		sprintf(disk->disk_name, "hd%c", 'a'+drive);
 		disk->private_data = p;
 		set_capacity(disk, p->head * p->sect * p->cyl);
 		disk->queue = hd_queue;
 		p->unit = drive;
 		hd_gendisk[drive] = disk;
 		printk("%s: %luMB, CHS=%d/%d/%d\n",
 			disk->disk_name, (unsigned long)get_capacity(disk)/2048,
 			p->cyl, p->head, p->sect);
 	}

 	if (request_irq(HD_IRQ, hd_interrupt, IRQF_DISABLED, "hd", NULL)) {
 		printk("hd: unable to get IRQ%d for the hard disk driver\n",
 			HD_IRQ);
 		goto out1;
 	}
 	if (!request_region(HD_DATA, 8, "hd")) {
 		printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
 		goto out2;
 	}
 	if (!request_region(HD_CMD, 1, "hd(cmd)")) {
 		printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
 		goto out3;
 	}

 	/* Let them fly */
 	for (drive = 0; drive < NR_HD; drive++)
 		add_disk(hd_gendisk[drive]);

 	return 0;

 out3:
 	release_region(HD_DATA, 8);
 out2:
 	free_irq(HD_IRQ, NULL);
 out1:
 	for (drive = 0; drive < NR_HD; drive++)
 		put_disk(hd_gendisk[drive]);
 	NR_HD = 0;
 out:
 	del_timer(&device_timer);
 	unregister_blkdev(MAJOR_NR, "hd");
 	blk_cleanup_queue(hd_queue);
 	return -1;
 Enomem:
 	while (drive--)
 		put_disk(hd_gendisk[drive]);
 	goto out;
 }

 static int __init parse_hd_setup(char *line)
 {
 	int ints[6];

 	(void) get_options(line, ARRAY_SIZE(ints), ints);
 	hd_setup(NULL, ints);

 	return 1;
 }
 __setup("hd=", parse_hd_setup);

 late_initcall(hd_init);
	/*
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* This is the low-level hd interrupt support. It traverses the
	* request-list, using interrupts to jump between functions. As
	* all the functions are called within interrupts, we may not
	* sleep. Special care is recommended.
	*
	* modified by Drew Eckhardt to check nr of hd's from the CMOS.
	*
	* Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
	* in the early extended-partition checks and added DM partitions
	*
	* IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
	* and general streamlining by Mark Lord.
	*
	* Removed 99% of above. Use Mark's ide driver for those options.
	* This is now a lightweight ST-506 driver. (Paul Gortmaker)
	*
	* Modified 1995 Russell King for ARM processor.
	*
	* Bugfix: max_sectors must be <= 255 or the wheels tend to come
	* off in a hurry once you queue things up - Paul G. 02/2001
	*/

	/* Uncomment the following if you want verbose error reports. */
	/* #define VERBOSE_ERRORS */

	#include <linux/blkdev.h>
	#include <linux/errno.h>
	#include <linux/signal.h>
	#include <linux/interrupt.h>
	#include <linux/timer.h>
	#include <linux/fs.h>
	#include <linux/kernel.h>
	#include <linux/genhd.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/ioport.h>
	#include <linux/init.h>
	#include <linux/blkpg.h>
	#include <linux/ata.h>
	#include <linux/hdreg.h>

	#define HD_IRQ 14

	#define REALLY_SLOW_IO
	#include <asm/system.h>
	#include <asm/io.h>
	#include <asm/uaccess.h>

	#ifdef __arm__
	#undef HD_IRQ
	#endif
	#include <asm/irq.h>
	#ifdef __arm__
	#define HD_IRQ IRQ_HARDDISK
	#endif

	/* Hd controller regster ports */

	#define HD_DATA 0x1f0 /* _CTL when writing */
	#define HD_ERROR 0x1f1 /* see err-bits */
	#define HD_NSECTOR 0x1f2 /* nr of sectors to read/write */
	#define HD_SECTOR 0x1f3 /* starting sector */
	#define HD_LCYL 0x1f4 /* starting cylinder */
	#define HD_HCYL 0x1f5 /* high byte of starting cyl */
	#define HD_CURRENT 0x1f6 /* 101dhhhh , d=drive, hhhh=head */
	#define HD_STATUS 0x1f7 /* see status-bits */
	#define HD_FEATURE HD_ERROR /* same io address, read=error, write=feature */
	#define HD_PRECOMP HD_FEATURE /* obsolete use of this port - predates IDE */
	#define HD_COMMAND HD_STATUS /* same io address, read=status, write=cmd */

	#define HD_CMD 0x3f6 /* used for resets */
	#define HD_ALTSTATUS 0x3f6 /* same as HD_STATUS but doesn't clear irq */

	/* Bits of HD_STATUS */
	#define ERR_STAT 0x01
	#define INDEX_STAT 0x02
	#define ECC_STAT 0x04 /* Corrected error */
	#define DRQ_STAT 0x08
	#define SEEK_STAT 0x10
	#define SERVICE_STAT SEEK_STAT
	#define WRERR_STAT 0x20
	#define READY_STAT 0x40
	#define BUSY_STAT 0x80

	/* Bits for HD_ERROR */
	#define MARK_ERR 0x01 /* Bad address mark */
	#define TRK0_ERR 0x02 /* couldn't find track 0 */
	#define ABRT_ERR 0x04 /* Command aborted */
	#define MCR_ERR 0x08 /* media change request */
	#define ID_ERR 0x10 /* ID field not found */
	#define MC_ERR 0x20 /* media changed */
	#define ECC_ERR 0x40 /* Uncorrectable ECC error */
	#define BBD_ERR 0x80 /* pre-EIDE meaning: block marked bad */
	#define ICRC_ERR 0x80 /* new meaning: CRC error during transfer */

	static DEFINE_SPINLOCK(hd_lock);
	static struct request_queue *hd_queue;

	#define MAJOR_NR HD_MAJOR
	#define QUEUE (hd_queue)
	#define CURRENT elv_next_request(hd_queue)

	#define TIMEOUT_VALUE (6*HZ)
	#define HD_DELAY 0

	#define MAX_ERRORS 16 /* Max read/write errors/sector */
	#define RESET_FREQ 8 /* Reset controller every 8th retry */
	#define RECAL_FREQ 4 /* Recalibrate every 4th retry */
	#define MAX_HD 2

	#define STAT_OK (READY_STAT\|SEEK_STAT)
	#define OK_STATUS(s) (((s)&(STAT_OK\|(BUSY_STAT\|WRERR_STAT\|ERR_STAT)))==STAT_OK)

	static void recal_intr(void);
	static void bad_rw_intr(void);

	static int reset;
	static int hd_error;

	/*
	* This struct defines the HD's and their types.
	*/
	struct hd_i_struct {
	unsigned int head, sect, cyl, wpcom, lzone, ctl;
	int unit;
	int recalibrate;
	int special_op;
	};

	#ifdef HD_TYPE
	static struct hd_i_struct hd_info[] = { HD_TYPE };
	static int NR_HD = ARRAY_SIZE(hd_info);
	#else
	static struct hd_i_struct hd_info[MAX_HD];
	static int NR_HD;
	#endif

	static struct gendisk *hd_gendisk[MAX_HD];

	static struct timer_list device_timer;

	#define TIMEOUT_VALUE (6*HZ)

	#define SET_TIMER \
	do { \
	mod_timer(&device_timer, jiffies + TIMEOUT_VALUE); \
	} while (0)

	static void (*do_hd)(void) = NULL;
	#define SET_HANDLER(x) \
	if ((do_hd = (x)) != NULL) \
	SET_TIMER; \
	else \
	del_timer(&device_timer);


	#if (HD_DELAY > 0)

	#include <asm/i8253.h>

	unsigned long last_req;

	unsigned long read_timer(void)
	{
	unsigned long t, flags;
	int i;

	spin_lock_irqsave(&i8253_lock, flags);
	t = jiffies * 11932;
	outb_p(0, 0x43);
	i = inb_p(0x40);
	i \|= inb(0x40) << 8;
	spin_unlock_irqrestore(&i8253_lock, flags);
	return(t - i);
	}
	#endif

	static void __init hd_setup(char str, int ints)
	{
	int hdind = 0;

	if (ints[0] != 3)
	return;
	if (hd_info[0].head != 0)
	hdind = 1;
	hd_info[hdind].head = ints[2];
	hd_info[hdind].sect = ints[3];
	hd_info[hdind].cyl = ints[1];
	hd_info[hdind].wpcom = 0;
	hd_info[hdind].lzone = ints[1];
	hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
	NR_HD = hdind+1;
	}

	static void dump_status(const char *msg, unsigned int stat)
	{
	char *name = "hd?";
	if (CURRENT)
	name = CURRENT->rq_disk->disk_name;

	#ifdef VERBOSE_ERRORS
	printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
	if (stat & BUSY_STAT) printk("Busy ");
	if (stat & READY_STAT) printk("DriveReady ");
	if (stat & WRERR_STAT) printk("WriteFault ");
	if (stat & SEEK_STAT) printk("SeekComplete ");
	if (stat & DRQ_STAT) printk("DataRequest ");
	if (stat & ECC_STAT) printk("CorrectedError ");
	if (stat & INDEX_STAT) printk("Index ");
	if (stat & ERR_STAT) printk("Error ");
	printk("}\n");
	if ((stat & ERR_STAT) == 0) {
	hd_error = 0;
	} else {
	hd_error = inb(HD_ERROR);
	printk("%s: %s: error=0x%02x { ", name, msg, hd_error & 0xff);
	if (hd_error & BBD_ERR) printk("BadSector ");
	if (hd_error & ECC_ERR) printk("UncorrectableError ");
	if (hd_error & ID_ERR) printk("SectorIdNotFound ");
	if (hd_error & ABRT_ERR) printk("DriveStatusError ");
	if (hd_error & TRK0_ERR) printk("TrackZeroNotFound ");
	if (hd_error & MARK_ERR) printk("AddrMarkNotFound ");
	printk("}");
	if (hd_error & (BBD_ERR\|ECC_ERR\|ID_ERR\|MARK_ERR)) {
	printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
	inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
	if (CURRENT)
	printk(", sector=%ld", CURRENT->sector);
	}
	printk("\n");
	}
	#else
	printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
	if ((stat & ERR_STAT) == 0) {
	hd_error = 0;
	} else {
	hd_error = inb(HD_ERROR);
	printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
	}
	#endif
	}

	static void check_status(void)
	{
	int i = inb_p(HD_STATUS);

	if (!OK_STATUS(i)) {
	dump_status("check_status", i);
	bad_rw_intr();
	}
	}

	static int controller_busy(void)
	{
	int retries = 100000;
	unsigned char status;

	do {
	status = inb_p(HD_STATUS);
	} while ((status & BUSY_STAT) && --retries);
	return status;
	}

	static int status_ok(void)
	{
	unsigned char status = inb_p(HD_STATUS);

	if (status & BUSY_STAT)
	return 1; /* Ancient, but does it make sense??? */
	if (status & WRERR_STAT)
	return 0;
	if (!(status & READY_STAT))
	return 0;
	if (!(status & SEEK_STAT))
	return 0;
	return 1;
	}

	static int controller_ready(unsigned int drive, unsigned int head)
	{
	int retry = 100;

	do {
	if (controller_busy() & BUSY_STAT)
	return 0;
	outb_p(0xA0 \| (drive<<4) \| head, HD_CURRENT);
	if (status_ok())
	return 1;
	} while (--retry);
	return 0;
	}

	static void hd_out(struct hd_i_struct *disk,
	unsigned int nsect,
	unsigned int sect,
	unsigned int head,
	unsigned int cyl,
	unsigned int cmd,
	void (*intr_addr)(void))
	{
	unsigned short port;

	#if (HD_DELAY > 0)
	while (read_timer() - last_req < HD_DELAY)
	/* nothing */;
	#endif
	if (reset)
	return;
	if (!controller_ready(disk->unit, head)) {
	reset = 1;
	return;
	}
	SET_HANDLER(intr_addr);
	outb_p(disk->ctl, HD_CMD);
	port = HD_DATA;
	outb_p(disk->wpcom >> 2, ++port);
	outb_p(nsect, ++port);
	outb_p(sect, ++port);
	outb_p(cyl, ++port);
	outb_p(cyl >> 8, ++port);
	outb_p(0xA0 \| (disk->unit << 4) \| head, ++port);
	outb_p(cmd, ++port);
	}

	static void hd_request (void);

	static int drive_busy(void)
	{
	unsigned int i;
	unsigned char c;

	for (i = 0; i < 500000 ; i++) {
	c = inb_p(HD_STATUS);
	if ((c & (BUSY_STAT \| READY_STAT \| SEEK_STAT)) == STAT_OK)
	return 0;
	}
	dump_status("reset timed out", c);
	return 1;
	}

	static void reset_controller(void)
	{
	int i;

	outb_p(4, HD_CMD);
	for (i = 0; i < 1000; i++) barrier();
	outb_p(hd_info[0].ctl & 0x0f, HD_CMD);
	for (i = 0; i < 1000; i++) barrier();
	if (drive_busy())
	printk("hd: controller still busy\n");
	else if ((hd_error = inb(HD_ERROR)) != 1)
	printk("hd: controller reset failed: %02x\n", hd_error);
	}

	static void reset_hd(void)
	{
	static int i;

	repeat:
	if (reset) {
	reset = 0;
	i = -1;
	reset_controller();
	} else {
	check_status();
	if (reset)
	goto repeat;
	}
	if (++i < NR_HD) {
	struct hd_i_struct *disk = &hd_info[i];
	disk->special_op = disk->recalibrate = 1;
	hd_out(disk, disk->sect, disk->sect, disk->head-1,
	disk->cyl, ATA_CMD_INIT_DEV_PARAMS, &reset_hd);
	if (reset)
	goto repeat;
	} else
	hd_request();
	}

	/*
	* Ok, don't know what to do with the unexpected interrupts: on some machines
	* doing a reset and a retry seems to result in an eternal loop. Right now I
	* ignore it, and just set the timeout.
	*
	* On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
	* drive enters "idle", "standby", or "sleep" mode, so if the status looks
	* "good", we just ignore the interrupt completely.
	*/
	static void unexpected_hd_interrupt(void)
	{
	unsigned int stat = inb_p(HD_STATUS);

	if (stat & (BUSY_STAT\|DRQ_STAT\|ECC_STAT\|ERR_STAT)) {
	dump_status("unexpected interrupt", stat);
	SET_TIMER;
	}
	}

	/*
	* bad_rw_intr() now tries to be a bit smarter and does things
	* according to the error returned by the controller.
	* -Mika Liljeberg (liljeber@cs.Helsinki.FI)
	*/
	static void bad_rw_intr(void)
	{
	struct request *req = CURRENT;
	if (req != NULL) {
	struct hd_i_struct *disk = req->rq_disk->private_data;
	if (++req->errors >= MAX_ERRORS \|\| (hd_error & BBD_ERR)) {
	end_request(req, 0);
	disk->special_op = disk->recalibrate = 1;
	} else if (req->errors % RESET_FREQ == 0)
	reset = 1;
	else if ((hd_error & TRK0_ERR) \|\| req->errors % RECAL_FREQ == 0)
	disk->special_op = disk->recalibrate = 1;
	/* Otherwise just retry */
	}
	}

	static inline int wait_DRQ(void)
	{
	int retries;
	int stat;

	for (retries = 0; retries < 100000; retries++) {
	stat = inb_p(HD_STATUS);
	if (stat & DRQ_STAT)
	return 0;
	}
	dump_status("wait_DRQ", stat);
	return -1;
	}

	static void read_intr(void)
	{
	struct request *req;
	int i, retries = 100000;

	do {
	i = (unsigned) inb_p(HD_STATUS);
	if (i & BUSY_STAT)
	continue;
	if (!OK_STATUS(i))
	break;
	if (i & DRQ_STAT)
	goto ok_to_read;
	} while (--retries > 0);
	dump_status("read_intr", i);
	bad_rw_intr();
	hd_request();
	return;
	ok_to_read:
	req = CURRENT;
	insw(HD_DATA, req->buffer, 256);
	req->sector++;
	req->buffer += 512;
	req->errors = 0;
	i = --req->nr_sectors;
	--req->current_nr_sectors;
	#ifdef DEBUG
	printk("%s: read: sector %ld, remaining = %ld, buffer=%p\n",
	req->rq_disk->disk_name, req->sector, req->nr_sectors,
	req->buffer+512);
	#endif
	if (req->current_nr_sectors <= 0)
	end_request(req, 1);
	if (i > 0) {
	SET_HANDLER(&read_intr);
	return;
	}
	(void) inb_p(HD_STATUS);
	#if (HD_DELAY > 0)
	last_req = read_timer();
	#endif
	if (elv_next_request(QUEUE))
	hd_request();
	return;
	}

	static void write_intr(void)
	{
	struct request *req = CURRENT;
	int i;
	int retries = 100000;

	do {
	i = (unsigned) inb_p(HD_STATUS);
	if (i & BUSY_STAT)
	continue;
	if (!OK_STATUS(i))
	break;
	if ((req->nr_sectors <= 1) \|\| (i & DRQ_STAT))
	goto ok_to_write;
	} while (--retries > 0);
	dump_status("write_intr", i);
	bad_rw_intr();
	hd_request();
	return;
	ok_to_write:
	req->sector++;
	i = --req->nr_sectors;
	--req->current_nr_sectors;
	req->buffer += 512;
	if (!i \|\| (req->bio && req->current_nr_sectors <= 0))
	end_request(req, 1);
	if (i > 0) {
	SET_HANDLER(&write_intr);
	outsw(HD_DATA, req->buffer, 256);
	local_irq_enable();
	} else {
	#if (HD_DELAY > 0)
	last_req = read_timer();
	#endif
	hd_request();
	}
	return;
	}

	static void recal_intr(void)
	{
	check_status();
	#if (HD_DELAY > 0)
	last_req = read_timer();
	#endif
	hd_request();
	}

	/*
	* This is another of the error-routines I don't know what to do with. The
	* best idea seems to just set reset, and start all over again.
	*/
	static void hd_times_out(unsigned long dummy)
	{
	char *name;

	do_hd = NULL;

	if (!CURRENT)
	return;

	disable_irq(HD_IRQ);
	local_irq_enable();
	reset = 1;
	name = CURRENT->rq_disk->disk_name;
	printk("%s: timeout\n", name);
	if (++CURRENT->errors >= MAX_ERRORS) {
	#ifdef DEBUG
	printk("%s: too many errors\n", name);
	#endif
	end_request(CURRENT, 0);
	}
	local_irq_disable();
	hd_request();
	enable_irq(HD_IRQ);
	}

	static int do_special_op(struct hd_i_struct disk, struct request req)
	{
	if (disk->recalibrate) {
	disk->recalibrate = 0;
	hd_out(disk, disk->sect, 0, 0, 0, ATA_CMD_RESTORE, &recal_intr);
	return reset;
	}
	if (disk->head > 16) {
	printk("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
	end_request(req, 0);
	}
	disk->special_op = 0;
	return 1;
	}

	/*
	* The driver enables interrupts as much as possible. In order to do this,
	* (a) the device-interrupt is disabled before entering hd_request(),
	* and (b) the timeout-interrupt is disabled before the sti().
	*
	* Interrupts are still masked (by default) whenever we are exchanging
	* data/cmds with a drive, because some drives seem to have very poor
	* tolerance for latency during I/O. The IDE driver has support to unmask
	* interrupts for non-broken hardware, so use that driver if required.
	*/
	static void hd_request(void)
	{
	unsigned int block, nsect, sec, track, head, cyl;
	struct hd_i_struct *disk;
	struct request *req;

	if (do_hd)
	return;
	repeat:
	del_timer(&device_timer);
	local_irq_enable();

	req = CURRENT;
	if (!req) {
	do_hd = NULL;
	return;
	}

	if (reset) {
	local_irq_disable();
	reset_hd();
	return;
	}
	disk = req->rq_disk->private_data;
	block = req->sector;
	nsect = req->nr_sectors;
	if (block >= get_capacity(req->rq_disk) \|\|
	((block+nsect) > get_capacity(req->rq_disk))) {
	printk("%s: bad access: block=%d, count=%d\n",
	req->rq_disk->disk_name, block, nsect);
	end_request(req, 0);
	goto repeat;
	}

	if (disk->special_op) {
	if (do_special_op(disk, req))
	goto repeat;
	return;
	}
	sec = block % disk->sect + 1;
	track = block / disk->sect;
	head = track % disk->head;
	cyl = track / disk->head;
	#ifdef DEBUG
	printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
	req->rq_disk->disk_name,
	req_data_dir(req) == READ ? "read" : "writ",
	cyl, head, sec, nsect, req->buffer);
	#endif
	if (blk_fs_request(req)) {
	switch (rq_data_dir(req)) {
	case READ:
	hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
	&read_intr);
	if (reset)
	goto repeat;
	break;
	case WRITE:
	hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
	&write_intr);
	if (reset)
	goto repeat;
	if (wait_DRQ()) {
	bad_rw_intr();
	goto repeat;
	}
	outsw(HD_DATA, req->buffer, 256);
	break;
	default:
	printk("unknown hd-command\n");
	end_request(req, 0);
	break;
	}
	}
	}

	static void do_hd_request(struct request_queue *q)
	{
	disable_irq(HD_IRQ);
	hd_request();
	enable_irq(HD_IRQ);
	}

	static int hd_getgeo(struct block_device bdev, struct hd_geometry geo)
	{
	struct hd_i_struct *disk = bdev->bd_disk->private_data;

	geo->heads = disk->head;
	geo->sectors = disk->sect;
	geo->cylinders = disk->cyl;
	return 0;
	}

	/*
	* Releasing a block device means we sync() it, so that it can safely
	* be forgotten about...
	*/

	static irqreturn_t hd_interrupt(int irq, void *dev_id)
	{
	void (*handler)(void) = do_hd;

	do_hd = NULL;
	del_timer(&device_timer);
	if (!handler)
	handler = unexpected_hd_interrupt;
	handler();
	local_irq_enable();
	return IRQ_HANDLED;
	}

	static struct block_device_operations hd_fops = {
	.getgeo = hd_getgeo,
	};

	/*
	* This is the hard disk IRQ description. The IRQF_DISABLED in sa_flags
	* means we run the IRQ-handler with interrupts disabled: this is bad for
	* interrupt latency, but anything else has led to problems on some
	* machines.
	*
	* We enable interrupts in some of the routines after making sure it's
	* safe.
	*/

	static int __init hd_init(void)
	{
	int drive;

	if (register_blkdev(MAJOR_NR, "hd"))
	return -1;

	hd_queue = blk_init_queue(do_hd_request, &hd_lock);
	if (!hd_queue) {
	unregister_blkdev(MAJOR_NR, "hd");
	return -ENOMEM;
	}

	blk_queue_max_sectors(hd_queue, 255);
	init_timer(&device_timer);
	device_timer.function = hd_times_out;
	blk_queue_hardsect_size(hd_queue, 512);

	if (!NR_HD) {
	/*
	* We don't know anything about the drive. This means
	* that you MUST specify the drive parameters to the
	* kernel yourself.
	*
	* If we were on an i386, we used to read this info from
	* the BIOS or CMOS. This doesn't work all that well,
	* since this assumes that this is a primary or secondary
	* drive, and if we're using this legacy driver, it's
	* probably an auxilliary controller added to recover
	* legacy data off an ST-506 drive. Either way, it's
	* definitely safest to have the user explicitly specify
	* the information.
	*/
	printk("hd: no drives specified - use hd=cyl,head,sectors"
	" on kernel command line\n");
	goto out;
	}

	for (drive = 0 ; drive < NR_HD ; drive++) {
	struct gendisk *disk = alloc_disk(64);
	struct hd_i_struct *p = &hd_info[drive];
	if (!disk)
	goto Enomem;
	disk->major = MAJOR_NR;
	disk->first_minor = drive << 6;
	disk->fops = &hd_fops;
	sprintf(disk->disk_name, "hd%c", 'a'+drive);
	disk->private_data = p;
	set_capacity(disk, p->head * p->sect * p->cyl);
	disk->queue = hd_queue;
	p->unit = drive;
	hd_gendisk[drive] = disk;
	printk("%s: %luMB, CHS=%d/%d/%d\n",
	disk->disk_name, (unsigned long)get_capacity(disk)/2048,
	p->cyl, p->head, p->sect);
	}

	if (request_irq(HD_IRQ, hd_interrupt, IRQF_DISABLED, "hd", NULL)) {
	printk("hd: unable to get IRQ%d for the hard disk driver\n",
	HD_IRQ);
	goto out1;
	}
	if (!request_region(HD_DATA, 8, "hd")) {
	printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
	goto out2;
	}
	if (!request_region(HD_CMD, 1, "hd(cmd)")) {
	printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
	goto out3;
	}

	/* Let them fly */
	for (drive = 0; drive < NR_HD; drive++)
	add_disk(hd_gendisk[drive]);

	return 0;

	out3:
	release_region(HD_DATA, 8);
	out2:
	free_irq(HD_IRQ, NULL);
	out1:
	for (drive = 0; drive < NR_HD; drive++)
	put_disk(hd_gendisk[drive]);
	NR_HD = 0;
	out:
	del_timer(&device_timer);
	unregister_blkdev(MAJOR_NR, "hd");
	blk_cleanup_queue(hd_queue);
	return -1;
	Enomem:
	while (drive--)
	put_disk(hd_gendisk[drive]);
	goto out;
	}

	static int __init parse_hd_setup(char *line)
	{
	int ints[6];

	(void) get_options(line, ARRAY_SIZE(ints), ints);
	hd_setup(NULL, ints);

	return 1;
	}
	__setup("hd=", parse_hd_setup);

	late_initcall(hd_init);