patch-2.3.99-pre1 linux/drivers/block/hd.c

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diff -u --recursive --new-file v2.3.51/linux/drivers/block/hd.c linux/drivers/block/hd.c
@@ -1,883 +0,0 @@
-/*
- *  linux/drivers/block/hd.c
- *
- *  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.
- */
-  
-/* Uncomment the following if you want verbose error reports. */
-/* #define VERBOSE_ERRORS */
-  
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/timer.h>
-#include <linux/fs.h>
-#include <linux/devfs_fs_kernel.h>
-#include <linux/kernel.h>
-#include <linux/hdreg.h>
-#include <linux/genhd.h>
-#include <linux/malloc.h>
-#include <linux/string.h>
-#include <linux/ioport.h>
-#include <linux/mc146818rtc.h> /* CMOS defines */
-#include <linux/init.h>
-#include <linux/blkpg.h>
-
-#define REALLY_SLOW_IO
-#include <asm/system.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
-
-#define MAJOR_NR HD_MAJOR
-#include <linux/blk.h>
-
-#ifdef __arm__
-#undef  HD_IRQ
-#endif
-#include <asm/irq.h>
-#ifdef __arm__
-#define HD_IRQ IRQ_HARDDISK
-#endif
-
-static int revalidate_hddisk(kdev_t, int);
-
-#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 char recalibrate[MAX_HD];
-static char special_op[MAX_HD];
-static int access_count[MAX_HD];
-static char busy[MAX_HD];
-static DECLARE_WAIT_QUEUE_HEAD(busy_wait);
-
-static int reset;
-static int hd_error;
-
-#define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)
-
-/*
- *  This struct defines the HD's and their types.
- */
-struct hd_i_struct {
-	unsigned int head,sect,cyl,wpcom,lzone,ctl;
-};
-	
-#ifdef HD_TYPE
-static struct hd_i_struct hd_info[] = { HD_TYPE };
-static int NR_HD = ((sizeof (hd_info))/(sizeof (struct hd_i_struct)));
-#else
-static struct hd_i_struct hd_info[MAX_HD];
-static int NR_HD;
-#endif
-
-static struct hd_struct hd[MAX_HD<<6];
-static int hd_sizes[MAX_HD<<6];
-static int hd_blocksizes[MAX_HD<<6];
-static int hd_hardsectsizes[MAX_HD<<6];
-
-#if (HD_DELAY > 0)
-unsigned long last_req;
-
-unsigned long read_timer(void)
-{
-	unsigned long t, flags;
-	int i;
-
-	save_flags(flags);
-	cli();
-	t = jiffies * 11932;
-    	outb_p(0, 0x43);
-	i = inb_p(0x40);
-	i |= inb(0x40) << 8;
-	restore_flags(flags);
-	return(t - i);
-}
-#endif
-
-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)
-{
-	unsigned long flags;
-	char devc;
-
-	devc = !QUEUE_EMPTY ? 'a' + DEVICE_NR(CURRENT->rq_dev) : '?';
-	save_flags (flags);
-	sti();
-#ifdef VERBOSE_ERRORS
-	printk("hd%c: %s: status=0x%02x { ", devc, 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("hd%c: %s: error=0x%02x { ", devc, 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 (!QUEUE_EMPTY)
-				printk(", sector=%ld", CURRENT->sector);
-		}
-		printk("\n");
-	}
-#else
-	printk("hd%c: %s: status=0x%02x.\n", devc, msg, stat & 0xff);
-	if ((stat & ERR_STAT) == 0) {
-		hd_error = 0;
-	} else {
-		hd_error = inb(HD_ERROR);
-		printk("hd%c: %s: error=0x%02x.\n", devc, msg, hd_error & 0xff);
-	}
-#endif	/* verbose errors */
-	restore_flags (flags);
-}
-
-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(unsigned int drive,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(drive, head)) {
-		reset = 1;
-		return;
-	}
-	SET_INTR(intr_addr);
-	outb_p(hd_info[drive].ctl,HD_CMD);
-	port=HD_DATA;
-	outb_p(hd_info[drive].wpcom>>2,++port);
-	outb_p(nsect,++port);
-	outb_p(sect,++port);
-	outb_p(cyl,++port);
-	outb_p(cyl>>8,++port);
-	outb_p(0xA0|(drive<<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) {
-		special_op[i] = recalibrate[i] = 1;
-		hd_out(i,hd_info[i].sect,hd_info[i].sect,hd_info[i].head-1,
-			hd_info[i].cyl,WIN_SPECIFY,&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.
- */
-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)
-{
-	int dev;
-
-	if (QUEUE_EMPTY)
-		return;
-	dev = DEVICE_NR(CURRENT->rq_dev);
-	if (++CURRENT->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
-		end_request(0);
-		special_op[dev] = recalibrate[dev] = 1;
-	} else if (CURRENT->errors % RESET_FREQ == 0)
-		reset = 1;
-	else if ((hd_error & TRK0_ERR) || CURRENT->errors % RECAL_FREQ == 0)
-		special_op[dev] = recalibrate[dev] = 1;
-	/* Otherwise just retry */
-}
-
-static inline int wait_DRQ(void)
-{
-	int retries = 100000, stat;
-
-	while (--retries > 0)
-		if ((stat = inb_p(HD_STATUS)) & DRQ_STAT)
-			return 0;
-	dump_status("wait_DRQ", stat);
-	return -1;
-}
-
-static void read_intr(void)
-{
-	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:
-	insw(HD_DATA,CURRENT->buffer,256);
-	CURRENT->sector++;
-	CURRENT->buffer += 512;
-	CURRENT->errors = 0;
-	i = --CURRENT->nr_sectors;
-	--CURRENT->current_nr_sectors;
-#ifdef DEBUG
-	printk("hd%c: read: sector %ld, remaining = %ld, buffer=0x%08lx\n",
-		dev+'a', CURRENT->sector, CURRENT->nr_sectors,
-		(unsigned long) CURRENT->buffer+512));
-#endif
-	if (CURRENT->current_nr_sectors <= 0)
-		end_request(1);
-	if (i > 0) {
-		SET_INTR(&read_intr);
-		return;
-	}
-	(void) inb_p(HD_STATUS);
-#if (HD_DELAY > 0)
-	last_req = read_timer();
-#endif
-	if (!QUEUE_EMPTY)
-		hd_request();
-	return;
-}
-
-static void write_intr(void)
-{
-	int i;
-	int retries = 100000;
-
-	do {
-		i = (unsigned) inb_p(HD_STATUS);
-		if (i & BUSY_STAT)
-			continue;
-		if (!OK_STATUS(i))
-			break;
-		if ((CURRENT->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:
-	CURRENT->sector++;
-	i = --CURRENT->nr_sectors;
-	--CURRENT->current_nr_sectors;
-	CURRENT->buffer += 512;
-	if (!i || (CURRENT->bh && !SUBSECTOR(i)))
-		end_request(1);
-	if (i > 0) {
-		SET_INTR(&write_intr);
-		outsw(HD_DATA,CURRENT->buffer,256);
-		sti();
-	} 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(void)
-{
-	unsigned int dev;
-
-	DEVICE_INTR = NULL;
-	if (QUEUE_EMPTY)
-		return;
-	disable_irq(HD_IRQ);
-	sti();
-	reset = 1;
-	dev = DEVICE_NR(CURRENT->rq_dev);
-	printk("hd%c: timeout\n", dev+'a');
-	if (++CURRENT->errors >= MAX_ERRORS) {
-#ifdef DEBUG
-		printk("hd%c: too many errors\n", dev+'a');
-#endif
-		end_request(0);
-	}
-	cli();
-	hd_request();
-	enable_irq(HD_IRQ);
-}
-
-int do_special_op (unsigned int dev)
-{
-	if (recalibrate[dev]) {
-		recalibrate[dev] = 0;
-		hd_out(dev,hd_info[dev].sect,0,0,0,WIN_RESTORE,&recal_intr);
-		return reset;
-	}
-	if (hd_info[dev].head > 16) {
-		printk ("hd%c: cannot handle device with more than 16 heads - giving up\n", dev+'a');
-		end_request(0);
-	}
-	special_op[dev] = 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 dev, block, nsect, sec, track, head, cyl;
-
-	if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE) return;
-	if (DEVICE_INTR)
-		return;
-repeat:
-	timer_active &= ~(1<<HD_TIMER);
-	sti();
-	INIT_REQUEST;
-	if (reset) {
-		cli();
-		reset_hd();
-		return;
-	}
-	dev = MINOR(CURRENT->rq_dev);
-	block = CURRENT->sector;
-	nsect = CURRENT->nr_sectors;
-	if (dev >= (NR_HD<<6) || block >= hd[dev].nr_sects || ((block+nsect) > hd[dev].nr_sects)) {
-#ifdef DEBUG
-		if (dev >= (NR_HD<<6))
-			printk("hd: bad minor number: device=%s\n",
-			       kdevname(CURRENT->rq_dev));
-		else
-			printk("hd%c: bad access: block=%d, count=%d\n",
-				(MINOR(CURRENT->rq_dev)>>6)+'a', block, nsect);
-#endif
-		end_request(0);
-		goto repeat;
-	}
-	block += hd[dev].start_sect;
-	dev >>= 6;
-	if (special_op[dev]) {
-		if (do_special_op(dev))
-			goto repeat;
-		return;
-	}
-	sec   = block % hd_info[dev].sect + 1;
-	track = block / hd_info[dev].sect;
-	head  = track % hd_info[dev].head;
-	cyl   = track / hd_info[dev].head;
-#ifdef DEBUG
-	printk("hd%c: %sing: CHS=%d/%d/%d, sectors=%d, buffer=0x%08lx\n",
-		dev+'a', (CURRENT->cmd == READ)?"read":"writ",
-		cyl, head, sec, nsect, (unsigned long) CURRENT->buffer);
-#endif
-	if (CURRENT->cmd == READ) {
-		hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
-		if (reset)
-			goto repeat;
-		return;
-	}
-	if (CURRENT->cmd == WRITE) {
-		hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
-		if (reset)
-			goto repeat;
-		if (wait_DRQ()) {
-			bad_rw_intr();
-			goto repeat;
-		}
-		outsw(HD_DATA,CURRENT->buffer,256);
-		return;
-	}
-	panic("unknown hd-command");
-}
-
-static void do_hd_request (request_queue_t * q)
-{
-	disable_irq(HD_IRQ);
-	hd_request();
-	enable_irq(HD_IRQ);
-}
-
-static int hd_ioctl(struct inode * inode, struct file * file,
-	unsigned int cmd, unsigned long arg)
-{
-	struct hd_geometry *loc = (struct hd_geometry *) arg;
-	int dev;
-
-	if ((!inode) || !(inode->i_rdev))
-		return -EINVAL;
-	dev = DEVICE_NR(inode->i_rdev);
-	if (dev >= NR_HD)
-		return -EINVAL;
-	switch (cmd) {
-		case HDIO_GETGEO:
-		{
-			struct hd_geometry g; 
-			if (!loc)  return -EINVAL;
-			g.heads = hd_info[dev].head;
-			g.sectors = hd_info[dev].sect;
-			g.cylinders = hd_info[dev].cyl;
-			g.start = hd[MINOR(inode->i_rdev)].start_sect;
-			return copy_to_user(loc, &g, sizeof g) ? -EFAULT : 0; 
-		}
-
-         	case BLKGETSIZE:   /* Return device size */
-			if (!arg)  return -EINVAL;
-			return put_user(hd[MINOR(inode->i_rdev)].nr_sects, 
-					(long *) arg);
-
-		case BLKRRPART: /* Re-read partition tables */
-			if (!capable(CAP_SYS_ADMIN))
-				return -EACCES;
-			return revalidate_hddisk(inode->i_rdev, 1);
-
-		case BLKROSET:
-		case BLKROGET:
-		case BLKRASET:
-		case BLKRAGET:
-		case BLKFLSBUF:
-		case BLKPG:
-			return blk_ioctl(inode->i_rdev, cmd, arg);
-
-		default:
-			return -EINVAL;
-	}
-}
-
-static int hd_open(struct inode * inode, struct file * filp)
-{
-	int target;
-	target =  DEVICE_NR(inode->i_rdev);
-
-	if (target >= NR_HD)
-		return -ENODEV;
-	while (busy[target])
-		sleep_on(&busy_wait);
-	access_count[target]++;
-	return 0;
-}
-
-/*
- * Releasing a block device means we sync() it, so that it can safely
- * be forgotten about...
- */
-static int hd_release(struct inode * inode, struct file * file)
-{
-        int target =  DEVICE_NR(inode->i_rdev);
-	access_count[target]--;
-	return 0;
-}
-
-extern struct block_device_operations hd_fops;
-
-static struct gendisk hd_gendisk = {
-	MAJOR_NR,	/* Major number */	
-	"hd",		/* Major name */
-	6,		/* Bits to shift to get real from partition */
-	1 << 6,		/* Number of partitions per real */
-	hd,		/* hd struct */
-	hd_sizes,	/* block sizes */
-	0,		/* number */
-	NULL,		/* internal use, not presently used */
-	NULL,		/* next */
-	&hd_fops,       /* file operations */
-};
-	
-static void hd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
-{
-	void (*handler)(void) = DEVICE_INTR;
-
-	DEVICE_INTR = NULL;
-	timer_active &= ~(1<<HD_TIMER);
-	if (!handler)
-		handler = unexpected_hd_interrupt;
-	handler();
-	sti();
-}
-
-static struct block_device_operations hd_fops = {
-	open:		hd_open,
-	release:	hd_release,
-	ioctl:		hd_ioctl,
-};
-
-/*
- * This is the hard disk IRQ description. The SA_INTERRUPT 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 void hd_geninit(void)
-{
-	int drive;
-
-	for(drive=0; drive < (MAX_HD << 6); drive++) {
-		hd_blocksizes[drive] = 1024;
-		hd_hardsectsizes[drive] = 512;
-	}
-	blksize_size[MAJOR_NR] = hd_blocksizes;
-	hardsect_size[MAJOR_NR] = hd_hardsectsizes;
-
-#ifdef __i386__
-	if (!NR_HD) {
-		extern struct drive_info drive_info;
-		unsigned char *BIOS = (unsigned char *) &drive_info;
-		int cmos_disks;
-
-		for (drive=0 ; drive<2 ; drive++) {
-			hd_info[drive].cyl = *(unsigned short *) BIOS;
-			hd_info[drive].head = *(2+BIOS);
-			hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
-			hd_info[drive].ctl = *(8+BIOS);
-			hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
-			hd_info[drive].sect = *(14+BIOS);
-#ifdef does_not_work_for_everybody_with_scsi_but_helps_ibm_vp
-			if (hd_info[drive].cyl && NR_HD == drive)
-				NR_HD++;
-#endif
-			BIOS += 16;
-		}
-
-	/*
-		We query CMOS about hard disks : it could be that 
-		we have a SCSI/ESDI/etc controller that is BIOS
-		compatible with ST-506, and thus showing up in our
-		BIOS table, but not register compatible, and therefore
-		not present in CMOS.
-
-		Furthermore, we will assume that our ST-506 drives
-		<if any> are the primary drives in the system, and 
-		the ones reflected as drive 1 or 2.
-
-		The first drive is stored in the high nibble of CMOS
-		byte 0x12, the second in the low nibble.  This will be
-		either a 4 bit drive type or 0xf indicating use byte 0x19 
-		for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
-
-		Needless to say, a non-zero value means we have 
-		an AT controller hard disk for that drive.
-
-		
-	*/
-
-		if ((cmos_disks = CMOS_READ(0x12)) & 0xf0) {
-			if (cmos_disks & 0x0f)
-				NR_HD = 2;
-			else
-				NR_HD = 1;
-		}
-	}
-#endif /* __i386__ */
-#ifdef __arm__
-	if (!NR_HD) {
-		/* We don't know anything about the drive.  This means
-		 * that you *MUST* specify the drive parameters to the
-		 * kernel yourself.
-		 */
-		printk("hd: no drives specified - use hd=cyl,head,sectors"
-			" on kernel command line\n");
-	}
-#endif
-
-	for (drive=0 ; drive < NR_HD ; drive++) {
-		printk ("hd%c: %ldMB, CHS=%d/%d/%d\n", drive+'a',
-			hd[drive<<6].nr_sects / 2048, hd_info[drive].cyl,
-			hd_info[drive].head, hd_info[drive].sect);
-	}
-	if (!NR_HD)
-		return;
-
-	if (request_irq(HD_IRQ, hd_interrupt, SA_INTERRUPT, "hd", NULL)) {
-		printk("hd: unable to get IRQ%d for the hard disk driver\n",
-			HD_IRQ);
-		NR_HD = 0;
-		return;
-	}
-	request_region(HD_DATA, 8, "hd");
-	request_region(HD_CMD, 1, "hd(cmd)");
-
-	hd_gendisk.nr_real = NR_HD;
-
-	for(drive=0; drive < NR_HD; drive++)
-		register_disk(&hd_gendisk, MKDEV(MAJOR_NR,drive<<6), 1<<6,
-			&hd_fops, hd_info[drive].head * hd_info[drive].sect *
-			hd_info[drive].cyl);
-}
-
-int __init hd_init(void)
-{
-	if (devfs_register_blkdev(MAJOR_NR,"hd",&hd_fops)) {
-		printk("hd: unable to get major %d for hard disk\n",MAJOR_NR);
-		return -1;
-	}
-	blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
-	read_ahead[MAJOR_NR] = 8;		/* 8 sector (4kB) read-ahead */
-	hd_gendisk.next = gendisk_head;
-	gendisk_head = &hd_gendisk;
-	timer_table[HD_TIMER].fn = hd_times_out;
-	hd_geninit();
-	return 0;
-}
-
-#define DEVICE_BUSY busy[target]
-#define USAGE access_count[target]
-#define CAPACITY (hd_info[target].head*hd_info[target].sect*hd_info[target].cyl)
-/* We assume that the BIOS parameters do not change, so the disk capacity
-   will not change */
-#undef MAYBE_REINIT
-#define GENDISK_STRUCT hd_gendisk
-
-/*
- * This routine is called to flush all partitions and partition tables
- * for a changed disk, and then re-read the new partition table.
- * If we are revalidating a disk because of a media change, then we
- * enter with usage == 0.  If we are using an ioctl, we automatically have
- * usage == 1 (we need an open channel to use an ioctl :-), so this
- * is our limit.
- */
-static int revalidate_hddisk(kdev_t dev, int maxusage)
-{
-	int target;
-	struct gendisk * gdev;
-	int max_p;
-	int start;
-	int i;
-	long flags;
-
-	target = DEVICE_NR(dev);
-	gdev = &GENDISK_STRUCT;
-
-	save_flags(flags);
-	cli();
-	if (DEVICE_BUSY || USAGE > maxusage) {
-		restore_flags(flags);
-		return -EBUSY;
-	}
-	DEVICE_BUSY = 1;
-	restore_flags(flags);
-
-	max_p = gdev->max_p;
-	start = target << gdev->minor_shift;
-
-	for (i=max_p - 1; i >=0 ; i--) {
-		int minor = start + i;
-		kdev_t devi = MKDEV(MAJOR_NR, minor);
-		struct super_block *sb = get_super(devi); 
-
-		sync_dev(devi);
-		if (sb)
-			invalidate_inodes(sb);
-		invalidate_buffers(devi);
-		gdev->part[minor].start_sect = 0;
-		gdev->part[minor].nr_sects = 0;
-	}
-
-#ifdef MAYBE_REINIT
-	MAYBE_REINIT;
-#endif
-
-	grok_partitions(gdev, target, 1<<6, CAPACITY);
-
-	DEVICE_BUSY = 0;
-	wake_up(&busy_wait);
-	return 0;
-}
-
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)