hd.c

arm平台上的uclinux系统全部源代码

/*
 *  linux/arch/arm/drivers/block/hd.c
 *   [ origional file: linux/drivers/block/hd.c ]
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Modified 1995  Russell King for ARM processor.
 */

/*
 * 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, [e-mail], 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.
 */

#define DEFAULT_MULT_COUNT  0	/* set to 0 to disable multiple mode at boot */
#define DEFAULT_UNMASK_INTR 0	/* set to 0 to *NOT* unmask irq's more often */

#include <asm/irq.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/fs.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>

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

#define MAJOR_NR HD_MAJOR
#include <linux/blk.h>

#undef  HD_IRQ
#define HD_IRQ 11

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 struct wait_queue * busy_wait;

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;
	};
static struct hd_driveid *hd_ident_info[MAX_HD];
	
#ifdef HD_TYPE
static struct hd_i_struct hd_info[] = { HD_TYPE };
struct hd_i_struct bios_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];
struct hd_i_struct bios_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_cli (flags);
	t = jiffies * 11932;
    	outb_p(0, 0x43);
	i = inb_p(0x40);
	i |= inb(0x40) << 8;
	restore_flags(flags);
	return(t - i);
}
#endif

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

	if (ints[0] != 3)
		return;
	if (bios_info[0].head != 0)
		hdind=1;
	bios_info[hdind].head  = hd_info[hdind].head = ints[2];
	bios_info[hdind].sect  = hd_info[hdind].sect = ints[3];
	bios_info[hdind].cyl   = hd_info[hdind].cyl = ints[1];
	bios_info[hdind].wpcom = hd_info[hdind].wpcom = 0;
	bios_info[hdind].lzone = hd_info[hdind].lzone = ints[1];
	bios_info[hdind].ctl   = 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 = CURRENT ? 'a' + DEVICE_NR(CURRENT->rq_dev) : '?';
	save_flags (flags);
	sti();
	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 (CURRENT)
				printk(", sector=%ld", CURRENT->sector);
		}
		printk("\n");
	}
	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 unsigned int identified  [MAX_HD]; /* 1 = drive ID already displayed   */
static unsigned int unmask_intr [MAX_HD]; /* 1 = unmask IRQs during I/O       */
static unsigned int max_mult    [MAX_HD]; /* max sectors for MultMode         */
static unsigned int mult_req    [MAX_HD]; /* requested MultMode count         */
static unsigned int mult_count  [MAX_HD]; /* currently enabled MultMode count */
static struct request WCURRENT;

static void fixstring (unsigned char *s, int bytecount)
{
	unsigned char *p, *end = &s[bytecount &= ~1];	/* bytecount must be even */

	/* convert from big-endian to little-endian */
	for (p = end ; p != s;) {
		unsigned short *pp = (unsigned short *) (p -= 2);
		*pp = (*pp >> 8) | (*pp << 8);
	}

	/* strip leading blanks */
	while (s != end && *s == ' ')
		++s;

	/* compress internal blanks and strip trailing blanks */
	while (s != end && *s) {
		if (*s++ != ' ' || (s != end && *s && *s != ' '))
			*p++ = *(s-1);
	}

	/* wipe out trailing garbage */
	while (p != end)
		*p++ = '\0';
}

static void identify_intr(void)
{
	unsigned int dev = DEVICE_NR(CURRENT->rq_dev);
	unsigned short stat = inb_p(HD_STATUS);
	struct hd_driveid *id = hd_ident_info[dev];

	if (unmask_intr[dev])
		sti();
	if (stat & (BUSY_STAT|ERR_STAT)) {
		printk ("  hd%c: non-IDE device, %dMB, CHS=%d/%d/%d\n", dev+'a',
			hd_info[dev].cyl*hd_info[dev].head*hd_info[dev].sect / 2048,
			hd_info[dev].cyl, hd_info[dev].head, hd_info[dev].sect);
		if (id != NULL) {
			hd_ident_info[dev] = NULL;
			kfree_s (id, 512);
		}
	} else {
		insw(HD_DATA, id, 256); /* get ID info */
		max_mult[dev] = id->max_multsect;
		if ((id->field_valid&1) && id->cur_cyls && id->cur_heads && (id->cur_heads <= 16) && id->cur_sectors) {
			/*
			 * Extract the physical drive geometry for our use.
			 * Note that we purposely do *not* update the bios_info.
			 * This way, programs that use it (like fdisk) will 
			 * still have the same logical view as the BIOS does,
			 * which keeps the partition table from being screwed.
			 */
			hd_info[dev].cyl  = id->cur_cyls;
			hd_info[dev].head = id->cur_heads;
			hd_info[dev].sect = id->cur_sectors; 
		}
		fixstring (id->serial_no, sizeof(id->serial_no));
		fixstring (id->fw_rev, sizeof(id->fw_rev));
		fixstring (id->model, sizeof(id->model));
		printk ("  hd%c: %.40s, %dMB w/%dKB Cache, CHS=%d/%d/%d, MaxMult=%d\n",
			dev+'a', id->model, id->cyls*id->heads*id->sectors/2048,
			id->buf_size/2, bios_info[dev].cyl, bios_info[dev].head,
			bios_info[dev].sect, id->max_multsect);
		/*
		 * Early model Quantum drives go weird at this point,
		 *   but doing a recalibrate seems to "fix" them.
		 * (Doing a full reset confuses some other model Quantums)
		 */
		if (!strncmp(id->model, "QUANTUM", 7))
			special_op[dev] = recalibrate[dev] = 1;
	}
#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	hd_request();
	return;
}

static void set_multmode_intr(void)
{
	unsigned int dev = DEVICE_NR(CURRENT->rq_dev), stat = inb_p(HD_STATUS);

	if (unmask_intr[dev])
		sti();
	if (stat & (BUSY_STAT|ERR_STAT)) {
		mult_req[dev] = mult_count[dev] = 0;
		dump_status("set multmode failed", stat);
	} else {
		if ((mult_count[dev] = mult_req[dev]))
			printk ("  hd%c: enabled %d-sector multiple mode\n",
				dev+'a', mult_count[dev]);
		else
			printk ("  hd%c: disabled multiple mode\n", dev+'a');
	}
#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	hd_request();
	return;
}

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;
		if (unmask_intr[i]) {
			unmask_intr[i] = DEFAULT_UNMASK_INTR;
			printk("hd%c: reset irq-unmasking to %d\n",i+'a',
				DEFAULT_UNMASK_INTR);
		}
		if (mult_req[i] || mult_count[i]) {
			mult_count[i] = 0;
			mult_req[i] = DEFAULT_MULT_COUNT;
			printk("hd%c: reset multiple mode to %d\n",i+'a',
				DEFAULT_MULT_COUNT);
		}
		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 ([e-mail])
 */
static void bad_rw_intr(void)
{
	int dev;

	if (!CURRENT)
		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)
{
	unsigned int dev = DEVICE_NR(CURRENT->rq_dev);
	int i, retries = 100000, msect = mult_count[dev], nsect;

	if (unmask_intr[dev])
		sti();			/* permit other IRQs during xfer */
	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:
	if (msect) {
		if ((nsect = CURRENT->current_nr_sectors) > msect)
			nsect = msect;
		msect -= nsect;
	} else
		nsect = 1;
	insw(HD_DATA,CURRENT->buffer,nsect<<8);
	CURRENT->sector += nsect;
	CURRENT->buffer += nsect<<9;
	CURRENT->errors = 0;
	i = (CURRENT->nr_sectors -= nsect);

#ifdef DEBUG
	printk("hd%c: read: sectors(%ld-%ld), remaining=%ld, buffer=0x%08lx\n",
		dev+'a', CURRENT->sector, CURRENT->sector+nsect,
		CURRENT->nr_sectors, (unsigned long) CURRENT->buffer+(nsect<<9));
#endif
	if ((CURRENT->current_nr_sectors -= nsect) <= 0)
		end_request(1);
	if (i > 0) {
		if (msect)
			goto ok_to_read;
		SET_INTR(&read_intr);
		return;
	}
	(void) inb_p(HD_STATUS);
#if (HD_DELAY > 0)
	last_req = read_timer();
#endif
	if (CURRENT)
		hd_request();
	return;
}

static inline void multwrite (unsigned int dev)
{
	unsigned int mcount = mult_count[dev];

	while (mcount--) {
		outsw(HD_DATA,WCURRENT.buffer,256);
		if (!--WCURRENT.nr_sectors)
			return;
		WCURRENT.buffer += 512;
		if (!--WCURRENT.current_nr_sectors) {
			WCURRENT.bh = WCURRENT.bh->b_reqnext;
			if (WCURRENT.bh == NULL)
				panic("buffer list corrupted\n");
			WCURRENT.current_nr_sectors = WCURRENT.bh->b_size>>9;
			WCURRENT.buffer             = WCURRENT.bh->b_data;
		}
	}
}

static void multwrite_intr(void)
{
	int i;
	unsigned int dev = DEVICE_NR(WCURRENT.rq_dev);

	if (unmask_intr[dev])
		sti();
	if (OK_STATUS(i=inb_p(HD_STATUS))) {
		if (i & DRQ_STAT) {
			if (WCURRENT.nr_sectors) {
				multwrite(dev);
				SET_INTR(&multwrite_intr);
				return;
			}
		} else {
			if (!WCURRENT.nr_sectors) {	/* all done? */
				for (i = CURRENT->nr_sectors; i > 0;){
					i -= CURRENT->current_nr_sectors;
					end_request(1);