xd.c

讲述linux的初始化过程

	xd_maxsectors = 0x01;		/* this one doesn't wrap properly either... */

	outb(0,XD_RESET);		/* reset the controller */

	xd_timer.expires = jiffies + XD_INIT_DISK_DELAY;
	add_timer(&xd_timer);
	sleep_on(&xdc_wait);
}

static void __init xd_wd_init_drive (u_char drive)
{
	/* values from controller's BIOS - BIOS may be disabled */
	static u_short geometry_table[][4] = {
		{0x264,4,0x1C2,0x1C2},   /* common part */
		{0x132,4,0x099,0x0},
		{0x267,2,0x1C2,0x1C2},
		{0x267,4,0x1C2,0x1C2},

		{0x334,6,0x335,0x335},   /* 1004 series RLL */
		{0x30E,4,0x30F,0x3DC},
		{0x30E,2,0x30F,0x30F},
		{0x267,4,0x268,0x268},

		{0x3D5,5,0x3D6,0x3D6},   /* 1002 series RLL */
		{0x3DB,7,0x3DC,0x3DC},
		{0x264,4,0x265,0x265},
		{0x267,4,0x268,0x268}};

	u_char cmdblk[6],buf[0x200];
	u_char n = 0,rll,jumper_state,use_jumper_geo;
	u_char wd_1002 = (xd_sigs[xd_type].string[7] == '6');
	
	jumper_state = ~(inb(0x322));
	if (jumper_state & 0x40)
		xd_irq = 9;
	rll = (jumper_state & 0x30) ? (0x04 << wd_1002) : 0;
	xd_build(cmdblk,CMD_READ,drive,0,0,0,1,0);
	if (!xd_command(cmdblk,PIO_MODE,buf,0,0,XD_TIMEOUT * 2)) {
		xd_info[drive].heads = buf[0x1AF];				/* heads */
		xd_info[drive].cylinders = ((u_short *) (buf + 1))[0xD6];	/* cylinders */
		xd_info[drive].sectors = 17;					/* sectors */
		if (xd_geo[3*drive])
			xd_manual_geo_set(drive);
#if 0
		xd_info[drive].rwrite = ((u_short *) (buf))[0xD8];		/* reduced write */
		xd_info[drive].wprecomp = ((u_short *) (buf))[0xDA];		/* write precomp */
		xd_info[drive].ecc = buf[0x1B4];				/* ecc length */
#endif /* 0 */
		xd_info[drive].control = buf[0x1B5];				/* control byte */
		use_jumper_geo = !(xd_info[drive].heads) || !(xd_info[drive].cylinders);
		if (xd_geo[3*drive]) {
			xd_manual_geo_set(drive);
			xd_info[drive].control = rll ? 7 : 5;
		}
		else if (use_jumper_geo) {
			n = (((jumper_state & 0x0F) >> (drive << 1)) & 0x03) | rll;
			xd_info[drive].cylinders = geometry_table[n][0];
			xd_info[drive].heads = (u_char)(geometry_table[n][1]);
			xd_info[drive].control = rll ? 7 : 5;
#if 0
			xd_info[drive].rwrite = geometry_table[n][2];
			xd_info[drive].wprecomp = geometry_table[n][3];
			xd_info[drive].ecc = 0x0B;
#endif /* 0 */
		}
		if (!wd_1002) {
			if (use_jumper_geo)
				xd_setparam(CMD_WDSETPARAM,drive,xd_info[drive].heads,xd_info[drive].cylinders,
					geometry_table[n][2],geometry_table[n][3],0x0B);
			else
				xd_setparam(CMD_WDSETPARAM,drive,xd_info[drive].heads,xd_info[drive].cylinders,
					((u_short *) (buf))[0xD8],((u_short *) (buf))[0xDA],buf[0x1B4]);
		}
	/* 1002 based RLL controler requests converted addressing, but reports physical 
	   (physical 26 sec., logical 17 sec.) 
	   1004 based ???? */
		if (rll & wd_1002) {
			if ((xd_info[drive].cylinders *= 26,
			     xd_info[drive].cylinders /= 17) > 1023)
				xd_info[drive].cylinders = 1023;  /* 1024 ? */
#if 0
			xd_info[drive].rwrite *= 26; 
			xd_info[drive].rwrite /= 17;
			xd_info[drive].wprecomp *= 26
			xd_info[drive].wprecomp /= 17;
#endif /* 0 */
		}
	}
	else
		printk("xd_wd_init_drive: error reading geometry for xd%c\n",'a'+drive);	

}

static void __init xd_seagate_init_controller (unsigned int address)
{
	switch (address) {
		case 0x00000:
		case 0xC8000:	break;			/*initial: 0x320 */
		case 0xD0000:	xd_iobase = 0x324; break;
		case 0xD8000:	xd_iobase = 0x328; break;
		case 0xE0000:	xd_iobase = 0x32C; break;
		default:	printk("xd_seagate_init_controller: unsupported BIOS address %06x\n",address);
				break;
	}
	xd_maxsectors = 0x40;

	outb(0,XD_RESET);		/* reset the controller */
}

static void __init xd_seagate_init_drive (u_char drive)
{
	u_char cmdblk[6],buf[0x200];

	xd_build(cmdblk,CMD_ST11GETGEOM,drive,0,0,0,1,0);
	if (!xd_command(cmdblk,PIO_MODE,buf,0,0,XD_TIMEOUT * 2)) {
		xd_info[drive].heads = buf[0x04];				/* heads */
		xd_info[drive].cylinders = (buf[0x02] << 8) | buf[0x03];	/* cylinders */
		xd_info[drive].sectors = buf[0x05];				/* sectors */
		xd_info[drive].control = 0;					/* control byte */
	}
	else
		printk("xd_seagate_init_drive: error reading geometry from xd%c\n", 'a'+drive);
}

/* Omti support courtesy Dirk Melchers */
static void __init xd_omti_init_controller (unsigned int address)
{
	switch (address) {
		case 0x00000:
		case 0xC8000:	break;			/*initial: 0x320 */
		case 0xD0000:	xd_iobase = 0x324; break;
		case 0xD8000:	xd_iobase = 0x328; break;
		case 0xE0000:	xd_iobase = 0x32C; break;
		default:	printk("xd_omti_init_controller: unsupported BIOS address %06x\n",address);
				break;
	}
	
	xd_maxsectors = 0x40;

	outb(0,XD_RESET);		/* reset the controller */
}

static void __init xd_omti_init_drive (u_char drive)
{
	/* gets infos from drive */
	xd_override_init_drive(drive);

	/* set other parameters, Hardcoded, not that nice :-) */
	xd_info[drive].control = 2;
}

/* Xebec support (AK) */
static void __init xd_xebec_init_controller (unsigned int address)
{
/* iobase may be set manually in range 0x300 - 0x33C
      irq may be set manually to 2(9),3,4,5,6,7
      dma may be set manually to 1,2,3
	(How to detect them ???)
BIOS address may be set manually in range 0x0 - 0xF8000
If you need non-standard settings use the xd=... command */

	switch (address) {
		case 0x00000:
		case 0xC8000:	/* initially: xd_iobase==0x320 */
		case 0xD0000:
		case 0xD2000:
		case 0xD4000:
		case 0xD6000:
		case 0xD8000:
		case 0xDA000:
		case 0xDC000:
		case 0xDE000:
		case 0xE0000:	break;
		default:	printk("xd_xebec_init_controller: unsupported BIOS address %06x\n",address);
				break;
		}

	xd_maxsectors = 0x01;
	outb(0,XD_RESET);		/* reset the controller */

	xd_timer.expires = jiffies + XD_INIT_DISK_DELAY;
	add_timer(&xd_timer);
	sleep_on(&xdc_wait);
}

static void __init xd_xebec_init_drive (u_char drive)
{
	/* values from controller's BIOS - BIOS chip may be removed */
	static u_short geometry_table[][5] = {
		{0x132,4,0x080,0x080,0x7},
		{0x132,4,0x080,0x080,0x17},
		{0x264,2,0x100,0x100,0x7},
		{0x264,2,0x100,0x100,0x17},
		{0x132,8,0x080,0x080,0x7},
		{0x132,8,0x080,0x080,0x17},
		{0x264,4,0x100,0x100,0x6},
		{0x264,4,0x100,0x100,0x17},
		{0x2BC,5,0x2BC,0x12C,0x6},
		{0x3A5,4,0x3A5,0x3A5,0x7},
		{0x26C,6,0x26C,0x26C,0x7},
		{0x200,8,0x200,0x100,0x17},
		{0x400,5,0x400,0x400,0x7},
		{0x400,6,0x400,0x400,0x7},
		{0x264,8,0x264,0x200,0x17},
		{0x33E,7,0x33E,0x200,0x7}};
	u_char n;

	n = inb(XD_JUMPER) & 0x0F; /* BIOS's drive number: same geometry 
					is assumed for BOTH drives */
	if (xd_geo[3*drive])
		xd_manual_geo_set(drive);
	else {
		xd_info[drive].heads = (u_char)(geometry_table[n][1]);			/* heads */
		xd_info[drive].cylinders = geometry_table[n][0];	/* cylinders */
		xd_info[drive].sectors = 17;				/* sectors */
#if 0
		xd_info[drive].rwrite = geometry_table[n][2];	/* reduced write */
		xd_info[drive].precomp = geometry_table[n][3]		/* write precomp */
		xd_info[drive].ecc = 0x0B;				/* ecc length */
#endif /* 0 */
	}
	xd_info[drive].control = geometry_table[n][4];			/* control byte */
	xd_setparam(CMD_XBSETPARAM,drive,xd_info[drive].heads,xd_info[drive].cylinders,geometry_table[n][2],geometry_table[n][3],0x0B);
	xd_recalibrate(drive);
}

/* xd_override_init_drive: this finds disk geometry in a "binary search" style, narrowing in on the "correct" number of heads
   etc. by trying values until it gets the highest successful value. Idea courtesy Salvador Abreu ([e-mail]). */
static void __init xd_override_init_drive (u_char drive)
{
	u_short min[] = { 0,0,0 },max[] = { 16,1024,64 },test[] = { 0,0,0 };
	u_char cmdblk[6],i;

	if (xd_geo[3*drive])
		xd_manual_geo_set(drive);
	else {
		for (i = 0; i < 3; i++) {
			while (min[i] != max[i] - 1) {
				test[i] = (min[i] + max[i]) / 2;
				xd_build(cmdblk,CMD_SEEK,drive,(u_char) test[0],(u_short) test[1],(u_char) test[2],0,0);
				if (!xd_command(cmdblk,PIO_MODE,0,0,0,XD_TIMEOUT * 2))
					min[i] = test[i];
				else
					max[i] = test[i];
			}
			test[i] = min[i];
		}
		xd_info[drive].heads = (u_char) min[0] + 1;
		xd_info[drive].cylinders = (u_short) min[1] + 1;
		xd_info[drive].sectors = (u_char) min[2] + 1;
	}
	xd_info[drive].control = 0;
}

/* xd_setup: initialise controler from command line parameters */
void __init do_xd_setup (int *integers)
{
	switch (integers[0]) {
		case 4: if (integers[4] < 0)
				nodma = 1;
			else if (integers[4] < 8)
				xd_dma = integers[4];
		case 3: if ((integers[3] > 0) && (integers[3] <= 0x3FC))
				xd_iobase = integers[3];
		case 2: if ((integers[2] > 0) && (integers[2] < 16))
				xd_irq = integers[2];
		case 1: xd_override = 1;
			if ((integers[1] >= 0) && (integers[1] < (sizeof(xd_sigs) / sizeof(xd_sigs[0]))))
				xd_type = integers[1];
		case 0: break;
		default:printk("xd: too many parameters for xd\n");
	}
	xd_maxsectors = 0x01;
}

/* xd_setparam: set the drive characteristics */
static void __init xd_setparam (u_char command,u_char drive,u_char heads,u_short cylinders,u_short rwrite,u_short wprecomp,u_char ecc)
{
	u_char cmdblk[14];

	xd_build(cmdblk,command,drive,0,0,0,0,0);
	cmdblk[6] = (u_char) (cylinders >> 8) & 0x03;
	cmdblk[7] = (u_char) (cylinders & 0xFF);
	cmdblk[8] = heads & 0x1F;
	cmdblk[9] = (u_char) (rwrite >> 8) & 0x03;
	cmdblk[10] = (u_char) (rwrite & 0xFF);
	cmdblk[11] = (u_char) (wprecomp >> 8) & 0x03;
	cmdblk[12] = (u_char) (wprecomp & 0xFF);
	cmdblk[13] = ecc;

	/* Some controllers require geometry info as data, not command */

	if (xd_command(cmdblk,PIO_MODE,0,&cmdblk[6],0,XD_TIMEOUT * 2))
		printk("xd: error setting characteristics for xd%c\n", 'a'+drive);
}


#ifdef MODULE
static int xd[5] = { -1,-1,-1,-1, };

MODULE_PARM(xd, "1-4i");
MODULE_PARM(xd_geo, "3-6i");
MODULE_PARM(nodma, "i");

static void xd_done (void)
{
	struct gendisk ** gdp;
	
	blksize_size[MAJOR_NR] = NULL;
	blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
	blk_size[MAJOR_NR] = NULL;
	hardsect_size[MAJOR_NR] = NULL;
	read_ahead[MAJOR_NR] = 0;
	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
		if (*gdp == &xd_gendisk)
			break;
	if (*gdp)
		*gdp = (*gdp)->next;
	release_region(xd_iobase,4);
}

int init_module(void)
{
	int i,count = 0;
	int error;

	for (i = 4; i > 0; i--)
		if(((xd[i] = xd[i-1]) >= 0) && !count)
			count = i;
	if((xd[0] = count))
		do_xd_setup(xd);

	error = xd_init();
	if (error) return error;

	printk(KERN_INFO "XD: Loaded as a module.\n");
	if (!xd_drives) {
		/* no drives detected - unload module */
		devfs_unregister_blkdev(MAJOR_NR, "xd");
		xd_done();
		return (-1);
	}
        
	return 0;
}

void cleanup_module(void)
{
	int partition,dev,start;

	devfs_unregister_blkdev(MAJOR_NR, "xd");
	for (dev = 0; dev < xd_drives; dev++) {
		start = dev << xd_gendisk.minor_shift; 
		for (partition = xd_gendisk.max_p - 1; partition >= 0; partition--) {
			int minor = (start | partition);
			kdev_t devp = MKDEV(MAJOR_NR, minor);
			start = dev << xd_gendisk.minor_shift; 
			sync_dev(devp);
			invalidate_buffers(devp);
		}
	}
	xd_done();
	devfs_unregister (devfs_handle);
	if (xd_drives) {
		free_irq(xd_irq, NULL);
		free_dma(xd_dma);
		if (xd_dma_buffer)
			xd_dma_mem_free((unsigned long)xd_dma_buffer, xd_maxsectors * 0x200);
	}
}
#else

static int __init xd_setup (char *str)
{
	int ints[5];
	get_options (str, ARRAY_SIZE (ints), ints);
	do_xd_setup (ints);
	return 1;
}

/* xd_manual_geo_init: initialise drive geometry from command line parameters
   (used only for WD drives) */
static int __init xd_manual_geo_init (char *str)
{
	int i, integers[1 + 3*XD_MAXDRIVES];

	get_options (str, ARRAY_SIZE (integers), integers);
	if (integers[0]%3 != 0) {
		printk("xd: incorrect number of parameters for xd_geo\n");
		return 1;
	}
	for (i = 0; (i < integers[0]) && (i < 3*XD_MAXDRIVES); i++)
		xd_geo[i] = integers[i+1];
	return 1;
}

__setup ("xd=", xd_setup);
__setup ("xd_geo=", xd_manual_geo_init);

#endif /* MODULE */