ide-disk.c

讲述linux的初始化过程

			 * of data to be written.  If we hit an error (corrupted buffer list)
			 * in ide_multwrite(), then we need to remove the handler/timer
			 * before returning.  Fortunately, this NEVER happens (right?).
			 *
			 * Except when you get an error it seems...
			 */
			hwgroup->wrq = *rq; /* scratchpad */
			ide_set_handler (drive, &multwrite_intr, WAIT_CMD, NULL);
			if (ide_multwrite(drive, drive->mult_count)) {
				unsigned long flags;
				spin_lock_irqsave(&io_request_lock, flags);
				hwgroup->handler = NULL;
				del_timer(&hwgroup->timer);
				spin_unlock_irqrestore(&io_request_lock, flags);
				return ide_stopped;
			}
		} else {
			ide_set_handler (drive, &write_intr, WAIT_CMD, NULL);
			idedisk_output_data(drive, rq->buffer, SECTOR_WORDS);
		}
		return ide_started;
	}
	printk(KERN_ERR "%s: bad command: %d\n", drive->name, rq->cmd);
	ide_end_request(0, HWGROUP(drive));
	return ide_stopped;
}

static int idedisk_open (struct inode *inode, struct file *filp, ide_drive_t *drive)
{
	MOD_INC_USE_COUNT;
	if (drive->removable && drive->usage == 1) {
		check_disk_change(inode->i_rdev);
		/*
		 * Ignore the return code from door_lock,
		 * since the open() has already succeeded,
		 * and the door_lock is irrelevant at this point.
		 */
		if (drive->doorlocking && ide_wait_cmd(drive, WIN_DOORLOCK, 0, 0, 0, NULL))
			drive->doorlocking = 0;
	}
	return 0;
}

static void idedisk_release (struct inode *inode, struct file *filp, ide_drive_t *drive)
{
	if (drive->removable && !drive->usage) {
		invalidate_buffers(inode->i_rdev);
		if (drive->doorlocking && ide_wait_cmd(drive, WIN_DOORUNLOCK, 0, 0, 0, NULL))
			drive->doorlocking = 0;
	}
	MOD_DEC_USE_COUNT;
}

static int idedisk_media_change (ide_drive_t *drive)
{
	return drive->removable;	/* if removable, always assume it was changed */
}

static void idedisk_revalidate (ide_drive_t *drive)
{
	grok_partitions(HWIF(drive)->gd, drive->select.b.unit,
			1<<PARTN_BITS,
			current_capacity(drive));
}

/*
 * Compute drive->capacity, the full capacity of the drive
 * Called with drive->id != NULL.
 */
static void init_idedisk_capacity (ide_drive_t  *drive)
{
	struct hd_driveid *id = drive->id;
	unsigned long capacity = drive->cyl * drive->head * drive->sect;

	drive->select.b.lba = 0;

	/* Determine capacity, and use LBA if the drive properly supports it */
	if ((id->capability & 2) && lba_capacity_is_ok(id)) {
		capacity = id->lba_capacity;
		drive->cyl = capacity / (drive->head * drive->sect);
		drive->select.b.lba = 1;
	}
	drive->capacity = capacity;
}

static unsigned long idedisk_capacity (ide_drive_t  *drive)
{
	return (drive->capacity - drive->sect0);
}

static ide_startstop_t idedisk_special (ide_drive_t *drive)
{
	special_t *s = &drive->special;

	if (s->b.set_geometry) {
		s->b.set_geometry = 0;
		OUT_BYTE(drive->sect,IDE_SECTOR_REG);
		OUT_BYTE(drive->cyl,IDE_LCYL_REG);
		OUT_BYTE(drive->cyl>>8,IDE_HCYL_REG);
		OUT_BYTE(((drive->head-1)|drive->select.all)&0xBF,IDE_SELECT_REG);
		if (!IS_PDC4030_DRIVE)
			ide_cmd(drive, WIN_SPECIFY, drive->sect, &set_geometry_intr);
	} else if (s->b.recalibrate) {
		s->b.recalibrate = 0;
		if (!IS_PDC4030_DRIVE)
			ide_cmd(drive, WIN_RESTORE, drive->sect, &recal_intr);
	} else if (s->b.set_multmode) {
		s->b.set_multmode = 0;
		if (drive->id && drive->mult_req > drive->id->max_multsect)
			drive->mult_req = drive->id->max_multsect;
		if (!IS_PDC4030_DRIVE)
			ide_cmd(drive, WIN_SETMULT, drive->mult_req, &set_multmode_intr);
	} else if (s->all) {
		int special = s->all;
		s->all = 0;
		printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
		return ide_stopped;
	}
	return IS_PDC4030_DRIVE ? ide_stopped : ide_started;
}

static void idedisk_pre_reset (ide_drive_t *drive)
{
	drive->special.all = 0;
	drive->special.b.set_geometry = 1;
	drive->special.b.recalibrate  = 1;
	if (OK_TO_RESET_CONTROLLER)
		drive->mult_count = 0;
	if (!drive->keep_settings && !drive->using_dma)
		drive->mult_req = 0;
	if (drive->mult_req != drive->mult_count)
		drive->special.b.set_multmode = 1;
}

#ifdef CONFIG_PROC_FS

static int smart_enable(ide_drive_t *drive)
{
	return ide_wait_cmd(drive, WIN_SMART, 0, SMART_ENABLE, 0, NULL);
}

static int get_smart_values(ide_drive_t *drive, byte *buf)
{
	(void) smart_enable(drive);
	return ide_wait_cmd(drive, WIN_SMART, 0, SMART_READ_VALUES, 1, buf);
}

static int get_smart_thresholds(ide_drive_t *drive, byte *buf)
{
	(void) smart_enable(drive);
	return ide_wait_cmd(drive, WIN_SMART, 0, SMART_READ_THRESHOLDS, 1, buf);
}

static int proc_idedisk_read_cache
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *) data;
	char		*out = page;
	int		len;

	if (drive->id)
		len = sprintf(out,"%i\n", drive->id->buf_size / 2);
	else
		len = sprintf(out,"(none)\n");
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static int proc_idedisk_read_smart_thresholds
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *)data;
	int		len = 0, i = 0;

	if (!get_smart_thresholds(drive, page)) {
		unsigned short *val = ((unsigned short *)page) + 2;
		char *out = ((char *)val) + (SECTOR_WORDS * 4);
		page = out;
		do {
			out += sprintf(out, "%04x%c", le16_to_cpu(*val), (++i & 7) ? ' ' : '\n');
			val += 1;
		} while (i < (SECTOR_WORDS * 2));
		len = out - page;
	}
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static int proc_idedisk_read_smart_values
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *)data;
	int		len = 0, i = 0;

	if (!get_smart_values(drive, page)) {
		unsigned short *val = ((unsigned short *)page) + 2;
		char *out = ((char *)val) + (SECTOR_WORDS * 4);
		page = out;
		do {
			out += sprintf(out, "%04x%c", le16_to_cpu(*val), (++i & 7) ? ' ' : '\n');
			val += 1;
		} while (i < (SECTOR_WORDS * 2));
		len = out - page;
	}
	PROC_IDE_READ_RETURN(page,start,off,count,eof,len);
}

static ide_proc_entry_t idedisk_proc[] = {
	{ "cache",		S_IFREG|S_IRUGO,	proc_idedisk_read_cache,		NULL },
	{ "geometry",		S_IFREG|S_IRUGO,	proc_ide_read_geometry,			NULL },
	{ "smart_values",	S_IFREG|S_IRUSR,	proc_idedisk_read_smart_values,		NULL },
	{ "smart_thresholds",	S_IFREG|S_IRUSR,	proc_idedisk_read_smart_thresholds,	NULL },
	{ NULL, 0, NULL, NULL }
};

#else

#define	idedisk_proc	NULL

#endif	/* CONFIG_PROC_FS */

static int set_multcount(ide_drive_t *drive, int arg)
{
	struct request rq;

	if (drive->special.b.set_multmode)
		return -EBUSY;
	ide_init_drive_cmd (&rq);
	drive->mult_req = arg;
	drive->special.b.set_multmode = 1;
	(void) ide_do_drive_cmd (drive, &rq, ide_wait);
	return (drive->mult_count == arg) ? 0 : -EIO;
}

static int set_nowerr(ide_drive_t *drive, int arg)
{
	if (ide_spin_wait_hwgroup(drive))
		return -EBUSY;
	drive->nowerr = arg;
	drive->bad_wstat = arg ? BAD_R_STAT : BAD_W_STAT;
	spin_unlock_irq(&io_request_lock);
	return 0;
}

static void idedisk_add_settings(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	int major = HWIF(drive)->major;
	int minor = drive->select.b.unit << PARTN_BITS;

	ide_add_setting(drive,	"bios_cyl",		SETTING_RW,					-1,			-1,			TYPE_INT,	0,	65535,				1,	1,	&drive->bios_cyl,		NULL);
	ide_add_setting(drive,	"bios_head",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	255,				1,	1,	&drive->bios_head,		NULL);
	ide_add_setting(drive,	"bios_sect",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	63,				1,	1,	&drive->bios_sect,		NULL);
	ide_add_setting(drive,	"bswap",		SETTING_READ,					-1,			-1,			TYPE_BYTE,	0,	1,				1,	1,	&drive->bswap,			NULL);
	ide_add_setting(drive,	"multcount",		id ? SETTING_RW : SETTING_READ,			HDIO_GET_MULTCOUNT,	HDIO_SET_MULTCOUNT,	TYPE_BYTE,	0,	id ? id->max_multsect : 0,	1,	2,	&drive->mult_count,		set_multcount);
	ide_add_setting(drive,	"nowerr",		SETTING_RW,					HDIO_GET_NOWERR,	HDIO_SET_NOWERR,	TYPE_BYTE,	0,	1,				1,	1,	&drive->nowerr,			set_nowerr);
	ide_add_setting(drive,	"breada_readahead",	SETTING_RW,					BLKRAGET,		BLKRASET,		TYPE_INT,	0,	255,				1,	2,	&read_ahead[major],		NULL);
	ide_add_setting(drive,	"file_readahead",	SETTING_RW,					BLKFRAGET,		BLKFRASET,		TYPE_INTA,	0,	INT_MAX,			1,	1024,	&max_readahead[major][minor],	NULL);
	ide_add_setting(drive,	"max_kb_per_request",	SETTING_RW,					BLKSECTGET,		BLKSECTSET,		TYPE_INTA,	1,	255,				1,	2,	&max_sectors[major][minor],	NULL);
	ide_add_setting(drive,	"lun",			SETTING_RW,					-1,			-1,			TYPE_INT,	0,	7,				1,	1,	&drive->lun,			NULL);
}

/*
 *	IDE subdriver functions, registered with ide.c
 */
static ide_driver_t idedisk_driver = {
	"ide-disk",		/* name */
	IDEDISK_VERSION,	/* version */
	ide_disk,		/* media */
	0,			/* busy */
	1,			/* supports_dma */
	0,			/* supports_dsc_overlap */
	NULL,			/* cleanup */
	do_rw_disk,		/* do_request */
	NULL,			/* end_request */
	NULL,			/* ioctl */
	idedisk_open,		/* open */
	idedisk_release,	/* release */
	idedisk_media_change,	/* media_change */
	idedisk_revalidate,	/* revalidate */
	idedisk_pre_reset,	/* pre_reset */
	idedisk_capacity,	/* capacity */
	idedisk_special,	/* special */
	idedisk_proc		/* proc */
};

int idedisk_init (void);
static ide_module_t idedisk_module = {
	IDE_DRIVER_MODULE,
	idedisk_init,
	&idedisk_driver,
	NULL
};

static int idedisk_cleanup (ide_drive_t *drive)
{
	return ide_unregister_subdriver(drive);
}

static void idedisk_setup (ide_drive_t *drive)
{
	int i;
	
	struct hd_driveid *id = drive->id;
	unsigned long capacity;
	
	idedisk_add_settings(drive);

	if (id == NULL)
		return;

	/*
	 * CompactFlash cards and their brethern look just like hard drives
	 * to us, but they are removable and don't have a doorlock mechanism.
	 */
	if (drive->removable && !drive_is_flashcard(drive)) {
		/*
		 * Removable disks (eg. SYQUEST); ignore 'WD' drives 
		 */
		if (id->model[0] != 'W' || id->model[1] != 'D') {
			drive->doorlocking = 1;
		}
	}
	for (i = 0; i < MAX_DRIVES; ++i) {
		ide_hwif_t *hwif = HWIF(drive);

		if (drive != &hwif->drives[i]) continue;
		hwif->gd->de_arr[i] = drive->de;
		if (drive->removable)
			hwif->gd->flags[i] |= GENHD_FL_REMOVABLE;
		break;
	}

	/* 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->cyls;
		drive->head    = drive->bios_head = id->heads;
		drive->sect    = drive->bios_sect = id->sectors;
	}

	/* Handle logical geometry translation by the drive */
	if ((id->field_valid & 1) && id->cur_cyls &&
	    id->cur_heads && (id->cur_heads <= 16) && id->cur_sectors) {
		drive->cyl  = id->cur_cyls;
		drive->head = id->cur_heads;
		drive->sect = id->cur_sectors;
	}

	/* Use physical geometry if what we have still makes no sense */
	if (drive->head > 16 && id->heads && id->heads <= 16) {
		drive->cyl  = id->cyls;
		drive->head = id->heads;
		drive->sect = id->sectors;
	}

	/* calculate drive capacity, and select LBA if possible */
	init_idedisk_capacity (drive);

	/*
	 * if possible, give fdisk access to more of the drive,
	 * by correcting bios_cyls:
	 */
	capacity = idedisk_capacity (drive);
	if ((capacity >= (drive->bios_cyl * drive->bios_sect * drive->bios_head)) &&
	    (!drive->forced_geom) && drive->bios_sect && drive->bios_head)
		drive->bios_cyl = (capacity / drive->bios_sect) / drive->bios_head;

	printk (KERN_INFO "%s: %ld sectors", drive->name, capacity);

	/* Give size in megabytes (MB), not mebibytes (MiB). */
	/* We compute the exact rounded value, avoiding overflow. */
	printk (" (%ld MB)", (capacity - capacity/625 + 974)/1950);

	/* Only print cache size when it was specified */
	if (id->buf_size)
		printk (" w/%dKiB Cache", id->buf_size/2);

	printk(", CHS=%d/%d/%d", 
	       drive->bios_cyl, drive->bios_head, drive->bios_sect);
#ifdef CONFIG_BLK_DEV_IDEDMA
	if (drive->using_dma)
		(void) HWIF(drive)->dmaproc(ide_dma_verbose, drive);
#endif /* CONFIG_BLK_DEV_IDEDMA */
	printk("\n");

	drive->mult_count = 0;
	if (id->max_multsect) {
#ifdef CONFIG_IDEDISK_MULTI_MODE
		id->multsect = ((id->max_multsect/2) > 1) ? id->max_multsect : 0;
		id->multsect_valid = id->multsect ? 1 : 0;
		drive->mult_req = id->multsect_valid ? id->max_multsect : INITIAL_MULT_COUNT;
		drive->special.b.set_multmode = drive->mult_req ? 1 : 0;
#else	/* original, pre IDE-NFG, per request of AC */
		drive->mult_req = INITIAL_MULT_COUNT;
		if (drive->mult_req > id->max_multsect)
			drive->mult_req = id->max_multsect;
		if (drive->mult_req || ((id->multsect_valid & 1) && id->multsect))
			drive->special.b.set_multmode = 1;
#endif
	}
	drive->no_io_32bit = id->dword_io ? 1 : 0;
}

int idedisk_init (void)
{
	ide_drive_t *drive;
	int failed = 0;
	
	MOD_INC_USE_COUNT;
	while ((drive = ide_scan_devices (ide_disk, idedisk_driver.name, NULL, failed++)) != NULL) {
		if (ide_register_subdriver (drive, &idedisk_driver, IDE_SUBDRIVER_VERSION)) {
			printk (KERN_ERR "ide-disk: %s: Failed to register the driver with ide.c\n", drive->name);
			continue;
		}
		idedisk_setup(drive);
		if ((!drive->head || drive->head > 16) && !drive->select.b.lba) {
			printk(KERN_ERR "%s: INVALID GEOMETRY: %d PHYSICAL HEADS?\n", drive->name, drive->head);
			(void) idedisk_cleanup(drive);
			continue;
		}
		failed--;
	}
	ide_register_module(&idedisk_module);
	MOD_DEC_USE_COUNT;
	return 0;
}

#ifdef MODULE
int init_module (void)
{
	return idedisk_init();
}

void cleanup_module (void)
{
	ide_drive_t *drive;
	int failed = 0;

	while ((drive = ide_scan_devices (ide_disk, idedisk_driver.name, &idedisk_driver, failed)) != NULL) {
		if (idedisk_cleanup (drive)) {
			printk (KERN_ERR "%s: cleanup_module() called while still busy\n", drive->name);
			failed++;
		}
		/* We must remove proc entries defined in this module.
		   Otherwise we oops while accessing these entries */
		if (drive->proc)
			ide_remove_proc_entries(drive->proc, idedisk_proc);
	}
	ide_unregister_module(&idedisk_module);
}
#endif /* MODULE */