ide.c

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 * This function issues a special IDE device request
 * onto the request queue.
 *
 * If action is ide_wait, then the rq is queued at the end of the
 * request queue, and the function sleeps until it has been processed.
 * This is for use when invoked from an ioctl handler.
 *
 * If action is ide_preempt, then the rq is queued at the head of
 * the request queue, displacing the currently-being-processed
 * request and this function returns immediately without waiting
 * for the new rq to be completed.  This is VERY DANGEROUS, and is
 * intended for careful use by the ATAPI tape/cdrom driver code.
 *
 * If action is ide_next, then the rq is queued immediately after
 * the currently-being-processed-request (if any), and the function
 * returns without waiting for the new rq to be completed.  As above,
 * This is VERY DANGEROUS, and is intended for careful use by the
 * ATAPI tape/cdrom driver code.
 *
 * If action is ide_end, then the rq is queued at the end of the
 * request queue, and the function returns immediately without waiting
 * for the new rq to be completed. This is again intended for careful
 * use by the ATAPI tape/cdrom driver code.
 */
int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
{
	unsigned long flags;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	unsigned int major = HWIF(drive)->major;
	struct list_head * queue_head;
	DECLARE_MUTEX_LOCKED(sem);

#ifdef CONFIG_BLK_DEV_PDC4030
	if (HWIF(drive)->chipset == ide_pdc4030 && rq->buffer != NULL)
		return -ENOSYS;  /* special drive cmds not supported */
#endif
	rq->errors = 0;
	rq->rq_status = RQ_ACTIVE;
	rq->rq_dev = MKDEV(major,(drive->select.b.unit)<<PARTN_BITS);
	if (action == ide_wait)
		rq->sem = &sem;
	spin_lock_irqsave(&io_request_lock, flags);
	queue_head = &drive->queue.queue_head;
	if (list_empty(queue_head) || action == ide_preempt) {
		if (action == ide_preempt)
			hwgroup->rq = NULL;
	} else {
		if (action == ide_wait || action == ide_end) {
			queue_head = queue_head->prev;
		} else
			queue_head = queue_head->next;
	}
	list_add(&rq->queue, queue_head);
	ide_do_request(hwgroup, 0);
	spin_unlock_irqrestore(&io_request_lock, flags);
	if (action == ide_wait) {
		down(&sem);			/* wait for it to be serviced */
		return rq->errors ? -EIO : 0;	/* return -EIO if errors */
	}
	return 0;

}

/*
 * 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.
 */
int ide_revalidate_disk (kdev_t i_rdev)
{
	ide_drive_t *drive;
	ide_hwgroup_t *hwgroup;
	unsigned int p, major, minor;
	long flags;

	if ((drive = get_info_ptr(i_rdev)) == NULL)
		return -ENODEV;
	major = MAJOR(i_rdev);
	minor = drive->select.b.unit << PARTN_BITS;
	hwgroup = HWGROUP(drive);
	spin_lock_irqsave(&io_request_lock, flags);
	if (drive->busy || (drive->usage > 1)) {
		spin_unlock_irqrestore(&io_request_lock, flags);
		return -EBUSY;
	};
	drive->busy = 1;
	MOD_INC_USE_COUNT;
	spin_unlock_irqrestore(&io_request_lock, flags);

	for (p = 0; p < (1<<PARTN_BITS); ++p) {
		if (drive->part[p].nr_sects > 0) {
			kdev_t devp = MKDEV(major, minor+p);
			struct super_block * sb = get_super(devp);
			fsync_dev          (devp);
			if (sb)
				invalidate_inodes(sb);
			invalidate_buffers (devp);
			set_blocksize(devp, 1024);
		}
		drive->part[p].start_sect = 0;
		drive->part[p].nr_sects   = 0;
	};

	if (DRIVER(drive)->revalidate)
		DRIVER(drive)->revalidate(drive);

	drive->busy = 0;
	wake_up(&drive->wqueue);
	MOD_DEC_USE_COUNT;
	return 0;
}

static void revalidate_drives (void)
{
	ide_hwif_t *hwif;
	ide_drive_t *drive;
	int index, unit;

	for (index = 0; index < MAX_HWIFS; ++index) {
		hwif = &ide_hwifs[index];
		for (unit = 0; unit < MAX_DRIVES; ++unit) {
			drive = &ide_hwifs[index].drives[unit];
			if (drive->revalidate) {
				drive->revalidate = 0;
				if (!initializing)
					(void) ide_revalidate_disk(MKDEV(hwif->major, unit<<PARTN_BITS));
			}
		}
	}
}

static void ide_probe_module (void)
{
	if (!ide_probe) {
#if defined(CONFIG_KMOD) && defined(CONFIG_BLK_DEV_IDE_MODULE)
		(void) request_module("ide-probe-mod");
#endif /* (CONFIG_KMOD) && (CONFIG_BLK_DEV_IDE_MODULE) */
	} else {
		(void) ide_probe->init();
	}
	revalidate_drives();
}

static void ide_driver_module (void)
{
	int index;
	ide_module_t *module = ide_modules;

	for (index = 0; index < MAX_HWIFS; ++index)
		if (ide_hwifs[index].present)
			goto search;
	ide_probe_module();
search:
	while (module) {
		(void) module->init();
		module = module->next;
	}
	revalidate_drives();
}

static int ide_open (struct inode * inode, struct file * filp)
{
	ide_drive_t *drive;
	int rc;

	if ((drive = get_info_ptr(inode->i_rdev)) == NULL)
		return -ENXIO;
	MOD_INC_USE_COUNT;
	if (drive->driver == NULL)
		ide_driver_module();
#ifdef CONFIG_KMOD
	if (drive->driver == NULL) {
		if (drive->media == ide_disk)
			(void) request_module("ide-disk");
		if (drive->media == ide_cdrom)
			(void) request_module("ide-cd");
		if (drive->media == ide_tape)
			(void) request_module("ide-tape");
		if (drive->media == ide_floppy)
			(void) request_module("ide-floppy");
	}
#endif /* CONFIG_KMOD */
	while (drive->busy)
		sleep_on(&drive->wqueue);
	drive->usage++;
	if (drive->driver != NULL) {
		if ((rc = DRIVER(drive)->open(inode, filp, drive)))
			MOD_DEC_USE_COUNT;
		return rc;
	}
	printk ("%s: driver not present\n", drive->name);
	drive->usage--;
	MOD_DEC_USE_COUNT;
	return -ENXIO;
}

/*
 * Releasing a block device means we sync() it, so that it can safely
 * be forgotten about...
 */
static int ide_release (struct inode * inode, struct file * file)
{
	ide_drive_t *drive;

	if ((drive = get_info_ptr(inode->i_rdev)) != NULL) {
		drive->usage--;
		if (drive->driver != NULL)
			DRIVER(drive)->release(inode, file, drive);
		MOD_DEC_USE_COUNT;
	}
	return 0;
}

int ide_replace_subdriver (ide_drive_t *drive, const char *driver)
{
	if (!drive->present || drive->busy || drive->usage)
		goto abort;
	if (drive->driver != NULL && DRIVER(drive)->cleanup(drive))
		goto abort;
	strncpy(drive->driver_req, driver, 9);
	ide_driver_module();
	drive->driver_req[0] = 0;
	ide_driver_module();
	if (DRIVER(drive) && !strcmp(DRIVER(drive)->name, driver))
		return 0;
abort:
	return 1;
}

#ifdef CONFIG_PROC_FS
ide_proc_entry_t generic_subdriver_entries[] = {
	{ "capacity",	S_IFREG|S_IRUGO,	proc_ide_read_capacity,	NULL },
	{ NULL, 0, NULL, NULL }
};
#endif

/*
 * Note that we only release the standard ports,
 * and do not even try to handle any extra ports
 * allocated for weird IDE interface chipsets.
 */
void hwif_unregister (ide_hwif_t *hwif)
{
	if (hwif->straight8) {
		ide_release_region(hwif->io_ports[IDE_DATA_OFFSET], 8);
		goto jump_eight;
	}
	if (hwif->io_ports[IDE_DATA_OFFSET])
		ide_release_region(hwif->io_ports[IDE_DATA_OFFSET], 1);
	if (hwif->io_ports[IDE_ERROR_OFFSET])
		ide_release_region(hwif->io_ports[IDE_ERROR_OFFSET], 1);
	if (hwif->io_ports[IDE_NSECTOR_OFFSET])
		ide_release_region(hwif->io_ports[IDE_NSECTOR_OFFSET], 1);
	if (hwif->io_ports[IDE_SECTOR_OFFSET])
		ide_release_region(hwif->io_ports[IDE_SECTOR_OFFSET], 1);
	if (hwif->io_ports[IDE_LCYL_OFFSET])
		ide_release_region(hwif->io_ports[IDE_LCYL_OFFSET], 1);
	if (hwif->io_ports[IDE_HCYL_OFFSET])
		ide_release_region(hwif->io_ports[IDE_HCYL_OFFSET], 1);
	if (hwif->io_ports[IDE_SELECT_OFFSET])
		ide_release_region(hwif->io_ports[IDE_SELECT_OFFSET], 1);
	if (hwif->io_ports[IDE_STATUS_OFFSET])
		ide_release_region(hwif->io_ports[IDE_STATUS_OFFSET], 1);
jump_eight:
	if (hwif->io_ports[IDE_CONTROL_OFFSET])
		ide_release_region(hwif->io_ports[IDE_CONTROL_OFFSET], 1);
#if defined(CONFIG_AMIGA) || defined(CONFIG_MAC)
	if (hwif->io_ports[IDE_IRQ_OFFSET])
		ide_release_region(hwif->io_ports[IDE_IRQ_OFFSET], 1);
#endif /* (CONFIG_AMIGA) || (CONFIG_MAC) */
}

void ide_unregister (unsigned int index)
{
	struct gendisk *gd, **gdp;
	ide_drive_t *drive, *d;
	ide_hwif_t *hwif, *g;
	ide_hwgroup_t *hwgroup;
	int irq_count = 0, unit, i;
	unsigned long flags;
	unsigned int p, minor;
	ide_hwif_t old_hwif;

	if (index >= MAX_HWIFS)
		return;
	save_flags(flags);	/* all CPUs */
	cli();			/* all CPUs */
	hwif = &ide_hwifs[index];
	if (!hwif->present)
		goto abort;
	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		drive = &hwif->drives[unit];
		if (!drive->present)
			continue;
		if (drive->busy || drive->usage)
			goto abort;
		if (drive->driver != NULL && DRIVER(drive)->cleanup(drive))
			goto abort;
	}
	hwif->present = 0;
	
	/*
	 * All clear?  Then blow away the buffer cache
	 */
	sti();
	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		drive = &hwif->drives[unit];
		if (!drive->present)
			continue;
		minor = drive->select.b.unit << PARTN_BITS;
		for (p = 0; p < (1<<PARTN_BITS); ++p) {
			if (drive->part[p].nr_sects > 0) {
				kdev_t devp = MKDEV(hwif->major, minor+p);
				struct super_block * sb = get_super(devp);
				if (sb) invalidate_inodes(sb);
				invalidate_buffers (devp);
			}
		}
#ifdef CONFIG_PROC_FS
		destroy_proc_ide_drives(hwif);
#endif
	}
	cli();
	hwgroup = hwif->hwgroup;

	/*
	 * free the irq if we were the only hwif using it
	 */
	g = hwgroup->hwif;
	do {
		if (g->irq == hwif->irq)
			++irq_count;
		g = g->next;
	} while (g != hwgroup->hwif);
	if (irq_count == 1)
		free_irq(hwif->irq, hwgroup);

	/*
	 * Note that we only release the standard ports,
	 * and do not even try to handle any extra ports
	 * allocated for weird IDE interface chipsets.
	 */
	hwif_unregister(hwif);

	/*
	 * Remove us from the hwgroup, and free
	 * the hwgroup if we were the only member
	 */
	d = hwgroup->drive;
	for (i = 0; i < MAX_DRIVES; ++i) {
		drive = &hwif->drives[i];
		if (drive->de) {
			devfs_unregister (drive->de);
			drive->de = NULL;
		}
		if (!drive->present)
			continue;
		while (hwgroup->drive->next != drive)
			hwgroup->drive = hwgroup->drive->next;
		hwgroup->drive->next = drive->next;
		if (hwgroup->drive == drive)
			hwgroup->drive = NULL;
		if (drive->id != NULL) {
			kfree(drive->id);
			drive->id = NULL;
		}
		drive->present = 0;
		blk_cleanup_queue(&drive->queue);
	}
	if (d->present)
		hwgroup->drive = d;
	while (hwgroup->hwif->next != hwif)
		hwgroup->hwif = hwgroup->hwif->next;
	hwgroup->hwif->next = hwif->next;
	if (hwgroup->hwif == hwif)
		kfree(hwgroup);
	else
		hwgroup->hwif = HWIF(hwgroup->drive);

#if defined(CONFIG_BLK_DEV_IDEDMA) && !defined(CONFIG_DMA_NONPCI)
	if (hwif->dma_base) {
		(void) ide_release_dma(hwif);
		hwif->dma_base = 0;
	}
#endif /* (CONFIG_BLK_DEV_IDEDMA) && !(CONFIG_DMA_NONPCI) */

	/*
	 * Remove us from the kernel's knowledge
	 */
	unregister_blkdev(hwif->major, hwif->name);
	kfree(blksize_size[hwif->major]);
	kfree(max_sectors[hwif->major]);
	kfree(max_readahead[hwif->major]);
	blk_dev[hwif->major].data = NULL;
	blk_dev[hwif->major].queue = NULL;
	blksize_size[hwif->major] = NULL;
	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
		if (*gdp == hwif->gd)
			break;
	if (*gdp == NULL)
		printk("gd not in disk chain!\n");
	else {
		gd = *gdp; *gdp = gd->next;
		kfree(gd->sizes);
		kfree(gd->part);
		if (gd->de_arr)
			kfree (gd->de_arr);
		if (gd->flags)
			kfree (gd->flags);
		kfree(gd);
	}
	old_hwif		= *hwif;
	init_hwif_data (index);	/* r