ide-probe.c

linux 内核源代码

	blk_queue_max_phys_segments(q, max_sg_entries);

	/* assign drive queue */
	drive->queue = q;

	/* needs drive->queue to be set */
	ide_toggle_bounce(drive, 1);

	return 0;
}

/*
 * This routine sets up the irq for an ide interface, and creates a new
 * hwgroup for the irq/hwif if none was previously assigned.
 *
 * Much of the code is for correctly detecting/handling irq sharing
 * and irq serialization situations.  This is somewhat complex because
 * it handles static as well as dynamic (PCMCIA) IDE interfaces.
 *
 * The IRQF_DISABLED in sa_flags means ide_intr() is always entered with
 * interrupts completely disabled.  This can be bad for interrupt latency,
 * but anything else has led to problems on some machines.  We re-enable
 * interrupts as much as we can safely do in most places.
 */
static int init_irq (ide_hwif_t *hwif)
{
	unsigned int index;
	ide_hwgroup_t *hwgroup;
	ide_hwif_t *match = NULL;


	BUG_ON(in_interrupt());
	BUG_ON(irqs_disabled());	
	BUG_ON(hwif == NULL);

	mutex_lock(&ide_cfg_mtx);
	hwif->hwgroup = NULL;
#if MAX_HWIFS > 1
	/*
	 * Group up with any other hwifs that share our irq(s).
	 */
	for (index = 0; index < MAX_HWIFS; index++) {
		ide_hwif_t *h = &ide_hwifs[index];
		if (h->hwgroup) {  /* scan only initialized hwif's */
			if (hwif->irq == h->irq) {
				hwif->sharing_irq = h->sharing_irq = 1;
				if (hwif->chipset != ide_pci ||
				    h->chipset != ide_pci) {
					save_match(hwif, h, &match);
				}
			}
			if (hwif->serialized) {
				if (hwif->mate && hwif->mate->irq == h->irq)
					save_match(hwif, h, &match);
			}
			if (h->serialized) {
				if (h->mate && hwif->irq == h->mate->irq)
					save_match(hwif, h, &match);
			}
		}
	}
#endif /* MAX_HWIFS > 1 */
	/*
	 * If we are still without a hwgroup, then form a new one
	 */
	if (match) {
		hwgroup = match->hwgroup;
		hwif->hwgroup = hwgroup;
		/*
		 * Link us into the hwgroup.
		 * This must be done early, do ensure that unexpected_intr
		 * can find the hwif and prevent irq storms.
		 * No drives are attached to the new hwif, choose_drive
		 * can't do anything stupid (yet).
		 * Add ourself as the 2nd entry to the hwgroup->hwif
		 * linked list, the first entry is the hwif that owns
		 * hwgroup->handler - do not change that.
		 */
		spin_lock_irq(&ide_lock);
		hwif->next = hwgroup->hwif->next;
		hwgroup->hwif->next = hwif;
		spin_unlock_irq(&ide_lock);
	} else {
		hwgroup = kmalloc_node(sizeof(ide_hwgroup_t),
					GFP_KERNEL | __GFP_ZERO,
					hwif_to_node(hwif->drives[0].hwif));
		if (!hwgroup)
	       		goto out_up;

		hwif->hwgroup = hwgroup;

		hwgroup->hwif     = hwif->next = hwif;
		hwgroup->rq       = NULL;
		hwgroup->handler  = NULL;
		hwgroup->drive    = NULL;
		hwgroup->busy     = 0;
		init_timer(&hwgroup->timer);
		hwgroup->timer.function = &ide_timer_expiry;
		hwgroup->timer.data = (unsigned long) hwgroup;
	}

	/*
	 * Allocate the irq, if not already obtained for another hwif
	 */
	if (!match || match->irq != hwif->irq) {
		int sa = IRQF_DISABLED;
#if defined(__mc68000__) || defined(CONFIG_APUS)
		sa = IRQF_SHARED;
#endif /* __mc68000__ || CONFIG_APUS */

		if (IDE_CHIPSET_IS_PCI(hwif->chipset)) {
			sa = IRQF_SHARED;
#ifndef CONFIG_IDEPCI_SHARE_IRQ
			sa |= IRQF_DISABLED;
#endif /* CONFIG_IDEPCI_SHARE_IRQ */
		}

		if (hwif->io_ports[IDE_CONTROL_OFFSET])
			/* clear nIEN */
			hwif->OUTB(0x08, hwif->io_ports[IDE_CONTROL_OFFSET]);

		if (request_irq(hwif->irq,&ide_intr,sa,hwif->name,hwgroup))
	       		goto out_unlink;
	}

	/*
	 * For any present drive:
	 * - allocate the block device queue
	 * - link drive into the hwgroup
	 */
	for (index = 0; index < MAX_DRIVES; ++index) {
		ide_drive_t *drive = &hwif->drives[index];
		if (!drive->present)
			continue;
		if (ide_init_queue(drive)) {
			printk(KERN_ERR "ide: failed to init %s\n",drive->name);
			continue;
		}
		spin_lock_irq(&ide_lock);
		if (!hwgroup->drive) {
			/* first drive for hwgroup. */
			drive->next = drive;
			hwgroup->drive = drive;
			hwgroup->hwif = HWIF(hwgroup->drive);
		} else {
			drive->next = hwgroup->drive->next;
			hwgroup->drive->next = drive;
		}
		spin_unlock_irq(&ide_lock);
	}

#if !defined(__mc68000__) && !defined(CONFIG_APUS)
	printk("%s at 0x%03lx-0x%03lx,0x%03lx on irq %d", hwif->name,
		hwif->io_ports[IDE_DATA_OFFSET],
		hwif->io_ports[IDE_DATA_OFFSET]+7,
		hwif->io_ports[IDE_CONTROL_OFFSET], hwif->irq);
#else
	printk("%s at 0x%08lx on irq %d", hwif->name,
		hwif->io_ports[IDE_DATA_OFFSET], hwif->irq);
#endif /* __mc68000__ && CONFIG_APUS */
	if (match)
		printk(" (%sed with %s)",
			hwif->sharing_irq ? "shar" : "serializ", match->name);
	printk("\n");
	mutex_unlock(&ide_cfg_mtx);
	return 0;
out_unlink:
	spin_lock_irq(&ide_lock);
	if (hwif->next == hwif) {
		BUG_ON(match);
		BUG_ON(hwgroup->hwif != hwif);
		kfree(hwgroup);
	} else {
		ide_hwif_t *g;
		g = hwgroup->hwif;
		while (g->next != hwif)
			g = g->next;
		g->next = hwif->next;
		if (hwgroup->hwif == hwif) {
			/* Impossible. */
			printk(KERN_ERR "Duh. Uninitialized hwif listed as active hwif.\n");
			hwgroup->hwif = g;
		}
		BUG_ON(hwgroup->hwif == hwif);
	}
	spin_unlock_irq(&ide_lock);
out_up:
	mutex_unlock(&ide_cfg_mtx);
	return 1;
}

static int ata_lock(dev_t dev, void *data)
{
	/* FIXME: we want to pin hwif down */
	return 0;
}

static struct kobject *ata_probe(dev_t dev, int *part, void *data)
{
	ide_hwif_t *hwif = data;
	int unit = *part >> PARTN_BITS;
	ide_drive_t *drive = &hwif->drives[unit];
	if (!drive->present)
		return NULL;

	if (drive->media == ide_disk)
		request_module("ide-disk");
	if (drive->scsi)
		request_module("ide-scsi");
	if (drive->media == ide_cdrom || drive->media == ide_optical)
		request_module("ide-cd");
	if (drive->media == ide_tape)
		request_module("ide-tape");
	if (drive->media == ide_floppy)
		request_module("ide-floppy");

	return NULL;
}

static struct kobject *exact_match(dev_t dev, int *part, void *data)
{
	struct gendisk *p = data;
	*part &= (1 << PARTN_BITS) - 1;
	return &p->kobj;
}

static int exact_lock(dev_t dev, void *data)
{
	struct gendisk *p = data;

	if (!get_disk(p))
		return -1;
	return 0;
}

void ide_register_region(struct gendisk *disk)
{
	blk_register_region(MKDEV(disk->major, disk->first_minor),
			    disk->minors, NULL, exact_match, exact_lock, disk);
}

EXPORT_SYMBOL_GPL(ide_register_region);

void ide_unregister_region(struct gendisk *disk)
{
	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
			      disk->minors);
}

EXPORT_SYMBOL_GPL(ide_unregister_region);

void ide_init_disk(struct gendisk *disk, ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	unsigned int unit = (drive->select.all >> 4) & 1;

	disk->major = hwif->major;
	disk->first_minor = unit << PARTN_BITS;
	sprintf(disk->disk_name, "hd%c", 'a' + hwif->index * MAX_DRIVES + unit);
	disk->queue = drive->queue;
}

EXPORT_SYMBOL_GPL(ide_init_disk);

static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	if (drive == drive->next) {
		/* special case: last drive from hwgroup. */
		BUG_ON(hwgroup->drive != drive);
		hwgroup->drive = NULL;
	} else {
		ide_drive_t *walk;

		walk = hwgroup->drive;
		while (walk->next != drive)
			walk = walk->next;
		walk->next = drive->next;
		if (hwgroup->drive == drive) {
			hwgroup->drive = drive->next;
			hwgroup->hwif = hwgroup->drive->hwif;
		}
	}
	BUG_ON(hwgroup->drive == drive);
}

static void drive_release_dev (struct device *dev)
{
	ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);

	spin_lock_irq(&ide_lock);
	ide_remove_drive_from_hwgroup(drive);
	kfree(drive->id);
	drive->id = NULL;
	drive->present = 0;
	/* Messed up locking ... */
	spin_unlock_irq(&ide_lock);
	blk_cleanup_queue(drive->queue);
	spin_lock_irq(&ide_lock);
	drive->queue = NULL;
	spin_unlock_irq(&ide_lock);

	complete(&drive->gendev_rel_comp);
}

/*
 * init_gendisk() (as opposed to ide_geninit) is called for each major device,
 * after probing for drives, to allocate partition tables and other data
 * structures needed for the routines in genhd.c.  ide_geninit() gets called
 * somewhat later, during the partition check.
 */
static void init_gendisk (ide_hwif_t *hwif)
{
	unsigned int unit;

	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t * drive = &hwif->drives[unit];
		ide_add_generic_settings(drive);
		snprintf(drive->gendev.bus_id,BUS_ID_SIZE,"%u.%u",
			 hwif->index,unit);
		drive->gendev.parent = &hwif->gendev;
		drive->gendev.bus = &ide_bus_type;
		drive->gendev.driver_data = drive;
		drive->gendev.release = drive_release_dev;
	}
	blk_register_region(MKDEV(hwif->major, 0), MAX_DRIVES << PARTN_BITS,
			THIS_MODULE, ata_probe, ata_lock, hwif);
}

static int hwif_init(ide_hwif_t *hwif)
{
	int old_irq;

	/* Return success if no device is connected */
	if (!hwif->present)
		return 1;

	if (!hwif->irq) {
		if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET])))
		{
			printk("%s: DISABLED, NO IRQ\n", hwif->name);
			return (hwif->present = 0);
		}
	}
#ifdef CONFIG_BLK_DEV_HD
	if (hwif->irq == HD_IRQ && hwif->io_ports[IDE_DATA_OFFSET] != HD_DATA) {
		printk("%s: CANNOT SHARE IRQ WITH OLD "
			"HARDDISK DRIVER (hd.c)\n", hwif->name);
		return (hwif->present = 0);
	}
#endif /* CONFIG_BLK_DEV_HD */

	/* we set it back to 1 if all is ok below */	
	hwif->present = 0;

	if (register_blkdev(hwif->major, hwif->name))
		return 0;

	if (!hwif->sg_max_nents)
		hwif->sg_max_nents = PRD_ENTRIES;

	hwif->sg_table = kmalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,
				 GFP_KERNEL);
	if (!hwif->sg_table) {
		printk(KERN_ERR "%s: unable to allocate SG table.\n", hwif->name);
		goto out;
	}

	sg_init_table(hwif->sg_table, hwif->sg_max_nents);
	
	if (init_irq(hwif) == 0)
		goto done;

	old_irq = hwif->irq;
	/*
	 *	It failed to initialise. Find the default IRQ for 
	 *	this port and try that.
	 */
	if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET]))) {
		printk("%s: Disabled unable to get IRQ %d.\n",
			hwif->name, old_irq);
		goto out;
	}
	if (init_irq(hwif)) {
		printk("%s: probed IRQ %d and default IRQ %d failed.\n",
			hwif->name, old_irq, hwif->irq);
		goto out;
	}
	printk("%s: probed IRQ %d failed, using default.\n",
		hwif->name, hwif->irq);

done:
	init_gendisk(hwif);

	ide_acpi_init(hwif);

	hwif->present = 1;	/* success */
	return 1;

out:
	unregister_blkdev(hwif->major, hwif->name);
	return 0;
}

static void hwif_register_devices(ide_hwif_t *hwif)
{
	unsigned int i;

	for (i = 0; i < MAX_DRIVES; i++) {
		ide_drive_t *drive = &hwif->drives[i];

		if (drive->present) {
			int ret = device_register(&drive->gendev);

			if (ret < 0)
				printk(KERN_WARNING "IDE: %s: "
					"device_register error: %d\n",
					__FUNCTION__, ret);
		}
	}
}

int ideprobe_init (void)
{
	unsigned int index;
	int probe[MAX_HWIFS];

	memset(probe, 0, MAX_HWIFS * sizeof(int));
	for (index = 0; index < MAX_HWIFS; ++index)
		probe[index] = !ide_hwifs[index].present;

	for (index = 0; index < MAX_HWIFS; ++index)
		if (probe[index])
			probe_hwif(&ide_hwifs[index]);
	for (index = 0; index < MAX_HWIFS; ++index)
		if (probe[index])
			hwif_init(&ide_hwifs[index]);
	for (index = 0; index < MAX_HWIFS; ++index) {
		if (probe[index]) {
			ide_hwif_t *hwif = &ide_hwifs[index];
			if (!hwif->present)
				continue;
			if (hwif->chipset == ide_unknown || hwif->chipset == ide_forced)
				hwif->chipset = ide_generic;
			hwif_register_devices(hwif);
		}
	}
	for (index = 0; index < MAX_HWIFS; ++index)
		if (probe[index])
			ide_proc_register_port(&ide_hwifs[index]);
	return 0;
}

EXPORT_SYMBOL_GPL(ideprobe_init);

int ide_device_add(u8 idx[4])
{
	int i, rc = 0;

	for (i = 0; i < 4; i++) {
		if (idx[i] != 0xff)
			rc |= probe_hwif_init(&ide_hwifs[idx[i]]);
	}

	for (i = 0; i < 4; i++) {
		if (idx[i] != 0xff)
			ide_proc_register_port(&ide_hwifs[idx[i]]);
	}

	return rc;
}

EXPORT_SYMBOL_GPL(ide_device_add);