ide-probe.c

linux 内核源代码

		rc = 3;
	}
	if (drive->select.b.unit != 0) {
		/* exit with drive0 selected */
		SELECT_DRIVE(&hwif->drives[0]);
		msleep(50);
		/* ensure drive irq is clear */
		(void) hwif->INB(IDE_STATUS_REG);
	}
	return rc;
}

/*
 *
 */
static void enable_nest (ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	unsigned long timeout;

	printk("%s: enabling %s -- ", hwif->name, drive->id->model);
	SELECT_DRIVE(drive);
	msleep(50);
	hwif->OUTB(EXABYTE_ENABLE_NEST, IDE_COMMAND_REG);
	timeout = jiffies + WAIT_WORSTCASE;
	do {
		if (time_after(jiffies, timeout)) {
			printk("failed (timeout)\n");
			return;
		}
		msleep(50);
	} while ((hwif->INB(IDE_STATUS_REG)) & BUSY_STAT);

	msleep(50);

	if (!OK_STAT((hwif->INB(IDE_STATUS_REG)), 0, BAD_STAT)) {
		printk("failed (status = 0x%02x)\n", hwif->INB(IDE_STATUS_REG));
	} else {
		printk("success\n");
	}

	/* if !(success||timed-out) */
	if (do_probe(drive, WIN_IDENTIFY) >= 2) {
		/* look for ATAPI device */
		(void) do_probe(drive, WIN_PIDENTIFY);
	}
}

/**
 *	probe_for_drives	-	upper level drive probe
 *	@drive: drive to probe for
 *
 *	probe_for_drive() tests for existence of a given drive using do_probe()
 *	and presents things to the user as needed.
 *
 *	Returns:	0  no device was found
 *			1  device was found (note: drive->present might
 *			   still be 0)
 */
 
static inline u8 probe_for_drive (ide_drive_t *drive)
{
	/*
	 *	In order to keep things simple we have an id
	 *	block for all drives at all times. If the device
	 *	is pre ATA or refuses ATA/ATAPI identify we
	 *	will add faked data to this.
	 *
	 *	Also note that 0 everywhere means "can't do X"
	 */
 
	drive->id = kzalloc(SECTOR_WORDS *4, GFP_KERNEL);
	drive->id_read = 0;
	if(drive->id == NULL)
	{
		printk(KERN_ERR "ide: out of memory for id data.\n");
		return 0;
	}
	strcpy(drive->id->model, "UNKNOWN");
	
	/* skip probing? */
	if (!drive->noprobe)
	{
		/* if !(success||timed-out) */
		if (do_probe(drive, WIN_IDENTIFY) >= 2) {
			/* look for ATAPI device */
			(void) do_probe(drive, WIN_PIDENTIFY);
		}
		if (!drive->present)
			/* drive not found */
			return 0;
		if (strstr(drive->id->model, "E X A B Y T E N E S T"))
			enable_nest(drive);
	
		/* identification failed? */
		if (!drive->id_read) {
			if (drive->media == ide_disk) {
				printk(KERN_INFO "%s: non-IDE drive, CHS=%d/%d/%d\n",
					drive->name, drive->cyl,
					drive->head, drive->sect);
			} else if (drive->media == ide_cdrom) {
				printk(KERN_INFO "%s: ATAPI cdrom (?)\n", drive->name);
			} else {
				/* nuke it */
				printk(KERN_WARNING "%s: Unknown device on bus refused identification. Ignoring.\n", drive->name);
				drive->present = 0;
			}
		}
		/* drive was found */
	}
	if(!drive->present)
		return 0;
	/* The drive wasn't being helpful. Add generic info only */
	if (drive->id_read == 0) {
		generic_id(drive);
		return 1;
	}

	if (drive->media == ide_disk) {
		ide_disk_init_chs(drive);
		ide_disk_init_mult_count(drive);
	}

	return drive->present;
}

static void hwif_release_dev (struct device *dev)
{
	ide_hwif_t *hwif = container_of(dev, ide_hwif_t, gendev);

	complete(&hwif->gendev_rel_comp);
}

static void hwif_register (ide_hwif_t *hwif)
{
	int ret;

	/* register with global device tree */
	strlcpy(hwif->gendev.bus_id,hwif->name,BUS_ID_SIZE);
	hwif->gendev.driver_data = hwif;
	if (hwif->gendev.parent == NULL) {
		if (hwif->pci_dev)
			hwif->gendev.parent = &hwif->pci_dev->dev;
		else
			/* Would like to do = &device_legacy */
			hwif->gendev.parent = NULL;
	}
	hwif->gendev.release = hwif_release_dev;
	ret = device_register(&hwif->gendev);
	if (ret < 0)
		printk(KERN_WARNING "IDE: %s: device_register error: %d\n",
			__FUNCTION__, ret);
}

static int wait_hwif_ready(ide_hwif_t *hwif)
{
	int unit, rc;

	printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name);

	/* Let HW settle down a bit from whatever init state we
	 * come from */
	mdelay(2);

	/* Wait for BSY bit to go away, spec timeout is 30 seconds,
	 * I know of at least one disk who takes 31 seconds, I use 35
	 * here to be safe
	 */
	rc = ide_wait_not_busy(hwif, 35000);
	if (rc)
		return rc;

	/* Now make sure both master & slave are ready */
	for (unit = 0; unit < MAX_DRIVES; unit++) {
		ide_drive_t *drive = &hwif->drives[unit];

		/* Ignore disks that we will not probe for later. */
		if (!drive->noprobe || drive->present) {
			SELECT_DRIVE(drive);
			if (IDE_CONTROL_REG)
				hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
			mdelay(2);
			rc = ide_wait_not_busy(hwif, 35000);
			if (rc)
				goto out;
		} else
			printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n",
					  drive->name);
	}
out:
	/* Exit function with master reselected (let's be sane) */
	if (unit)
		SELECT_DRIVE(&hwif->drives[0]);

	return rc;
}

/**
 *	ide_undecoded_slave	-	look for bad CF adapters
 *	@hwif: interface
 *
 *	Analyse the drives on the interface and attempt to decide if we
 *	have the same drive viewed twice. This occurs with crap CF adapters
 *	and PCMCIA sometimes.
 */

void ide_undecoded_slave(ide_hwif_t *hwif)
{
	ide_drive_t *drive0 = &hwif->drives[0];
	ide_drive_t *drive1 = &hwif->drives[1];

	if (drive0->present == 0 || drive1->present == 0)
		return;

	/* If the models don't match they are not the same product */
	if (strcmp(drive0->id->model, drive1->id->model))
		return;

	/* Serial numbers do not match */
	if (strncmp(drive0->id->serial_no, drive1->id->serial_no, 20))
		return;

	/* No serial number, thankfully very rare for CF */
	if (drive0->id->serial_no[0] == 0)
		return;

	/* Appears to be an IDE flash adapter with decode bugs */
	printk(KERN_WARNING "ide-probe: ignoring undecoded slave\n");

	drive1->present = 0;
}

EXPORT_SYMBOL_GPL(ide_undecoded_slave);

/*
 * This routine only knows how to look for drive units 0 and 1
 * on an interface, so any setting of MAX_DRIVES > 2 won't work here.
 */
static void probe_hwif(ide_hwif_t *hwif)
{
	unsigned long flags;
	unsigned int irqd;
	int unit;

	if (hwif->noprobe)
		return;

	if ((hwif->chipset != ide_4drives || !hwif->mate || !hwif->mate->present) &&
	    (ide_hwif_request_regions(hwif))) {
		u16 msgout = 0;
		for (unit = 0; unit < MAX_DRIVES; ++unit) {
			ide_drive_t *drive = &hwif->drives[unit];
			if (drive->present) {
				drive->present = 0;
				printk(KERN_ERR "%s: ERROR, PORTS ALREADY IN USE\n",
					drive->name);
				msgout = 1;
			}
		}
		if (!msgout)
			printk(KERN_ERR "%s: ports already in use, skipping probe\n",
				hwif->name);
		return;	
	}

	/*
	 * We must always disable IRQ, as probe_for_drive will assert IRQ, but
	 * we'll install our IRQ driver much later...
	 */
	irqd = hwif->irq;
	if (irqd)
		disable_irq(hwif->irq);

	local_irq_set(flags);

	/* This is needed on some PPCs and a bunch of BIOS-less embedded
	 * platforms. Typical cases are:
	 * 
	 *  - The firmware hard reset the disk before booting the kernel,
	 *    the drive is still doing it's poweron-reset sequence, that
	 *    can take up to 30 seconds
	 *  - The firmware does nothing (or no firmware), the device is
	 *    still in POST state (same as above actually).
	 *  - Some CD/DVD/Writer combo drives tend to drive the bus during
	 *    their reset sequence even when they are non-selected slave
	 *    devices, thus preventing discovery of the main HD
	 *    
	 *  Doing this wait-for-busy should not harm any existing configuration
	 *  (at least things won't be worse than what current code does, that
	 *  is blindly go & talk to the drive) and fix some issues like the
	 *  above.
	 *  
	 *  BenH.
	 */
	if (wait_hwif_ready(hwif) == -EBUSY)
		printk(KERN_DEBUG "%s: Wait for ready failed before probe !\n", hwif->name);

	/*
	 * Need to probe slave device first to make it release PDIAG-.
	 */
	for (unit = MAX_DRIVES - 1; unit >= 0; unit--) {
		ide_drive_t *drive = &hwif->drives[unit];
		drive->dn = (hwif->channel ? 2 : 0) + unit;
		(void) probe_for_drive(drive);
		if (drive->present && !hwif->present) {
			hwif->present = 1;
			if (hwif->chipset != ide_4drives ||
			    !hwif->mate || 
			    !hwif->mate->present) {
				hwif_register(hwif);
			}
		}
	}
	if (hwif->io_ports[IDE_CONTROL_OFFSET] && hwif->reset) {
		unsigned long timeout = jiffies + WAIT_WORSTCASE;
		u8 stat;

		printk(KERN_WARNING "%s: reset\n", hwif->name);
		hwif->OUTB(12, hwif->io_ports[IDE_CONTROL_OFFSET]);
		udelay(10);
		hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
		do {
			msleep(50);
			stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
		} while ((stat & BUSY_STAT) && time_after(timeout, jiffies));

	}
	local_irq_restore(flags);
	/*
	 * Use cached IRQ number. It might be (and is...) changed by probe
	 * code above
	 */
	if (irqd)
		enable_irq(irqd);

	if (!hwif->present) {
		ide_hwif_release_regions(hwif);
		return;
	}

	if (hwif->fixup)
		hwif->fixup(hwif);

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

		if (drive->present) {
			if (drive->autotune == IDE_TUNE_AUTO)
				ide_set_max_pio(drive);

			if (drive->autotune != IDE_TUNE_DEFAULT &&
			    drive->autotune != IDE_TUNE_AUTO)
				continue;

			drive->nice1 = 1;

			if (hwif->ide_dma_on) {
				/*
				 * Force DMAing for the beginning of the check.
				 * Some chipsets appear to do interesting
				 * things, if not checked and cleared.
				 *   PARANOIA!!!
				 */
				hwif->dma_off_quietly(drive);
				ide_set_dma(drive);
			}
		}
	}

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

		if (hwif->no_io_32bit)
			drive->no_io_32bit = 1;
		else
			drive->no_io_32bit = drive->id->dword_io ? 1 : 0;
	}
}

static int hwif_init(ide_hwif_t *hwif);
static void hwif_register_devices(ide_hwif_t *hwif);

static int probe_hwif_init(ide_hwif_t *hwif)
{
	probe_hwif(hwif);

	if (!hwif_init(hwif)) {
		printk(KERN_INFO "%s: failed to initialize IDE interface\n",
				 hwif->name);
		return -1;
	}

	if (hwif->present)
		hwif_register_devices(hwif);

	return 0;
}

#if MAX_HWIFS > 1
/*
 * save_match() is used to simplify logic in init_irq() below.
 *
 * A loophole here is that we may not know about a particular
 * hwif's irq until after that hwif is actually probed/initialized..
 * This could be a problem for the case where an hwif is on a
 * dual interface that requires serialization (eg. cmd640) and another
 * hwif using one of the same irqs is initialized beforehand.
 *
 * This routine detects and reports such situations, but does not fix them.
 */
static void save_match(ide_hwif_t *hwif, ide_hwif_t *new, ide_hwif_t **match)
{
	ide_hwif_t *m = *match;

	if (m && m->hwgroup && m->hwgroup != new->hwgroup) {
		if (!new->hwgroup)
			return;
		printk("%s: potential irq problem with %s and %s\n",
			hwif->name, new->name, m->name);
	}
	if (!m || m->irq != hwif->irq) /* don't undo a prior perfect match */
		*match = new;
}
#endif /* MAX_HWIFS > 1 */

/*
 * init request queue
 */
static int ide_init_queue(ide_drive_t *drive)
{
	struct request_queue *q;
	ide_hwif_t *hwif = HWIF(drive);
	int max_sectors = 256;
	int max_sg_entries = PRD_ENTRIES;

	/*
	 *	Our default set up assumes the normal IDE case,
	 *	that is 64K segmenting, standard PRD setup
	 *	and LBA28. Some drivers then impose their own
	 *	limits and LBA48 we could raise it but as yet
	 *	do not.
	 */

	q = blk_init_queue_node(do_ide_request, &ide_lock, hwif_to_node(hwif));
	if (!q)
		return 1;

	q->queuedata = drive;
	blk_queue_segment_boundary(q, 0xffff);

	if (!hwif->rqsize) {
		if ((hwif->host_flags & IDE_HFLAG_NO_LBA48) ||
		    (hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA))
			hwif->rqsize = 256;
		else
			hwif->rqsize = 65536;
	}
	if (hwif->rqsize < max_sectors)
		max_sectors = hwif->rqsize;
	blk_queue_max_sectors(q, max_sectors);

#ifdef CONFIG_PCI
	/* When we have an IOMMU, we may have a problem where pci_map_sg()
	 * creates segments that don't completely match our boundary
	 * requirements and thus need to be broken up again. Because it
	 * doesn't align properly either, we may actually have to break up
	 * to more segments than what was we got in the first place, a max
	 * worst case is twice as many.
	 * This will be fixed once we teach pci_map_sg() about our boundary
	 * requirements, hopefully soon. *FIXME*
	 */
	if (!PCI_DMA_BUS_IS_PHYS)
		max_sg_entries >>= 1;
#endif /* CONFIG_PCI */

	blk_queue_max_hw_segments(q, max_sg_entries);