ide-iops.c

linux 内核源代码

	drive->id->dma_mword &= ~0x0F00;
	drive->id->dma_1word &= ~0x0F00;

 skip:
#ifdef CONFIG_BLK_DEV_IDEDMA
	if (speed >= XFER_SW_DMA_0)
		hwif->dma_host_on(drive);
	else if (hwif->ide_dma_on)	/* check if host supports DMA */
		hwif->dma_off_quietly(drive);
#endif

	switch(speed) {
		case XFER_UDMA_7:   drive->id->dma_ultra |= 0x8080; break;
		case XFER_UDMA_6:   drive->id->dma_ultra |= 0x4040; break;
		case XFER_UDMA_5:   drive->id->dma_ultra |= 0x2020; break;
		case XFER_UDMA_4:   drive->id->dma_ultra |= 0x1010; break;
		case XFER_UDMA_3:   drive->id->dma_ultra |= 0x0808; break;
		case XFER_UDMA_2:   drive->id->dma_ultra |= 0x0404; break;
		case XFER_UDMA_1:   drive->id->dma_ultra |= 0x0202; break;
		case XFER_UDMA_0:   drive->id->dma_ultra |= 0x0101; break;
		case XFER_MW_DMA_2: drive->id->dma_mword |= 0x0404; break;
		case XFER_MW_DMA_1: drive->id->dma_mword |= 0x0202; break;
		case XFER_MW_DMA_0: drive->id->dma_mword |= 0x0101; break;
		case XFER_SW_DMA_2: drive->id->dma_1word |= 0x0404; break;
		case XFER_SW_DMA_1: drive->id->dma_1word |= 0x0202; break;
		case XFER_SW_DMA_0: drive->id->dma_1word |= 0x0101; break;
		default: break;
	}
	if (!drive->init_speed)
		drive->init_speed = speed;
	drive->current_speed = speed;
	return error;
}

/*
 * This should get invoked any time we exit the driver to
 * wait for an interrupt response from a drive.  handler() points
 * at the appropriate code to handle the next interrupt, and a
 * timer is started to prevent us from waiting forever in case
 * something goes wrong (see the ide_timer_expiry() handler later on).
 *
 * See also ide_execute_command
 */
static void __ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
		      unsigned int timeout, ide_expiry_t *expiry)
{
	ide_hwgroup_t *hwgroup = HWGROUP(drive);

	if (hwgroup->handler != NULL) {
		printk(KERN_CRIT "%s: ide_set_handler: handler not null; "
			"old=%p, new=%p\n",
			drive->name, hwgroup->handler, handler);
	}
	hwgroup->handler	= handler;
	hwgroup->expiry		= expiry;
	hwgroup->timer.expires	= jiffies + timeout;
	hwgroup->req_gen_timer = hwgroup->req_gen;
	add_timer(&hwgroup->timer);
}

void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,
		      unsigned int timeout, ide_expiry_t *expiry)
{
	unsigned long flags;
	spin_lock_irqsave(&ide_lock, flags);
	__ide_set_handler(drive, handler, timeout, expiry);
	spin_unlock_irqrestore(&ide_lock, flags);
}

EXPORT_SYMBOL(ide_set_handler);
 
/**
 *	ide_execute_command	-	execute an IDE command
 *	@drive: IDE drive to issue the command against
 *	@command: command byte to write
 *	@handler: handler for next phase
 *	@timeout: timeout for command
 *	@expiry:  handler to run on timeout
 *
 *	Helper function to issue an IDE command. This handles the
 *	atomicity requirements, command timing and ensures that the 
 *	handler and IRQ setup do not race. All IDE command kick off
 *	should go via this function or do equivalent locking.
 */
 
void ide_execute_command(ide_drive_t *drive, task_ioreg_t cmd, ide_handler_t *handler, unsigned timeout, ide_expiry_t *expiry)
{
	unsigned long flags;
	ide_hwgroup_t *hwgroup = HWGROUP(drive);
	ide_hwif_t *hwif = HWIF(drive);
	
	spin_lock_irqsave(&ide_lock, flags);
	
	BUG_ON(hwgroup->handler);
	hwgroup->handler	= handler;
	hwgroup->expiry		= expiry;
	hwgroup->timer.expires	= jiffies + timeout;
	hwgroup->req_gen_timer = hwgroup->req_gen;
	add_timer(&hwgroup->timer);
	hwif->OUTBSYNC(drive, cmd, IDE_COMMAND_REG);
	/* Drive takes 400nS to respond, we must avoid the IRQ being
	   serviced before that. 
	   
	   FIXME: we could skip this delay with care on non shared
	   devices 
	*/
	ndelay(400);
	spin_unlock_irqrestore(&ide_lock, flags);
}

EXPORT_SYMBOL(ide_execute_command);


/* needed below */
static ide_startstop_t do_reset1 (ide_drive_t *, int);

/*
 * atapi_reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an atapi drive reset operation. If the drive has not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t atapi_reset_pollfunc (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	u8 stat;

	SELECT_DRIVE(drive);
	udelay (10);

	if (OK_STAT(stat = hwif->INB(IDE_STATUS_REG), 0, BUSY_STAT)) {
		printk("%s: ATAPI reset complete\n", drive->name);
	} else {
		if (time_before(jiffies, hwgroup->poll_timeout)) {
			BUG_ON(HWGROUP(drive)->handler != NULL);
			ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
			/* continue polling */
			return ide_started;
		}
		/* end of polling */
		hwgroup->polling = 0;
		printk("%s: ATAPI reset timed-out, status=0x%02x\n",
				drive->name, stat);
		/* do it the old fashioned way */
		return do_reset1(drive, 1);
	}
	/* done polling */
	hwgroup->polling = 0;
	hwgroup->resetting = 0;
	return ide_stopped;
}

/*
 * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
 * during an ide reset operation. If the drives have not yet responded,
 * and we have not yet hit our maximum waiting time, then the timer is restarted
 * for another 50ms.
 */
static ide_startstop_t reset_pollfunc (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	u8 tmp;

	if (hwif->reset_poll != NULL) {
		if (hwif->reset_poll(drive)) {
			printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
				hwif->name, drive->name);
			return ide_stopped;
		}
	}

	if (!OK_STAT(tmp = hwif->INB(IDE_STATUS_REG), 0, BUSY_STAT)) {
		if (time_before(jiffies, hwgroup->poll_timeout)) {
			BUG_ON(HWGROUP(drive)->handler != NULL);
			ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);
			/* continue polling */
			return ide_started;
		}
		printk("%s: reset timed-out, status=0x%02x\n", hwif->name, tmp);
		drive->failures++;
	} else  {
		printk("%s: reset: ", hwif->name);
		if ((tmp = hwif->INB(IDE_ERROR_REG)) == 1) {
			printk("success\n");
			drive->failures = 0;
		} else {
			drive->failures++;
			printk("master: ");
			switch (tmp & 0x7f) {
				case 1: printk("passed");
					break;
				case 2: printk("formatter device error");
					break;
				case 3: printk("sector buffer error");
					break;
				case 4: printk("ECC circuitry error");
					break;
				case 5: printk("controlling MPU error");
					break;
				default:printk("error (0x%02x?)", tmp);
			}
			if (tmp & 0x80)
				printk("; slave: failed");
			printk("\n");
		}
	}
	hwgroup->polling = 0;	/* done polling */
	hwgroup->resetting = 0; /* done reset attempt */
	return ide_stopped;
}

static void check_dma_crc(ide_drive_t *drive)
{
#ifdef CONFIG_BLK_DEV_IDEDMA
	if (drive->crc_count) {
		drive->hwif->dma_off_quietly(drive);
		ide_set_xfer_rate(drive, ide_auto_reduce_xfer(drive));
		if (drive->current_speed >= XFER_SW_DMA_0)
			(void) HWIF(drive)->ide_dma_on(drive);
	} else
		ide_dma_off(drive);
#endif
}

static void ide_disk_pre_reset(ide_drive_t *drive)
{
	int legacy = (drive->id->cfs_enable_2 & 0x0400) ? 0 : 1;

	drive->special.all = 0;
	drive->special.b.set_geometry = legacy;
	drive->special.b.recalibrate  = legacy;
	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;
}

static void pre_reset(ide_drive_t *drive)
{
	if (drive->media == ide_disk)
		ide_disk_pre_reset(drive);
	else
		drive->post_reset = 1;

	if (!drive->keep_settings) {
		if (drive->using_dma) {
			check_dma_crc(drive);
		} else {
			drive->unmask = 0;
			drive->io_32bit = 0;
		}
		return;
	}
	if (drive->using_dma)
		check_dma_crc(drive);

	if (HWIF(drive)->pre_reset != NULL)
		HWIF(drive)->pre_reset(drive);

	if (drive->current_speed != 0xff)
		drive->desired_speed = drive->current_speed;
	drive->current_speed = 0xff;
}

/*
 * do_reset1() attempts to recover a confused drive by resetting it.
 * Unfortunately, resetting a disk drive actually resets all devices on
 * the same interface, so it can really be thought of as resetting the
 * interface rather than resetting the drive.
 *
 * ATAPI devices have their own reset mechanism which allows them to be
 * individually reset without clobbering other devices on the same interface.
 *
 * Unfortunately, the IDE interface does not generate an interrupt to let
 * us know when the reset operation has finished, so we must poll for this.
 * Equally poor, though, is the fact that this may a very long time to complete,
 * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
 * we set a timer to poll at 50ms intervals.
 */
static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)
{
	unsigned int unit;
	unsigned long flags;
	ide_hwif_t *hwif;
	ide_hwgroup_t *hwgroup;
	
	spin_lock_irqsave(&ide_lock, flags);
	hwif = HWIF(drive);
	hwgroup = HWGROUP(drive);

	/* We must not reset with running handlers */
	BUG_ON(hwgroup->handler != NULL);

	/* For an ATAPI device, first try an ATAPI SRST. */
	if (drive->media != ide_disk && !do_not_try_atapi) {
		hwgroup->resetting = 1;
		pre_reset(drive);
		SELECT_DRIVE(drive);
		udelay (20);
		hwif->OUTBSYNC(drive, WIN_SRST, IDE_COMMAND_REG);
		ndelay(400);
		hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
		hwgroup->polling = 1;
		__ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);
		spin_unlock_irqrestore(&ide_lock, flags);
		return ide_started;
	}

	/*
	 * First, reset any device state data we were maintaining
	 * for any of the drives on this interface.
	 */
	for (unit = 0; unit < MAX_DRIVES; ++unit)
		pre_reset(&hwif->drives[unit]);

#if OK_TO_RESET_CONTROLLER
	if (!IDE_CONTROL_REG) {
		spin_unlock_irqrestore(&ide_lock, flags);
		return ide_stopped;
	}

	hwgroup->resetting = 1;
	/*
	 * Note that we also set nIEN while resetting the device,
	 * to mask unwanted interrupts from the interface during the reset.
	 * However, due to the design of PC hardware, this will cause an
	 * immediate interrupt due to the edge transition it produces.
	 * This single interrupt gives us a "fast poll" for drives that
	 * recover from reset very quickly, saving us the first 50ms wait time.
	 */
	/* set SRST and nIEN */
	hwif->OUTBSYNC(drive, drive->ctl|6,IDE_CONTROL_REG);
	/* more than enough time */
	udelay(10);
	if (drive->quirk_list == 2) {
		/* clear SRST and nIEN */
		hwif->OUTBSYNC(drive, drive->ctl, IDE_CONTROL_REG);
	} else {
		/* clear SRST, leave nIEN */
		hwif->OUTBSYNC(drive, drive->ctl|2, IDE_CONTROL_REG);
	}
	/* more than enough time */
	udelay(10);
	hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;
	hwgroup->polling = 1;
	__ide_set_handler(drive, &reset_pollfunc, HZ/20, NULL);

	/*
	 * Some weird controller like resetting themselves to a strange
	 * state when the disks are reset this way. At least, the Winbond
	 * 553 documentation says that
	 */
	if (hwif->resetproc != NULL) {
		hwif->resetproc(drive);
	}
	
#endif	/* OK_TO_RESET_CONTROLLER */

	spin_unlock_irqrestore(&ide_lock, flags);
	return ide_started;
}

/*
 * ide_do_reset() is the entry point to the drive/interface reset code.
 */

ide_startstop_t ide_do_reset (ide_drive_t *drive)
{
	return do_reset1(drive, 0);
}

EXPORT_SYMBOL(ide_do_reset);

/*
 * ide_wait_not_busy() waits for the currently selected device on the hwif
 * to report a non-busy status, see comments in probe_hwif().
 */
int ide_wait_not_busy(ide_hwif_t *hwif, unsigned long timeout)
{
	u8 stat = 0;

	while(timeout--) {
		/*
		 * Turn this into a schedule() sleep once I'm sure
		 * about locking issues (2.5 work ?).
		 */
		mdelay(1);
		stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
		if ((stat & BUSY_STAT) == 0)
			return 0;
		/*
		 * Assume a value of 0xff means nothing is connected to
		 * the interface and it doesn't implement the pull-down
		 * resistor on D7.
		 */
		if (stat == 0xff)
			return -ENODEV;
		touch_softlockup_watchdog();
		touch_nmi_watchdog();
	}
	return -EBUSY;
}

EXPORT_SYMBOL_GPL(ide_wait_not_busy);