i2o_block.c

MIZI Research, Inc.发布的嵌入式Linux内核源码

		 *    The device list connected to the I2O Controller is doubly linked
		 * Here we traverse the end of the list , and start claiming devices
		 * from that end. This assures that within an I2O controller atleast
		 * the newly created volumes get claimed after the older ones, thus
		 * mapping to same major/minor (and hence device file name) after 
		 * every reboot.
		 * The exception being: 
		 * 1. If there was a TID reuse.
		 * 2. There was more than one I2O controller. 
		 */

		if(!bios)
		{
			for (d=c->devices;d!=NULL;d=d->next)
			if(d->next == NULL)
				b = d;
		}
		else
			b = c->devices;

		while(b != NULL)
		{
			d=b;
			if(bios)
				b = b->next;
			else
				b = b->prev;

			if(d->lct_data.class_id!=I2O_CLASS_RANDOM_BLOCK_STORAGE)
				continue;

			if(d->lct_data.user_tid != 0xFFF)
				continue;

			if(bios)
			{
				if(d->lct_data.bios_info != 0x80)
					continue;
				printk(KERN_INFO "Claiming as Boot device: Controller %d, TID %d\n", c->unit, d->lct_data.tid);
			}
			else
			{
				if(d->lct_data.bios_info == 0x80)
					continue; /*Already claimed on pass 1 */
			}

			if(i2o_claim_device(d, &i2o_block_handler))
			{
				printk(KERN_WARNING "i2o_block: Controller %d, TID %d\n", c->unit,
					d->lct_data.tid);
				printk(KERN_WARNING "\t%sevice refused claim! Skipping installation\n", bios?"Boot d":"D");
				continue;
			}

			if(scan_unit<MAX_I2OB<<4)
			{
 				/*
				 * Get the device and fill in the
				 * Tid and controller.
				 */
				dev=&i2ob_dev[scan_unit];
				dev->i2odev = d; 
				dev->controller = c;
				dev->unit = c->unit;
				dev->tid = d->lct_data.tid;

				if(i2ob_install_device(c,d,scan_unit))
					printk(KERN_WARNING "Could not install I2O block device\n");
				else
				{
					scan_unit+=16;
					i2ob_dev_count++;

					/* We want to know when device goes away */
					i2o_device_notify_on(d, &i2o_block_handler);
				}
			}
			else
			{
				if(!warned++)
					printk(KERN_WARNING "i2o_block: too many device, registering only %d.\n", scan_unit>>4);
			}
			i2o_release_device(d, &i2o_block_handler);
		}
		i2o_unlock_controller(c);
	}
}

static void i2ob_probe(void)
{
	/*
	 *      Some overhead/redundancy involved here, while trying to
	 *      claim the first boot volume encountered as /dev/i2o/hda
	 *      everytime. All the i2o_controllers are searched and the
	 *      first i2o block device marked as bootable is claimed
	 *      If an I2O block device was booted off , the bios sets
	 *      its bios_info field to 0x80, this what we search for.
	 *      Assuming that the bootable volume is /dev/i2o/hda
	 *      everytime will prevent any kernel panic while mounting
	 *      root partition
	 */

	printk(KERN_INFO "i2o_block: Checking for Boot device...\n");
	i2ob_scan(1);

	/*
	 *      Now the remainder.
	 */
	printk(KERN_INFO "i2o_block: Checking for I2O Block devices...\n");
	i2ob_scan(0);
}


/*
 * New device notification handler.  Called whenever a new
 * I2O block storage device is added to the system.
 * 
 * Should we spin lock around this to keep multiple devs from 
 * getting updated at the same time? 
 * 
 */
void i2ob_new_device(struct i2o_controller *c, struct i2o_device *d)
{
	struct i2ob_device *dev;
	int unit = 0;

	printk(KERN_INFO "i2o_block: New device detected\n");
	printk(KERN_INFO "   Controller %d Tid %d\n",c->unit, d->lct_data.tid);

	/* Check for available space */
	if(i2ob_dev_count>=MAX_I2OB<<4)
	{
		printk(KERN_ERR "i2o_block: No more devices allowed!\n");
		return;
	}
	for(unit = 0; unit < (MAX_I2OB<<4); unit += 16)
	{
		if(!i2ob_dev[unit].i2odev)
			break;
	}

	if(i2o_claim_device(d, &i2o_block_handler))
	{
		printk(KERN_INFO 
			"i2o_block: Unable to claim device. Installation aborted\n");
		return;
	}

	dev = &i2ob_dev[unit];
	dev->i2odev = d; 
	dev->controller = c;
	dev->tid = d->lct_data.tid;

	if(i2ob_install_device(c,d,unit))
		printk(KERN_ERR "i2o_block: Could not install new device\n");
	else	
	{
		i2ob_dev_count++;
		i2o_device_notify_on(d, &i2o_block_handler);
	}

	i2o_release_device(d, &i2o_block_handler);
 
	return;
}

/*
 * Deleted device notification handler.  Called when a device we
 * are talking to has been deleted by the user or some other
 * mysterious fource outside the kernel.
 */
void i2ob_del_device(struct i2o_controller *c, struct i2o_device *d)
{	
	int unit = 0;
	int i = 0;
	unsigned long flags;

	spin_lock_irqsave(&io_request_lock, flags);

	/*
	 * Need to do this...we somtimes get two events from the IRTOS
	 * in a row and that causes lots of problems.
	 */
	i2o_device_notify_off(d, &i2o_block_handler);

	printk(KERN_INFO "I2O Block Device Deleted\n");

	for(unit = 0; unit < MAX_I2OB<<4; unit += 16)
	{
		if(i2ob_dev[unit].i2odev == d)
		{
			printk(KERN_INFO "  /dev/%s: Controller %d Tid %d\n", 
				d->dev_name, c->unit, d->lct_data.tid);
			break;
		}
	}
	if(unit >= MAX_I2OB<<4)
	{
		printk(KERN_ERR "i2ob_del_device called, but not in dev table!\n");
		spin_unlock_irqrestore(&io_request_lock, flags);
		return;
	}

	/* 
	 * This will force errors when i2ob_get_queue() is called
	 * by the kenrel.
	 */
	i2ob_dev[unit].req_queue = NULL;
	for(i = unit; i <= unit+15; i++)
	{
		i2ob_dev[i].i2odev = NULL;
		i2ob_sizes[i] = 0;
		i2ob_hardsizes[i] = 0;
		i2ob_max_sectors[i] = 0;
		i2ob[i].nr_sects = 0;
		i2ob_gendisk.part[i].nr_sects = 0;
	}
	spin_unlock_irqrestore(&io_request_lock, flags);

	/*
	 * Decrease usage count for module
	 */	

	while(i2ob_dev[unit].refcnt--)
		MOD_DEC_USE_COUNT;

	i2ob_dev[unit].refcnt = 0;
	
	i2ob_dev[i].tid = 0;

	/* 
	 * Do we need this?
	 * The media didn't really change...the device is just gone
	 */
	i2ob_media_change_flag[unit] = 1;

	i2ob_dev_count--;	
}

/*
 *	Have we seen a media change ?
 */
static int i2ob_media_change(kdev_t dev)
{
	int i=MINOR(dev);
	i>>=4;
	if(i2ob_media_change_flag[i])
	{
		i2ob_media_change_flag[i]=0;
		return 1;
	}
	return 0;
}

static int i2ob_revalidate(kdev_t dev)
{
	return do_i2ob_revalidate(dev, 0);
}

/*
 * Reboot notifier.  This is called by i2o_core when the system
 * shuts down.
 */
static void i2ob_reboot_event(void)
{
	int i;
	
	for(i=0;i<MAX_I2OB;i++)
	{
		struct i2ob_device *dev=&i2ob_dev[(i<<4)];
		
		if(dev->refcnt!=0)
		{
			/*
			 *	Flush the onboard cache
			 */
			u32 msg[5];
			int *query_done = &dev->done_flag;
			msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
			msg[1] = I2O_CMD_BLOCK_CFLUSH<<24|HOST_TID<<12|dev->tid;
			msg[2] = i2ob_context|0x40000000;
			msg[3] = (u32)query_done;
			msg[4] = 60<<16;
			
			DEBUG("Flushing...");
			i2o_post_wait(dev->controller, msg, 20, 60);

			DEBUG("Unlocking...");
			/*
			 *	Unlock the media
			 */
			msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
			msg[1] = I2O_CMD_BLOCK_MUNLOCK<<24|HOST_TID<<12|dev->tid;
			msg[2] = i2ob_context|0x40000000;
			msg[3] = (u32)query_done;
			msg[4] = -1;
			i2o_post_wait(dev->controller, msg, 20, 2);
			
			DEBUG("Unlocked.\n");
		}
	}	
}

static struct block_device_operations i2ob_fops =
{
	owner:			THIS_MODULE,
	open:			i2ob_open,
	release:		i2ob_release,
	ioctl:			i2ob_ioctl,
	check_media_change:	i2ob_media_change,
	revalidate:		i2ob_revalidate,
};

static struct gendisk i2ob_gendisk = 
{
	major:		MAJOR_NR,
	major_name:	"i2o/hd",
	minor_shift:	4,
	max_p:		1<<4,
	part:		i2ob,
	sizes:		i2ob_sizes,
	nr_real:	MAX_I2OB,
	fops:		&i2ob_fops,
};


/*
 * And here should be modules and kernel interface 
 *  (Just smiley confuses emacs :-)
 */

#ifdef MODULE
#define i2o_block_init init_module
#endif

int i2o_block_init(void)
{
	int i;

	printk(KERN_INFO "I2O Block Storage OSM v0.9\n");
	printk(KERN_INFO "   (c) Copyright 1999-2001 Red Hat Software.\n");
	
	/*
	 *	Register the block device interfaces
	 */

	if (register_blkdev(MAJOR_NR, "i2o_block", &i2ob_fops)) {
		printk(KERN_ERR "Unable to get major number %d for i2o_block\n",
		       MAJOR_NR);
		return -EIO;
	}
#ifdef MODULE
	printk(KERN_INFO "i2o_block: registered device at major %d\n", MAJOR_NR);
#endif

	/*
	 *	Now fill in the boiler plate
	 */
	 
	blksize_size[MAJOR_NR] = i2ob_blksizes;
	hardsect_size[MAJOR_NR] = i2ob_hardsizes;
	blk_size[MAJOR_NR] = i2ob_sizes;
	max_sectors[MAJOR_NR] = i2ob_max_sectors;
	blk_dev[MAJOR_NR].queue = i2ob_get_queue;
	
	blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), i2ob_request);
	blk_queue_headactive(BLK_DEFAULT_QUEUE(MAJOR_NR), 0);

	for (i = 0; i < MAX_I2OB << 4; i++) {
		i2ob_dev[i].refcnt = 0;
		i2ob_dev[i].flags = 0;
		i2ob_dev[i].controller = NULL;
		i2ob_dev[i].i2odev = NULL;
		i2ob_dev[i].tid = 0;
		i2ob_dev[i].head = NULL;
		i2ob_dev[i].tail = NULL;
		i2ob_dev[i].depth = MAX_I2OB_DEPTH;
		i2ob_blksizes[i] = 1024;
		i2ob_max_sectors[i] = 2;
	}
	
	/*
	 *	Set up the queue
	 */
	for(i = 0; i < MAX_I2O_CONTROLLERS; i++)
	{
		i2ob_queues[i] = NULL;
	}

	/*
	 *	Timers
	 */
	 
	init_timer(&i2ob_timer);
	i2ob_timer.function = i2ob_timer_handler;
	i2ob_timer.data = 0;
	
	/*
	 *	Register the OSM handler as we will need this to probe for
	 *	drives, geometry and other goodies.
	 */

	if(i2o_install_handler(&i2o_block_handler)<0)
	{
		unregister_blkdev(MAJOR_NR, "i2o_block");
		blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
		printk(KERN_ERR "i2o_block: unable to register OSM.\n");
		return -EINVAL;
	}
	i2ob_context = i2o_block_handler.context;	 

	/*
	 * Initialize event handling thread
	 */
	init_MUTEX_LOCKED(&i2ob_evt_sem);
	evt_pid = kernel_thread(i2ob_evt, NULL, CLONE_SIGHAND);
	if(evt_pid < 0)
	{
		printk(KERN_ERR 
			"i2o_block: Could not initialize event thread.  Aborting\n");
		i2o_remove_handler(&i2o_block_handler);
		return 0;
	}

	/*
	 *	Finally see what is actually plugged in to our controllers
	 */
	for (i = 0; i < MAX_I2OB; i++)
		register_disk(&i2ob_gendisk, MKDEV(MAJOR_NR,i<<4), 1<<4,
			&i2ob_fops, 0);
	i2ob_probe();

	/*
	 *	Adding i2ob_gendisk into the gendisk list.
	 */
	add_gendisk(&i2ob_gendisk);

	return 0;
}

#ifdef MODULE

EXPORT_NO_SYMBOLS;
MODULE_AUTHOR("Red Hat Software");
MODULE_DESCRIPTION("I2O Block Device OSM");
MODULE_LICENSE("GPL");


void cleanup_module(void)
{
	int i;
	
	if(evt_running) {
		printk(KERN_INFO "Killing I2O block threads...");
		i = kill_proc(evt_pid, SIGTERM, 1);
		if(!i) {
			printk("waiting...");
		}
		/* Be sure it died */
		wait_for_completion(&i2ob_thread_dead);
		printk("done.\n");
	}

	/*
	 * Unregister for updates from any devices..otherwise we still
	 * get them and the core jumps to random memory :O
	 */
	if(i2ob_dev_count) {
		struct i2o_device *d;
		for(i = 0; i < MAX_I2OB; i++)
		if((d=i2ob_dev[i<<4].i2odev)) {
			i2o_device_notify_off(d, &i2o_block_handler);
			i2o_event_register(d->controller, d->lct_data.tid, 
				i2ob_context, i<<4, 0);
		}
	}
	
	/*
	 *	We may get further callbacks for ourself. The i2o_core
	 *	code handles this case reasonably sanely. The problem here
	 *	is we shouldn't get them .. but a couple of cards feel 
	 *	obliged to tell us stuff we dont care about.
	 *
	 *	This isnt ideal at all but will do for now.
	 */
	 
	set_current_state(TASK_UNINTERRUPTIBLE);
	schedule_timeout(HZ);
	
	/*
	 *	Flush the OSM
	 */

	i2o_remove_handler(&i2o_block_handler);
		 
	/*
	 *	Return the block device
	 */
	if (unregister_blkdev(MAJOR_NR, "i2o_block") != 0)
		printk("i2o_block: cleanup_module failed\n");

	/*
	 * free request queue
	 */
	blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));

	del_gendisk(&i2ob_gendisk);
}
#endif