eql.c

powerpc内核mpc8241linux系统下net驱动程序

			if (err) 
				return err;
			copy_to_user (scp, &sc, sizeof (slave_config_t));
			return 0;
		}
	}
	return -EINVAL;
}


static int eql_s_slave_cfg(struct device *dev, slave_config_t *scp)
{
	slave_t *slave;
	equalizer_t *eql;
	struct device *slave_dev;
	slave_config_t sc;
	int err;

	err = verify_area(VERIFY_READ, (void *)scp, sizeof (slave_config_t));
	if (err) 
		return err;

#ifdef EQL_DEBUG
	if (eql_debug >= 20)
		printk ("%s: set config for slave `%s'\n", dev->name, sc.slave_name);
#endif
  
	copy_from_user (&sc, scp, sizeof (slave_config_t));

	eql = (equalizer_t *) dev->priv;
	slave_dev = dev_get (sc.slave_name);

	if ( eql_is_slave (slave_dev) )
	{
		slave = eql_find_slave_dev (eql->queue, slave_dev);
		if (slave != 0)
		{
			slave->priority = sc.priority;
			slave->priority_bps = sc.priority;
			slave->priority_Bps = sc.priority / 8;
			return 0;
		}
	}
	return -EINVAL;
}


static int eql_g_master_cfg(struct device *dev, master_config_t *mcp)
{
	equalizer_t *eql;
	master_config_t mc;

#if EQL_DEBUG
	if (eql_debug >= 20)
		printk ("%s: get master config\n", dev->name);
#endif

	if ( eql_is_master (dev) )
	{
		int err;
		err = verify_area(VERIFY_WRITE, (void *)mcp, sizeof (master_config_t));
		if (err) 
			return err;
		eql = (equalizer_t *) dev->priv;
		mc.max_slaves = eql->max_slaves;
		mc.min_slaves = eql->min_slaves;
		copy_to_user (mcp, &mc, sizeof (master_config_t));
		return 0;
	}
	return -EINVAL;
}


static int eql_s_master_cfg(struct device *dev, master_config_t *mcp)
{
	equalizer_t *eql;
	master_config_t mc;
	int err;

	err = verify_area(VERIFY_READ, (void *)mcp, sizeof (master_config_t));
	if (err)
		return err;
#if EQL_DEBUG
	if (eql_debug >= 20)
		printk ("%s: set master config\n", dev->name);
#endif
	copy_from_user (&mc, mcp, sizeof (master_config_t));
	if ( eql_is_master (dev) )
	{
		eql = (equalizer_t *) dev->priv;
		eql->max_slaves = mc.max_slaves;
		eql->min_slaves = mc.min_slaves;
		return 0;
	}
	return -EINVAL;
}

/*
 *	Private device support functions
 */

static inline int eql_is_slave(struct device *dev)
{
	if (dev)
	{
		if ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
			return 1;
	}
	return 0;
}


static inline int eql_is_master(struct device *dev)
{
	if (dev)
	{
		if ((dev->flags & IFF_MASTER) == IFF_MASTER)
		return 1;
	}
	return 0;
}


static slave_t *eql_new_slave(void)
{
	slave_t *slave;

	slave = (slave_t *) kmalloc (sizeof (slave_t), GFP_KERNEL);
	if (slave)
	{
		memset(slave, 0, sizeof (slave_t));
		return slave;
	}
	return 0;
}


static void eql_delete_slave(slave_t *slave)
{
	kfree (slave);
}


#if 0				/* not currently used, will be used
				   when we really use a priority queue */
static long slave_Bps(slave_t *slave)
{
	return (slave->priority_Bps);
}

static long slave_bps(slave_t *slave)
{
	return (slave->priority_bps);
}

#endif

static inline int eql_number_slaves(slave_queue_t *queue)
{
	return queue->num_slaves;
}

static inline int eql_is_empty(slave_queue_t *queue)
{
	if (eql_number_slaves (queue) == 0)
		return 1;
	return 0;
}

static inline int eql_is_full(slave_queue_t *queue)
{
	equalizer_t *eql = (equalizer_t *) queue->master_dev->priv;

	if (eql_number_slaves (queue) == eql->max_slaves)
		return 1;
	return 0;
}

static slave_queue_t *eql_new_slave_queue(struct device *dev)
{
	slave_queue_t *queue;
	slave_t *head_slave;
	slave_t *tail_slave;

	queue = (slave_queue_t *) kmalloc (sizeof (slave_queue_t), GFP_KERNEL);
	if (queue == NULL)
		return 0;
	memset (queue, 0, sizeof (slave_queue_t));
	head_slave = eql_new_slave ();
	tail_slave = eql_new_slave ();

	if ( head_slave != 0 &&
		tail_slave != 0 )
	{
		head_slave->next = tail_slave;
		tail_slave->next = 0;
		queue->head = head_slave;
		queue->num_slaves = 0;
		queue->master_dev = dev;
	}
	else
	{
		if (head_slave)
			kfree(head_slave);
		if (tail_slave)
			kfree(tail_slave);
		kfree (queue);
		return 0;
	}
	return queue;
}


static void eql_delete_slave_queue(slave_queue_t *queue)
{ 
	slave_t *zapped;
	/*
	 *	This should only be called when there isn't a
	 *	timer running that scans the data periodically.. 
	 *	dev_close stops the timer... 
	 */

	while ( ! eql_is_empty (queue) )
	{
		zapped = eql_remove_slave (queue, queue->head->next);
		eql_delete_slave (zapped);
	}
	kfree (queue->head->next);
	kfree (queue->head);
	kfree (queue);
}

static int eql_insert_slave(slave_queue_t *queue, slave_t *slave)
{
	cli ();

	if ( ! eql_is_full (queue) )
	{
		slave_t *duplicate_slave = 0;
		duplicate_slave = eql_find_slave_dev (queue, slave->dev);
		if (duplicate_slave != 0)
		{
/*			  printk ("%s: found a duplicate, killing it and replacing\n",
				  queue->master_dev->name); */
			eql_delete_slave (eql_remove_slave (queue, duplicate_slave));
		}
		slave->next = queue->head->next;
		queue->head->next = slave;
		queue->num_slaves++;
		sti ();
		return 0;
	}
	sti ();
	return 1;
}


static slave_t *eql_remove_slave(slave_queue_t *queue, slave_t *slave)
{
	slave_t *prev;
	slave_t *curr;

	cli ();

	prev = queue->head;
	curr = queue->head->next;
	while (curr != slave && 
		curr->dev != 0 )
	{
/* 		printk ("%s: remove_slave; searching...\n", queue->master_dev->name); */
		prev = curr;
		curr = curr->next;
	}

	if (curr == slave)
	{
		prev->next = curr->next;
		queue->num_slaves--;
		curr->dev->flags = curr->dev->flags & ~IFF_SLAVE;
		sti();
		return curr;
	}
	sti ();
	return 0;			/* not found */
}


static int eql_remove_slave_dev(slave_queue_t *queue, struct device *dev)
{
	slave_t *prev;
	slave_t *curr;
	slave_t *target;

	target = eql_find_slave_dev (queue, dev);

	if (target != 0)
	{
		cli ();
		prev = queue->head;
		curr = prev->next;
		while (curr != target)
		{
			prev = curr;
			curr = curr->next;
		}
		prev->next = curr->next;
		queue->num_slaves--;
		sti ();
		eql_delete_slave (curr);
		return 0;
	}
	return 1;
}


static inline struct device *eql_best_slave_dev(slave_queue_t *queue)
{
	if (queue->best_slave != 0)
	{
		if (queue->best_slave->dev != 0)
			return queue->best_slave->dev;
		else
			return 0;
	}
	else
		return 0;
}


static inline slave_t *eql_best_slave(slave_queue_t *queue)
{
	return queue->best_slave;
}

static inline void eql_schedule_slaves(slave_queue_t *queue)
{
	struct device *master_dev = queue->master_dev;
	slave_t *best_slave = 0;
	slave_t *slave_corpse = 0;

#ifdef EQL_DEBUG
	if (eql_debug >= 100)
		printk ("%s: schedule %d slaves\n", 
			master_dev->name, eql_number_slaves (queue));
#endif
	if ( eql_is_empty (queue) )
	{
		/*
		 *	No slaves to play with 
		 */
		eql_set_best_slave (queue, (slave_t *) 0);
		return;
	}
	else
	{		
		/*
		 *	Make a pass to set the best slave 
		 */
		unsigned long best_load = (unsigned long) ULONG_MAX;
		slave_t *slave = 0;
		int i;

		cli ();
		for (i = 1, slave = eql_first_slave (queue);
			i <= eql_number_slaves (queue);
			i++, slave = eql_next_slave (queue, slave))
		{
			/*
			 *	Go through the slave list once, updating best_slave 
			 *      whenever a new best_load is found, whenever a dead
			 *	slave is found, it is marked to be pulled out of the 
			 *	queue 
			 */
		
			unsigned long slave_load;
			unsigned long bytes_queued; 
			unsigned long priority_Bps; 
	  	
	  		if (slave != 0)
			{
				bytes_queued = slave->bytes_queued;
				priority_Bps = slave->priority_Bps;    
				if ( slave->dev != 0)
				{
					if ((slave->dev->flags & IFF_UP) == IFF_UP )
					{
						slave_load = (ULONG_MAX - (ULONG_MAX / 2)) - 
							(priority_Bps) + bytes_queued * 8;

		      				if (slave_load < best_load)
						{
							best_load = slave_load;
							best_slave = slave;
						}
					}
					else		/* we found a dead slave */
					{
						/* 
						 *	We only bury one slave at a time, if more than
						 *	one slave dies, we will bury him on the next 
						 *	reschedule. slaves don't die all at once that 
						 *	much anyway 
						 */
						slave_corpse = slave;
					}
				}
			}
		} /* for */
		sti ();
		eql_set_best_slave (queue, best_slave);
	} /* else */
	if (slave_corpse != 0)
	{
		printk ("eql: scheduler found dead slave, burying...\n");
		eql_delete_slave (eql_remove_slave (queue, slave_corpse));
	}
	return;
}


static slave_t * eql_find_slave_dev(slave_queue_t *queue, struct device *dev)
{
	slave_t *slave = 0;
	slave = eql_first_slave(queue);

	while (slave != 0 && slave->dev != dev && slave != 0)
	{
#if 0
		if (slave->dev != 0)
			printk ("eql: find_slave_dev; looked at '%s'...\n", slave->dev->name);
		else
			printk ("eql: find_slave_dev; looked at nothing...\n");
#endif
		slave = slave->next;
	}
	return slave;
}


static inline slave_t *eql_first_slave(slave_queue_t *queue)
{
	return queue->head->next;
}


static inline slave_t *eql_next_slave(slave_queue_t *queue, slave_t *slave)
{
	return slave->next;
}

static inline void eql_set_best_slave(slave_queue_t *queue, slave_t *slave)
{
	queue->best_slave = slave;
}

static void eql_timer(unsigned long param)
{
	equalizer_t *eql = (equalizer_t *) param;
	slave_t *slave;
	slave_t *slave_corpse = 0;
	int i;
	
	if ( ! eql_is_empty (eql->queue) )
	{
		cli ();
		for (i = 1, slave = eql_first_slave (eql->queue);
			i <= eql_number_slaves (eql->queue);
			i++, slave = eql_next_slave (eql->queue, slave))
		{
			if (slave != 0)
			{
				if ((slave->dev->flags & IFF_UP) == IFF_UP )
				{
					slave->bytes_queued -= slave->priority_Bps;
					if (slave->bytes_queued < 0)
						slave->bytes_queued = 0;
				}
				else
					slave_corpse = slave;
			}
		}
		sti ();
		if (slave_corpse != 0)
		{
			printk ("eql: timer found dead slave, burying...\n");
			eql_delete_slave (eql_remove_slave (eql->queue, slave_corpse));
		}
	}

	if (eql->timer_on != 0) 
	{
		eql->timer.expires = jiffies+EQL_DEFAULT_RESCHED_IVAL;
		add_timer (&eql->timer);
	}
}

#ifdef MODULE
static struct device dev_eql = 
{
	"eql", 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, eql_init 
};

int init_module(void)
{
	if (register_netdev(&dev_eql) != 0) {
		printk("eql: register_netdev() returned non-zero.\n");
		return -EIO;
	}
	return 0;
}

void cleanup_module(void)
{
	unregister_netdev(&dev_eql);
}
#endif /* MODULE */

/*
 * Local Variables: 
 * compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/net/inet -Wall -Wstrict-prototypes -O6 -m486 -c eql.c"
 * version-control: t
 * kept-new-versions: 20
 * End:
 */