eql.c

powerpc内核mpc8241linux系统下net驱动程序

/*
 * Equalizer Load-balancer for serial network interfaces.
 *
 * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
 * NCM: Network and Communications Management, Inc.
 *
 *
 *	This software may be used and distributed according to the terms
 *	of the GNU Public License, incorporated herein by reference.
 * 
 * The author may be reached as [e-mail], or C/O
 *    NCM
 *    Attn: Simon Janes
 *    6803 Whittier Ave
 *    McLean VA 22101
 *    Phone: [phone] ext 103
 */

static const char *version = 
	"Equalizer1996: $Revision: 1.2.1 $ $Date: 1996/09/22 13:52:00 $ Simon Janes ([e-mail])\n";

/*
 * Sources:
 *   skeleton.c by Donald Becker.
 * Inspirations:
 *   The Harried and Overworked Alan Cox
 * Conspiracies:
 *   The Alan Cox and Mike McLagan plot to get someone else to do the code, 
 *   which turned out to be me.
 */

/*
 * $Log: eql.c,v $
 * Revision 1.2  1996/04/11 17:51:52  guru
 * Added one-line eql_remove_slave patch.
 *
 * Revision 1.1  1996/04/11 17:44:17  guru
 * Initial revision
 *
 * Revision 3.13  1996/01/21  15:17:18  alan
 * tx_queue_len changes.
 * reformatted.
 *
 * Revision 3.12  1995/03/22  21:07:51  anarchy
 * Added suser() checks on configuration.
 * Moved header file.
 *
 * Revision 3.11  1995/01/19  23:14:31  guru
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 8;
 *
 * Revision 3.10  1995/01/19  23:07:53  guru
 * back to
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued;
 *
 * Revision 3.9  1995/01/19  22:38:20  guru
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 4;
 *
 * Revision 3.8  1995/01/19  22:30:55  guru
 *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 2;
 *
 * Revision 3.7  1995/01/19  21:52:35  guru
 * printk's trimmed out.
 *
 * Revision 3.6  1995/01/19  21:49:56  guru
 * This is working pretty well. I gained 1 K/s in speed.. now it's just
 * robustness and printk's to be diked out.
 *
 * Revision 3.5  1995/01/18  22:29:59  guru
 * still crashes the kernel when the lock_wait thing is woken up.
 *
 * Revision 3.4  1995/01/18  21:59:47  guru
 * Broken set-bit locking snapshot
 *
 * Revision 3.3  1995/01/17  22:09:18  guru
 * infinite sleep in a lock somewhere..
 *
 * Revision 3.2  1995/01/15  16:46:06  guru
 * Log trimmed of non-pertinent 1.x branch messages
 *
 * Revision 3.1  1995/01/15  14:41:45  guru
 * New Scheduler and timer stuff...
 *
 * Revision 1.15  1995/01/15  14:29:02  guru
 * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
 * with the dumber scheduler
 *
 * Revision 1.14  1995/01/15  02:37:08  guru
 * shock.. the kept-new-versions could have zonked working
 * stuff.. shudder
 *
 * Revision 1.13  1995/01/15  02:36:31  guru
 * big changes
 *
 * 	scheduler was torn out and replaced with something smarter
 *
 * 	global names not prefixed with eql_ were renamed to protect
 * 	against namespace collisions
 *
 * 	a few more abstract interfaces were added to facilitate any
 * 	potential change of datastructure.  the driver is still using
 * 	a linked list of slaves.  going to a heap would be a bit of
 * 	an overkill.
 *
 * 	this compiles fine with no warnings.
 *
 * 	the locking mechanism and timer stuff must be written however,
 * 	this version will not work otherwise
 *
 */

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/malloc.h>
#include <linux/string.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>
#include <linux/errno.h>              
#include <linux/init.h>

#include <linux/netdevice.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include <linux/timer.h>

#include <linux/if_eql.h>

#ifndef EQL_DEBUG
/* #undef EQL_DEBUG      -* print nothing at all, not even a boot-banner */
/* #define EQL_DEBUG 1   -* print only the boot-banner */
/* #define EQL_DEBUG 5   -* print major function entries */
/* #define EQL_DEBUG 20  -* print subfunction entries */
/* #define EQL_DEBUG 50  -* print utility entries */
/* #define EQL_DEBUG 100 -* print voluminous function entries */
#define EQL_DEBUG 1
#endif
static unsigned int eql_debug = EQL_DEBUG;

int        eql_init(struct device *dev); /*  */
static int eql_open(struct device *dev); /*  */
static int eql_close(struct device *dev); /*  */
static int eql_ioctl(struct device *dev, struct ifreq *ifr, int cmd); /*  */
static int eql_slave_xmit(struct sk_buff *skb, struct device *dev); /*  */

static struct net_device_stats *eql_get_stats(struct device *dev); /*  */

/* ioctl() handlers
   ---------------- */
static int eql_enslave(struct device *dev,  slaving_request_t *srq); /*  */
static int eql_emancipate(struct device *dev, slaving_request_t *srq); /*  */

static int eql_g_slave_cfg(struct device *dev, slave_config_t *sc); /*  */
static int eql_s_slave_cfg(struct device *dev, slave_config_t *sc); /*  */

static int eql_g_master_cfg(struct device *dev, master_config_t *mc); /*  */
static int eql_s_master_cfg(struct device *dev, master_config_t *mc); /*  */

static inline int eql_is_slave(struct device *dev); /*  */
static inline int eql_is_master(struct device *dev); /*  */

static slave_t *eql_new_slave(void); /*  */
static void eql_delete_slave(slave_t *slave); /*  */

/* static long eql_slave_priority(slave_t *slave); -*  */
static inline int eql_number_slaves(slave_queue_t *queue); /*  */

static inline int eql_is_empty(slave_queue_t *queue); /*  */
static inline int eql_is_full(slave_queue_t *queue); /*  */

static slave_queue_t *eql_new_slave_queue(struct device *dev); /*  */
static void eql_delete_slave_queue(slave_queue_t *queue); /*  */

static int eql_insert_slave(slave_queue_t *queue, slave_t *slave); /*  */
static slave_t *eql_remove_slave(slave_queue_t *queue, slave_t *slave); /*  */

/* static int eql_insert_slave_dev(slave_queue_t *queue, struct device *dev); -*  */
static int eql_remove_slave_dev(slave_queue_t *queue, struct device *dev); /*  */

static inline struct device *eql_best_slave_dev(slave_queue_t *queue); /*  */
static inline slave_t *eql_best_slave(slave_queue_t *queue); /*  */
static inline slave_t *eql_first_slave(slave_queue_t *queue); /*  */
static inline slave_t *eql_next_slave(slave_queue_t *queue, slave_t *slave); /*  */

static inline void eql_set_best_slave(slave_queue_t *queue, slave_t *slave); /*  */
static inline void eql_schedule_slaves(slave_queue_t *queue); /*  */

static slave_t *eql_find_slave_dev(slave_queue_t *queue, struct device *dev); /*  */

/* static inline eql_lock_slave_queue(slave_queue_t *queue); -*  */
/* static inline eql_unlock_slave_queue(slave_queue_t *queue); -*  */

static void eql_timer(unsigned long param);	/*  */

/* struct device * interface functions 
   ---------------------------------------------------------
   */

__initfunc(int eql_init(struct device *dev))
{
	static unsigned version_printed = 0;
	/* static unsigned num_masters     = 0; */
	equalizer_t *eql = 0;

	if ( version_printed++ == 0 && eql_debug > 0)
		printk(version);
	/*
	 *	Initialize the device structure. 
	 */
	dev->priv = kmalloc (sizeof (equalizer_t), GFP_KERNEL);
	if (dev->priv == NULL)
		return -ENOMEM;
	memset (dev->priv, 0, sizeof (equalizer_t));
	eql = (equalizer_t *) dev->priv;

	eql->stats = kmalloc (sizeof (struct net_device_stats), GFP_KERNEL);
	if (eql->stats == NULL) 
	{
		kfree(dev->priv);
		dev->priv = NULL;
		return -ENOMEM;
	}
	memset (eql->stats, 0, sizeof (struct net_device_stats));

	init_timer (&eql->timer);
	eql->timer.data     	= (unsigned long) dev->priv;
	eql->timer.expires  	= jiffies+EQL_DEFAULT_RESCHED_IVAL;
	eql->timer.function 	= &eql_timer;
	eql->timer_on       	= 0;

	dev->open		= eql_open;
	dev->stop		= eql_close;
	dev->do_ioctl		= eql_ioctl;
	dev->hard_start_xmit	= eql_slave_xmit;
	dev->get_stats		= eql_get_stats;
  
  	/*
  	 *	Fill in the fields of the device structure with 
	 *	eql-generic values. 
	 */

	dev_init_buffers(dev);
	
	/*
	 *	Now we undo some of the things that eth_setup does
	 * 	that we don't like 
	 */
	 
	dev->mtu        	= EQL_DEFAULT_MTU;	/* set to 576 in eql.h */
	dev->flags      	= IFF_MASTER;

	dev->type       	= ARPHRD_SLIP;
	dev->tx_queue_len 	= 5;		/* Hands them off fast */

	return 0;
}

static int eql_open(struct device *dev)
{
	equalizer_t *eql = (equalizer_t *) dev->priv;
	slave_queue_t *new_queue;

#ifdef EQL_DEBUG
	if (eql_debug >= 5)
		printk ("%s: open\n", dev->name);
#endif

	printk ("%s: remember to turn off Van-Jacobson compression on your slave devices.\n", dev->name);

	new_queue = eql_new_slave_queue (dev);
    
	if (new_queue != 0)
	{
		new_queue->master_dev = dev;
		eql->queue = new_queue;
		eql->queue->lock = 0;
		eql->min_slaves = 1;
		eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */

		printk ("%s: adding timer\n", dev->name);
		eql->timer_on = 1;
		add_timer (&eql->timer);

		MOD_INC_USE_COUNT;
		return 0;
	}
	return 1;
}


static int eql_close(struct device *dev)
{
	equalizer_t *eql = (equalizer_t *) dev->priv;

#ifdef EQL_DEBUG
	if ( eql_debug >= 5)
		printk ("%s: close\n", dev->name);
#endif
	/*
	 *	The timer has to be stopped first before we start hacking away
	 *	at the data structure it scans every so often... 
	 */

#ifdef EQL_DEBUG
	printk ("%s: stopping timer\n", dev->name);
#endif	
	eql->timer_on = 0;
	del_timer (&eql->timer);

	eql_delete_slave_queue (eql->queue);

	MOD_DEC_USE_COUNT;
	return 0;
}


static int eql_ioctl(struct device *dev, struct ifreq *ifr, int cmd)
{  
	if(cmd!=EQL_GETMASTRCFG && cmd!=EQL_GETSLAVECFG && 
	   !capable(CAP_NET_ADMIN))
	  	return -EPERM;
	switch (cmd)
	{
		case EQL_ENSLAVE:
			return eql_enslave (dev, (slaving_request_t *) ifr->ifr_data);
		case EQL_EMANCIPATE:
			return eql_emancipate (dev, (slaving_request_t *) ifr->ifr_data);
		case EQL_GETSLAVECFG:
			return eql_g_slave_cfg (dev, (slave_config_t *) ifr->ifr_data);
		case EQL_SETSLAVECFG:
			return eql_s_slave_cfg (dev, (slave_config_t *) ifr->ifr_data);
		case EQL_GETMASTRCFG:
			return eql_g_master_cfg (dev, (master_config_t *) ifr->ifr_data);
		case EQL_SETMASTRCFG:
			return eql_s_master_cfg (dev, (master_config_t *) ifr->ifr_data);
		default:
			return -EOPNOTSUPP;
	}
}


static int eql_slave_xmit(struct sk_buff *skb, struct device *dev)
{
	equalizer_t *eql = (equalizer_t *) dev->priv;
	struct device *slave_dev = 0;
	slave_t *slave;

	if (skb == NULL)
		return 0;

	eql_schedule_slaves (eql->queue);
  
	slave_dev = eql_best_slave_dev (eql->queue);
	slave = eql_best_slave (eql->queue); 

	if ( slave_dev != 0 )
	{
#ifdef EQL_DEBUG
		if (eql_debug >= 100)
			printk ("%s: %d slaves xmitng %d B %s\n", 
				dev->name, eql_number_slaves (eql->queue), skb->len,
				slave_dev->name);
#endif
		skb->dev = slave_dev;
		skb->priority = 1;
		dev_queue_xmit (skb);
		eql->stats->tx_packets++;
		slave->bytes_queued += skb->len; 
	}
	else
	{
		/*
		 *	The alternative for this is the return 1 and have
		 *	dev_queue_xmit just queue it up on the eql's queue. 
		 */

		eql->stats->tx_dropped++;
		dev_kfree_skb(skb);
	}	  
	return 0;
}


static struct net_device_stats * eql_get_stats(struct device *dev)
{
	equalizer_t *eql = (equalizer_t *) dev->priv;
	return eql->stats;
}

/*
 *	Private ioctl functions
 */

static int eql_enslave(struct device *dev, slaving_request_t *srqp)
{
	struct device *master_dev;
	struct device *slave_dev;
	slaving_request_t srq;
	int err;

	err = verify_area(VERIFY_READ, (void *)srqp, sizeof (slaving_request_t));
	if (err)  
	  {
#ifdef EQL_DEBUG
	if (eql_debug >= 20)
		printk ("EQL enslave: error detected by verify_area\n");
#endif  
		return err;
	  }
	copy_from_user (&srq, srqp, sizeof (slaving_request_t));

#ifdef EQL_DEBUG
	if (eql_debug >= 20)
		printk ("%s: enslave '%s' %ld bps\n", dev->name, 
			srq.slave_name, srq.priority);
#endif  
	master_dev = dev;		/* for "clarity" */
	slave_dev  = dev_get (srq.slave_name);

	if (master_dev != 0 && slave_dev != 0)
	{
		if ((master_dev->flags & IFF_UP) == IFF_UP)
                {
			/*slave is not a master & not already a slave:*/
			if (! eql_is_master (slave_dev)  &&
			    ! eql_is_slave (slave_dev) )
			{
				slave_t *s = eql_new_slave ();
				equalizer_t *eql = 
					(equalizer_t *) master_dev->priv;
				s->dev = slave_dev;
				s->priority = srq.priority;
				s->priority_bps = srq.priority;
				s->priority_Bps = srq.priority / 8;
				slave_dev->flags |= IFF_SLAVE;
				eql_insert_slave (eql->queue, s);
				return 0;
			}
#ifdef EQL_DEBUG
			else if (eql_debug >= 20)
				printk ("EQL enslave: slave is master or slave is already slave\n");
#endif  
		}
#ifdef EQL_DEBUG
		else if (eql_debug >= 20)
			printk ("EQL enslave: master device not up!\n");
#endif  
	}
#ifdef EQL_DEBUG
	else if (eql_debug >= 20)
		printk ("EQL enslave: master or slave are NULL");
#endif  
	return -EINVAL;
}

static int eql_emancipate(struct device *dev, slaving_request_t *srqp)
{
	struct device *master_dev;
	struct device *slave_dev;
	slaving_request_t srq;
	int err;

	err = verify_area(VERIFY_READ, (void *)srqp, sizeof (slaving_request_t));
	if (err) 
		return err;

	copy_from_user (&srq, srqp, sizeof (slaving_request_t));
#ifdef EQL_DEBUG
	if (eql_debug >= 20)
		printk ("%s: emancipate `%s`\n", dev->name, srq.slave_name);
#endif
	master_dev = dev;		/* for "clarity" */
	slave_dev  = dev_get (srq.slave_name);

	if ( eql_is_slave (slave_dev) )	/* really is a slave */
	{
		equalizer_t *eql = (equalizer_t *) master_dev->priv;
		slave_dev->flags = slave_dev->flags & ~IFF_SLAVE;
		eql_remove_slave_dev (eql->queue, slave_dev);
		return 0;
	}
	return -EINVAL;
}


static int eql_g_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;

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