/*
* 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 simon@ncm.com, or C/O
* NCM
* Attn: Simon Janes
* 6803 Whittier Ave
* McLean VA 22101
* Phone: 1-703-847-0040 ext 103
*/
static const char *version =
"Equalizer1996: $Revision: 1.9 $ $Date: 1996/10/12 11:14:37 $ Simon Janes (simon@ncm.com)\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 1.9 1996/10/12 11:14:37 davem
* Quick merge to 2.0.20
*
* 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 <linux/errno.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 enet_statistics *eql_get_stats(struct device *dev); /* */
static int eql_header(struct sk_buff *skb, struct device *dev,
unsigned short type, void *daddr, void *saddr,
unsigned len); /* */
static int eql_rebuild_header(void *buff, struct device *dev,
unsigned long raddr, struct sk_buff *skb); /* */
/* 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
---------------------------------------------------------
*/
int eql_init(struct device *dev)
{
static unsigned version_printed = 0;
/* static unsigned num_masters = 0; */
equalizer_t *eql = 0;
int i;
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 enet_statistics), GFP_KERNEL);
if (eql->stats == NULL)
{
kfree(dev->priv);
dev->priv = NULL;
return -ENOMEM;
}
memset (eql->stats, 0, sizeof (struct enet_statistics));
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. This should be in a common
* file instead of per-driver.
*/
for (i = 0; i < DEV_NUMBUFFS; i++)
skb_queue_head_init(&dev->buffs[i]);
dev->hard_header = eql_header;
dev->rebuild_header = eql_rebuild_header;
dev->hard_header_len = MAX_HEADER; /* enough space for any slave */
/*
* 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->family = AF_INET;
dev->pa_addr = 0;
dev->pa_brdaddr = 0;
dev->pa_mask = 0;
dev->pa_alen = 4;
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(!suser() && cmd!=EQL_GETMASTRCFG && cmd!=EQL_GETSLAVECFG)
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;
struct sk_buff *skb2;
if (skb == NULL)
return 0;
#if 0
/* Make a copy we can free so we don't mess up the skb->dev pointer */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
return 1;
#endif
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 %ld B %s\n",
dev->name, eql_number_slaves (eql->queue), skb->len,
slave_dev->name);
#endif
/* Rip off the fake header */
skb_pull(skb,MAX_HEADER);
/* The original code had no hard header constructed.
* If a frame is fragmented on EQL and then passed to PPP,
* or ISDN, the result will be a panic.
* The solution is to call the hard_header constructor
* for the device we point to just before we send the packet.
* If this fails we drop the packet.
* We don't know any special parameters for the hard_header
* constructor at this point, so we pass in made up values
* that will cause the constructor to fail on every device
* except those that we are allowed to use EQL on:
* PPP, SLIP and ISDN (in some cases!).
* The worst thing that happens is if some fool
* configures EQL to enslave something that needs
* these parameters it throws out packets.
* This is not an issue for the things EQL is intended for
* anyway, and probably would have crashed the kernel
* or sent garbage down the wire previously.
*/
if (slave_dev->hard_header == NULL
|| slave_dev->hard_header(skb,slave_dev,
ETH_P_IP,NULL,NULL,skb->len) >= 0) {
dev_queue_xmit (skb, slave_dev, 1);
eql->stats->tx_packets++;
slave->bytes_queued += skb->len;
/* dev_kfree_skb(skb, FREE_WRITE); */
return 0;
}
}
/*
* 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(skb2, FREE_WRITE); */
dev_kfree_skb(skb, FREE_WRITE);
return 0;
}
static struct enet_statistics * eql_get_stats(struct device *dev)
{
equalizer_t *eql = (equalizer_t *) dev->priv;
return eql->stats;
}
static int eql_header(struct sk_buff *skb, struct device *dev,
unsigned short type, void *daddr, void *saddr,
unsigned len)
{
/* Fake header to keep space during buggy IP fragmentation. */
skb_push(skb,MAX_HEADER);
return MAX_HEADER;
}
static int eql_rebuild_header(void *buff, struct device *dev,
unsigned long raddr, struct sk_buff *skb)
{
return 0;
}
/*
* 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;
}
memcpy_fromfs (&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;
memcpy_fromfs (&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;
memcpy_fromfs (&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));
if (err)
return err;
memcpy_tofs (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
memcpy_fromfs (&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;
memcpy_tofs (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
memcpy_fromfs (&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:
*/
