Merge branch 'sched/urgent'
[linux-2.6/x86.git] / drivers / net / eql.c
bloba59cf961a436be4fc151b62160f2ad3d17429491
1 /*
2 * Equalizer Load-balancer for serial network interfaces.
4 * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
5 * NCM: Network and Communications Management, Inc.
7 * (c) Copyright 2002 David S. Miller (davem@redhat.com)
9 * This software may be used and distributed according to the terms
10 * of the GNU General Public License, incorporated herein by reference.
12 * The author may be reached as simon@ncm.com, or C/O
13 * NCM
14 * Attn: Simon Janes
15 * 6803 Whittier Ave
16 * McLean VA 22101
17 * Phone: 1-703-847-0040 ext 103
21 * Sources:
22 * skeleton.c by Donald Becker.
23 * Inspirations:
24 * The Harried and Overworked Alan Cox
25 * Conspiracies:
26 * The Alan Cox and Mike McLagan plot to get someone else to do the code,
27 * which turned out to be me.
31 * $Log: eql.c,v $
32 * Revision 1.2 1996/04/11 17:51:52 guru
33 * Added one-line eql_remove_slave patch.
35 * Revision 1.1 1996/04/11 17:44:17 guru
36 * Initial revision
38 * Revision 3.13 1996/01/21 15:17:18 alan
39 * tx_queue_len changes.
40 * reformatted.
42 * Revision 3.12 1995/03/22 21:07:51 anarchy
43 * Added capable() checks on configuration.
44 * Moved header file.
46 * Revision 3.11 1995/01/19 23:14:31 guru
47 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
48 * (priority_Bps) + bytes_queued * 8;
50 * Revision 3.10 1995/01/19 23:07:53 guru
51 * back to
52 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
53 * (priority_Bps) + bytes_queued;
55 * Revision 3.9 1995/01/19 22:38:20 guru
56 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
57 * (priority_Bps) + bytes_queued * 4;
59 * Revision 3.8 1995/01/19 22:30:55 guru
60 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
61 * (priority_Bps) + bytes_queued * 2;
63 * Revision 3.7 1995/01/19 21:52:35 guru
64 * printk's trimmed out.
66 * Revision 3.6 1995/01/19 21:49:56 guru
67 * This is working pretty well. I gained 1 K/s in speed.. now it's just
68 * robustness and printk's to be diked out.
70 * Revision 3.5 1995/01/18 22:29:59 guru
71 * still crashes the kernel when the lock_wait thing is woken up.
73 * Revision 3.4 1995/01/18 21:59:47 guru
74 * Broken set-bit locking snapshot
76 * Revision 3.3 1995/01/17 22:09:18 guru
77 * infinite sleep in a lock somewhere..
79 * Revision 3.2 1995/01/15 16:46:06 guru
80 * Log trimmed of non-pertinent 1.x branch messages
82 * Revision 3.1 1995/01/15 14:41:45 guru
83 * New Scheduler and timer stuff...
85 * Revision 1.15 1995/01/15 14:29:02 guru
86 * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
87 * with the dumber scheduler
89 * Revision 1.14 1995/01/15 02:37:08 guru
90 * shock.. the kept-new-versions could have zonked working
91 * stuff.. shudder
93 * Revision 1.13 1995/01/15 02:36:31 guru
94 * big changes
96 * scheduler was torn out and replaced with something smarter
98 * global names not prefixed with eql_ were renamed to protect
99 * against namespace collisions
101 * a few more abstract interfaces were added to facilitate any
102 * potential change of datastructure. the driver is still using
103 * a linked list of slaves. going to a heap would be a bit of
104 * an overkill.
106 * this compiles fine with no warnings.
108 * the locking mechanism and timer stuff must be written however,
109 * this version will not work otherwise
111 * Sorry, I had to rewrite most of this for 2.5.x -DaveM
114 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
116 #include <linux/capability.h>
117 #include <linux/module.h>
118 #include <linux/kernel.h>
119 #include <linux/init.h>
120 #include <linux/slab.h>
121 #include <linux/timer.h>
122 #include <linux/netdevice.h>
123 #include <net/net_namespace.h>
125 #include <linux/if.h>
126 #include <linux/if_arp.h>
127 #include <linux/if_eql.h>
129 #include <asm/uaccess.h>
131 static int eql_open(struct net_device *dev);
132 static int eql_close(struct net_device *dev);
133 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
134 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
136 #define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
137 #define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
139 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
141 static void eql_timer(unsigned long param)
143 equalizer_t *eql = (equalizer_t *) param;
144 struct list_head *this, *tmp, *head;
146 spin_lock_bh(&eql->queue.lock);
147 head = &eql->queue.all_slaves;
148 list_for_each_safe(this, tmp, head) {
149 slave_t *slave = list_entry(this, slave_t, list);
151 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
152 slave->bytes_queued -= slave->priority_Bps;
153 if (slave->bytes_queued < 0)
154 slave->bytes_queued = 0;
155 } else {
156 eql_kill_one_slave(&eql->queue, slave);
160 spin_unlock_bh(&eql->queue.lock);
162 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
163 add_timer(&eql->timer);
166 static const char version[] __initconst =
167 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";
169 static const struct net_device_ops eql_netdev_ops = {
170 .ndo_open = eql_open,
171 .ndo_stop = eql_close,
172 .ndo_do_ioctl = eql_ioctl,
173 .ndo_start_xmit = eql_slave_xmit,
176 static void __init eql_setup(struct net_device *dev)
178 equalizer_t *eql = netdev_priv(dev);
180 init_timer(&eql->timer);
181 eql->timer.data = (unsigned long) eql;
182 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
183 eql->timer.function = eql_timer;
185 spin_lock_init(&eql->queue.lock);
186 INIT_LIST_HEAD(&eql->queue.all_slaves);
187 eql->queue.master_dev = dev;
189 dev->netdev_ops = &eql_netdev_ops;
192 * Now we undo some of the things that eth_setup does
193 * that we don't like
196 dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
197 dev->flags = IFF_MASTER;
199 dev->type = ARPHRD_SLIP;
200 dev->tx_queue_len = 5; /* Hands them off fast */
201 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
204 static int eql_open(struct net_device *dev)
206 equalizer_t *eql = netdev_priv(dev);
208 /* XXX We should force this off automatically for the user. */
209 netdev_info(dev,
210 "remember to turn off Van-Jacobson compression on your slave devices\n");
212 BUG_ON(!list_empty(&eql->queue.all_slaves));
214 eql->min_slaves = 1;
215 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
217 add_timer(&eql->timer);
219 return 0;
222 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
224 list_del(&slave->list);
225 queue->num_slaves--;
226 slave->dev->flags &= ~IFF_SLAVE;
227 dev_put(slave->dev);
228 kfree(slave);
231 static void eql_kill_slave_queue(slave_queue_t *queue)
233 struct list_head *head, *tmp, *this;
235 spin_lock_bh(&queue->lock);
237 head = &queue->all_slaves;
238 list_for_each_safe(this, tmp, head) {
239 slave_t *s = list_entry(this, slave_t, list);
241 eql_kill_one_slave(queue, s);
244 spin_unlock_bh(&queue->lock);
247 static int eql_close(struct net_device *dev)
249 equalizer_t *eql = netdev_priv(dev);
252 * The timer has to be stopped first before we start hacking away
253 * at the data structure it scans every so often...
256 del_timer_sync(&eql->timer);
258 eql_kill_slave_queue(&eql->queue);
260 return 0;
263 static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
264 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
266 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
267 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
269 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
270 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
272 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
274 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
275 !capable(CAP_NET_ADMIN))
276 return -EPERM;
278 switch (cmd) {
279 case EQL_ENSLAVE:
280 return eql_enslave(dev, ifr->ifr_data);
281 case EQL_EMANCIPATE:
282 return eql_emancipate(dev, ifr->ifr_data);
283 case EQL_GETSLAVECFG:
284 return eql_g_slave_cfg(dev, ifr->ifr_data);
285 case EQL_SETSLAVECFG:
286 return eql_s_slave_cfg(dev, ifr->ifr_data);
287 case EQL_GETMASTRCFG:
288 return eql_g_master_cfg(dev, ifr->ifr_data);
289 case EQL_SETMASTRCFG:
290 return eql_s_master_cfg(dev, ifr->ifr_data);
291 default:
292 return -EOPNOTSUPP;
296 /* queue->lock must be held */
297 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
299 unsigned long best_load = ~0UL;
300 struct list_head *this, *tmp, *head;
301 slave_t *best_slave;
303 best_slave = NULL;
305 /* Make a pass to set the best slave. */
306 head = &queue->all_slaves;
307 list_for_each_safe(this, tmp, head) {
308 slave_t *slave = list_entry(this, slave_t, list);
309 unsigned long slave_load, bytes_queued, priority_Bps;
311 /* Go through the slave list once, updating best_slave
312 * whenever a new best_load is found.
314 bytes_queued = slave->bytes_queued;
315 priority_Bps = slave->priority_Bps;
316 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
317 slave_load = (~0UL - (~0UL / 2)) -
318 (priority_Bps) + bytes_queued * 8;
320 if (slave_load < best_load) {
321 best_load = slave_load;
322 best_slave = slave;
324 } else {
325 /* We found a dead slave, kill it. */
326 eql_kill_one_slave(queue, slave);
329 return best_slave;
332 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
334 equalizer_t *eql = netdev_priv(dev);
335 slave_t *slave;
337 spin_lock(&eql->queue.lock);
339 slave = __eql_schedule_slaves(&eql->queue);
340 if (slave) {
341 struct net_device *slave_dev = slave->dev;
343 skb->dev = slave_dev;
344 skb->priority = 1;
345 slave->bytes_queued += skb->len;
346 dev_queue_xmit(skb);
347 dev->stats.tx_packets++;
348 } else {
349 dev->stats.tx_dropped++;
350 dev_kfree_skb(skb);
353 spin_unlock(&eql->queue.lock);
355 return NETDEV_TX_OK;
359 * Private ioctl functions
362 /* queue->lock must be held */
363 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
365 struct list_head *this, *head;
367 head = &queue->all_slaves;
368 list_for_each(this, head) {
369 slave_t *slave = list_entry(this, slave_t, list);
371 if (slave->dev == dev)
372 return slave;
375 return NULL;
378 static inline int eql_is_full(slave_queue_t *queue)
380 equalizer_t *eql = netdev_priv(queue->master_dev);
382 if (queue->num_slaves >= eql->max_slaves)
383 return 1;
384 return 0;
387 /* queue->lock must be held */
388 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
390 if (!eql_is_full(queue)) {
391 slave_t *duplicate_slave = NULL;
393 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
394 if (duplicate_slave)
395 eql_kill_one_slave(queue, duplicate_slave);
397 list_add(&slave->list, &queue->all_slaves);
398 queue->num_slaves++;
399 slave->dev->flags |= IFF_SLAVE;
401 return 0;
404 return -ENOSPC;
407 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
409 struct net_device *slave_dev;
410 slaving_request_t srq;
412 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
413 return -EFAULT;
415 slave_dev = dev_get_by_name(&init_net, srq.slave_name);
416 if (slave_dev) {
417 if ((master_dev->flags & IFF_UP) == IFF_UP) {
418 /* slave is not a master & not already a slave: */
419 if (!eql_is_master(slave_dev) &&
420 !eql_is_slave(slave_dev)) {
421 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
422 equalizer_t *eql = netdev_priv(master_dev);
423 int ret;
425 if (!s) {
426 dev_put(slave_dev);
427 return -ENOMEM;
430 memset(s, 0, sizeof(*s));
431 s->dev = slave_dev;
432 s->priority = srq.priority;
433 s->priority_bps = srq.priority;
434 s->priority_Bps = srq.priority / 8;
436 spin_lock_bh(&eql->queue.lock);
437 ret = __eql_insert_slave(&eql->queue, s);
438 if (ret) {
439 dev_put(slave_dev);
440 kfree(s);
442 spin_unlock_bh(&eql->queue.lock);
444 return ret;
447 dev_put(slave_dev);
450 return -EINVAL;
453 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
455 equalizer_t *eql = netdev_priv(master_dev);
456 struct net_device *slave_dev;
457 slaving_request_t srq;
458 int ret;
460 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
461 return -EFAULT;
463 slave_dev = dev_get_by_name(&init_net, srq.slave_name);
464 ret = -EINVAL;
465 if (slave_dev) {
466 spin_lock_bh(&eql->queue.lock);
468 if (eql_is_slave(slave_dev)) {
469 slave_t *slave = __eql_find_slave_dev(&eql->queue,
470 slave_dev);
472 if (slave) {
473 eql_kill_one_slave(&eql->queue, slave);
474 ret = 0;
477 dev_put(slave_dev);
479 spin_unlock_bh(&eql->queue.lock);
482 return ret;
485 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
487 equalizer_t *eql = netdev_priv(dev);
488 slave_t *slave;
489 struct net_device *slave_dev;
490 slave_config_t sc;
491 int ret;
493 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
494 return -EFAULT;
496 slave_dev = dev_get_by_name(&init_net, sc.slave_name);
497 if (!slave_dev)
498 return -ENODEV;
500 ret = -EINVAL;
502 spin_lock_bh(&eql->queue.lock);
503 if (eql_is_slave(slave_dev)) {
504 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
505 if (slave) {
506 sc.priority = slave->priority;
507 ret = 0;
510 spin_unlock_bh(&eql->queue.lock);
512 dev_put(slave_dev);
514 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
515 ret = -EFAULT;
517 return ret;
520 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
522 slave_t *slave;
523 equalizer_t *eql;
524 struct net_device *slave_dev;
525 slave_config_t sc;
526 int ret;
528 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
529 return -EFAULT;
531 slave_dev = dev_get_by_name(&init_net, sc.slave_name);
532 if (!slave_dev)
533 return -ENODEV;
535 ret = -EINVAL;
537 eql = netdev_priv(dev);
538 spin_lock_bh(&eql->queue.lock);
539 if (eql_is_slave(slave_dev)) {
540 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
541 if (slave) {
542 slave->priority = sc.priority;
543 slave->priority_bps = sc.priority;
544 slave->priority_Bps = sc.priority / 8;
545 ret = 0;
548 spin_unlock_bh(&eql->queue.lock);
550 dev_put(slave_dev);
552 return ret;
555 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
557 equalizer_t *eql;
558 master_config_t mc;
560 memset(&mc, 0, sizeof(master_config_t));
562 if (eql_is_master(dev)) {
563 eql = netdev_priv(dev);
564 mc.max_slaves = eql->max_slaves;
565 mc.min_slaves = eql->min_slaves;
566 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
567 return -EFAULT;
568 return 0;
570 return -EINVAL;
573 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
575 equalizer_t *eql;
576 master_config_t mc;
578 if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
579 return -EFAULT;
581 if (eql_is_master(dev)) {
582 eql = netdev_priv(dev);
583 eql->max_slaves = mc.max_slaves;
584 eql->min_slaves = mc.min_slaves;
585 return 0;
587 return -EINVAL;
590 static struct net_device *dev_eql;
592 static int __init eql_init_module(void)
594 int err;
596 pr_info("%s\n", version);
598 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
599 if (!dev_eql)
600 return -ENOMEM;
602 err = register_netdev(dev_eql);
603 if (err)
604 free_netdev(dev_eql);
605 return err;
608 static void __exit eql_cleanup_module(void)
610 unregister_netdev(dev_eql);
611 free_netdev(dev_eql);
614 module_init(eql_init_module);
615 module_exit(eql_cleanup_module);
616 MODULE_LICENSE("GPL");