Add support the Korina (IDT RC32434) Ethernet MAC
[linux-2.6.git] / drivers / net / eql.c
1 /*
2  * Equalizer Load-balancer for serial network interfaces.
3  *
4  * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
5  * NCM: Network and Communications Management, Inc.
6  *
7  * (c) Copyright 2002 David S. Miller (davem@redhat.com)
8  *
9  *      This software may be used and distributed according to the terms
10  *      of the GNU General Public License, incorporated herein by reference.
11  *
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
18  */
19
20 /*
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.
28  */
29
30 /*
31  * $Log: eql.c,v $
32  * Revision 1.2  1996/04/11 17:51:52  guru
33  * Added one-line eql_remove_slave patch.
34  *
35  * Revision 1.1  1996/04/11 17:44:17  guru
36  * Initial revision
37  *
38  * Revision 3.13  1996/01/21  15:17:18  alan
39  * tx_queue_len changes.
40  * reformatted.
41  *
42  * Revision 3.12  1995/03/22  21:07:51  anarchy
43  * Added capable() checks on configuration.
44  * Moved header file.
45  *
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;
49  *
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;
54  *
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;
58  *
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;
62  *
63  * Revision 3.7  1995/01/19  21:52:35  guru
64  * printk's trimmed out.
65  *
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.
69  *
70  * Revision 3.5  1995/01/18  22:29:59  guru
71  * still crashes the kernel when the lock_wait thing is woken up.
72  *
73  * Revision 3.4  1995/01/18  21:59:47  guru
74  * Broken set-bit locking snapshot
75  *
76  * Revision 3.3  1995/01/17  22:09:18  guru
77  * infinite sleep in a lock somewhere..
78  *
79  * Revision 3.2  1995/01/15  16:46:06  guru
80  * Log trimmed of non-pertinent 1.x branch messages
81  *
82  * Revision 3.1  1995/01/15  14:41:45  guru
83  * New Scheduler and timer stuff...
84  *
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
88  *
89  * Revision 1.14  1995/01/15  02:37:08  guru
90  * shock.. the kept-new-versions could have zonked working
91  * stuff.. shudder
92  *
93  * Revision 1.13  1995/01/15  02:36:31  guru
94  * big changes
95  *
96  *      scheduler was torn out and replaced with something smarter
97  *
98  *      global names not prefixed with eql_ were renamed to protect
99  *      against namespace collisions
100  *
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.
105  *
106  *      this compiles fine with no warnings.
107  *
108  *      the locking mechanism and timer stuff must be written however,
109  *      this version will not work otherwise
110  *
111  * Sorry, I had to rewrite most of this for 2.5.x -DaveM
112  */
113
114 #include <linux/module.h>
115 #include <linux/kernel.h>
116 #include <linux/init.h>
117 #include <linux/timer.h>
118 #include <linux/netdevice.h>
119 #include <net/net_namespace.h>
120
121 #include <linux/if.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_eql.h>
124
125 #include <asm/uaccess.h>
126
127 static int eql_open(struct net_device *dev);
128 static int eql_close(struct net_device *dev);
129 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
130 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
131
132 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
133 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
134
135 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
136
137 static void eql_timer(unsigned long param)
138 {
139         equalizer_t *eql = (equalizer_t *) param;
140         struct list_head *this, *tmp, *head;
141
142         spin_lock_bh(&eql->queue.lock);
143         head = &eql->queue.all_slaves;
144         list_for_each_safe(this, tmp, head) {
145                 slave_t *slave = list_entry(this, slave_t, list);
146
147                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
148                         slave->bytes_queued -= slave->priority_Bps;
149                         if (slave->bytes_queued < 0)
150                                 slave->bytes_queued = 0;
151                 } else {
152                         eql_kill_one_slave(&eql->queue, slave);
153                 }
154
155         }
156         spin_unlock_bh(&eql->queue.lock);
157
158         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
159         add_timer(&eql->timer);
160 }
161
162 static char version[] __initdata =
163         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
164
165 static void __init eql_setup(struct net_device *dev)
166 {
167         equalizer_t *eql = netdev_priv(dev);
168
169         init_timer(&eql->timer);
170         eql->timer.data         = (unsigned long) eql;
171         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
172         eql->timer.function     = eql_timer;
173
174         spin_lock_init(&eql->queue.lock);
175         INIT_LIST_HEAD(&eql->queue.all_slaves);
176         eql->queue.master_dev   = dev;
177
178         dev->open               = eql_open;
179         dev->stop               = eql_close;
180         dev->do_ioctl           = eql_ioctl;
181         dev->hard_start_xmit    = eql_slave_xmit;
182
183         /*
184          *      Now we undo some of the things that eth_setup does
185          *      that we don't like
186          */
187
188         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
189         dev->flags              = IFF_MASTER;
190
191         dev->type               = ARPHRD_SLIP;
192         dev->tx_queue_len       = 5;            /* Hands them off fast */
193 }
194
195 static int eql_open(struct net_device *dev)
196 {
197         equalizer_t *eql = netdev_priv(dev);
198
199         /* XXX We should force this off automatically for the user. */
200         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
201                "your slave devices.\n", dev->name);
202
203         BUG_ON(!list_empty(&eql->queue.all_slaves));
204
205         eql->min_slaves = 1;
206         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
207
208         add_timer(&eql->timer);
209
210         return 0;
211 }
212
213 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
214 {
215         list_del(&slave->list);
216         queue->num_slaves--;
217         slave->dev->flags &= ~IFF_SLAVE;
218         dev_put(slave->dev);
219         kfree(slave);
220 }
221
222 static void eql_kill_slave_queue(slave_queue_t *queue)
223 {
224         struct list_head *head, *tmp, *this;
225
226         spin_lock_bh(&queue->lock);
227
228         head = &queue->all_slaves;
229         list_for_each_safe(this, tmp, head) {
230                 slave_t *s = list_entry(this, slave_t, list);
231
232                 eql_kill_one_slave(queue, s);
233         }
234
235         spin_unlock_bh(&queue->lock);
236 }
237
238 static int eql_close(struct net_device *dev)
239 {
240         equalizer_t *eql = netdev_priv(dev);
241
242         /*
243          *      The timer has to be stopped first before we start hacking away
244          *      at the data structure it scans every so often...
245          */
246
247         del_timer_sync(&eql->timer);
248
249         eql_kill_slave_queue(&eql->queue);
250
251         return 0;
252 }
253
254 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
255 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
256
257 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
258 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
259
260 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
261 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
262
263 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
264 {
265         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
266             !capable(CAP_NET_ADMIN))
267                 return -EPERM;
268
269         switch (cmd) {
270                 case EQL_ENSLAVE:
271                         return eql_enslave(dev, ifr->ifr_data);
272                 case EQL_EMANCIPATE:
273                         return eql_emancipate(dev, ifr->ifr_data);
274                 case EQL_GETSLAVECFG:
275                         return eql_g_slave_cfg(dev, ifr->ifr_data);
276                 case EQL_SETSLAVECFG:
277                         return eql_s_slave_cfg(dev, ifr->ifr_data);
278                 case EQL_GETMASTRCFG:
279                         return eql_g_master_cfg(dev, ifr->ifr_data);
280                 case EQL_SETMASTRCFG:
281                         return eql_s_master_cfg(dev, ifr->ifr_data);
282                 default:
283                         return -EOPNOTSUPP;
284         };
285 }
286
287 /* queue->lock must be held */
288 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
289 {
290         unsigned long best_load = ~0UL;
291         struct list_head *this, *tmp, *head;
292         slave_t *best_slave;
293
294         best_slave = NULL;
295
296         /* Make a pass to set the best slave. */
297         head = &queue->all_slaves;
298         list_for_each_safe(this, tmp, head) {
299                 slave_t *slave = list_entry(this, slave_t, list);
300                 unsigned long slave_load, bytes_queued, priority_Bps;
301
302                 /* Go through the slave list once, updating best_slave
303                  * whenever a new best_load is found.
304                  */
305                 bytes_queued = slave->bytes_queued;
306                 priority_Bps = slave->priority_Bps;
307                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
308                         slave_load = (~0UL - (~0UL / 2)) -
309                                 (priority_Bps) + bytes_queued * 8;
310
311                         if (slave_load < best_load) {
312                                 best_load = slave_load;
313                                 best_slave = slave;
314                         }
315                 } else {
316                         /* We found a dead slave, kill it. */
317                         eql_kill_one_slave(queue, slave);
318                 }
319         }
320         return best_slave;
321 }
322
323 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
324 {
325         equalizer_t *eql = netdev_priv(dev);
326         slave_t *slave;
327
328         spin_lock(&eql->queue.lock);
329
330         slave = __eql_schedule_slaves(&eql->queue);
331         if (slave) {
332                 struct net_device *slave_dev = slave->dev;
333
334                 skb->dev = slave_dev;
335                 skb->priority = 1;
336                 slave->bytes_queued += skb->len;
337                 dev_queue_xmit(skb);
338                 dev->stats.tx_packets++;
339         } else {
340                 dev->stats.tx_dropped++;
341                 dev_kfree_skb(skb);
342         }
343
344         spin_unlock(&eql->queue.lock);
345
346         return 0;
347 }
348
349 /*
350  *      Private ioctl functions
351  */
352
353 /* queue->lock must be held */
354 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
355 {
356         struct list_head *this, *head;
357
358         head = &queue->all_slaves;
359         list_for_each(this, head) {
360                 slave_t *slave = list_entry(this, slave_t, list);
361
362                 if (slave->dev == dev)
363                         return slave;
364         }
365
366         return NULL;
367 }
368
369 static inline int eql_is_full(slave_queue_t *queue)
370 {
371         equalizer_t *eql = netdev_priv(queue->master_dev);
372
373         if (queue->num_slaves >= eql->max_slaves)
374                 return 1;
375         return 0;
376 }
377
378 /* queue->lock must be held */
379 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
380 {
381         if (!eql_is_full(queue)) {
382                 slave_t *duplicate_slave = NULL;
383
384                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
385                 if (duplicate_slave)
386                         eql_kill_one_slave(queue, duplicate_slave);
387
388                 list_add(&slave->list, &queue->all_slaves);
389                 queue->num_slaves++;
390                 slave->dev->flags |= IFF_SLAVE;
391
392                 return 0;
393         }
394
395         return -ENOSPC;
396 }
397
398 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
399 {
400         struct net_device *slave_dev;
401         slaving_request_t srq;
402
403         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
404                 return -EFAULT;
405
406         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
407         if (slave_dev) {
408                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
409                         /* slave is not a master & not already a slave: */
410                         if (!eql_is_master(slave_dev) &&
411                             !eql_is_slave(slave_dev)) {
412                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
413                                 equalizer_t *eql = netdev_priv(master_dev);
414                                 int ret;
415
416                                 if (!s) {
417                                         dev_put(slave_dev);
418                                         return -ENOMEM;
419                                 }
420
421                                 memset(s, 0, sizeof(*s));
422                                 s->dev = slave_dev;
423                                 s->priority = srq.priority;
424                                 s->priority_bps = srq.priority;
425                                 s->priority_Bps = srq.priority / 8;
426
427                                 spin_lock_bh(&eql->queue.lock);
428                                 ret = __eql_insert_slave(&eql->queue, s);
429                                 if (ret) {
430                                         dev_put(slave_dev);
431                                         kfree(s);
432                                 }
433                                 spin_unlock_bh(&eql->queue.lock);
434
435                                 return ret;
436                         }
437                 }
438                 dev_put(slave_dev);
439         }
440
441         return -EINVAL;
442 }
443
444 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
445 {
446         equalizer_t *eql = netdev_priv(master_dev);
447         struct net_device *slave_dev;
448         slaving_request_t srq;
449         int ret;
450
451         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
452                 return -EFAULT;
453
454         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
455         ret = -EINVAL;
456         if (slave_dev) {
457                 spin_lock_bh(&eql->queue.lock);
458
459                 if (eql_is_slave(slave_dev)) {
460                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
461                                                               slave_dev);
462
463                         if (slave) {
464                                 eql_kill_one_slave(&eql->queue, slave);
465                                 ret = 0;
466                         }
467                 }
468                 dev_put(slave_dev);
469
470                 spin_unlock_bh(&eql->queue.lock);
471         }
472
473         return ret;
474 }
475
476 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
477 {
478         equalizer_t *eql = netdev_priv(dev);
479         slave_t *slave;
480         struct net_device *slave_dev;
481         slave_config_t sc;
482         int ret;
483
484         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
485                 return -EFAULT;
486
487         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
488         if (!slave_dev)
489                 return -ENODEV;
490
491         ret = -EINVAL;
492
493         spin_lock_bh(&eql->queue.lock);
494         if (eql_is_slave(slave_dev)) {
495                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
496                 if (slave) {
497                         sc.priority = slave->priority;
498                         ret = 0;
499                 }
500         }
501         spin_unlock_bh(&eql->queue.lock);
502
503         dev_put(slave_dev);
504
505         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
506                 ret = -EFAULT;
507
508         return ret;
509 }
510
511 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
512 {
513         slave_t *slave;
514         equalizer_t *eql;
515         struct net_device *slave_dev;
516         slave_config_t sc;
517         int ret;
518
519         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
520                 return -EFAULT;
521
522         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
523         if (!slave_dev)
524                 return -ENODEV;
525
526         ret = -EINVAL;
527
528         eql = netdev_priv(dev);
529         spin_lock_bh(&eql->queue.lock);
530         if (eql_is_slave(slave_dev)) {
531                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
532                 if (slave) {
533                         slave->priority = sc.priority;
534                         slave->priority_bps = sc.priority;
535                         slave->priority_Bps = sc.priority / 8;
536                         ret = 0;
537                 }
538         }
539         spin_unlock_bh(&eql->queue.lock);
540
541         return ret;
542 }
543
544 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
545 {
546         equalizer_t *eql;
547         master_config_t mc;
548
549         if (eql_is_master(dev)) {
550                 eql = netdev_priv(dev);
551                 mc.max_slaves = eql->max_slaves;
552                 mc.min_slaves = eql->min_slaves;
553                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
554                         return -EFAULT;
555                 return 0;
556         }
557         return -EINVAL;
558 }
559
560 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
561 {
562         equalizer_t *eql;
563         master_config_t mc;
564
565         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
566                 return -EFAULT;
567
568         if (eql_is_master(dev)) {
569                 eql = netdev_priv(dev);
570                 eql->max_slaves = mc.max_slaves;
571                 eql->min_slaves = mc.min_slaves;
572                 return 0;
573         }
574         return -EINVAL;
575 }
576
577 static struct net_device *dev_eql;
578
579 static int __init eql_init_module(void)
580 {
581         int err;
582
583         printk(version);
584
585         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
586         if (!dev_eql)
587                 return -ENOMEM;
588
589         err = register_netdev(dev_eql);
590         if (err)
591                 free_netdev(dev_eql);
592         return err;
593 }
594
595 static void __exit eql_cleanup_module(void)
596 {
597         unregister_netdev(dev_eql);
598         free_netdev(dev_eql);
599 }
600
601 module_init(eql_init_module);
602 module_exit(eql_cleanup_module);
603 MODULE_LICENSE("GPL");