drivers/net: const-ify ethtool_ops declarations
[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
120 #include <linux/if.h>
121 #include <linux/if_arp.h>
122 #include <linux/if_eql.h>
123
124 #include <asm/uaccess.h>
125
126 static int eql_open(struct net_device *dev);
127 static int eql_close(struct net_device *dev);
128 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
129 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
130 static struct net_device_stats *eql_get_stats(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         SET_MODULE_OWNER(dev);
170
171         init_timer(&eql->timer);
172         eql->timer.data         = (unsigned long) eql;
173         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
174         eql->timer.function     = eql_timer;
175
176         spin_lock_init(&eql->queue.lock);
177         INIT_LIST_HEAD(&eql->queue.all_slaves);
178         eql->queue.master_dev   = dev;
179
180         dev->open               = eql_open;
181         dev->stop               = eql_close;
182         dev->do_ioctl           = eql_ioctl;
183         dev->hard_start_xmit    = eql_slave_xmit;
184         dev->get_stats          = eql_get_stats;
185
186         /*
187          *      Now we undo some of the things that eth_setup does
188          *      that we don't like
189          */
190
191         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
192         dev->flags              = IFF_MASTER;
193
194         dev->type               = ARPHRD_SLIP;
195         dev->tx_queue_len       = 5;            /* Hands them off fast */
196 }
197
198 static int eql_open(struct net_device *dev)
199 {
200         equalizer_t *eql = netdev_priv(dev);
201
202         /* XXX We should force this off automatically for the user. */
203         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
204                "your slave devices.\n", dev->name);
205
206         BUG_ON(!list_empty(&eql->queue.all_slaves));
207
208         eql->min_slaves = 1;
209         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
210
211         add_timer(&eql->timer);
212
213         return 0;
214 }
215
216 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
217 {
218         list_del(&slave->list);
219         queue->num_slaves--;
220         slave->dev->flags &= ~IFF_SLAVE;
221         dev_put(slave->dev);
222         kfree(slave);
223 }
224
225 static void eql_kill_slave_queue(slave_queue_t *queue)
226 {
227         struct list_head *head, *tmp, *this;
228
229         spin_lock_bh(&queue->lock);
230
231         head = &queue->all_slaves;
232         list_for_each_safe(this, tmp, head) {
233                 slave_t *s = list_entry(this, slave_t, list);
234
235                 eql_kill_one_slave(queue, s);
236         }
237
238         spin_unlock_bh(&queue->lock);
239 }
240
241 static int eql_close(struct net_device *dev)
242 {
243         equalizer_t *eql = netdev_priv(dev);
244
245         /*
246          *      The timer has to be stopped first before we start hacking away
247          *      at the data structure it scans every so often...
248          */
249
250         del_timer_sync(&eql->timer);
251
252         eql_kill_slave_queue(&eql->queue);
253
254         return 0;
255 }
256
257 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
258 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
259
260 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
261 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
262
263 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
264 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
265
266 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
267 {
268         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
269             !capable(CAP_NET_ADMIN))
270                 return -EPERM;
271
272         switch (cmd) {
273                 case EQL_ENSLAVE:
274                         return eql_enslave(dev, ifr->ifr_data);
275                 case EQL_EMANCIPATE:
276                         return eql_emancipate(dev, ifr->ifr_data);
277                 case EQL_GETSLAVECFG:
278                         return eql_g_slave_cfg(dev, ifr->ifr_data);
279                 case EQL_SETSLAVECFG:
280                         return eql_s_slave_cfg(dev, ifr->ifr_data);
281                 case EQL_GETMASTRCFG:
282                         return eql_g_master_cfg(dev, ifr->ifr_data);
283                 case EQL_SETMASTRCFG:
284                         return eql_s_master_cfg(dev, ifr->ifr_data);
285                 default:
286                         return -EOPNOTSUPP;
287         };
288 }
289
290 /* queue->lock must be held */
291 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
292 {
293         unsigned long best_load = ~0UL;
294         struct list_head *this, *tmp, *head;
295         slave_t *best_slave;
296
297         best_slave = NULL;
298
299         /* Make a pass to set the best slave. */
300         head = &queue->all_slaves;
301         list_for_each_safe(this, tmp, head) {
302                 slave_t *slave = list_entry(this, slave_t, list);
303                 unsigned long slave_load, bytes_queued, priority_Bps;
304
305                 /* Go through the slave list once, updating best_slave
306                  * whenever a new best_load is found.
307                  */
308                 bytes_queued = slave->bytes_queued;
309                 priority_Bps = slave->priority_Bps;
310                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
311                         slave_load = (~0UL - (~0UL / 2)) -
312                                 (priority_Bps) + bytes_queued * 8;
313
314                         if (slave_load < best_load) {
315                                 best_load = slave_load;
316                                 best_slave = slave;
317                         }
318                 } else {
319                         /* We found a dead slave, kill it. */
320                         eql_kill_one_slave(queue, slave);
321                 }
322         }
323         return best_slave;
324 }
325
326 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
327 {
328         equalizer_t *eql = netdev_priv(dev);
329         slave_t *slave;
330
331         spin_lock(&eql->queue.lock);
332
333         slave = __eql_schedule_slaves(&eql->queue);
334         if (slave) {
335                 struct net_device *slave_dev = slave->dev;
336
337                 skb->dev = slave_dev;
338                 skb->priority = 1;
339                 slave->bytes_queued += skb->len;
340                 dev_queue_xmit(skb);
341                 eql->stats.tx_packets++;
342         } else {
343                 eql->stats.tx_dropped++;
344                 dev_kfree_skb(skb);
345         }
346
347         spin_unlock(&eql->queue.lock);
348
349         return 0;
350 }
351
352 static struct net_device_stats * eql_get_stats(struct net_device *dev)
353 {
354         equalizer_t *eql = netdev_priv(dev);
355         return &eql->stats;
356 }
357
358 /*
359  *      Private ioctl functions
360  */
361
362 /* queue->lock must be held */
363 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
364 {
365         struct list_head *this, *head;
366
367         head = &queue->all_slaves;
368         list_for_each(this, head) {
369                 slave_t *slave = list_entry(this, slave_t, list);
370
371                 if (slave->dev == dev)
372                         return slave;
373         }
374
375         return NULL;
376 }
377
378 static inline int eql_is_full(slave_queue_t *queue)
379 {
380         equalizer_t *eql = netdev_priv(queue->master_dev);
381
382         if (queue->num_slaves >= eql->max_slaves)
383                 return 1;
384         return 0;
385 }
386
387 /* queue->lock must be held */
388 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
389 {
390         if (!eql_is_full(queue)) {
391                 slave_t *duplicate_slave = NULL;
392
393                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
394                 if (duplicate_slave != 0)
395                         eql_kill_one_slave(queue, duplicate_slave);
396
397                 list_add(&slave->list, &queue->all_slaves);
398                 queue->num_slaves++;
399                 slave->dev->flags |= IFF_SLAVE;
400
401                 return 0;
402         }
403
404         return -ENOSPC;
405 }
406
407 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
408 {
409         struct net_device *slave_dev;
410         slaving_request_t srq;
411
412         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
413                 return -EFAULT;
414
415         slave_dev  = dev_get_by_name(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;
424
425                                 if (!s) {
426                                         dev_put(slave_dev);
427                                         return -ENOMEM;
428                                 }
429
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;
435
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);
441                                 }
442                                 spin_unlock_bh(&eql->queue.lock);
443
444                                 return ret;
445                         }
446                 }
447                 dev_put(slave_dev);
448         }
449
450         return -EINVAL;
451 }
452
453 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
454 {
455         equalizer_t *eql = netdev_priv(master_dev);
456         struct net_device *slave_dev;
457         slaving_request_t srq;
458         int ret;
459
460         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
461                 return -EFAULT;
462
463         slave_dev = dev_get_by_name(srq.slave_name);
464         ret = -EINVAL;
465         if (slave_dev) {
466                 spin_lock_bh(&eql->queue.lock);
467
468                 if (eql_is_slave(slave_dev)) {
469                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
470                                                               slave_dev);
471
472                         if (slave) {
473                                 eql_kill_one_slave(&eql->queue, slave);
474                                 ret = 0;
475                         }
476                 }
477                 dev_put(slave_dev);
478
479                 spin_unlock_bh(&eql->queue.lock);
480         }
481
482         return ret;
483 }
484
485 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
486 {
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;
492
493         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
494                 return -EFAULT;
495
496         slave_dev = dev_get_by_name(sc.slave_name);
497         if (!slave_dev)
498                 return -ENODEV;
499
500         ret = -EINVAL;
501
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;
508                 }
509         }
510         spin_unlock_bh(&eql->queue.lock);
511
512         dev_put(slave_dev);
513
514         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
515                 ret = -EFAULT;
516
517         return ret;
518 }
519
520 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
521 {
522         slave_t *slave;
523         equalizer_t *eql;
524         struct net_device *slave_dev;
525         slave_config_t sc;
526         int ret;
527
528         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
529                 return -EFAULT;
530
531         slave_dev = dev_get_by_name(sc.slave_name);
532         if (!slave_dev)
533                 return -ENODEV;
534
535         ret = -EINVAL;
536
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;
546                 }
547         }
548         spin_unlock_bh(&eql->queue.lock);
549
550         return ret;
551 }
552
553 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
554 {
555         equalizer_t *eql;
556         master_config_t mc;
557
558         if (eql_is_master(dev)) {
559                 eql = netdev_priv(dev);
560                 mc.max_slaves = eql->max_slaves;
561                 mc.min_slaves = eql->min_slaves;
562                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
563                         return -EFAULT;
564                 return 0;
565         }
566         return -EINVAL;
567 }
568
569 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
570 {
571         equalizer_t *eql;
572         master_config_t mc;
573
574         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
575                 return -EFAULT;
576
577         if (eql_is_master(dev)) {
578                 eql = netdev_priv(dev);
579                 eql->max_slaves = mc.max_slaves;
580                 eql->min_slaves = mc.min_slaves;
581                 return 0;
582         }
583         return -EINVAL;
584 }
585
586 static struct net_device *dev_eql;
587
588 static int __init eql_init_module(void)
589 {
590         int err;
591
592         printk(version);
593
594         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
595         if (!dev_eql)
596                 return -ENOMEM;
597
598         err = register_netdev(dev_eql);
599         if (err)
600                 free_netdev(dev_eql);
601         return err;
602 }
603
604 static void __exit eql_cleanup_module(void)
605 {
606         unregister_netdev(dev_eql);
607         free_netdev(dev_eql);
608 }
609
610 module_init(eql_init_module);
611 module_exit(eql_cleanup_module);
612 MODULE_LICENSE("GPL");