[PATCH] libertas: use LBS_DEB_HOST for host-to-card communications
[linux-2.6] / 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 static struct net_device_stats *eql_get_stats(struct net_device *dev);
132
133 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
134 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
135
136 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
137
138 static void eql_timer(unsigned long param)
139 {
140         equalizer_t *eql = (equalizer_t *) param;
141         struct list_head *this, *tmp, *head;
142
143         spin_lock_bh(&eql->queue.lock);
144         head = &eql->queue.all_slaves;
145         list_for_each_safe(this, tmp, head) {
146                 slave_t *slave = list_entry(this, slave_t, list);
147
148                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
149                         slave->bytes_queued -= slave->priority_Bps;
150                         if (slave->bytes_queued < 0)
151                                 slave->bytes_queued = 0;
152                 } else {
153                         eql_kill_one_slave(&eql->queue, slave);
154                 }
155
156         }
157         spin_unlock_bh(&eql->queue.lock);
158
159         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
160         add_timer(&eql->timer);
161 }
162
163 static char version[] __initdata =
164         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
165
166 static void __init eql_setup(struct net_device *dev)
167 {
168         equalizer_t *eql = netdev_priv(dev);
169
170         SET_MODULE_OWNER(dev);
171
172         init_timer(&eql->timer);
173         eql->timer.data         = (unsigned long) eql;
174         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
175         eql->timer.function     = eql_timer;
176
177         spin_lock_init(&eql->queue.lock);
178         INIT_LIST_HEAD(&eql->queue.all_slaves);
179         eql->queue.master_dev   = dev;
180
181         dev->open               = eql_open;
182         dev->stop               = eql_close;
183         dev->do_ioctl           = eql_ioctl;
184         dev->hard_start_xmit    = eql_slave_xmit;
185         dev->get_stats          = eql_get_stats;
186
187         /*
188          *      Now we undo some of the things that eth_setup does
189          *      that we don't like
190          */
191
192         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
193         dev->flags              = IFF_MASTER;
194
195         dev->type               = ARPHRD_SLIP;
196         dev->tx_queue_len       = 5;            /* Hands them off fast */
197 }
198
199 static int eql_open(struct net_device *dev)
200 {
201         equalizer_t *eql = netdev_priv(dev);
202
203         /* XXX We should force this off automatically for the user. */
204         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
205                "your slave devices.\n", dev->name);
206
207         BUG_ON(!list_empty(&eql->queue.all_slaves));
208
209         eql->min_slaves = 1;
210         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
211
212         add_timer(&eql->timer);
213
214         return 0;
215 }
216
217 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
218 {
219         list_del(&slave->list);
220         queue->num_slaves--;
221         slave->dev->flags &= ~IFF_SLAVE;
222         dev_put(slave->dev);
223         kfree(slave);
224 }
225
226 static void eql_kill_slave_queue(slave_queue_t *queue)
227 {
228         struct list_head *head, *tmp, *this;
229
230         spin_lock_bh(&queue->lock);
231
232         head = &queue->all_slaves;
233         list_for_each_safe(this, tmp, head) {
234                 slave_t *s = list_entry(this, slave_t, list);
235
236                 eql_kill_one_slave(queue, s);
237         }
238
239         spin_unlock_bh(&queue->lock);
240 }
241
242 static int eql_close(struct net_device *dev)
243 {
244         equalizer_t *eql = netdev_priv(dev);
245
246         /*
247          *      The timer has to be stopped first before we start hacking away
248          *      at the data structure it scans every so often...
249          */
250
251         del_timer_sync(&eql->timer);
252
253         eql_kill_slave_queue(&eql->queue);
254
255         return 0;
256 }
257
258 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
259 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
260
261 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
262 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
263
264 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
265 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
266
267 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
268 {
269         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
270             !capable(CAP_NET_ADMIN))
271                 return -EPERM;
272
273         switch (cmd) {
274                 case EQL_ENSLAVE:
275                         return eql_enslave(dev, ifr->ifr_data);
276                 case EQL_EMANCIPATE:
277                         return eql_emancipate(dev, ifr->ifr_data);
278                 case EQL_GETSLAVECFG:
279                         return eql_g_slave_cfg(dev, ifr->ifr_data);
280                 case EQL_SETSLAVECFG:
281                         return eql_s_slave_cfg(dev, ifr->ifr_data);
282                 case EQL_GETMASTRCFG:
283                         return eql_g_master_cfg(dev, ifr->ifr_data);
284                 case EQL_SETMASTRCFG:
285                         return eql_s_master_cfg(dev, ifr->ifr_data);
286                 default:
287                         return -EOPNOTSUPP;
288         };
289 }
290
291 /* queue->lock must be held */
292 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
293 {
294         unsigned long best_load = ~0UL;
295         struct list_head *this, *tmp, *head;
296         slave_t *best_slave;
297
298         best_slave = NULL;
299
300         /* Make a pass to set the best slave. */
301         head = &queue->all_slaves;
302         list_for_each_safe(this, tmp, head) {
303                 slave_t *slave = list_entry(this, slave_t, list);
304                 unsigned long slave_load, bytes_queued, priority_Bps;
305
306                 /* Go through the slave list once, updating best_slave
307                  * whenever a new best_load is found.
308                  */
309                 bytes_queued = slave->bytes_queued;
310                 priority_Bps = slave->priority_Bps;
311                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
312                         slave_load = (~0UL - (~0UL / 2)) -
313                                 (priority_Bps) + bytes_queued * 8;
314
315                         if (slave_load < best_load) {
316                                 best_load = slave_load;
317                                 best_slave = slave;
318                         }
319                 } else {
320                         /* We found a dead slave, kill it. */
321                         eql_kill_one_slave(queue, slave);
322                 }
323         }
324         return best_slave;
325 }
326
327 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
328 {
329         equalizer_t *eql = netdev_priv(dev);
330         slave_t *slave;
331
332         spin_lock(&eql->queue.lock);
333
334         slave = __eql_schedule_slaves(&eql->queue);
335         if (slave) {
336                 struct net_device *slave_dev = slave->dev;
337
338                 skb->dev = slave_dev;
339                 skb->priority = 1;
340                 slave->bytes_queued += skb->len;
341                 dev_queue_xmit(skb);
342                 eql->stats.tx_packets++;
343         } else {
344                 eql->stats.tx_dropped++;
345                 dev_kfree_skb(skb);
346         }
347
348         spin_unlock(&eql->queue.lock);
349
350         return 0;
351 }
352
353 static struct net_device_stats * eql_get_stats(struct net_device *dev)
354 {
355         equalizer_t *eql = netdev_priv(dev);
356         return &eql->stats;
357 }
358
359 /*
360  *      Private ioctl functions
361  */
362
363 /* queue->lock must be held */
364 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
365 {
366         struct list_head *this, *head;
367
368         head = &queue->all_slaves;
369         list_for_each(this, head) {
370                 slave_t *slave = list_entry(this, slave_t, list);
371
372                 if (slave->dev == dev)
373                         return slave;
374         }
375
376         return NULL;
377 }
378
379 static inline int eql_is_full(slave_queue_t *queue)
380 {
381         equalizer_t *eql = netdev_priv(queue->master_dev);
382
383         if (queue->num_slaves >= eql->max_slaves)
384                 return 1;
385         return 0;
386 }
387
388 /* queue->lock must be held */
389 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
390 {
391         if (!eql_is_full(queue)) {
392                 slave_t *duplicate_slave = NULL;
393
394                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
395                 if (duplicate_slave)
396                         eql_kill_one_slave(queue, duplicate_slave);
397
398                 list_add(&slave->list, &queue->all_slaves);
399                 queue->num_slaves++;
400                 slave->dev->flags |= IFF_SLAVE;
401
402                 return 0;
403         }
404
405         return -ENOSPC;
406 }
407
408 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
409 {
410         struct net_device *slave_dev;
411         slaving_request_t srq;
412
413         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
414                 return -EFAULT;
415
416         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
417         if (slave_dev) {
418                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
419                         /* slave is not a master & not already a slave: */
420                         if (!eql_is_master(slave_dev) &&
421                             !eql_is_slave(slave_dev)) {
422                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
423                                 equalizer_t *eql = netdev_priv(master_dev);
424                                 int ret;
425
426                                 if (!s) {
427                                         dev_put(slave_dev);
428                                         return -ENOMEM;
429                                 }
430
431                                 memset(s, 0, sizeof(*s));
432                                 s->dev = slave_dev;
433                                 s->priority = srq.priority;
434                                 s->priority_bps = srq.priority;
435                                 s->priority_Bps = srq.priority / 8;
436
437                                 spin_lock_bh(&eql->queue.lock);
438                                 ret = __eql_insert_slave(&eql->queue, s);
439                                 if (ret) {
440                                         dev_put(slave_dev);
441                                         kfree(s);
442                                 }
443                                 spin_unlock_bh(&eql->queue.lock);
444
445                                 return ret;
446                         }
447                 }
448                 dev_put(slave_dev);
449         }
450
451         return -EINVAL;
452 }
453
454 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
455 {
456         equalizer_t *eql = netdev_priv(master_dev);
457         struct net_device *slave_dev;
458         slaving_request_t srq;
459         int ret;
460
461         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
462                 return -EFAULT;
463
464         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
465         ret = -EINVAL;
466         if (slave_dev) {
467                 spin_lock_bh(&eql->queue.lock);
468
469                 if (eql_is_slave(slave_dev)) {
470                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
471                                                               slave_dev);
472
473                         if (slave) {
474                                 eql_kill_one_slave(&eql->queue, slave);
475                                 ret = 0;
476                         }
477                 }
478                 dev_put(slave_dev);
479
480                 spin_unlock_bh(&eql->queue.lock);
481         }
482
483         return ret;
484 }
485
486 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
487 {
488         equalizer_t *eql = netdev_priv(dev);
489         slave_t *slave;
490         struct net_device *slave_dev;
491         slave_config_t sc;
492         int ret;
493
494         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
495                 return -EFAULT;
496
497         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
498         if (!slave_dev)
499                 return -ENODEV;
500
501         ret = -EINVAL;
502
503         spin_lock_bh(&eql->queue.lock);
504         if (eql_is_slave(slave_dev)) {
505                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
506                 if (slave) {
507                         sc.priority = slave->priority;
508                         ret = 0;
509                 }
510         }
511         spin_unlock_bh(&eql->queue.lock);
512
513         dev_put(slave_dev);
514
515         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
516                 ret = -EFAULT;
517
518         return ret;
519 }
520
521 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
522 {
523         slave_t *slave;
524         equalizer_t *eql;
525         struct net_device *slave_dev;
526         slave_config_t sc;
527         int ret;
528
529         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
530                 return -EFAULT;
531
532         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
533         if (!slave_dev)
534                 return -ENODEV;
535
536         ret = -EINVAL;
537
538         eql = netdev_priv(dev);
539         spin_lock_bh(&eql->queue.lock);
540         if (eql_is_slave(slave_dev)) {
541                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
542                 if (slave) {
543                         slave->priority = sc.priority;
544                         slave->priority_bps = sc.priority;
545                         slave->priority_Bps = sc.priority / 8;
546                         ret = 0;
547                 }
548         }
549         spin_unlock_bh(&eql->queue.lock);
550
551         return ret;
552 }
553
554 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
555 {
556         equalizer_t *eql;
557         master_config_t mc;
558
559         if (eql_is_master(dev)) {
560                 eql = netdev_priv(dev);
561                 mc.max_slaves = eql->max_slaves;
562                 mc.min_slaves = eql->min_slaves;
563                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
564                         return -EFAULT;
565                 return 0;
566         }
567         return -EINVAL;
568 }
569
570 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
571 {
572         equalizer_t *eql;
573         master_config_t mc;
574
575         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
576                 return -EFAULT;
577
578         if (eql_is_master(dev)) {
579                 eql = netdev_priv(dev);
580                 eql->max_slaves = mc.max_slaves;
581                 eql->min_slaves = mc.min_slaves;
582                 return 0;
583         }
584         return -EINVAL;
585 }
586
587 static struct net_device *dev_eql;
588
589 static int __init eql_init_module(void)
590 {
591         int err;
592
593         printk(version);
594
595         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
596         if (!dev_eql)
597                 return -ENOMEM;
598
599         err = register_netdev(dev_eql);
600         if (err)
601                 free_netdev(dev_eql);
602         return err;
603 }
604
605 static void __exit eql_cleanup_module(void)
606 {
607         unregister_netdev(dev_eql);
608         free_netdev(dev_eql);
609 }
610
611 module_init(eql_init_module);
612 module_exit(eql_cleanup_module);
613 MODULE_LICENSE("GPL");