drivers/net/pcmcia: Use pr_<level> and netdev_<level>
[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/capability.h>
115 #include <linux/module.h>
116 #include <linux/kernel.h>
117 #include <linux/init.h>
118 #include <linux/slab.h>
119 #include <linux/timer.h>
120 #include <linux/netdevice.h>
121 #include <net/net_namespace.h>
122
123 #include <linux/if.h>
124 #include <linux/if_arp.h>
125 #include <linux/if_eql.h>
126
127 #include <asm/uaccess.h>
128
129 static int eql_open(struct net_device *dev);
130 static int eql_close(struct net_device *dev);
131 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
132 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
133
134 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
135 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
136
137 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
138
139 static void eql_timer(unsigned long param)
140 {
141         equalizer_t *eql = (equalizer_t *) param;
142         struct list_head *this, *tmp, *head;
143
144         spin_lock_bh(&eql->queue.lock);
145         head = &eql->queue.all_slaves;
146         list_for_each_safe(this, tmp, head) {
147                 slave_t *slave = list_entry(this, slave_t, list);
148
149                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
150                         slave->bytes_queued -= slave->priority_Bps;
151                         if (slave->bytes_queued < 0)
152                                 slave->bytes_queued = 0;
153                 } else {
154                         eql_kill_one_slave(&eql->queue, slave);
155                 }
156
157         }
158         spin_unlock_bh(&eql->queue.lock);
159
160         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
161         add_timer(&eql->timer);
162 }
163
164 static const char version[] __initconst =
165         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
166
167 static const struct net_device_ops eql_netdev_ops = {
168         .ndo_open       = eql_open,
169         .ndo_stop       = eql_close,
170         .ndo_do_ioctl   = eql_ioctl,
171         .ndo_start_xmit = eql_slave_xmit,
172 };
173
174 static void __init eql_setup(struct net_device *dev)
175 {
176         equalizer_t *eql = netdev_priv(dev);
177
178         init_timer(&eql->timer);
179         eql->timer.data         = (unsigned long) eql;
180         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
181         eql->timer.function     = eql_timer;
182
183         spin_lock_init(&eql->queue.lock);
184         INIT_LIST_HEAD(&eql->queue.all_slaves);
185         eql->queue.master_dev   = dev;
186
187         dev->netdev_ops         = &eql_netdev_ops;
188
189         /*
190          *      Now we undo some of the things that eth_setup does
191          *      that we don't like
192          */
193
194         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
195         dev->flags              = IFF_MASTER;
196
197         dev->type               = ARPHRD_SLIP;
198         dev->tx_queue_len       = 5;            /* Hands them off fast */
199         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
200 }
201
202 static int eql_open(struct net_device *dev)
203 {
204         equalizer_t *eql = netdev_priv(dev);
205
206         /* XXX We should force this off automatically for the user. */
207         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
208                "your slave devices.\n", dev->name);
209
210         BUG_ON(!list_empty(&eql->queue.all_slaves));
211
212         eql->min_slaves = 1;
213         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
214
215         add_timer(&eql->timer);
216
217         return 0;
218 }
219
220 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
221 {
222         list_del(&slave->list);
223         queue->num_slaves--;
224         slave->dev->flags &= ~IFF_SLAVE;
225         dev_put(slave->dev);
226         kfree(slave);
227 }
228
229 static void eql_kill_slave_queue(slave_queue_t *queue)
230 {
231         struct list_head *head, *tmp, *this;
232
233         spin_lock_bh(&queue->lock);
234
235         head = &queue->all_slaves;
236         list_for_each_safe(this, tmp, head) {
237                 slave_t *s = list_entry(this, slave_t, list);
238
239                 eql_kill_one_slave(queue, s);
240         }
241
242         spin_unlock_bh(&queue->lock);
243 }
244
245 static int eql_close(struct net_device *dev)
246 {
247         equalizer_t *eql = netdev_priv(dev);
248
249         /*
250          *      The timer has to be stopped first before we start hacking away
251          *      at the data structure it scans every so often...
252          */
253
254         del_timer_sync(&eql->timer);
255
256         eql_kill_slave_queue(&eql->queue);
257
258         return 0;
259 }
260
261 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
262 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
263
264 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
265 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
266
267 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
268 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
269
270 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
271 {
272         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
273             !capable(CAP_NET_ADMIN))
274                 return -EPERM;
275
276         switch (cmd) {
277                 case EQL_ENSLAVE:
278                         return eql_enslave(dev, ifr->ifr_data);
279                 case EQL_EMANCIPATE:
280                         return eql_emancipate(dev, ifr->ifr_data);
281                 case EQL_GETSLAVECFG:
282                         return eql_g_slave_cfg(dev, ifr->ifr_data);
283                 case EQL_SETSLAVECFG:
284                         return eql_s_slave_cfg(dev, ifr->ifr_data);
285                 case EQL_GETMASTRCFG:
286                         return eql_g_master_cfg(dev, ifr->ifr_data);
287                 case EQL_SETMASTRCFG:
288                         return eql_s_master_cfg(dev, ifr->ifr_data);
289                 default:
290                         return -EOPNOTSUPP;
291         }
292 }
293
294 /* queue->lock must be held */
295 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
296 {
297         unsigned long best_load = ~0UL;
298         struct list_head *this, *tmp, *head;
299         slave_t *best_slave;
300
301         best_slave = NULL;
302
303         /* Make a pass to set the best slave. */
304         head = &queue->all_slaves;
305         list_for_each_safe(this, tmp, head) {
306                 slave_t *slave = list_entry(this, slave_t, list);
307                 unsigned long slave_load, bytes_queued, priority_Bps;
308
309                 /* Go through the slave list once, updating best_slave
310                  * whenever a new best_load is found.
311                  */
312                 bytes_queued = slave->bytes_queued;
313                 priority_Bps = slave->priority_Bps;
314                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
315                         slave_load = (~0UL - (~0UL / 2)) -
316                                 (priority_Bps) + bytes_queued * 8;
317
318                         if (slave_load < best_load) {
319                                 best_load = slave_load;
320                                 best_slave = slave;
321                         }
322                 } else {
323                         /* We found a dead slave, kill it. */
324                         eql_kill_one_slave(queue, slave);
325                 }
326         }
327         return best_slave;
328 }
329
330 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
331 {
332         equalizer_t *eql = netdev_priv(dev);
333         slave_t *slave;
334
335         spin_lock(&eql->queue.lock);
336
337         slave = __eql_schedule_slaves(&eql->queue);
338         if (slave) {
339                 struct net_device *slave_dev = slave->dev;
340
341                 skb->dev = slave_dev;
342                 skb->priority = 1;
343                 slave->bytes_queued += skb->len;
344                 dev_queue_xmit(skb);
345                 dev->stats.tx_packets++;
346         } else {
347                 dev->stats.tx_dropped++;
348                 dev_kfree_skb(skb);
349         }
350
351         spin_unlock(&eql->queue.lock);
352
353         return NETDEV_TX_OK;
354 }
355
356 /*
357  *      Private ioctl functions
358  */
359
360 /* queue->lock must be held */
361 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
362 {
363         struct list_head *this, *head;
364
365         head = &queue->all_slaves;
366         list_for_each(this, head) {
367                 slave_t *slave = list_entry(this, slave_t, list);
368
369                 if (slave->dev == dev)
370                         return slave;
371         }
372
373         return NULL;
374 }
375
376 static inline int eql_is_full(slave_queue_t *queue)
377 {
378         equalizer_t *eql = netdev_priv(queue->master_dev);
379
380         if (queue->num_slaves >= eql->max_slaves)
381                 return 1;
382         return 0;
383 }
384
385 /* queue->lock must be held */
386 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
387 {
388         if (!eql_is_full(queue)) {
389                 slave_t *duplicate_slave = NULL;
390
391                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
392                 if (duplicate_slave)
393                         eql_kill_one_slave(queue, duplicate_slave);
394
395                 list_add(&slave->list, &queue->all_slaves);
396                 queue->num_slaves++;
397                 slave->dev->flags |= IFF_SLAVE;
398
399                 return 0;
400         }
401
402         return -ENOSPC;
403 }
404
405 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
406 {
407         struct net_device *slave_dev;
408         slaving_request_t srq;
409
410         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
411                 return -EFAULT;
412
413         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
414         if (slave_dev) {
415                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
416                         /* slave is not a master & not already a slave: */
417                         if (!eql_is_master(slave_dev) &&
418                             !eql_is_slave(slave_dev)) {
419                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
420                                 equalizer_t *eql = netdev_priv(master_dev);
421                                 int ret;
422
423                                 if (!s) {
424                                         dev_put(slave_dev);
425                                         return -ENOMEM;
426                                 }
427
428                                 memset(s, 0, sizeof(*s));
429                                 s->dev = slave_dev;
430                                 s->priority = srq.priority;
431                                 s->priority_bps = srq.priority;
432                                 s->priority_Bps = srq.priority / 8;
433
434                                 spin_lock_bh(&eql->queue.lock);
435                                 ret = __eql_insert_slave(&eql->queue, s);
436                                 if (ret) {
437                                         dev_put(slave_dev);
438                                         kfree(s);
439                                 }
440                                 spin_unlock_bh(&eql->queue.lock);
441
442                                 return ret;
443                         }
444                 }
445                 dev_put(slave_dev);
446         }
447
448         return -EINVAL;
449 }
450
451 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
452 {
453         equalizer_t *eql = netdev_priv(master_dev);
454         struct net_device *slave_dev;
455         slaving_request_t srq;
456         int ret;
457
458         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
459                 return -EFAULT;
460
461         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
462         ret = -EINVAL;
463         if (slave_dev) {
464                 spin_lock_bh(&eql->queue.lock);
465
466                 if (eql_is_slave(slave_dev)) {
467                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
468                                                               slave_dev);
469
470                         if (slave) {
471                                 eql_kill_one_slave(&eql->queue, slave);
472                                 ret = 0;
473                         }
474                 }
475                 dev_put(slave_dev);
476
477                 spin_unlock_bh(&eql->queue.lock);
478         }
479
480         return ret;
481 }
482
483 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
484 {
485         equalizer_t *eql = netdev_priv(dev);
486         slave_t *slave;
487         struct net_device *slave_dev;
488         slave_config_t sc;
489         int ret;
490
491         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
492                 return -EFAULT;
493
494         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
495         if (!slave_dev)
496                 return -ENODEV;
497
498         ret = -EINVAL;
499
500         spin_lock_bh(&eql->queue.lock);
501         if (eql_is_slave(slave_dev)) {
502                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
503                 if (slave) {
504                         sc.priority = slave->priority;
505                         ret = 0;
506                 }
507         }
508         spin_unlock_bh(&eql->queue.lock);
509
510         dev_put(slave_dev);
511
512         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
513                 ret = -EFAULT;
514
515         return ret;
516 }
517
518 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
519 {
520         slave_t *slave;
521         equalizer_t *eql;
522         struct net_device *slave_dev;
523         slave_config_t sc;
524         int ret;
525
526         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
527                 return -EFAULT;
528
529         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
530         if (!slave_dev)
531                 return -ENODEV;
532
533         ret = -EINVAL;
534
535         eql = netdev_priv(dev);
536         spin_lock_bh(&eql->queue.lock);
537         if (eql_is_slave(slave_dev)) {
538                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
539                 if (slave) {
540                         slave->priority = sc.priority;
541                         slave->priority_bps = sc.priority;
542                         slave->priority_Bps = sc.priority / 8;
543                         ret = 0;
544                 }
545         }
546         spin_unlock_bh(&eql->queue.lock);
547
548         dev_put(slave_dev);
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");