netdev: convert pseudo drivers to netdev_tx_t
[linux-3.10.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 netdev_tx_t 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 const char version[] __initconst =
163         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
164
165 static const struct net_device_ops eql_netdev_ops = {
166         .ndo_open       = eql_open,
167         .ndo_stop       = eql_close,
168         .ndo_do_ioctl   = eql_ioctl,
169         .ndo_start_xmit = eql_slave_xmit,
170 };
171
172 static void __init eql_setup(struct net_device *dev)
173 {
174         equalizer_t *eql = netdev_priv(dev);
175
176         init_timer(&eql->timer);
177         eql->timer.data         = (unsigned long) eql;
178         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
179         eql->timer.function     = eql_timer;
180
181         spin_lock_init(&eql->queue.lock);
182         INIT_LIST_HEAD(&eql->queue.all_slaves);
183         eql->queue.master_dev   = dev;
184
185         dev->netdev_ops         = &eql_netdev_ops;
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         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
198 }
199
200 static int eql_open(struct net_device *dev)
201 {
202         equalizer_t *eql = netdev_priv(dev);
203
204         /* XXX We should force this off automatically for the user. */
205         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
206                "your slave devices.\n", dev->name);
207
208         BUG_ON(!list_empty(&eql->queue.all_slaves));
209
210         eql->min_slaves = 1;
211         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
212
213         add_timer(&eql->timer);
214
215         return 0;
216 }
217
218 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
219 {
220         list_del(&slave->list);
221         queue->num_slaves--;
222         slave->dev->flags &= ~IFF_SLAVE;
223         dev_put(slave->dev);
224         kfree(slave);
225 }
226
227 static void eql_kill_slave_queue(slave_queue_t *queue)
228 {
229         struct list_head *head, *tmp, *this;
230
231         spin_lock_bh(&queue->lock);
232
233         head = &queue->all_slaves;
234         list_for_each_safe(this, tmp, head) {
235                 slave_t *s = list_entry(this, slave_t, list);
236
237                 eql_kill_one_slave(queue, s);
238         }
239
240         spin_unlock_bh(&queue->lock);
241 }
242
243 static int eql_close(struct net_device *dev)
244 {
245         equalizer_t *eql = netdev_priv(dev);
246
247         /*
248          *      The timer has to be stopped first before we start hacking away
249          *      at the data structure it scans every so often...
250          */
251
252         del_timer_sync(&eql->timer);
253
254         eql_kill_slave_queue(&eql->queue);
255
256         return 0;
257 }
258
259 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
260 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
261
262 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
263 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
264
265 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
266 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
267
268 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
269 {
270         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
271             !capable(CAP_NET_ADMIN))
272                 return -EPERM;
273
274         switch (cmd) {
275                 case EQL_ENSLAVE:
276                         return eql_enslave(dev, ifr->ifr_data);
277                 case EQL_EMANCIPATE:
278                         return eql_emancipate(dev, ifr->ifr_data);
279                 case EQL_GETSLAVECFG:
280                         return eql_g_slave_cfg(dev, ifr->ifr_data);
281                 case EQL_SETSLAVECFG:
282                         return eql_s_slave_cfg(dev, ifr->ifr_data);
283                 case EQL_GETMASTRCFG:
284                         return eql_g_master_cfg(dev, ifr->ifr_data);
285                 case EQL_SETMASTRCFG:
286                         return eql_s_master_cfg(dev, ifr->ifr_data);
287                 default:
288                         return -EOPNOTSUPP;
289         };
290 }
291
292 /* queue->lock must be held */
293 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
294 {
295         unsigned long best_load = ~0UL;
296         struct list_head *this, *tmp, *head;
297         slave_t *best_slave;
298
299         best_slave = NULL;
300
301         /* Make a pass to set the best slave. */
302         head = &queue->all_slaves;
303         list_for_each_safe(this, tmp, head) {
304                 slave_t *slave = list_entry(this, slave_t, list);
305                 unsigned long slave_load, bytes_queued, priority_Bps;
306
307                 /* Go through the slave list once, updating best_slave
308                  * whenever a new best_load is found.
309                  */
310                 bytes_queued = slave->bytes_queued;
311                 priority_Bps = slave->priority_Bps;
312                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
313                         slave_load = (~0UL - (~0UL / 2)) -
314                                 (priority_Bps) + bytes_queued * 8;
315
316                         if (slave_load < best_load) {
317                                 best_load = slave_load;
318                                 best_slave = slave;
319                         }
320                 } else {
321                         /* We found a dead slave, kill it. */
322                         eql_kill_one_slave(queue, slave);
323                 }
324         }
325         return best_slave;
326 }
327
328 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
329 {
330         equalizer_t *eql = netdev_priv(dev);
331         slave_t *slave;
332
333         spin_lock(&eql->queue.lock);
334
335         slave = __eql_schedule_slaves(&eql->queue);
336         if (slave) {
337                 struct net_device *slave_dev = slave->dev;
338
339                 skb->dev = slave_dev;
340                 skb->priority = 1;
341                 slave->bytes_queued += skb->len;
342                 dev_queue_xmit(skb);
343                 dev->stats.tx_packets++;
344         } else {
345                 dev->stats.tx_dropped++;
346                 dev_kfree_skb(skb);
347         }
348
349         spin_unlock(&eql->queue.lock);
350
351         return NETDEV_TX_OK;
352 }
353
354 /*
355  *      Private ioctl functions
356  */
357
358 /* queue->lock must be held */
359 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
360 {
361         struct list_head *this, *head;
362
363         head = &queue->all_slaves;
364         list_for_each(this, head) {
365                 slave_t *slave = list_entry(this, slave_t, list);
366
367                 if (slave->dev == dev)
368                         return slave;
369         }
370
371         return NULL;
372 }
373
374 static inline int eql_is_full(slave_queue_t *queue)
375 {
376         equalizer_t *eql = netdev_priv(queue->master_dev);
377
378         if (queue->num_slaves >= eql->max_slaves)
379                 return 1;
380         return 0;
381 }
382
383 /* queue->lock must be held */
384 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
385 {
386         if (!eql_is_full(queue)) {
387                 slave_t *duplicate_slave = NULL;
388
389                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
390                 if (duplicate_slave)
391                         eql_kill_one_slave(queue, duplicate_slave);
392
393                 list_add(&slave->list, &queue->all_slaves);
394                 queue->num_slaves++;
395                 slave->dev->flags |= IFF_SLAVE;
396
397                 return 0;
398         }
399
400         return -ENOSPC;
401 }
402
403 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
404 {
405         struct net_device *slave_dev;
406         slaving_request_t srq;
407
408         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
409                 return -EFAULT;
410
411         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
412         if (slave_dev) {
413                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
414                         /* slave is not a master & not already a slave: */
415                         if (!eql_is_master(slave_dev) &&
416                             !eql_is_slave(slave_dev)) {
417                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
418                                 equalizer_t *eql = netdev_priv(master_dev);
419                                 int ret;
420
421                                 if (!s) {
422                                         dev_put(slave_dev);
423                                         return -ENOMEM;
424                                 }
425
426                                 memset(s, 0, sizeof(*s));
427                                 s->dev = slave_dev;
428                                 s->priority = srq.priority;
429                                 s->priority_bps = srq.priority;
430                                 s->priority_Bps = srq.priority / 8;
431
432                                 spin_lock_bh(&eql->queue.lock);
433                                 ret = __eql_insert_slave(&eql->queue, s);
434                                 if (ret) {
435                                         dev_put(slave_dev);
436                                         kfree(s);
437                                 }
438                                 spin_unlock_bh(&eql->queue.lock);
439
440                                 return ret;
441                         }
442                 }
443                 dev_put(slave_dev);
444         }
445
446         return -EINVAL;
447 }
448
449 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
450 {
451         equalizer_t *eql = netdev_priv(master_dev);
452         struct net_device *slave_dev;
453         slaving_request_t srq;
454         int ret;
455
456         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
457                 return -EFAULT;
458
459         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
460         ret = -EINVAL;
461         if (slave_dev) {
462                 spin_lock_bh(&eql->queue.lock);
463
464                 if (eql_is_slave(slave_dev)) {
465                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
466                                                               slave_dev);
467
468                         if (slave) {
469                                 eql_kill_one_slave(&eql->queue, slave);
470                                 ret = 0;
471                         }
472                 }
473                 dev_put(slave_dev);
474
475                 spin_unlock_bh(&eql->queue.lock);
476         }
477
478         return ret;
479 }
480
481 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
482 {
483         equalizer_t *eql = netdev_priv(dev);
484         slave_t *slave;
485         struct net_device *slave_dev;
486         slave_config_t sc;
487         int ret;
488
489         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
490                 return -EFAULT;
491
492         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
493         if (!slave_dev)
494                 return -ENODEV;
495
496         ret = -EINVAL;
497
498         spin_lock_bh(&eql->queue.lock);
499         if (eql_is_slave(slave_dev)) {
500                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
501                 if (slave) {
502                         sc.priority = slave->priority;
503                         ret = 0;
504                 }
505         }
506         spin_unlock_bh(&eql->queue.lock);
507
508         dev_put(slave_dev);
509
510         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
511                 ret = -EFAULT;
512
513         return ret;
514 }
515
516 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
517 {
518         slave_t *slave;
519         equalizer_t *eql;
520         struct net_device *slave_dev;
521         slave_config_t sc;
522         int ret;
523
524         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
525                 return -EFAULT;
526
527         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
528         if (!slave_dev)
529                 return -ENODEV;
530
531         ret = -EINVAL;
532
533         eql = netdev_priv(dev);
534         spin_lock_bh(&eql->queue.lock);
535         if (eql_is_slave(slave_dev)) {
536                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
537                 if (slave) {
538                         slave->priority = sc.priority;
539                         slave->priority_bps = sc.priority;
540                         slave->priority_Bps = sc.priority / 8;
541                         ret = 0;
542                 }
543         }
544         spin_unlock_bh(&eql->queue.lock);
545
546         dev_put(slave_dev);
547
548         return ret;
549 }
550
551 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
552 {
553         equalizer_t *eql;
554         master_config_t mc;
555
556         if (eql_is_master(dev)) {
557                 eql = netdev_priv(dev);
558                 mc.max_slaves = eql->max_slaves;
559                 mc.min_slaves = eql->min_slaves;
560                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
561                         return -EFAULT;
562                 return 0;
563         }
564         return -EINVAL;
565 }
566
567 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
568 {
569         equalizer_t *eql;
570         master_config_t mc;
571
572         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
573                 return -EFAULT;
574
575         if (eql_is_master(dev)) {
576                 eql = netdev_priv(dev);
577                 eql->max_slaves = mc.max_slaves;
578                 eql->min_slaves = mc.min_slaves;
579                 return 0;
580         }
581         return -EINVAL;
582 }
583
584 static struct net_device *dev_eql;
585
586 static int __init eql_init_module(void)
587 {
588         int err;
589
590         printk(version);
591
592         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
593         if (!dev_eql)
594                 return -ENOMEM;
595
596         err = register_netdev(dev_eql);
597         if (err)
598                 free_netdev(dev_eql);
599         return err;
600 }
601
602 static void __exit eql_cleanup_module(void)
603 {
604         unregister_netdev(dev_eql);
605         free_netdev(dev_eql);
606 }
607
608 module_init(eql_init_module);
609 module_exit(eql_cleanup_module);
610 MODULE_LICENSE("GPL");