net: usbnet: support 64bit stats
[sfrench/cifs-2.6.git] / drivers / net / usb / usbnet.c
1 /*
2  * USB Network driver infrastructure
3  * Copyright (C) 2000-2005 by David Brownell
4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19
20 /*
21  * This is a generic "USB networking" framework that works with several
22  * kinds of full and high speed networking devices:  host-to-host cables,
23  * smart usb peripherals, and actual Ethernet adapters.
24  *
25  * These devices usually differ in terms of control protocols (if they
26  * even have one!) and sometimes they define new framing to wrap or batch
27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
29  * issues can usefully be addressed by this framework.
30  */
31
32 // #define      DEBUG                   // error path messages, extra info
33 // #define      VERBOSE                 // more; success messages
34
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/netdevice.h>
38 #include <linux/etherdevice.h>
39 #include <linux/ctype.h>
40 #include <linux/ethtool.h>
41 #include <linux/workqueue.h>
42 #include <linux/mii.h>
43 #include <linux/usb.h>
44 #include <linux/usb/usbnet.h>
45 #include <linux/slab.h>
46 #include <linux/kernel.h>
47 #include <linux/pm_runtime.h>
48
49 #define DRIVER_VERSION          "22-Aug-2005"
50
51
52 /*-------------------------------------------------------------------------*/
53
54 /*
55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
56  * Several dozen bytes of IPv4 data can fit in two such transactions.
57  * One maximum size Ethernet packet takes twenty four of them.
58  * For high speed, each frame comfortably fits almost 36 max size
59  * Ethernet packets (so queues should be bigger).
60  *
61  * The goal is to let the USB host controller be busy for 5msec or
62  * more before an irq is required, under load.  Jumbograms change
63  * the equation.
64  */
65 #define MAX_QUEUE_MEMORY        (60 * 1518)
66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
68
69 // reawaken network queue this soon after stopping; else watchdog barks
70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
71
72 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
73  * us (it polls at HZ/4 usually) before we report too many false errors.
74  */
75 #define THROTTLE_JIFFIES        (HZ/8)
76
77 // between wakeups
78 #define UNLINK_TIMEOUT_MS       3
79
80 /*-------------------------------------------------------------------------*/
81
82 // randomly generated ethernet address
83 static u8       node_id [ETH_ALEN];
84
85 static const char driver_name [] = "usbnet";
86
87 /* use ethtool to change the level for any given device */
88 static int msg_level = -1;
89 module_param (msg_level, int, 0);
90 MODULE_PARM_DESC (msg_level, "Override default message level");
91
92 /*-------------------------------------------------------------------------*/
93
94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
96 {
97         int                             tmp;
98         struct usb_host_interface       *alt = NULL;
99         struct usb_host_endpoint        *in = NULL, *out = NULL;
100         struct usb_host_endpoint        *status = NULL;
101
102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
103                 unsigned        ep;
104
105                 in = out = status = NULL;
106                 alt = intf->altsetting + tmp;
107
108                 /* take the first altsetting with in-bulk + out-bulk;
109                  * remember any status endpoint, just in case;
110                  * ignore other endpoints and altsettings.
111                  */
112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
113                         struct usb_host_endpoint        *e;
114                         int                             intr = 0;
115
116                         e = alt->endpoint + ep;
117                         switch (e->desc.bmAttributes) {
118                         case USB_ENDPOINT_XFER_INT:
119                                 if (!usb_endpoint_dir_in(&e->desc))
120                                         continue;
121                                 intr = 1;
122                                 /* FALLTHROUGH */
123                         case USB_ENDPOINT_XFER_BULK:
124                                 break;
125                         default:
126                                 continue;
127                         }
128                         if (usb_endpoint_dir_in(&e->desc)) {
129                                 if (!intr && !in)
130                                         in = e;
131                                 else if (intr && !status)
132                                         status = e;
133                         } else {
134                                 if (!out)
135                                         out = e;
136                         }
137                 }
138                 if (in && out)
139                         break;
140         }
141         if (!alt || !in || !out)
142                 return -EINVAL;
143
144         if (alt->desc.bAlternateSetting != 0 ||
145             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
146                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
147                                 alt->desc.bAlternateSetting);
148                 if (tmp < 0)
149                         return tmp;
150         }
151
152         dev->in = usb_rcvbulkpipe (dev->udev,
153                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
154         dev->out = usb_sndbulkpipe (dev->udev,
155                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
156         dev->status = status;
157         return 0;
158 }
159 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
160
161 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
162 {
163         int             tmp = -1, ret;
164         unsigned char   buf [13];
165
166         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
167         if (ret == 12)
168                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
169         if (tmp < 0) {
170                 dev_dbg(&dev->udev->dev,
171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
172                 if (ret >= 0)
173                         ret = -EINVAL;
174                 return ret;
175         }
176         return 0;
177 }
178 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
179
180 static void intr_complete (struct urb *urb)
181 {
182         struct usbnet   *dev = urb->context;
183         int             status = urb->status;
184
185         switch (status) {
186         /* success */
187         case 0:
188                 dev->driver_info->status(dev, urb);
189                 break;
190
191         /* software-driven interface shutdown */
192         case -ENOENT:           /* urb killed */
193         case -ESHUTDOWN:        /* hardware gone */
194                 netif_dbg(dev, ifdown, dev->net,
195                           "intr shutdown, code %d\n", status);
196                 return;
197
198         /* NOTE:  not throttling like RX/TX, since this endpoint
199          * already polls infrequently
200          */
201         default:
202                 netdev_dbg(dev->net, "intr status %d\n", status);
203                 break;
204         }
205
206         status = usb_submit_urb (urb, GFP_ATOMIC);
207         if (status != 0)
208                 netif_err(dev, timer, dev->net,
209                           "intr resubmit --> %d\n", status);
210 }
211
212 static int init_status (struct usbnet *dev, struct usb_interface *intf)
213 {
214         char            *buf = NULL;
215         unsigned        pipe = 0;
216         unsigned        maxp;
217         unsigned        period;
218
219         if (!dev->driver_info->status)
220                 return 0;
221
222         pipe = usb_rcvintpipe (dev->udev,
223                         dev->status->desc.bEndpointAddress
224                                 & USB_ENDPOINT_NUMBER_MASK);
225         maxp = usb_maxpacket (dev->udev, pipe, 0);
226
227         /* avoid 1 msec chatter:  min 8 msec poll rate */
228         period = max ((int) dev->status->desc.bInterval,
229                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
230
231         buf = kmalloc (maxp, GFP_KERNEL);
232         if (buf) {
233                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
234                 if (!dev->interrupt) {
235                         kfree (buf);
236                         return -ENOMEM;
237                 } else {
238                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
239                                 buf, maxp, intr_complete, dev, period);
240                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
241                         dev_dbg(&intf->dev,
242                                 "status ep%din, %d bytes period %d\n",
243                                 usb_pipeendpoint(pipe), maxp, period);
244                 }
245         }
246         return 0;
247 }
248
249 /* Submit the interrupt URB if not previously submitted, increasing refcount */
250 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
251 {
252         int ret = 0;
253
254         WARN_ON_ONCE(dev->interrupt == NULL);
255         if (dev->interrupt) {
256                 mutex_lock(&dev->interrupt_mutex);
257
258                 if (++dev->interrupt_count == 1)
259                         ret = usb_submit_urb(dev->interrupt, mem_flags);
260
261                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
262                         dev->interrupt_count);
263                 mutex_unlock(&dev->interrupt_mutex);
264         }
265         return ret;
266 }
267 EXPORT_SYMBOL_GPL(usbnet_status_start);
268
269 /* For resume; submit interrupt URB if previously submitted */
270 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
271 {
272         int ret = 0;
273
274         mutex_lock(&dev->interrupt_mutex);
275         if (dev->interrupt_count) {
276                 ret = usb_submit_urb(dev->interrupt, mem_flags);
277                 dev_dbg(&dev->udev->dev,
278                         "submitted interrupt URB for resume\n");
279         }
280         mutex_unlock(&dev->interrupt_mutex);
281         return ret;
282 }
283
284 /* Kill the interrupt URB if all submitters want it killed */
285 void usbnet_status_stop(struct usbnet *dev)
286 {
287         if (dev->interrupt) {
288                 mutex_lock(&dev->interrupt_mutex);
289                 WARN_ON(dev->interrupt_count == 0);
290
291                 if (dev->interrupt_count && --dev->interrupt_count == 0)
292                         usb_kill_urb(dev->interrupt);
293
294                 dev_dbg(&dev->udev->dev,
295                         "decremented interrupt URB count to %d\n",
296                         dev->interrupt_count);
297                 mutex_unlock(&dev->interrupt_mutex);
298         }
299 }
300 EXPORT_SYMBOL_GPL(usbnet_status_stop);
301
302 /* For suspend; always kill interrupt URB */
303 static void __usbnet_status_stop_force(struct usbnet *dev)
304 {
305         if (dev->interrupt) {
306                 mutex_lock(&dev->interrupt_mutex);
307                 usb_kill_urb(dev->interrupt);
308                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
309                 mutex_unlock(&dev->interrupt_mutex);
310         }
311 }
312
313 /* Passes this packet up the stack, updating its accounting.
314  * Some link protocols batch packets, so their rx_fixup paths
315  * can return clones as well as just modify the original skb.
316  */
317 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
318 {
319         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
320         int     status;
321
322         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
323                 skb_queue_tail(&dev->rxq_pause, skb);
324                 return;
325         }
326
327         /* only update if unset to allow minidriver rx_fixup override */
328         if (skb->protocol == 0)
329                 skb->protocol = eth_type_trans (skb, dev->net);
330
331         u64_stats_update_begin(&stats64->syncp);
332         stats64->rx_packets++;
333         stats64->rx_bytes += skb->len;
334         u64_stats_update_end(&stats64->syncp);
335
336         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
337                   skb->len + sizeof (struct ethhdr), skb->protocol);
338         memset (skb->cb, 0, sizeof (struct skb_data));
339
340         if (skb_defer_rx_timestamp(skb))
341                 return;
342
343         status = netif_rx (skb);
344         if (status != NET_RX_SUCCESS)
345                 netif_dbg(dev, rx_err, dev->net,
346                           "netif_rx status %d\n", status);
347 }
348 EXPORT_SYMBOL_GPL(usbnet_skb_return);
349
350 /* must be called if hard_mtu or rx_urb_size changed */
351 void usbnet_update_max_qlen(struct usbnet *dev)
352 {
353         enum usb_device_speed speed = dev->udev->speed;
354
355         switch (speed) {
356         case USB_SPEED_HIGH:
357                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
358                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
359                 break;
360         case USB_SPEED_SUPER:
361         case USB_SPEED_SUPER_PLUS:
362                 /*
363                  * Not take default 5ms qlen for super speed HC to
364                  * save memory, and iperf tests show 2.5ms qlen can
365                  * work well
366                  */
367                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
368                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
369                 break;
370         default:
371                 dev->rx_qlen = dev->tx_qlen = 4;
372         }
373 }
374 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
375
376 \f
377 /*-------------------------------------------------------------------------
378  *
379  * Network Device Driver (peer link to "Host Device", from USB host)
380  *
381  *-------------------------------------------------------------------------*/
382
383 int usbnet_change_mtu (struct net_device *net, int new_mtu)
384 {
385         struct usbnet   *dev = netdev_priv(net);
386         int             ll_mtu = new_mtu + net->hard_header_len;
387         int             old_hard_mtu = dev->hard_mtu;
388         int             old_rx_urb_size = dev->rx_urb_size;
389
390         // no second zero-length packet read wanted after mtu-sized packets
391         if ((ll_mtu % dev->maxpacket) == 0)
392                 return -EDOM;
393         net->mtu = new_mtu;
394
395         dev->hard_mtu = net->mtu + net->hard_header_len;
396         if (dev->rx_urb_size == old_hard_mtu) {
397                 dev->rx_urb_size = dev->hard_mtu;
398                 if (dev->rx_urb_size > old_rx_urb_size) {
399                         usbnet_pause_rx(dev);
400                         usbnet_unlink_rx_urbs(dev);
401                         usbnet_resume_rx(dev);
402                 }
403         }
404
405         /* max qlen depend on hard_mtu and rx_urb_size */
406         usbnet_update_max_qlen(dev);
407
408         return 0;
409 }
410 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
411
412 /* The caller must hold list->lock */
413 static void __usbnet_queue_skb(struct sk_buff_head *list,
414                         struct sk_buff *newsk, enum skb_state state)
415 {
416         struct skb_data *entry = (struct skb_data *) newsk->cb;
417
418         __skb_queue_tail(list, newsk);
419         entry->state = state;
420 }
421
422 /*-------------------------------------------------------------------------*/
423
424 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
425  * completion callbacks.  2.5 should have fixed those bugs...
426  */
427
428 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
429                 struct sk_buff_head *list, enum skb_state state)
430 {
431         unsigned long           flags;
432         enum skb_state          old_state;
433         struct skb_data *entry = (struct skb_data *) skb->cb;
434
435         spin_lock_irqsave(&list->lock, flags);
436         old_state = entry->state;
437         entry->state = state;
438         __skb_unlink(skb, list);
439
440         /* defer_bh() is never called with list == &dev->done.
441          * spin_lock_nested() tells lockdep that it is OK to take
442          * dev->done.lock here with list->lock held.
443          */
444         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
445
446         __skb_queue_tail(&dev->done, skb);
447         if (dev->done.qlen == 1)
448                 tasklet_schedule(&dev->bh);
449         spin_unlock(&dev->done.lock);
450         spin_unlock_irqrestore(&list->lock, flags);
451         return old_state;
452 }
453
454 /* some work can't be done in tasklets, so we use keventd
455  *
456  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
457  * but tasklet_schedule() doesn't.  hope the failure is rare.
458  */
459 void usbnet_defer_kevent (struct usbnet *dev, int work)
460 {
461         set_bit (work, &dev->flags);
462         if (!schedule_work (&dev->kevent)) {
463                 if (net_ratelimit())
464                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
465         } else {
466                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
467         }
468 }
469 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
470
471 /*-------------------------------------------------------------------------*/
472
473 static void rx_complete (struct urb *urb);
474
475 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
476 {
477         struct sk_buff          *skb;
478         struct skb_data         *entry;
479         int                     retval = 0;
480         unsigned long           lockflags;
481         size_t                  size = dev->rx_urb_size;
482
483         /* prevent rx skb allocation when error ratio is high */
484         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
485                 usb_free_urb(urb);
486                 return -ENOLINK;
487         }
488
489         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
490         if (!skb) {
491                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
492                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
493                 usb_free_urb (urb);
494                 return -ENOMEM;
495         }
496
497         entry = (struct skb_data *) skb->cb;
498         entry->urb = urb;
499         entry->dev = dev;
500         entry->length = 0;
501
502         usb_fill_bulk_urb (urb, dev->udev, dev->in,
503                 skb->data, size, rx_complete, skb);
504
505         spin_lock_irqsave (&dev->rxq.lock, lockflags);
506
507         if (netif_running (dev->net) &&
508             netif_device_present (dev->net) &&
509             !test_bit (EVENT_RX_HALT, &dev->flags) &&
510             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
511                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
512                 case -EPIPE:
513                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
514                         break;
515                 case -ENOMEM:
516                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
517                         break;
518                 case -ENODEV:
519                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
520                         netif_device_detach (dev->net);
521                         break;
522                 case -EHOSTUNREACH:
523                         retval = -ENOLINK;
524                         break;
525                 default:
526                         netif_dbg(dev, rx_err, dev->net,
527                                   "rx submit, %d\n", retval);
528                         tasklet_schedule (&dev->bh);
529                         break;
530                 case 0:
531                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
532                 }
533         } else {
534                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
535                 retval = -ENOLINK;
536         }
537         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
538         if (retval) {
539                 dev_kfree_skb_any (skb);
540                 usb_free_urb (urb);
541         }
542         return retval;
543 }
544
545
546 /*-------------------------------------------------------------------------*/
547
548 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
549 {
550         if (dev->driver_info->rx_fixup &&
551             !dev->driver_info->rx_fixup (dev, skb)) {
552                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
553                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
554                         dev->net->stats.rx_errors++;
555                 goto done;
556         }
557         // else network stack removes extra byte if we forced a short packet
558
559         /* all data was already cloned from skb inside the driver */
560         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
561                 goto done;
562
563         if (skb->len < ETH_HLEN) {
564                 dev->net->stats.rx_errors++;
565                 dev->net->stats.rx_length_errors++;
566                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
567         } else {
568                 usbnet_skb_return(dev, skb);
569                 return;
570         }
571
572 done:
573         skb_queue_tail(&dev->done, skb);
574 }
575
576 /*-------------------------------------------------------------------------*/
577
578 static void rx_complete (struct urb *urb)
579 {
580         struct sk_buff          *skb = (struct sk_buff *) urb->context;
581         struct skb_data         *entry = (struct skb_data *) skb->cb;
582         struct usbnet           *dev = entry->dev;
583         int                     urb_status = urb->status;
584         enum skb_state          state;
585
586         skb_put (skb, urb->actual_length);
587         state = rx_done;
588         entry->urb = NULL;
589
590         switch (urb_status) {
591         /* success */
592         case 0:
593                 break;
594
595         /* stalls need manual reset. this is rare ... except that
596          * when going through USB 2.0 TTs, unplug appears this way.
597          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
598          * storm, recovering as needed.
599          */
600         case -EPIPE:
601                 dev->net->stats.rx_errors++;
602                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
603                 // FALLTHROUGH
604
605         /* software-driven interface shutdown */
606         case -ECONNRESET:               /* async unlink */
607         case -ESHUTDOWN:                /* hardware gone */
608                 netif_dbg(dev, ifdown, dev->net,
609                           "rx shutdown, code %d\n", urb_status);
610                 goto block;
611
612         /* we get controller i/o faults during hub_wq disconnect() delays.
613          * throttle down resubmits, to avoid log floods; just temporarily,
614          * so we still recover when the fault isn't a hub_wq delay.
615          */
616         case -EPROTO:
617         case -ETIME:
618         case -EILSEQ:
619                 dev->net->stats.rx_errors++;
620                 if (!timer_pending (&dev->delay)) {
621                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
622                         netif_dbg(dev, link, dev->net,
623                                   "rx throttle %d\n", urb_status);
624                 }
625 block:
626                 state = rx_cleanup;
627                 entry->urb = urb;
628                 urb = NULL;
629                 break;
630
631         /* data overrun ... flush fifo? */
632         case -EOVERFLOW:
633                 dev->net->stats.rx_over_errors++;
634                 // FALLTHROUGH
635
636         default:
637                 state = rx_cleanup;
638                 dev->net->stats.rx_errors++;
639                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
640                 break;
641         }
642
643         /* stop rx if packet error rate is high */
644         if (++dev->pkt_cnt > 30) {
645                 dev->pkt_cnt = 0;
646                 dev->pkt_err = 0;
647         } else {
648                 if (state == rx_cleanup)
649                         dev->pkt_err++;
650                 if (dev->pkt_err > 20)
651                         set_bit(EVENT_RX_KILL, &dev->flags);
652         }
653
654         state = defer_bh(dev, skb, &dev->rxq, state);
655
656         if (urb) {
657                 if (netif_running (dev->net) &&
658                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
659                     state != unlink_start) {
660                         rx_submit (dev, urb, GFP_ATOMIC);
661                         usb_mark_last_busy(dev->udev);
662                         return;
663                 }
664                 usb_free_urb (urb);
665         }
666         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
667 }
668
669 /*-------------------------------------------------------------------------*/
670 void usbnet_pause_rx(struct usbnet *dev)
671 {
672         set_bit(EVENT_RX_PAUSED, &dev->flags);
673
674         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
675 }
676 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
677
678 void usbnet_resume_rx(struct usbnet *dev)
679 {
680         struct sk_buff *skb;
681         int num = 0;
682
683         clear_bit(EVENT_RX_PAUSED, &dev->flags);
684
685         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
686                 usbnet_skb_return(dev, skb);
687                 num++;
688         }
689
690         tasklet_schedule(&dev->bh);
691
692         netif_dbg(dev, rx_status, dev->net,
693                   "paused rx queue disabled, %d skbs requeued\n", num);
694 }
695 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
696
697 void usbnet_purge_paused_rxq(struct usbnet *dev)
698 {
699         skb_queue_purge(&dev->rxq_pause);
700 }
701 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
702
703 /*-------------------------------------------------------------------------*/
704
705 // unlink pending rx/tx; completion handlers do all other cleanup
706
707 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
708 {
709         unsigned long           flags;
710         struct sk_buff          *skb;
711         int                     count = 0;
712
713         spin_lock_irqsave (&q->lock, flags);
714         while (!skb_queue_empty(q)) {
715                 struct skb_data         *entry;
716                 struct urb              *urb;
717                 int                     retval;
718
719                 skb_queue_walk(q, skb) {
720                         entry = (struct skb_data *) skb->cb;
721                         if (entry->state != unlink_start)
722                                 goto found;
723                 }
724                 break;
725 found:
726                 entry->state = unlink_start;
727                 urb = entry->urb;
728
729                 /*
730                  * Get reference count of the URB to avoid it to be
731                  * freed during usb_unlink_urb, which may trigger
732                  * use-after-free problem inside usb_unlink_urb since
733                  * usb_unlink_urb is always racing with .complete
734                  * handler(include defer_bh).
735                  */
736                 usb_get_urb(urb);
737                 spin_unlock_irqrestore(&q->lock, flags);
738                 // during some PM-driven resume scenarios,
739                 // these (async) unlinks complete immediately
740                 retval = usb_unlink_urb (urb);
741                 if (retval != -EINPROGRESS && retval != 0)
742                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
743                 else
744                         count++;
745                 usb_put_urb(urb);
746                 spin_lock_irqsave(&q->lock, flags);
747         }
748         spin_unlock_irqrestore (&q->lock, flags);
749         return count;
750 }
751
752 // Flush all pending rx urbs
753 // minidrivers may need to do this when the MTU changes
754
755 void usbnet_unlink_rx_urbs(struct usbnet *dev)
756 {
757         if (netif_running(dev->net)) {
758                 (void) unlink_urbs (dev, &dev->rxq);
759                 tasklet_schedule(&dev->bh);
760         }
761 }
762 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
763
764 /*-------------------------------------------------------------------------*/
765
766 static void wait_skb_queue_empty(struct sk_buff_head *q)
767 {
768         unsigned long flags;
769
770         spin_lock_irqsave(&q->lock, flags);
771         while (!skb_queue_empty(q)) {
772                 spin_unlock_irqrestore(&q->lock, flags);
773                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
774                 set_current_state(TASK_UNINTERRUPTIBLE);
775                 spin_lock_irqsave(&q->lock, flags);
776         }
777         spin_unlock_irqrestore(&q->lock, flags);
778 }
779
780 // precondition: never called in_interrupt
781 static void usbnet_terminate_urbs(struct usbnet *dev)
782 {
783         DECLARE_WAITQUEUE(wait, current);
784         int temp;
785
786         /* ensure there are no more active urbs */
787         add_wait_queue(&dev->wait, &wait);
788         set_current_state(TASK_UNINTERRUPTIBLE);
789         temp = unlink_urbs(dev, &dev->txq) +
790                 unlink_urbs(dev, &dev->rxq);
791
792         /* maybe wait for deletions to finish. */
793         wait_skb_queue_empty(&dev->rxq);
794         wait_skb_queue_empty(&dev->txq);
795         wait_skb_queue_empty(&dev->done);
796         netif_dbg(dev, ifdown, dev->net,
797                   "waited for %d urb completions\n", temp);
798         set_current_state(TASK_RUNNING);
799         remove_wait_queue(&dev->wait, &wait);
800 }
801
802 int usbnet_stop (struct net_device *net)
803 {
804         struct usbnet           *dev = netdev_priv(net);
805         struct driver_info      *info = dev->driver_info;
806         int                     retval, pm, mpn;
807
808         clear_bit(EVENT_DEV_OPEN, &dev->flags);
809         netif_stop_queue (net);
810
811         netif_info(dev, ifdown, dev->net,
812                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
813                    net->stats.rx_packets, net->stats.tx_packets,
814                    net->stats.rx_errors, net->stats.tx_errors);
815
816         /* to not race resume */
817         pm = usb_autopm_get_interface(dev->intf);
818         /* allow minidriver to stop correctly (wireless devices to turn off
819          * radio etc) */
820         if (info->stop) {
821                 retval = info->stop(dev);
822                 if (retval < 0)
823                         netif_info(dev, ifdown, dev->net,
824                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
825                                    retval,
826                                    dev->udev->bus->bus_name, dev->udev->devpath,
827                                    info->description);
828         }
829
830         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
831                 usbnet_terminate_urbs(dev);
832
833         usbnet_status_stop(dev);
834
835         usbnet_purge_paused_rxq(dev);
836
837         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
838
839         /* deferred work (task, timer, softirq) must also stop.
840          * can't flush_scheduled_work() until we drop rtnl (later),
841          * else workers could deadlock; so make workers a NOP.
842          */
843         dev->flags = 0;
844         del_timer_sync (&dev->delay);
845         tasklet_kill (&dev->bh);
846         if (!pm)
847                 usb_autopm_put_interface(dev->intf);
848
849         if (info->manage_power && mpn)
850                 info->manage_power(dev, 0);
851         else
852                 usb_autopm_put_interface(dev->intf);
853
854         return 0;
855 }
856 EXPORT_SYMBOL_GPL(usbnet_stop);
857
858 /*-------------------------------------------------------------------------*/
859
860 // posts reads, and enables write queuing
861
862 // precondition: never called in_interrupt
863
864 int usbnet_open (struct net_device *net)
865 {
866         struct usbnet           *dev = netdev_priv(net);
867         int                     retval;
868         struct driver_info      *info = dev->driver_info;
869
870         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
871                 netif_info(dev, ifup, dev->net,
872                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
873                            retval,
874                            dev->udev->bus->bus_name,
875                            dev->udev->devpath,
876                            info->description);
877                 goto done_nopm;
878         }
879
880         // put into "known safe" state
881         if (info->reset && (retval = info->reset (dev)) < 0) {
882                 netif_info(dev, ifup, dev->net,
883                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
884                            retval,
885                            dev->udev->bus->bus_name,
886                            dev->udev->devpath,
887                            info->description);
888                 goto done;
889         }
890
891         /* hard_mtu or rx_urb_size may change in reset() */
892         usbnet_update_max_qlen(dev);
893
894         // insist peer be connected
895         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
896                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
897                 goto done;
898         }
899
900         /* start any status interrupt transfer */
901         if (dev->interrupt) {
902                 retval = usbnet_status_start(dev, GFP_KERNEL);
903                 if (retval < 0) {
904                         netif_err(dev, ifup, dev->net,
905                                   "intr submit %d\n", retval);
906                         goto done;
907                 }
908         }
909
910         set_bit(EVENT_DEV_OPEN, &dev->flags);
911         netif_start_queue (net);
912         netif_info(dev, ifup, dev->net,
913                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
914                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
915                    dev->net->mtu,
916                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
917                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
918                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
919                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
920                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
921                    "simple");
922
923         /* reset rx error state */
924         dev->pkt_cnt = 0;
925         dev->pkt_err = 0;
926         clear_bit(EVENT_RX_KILL, &dev->flags);
927
928         // delay posting reads until we're fully open
929         tasklet_schedule (&dev->bh);
930         if (info->manage_power) {
931                 retval = info->manage_power(dev, 1);
932                 if (retval < 0) {
933                         retval = 0;
934                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
935                 } else {
936                         usb_autopm_put_interface(dev->intf);
937                 }
938         }
939         return retval;
940 done:
941         usb_autopm_put_interface(dev->intf);
942 done_nopm:
943         return retval;
944 }
945 EXPORT_SYMBOL_GPL(usbnet_open);
946
947 /*-------------------------------------------------------------------------*/
948
949 /* ethtool methods; minidrivers may need to add some more, but
950  * they'll probably want to use this base set.
951  */
952
953 int usbnet_get_link_ksettings(struct net_device *net,
954                               struct ethtool_link_ksettings *cmd)
955 {
956         struct usbnet *dev = netdev_priv(net);
957
958         if (!dev->mii.mdio_read)
959                 return -EOPNOTSUPP;
960
961         return mii_ethtool_get_link_ksettings(&dev->mii, cmd);
962 }
963 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
964
965 int usbnet_set_link_ksettings(struct net_device *net,
966                               const struct ethtool_link_ksettings *cmd)
967 {
968         struct usbnet *dev = netdev_priv(net);
969         int retval;
970
971         if (!dev->mii.mdio_write)
972                 return -EOPNOTSUPP;
973
974         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
975
976         /* link speed/duplex might have changed */
977         if (dev->driver_info->link_reset)
978                 dev->driver_info->link_reset(dev);
979
980         /* hard_mtu or rx_urb_size may change in link_reset() */
981         usbnet_update_max_qlen(dev);
982
983         return retval;
984 }
985 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
986
987 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
988 {
989         struct usbnet *dev = netdev_priv(net);
990         unsigned int start;
991         int cpu;
992
993         netdev_stats_to_stats64(stats, &net->stats);
994
995         for_each_possible_cpu(cpu) {
996                 struct pcpu_sw_netstats *stats64;
997                 u64 rx_packets, rx_bytes;
998                 u64 tx_packets, tx_bytes;
999
1000                 stats64 = per_cpu_ptr(dev->stats64, cpu);
1001
1002                 do {
1003                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1004                         rx_packets = stats64->rx_packets;
1005                         rx_bytes = stats64->rx_bytes;
1006                         tx_packets = stats64->tx_packets;
1007                         tx_bytes = stats64->tx_bytes;
1008                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1009
1010                 stats->rx_packets += rx_packets;
1011                 stats->rx_bytes += rx_bytes;
1012                 stats->tx_packets += tx_packets;
1013                 stats->tx_bytes += tx_bytes;
1014         }
1015 }
1016 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1017
1018 u32 usbnet_get_link (struct net_device *net)
1019 {
1020         struct usbnet *dev = netdev_priv(net);
1021
1022         /* If a check_connect is defined, return its result */
1023         if (dev->driver_info->check_connect)
1024                 return dev->driver_info->check_connect (dev) == 0;
1025
1026         /* if the device has mii operations, use those */
1027         if (dev->mii.mdio_read)
1028                 return mii_link_ok(&dev->mii);
1029
1030         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1031         return ethtool_op_get_link(net);
1032 }
1033 EXPORT_SYMBOL_GPL(usbnet_get_link);
1034
1035 int usbnet_nway_reset(struct net_device *net)
1036 {
1037         struct usbnet *dev = netdev_priv(net);
1038
1039         if (!dev->mii.mdio_write)
1040                 return -EOPNOTSUPP;
1041
1042         return mii_nway_restart(&dev->mii);
1043 }
1044 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1045
1046 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1047 {
1048         struct usbnet *dev = netdev_priv(net);
1049
1050         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1051         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1052         strlcpy (info->fw_version, dev->driver_info->description,
1053                 sizeof info->fw_version);
1054         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1055 }
1056 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1057
1058 u32 usbnet_get_msglevel (struct net_device *net)
1059 {
1060         struct usbnet *dev = netdev_priv(net);
1061
1062         return dev->msg_enable;
1063 }
1064 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1065
1066 void usbnet_set_msglevel (struct net_device *net, u32 level)
1067 {
1068         struct usbnet *dev = netdev_priv(net);
1069
1070         dev->msg_enable = level;
1071 }
1072 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1073
1074 /* drivers may override default ethtool_ops in their bind() routine */
1075 static const struct ethtool_ops usbnet_ethtool_ops = {
1076         .get_link               = usbnet_get_link,
1077         .nway_reset             = usbnet_nway_reset,
1078         .get_drvinfo            = usbnet_get_drvinfo,
1079         .get_msglevel           = usbnet_get_msglevel,
1080         .set_msglevel           = usbnet_set_msglevel,
1081         .get_ts_info            = ethtool_op_get_ts_info,
1082         .get_link_ksettings     = usbnet_get_link_ksettings,
1083         .set_link_ksettings     = usbnet_set_link_ksettings,
1084 };
1085
1086 /*-------------------------------------------------------------------------*/
1087
1088 static void __handle_link_change(struct usbnet *dev)
1089 {
1090         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1091                 return;
1092
1093         if (!netif_carrier_ok(dev->net)) {
1094                 /* kill URBs for reading packets to save bus bandwidth */
1095                 unlink_urbs(dev, &dev->rxq);
1096
1097                 /*
1098                  * tx_timeout will unlink URBs for sending packets and
1099                  * tx queue is stopped by netcore after link becomes off
1100                  */
1101         } else {
1102                 /* submitting URBs for reading packets */
1103                 tasklet_schedule(&dev->bh);
1104         }
1105
1106         /* hard_mtu or rx_urb_size may change during link change */
1107         usbnet_update_max_qlen(dev);
1108
1109         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1110 }
1111
1112 static void usbnet_set_rx_mode(struct net_device *net)
1113 {
1114         struct usbnet           *dev = netdev_priv(net);
1115
1116         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1117 }
1118
1119 static void __handle_set_rx_mode(struct usbnet *dev)
1120 {
1121         if (dev->driver_info->set_rx_mode)
1122                 (dev->driver_info->set_rx_mode)(dev);
1123
1124         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1125 }
1126
1127 /* work that cannot be done in interrupt context uses keventd.
1128  *
1129  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1130  * especially now that control transfers can be queued.
1131  */
1132 static void
1133 usbnet_deferred_kevent (struct work_struct *work)
1134 {
1135         struct usbnet           *dev =
1136                 container_of(work, struct usbnet, kevent);
1137         int                     status;
1138
1139         /* usb_clear_halt() needs a thread context */
1140         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1141                 unlink_urbs (dev, &dev->txq);
1142                 status = usb_autopm_get_interface(dev->intf);
1143                 if (status < 0)
1144                         goto fail_pipe;
1145                 status = usb_clear_halt (dev->udev, dev->out);
1146                 usb_autopm_put_interface(dev->intf);
1147                 if (status < 0 &&
1148                     status != -EPIPE &&
1149                     status != -ESHUTDOWN) {
1150                         if (netif_msg_tx_err (dev))
1151 fail_pipe:
1152                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1153                                            status);
1154                 } else {
1155                         clear_bit (EVENT_TX_HALT, &dev->flags);
1156                         if (status != -ESHUTDOWN)
1157                                 netif_wake_queue (dev->net);
1158                 }
1159         }
1160         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1161                 unlink_urbs (dev, &dev->rxq);
1162                 status = usb_autopm_get_interface(dev->intf);
1163                 if (status < 0)
1164                         goto fail_halt;
1165                 status = usb_clear_halt (dev->udev, dev->in);
1166                 usb_autopm_put_interface(dev->intf);
1167                 if (status < 0 &&
1168                     status != -EPIPE &&
1169                     status != -ESHUTDOWN) {
1170                         if (netif_msg_rx_err (dev))
1171 fail_halt:
1172                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1173                                            status);
1174                 } else {
1175                         clear_bit (EVENT_RX_HALT, &dev->flags);
1176                         tasklet_schedule (&dev->bh);
1177                 }
1178         }
1179
1180         /* tasklet could resubmit itself forever if memory is tight */
1181         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1182                 struct urb      *urb = NULL;
1183                 int resched = 1;
1184
1185                 if (netif_running (dev->net))
1186                         urb = usb_alloc_urb (0, GFP_KERNEL);
1187                 else
1188                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1189                 if (urb != NULL) {
1190                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1191                         status = usb_autopm_get_interface(dev->intf);
1192                         if (status < 0) {
1193                                 usb_free_urb(urb);
1194                                 goto fail_lowmem;
1195                         }
1196                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1197                                 resched = 0;
1198                         usb_autopm_put_interface(dev->intf);
1199 fail_lowmem:
1200                         if (resched)
1201                                 tasklet_schedule (&dev->bh);
1202                 }
1203         }
1204
1205         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1206                 struct driver_info      *info = dev->driver_info;
1207                 int                     retval = 0;
1208
1209                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1210                 status = usb_autopm_get_interface(dev->intf);
1211                 if (status < 0)
1212                         goto skip_reset;
1213                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1214                         usb_autopm_put_interface(dev->intf);
1215 skip_reset:
1216                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1217                                     retval,
1218                                     dev->udev->bus->bus_name,
1219                                     dev->udev->devpath,
1220                                     info->description);
1221                 } else {
1222                         usb_autopm_put_interface(dev->intf);
1223                 }
1224
1225                 /* handle link change from link resetting */
1226                 __handle_link_change(dev);
1227         }
1228
1229         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1230                 __handle_link_change(dev);
1231
1232         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1233                 __handle_set_rx_mode(dev);
1234
1235
1236         if (dev->flags)
1237                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1238 }
1239
1240 /*-------------------------------------------------------------------------*/
1241
1242 static void tx_complete (struct urb *urb)
1243 {
1244         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1245         struct skb_data         *entry = (struct skb_data *) skb->cb;
1246         struct usbnet           *dev = entry->dev;
1247
1248         if (urb->status == 0) {
1249                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1250
1251                 u64_stats_update_begin(&stats64->syncp);
1252                 stats64->tx_packets += entry->packets;
1253                 stats64->tx_bytes += entry->length;
1254                 u64_stats_update_end(&stats64->syncp);
1255         } else {
1256                 dev->net->stats.tx_errors++;
1257
1258                 switch (urb->status) {
1259                 case -EPIPE:
1260                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1261                         break;
1262
1263                 /* software-driven interface shutdown */
1264                 case -ECONNRESET:               // async unlink
1265                 case -ESHUTDOWN:                // hardware gone
1266                         break;
1267
1268                 /* like rx, tx gets controller i/o faults during hub_wq
1269                  * delays and so it uses the same throttling mechanism.
1270                  */
1271                 case -EPROTO:
1272                 case -ETIME:
1273                 case -EILSEQ:
1274                         usb_mark_last_busy(dev->udev);
1275                         if (!timer_pending (&dev->delay)) {
1276                                 mod_timer (&dev->delay,
1277                                         jiffies + THROTTLE_JIFFIES);
1278                                 netif_dbg(dev, link, dev->net,
1279                                           "tx throttle %d\n", urb->status);
1280                         }
1281                         netif_stop_queue (dev->net);
1282                         break;
1283                 default:
1284                         netif_dbg(dev, tx_err, dev->net,
1285                                   "tx err %d\n", entry->urb->status);
1286                         break;
1287                 }
1288         }
1289
1290         usb_autopm_put_interface_async(dev->intf);
1291         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1292 }
1293
1294 /*-------------------------------------------------------------------------*/
1295
1296 void usbnet_tx_timeout (struct net_device *net)
1297 {
1298         struct usbnet           *dev = netdev_priv(net);
1299
1300         unlink_urbs (dev, &dev->txq);
1301         tasklet_schedule (&dev->bh);
1302         /* this needs to be handled individually because the generic layer
1303          * doesn't know what is sufficient and could not restore private
1304          * information if a remedy of an unconditional reset were used.
1305          */
1306         if (dev->driver_info->recover)
1307                 (dev->driver_info->recover)(dev);
1308 }
1309 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1310
1311 /*-------------------------------------------------------------------------*/
1312
1313 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1314 {
1315         unsigned num_sgs, total_len = 0;
1316         int i, s = 0;
1317
1318         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1319         if (num_sgs == 1)
1320                 return 0;
1321
1322         /* reserve one for zero packet */
1323         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1324                           GFP_ATOMIC);
1325         if (!urb->sg)
1326                 return -ENOMEM;
1327
1328         urb->num_sgs = num_sgs;
1329         sg_init_table(urb->sg, urb->num_sgs + 1);
1330
1331         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1332         total_len += skb_headlen(skb);
1333
1334         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1335                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1336
1337                 total_len += skb_frag_size(f);
1338                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1339                                 f->page_offset);
1340         }
1341         urb->transfer_buffer_length = total_len;
1342
1343         return 1;
1344 }
1345
1346 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1347                                      struct net_device *net)
1348 {
1349         struct usbnet           *dev = netdev_priv(net);
1350         unsigned int                    length;
1351         struct urb              *urb = NULL;
1352         struct skb_data         *entry;
1353         struct driver_info      *info = dev->driver_info;
1354         unsigned long           flags;
1355         int retval;
1356
1357         if (skb)
1358                 skb_tx_timestamp(skb);
1359
1360         // some devices want funky USB-level framing, for
1361         // win32 driver (usually) and/or hardware quirks
1362         if (info->tx_fixup) {
1363                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1364                 if (!skb) {
1365                         /* packet collected; minidriver waiting for more */
1366                         if (info->flags & FLAG_MULTI_PACKET)
1367                                 goto not_drop;
1368                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1369                         goto drop;
1370                 }
1371         }
1372
1373         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1374                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1375                 goto drop;
1376         }
1377
1378         entry = (struct skb_data *) skb->cb;
1379         entry->urb = urb;
1380         entry->dev = dev;
1381
1382         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1383                         skb->data, skb->len, tx_complete, skb);
1384         if (dev->can_dma_sg) {
1385                 if (build_dma_sg(skb, urb) < 0)
1386                         goto drop;
1387         }
1388         length = urb->transfer_buffer_length;
1389
1390         /* don't assume the hardware handles USB_ZERO_PACKET
1391          * NOTE:  strictly conforming cdc-ether devices should expect
1392          * the ZLP here, but ignore the one-byte packet.
1393          * NOTE2: CDC NCM specification is different from CDC ECM when
1394          * handling ZLP/short packets, so cdc_ncm driver will make short
1395          * packet itself if needed.
1396          */
1397         if (length % dev->maxpacket == 0) {
1398                 if (!(info->flags & FLAG_SEND_ZLP)) {
1399                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1400                                 length++;
1401                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1402                                         skb->data[skb->len] = 0;
1403                                         __skb_put(skb, 1);
1404                                 } else if (urb->num_sgs)
1405                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1406                                                         dev->padding_pkt, 1);
1407                         }
1408                 } else
1409                         urb->transfer_flags |= URB_ZERO_PACKET;
1410         }
1411         urb->transfer_buffer_length = length;
1412
1413         if (info->flags & FLAG_MULTI_PACKET) {
1414                 /* Driver has set number of packets and a length delta.
1415                  * Calculate the complete length and ensure that it's
1416                  * positive.
1417                  */
1418                 entry->length += length;
1419                 if (WARN_ON_ONCE(entry->length <= 0))
1420                         entry->length = length;
1421         } else {
1422                 usbnet_set_skb_tx_stats(skb, 1, length);
1423         }
1424
1425         spin_lock_irqsave(&dev->txq.lock, flags);
1426         retval = usb_autopm_get_interface_async(dev->intf);
1427         if (retval < 0) {
1428                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1429                 goto drop;
1430         }
1431
1432 #ifdef CONFIG_PM
1433         /* if this triggers the device is still a sleep */
1434         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1435                 /* transmission will be done in resume */
1436                 usb_anchor_urb(urb, &dev->deferred);
1437                 /* no use to process more packets */
1438                 netif_stop_queue(net);
1439                 usb_put_urb(urb);
1440                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1441                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1442                 goto deferred;
1443         }
1444 #endif
1445
1446         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1447         case -EPIPE:
1448                 netif_stop_queue (net);
1449                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1450                 usb_autopm_put_interface_async(dev->intf);
1451                 break;
1452         default:
1453                 usb_autopm_put_interface_async(dev->intf);
1454                 netif_dbg(dev, tx_err, dev->net,
1455                           "tx: submit urb err %d\n", retval);
1456                 break;
1457         case 0:
1458                 netif_trans_update(net);
1459                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1460                 if (dev->txq.qlen >= TX_QLEN (dev))
1461                         netif_stop_queue (net);
1462         }
1463         spin_unlock_irqrestore (&dev->txq.lock, flags);
1464
1465         if (retval) {
1466                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1467 drop:
1468                 dev->net->stats.tx_dropped++;
1469 not_drop:
1470                 if (skb)
1471                         dev_kfree_skb_any (skb);
1472                 if (urb) {
1473                         kfree(urb->sg);
1474                         usb_free_urb(urb);
1475                 }
1476         } else
1477                 netif_dbg(dev, tx_queued, dev->net,
1478                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1479 #ifdef CONFIG_PM
1480 deferred:
1481 #endif
1482         return NETDEV_TX_OK;
1483 }
1484 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1485
1486 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1487 {
1488         struct urb      *urb;
1489         int             i;
1490         int             ret = 0;
1491
1492         /* don't refill the queue all at once */
1493         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1494                 urb = usb_alloc_urb(0, flags);
1495                 if (urb != NULL) {
1496                         ret = rx_submit(dev, urb, flags);
1497                         if (ret)
1498                                 goto err;
1499                 } else {
1500                         ret = -ENOMEM;
1501                         goto err;
1502                 }
1503         }
1504 err:
1505         return ret;
1506 }
1507
1508 /*-------------------------------------------------------------------------*/
1509
1510 // tasklet (work deferred from completions, in_irq) or timer
1511
1512 static void usbnet_bh (unsigned long param)
1513 {
1514         struct usbnet           *dev = (struct usbnet *) param;
1515         struct sk_buff          *skb;
1516         struct skb_data         *entry;
1517
1518         while ((skb = skb_dequeue (&dev->done))) {
1519                 entry = (struct skb_data *) skb->cb;
1520                 switch (entry->state) {
1521                 case rx_done:
1522                         entry->state = rx_cleanup;
1523                         rx_process (dev, skb);
1524                         continue;
1525                 case tx_done:
1526                         kfree(entry->urb->sg);
1527                 case rx_cleanup:
1528                         usb_free_urb (entry->urb);
1529                         dev_kfree_skb (skb);
1530                         continue;
1531                 default:
1532                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1533                 }
1534         }
1535
1536         /* restart RX again after disabling due to high error rate */
1537         clear_bit(EVENT_RX_KILL, &dev->flags);
1538
1539         /* waiting for all pending urbs to complete?
1540          * only then can we forgo submitting anew
1541          */
1542         if (waitqueue_active(&dev->wait)) {
1543                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1544                         wake_up_all(&dev->wait);
1545
1546         // or are we maybe short a few urbs?
1547         } else if (netif_running (dev->net) &&
1548                    netif_device_present (dev->net) &&
1549                    netif_carrier_ok(dev->net) &&
1550                    !timer_pending(&dev->delay) &&
1551                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1552                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1553                 int     temp = dev->rxq.qlen;
1554
1555                 if (temp < RX_QLEN(dev)) {
1556                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1557                                 return;
1558                         if (temp != dev->rxq.qlen)
1559                                 netif_dbg(dev, link, dev->net,
1560                                           "rxqlen %d --> %d\n",
1561                                           temp, dev->rxq.qlen);
1562                         if (dev->rxq.qlen < RX_QLEN(dev))
1563                                 tasklet_schedule (&dev->bh);
1564                 }
1565                 if (dev->txq.qlen < TX_QLEN (dev))
1566                         netif_wake_queue (dev->net);
1567         }
1568 }
1569
1570
1571 /*-------------------------------------------------------------------------
1572  *
1573  * USB Device Driver support
1574  *
1575  *-------------------------------------------------------------------------*/
1576
1577 // precondition: never called in_interrupt
1578
1579 void usbnet_disconnect (struct usb_interface *intf)
1580 {
1581         struct usbnet           *dev;
1582         struct usb_device       *xdev;
1583         struct net_device       *net;
1584
1585         dev = usb_get_intfdata(intf);
1586         usb_set_intfdata(intf, NULL);
1587         if (!dev)
1588                 return;
1589
1590         xdev = interface_to_usbdev (intf);
1591
1592         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1593                    intf->dev.driver->name,
1594                    xdev->bus->bus_name, xdev->devpath,
1595                    dev->driver_info->description);
1596
1597         net = dev->net;
1598         unregister_netdev (net);
1599
1600         cancel_work_sync(&dev->kevent);
1601
1602         usb_scuttle_anchored_urbs(&dev->deferred);
1603
1604         if (dev->driver_info->unbind)
1605                 dev->driver_info->unbind (dev, intf);
1606
1607         usb_kill_urb(dev->interrupt);
1608         usb_free_urb(dev->interrupt);
1609         kfree(dev->padding_pkt);
1610
1611         free_percpu(dev->stats64);
1612         free_netdev(net);
1613 }
1614 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1615
1616 static const struct net_device_ops usbnet_netdev_ops = {
1617         .ndo_open               = usbnet_open,
1618         .ndo_stop               = usbnet_stop,
1619         .ndo_start_xmit         = usbnet_start_xmit,
1620         .ndo_tx_timeout         = usbnet_tx_timeout,
1621         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1622         .ndo_change_mtu         = usbnet_change_mtu,
1623         .ndo_get_stats64        = usbnet_get_stats64,
1624         .ndo_set_mac_address    = eth_mac_addr,
1625         .ndo_validate_addr      = eth_validate_addr,
1626 };
1627
1628 /*-------------------------------------------------------------------------*/
1629
1630 // precondition: never called in_interrupt
1631
1632 static struct device_type wlan_type = {
1633         .name   = "wlan",
1634 };
1635
1636 static struct device_type wwan_type = {
1637         .name   = "wwan",
1638 };
1639
1640 int
1641 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1642 {
1643         struct usbnet                   *dev;
1644         struct net_device               *net;
1645         struct usb_host_interface       *interface;
1646         struct driver_info              *info;
1647         struct usb_device               *xdev;
1648         int                             status;
1649         const char                      *name;
1650         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1651
1652         /* usbnet already took usb runtime pm, so have to enable the feature
1653          * for usb interface, otherwise usb_autopm_get_interface may return
1654          * failure if RUNTIME_PM is enabled.
1655          */
1656         if (!driver->supports_autosuspend) {
1657                 driver->supports_autosuspend = 1;
1658                 pm_runtime_enable(&udev->dev);
1659         }
1660
1661         name = udev->dev.driver->name;
1662         info = (struct driver_info *) prod->driver_info;
1663         if (!info) {
1664                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1665                 return -ENODEV;
1666         }
1667         xdev = interface_to_usbdev (udev);
1668         interface = udev->cur_altsetting;
1669
1670         status = -ENOMEM;
1671
1672         // set up our own records
1673         net = alloc_etherdev(sizeof(*dev));
1674         if (!net)
1675                 goto out;
1676
1677         /* netdev_printk() needs this so do it as early as possible */
1678         SET_NETDEV_DEV(net, &udev->dev);
1679
1680         dev = netdev_priv(net);
1681         dev->udev = xdev;
1682         dev->intf = udev;
1683         dev->driver_info = info;
1684         dev->driver_name = name;
1685
1686         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1687         if (!dev->stats64)
1688                 goto out0;
1689
1690         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1691                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1692         init_waitqueue_head(&dev->wait);
1693         skb_queue_head_init (&dev->rxq);
1694         skb_queue_head_init (&dev->txq);
1695         skb_queue_head_init (&dev->done);
1696         skb_queue_head_init(&dev->rxq_pause);
1697         dev->bh.func = usbnet_bh;
1698         dev->bh.data = (unsigned long) dev;
1699         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1700         init_usb_anchor(&dev->deferred);
1701         dev->delay.function = usbnet_bh;
1702         dev->delay.data = (unsigned long) dev;
1703         init_timer (&dev->delay);
1704         mutex_init (&dev->phy_mutex);
1705         mutex_init(&dev->interrupt_mutex);
1706         dev->interrupt_count = 0;
1707
1708         dev->net = net;
1709         strcpy (net->name, "usb%d");
1710         memcpy (net->dev_addr, node_id, sizeof node_id);
1711
1712         /* rx and tx sides can use different message sizes;
1713          * bind() should set rx_urb_size in that case.
1714          */
1715         dev->hard_mtu = net->mtu + net->hard_header_len;
1716         net->min_mtu = 0;
1717         net->max_mtu = ETH_MAX_MTU;
1718
1719         net->netdev_ops = &usbnet_netdev_ops;
1720         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1721         net->ethtool_ops = &usbnet_ethtool_ops;
1722
1723         // allow device-specific bind/init procedures
1724         // NOTE net->name still not usable ...
1725         if (info->bind) {
1726                 status = info->bind (dev, udev);
1727                 if (status < 0)
1728                         goto out1;
1729
1730                 // heuristic:  "usb%d" for links we know are two-host,
1731                 // else "eth%d" when there's reasonable doubt.  userspace
1732                 // can rename the link if it knows better.
1733                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1734                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1735                      (net->dev_addr [0] & 0x02) == 0))
1736                         strcpy (net->name, "eth%d");
1737                 /* WLAN devices should always be named "wlan%d" */
1738                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1739                         strcpy(net->name, "wlan%d");
1740                 /* WWAN devices should always be named "wwan%d" */
1741                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1742                         strcpy(net->name, "wwan%d");
1743
1744                 /* devices that cannot do ARP */
1745                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1746                         net->flags |= IFF_NOARP;
1747
1748                 /* maybe the remote can't receive an Ethernet MTU */
1749                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1750                         net->mtu = dev->hard_mtu - net->hard_header_len;
1751         } else if (!info->in || !info->out)
1752                 status = usbnet_get_endpoints (dev, udev);
1753         else {
1754                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1755                 dev->out = usb_sndbulkpipe (xdev, info->out);
1756                 if (!(info->flags & FLAG_NO_SETINT))
1757                         status = usb_set_interface (xdev,
1758                                 interface->desc.bInterfaceNumber,
1759                                 interface->desc.bAlternateSetting);
1760                 else
1761                         status = 0;
1762
1763         }
1764         if (status >= 0 && dev->status)
1765                 status = init_status (dev, udev);
1766         if (status < 0)
1767                 goto out3;
1768
1769         if (!dev->rx_urb_size)
1770                 dev->rx_urb_size = dev->hard_mtu;
1771         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1772
1773         /* let userspace know we have a random address */
1774         if (ether_addr_equal(net->dev_addr, node_id))
1775                 net->addr_assign_type = NET_ADDR_RANDOM;
1776
1777         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1778                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1779         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1780                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1781
1782         /* initialize max rx_qlen and tx_qlen */
1783         usbnet_update_max_qlen(dev);
1784
1785         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1786                 !(info->flags & FLAG_MULTI_PACKET)) {
1787                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1788                 if (!dev->padding_pkt) {
1789                         status = -ENOMEM;
1790                         goto out4;
1791                 }
1792         }
1793
1794         status = register_netdev (net);
1795         if (status)
1796                 goto out5;
1797         netif_info(dev, probe, dev->net,
1798                    "register '%s' at usb-%s-%s, %s, %pM\n",
1799                    udev->dev.driver->name,
1800                    xdev->bus->bus_name, xdev->devpath,
1801                    dev->driver_info->description,
1802                    net->dev_addr);
1803
1804         // ok, it's ready to go.
1805         usb_set_intfdata (udev, dev);
1806
1807         netif_device_attach (net);
1808
1809         if (dev->driver_info->flags & FLAG_LINK_INTR)
1810                 usbnet_link_change(dev, 0, 0);
1811
1812         return 0;
1813
1814 out5:
1815         kfree(dev->padding_pkt);
1816 out4:
1817         usb_free_urb(dev->interrupt);
1818 out3:
1819         if (info->unbind)
1820                 info->unbind (dev, udev);
1821 out1:
1822         /* subdrivers must undo all they did in bind() if they
1823          * fail it, but we may fail later and a deferred kevent
1824          * may trigger an error resubmitting itself and, worse,
1825          * schedule a timer. So we kill it all just in case.
1826          */
1827         cancel_work_sync(&dev->kevent);
1828         del_timer_sync(&dev->delay);
1829         free_percpu(dev->stats64);
1830 out0:
1831         free_netdev(net);
1832 out:
1833         return status;
1834 }
1835 EXPORT_SYMBOL_GPL(usbnet_probe);
1836
1837 /*-------------------------------------------------------------------------*/
1838
1839 /*
1840  * suspend the whole driver as soon as the first interface is suspended
1841  * resume only when the last interface is resumed
1842  */
1843
1844 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1845 {
1846         struct usbnet           *dev = usb_get_intfdata(intf);
1847
1848         if (!dev->suspend_count++) {
1849                 spin_lock_irq(&dev->txq.lock);
1850                 /* don't autosuspend while transmitting */
1851                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1852                         dev->suspend_count--;
1853                         spin_unlock_irq(&dev->txq.lock);
1854                         return -EBUSY;
1855                 } else {
1856                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1857                         spin_unlock_irq(&dev->txq.lock);
1858                 }
1859                 /*
1860                  * accelerate emptying of the rx and queues, to avoid
1861                  * having everything error out.
1862                  */
1863                 netif_device_detach (dev->net);
1864                 usbnet_terminate_urbs(dev);
1865                 __usbnet_status_stop_force(dev);
1866
1867                 /*
1868                  * reattach so runtime management can use and
1869                  * wake the device
1870                  */
1871                 netif_device_attach (dev->net);
1872         }
1873         return 0;
1874 }
1875 EXPORT_SYMBOL_GPL(usbnet_suspend);
1876
1877 int usbnet_resume (struct usb_interface *intf)
1878 {
1879         struct usbnet           *dev = usb_get_intfdata(intf);
1880         struct sk_buff          *skb;
1881         struct urb              *res;
1882         int                     retval;
1883
1884         if (!--dev->suspend_count) {
1885                 /* resume interrupt URB if it was previously submitted */
1886                 __usbnet_status_start_force(dev, GFP_NOIO);
1887
1888                 spin_lock_irq(&dev->txq.lock);
1889                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1890
1891                         skb = (struct sk_buff *)res->context;
1892                         retval = usb_submit_urb(res, GFP_ATOMIC);
1893                         if (retval < 0) {
1894                                 dev_kfree_skb_any(skb);
1895                                 kfree(res->sg);
1896                                 usb_free_urb(res);
1897                                 usb_autopm_put_interface_async(dev->intf);
1898                         } else {
1899                                 netif_trans_update(dev->net);
1900                                 __skb_queue_tail(&dev->txq, skb);
1901                         }
1902                 }
1903
1904                 smp_mb();
1905                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1906                 spin_unlock_irq(&dev->txq.lock);
1907
1908                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1909                         /* handle remote wakeup ASAP
1910                          * we cannot race against stop
1911                          */
1912                         if (netif_device_present(dev->net) &&
1913                                 !timer_pending(&dev->delay) &&
1914                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1915                                         rx_alloc_submit(dev, GFP_NOIO);
1916
1917                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1918                                 netif_tx_wake_all_queues(dev->net);
1919                         tasklet_schedule (&dev->bh);
1920                 }
1921         }
1922
1923         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1924                 usb_autopm_get_interface_no_resume(intf);
1925
1926         return 0;
1927 }
1928 EXPORT_SYMBOL_GPL(usbnet_resume);
1929
1930 /*
1931  * Either a subdriver implements manage_power, then it is assumed to always
1932  * be ready to be suspended or it reports the readiness to be suspended
1933  * explicitly
1934  */
1935 void usbnet_device_suggests_idle(struct usbnet *dev)
1936 {
1937         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1938                 dev->intf->needs_remote_wakeup = 1;
1939                 usb_autopm_put_interface_async(dev->intf);
1940         }
1941 }
1942 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1943
1944 /*
1945  * For devices that can do without special commands
1946  */
1947 int usbnet_manage_power(struct usbnet *dev, int on)
1948 {
1949         dev->intf->needs_remote_wakeup = on;
1950         return 0;
1951 }
1952 EXPORT_SYMBOL(usbnet_manage_power);
1953
1954 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1955 {
1956         /* update link after link is reseted */
1957         if (link && !need_reset)
1958                 netif_carrier_on(dev->net);
1959         else
1960                 netif_carrier_off(dev->net);
1961
1962         if (need_reset && link)
1963                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1964         else
1965                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1966 }
1967 EXPORT_SYMBOL(usbnet_link_change);
1968
1969 /*-------------------------------------------------------------------------*/
1970 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1971                              u16 value, u16 index, void *data, u16 size)
1972 {
1973         void *buf = NULL;
1974         int err = -ENOMEM;
1975
1976         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1977                    " value=0x%04x index=0x%04x size=%d\n",
1978                    cmd, reqtype, value, index, size);
1979
1980         if (data) {
1981                 buf = kmalloc(size, GFP_KERNEL);
1982                 if (!buf)
1983                         goto out;
1984         }
1985
1986         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1987                               cmd, reqtype, value, index, buf, size,
1988                               USB_CTRL_GET_TIMEOUT);
1989         if (err > 0 && err <= size)
1990                 memcpy(data, buf, err);
1991         kfree(buf);
1992 out:
1993         return err;
1994 }
1995
1996 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1997                               u16 value, u16 index, const void *data,
1998                               u16 size)
1999 {
2000         void *buf = NULL;
2001         int err = -ENOMEM;
2002
2003         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2004                    " value=0x%04x index=0x%04x size=%d\n",
2005                    cmd, reqtype, value, index, size);
2006
2007         if (data) {
2008                 buf = kmemdup(data, size, GFP_KERNEL);
2009                 if (!buf)
2010                         goto out;
2011         }
2012
2013         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2014                               cmd, reqtype, value, index, buf, size,
2015                               USB_CTRL_SET_TIMEOUT);
2016         kfree(buf);
2017
2018 out:
2019         return err;
2020 }
2021
2022 /*
2023  * The function can't be called inside suspend/resume callback,
2024  * otherwise deadlock will be caused.
2025  */
2026 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2027                     u16 value, u16 index, void *data, u16 size)
2028 {
2029         int ret;
2030
2031         if (usb_autopm_get_interface(dev->intf) < 0)
2032                 return -ENODEV;
2033         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2034                                 data, size);
2035         usb_autopm_put_interface(dev->intf);
2036         return ret;
2037 }
2038 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2039
2040 /*
2041  * The function can't be called inside suspend/resume callback,
2042  * otherwise deadlock will be caused.
2043  */
2044 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2045                      u16 value, u16 index, const void *data, u16 size)
2046 {
2047         int ret;
2048
2049         if (usb_autopm_get_interface(dev->intf) < 0)
2050                 return -ENODEV;
2051         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2052                                  data, size);
2053         usb_autopm_put_interface(dev->intf);
2054         return ret;
2055 }
2056 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2057
2058 /*
2059  * The function can be called inside suspend/resume callback safely
2060  * and should only be called by suspend/resume callback generally.
2061  */
2062 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2063                           u16 value, u16 index, void *data, u16 size)
2064 {
2065         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2066                                  data, size);
2067 }
2068 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2069
2070 /*
2071  * The function can be called inside suspend/resume callback safely
2072  * and should only be called by suspend/resume callback generally.
2073  */
2074 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2075                           u16 value, u16 index, const void *data,
2076                           u16 size)
2077 {
2078         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2079                                   data, size);
2080 }
2081 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2082
2083 static void usbnet_async_cmd_cb(struct urb *urb)
2084 {
2085         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2086         int status = urb->status;
2087
2088         if (status < 0)
2089                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2090                         __func__, status);
2091
2092         kfree(req);
2093         usb_free_urb(urb);
2094 }
2095
2096 /*
2097  * The caller must make sure that device can't be put into suspend
2098  * state until the control URB completes.
2099  */
2100 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2101                            u16 value, u16 index, const void *data, u16 size)
2102 {
2103         struct usb_ctrlrequest *req = NULL;
2104         struct urb *urb;
2105         int err = -ENOMEM;
2106         void *buf = NULL;
2107
2108         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2109                    " value=0x%04x index=0x%04x size=%d\n",
2110                    cmd, reqtype, value, index, size);
2111
2112         urb = usb_alloc_urb(0, GFP_ATOMIC);
2113         if (!urb)
2114                 goto fail;
2115
2116         if (data) {
2117                 buf = kmemdup(data, size, GFP_ATOMIC);
2118                 if (!buf) {
2119                         netdev_err(dev->net, "Error allocating buffer"
2120                                    " in %s!\n", __func__);
2121                         goto fail_free;
2122                 }
2123         }
2124
2125         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2126         if (!req)
2127                 goto fail_free_buf;
2128
2129         req->bRequestType = reqtype;
2130         req->bRequest = cmd;
2131         req->wValue = cpu_to_le16(value);
2132         req->wIndex = cpu_to_le16(index);
2133         req->wLength = cpu_to_le16(size);
2134
2135         usb_fill_control_urb(urb, dev->udev,
2136                              usb_sndctrlpipe(dev->udev, 0),
2137                              (void *)req, buf, size,
2138                              usbnet_async_cmd_cb, req);
2139         urb->transfer_flags |= URB_FREE_BUFFER;
2140
2141         err = usb_submit_urb(urb, GFP_ATOMIC);
2142         if (err < 0) {
2143                 netdev_err(dev->net, "Error submitting the control"
2144                            " message: status=%d\n", err);
2145                 goto fail_free;
2146         }
2147         return 0;
2148
2149 fail_free_buf:
2150         kfree(buf);
2151 fail_free:
2152         kfree(req);
2153         usb_free_urb(urb);
2154 fail:
2155         return err;
2156
2157 }
2158 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2159 /*-------------------------------------------------------------------------*/
2160
2161 static int __init usbnet_init(void)
2162 {
2163         /* Compiler should optimize this out. */
2164         BUILD_BUG_ON(
2165                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2166
2167         eth_random_addr(node_id);
2168         return 0;
2169 }
2170 module_init(usbnet_init);
2171
2172 static void __exit usbnet_exit(void)
2173 {
2174 }
2175 module_exit(usbnet_exit);
2176
2177 MODULE_AUTHOR("David Brownell");
2178 MODULE_DESCRIPTION("USB network driver framework");
2179 MODULE_LICENSE("GPL");