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1/*
2 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14/* #define VERBOSE_DEBUG */
15
16#include <linux/kernel.h>
17#include <linux/gfp.h>
18#include <linux/device.h>
19#include <linux/ctype.h>
20#include <linux/etherdevice.h>
21#include <linux/ethtool.h>
22
23#include "u_ether.h"
24
25
26/*
27 * This component encapsulates the Ethernet link glue needed to provide
28 * one (!) network link through the USB gadget stack, normally "usb0".
29 *
30 * The control and data models are handled by the function driver which
31 * connects to this code; such as CDC Ethernet (ECM or EEM),
32 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
33 * management.
34 *
35 * Link level addressing is handled by this component using module
36 * parameters; if no such parameters are provided, random link level
37 * addresses are used. Each end of the link uses one address. The
38 * host end address is exported in various ways, and is often recorded
39 * in configuration databases.
40 *
41 * The driver which assembles each configuration using such a link is
42 * responsible for ensuring that each configuration includes at most one
43 * instance of is network link. (The network layer provides ways for
44 * this single "physical" link to be used by multiple virtual links.)
45 */
46
47#define UETH__VERSION "29-May-2008"
48
49struct eth_dev {
50 /* lock is held while accessing port_usb
51 * or updating its backlink port_usb->ioport
52 */
53 spinlock_t lock;
54 struct gether *port_usb;
55
56 struct net_device *net;
57 struct usb_gadget *gadget;
58
59 spinlock_t req_lock; /* guard {rx,tx}_reqs */
60 struct list_head tx_reqs, rx_reqs;
61 atomic_t tx_qlen;
62
63 struct sk_buff_head rx_frames;
64
65 unsigned header_len;
66 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
67 int (*unwrap)(struct gether *,
68 struct sk_buff *skb,
69 struct sk_buff_head *list);
70
71 struct work_struct work;
72
73 unsigned long todo;
74#define WORK_RX_MEMORY 0
75
76 bool zlp;
77 u8 host_mac[ETH_ALEN];
78};
79
80/*-------------------------------------------------------------------------*/
81
82#define RX_EXTRA 20 /* bytes guarding against rx overflows */
83
84#define DEFAULT_QLEN 2 /* double buffering by default */
85
86
87#ifdef CONFIG_USB_GADGET_DUALSPEED
88
89static unsigned qmult = 5;
90module_param(qmult, uint, S_IRUGO|S_IWUSR);
91MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
92
93#else /* full speed (low speed doesn't do bulk) */
94#define qmult 1
95#endif
96
97/* for dual-speed hardware, use deeper queues at high/super speed */
98static inline int qlen(struct usb_gadget *gadget)
99{
100 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
101 gadget->speed == USB_SPEED_SUPER))
102 return qmult * DEFAULT_QLEN;
103 else
104 return DEFAULT_QLEN;
105}
106
107/*-------------------------------------------------------------------------*/
108
109/* REVISIT there must be a better way than having two sets
110 * of debug calls ...
111 */
112
113#undef DBG
114#undef VDBG
115#undef ERROR
116#undef INFO
117
118#define xprintk(d, level, fmt, args...) \
119 printk(level "%s: " fmt , (d)->net->name , ## args)
120
121#ifdef DEBUG
122#undef DEBUG
123#define DBG(dev, fmt, args...) \
124 xprintk(dev , KERN_DEBUG , fmt , ## args)
125#else
126#define DBG(dev, fmt, args...) \
127 do { } while (0)
128#endif /* DEBUG */
129
130#ifdef VERBOSE_DEBUG
131#define VDBG DBG
132#else
133#define VDBG(dev, fmt, args...) \
134 do { } while (0)
135#endif /* DEBUG */
136
137#define ERROR(dev, fmt, args...) \
138 xprintk(dev , KERN_ERR , fmt , ## args)
139#define INFO(dev, fmt, args...) \
140 xprintk(dev , KERN_INFO , fmt , ## args)
141
142/*-------------------------------------------------------------------------*/
143
144/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
145
146static int ueth_change_mtu(struct net_device *net, int new_mtu)
147{
148 struct eth_dev *dev = netdev_priv(net);
149 unsigned long flags;
150 int status = 0;
151
152 /* don't change MTU on "live" link (peer won't know) */
153 spin_lock_irqsave(&dev->lock, flags);
154 if (dev->port_usb)
155 status = -EBUSY;
156 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
157 status = -ERANGE;
158 else
159 net->mtu = new_mtu;
160 spin_unlock_irqrestore(&dev->lock, flags);
161
162 return status;
163}
164
165static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
166{
167 struct eth_dev *dev = netdev_priv(net);
168
169 strlcpy(p->driver, "g_ether", sizeof p->driver);
170 strlcpy(p->version, UETH__VERSION, sizeof p->version);
171 strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
172 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
173}
174
175/* REVISIT can also support:
176 * - WOL (by tracking suspends and issuing remote wakeup)
177 * - msglevel (implies updated messaging)
178 * - ... probably more ethtool ops
179 */
180
181static const struct ethtool_ops ops = {
182 .get_drvinfo = eth_get_drvinfo,
183 .get_link = ethtool_op_get_link,
184};
185
186static void defer_kevent(struct eth_dev *dev, int flag)
187{
188 if (test_and_set_bit(flag, &dev->todo))
189 return;
190 if (!schedule_work(&dev->work))
191 ERROR(dev, "kevent %d may have been dropped\n", flag);
192 else
193 DBG(dev, "kevent %d scheduled\n", flag);
194}
195
196static void rx_complete(struct usb_ep *ep, struct usb_request *req);
197
198static int
199rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
200{
201 struct sk_buff *skb;
202 int retval = -ENOMEM;
203 size_t size = 0;
204 struct usb_ep *out;
205 unsigned long flags;
206
207 spin_lock_irqsave(&dev->lock, flags);
208 if (dev->port_usb)
209 out = dev->port_usb->out_ep;
210 else
211 out = NULL;
212 spin_unlock_irqrestore(&dev->lock, flags);
213
214 if (!out)
215 return -ENOTCONN;
216
217
218 /* Padding up to RX_EXTRA handles minor disagreements with host.
219 * Normally we use the USB "terminate on short read" convention;
220 * so allow up to (N*maxpacket), since that memory is normally
221 * already allocated. Some hardware doesn't deal well with short
222 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
223 * byte off the end (to force hardware errors on overflow).
224 *
225 * RNDIS uses internal framing, and explicitly allows senders to
226 * pad to end-of-packet. That's potentially nice for speed, but
227 * means receivers can't recover lost synch on their own (because
228 * new packets don't only start after a short RX).
229 */
230 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
231 size += dev->port_usb->header_len;
232 size += out->maxpacket - 1;
233 size -= size % out->maxpacket;
234
235 if (dev->port_usb->is_fixed)
236 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
237
238 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
239 if (skb == NULL) {
240 DBG(dev, "no rx skb\n");
241 goto enomem;
242 }
243
244 /* Some platforms perform better when IP packets are aligned,
245 * but on at least one, checksumming fails otherwise. Note:
246 * RNDIS headers involve variable numbers of LE32 values.
247 */
248 skb_reserve(skb, NET_IP_ALIGN);
249
250 req->buf = skb->data;
251 req->length = size;
252 req->complete = rx_complete;
253 req->context = skb;
254
255 retval = usb_ep_queue(out, req, gfp_flags);
256 if (retval == -ENOMEM)
257enomem:
258 defer_kevent(dev, WORK_RX_MEMORY);
259 if (retval) {
260 DBG(dev, "rx submit --> %d\n", retval);
261 if (skb)
262 dev_kfree_skb_any(skb);
263 spin_lock_irqsave(&dev->req_lock, flags);
264 list_add(&req->list, &dev->rx_reqs);
265 spin_unlock_irqrestore(&dev->req_lock, flags);
266 }
267 return retval;
268}
269
270static void rx_complete(struct usb_ep *ep, struct usb_request *req)
271{
272 struct sk_buff *skb = req->context, *skb2;
273 struct eth_dev *dev = ep->driver_data;
274 int status = req->status;
275
276 switch (status) {
277
278 /* normal completion */
279 case 0:
280 skb_put(skb, req->actual);
281
282 if (dev->unwrap) {
283 unsigned long flags;
284
285 spin_lock_irqsave(&dev->lock, flags);
286 if (dev->port_usb) {
287 status = dev->unwrap(dev->port_usb,
288 skb,
289 &dev->rx_frames);
290 } else {
291 dev_kfree_skb_any(skb);
292 status = -ENOTCONN;
293 }
294 spin_unlock_irqrestore(&dev->lock, flags);
295 } else {
296 skb_queue_tail(&dev->rx_frames, skb);
297 }
298 skb = NULL;
299
300 skb2 = skb_dequeue(&dev->rx_frames);
301 while (skb2) {
302 if (status < 0
303 || ETH_HLEN > skb2->len
304 || skb2->len > ETH_FRAME_LEN) {
305 dev->net->stats.rx_errors++;
306 dev->net->stats.rx_length_errors++;
307 DBG(dev, "rx length %d\n", skb2->len);
308 dev_kfree_skb_any(skb2);
309 goto next_frame;
310 }
311 skb2->protocol = eth_type_trans(skb2, dev->net);
312 dev->net->stats.rx_packets++;
313 dev->net->stats.rx_bytes += skb2->len;
314
315 /* no buffer copies needed, unless hardware can't
316 * use skb buffers.
317 */
318 status = netif_rx(skb2);
319next_frame:
320 skb2 = skb_dequeue(&dev->rx_frames);
321 }
322 break;
323
324 /* software-driven interface shutdown */
325 case -ECONNRESET: /* unlink */
326 case -ESHUTDOWN: /* disconnect etc */
327 VDBG(dev, "rx shutdown, code %d\n", status);
328 goto quiesce;
329
330 /* for hardware automagic (such as pxa) */
331 case -ECONNABORTED: /* endpoint reset */
332 DBG(dev, "rx %s reset\n", ep->name);
333 defer_kevent(dev, WORK_RX_MEMORY);
334quiesce:
335 dev_kfree_skb_any(skb);
336 goto clean;
337
338 /* data overrun */
339 case -EOVERFLOW:
340 dev->net->stats.rx_over_errors++;
341 /* FALLTHROUGH */
342
343 default:
344 dev->net->stats.rx_errors++;
345 DBG(dev, "rx status %d\n", status);
346 break;
347 }
348
349 if (skb)
350 dev_kfree_skb_any(skb);
351 if (!netif_running(dev->net)) {
352clean:
353 spin_lock(&dev->req_lock);
354 list_add(&req->list, &dev->rx_reqs);
355 spin_unlock(&dev->req_lock);
356 req = NULL;
357 }
358 if (req)
359 rx_submit(dev, req, GFP_ATOMIC);
360}
361
362static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
363{
364 unsigned i;
365 struct usb_request *req;
366
367 if (!n)
368 return -ENOMEM;
369
370 /* queue/recycle up to N requests */
371 i = n;
372 list_for_each_entry(req, list, list) {
373 if (i-- == 0)
374 goto extra;
375 }
376 while (i--) {
377 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
378 if (!req)
379 return list_empty(list) ? -ENOMEM : 0;
380 list_add(&req->list, list);
381 }
382 return 0;
383
384extra:
385 /* free extras */
386 for (;;) {
387 struct list_head *next;
388
389 next = req->list.next;
390 list_del(&req->list);
391 usb_ep_free_request(ep, req);
392
393 if (next == list)
394 break;
395
396 req = container_of(next, struct usb_request, list);
397 }
398 return 0;
399}
400
401static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
402{
403 int status;
404
405 spin_lock(&dev->req_lock);
406 status = prealloc(&dev->tx_reqs, link->in_ep, n);
407 if (status < 0)
408 goto fail;
409 status = prealloc(&dev->rx_reqs, link->out_ep, n);
410 if (status < 0)
411 goto fail;
412 goto done;
413fail:
414 DBG(dev, "can't alloc requests\n");
415done:
416 spin_unlock(&dev->req_lock);
417 return status;
418}
419
420static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
421{
422 struct usb_request *req;
423 unsigned long flags;
424
425 /* fill unused rxq slots with some skb */
426 spin_lock_irqsave(&dev->req_lock, flags);
427 while (!list_empty(&dev->rx_reqs)) {
428 req = container_of(dev->rx_reqs.next,
429 struct usb_request, list);
430 list_del_init(&req->list);
431 spin_unlock_irqrestore(&dev->req_lock, flags);
432
433 if (rx_submit(dev, req, gfp_flags) < 0) {
434 defer_kevent(dev, WORK_RX_MEMORY);
435 return;
436 }
437
438 spin_lock_irqsave(&dev->req_lock, flags);
439 }
440 spin_unlock_irqrestore(&dev->req_lock, flags);
441}
442
443static void eth_work(struct work_struct *work)
444{
445 struct eth_dev *dev = container_of(work, struct eth_dev, work);
446
447 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
448 if (netif_running(dev->net))
449 rx_fill(dev, GFP_KERNEL);
450 }
451
452 if (dev->todo)
453 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
454}
455
456static void tx_complete(struct usb_ep *ep, struct usb_request *req)
457{
458 struct sk_buff *skb = req->context;
459 struct eth_dev *dev = ep->driver_data;
460
461 switch (req->status) {
462 default:
463 dev->net->stats.tx_errors++;
464 VDBG(dev, "tx err %d\n", req->status);
465 /* FALLTHROUGH */
466 case -ECONNRESET: /* unlink */
467 case -ESHUTDOWN: /* disconnect etc */
468 break;
469 case 0:
470 dev->net->stats.tx_bytes += skb->len;
471 }
472 dev->net->stats.tx_packets++;
473
474 spin_lock(&dev->req_lock);
475 list_add(&req->list, &dev->tx_reqs);
476 spin_unlock(&dev->req_lock);
477 dev_kfree_skb_any(skb);
478
479 atomic_dec(&dev->tx_qlen);
480 if (netif_carrier_ok(dev->net))
481 netif_wake_queue(dev->net);
482}
483
484static inline int is_promisc(u16 cdc_filter)
485{
486 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
487}
488
489static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
490 struct net_device *net)
491{
492 struct eth_dev *dev = netdev_priv(net);
493 int length = skb->len;
494 int retval;
495 struct usb_request *req = NULL;
496 unsigned long flags;
497 struct usb_ep *in;
498 u16 cdc_filter;
499
500 spin_lock_irqsave(&dev->lock, flags);
501 if (dev->port_usb) {
502 in = dev->port_usb->in_ep;
503 cdc_filter = dev->port_usb->cdc_filter;
504 } else {
505 in = NULL;
506 cdc_filter = 0;
507 }
508 spin_unlock_irqrestore(&dev->lock, flags);
509
510 if (!in) {
511 dev_kfree_skb_any(skb);
512 return NETDEV_TX_OK;
513 }
514
515 /* apply outgoing CDC or RNDIS filters */
516 if (!is_promisc(cdc_filter)) {
517 u8 *dest = skb->data;
518
519 if (is_multicast_ether_addr(dest)) {
520 u16 type;
521
522 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
523 * SET_ETHERNET_MULTICAST_FILTERS requests
524 */
525 if (is_broadcast_ether_addr(dest))
526 type = USB_CDC_PACKET_TYPE_BROADCAST;
527 else
528 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
529 if (!(cdc_filter & type)) {
530 dev_kfree_skb_any(skb);
531 return NETDEV_TX_OK;
532 }
533 }
534 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
535 }
536
537 spin_lock_irqsave(&dev->req_lock, flags);
538 /*
539 * this freelist can be empty if an interrupt triggered disconnect()
540 * and reconfigured the gadget (shutting down this queue) after the
541 * network stack decided to xmit but before we got the spinlock.
542 */
543 if (list_empty(&dev->tx_reqs)) {
544 spin_unlock_irqrestore(&dev->req_lock, flags);
545 return NETDEV_TX_BUSY;
546 }
547
548 req = container_of(dev->tx_reqs.next, struct usb_request, list);
549 list_del(&req->list);
550
551 /* temporarily stop TX queue when the freelist empties */
552 if (list_empty(&dev->tx_reqs))
553 netif_stop_queue(net);
554 spin_unlock_irqrestore(&dev->req_lock, flags);
555
556 /* no buffer copies needed, unless the network stack did it
557 * or the hardware can't use skb buffers.
558 * or there's not enough space for extra headers we need
559 */
560 if (dev->wrap) {
561 unsigned long flags;
562
563 spin_lock_irqsave(&dev->lock, flags);
564 if (dev->port_usb)
565 skb = dev->wrap(dev->port_usb, skb);
566 spin_unlock_irqrestore(&dev->lock, flags);
567 if (!skb)
568 goto drop;
569
570 length = skb->len;
571 }
572 req->buf = skb->data;
573 req->context = skb;
574 req->complete = tx_complete;
575
576 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
577 if (dev->port_usb->is_fixed &&
578 length == dev->port_usb->fixed_in_len &&
579 (length % in->maxpacket) == 0)
580 req->zero = 0;
581 else
582 req->zero = 1;
583
584 /* use zlp framing on tx for strict CDC-Ether conformance,
585 * though any robust network rx path ignores extra padding.
586 * and some hardware doesn't like to write zlps.
587 */
588 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
589 length++;
590
591 req->length = length;
592
593 /* throttle high/super speed IRQ rate back slightly */
594 if (gadget_is_dualspeed(dev->gadget))
595 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
596 dev->gadget->speed == USB_SPEED_SUPER)
597 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
598 : 0;
599
600 retval = usb_ep_queue(in, req, GFP_ATOMIC);
601 switch (retval) {
602 default:
603 DBG(dev, "tx queue err %d\n", retval);
604 break;
605 case 0:
606 net->trans_start = jiffies;
607 atomic_inc(&dev->tx_qlen);
608 }
609
610 if (retval) {
611 dev_kfree_skb_any(skb);
612drop:
613 dev->net->stats.tx_dropped++;
614 spin_lock_irqsave(&dev->req_lock, flags);
615 if (list_empty(&dev->tx_reqs))
616 netif_start_queue(net);
617 list_add(&req->list, &dev->tx_reqs);
618 spin_unlock_irqrestore(&dev->req_lock, flags);
619 }
620 return NETDEV_TX_OK;
621}
622
623/*-------------------------------------------------------------------------*/
624
625static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
626{
627 DBG(dev, "%s\n", __func__);
628
629 /* fill the rx queue */
630 rx_fill(dev, gfp_flags);
631
632 /* and open the tx floodgates */
633 atomic_set(&dev->tx_qlen, 0);
634 netif_wake_queue(dev->net);
635}
636
637static int eth_open(struct net_device *net)
638{
639 struct eth_dev *dev = netdev_priv(net);
640 struct gether *link;
641
642 DBG(dev, "%s\n", __func__);
643 if (netif_carrier_ok(dev->net))
644 eth_start(dev, GFP_KERNEL);
645
646 spin_lock_irq(&dev->lock);
647 link = dev->port_usb;
648 if (link && link->open)
649 link->open(link);
650 spin_unlock_irq(&dev->lock);
651
652 return 0;
653}
654
655static int eth_stop(struct net_device *net)
656{
657 struct eth_dev *dev = netdev_priv(net);
658 unsigned long flags;
659
660 VDBG(dev, "%s\n", __func__);
661 netif_stop_queue(net);
662
663 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
664 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
665 dev->net->stats.rx_errors, dev->net->stats.tx_errors
666 );
667
668 /* ensure there are no more active requests */
669 spin_lock_irqsave(&dev->lock, flags);
670 if (dev->port_usb) {
671 struct gether *link = dev->port_usb;
672 const struct usb_endpoint_descriptor *in;
673 const struct usb_endpoint_descriptor *out;
674
675 if (link->close)
676 link->close(link);
677
678 /* NOTE: we have no abort-queue primitive we could use
679 * to cancel all pending I/O. Instead, we disable then
680 * reenable the endpoints ... this idiom may leave toggle
681 * wrong, but that's a self-correcting error.
682 *
683 * REVISIT: we *COULD* just let the transfers complete at
684 * their own pace; the network stack can handle old packets.
685 * For the moment we leave this here, since it works.
686 */
687 in = link->in_ep->desc;
688 out = link->out_ep->desc;
689 usb_ep_disable(link->in_ep);
690 usb_ep_disable(link->out_ep);
691 if (netif_carrier_ok(net)) {
692 DBG(dev, "host still using in/out endpoints\n");
693 link->in_ep->desc = in;
694 link->out_ep->desc = out;
695 usb_ep_enable(link->in_ep);
696 usb_ep_enable(link->out_ep);
697 }
698 }
699 spin_unlock_irqrestore(&dev->lock, flags);
700
701 return 0;
702}
703
704/*-------------------------------------------------------------------------*/
705
706/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
707static char *dev_addr;
708module_param(dev_addr, charp, S_IRUGO);
709MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
710
711/* this address is invisible to ifconfig */
712static char *host_addr;
713module_param(host_addr, charp, S_IRUGO);
714MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
715
716static int get_ether_addr(const char *str, u8 *dev_addr)
717{
718 if (str) {
719 unsigned i;
720
721 for (i = 0; i < 6; i++) {
722 unsigned char num;
723
724 if ((*str == '.') || (*str == ':'))
725 str++;
726 num = hex_to_bin(*str++) << 4;
727 num |= hex_to_bin(*str++);
728 dev_addr [i] = num;
729 }
730 if (is_valid_ether_addr(dev_addr))
731 return 0;
732 }
733 random_ether_addr(dev_addr);
734 return 1;
735}
736
737static struct eth_dev *the_dev;
738
739static const struct net_device_ops eth_netdev_ops = {
740 .ndo_open = eth_open,
741 .ndo_stop = eth_stop,
742 .ndo_start_xmit = eth_start_xmit,
743 .ndo_change_mtu = ueth_change_mtu,
744 .ndo_set_mac_address = eth_mac_addr,
745 .ndo_validate_addr = eth_validate_addr,
746};
747
748static struct device_type gadget_type = {
749 .name = "gadget",
750};
751
752/**
753 * gether_setup_name - initialize one ethernet-over-usb link
754 * @g: gadget to associated with these links
755 * @ethaddr: NULL, or a buffer in which the ethernet address of the
756 * host side of the link is recorded
757 * @netname: name for network device (for example, "usb")
758 * Context: may sleep
759 *
760 * This sets up the single network link that may be exported by a
761 * gadget driver using this framework. The link layer addresses are
762 * set up using module parameters.
763 *
764 * Returns negative errno, or zero on success
765 */
766int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
767 const char *netname)
768{
769 struct eth_dev *dev;
770 struct net_device *net;
771 int status;
772
773 if (the_dev)
774 return -EBUSY;
775
776 net = alloc_etherdev(sizeof *dev);
777 if (!net)
778 return -ENOMEM;
779
780 dev = netdev_priv(net);
781 spin_lock_init(&dev->lock);
782 spin_lock_init(&dev->req_lock);
783 INIT_WORK(&dev->work, eth_work);
784 INIT_LIST_HEAD(&dev->tx_reqs);
785 INIT_LIST_HEAD(&dev->rx_reqs);
786
787 skb_queue_head_init(&dev->rx_frames);
788
789 /* network device setup */
790 dev->net = net;
791 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
792
793 if (get_ether_addr(dev_addr, net->dev_addr))
794 dev_warn(&g->dev,
795 "using random %s ethernet address\n", "self");
796 if (get_ether_addr(host_addr, dev->host_mac))
797 dev_warn(&g->dev,
798 "using random %s ethernet address\n", "host");
799
800 if (ethaddr)
801 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
802
803 net->netdev_ops = ð_netdev_ops;
804
805 SET_ETHTOOL_OPS(net, &ops);
806
807 dev->gadget = g;
808 SET_NETDEV_DEV(net, &g->dev);
809 SET_NETDEV_DEVTYPE(net, &gadget_type);
810
811 status = register_netdev(net);
812 if (status < 0) {
813 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
814 free_netdev(net);
815 } else {
816 INFO(dev, "MAC %pM\n", net->dev_addr);
817 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
818
819 the_dev = dev;
820
821 /* two kinds of host-initiated state changes:
822 * - iff DATA transfer is active, carrier is "on"
823 * - tx queueing enabled if open *and* carrier is "on"
824 */
825 netif_carrier_off(net);
826 }
827
828 return status;
829}
830
831/**
832 * gether_cleanup - remove Ethernet-over-USB device
833 * Context: may sleep
834 *
835 * This is called to free all resources allocated by @gether_setup().
836 */
837void gether_cleanup(void)
838{
839 if (!the_dev)
840 return;
841
842 unregister_netdev(the_dev->net);
843 flush_work_sync(&the_dev->work);
844 free_netdev(the_dev->net);
845
846 the_dev = NULL;
847}
848
849
850/**
851 * gether_connect - notify network layer that USB link is active
852 * @link: the USB link, set up with endpoints, descriptors matching
853 * current device speed, and any framing wrapper(s) set up.
854 * Context: irqs blocked
855 *
856 * This is called to activate endpoints and let the network layer know
857 * the connection is active ("carrier detect"). It may cause the I/O
858 * queues to open and start letting network packets flow, but will in
859 * any case activate the endpoints so that they respond properly to the
860 * USB host.
861 *
862 * Verify net_device pointer returned using IS_ERR(). If it doesn't
863 * indicate some error code (negative errno), ep->driver_data values
864 * have been overwritten.
865 */
866struct net_device *gether_connect(struct gether *link)
867{
868 struct eth_dev *dev = the_dev;
869 int result = 0;
870
871 if (!dev)
872 return ERR_PTR(-EINVAL);
873
874 link->in_ep->driver_data = dev;
875 result = usb_ep_enable(link->in_ep);
876 if (result != 0) {
877 DBG(dev, "enable %s --> %d\n",
878 link->in_ep->name, result);
879 goto fail0;
880 }
881
882 link->out_ep->driver_data = dev;
883 result = usb_ep_enable(link->out_ep);
884 if (result != 0) {
885 DBG(dev, "enable %s --> %d\n",
886 link->out_ep->name, result);
887 goto fail1;
888 }
889
890 if (result == 0)
891 result = alloc_requests(dev, link, qlen(dev->gadget));
892
893 if (result == 0) {
894 dev->zlp = link->is_zlp_ok;
895 DBG(dev, "qlen %d\n", qlen(dev->gadget));
896
897 dev->header_len = link->header_len;
898 dev->unwrap = link->unwrap;
899 dev->wrap = link->wrap;
900
901 spin_lock(&dev->lock);
902 dev->port_usb = link;
903 link->ioport = dev;
904 if (netif_running(dev->net)) {
905 if (link->open)
906 link->open(link);
907 } else {
908 if (link->close)
909 link->close(link);
910 }
911 spin_unlock(&dev->lock);
912
913 netif_carrier_on(dev->net);
914 if (netif_running(dev->net))
915 eth_start(dev, GFP_ATOMIC);
916
917 /* on error, disable any endpoints */
918 } else {
919 (void) usb_ep_disable(link->out_ep);
920fail1:
921 (void) usb_ep_disable(link->in_ep);
922 }
923fail0:
924 /* caller is responsible for cleanup on error */
925 if (result < 0)
926 return ERR_PTR(result);
927 return dev->net;
928}
929
930/**
931 * gether_disconnect - notify network layer that USB link is inactive
932 * @link: the USB link, on which gether_connect() was called
933 * Context: irqs blocked
934 *
935 * This is called to deactivate endpoints and let the network layer know
936 * the connection went inactive ("no carrier").
937 *
938 * On return, the state is as if gether_connect() had never been called.
939 * The endpoints are inactive, and accordingly without active USB I/O.
940 * Pointers to endpoint descriptors and endpoint private data are nulled.
941 */
942void gether_disconnect(struct gether *link)
943{
944 struct eth_dev *dev = link->ioport;
945 struct usb_request *req;
946
947 WARN_ON(!dev);
948 if (!dev)
949 return;
950
951 DBG(dev, "%s\n", __func__);
952
953 netif_stop_queue(dev->net);
954 netif_carrier_off(dev->net);
955
956 /* disable endpoints, forcing (synchronous) completion
957 * of all pending i/o. then free the request objects
958 * and forget about the endpoints.
959 */
960 usb_ep_disable(link->in_ep);
961 spin_lock(&dev->req_lock);
962 while (!list_empty(&dev->tx_reqs)) {
963 req = container_of(dev->tx_reqs.next,
964 struct usb_request, list);
965 list_del(&req->list);
966
967 spin_unlock(&dev->req_lock);
968 usb_ep_free_request(link->in_ep, req);
969 spin_lock(&dev->req_lock);
970 }
971 spin_unlock(&dev->req_lock);
972 link->in_ep->driver_data = NULL;
973 link->in_ep->desc = NULL;
974
975 usb_ep_disable(link->out_ep);
976 spin_lock(&dev->req_lock);
977 while (!list_empty(&dev->rx_reqs)) {
978 req = container_of(dev->rx_reqs.next,
979 struct usb_request, list);
980 list_del(&req->list);
981
982 spin_unlock(&dev->req_lock);
983 usb_ep_free_request(link->out_ep, req);
984 spin_lock(&dev->req_lock);
985 }
986 spin_unlock(&dev->req_lock);
987 link->out_ep->driver_data = NULL;
988 link->out_ep->desc = NULL;
989
990 /* finish forgetting about this USB link episode */
991 dev->header_len = 0;
992 dev->unwrap = NULL;
993 dev->wrap = NULL;
994
995 spin_lock(&dev->lock);
996 dev->port_usb = NULL;
997 link->ioport = NULL;
998 spin_unlock(&dev->lock);
999}