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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 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23/* #define VERBOSE_DEBUG */
24
25#include <linux/kernel.h>
26#include <linux/gfp.h>
27#include <linux/device.h>
28#include <linux/ctype.h>
29#include <linux/etherdevice.h>
30#include <linux/ethtool.h>
31
32#include "u_ether.h"
33
34
35/*
36 * This component encapsulates the Ethernet link glue needed to provide
37 * one (!) network link through the USB gadget stack, normally "usb0".
38 *
39 * The control and data models are handled by the function driver which
40 * connects to this code; such as CDC Ethernet (ECM or EEM),
41 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
42 * management.
43 *
44 * Link level addressing is handled by this component using module
45 * parameters; if no such parameters are provided, random link level
46 * addresses are used. Each end of the link uses one address. The
47 * host end address is exported in various ways, and is often recorded
48 * in configuration databases.
49 *
50 * The driver which assembles each configuration using such a link is
51 * responsible for ensuring that each configuration includes at most one
52 * instance of is network link. (The network layer provides ways for
53 * this single "physical" link to be used by multiple virtual links.)
54 */
55
56#define UETH__VERSION "29-May-2008"
57
58struct eth_dev {
59 /* lock is held while accessing port_usb
60 * or updating its backlink port_usb->ioport
61 */
62 spinlock_t lock;
63 struct gether *port_usb;
64
65 struct net_device *net;
66 struct usb_gadget *gadget;
67
68 spinlock_t req_lock; /* guard {rx,tx}_reqs */
69 struct list_head tx_reqs, rx_reqs;
70 atomic_t tx_qlen;
71
72 struct sk_buff_head rx_frames;
73
74 unsigned header_len;
75 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
76 int (*unwrap)(struct gether *,
77 struct sk_buff *skb,
78 struct sk_buff_head *list);
79
80 struct work_struct work;
81
82 unsigned long todo;
83#define WORK_RX_MEMORY 0
84
85 bool zlp;
86 u8 host_mac[ETH_ALEN];
87};
88
89/*-------------------------------------------------------------------------*/
90
91#define RX_EXTRA 20 /* bytes guarding against rx overflows */
92
93#define DEFAULT_QLEN 2 /* double buffering by default */
94
95
96#ifdef CONFIG_USB_GADGET_DUALSPEED
97
98static unsigned qmult = 5;
99module_param(qmult, uint, S_IRUGO|S_IWUSR);
100MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
101
102#else /* full speed (low speed doesn't do bulk) */
103#define qmult 1
104#endif
105
106/* for dual-speed hardware, use deeper queues at high/super speed */
107static inline int qlen(struct usb_gadget *gadget)
108{
109 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
110 gadget->speed == USB_SPEED_SUPER))
111 return qmult * DEFAULT_QLEN;
112 else
113 return DEFAULT_QLEN;
114}
115
116/*-------------------------------------------------------------------------*/
117
118/* REVISIT there must be a better way than having two sets
119 * of debug calls ...
120 */
121
122#undef DBG
123#undef VDBG
124#undef ERROR
125#undef INFO
126
127#define xprintk(d, level, fmt, args...) \
128 printk(level "%s: " fmt , (d)->net->name , ## args)
129
130#ifdef DEBUG
131#undef DEBUG
132#define DBG(dev, fmt, args...) \
133 xprintk(dev , KERN_DEBUG , fmt , ## args)
134#else
135#define DBG(dev, fmt, args...) \
136 do { } while (0)
137#endif /* DEBUG */
138
139#ifdef VERBOSE_DEBUG
140#define VDBG DBG
141#else
142#define VDBG(dev, fmt, args...) \
143 do { } while (0)
144#endif /* DEBUG */
145
146#define ERROR(dev, fmt, args...) \
147 xprintk(dev , KERN_ERR , fmt , ## args)
148#define INFO(dev, fmt, args...) \
149 xprintk(dev , KERN_INFO , fmt , ## args)
150
151/*-------------------------------------------------------------------------*/
152
153/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
154
155static int ueth_change_mtu(struct net_device *net, int new_mtu)
156{
157 struct eth_dev *dev = netdev_priv(net);
158 unsigned long flags;
159 int status = 0;
160
161 /* don't change MTU on "live" link (peer won't know) */
162 spin_lock_irqsave(&dev->lock, flags);
163 if (dev->port_usb)
164 status = -EBUSY;
165 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
166 status = -ERANGE;
167 else
168 net->mtu = new_mtu;
169 spin_unlock_irqrestore(&dev->lock, flags);
170
171 return status;
172}
173
174static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
175{
176 struct eth_dev *dev = netdev_priv(net);
177
178 strlcpy(p->driver, "g_ether", sizeof p->driver);
179 strlcpy(p->version, UETH__VERSION, sizeof p->version);
180 strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
181 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
182}
183
184/* REVISIT can also support:
185 * - WOL (by tracking suspends and issuing remote wakeup)
186 * - msglevel (implies updated messaging)
187 * - ... probably more ethtool ops
188 */
189
190static const struct ethtool_ops ops = {
191 .get_drvinfo = eth_get_drvinfo,
192 .get_link = ethtool_op_get_link,
193};
194
195static void defer_kevent(struct eth_dev *dev, int flag)
196{
197 if (test_and_set_bit(flag, &dev->todo))
198 return;
199 if (!schedule_work(&dev->work))
200 ERROR(dev, "kevent %d may have been dropped\n", flag);
201 else
202 DBG(dev, "kevent %d scheduled\n", flag);
203}
204
205static void rx_complete(struct usb_ep *ep, struct usb_request *req);
206
207static int
208rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
209{
210 struct sk_buff *skb;
211 int retval = -ENOMEM;
212 size_t size = 0;
213 struct usb_ep *out;
214 unsigned long flags;
215
216 spin_lock_irqsave(&dev->lock, flags);
217 if (dev->port_usb)
218 out = dev->port_usb->out_ep;
219 else
220 out = NULL;
221 spin_unlock_irqrestore(&dev->lock, flags);
222
223 if (!out)
224 return -ENOTCONN;
225
226
227 /* Padding up to RX_EXTRA handles minor disagreements with host.
228 * Normally we use the USB "terminate on short read" convention;
229 * so allow up to (N*maxpacket), since that memory is normally
230 * already allocated. Some hardware doesn't deal well with short
231 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
232 * byte off the end (to force hardware errors on overflow).
233 *
234 * RNDIS uses internal framing, and explicitly allows senders to
235 * pad to end-of-packet. That's potentially nice for speed, but
236 * means receivers can't recover lost synch on their own (because
237 * new packets don't only start after a short RX).
238 */
239 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
240 size += dev->port_usb->header_len;
241 size += out->maxpacket - 1;
242 size -= size % out->maxpacket;
243
244 if (dev->port_usb->is_fixed)
245 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
246
247 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
248 if (skb == NULL) {
249 DBG(dev, "no rx skb\n");
250 goto enomem;
251 }
252
253 /* Some platforms perform better when IP packets are aligned,
254 * but on at least one, checksumming fails otherwise. Note:
255 * RNDIS headers involve variable numbers of LE32 values.
256 */
257 skb_reserve(skb, NET_IP_ALIGN);
258
259 req->buf = skb->data;
260 req->length = size;
261 req->complete = rx_complete;
262 req->context = skb;
263
264 retval = usb_ep_queue(out, req, gfp_flags);
265 if (retval == -ENOMEM)
266enomem:
267 defer_kevent(dev, WORK_RX_MEMORY);
268 if (retval) {
269 DBG(dev, "rx submit --> %d\n", retval);
270 if (skb)
271 dev_kfree_skb_any(skb);
272 spin_lock_irqsave(&dev->req_lock, flags);
273 list_add(&req->list, &dev->rx_reqs);
274 spin_unlock_irqrestore(&dev->req_lock, flags);
275 }
276 return retval;
277}
278
279static void rx_complete(struct usb_ep *ep, struct usb_request *req)
280{
281 struct sk_buff *skb = req->context, *skb2;
282 struct eth_dev *dev = ep->driver_data;
283 int status = req->status;
284
285 switch (status) {
286
287 /* normal completion */
288 case 0:
289 skb_put(skb, req->actual);
290
291 if (dev->unwrap) {
292 unsigned long flags;
293
294 spin_lock_irqsave(&dev->lock, flags);
295 if (dev->port_usb) {
296 status = dev->unwrap(dev->port_usb,
297 skb,
298 &dev->rx_frames);
299 } else {
300 dev_kfree_skb_any(skb);
301 status = -ENOTCONN;
302 }
303 spin_unlock_irqrestore(&dev->lock, flags);
304 } else {
305 skb_queue_tail(&dev->rx_frames, skb);
306 }
307 skb = NULL;
308
309 skb2 = skb_dequeue(&dev->rx_frames);
310 while (skb2) {
311 if (status < 0
312 || ETH_HLEN > skb2->len
313 || skb2->len > ETH_FRAME_LEN) {
314 dev->net->stats.rx_errors++;
315 dev->net->stats.rx_length_errors++;
316 DBG(dev, "rx length %d\n", skb2->len);
317 dev_kfree_skb_any(skb2);
318 goto next_frame;
319 }
320 skb2->protocol = eth_type_trans(skb2, dev->net);
321 dev->net->stats.rx_packets++;
322 dev->net->stats.rx_bytes += skb2->len;
323
324 /* no buffer copies needed, unless hardware can't
325 * use skb buffers.
326 */
327 status = netif_rx(skb2);
328next_frame:
329 skb2 = skb_dequeue(&dev->rx_frames);
330 }
331 break;
332
333 /* software-driven interface shutdown */
334 case -ECONNRESET: /* unlink */
335 case -ESHUTDOWN: /* disconnect etc */
336 VDBG(dev, "rx shutdown, code %d\n", status);
337 goto quiesce;
338
339 /* for hardware automagic (such as pxa) */
340 case -ECONNABORTED: /* endpoint reset */
341 DBG(dev, "rx %s reset\n", ep->name);
342 defer_kevent(dev, WORK_RX_MEMORY);
343quiesce:
344 dev_kfree_skb_any(skb);
345 goto clean;
346
347 /* data overrun */
348 case -EOVERFLOW:
349 dev->net->stats.rx_over_errors++;
350 /* FALLTHROUGH */
351
352 default:
353 dev->net->stats.rx_errors++;
354 DBG(dev, "rx status %d\n", status);
355 break;
356 }
357
358 if (skb)
359 dev_kfree_skb_any(skb);
360 if (!netif_running(dev->net)) {
361clean:
362 spin_lock(&dev->req_lock);
363 list_add(&req->list, &dev->rx_reqs);
364 spin_unlock(&dev->req_lock);
365 req = NULL;
366 }
367 if (req)
368 rx_submit(dev, req, GFP_ATOMIC);
369}
370
371static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
372{
373 unsigned i;
374 struct usb_request *req;
375
376 if (!n)
377 return -ENOMEM;
378
379 /* queue/recycle up to N requests */
380 i = n;
381 list_for_each_entry(req, list, list) {
382 if (i-- == 0)
383 goto extra;
384 }
385 while (i--) {
386 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
387 if (!req)
388 return list_empty(list) ? -ENOMEM : 0;
389 list_add(&req->list, list);
390 }
391 return 0;
392
393extra:
394 /* free extras */
395 for (;;) {
396 struct list_head *next;
397
398 next = req->list.next;
399 list_del(&req->list);
400 usb_ep_free_request(ep, req);
401
402 if (next == list)
403 break;
404
405 req = container_of(next, struct usb_request, list);
406 }
407 return 0;
408}
409
410static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
411{
412 int status;
413
414 spin_lock(&dev->req_lock);
415 status = prealloc(&dev->tx_reqs, link->in_ep, n);
416 if (status < 0)
417 goto fail;
418 status = prealloc(&dev->rx_reqs, link->out_ep, n);
419 if (status < 0)
420 goto fail;
421 goto done;
422fail:
423 DBG(dev, "can't alloc requests\n");
424done:
425 spin_unlock(&dev->req_lock);
426 return status;
427}
428
429static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
430{
431 struct usb_request *req;
432 unsigned long flags;
433
434 /* fill unused rxq slots with some skb */
435 spin_lock_irqsave(&dev->req_lock, flags);
436 while (!list_empty(&dev->rx_reqs)) {
437 req = container_of(dev->rx_reqs.next,
438 struct usb_request, list);
439 list_del_init(&req->list);
440 spin_unlock_irqrestore(&dev->req_lock, flags);
441
442 if (rx_submit(dev, req, gfp_flags) < 0) {
443 defer_kevent(dev, WORK_RX_MEMORY);
444 return;
445 }
446
447 spin_lock_irqsave(&dev->req_lock, flags);
448 }
449 spin_unlock_irqrestore(&dev->req_lock, flags);
450}
451
452static void eth_work(struct work_struct *work)
453{
454 struct eth_dev *dev = container_of(work, struct eth_dev, work);
455
456 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
457 if (netif_running(dev->net))
458 rx_fill(dev, GFP_KERNEL);
459 }
460
461 if (dev->todo)
462 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
463}
464
465static void tx_complete(struct usb_ep *ep, struct usb_request *req)
466{
467 struct sk_buff *skb = req->context;
468 struct eth_dev *dev = ep->driver_data;
469
470 switch (req->status) {
471 default:
472 dev->net->stats.tx_errors++;
473 VDBG(dev, "tx err %d\n", req->status);
474 /* FALLTHROUGH */
475 case -ECONNRESET: /* unlink */
476 case -ESHUTDOWN: /* disconnect etc */
477 break;
478 case 0:
479 dev->net->stats.tx_bytes += skb->len;
480 }
481 dev->net->stats.tx_packets++;
482
483 spin_lock(&dev->req_lock);
484 list_add(&req->list, &dev->tx_reqs);
485 spin_unlock(&dev->req_lock);
486 dev_kfree_skb_any(skb);
487
488 atomic_dec(&dev->tx_qlen);
489 if (netif_carrier_ok(dev->net))
490 netif_wake_queue(dev->net);
491}
492
493static inline int is_promisc(u16 cdc_filter)
494{
495 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
496}
497
498static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
499 struct net_device *net)
500{
501 struct eth_dev *dev = netdev_priv(net);
502 int length = skb->len;
503 int retval;
504 struct usb_request *req = NULL;
505 unsigned long flags;
506 struct usb_ep *in;
507 u16 cdc_filter;
508
509 spin_lock_irqsave(&dev->lock, flags);
510 if (dev->port_usb) {
511 in = dev->port_usb->in_ep;
512 cdc_filter = dev->port_usb->cdc_filter;
513 } else {
514 in = NULL;
515 cdc_filter = 0;
516 }
517 spin_unlock_irqrestore(&dev->lock, flags);
518
519 if (!in) {
520 dev_kfree_skb_any(skb);
521 return NETDEV_TX_OK;
522 }
523
524 /* apply outgoing CDC or RNDIS filters */
525 if (!is_promisc(cdc_filter)) {
526 u8 *dest = skb->data;
527
528 if (is_multicast_ether_addr(dest)) {
529 u16 type;
530
531 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
532 * SET_ETHERNET_MULTICAST_FILTERS requests
533 */
534 if (is_broadcast_ether_addr(dest))
535 type = USB_CDC_PACKET_TYPE_BROADCAST;
536 else
537 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
538 if (!(cdc_filter & type)) {
539 dev_kfree_skb_any(skb);
540 return NETDEV_TX_OK;
541 }
542 }
543 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
544 }
545
546 spin_lock_irqsave(&dev->req_lock, flags);
547 /*
548 * this freelist can be empty if an interrupt triggered disconnect()
549 * and reconfigured the gadget (shutting down this queue) after the
550 * network stack decided to xmit but before we got the spinlock.
551 */
552 if (list_empty(&dev->tx_reqs)) {
553 spin_unlock_irqrestore(&dev->req_lock, flags);
554 return NETDEV_TX_BUSY;
555 }
556
557 req = container_of(dev->tx_reqs.next, struct usb_request, list);
558 list_del(&req->list);
559
560 /* temporarily stop TX queue when the freelist empties */
561 if (list_empty(&dev->tx_reqs))
562 netif_stop_queue(net);
563 spin_unlock_irqrestore(&dev->req_lock, flags);
564
565 /* no buffer copies needed, unless the network stack did it
566 * or the hardware can't use skb buffers.
567 * or there's not enough space for extra headers we need
568 */
569 if (dev->wrap) {
570 unsigned long flags;
571
572 spin_lock_irqsave(&dev->lock, flags);
573 if (dev->port_usb)
574 skb = dev->wrap(dev->port_usb, skb);
575 spin_unlock_irqrestore(&dev->lock, flags);
576 if (!skb)
577 goto drop;
578
579 length = skb->len;
580 }
581 req->buf = skb->data;
582 req->context = skb;
583 req->complete = tx_complete;
584
585 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
586 if (dev->port_usb->is_fixed &&
587 length == dev->port_usb->fixed_in_len &&
588 (length % in->maxpacket) == 0)
589 req->zero = 0;
590 else
591 req->zero = 1;
592
593 /* use zlp framing on tx for strict CDC-Ether conformance,
594 * though any robust network rx path ignores extra padding.
595 * and some hardware doesn't like to write zlps.
596 */
597 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
598 length++;
599
600 req->length = length;
601
602 /* throttle high/super speed IRQ rate back slightly */
603 if (gadget_is_dualspeed(dev->gadget))
604 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
605 dev->gadget->speed == USB_SPEED_SUPER)
606 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
607 : 0;
608
609 retval = usb_ep_queue(in, req, GFP_ATOMIC);
610 switch (retval) {
611 default:
612 DBG(dev, "tx queue err %d\n", retval);
613 break;
614 case 0:
615 net->trans_start = jiffies;
616 atomic_inc(&dev->tx_qlen);
617 }
618
619 if (retval) {
620 dev_kfree_skb_any(skb);
621drop:
622 dev->net->stats.tx_dropped++;
623 spin_lock_irqsave(&dev->req_lock, flags);
624 if (list_empty(&dev->tx_reqs))
625 netif_start_queue(net);
626 list_add(&req->list, &dev->tx_reqs);
627 spin_unlock_irqrestore(&dev->req_lock, flags);
628 }
629 return NETDEV_TX_OK;
630}
631
632/*-------------------------------------------------------------------------*/
633
634static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
635{
636 DBG(dev, "%s\n", __func__);
637
638 /* fill the rx queue */
639 rx_fill(dev, gfp_flags);
640
641 /* and open the tx floodgates */
642 atomic_set(&dev->tx_qlen, 0);
643 netif_wake_queue(dev->net);
644}
645
646static int eth_open(struct net_device *net)
647{
648 struct eth_dev *dev = netdev_priv(net);
649 struct gether *link;
650
651 DBG(dev, "%s\n", __func__);
652 if (netif_carrier_ok(dev->net))
653 eth_start(dev, GFP_KERNEL);
654
655 spin_lock_irq(&dev->lock);
656 link = dev->port_usb;
657 if (link && link->open)
658 link->open(link);
659 spin_unlock_irq(&dev->lock);
660
661 return 0;
662}
663
664static int eth_stop(struct net_device *net)
665{
666 struct eth_dev *dev = netdev_priv(net);
667 unsigned long flags;
668
669 VDBG(dev, "%s\n", __func__);
670 netif_stop_queue(net);
671
672 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
673 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
674 dev->net->stats.rx_errors, dev->net->stats.tx_errors
675 );
676
677 /* ensure there are no more active requests */
678 spin_lock_irqsave(&dev->lock, flags);
679 if (dev->port_usb) {
680 struct gether *link = dev->port_usb;
681
682 if (link->close)
683 link->close(link);
684
685 /* NOTE: we have no abort-queue primitive we could use
686 * to cancel all pending I/O. Instead, we disable then
687 * reenable the endpoints ... this idiom may leave toggle
688 * wrong, but that's a self-correcting error.
689 *
690 * REVISIT: we *COULD* just let the transfers complete at
691 * their own pace; the network stack can handle old packets.
692 * For the moment we leave this here, since it works.
693 */
694 usb_ep_disable(link->in_ep);
695 usb_ep_disable(link->out_ep);
696 if (netif_carrier_ok(net)) {
697 DBG(dev, "host still using in/out endpoints\n");
698 usb_ep_enable(link->in_ep);
699 usb_ep_enable(link->out_ep);
700 }
701 }
702 spin_unlock_irqrestore(&dev->lock, flags);
703
704 return 0;
705}
706
707/*-------------------------------------------------------------------------*/
708
709/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
710static char *dev_addr;
711module_param(dev_addr, charp, S_IRUGO);
712MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
713
714/* this address is invisible to ifconfig */
715static char *host_addr;
716module_param(host_addr, charp, S_IRUGO);
717MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
718
719static int get_ether_addr(const char *str, u8 *dev_addr)
720{
721 if (str) {
722 unsigned i;
723
724 for (i = 0; i < 6; i++) {
725 unsigned char num;
726
727 if ((*str == '.') || (*str == ':'))
728 str++;
729 num = hex_to_bin(*str++) << 4;
730 num |= hex_to_bin(*str++);
731 dev_addr [i] = num;
732 }
733 if (is_valid_ether_addr(dev_addr))
734 return 0;
735 }
736 random_ether_addr(dev_addr);
737 return 1;
738}
739
740static struct eth_dev *the_dev;
741
742static const struct net_device_ops eth_netdev_ops = {
743 .ndo_open = eth_open,
744 .ndo_stop = eth_stop,
745 .ndo_start_xmit = eth_start_xmit,
746 .ndo_change_mtu = ueth_change_mtu,
747 .ndo_set_mac_address = eth_mac_addr,
748 .ndo_validate_addr = eth_validate_addr,
749};
750
751static struct device_type gadget_type = {
752 .name = "gadget",
753};
754
755/**
756 * gether_setup - initialize one ethernet-over-usb link
757 * @g: gadget to associated with these links
758 * @ethaddr: NULL, or a buffer in which the ethernet address of the
759 * host side of the link is recorded
760 * Context: may sleep
761 *
762 * This sets up the single network link that may be exported by a
763 * gadget driver using this framework. The link layer addresses are
764 * set up using module parameters.
765 *
766 * Returns negative errno, or zero on success
767 */
768int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
769{
770 struct eth_dev *dev;
771 struct net_device *net;
772 int status;
773
774 if (the_dev)
775 return -EBUSY;
776
777 net = alloc_etherdev(sizeof *dev);
778 if (!net)
779 return -ENOMEM;
780
781 dev = netdev_priv(net);
782 spin_lock_init(&dev->lock);
783 spin_lock_init(&dev->req_lock);
784 INIT_WORK(&dev->work, eth_work);
785 INIT_LIST_HEAD(&dev->tx_reqs);
786 INIT_LIST_HEAD(&dev->rx_reqs);
787
788 skb_queue_head_init(&dev->rx_frames);
789
790 /* network device setup */
791 dev->net = net;
792 strcpy(net->name, "usb%d");
793
794 if (get_ether_addr(dev_addr, net->dev_addr))
795 dev_warn(&g->dev,
796 "using random %s ethernet address\n", "self");
797 if (get_ether_addr(host_addr, dev->host_mac))
798 dev_warn(&g->dev,
799 "using random %s ethernet address\n", "host");
800
801 if (ethaddr)
802 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
803
804 net->netdev_ops = ð_netdev_ops;
805
806 SET_ETHTOOL_OPS(net, &ops);
807
808 /* two kinds of host-initiated state changes:
809 * - iff DATA transfer is active, carrier is "on"
810 * - tx queueing enabled if open *and* carrier is "on"
811 */
812 netif_carrier_off(net);
813
814 dev->gadget = g;
815 SET_NETDEV_DEV(net, &g->dev);
816 SET_NETDEV_DEVTYPE(net, &gadget_type);
817
818 status = register_netdev(net);
819 if (status < 0) {
820 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
821 free_netdev(net);
822 } else {
823 INFO(dev, "MAC %pM\n", net->dev_addr);
824 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
825
826 the_dev = dev;
827 }
828
829 return status;
830}
831
832/**
833 * gether_cleanup - remove Ethernet-over-USB device
834 * Context: may sleep
835 *
836 * This is called to free all resources allocated by @gether_setup().
837 */
838void gether_cleanup(void)
839{
840 if (!the_dev)
841 return;
842
843 unregister_netdev(the_dev->net);
844 flush_work_sync(&the_dev->work);
845 free_netdev(the_dev->net);
846
847 the_dev = NULL;
848}
849
850
851/**
852 * gether_connect - notify network layer that USB link is active
853 * @link: the USB link, set up with endpoints, descriptors matching
854 * current device speed, and any framing wrapper(s) set up.
855 * Context: irqs blocked
856 *
857 * This is called to activate endpoints and let the network layer know
858 * the connection is active ("carrier detect"). It may cause the I/O
859 * queues to open and start letting network packets flow, but will in
860 * any case activate the endpoints so that they respond properly to the
861 * USB host.
862 *
863 * Verify net_device pointer returned using IS_ERR(). If it doesn't
864 * indicate some error code (negative errno), ep->driver_data values
865 * have been overwritten.
866 */
867struct net_device *gether_connect(struct gether *link)
868{
869 struct eth_dev *dev = the_dev;
870 int result = 0;
871
872 if (!dev)
873 return ERR_PTR(-EINVAL);
874
875 link->in_ep->driver_data = dev;
876 result = usb_ep_enable(link->in_ep);
877 if (result != 0) {
878 DBG(dev, "enable %s --> %d\n",
879 link->in_ep->name, result);
880 goto fail0;
881 }
882
883 link->out_ep->driver_data = dev;
884 result = usb_ep_enable(link->out_ep);
885 if (result != 0) {
886 DBG(dev, "enable %s --> %d\n",
887 link->out_ep->name, result);
888 goto fail1;
889 }
890
891 if (result == 0)
892 result = alloc_requests(dev, link, qlen(dev->gadget));
893
894 if (result == 0) {
895 dev->zlp = link->is_zlp_ok;
896 DBG(dev, "qlen %d\n", qlen(dev->gadget));
897
898 dev->header_len = link->header_len;
899 dev->unwrap = link->unwrap;
900 dev->wrap = link->wrap;
901
902 spin_lock(&dev->lock);
903 dev->port_usb = link;
904 link->ioport = dev;
905 if (netif_running(dev->net)) {
906 if (link->open)
907 link->open(link);
908 } else {
909 if (link->close)
910 link->close(link);
911 }
912 spin_unlock(&dev->lock);
913
914 netif_carrier_on(dev->net);
915 if (netif_running(dev->net))
916 eth_start(dev, GFP_ATOMIC);
917
918 /* on error, disable any endpoints */
919 } else {
920 (void) usb_ep_disable(link->out_ep);
921fail1:
922 (void) usb_ep_disable(link->in_ep);
923 }
924fail0:
925 /* caller is responsible for cleanup on error */
926 if (result < 0)
927 return ERR_PTR(result);
928 return dev->net;
929}
930
931/**
932 * gether_disconnect - notify network layer that USB link is inactive
933 * @link: the USB link, on which gether_connect() was called
934 * Context: irqs blocked
935 *
936 * This is called to deactivate endpoints and let the network layer know
937 * the connection went inactive ("no carrier").
938 *
939 * On return, the state is as if gether_connect() had never been called.
940 * The endpoints are inactive, and accordingly without active USB I/O.
941 * Pointers to endpoint descriptors and endpoint private data are nulled.
942 */
943void gether_disconnect(struct gether *link)
944{
945 struct eth_dev *dev = link->ioport;
946 struct usb_request *req;
947
948 WARN_ON(!dev);
949 if (!dev)
950 return;
951
952 DBG(dev, "%s\n", __func__);
953
954 netif_stop_queue(dev->net);
955 netif_carrier_off(dev->net);
956
957 /* disable endpoints, forcing (synchronous) completion
958 * of all pending i/o. then free the request objects
959 * and forget about the endpoints.
960 */
961 usb_ep_disable(link->in_ep);
962 spin_lock(&dev->req_lock);
963 while (!list_empty(&dev->tx_reqs)) {
964 req = container_of(dev->tx_reqs.next,
965 struct usb_request, list);
966 list_del(&req->list);
967
968 spin_unlock(&dev->req_lock);
969 usb_ep_free_request(link->in_ep, req);
970 spin_lock(&dev->req_lock);
971 }
972 spin_unlock(&dev->req_lock);
973 link->in_ep->driver_data = NULL;
974 link->in_ep->desc = NULL;
975
976 usb_ep_disable(link->out_ep);
977 spin_lock(&dev->req_lock);
978 while (!list_empty(&dev->rx_reqs)) {
979 req = container_of(dev->rx_reqs.next,
980 struct usb_request, list);
981 list_del(&req->list);
982
983 spin_unlock(&dev->req_lock);
984 usb_ep_free_request(link->out_ep, req);
985 spin_lock(&dev->req_lock);
986 }
987 spin_unlock(&dev->req_lock);
988 link->out_ep->driver_data = NULL;
989 link->out_ep->desc = NULL;
990
991 /* finish forgetting about this USB link episode */
992 dev->header_len = 0;
993 dev->unwrap = NULL;
994 dev->wrap = NULL;
995
996 spin_lock(&dev->lock);
997 dev->port_usb = NULL;
998 link->ioport = NULL;
999 spin_unlock(&dev->lock);
1000}