/drivers/usb/gadget/u_ether.c
C | 1017 lines | 655 code | 165 blank | 197 comment | 114 complexity | 5be4e698f71167489d005149a670d8d6 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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 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 highspeed */
107static inline int qlen(struct usb_gadget *gadget)
108{
109 if (gadget_is_dualspeed(gadget) && gadget->speed == USB_SPEED_HIGH)
110 return qmult * DEFAULT_QLEN;
111 else
112 return DEFAULT_QLEN;
113}
114
115/*-------------------------------------------------------------------------*/
116
117/* REVISIT there must be a better way than having two sets
118 * of debug calls ...
119 */
120
121#undef DBG
122#undef VDBG
123#undef ERROR
124#undef INFO
125
126#define xprintk(d, level, fmt, args...) \
127 printk(level "%s: " fmt , (d)->net->name , ## args)
128
129#ifdef DEBUG
130#undef DEBUG
131#define DBG(dev, fmt, args...) \
132 xprintk(dev , KERN_DEBUG , fmt , ## args)
133#else
134#define DBG(dev, fmt, args...) \
135 do { } while (0)
136#endif /* DEBUG */
137
138#ifdef VERBOSE_DEBUG
139#define VDBG DBG
140#else
141#define VDBG(dev, fmt, args...) \
142 do { } while (0)
143#endif /* DEBUG */
144
145#define ERROR(dev, fmt, args...) \
146 xprintk(dev , KERN_ERR , fmt , ## args)
147#define INFO(dev, fmt, args...) \
148 xprintk(dev , KERN_INFO , fmt , ## args)
149
150/*-------------------------------------------------------------------------*/
151
152/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
153
154static int ueth_change_mtu(struct net_device *net, int new_mtu)
155{
156 struct eth_dev *dev = netdev_priv(net);
157 unsigned long flags;
158 int status = 0;
159
160 /* don't change MTU on "live" link (peer won't know) */
161 spin_lock_irqsave(&dev->lock, flags);
162 if (dev->port_usb)
163 status = -EBUSY;
164 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
165 status = -ERANGE;
166 else
167 net->mtu = new_mtu;
168 spin_unlock_irqrestore(&dev->lock, flags);
169
170 return status;
171}
172
173static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
174{
175 struct eth_dev *dev = netdev_priv(net);
176
177 strlcpy(p->driver, "g_ether", sizeof p->driver);
178 strlcpy(p->version, UETH__VERSION, sizeof p->version);
179 strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
180 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
181}
182
183/* REVISIT can also support:
184 * - WOL (by tracking suspends and issuing remote wakeup)
185 * - msglevel (implies updated messaging)
186 * - ... probably more ethtool ops
187 */
188
189static const struct ethtool_ops ops = {
190 .get_drvinfo = eth_get_drvinfo,
191 .get_link = ethtool_op_get_link,
192};
193
194static void defer_kevent(struct eth_dev *dev, int flag)
195{
196 if (test_and_set_bit(flag, &dev->todo))
197 return;
198 if (!schedule_work(&dev->work))
199 ERROR(dev, "kevent %d may have been dropped\n", flag);
200 else
201 DBG(dev, "kevent %d scheduled\n", flag);
202}
203
204static void rx_complete(struct usb_ep *ep, struct usb_request *req);
205
206static int
207rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
208{
209 struct sk_buff *skb;
210 int retval = -ENOMEM;
211 size_t size = 0;
212 struct usb_ep *out;
213 unsigned long flags;
214
215 spin_lock_irqsave(&dev->lock, flags);
216 if (dev->port_usb)
217 out = dev->port_usb->out_ep;
218 else
219 out = NULL;
220 spin_unlock_irqrestore(&dev->lock, flags);
221
222 if (!out)
223 return -ENOTCONN;
224
225
226 /* Padding up to RX_EXTRA handles minor disagreements with host.
227 * Normally we use the USB "terminate on short read" convention;
228 * so allow up to (N*maxpacket), since that memory is normally
229 * already allocated. Some hardware doesn't deal well with short
230 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
231 * byte off the end (to force hardware errors on overflow).
232 *
233 * RNDIS uses internal framing, and explicitly allows senders to
234 * pad to end-of-packet. That's potentially nice for speed, but
235 * means receivers can't recover lost synch on their own (because
236 * new packets don't only start after a short RX).
237 */
238 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
239 size += dev->port_usb->header_len;
240 size += out->maxpacket - 1;
241 size -= size % out->maxpacket;
242
243 if (dev->port_usb->is_fixed)
244 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
245
246 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
247 if (skb == NULL) {
248 DBG(dev, "no rx skb\n");
249 goto enomem;
250 }
251
252 /* Some platforms perform better when IP packets are aligned,
253 * but on at least one, checksumming fails otherwise. Note:
254 * RNDIS headers involve variable numbers of LE32 values.
255 */
256 skb_reserve(skb, NET_IP_ALIGN);
257
258 req->buf = skb->data;
259 req->length = size;
260 req->complete = rx_complete;
261 req->context = skb;
262
263 retval = usb_ep_queue(out, req, gfp_flags);
264 if (retval == -ENOMEM)
265enomem:
266 defer_kevent(dev, WORK_RX_MEMORY);
267 if (retval) {
268 DBG(dev, "rx submit --> %d\n", retval);
269 if (skb)
270 dev_kfree_skb_any(skb);
271 spin_lock_irqsave(&dev->req_lock, flags);
272 list_add(&req->list, &dev->rx_reqs);
273 spin_unlock_irqrestore(&dev->req_lock, flags);
274 }
275 return retval;
276}
277
278static void rx_complete(struct usb_ep *ep, struct usb_request *req)
279{
280 struct sk_buff *skb = req->context, *skb2;
281 struct eth_dev *dev = ep->driver_data;
282 int status = req->status;
283
284 switch (status) {
285
286 /* normal completion */
287 case 0:
288 skb_put(skb, req->actual);
289
290 if (dev->unwrap) {
291 unsigned long flags;
292
293 spin_lock_irqsave(&dev->lock, flags);
294 if (dev->port_usb) {
295 status = dev->unwrap(dev->port_usb,
296 skb,
297 &dev->rx_frames);
298 } else {
299 dev_kfree_skb_any(skb);
300 status = -ENOTCONN;
301 }
302 spin_unlock_irqrestore(&dev->lock, flags);
303 } else {
304 skb_queue_tail(&dev->rx_frames, skb);
305 }
306 skb = NULL;
307
308 skb2 = skb_dequeue(&dev->rx_frames);
309 while (skb2) {
310 if (status < 0
311 || ETH_HLEN > skb2->len
312 || skb2->len > ETH_FRAME_LEN) {
313 dev->net->stats.rx_errors++;
314 dev->net->stats.rx_length_errors++;
315 DBG(dev, "rx length %d\n", skb2->len);
316 dev_kfree_skb_any(skb2);
317 goto next_frame;
318 }
319 skb2->protocol = eth_type_trans(skb2, dev->net);
320 dev->net->stats.rx_packets++;
321 dev->net->stats.rx_bytes += skb2->len;
322
323 /* no buffer copies needed, unless hardware can't
324 * use skb buffers.
325 */
326 status = netif_rx(skb2);
327next_frame:
328 skb2 = skb_dequeue(&dev->rx_frames);
329 }
330 break;
331
332 /* software-driven interface shutdown */
333 case -ECONNRESET: /* unlink */
334 case -ESHUTDOWN: /* disconnect etc */
335 VDBG(dev, "rx shutdown, code %d\n", status);
336 goto quiesce;
337
338 /* for hardware automagic (such as pxa) */
339 case -ECONNABORTED: /* endpoint reset */
340 DBG(dev, "rx %s reset\n", ep->name);
341 defer_kevent(dev, WORK_RX_MEMORY);
342quiesce:
343 dev_kfree_skb_any(skb);
344 goto clean;
345
346 /* data overrun */
347 case -EOVERFLOW:
348 dev->net->stats.rx_over_errors++;
349 /* FALLTHROUGH */
350
351 default:
352 dev->net->stats.rx_errors++;
353 DBG(dev, "rx status %d\n", status);
354 break;
355 }
356
357 if (skb)
358 dev_kfree_skb_any(skb);
359 if (!netif_running(dev->net)) {
360clean:
361 spin_lock(&dev->req_lock);
362 list_add(&req->list, &dev->rx_reqs);
363 spin_unlock(&dev->req_lock);
364 req = NULL;
365 }
366 if (req)
367 rx_submit(dev, req, GFP_ATOMIC);
368}
369
370static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
371{
372 unsigned i;
373 struct usb_request *req;
374
375 if (!n)
376 return -ENOMEM;
377
378 /* queue/recycle up to N requests */
379 i = n;
380 list_for_each_entry(req, list, list) {
381 if (i-- == 0)
382 goto extra;
383 }
384 while (i--) {
385 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
386 if (!req)
387 return list_empty(list) ? -ENOMEM : 0;
388 list_add(&req->list, list);
389 }
390 return 0;
391
392extra:
393 /* free extras */
394 for (;;) {
395 struct list_head *next;
396
397 next = req->list.next;
398 list_del(&req->list);
399 usb_ep_free_request(ep, req);
400
401 if (next == list)
402 break;
403
404 req = container_of(next, struct usb_request, list);
405 }
406 return 0;
407}
408
409static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
410{
411 int status;
412
413 spin_lock(&dev->req_lock);
414 status = prealloc(&dev->tx_reqs, link->in_ep, n);
415 if (status < 0)
416 goto fail;
417 status = prealloc(&dev->rx_reqs, link->out_ep, n);
418 if (status < 0)
419 goto fail;
420 goto done;
421fail:
422 DBG(dev, "can't alloc requests\n");
423done:
424 spin_unlock(&dev->req_lock);
425 return status;
426}
427
428static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
429{
430 struct usb_request *req;
431 unsigned long flags;
432
433 /* fill unused rxq slots with some skb */
434 spin_lock_irqsave(&dev->req_lock, flags);
435 while (!list_empty(&dev->rx_reqs)) {
436 req = container_of(dev->rx_reqs.next,
437 struct usb_request, list);
438 list_del_init(&req->list);
439 spin_unlock_irqrestore(&dev->req_lock, flags);
440
441 if (rx_submit(dev, req, gfp_flags) < 0) {
442 defer_kevent(dev, WORK_RX_MEMORY);
443 return;
444 }
445
446 spin_lock_irqsave(&dev->req_lock, flags);
447 }
448 spin_unlock_irqrestore(&dev->req_lock, flags);
449}
450
451static void eth_work(struct work_struct *work)
452{
453 struct eth_dev *dev = container_of(work, struct eth_dev, work);
454
455 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
456 if (netif_running(dev->net))
457 rx_fill(dev, GFP_KERNEL);
458 }
459
460 if (dev->todo)
461 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
462}
463
464static void tx_complete(struct usb_ep *ep, struct usb_request *req)
465{
466 struct sk_buff *skb = req->context;
467 struct eth_dev *dev = ep->driver_data;
468
469 switch (req->status) {
470 default:
471 dev->net->stats.tx_errors++;
472 VDBG(dev, "tx err %d\n", req->status);
473 /* FALLTHROUGH */
474 case -ECONNRESET: /* unlink */
475 case -ESHUTDOWN: /* disconnect etc */
476 break;
477 case 0:
478 dev->net->stats.tx_bytes += skb->len;
479 }
480 dev->net->stats.tx_packets++;
481
482 spin_lock(&dev->req_lock);
483 list_add(&req->list, &dev->tx_reqs);
484 spin_unlock(&dev->req_lock);
485 dev_kfree_skb_any(skb);
486
487 atomic_dec(&dev->tx_qlen);
488 if (netif_carrier_ok(dev->net))
489 netif_wake_queue(dev->net);
490}
491
492static inline int is_promisc(u16 cdc_filter)
493{
494 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
495}
496
497static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
498 struct net_device *net)
499{
500 struct eth_dev *dev = netdev_priv(net);
501 int length = skb->len;
502 int retval;
503 struct usb_request *req = NULL;
504 unsigned long flags;
505 struct usb_ep *in;
506 u16 cdc_filter;
507
508 spin_lock_irqsave(&dev->lock, flags);
509 if (dev->port_usb) {
510 in = dev->port_usb->in_ep;
511 cdc_filter = dev->port_usb->cdc_filter;
512 } else {
513 in = NULL;
514 cdc_filter = 0;
515 }
516 spin_unlock_irqrestore(&dev->lock, flags);
517
518 if (!in) {
519 dev_kfree_skb_any(skb);
520 return NETDEV_TX_OK;
521 }
522
523 /* apply outgoing CDC or RNDIS filters */
524 if (!is_promisc(cdc_filter)) {
525 u8 *dest = skb->data;
526
527 if (is_multicast_ether_addr(dest)) {
528 u16 type;
529
530 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
531 * SET_ETHERNET_MULTICAST_FILTERS requests
532 */
533 if (is_broadcast_ether_addr(dest))
534 type = USB_CDC_PACKET_TYPE_BROADCAST;
535 else
536 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
537 if (!(cdc_filter & type)) {
538 dev_kfree_skb_any(skb);
539 return NETDEV_TX_OK;
540 }
541 }
542 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
543 }
544
545 spin_lock_irqsave(&dev->req_lock, flags);
546 /*
547 * this freelist can be empty if an interrupt triggered disconnect()
548 * and reconfigured the gadget (shutting down this queue) after the
549 * network stack decided to xmit but before we got the spinlock.
550 */
551 if (list_empty(&dev->tx_reqs)) {
552 spin_unlock_irqrestore(&dev->req_lock, flags);
553 return NETDEV_TX_BUSY;
554 }
555
556 req = container_of(dev->tx_reqs.next, struct usb_request, list);
557 list_del(&req->list);
558
559 /* temporarily stop TX queue when the freelist empties */
560 if (list_empty(&dev->tx_reqs))
561 netif_stop_queue(net);
562 spin_unlock_irqrestore(&dev->req_lock, flags);
563
564 /* no buffer copies needed, unless the network stack did it
565 * or the hardware can't use skb buffers.
566 * or there's not enough space for extra headers we need
567 */
568 if (dev->wrap) {
569 unsigned long flags;
570
571 spin_lock_irqsave(&dev->lock, flags);
572 if (dev->port_usb)
573 skb = dev->wrap(dev->port_usb, skb);
574 spin_unlock_irqrestore(&dev->lock, flags);
575 if (!skb)
576 goto drop;
577
578 length = skb->len;
579 }
580 req->buf = skb->data;
581 req->context = skb;
582 req->complete = tx_complete;
583
584 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
585 if (dev->port_usb->is_fixed &&
586 length == dev->port_usb->fixed_in_len &&
587 (length % in->maxpacket) == 0)
588 req->zero = 0;
589 else
590 req->zero = 1;
591
592 /* use zlp framing on tx for strict CDC-Ether conformance,
593 * though any robust network rx path ignores extra padding.
594 * and some hardware doesn't like to write zlps.
595 */
596 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
597 length++;
598
599 req->length = length;
600
601 /* throttle highspeed IRQ rate back slightly */
602 if (gadget_is_dualspeed(dev->gadget))
603 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
604 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
605 : 0;
606
607 retval = usb_ep_queue(in, req, GFP_ATOMIC);
608 switch (retval) {
609 default:
610 DBG(dev, "tx queue err %d\n", retval);
611 break;
612 case 0:
613 net->trans_start = jiffies;
614 atomic_inc(&dev->tx_qlen);
615 }
616
617 if (retval) {
618 dev_kfree_skb_any(skb);
619drop:
620 dev->net->stats.tx_dropped++;
621 spin_lock_irqsave(&dev->req_lock, flags);
622 if (list_empty(&dev->tx_reqs))
623 netif_start_queue(net);
624 list_add(&req->list, &dev->tx_reqs);
625 spin_unlock_irqrestore(&dev->req_lock, flags);
626 }
627 return NETDEV_TX_OK;
628}
629
630/*-------------------------------------------------------------------------*/
631
632static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
633{
634 DBG(dev, "%s\n", __func__);
635
636 /* fill the rx queue */
637 rx_fill(dev, gfp_flags);
638
639 /* and open the tx floodgates */
640 atomic_set(&dev->tx_qlen, 0);
641 netif_wake_queue(dev->net);
642}
643
644static int eth_open(struct net_device *net)
645{
646 struct eth_dev *dev = netdev_priv(net);
647 struct gether *link;
648
649 DBG(dev, "%s\n", __func__);
650 if (netif_carrier_ok(dev->net))
651 eth_start(dev, GFP_KERNEL);
652
653 spin_lock_irq(&dev->lock);
654 link = dev->port_usb;
655 if (link && link->open)
656 link->open(link);
657 spin_unlock_irq(&dev->lock);
658
659 return 0;
660}
661
662static int eth_stop(struct net_device *net)
663{
664 struct eth_dev *dev = netdev_priv(net);
665 unsigned long flags;
666
667 VDBG(dev, "%s\n", __func__);
668 netif_stop_queue(net);
669
670 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
671 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
672 dev->net->stats.rx_errors, dev->net->stats.tx_errors
673 );
674
675 /* ensure there are no more active requests */
676 spin_lock_irqsave(&dev->lock, flags);
677 if (dev->port_usb) {
678 struct gether *link = dev->port_usb;
679
680 if (link->close)
681 link->close(link);
682
683 /* NOTE: we have no abort-queue primitive we could use
684 * to cancel all pending I/O. Instead, we disable then
685 * reenable the endpoints ... this idiom may leave toggle
686 * wrong, but that's a self-correcting error.
687 *
688 * REVISIT: we *COULD* just let the transfers complete at
689 * their own pace; the network stack can handle old packets.
690 * For the moment we leave this here, since it works.
691 */
692 usb_ep_disable(link->in_ep);
693 usb_ep_disable(link->out_ep);
694 if (netif_carrier_ok(net)) {
695 DBG(dev, "host still using in/out endpoints\n");
696 usb_ep_enable(link->in_ep, link->in);
697 usb_ep_enable(link->out_ep, link->out);
698 }
699 }
700 spin_unlock_irqrestore(&dev->lock, flags);
701
702 return 0;
703}
704
705/*-------------------------------------------------------------------------*/
706
707/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
708static char *dev_addr;
709module_param(dev_addr, charp, S_IRUGO);
710MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
711
712/* this address is invisible to ifconfig */
713static char *host_addr;
714module_param(host_addr, charp, S_IRUGO);
715MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
716
717static int get_ether_addr(const char *str, u8 *dev_addr)
718{
719 if (str) {
720 unsigned i;
721
722 for (i = 0; i < 6; i++) {
723 unsigned char num;
724
725 if ((*str == '.') || (*str == ':'))
726 str++;
727 num = hex_to_bin(*str++) << 4;
728 num |= hex_to_bin(*str++);
729 dev_addr [i] = num;
730 }
731 if (is_valid_ether_addr(dev_addr))
732 return 0;
733 }
734 random_ether_addr(dev_addr);
735 return 1;
736}
737
738static struct eth_dev *the_dev;
739
740static const struct net_device_ops eth_netdev_ops = {
741 .ndo_open = eth_open,
742 .ndo_stop = eth_stop,
743 .ndo_start_xmit = eth_start_xmit,
744 .ndo_change_mtu = ueth_change_mtu,
745 .ndo_set_mac_address = eth_mac_addr,
746 .ndo_validate_addr = eth_validate_addr,
747};
748
749static struct device_type gadget_type = {
750 .name = "gadget",
751};
752
753/**
754 * gether_setup - initialize one ethernet-over-usb link
755 * @g: gadget to associated with these links
756 * @ethaddr: NULL, or a buffer in which the ethernet address of the
757 * host side of the link is recorded
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(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
767{
768 return gether_setup_name(g, ethaddr, "usb");
769}
770
771/**
772 * gether_setup_name - initialize one ethernet-over-usb link
773 * @g: gadget to associated with these links
774 * @ethaddr: NULL, or a buffer in which the ethernet address of the
775 * host side of the link is recorded
776 * @netname: name for network device (for example, "usb")
777 * Context: may sleep
778 *
779 * This sets up the single network link that may be exported by a
780 * gadget driver using this framework. The link layer addresses are
781 * set up using module parameters.
782 *
783 * Returns negative errno, or zero on success
784 */
785int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
786 const char *netname)
787{
788 struct eth_dev *dev;
789 struct net_device *net;
790 int status;
791
792 if (the_dev)
793 return -EBUSY;
794
795 net = alloc_etherdev(sizeof *dev);
796 if (!net)
797 return -ENOMEM;
798
799 dev = netdev_priv(net);
800 spin_lock_init(&dev->lock);
801 spin_lock_init(&dev->req_lock);
802 INIT_WORK(&dev->work, eth_work);
803 INIT_LIST_HEAD(&dev->tx_reqs);
804 INIT_LIST_HEAD(&dev->rx_reqs);
805
806 skb_queue_head_init(&dev->rx_frames);
807
808 /* network device setup */
809 dev->net = net;
810 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
811
812 if (get_ether_addr(dev_addr, net->dev_addr))
813 dev_warn(&g->dev,
814 "using random %s ethernet address\n", "self");
815 if (get_ether_addr(host_addr, dev->host_mac))
816 dev_warn(&g->dev,
817 "using random %s ethernet address\n", "host");
818
819 if (ethaddr)
820 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
821
822 net->netdev_ops = ð_netdev_ops;
823
824 SET_ETHTOOL_OPS(net, &ops);
825
826 /* two kinds of host-initiated state changes:
827 * - iff DATA transfer is active, carrier is "on"
828 * - tx queueing enabled if open *and* carrier is "on"
829 */
830 netif_carrier_off(net);
831
832 dev->gadget = g;
833 SET_NETDEV_DEV(net, &g->dev);
834 SET_NETDEV_DEVTYPE(net, &gadget_type);
835
836 status = register_netdev(net);
837 if (status < 0) {
838 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
839 free_netdev(net);
840 } else {
841 INFO(dev, "MAC %pM\n", net->dev_addr);
842 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
843
844 the_dev = dev;
845 }
846
847 return status;
848}
849
850/**
851 * gether_cleanup - remove Ethernet-over-USB device
852 * Context: may sleep
853 *
854 * This is called to free all resources allocated by @gether_setup().
855 */
856void gether_cleanup(void)
857{
858 if (!the_dev)
859 return;
860
861 unregister_netdev(the_dev->net);
862 flush_work_sync(&the_dev->work);
863 free_netdev(the_dev->net);
864
865 the_dev = NULL;
866}
867
868
869/**
870 * gether_connect - notify network layer that USB link is active
871 * @link: the USB link, set up with endpoints, descriptors matching
872 * current device speed, and any framing wrapper(s) set up.
873 * Context: irqs blocked
874 *
875 * This is called to activate endpoints and let the network layer know
876 * the connection is active ("carrier detect"). It may cause the I/O
877 * queues to open and start letting network packets flow, but will in
878 * any case activate the endpoints so that they respond properly to the
879 * USB host.
880 *
881 * Verify net_device pointer returned using IS_ERR(). If it doesn't
882 * indicate some error code (negative errno), ep->driver_data values
883 * have been overwritten.
884 */
885struct net_device *gether_connect(struct gether *link)
886{
887 struct eth_dev *dev = the_dev;
888 int result = 0;
889
890 if (!dev)
891 return ERR_PTR(-EINVAL);
892
893 link->in_ep->driver_data = dev;
894 result = usb_ep_enable(link->in_ep, link->in);
895 if (result != 0) {
896 DBG(dev, "enable %s --> %d\n",
897 link->in_ep->name, result);
898 goto fail0;
899 }
900
901 link->out_ep->driver_data = dev;
902 result = usb_ep_enable(link->out_ep, link->out);
903 if (result != 0) {
904 DBG(dev, "enable %s --> %d\n",
905 link->out_ep->name, result);
906 goto fail1;
907 }
908
909 if (result == 0)
910 result = alloc_requests(dev, link, qlen(dev->gadget));
911
912 if (result == 0) {
913 dev->zlp = link->is_zlp_ok;
914 DBG(dev, "qlen %d\n", qlen(dev->gadget));
915
916 dev->header_len = link->header_len;
917 dev->unwrap = link->unwrap;
918 dev->wrap = link->wrap;
919
920 spin_lock(&dev->lock);
921 dev->port_usb = link;
922 link->ioport = dev;
923 if (netif_running(dev->net)) {
924 if (link->open)
925 link->open(link);
926 } else {
927 if (link->close)
928 link->close(link);
929 }
930 spin_unlock(&dev->lock);
931
932 netif_carrier_on(dev->net);
933 if (netif_running(dev->net))
934 eth_start(dev, GFP_ATOMIC);
935
936 /* on error, disable any endpoints */
937 } else {
938 (void) usb_ep_disable(link->out_ep);
939fail1:
940 (void) usb_ep_disable(link->in_ep);
941 }
942fail0:
943 /* caller is responsible for cleanup on error */
944 if (result < 0)
945 return ERR_PTR(result);
946 return dev->net;
947}
948
949/**
950 * gether_disconnect - notify network layer that USB link is inactive
951 * @link: the USB link, on which gether_connect() was called
952 * Context: irqs blocked
953 *
954 * This is called to deactivate endpoints and let the network layer know
955 * the connection went inactive ("no carrier").
956 *
957 * On return, the state is as if gether_connect() had never been called.
958 * The endpoints are inactive, and accordingly without active USB I/O.
959 * Pointers to endpoint descriptors and endpoint private data are nulled.
960 */
961void gether_disconnect(struct gether *link)
962{
963 struct eth_dev *dev = link->ioport;
964 struct usb_request *req;
965
966 if (!dev)
967 return;
968
969 DBG(dev, "%s\n", __func__);
970
971 netif_stop_queue(dev->net);
972 netif_carrier_off(dev->net);
973
974 /* disable endpoints, forcing (synchronous) completion
975 * of all pending i/o. then free the request objects
976 * and forget about the endpoints.
977 */
978 usb_ep_disable(link->in_ep);
979 spin_lock(&dev->req_lock);
980 while (!list_empty(&dev->tx_reqs)) {
981 req = container_of(dev->tx_reqs.next,
982 struct usb_request, list);
983 list_del(&req->list);
984
985 spin_unlock(&dev->req_lock);
986 usb_ep_free_request(link->in_ep, req);
987 spin_lock(&dev->req_lock);
988 }
989 spin_unlock(&dev->req_lock);
990 link->in_ep->driver_data = NULL;
991 link->in = NULL;
992
993 usb_ep_disable(link->out_ep);
994 spin_lock(&dev->req_lock);
995 while (!list_empty(&dev->rx_reqs)) {
996 req = container_of(dev->rx_reqs.next,
997 struct usb_request, list);
998 list_del(&req->list);
999
1000 spin_unlock(&dev->req_lock);
1001 usb_ep_free_request(link->out_ep, req);
1002 spin_lock(&dev->req_lock);
1003 }
1004 spin_unlock(&dev->req_lock);
1005 link->out_ep->driver_data = NULL;
1006 link->out = NULL;
1007
1008 /* finish forgetting about this USB link episode */
1009 dev->header_len = 0;
1010 dev->unwrap = NULL;
1011 dev->wrap = NULL;
1012
1013 spin_lock(&dev->lock);
1014 dev->port_usb = NULL;
1015 link->ioport = NULL;
1016 spin_unlock(&dev->lock);
1017}