blob: f8751ff863cdfa0711e661812f4ed0bc066aae59 [file] [log] [blame]
David Brownell2b3d9422008-06-19 18:19:28 -07001/*
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/utsname.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
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050040 * connects to this code; such as CDC Ethernet (ECM or EEM),
41 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
42 * management.
David Brownell2b3d9422008-06-19 18:19:28 -070043 *
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
David Brownell8a1ce2c2008-08-18 17:43:56 -070056#define UETH__VERSION "29-May-2008"
David Brownell2b3d9422008-06-19 18:19:28 -070057
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
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050072 struct sk_buff_head rx_frames;
73
David Brownell2b3d9422008-06-19 18:19:28 -070074 unsigned header_len;
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050075 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);
David Brownell2b3d9422008-06-19 18:19:28 -070079
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
David Brownell2b3d9422008-06-19 18:19:28 -0700124#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)
David Brownell2b3d9422008-06-19 18:19:28 -0700147#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
Stephen Hemmingerccad6372008-11-19 22:42:31 -0800154static int ueth_change_mtu(struct net_device *net, int new_mtu)
David Brownell2b3d9422008-06-19 18:19:28 -0700155{
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);
David Brownell8a1ce2c2008-08-18 17:43:56 -0700178 strlcpy(p->version, UETH__VERSION, sizeof p->version);
David Brownell2b3d9422008-06-19 18:19:28 -0700179 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
David Brownell2b3d9422008-06-19 18:19:28 -0700183/* 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
Stephen Hemminger0fc0b732009-09-02 01:03:33 -0700189static const struct ethtool_ops ops = {
David Brownell2b3d9422008-06-19 18:19:28 -0700190 .get_drvinfo = eth_get_drvinfo,
Jonathan McDowell237e75b2009-03-26 00:45:27 -0700191 .get_link = ethtool_op_get_link,
David Brownell2b3d9422008-06-19 18:19:28 -0700192};
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 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
244 if (skb == NULL) {
245 DBG(dev, "no rx skb\n");
246 goto enomem;
247 }
248
249 /* Some platforms perform better when IP packets are aligned,
250 * but on at least one, checksumming fails otherwise. Note:
251 * RNDIS headers involve variable numbers of LE32 values.
252 */
253 skb_reserve(skb, NET_IP_ALIGN);
254
255 req->buf = skb->data;
256 req->length = size;
257 req->complete = rx_complete;
258 req->context = skb;
259
260 retval = usb_ep_queue(out, req, gfp_flags);
261 if (retval == -ENOMEM)
262enomem:
263 defer_kevent(dev, WORK_RX_MEMORY);
264 if (retval) {
265 DBG(dev, "rx submit --> %d\n", retval);
266 if (skb)
267 dev_kfree_skb_any(skb);
268 spin_lock_irqsave(&dev->req_lock, flags);
269 list_add(&req->list, &dev->rx_reqs);
270 spin_unlock_irqrestore(&dev->req_lock, flags);
271 }
272 return retval;
273}
274
275static void rx_complete(struct usb_ep *ep, struct usb_request *req)
276{
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500277 struct sk_buff *skb = req->context, *skb2;
David Brownell2b3d9422008-06-19 18:19:28 -0700278 struct eth_dev *dev = ep->driver_data;
279 int status = req->status;
280
281 switch (status) {
282
283 /* normal completion */
284 case 0:
285 skb_put(skb, req->actual);
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500286
287 if (dev->unwrap) {
288 unsigned long flags;
289
290 spin_lock_irqsave(&dev->lock, flags);
291 if (dev->port_usb) {
292 status = dev->unwrap(dev->port_usb,
293 skb,
294 &dev->rx_frames);
295 } else {
296 dev_kfree_skb_any(skb);
297 status = -ENOTCONN;
298 }
299 spin_unlock_irqrestore(&dev->lock, flags);
300 } else {
301 skb_queue_tail(&dev->rx_frames, skb);
David Brownell2b3d9422008-06-19 18:19:28 -0700302 }
David Brownell2b3d9422008-06-19 18:19:28 -0700303 skb = NULL;
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500304
305 skb2 = skb_dequeue(&dev->rx_frames);
306 while (skb2) {
307 if (status < 0
308 || ETH_HLEN > skb2->len
309 || skb2->len > ETH_FRAME_LEN) {
310 dev->net->stats.rx_errors++;
311 dev->net->stats.rx_length_errors++;
312 DBG(dev, "rx length %d\n", skb2->len);
313 dev_kfree_skb_any(skb2);
314 goto next_frame;
315 }
316 skb2->protocol = eth_type_trans(skb2, dev->net);
317 dev->net->stats.rx_packets++;
318 dev->net->stats.rx_bytes += skb2->len;
319
320 /* no buffer copies needed, unless hardware can't
321 * use skb buffers.
322 */
323 status = netif_rx(skb2);
324next_frame:
325 skb2 = skb_dequeue(&dev->rx_frames);
326 }
David Brownell2b3d9422008-06-19 18:19:28 -0700327 break;
328
329 /* software-driven interface shutdown */
330 case -ECONNRESET: /* unlink */
331 case -ESHUTDOWN: /* disconnect etc */
332 VDBG(dev, "rx shutdown, code %d\n", status);
333 goto quiesce;
334
335 /* for hardware automagic (such as pxa) */
336 case -ECONNABORTED: /* endpoint reset */
337 DBG(dev, "rx %s reset\n", ep->name);
338 defer_kevent(dev, WORK_RX_MEMORY);
339quiesce:
340 dev_kfree_skb_any(skb);
341 goto clean;
342
343 /* data overrun */
344 case -EOVERFLOW:
345 dev->net->stats.rx_over_errors++;
346 /* FALLTHROUGH */
347
348 default:
349 dev->net->stats.rx_errors++;
350 DBG(dev, "rx status %d\n", status);
351 break;
352 }
353
354 if (skb)
355 dev_kfree_skb_any(skb);
356 if (!netif_running(dev->net)) {
357clean:
358 spin_lock(&dev->req_lock);
359 list_add(&req->list, &dev->rx_reqs);
360 spin_unlock(&dev->req_lock);
361 req = NULL;
362 }
363 if (req)
364 rx_submit(dev, req, GFP_ATOMIC);
365}
366
367static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
368{
369 unsigned i;
370 struct usb_request *req;
371
372 if (!n)
373 return -ENOMEM;
374
375 /* queue/recycle up to N requests */
376 i = n;
377 list_for_each_entry(req, list, list) {
378 if (i-- == 0)
379 goto extra;
380 }
381 while (i--) {
382 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
383 if (!req)
384 return list_empty(list) ? -ENOMEM : 0;
385 list_add(&req->list, list);
386 }
387 return 0;
388
389extra:
390 /* free extras */
391 for (;;) {
392 struct list_head *next;
393
394 next = req->list.next;
395 list_del(&req->list);
396 usb_ep_free_request(ep, req);
397
398 if (next == list)
399 break;
400
401 req = container_of(next, struct usb_request, list);
402 }
403 return 0;
404}
405
406static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
407{
408 int status;
409
410 spin_lock(&dev->req_lock);
411 status = prealloc(&dev->tx_reqs, link->in_ep, n);
412 if (status < 0)
413 goto fail;
414 status = prealloc(&dev->rx_reqs, link->out_ep, n);
415 if (status < 0)
416 goto fail;
417 goto done;
418fail:
419 DBG(dev, "can't alloc requests\n");
420done:
421 spin_unlock(&dev->req_lock);
422 return status;
423}
424
425static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
426{
427 struct usb_request *req;
428 unsigned long flags;
429
430 /* fill unused rxq slots with some skb */
431 spin_lock_irqsave(&dev->req_lock, flags);
432 while (!list_empty(&dev->rx_reqs)) {
433 req = container_of(dev->rx_reqs.next,
434 struct usb_request, list);
435 list_del_init(&req->list);
436 spin_unlock_irqrestore(&dev->req_lock, flags);
437
438 if (rx_submit(dev, req, gfp_flags) < 0) {
439 defer_kevent(dev, WORK_RX_MEMORY);
440 return;
441 }
442
443 spin_lock_irqsave(&dev->req_lock, flags);
444 }
445 spin_unlock_irqrestore(&dev->req_lock, flags);
446}
447
448static void eth_work(struct work_struct *work)
449{
450 struct eth_dev *dev = container_of(work, struct eth_dev, work);
451
452 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
453 if (netif_running(dev->net))
454 rx_fill(dev, GFP_KERNEL);
455 }
456
457 if (dev->todo)
458 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
459}
460
461static void tx_complete(struct usb_ep *ep, struct usb_request *req)
462{
463 struct sk_buff *skb = req->context;
464 struct eth_dev *dev = ep->driver_data;
465
466 switch (req->status) {
467 default:
468 dev->net->stats.tx_errors++;
469 VDBG(dev, "tx err %d\n", req->status);
470 /* FALLTHROUGH */
471 case -ECONNRESET: /* unlink */
472 case -ESHUTDOWN: /* disconnect etc */
473 break;
474 case 0:
475 dev->net->stats.tx_bytes += skb->len;
476 }
477 dev->net->stats.tx_packets++;
478
479 spin_lock(&dev->req_lock);
480 list_add(&req->list, &dev->tx_reqs);
481 spin_unlock(&dev->req_lock);
482 dev_kfree_skb_any(skb);
483
484 atomic_dec(&dev->tx_qlen);
485 if (netif_carrier_ok(dev->net))
486 netif_wake_queue(dev->net);
487}
488
489static inline int is_promisc(u16 cdc_filter)
490{
491 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
492}
493
Stephen Hemminger25a79c42009-08-31 19:50:45 +0000494static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
495 struct net_device *net)
David Brownell2b3d9422008-06-19 18:19:28 -0700496{
497 struct eth_dev *dev = netdev_priv(net);
498 int length = skb->len;
499 int retval;
500 struct usb_request *req = NULL;
501 unsigned long flags;
502 struct usb_ep *in;
503 u16 cdc_filter;
504
505 spin_lock_irqsave(&dev->lock, flags);
506 if (dev->port_usb) {
507 in = dev->port_usb->in_ep;
508 cdc_filter = dev->port_usb->cdc_filter;
509 } else {
510 in = NULL;
511 cdc_filter = 0;
512 }
513 spin_unlock_irqrestore(&dev->lock, flags);
514
515 if (!in) {
516 dev_kfree_skb_any(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000517 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700518 }
519
520 /* apply outgoing CDC or RNDIS filters */
521 if (!is_promisc(cdc_filter)) {
522 u8 *dest = skb->data;
523
524 if (is_multicast_ether_addr(dest)) {
525 u16 type;
526
527 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
528 * SET_ETHERNET_MULTICAST_FILTERS requests
529 */
530 if (is_broadcast_ether_addr(dest))
531 type = USB_CDC_PACKET_TYPE_BROADCAST;
532 else
533 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
534 if (!(cdc_filter & type)) {
535 dev_kfree_skb_any(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000536 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700537 }
538 }
539 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
540 }
541
542 spin_lock_irqsave(&dev->req_lock, flags);
543 /*
544 * this freelist can be empty if an interrupt triggered disconnect()
545 * and reconfigured the gadget (shutting down this queue) after the
546 * network stack decided to xmit but before we got the spinlock.
547 */
548 if (list_empty(&dev->tx_reqs)) {
549 spin_unlock_irqrestore(&dev->req_lock, flags);
Patrick McHardy5b548142009-06-12 06:22:29 +0000550 return NETDEV_TX_BUSY;
David Brownell2b3d9422008-06-19 18:19:28 -0700551 }
552
553 req = container_of(dev->tx_reqs.next, struct usb_request, list);
554 list_del(&req->list);
555
556 /* temporarily stop TX queue when the freelist empties */
557 if (list_empty(&dev->tx_reqs))
558 netif_stop_queue(net);
559 spin_unlock_irqrestore(&dev->req_lock, flags);
560
561 /* no buffer copies needed, unless the network stack did it
562 * or the hardware can't use skb buffers.
563 * or there's not enough space for extra headers we need
564 */
565 if (dev->wrap) {
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500566 unsigned long flags;
David Brownell2b3d9422008-06-19 18:19:28 -0700567
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500568 spin_lock_irqsave(&dev->lock, flags);
569 if (dev->port_usb)
570 skb = dev->wrap(dev->port_usb, skb);
571 spin_unlock_irqrestore(&dev->lock, flags);
572 if (!skb)
David Brownell2b3d9422008-06-19 18:19:28 -0700573 goto drop;
574
David Brownell2b3d9422008-06-19 18:19:28 -0700575 length = skb->len;
576 }
577 req->buf = skb->data;
578 req->context = skb;
579 req->complete = tx_complete;
580
581 /* use zlp framing on tx for strict CDC-Ether conformance,
582 * though any robust network rx path ignores extra padding.
583 * and some hardware doesn't like to write zlps.
584 */
585 req->zero = 1;
586 if (!dev->zlp && (length % in->maxpacket) == 0)
587 length++;
588
589 req->length = length;
590
591 /* throttle highspeed IRQ rate back slightly */
592 if (gadget_is_dualspeed(dev->gadget))
593 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
594 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
595 : 0;
596
597 retval = usb_ep_queue(in, req, GFP_ATOMIC);
598 switch (retval) {
599 default:
600 DBG(dev, "tx queue err %d\n", retval);
601 break;
602 case 0:
603 net->trans_start = jiffies;
604 atomic_inc(&dev->tx_qlen);
605 }
606
607 if (retval) {
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500608 dev_kfree_skb_any(skb);
David Brownell2b3d9422008-06-19 18:19:28 -0700609drop:
610 dev->net->stats.tx_dropped++;
David Brownell2b3d9422008-06-19 18:19:28 -0700611 spin_lock_irqsave(&dev->req_lock, flags);
612 if (list_empty(&dev->tx_reqs))
613 netif_start_queue(net);
614 list_add(&req->list, &dev->tx_reqs);
615 spin_unlock_irqrestore(&dev->req_lock, flags);
616 }
Patrick McHardy6ed10652009-06-23 06:03:08 +0000617 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700618}
619
620/*-------------------------------------------------------------------------*/
621
622static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
623{
624 DBG(dev, "%s\n", __func__);
625
626 /* fill the rx queue */
627 rx_fill(dev, gfp_flags);
628
629 /* and open the tx floodgates */
630 atomic_set(&dev->tx_qlen, 0);
631 netif_wake_queue(dev->net);
632}
633
634static int eth_open(struct net_device *net)
635{
636 struct eth_dev *dev = netdev_priv(net);
637 struct gether *link;
638
639 DBG(dev, "%s\n", __func__);
640 if (netif_carrier_ok(dev->net))
641 eth_start(dev, GFP_KERNEL);
642
643 spin_lock_irq(&dev->lock);
644 link = dev->port_usb;
645 if (link && link->open)
646 link->open(link);
647 spin_unlock_irq(&dev->lock);
648
649 return 0;
650}
651
652static int eth_stop(struct net_device *net)
653{
654 struct eth_dev *dev = netdev_priv(net);
655 unsigned long flags;
656
657 VDBG(dev, "%s\n", __func__);
658 netif_stop_queue(net);
659
660 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
661 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
662 dev->net->stats.rx_errors, dev->net->stats.tx_errors
663 );
664
665 /* ensure there are no more active requests */
666 spin_lock_irqsave(&dev->lock, flags);
667 if (dev->port_usb) {
668 struct gether *link = dev->port_usb;
669
670 if (link->close)
671 link->close(link);
672
673 /* NOTE: we have no abort-queue primitive we could use
674 * to cancel all pending I/O. Instead, we disable then
675 * reenable the endpoints ... this idiom may leave toggle
676 * wrong, but that's a self-correcting error.
677 *
678 * REVISIT: we *COULD* just let the transfers complete at
679 * their own pace; the network stack can handle old packets.
680 * For the moment we leave this here, since it works.
681 */
682 usb_ep_disable(link->in_ep);
683 usb_ep_disable(link->out_ep);
684 if (netif_carrier_ok(net)) {
685 DBG(dev, "host still using in/out endpoints\n");
686 usb_ep_enable(link->in_ep, link->in);
687 usb_ep_enable(link->out_ep, link->out);
688 }
689 }
690 spin_unlock_irqrestore(&dev->lock, flags);
691
692 return 0;
693}
694
695/*-------------------------------------------------------------------------*/
696
697/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
698static char *dev_addr;
699module_param(dev_addr, charp, S_IRUGO);
700MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
701
702/* this address is invisible to ifconfig */
703static char *host_addr;
704module_param(host_addr, charp, S_IRUGO);
705MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
706
707
708static u8 __init nibble(unsigned char c)
709{
710 if (isdigit(c))
711 return c - '0';
712 c = toupper(c);
713 if (isxdigit(c))
714 return 10 + c - 'A';
715 return 0;
716}
717
718static int __init get_ether_addr(const char *str, u8 *dev_addr)
719{
720 if (str) {
721 unsigned i;
722
723 for (i = 0; i < 6; i++) {
724 unsigned char num;
725
726 if ((*str == '.') || (*str == ':'))
727 str++;
728 num = nibble(*str++) << 4;
729 num |= (nibble(*str++));
730 dev_addr [i] = num;
731 }
732 if (is_valid_ether_addr(dev_addr))
733 return 0;
734 }
735 random_ether_addr(dev_addr);
736 return 1;
737}
738
739static struct eth_dev *the_dev;
740
Stephen Hemminger5ec38f32009-01-07 18:05:39 -0800741static const struct net_device_ops eth_netdev_ops = {
742 .ndo_open = eth_open,
743 .ndo_stop = eth_stop,
744 .ndo_start_xmit = eth_start_xmit,
745 .ndo_change_mtu = ueth_change_mtu,
746 .ndo_set_mac_address = eth_mac_addr,
747 .ndo_validate_addr = eth_validate_addr,
748};
David Brownell2b3d9422008-06-19 18:19:28 -0700749
750/**
751 * gether_setup - initialize one ethernet-over-usb link
752 * @g: gadget to associated with these links
753 * @ethaddr: NULL, or a buffer in which the ethernet address of the
754 * host side of the link is recorded
755 * Context: may sleep
756 *
757 * This sets up the single network link that may be exported by a
758 * gadget driver using this framework. The link layer addresses are
759 * set up using module parameters.
760 *
761 * Returns negative errno, or zero on success
762 */
763int __init gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
764{
765 struct eth_dev *dev;
766 struct net_device *net;
767 int status;
768
769 if (the_dev)
770 return -EBUSY;
771
772 net = alloc_etherdev(sizeof *dev);
773 if (!net)
774 return -ENOMEM;
775
776 dev = netdev_priv(net);
777 spin_lock_init(&dev->lock);
778 spin_lock_init(&dev->req_lock);
779 INIT_WORK(&dev->work, eth_work);
780 INIT_LIST_HEAD(&dev->tx_reqs);
781 INIT_LIST_HEAD(&dev->rx_reqs);
782
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500783 skb_queue_head_init(&dev->rx_frames);
784
David Brownell2b3d9422008-06-19 18:19:28 -0700785 /* network device setup */
786 dev->net = net;
787 strcpy(net->name, "usb%d");
788
789 if (get_ether_addr(dev_addr, net->dev_addr))
790 dev_warn(&g->dev,
791 "using random %s ethernet address\n", "self");
792 if (get_ether_addr(host_addr, dev->host_mac))
793 dev_warn(&g->dev,
794 "using random %s ethernet address\n", "host");
795
796 if (ethaddr)
797 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
798
Stephen Hemminger5ec38f32009-01-07 18:05:39 -0800799 net->netdev_ops = &eth_netdev_ops;
800
David Brownell2b3d9422008-06-19 18:19:28 -0700801 SET_ETHTOOL_OPS(net, &ops);
802
803 /* two kinds of host-initiated state changes:
804 * - iff DATA transfer is active, carrier is "on"
805 * - tx queueing enabled if open *and* carrier is "on"
806 */
807 netif_stop_queue(net);
808 netif_carrier_off(net);
809
810 dev->gadget = g;
811 SET_NETDEV_DEV(net, &g->dev);
812
813 status = register_netdev(net);
814 if (status < 0) {
815 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
816 free_netdev(net);
817 } else {
Johannes Berge1749612008-10-27 15:59:26 -0700818 INFO(dev, "MAC %pM\n", net->dev_addr);
819 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
David Brownell2b3d9422008-06-19 18:19:28 -0700820
821 the_dev = dev;
822 }
823
824 return status;
825}
826
827/**
828 * gether_cleanup - remove Ethernet-over-USB device
829 * Context: may sleep
830 *
831 * This is called to free all resources allocated by @gether_setup().
832 */
833void gether_cleanup(void)
834{
835 if (!the_dev)
836 return;
837
838 unregister_netdev(the_dev->net);
839 free_netdev(the_dev->net);
840
841 /* assuming we used keventd, it must quiesce too */
842 flush_scheduled_work();
843
844 the_dev = NULL;
845}
846
847
848/**
849 * gether_connect - notify network layer that USB link is active
850 * @link: the USB link, set up with endpoints, descriptors matching
851 * current device speed, and any framing wrapper(s) set up.
852 * Context: irqs blocked
853 *
854 * This is called to activate endpoints and let the network layer know
855 * the connection is active ("carrier detect"). It may cause the I/O
856 * queues to open and start letting network packets flow, but will in
857 * any case activate the endpoints so that they respond properly to the
858 * USB host.
859 *
860 * Verify net_device pointer returned using IS_ERR(). If it doesn't
861 * indicate some error code (negative errno), ep->driver_data values
862 * have been overwritten.
863 */
864struct net_device *gether_connect(struct gether *link)
865{
866 struct eth_dev *dev = the_dev;
867 int result = 0;
868
869 if (!dev)
870 return ERR_PTR(-EINVAL);
871
872 link->in_ep->driver_data = dev;
873 result = usb_ep_enable(link->in_ep, link->in);
874 if (result != 0) {
875 DBG(dev, "enable %s --> %d\n",
876 link->in_ep->name, result);
877 goto fail0;
878 }
879
880 link->out_ep->driver_data = dev;
881 result = usb_ep_enable(link->out_ep, link->out);
882 if (result != 0) {
883 DBG(dev, "enable %s --> %d\n",
884 link->out_ep->name, result);
885 goto fail1;
886 }
887
888 if (result == 0)
889 result = alloc_requests(dev, link, qlen(dev->gadget));
890
891 if (result == 0) {
892 dev->zlp = link->is_zlp_ok;
893 DBG(dev, "qlen %d\n", qlen(dev->gadget));
894
895 dev->header_len = link->header_len;
896 dev->unwrap = link->unwrap;
897 dev->wrap = link->wrap;
898
899 spin_lock(&dev->lock);
900 dev->port_usb = link;
901 link->ioport = dev;
David Brownell29bac7b2008-09-06 21:33:49 -0700902 if (netif_running(dev->net)) {
903 if (link->open)
904 link->open(link);
905 } else {
906 if (link->close)
907 link->close(link);
908 }
David Brownell2b3d9422008-06-19 18:19:28 -0700909 spin_unlock(&dev->lock);
910
911 netif_carrier_on(dev->net);
912 if (netif_running(dev->net))
913 eth_start(dev, GFP_ATOMIC);
914
915 /* on error, disable any endpoints */
916 } else {
917 (void) usb_ep_disable(link->out_ep);
918fail1:
919 (void) usb_ep_disable(link->in_ep);
920 }
921fail0:
922 /* caller is responsible for cleanup on error */
923 if (result < 0)
924 return ERR_PTR(result);
925 return dev->net;
926}
927
928/**
929 * gether_disconnect - notify network layer that USB link is inactive
930 * @link: the USB link, on which gether_connect() was called
931 * Context: irqs blocked
932 *
933 * This is called to deactivate endpoints and let the network layer know
934 * the connection went inactive ("no carrier").
935 *
936 * On return, the state is as if gether_connect() had never been called.
937 * The endpoints are inactive, and accordingly without active USB I/O.
938 * Pointers to endpoint descriptors and endpoint private data are nulled.
939 */
940void gether_disconnect(struct gether *link)
941{
942 struct eth_dev *dev = link->ioport;
943 struct usb_request *req;
944
945 WARN_ON(!dev);
946 if (!dev)
947 return;
948
949 DBG(dev, "%s\n", __func__);
950
951 netif_stop_queue(dev->net);
952 netif_carrier_off(dev->net);
953
954 /* disable endpoints, forcing (synchronous) completion
955 * of all pending i/o. then free the request objects
956 * and forget about the endpoints.
957 */
958 usb_ep_disable(link->in_ep);
959 spin_lock(&dev->req_lock);
960 while (!list_empty(&dev->tx_reqs)) {
961 req = container_of(dev->tx_reqs.next,
962 struct usb_request, list);
963 list_del(&req->list);
964
965 spin_unlock(&dev->req_lock);
966 usb_ep_free_request(link->in_ep, req);
967 spin_lock(&dev->req_lock);
968 }
969 spin_unlock(&dev->req_lock);
970 link->in_ep->driver_data = NULL;
971 link->in = NULL;
972
973 usb_ep_disable(link->out_ep);
974 spin_lock(&dev->req_lock);
975 while (!list_empty(&dev->rx_reqs)) {
976 req = container_of(dev->rx_reqs.next,
977 struct usb_request, list);
978 list_del(&req->list);
979
980 spin_unlock(&dev->req_lock);
981 usb_ep_free_request(link->out_ep, req);
982 spin_lock(&dev->req_lock);
983 }
984 spin_unlock(&dev->req_lock);
985 link->out_ep->driver_data = NULL;
986 link->out = NULL;
987
988 /* finish forgetting about this USB link episode */
989 dev->header_len = 0;
990 dev->unwrap = NULL;
991 dev->wrap = NULL;
992
993 spin_lock(&dev->lock);
994 dev->port_usb = NULL;
995 link->ioport = NULL;
996 spin_unlock(&dev->lock);
997}