blob: a0aa721d8b216bb29350be51270a9e4c6330eaed [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.
David Brownell2b3d9422008-06-19 18:19:28 -070012 */
13
14/* #define VERBOSE_DEBUG */
15
16#include <linux/kernel.h>
Sebastian Andrzej Siewior98303172012-09-10 16:30:50 +020017#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/gfp.h>
David Brownell2b3d9422008-06-19 18:19:28 -070019#include <linux/device.h>
20#include <linux/ctype.h>
21#include <linux/etherdevice.h>
22#include <linux/ethtool.h>
Ian Coolidge4fe5f072012-11-07 14:39:18 +000023#include <linux/if_vlan.h>
David Brownell2b3d9422008-06-19 18:19:28 -070024
25#include "u_ether.h"
26
27
28/*
29 * This component encapsulates the Ethernet link glue needed to provide
30 * one (!) network link through the USB gadget stack, normally "usb0".
31 *
32 * The control and data models are handled by the function driver which
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050033 * connects to this code; such as CDC Ethernet (ECM or EEM),
34 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
35 * management.
David Brownell2b3d9422008-06-19 18:19:28 -070036 *
37 * Link level addressing is handled by this component using module
38 * parameters; if no such parameters are provided, random link level
39 * addresses are used. Each end of the link uses one address. The
40 * host end address is exported in various ways, and is often recorded
41 * in configuration databases.
42 *
43 * The driver which assembles each configuration using such a link is
44 * responsible for ensuring that each configuration includes at most one
45 * instance of is network link. (The network layer provides ways for
46 * this single "physical" link to be used by multiple virtual links.)
47 */
48
David Brownell8a1ce2c2008-08-18 17:43:56 -070049#define UETH__VERSION "29-May-2008"
David Brownell2b3d9422008-06-19 18:19:28 -070050
51struct eth_dev {
52 /* lock is held while accessing port_usb
53 * or updating its backlink port_usb->ioport
54 */
55 spinlock_t lock;
56 struct gether *port_usb;
57
58 struct net_device *net;
59 struct usb_gadget *gadget;
60
61 spinlock_t req_lock; /* guard {rx,tx}_reqs */
62 struct list_head tx_reqs, rx_reqs;
63 atomic_t tx_qlen;
64
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050065 struct sk_buff_head rx_frames;
66
David Brownell2b3d9422008-06-19 18:19:28 -070067 unsigned header_len;
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -050068 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
69 int (*unwrap)(struct gether *,
70 struct sk_buff *skb,
71 struct sk_buff_head *list);
David Brownell2b3d9422008-06-19 18:19:28 -070072
73 struct work_struct work;
74
75 unsigned long todo;
76#define WORK_RX_MEMORY 0
77
78 bool zlp;
79 u8 host_mac[ETH_ALEN];
80};
81
82/*-------------------------------------------------------------------------*/
83
84#define RX_EXTRA 20 /* bytes guarding against rx overflows */
85
86#define DEFAULT_QLEN 2 /* double buffering by default */
87
David Brownell2b3d9422008-06-19 18:19:28 -070088static unsigned qmult = 5;
89module_param(qmult, uint, S_IRUGO|S_IWUSR);
Paul Zimmerman04617db2011-06-27 14:13:18 -070090MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
David Brownell2b3d9422008-06-19 18:19:28 -070091
Paul Zimmerman04617db2011-06-27 14:13:18 -070092/* for dual-speed hardware, use deeper queues at high/super speed */
David Brownell2b3d9422008-06-19 18:19:28 -070093static inline int qlen(struct usb_gadget *gadget)
94{
Paul Zimmerman04617db2011-06-27 14:13:18 -070095 if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
96 gadget->speed == USB_SPEED_SUPER))
David Brownell2b3d9422008-06-19 18:19:28 -070097 return qmult * DEFAULT_QLEN;
98 else
99 return DEFAULT_QLEN;
100}
101
102/*-------------------------------------------------------------------------*/
103
104/* REVISIT there must be a better way than having two sets
105 * of debug calls ...
106 */
107
108#undef DBG
109#undef VDBG
110#undef ERROR
David Brownell2b3d9422008-06-19 18:19:28 -0700111#undef INFO
112
113#define xprintk(d, level, fmt, args...) \
114 printk(level "%s: " fmt , (d)->net->name , ## args)
115
116#ifdef DEBUG
117#undef DEBUG
118#define DBG(dev, fmt, args...) \
119 xprintk(dev , KERN_DEBUG , fmt , ## args)
120#else
121#define DBG(dev, fmt, args...) \
122 do { } while (0)
123#endif /* DEBUG */
124
125#ifdef VERBOSE_DEBUG
126#define VDBG DBG
127#else
128#define VDBG(dev, fmt, args...) \
129 do { } while (0)
130#endif /* DEBUG */
131
132#define ERROR(dev, fmt, args...) \
133 xprintk(dev , KERN_ERR , fmt , ## args)
David Brownell2b3d9422008-06-19 18:19:28 -0700134#define INFO(dev, fmt, args...) \
135 xprintk(dev , KERN_INFO , fmt , ## args)
136
137/*-------------------------------------------------------------------------*/
138
139/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
140
Stephen Hemmingerccad6372008-11-19 22:42:31 -0800141static int ueth_change_mtu(struct net_device *net, int new_mtu)
David Brownell2b3d9422008-06-19 18:19:28 -0700142{
143 struct eth_dev *dev = netdev_priv(net);
144 unsigned long flags;
145 int status = 0;
146
147 /* don't change MTU on "live" link (peer won't know) */
148 spin_lock_irqsave(&dev->lock, flags);
149 if (dev->port_usb)
150 status = -EBUSY;
151 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
152 status = -ERANGE;
153 else
154 net->mtu = new_mtu;
155 spin_unlock_irqrestore(&dev->lock, flags);
156
157 return status;
158}
159
160static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
161{
Jiri Pirko7826d432013-01-06 00:44:26 +0000162 struct eth_dev *dev = netdev_priv(net);
David Brownell2b3d9422008-06-19 18:19:28 -0700163
Jiri Pirko7826d432013-01-06 00:44:26 +0000164 strlcpy(p->driver, "g_ether", sizeof(p->driver));
165 strlcpy(p->version, UETH__VERSION, sizeof(p->version));
166 strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
167 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
David Brownell2b3d9422008-06-19 18:19:28 -0700168}
169
David Brownell2b3d9422008-06-19 18:19:28 -0700170/* REVISIT can also support:
171 * - WOL (by tracking suspends and issuing remote wakeup)
172 * - msglevel (implies updated messaging)
173 * - ... probably more ethtool ops
174 */
175
Stephen Hemminger0fc0b732009-09-02 01:03:33 -0700176static const struct ethtool_ops ops = {
David Brownell2b3d9422008-06-19 18:19:28 -0700177 .get_drvinfo = eth_get_drvinfo,
Jonathan McDowell237e75b2009-03-26 00:45:27 -0700178 .get_link = ethtool_op_get_link,
David Brownell2b3d9422008-06-19 18:19:28 -0700179};
180
181static void defer_kevent(struct eth_dev *dev, int flag)
182{
183 if (test_and_set_bit(flag, &dev->todo))
184 return;
185 if (!schedule_work(&dev->work))
186 ERROR(dev, "kevent %d may have been dropped\n", flag);
187 else
188 DBG(dev, "kevent %d scheduled\n", flag);
189}
190
191static void rx_complete(struct usb_ep *ep, struct usb_request *req);
192
193static int
194rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
195{
196 struct sk_buff *skb;
197 int retval = -ENOMEM;
198 size_t size = 0;
199 struct usb_ep *out;
200 unsigned long flags;
201
202 spin_lock_irqsave(&dev->lock, flags);
203 if (dev->port_usb)
204 out = dev->port_usb->out_ep;
205 else
206 out = NULL;
207 spin_unlock_irqrestore(&dev->lock, flags);
208
209 if (!out)
210 return -ENOTCONN;
211
212
213 /* Padding up to RX_EXTRA handles minor disagreements with host.
214 * Normally we use the USB "terminate on short read" convention;
215 * so allow up to (N*maxpacket), since that memory is normally
216 * already allocated. Some hardware doesn't deal well with short
217 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
218 * byte off the end (to force hardware errors on overflow).
219 *
220 * RNDIS uses internal framing, and explicitly allows senders to
221 * pad to end-of-packet. That's potentially nice for speed, but
222 * means receivers can't recover lost synch on their own (because
223 * new packets don't only start after a short RX).
224 */
225 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
226 size += dev->port_usb->header_len;
227 size += out->maxpacket - 1;
228 size -= size % out->maxpacket;
229
Yauheni Kaliuta5c1168d2010-12-08 13:12:04 +0200230 if (dev->port_usb->is_fixed)
Stephen Hemminger45d1b7a2011-03-01 22:40:57 -0800231 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
Yauheni Kaliuta5c1168d2010-12-08 13:12:04 +0200232
David Brownell2b3d9422008-06-19 18:19:28 -0700233 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
234 if (skb == NULL) {
235 DBG(dev, "no rx skb\n");
236 goto enomem;
237 }
238
239 /* Some platforms perform better when IP packets are aligned,
240 * but on at least one, checksumming fails otherwise. Note:
241 * RNDIS headers involve variable numbers of LE32 values.
242 */
243 skb_reserve(skb, NET_IP_ALIGN);
244
245 req->buf = skb->data;
246 req->length = size;
247 req->complete = rx_complete;
248 req->context = skb;
249
250 retval = usb_ep_queue(out, req, gfp_flags);
251 if (retval == -ENOMEM)
252enomem:
253 defer_kevent(dev, WORK_RX_MEMORY);
254 if (retval) {
255 DBG(dev, "rx submit --> %d\n", retval);
256 if (skb)
257 dev_kfree_skb_any(skb);
258 spin_lock_irqsave(&dev->req_lock, flags);
259 list_add(&req->list, &dev->rx_reqs);
260 spin_unlock_irqrestore(&dev->req_lock, flags);
261 }
262 return retval;
263}
264
265static void rx_complete(struct usb_ep *ep, struct usb_request *req)
266{
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500267 struct sk_buff *skb = req->context, *skb2;
David Brownell2b3d9422008-06-19 18:19:28 -0700268 struct eth_dev *dev = ep->driver_data;
269 int status = req->status;
270
271 switch (status) {
272
273 /* normal completion */
274 case 0:
275 skb_put(skb, req->actual);
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500276
277 if (dev->unwrap) {
278 unsigned long flags;
279
280 spin_lock_irqsave(&dev->lock, flags);
281 if (dev->port_usb) {
282 status = dev->unwrap(dev->port_usb,
283 skb,
284 &dev->rx_frames);
285 } else {
286 dev_kfree_skb_any(skb);
287 status = -ENOTCONN;
288 }
289 spin_unlock_irqrestore(&dev->lock, flags);
290 } else {
291 skb_queue_tail(&dev->rx_frames, skb);
David Brownell2b3d9422008-06-19 18:19:28 -0700292 }
David Brownell2b3d9422008-06-19 18:19:28 -0700293 skb = NULL;
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500294
295 skb2 = skb_dequeue(&dev->rx_frames);
296 while (skb2) {
297 if (status < 0
298 || ETH_HLEN > skb2->len
Ian Coolidge4fe5f072012-11-07 14:39:18 +0000299 || skb2->len > VLAN_ETH_FRAME_LEN) {
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500300 dev->net->stats.rx_errors++;
301 dev->net->stats.rx_length_errors++;
302 DBG(dev, "rx length %d\n", skb2->len);
303 dev_kfree_skb_any(skb2);
304 goto next_frame;
305 }
306 skb2->protocol = eth_type_trans(skb2, dev->net);
307 dev->net->stats.rx_packets++;
308 dev->net->stats.rx_bytes += skb2->len;
309
310 /* no buffer copies needed, unless hardware can't
311 * use skb buffers.
312 */
313 status = netif_rx(skb2);
314next_frame:
315 skb2 = skb_dequeue(&dev->rx_frames);
316 }
David Brownell2b3d9422008-06-19 18:19:28 -0700317 break;
318
319 /* software-driven interface shutdown */
320 case -ECONNRESET: /* unlink */
321 case -ESHUTDOWN: /* disconnect etc */
322 VDBG(dev, "rx shutdown, code %d\n", status);
323 goto quiesce;
324
325 /* for hardware automagic (such as pxa) */
326 case -ECONNABORTED: /* endpoint reset */
327 DBG(dev, "rx %s reset\n", ep->name);
328 defer_kevent(dev, WORK_RX_MEMORY);
329quiesce:
330 dev_kfree_skb_any(skb);
331 goto clean;
332
333 /* data overrun */
334 case -EOVERFLOW:
335 dev->net->stats.rx_over_errors++;
336 /* FALLTHROUGH */
337
338 default:
339 dev->net->stats.rx_errors++;
340 DBG(dev, "rx status %d\n", status);
341 break;
342 }
343
344 if (skb)
345 dev_kfree_skb_any(skb);
346 if (!netif_running(dev->net)) {
347clean:
348 spin_lock(&dev->req_lock);
349 list_add(&req->list, &dev->rx_reqs);
350 spin_unlock(&dev->req_lock);
351 req = NULL;
352 }
353 if (req)
354 rx_submit(dev, req, GFP_ATOMIC);
355}
356
357static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
358{
359 unsigned i;
360 struct usb_request *req;
361
362 if (!n)
363 return -ENOMEM;
364
365 /* queue/recycle up to N requests */
366 i = n;
367 list_for_each_entry(req, list, list) {
368 if (i-- == 0)
369 goto extra;
370 }
371 while (i--) {
372 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
373 if (!req)
374 return list_empty(list) ? -ENOMEM : 0;
375 list_add(&req->list, list);
376 }
377 return 0;
378
379extra:
380 /* free extras */
381 for (;;) {
382 struct list_head *next;
383
384 next = req->list.next;
385 list_del(&req->list);
386 usb_ep_free_request(ep, req);
387
388 if (next == list)
389 break;
390
391 req = container_of(next, struct usb_request, list);
392 }
393 return 0;
394}
395
396static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
397{
398 int status;
399
400 spin_lock(&dev->req_lock);
401 status = prealloc(&dev->tx_reqs, link->in_ep, n);
402 if (status < 0)
403 goto fail;
404 status = prealloc(&dev->rx_reqs, link->out_ep, n);
405 if (status < 0)
406 goto fail;
407 goto done;
408fail:
409 DBG(dev, "can't alloc requests\n");
410done:
411 spin_unlock(&dev->req_lock);
412 return status;
413}
414
415static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
416{
417 struct usb_request *req;
418 unsigned long flags;
419
420 /* fill unused rxq slots with some skb */
421 spin_lock_irqsave(&dev->req_lock, flags);
422 while (!list_empty(&dev->rx_reqs)) {
423 req = container_of(dev->rx_reqs.next,
424 struct usb_request, list);
425 list_del_init(&req->list);
426 spin_unlock_irqrestore(&dev->req_lock, flags);
427
428 if (rx_submit(dev, req, gfp_flags) < 0) {
429 defer_kevent(dev, WORK_RX_MEMORY);
430 return;
431 }
432
433 spin_lock_irqsave(&dev->req_lock, flags);
434 }
435 spin_unlock_irqrestore(&dev->req_lock, flags);
436}
437
438static void eth_work(struct work_struct *work)
439{
440 struct eth_dev *dev = container_of(work, struct eth_dev, work);
441
442 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
443 if (netif_running(dev->net))
444 rx_fill(dev, GFP_KERNEL);
445 }
446
447 if (dev->todo)
448 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
449}
450
451static void tx_complete(struct usb_ep *ep, struct usb_request *req)
452{
453 struct sk_buff *skb = req->context;
454 struct eth_dev *dev = ep->driver_data;
455
456 switch (req->status) {
457 default:
458 dev->net->stats.tx_errors++;
459 VDBG(dev, "tx err %d\n", req->status);
460 /* FALLTHROUGH */
461 case -ECONNRESET: /* unlink */
462 case -ESHUTDOWN: /* disconnect etc */
463 break;
464 case 0:
465 dev->net->stats.tx_bytes += skb->len;
466 }
467 dev->net->stats.tx_packets++;
468
469 spin_lock(&dev->req_lock);
470 list_add(&req->list, &dev->tx_reqs);
471 spin_unlock(&dev->req_lock);
472 dev_kfree_skb_any(skb);
473
474 atomic_dec(&dev->tx_qlen);
475 if (netif_carrier_ok(dev->net))
476 netif_wake_queue(dev->net);
477}
478
479static inline int is_promisc(u16 cdc_filter)
480{
481 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
482}
483
Stephen Hemminger25a79c42009-08-31 19:50:45 +0000484static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
485 struct net_device *net)
David Brownell2b3d9422008-06-19 18:19:28 -0700486{
487 struct eth_dev *dev = netdev_priv(net);
488 int length = skb->len;
489 int retval;
490 struct usb_request *req = NULL;
491 unsigned long flags;
492 struct usb_ep *in;
493 u16 cdc_filter;
494
495 spin_lock_irqsave(&dev->lock, flags);
496 if (dev->port_usb) {
497 in = dev->port_usb->in_ep;
498 cdc_filter = dev->port_usb->cdc_filter;
499 } else {
500 in = NULL;
501 cdc_filter = 0;
502 }
503 spin_unlock_irqrestore(&dev->lock, flags);
504
505 if (!in) {
506 dev_kfree_skb_any(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000507 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700508 }
509
510 /* apply outgoing CDC or RNDIS filters */
511 if (!is_promisc(cdc_filter)) {
512 u8 *dest = skb->data;
513
514 if (is_multicast_ether_addr(dest)) {
515 u16 type;
516
517 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
518 * SET_ETHERNET_MULTICAST_FILTERS requests
519 */
520 if (is_broadcast_ether_addr(dest))
521 type = USB_CDC_PACKET_TYPE_BROADCAST;
522 else
523 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
524 if (!(cdc_filter & type)) {
525 dev_kfree_skb_any(skb);
Patrick McHardy6ed10652009-06-23 06:03:08 +0000526 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700527 }
528 }
529 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
530 }
531
532 spin_lock_irqsave(&dev->req_lock, flags);
533 /*
534 * this freelist can be empty if an interrupt triggered disconnect()
535 * and reconfigured the gadget (shutting down this queue) after the
536 * network stack decided to xmit but before we got the spinlock.
537 */
538 if (list_empty(&dev->tx_reqs)) {
539 spin_unlock_irqrestore(&dev->req_lock, flags);
Patrick McHardy5b548142009-06-12 06:22:29 +0000540 return NETDEV_TX_BUSY;
David Brownell2b3d9422008-06-19 18:19:28 -0700541 }
542
543 req = container_of(dev->tx_reqs.next, struct usb_request, list);
544 list_del(&req->list);
545
546 /* temporarily stop TX queue when the freelist empties */
547 if (list_empty(&dev->tx_reqs))
548 netif_stop_queue(net);
549 spin_unlock_irqrestore(&dev->req_lock, flags);
550
551 /* no buffer copies needed, unless the network stack did it
552 * or the hardware can't use skb buffers.
553 * or there's not enough space for extra headers we need
554 */
555 if (dev->wrap) {
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500556 unsigned long flags;
David Brownell2b3d9422008-06-19 18:19:28 -0700557
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500558 spin_lock_irqsave(&dev->lock, flags);
559 if (dev->port_usb)
560 skb = dev->wrap(dev->port_usb, skb);
561 spin_unlock_irqrestore(&dev->lock, flags);
562 if (!skb)
David Brownell2b3d9422008-06-19 18:19:28 -0700563 goto drop;
564
David Brownell2b3d9422008-06-19 18:19:28 -0700565 length = skb->len;
566 }
567 req->buf = skb->data;
568 req->context = skb;
569 req->complete = tx_complete;
570
Yauheni Kaliuta5c1168d2010-12-08 13:12:04 +0200571 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
572 if (dev->port_usb->is_fixed &&
573 length == dev->port_usb->fixed_in_len &&
574 (length % in->maxpacket) == 0)
575 req->zero = 0;
576 else
577 req->zero = 1;
578
David Brownell2b3d9422008-06-19 18:19:28 -0700579 /* use zlp framing on tx for strict CDC-Ether conformance,
580 * though any robust network rx path ignores extra padding.
581 * and some hardware doesn't like to write zlps.
582 */
Yauheni Kaliuta5c1168d2010-12-08 13:12:04 +0200583 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
David Brownell2b3d9422008-06-19 18:19:28 -0700584 length++;
585
586 req->length = length;
587
Paul Zimmerman04617db2011-06-27 14:13:18 -0700588 /* throttle high/super speed IRQ rate back slightly */
David Brownell2b3d9422008-06-19 18:19:28 -0700589 if (gadget_is_dualspeed(dev->gadget))
Paul Zimmerman04617db2011-06-27 14:13:18 -0700590 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
591 dev->gadget->speed == USB_SPEED_SUPER)
David Brownell2b3d9422008-06-19 18:19:28 -0700592 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
593 : 0;
594
595 retval = usb_ep_queue(in, req, GFP_ATOMIC);
596 switch (retval) {
597 default:
598 DBG(dev, "tx queue err %d\n", retval);
599 break;
600 case 0:
601 net->trans_start = jiffies;
602 atomic_inc(&dev->tx_qlen);
603 }
604
605 if (retval) {
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500606 dev_kfree_skb_any(skb);
David Brownell2b3d9422008-06-19 18:19:28 -0700607drop:
608 dev->net->stats.tx_dropped++;
David Brownell2b3d9422008-06-19 18:19:28 -0700609 spin_lock_irqsave(&dev->req_lock, flags);
610 if (list_empty(&dev->tx_reqs))
611 netif_start_queue(net);
612 list_add(&req->list, &dev->tx_reqs);
613 spin_unlock_irqrestore(&dev->req_lock, flags);
614 }
Patrick McHardy6ed10652009-06-23 06:03:08 +0000615 return NETDEV_TX_OK;
David Brownell2b3d9422008-06-19 18:19:28 -0700616}
617
618/*-------------------------------------------------------------------------*/
619
620static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
621{
622 DBG(dev, "%s\n", __func__);
623
624 /* fill the rx queue */
625 rx_fill(dev, gfp_flags);
626
627 /* and open the tx floodgates */
628 atomic_set(&dev->tx_qlen, 0);
629 netif_wake_queue(dev->net);
630}
631
632static int eth_open(struct net_device *net)
633{
634 struct eth_dev *dev = netdev_priv(net);
635 struct gether *link;
636
637 DBG(dev, "%s\n", __func__);
638 if (netif_carrier_ok(dev->net))
639 eth_start(dev, GFP_KERNEL);
640
641 spin_lock_irq(&dev->lock);
642 link = dev->port_usb;
643 if (link && link->open)
644 link->open(link);
645 spin_unlock_irq(&dev->lock);
646
647 return 0;
648}
649
650static int eth_stop(struct net_device *net)
651{
652 struct eth_dev *dev = netdev_priv(net);
653 unsigned long flags;
654
655 VDBG(dev, "%s\n", __func__);
656 netif_stop_queue(net);
657
658 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
659 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
660 dev->net->stats.rx_errors, dev->net->stats.tx_errors
661 );
662
663 /* ensure there are no more active requests */
664 spin_lock_irqsave(&dev->lock, flags);
665 if (dev->port_usb) {
666 struct gether *link = dev->port_usb;
Michael Grzeschikb1b552a2012-08-08 11:48:10 +0200667 const struct usb_endpoint_descriptor *in;
668 const struct usb_endpoint_descriptor *out;
David Brownell2b3d9422008-06-19 18:19:28 -0700669
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 */
Michael Grzeschikb1b552a2012-08-08 11:48:10 +0200682 in = link->in_ep->desc;
683 out = link->out_ep->desc;
David Brownell2b3d9422008-06-19 18:19:28 -0700684 usb_ep_disable(link->in_ep);
685 usb_ep_disable(link->out_ep);
686 if (netif_carrier_ok(net)) {
687 DBG(dev, "host still using in/out endpoints\n");
Michael Grzeschikb1b552a2012-08-08 11:48:10 +0200688 link->in_ep->desc = in;
689 link->out_ep->desc = out;
Tatyana Brokhman72c973d2011-06-28 16:33:48 +0300690 usb_ep_enable(link->in_ep);
691 usb_ep_enable(link->out_ep);
David Brownell2b3d9422008-06-19 18:19:28 -0700692 }
693 }
694 spin_unlock_irqrestore(&dev->lock, flags);
695
696 return 0;
697}
698
699/*-------------------------------------------------------------------------*/
700
701/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
702static char *dev_addr;
703module_param(dev_addr, charp, S_IRUGO);
704MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
705
706/* this address is invisible to ifconfig */
707static char *host_addr;
708module_param(host_addr, charp, S_IRUGO);
709MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
710
Michal Nazarewicz28824b12010-05-05 12:53:13 +0200711static int get_ether_addr(const char *str, u8 *dev_addr)
David Brownell2b3d9422008-06-19 18:19:28 -0700712{
713 if (str) {
714 unsigned i;
715
716 for (i = 0; i < 6; i++) {
717 unsigned char num;
718
719 if ((*str == '.') || (*str == ':'))
720 str++;
Andy Shevchenkoe6448142010-06-15 17:04:44 +0300721 num = hex_to_bin(*str++) << 4;
722 num |= hex_to_bin(*str++);
David Brownell2b3d9422008-06-19 18:19:28 -0700723 dev_addr [i] = num;
724 }
725 if (is_valid_ether_addr(dev_addr))
726 return 0;
727 }
Joe Perches006c9132012-07-12 22:33:11 -0700728 eth_random_addr(dev_addr);
David Brownell2b3d9422008-06-19 18:19:28 -0700729 return 1;
730}
731
732static struct eth_dev *the_dev;
733
Stephen Hemminger5ec38f32009-01-07 18:05:39 -0800734static const struct net_device_ops eth_netdev_ops = {
735 .ndo_open = eth_open,
736 .ndo_stop = eth_stop,
737 .ndo_start_xmit = eth_start_xmit,
738 .ndo_change_mtu = ueth_change_mtu,
739 .ndo_set_mac_address = eth_mac_addr,
740 .ndo_validate_addr = eth_validate_addr,
741};
David Brownell2b3d9422008-06-19 18:19:28 -0700742
Marcel Holtmannaa790742010-01-15 22:13:58 -0800743static struct device_type gadget_type = {
744 .name = "gadget",
745};
746
David Brownell2b3d9422008-06-19 18:19:28 -0700747/**
Mike Lockwood036e98b2012-05-10 10:08:02 +0200748 * gether_setup_name - initialize one ethernet-over-usb link
David Brownell2b3d9422008-06-19 18:19:28 -0700749 * @g: gadget to associated with these links
750 * @ethaddr: NULL, or a buffer in which the ethernet address of the
751 * host side of the link is recorded
Mike Lockwood036e98b2012-05-10 10:08:02 +0200752 * @netname: name for network device (for example, "usb")
David Brownell2b3d9422008-06-19 18:19:28 -0700753 * Context: may sleep
754 *
755 * This sets up the single network link that may be exported by a
756 * gadget driver using this framework. The link layer addresses are
757 * set up using module parameters.
758 *
759 * Returns negative errno, or zero on success
760 */
Mike Lockwood036e98b2012-05-10 10:08:02 +0200761int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
762 const char *netname)
David Brownell2b3d9422008-06-19 18:19:28 -0700763{
764 struct eth_dev *dev;
765 struct net_device *net;
766 int status;
767
768 if (the_dev)
769 return -EBUSY;
770
771 net = alloc_etherdev(sizeof *dev);
772 if (!net)
773 return -ENOMEM;
774
775 dev = netdev_priv(net);
776 spin_lock_init(&dev->lock);
777 spin_lock_init(&dev->req_lock);
778 INIT_WORK(&dev->work, eth_work);
779 INIT_LIST_HEAD(&dev->tx_reqs);
780 INIT_LIST_HEAD(&dev->rx_reqs);
781
Brian Niebuhr9b39e9d2009-08-14 10:04:22 -0500782 skb_queue_head_init(&dev->rx_frames);
783
David Brownell2b3d9422008-06-19 18:19:28 -0700784 /* network device setup */
785 dev->net = net;
Mike Lockwood036e98b2012-05-10 10:08:02 +0200786 snprintf(net->name, sizeof(net->name), "%s%%d", netname);
David Brownell2b3d9422008-06-19 18:19:28 -0700787
788 if (get_ether_addr(dev_addr, net->dev_addr))
789 dev_warn(&g->dev,
790 "using random %s ethernet address\n", "self");
791 if (get_ether_addr(host_addr, dev->host_mac))
792 dev_warn(&g->dev,
793 "using random %s ethernet address\n", "host");
794
795 if (ethaddr)
796 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
797
Stephen Hemminger5ec38f32009-01-07 18:05:39 -0800798 net->netdev_ops = &eth_netdev_ops;
799
David Brownell2b3d9422008-06-19 18:19:28 -0700800 SET_ETHTOOL_OPS(net, &ops);
801
David Brownell2b3d9422008-06-19 18:19:28 -0700802 dev->gadget = g;
803 SET_NETDEV_DEV(net, &g->dev);
Marcel Holtmannaa790742010-01-15 22:13:58 -0800804 SET_NETDEV_DEVTYPE(net, &gadget_type);
David Brownell2b3d9422008-06-19 18:19:28 -0700805
806 status = register_netdev(net);
807 if (status < 0) {
808 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
809 free_netdev(net);
810 } else {
Johannes Berge1749612008-10-27 15:59:26 -0700811 INFO(dev, "MAC %pM\n", net->dev_addr);
812 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
David Brownell2b3d9422008-06-19 18:19:28 -0700813
814 the_dev = dev;
Kevin Cernekee31bde1c2012-06-24 21:11:22 -0700815
816 /* two kinds of host-initiated state changes:
817 * - iff DATA transfer is active, carrier is "on"
818 * - tx queueing enabled if open *and* carrier is "on"
819 */
820 netif_carrier_off(net);
David Brownell2b3d9422008-06-19 18:19:28 -0700821 }
822
823 return status;
824}
825
826/**
827 * gether_cleanup - remove Ethernet-over-USB device
828 * Context: may sleep
829 *
830 * This is called to free all resources allocated by @gether_setup().
831 */
832void gether_cleanup(void)
833{
834 if (!the_dev)
835 return;
836
837 unregister_netdev(the_dev->net);
Tejun Heo43829732012-08-20 14:51:24 -0700838 flush_work(&the_dev->work);
David Brownell2b3d9422008-06-19 18:19:28 -0700839 free_netdev(the_dev->net);
840
David Brownell2b3d9422008-06-19 18:19:28 -0700841 the_dev = NULL;
842}
843
844
845/**
846 * gether_connect - notify network layer that USB link is active
847 * @link: the USB link, set up with endpoints, descriptors matching
848 * current device speed, and any framing wrapper(s) set up.
849 * Context: irqs blocked
850 *
851 * This is called to activate endpoints and let the network layer know
852 * the connection is active ("carrier detect"). It may cause the I/O
853 * queues to open and start letting network packets flow, but will in
854 * any case activate the endpoints so that they respond properly to the
855 * USB host.
856 *
857 * Verify net_device pointer returned using IS_ERR(). If it doesn't
858 * indicate some error code (negative errno), ep->driver_data values
859 * have been overwritten.
860 */
861struct net_device *gether_connect(struct gether *link)
862{
863 struct eth_dev *dev = the_dev;
864 int result = 0;
865
866 if (!dev)
867 return ERR_PTR(-EINVAL);
868
869 link->in_ep->driver_data = dev;
Tatyana Brokhman72c973d2011-06-28 16:33:48 +0300870 result = usb_ep_enable(link->in_ep);
David Brownell2b3d9422008-06-19 18:19:28 -0700871 if (result != 0) {
872 DBG(dev, "enable %s --> %d\n",
873 link->in_ep->name, result);
874 goto fail0;
875 }
876
877 link->out_ep->driver_data = dev;
Tatyana Brokhman72c973d2011-06-28 16:33:48 +0300878 result = usb_ep_enable(link->out_ep);
David Brownell2b3d9422008-06-19 18:19:28 -0700879 if (result != 0) {
880 DBG(dev, "enable %s --> %d\n",
881 link->out_ep->name, result);
882 goto fail1;
883 }
884
885 if (result == 0)
886 result = alloc_requests(dev, link, qlen(dev->gadget));
887
888 if (result == 0) {
889 dev->zlp = link->is_zlp_ok;
890 DBG(dev, "qlen %d\n", qlen(dev->gadget));
891
892 dev->header_len = link->header_len;
893 dev->unwrap = link->unwrap;
894 dev->wrap = link->wrap;
895
896 spin_lock(&dev->lock);
897 dev->port_usb = link;
898 link->ioport = dev;
David Brownell29bac7b2008-09-06 21:33:49 -0700899 if (netif_running(dev->net)) {
900 if (link->open)
901 link->open(link);
902 } else {
903 if (link->close)
904 link->close(link);
905 }
David Brownell2b3d9422008-06-19 18:19:28 -0700906 spin_unlock(&dev->lock);
907
908 netif_carrier_on(dev->net);
909 if (netif_running(dev->net))
910 eth_start(dev, GFP_ATOMIC);
911
912 /* on error, disable any endpoints */
913 } else {
914 (void) usb_ep_disable(link->out_ep);
915fail1:
916 (void) usb_ep_disable(link->in_ep);
917 }
918fail0:
919 /* caller is responsible for cleanup on error */
920 if (result < 0)
921 return ERR_PTR(result);
922 return dev->net;
923}
924
925/**
926 * gether_disconnect - notify network layer that USB link is inactive
927 * @link: the USB link, on which gether_connect() was called
928 * Context: irqs blocked
929 *
930 * This is called to deactivate endpoints and let the network layer know
931 * the connection went inactive ("no carrier").
932 *
933 * On return, the state is as if gether_connect() had never been called.
934 * The endpoints are inactive, and accordingly without active USB I/O.
935 * Pointers to endpoint descriptors and endpoint private data are nulled.
936 */
937void gether_disconnect(struct gether *link)
938{
939 struct eth_dev *dev = link->ioport;
940 struct usb_request *req;
941
942 WARN_ON(!dev);
943 if (!dev)
944 return;
945
946 DBG(dev, "%s\n", __func__);
947
948 netif_stop_queue(dev->net);
949 netif_carrier_off(dev->net);
950
951 /* disable endpoints, forcing (synchronous) completion
952 * of all pending i/o. then free the request objects
953 * and forget about the endpoints.
954 */
955 usb_ep_disable(link->in_ep);
956 spin_lock(&dev->req_lock);
957 while (!list_empty(&dev->tx_reqs)) {
958 req = container_of(dev->tx_reqs.next,
959 struct usb_request, list);
960 list_del(&req->list);
961
962 spin_unlock(&dev->req_lock);
963 usb_ep_free_request(link->in_ep, req);
964 spin_lock(&dev->req_lock);
965 }
966 spin_unlock(&dev->req_lock);
967 link->in_ep->driver_data = NULL;
Tatyana Brokhman72c973d2011-06-28 16:33:48 +0300968 link->in_ep->desc = NULL;
David Brownell2b3d9422008-06-19 18:19:28 -0700969
970 usb_ep_disable(link->out_ep);
971 spin_lock(&dev->req_lock);
972 while (!list_empty(&dev->rx_reqs)) {
973 req = container_of(dev->rx_reqs.next,
974 struct usb_request, list);
975 list_del(&req->list);
976
977 spin_unlock(&dev->req_lock);
978 usb_ep_free_request(link->out_ep, req);
979 spin_lock(&dev->req_lock);
980 }
981 spin_unlock(&dev->req_lock);
982 link->out_ep->driver_data = NULL;
Tatyana Brokhman72c973d2011-06-28 16:33:48 +0300983 link->out_ep->desc = NULL;
David Brownell2b3d9422008-06-19 18:19:28 -0700984
985 /* finish forgetting about this USB link episode */
986 dev->header_len = 0;
987 dev->unwrap = NULL;
988 dev->wrap = NULL;
989
990 spin_lock(&dev->lock);
991 dev->port_usb = NULL;
992 link->ioport = NULL;
993 spin_unlock(&dev->lock);
994}