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2b3d942c DB |
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> | |
5a0e3ad6 | 26 | #include <linux/gfp.h> |
2b3d942c DB |
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 | |
9b39e9dd BN |
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. | |
2b3d942c DB |
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 | ||
8a1ce2c0 | 56 | #define UETH__VERSION "29-May-2008" |
2b3d942c DB |
57 | |
58 | struct 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 | ||
9b39e9dd BN |
72 | struct sk_buff_head rx_frames; |
73 | ||
2b3d942c | 74 | unsigned header_len; |
9b39e9dd BN |
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); | |
2b3d942c DB |
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 | ||
98 | static unsigned qmult = 5; | |
99 | module_param(qmult, uint, S_IRUGO|S_IWUSR); | |
100 | MODULE_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 */ | |
107 | static 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 | |
2b3d942c DB |
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) | |
2b3d942c DB |
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 | ||
ccad637b | 154 | static int ueth_change_mtu(struct net_device *net, int new_mtu) |
2b3d942c DB |
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 | ||
173 | static 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); | |
8a1ce2c0 | 178 | strlcpy(p->version, UETH__VERSION, sizeof p->version); |
2b3d942c DB |
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 | ||
2b3d942c DB |
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 | ||
0fc0b732 | 189 | static const struct ethtool_ops ops = { |
2b3d942c | 190 | .get_drvinfo = eth_get_drvinfo, |
237e75bf | 191 | .get_link = ethtool_op_get_link, |
2b3d942c DB |
192 | }; |
193 | ||
194 | static 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 | ||
204 | static void rx_complete(struct usb_ep *ep, struct usb_request *req); | |
205 | ||
206 | static int | |
207 | rx_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) | |
262 | enomem: | |
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 | ||
275 | static void rx_complete(struct usb_ep *ep, struct usb_request *req) | |
276 | { | |
9b39e9dd | 277 | struct sk_buff *skb = req->context, *skb2; |
2b3d942c DB |
278 | 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); | |
2b3d942c | 286 | |
9b39e9dd BN |
287 | if (dev->unwrap) { |
288 | unsigned long flags; | |
2b3d942c | 289 | |
9b39e9dd BN |
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); | |
302 | } | |
2b3d942c | 303 | skb = NULL; |
9b39e9dd BN |
304 | |
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); | |
324 | next_frame: | |
325 | skb2 = skb_dequeue(&dev->rx_frames); | |
326 | } | |
2b3d942c DB |
327 | 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); | |
339 | quiesce: | |
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)) { | |
357 | clean: | |
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 | ||
367 | static 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 | ||
389 | extra: | |
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 | ||
406 | static 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; | |
418 | fail: | |
419 | DBG(dev, "can't alloc requests\n"); | |
420 | done: | |
421 | spin_unlock(&dev->req_lock); | |
422 | return status; | |
423 | } | |
424 | ||
425 | static 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 | ||
448 | static 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 | ||
461 | static 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 | ||
489 | static inline int is_promisc(u16 cdc_filter) | |
490 | { | |
491 | return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS; | |
492 | } | |
493 | ||
25a79c41 SH |
494 | static netdev_tx_t eth_start_xmit(struct sk_buff *skb, |
495 | struct net_device *net) | |
2b3d942c DB |
496 | { |
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); | |
6ed10654 | 517 | return NETDEV_TX_OK; |
2b3d942c DB |
518 | } |
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); | |
6ed10654 | 536 | return NETDEV_TX_OK; |
2b3d942c DB |
537 | } |
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); | |
5b548140 | 550 | return NETDEV_TX_BUSY; |
2b3d942c DB |
551 | } |
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) { | |
9b39e9dd | 566 | unsigned long flags; |
2b3d942c | 567 | |
9b39e9dd BN |
568 | 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) | |
2b3d942c DB |
573 | goto drop; |
574 | ||
2b3d942c DB |
575 | 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) { | |
9b39e9dd | 608 | dev_kfree_skb_any(skb); |
2b3d942c DB |
609 | drop: |
610 | dev->net->stats.tx_dropped++; | |
2b3d942c DB |
611 | 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 | } | |
6ed10654 | 617 | return NETDEV_TX_OK; |
2b3d942c DB |
618 | } |
619 | ||
620 | /*-------------------------------------------------------------------------*/ | |
621 | ||
622 | static 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 | ||
634 | static 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 | ||
652 | static 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" */ | |
698 | static char *dev_addr; | |
699 | module_param(dev_addr, charp, S_IRUGO); | |
700 | MODULE_PARM_DESC(dev_addr, "Device Ethernet Address"); | |
701 | ||
702 | /* this address is invisible to ifconfig */ | |
703 | static char *host_addr; | |
704 | module_param(host_addr, charp, S_IRUGO); | |
705 | MODULE_PARM_DESC(host_addr, "Host Ethernet Address"); | |
706 | ||
707 | ||
708 | static 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 | ||
28824b18 | 718 | static int get_ether_addr(const char *str, u8 *dev_addr) |
2b3d942c DB |
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 | ||
739 | static struct eth_dev *the_dev; | |
740 | ||
5ec38f30 SH |
741 | static 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 | }; | |
2b3d942c | 749 | |
aa790740 MH |
750 | static struct device_type gadget_type = { |
751 | .name = "gadget", | |
752 | }; | |
753 | ||
2b3d942c DB |
754 | /** |
755 | * gether_setup - initialize one ethernet-over-usb link | |
756 | * @g: gadget to associated with these links | |
757 | * @ethaddr: NULL, or a buffer in which the ethernet address of the | |
758 | * host side of the link is recorded | |
759 | * Context: may sleep | |
760 | * | |
761 | * This sets up the single network link that may be exported by a | |
762 | * gadget driver using this framework. The link layer addresses are | |
763 | * set up using module parameters. | |
764 | * | |
765 | * Returns negative errno, or zero on success | |
766 | */ | |
28824b18 | 767 | int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]) |
2b3d942c DB |
768 | { |
769 | struct eth_dev *dev; | |
770 | struct net_device *net; | |
771 | int status; | |
772 | ||
773 | if (the_dev) | |
774 | return -EBUSY; | |
775 | ||
776 | net = alloc_etherdev(sizeof *dev); | |
777 | if (!net) | |
778 | return -ENOMEM; | |
779 | ||
780 | dev = netdev_priv(net); | |
781 | spin_lock_init(&dev->lock); | |
782 | spin_lock_init(&dev->req_lock); | |
783 | INIT_WORK(&dev->work, eth_work); | |
784 | INIT_LIST_HEAD(&dev->tx_reqs); | |
785 | INIT_LIST_HEAD(&dev->rx_reqs); | |
786 | ||
9b39e9dd BN |
787 | skb_queue_head_init(&dev->rx_frames); |
788 | ||
2b3d942c DB |
789 | /* network device setup */ |
790 | dev->net = net; | |
791 | strcpy(net->name, "usb%d"); | |
792 | ||
793 | if (get_ether_addr(dev_addr, net->dev_addr)) | |
794 | dev_warn(&g->dev, | |
795 | "using random %s ethernet address\n", "self"); | |
796 | if (get_ether_addr(host_addr, dev->host_mac)) | |
797 | dev_warn(&g->dev, | |
798 | "using random %s ethernet address\n", "host"); | |
799 | ||
800 | if (ethaddr) | |
801 | memcpy(ethaddr, dev->host_mac, ETH_ALEN); | |
802 | ||
5ec38f30 SH |
803 | net->netdev_ops = ð_netdev_ops; |
804 | ||
2b3d942c DB |
805 | SET_ETHTOOL_OPS(net, &ops); |
806 | ||
807 | /* two kinds of host-initiated state changes: | |
808 | * - iff DATA transfer is active, carrier is "on" | |
809 | * - tx queueing enabled if open *and* carrier is "on" | |
810 | */ | |
811 | netif_stop_queue(net); | |
812 | netif_carrier_off(net); | |
813 | ||
814 | dev->gadget = g; | |
815 | SET_NETDEV_DEV(net, &g->dev); | |
aa790740 | 816 | SET_NETDEV_DEVTYPE(net, &gadget_type); |
2b3d942c DB |
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 { | |
e174961c JB |
823 | INFO(dev, "MAC %pM\n", net->dev_addr); |
824 | INFO(dev, "HOST MAC %pM\n", dev->host_mac); | |
2b3d942c DB |
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 | */ | |
838 | void gether_cleanup(void) | |
839 | { | |
840 | if (!the_dev) | |
841 | return; | |
842 | ||
843 | unregister_netdev(the_dev->net); | |
844 | free_netdev(the_dev->net); | |
845 | ||
846 | /* assuming we used keventd, it must quiesce too */ | |
847 | flush_scheduled_work(); | |
848 | ||
849 | the_dev = NULL; | |
850 | } | |
851 | ||
852 | ||
853 | /** | |
854 | * gether_connect - notify network layer that USB link is active | |
855 | * @link: the USB link, set up with endpoints, descriptors matching | |
856 | * current device speed, and any framing wrapper(s) set up. | |
857 | * Context: irqs blocked | |
858 | * | |
859 | * This is called to activate endpoints and let the network layer know | |
860 | * the connection is active ("carrier detect"). It may cause the I/O | |
861 | * queues to open and start letting network packets flow, but will in | |
862 | * any case activate the endpoints so that they respond properly to the | |
863 | * USB host. | |
864 | * | |
865 | * Verify net_device pointer returned using IS_ERR(). If it doesn't | |
866 | * indicate some error code (negative errno), ep->driver_data values | |
867 | * have been overwritten. | |
868 | */ | |
869 | struct net_device *gether_connect(struct gether *link) | |
870 | { | |
871 | struct eth_dev *dev = the_dev; | |
872 | int result = 0; | |
873 | ||
874 | if (!dev) | |
875 | return ERR_PTR(-EINVAL); | |
876 | ||
877 | link->in_ep->driver_data = dev; | |
878 | result = usb_ep_enable(link->in_ep, link->in); | |
879 | if (result != 0) { | |
880 | DBG(dev, "enable %s --> %d\n", | |
881 | link->in_ep->name, result); | |
882 | goto fail0; | |
883 | } | |
884 | ||
885 | link->out_ep->driver_data = dev; | |
886 | result = usb_ep_enable(link->out_ep, link->out); | |
887 | if (result != 0) { | |
888 | DBG(dev, "enable %s --> %d\n", | |
889 | link->out_ep->name, result); | |
890 | goto fail1; | |
891 | } | |
892 | ||
893 | if (result == 0) | |
894 | result = alloc_requests(dev, link, qlen(dev->gadget)); | |
895 | ||
896 | if (result == 0) { | |
897 | dev->zlp = link->is_zlp_ok; | |
898 | DBG(dev, "qlen %d\n", qlen(dev->gadget)); | |
899 | ||
900 | dev->header_len = link->header_len; | |
901 | dev->unwrap = link->unwrap; | |
902 | dev->wrap = link->wrap; | |
903 | ||
904 | spin_lock(&dev->lock); | |
905 | dev->port_usb = link; | |
906 | link->ioport = dev; | |
29bac7b7 DB |
907 | if (netif_running(dev->net)) { |
908 | if (link->open) | |
909 | link->open(link); | |
910 | } else { | |
911 | if (link->close) | |
912 | link->close(link); | |
913 | } | |
2b3d942c DB |
914 | spin_unlock(&dev->lock); |
915 | ||
916 | netif_carrier_on(dev->net); | |
917 | if (netif_running(dev->net)) | |
918 | eth_start(dev, GFP_ATOMIC); | |
919 | ||
920 | /* on error, disable any endpoints */ | |
921 | } else { | |
922 | (void) usb_ep_disable(link->out_ep); | |
923 | fail1: | |
924 | (void) usb_ep_disable(link->in_ep); | |
925 | } | |
926 | fail0: | |
927 | /* caller is responsible for cleanup on error */ | |
928 | if (result < 0) | |
929 | return ERR_PTR(result); | |
930 | return dev->net; | |
931 | } | |
932 | ||
933 | /** | |
934 | * gether_disconnect - notify network layer that USB link is inactive | |
935 | * @link: the USB link, on which gether_connect() was called | |
936 | * Context: irqs blocked | |
937 | * | |
938 | * This is called to deactivate endpoints and let the network layer know | |
939 | * the connection went inactive ("no carrier"). | |
940 | * | |
941 | * On return, the state is as if gether_connect() had never been called. | |
942 | * The endpoints are inactive, and accordingly without active USB I/O. | |
943 | * Pointers to endpoint descriptors and endpoint private data are nulled. | |
944 | */ | |
945 | void gether_disconnect(struct gether *link) | |
946 | { | |
947 | struct eth_dev *dev = link->ioport; | |
948 | struct usb_request *req; | |
949 | ||
950 | WARN_ON(!dev); | |
951 | if (!dev) | |
952 | return; | |
953 | ||
954 | DBG(dev, "%s\n", __func__); | |
955 | ||
956 | netif_stop_queue(dev->net); | |
957 | netif_carrier_off(dev->net); | |
958 | ||
959 | /* disable endpoints, forcing (synchronous) completion | |
960 | * of all pending i/o. then free the request objects | |
961 | * and forget about the endpoints. | |
962 | */ | |
963 | usb_ep_disable(link->in_ep); | |
964 | spin_lock(&dev->req_lock); | |
965 | while (!list_empty(&dev->tx_reqs)) { | |
966 | req = container_of(dev->tx_reqs.next, | |
967 | struct usb_request, list); | |
968 | list_del(&req->list); | |
969 | ||
970 | spin_unlock(&dev->req_lock); | |
971 | usb_ep_free_request(link->in_ep, req); | |
972 | spin_lock(&dev->req_lock); | |
973 | } | |
974 | spin_unlock(&dev->req_lock); | |
975 | link->in_ep->driver_data = NULL; | |
976 | link->in = NULL; | |
977 | ||
978 | usb_ep_disable(link->out_ep); | |
979 | spin_lock(&dev->req_lock); | |
980 | while (!list_empty(&dev->rx_reqs)) { | |
981 | req = container_of(dev->rx_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->out_ep, req); | |
987 | spin_lock(&dev->req_lock); | |
988 | } | |
989 | spin_unlock(&dev->req_lock); | |
990 | link->out_ep->driver_data = NULL; | |
991 | link->out = NULL; | |
992 | ||
993 | /* finish forgetting about this USB link episode */ | |
994 | dev->header_len = 0; | |
995 | dev->unwrap = NULL; | |
996 | dev->wrap = NULL; | |
997 | ||
998 | spin_lock(&dev->lock); | |
999 | dev->port_usb = NULL; | |
1000 | link->ioport = NULL; | |
1001 | spin_unlock(&dev->lock); | |
1002 | } |