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1 /*
2  * USB Network driver infrastructure
3  * Copyright (C) 2000-2005 by David Brownell
4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 /*
21  * This is a generic "USB networking" framework that works with several
22  * kinds of full and high speed networking devices:  host-to-host cables,
23  * smart usb peripherals, and actual Ethernet adapters.
24  *
25  * These devices usually differ in terms of control protocols (if they
26  * even have one!) and sometimes they define new framing to wrap or batch
27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
29  * issues can usefully be addressed by this framework.
30  */
31 
32 // #define	DEBUG			// error path messages, extra info
33 // #define	VERBOSE			// more; success messages
34 
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/netdevice.h>
38 #include <linux/etherdevice.h>
39 #include <linux/ctype.h>
40 #include <linux/ethtool.h>
41 #include <linux/workqueue.h>
42 #include <linux/mii.h>
43 #include <linux/usb.h>
44 #include <linux/usb/usbnet.h>
45 #include <linux/usb/cdc.h>
46 #include <linux/slab.h>
47 #include <linux/kernel.h>
48 #include <linux/pm_runtime.h>
49 
50 #define DRIVER_VERSION		"22-Aug-2005"
51 
52 
53 /*-------------------------------------------------------------------------*/
54 
55 /*
56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
57  * Several dozen bytes of IPv4 data can fit in two such transactions.
58  * One maximum size Ethernet packet takes twenty four of them.
59  * For high speed, each frame comfortably fits almost 36 max size
60  * Ethernet packets (so queues should be bigger).
61  *
62  * The goal is to let the USB host controller be busy for 5msec or
63  * more before an irq is required, under load.  Jumbograms change
64  * the equation.
65  */
66 #define	MAX_QUEUE_MEMORY	(60 * 1518)
67 #define	RX_QLEN(dev)		((dev)->rx_qlen)
68 #define	TX_QLEN(dev)		((dev)->tx_qlen)
69 
70 // reawaken network queue this soon after stopping; else watchdog barks
71 #define TX_TIMEOUT_JIFFIES	(5*HZ)
72 
73 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
74  * us (it polls at HZ/4 usually) before we report too many false errors.
75  */
76 #define THROTTLE_JIFFIES	(HZ/8)
77 
78 // between wakeups
79 #define UNLINK_TIMEOUT_MS	3
80 
81 /*-------------------------------------------------------------------------*/
82 
83 // randomly generated ethernet address
84 static u8	node_id [ETH_ALEN];
85 
86 static const char driver_name [] = "usbnet";
87 
88 /* use ethtool to change the level for any given device */
89 static int msg_level = -1;
90 module_param (msg_level, int, 0);
91 MODULE_PARM_DESC (msg_level, "Override default message level");
92 
93 /*-------------------------------------------------------------------------*/
94 
95 /* handles CDC Ethernet and many other network "bulk data" interfaces */
usbnet_get_endpoints(struct usbnet * dev,struct usb_interface * intf)96 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
97 {
98 	int				tmp;
99 	struct usb_host_interface	*alt = NULL;
100 	struct usb_host_endpoint	*in = NULL, *out = NULL;
101 	struct usb_host_endpoint	*status = NULL;
102 
103 	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
104 		unsigned	ep;
105 
106 		in = out = status = NULL;
107 		alt = intf->altsetting + tmp;
108 
109 		/* take the first altsetting with in-bulk + out-bulk;
110 		 * remember any status endpoint, just in case;
111 		 * ignore other endpoints and altsettings.
112 		 */
113 		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
114 			struct usb_host_endpoint	*e;
115 			int				intr = 0;
116 
117 			e = alt->endpoint + ep;
118 
119 			/* ignore endpoints which cannot transfer data */
120 			if (!usb_endpoint_maxp(&e->desc))
121 				continue;
122 
123 			switch (e->desc.bmAttributes) {
124 			case USB_ENDPOINT_XFER_INT:
125 				if (!usb_endpoint_dir_in(&e->desc))
126 					continue;
127 				intr = 1;
128 				/* FALLTHROUGH */
129 			case USB_ENDPOINT_XFER_BULK:
130 				break;
131 			default:
132 				continue;
133 			}
134 			if (usb_endpoint_dir_in(&e->desc)) {
135 				if (!intr && !in)
136 					in = e;
137 				else if (intr && !status)
138 					status = e;
139 			} else {
140 				if (!out)
141 					out = e;
142 			}
143 		}
144 		if (in && out)
145 			break;
146 	}
147 	if (!alt || !in || !out)
148 		return -EINVAL;
149 
150 	if (alt->desc.bAlternateSetting != 0 ||
151 	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
152 		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
153 				alt->desc.bAlternateSetting);
154 		if (tmp < 0)
155 			return tmp;
156 	}
157 
158 	dev->in = usb_rcvbulkpipe (dev->udev,
159 			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
160 	dev->out = usb_sndbulkpipe (dev->udev,
161 			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
162 	dev->status = status;
163 	return 0;
164 }
165 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
166 
usbnet_get_ethernet_addr(struct usbnet * dev,int iMACAddress)167 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
168 {
169 	int 		tmp = -1, ret;
170 	unsigned char	buf [13];
171 
172 	ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
173 	if (ret == 12)
174 		tmp = hex2bin(dev->net->dev_addr, buf, 6);
175 	if (tmp < 0) {
176 		dev_dbg(&dev->udev->dev,
177 			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
178 		if (ret >= 0)
179 			ret = -EINVAL;
180 		return ret;
181 	}
182 	return 0;
183 }
184 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
185 
intr_complete(struct urb * urb)186 static void intr_complete (struct urb *urb)
187 {
188 	struct usbnet	*dev = urb->context;
189 	int		status = urb->status;
190 
191 	switch (status) {
192 	/* success */
193 	case 0:
194 		dev->driver_info->status(dev, urb);
195 		break;
196 
197 	/* software-driven interface shutdown */
198 	case -ENOENT:		/* urb killed */
199 	case -ESHUTDOWN:	/* hardware gone */
200 		netif_dbg(dev, ifdown, dev->net,
201 			  "intr shutdown, code %d\n", status);
202 		return;
203 
204 	/* NOTE:  not throttling like RX/TX, since this endpoint
205 	 * already polls infrequently
206 	 */
207 	default:
208 		netdev_dbg(dev->net, "intr status %d\n", status);
209 		break;
210 	}
211 
212 	status = usb_submit_urb (urb, GFP_ATOMIC);
213 	if (status != 0)
214 		netif_err(dev, timer, dev->net,
215 			  "intr resubmit --> %d\n", status);
216 }
217 
init_status(struct usbnet * dev,struct usb_interface * intf)218 static int init_status (struct usbnet *dev, struct usb_interface *intf)
219 {
220 	char		*buf = NULL;
221 	unsigned	pipe = 0;
222 	unsigned	maxp;
223 	unsigned	period;
224 
225 	if (!dev->driver_info->status)
226 		return 0;
227 
228 	pipe = usb_rcvintpipe (dev->udev,
229 			dev->status->desc.bEndpointAddress
230 				& USB_ENDPOINT_NUMBER_MASK);
231 	maxp = usb_maxpacket (dev->udev, pipe, 0);
232 
233 	/* avoid 1 msec chatter:  min 8 msec poll rate */
234 	period = max ((int) dev->status->desc.bInterval,
235 		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
236 
237 	buf = kmalloc (maxp, GFP_KERNEL);
238 	if (buf) {
239 		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
240 		if (!dev->interrupt) {
241 			kfree (buf);
242 			return -ENOMEM;
243 		} else {
244 			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
245 				buf, maxp, intr_complete, dev, period);
246 			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
247 			dev_dbg(&intf->dev,
248 				"status ep%din, %d bytes period %d\n",
249 				usb_pipeendpoint(pipe), maxp, period);
250 		}
251 	}
252 	return 0;
253 }
254 
255 /* Submit the interrupt URB if not previously submitted, increasing refcount */
usbnet_status_start(struct usbnet * dev,gfp_t mem_flags)256 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
257 {
258 	int ret = 0;
259 
260 	WARN_ON_ONCE(dev->interrupt == NULL);
261 	if (dev->interrupt) {
262 		mutex_lock(&dev->interrupt_mutex);
263 
264 		if (++dev->interrupt_count == 1)
265 			ret = usb_submit_urb(dev->interrupt, mem_flags);
266 
267 		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
268 			dev->interrupt_count);
269 		mutex_unlock(&dev->interrupt_mutex);
270 	}
271 	return ret;
272 }
273 EXPORT_SYMBOL_GPL(usbnet_status_start);
274 
275 /* For resume; submit interrupt URB if previously submitted */
__usbnet_status_start_force(struct usbnet * dev,gfp_t mem_flags)276 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
277 {
278 	int ret = 0;
279 
280 	mutex_lock(&dev->interrupt_mutex);
281 	if (dev->interrupt_count) {
282 		ret = usb_submit_urb(dev->interrupt, mem_flags);
283 		dev_dbg(&dev->udev->dev,
284 			"submitted interrupt URB for resume\n");
285 	}
286 	mutex_unlock(&dev->interrupt_mutex);
287 	return ret;
288 }
289 
290 /* Kill the interrupt URB if all submitters want it killed */
usbnet_status_stop(struct usbnet * dev)291 void usbnet_status_stop(struct usbnet *dev)
292 {
293 	if (dev->interrupt) {
294 		mutex_lock(&dev->interrupt_mutex);
295 		WARN_ON(dev->interrupt_count == 0);
296 
297 		if (dev->interrupt_count && --dev->interrupt_count == 0)
298 			usb_kill_urb(dev->interrupt);
299 
300 		dev_dbg(&dev->udev->dev,
301 			"decremented interrupt URB count to %d\n",
302 			dev->interrupt_count);
303 		mutex_unlock(&dev->interrupt_mutex);
304 	}
305 }
306 EXPORT_SYMBOL_GPL(usbnet_status_stop);
307 
308 /* For suspend; always kill interrupt URB */
__usbnet_status_stop_force(struct usbnet * dev)309 static void __usbnet_status_stop_force(struct usbnet *dev)
310 {
311 	if (dev->interrupt) {
312 		mutex_lock(&dev->interrupt_mutex);
313 		usb_kill_urb(dev->interrupt);
314 		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
315 		mutex_unlock(&dev->interrupt_mutex);
316 	}
317 }
318 
319 /* Passes this packet up the stack, updating its accounting.
320  * Some link protocols batch packets, so their rx_fixup paths
321  * can return clones as well as just modify the original skb.
322  */
usbnet_skb_return(struct usbnet * dev,struct sk_buff * skb)323 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
324 {
325 	int	status;
326 
327 	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
328 		skb_queue_tail(&dev->rxq_pause, skb);
329 		return;
330 	}
331 
332 	skb->protocol = eth_type_trans (skb, dev->net);
333 	dev->net->stats.rx_packets++;
334 	dev->net->stats.rx_bytes += skb->len;
335 
336 	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
337 		  skb->len + sizeof (struct ethhdr), skb->protocol);
338 	memset (skb->cb, 0, sizeof (struct skb_data));
339 
340 	if (skb_defer_rx_timestamp(skb))
341 		return;
342 
343 	status = netif_rx (skb);
344 	if (status != NET_RX_SUCCESS)
345 		netif_dbg(dev, rx_err, dev->net,
346 			  "netif_rx status %d\n", status);
347 }
348 EXPORT_SYMBOL_GPL(usbnet_skb_return);
349 
350 /* must be called if hard_mtu or rx_urb_size changed */
usbnet_update_max_qlen(struct usbnet * dev)351 void usbnet_update_max_qlen(struct usbnet *dev)
352 {
353 	enum usb_device_speed speed = dev->udev->speed;
354 
355 	if (!dev->rx_urb_size || !dev->hard_mtu)
356 		goto insanity;
357 	switch (speed) {
358 	case USB_SPEED_HIGH:
359 		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
360 		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
361 		break;
362 	case USB_SPEED_SUPER:
363 		/*
364 		 * Not take default 5ms qlen for super speed HC to
365 		 * save memory, and iperf tests show 2.5ms qlen can
366 		 * work well
367 		 */
368 		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
369 		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
370 		break;
371 	default:
372 insanity:
373 		dev->rx_qlen = dev->tx_qlen = 4;
374 	}
375 }
376 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
377 
378 
379 /*-------------------------------------------------------------------------
380  *
381  * Network Device Driver (peer link to "Host Device", from USB host)
382  *
383  *-------------------------------------------------------------------------*/
384 
usbnet_change_mtu(struct net_device * net,int new_mtu)385 int usbnet_change_mtu (struct net_device *net, int new_mtu)
386 {
387 	struct usbnet	*dev = netdev_priv(net);
388 	int		ll_mtu = new_mtu + net->hard_header_len;
389 	int		old_hard_mtu = dev->hard_mtu;
390 	int		old_rx_urb_size = dev->rx_urb_size;
391 
392 	if (new_mtu <= 0)
393 		return -EINVAL;
394 	// no second zero-length packet read wanted after mtu-sized packets
395 	if ((ll_mtu % dev->maxpacket) == 0)
396 		return -EDOM;
397 	net->mtu = new_mtu;
398 
399 	dev->hard_mtu = net->mtu + net->hard_header_len;
400 	if (dev->rx_urb_size == old_hard_mtu) {
401 		dev->rx_urb_size = dev->hard_mtu;
402 		if (dev->rx_urb_size > old_rx_urb_size)
403 			usbnet_unlink_rx_urbs(dev);
404 	}
405 
406 	/* max qlen depend on hard_mtu and rx_urb_size */
407 	usbnet_update_max_qlen(dev);
408 
409 	return 0;
410 }
411 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
412 
413 /* The caller must hold list->lock */
__usbnet_queue_skb(struct sk_buff_head * list,struct sk_buff * newsk,enum skb_state state)414 static void __usbnet_queue_skb(struct sk_buff_head *list,
415 			struct sk_buff *newsk, enum skb_state state)
416 {
417 	struct skb_data *entry = (struct skb_data *) newsk->cb;
418 
419 	__skb_queue_tail(list, newsk);
420 	entry->state = state;
421 }
422 
423 /*-------------------------------------------------------------------------*/
424 
425 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
426  * completion callbacks.  2.5 should have fixed those bugs...
427  */
428 
defer_bh(struct usbnet * dev,struct sk_buff * skb,struct sk_buff_head * list,enum skb_state state)429 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
430 		struct sk_buff_head *list, enum skb_state state)
431 {
432 	unsigned long		flags;
433 	enum skb_state 		old_state;
434 	struct skb_data *entry = (struct skb_data *) skb->cb;
435 
436 	spin_lock_irqsave(&list->lock, flags);
437 	old_state = entry->state;
438 	entry->state = state;
439 	__skb_unlink(skb, list);
440 
441 	/* defer_bh() is never called with list == &dev->done.
442 	 * spin_lock_nested() tells lockdep that it is OK to take
443 	 * dev->done.lock here with list->lock held.
444 	 */
445 	spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
446 
447 	__skb_queue_tail(&dev->done, skb);
448 	if (dev->done.qlen == 1)
449 		tasklet_schedule(&dev->bh);
450 	spin_unlock(&dev->done.lock);
451 	spin_unlock_irqrestore(&list->lock, flags);
452 	return old_state;
453 }
454 
455 /* some work can't be done in tasklets, so we use keventd
456  *
457  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
458  * but tasklet_schedule() doesn't.  hope the failure is rare.
459  */
usbnet_defer_kevent(struct usbnet * dev,int work)460 void usbnet_defer_kevent (struct usbnet *dev, int work)
461 {
462 	set_bit (work, &dev->flags);
463 	if (!schedule_work (&dev->kevent)) {
464 		if (net_ratelimit())
465 			netdev_err(dev->net, "kevent %d may have been dropped\n", work);
466 	} else {
467 		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
468 	}
469 }
470 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
471 
472 /*-------------------------------------------------------------------------*/
473 
474 static void rx_complete (struct urb *urb);
475 
rx_submit(struct usbnet * dev,struct urb * urb,gfp_t flags)476 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
477 {
478 	struct sk_buff		*skb;
479 	struct skb_data		*entry;
480 	int			retval = 0;
481 	unsigned long		lockflags;
482 	size_t			size = dev->rx_urb_size;
483 
484 	/* prevent rx skb allocation when error ratio is high */
485 	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
486 		usb_free_urb(urb);
487 		return -ENOLINK;
488 	}
489 
490 	skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
491 	if (!skb) {
492 		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
493 		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
494 		usb_free_urb (urb);
495 		return -ENOMEM;
496 	}
497 
498 	entry = (struct skb_data *) skb->cb;
499 	entry->urb = urb;
500 	entry->dev = dev;
501 	entry->length = 0;
502 
503 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
504 		skb->data, size, rx_complete, skb);
505 
506 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
507 
508 	if (netif_running (dev->net) &&
509 	    netif_device_present (dev->net) &&
510 	    test_bit(EVENT_DEV_OPEN, &dev->flags) &&
511 	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
512 	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
513 		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
514 		case -EPIPE:
515 			usbnet_defer_kevent (dev, EVENT_RX_HALT);
516 			break;
517 		case -ENOMEM:
518 			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
519 			break;
520 		case -ENODEV:
521 			netif_dbg(dev, ifdown, dev->net, "device gone\n");
522 			netif_device_detach (dev->net);
523 			break;
524 		case -EHOSTUNREACH:
525 			retval = -ENOLINK;
526 			break;
527 		default:
528 			netif_dbg(dev, rx_err, dev->net,
529 				  "rx submit, %d\n", retval);
530 			tasklet_schedule (&dev->bh);
531 			break;
532 		case 0:
533 			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
534 		}
535 	} else {
536 		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
537 		retval = -ENOLINK;
538 	}
539 	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
540 	if (retval) {
541 		dev_kfree_skb_any (skb);
542 		usb_free_urb (urb);
543 	}
544 	return retval;
545 }
546 
547 
548 /*-------------------------------------------------------------------------*/
549 
rx_process(struct usbnet * dev,struct sk_buff * skb)550 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
551 {
552 	if (dev->driver_info->rx_fixup &&
553 	    !dev->driver_info->rx_fixup (dev, skb)) {
554 		/* With RX_ASSEMBLE, rx_fixup() must update counters */
555 		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
556 			dev->net->stats.rx_errors++;
557 		goto done;
558 	}
559 	// else network stack removes extra byte if we forced a short packet
560 
561 	/* all data was already cloned from skb inside the driver */
562 	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
563 		goto done;
564 
565 	if (skb->len < ETH_HLEN) {
566 		dev->net->stats.rx_errors++;
567 		dev->net->stats.rx_length_errors++;
568 		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
569 	} else {
570 		usbnet_skb_return(dev, skb);
571 		return;
572 	}
573 
574 done:
575 	skb_queue_tail(&dev->done, skb);
576 }
577 
578 /*-------------------------------------------------------------------------*/
579 
rx_complete(struct urb * urb)580 static void rx_complete (struct urb *urb)
581 {
582 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
583 	struct skb_data		*entry = (struct skb_data *) skb->cb;
584 	struct usbnet		*dev = entry->dev;
585 	int			urb_status = urb->status;
586 	enum skb_state		state;
587 
588 	skb_put (skb, urb->actual_length);
589 	state = rx_done;
590 	entry->urb = NULL;
591 
592 	switch (urb_status) {
593 	/* success */
594 	case 0:
595 		break;
596 
597 	/* stalls need manual reset. this is rare ... except that
598 	 * when going through USB 2.0 TTs, unplug appears this way.
599 	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
600 	 * storm, recovering as needed.
601 	 */
602 	case -EPIPE:
603 		dev->net->stats.rx_errors++;
604 		usbnet_defer_kevent (dev, EVENT_RX_HALT);
605 		// FALLTHROUGH
606 
607 	/* software-driven interface shutdown */
608 	case -ECONNRESET:		/* async unlink */
609 	case -ESHUTDOWN:		/* hardware gone */
610 		netif_dbg(dev, ifdown, dev->net,
611 			  "rx shutdown, code %d\n", urb_status);
612 		goto block;
613 
614 	/* we get controller i/o faults during hub_wq disconnect() delays.
615 	 * throttle down resubmits, to avoid log floods; just temporarily,
616 	 * so we still recover when the fault isn't a hub_wq delay.
617 	 */
618 	case -EPROTO:
619 	case -ETIME:
620 	case -EILSEQ:
621 		dev->net->stats.rx_errors++;
622 		if (!timer_pending (&dev->delay)) {
623 			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
624 			netif_dbg(dev, link, dev->net,
625 				  "rx throttle %d\n", urb_status);
626 		}
627 block:
628 		state = rx_cleanup;
629 		entry->urb = urb;
630 		urb = NULL;
631 		break;
632 
633 	/* data overrun ... flush fifo? */
634 	case -EOVERFLOW:
635 		dev->net->stats.rx_over_errors++;
636 		// FALLTHROUGH
637 
638 	default:
639 		state = rx_cleanup;
640 		dev->net->stats.rx_errors++;
641 		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
642 		break;
643 	}
644 
645 	/* stop rx if packet error rate is high */
646 	if (++dev->pkt_cnt > 30) {
647 		dev->pkt_cnt = 0;
648 		dev->pkt_err = 0;
649 	} else {
650 		if (state == rx_cleanup)
651 			dev->pkt_err++;
652 		if (dev->pkt_err > 20)
653 			set_bit(EVENT_RX_KILL, &dev->flags);
654 	}
655 
656 	state = defer_bh(dev, skb, &dev->rxq, state);
657 
658 	if (urb) {
659 		if (netif_running (dev->net) &&
660 		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
661 		    state != unlink_start) {
662 			rx_submit (dev, urb, GFP_ATOMIC);
663 			usb_mark_last_busy(dev->udev);
664 			return;
665 		}
666 		usb_free_urb (urb);
667 	}
668 	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
669 }
670 
671 /*-------------------------------------------------------------------------*/
usbnet_pause_rx(struct usbnet * dev)672 void usbnet_pause_rx(struct usbnet *dev)
673 {
674 	set_bit(EVENT_RX_PAUSED, &dev->flags);
675 
676 	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
677 }
678 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
679 
usbnet_resume_rx(struct usbnet * dev)680 void usbnet_resume_rx(struct usbnet *dev)
681 {
682 	struct sk_buff *skb;
683 	int num = 0;
684 
685 	clear_bit(EVENT_RX_PAUSED, &dev->flags);
686 
687 	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
688 		usbnet_skb_return(dev, skb);
689 		num++;
690 	}
691 
692 	tasklet_schedule(&dev->bh);
693 
694 	netif_dbg(dev, rx_status, dev->net,
695 		  "paused rx queue disabled, %d skbs requeued\n", num);
696 }
697 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
698 
usbnet_purge_paused_rxq(struct usbnet * dev)699 void usbnet_purge_paused_rxq(struct usbnet *dev)
700 {
701 	skb_queue_purge(&dev->rxq_pause);
702 }
703 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
704 
705 /*-------------------------------------------------------------------------*/
706 
707 // unlink pending rx/tx; completion handlers do all other cleanup
708 
unlink_urbs(struct usbnet * dev,struct sk_buff_head * q)709 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
710 {
711 	unsigned long		flags;
712 	struct sk_buff		*skb;
713 	int			count = 0;
714 
715 	spin_lock_irqsave (&q->lock, flags);
716 	while (!skb_queue_empty(q)) {
717 		struct skb_data		*entry;
718 		struct urb		*urb;
719 		int			retval;
720 
721 		skb_queue_walk(q, skb) {
722 			entry = (struct skb_data *) skb->cb;
723 			if (entry->state != unlink_start)
724 				goto found;
725 		}
726 		break;
727 found:
728 		entry->state = unlink_start;
729 		urb = entry->urb;
730 
731 		/*
732 		 * Get reference count of the URB to avoid it to be
733 		 * freed during usb_unlink_urb, which may trigger
734 		 * use-after-free problem inside usb_unlink_urb since
735 		 * usb_unlink_urb is always racing with .complete
736 		 * handler(include defer_bh).
737 		 */
738 		usb_get_urb(urb);
739 		spin_unlock_irqrestore(&q->lock, flags);
740 		// during some PM-driven resume scenarios,
741 		// these (async) unlinks complete immediately
742 		retval = usb_unlink_urb (urb);
743 		if (retval != -EINPROGRESS && retval != 0)
744 			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
745 		else
746 			count++;
747 		usb_put_urb(urb);
748 		spin_lock_irqsave(&q->lock, flags);
749 	}
750 	spin_unlock_irqrestore (&q->lock, flags);
751 	return count;
752 }
753 
754 // Flush all pending rx urbs
755 // minidrivers may need to do this when the MTU changes
756 
usbnet_unlink_rx_urbs(struct usbnet * dev)757 void usbnet_unlink_rx_urbs(struct usbnet *dev)
758 {
759 	if (netif_running(dev->net)) {
760 		(void) unlink_urbs (dev, &dev->rxq);
761 		tasklet_schedule(&dev->bh);
762 	}
763 }
764 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
765 
766 /*-------------------------------------------------------------------------*/
767 
wait_skb_queue_empty(struct sk_buff_head * q)768 static void wait_skb_queue_empty(struct sk_buff_head *q)
769 {
770 	unsigned long flags;
771 
772 	spin_lock_irqsave(&q->lock, flags);
773 	while (!skb_queue_empty(q)) {
774 		spin_unlock_irqrestore(&q->lock, flags);
775 		schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
776 		set_current_state(TASK_UNINTERRUPTIBLE);
777 		spin_lock_irqsave(&q->lock, flags);
778 	}
779 	spin_unlock_irqrestore(&q->lock, flags);
780 }
781 
782 // precondition: never called in_interrupt
usbnet_terminate_urbs(struct usbnet * dev)783 static void usbnet_terminate_urbs(struct usbnet *dev)
784 {
785 	DECLARE_WAITQUEUE(wait, current);
786 	int temp;
787 
788 	/* ensure there are no more active urbs */
789 	add_wait_queue(&dev->wait, &wait);
790 	set_current_state(TASK_UNINTERRUPTIBLE);
791 	temp = unlink_urbs(dev, &dev->txq) +
792 		unlink_urbs(dev, &dev->rxq);
793 
794 	/* maybe wait for deletions to finish. */
795 	wait_skb_queue_empty(&dev->rxq);
796 	wait_skb_queue_empty(&dev->txq);
797 	wait_skb_queue_empty(&dev->done);
798 	netif_dbg(dev, ifdown, dev->net,
799 		  "waited for %d urb completions\n", temp);
800 	set_current_state(TASK_RUNNING);
801 	remove_wait_queue(&dev->wait, &wait);
802 }
803 
usbnet_stop(struct net_device * net)804 int usbnet_stop (struct net_device *net)
805 {
806 	struct usbnet		*dev = netdev_priv(net);
807 	struct driver_info	*info = dev->driver_info;
808 	int			retval, pm, mpn;
809 
810 	clear_bit(EVENT_DEV_OPEN, &dev->flags);
811 	netif_stop_queue (net);
812 
813 	netif_info(dev, ifdown, dev->net,
814 		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
815 		   net->stats.rx_packets, net->stats.tx_packets,
816 		   net->stats.rx_errors, net->stats.tx_errors);
817 
818 	/* to not race resume */
819 	pm = usb_autopm_get_interface(dev->intf);
820 	/* allow minidriver to stop correctly (wireless devices to turn off
821 	 * radio etc) */
822 	if (info->stop) {
823 		retval = info->stop(dev);
824 		if (retval < 0)
825 			netif_info(dev, ifdown, dev->net,
826 				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
827 				   retval,
828 				   dev->udev->bus->bus_name, dev->udev->devpath,
829 				   info->description);
830 	}
831 
832 	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
833 		usbnet_terminate_urbs(dev);
834 
835 	usbnet_status_stop(dev);
836 
837 	usbnet_purge_paused_rxq(dev);
838 
839 	mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
840 
841 	/* deferred work (task, timer, softirq) must also stop.
842 	 * can't flush_scheduled_work() until we drop rtnl (later),
843 	 * else workers could deadlock; so make workers a NOP.
844 	 */
845 	dev->flags = 0;
846 	del_timer_sync (&dev->delay);
847 	tasklet_kill (&dev->bh);
848 	if (!pm)
849 		usb_autopm_put_interface(dev->intf);
850 
851 	if (info->manage_power && mpn)
852 		info->manage_power(dev, 0);
853 	else
854 		usb_autopm_put_interface(dev->intf);
855 
856 	return 0;
857 }
858 EXPORT_SYMBOL_GPL(usbnet_stop);
859 
860 /*-------------------------------------------------------------------------*/
861 
862 // posts reads, and enables write queuing
863 
864 // precondition: never called in_interrupt
865 
usbnet_open(struct net_device * net)866 int usbnet_open (struct net_device *net)
867 {
868 	struct usbnet		*dev = netdev_priv(net);
869 	int			retval;
870 	struct driver_info	*info = dev->driver_info;
871 
872 	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
873 		netif_info(dev, ifup, dev->net,
874 			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
875 			   retval,
876 			   dev->udev->bus->bus_name,
877 			   dev->udev->devpath,
878 			   info->description);
879 		goto done_nopm;
880 	}
881 
882 	// put into "known safe" state
883 	if (info->reset && (retval = info->reset (dev)) < 0) {
884 		netif_info(dev, ifup, dev->net,
885 			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
886 			   retval,
887 			   dev->udev->bus->bus_name,
888 			   dev->udev->devpath,
889 			   info->description);
890 		goto done;
891 	}
892 
893 	/* hard_mtu or rx_urb_size may change in reset() */
894 	usbnet_update_max_qlen(dev);
895 
896 	// insist peer be connected
897 	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
898 		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
899 		goto done;
900 	}
901 
902 	/* start any status interrupt transfer */
903 	if (dev->interrupt) {
904 		retval = usbnet_status_start(dev, GFP_KERNEL);
905 		if (retval < 0) {
906 			netif_err(dev, ifup, dev->net,
907 				  "intr submit %d\n", retval);
908 			goto done;
909 		}
910 	}
911 
912 	set_bit(EVENT_DEV_OPEN, &dev->flags);
913 	netif_start_queue (net);
914 	netif_info(dev, ifup, dev->net,
915 		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
916 		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
917 		   dev->net->mtu,
918 		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
919 		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
920 		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
921 		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
922 		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
923 		   "simple");
924 
925 	/* reset rx error state */
926 	dev->pkt_cnt = 0;
927 	dev->pkt_err = 0;
928 	clear_bit(EVENT_RX_KILL, &dev->flags);
929 
930 	// delay posting reads until we're fully open
931 	tasklet_schedule (&dev->bh);
932 	if (info->manage_power) {
933 		retval = info->manage_power(dev, 1);
934 		if (retval < 0) {
935 			retval = 0;
936 			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
937 		} else {
938 			usb_autopm_put_interface(dev->intf);
939 		}
940 	}
941 	return retval;
942 done:
943 	usb_autopm_put_interface(dev->intf);
944 done_nopm:
945 	return retval;
946 }
947 EXPORT_SYMBOL_GPL(usbnet_open);
948 
949 /*-------------------------------------------------------------------------*/
950 
951 /* ethtool methods; minidrivers may need to add some more, but
952  * they'll probably want to use this base set.
953  */
954 
usbnet_get_settings(struct net_device * net,struct ethtool_cmd * cmd)955 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
956 {
957 	struct usbnet *dev = netdev_priv(net);
958 
959 	if (!dev->mii.mdio_read)
960 		return -EOPNOTSUPP;
961 
962 	return mii_ethtool_gset(&dev->mii, cmd);
963 }
964 EXPORT_SYMBOL_GPL(usbnet_get_settings);
965 
usbnet_set_settings(struct net_device * net,struct ethtool_cmd * cmd)966 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
967 {
968 	struct usbnet *dev = netdev_priv(net);
969 	int retval;
970 
971 	if (!dev->mii.mdio_write)
972 		return -EOPNOTSUPP;
973 
974 	retval = mii_ethtool_sset(&dev->mii, cmd);
975 
976 	/* link speed/duplex might have changed */
977 	if (dev->driver_info->link_reset)
978 		dev->driver_info->link_reset(dev);
979 
980 	/* hard_mtu or rx_urb_size may change in link_reset() */
981 	usbnet_update_max_qlen(dev);
982 
983 	return retval;
984 
985 }
986 EXPORT_SYMBOL_GPL(usbnet_set_settings);
987 
usbnet_get_link(struct net_device * net)988 u32 usbnet_get_link (struct net_device *net)
989 {
990 	struct usbnet *dev = netdev_priv(net);
991 
992 	/* If a check_connect is defined, return its result */
993 	if (dev->driver_info->check_connect)
994 		return dev->driver_info->check_connect (dev) == 0;
995 
996 	/* if the device has mii operations, use those */
997 	if (dev->mii.mdio_read)
998 		return mii_link_ok(&dev->mii);
999 
1000 	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1001 	return ethtool_op_get_link(net);
1002 }
1003 EXPORT_SYMBOL_GPL(usbnet_get_link);
1004 
usbnet_nway_reset(struct net_device * net)1005 int usbnet_nway_reset(struct net_device *net)
1006 {
1007 	struct usbnet *dev = netdev_priv(net);
1008 
1009 	if (!dev->mii.mdio_write)
1010 		return -EOPNOTSUPP;
1011 
1012 	return mii_nway_restart(&dev->mii);
1013 }
1014 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1015 
usbnet_get_drvinfo(struct net_device * net,struct ethtool_drvinfo * info)1016 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1017 {
1018 	struct usbnet *dev = netdev_priv(net);
1019 
1020 	strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1021 	strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1022 	strlcpy (info->fw_version, dev->driver_info->description,
1023 		sizeof info->fw_version);
1024 	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1025 }
1026 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1027 
usbnet_get_msglevel(struct net_device * net)1028 u32 usbnet_get_msglevel (struct net_device *net)
1029 {
1030 	struct usbnet *dev = netdev_priv(net);
1031 
1032 	return dev->msg_enable;
1033 }
1034 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1035 
usbnet_set_msglevel(struct net_device * net,u32 level)1036 void usbnet_set_msglevel (struct net_device *net, u32 level)
1037 {
1038 	struct usbnet *dev = netdev_priv(net);
1039 
1040 	dev->msg_enable = level;
1041 }
1042 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1043 
1044 /* drivers may override default ethtool_ops in their bind() routine */
1045 static const struct ethtool_ops usbnet_ethtool_ops = {
1046 	.get_settings		= usbnet_get_settings,
1047 	.set_settings		= usbnet_set_settings,
1048 	.get_link		= usbnet_get_link,
1049 	.nway_reset		= usbnet_nway_reset,
1050 	.get_drvinfo		= usbnet_get_drvinfo,
1051 	.get_msglevel		= usbnet_get_msglevel,
1052 	.set_msglevel		= usbnet_set_msglevel,
1053 	.get_ts_info		= ethtool_op_get_ts_info,
1054 };
1055 
1056 /*-------------------------------------------------------------------------*/
1057 
__handle_link_change(struct usbnet * dev)1058 static void __handle_link_change(struct usbnet *dev)
1059 {
1060 	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1061 		return;
1062 
1063 	if (!netif_carrier_ok(dev->net)) {
1064 		/* kill URBs for reading packets to save bus bandwidth */
1065 		unlink_urbs(dev, &dev->rxq);
1066 
1067 		/*
1068 		 * tx_timeout will unlink URBs for sending packets and
1069 		 * tx queue is stopped by netcore after link becomes off
1070 		 */
1071 	} else {
1072 		/* submitting URBs for reading packets */
1073 		tasklet_schedule(&dev->bh);
1074 	}
1075 
1076 	/* hard_mtu or rx_urb_size may change during link change */
1077 	usbnet_update_max_qlen(dev);
1078 
1079 	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1080 }
1081 
usbnet_set_rx_mode(struct net_device * net)1082 static void usbnet_set_rx_mode(struct net_device *net)
1083 {
1084 	struct usbnet		*dev = netdev_priv(net);
1085 
1086 	usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1087 }
1088 
__handle_set_rx_mode(struct usbnet * dev)1089 static void __handle_set_rx_mode(struct usbnet *dev)
1090 {
1091 	if (dev->driver_info->set_rx_mode)
1092 		(dev->driver_info->set_rx_mode)(dev);
1093 
1094 	clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1095 }
1096 
1097 /* work that cannot be done in interrupt context uses keventd.
1098  *
1099  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1100  * especially now that control transfers can be queued.
1101  */
1102 static void
usbnet_deferred_kevent(struct work_struct * work)1103 usbnet_deferred_kevent (struct work_struct *work)
1104 {
1105 	struct usbnet		*dev =
1106 		container_of(work, struct usbnet, kevent);
1107 	int			status;
1108 
1109 	/* usb_clear_halt() needs a thread context */
1110 	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1111 		unlink_urbs (dev, &dev->txq);
1112 		status = usb_autopm_get_interface(dev->intf);
1113 		if (status < 0)
1114 			goto fail_pipe;
1115 		status = usb_clear_halt (dev->udev, dev->out);
1116 		usb_autopm_put_interface(dev->intf);
1117 		if (status < 0 &&
1118 		    status != -EPIPE &&
1119 		    status != -ESHUTDOWN) {
1120 			if (netif_msg_tx_err (dev))
1121 fail_pipe:
1122 				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1123 					   status);
1124 		} else {
1125 			clear_bit (EVENT_TX_HALT, &dev->flags);
1126 			if (status != -ESHUTDOWN)
1127 				netif_wake_queue (dev->net);
1128 		}
1129 	}
1130 	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1131 		unlink_urbs (dev, &dev->rxq);
1132 		status = usb_autopm_get_interface(dev->intf);
1133 		if (status < 0)
1134 			goto fail_halt;
1135 		status = usb_clear_halt (dev->udev, dev->in);
1136 		usb_autopm_put_interface(dev->intf);
1137 		if (status < 0 &&
1138 		    status != -EPIPE &&
1139 		    status != -ESHUTDOWN) {
1140 			if (netif_msg_rx_err (dev))
1141 fail_halt:
1142 				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1143 					   status);
1144 		} else {
1145 			clear_bit (EVENT_RX_HALT, &dev->flags);
1146 			tasklet_schedule (&dev->bh);
1147 		}
1148 	}
1149 
1150 	/* tasklet could resubmit itself forever if memory is tight */
1151 	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1152 		struct urb	*urb = NULL;
1153 		int resched = 1;
1154 
1155 		if (netif_running (dev->net))
1156 			urb = usb_alloc_urb (0, GFP_KERNEL);
1157 		else
1158 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1159 		if (urb != NULL) {
1160 			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1161 			status = usb_autopm_get_interface(dev->intf);
1162 			if (status < 0) {
1163 				usb_free_urb(urb);
1164 				goto fail_lowmem;
1165 			}
1166 			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1167 				resched = 0;
1168 			usb_autopm_put_interface(dev->intf);
1169 fail_lowmem:
1170 			if (resched)
1171 				tasklet_schedule (&dev->bh);
1172 		}
1173 	}
1174 
1175 	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1176 		struct driver_info	*info = dev->driver_info;
1177 		int			retval = 0;
1178 
1179 		clear_bit (EVENT_LINK_RESET, &dev->flags);
1180 		status = usb_autopm_get_interface(dev->intf);
1181 		if (status < 0)
1182 			goto skip_reset;
1183 		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1184 			usb_autopm_put_interface(dev->intf);
1185 skip_reset:
1186 			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1187 				    retval,
1188 				    dev->udev->bus->bus_name,
1189 				    dev->udev->devpath,
1190 				    info->description);
1191 		} else {
1192 			usb_autopm_put_interface(dev->intf);
1193 		}
1194 
1195 		/* handle link change from link resetting */
1196 		__handle_link_change(dev);
1197 	}
1198 
1199 	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1200 		__handle_link_change(dev);
1201 
1202 	if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1203 		__handle_set_rx_mode(dev);
1204 
1205 
1206 	if (dev->flags)
1207 		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1208 }
1209 
1210 /*-------------------------------------------------------------------------*/
1211 
tx_complete(struct urb * urb)1212 static void tx_complete (struct urb *urb)
1213 {
1214 	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1215 	struct skb_data		*entry = (struct skb_data *) skb->cb;
1216 	struct usbnet		*dev = entry->dev;
1217 
1218 	if (urb->status == 0) {
1219 		dev->net->stats.tx_packets += entry->packets;
1220 		dev->net->stats.tx_bytes += entry->length;
1221 	} else {
1222 		dev->net->stats.tx_errors++;
1223 
1224 		switch (urb->status) {
1225 		case -EPIPE:
1226 			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1227 			break;
1228 
1229 		/* software-driven interface shutdown */
1230 		case -ECONNRESET:		// async unlink
1231 		case -ESHUTDOWN:		// hardware gone
1232 			break;
1233 
1234 		/* like rx, tx gets controller i/o faults during hub_wq
1235 		 * delays and so it uses the same throttling mechanism.
1236 		 */
1237 		case -EPROTO:
1238 		case -ETIME:
1239 		case -EILSEQ:
1240 			usb_mark_last_busy(dev->udev);
1241 			if (!timer_pending (&dev->delay)) {
1242 				mod_timer (&dev->delay,
1243 					jiffies + THROTTLE_JIFFIES);
1244 				netif_dbg(dev, link, dev->net,
1245 					  "tx throttle %d\n", urb->status);
1246 			}
1247 			netif_stop_queue (dev->net);
1248 			break;
1249 		default:
1250 			netif_dbg(dev, tx_err, dev->net,
1251 				  "tx err %d\n", entry->urb->status);
1252 			break;
1253 		}
1254 	}
1255 
1256 	usb_autopm_put_interface_async(dev->intf);
1257 	(void) defer_bh(dev, skb, &dev->txq, tx_done);
1258 }
1259 
1260 /*-------------------------------------------------------------------------*/
1261 
usbnet_tx_timeout(struct net_device * net)1262 void usbnet_tx_timeout (struct net_device *net)
1263 {
1264 	struct usbnet		*dev = netdev_priv(net);
1265 
1266 	unlink_urbs (dev, &dev->txq);
1267 	tasklet_schedule (&dev->bh);
1268 	/* this needs to be handled individually because the generic layer
1269 	 * doesn't know what is sufficient and could not restore private
1270 	 * information if a remedy of an unconditional reset were used.
1271 	 */
1272 	if (dev->driver_info->recover)
1273 		(dev->driver_info->recover)(dev);
1274 }
1275 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1276 
1277 /*-------------------------------------------------------------------------*/
1278 
build_dma_sg(const struct sk_buff * skb,struct urb * urb)1279 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1280 {
1281 	unsigned num_sgs, total_len = 0;
1282 	int i, s = 0;
1283 
1284 	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1285 	if (num_sgs == 1)
1286 		return 0;
1287 
1288 	/* reserve one for zero packet */
1289 	urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1290 			  GFP_ATOMIC);
1291 	if (!urb->sg)
1292 		return -ENOMEM;
1293 
1294 	urb->num_sgs = num_sgs;
1295 	sg_init_table(urb->sg, urb->num_sgs + 1);
1296 
1297 	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1298 	total_len += skb_headlen(skb);
1299 
1300 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1301 		struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1302 
1303 		total_len += skb_frag_size(f);
1304 		sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1305 				f->page_offset);
1306 	}
1307 	urb->transfer_buffer_length = total_len;
1308 
1309 	return 1;
1310 }
1311 
usbnet_start_xmit(struct sk_buff * skb,struct net_device * net)1312 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1313 				     struct net_device *net)
1314 {
1315 	struct usbnet		*dev = netdev_priv(net);
1316 	unsigned int			length;
1317 	struct urb		*urb = NULL;
1318 	struct skb_data		*entry;
1319 	struct driver_info	*info = dev->driver_info;
1320 	unsigned long		flags;
1321 	int retval;
1322 
1323 	if (skb)
1324 		skb_tx_timestamp(skb);
1325 
1326 	// some devices want funky USB-level framing, for
1327 	// win32 driver (usually) and/or hardware quirks
1328 	if (info->tx_fixup) {
1329 		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1330 		if (!skb) {
1331 			/* packet collected; minidriver waiting for more */
1332 			if (info->flags & FLAG_MULTI_PACKET)
1333 				goto not_drop;
1334 			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1335 			goto drop;
1336 		}
1337 	}
1338 
1339 	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1340 		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1341 		goto drop;
1342 	}
1343 
1344 	entry = (struct skb_data *) skb->cb;
1345 	entry->urb = urb;
1346 	entry->dev = dev;
1347 
1348 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1349 			skb->data, skb->len, tx_complete, skb);
1350 	if (dev->can_dma_sg) {
1351 		if (build_dma_sg(skb, urb) < 0)
1352 			goto drop;
1353 	}
1354 	length = urb->transfer_buffer_length;
1355 
1356 	/* don't assume the hardware handles USB_ZERO_PACKET
1357 	 * NOTE:  strictly conforming cdc-ether devices should expect
1358 	 * the ZLP here, but ignore the one-byte packet.
1359 	 * NOTE2: CDC NCM specification is different from CDC ECM when
1360 	 * handling ZLP/short packets, so cdc_ncm driver will make short
1361 	 * packet itself if needed.
1362 	 */
1363 	if (length % dev->maxpacket == 0) {
1364 		if (!(info->flags & FLAG_SEND_ZLP)) {
1365 			if (!(info->flags & FLAG_MULTI_PACKET)) {
1366 				length++;
1367 				if (skb_tailroom(skb) && !urb->num_sgs) {
1368 					skb->data[skb->len] = 0;
1369 					__skb_put(skb, 1);
1370 				} else if (urb->num_sgs)
1371 					sg_set_buf(&urb->sg[urb->num_sgs++],
1372 							dev->padding_pkt, 1);
1373 			}
1374 		} else
1375 			urb->transfer_flags |= URB_ZERO_PACKET;
1376 	}
1377 	urb->transfer_buffer_length = length;
1378 
1379 	if (info->flags & FLAG_MULTI_PACKET) {
1380 		/* Driver has set number of packets and a length delta.
1381 		 * Calculate the complete length and ensure that it's
1382 		 * positive.
1383 		 */
1384 		entry->length += length;
1385 		if (WARN_ON_ONCE(entry->length <= 0))
1386 			entry->length = length;
1387 	} else {
1388 		usbnet_set_skb_tx_stats(skb, 1, length);
1389 	}
1390 
1391 	spin_lock_irqsave(&dev->txq.lock, flags);
1392 	retval = usb_autopm_get_interface_async(dev->intf);
1393 	if (retval < 0) {
1394 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1395 		goto drop;
1396 	}
1397 	if (netif_queue_stopped(net)) {
1398 		usb_autopm_put_interface_async(dev->intf);
1399 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1400 		goto drop;
1401 	}
1402 
1403 #ifdef CONFIG_PM
1404 	/* if this triggers the device is still a sleep */
1405 	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1406 		/* transmission will be done in resume */
1407 		usb_anchor_urb(urb, &dev->deferred);
1408 		/* no use to process more packets */
1409 		netif_stop_queue(net);
1410 		usb_put_urb(urb);
1411 		spin_unlock_irqrestore(&dev->txq.lock, flags);
1412 		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1413 		goto deferred;
1414 	}
1415 #endif
1416 
1417 	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1418 	case -EPIPE:
1419 		netif_stop_queue (net);
1420 		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1421 		usb_autopm_put_interface_async(dev->intf);
1422 		break;
1423 	default:
1424 		usb_autopm_put_interface_async(dev->intf);
1425 		netif_dbg(dev, tx_err, dev->net,
1426 			  "tx: submit urb err %d\n", retval);
1427 		break;
1428 	case 0:
1429 		net->trans_start = jiffies;
1430 		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1431 		if (dev->txq.qlen >= TX_QLEN (dev))
1432 			netif_stop_queue (net);
1433 	}
1434 	spin_unlock_irqrestore (&dev->txq.lock, flags);
1435 
1436 	if (retval) {
1437 		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1438 drop:
1439 		dev->net->stats.tx_dropped++;
1440 not_drop:
1441 		if (skb)
1442 			dev_kfree_skb_any (skb);
1443 		if (urb) {
1444 			kfree(urb->sg);
1445 			usb_free_urb(urb);
1446 		}
1447 	} else
1448 		netif_dbg(dev, tx_queued, dev->net,
1449 			  "> tx, len %u, type 0x%x\n", length, skb->protocol);
1450 #ifdef CONFIG_PM
1451 deferred:
1452 #endif
1453 	return NETDEV_TX_OK;
1454 }
1455 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1456 
rx_alloc_submit(struct usbnet * dev,gfp_t flags)1457 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1458 {
1459 	struct urb	*urb;
1460 	int		i;
1461 	int		ret = 0;
1462 
1463 	/* don't refill the queue all at once */
1464 	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1465 		urb = usb_alloc_urb(0, flags);
1466 		if (urb != NULL) {
1467 			ret = rx_submit(dev, urb, flags);
1468 			if (ret)
1469 				goto err;
1470 		} else {
1471 			ret = -ENOMEM;
1472 			goto err;
1473 		}
1474 	}
1475 err:
1476 	return ret;
1477 }
1478 
1479 /*-------------------------------------------------------------------------*/
1480 
1481 // tasklet (work deferred from completions, in_irq) or timer
1482 
usbnet_bh(unsigned long param)1483 static void usbnet_bh (unsigned long param)
1484 {
1485 	struct usbnet		*dev = (struct usbnet *) param;
1486 	struct sk_buff		*skb;
1487 	struct skb_data		*entry;
1488 
1489 	while ((skb = skb_dequeue (&dev->done))) {
1490 		entry = (struct skb_data *) skb->cb;
1491 		switch (entry->state) {
1492 		case rx_done:
1493 			entry->state = rx_cleanup;
1494 			rx_process (dev, skb);
1495 			continue;
1496 		case tx_done:
1497 			kfree(entry->urb->sg);
1498 		case rx_cleanup:
1499 			usb_free_urb (entry->urb);
1500 			dev_kfree_skb (skb);
1501 			continue;
1502 		default:
1503 			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1504 		}
1505 	}
1506 
1507 	/* restart RX again after disabling due to high error rate */
1508 	clear_bit(EVENT_RX_KILL, &dev->flags);
1509 
1510 	/* waiting for all pending urbs to complete?
1511 	 * only then can we forgo submitting anew
1512 	 */
1513 	if (waitqueue_active(&dev->wait)) {
1514 		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1515 			wake_up_all(&dev->wait);
1516 
1517 	// or are we maybe short a few urbs?
1518 	} else if (netif_running (dev->net) &&
1519 		   netif_device_present (dev->net) &&
1520 		   netif_carrier_ok(dev->net) &&
1521 		   !timer_pending (&dev->delay) &&
1522 		   !test_bit (EVENT_RX_HALT, &dev->flags)) {
1523 		int	temp = dev->rxq.qlen;
1524 
1525 		if (temp < RX_QLEN(dev)) {
1526 			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1527 				return;
1528 			if (temp != dev->rxq.qlen)
1529 				netif_dbg(dev, link, dev->net,
1530 					  "rxqlen %d --> %d\n",
1531 					  temp, dev->rxq.qlen);
1532 			if (dev->rxq.qlen < RX_QLEN(dev))
1533 				tasklet_schedule (&dev->bh);
1534 		}
1535 		if (dev->txq.qlen < TX_QLEN (dev))
1536 			netif_wake_queue (dev->net);
1537 	}
1538 }
1539 
1540 
1541 /*-------------------------------------------------------------------------
1542  *
1543  * USB Device Driver support
1544  *
1545  *-------------------------------------------------------------------------*/
1546 
1547 // precondition: never called in_interrupt
1548 
usbnet_disconnect(struct usb_interface * intf)1549 void usbnet_disconnect (struct usb_interface *intf)
1550 {
1551 	struct usbnet		*dev;
1552 	struct usb_device	*xdev;
1553 	struct net_device	*net;
1554 
1555 	dev = usb_get_intfdata(intf);
1556 	usb_set_intfdata(intf, NULL);
1557 	if (!dev)
1558 		return;
1559 
1560 	xdev = interface_to_usbdev (intf);
1561 
1562 	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1563 		   intf->dev.driver->name,
1564 		   xdev->bus->bus_name, xdev->devpath,
1565 		   dev->driver_info->description);
1566 
1567 	net = dev->net;
1568 	unregister_netdev (net);
1569 
1570 	cancel_work_sync(&dev->kevent);
1571 
1572 	usb_scuttle_anchored_urbs(&dev->deferred);
1573 
1574 	if (dev->driver_info->unbind)
1575 		dev->driver_info->unbind (dev, intf);
1576 
1577 	usb_kill_urb(dev->interrupt);
1578 	usb_free_urb(dev->interrupt);
1579 	kfree(dev->padding_pkt);
1580 
1581 	free_netdev(net);
1582 }
1583 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1584 
1585 static const struct net_device_ops usbnet_netdev_ops = {
1586 	.ndo_open		= usbnet_open,
1587 	.ndo_stop		= usbnet_stop,
1588 	.ndo_start_xmit		= usbnet_start_xmit,
1589 	.ndo_tx_timeout		= usbnet_tx_timeout,
1590 	.ndo_set_rx_mode	= usbnet_set_rx_mode,
1591 	.ndo_change_mtu		= usbnet_change_mtu,
1592 	.ndo_set_mac_address 	= eth_mac_addr,
1593 	.ndo_validate_addr	= eth_validate_addr,
1594 };
1595 
1596 /*-------------------------------------------------------------------------*/
1597 
1598 // precondition: never called in_interrupt
1599 
1600 static struct device_type wlan_type = {
1601 	.name	= "wlan",
1602 };
1603 
1604 static struct device_type wwan_type = {
1605 	.name	= "wwan",
1606 };
1607 
1608 int
usbnet_probe(struct usb_interface * udev,const struct usb_device_id * prod)1609 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1610 {
1611 	struct usbnet			*dev;
1612 	struct net_device		*net;
1613 	struct usb_host_interface	*interface;
1614 	struct driver_info		*info;
1615 	struct usb_device		*xdev;
1616 	int				status;
1617 	const char			*name;
1618 	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1619 
1620 	/* usbnet already took usb runtime pm, so have to enable the feature
1621 	 * for usb interface, otherwise usb_autopm_get_interface may return
1622 	 * failure if RUNTIME_PM is enabled.
1623 	 */
1624 	if (!driver->supports_autosuspend) {
1625 		driver->supports_autosuspend = 1;
1626 		pm_runtime_enable(&udev->dev);
1627 	}
1628 
1629 	name = udev->dev.driver->name;
1630 	info = (struct driver_info *) prod->driver_info;
1631 	if (!info) {
1632 		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1633 		return -ENODEV;
1634 	}
1635 	xdev = interface_to_usbdev (udev);
1636 	interface = udev->cur_altsetting;
1637 
1638 	status = -ENOMEM;
1639 
1640 	// set up our own records
1641 	net = alloc_etherdev(sizeof(*dev));
1642 	if (!net)
1643 		goto out;
1644 
1645 	/* netdev_printk() needs this so do it as early as possible */
1646 	SET_NETDEV_DEV(net, &udev->dev);
1647 
1648 	dev = netdev_priv(net);
1649 	dev->udev = xdev;
1650 	dev->intf = udev;
1651 	dev->driver_info = info;
1652 	dev->driver_name = name;
1653 	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1654 				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1655 	init_waitqueue_head(&dev->wait);
1656 	skb_queue_head_init (&dev->rxq);
1657 	skb_queue_head_init (&dev->txq);
1658 	skb_queue_head_init (&dev->done);
1659 	skb_queue_head_init(&dev->rxq_pause);
1660 	dev->bh.func = usbnet_bh;
1661 	dev->bh.data = (unsigned long) dev;
1662 	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1663 	init_usb_anchor(&dev->deferred);
1664 	dev->delay.function = usbnet_bh;
1665 	dev->delay.data = (unsigned long) dev;
1666 	init_timer (&dev->delay);
1667 	mutex_init (&dev->phy_mutex);
1668 	mutex_init(&dev->interrupt_mutex);
1669 	dev->interrupt_count = 0;
1670 
1671 	dev->net = net;
1672 	strcpy (net->name, "usb%d");
1673 	memcpy (net->dev_addr, node_id, sizeof node_id);
1674 
1675 	/* rx and tx sides can use different message sizes;
1676 	 * bind() should set rx_urb_size in that case.
1677 	 */
1678 	dev->hard_mtu = net->mtu + net->hard_header_len;
1679 
1680 	net->netdev_ops = &usbnet_netdev_ops;
1681 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1682 	net->ethtool_ops = &usbnet_ethtool_ops;
1683 
1684 	// allow device-specific bind/init procedures
1685 	// NOTE net->name still not usable ...
1686 	if (info->bind) {
1687 		status = info->bind (dev, udev);
1688 		if (status < 0)
1689 			goto out1;
1690 
1691 		// heuristic:  "usb%d" for links we know are two-host,
1692 		// else "eth%d" when there's reasonable doubt.  userspace
1693 		// can rename the link if it knows better.
1694 		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1695 		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1696 		     (net->dev_addr [0] & 0x02) == 0))
1697 			strcpy (net->name, "eth%d");
1698 		/* WLAN devices should always be named "wlan%d" */
1699 		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1700 			strcpy(net->name, "wlan%d");
1701 		/* WWAN devices should always be named "wwan%d" */
1702 		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1703 			strcpy(net->name, "wwan%d");
1704 
1705 		/* devices that cannot do ARP */
1706 		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1707 			net->flags |= IFF_NOARP;
1708 
1709 		/* maybe the remote can't receive an Ethernet MTU */
1710 		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1711 			net->mtu = dev->hard_mtu - net->hard_header_len;
1712 	} else if (!info->in || !info->out)
1713 		status = usbnet_get_endpoints (dev, udev);
1714 	else {
1715 		dev->in = usb_rcvbulkpipe (xdev, info->in);
1716 		dev->out = usb_sndbulkpipe (xdev, info->out);
1717 		if (!(info->flags & FLAG_NO_SETINT))
1718 			status = usb_set_interface (xdev,
1719 				interface->desc.bInterfaceNumber,
1720 				interface->desc.bAlternateSetting);
1721 		else
1722 			status = 0;
1723 
1724 	}
1725 	if (status >= 0 && dev->status)
1726 		status = init_status (dev, udev);
1727 	if (status < 0)
1728 		goto out3;
1729 
1730 	if (!dev->rx_urb_size)
1731 		dev->rx_urb_size = dev->hard_mtu;
1732 	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1733 	if (dev->maxpacket == 0) {
1734 		/* that is a broken device */
1735 		status = -ENODEV;
1736 		goto out4;
1737 	}
1738 
1739 	/* let userspace know we have a random address */
1740 	if (ether_addr_equal(net->dev_addr, node_id))
1741 		net->addr_assign_type = NET_ADDR_RANDOM;
1742 
1743 	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1744 		SET_NETDEV_DEVTYPE(net, &wlan_type);
1745 	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1746 		SET_NETDEV_DEVTYPE(net, &wwan_type);
1747 
1748 	/* initialize max rx_qlen and tx_qlen */
1749 	usbnet_update_max_qlen(dev);
1750 
1751 	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1752 		!(info->flags & FLAG_MULTI_PACKET)) {
1753 		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1754 		if (!dev->padding_pkt) {
1755 			status = -ENOMEM;
1756 			goto out4;
1757 		}
1758 	}
1759 
1760 	status = register_netdev (net);
1761 	if (status)
1762 		goto out5;
1763 	netif_info(dev, probe, dev->net,
1764 		   "register '%s' at usb-%s-%s, %s, %pM\n",
1765 		   udev->dev.driver->name,
1766 		   xdev->bus->bus_name, xdev->devpath,
1767 		   dev->driver_info->description,
1768 		   net->dev_addr);
1769 
1770 	// ok, it's ready to go.
1771 	usb_set_intfdata (udev, dev);
1772 
1773 	netif_device_attach (net);
1774 
1775 	if (dev->driver_info->flags & FLAG_LINK_INTR)
1776 		usbnet_link_change(dev, 0, 0);
1777 
1778 	return 0;
1779 
1780 out5:
1781 	kfree(dev->padding_pkt);
1782 out4:
1783 	usb_free_urb(dev->interrupt);
1784 out3:
1785 	if (info->unbind)
1786 		info->unbind (dev, udev);
1787 out1:
1788 	/* subdrivers must undo all they did in bind() if they
1789 	 * fail it, but we may fail later and a deferred kevent
1790 	 * may trigger an error resubmitting itself and, worse,
1791 	 * schedule a timer. So we kill it all just in case.
1792 	 */
1793 	cancel_work_sync(&dev->kevent);
1794 	del_timer_sync(&dev->delay);
1795 	free_netdev(net);
1796 out:
1797 	return status;
1798 }
1799 EXPORT_SYMBOL_GPL(usbnet_probe);
1800 
1801 /*-------------------------------------------------------------------------*/
1802 
1803 /*
1804  * suspend the whole driver as soon as the first interface is suspended
1805  * resume only when the last interface is resumed
1806  */
1807 
usbnet_suspend(struct usb_interface * intf,pm_message_t message)1808 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1809 {
1810 	struct usbnet		*dev = usb_get_intfdata(intf);
1811 
1812 	if (!dev->suspend_count++) {
1813 		spin_lock_irq(&dev->txq.lock);
1814 		/* don't autosuspend while transmitting */
1815 		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1816 			dev->suspend_count--;
1817 			spin_unlock_irq(&dev->txq.lock);
1818 			return -EBUSY;
1819 		} else {
1820 			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1821 			spin_unlock_irq(&dev->txq.lock);
1822 		}
1823 		/*
1824 		 * accelerate emptying of the rx and queues, to avoid
1825 		 * having everything error out.
1826 		 */
1827 		netif_device_detach (dev->net);
1828 		usbnet_terminate_urbs(dev);
1829 		__usbnet_status_stop_force(dev);
1830 
1831 		/*
1832 		 * reattach so runtime management can use and
1833 		 * wake the device
1834 		 */
1835 		netif_device_attach (dev->net);
1836 	}
1837 	return 0;
1838 }
1839 EXPORT_SYMBOL_GPL(usbnet_suspend);
1840 
usbnet_resume(struct usb_interface * intf)1841 int usbnet_resume (struct usb_interface *intf)
1842 {
1843 	struct usbnet		*dev = usb_get_intfdata(intf);
1844 	struct sk_buff          *skb;
1845 	struct urb              *res;
1846 	int                     retval;
1847 
1848 	if (!--dev->suspend_count) {
1849 		/* resume interrupt URB if it was previously submitted */
1850 		__usbnet_status_start_force(dev, GFP_NOIO);
1851 
1852 		spin_lock_irq(&dev->txq.lock);
1853 		while ((res = usb_get_from_anchor(&dev->deferred))) {
1854 
1855 			skb = (struct sk_buff *)res->context;
1856 			retval = usb_submit_urb(res, GFP_ATOMIC);
1857 			if (retval < 0) {
1858 				dev_kfree_skb_any(skb);
1859 				kfree(res->sg);
1860 				usb_free_urb(res);
1861 				usb_autopm_put_interface_async(dev->intf);
1862 			} else {
1863 				dev->net->trans_start = jiffies;
1864 				__skb_queue_tail(&dev->txq, skb);
1865 			}
1866 		}
1867 
1868 		smp_mb();
1869 		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1870 		spin_unlock_irq(&dev->txq.lock);
1871 
1872 		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1873 			/* handle remote wakeup ASAP
1874 			 * we cannot race against stop
1875 			 */
1876 			if (netif_device_present(dev->net) &&
1877 				!timer_pending(&dev->delay) &&
1878 				!test_bit(EVENT_RX_HALT, &dev->flags))
1879 					rx_alloc_submit(dev, GFP_NOIO);
1880 
1881 			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1882 				netif_tx_wake_all_queues(dev->net);
1883 			tasklet_schedule (&dev->bh);
1884 		}
1885 	}
1886 
1887 	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1888 		usb_autopm_get_interface_no_resume(intf);
1889 
1890 	return 0;
1891 }
1892 EXPORT_SYMBOL_GPL(usbnet_resume);
1893 
1894 /*
1895  * Either a subdriver implements manage_power, then it is assumed to always
1896  * be ready to be suspended or it reports the readiness to be suspended
1897  * explicitly
1898  */
usbnet_device_suggests_idle(struct usbnet * dev)1899 void usbnet_device_suggests_idle(struct usbnet *dev)
1900 {
1901 	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1902 		dev->intf->needs_remote_wakeup = 1;
1903 		usb_autopm_put_interface_async(dev->intf);
1904 	}
1905 }
1906 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1907 
1908 /*
1909  * For devices that can do without special commands
1910  */
usbnet_manage_power(struct usbnet * dev,int on)1911 int usbnet_manage_power(struct usbnet *dev, int on)
1912 {
1913 	dev->intf->needs_remote_wakeup = on;
1914 	return 0;
1915 }
1916 EXPORT_SYMBOL(usbnet_manage_power);
1917 
usbnet_link_change(struct usbnet * dev,bool link,bool need_reset)1918 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1919 {
1920 	/* update link after link is reseted */
1921 	if (link && !need_reset)
1922 		netif_carrier_on(dev->net);
1923 	else
1924 		netif_carrier_off(dev->net);
1925 
1926 	if (need_reset && link)
1927 		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1928 	else
1929 		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1930 }
1931 EXPORT_SYMBOL(usbnet_link_change);
1932 
1933 /*-------------------------------------------------------------------------*/
__usbnet_read_cmd(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,void * data,u16 size)1934 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1935 			     u16 value, u16 index, void *data, u16 size)
1936 {
1937 	void *buf = NULL;
1938 	int err = -ENOMEM;
1939 
1940 	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1941 		   " value=0x%04x index=0x%04x size=%d\n",
1942 		   cmd, reqtype, value, index, size);
1943 
1944 	if (data) {
1945 		buf = kmalloc(size, GFP_KERNEL);
1946 		if (!buf)
1947 			goto out;
1948 	}
1949 
1950 	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1951 			      cmd, reqtype, value, index, buf, size,
1952 			      USB_CTRL_GET_TIMEOUT);
1953 	if (err > 0 && err <= size)
1954 		memcpy(data, buf, err);
1955 	kfree(buf);
1956 out:
1957 	return err;
1958 }
1959 
__usbnet_write_cmd(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,const void * data,u16 size)1960 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1961 			      u16 value, u16 index, const void *data,
1962 			      u16 size)
1963 {
1964 	void *buf = NULL;
1965 	int err = -ENOMEM;
1966 
1967 	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1968 		   " value=0x%04x index=0x%04x size=%d\n",
1969 		   cmd, reqtype, value, index, size);
1970 
1971 	if (data) {
1972 		buf = kmemdup(data, size, GFP_KERNEL);
1973 		if (!buf)
1974 			goto out;
1975 	}
1976 
1977 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1978 			      cmd, reqtype, value, index, buf, size,
1979 			      USB_CTRL_SET_TIMEOUT);
1980 	kfree(buf);
1981 
1982 out:
1983 	return err;
1984 }
1985 
cdc_parse_cdc_header(struct usb_cdc_parsed_header * hdr,struct usb_interface * intf,u8 * buffer,int buflen)1986 int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
1987 				struct usb_interface *intf,
1988 				u8 *buffer,
1989 				int buflen)
1990 {
1991 	/* duplicates are ignored */
1992 	struct usb_cdc_union_desc *union_header = NULL;
1993 
1994 	/* duplicates are not tolerated */
1995 	struct usb_cdc_header_desc *header = NULL;
1996 	struct usb_cdc_ether_desc *ether = NULL;
1997 	struct usb_cdc_mdlm_detail_desc *detail = NULL;
1998 	struct usb_cdc_mdlm_desc *desc = NULL;
1999 
2000 	unsigned int elength;
2001 	int cnt = 0;
2002 
2003 	memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2004 	hdr->phonet_magic_present = false;
2005 	while (buflen > 0) {
2006 		elength = buffer[0];
2007 		if (!elength) {
2008 			dev_err(&intf->dev, "skipping garbage byte\n");
2009 			elength = 1;
2010 			goto next_desc;
2011 		}
2012 		if ((buflen < elength) || (elength < 3)) {
2013 			dev_err(&intf->dev, "invalid descriptor buffer length\n");
2014 			break;
2015 		}
2016 		if (buffer[1] != USB_DT_CS_INTERFACE) {
2017 			dev_err(&intf->dev, "skipping garbage\n");
2018 			goto next_desc;
2019 		}
2020 
2021 		switch (buffer[2]) {
2022 		case USB_CDC_UNION_TYPE: /* we've found it */
2023 			if (elength < sizeof(struct usb_cdc_union_desc))
2024 				goto next_desc;
2025 			if (union_header) {
2026 				dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2027 				goto next_desc;
2028 			}
2029 			union_header = (struct usb_cdc_union_desc *)buffer;
2030 			break;
2031 		case USB_CDC_COUNTRY_TYPE:
2032 			if (elength < sizeof(struct usb_cdc_country_functional_desc))
2033 				goto next_desc;
2034 			hdr->usb_cdc_country_functional_desc =
2035 				(struct usb_cdc_country_functional_desc *)buffer;
2036 			break;
2037 		case USB_CDC_HEADER_TYPE:
2038 			if (elength != sizeof(struct usb_cdc_header_desc))
2039 				goto next_desc;
2040 			if (header)
2041 				return -EINVAL;
2042 			header = (struct usb_cdc_header_desc *)buffer;
2043 			break;
2044 		case USB_CDC_ACM_TYPE:
2045 			if (elength < sizeof(struct usb_cdc_acm_descriptor))
2046 				goto next_desc;
2047 			hdr->usb_cdc_acm_descriptor =
2048 				(struct usb_cdc_acm_descriptor *)buffer;
2049 			break;
2050 		case USB_CDC_ETHERNET_TYPE:
2051 			if (elength != sizeof(struct usb_cdc_ether_desc))
2052 				goto next_desc;
2053 			if (ether)
2054 				return -EINVAL;
2055 			ether = (struct usb_cdc_ether_desc *)buffer;
2056 			break;
2057 		case USB_CDC_CALL_MANAGEMENT_TYPE:
2058 			if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2059 				goto next_desc;
2060 			hdr->usb_cdc_call_mgmt_descriptor =
2061 				(struct usb_cdc_call_mgmt_descriptor *)buffer;
2062 			break;
2063 		case USB_CDC_DMM_TYPE:
2064 			if (elength < sizeof(struct usb_cdc_dmm_desc))
2065 				goto next_desc;
2066 			hdr->usb_cdc_dmm_desc =
2067 				(struct usb_cdc_dmm_desc *)buffer;
2068 			break;
2069 		case USB_CDC_MDLM_TYPE:
2070 			if (elength < sizeof(struct usb_cdc_mdlm_desc *))
2071 				goto next_desc;
2072 			if (desc)
2073 				return -EINVAL;
2074 			desc = (struct usb_cdc_mdlm_desc *)buffer;
2075 			break;
2076 		case USB_CDC_MDLM_DETAIL_TYPE:
2077 			if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *))
2078 				goto next_desc;
2079 			if (detail)
2080 				return -EINVAL;
2081 			detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2082 			break;
2083 		case USB_CDC_NCM_TYPE:
2084 			if (elength < sizeof(struct usb_cdc_ncm_desc))
2085 				goto next_desc;
2086 			hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2087 			break;
2088 		case USB_CDC_MBIM_TYPE:
2089 			if (elength < sizeof(struct usb_cdc_mbim_desc))
2090 				goto next_desc;
2091 
2092 			hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2093 			break;
2094 		case USB_CDC_MBIM_EXTENDED_TYPE:
2095 			if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2096 				break;
2097 			hdr->usb_cdc_mbim_extended_desc =
2098 				(struct usb_cdc_mbim_extended_desc *)buffer;
2099 			break;
2100 		case CDC_PHONET_MAGIC_NUMBER:
2101 			hdr->phonet_magic_present = true;
2102 			break;
2103 		default:
2104 			/*
2105 			 * there are LOTS more CDC descriptors that
2106 			 * could legitimately be found here.
2107 			 */
2108 			dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2109 					buffer[2], elength);
2110 			goto next_desc;
2111 		}
2112 		cnt++;
2113 next_desc:
2114 		buflen -= elength;
2115 		buffer += elength;
2116 	}
2117 	hdr->usb_cdc_union_desc = union_header;
2118 	hdr->usb_cdc_header_desc = header;
2119 	hdr->usb_cdc_mdlm_detail_desc = detail;
2120 	hdr->usb_cdc_mdlm_desc = desc;
2121 	hdr->usb_cdc_ether_desc = ether;
2122 	return cnt;
2123 }
2124 
2125 EXPORT_SYMBOL(cdc_parse_cdc_header);
2126 
2127 /*
2128  * The function can't be called inside suspend/resume callback,
2129  * otherwise deadlock will be caused.
2130  */
usbnet_read_cmd(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,void * data,u16 size)2131 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2132 		    u16 value, u16 index, void *data, u16 size)
2133 {
2134 	int ret;
2135 
2136 	if (usb_autopm_get_interface(dev->intf) < 0)
2137 		return -ENODEV;
2138 	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2139 				data, size);
2140 	usb_autopm_put_interface(dev->intf);
2141 	return ret;
2142 }
2143 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2144 
2145 /*
2146  * The function can't be called inside suspend/resume callback,
2147  * otherwise deadlock will be caused.
2148  */
usbnet_write_cmd(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,const void * data,u16 size)2149 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2150 		     u16 value, u16 index, const void *data, u16 size)
2151 {
2152 	int ret;
2153 
2154 	if (usb_autopm_get_interface(dev->intf) < 0)
2155 		return -ENODEV;
2156 	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2157 				 data, size);
2158 	usb_autopm_put_interface(dev->intf);
2159 	return ret;
2160 }
2161 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2162 
2163 /*
2164  * The function can be called inside suspend/resume callback safely
2165  * and should only be called by suspend/resume callback generally.
2166  */
usbnet_read_cmd_nopm(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,void * data,u16 size)2167 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2168 			  u16 value, u16 index, void *data, u16 size)
2169 {
2170 	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2171 				 data, size);
2172 }
2173 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2174 
2175 /*
2176  * The function can be called inside suspend/resume callback safely
2177  * and should only be called by suspend/resume callback generally.
2178  */
usbnet_write_cmd_nopm(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,const void * data,u16 size)2179 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2180 			  u16 value, u16 index, const void *data,
2181 			  u16 size)
2182 {
2183 	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2184 				  data, size);
2185 }
2186 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2187 
usbnet_async_cmd_cb(struct urb * urb)2188 static void usbnet_async_cmd_cb(struct urb *urb)
2189 {
2190 	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2191 	int status = urb->status;
2192 
2193 	if (status < 0)
2194 		dev_dbg(&urb->dev->dev, "%s failed with %d",
2195 			__func__, status);
2196 
2197 	kfree(req);
2198 	usb_free_urb(urb);
2199 }
2200 
2201 /*
2202  * The caller must make sure that device can't be put into suspend
2203  * state until the control URB completes.
2204  */
usbnet_write_cmd_async(struct usbnet * dev,u8 cmd,u8 reqtype,u16 value,u16 index,const void * data,u16 size)2205 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2206 			   u16 value, u16 index, const void *data, u16 size)
2207 {
2208 	struct usb_ctrlrequest *req = NULL;
2209 	struct urb *urb;
2210 	int err = -ENOMEM;
2211 	void *buf = NULL;
2212 
2213 	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2214 		   " value=0x%04x index=0x%04x size=%d\n",
2215 		   cmd, reqtype, value, index, size);
2216 
2217 	urb = usb_alloc_urb(0, GFP_ATOMIC);
2218 	if (!urb) {
2219 		netdev_err(dev->net, "Error allocating URB in"
2220 			   " %s!\n", __func__);
2221 		goto fail;
2222 	}
2223 
2224 	if (data) {
2225 		buf = kmemdup(data, size, GFP_ATOMIC);
2226 		if (!buf) {
2227 			netdev_err(dev->net, "Error allocating buffer"
2228 				   " in %s!\n", __func__);
2229 			goto fail_free;
2230 		}
2231 	}
2232 
2233 	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2234 	if (!req)
2235 		goto fail_free_buf;
2236 
2237 	req->bRequestType = reqtype;
2238 	req->bRequest = cmd;
2239 	req->wValue = cpu_to_le16(value);
2240 	req->wIndex = cpu_to_le16(index);
2241 	req->wLength = cpu_to_le16(size);
2242 
2243 	usb_fill_control_urb(urb, dev->udev,
2244 			     usb_sndctrlpipe(dev->udev, 0),
2245 			     (void *)req, buf, size,
2246 			     usbnet_async_cmd_cb, req);
2247 	urb->transfer_flags |= URB_FREE_BUFFER;
2248 
2249 	err = usb_submit_urb(urb, GFP_ATOMIC);
2250 	if (err < 0) {
2251 		netdev_err(dev->net, "Error submitting the control"
2252 			   " message: status=%d\n", err);
2253 		goto fail_free;
2254 	}
2255 	return 0;
2256 
2257 fail_free_buf:
2258 	kfree(buf);
2259 fail_free:
2260 	kfree(req);
2261 	usb_free_urb(urb);
2262 fail:
2263 	return err;
2264 
2265 }
2266 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2267 /*-------------------------------------------------------------------------*/
2268 
usbnet_init(void)2269 static int __init usbnet_init(void)
2270 {
2271 	/* Compiler should optimize this out. */
2272 	BUILD_BUG_ON(
2273 		FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2274 
2275 	eth_random_addr(node_id);
2276 	return 0;
2277 }
2278 module_init(usbnet_init);
2279 
usbnet_exit(void)2280 static void __exit usbnet_exit(void)
2281 {
2282 }
2283 module_exit(usbnet_exit);
2284 
2285 MODULE_AUTHOR("David Brownell");
2286 MODULE_DESCRIPTION("USB network driver framework");
2287 MODULE_LICENSE("GPL");
2288