xref: /linux/drivers/net/usb/cdc_ncm.c (revision 8137a49e1567726eb10fcf55ad141ac19804ca6b)
1 /*
2  * cdc_ncm.c
3  *
4  * Copyright (C) ST-Ericsson 2010-2012
5  * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
6  * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
7  *
8  * USB Host Driver for Network Control Model (NCM)
9  * http://www.usb.org/developers/docs/devclass_docs/NCM10_012011.zip
10  *
11  * The NCM encoding, decoding and initialization logic
12  * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
13  *
14  * This software is available to you under a choice of one of two
15  * licenses. You may choose this file to be licensed under the terms
16  * of the GNU General Public License (GPL) Version 2 or the 2-clause
17  * BSD license listed below:
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #include <linux/module.h>
42 #include <linux/netdevice.h>
43 #include <linux/ctype.h>
44 #include <linux/etherdevice.h>
45 #include <linux/ethtool.h>
46 #include <linux/workqueue.h>
47 #include <linux/mii.h>
48 #include <linux/crc32.h>
49 #include <linux/usb.h>
50 #include <linux/hrtimer.h>
51 #include <linux/atomic.h>
52 #include <linux/usb/usbnet.h>
53 #include <linux/usb/cdc.h>
54 #include <linux/usb/cdc_ncm.h>
55 
56 #if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
57 static bool prefer_mbim = true;
58 #else
59 static bool prefer_mbim;
60 #endif
61 module_param(prefer_mbim, bool, 0644);
62 MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
63 
64 static void cdc_ncm_txpath_bh(struct tasklet_struct *t);
65 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
66 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
67 static struct usb_driver cdc_ncm_driver;
68 
69 struct cdc_ncm_stats {
70 	char stat_string[ETH_GSTRING_LEN];
71 	int sizeof_stat;
72 	int stat_offset;
73 };
74 
75 #define CDC_NCM_STAT(str, m) { \
76 		.stat_string = str, \
77 		.sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
78 		.stat_offset = offsetof(struct cdc_ncm_ctx, m) }
79 #define CDC_NCM_SIMPLE_STAT(m)	CDC_NCM_STAT(__stringify(m), m)
80 
81 static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
82 	CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
83 	CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
84 	CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
85 	CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
86 	CDC_NCM_SIMPLE_STAT(tx_overhead),
87 	CDC_NCM_SIMPLE_STAT(tx_ntbs),
88 	CDC_NCM_SIMPLE_STAT(rx_overhead),
89 	CDC_NCM_SIMPLE_STAT(rx_ntbs),
90 };
91 
92 #define CDC_NCM_LOW_MEM_MAX_CNT 10
93 
94 static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
95 {
96 	switch (sset) {
97 	case ETH_SS_STATS:
98 		return ARRAY_SIZE(cdc_ncm_gstrings_stats);
99 	default:
100 		return -EOPNOTSUPP;
101 	}
102 }
103 
104 static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
105 				    struct ethtool_stats __always_unused *stats,
106 				    u64 *data)
107 {
108 	struct usbnet *dev = netdev_priv(netdev);
109 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
110 	int i;
111 	char *p = NULL;
112 
113 	for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
114 		p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
115 		data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
116 	}
117 }
118 
119 static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
120 {
121 	u8 *p = data;
122 	int i;
123 
124 	switch (stringset) {
125 	case ETH_SS_STATS:
126 		for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
127 			memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
128 			p += ETH_GSTRING_LEN;
129 		}
130 	}
131 }
132 
133 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
134 
135 static const struct ethtool_ops cdc_ncm_ethtool_ops = {
136 	.get_link		= usbnet_get_link,
137 	.nway_reset		= usbnet_nway_reset,
138 	.get_drvinfo		= usbnet_get_drvinfo,
139 	.get_msglevel		= usbnet_get_msglevel,
140 	.set_msglevel		= usbnet_set_msglevel,
141 	.get_ts_info		= ethtool_op_get_ts_info,
142 	.get_sset_count		= cdc_ncm_get_sset_count,
143 	.get_strings		= cdc_ncm_get_strings,
144 	.get_ethtool_stats	= cdc_ncm_get_ethtool_stats,
145 	.get_link_ksettings	= usbnet_get_link_ksettings_internal,
146 	.set_link_ksettings	= NULL,
147 };
148 
149 static u32 cdc_ncm_check_rx_max(struct usbnet *dev, u32 new_rx)
150 {
151 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
152 	u32 val, max, min;
153 
154 	/* clamp new_rx to sane values */
155 	min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
156 	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
157 
158 	/* dwNtbInMaxSize spec violation? Use MIN size for both limits */
159 	if (max < min) {
160 		dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
161 			 le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
162 		max = min;
163 	}
164 
165 	val = clamp_t(u32, new_rx, min, max);
166 	if (val != new_rx)
167 		dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range\n", min, max);
168 
169 	return val;
170 }
171 
172 static u32 cdc_ncm_check_tx_max(struct usbnet *dev, u32 new_tx)
173 {
174 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
175 	u32 val, max, min;
176 
177 	/* clamp new_tx to sane values */
178 	if (ctx->is_ndp16)
179 		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
180 	else
181 		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth32);
182 
183 	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
184 
185 	/* some devices set dwNtbOutMaxSize too low for the above default */
186 	min = min(min, max);
187 
188 	val = clamp_t(u32, new_tx, min, max);
189 	if (val != new_tx)
190 		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
191 
192 	return val;
193 }
194 
195 static ssize_t min_tx_pkt_show(struct device *d,
196 			       struct device_attribute *attr, char *buf)
197 {
198 	struct usbnet *dev = netdev_priv(to_net_dev(d));
199 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
200 
201 	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
202 }
203 
204 static ssize_t rx_max_show(struct device *d,
205 			   struct device_attribute *attr, char *buf)
206 {
207 	struct usbnet *dev = netdev_priv(to_net_dev(d));
208 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
209 
210 	return sprintf(buf, "%u\n", ctx->rx_max);
211 }
212 
213 static ssize_t tx_max_show(struct device *d,
214 			   struct device_attribute *attr, char *buf)
215 {
216 	struct usbnet *dev = netdev_priv(to_net_dev(d));
217 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
218 
219 	return sprintf(buf, "%u\n", ctx->tx_max);
220 }
221 
222 static ssize_t tx_timer_usecs_show(struct device *d,
223 				   struct device_attribute *attr, char *buf)
224 {
225 	struct usbnet *dev = netdev_priv(to_net_dev(d));
226 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
227 
228 	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
229 }
230 
231 static ssize_t min_tx_pkt_store(struct device *d,
232 				struct device_attribute *attr,
233 				const char *buf, size_t len)
234 {
235 	struct usbnet *dev = netdev_priv(to_net_dev(d));
236 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
237 	unsigned long val;
238 
239 	/* no need to restrict values - anything from 0 to infinity is OK */
240 	if (kstrtoul(buf, 0, &val))
241 		return -EINVAL;
242 
243 	ctx->min_tx_pkt = val;
244 	return len;
245 }
246 
247 static ssize_t rx_max_store(struct device *d,
248 			    struct device_attribute *attr,
249 			    const char *buf, size_t len)
250 {
251 	struct usbnet *dev = netdev_priv(to_net_dev(d));
252 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
253 	unsigned long val;
254 
255 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
256 		return -EINVAL;
257 
258 	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
259 	return len;
260 }
261 
262 static ssize_t tx_max_store(struct device *d,
263 			    struct device_attribute *attr,
264 			    const char *buf, size_t len)
265 {
266 	struct usbnet *dev = netdev_priv(to_net_dev(d));
267 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
268 	unsigned long val;
269 
270 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
271 		return -EINVAL;
272 
273 	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
274 	return len;
275 }
276 
277 static ssize_t tx_timer_usecs_store(struct device *d,
278 				    struct device_attribute *attr,
279 				    const char *buf, size_t len)
280 {
281 	struct usbnet *dev = netdev_priv(to_net_dev(d));
282 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
283 	ssize_t ret;
284 	unsigned long val;
285 
286 	ret = kstrtoul(buf, 0, &val);
287 	if (ret)
288 		return ret;
289 	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
290 		return -EINVAL;
291 
292 	spin_lock_bh(&ctx->mtx);
293 	ctx->timer_interval = val * NSEC_PER_USEC;
294 	if (!ctx->timer_interval)
295 		ctx->tx_timer_pending = 0;
296 	spin_unlock_bh(&ctx->mtx);
297 	return len;
298 }
299 
300 static DEVICE_ATTR_RW(min_tx_pkt);
301 static DEVICE_ATTR_RW(rx_max);
302 static DEVICE_ATTR_RW(tx_max);
303 static DEVICE_ATTR_RW(tx_timer_usecs);
304 
305 static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
306 {
307 	struct usbnet *dev = netdev_priv(to_net_dev(d));
308 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
309 
310 	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
311 }
312 
313 static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
314 {
315 	struct usbnet *dev = netdev_priv(to_net_dev(d));
316 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
317 	bool enable;
318 
319 	if (strtobool(buf, &enable))
320 		return -EINVAL;
321 
322 	/* no change? */
323 	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
324 		return len;
325 
326 	if (enable) {
327 		if (ctx->is_ndp16 && !ctx->delayed_ndp16) {
328 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
329 			if (!ctx->delayed_ndp16)
330 				return -ENOMEM;
331 		}
332 		if (!ctx->is_ndp16 && !ctx->delayed_ndp32) {
333 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
334 			if (!ctx->delayed_ndp32)
335 				return -ENOMEM;
336 		}
337 	}
338 
339 	/* flush pending data before changing flag */
340 	netif_tx_lock_bh(dev->net);
341 	usbnet_start_xmit(NULL, dev->net);
342 	spin_lock_bh(&ctx->mtx);
343 	if (enable)
344 		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
345 	else
346 		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
347 	spin_unlock_bh(&ctx->mtx);
348 	netif_tx_unlock_bh(dev->net);
349 
350 	return len;
351 }
352 static DEVICE_ATTR_RW(ndp_to_end);
353 
354 #define NCM_PARM_ATTR(name, format, tocpu)				\
355 static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
356 { \
357 	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
358 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
359 	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
360 } \
361 static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
362 
363 NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
364 NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
365 NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
366 NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
367 NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
368 NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
369 NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
370 NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
371 NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
372 NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
373 
374 static struct attribute *cdc_ncm_sysfs_attrs[] = {
375 	&dev_attr_min_tx_pkt.attr,
376 	&dev_attr_ndp_to_end.attr,
377 	&dev_attr_rx_max.attr,
378 	&dev_attr_tx_max.attr,
379 	&dev_attr_tx_timer_usecs.attr,
380 	&dev_attr_bmNtbFormatsSupported.attr,
381 	&dev_attr_dwNtbInMaxSize.attr,
382 	&dev_attr_wNdpInDivisor.attr,
383 	&dev_attr_wNdpInPayloadRemainder.attr,
384 	&dev_attr_wNdpInAlignment.attr,
385 	&dev_attr_dwNtbOutMaxSize.attr,
386 	&dev_attr_wNdpOutDivisor.attr,
387 	&dev_attr_wNdpOutPayloadRemainder.attr,
388 	&dev_attr_wNdpOutAlignment.attr,
389 	&dev_attr_wNtbOutMaxDatagrams.attr,
390 	NULL,
391 };
392 
393 static const struct attribute_group cdc_ncm_sysfs_attr_group = {
394 	.name = "cdc_ncm",
395 	.attrs = cdc_ncm_sysfs_attrs,
396 };
397 
398 /* handle rx_max and tx_max changes */
399 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
400 {
401 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
402 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
403 	u32 val;
404 
405 	val = cdc_ncm_check_rx_max(dev, new_rx);
406 
407 	/* inform device about NTB input size changes */
408 	if (val != ctx->rx_max) {
409 		__le32 dwNtbInMaxSize = cpu_to_le32(val);
410 
411 		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
412 
413 		/* tell device to use new size */
414 		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
415 				     USB_TYPE_CLASS | USB_DIR_OUT
416 				     | USB_RECIP_INTERFACE,
417 				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
418 			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
419 		else
420 			ctx->rx_max = val;
421 	}
422 
423 	/* usbnet use these values for sizing rx queues */
424 	if (dev->rx_urb_size != ctx->rx_max) {
425 		dev->rx_urb_size = ctx->rx_max;
426 		if (netif_running(dev->net))
427 			usbnet_unlink_rx_urbs(dev);
428 	}
429 
430 	val = cdc_ncm_check_tx_max(dev, new_tx);
431 	if (val != ctx->tx_max)
432 		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
433 
434 	/* Adding a pad byte here if necessary simplifies the handling
435 	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
436 	 * the real skb max size.
437 	 *
438 	 * We cannot use dev->maxpacket here because this is called from
439 	 * .bind which is called before usbnet sets up dev->maxpacket
440 	 */
441 	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
442 	    val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
443 		val++;
444 
445 	/* we might need to flush any pending tx buffers if running */
446 	if (netif_running(dev->net) && val > ctx->tx_max) {
447 		netif_tx_lock_bh(dev->net);
448 		usbnet_start_xmit(NULL, dev->net);
449 		/* make sure tx_curr_skb is reallocated if it was empty */
450 		if (ctx->tx_curr_skb) {
451 			dev_kfree_skb_any(ctx->tx_curr_skb);
452 			ctx->tx_curr_skb = NULL;
453 		}
454 		ctx->tx_max = val;
455 		netif_tx_unlock_bh(dev->net);
456 	} else {
457 		ctx->tx_max = val;
458 	}
459 
460 	dev->hard_mtu = ctx->tx_max;
461 
462 	/* max qlen depend on hard_mtu and rx_urb_size */
463 	usbnet_update_max_qlen(dev);
464 
465 	/* never pad more than 3 full USB packets per transfer */
466 	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out, 1),
467 				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
468 }
469 
470 /* helpers for NCM and MBIM differences */
471 static u8 cdc_ncm_flags(struct usbnet *dev)
472 {
473 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
474 
475 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
476 		return ctx->mbim_desc->bmNetworkCapabilities;
477 	if (ctx->func_desc)
478 		return ctx->func_desc->bmNetworkCapabilities;
479 	return 0;
480 }
481 
482 static int cdc_ncm_eth_hlen(struct usbnet *dev)
483 {
484 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
485 		return 0;
486 	return ETH_HLEN;
487 }
488 
489 static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
490 {
491 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
492 		return CDC_MBIM_MIN_DATAGRAM_SIZE;
493 	return CDC_NCM_MIN_DATAGRAM_SIZE;
494 }
495 
496 static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
497 {
498 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
499 
500 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
501 		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
502 	if (ctx->ether_desc)
503 		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
504 	return CDC_NCM_MAX_DATAGRAM_SIZE;
505 }
506 
507 /* initial one-time device setup.  MUST be called with the data interface
508  * in altsetting 0
509  */
510 static int cdc_ncm_init(struct usbnet *dev)
511 {
512 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
513 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
514 	int err;
515 
516 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
517 			      USB_TYPE_CLASS | USB_DIR_IN
518 			      |USB_RECIP_INTERFACE,
519 			      0, iface_no, &ctx->ncm_parm,
520 			      sizeof(ctx->ncm_parm));
521 	if (err < 0) {
522 		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
523 		return err; /* GET_NTB_PARAMETERS is required */
524 	}
525 
526 	/* set CRC Mode */
527 	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
528 		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
529 		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
530 				       USB_TYPE_CLASS | USB_DIR_OUT
531 				       | USB_RECIP_INTERFACE,
532 				       USB_CDC_NCM_CRC_NOT_APPENDED,
533 				       iface_no, NULL, 0);
534 		if (err < 0)
535 			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
536 	}
537 
538 	/* use ndp16 by default */
539 	ctx->is_ndp16 = 1;
540 
541 	/* set NTB format, if both formats are supported.
542 	 *
543 	 * "The host shall only send this command while the NCM Data
544 	 *  Interface is in alternate setting 0."
545 	 */
546 	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
547 						USB_CDC_NCM_NTB32_SUPPORTED) {
548 		if (ctx->drvflags & CDC_NCM_FLAG_PREFER_NTB32) {
549 			ctx->is_ndp16 = 0;
550 			dev_dbg(&dev->intf->dev, "Setting NTB format to 32-bit\n");
551 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
552 					       USB_TYPE_CLASS | USB_DIR_OUT
553 					       | USB_RECIP_INTERFACE,
554 					       USB_CDC_NCM_NTB32_FORMAT,
555 					       iface_no, NULL, 0);
556 		} else {
557 			ctx->is_ndp16 = 1;
558 			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
559 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
560 					       USB_TYPE_CLASS | USB_DIR_OUT
561 					       | USB_RECIP_INTERFACE,
562 					       USB_CDC_NCM_NTB16_FORMAT,
563 					       iface_no, NULL, 0);
564 		}
565 		if (err < 0) {
566 			ctx->is_ndp16 = 1;
567 			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
568 		}
569 	}
570 
571 	/* set initial device values */
572 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
573 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
574 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
575 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
576 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
577 	/* devices prior to NCM Errata shall set this field to zero */
578 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
579 
580 	dev_dbg(&dev->intf->dev,
581 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
582 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
583 		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
584 
585 	/* max count of tx datagrams */
586 	if ((ctx->tx_max_datagrams == 0) ||
587 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
588 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
589 
590 	/* set up maximum NDP size */
591 	if (ctx->is_ndp16)
592 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
593 	else
594 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp32) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe32);
595 
596 	/* initial coalescing timer interval */
597 	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
598 
599 	return 0;
600 }
601 
602 /* set a new max datagram size */
603 static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
604 {
605 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
606 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
607 	__le16 max_datagram_size;
608 	u16 mbim_mtu;
609 	int err;
610 
611 	/* set default based on descriptors */
612 	ctx->max_datagram_size = clamp_t(u32, new_size,
613 					 cdc_ncm_min_dgram_size(dev),
614 					 CDC_NCM_MAX_DATAGRAM_SIZE);
615 
616 	/* inform the device about the selected Max Datagram Size? */
617 	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
618 		goto out;
619 
620 	/* read current mtu value from device */
621 	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
622 			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
623 			      0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
624 	if (err != sizeof(max_datagram_size)) {
625 		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
626 		goto out;
627 	}
628 
629 	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
630 		goto out;
631 
632 	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
633 	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
634 			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
635 			       0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
636 	if (err < 0)
637 		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
638 
639 out:
640 	/* set MTU to max supported by the device if necessary */
641 	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
642 
643 	/* do not exceed operator preferred MTU */
644 	if (ctx->mbim_extended_desc) {
645 		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
646 		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
647 			dev->net->mtu = mbim_mtu;
648 	}
649 }
650 
651 static void cdc_ncm_fix_modulus(struct usbnet *dev)
652 {
653 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
654 	u32 val;
655 
656 	/*
657 	 * verify that the structure alignment is:
658 	 * - power of two
659 	 * - not greater than the maximum transmit length
660 	 * - not less than four bytes
661 	 */
662 	val = ctx->tx_ndp_modulus;
663 
664 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
665 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
666 		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
667 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
668 	}
669 
670 	/*
671 	 * verify that the payload alignment is:
672 	 * - power of two
673 	 * - not greater than the maximum transmit length
674 	 * - not less than four bytes
675 	 */
676 	val = ctx->tx_modulus;
677 
678 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
679 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
680 		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
681 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
682 	}
683 
684 	/* verify the payload remainder */
685 	if (ctx->tx_remainder >= ctx->tx_modulus) {
686 		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
687 		ctx->tx_remainder = 0;
688 	}
689 
690 	/* adjust TX-remainder according to NCM specification. */
691 	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
692 			     (ctx->tx_modulus - 1));
693 }
694 
695 static int cdc_ncm_setup(struct usbnet *dev)
696 {
697 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
698 	u32 def_rx, def_tx;
699 
700 	/* be conservative when selecting initial buffer size to
701 	 * increase the number of hosts this will work for
702 	 */
703 	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
704 		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
705 	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
706 		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
707 
708 	/* clamp rx_max and tx_max and inform device */
709 	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
710 
711 	/* sanitize the modulus and remainder values */
712 	cdc_ncm_fix_modulus(dev);
713 
714 	/* set max datagram size */
715 	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
716 	return 0;
717 }
718 
719 static void
720 cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
721 {
722 	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
723 	u8 ep;
724 
725 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
726 		e = intf->cur_altsetting->endpoint + ep;
727 
728 		/* ignore endpoints which cannot transfer data */
729 		if (!usb_endpoint_maxp(&e->desc))
730 			continue;
731 
732 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
733 		case USB_ENDPOINT_XFER_INT:
734 			if (usb_endpoint_dir_in(&e->desc)) {
735 				if (!dev->status)
736 					dev->status = e;
737 			}
738 			break;
739 
740 		case USB_ENDPOINT_XFER_BULK:
741 			if (usb_endpoint_dir_in(&e->desc)) {
742 				if (!in)
743 					in = e;
744 			} else {
745 				if (!out)
746 					out = e;
747 			}
748 			break;
749 
750 		default:
751 			break;
752 		}
753 	}
754 	if (in && !dev->in)
755 		dev->in = usb_rcvbulkpipe(dev->udev,
756 					  in->desc.bEndpointAddress &
757 					  USB_ENDPOINT_NUMBER_MASK);
758 	if (out && !dev->out)
759 		dev->out = usb_sndbulkpipe(dev->udev,
760 					   out->desc.bEndpointAddress &
761 					   USB_ENDPOINT_NUMBER_MASK);
762 }
763 
764 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
765 {
766 	if (ctx == NULL)
767 		return;
768 
769 	if (ctx->tx_rem_skb != NULL) {
770 		dev_kfree_skb_any(ctx->tx_rem_skb);
771 		ctx->tx_rem_skb = NULL;
772 	}
773 
774 	if (ctx->tx_curr_skb != NULL) {
775 		dev_kfree_skb_any(ctx->tx_curr_skb);
776 		ctx->tx_curr_skb = NULL;
777 	}
778 
779 	if (ctx->is_ndp16)
780 		kfree(ctx->delayed_ndp16);
781 	else
782 		kfree(ctx->delayed_ndp32);
783 
784 	kfree(ctx);
785 }
786 
787 /* we need to override the usbnet change_mtu ndo for two reasons:
788  *  - respect the negotiated maximum datagram size
789  *  - avoid unwanted changes to rx and tx buffers
790  */
791 int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
792 {
793 	struct usbnet *dev = netdev_priv(net);
794 
795 	net->mtu = new_mtu;
796 	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
797 
798 	return 0;
799 }
800 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
801 
802 static const struct net_device_ops cdc_ncm_netdev_ops = {
803 	.ndo_open	     = usbnet_open,
804 	.ndo_stop	     = usbnet_stop,
805 	.ndo_start_xmit	     = usbnet_start_xmit,
806 	.ndo_tx_timeout	     = usbnet_tx_timeout,
807 	.ndo_set_rx_mode     = usbnet_set_rx_mode,
808 	.ndo_get_stats64     = dev_get_tstats64,
809 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
810 	.ndo_set_mac_address = eth_mac_addr,
811 	.ndo_validate_addr   = eth_validate_addr,
812 };
813 
814 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
815 {
816 	struct cdc_ncm_ctx *ctx;
817 	struct usb_driver *driver;
818 	u8 *buf;
819 	int len;
820 	int temp;
821 	u8 iface_no;
822 	struct usb_cdc_parsed_header hdr;
823 
824 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
825 	if (!ctx)
826 		return -ENOMEM;
827 
828 	ctx->dev = dev;
829 
830 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
831 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
832 	tasklet_setup(&ctx->bh, cdc_ncm_txpath_bh);
833 	atomic_set(&ctx->stop, 0);
834 	spin_lock_init(&ctx->mtx);
835 
836 	/* store ctx pointer in device data field */
837 	dev->data[0] = (unsigned long)ctx;
838 
839 	/* only the control interface can be successfully probed */
840 	ctx->control = intf;
841 
842 	/* get some pointers */
843 	driver = driver_of(intf);
844 	buf = intf->cur_altsetting->extra;
845 	len = intf->cur_altsetting->extralen;
846 
847 	/* parse through descriptors associated with control interface */
848 	cdc_parse_cdc_header(&hdr, intf, buf, len);
849 
850 	if (hdr.usb_cdc_union_desc)
851 		ctx->data = usb_ifnum_to_if(dev->udev,
852 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
853 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
854 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
855 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
856 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
857 
858 	/* some buggy devices have an IAD but no CDC Union */
859 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
860 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
861 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
862 	}
863 
864 	/* check if we got everything */
865 	if (!ctx->data) {
866 		dev_err(&intf->dev, "CDC Union missing and no IAD found\n");
867 		goto error;
868 	}
869 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
870 		if (!ctx->mbim_desc) {
871 			dev_err(&intf->dev, "MBIM functional descriptor missing\n");
872 			goto error;
873 		}
874 	} else {
875 		if (!ctx->ether_desc || !ctx->func_desc) {
876 			dev_err(&intf->dev, "NCM or ECM functional descriptors missing\n");
877 			goto error;
878 		}
879 	}
880 
881 	/* claim data interface, if different from control */
882 	if (ctx->data != ctx->control) {
883 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
884 		if (temp) {
885 			dev_err(&intf->dev, "failed to claim data intf\n");
886 			goto error;
887 		}
888 	}
889 
890 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
891 
892 	/* Device-specific flags */
893 	ctx->drvflags = drvflags;
894 
895 	/* Reset data interface. Some devices will not reset properly
896 	 * unless they are configured first.  Toggle the altsetting to
897 	 * force a reset.
898 	 * Some other devices do not work properly with this procedure
899 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
900 	 */
901 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
902 		usb_set_interface(dev->udev, iface_no, data_altsetting);
903 
904 	temp = usb_set_interface(dev->udev, iface_no, 0);
905 	if (temp) {
906 		dev_dbg(&intf->dev, "set interface failed\n");
907 		goto error2;
908 	}
909 
910 	/* initialize basic device settings */
911 	if (cdc_ncm_init(dev))
912 		goto error2;
913 
914 	/* Some firmwares need a pause here or they will silently fail
915 	 * to set up the interface properly.  This value was decided
916 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
917 	 * firmware.
918 	 */
919 	usleep_range(10000, 20000);
920 
921 	/* configure data interface */
922 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
923 	if (temp) {
924 		dev_dbg(&intf->dev, "set interface failed\n");
925 		goto error2;
926 	}
927 
928 	cdc_ncm_find_endpoints(dev, ctx->data);
929 	cdc_ncm_find_endpoints(dev, ctx->control);
930 	if (!dev->in || !dev->out || !dev->status) {
931 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
932 		goto error2;
933 	}
934 
935 	usb_set_intfdata(ctx->control, dev);
936 
937 	if (ctx->ether_desc) {
938 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
939 		if (temp) {
940 			dev_err(&intf->dev, "failed to get mac address\n");
941 			goto error2;
942 		}
943 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
944 	}
945 
946 	/* finish setting up the device specific data */
947 	cdc_ncm_setup(dev);
948 
949 	/* Allocate the delayed NDP if needed. */
950 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
951 		if (ctx->is_ndp16) {
952 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
953 			if (!ctx->delayed_ndp16)
954 				goto error2;
955 		} else {
956 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
957 			if (!ctx->delayed_ndp32)
958 				goto error2;
959 		}
960 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
961 	}
962 
963 	/* override ethtool_ops */
964 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
965 
966 	/* add our sysfs attrs */
967 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
968 
969 	/* must handle MTU changes */
970 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
971 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
972 
973 	return 0;
974 
975 error2:
976 	usb_set_intfdata(ctx->control, NULL);
977 	usb_set_intfdata(ctx->data, NULL);
978 	if (ctx->data != ctx->control)
979 		usb_driver_release_interface(driver, ctx->data);
980 error:
981 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
982 	dev->data[0] = 0;
983 	dev_info(&intf->dev, "bind() failure\n");
984 	return -ENODEV;
985 }
986 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
987 
988 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
989 {
990 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
991 	struct usb_driver *driver = driver_of(intf);
992 
993 	if (ctx == NULL)
994 		return;		/* no setup */
995 
996 	atomic_set(&ctx->stop, 1);
997 
998 	hrtimer_cancel(&ctx->tx_timer);
999 
1000 	tasklet_kill(&ctx->bh);
1001 
1002 	/* handle devices with combined control and data interface */
1003 	if (ctx->control == ctx->data)
1004 		ctx->data = NULL;
1005 
1006 	/* disconnect master --> disconnect slave */
1007 	if (intf == ctx->control && ctx->data) {
1008 		usb_set_intfdata(ctx->data, NULL);
1009 		usb_driver_release_interface(driver, ctx->data);
1010 		ctx->data = NULL;
1011 
1012 	} else if (intf == ctx->data && ctx->control) {
1013 		usb_set_intfdata(ctx->control, NULL);
1014 		usb_driver_release_interface(driver, ctx->control);
1015 		ctx->control = NULL;
1016 	}
1017 
1018 	usb_set_intfdata(intf, NULL);
1019 	cdc_ncm_free(ctx);
1020 }
1021 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1022 
1023 /* Return the number of the MBIM control interface altsetting iff it
1024  * is preferred and available,
1025  */
1026 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1027 {
1028 	struct usb_host_interface *alt;
1029 
1030 	/* The MBIM spec defines a NCM compatible default altsetting,
1031 	 * which we may have matched:
1032 	 *
1033 	 *  "Functions that implement both NCM 1.0 and MBIM (an
1034 	 *   “NCM/MBIM function”) according to this recommendation
1035 	 *   shall provide two alternate settings for the
1036 	 *   Communication Interface.  Alternate setting 0, and the
1037 	 *   associated class and endpoint descriptors, shall be
1038 	 *   constructed according to the rules given for the
1039 	 *   Communication Interface in section 5 of [USBNCM10].
1040 	 *   Alternate setting 1, and the associated class and
1041 	 *   endpoint descriptors, shall be constructed according to
1042 	 *   the rules given in section 6 (USB Device Model) of this
1043 	 *   specification."
1044 	 */
1045 	if (intf->num_altsetting < 2)
1046 		return intf->cur_altsetting->desc.bAlternateSetting;
1047 
1048 	if (prefer_mbim) {
1049 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1050 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1051 			return CDC_NCM_COMM_ALTSETTING_MBIM;
1052 	}
1053 	return CDC_NCM_COMM_ALTSETTING_NCM;
1054 }
1055 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1056 
1057 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1058 {
1059 	/* MBIM backwards compatible function? */
1060 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1061 		return -ENODEV;
1062 
1063 	/* The NCM data altsetting is fixed, so we hard-coded it.
1064 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1065 	 * placed NDP.
1066 	 */
1067 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1068 }
1069 
1070 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1071 {
1072 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1073 
1074 	if (skb->len + align > max)
1075 		align = max - skb->len;
1076 	if (align && skb_tailroom(skb) >= align)
1077 		skb_put_zero(skb, align);
1078 }
1079 
1080 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1081  * allocating a new one within skb
1082  */
1083 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1084 {
1085 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1086 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1087 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1088 
1089 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1090 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1091 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1092 	*/
1093 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1094 		if (ctx->delayed_ndp16->dwSignature == sign)
1095 			return ctx->delayed_ndp16;
1096 
1097 		/* We can only push a single NDP to the end. Return
1098 		 * NULL to send what we've already got and queue this
1099 		 * skb for later.
1100 		 */
1101 		else if (ctx->delayed_ndp16->dwSignature)
1102 			return NULL;
1103 	}
1104 
1105 	/* follow the chain of NDPs, looking for a match */
1106 	while (ndpoffset) {
1107 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1108 		if  (ndp16->dwSignature == sign)
1109 			return ndp16;
1110 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1111 	}
1112 
1113 	/* align new NDP */
1114 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1115 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1116 
1117 	/* verify that there is room for the NDP and the datagram (reserve) */
1118 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1119 		return NULL;
1120 
1121 	/* link to it */
1122 	if (ndp16)
1123 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1124 	else
1125 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1126 
1127 	/* push a new empty NDP */
1128 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1129 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1130 	else
1131 		ndp16 = ctx->delayed_ndp16;
1132 
1133 	ndp16->dwSignature = sign;
1134 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1135 	return ndp16;
1136 }
1137 
1138 static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1139 {
1140 	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1141 	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1142 	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1143 
1144 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1145 	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1146 	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1147 	 */
1148 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1149 		if (ctx->delayed_ndp32->dwSignature == sign)
1150 			return ctx->delayed_ndp32;
1151 
1152 		/* We can only push a single NDP to the end. Return
1153 		 * NULL to send what we've already got and queue this
1154 		 * skb for later.
1155 		 */
1156 		else if (ctx->delayed_ndp32->dwSignature)
1157 			return NULL;
1158 	}
1159 
1160 	/* follow the chain of NDPs, looking for a match */
1161 	while (ndpoffset) {
1162 		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1163 		if  (ndp32->dwSignature == sign)
1164 			return ndp32;
1165 		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1166 	}
1167 
1168 	/* align new NDP */
1169 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1170 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1171 
1172 	/* verify that there is room for the NDP and the datagram (reserve) */
1173 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1174 		return NULL;
1175 
1176 	/* link to it */
1177 	if (ndp32)
1178 		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1179 	else
1180 		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1181 
1182 	/* push a new empty NDP */
1183 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1184 		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1185 	else
1186 		ndp32 = ctx->delayed_ndp32;
1187 
1188 	ndp32->dwSignature = sign;
1189 	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1190 	return ndp32;
1191 }
1192 
1193 struct sk_buff *
1194 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1195 {
1196 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1197 	union {
1198 		struct usb_cdc_ncm_nth16 *nth16;
1199 		struct usb_cdc_ncm_nth32 *nth32;
1200 	} nth;
1201 	union {
1202 		struct usb_cdc_ncm_ndp16 *ndp16;
1203 		struct usb_cdc_ncm_ndp32 *ndp32;
1204 	} ndp;
1205 	struct sk_buff *skb_out;
1206 	u16 n = 0, index, ndplen;
1207 	u8 ready2send = 0;
1208 	u32 delayed_ndp_size;
1209 	size_t padding_count;
1210 
1211 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1212 	 * accordingly. Otherwise, we should check here.
1213 	 */
1214 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1215 		delayed_ndp_size = ctx->max_ndp_size +
1216 			max_t(u32,
1217 			      ctx->tx_ndp_modulus,
1218 			      ctx->tx_modulus + ctx->tx_remainder) - 1;
1219 	else
1220 		delayed_ndp_size = 0;
1221 
1222 	/* if there is a remaining skb, it gets priority */
1223 	if (skb != NULL) {
1224 		swap(skb, ctx->tx_rem_skb);
1225 		swap(sign, ctx->tx_rem_sign);
1226 	} else {
1227 		ready2send = 1;
1228 	}
1229 
1230 	/* check if we are resuming an OUT skb */
1231 	skb_out = ctx->tx_curr_skb;
1232 
1233 	/* allocate a new OUT skb */
1234 	if (!skb_out) {
1235 		if (ctx->tx_low_mem_val == 0) {
1236 			ctx->tx_curr_size = ctx->tx_max;
1237 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1238 			/* If the memory allocation fails we will wait longer
1239 			 * each time before attempting another full size
1240 			 * allocation again to not overload the system
1241 			 * further.
1242 			 */
1243 			if (skb_out == NULL) {
1244 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1245 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1246 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1247 			}
1248 		}
1249 		if (skb_out == NULL) {
1250 			/* See if a very small allocation is possible.
1251 			 * We will send this packet immediately and hope
1252 			 * that there is more memory available later.
1253 			 */
1254 			if (skb)
1255 				ctx->tx_curr_size = max(skb->len,
1256 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1257 			else
1258 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1259 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1260 
1261 			/* No allocation possible so we will abort */
1262 			if (skb_out == NULL) {
1263 				if (skb != NULL) {
1264 					dev_kfree_skb_any(skb);
1265 					dev->net->stats.tx_dropped++;
1266 				}
1267 				goto exit_no_skb;
1268 			}
1269 			ctx->tx_low_mem_val--;
1270 		}
1271 		if (ctx->is_ndp16) {
1272 			/* fill out the initial 16-bit NTB header */
1273 			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1274 			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1275 			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1276 			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1277 		} else {
1278 			/* fill out the initial 32-bit NTB header */
1279 			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1280 			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1281 			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1282 			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1283 		}
1284 
1285 		/* count total number of frames in this NTB */
1286 		ctx->tx_curr_frame_num = 0;
1287 
1288 		/* recent payload counter for this skb_out */
1289 		ctx->tx_curr_frame_payload = 0;
1290 	}
1291 
1292 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1293 		/* send any remaining skb first */
1294 		if (skb == NULL) {
1295 			skb = ctx->tx_rem_skb;
1296 			sign = ctx->tx_rem_sign;
1297 			ctx->tx_rem_skb = NULL;
1298 
1299 			/* check for end of skb */
1300 			if (skb == NULL)
1301 				break;
1302 		}
1303 
1304 		/* get the appropriate NDP for this skb */
1305 		if (ctx->is_ndp16)
1306 			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1307 		else
1308 			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1309 
1310 		/* align beginning of next frame */
1311 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1312 
1313 		/* check if we had enough room left for both NDP and frame */
1314 		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1315 		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1316 			if (n == 0) {
1317 				/* won't fit, MTU problem? */
1318 				dev_kfree_skb_any(skb);
1319 				skb = NULL;
1320 				dev->net->stats.tx_dropped++;
1321 			} else {
1322 				/* no room for skb - store for later */
1323 				if (ctx->tx_rem_skb != NULL) {
1324 					dev_kfree_skb_any(ctx->tx_rem_skb);
1325 					dev->net->stats.tx_dropped++;
1326 				}
1327 				ctx->tx_rem_skb = skb;
1328 				ctx->tx_rem_sign = sign;
1329 				skb = NULL;
1330 				ready2send = 1;
1331 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1332 			}
1333 			break;
1334 		}
1335 
1336 		/* calculate frame number within this NDP */
1337 		if (ctx->is_ndp16) {
1338 			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1339 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1340 
1341 			/* OK, add this skb */
1342 			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1343 			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1344 			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1345 		} else {
1346 			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1347 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1348 
1349 			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1350 			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1351 			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1352 		}
1353 		skb_put_data(skb_out, skb->data, skb->len);
1354 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1355 		dev_kfree_skb_any(skb);
1356 		skb = NULL;
1357 
1358 		/* send now if this NDP is full */
1359 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1360 			ready2send = 1;
1361 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1362 			break;
1363 		}
1364 	}
1365 
1366 	/* free up any dangling skb */
1367 	if (skb != NULL) {
1368 		dev_kfree_skb_any(skb);
1369 		skb = NULL;
1370 		dev->net->stats.tx_dropped++;
1371 	}
1372 
1373 	ctx->tx_curr_frame_num = n;
1374 
1375 	if (n == 0) {
1376 		/* wait for more frames */
1377 		/* push variables */
1378 		ctx->tx_curr_skb = skb_out;
1379 		goto exit_no_skb;
1380 
1381 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1382 		/* wait for more frames */
1383 		/* push variables */
1384 		ctx->tx_curr_skb = skb_out;
1385 		/* set the pending count */
1386 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1387 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1388 		goto exit_no_skb;
1389 
1390 	} else {
1391 		if (n == ctx->tx_max_datagrams)
1392 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1393 		/* frame goes out */
1394 		/* variables will be reset at next call */
1395 	}
1396 
1397 	/* If requested, put NDP at end of frame. */
1398 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1399 		if (ctx->is_ndp16) {
1400 			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1401 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1402 			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1403 			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1404 
1405 			/* Zero out delayed NDP - signature checking will naturally fail. */
1406 			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1407 		} else {
1408 			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1409 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1410 			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1411 			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1412 
1413 			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1414 		}
1415 	}
1416 
1417 	/* If collected data size is less or equal ctx->min_tx_pkt
1418 	 * bytes, we send buffers as it is. If we get more data, it
1419 	 * would be more efficient for USB HS mobile device with DMA
1420 	 * engine to receive a full size NTB, than canceling DMA
1421 	 * transfer and receiving a short packet.
1422 	 *
1423 	 * This optimization support is pointless if we end up sending
1424 	 * a ZLP after full sized NTBs.
1425 	 */
1426 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1427 	    skb_out->len > ctx->min_tx_pkt) {
1428 		padding_count = ctx->tx_curr_size - skb_out->len;
1429 		if (!WARN_ON(padding_count > ctx->tx_curr_size))
1430 			skb_put_zero(skb_out, padding_count);
1431 	} else if (skb_out->len < ctx->tx_curr_size &&
1432 		   (skb_out->len % dev->maxpacket) == 0) {
1433 		skb_put_u8(skb_out, 0);	/* force short packet */
1434 	}
1435 
1436 	/* set final frame length */
1437 	if (ctx->is_ndp16) {
1438 		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1439 		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1440 	} else {
1441 		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1442 		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1443 	}
1444 
1445 	/* return skb */
1446 	ctx->tx_curr_skb = NULL;
1447 
1448 	/* keep private stats: framing overhead and number of NTBs */
1449 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1450 	ctx->tx_ntbs++;
1451 
1452 	/* usbnet will count all the framing overhead by default.
1453 	 * Adjust the stats so that the tx_bytes counter show real
1454 	 * payload data instead.
1455 	 */
1456 	usbnet_set_skb_tx_stats(skb_out, n,
1457 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1458 
1459 	return skb_out;
1460 
1461 exit_no_skb:
1462 	/* Start timer, if there is a remaining non-empty skb */
1463 	if (ctx->tx_curr_skb != NULL && n > 0)
1464 		cdc_ncm_tx_timeout_start(ctx);
1465 	return NULL;
1466 }
1467 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1468 
1469 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1470 {
1471 	/* start timer, if not already started */
1472 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1473 		hrtimer_start(&ctx->tx_timer,
1474 				ctx->timer_interval,
1475 				HRTIMER_MODE_REL);
1476 }
1477 
1478 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1479 {
1480 	struct cdc_ncm_ctx *ctx =
1481 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1482 
1483 	if (!atomic_read(&ctx->stop))
1484 		tasklet_schedule(&ctx->bh);
1485 	return HRTIMER_NORESTART;
1486 }
1487 
1488 static void cdc_ncm_txpath_bh(struct tasklet_struct *t)
1489 {
1490 	struct cdc_ncm_ctx *ctx = from_tasklet(ctx, t, bh);
1491 	struct usbnet *dev = ctx->dev;
1492 
1493 	spin_lock_bh(&ctx->mtx);
1494 	if (ctx->tx_timer_pending != 0) {
1495 		ctx->tx_timer_pending--;
1496 		cdc_ncm_tx_timeout_start(ctx);
1497 		spin_unlock_bh(&ctx->mtx);
1498 	} else if (dev->net != NULL) {
1499 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1500 		spin_unlock_bh(&ctx->mtx);
1501 		netif_tx_lock_bh(dev->net);
1502 		usbnet_start_xmit(NULL, dev->net);
1503 		netif_tx_unlock_bh(dev->net);
1504 	} else {
1505 		spin_unlock_bh(&ctx->mtx);
1506 	}
1507 }
1508 
1509 struct sk_buff *
1510 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1511 {
1512 	struct sk_buff *skb_out;
1513 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1514 
1515 	/*
1516 	 * The Ethernet API we are using does not support transmitting
1517 	 * multiple Ethernet frames in a single call. This driver will
1518 	 * accumulate multiple Ethernet frames and send out a larger
1519 	 * USB frame when the USB buffer is full or when a single jiffies
1520 	 * timeout happens.
1521 	 */
1522 	if (ctx == NULL)
1523 		goto error;
1524 
1525 	spin_lock_bh(&ctx->mtx);
1526 
1527 	if (ctx->is_ndp16)
1528 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1529 	else
1530 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1531 
1532 	spin_unlock_bh(&ctx->mtx);
1533 	return skb_out;
1534 
1535 error:
1536 	if (skb != NULL)
1537 		dev_kfree_skb_any(skb);
1538 
1539 	return NULL;
1540 }
1541 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1542 
1543 /* verify NTB header and return offset of first NDP, or negative error */
1544 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1545 {
1546 	struct usbnet *dev = netdev_priv(skb_in->dev);
1547 	struct usb_cdc_ncm_nth16 *nth16;
1548 	int len;
1549 	int ret = -EINVAL;
1550 
1551 	if (ctx == NULL)
1552 		goto error;
1553 
1554 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1555 					sizeof(struct usb_cdc_ncm_ndp16))) {
1556 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1557 		goto error;
1558 	}
1559 
1560 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1561 
1562 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1563 		netif_dbg(dev, rx_err, dev->net,
1564 			  "invalid NTH16 signature <%#010x>\n",
1565 			  le32_to_cpu(nth16->dwSignature));
1566 		goto error;
1567 	}
1568 
1569 	len = le16_to_cpu(nth16->wBlockLength);
1570 	if (len > ctx->rx_max) {
1571 		netif_dbg(dev, rx_err, dev->net,
1572 			  "unsupported NTB block length %u/%u\n", len,
1573 			  ctx->rx_max);
1574 		goto error;
1575 	}
1576 
1577 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1578 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1579 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1580 		netif_dbg(dev, rx_err, dev->net,
1581 			  "sequence number glitch prev=%d curr=%d\n",
1582 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1583 	}
1584 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1585 
1586 	ret = le16_to_cpu(nth16->wNdpIndex);
1587 error:
1588 	return ret;
1589 }
1590 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1591 
1592 int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1593 {
1594 	struct usbnet *dev = netdev_priv(skb_in->dev);
1595 	struct usb_cdc_ncm_nth32 *nth32;
1596 	int len;
1597 	int ret = -EINVAL;
1598 
1599 	if (ctx == NULL)
1600 		goto error;
1601 
1602 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1603 					sizeof(struct usb_cdc_ncm_ndp32))) {
1604 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1605 		goto error;
1606 	}
1607 
1608 	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1609 
1610 	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1611 		netif_dbg(dev, rx_err, dev->net,
1612 			  "invalid NTH32 signature <%#010x>\n",
1613 			  le32_to_cpu(nth32->dwSignature));
1614 		goto error;
1615 	}
1616 
1617 	len = le32_to_cpu(nth32->dwBlockLength);
1618 	if (len > ctx->rx_max) {
1619 		netif_dbg(dev, rx_err, dev->net,
1620 			  "unsupported NTB block length %u/%u\n", len,
1621 			  ctx->rx_max);
1622 		goto error;
1623 	}
1624 
1625 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1626 	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1627 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1628 		netif_dbg(dev, rx_err, dev->net,
1629 			  "sequence number glitch prev=%d curr=%d\n",
1630 			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1631 	}
1632 	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1633 
1634 	ret = le32_to_cpu(nth32->dwNdpIndex);
1635 error:
1636 	return ret;
1637 }
1638 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1639 
1640 /* verify NDP header and return number of datagrams, or negative error */
1641 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1642 {
1643 	struct usbnet *dev = netdev_priv(skb_in->dev);
1644 	struct usb_cdc_ncm_ndp16 *ndp16;
1645 	int ret = -EINVAL;
1646 
1647 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1648 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1649 			  ndpoffset);
1650 		goto error;
1651 	}
1652 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1653 
1654 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1655 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1656 			  le16_to_cpu(ndp16->wLength));
1657 		goto error;
1658 	}
1659 
1660 	ret = ((le16_to_cpu(ndp16->wLength) -
1661 					sizeof(struct usb_cdc_ncm_ndp16)) /
1662 					sizeof(struct usb_cdc_ncm_dpe16));
1663 	ret--; /* we process NDP entries except for the last one */
1664 
1665 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1666 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1667 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1668 		ret = -EINVAL;
1669 	}
1670 
1671 error:
1672 	return ret;
1673 }
1674 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1675 
1676 /* verify NDP header and return number of datagrams, or negative error */
1677 int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1678 {
1679 	struct usbnet *dev = netdev_priv(skb_in->dev);
1680 	struct usb_cdc_ncm_ndp32 *ndp32;
1681 	int ret = -EINVAL;
1682 
1683 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1684 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1685 			  ndpoffset);
1686 		goto error;
1687 	}
1688 	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1689 
1690 	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1691 		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1692 			  le16_to_cpu(ndp32->wLength));
1693 		goto error;
1694 	}
1695 
1696 	ret = ((le16_to_cpu(ndp32->wLength) -
1697 					sizeof(struct usb_cdc_ncm_ndp32)) /
1698 					sizeof(struct usb_cdc_ncm_dpe32));
1699 	ret--; /* we process NDP entries except for the last one */
1700 
1701 	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1702 	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1703 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1704 		ret = -EINVAL;
1705 	}
1706 
1707 error:
1708 	return ret;
1709 }
1710 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1711 
1712 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1713 {
1714 	struct sk_buff *skb;
1715 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1716 	int len;
1717 	int nframes;
1718 	int x;
1719 	int offset;
1720 	union {
1721 		struct usb_cdc_ncm_ndp16 *ndp16;
1722 		struct usb_cdc_ncm_ndp32 *ndp32;
1723 	} ndp;
1724 	union {
1725 		struct usb_cdc_ncm_dpe16 *dpe16;
1726 		struct usb_cdc_ncm_dpe32 *dpe32;
1727 	} dpe;
1728 
1729 	int ndpoffset;
1730 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1731 	u32 payload = 0;
1732 
1733 	if (ctx->is_ndp16)
1734 		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1735 	else
1736 		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1737 
1738 	if (ndpoffset < 0)
1739 		goto error;
1740 
1741 next_ndp:
1742 	if (ctx->is_ndp16) {
1743 		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1744 		if (nframes < 0)
1745 			goto error;
1746 
1747 		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1748 
1749 		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1750 			netif_dbg(dev, rx_err, dev->net,
1751 				  "invalid DPT16 signature <%#010x>\n",
1752 				  le32_to_cpu(ndp.ndp16->dwSignature));
1753 			goto err_ndp;
1754 		}
1755 		dpe.dpe16 = ndp.ndp16->dpe16;
1756 	} else {
1757 		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1758 		if (nframes < 0)
1759 			goto error;
1760 
1761 		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1762 
1763 		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1764 			netif_dbg(dev, rx_err, dev->net,
1765 				  "invalid DPT32 signature <%#010x>\n",
1766 				  le32_to_cpu(ndp.ndp32->dwSignature));
1767 			goto err_ndp;
1768 		}
1769 		dpe.dpe32 = ndp.ndp32->dpe32;
1770 	}
1771 
1772 	for (x = 0; x < nframes; x++) {
1773 		if (ctx->is_ndp16) {
1774 			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1775 			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1776 		} else {
1777 			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1778 			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1779 		}
1780 
1781 		/*
1782 		 * CDC NCM ch. 3.7
1783 		 * All entries after first NULL entry are to be ignored
1784 		 */
1785 		if ((offset == 0) || (len == 0)) {
1786 			if (!x)
1787 				goto err_ndp; /* empty NTB */
1788 			break;
1789 		}
1790 
1791 		/* sanity checking */
1792 		if (((offset + len) > skb_in->len) ||
1793 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1794 			netif_dbg(dev, rx_err, dev->net,
1795 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1796 				  x, offset, len, skb_in);
1797 			if (!x)
1798 				goto err_ndp;
1799 			break;
1800 
1801 		} else {
1802 			/* create a fresh copy to reduce truesize */
1803 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1804 			if (!skb)
1805 				goto error;
1806 			skb_put_data(skb, skb_in->data + offset, len);
1807 			usbnet_skb_return(dev, skb);
1808 			payload += len;	/* count payload bytes in this NTB */
1809 		}
1810 
1811 		if (ctx->is_ndp16)
1812 			dpe.dpe16++;
1813 		else
1814 			dpe.dpe32++;
1815 	}
1816 err_ndp:
1817 	/* are there more NDPs to process? */
1818 	if (ctx->is_ndp16)
1819 		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1820 	else
1821 		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1822 
1823 	if (ndpoffset && loopcount--)
1824 		goto next_ndp;
1825 
1826 	/* update stats */
1827 	ctx->rx_overhead += skb_in->len - payload;
1828 	ctx->rx_ntbs++;
1829 
1830 	return 1;
1831 error:
1832 	return 0;
1833 }
1834 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1835 
1836 static void
1837 cdc_ncm_speed_change(struct usbnet *dev,
1838 		     struct usb_cdc_speed_change *data)
1839 {
1840 	/* RTL8156 shipped before 2021 sends notification about every 32ms. */
1841 	dev->rx_speed = le32_to_cpu(data->DLBitRRate);
1842 	dev->tx_speed = le32_to_cpu(data->ULBitRate);
1843 }
1844 
1845 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1846 {
1847 	struct usb_cdc_notification *event;
1848 
1849 	if (urb->actual_length < sizeof(*event))
1850 		return;
1851 
1852 	/* test for split data in 8-byte chunks */
1853 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1854 		cdc_ncm_speed_change(dev,
1855 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1856 		return;
1857 	}
1858 
1859 	event = urb->transfer_buffer;
1860 
1861 	switch (event->bNotificationType) {
1862 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1863 		/*
1864 		 * According to the CDC NCM specification ch.7.1
1865 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1866 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1867 		 */
1868 		/* RTL8156 shipped before 2021 sends notification about
1869 		 * every 32ms. Don't forward notification if state is same.
1870 		 */
1871 		if (netif_carrier_ok(dev->net) != !!event->wValue)
1872 			usbnet_link_change(dev, !!event->wValue, 0);
1873 		break;
1874 
1875 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1876 		if (urb->actual_length < (sizeof(*event) +
1877 					sizeof(struct usb_cdc_speed_change)))
1878 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1879 		else
1880 			cdc_ncm_speed_change(dev,
1881 					     (struct usb_cdc_speed_change *)&event[1]);
1882 		break;
1883 
1884 	default:
1885 		dev_dbg(&dev->udev->dev,
1886 			"NCM: unexpected notification 0x%02x!\n",
1887 			event->bNotificationType);
1888 		break;
1889 	}
1890 }
1891 
1892 static const struct driver_info cdc_ncm_info = {
1893 	.description = "CDC NCM",
1894 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1895 			| FLAG_LINK_INTR | FLAG_ETHER,
1896 	.bind = cdc_ncm_bind,
1897 	.unbind = cdc_ncm_unbind,
1898 	.manage_power = usbnet_manage_power,
1899 	.status = cdc_ncm_status,
1900 	.rx_fixup = cdc_ncm_rx_fixup,
1901 	.tx_fixup = cdc_ncm_tx_fixup,
1902 	.set_rx_mode = usbnet_cdc_update_filter,
1903 };
1904 
1905 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1906 static const struct driver_info wwan_info = {
1907 	.description = "Mobile Broadband Network Device",
1908 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1909 			| FLAG_LINK_INTR | FLAG_WWAN,
1910 	.bind = cdc_ncm_bind,
1911 	.unbind = cdc_ncm_unbind,
1912 	.manage_power = usbnet_manage_power,
1913 	.status = cdc_ncm_status,
1914 	.rx_fixup = cdc_ncm_rx_fixup,
1915 	.tx_fixup = cdc_ncm_tx_fixup,
1916 	.set_rx_mode = usbnet_cdc_update_filter,
1917 };
1918 
1919 /* Same as wwan_info, but with FLAG_NOARP  */
1920 static const struct driver_info wwan_noarp_info = {
1921 	.description = "Mobile Broadband Network Device (NO ARP)",
1922 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1923 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1924 	.bind = cdc_ncm_bind,
1925 	.unbind = cdc_ncm_unbind,
1926 	.manage_power = usbnet_manage_power,
1927 	.status = cdc_ncm_status,
1928 	.rx_fixup = cdc_ncm_rx_fixup,
1929 	.tx_fixup = cdc_ncm_tx_fixup,
1930 	.set_rx_mode = usbnet_cdc_update_filter,
1931 };
1932 
1933 static const struct usb_device_id cdc_devs[] = {
1934 	/* Ericsson MBM devices like F5521gw */
1935 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1936 		| USB_DEVICE_ID_MATCH_VENDOR,
1937 	  .idVendor = 0x0bdb,
1938 	  .bInterfaceClass = USB_CLASS_COMM,
1939 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1940 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1941 	  .driver_info = (unsigned long) &wwan_info,
1942 	},
1943 
1944 	/* Telit LE910 V2 */
1945 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1946 		USB_CLASS_COMM,
1947 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1948 	  .driver_info = (unsigned long)&wwan_noarp_info,
1949 	},
1950 
1951 	/* DW5812 LTE Verizon Mobile Broadband Card
1952 	 * Unlike DW5550 this device requires FLAG_NOARP
1953 	 */
1954 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1955 		USB_CLASS_COMM,
1956 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1957 	  .driver_info = (unsigned long)&wwan_noarp_info,
1958 	},
1959 
1960 	/* DW5813 LTE AT&T Mobile Broadband Card
1961 	 * Unlike DW5550 this device requires FLAG_NOARP
1962 	 */
1963 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1964 		USB_CLASS_COMM,
1965 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1966 	  .driver_info = (unsigned long)&wwan_noarp_info,
1967 	},
1968 
1969 	/* Dell branded MBM devices like DW5550 */
1970 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1971 		| USB_DEVICE_ID_MATCH_VENDOR,
1972 	  .idVendor = 0x413c,
1973 	  .bInterfaceClass = USB_CLASS_COMM,
1974 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1975 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1976 	  .driver_info = (unsigned long) &wwan_info,
1977 	},
1978 
1979 	/* Toshiba branded MBM devices */
1980 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1981 		| USB_DEVICE_ID_MATCH_VENDOR,
1982 	  .idVendor = 0x0930,
1983 	  .bInterfaceClass = USB_CLASS_COMM,
1984 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1985 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1986 	  .driver_info = (unsigned long) &wwan_info,
1987 	},
1988 
1989 	/* tag Huawei devices as wwan */
1990 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
1991 					USB_CLASS_COMM,
1992 					USB_CDC_SUBCLASS_NCM,
1993 					USB_CDC_PROTO_NONE),
1994 	  .driver_info = (unsigned long)&wwan_info,
1995 	},
1996 
1997 	/* Infineon(now Intel) HSPA Modem platform */
1998 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
1999 		USB_CLASS_COMM,
2000 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2001 	  .driver_info = (unsigned long)&wwan_noarp_info,
2002 	},
2003 
2004 	/* u-blox TOBY-L4 */
2005 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
2006 		USB_CLASS_COMM,
2007 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2008 	  .driver_info = (unsigned long)&wwan_info,
2009 	},
2010 
2011 	/* Generic CDC-NCM devices */
2012 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2013 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2014 		.driver_info = (unsigned long)&cdc_ncm_info,
2015 	},
2016 	{
2017 	},
2018 };
2019 MODULE_DEVICE_TABLE(usb, cdc_devs);
2020 
2021 static struct usb_driver cdc_ncm_driver = {
2022 	.name = "cdc_ncm",
2023 	.id_table = cdc_devs,
2024 	.probe = usbnet_probe,
2025 	.disconnect = usbnet_disconnect,
2026 	.suspend = usbnet_suspend,
2027 	.resume = usbnet_resume,
2028 	.reset_resume =	usbnet_resume,
2029 	.supports_autosuspend = 1,
2030 	.disable_hub_initiated_lpm = 1,
2031 };
2032 
2033 module_usb_driver(cdc_ncm_driver);
2034 
2035 MODULE_AUTHOR("Hans Petter Selasky");
2036 MODULE_DESCRIPTION("USB CDC NCM host driver");
2037 MODULE_LICENSE("Dual BSD/GPL");
2038