xref: /linux/drivers/net/usb/cdc_ncm.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
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 cdc_ncm_show_min_tx_pkt(struct device *d, struct device_attribute *attr, char *buf)
196 {
197 	struct usbnet *dev = netdev_priv(to_net_dev(d));
198 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
199 
200 	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
201 }
202 
203 static ssize_t cdc_ncm_show_rx_max(struct device *d, struct device_attribute *attr, char *buf)
204 {
205 	struct usbnet *dev = netdev_priv(to_net_dev(d));
206 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
207 
208 	return sprintf(buf, "%u\n", ctx->rx_max);
209 }
210 
211 static ssize_t cdc_ncm_show_tx_max(struct device *d, struct device_attribute *attr, char *buf)
212 {
213 	struct usbnet *dev = netdev_priv(to_net_dev(d));
214 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
215 
216 	return sprintf(buf, "%u\n", ctx->tx_max);
217 }
218 
219 static ssize_t cdc_ncm_show_tx_timer_usecs(struct device *d, struct device_attribute *attr, char *buf)
220 {
221 	struct usbnet *dev = netdev_priv(to_net_dev(d));
222 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
223 
224 	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
225 }
226 
227 static ssize_t cdc_ncm_store_min_tx_pkt(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
228 {
229 	struct usbnet *dev = netdev_priv(to_net_dev(d));
230 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
231 	unsigned long val;
232 
233 	/* no need to restrict values - anything from 0 to infinity is OK */
234 	if (kstrtoul(buf, 0, &val))
235 		return -EINVAL;
236 
237 	ctx->min_tx_pkt = val;
238 	return len;
239 }
240 
241 static ssize_t cdc_ncm_store_rx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
242 {
243 	struct usbnet *dev = netdev_priv(to_net_dev(d));
244 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
245 	unsigned long val;
246 
247 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
248 		return -EINVAL;
249 
250 	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
251 	return len;
252 }
253 
254 static ssize_t cdc_ncm_store_tx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
255 {
256 	struct usbnet *dev = netdev_priv(to_net_dev(d));
257 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
258 	unsigned long val;
259 
260 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
261 		return -EINVAL;
262 
263 	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
264 	return len;
265 }
266 
267 static ssize_t cdc_ncm_store_tx_timer_usecs(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
268 {
269 	struct usbnet *dev = netdev_priv(to_net_dev(d));
270 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
271 	ssize_t ret;
272 	unsigned long val;
273 
274 	ret = kstrtoul(buf, 0, &val);
275 	if (ret)
276 		return ret;
277 	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
278 		return -EINVAL;
279 
280 	spin_lock_bh(&ctx->mtx);
281 	ctx->timer_interval = val * NSEC_PER_USEC;
282 	if (!ctx->timer_interval)
283 		ctx->tx_timer_pending = 0;
284 	spin_unlock_bh(&ctx->mtx);
285 	return len;
286 }
287 
288 static DEVICE_ATTR(min_tx_pkt, 0644, cdc_ncm_show_min_tx_pkt, cdc_ncm_store_min_tx_pkt);
289 static DEVICE_ATTR(rx_max, 0644, cdc_ncm_show_rx_max, cdc_ncm_store_rx_max);
290 static DEVICE_ATTR(tx_max, 0644, cdc_ncm_show_tx_max, cdc_ncm_store_tx_max);
291 static DEVICE_ATTR(tx_timer_usecs, 0644, cdc_ncm_show_tx_timer_usecs, cdc_ncm_store_tx_timer_usecs);
292 
293 static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
294 {
295 	struct usbnet *dev = netdev_priv(to_net_dev(d));
296 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
297 
298 	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
299 }
300 
301 static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
302 {
303 	struct usbnet *dev = netdev_priv(to_net_dev(d));
304 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
305 	bool enable;
306 
307 	if (strtobool(buf, &enable))
308 		return -EINVAL;
309 
310 	/* no change? */
311 	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
312 		return len;
313 
314 	if (enable) {
315 		if (ctx->is_ndp16 && !ctx->delayed_ndp16) {
316 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
317 			if (!ctx->delayed_ndp16)
318 				return -ENOMEM;
319 		}
320 		if (!ctx->is_ndp16 && !ctx->delayed_ndp32) {
321 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
322 			if (!ctx->delayed_ndp32)
323 				return -ENOMEM;
324 		}
325 	}
326 
327 	/* flush pending data before changing flag */
328 	netif_tx_lock_bh(dev->net);
329 	usbnet_start_xmit(NULL, dev->net);
330 	spin_lock_bh(&ctx->mtx);
331 	if (enable)
332 		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
333 	else
334 		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
335 	spin_unlock_bh(&ctx->mtx);
336 	netif_tx_unlock_bh(dev->net);
337 
338 	return len;
339 }
340 static DEVICE_ATTR_RW(ndp_to_end);
341 
342 #define NCM_PARM_ATTR(name, format, tocpu)				\
343 static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
344 { \
345 	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
346 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
347 	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
348 } \
349 static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
350 
351 NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
352 NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
353 NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
354 NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
355 NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
356 NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
357 NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
358 NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
359 NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
360 NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
361 
362 static struct attribute *cdc_ncm_sysfs_attrs[] = {
363 	&dev_attr_min_tx_pkt.attr,
364 	&dev_attr_ndp_to_end.attr,
365 	&dev_attr_rx_max.attr,
366 	&dev_attr_tx_max.attr,
367 	&dev_attr_tx_timer_usecs.attr,
368 	&dev_attr_bmNtbFormatsSupported.attr,
369 	&dev_attr_dwNtbInMaxSize.attr,
370 	&dev_attr_wNdpInDivisor.attr,
371 	&dev_attr_wNdpInPayloadRemainder.attr,
372 	&dev_attr_wNdpInAlignment.attr,
373 	&dev_attr_dwNtbOutMaxSize.attr,
374 	&dev_attr_wNdpOutDivisor.attr,
375 	&dev_attr_wNdpOutPayloadRemainder.attr,
376 	&dev_attr_wNdpOutAlignment.attr,
377 	&dev_attr_wNtbOutMaxDatagrams.attr,
378 	NULL,
379 };
380 
381 static const struct attribute_group cdc_ncm_sysfs_attr_group = {
382 	.name = "cdc_ncm",
383 	.attrs = cdc_ncm_sysfs_attrs,
384 };
385 
386 /* handle rx_max and tx_max changes */
387 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
388 {
389 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
390 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
391 	u32 val;
392 
393 	val = cdc_ncm_check_rx_max(dev, new_rx);
394 
395 	/* inform device about NTB input size changes */
396 	if (val != ctx->rx_max) {
397 		__le32 dwNtbInMaxSize = cpu_to_le32(val);
398 
399 		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
400 
401 		/* tell device to use new size */
402 		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
403 				     USB_TYPE_CLASS | USB_DIR_OUT
404 				     | USB_RECIP_INTERFACE,
405 				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
406 			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
407 		else
408 			ctx->rx_max = val;
409 	}
410 
411 	/* usbnet use these values for sizing rx queues */
412 	if (dev->rx_urb_size != ctx->rx_max) {
413 		dev->rx_urb_size = ctx->rx_max;
414 		if (netif_running(dev->net))
415 			usbnet_unlink_rx_urbs(dev);
416 	}
417 
418 	val = cdc_ncm_check_tx_max(dev, new_tx);
419 	if (val != ctx->tx_max)
420 		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
421 
422 	/* Adding a pad byte here if necessary simplifies the handling
423 	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
424 	 * the real skb max size.
425 	 *
426 	 * We cannot use dev->maxpacket here because this is called from
427 	 * .bind which is called before usbnet sets up dev->maxpacket
428 	 */
429 	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
430 	    val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
431 		val++;
432 
433 	/* we might need to flush any pending tx buffers if running */
434 	if (netif_running(dev->net) && val > ctx->tx_max) {
435 		netif_tx_lock_bh(dev->net);
436 		usbnet_start_xmit(NULL, dev->net);
437 		/* make sure tx_curr_skb is reallocated if it was empty */
438 		if (ctx->tx_curr_skb) {
439 			dev_kfree_skb_any(ctx->tx_curr_skb);
440 			ctx->tx_curr_skb = NULL;
441 		}
442 		ctx->tx_max = val;
443 		netif_tx_unlock_bh(dev->net);
444 	} else {
445 		ctx->tx_max = val;
446 	}
447 
448 	dev->hard_mtu = ctx->tx_max;
449 
450 	/* max qlen depend on hard_mtu and rx_urb_size */
451 	usbnet_update_max_qlen(dev);
452 
453 	/* never pad more than 3 full USB packets per transfer */
454 	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out, 1),
455 				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
456 }
457 
458 /* helpers for NCM and MBIM differences */
459 static u8 cdc_ncm_flags(struct usbnet *dev)
460 {
461 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
462 
463 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
464 		return ctx->mbim_desc->bmNetworkCapabilities;
465 	if (ctx->func_desc)
466 		return ctx->func_desc->bmNetworkCapabilities;
467 	return 0;
468 }
469 
470 static int cdc_ncm_eth_hlen(struct usbnet *dev)
471 {
472 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
473 		return 0;
474 	return ETH_HLEN;
475 }
476 
477 static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
478 {
479 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
480 		return CDC_MBIM_MIN_DATAGRAM_SIZE;
481 	return CDC_NCM_MIN_DATAGRAM_SIZE;
482 }
483 
484 static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
485 {
486 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
487 
488 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
489 		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
490 	if (ctx->ether_desc)
491 		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
492 	return CDC_NCM_MAX_DATAGRAM_SIZE;
493 }
494 
495 /* initial one-time device setup.  MUST be called with the data interface
496  * in altsetting 0
497  */
498 static int cdc_ncm_init(struct usbnet *dev)
499 {
500 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
501 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
502 	int err;
503 
504 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
505 			      USB_TYPE_CLASS | USB_DIR_IN
506 			      |USB_RECIP_INTERFACE,
507 			      0, iface_no, &ctx->ncm_parm,
508 			      sizeof(ctx->ncm_parm));
509 	if (err < 0) {
510 		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
511 		return err; /* GET_NTB_PARAMETERS is required */
512 	}
513 
514 	/* set CRC Mode */
515 	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
516 		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
517 		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
518 				       USB_TYPE_CLASS | USB_DIR_OUT
519 				       | USB_RECIP_INTERFACE,
520 				       USB_CDC_NCM_CRC_NOT_APPENDED,
521 				       iface_no, NULL, 0);
522 		if (err < 0)
523 			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
524 	}
525 
526 	/* use ndp16 by default */
527 	ctx->is_ndp16 = 1;
528 
529 	/* set NTB format, if both formats are supported.
530 	 *
531 	 * "The host shall only send this command while the NCM Data
532 	 *  Interface is in alternate setting 0."
533 	 */
534 	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
535 						USB_CDC_NCM_NTB32_SUPPORTED) {
536 		if (ctx->drvflags & CDC_NCM_FLAG_PREFER_NTB32) {
537 			ctx->is_ndp16 = 0;
538 			dev_dbg(&dev->intf->dev, "Setting NTB format to 32-bit\n");
539 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
540 					       USB_TYPE_CLASS | USB_DIR_OUT
541 					       | USB_RECIP_INTERFACE,
542 					       USB_CDC_NCM_NTB32_FORMAT,
543 					       iface_no, NULL, 0);
544 		} else {
545 			ctx->is_ndp16 = 1;
546 			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
547 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
548 					       USB_TYPE_CLASS | USB_DIR_OUT
549 					       | USB_RECIP_INTERFACE,
550 					       USB_CDC_NCM_NTB16_FORMAT,
551 					       iface_no, NULL, 0);
552 		}
553 		if (err < 0) {
554 			ctx->is_ndp16 = 1;
555 			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
556 		}
557 	}
558 
559 	/* set initial device values */
560 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
561 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
562 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
563 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
564 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
565 	/* devices prior to NCM Errata shall set this field to zero */
566 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
567 
568 	dev_dbg(&dev->intf->dev,
569 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
570 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
571 		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
572 
573 	/* max count of tx datagrams */
574 	if ((ctx->tx_max_datagrams == 0) ||
575 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
576 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
577 
578 	/* set up maximum NDP size */
579 	if (ctx->is_ndp16)
580 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
581 	else
582 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp32) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe32);
583 
584 	/* initial coalescing timer interval */
585 	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
586 
587 	return 0;
588 }
589 
590 /* set a new max datagram size */
591 static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
592 {
593 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
594 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
595 	__le16 max_datagram_size;
596 	u16 mbim_mtu;
597 	int err;
598 
599 	/* set default based on descriptors */
600 	ctx->max_datagram_size = clamp_t(u32, new_size,
601 					 cdc_ncm_min_dgram_size(dev),
602 					 CDC_NCM_MAX_DATAGRAM_SIZE);
603 
604 	/* inform the device about the selected Max Datagram Size? */
605 	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
606 		goto out;
607 
608 	/* read current mtu value from device */
609 	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
610 			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
611 			      0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
612 	if (err != sizeof(max_datagram_size)) {
613 		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
614 		goto out;
615 	}
616 
617 	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
618 		goto out;
619 
620 	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
621 	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
622 			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
623 			       0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
624 	if (err < 0)
625 		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
626 
627 out:
628 	/* set MTU to max supported by the device if necessary */
629 	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
630 
631 	/* do not exceed operater preferred MTU */
632 	if (ctx->mbim_extended_desc) {
633 		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
634 		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
635 			dev->net->mtu = mbim_mtu;
636 	}
637 }
638 
639 static void cdc_ncm_fix_modulus(struct usbnet *dev)
640 {
641 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
642 	u32 val;
643 
644 	/*
645 	 * verify that the structure alignment is:
646 	 * - power of two
647 	 * - not greater than the maximum transmit length
648 	 * - not less than four bytes
649 	 */
650 	val = ctx->tx_ndp_modulus;
651 
652 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
653 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
654 		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
655 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
656 	}
657 
658 	/*
659 	 * verify that the payload alignment is:
660 	 * - power of two
661 	 * - not greater than the maximum transmit length
662 	 * - not less than four bytes
663 	 */
664 	val = ctx->tx_modulus;
665 
666 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
667 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
668 		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
669 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
670 	}
671 
672 	/* verify the payload remainder */
673 	if (ctx->tx_remainder >= ctx->tx_modulus) {
674 		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
675 		ctx->tx_remainder = 0;
676 	}
677 
678 	/* adjust TX-remainder according to NCM specification. */
679 	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
680 			     (ctx->tx_modulus - 1));
681 }
682 
683 static int cdc_ncm_setup(struct usbnet *dev)
684 {
685 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
686 	u32 def_rx, def_tx;
687 
688 	/* be conservative when selecting intial buffer size to
689 	 * increase the number of hosts this will work for
690 	 */
691 	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
692 		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
693 	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
694 		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
695 
696 	/* clamp rx_max and tx_max and inform device */
697 	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
698 
699 	/* sanitize the modulus and remainder values */
700 	cdc_ncm_fix_modulus(dev);
701 
702 	/* set max datagram size */
703 	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
704 	return 0;
705 }
706 
707 static void
708 cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
709 {
710 	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
711 	u8 ep;
712 
713 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
714 		e = intf->cur_altsetting->endpoint + ep;
715 
716 		/* ignore endpoints which cannot transfer data */
717 		if (!usb_endpoint_maxp(&e->desc))
718 			continue;
719 
720 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
721 		case USB_ENDPOINT_XFER_INT:
722 			if (usb_endpoint_dir_in(&e->desc)) {
723 				if (!dev->status)
724 					dev->status = e;
725 			}
726 			break;
727 
728 		case USB_ENDPOINT_XFER_BULK:
729 			if (usb_endpoint_dir_in(&e->desc)) {
730 				if (!in)
731 					in = e;
732 			} else {
733 				if (!out)
734 					out = e;
735 			}
736 			break;
737 
738 		default:
739 			break;
740 		}
741 	}
742 	if (in && !dev->in)
743 		dev->in = usb_rcvbulkpipe(dev->udev,
744 					  in->desc.bEndpointAddress &
745 					  USB_ENDPOINT_NUMBER_MASK);
746 	if (out && !dev->out)
747 		dev->out = usb_sndbulkpipe(dev->udev,
748 					   out->desc.bEndpointAddress &
749 					   USB_ENDPOINT_NUMBER_MASK);
750 }
751 
752 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
753 {
754 	if (ctx == NULL)
755 		return;
756 
757 	if (ctx->tx_rem_skb != NULL) {
758 		dev_kfree_skb_any(ctx->tx_rem_skb);
759 		ctx->tx_rem_skb = NULL;
760 	}
761 
762 	if (ctx->tx_curr_skb != NULL) {
763 		dev_kfree_skb_any(ctx->tx_curr_skb);
764 		ctx->tx_curr_skb = NULL;
765 	}
766 
767 	if (ctx->is_ndp16)
768 		kfree(ctx->delayed_ndp16);
769 	else
770 		kfree(ctx->delayed_ndp32);
771 
772 	kfree(ctx);
773 }
774 
775 /* we need to override the usbnet change_mtu ndo for two reasons:
776  *  - respect the negotiated maximum datagram size
777  *  - avoid unwanted changes to rx and tx buffers
778  */
779 int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
780 {
781 	struct usbnet *dev = netdev_priv(net);
782 
783 	net->mtu = new_mtu;
784 	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
785 
786 	return 0;
787 }
788 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
789 
790 static const struct net_device_ops cdc_ncm_netdev_ops = {
791 	.ndo_open	     = usbnet_open,
792 	.ndo_stop	     = usbnet_stop,
793 	.ndo_start_xmit	     = usbnet_start_xmit,
794 	.ndo_tx_timeout	     = usbnet_tx_timeout,
795 	.ndo_set_rx_mode     = usbnet_set_rx_mode,
796 	.ndo_get_stats64     = dev_get_tstats64,
797 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
798 	.ndo_set_mac_address = eth_mac_addr,
799 	.ndo_validate_addr   = eth_validate_addr,
800 };
801 
802 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
803 {
804 	struct cdc_ncm_ctx *ctx;
805 	struct usb_driver *driver;
806 	u8 *buf;
807 	int len;
808 	int temp;
809 	u8 iface_no;
810 	struct usb_cdc_parsed_header hdr;
811 
812 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
813 	if (!ctx)
814 		return -ENOMEM;
815 
816 	ctx->dev = dev;
817 
818 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
819 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
820 	tasklet_setup(&ctx->bh, cdc_ncm_txpath_bh);
821 	atomic_set(&ctx->stop, 0);
822 	spin_lock_init(&ctx->mtx);
823 
824 	/* store ctx pointer in device data field */
825 	dev->data[0] = (unsigned long)ctx;
826 
827 	/* only the control interface can be successfully probed */
828 	ctx->control = intf;
829 
830 	/* get some pointers */
831 	driver = driver_of(intf);
832 	buf = intf->cur_altsetting->extra;
833 	len = intf->cur_altsetting->extralen;
834 
835 	/* parse through descriptors associated with control interface */
836 	cdc_parse_cdc_header(&hdr, intf, buf, len);
837 
838 	if (hdr.usb_cdc_union_desc)
839 		ctx->data = usb_ifnum_to_if(dev->udev,
840 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
841 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
842 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
843 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
844 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
845 
846 	/* some buggy devices have an IAD but no CDC Union */
847 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
848 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
849 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
850 	}
851 
852 	/* check if we got everything */
853 	if (!ctx->data) {
854 		dev_err(&intf->dev, "CDC Union missing and no IAD found\n");
855 		goto error;
856 	}
857 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
858 		if (!ctx->mbim_desc) {
859 			dev_err(&intf->dev, "MBIM functional descriptor missing\n");
860 			goto error;
861 		}
862 	} else {
863 		if (!ctx->ether_desc || !ctx->func_desc) {
864 			dev_err(&intf->dev, "NCM or ECM functional descriptors missing\n");
865 			goto error;
866 		}
867 	}
868 
869 	/* claim data interface, if different from control */
870 	if (ctx->data != ctx->control) {
871 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
872 		if (temp) {
873 			dev_err(&intf->dev, "failed to claim data intf\n");
874 			goto error;
875 		}
876 	}
877 
878 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
879 
880 	/* Device-specific flags */
881 	ctx->drvflags = drvflags;
882 
883 	/* Reset data interface. Some devices will not reset properly
884 	 * unless they are configured first.  Toggle the altsetting to
885 	 * force a reset.
886 	 * Some other devices do not work properly with this procedure
887 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
888 	 */
889 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
890 		usb_set_interface(dev->udev, iface_no, data_altsetting);
891 
892 	temp = usb_set_interface(dev->udev, iface_no, 0);
893 	if (temp) {
894 		dev_dbg(&intf->dev, "set interface failed\n");
895 		goto error2;
896 	}
897 
898 	/* initialize basic device settings */
899 	if (cdc_ncm_init(dev))
900 		goto error2;
901 
902 	/* Some firmwares need a pause here or they will silently fail
903 	 * to set up the interface properly.  This value was decided
904 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
905 	 * firmware.
906 	 */
907 	usleep_range(10000, 20000);
908 
909 	/* configure data interface */
910 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
911 	if (temp) {
912 		dev_dbg(&intf->dev, "set interface failed\n");
913 		goto error2;
914 	}
915 
916 	cdc_ncm_find_endpoints(dev, ctx->data);
917 	cdc_ncm_find_endpoints(dev, ctx->control);
918 	if (!dev->in || !dev->out || !dev->status) {
919 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
920 		goto error2;
921 	}
922 
923 	usb_set_intfdata(ctx->control, dev);
924 
925 	if (ctx->ether_desc) {
926 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
927 		if (temp) {
928 			dev_err(&intf->dev, "failed to get mac address\n");
929 			goto error2;
930 		}
931 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
932 	}
933 
934 	/* finish setting up the device specific data */
935 	cdc_ncm_setup(dev);
936 
937 	/* Allocate the delayed NDP if needed. */
938 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
939 		if (ctx->is_ndp16) {
940 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
941 			if (!ctx->delayed_ndp16)
942 				goto error2;
943 		} else {
944 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
945 			if (!ctx->delayed_ndp32)
946 				goto error2;
947 		}
948 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
949 	}
950 
951 	/* override ethtool_ops */
952 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
953 
954 	/* add our sysfs attrs */
955 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
956 
957 	/* must handle MTU changes */
958 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
959 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
960 
961 	return 0;
962 
963 error2:
964 	usb_set_intfdata(ctx->control, NULL);
965 	usb_set_intfdata(ctx->data, NULL);
966 	if (ctx->data != ctx->control)
967 		usb_driver_release_interface(driver, ctx->data);
968 error:
969 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
970 	dev->data[0] = 0;
971 	dev_info(&intf->dev, "bind() failure\n");
972 	return -ENODEV;
973 }
974 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
975 
976 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
977 {
978 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
979 	struct usb_driver *driver = driver_of(intf);
980 
981 	if (ctx == NULL)
982 		return;		/* no setup */
983 
984 	atomic_set(&ctx->stop, 1);
985 
986 	hrtimer_cancel(&ctx->tx_timer);
987 
988 	tasklet_kill(&ctx->bh);
989 
990 	/* handle devices with combined control and data interface */
991 	if (ctx->control == ctx->data)
992 		ctx->data = NULL;
993 
994 	/* disconnect master --> disconnect slave */
995 	if (intf == ctx->control && ctx->data) {
996 		usb_set_intfdata(ctx->data, NULL);
997 		usb_driver_release_interface(driver, ctx->data);
998 		ctx->data = NULL;
999 
1000 	} else if (intf == ctx->data && ctx->control) {
1001 		usb_set_intfdata(ctx->control, NULL);
1002 		usb_driver_release_interface(driver, ctx->control);
1003 		ctx->control = NULL;
1004 	}
1005 
1006 	usb_set_intfdata(intf, NULL);
1007 	cdc_ncm_free(ctx);
1008 }
1009 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1010 
1011 /* Return the number of the MBIM control interface altsetting iff it
1012  * is preferred and available,
1013  */
1014 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1015 {
1016 	struct usb_host_interface *alt;
1017 
1018 	/* The MBIM spec defines a NCM compatible default altsetting,
1019 	 * which we may have matched:
1020 	 *
1021 	 *  "Functions that implement both NCM 1.0 and MBIM (an
1022 	 *   “NCM/MBIM function”) according to this recommendation
1023 	 *   shall provide two alternate settings for the
1024 	 *   Communication Interface.  Alternate setting 0, and the
1025 	 *   associated class and endpoint descriptors, shall be
1026 	 *   constructed according to the rules given for the
1027 	 *   Communication Interface in section 5 of [USBNCM10].
1028 	 *   Alternate setting 1, and the associated class and
1029 	 *   endpoint descriptors, shall be constructed according to
1030 	 *   the rules given in section 6 (USB Device Model) of this
1031 	 *   specification."
1032 	 */
1033 	if (intf->num_altsetting < 2)
1034 		return intf->cur_altsetting->desc.bAlternateSetting;
1035 
1036 	if (prefer_mbim) {
1037 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1038 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1039 			return CDC_NCM_COMM_ALTSETTING_MBIM;
1040 	}
1041 	return CDC_NCM_COMM_ALTSETTING_NCM;
1042 }
1043 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1044 
1045 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1046 {
1047 	/* MBIM backwards compatible function? */
1048 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1049 		return -ENODEV;
1050 
1051 	/* The NCM data altsetting is fixed, so we hard-coded it.
1052 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1053 	 * placed NDP.
1054 	 */
1055 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1056 }
1057 
1058 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1059 {
1060 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1061 
1062 	if (skb->len + align > max)
1063 		align = max - skb->len;
1064 	if (align && skb_tailroom(skb) >= align)
1065 		skb_put_zero(skb, align);
1066 }
1067 
1068 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1069  * allocating a new one within skb
1070  */
1071 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1072 {
1073 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1074 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1075 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1076 
1077 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1078 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1079 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1080 	*/
1081 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1082 		if (ctx->delayed_ndp16->dwSignature == sign)
1083 			return ctx->delayed_ndp16;
1084 
1085 		/* We can only push a single NDP to the end. Return
1086 		 * NULL to send what we've already got and queue this
1087 		 * skb for later.
1088 		 */
1089 		else if (ctx->delayed_ndp16->dwSignature)
1090 			return NULL;
1091 	}
1092 
1093 	/* follow the chain of NDPs, looking for a match */
1094 	while (ndpoffset) {
1095 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1096 		if  (ndp16->dwSignature == sign)
1097 			return ndp16;
1098 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1099 	}
1100 
1101 	/* align new NDP */
1102 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1103 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1104 
1105 	/* verify that there is room for the NDP and the datagram (reserve) */
1106 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1107 		return NULL;
1108 
1109 	/* link to it */
1110 	if (ndp16)
1111 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1112 	else
1113 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1114 
1115 	/* push a new empty NDP */
1116 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1117 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1118 	else
1119 		ndp16 = ctx->delayed_ndp16;
1120 
1121 	ndp16->dwSignature = sign;
1122 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1123 	return ndp16;
1124 }
1125 
1126 static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1127 {
1128 	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1129 	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1130 	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1131 
1132 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1133 	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1134 	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1135 	 */
1136 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1137 		if (ctx->delayed_ndp32->dwSignature == sign)
1138 			return ctx->delayed_ndp32;
1139 
1140 		/* We can only push a single NDP to the end. Return
1141 		 * NULL to send what we've already got and queue this
1142 		 * skb for later.
1143 		 */
1144 		else if (ctx->delayed_ndp32->dwSignature)
1145 			return NULL;
1146 	}
1147 
1148 	/* follow the chain of NDPs, looking for a match */
1149 	while (ndpoffset) {
1150 		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1151 		if  (ndp32->dwSignature == sign)
1152 			return ndp32;
1153 		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1154 	}
1155 
1156 	/* align new NDP */
1157 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1158 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1159 
1160 	/* verify that there is room for the NDP and the datagram (reserve) */
1161 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1162 		return NULL;
1163 
1164 	/* link to it */
1165 	if (ndp32)
1166 		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1167 	else
1168 		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1169 
1170 	/* push a new empty NDP */
1171 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1172 		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1173 	else
1174 		ndp32 = ctx->delayed_ndp32;
1175 
1176 	ndp32->dwSignature = sign;
1177 	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1178 	return ndp32;
1179 }
1180 
1181 struct sk_buff *
1182 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1183 {
1184 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1185 	union {
1186 		struct usb_cdc_ncm_nth16 *nth16;
1187 		struct usb_cdc_ncm_nth32 *nth32;
1188 	} nth;
1189 	union {
1190 		struct usb_cdc_ncm_ndp16 *ndp16;
1191 		struct usb_cdc_ncm_ndp32 *ndp32;
1192 	} ndp;
1193 	struct sk_buff *skb_out;
1194 	u16 n = 0, index, ndplen;
1195 	u8 ready2send = 0;
1196 	u32 delayed_ndp_size;
1197 	size_t padding_count;
1198 
1199 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1200 	 * accordingly. Otherwise, we should check here.
1201 	 */
1202 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1203 		delayed_ndp_size = ctx->max_ndp_size +
1204 			max_t(u32,
1205 			      ctx->tx_ndp_modulus,
1206 			      ctx->tx_modulus + ctx->tx_remainder) - 1;
1207 	else
1208 		delayed_ndp_size = 0;
1209 
1210 	/* if there is a remaining skb, it gets priority */
1211 	if (skb != NULL) {
1212 		swap(skb, ctx->tx_rem_skb);
1213 		swap(sign, ctx->tx_rem_sign);
1214 	} else {
1215 		ready2send = 1;
1216 	}
1217 
1218 	/* check if we are resuming an OUT skb */
1219 	skb_out = ctx->tx_curr_skb;
1220 
1221 	/* allocate a new OUT skb */
1222 	if (!skb_out) {
1223 		if (ctx->tx_low_mem_val == 0) {
1224 			ctx->tx_curr_size = ctx->tx_max;
1225 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1226 			/* If the memory allocation fails we will wait longer
1227 			 * each time before attempting another full size
1228 			 * allocation again to not overload the system
1229 			 * further.
1230 			 */
1231 			if (skb_out == NULL) {
1232 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1233 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1234 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1235 			}
1236 		}
1237 		if (skb_out == NULL) {
1238 			/* See if a very small allocation is possible.
1239 			 * We will send this packet immediately and hope
1240 			 * that there is more memory available later.
1241 			 */
1242 			if (skb)
1243 				ctx->tx_curr_size = max(skb->len,
1244 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1245 			else
1246 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1247 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1248 
1249 			/* No allocation possible so we will abort */
1250 			if (skb_out == NULL) {
1251 				if (skb != NULL) {
1252 					dev_kfree_skb_any(skb);
1253 					dev->net->stats.tx_dropped++;
1254 				}
1255 				goto exit_no_skb;
1256 			}
1257 			ctx->tx_low_mem_val--;
1258 		}
1259 		if (ctx->is_ndp16) {
1260 			/* fill out the initial 16-bit NTB header */
1261 			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1262 			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1263 			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1264 			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1265 		} else {
1266 			/* fill out the initial 32-bit NTB header */
1267 			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1268 			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1269 			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1270 			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1271 		}
1272 
1273 		/* count total number of frames in this NTB */
1274 		ctx->tx_curr_frame_num = 0;
1275 
1276 		/* recent payload counter for this skb_out */
1277 		ctx->tx_curr_frame_payload = 0;
1278 	}
1279 
1280 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1281 		/* send any remaining skb first */
1282 		if (skb == NULL) {
1283 			skb = ctx->tx_rem_skb;
1284 			sign = ctx->tx_rem_sign;
1285 			ctx->tx_rem_skb = NULL;
1286 
1287 			/* check for end of skb */
1288 			if (skb == NULL)
1289 				break;
1290 		}
1291 
1292 		/* get the appropriate NDP for this skb */
1293 		if (ctx->is_ndp16)
1294 			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1295 		else
1296 			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1297 
1298 		/* align beginning of next frame */
1299 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1300 
1301 		/* check if we had enough room left for both NDP and frame */
1302 		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1303 		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1304 			if (n == 0) {
1305 				/* won't fit, MTU problem? */
1306 				dev_kfree_skb_any(skb);
1307 				skb = NULL;
1308 				dev->net->stats.tx_dropped++;
1309 			} else {
1310 				/* no room for skb - store for later */
1311 				if (ctx->tx_rem_skb != NULL) {
1312 					dev_kfree_skb_any(ctx->tx_rem_skb);
1313 					dev->net->stats.tx_dropped++;
1314 				}
1315 				ctx->tx_rem_skb = skb;
1316 				ctx->tx_rem_sign = sign;
1317 				skb = NULL;
1318 				ready2send = 1;
1319 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1320 			}
1321 			break;
1322 		}
1323 
1324 		/* calculate frame number within this NDP */
1325 		if (ctx->is_ndp16) {
1326 			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1327 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1328 
1329 			/* OK, add this skb */
1330 			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1331 			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1332 			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1333 		} else {
1334 			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1335 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1336 
1337 			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1338 			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1339 			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1340 		}
1341 		skb_put_data(skb_out, skb->data, skb->len);
1342 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1343 		dev_kfree_skb_any(skb);
1344 		skb = NULL;
1345 
1346 		/* send now if this NDP is full */
1347 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1348 			ready2send = 1;
1349 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1350 			break;
1351 		}
1352 	}
1353 
1354 	/* free up any dangling skb */
1355 	if (skb != NULL) {
1356 		dev_kfree_skb_any(skb);
1357 		skb = NULL;
1358 		dev->net->stats.tx_dropped++;
1359 	}
1360 
1361 	ctx->tx_curr_frame_num = n;
1362 
1363 	if (n == 0) {
1364 		/* wait for more frames */
1365 		/* push variables */
1366 		ctx->tx_curr_skb = skb_out;
1367 		goto exit_no_skb;
1368 
1369 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1370 		/* wait for more frames */
1371 		/* push variables */
1372 		ctx->tx_curr_skb = skb_out;
1373 		/* set the pending count */
1374 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1375 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1376 		goto exit_no_skb;
1377 
1378 	} else {
1379 		if (n == ctx->tx_max_datagrams)
1380 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1381 		/* frame goes out */
1382 		/* variables will be reset at next call */
1383 	}
1384 
1385 	/* If requested, put NDP at end of frame. */
1386 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1387 		if (ctx->is_ndp16) {
1388 			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1389 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1390 			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1391 			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1392 
1393 			/* Zero out delayed NDP - signature checking will naturally fail. */
1394 			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1395 		} else {
1396 			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1397 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1398 			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1399 			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1400 
1401 			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1402 		}
1403 	}
1404 
1405 	/* If collected data size is less or equal ctx->min_tx_pkt
1406 	 * bytes, we send buffers as it is. If we get more data, it
1407 	 * would be more efficient for USB HS mobile device with DMA
1408 	 * engine to receive a full size NTB, than canceling DMA
1409 	 * transfer and receiving a short packet.
1410 	 *
1411 	 * This optimization support is pointless if we end up sending
1412 	 * a ZLP after full sized NTBs.
1413 	 */
1414 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1415 	    skb_out->len > ctx->min_tx_pkt) {
1416 		padding_count = ctx->tx_curr_size - skb_out->len;
1417 		if (!WARN_ON(padding_count > ctx->tx_curr_size))
1418 			skb_put_zero(skb_out, padding_count);
1419 	} else if (skb_out->len < ctx->tx_curr_size &&
1420 		   (skb_out->len % dev->maxpacket) == 0) {
1421 		skb_put_u8(skb_out, 0);	/* force short packet */
1422 	}
1423 
1424 	/* set final frame length */
1425 	if (ctx->is_ndp16) {
1426 		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1427 		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1428 	} else {
1429 		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1430 		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1431 	}
1432 
1433 	/* return skb */
1434 	ctx->tx_curr_skb = NULL;
1435 
1436 	/* keep private stats: framing overhead and number of NTBs */
1437 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1438 	ctx->tx_ntbs++;
1439 
1440 	/* usbnet will count all the framing overhead by default.
1441 	 * Adjust the stats so that the tx_bytes counter show real
1442 	 * payload data instead.
1443 	 */
1444 	usbnet_set_skb_tx_stats(skb_out, n,
1445 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1446 
1447 	return skb_out;
1448 
1449 exit_no_skb:
1450 	/* Start timer, if there is a remaining non-empty skb */
1451 	if (ctx->tx_curr_skb != NULL && n > 0)
1452 		cdc_ncm_tx_timeout_start(ctx);
1453 	return NULL;
1454 }
1455 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1456 
1457 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1458 {
1459 	/* start timer, if not already started */
1460 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1461 		hrtimer_start(&ctx->tx_timer,
1462 				ctx->timer_interval,
1463 				HRTIMER_MODE_REL);
1464 }
1465 
1466 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1467 {
1468 	struct cdc_ncm_ctx *ctx =
1469 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1470 
1471 	if (!atomic_read(&ctx->stop))
1472 		tasklet_schedule(&ctx->bh);
1473 	return HRTIMER_NORESTART;
1474 }
1475 
1476 static void cdc_ncm_txpath_bh(struct tasklet_struct *t)
1477 {
1478 	struct cdc_ncm_ctx *ctx = from_tasklet(ctx, t, bh);
1479 	struct usbnet *dev = ctx->dev;
1480 
1481 	spin_lock_bh(&ctx->mtx);
1482 	if (ctx->tx_timer_pending != 0) {
1483 		ctx->tx_timer_pending--;
1484 		cdc_ncm_tx_timeout_start(ctx);
1485 		spin_unlock_bh(&ctx->mtx);
1486 	} else if (dev->net != NULL) {
1487 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1488 		spin_unlock_bh(&ctx->mtx);
1489 		netif_tx_lock_bh(dev->net);
1490 		usbnet_start_xmit(NULL, dev->net);
1491 		netif_tx_unlock_bh(dev->net);
1492 	} else {
1493 		spin_unlock_bh(&ctx->mtx);
1494 	}
1495 }
1496 
1497 struct sk_buff *
1498 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1499 {
1500 	struct sk_buff *skb_out;
1501 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1502 
1503 	/*
1504 	 * The Ethernet API we are using does not support transmitting
1505 	 * multiple Ethernet frames in a single call. This driver will
1506 	 * accumulate multiple Ethernet frames and send out a larger
1507 	 * USB frame when the USB buffer is full or when a single jiffies
1508 	 * timeout happens.
1509 	 */
1510 	if (ctx == NULL)
1511 		goto error;
1512 
1513 	spin_lock_bh(&ctx->mtx);
1514 
1515 	if (ctx->is_ndp16)
1516 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1517 	else
1518 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1519 
1520 	spin_unlock_bh(&ctx->mtx);
1521 	return skb_out;
1522 
1523 error:
1524 	if (skb != NULL)
1525 		dev_kfree_skb_any(skb);
1526 
1527 	return NULL;
1528 }
1529 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1530 
1531 /* verify NTB header and return offset of first NDP, or negative error */
1532 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1533 {
1534 	struct usbnet *dev = netdev_priv(skb_in->dev);
1535 	struct usb_cdc_ncm_nth16 *nth16;
1536 	int len;
1537 	int ret = -EINVAL;
1538 
1539 	if (ctx == NULL)
1540 		goto error;
1541 
1542 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1543 					sizeof(struct usb_cdc_ncm_ndp16))) {
1544 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1545 		goto error;
1546 	}
1547 
1548 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1549 
1550 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1551 		netif_dbg(dev, rx_err, dev->net,
1552 			  "invalid NTH16 signature <%#010x>\n",
1553 			  le32_to_cpu(nth16->dwSignature));
1554 		goto error;
1555 	}
1556 
1557 	len = le16_to_cpu(nth16->wBlockLength);
1558 	if (len > ctx->rx_max) {
1559 		netif_dbg(dev, rx_err, dev->net,
1560 			  "unsupported NTB block length %u/%u\n", len,
1561 			  ctx->rx_max);
1562 		goto error;
1563 	}
1564 
1565 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1566 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1567 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1568 		netif_dbg(dev, rx_err, dev->net,
1569 			  "sequence number glitch prev=%d curr=%d\n",
1570 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1571 	}
1572 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1573 
1574 	ret = le16_to_cpu(nth16->wNdpIndex);
1575 error:
1576 	return ret;
1577 }
1578 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1579 
1580 int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1581 {
1582 	struct usbnet *dev = netdev_priv(skb_in->dev);
1583 	struct usb_cdc_ncm_nth32 *nth32;
1584 	int len;
1585 	int ret = -EINVAL;
1586 
1587 	if (ctx == NULL)
1588 		goto error;
1589 
1590 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1591 					sizeof(struct usb_cdc_ncm_ndp32))) {
1592 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1593 		goto error;
1594 	}
1595 
1596 	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1597 
1598 	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1599 		netif_dbg(dev, rx_err, dev->net,
1600 			  "invalid NTH32 signature <%#010x>\n",
1601 			  le32_to_cpu(nth32->dwSignature));
1602 		goto error;
1603 	}
1604 
1605 	len = le32_to_cpu(nth32->dwBlockLength);
1606 	if (len > ctx->rx_max) {
1607 		netif_dbg(dev, rx_err, dev->net,
1608 			  "unsupported NTB block length %u/%u\n", len,
1609 			  ctx->rx_max);
1610 		goto error;
1611 	}
1612 
1613 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1614 	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1615 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1616 		netif_dbg(dev, rx_err, dev->net,
1617 			  "sequence number glitch prev=%d curr=%d\n",
1618 			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1619 	}
1620 	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1621 
1622 	ret = le32_to_cpu(nth32->dwNdpIndex);
1623 error:
1624 	return ret;
1625 }
1626 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1627 
1628 /* verify NDP header and return number of datagrams, or negative error */
1629 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1630 {
1631 	struct usbnet *dev = netdev_priv(skb_in->dev);
1632 	struct usb_cdc_ncm_ndp16 *ndp16;
1633 	int ret = -EINVAL;
1634 
1635 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1636 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1637 			  ndpoffset);
1638 		goto error;
1639 	}
1640 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1641 
1642 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1643 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1644 			  le16_to_cpu(ndp16->wLength));
1645 		goto error;
1646 	}
1647 
1648 	ret = ((le16_to_cpu(ndp16->wLength) -
1649 					sizeof(struct usb_cdc_ncm_ndp16)) /
1650 					sizeof(struct usb_cdc_ncm_dpe16));
1651 	ret--; /* we process NDP entries except for the last one */
1652 
1653 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1654 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1655 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1656 		ret = -EINVAL;
1657 	}
1658 
1659 error:
1660 	return ret;
1661 }
1662 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1663 
1664 /* verify NDP header and return number of datagrams, or negative error */
1665 int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1666 {
1667 	struct usbnet *dev = netdev_priv(skb_in->dev);
1668 	struct usb_cdc_ncm_ndp32 *ndp32;
1669 	int ret = -EINVAL;
1670 
1671 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1672 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1673 			  ndpoffset);
1674 		goto error;
1675 	}
1676 	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1677 
1678 	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1679 		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1680 			  le16_to_cpu(ndp32->wLength));
1681 		goto error;
1682 	}
1683 
1684 	ret = ((le16_to_cpu(ndp32->wLength) -
1685 					sizeof(struct usb_cdc_ncm_ndp32)) /
1686 					sizeof(struct usb_cdc_ncm_dpe32));
1687 	ret--; /* we process NDP entries except for the last one */
1688 
1689 	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1690 	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1691 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1692 		ret = -EINVAL;
1693 	}
1694 
1695 error:
1696 	return ret;
1697 }
1698 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1699 
1700 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1701 {
1702 	struct sk_buff *skb;
1703 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1704 	int len;
1705 	int nframes;
1706 	int x;
1707 	int offset;
1708 	union {
1709 		struct usb_cdc_ncm_ndp16 *ndp16;
1710 		struct usb_cdc_ncm_ndp32 *ndp32;
1711 	} ndp;
1712 	union {
1713 		struct usb_cdc_ncm_dpe16 *dpe16;
1714 		struct usb_cdc_ncm_dpe32 *dpe32;
1715 	} dpe;
1716 
1717 	int ndpoffset;
1718 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1719 	u32 payload = 0;
1720 
1721 	if (ctx->is_ndp16)
1722 		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1723 	else
1724 		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1725 
1726 	if (ndpoffset < 0)
1727 		goto error;
1728 
1729 next_ndp:
1730 	if (ctx->is_ndp16) {
1731 		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1732 		if (nframes < 0)
1733 			goto error;
1734 
1735 		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1736 
1737 		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1738 			netif_dbg(dev, rx_err, dev->net,
1739 				  "invalid DPT16 signature <%#010x>\n",
1740 				  le32_to_cpu(ndp.ndp16->dwSignature));
1741 			goto err_ndp;
1742 		}
1743 		dpe.dpe16 = ndp.ndp16->dpe16;
1744 	} else {
1745 		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1746 		if (nframes < 0)
1747 			goto error;
1748 
1749 		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1750 
1751 		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1752 			netif_dbg(dev, rx_err, dev->net,
1753 				  "invalid DPT32 signature <%#010x>\n",
1754 				  le32_to_cpu(ndp.ndp32->dwSignature));
1755 			goto err_ndp;
1756 		}
1757 		dpe.dpe32 = ndp.ndp32->dpe32;
1758 	}
1759 
1760 	for (x = 0; x < nframes; x++) {
1761 		if (ctx->is_ndp16) {
1762 			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1763 			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1764 		} else {
1765 			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1766 			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1767 		}
1768 
1769 		/*
1770 		 * CDC NCM ch. 3.7
1771 		 * All entries after first NULL entry are to be ignored
1772 		 */
1773 		if ((offset == 0) || (len == 0)) {
1774 			if (!x)
1775 				goto err_ndp; /* empty NTB */
1776 			break;
1777 		}
1778 
1779 		/* sanity checking */
1780 		if (((offset + len) > skb_in->len) ||
1781 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1782 			netif_dbg(dev, rx_err, dev->net,
1783 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1784 				  x, offset, len, skb_in);
1785 			if (!x)
1786 				goto err_ndp;
1787 			break;
1788 
1789 		} else {
1790 			/* create a fresh copy to reduce truesize */
1791 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1792 			if (!skb)
1793 				goto error;
1794 			skb_put_data(skb, skb_in->data + offset, len);
1795 			usbnet_skb_return(dev, skb);
1796 			payload += len;	/* count payload bytes in this NTB */
1797 		}
1798 
1799 		if (ctx->is_ndp16)
1800 			dpe.dpe16++;
1801 		else
1802 			dpe.dpe32++;
1803 	}
1804 err_ndp:
1805 	/* are there more NDPs to process? */
1806 	if (ctx->is_ndp16)
1807 		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1808 	else
1809 		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1810 
1811 	if (ndpoffset && loopcount--)
1812 		goto next_ndp;
1813 
1814 	/* update stats */
1815 	ctx->rx_overhead += skb_in->len - payload;
1816 	ctx->rx_ntbs++;
1817 
1818 	return 1;
1819 error:
1820 	return 0;
1821 }
1822 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1823 
1824 static void
1825 cdc_ncm_speed_change(struct usbnet *dev,
1826 		     struct usb_cdc_speed_change *data)
1827 {
1828 	/* RTL8156 shipped before 2021 sends notification about every 32ms. */
1829 	dev->rx_speed = le32_to_cpu(data->DLBitRRate);
1830 	dev->tx_speed = le32_to_cpu(data->ULBitRate);
1831 }
1832 
1833 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1834 {
1835 	struct usb_cdc_notification *event;
1836 
1837 	if (urb->actual_length < sizeof(*event))
1838 		return;
1839 
1840 	/* test for split data in 8-byte chunks */
1841 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1842 		cdc_ncm_speed_change(dev,
1843 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1844 		return;
1845 	}
1846 
1847 	event = urb->transfer_buffer;
1848 
1849 	switch (event->bNotificationType) {
1850 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1851 		/*
1852 		 * According to the CDC NCM specification ch.7.1
1853 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1854 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1855 		 */
1856 		/* RTL8156 shipped before 2021 sends notification about
1857 		 * every 32ms. Don't forward notification if state is same.
1858 		 */
1859 		if (netif_carrier_ok(dev->net) != !!event->wValue)
1860 			usbnet_link_change(dev, !!event->wValue, 0);
1861 		break;
1862 
1863 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1864 		if (urb->actual_length < (sizeof(*event) +
1865 					sizeof(struct usb_cdc_speed_change)))
1866 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1867 		else
1868 			cdc_ncm_speed_change(dev,
1869 					     (struct usb_cdc_speed_change *)&event[1]);
1870 		break;
1871 
1872 	default:
1873 		dev_dbg(&dev->udev->dev,
1874 			"NCM: unexpected notification 0x%02x!\n",
1875 			event->bNotificationType);
1876 		break;
1877 	}
1878 }
1879 
1880 static const struct driver_info cdc_ncm_info = {
1881 	.description = "CDC NCM",
1882 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1883 			| FLAG_LINK_INTR,
1884 	.bind = cdc_ncm_bind,
1885 	.unbind = cdc_ncm_unbind,
1886 	.manage_power = usbnet_manage_power,
1887 	.status = cdc_ncm_status,
1888 	.rx_fixup = cdc_ncm_rx_fixup,
1889 	.tx_fixup = cdc_ncm_tx_fixup,
1890 	.set_rx_mode = usbnet_cdc_update_filter,
1891 };
1892 
1893 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1894 static const struct driver_info wwan_info = {
1895 	.description = "Mobile Broadband Network Device",
1896 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1897 			| FLAG_LINK_INTR | FLAG_WWAN,
1898 	.bind = cdc_ncm_bind,
1899 	.unbind = cdc_ncm_unbind,
1900 	.manage_power = usbnet_manage_power,
1901 	.status = cdc_ncm_status,
1902 	.rx_fixup = cdc_ncm_rx_fixup,
1903 	.tx_fixup = cdc_ncm_tx_fixup,
1904 	.set_rx_mode = usbnet_cdc_update_filter,
1905 };
1906 
1907 /* Same as wwan_info, but with FLAG_NOARP  */
1908 static const struct driver_info wwan_noarp_info = {
1909 	.description = "Mobile Broadband Network Device (NO ARP)",
1910 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1911 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1912 	.bind = cdc_ncm_bind,
1913 	.unbind = cdc_ncm_unbind,
1914 	.manage_power = usbnet_manage_power,
1915 	.status = cdc_ncm_status,
1916 	.rx_fixup = cdc_ncm_rx_fixup,
1917 	.tx_fixup = cdc_ncm_tx_fixup,
1918 	.set_rx_mode = usbnet_cdc_update_filter,
1919 };
1920 
1921 static const struct usb_device_id cdc_devs[] = {
1922 	/* Ericsson MBM devices like F5521gw */
1923 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1924 		| USB_DEVICE_ID_MATCH_VENDOR,
1925 	  .idVendor = 0x0bdb,
1926 	  .bInterfaceClass = USB_CLASS_COMM,
1927 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1928 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1929 	  .driver_info = (unsigned long) &wwan_info,
1930 	},
1931 
1932 	/* Telit LE910 V2 */
1933 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1934 		USB_CLASS_COMM,
1935 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1936 	  .driver_info = (unsigned long)&wwan_noarp_info,
1937 	},
1938 
1939 	/* DW5812 LTE Verizon Mobile Broadband Card
1940 	 * Unlike DW5550 this device requires FLAG_NOARP
1941 	 */
1942 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1943 		USB_CLASS_COMM,
1944 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1945 	  .driver_info = (unsigned long)&wwan_noarp_info,
1946 	},
1947 
1948 	/* DW5813 LTE AT&T Mobile Broadband Card
1949 	 * Unlike DW5550 this device requires FLAG_NOARP
1950 	 */
1951 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1952 		USB_CLASS_COMM,
1953 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1954 	  .driver_info = (unsigned long)&wwan_noarp_info,
1955 	},
1956 
1957 	/* Dell branded MBM devices like DW5550 */
1958 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1959 		| USB_DEVICE_ID_MATCH_VENDOR,
1960 	  .idVendor = 0x413c,
1961 	  .bInterfaceClass = USB_CLASS_COMM,
1962 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1963 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1964 	  .driver_info = (unsigned long) &wwan_info,
1965 	},
1966 
1967 	/* Toshiba branded MBM devices */
1968 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1969 		| USB_DEVICE_ID_MATCH_VENDOR,
1970 	  .idVendor = 0x0930,
1971 	  .bInterfaceClass = USB_CLASS_COMM,
1972 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1973 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1974 	  .driver_info = (unsigned long) &wwan_info,
1975 	},
1976 
1977 	/* tag Huawei devices as wwan */
1978 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
1979 					USB_CLASS_COMM,
1980 					USB_CDC_SUBCLASS_NCM,
1981 					USB_CDC_PROTO_NONE),
1982 	  .driver_info = (unsigned long)&wwan_info,
1983 	},
1984 
1985 	/* Infineon(now Intel) HSPA Modem platform */
1986 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
1987 		USB_CLASS_COMM,
1988 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1989 	  .driver_info = (unsigned long)&wwan_noarp_info,
1990 	},
1991 
1992 	/* u-blox TOBY-L4 */
1993 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
1994 		USB_CLASS_COMM,
1995 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1996 	  .driver_info = (unsigned long)&wwan_info,
1997 	},
1998 
1999 	/* Generic CDC-NCM devices */
2000 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2001 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2002 		.driver_info = (unsigned long)&cdc_ncm_info,
2003 	},
2004 	{
2005 	},
2006 };
2007 MODULE_DEVICE_TABLE(usb, cdc_devs);
2008 
2009 static struct usb_driver cdc_ncm_driver = {
2010 	.name = "cdc_ncm",
2011 	.id_table = cdc_devs,
2012 	.probe = usbnet_probe,
2013 	.disconnect = usbnet_disconnect,
2014 	.suspend = usbnet_suspend,
2015 	.resume = usbnet_resume,
2016 	.reset_resume =	usbnet_resume,
2017 	.supports_autosuspend = 1,
2018 	.disable_hub_initiated_lpm = 1,
2019 };
2020 
2021 module_usb_driver(cdc_ncm_driver);
2022 
2023 MODULE_AUTHOR("Hans Petter Selasky");
2024 MODULE_DESCRIPTION("USB CDC NCM host driver");
2025 MODULE_LICENSE("Dual BSD/GPL");
2026