xref: /linux/drivers/net/usb/cdc_ncm.c (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
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/kstrtox.h>
47 #include <linux/workqueue.h>
48 #include <linux/mii.h>
49 #include <linux/crc32.h>
50 #include <linux/usb.h>
51 #include <linux/hrtimer.h>
52 #include <linux/atomic.h>
53 #include <linux/usb/usbnet.h>
54 #include <linux/usb/cdc.h>
55 #include <linux/usb/cdc_ncm.h>
56 
57 #if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
58 static bool prefer_mbim = true;
59 #else
60 static bool prefer_mbim;
61 #endif
62 module_param(prefer_mbim, bool, 0644);
63 MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
64 
65 static void cdc_ncm_txpath_bh(struct tasklet_struct *t);
66 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
67 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
68 static struct usb_driver cdc_ncm_driver;
69 
70 struct cdc_ncm_stats {
71 	char stat_string[ETH_GSTRING_LEN];
72 	int sizeof_stat;
73 	int stat_offset;
74 };
75 
76 #define CDC_NCM_STAT(str, m) { \
77 		.stat_string = str, \
78 		.sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
79 		.stat_offset = offsetof(struct cdc_ncm_ctx, m) }
80 #define CDC_NCM_SIMPLE_STAT(m)	CDC_NCM_STAT(__stringify(m), m)
81 
82 static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
83 	CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
84 	CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
85 	CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
86 	CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
87 	CDC_NCM_SIMPLE_STAT(tx_overhead),
88 	CDC_NCM_SIMPLE_STAT(tx_ntbs),
89 	CDC_NCM_SIMPLE_STAT(rx_overhead),
90 	CDC_NCM_SIMPLE_STAT(rx_ntbs),
91 };
92 
93 #define CDC_NCM_LOW_MEM_MAX_CNT 10
94 
95 static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
96 {
97 	switch (sset) {
98 	case ETH_SS_STATS:
99 		return ARRAY_SIZE(cdc_ncm_gstrings_stats);
100 	default:
101 		return -EOPNOTSUPP;
102 	}
103 }
104 
105 static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
106 				    struct ethtool_stats __always_unused *stats,
107 				    u64 *data)
108 {
109 	struct usbnet *dev = netdev_priv(netdev);
110 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
111 	int i;
112 	char *p = NULL;
113 
114 	for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
115 		p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
116 		data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
117 	}
118 }
119 
120 static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
121 {
122 	u8 *p = data;
123 	int i;
124 
125 	switch (stringset) {
126 	case ETH_SS_STATS:
127 		for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
128 			memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
129 			p += ETH_GSTRING_LEN;
130 		}
131 	}
132 }
133 
134 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
135 
136 static const struct ethtool_ops cdc_ncm_ethtool_ops = {
137 	.get_link		= usbnet_get_link,
138 	.nway_reset		= usbnet_nway_reset,
139 	.get_drvinfo		= usbnet_get_drvinfo,
140 	.get_msglevel		= usbnet_get_msglevel,
141 	.set_msglevel		= usbnet_set_msglevel,
142 	.get_ts_info		= ethtool_op_get_ts_info,
143 	.get_sset_count		= cdc_ncm_get_sset_count,
144 	.get_strings		= cdc_ncm_get_strings,
145 	.get_ethtool_stats	= cdc_ncm_get_ethtool_stats,
146 	.get_link_ksettings	= usbnet_get_link_ksettings_internal,
147 	.set_link_ksettings	= NULL,
148 };
149 
150 static u32 cdc_ncm_check_rx_max(struct usbnet *dev, u32 new_rx)
151 {
152 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
153 	u32 val, max, min;
154 
155 	/* clamp new_rx to sane values */
156 	min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
157 	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
158 
159 	/* dwNtbInMaxSize spec violation? Use MIN size for both limits */
160 	if (max < min) {
161 		dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
162 			 le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
163 		max = min;
164 	}
165 
166 	val = clamp_t(u32, new_rx, min, max);
167 	if (val != new_rx)
168 		dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range\n", min, max);
169 
170 	return val;
171 }
172 
173 static u32 cdc_ncm_check_tx_max(struct usbnet *dev, u32 new_tx)
174 {
175 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
176 	u32 val, max, min;
177 
178 	/* clamp new_tx to sane values */
179 	if (ctx->is_ndp16)
180 		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
181 	else
182 		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth32);
183 
184 	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
185 	if (max == 0)
186 		max = CDC_NCM_NTB_MAX_SIZE_TX; /* dwNtbOutMaxSize not set */
187 
188 	/* some devices set dwNtbOutMaxSize too low for the above default */
189 	min = min(min, max);
190 
191 	val = clamp_t(u32, new_tx, min, max);
192 	if (val != new_tx)
193 		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
194 
195 	return val;
196 }
197 
198 static ssize_t min_tx_pkt_show(struct device *d,
199 			       struct device_attribute *attr, char *buf)
200 {
201 	struct usbnet *dev = netdev_priv(to_net_dev(d));
202 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
203 
204 	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
205 }
206 
207 static ssize_t rx_max_show(struct device *d,
208 			   struct device_attribute *attr, char *buf)
209 {
210 	struct usbnet *dev = netdev_priv(to_net_dev(d));
211 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
212 
213 	return sprintf(buf, "%u\n", ctx->rx_max);
214 }
215 
216 static ssize_t tx_max_show(struct device *d,
217 			   struct device_attribute *attr, char *buf)
218 {
219 	struct usbnet *dev = netdev_priv(to_net_dev(d));
220 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
221 
222 	return sprintf(buf, "%u\n", ctx->tx_max);
223 }
224 
225 static ssize_t tx_timer_usecs_show(struct device *d,
226 				   struct device_attribute *attr, char *buf)
227 {
228 	struct usbnet *dev = netdev_priv(to_net_dev(d));
229 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
230 
231 	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
232 }
233 
234 static ssize_t min_tx_pkt_store(struct device *d,
235 				struct device_attribute *attr,
236 				const char *buf, size_t len)
237 {
238 	struct usbnet *dev = netdev_priv(to_net_dev(d));
239 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
240 	unsigned long val;
241 
242 	/* no need to restrict values - anything from 0 to infinity is OK */
243 	if (kstrtoul(buf, 0, &val))
244 		return -EINVAL;
245 
246 	ctx->min_tx_pkt = val;
247 	return len;
248 }
249 
250 static ssize_t rx_max_store(struct device *d,
251 			    struct device_attribute *attr,
252 			    const char *buf, size_t len)
253 {
254 	struct usbnet *dev = netdev_priv(to_net_dev(d));
255 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
256 	unsigned long val;
257 
258 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
259 		return -EINVAL;
260 
261 	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
262 	return len;
263 }
264 
265 static ssize_t tx_max_store(struct device *d,
266 			    struct device_attribute *attr,
267 			    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 	unsigned long val;
272 
273 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
274 		return -EINVAL;
275 
276 	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
277 	return len;
278 }
279 
280 static ssize_t tx_timer_usecs_store(struct device *d,
281 				    struct device_attribute *attr,
282 				    const char *buf, size_t len)
283 {
284 	struct usbnet *dev = netdev_priv(to_net_dev(d));
285 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
286 	ssize_t ret;
287 	unsigned long val;
288 
289 	ret = kstrtoul(buf, 0, &val);
290 	if (ret)
291 		return ret;
292 	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
293 		return -EINVAL;
294 
295 	spin_lock_bh(&ctx->mtx);
296 	ctx->timer_interval = val * NSEC_PER_USEC;
297 	if (!ctx->timer_interval)
298 		ctx->tx_timer_pending = 0;
299 	spin_unlock_bh(&ctx->mtx);
300 	return len;
301 }
302 
303 static DEVICE_ATTR_RW(min_tx_pkt);
304 static DEVICE_ATTR_RW(rx_max);
305 static DEVICE_ATTR_RW(tx_max);
306 static DEVICE_ATTR_RW(tx_timer_usecs);
307 
308 static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
309 {
310 	struct usbnet *dev = netdev_priv(to_net_dev(d));
311 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
312 
313 	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
314 }
315 
316 static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
317 {
318 	struct usbnet *dev = netdev_priv(to_net_dev(d));
319 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
320 	bool enable;
321 
322 	if (kstrtobool(buf, &enable))
323 		return -EINVAL;
324 
325 	/* no change? */
326 	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
327 		return len;
328 
329 	if (enable) {
330 		if (ctx->is_ndp16 && !ctx->delayed_ndp16) {
331 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
332 			if (!ctx->delayed_ndp16)
333 				return -ENOMEM;
334 		}
335 		if (!ctx->is_ndp16 && !ctx->delayed_ndp32) {
336 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
337 			if (!ctx->delayed_ndp32)
338 				return -ENOMEM;
339 		}
340 	}
341 
342 	/* flush pending data before changing flag */
343 	netif_tx_lock_bh(dev->net);
344 	usbnet_start_xmit(NULL, dev->net);
345 	spin_lock_bh(&ctx->mtx);
346 	if (enable)
347 		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
348 	else
349 		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
350 	spin_unlock_bh(&ctx->mtx);
351 	netif_tx_unlock_bh(dev->net);
352 
353 	return len;
354 }
355 static DEVICE_ATTR_RW(ndp_to_end);
356 
357 #define NCM_PARM_ATTR(name, format, tocpu)				\
358 static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
359 { \
360 	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
361 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
362 	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
363 } \
364 static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
365 
366 NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
367 NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
368 NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
369 NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
370 NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
371 NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
372 NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
373 NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
374 NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
375 NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
376 
377 static struct attribute *cdc_ncm_sysfs_attrs[] = {
378 	&dev_attr_min_tx_pkt.attr,
379 	&dev_attr_ndp_to_end.attr,
380 	&dev_attr_rx_max.attr,
381 	&dev_attr_tx_max.attr,
382 	&dev_attr_tx_timer_usecs.attr,
383 	&dev_attr_bmNtbFormatsSupported.attr,
384 	&dev_attr_dwNtbInMaxSize.attr,
385 	&dev_attr_wNdpInDivisor.attr,
386 	&dev_attr_wNdpInPayloadRemainder.attr,
387 	&dev_attr_wNdpInAlignment.attr,
388 	&dev_attr_dwNtbOutMaxSize.attr,
389 	&dev_attr_wNdpOutDivisor.attr,
390 	&dev_attr_wNdpOutPayloadRemainder.attr,
391 	&dev_attr_wNdpOutAlignment.attr,
392 	&dev_attr_wNtbOutMaxDatagrams.attr,
393 	NULL,
394 };
395 
396 static const struct attribute_group cdc_ncm_sysfs_attr_group = {
397 	.name = "cdc_ncm",
398 	.attrs = cdc_ncm_sysfs_attrs,
399 };
400 
401 /* handle rx_max and tx_max changes */
402 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
403 {
404 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
405 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
406 	u32 val;
407 
408 	val = cdc_ncm_check_rx_max(dev, new_rx);
409 
410 	/* inform device about NTB input size changes */
411 	if (val != ctx->rx_max) {
412 		__le32 dwNtbInMaxSize = cpu_to_le32(val);
413 
414 		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
415 
416 		/* tell device to use new size */
417 		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
418 				     USB_TYPE_CLASS | USB_DIR_OUT
419 				     | USB_RECIP_INTERFACE,
420 				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
421 			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
422 		else
423 			ctx->rx_max = val;
424 	}
425 
426 	/* usbnet use these values for sizing rx queues */
427 	if (dev->rx_urb_size != ctx->rx_max) {
428 		dev->rx_urb_size = ctx->rx_max;
429 		if (netif_running(dev->net))
430 			usbnet_unlink_rx_urbs(dev);
431 	}
432 
433 	val = cdc_ncm_check_tx_max(dev, new_tx);
434 	if (val != ctx->tx_max)
435 		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
436 
437 	/* Adding a pad byte here if necessary simplifies the handling
438 	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
439 	 * the real skb max size.
440 	 *
441 	 * We cannot use dev->maxpacket here because this is called from
442 	 * .bind which is called before usbnet sets up dev->maxpacket
443 	 */
444 	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
445 	    val % usb_maxpacket(dev->udev, dev->out) == 0)
446 		val++;
447 
448 	/* we might need to flush any pending tx buffers if running */
449 	if (netif_running(dev->net) && val > ctx->tx_max) {
450 		netif_tx_lock_bh(dev->net);
451 		usbnet_start_xmit(NULL, dev->net);
452 		/* make sure tx_curr_skb is reallocated if it was empty */
453 		if (ctx->tx_curr_skb) {
454 			dev_kfree_skb_any(ctx->tx_curr_skb);
455 			ctx->tx_curr_skb = NULL;
456 		}
457 		ctx->tx_max = val;
458 		netif_tx_unlock_bh(dev->net);
459 	} else {
460 		ctx->tx_max = val;
461 	}
462 
463 	dev->hard_mtu = ctx->tx_max;
464 
465 	/* max qlen depend on hard_mtu and rx_urb_size */
466 	usbnet_update_max_qlen(dev);
467 
468 	/* never pad more than 3 full USB packets per transfer */
469 	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out),
470 				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
471 }
472 
473 /* helpers for NCM and MBIM differences */
474 static u8 cdc_ncm_flags(struct usbnet *dev)
475 {
476 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
477 
478 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
479 		return ctx->mbim_desc->bmNetworkCapabilities;
480 	if (ctx->func_desc)
481 		return ctx->func_desc->bmNetworkCapabilities;
482 	return 0;
483 }
484 
485 static int cdc_ncm_eth_hlen(struct usbnet *dev)
486 {
487 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
488 		return 0;
489 	return ETH_HLEN;
490 }
491 
492 static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
493 {
494 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
495 		return CDC_MBIM_MIN_DATAGRAM_SIZE;
496 	return CDC_NCM_MIN_DATAGRAM_SIZE;
497 }
498 
499 static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
500 {
501 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
502 
503 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
504 		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
505 	if (ctx->ether_desc)
506 		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
507 	return CDC_NCM_MAX_DATAGRAM_SIZE;
508 }
509 
510 /* initial one-time device setup.  MUST be called with the data interface
511  * in altsetting 0
512  */
513 static int cdc_ncm_init(struct usbnet *dev)
514 {
515 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
516 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
517 	int err;
518 
519 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
520 			      USB_TYPE_CLASS | USB_DIR_IN
521 			      |USB_RECIP_INTERFACE,
522 			      0, iface_no, &ctx->ncm_parm,
523 			      sizeof(ctx->ncm_parm));
524 	if (err < 0) {
525 		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
526 		return err; /* GET_NTB_PARAMETERS is required */
527 	}
528 
529 	/* set CRC Mode */
530 	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
531 		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
532 		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
533 				       USB_TYPE_CLASS | USB_DIR_OUT
534 				       | USB_RECIP_INTERFACE,
535 				       USB_CDC_NCM_CRC_NOT_APPENDED,
536 				       iface_no, NULL, 0);
537 		if (err < 0)
538 			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
539 	}
540 
541 	/* use ndp16 by default */
542 	ctx->is_ndp16 = 1;
543 
544 	/* set NTB format, if both formats are supported.
545 	 *
546 	 * "The host shall only send this command while the NCM Data
547 	 *  Interface is in alternate setting 0."
548 	 */
549 	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
550 						USB_CDC_NCM_NTB32_SUPPORTED) {
551 		if (ctx->drvflags & CDC_NCM_FLAG_PREFER_NTB32) {
552 			ctx->is_ndp16 = 0;
553 			dev_dbg(&dev->intf->dev, "Setting NTB format to 32-bit\n");
554 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
555 					       USB_TYPE_CLASS | USB_DIR_OUT
556 					       | USB_RECIP_INTERFACE,
557 					       USB_CDC_NCM_NTB32_FORMAT,
558 					       iface_no, NULL, 0);
559 		} else {
560 			ctx->is_ndp16 = 1;
561 			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
562 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
563 					       USB_TYPE_CLASS | USB_DIR_OUT
564 					       | USB_RECIP_INTERFACE,
565 					       USB_CDC_NCM_NTB16_FORMAT,
566 					       iface_no, NULL, 0);
567 		}
568 		if (err < 0) {
569 			ctx->is_ndp16 = 1;
570 			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
571 		}
572 	}
573 
574 	/* set initial device values */
575 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
576 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
577 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
578 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
579 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
580 	/* devices prior to NCM Errata shall set this field to zero */
581 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
582 
583 	dev_dbg(&dev->intf->dev,
584 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
585 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
586 		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
587 
588 	/* max count of tx datagrams */
589 	if ((ctx->tx_max_datagrams == 0) ||
590 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
591 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
592 
593 	/* set up maximum NDP size */
594 	if (ctx->is_ndp16)
595 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
596 	else
597 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp32) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe32);
598 
599 	/* initial coalescing timer interval */
600 	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
601 
602 	return 0;
603 }
604 
605 /* set a new max datagram size */
606 static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
607 {
608 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
609 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
610 	__le16 max_datagram_size;
611 	u16 mbim_mtu;
612 	int err;
613 
614 	/* set default based on descriptors */
615 	ctx->max_datagram_size = clamp_t(u32, new_size,
616 					 cdc_ncm_min_dgram_size(dev),
617 					 CDC_NCM_MAX_DATAGRAM_SIZE);
618 
619 	/* inform the device about the selected Max Datagram Size? */
620 	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
621 		goto out;
622 
623 	/* read current mtu value from device */
624 	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
625 			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
626 			      0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
627 	if (err != sizeof(max_datagram_size)) {
628 		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
629 		goto out;
630 	}
631 
632 	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
633 		goto out;
634 
635 	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
636 	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
637 			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
638 			       0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
639 	if (err < 0)
640 		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
641 
642 out:
643 	/* set MTU to max supported by the device if necessary */
644 	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
645 
646 	/* do not exceed operator preferred MTU */
647 	if (ctx->mbim_extended_desc) {
648 		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
649 		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
650 			dev->net->mtu = mbim_mtu;
651 	}
652 }
653 
654 static void cdc_ncm_fix_modulus(struct usbnet *dev)
655 {
656 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
657 	u32 val;
658 
659 	/*
660 	 * verify that the structure alignment is:
661 	 * - power of two
662 	 * - not greater than the maximum transmit length
663 	 * - not less than four bytes
664 	 */
665 	val = ctx->tx_ndp_modulus;
666 
667 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
668 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
669 		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
670 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
671 	}
672 
673 	/*
674 	 * verify that the payload alignment is:
675 	 * - power of two
676 	 * - not greater than the maximum transmit length
677 	 * - not less than four bytes
678 	 */
679 	val = ctx->tx_modulus;
680 
681 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
682 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
683 		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
684 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
685 	}
686 
687 	/* verify the payload remainder */
688 	if (ctx->tx_remainder >= ctx->tx_modulus) {
689 		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
690 		ctx->tx_remainder = 0;
691 	}
692 
693 	/* adjust TX-remainder according to NCM specification. */
694 	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
695 			     (ctx->tx_modulus - 1));
696 }
697 
698 static int cdc_ncm_setup(struct usbnet *dev)
699 {
700 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
701 	u32 def_rx, def_tx;
702 
703 	/* be conservative when selecting initial buffer size to
704 	 * increase the number of hosts this will work for
705 	 */
706 	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
707 		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
708 	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
709 		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
710 
711 	/* clamp rx_max and tx_max and inform device */
712 	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
713 
714 	/* sanitize the modulus and remainder values */
715 	cdc_ncm_fix_modulus(dev);
716 
717 	/* set max datagram size */
718 	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
719 	return 0;
720 }
721 
722 static void
723 cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
724 {
725 	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
726 	u8 ep;
727 
728 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
729 		e = intf->cur_altsetting->endpoint + ep;
730 
731 		/* ignore endpoints which cannot transfer data */
732 		if (!usb_endpoint_maxp(&e->desc))
733 			continue;
734 
735 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
736 		case USB_ENDPOINT_XFER_INT:
737 			if (usb_endpoint_dir_in(&e->desc)) {
738 				if (!dev->status)
739 					dev->status = e;
740 			}
741 			break;
742 
743 		case USB_ENDPOINT_XFER_BULK:
744 			if (usb_endpoint_dir_in(&e->desc)) {
745 				if (!in)
746 					in = e;
747 			} else {
748 				if (!out)
749 					out = e;
750 			}
751 			break;
752 
753 		default:
754 			break;
755 		}
756 	}
757 	if (in && !dev->in)
758 		dev->in = usb_rcvbulkpipe(dev->udev,
759 					  in->desc.bEndpointAddress &
760 					  USB_ENDPOINT_NUMBER_MASK);
761 	if (out && !dev->out)
762 		dev->out = usb_sndbulkpipe(dev->udev,
763 					   out->desc.bEndpointAddress &
764 					   USB_ENDPOINT_NUMBER_MASK);
765 }
766 
767 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
768 {
769 	if (ctx == NULL)
770 		return;
771 
772 	if (ctx->tx_rem_skb != NULL) {
773 		dev_kfree_skb_any(ctx->tx_rem_skb);
774 		ctx->tx_rem_skb = NULL;
775 	}
776 
777 	if (ctx->tx_curr_skb != NULL) {
778 		dev_kfree_skb_any(ctx->tx_curr_skb);
779 		ctx->tx_curr_skb = NULL;
780 	}
781 
782 	if (ctx->is_ndp16)
783 		kfree(ctx->delayed_ndp16);
784 	else
785 		kfree(ctx->delayed_ndp32);
786 
787 	kfree(ctx);
788 }
789 
790 /* we need to override the usbnet change_mtu ndo for two reasons:
791  *  - respect the negotiated maximum datagram size
792  *  - avoid unwanted changes to rx and tx buffers
793  */
794 int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
795 {
796 	struct usbnet *dev = netdev_priv(net);
797 
798 	net->mtu = new_mtu;
799 	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
800 
801 	return 0;
802 }
803 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
804 
805 static const struct net_device_ops cdc_ncm_netdev_ops = {
806 	.ndo_open	     = usbnet_open,
807 	.ndo_stop	     = usbnet_stop,
808 	.ndo_start_xmit	     = usbnet_start_xmit,
809 	.ndo_tx_timeout	     = usbnet_tx_timeout,
810 	.ndo_set_rx_mode     = usbnet_set_rx_mode,
811 	.ndo_get_stats64     = dev_get_tstats64,
812 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
813 	.ndo_set_mac_address = eth_mac_addr,
814 	.ndo_validate_addr   = eth_validate_addr,
815 };
816 
817 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
818 {
819 	struct cdc_ncm_ctx *ctx;
820 	struct usb_driver *driver;
821 	u8 *buf;
822 	int len;
823 	int temp;
824 	u8 iface_no;
825 	struct usb_cdc_parsed_header hdr;
826 
827 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
828 	if (!ctx)
829 		return -ENOMEM;
830 
831 	ctx->dev = dev;
832 
833 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
834 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
835 	tasklet_setup(&ctx->bh, cdc_ncm_txpath_bh);
836 	atomic_set(&ctx->stop, 0);
837 	spin_lock_init(&ctx->mtx);
838 
839 	/* store ctx pointer in device data field */
840 	dev->data[0] = (unsigned long)ctx;
841 
842 	/* only the control interface can be successfully probed */
843 	ctx->control = intf;
844 
845 	/* get some pointers */
846 	driver = driver_of(intf);
847 	buf = intf->cur_altsetting->extra;
848 	len = intf->cur_altsetting->extralen;
849 
850 	/* parse through descriptors associated with control interface */
851 	cdc_parse_cdc_header(&hdr, intf, buf, len);
852 
853 	if (hdr.usb_cdc_union_desc)
854 		ctx->data = usb_ifnum_to_if(dev->udev,
855 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
856 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
857 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
858 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
859 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
860 
861 	/* some buggy devices have an IAD but no CDC Union */
862 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
863 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
864 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
865 	}
866 
867 	/* check if we got everything */
868 	if (!ctx->data) {
869 		dev_err(&intf->dev, "CDC Union missing and no IAD found\n");
870 		goto error;
871 	}
872 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
873 		if (!ctx->mbim_desc) {
874 			dev_err(&intf->dev, "MBIM functional descriptor missing\n");
875 			goto error;
876 		}
877 	} else {
878 		if (!ctx->ether_desc || !ctx->func_desc) {
879 			dev_err(&intf->dev, "NCM or ECM functional descriptors missing\n");
880 			goto error;
881 		}
882 	}
883 
884 	/* claim data interface, if different from control */
885 	if (ctx->data != ctx->control) {
886 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
887 		if (temp) {
888 			dev_err(&intf->dev, "failed to claim data intf\n");
889 			goto error;
890 		}
891 	}
892 
893 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
894 
895 	/* Device-specific flags */
896 	ctx->drvflags = drvflags;
897 
898 	/* Reset data interface. Some devices will not reset properly
899 	 * unless they are configured first.  Toggle the altsetting to
900 	 * force a reset.
901 	 * Some other devices do not work properly with this procedure
902 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
903 	 */
904 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
905 		usb_set_interface(dev->udev, iface_no, data_altsetting);
906 
907 	temp = usb_set_interface(dev->udev, iface_no, 0);
908 	if (temp) {
909 		dev_dbg(&intf->dev, "set interface failed\n");
910 		goto error2;
911 	}
912 
913 	/* initialize basic device settings */
914 	if (cdc_ncm_init(dev))
915 		goto error2;
916 
917 	/* Some firmwares need a pause here or they will silently fail
918 	 * to set up the interface properly.  This value was decided
919 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
920 	 * firmware.
921 	 */
922 	usleep_range(10000, 20000);
923 
924 	/* configure data interface */
925 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
926 	if (temp) {
927 		dev_dbg(&intf->dev, "set interface failed\n");
928 		goto error2;
929 	}
930 
931 	cdc_ncm_find_endpoints(dev, ctx->data);
932 	cdc_ncm_find_endpoints(dev, ctx->control);
933 	if (!dev->in || !dev->out || !dev->status) {
934 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
935 		goto error2;
936 	}
937 
938 	usb_set_intfdata(ctx->control, dev);
939 
940 	if (ctx->ether_desc) {
941 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
942 		if (temp) {
943 			dev_err(&intf->dev, "failed to get mac address\n");
944 			goto error2;
945 		}
946 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
947 	}
948 
949 	/* finish setting up the device specific data */
950 	cdc_ncm_setup(dev);
951 
952 	/* Allocate the delayed NDP if needed. */
953 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
954 		if (ctx->is_ndp16) {
955 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
956 			if (!ctx->delayed_ndp16)
957 				goto error2;
958 		} else {
959 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
960 			if (!ctx->delayed_ndp32)
961 				goto error2;
962 		}
963 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
964 	}
965 
966 	/* override ethtool_ops */
967 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
968 
969 	/* add our sysfs attrs */
970 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
971 
972 	/* must handle MTU changes */
973 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
974 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
975 
976 	return 0;
977 
978 error2:
979 	usb_set_intfdata(ctx->control, NULL);
980 	usb_set_intfdata(ctx->data, NULL);
981 	if (ctx->data != ctx->control)
982 		usb_driver_release_interface(driver, ctx->data);
983 error:
984 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
985 	dev->data[0] = 0;
986 	dev_info(&intf->dev, "bind() failure\n");
987 	return -ENODEV;
988 }
989 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
990 
991 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
992 {
993 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
994 	struct usb_driver *driver = driver_of(intf);
995 
996 	if (ctx == NULL)
997 		return;		/* no setup */
998 
999 	atomic_set(&ctx->stop, 1);
1000 
1001 	hrtimer_cancel(&ctx->tx_timer);
1002 
1003 	tasklet_kill(&ctx->bh);
1004 
1005 	/* handle devices with combined control and data interface */
1006 	if (ctx->control == ctx->data)
1007 		ctx->data = NULL;
1008 
1009 	/* disconnect master --> disconnect slave */
1010 	if (intf == ctx->control && ctx->data) {
1011 		usb_set_intfdata(ctx->data, NULL);
1012 		usb_driver_release_interface(driver, ctx->data);
1013 		ctx->data = NULL;
1014 
1015 	} else if (intf == ctx->data && ctx->control) {
1016 		usb_set_intfdata(ctx->control, NULL);
1017 		usb_driver_release_interface(driver, ctx->control);
1018 		ctx->control = NULL;
1019 	}
1020 
1021 	usb_set_intfdata(intf, NULL);
1022 	cdc_ncm_free(ctx);
1023 }
1024 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1025 
1026 /* Return the number of the MBIM control interface altsetting iff it
1027  * is preferred and available,
1028  */
1029 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1030 {
1031 	struct usb_host_interface *alt;
1032 
1033 	/* The MBIM spec defines a NCM compatible default altsetting,
1034 	 * which we may have matched:
1035 	 *
1036 	 *  "Functions that implement both NCM 1.0 and MBIM (an
1037 	 *   “NCM/MBIM function”) according to this recommendation
1038 	 *   shall provide two alternate settings for the
1039 	 *   Communication Interface.  Alternate setting 0, and the
1040 	 *   associated class and endpoint descriptors, shall be
1041 	 *   constructed according to the rules given for the
1042 	 *   Communication Interface in section 5 of [USBNCM10].
1043 	 *   Alternate setting 1, and the associated class and
1044 	 *   endpoint descriptors, shall be constructed according to
1045 	 *   the rules given in section 6 (USB Device Model) of this
1046 	 *   specification."
1047 	 */
1048 	if (intf->num_altsetting < 2)
1049 		return intf->cur_altsetting->desc.bAlternateSetting;
1050 
1051 	if (prefer_mbim) {
1052 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1053 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1054 			return CDC_NCM_COMM_ALTSETTING_MBIM;
1055 	}
1056 	return CDC_NCM_COMM_ALTSETTING_NCM;
1057 }
1058 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1059 
1060 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1061 {
1062 	/* MBIM backwards compatible function? */
1063 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1064 		return -ENODEV;
1065 
1066 	/* The NCM data altsetting is fixed, so we hard-coded it.
1067 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1068 	 * placed NDP.
1069 	 */
1070 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1071 }
1072 
1073 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1074 {
1075 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1076 
1077 	if (skb->len + align > max)
1078 		align = max - skb->len;
1079 	if (align && skb_tailroom(skb) >= align)
1080 		skb_put_zero(skb, align);
1081 }
1082 
1083 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1084  * allocating a new one within skb
1085  */
1086 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1087 {
1088 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1089 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1090 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1091 
1092 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1093 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1094 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1095 	*/
1096 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1097 		if (ctx->delayed_ndp16->dwSignature == sign)
1098 			return ctx->delayed_ndp16;
1099 
1100 		/* We can only push a single NDP to the end. Return
1101 		 * NULL to send what we've already got and queue this
1102 		 * skb for later.
1103 		 */
1104 		else if (ctx->delayed_ndp16->dwSignature)
1105 			return NULL;
1106 	}
1107 
1108 	/* follow the chain of NDPs, looking for a match */
1109 	while (ndpoffset) {
1110 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1111 		if  (ndp16->dwSignature == sign)
1112 			return ndp16;
1113 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1114 	}
1115 
1116 	/* align new NDP */
1117 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1118 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1119 
1120 	/* verify that there is room for the NDP and the datagram (reserve) */
1121 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1122 		return NULL;
1123 
1124 	/* link to it */
1125 	if (ndp16)
1126 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1127 	else
1128 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1129 
1130 	/* push a new empty NDP */
1131 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1132 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1133 	else
1134 		ndp16 = ctx->delayed_ndp16;
1135 
1136 	ndp16->dwSignature = sign;
1137 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1138 	return ndp16;
1139 }
1140 
1141 static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1142 {
1143 	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1144 	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1145 	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1146 
1147 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1148 	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1149 	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1150 	 */
1151 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1152 		if (ctx->delayed_ndp32->dwSignature == sign)
1153 			return ctx->delayed_ndp32;
1154 
1155 		/* We can only push a single NDP to the end. Return
1156 		 * NULL to send what we've already got and queue this
1157 		 * skb for later.
1158 		 */
1159 		else if (ctx->delayed_ndp32->dwSignature)
1160 			return NULL;
1161 	}
1162 
1163 	/* follow the chain of NDPs, looking for a match */
1164 	while (ndpoffset) {
1165 		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1166 		if  (ndp32->dwSignature == sign)
1167 			return ndp32;
1168 		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1169 	}
1170 
1171 	/* align new NDP */
1172 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1173 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1174 
1175 	/* verify that there is room for the NDP and the datagram (reserve) */
1176 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1177 		return NULL;
1178 
1179 	/* link to it */
1180 	if (ndp32)
1181 		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1182 	else
1183 		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1184 
1185 	/* push a new empty NDP */
1186 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1187 		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1188 	else
1189 		ndp32 = ctx->delayed_ndp32;
1190 
1191 	ndp32->dwSignature = sign;
1192 	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1193 	return ndp32;
1194 }
1195 
1196 struct sk_buff *
1197 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1198 {
1199 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1200 	union {
1201 		struct usb_cdc_ncm_nth16 *nth16;
1202 		struct usb_cdc_ncm_nth32 *nth32;
1203 	} nth;
1204 	union {
1205 		struct usb_cdc_ncm_ndp16 *ndp16;
1206 		struct usb_cdc_ncm_ndp32 *ndp32;
1207 	} ndp;
1208 	struct sk_buff *skb_out;
1209 	u16 n = 0, index, ndplen;
1210 	u8 ready2send = 0;
1211 	u32 delayed_ndp_size;
1212 	size_t padding_count;
1213 
1214 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1215 	 * accordingly. Otherwise, we should check here.
1216 	 */
1217 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1218 		delayed_ndp_size = ctx->max_ndp_size +
1219 			max_t(u32,
1220 			      ctx->tx_ndp_modulus,
1221 			      ctx->tx_modulus + ctx->tx_remainder) - 1;
1222 	else
1223 		delayed_ndp_size = 0;
1224 
1225 	/* if there is a remaining skb, it gets priority */
1226 	if (skb != NULL) {
1227 		swap(skb, ctx->tx_rem_skb);
1228 		swap(sign, ctx->tx_rem_sign);
1229 	} else {
1230 		ready2send = 1;
1231 	}
1232 
1233 	/* check if we are resuming an OUT skb */
1234 	skb_out = ctx->tx_curr_skb;
1235 
1236 	/* allocate a new OUT skb */
1237 	if (!skb_out) {
1238 		if (ctx->tx_low_mem_val == 0) {
1239 			ctx->tx_curr_size = ctx->tx_max;
1240 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1241 			/* If the memory allocation fails we will wait longer
1242 			 * each time before attempting another full size
1243 			 * allocation again to not overload the system
1244 			 * further.
1245 			 */
1246 			if (skb_out == NULL) {
1247 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1248 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1249 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1250 			}
1251 		}
1252 		if (skb_out == NULL) {
1253 			/* See if a very small allocation is possible.
1254 			 * We will send this packet immediately and hope
1255 			 * that there is more memory available later.
1256 			 */
1257 			if (skb)
1258 				ctx->tx_curr_size = max(skb->len,
1259 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1260 			else
1261 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1262 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1263 
1264 			/* No allocation possible so we will abort */
1265 			if (skb_out == NULL) {
1266 				if (skb != NULL) {
1267 					dev_kfree_skb_any(skb);
1268 					dev->net->stats.tx_dropped++;
1269 				}
1270 				goto exit_no_skb;
1271 			}
1272 			ctx->tx_low_mem_val--;
1273 		}
1274 		if (ctx->is_ndp16) {
1275 			/* fill out the initial 16-bit NTB header */
1276 			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1277 			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1278 			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1279 			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1280 		} else {
1281 			/* fill out the initial 32-bit NTB header */
1282 			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1283 			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1284 			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1285 			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1286 		}
1287 
1288 		/* count total number of frames in this NTB */
1289 		ctx->tx_curr_frame_num = 0;
1290 
1291 		/* recent payload counter for this skb_out */
1292 		ctx->tx_curr_frame_payload = 0;
1293 	}
1294 
1295 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1296 		/* send any remaining skb first */
1297 		if (skb == NULL) {
1298 			skb = ctx->tx_rem_skb;
1299 			sign = ctx->tx_rem_sign;
1300 			ctx->tx_rem_skb = NULL;
1301 
1302 			/* check for end of skb */
1303 			if (skb == NULL)
1304 				break;
1305 		}
1306 
1307 		/* get the appropriate NDP for this skb */
1308 		if (ctx->is_ndp16)
1309 			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1310 		else
1311 			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1312 
1313 		/* align beginning of next frame */
1314 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1315 
1316 		/* check if we had enough room left for both NDP and frame */
1317 		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1318 		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1319 			if (n == 0) {
1320 				/* won't fit, MTU problem? */
1321 				dev_kfree_skb_any(skb);
1322 				skb = NULL;
1323 				dev->net->stats.tx_dropped++;
1324 			} else {
1325 				/* no room for skb - store for later */
1326 				if (ctx->tx_rem_skb != NULL) {
1327 					dev_kfree_skb_any(ctx->tx_rem_skb);
1328 					dev->net->stats.tx_dropped++;
1329 				}
1330 				ctx->tx_rem_skb = skb;
1331 				ctx->tx_rem_sign = sign;
1332 				skb = NULL;
1333 				ready2send = 1;
1334 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1335 			}
1336 			break;
1337 		}
1338 
1339 		/* calculate frame number within this NDP */
1340 		if (ctx->is_ndp16) {
1341 			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1342 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1343 
1344 			/* OK, add this skb */
1345 			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1346 			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1347 			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1348 		} else {
1349 			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1350 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1351 
1352 			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1353 			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1354 			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1355 		}
1356 		skb_put_data(skb_out, skb->data, skb->len);
1357 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1358 		dev_kfree_skb_any(skb);
1359 		skb = NULL;
1360 
1361 		/* send now if this NDP is full */
1362 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1363 			ready2send = 1;
1364 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1365 			break;
1366 		}
1367 	}
1368 
1369 	/* free up any dangling skb */
1370 	if (skb != NULL) {
1371 		dev_kfree_skb_any(skb);
1372 		skb = NULL;
1373 		dev->net->stats.tx_dropped++;
1374 	}
1375 
1376 	ctx->tx_curr_frame_num = n;
1377 
1378 	if (n == 0) {
1379 		/* wait for more frames */
1380 		/* push variables */
1381 		ctx->tx_curr_skb = skb_out;
1382 		goto exit_no_skb;
1383 
1384 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1385 		/* wait for more frames */
1386 		/* push variables */
1387 		ctx->tx_curr_skb = skb_out;
1388 		/* set the pending count */
1389 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1390 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1391 		goto exit_no_skb;
1392 
1393 	} else {
1394 		if (n == ctx->tx_max_datagrams)
1395 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1396 		/* frame goes out */
1397 		/* variables will be reset at next call */
1398 	}
1399 
1400 	/* If requested, put NDP at end of frame. */
1401 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1402 		if (ctx->is_ndp16) {
1403 			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1404 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1405 			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1406 			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1407 
1408 			/* Zero out delayed NDP - signature checking will naturally fail. */
1409 			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1410 		} else {
1411 			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1412 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1413 			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1414 			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1415 
1416 			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1417 		}
1418 	}
1419 
1420 	/* If collected data size is less or equal ctx->min_tx_pkt
1421 	 * bytes, we send buffers as it is. If we get more data, it
1422 	 * would be more efficient for USB HS mobile device with DMA
1423 	 * engine to receive a full size NTB, than canceling DMA
1424 	 * transfer and receiving a short packet.
1425 	 *
1426 	 * This optimization support is pointless if we end up sending
1427 	 * a ZLP after full sized NTBs.
1428 	 */
1429 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1430 	    skb_out->len > ctx->min_tx_pkt) {
1431 		padding_count = ctx->tx_curr_size - skb_out->len;
1432 		if (!WARN_ON(padding_count > ctx->tx_curr_size))
1433 			skb_put_zero(skb_out, padding_count);
1434 	} else if (skb_out->len < ctx->tx_curr_size &&
1435 		   (skb_out->len % dev->maxpacket) == 0) {
1436 		skb_put_u8(skb_out, 0);	/* force short packet */
1437 	}
1438 
1439 	/* set final frame length */
1440 	if (ctx->is_ndp16) {
1441 		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1442 		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1443 	} else {
1444 		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1445 		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1446 	}
1447 
1448 	/* return skb */
1449 	ctx->tx_curr_skb = NULL;
1450 
1451 	/* keep private stats: framing overhead and number of NTBs */
1452 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1453 	ctx->tx_ntbs++;
1454 
1455 	/* usbnet will count all the framing overhead by default.
1456 	 * Adjust the stats so that the tx_bytes counter show real
1457 	 * payload data instead.
1458 	 */
1459 	usbnet_set_skb_tx_stats(skb_out, n,
1460 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1461 
1462 	return skb_out;
1463 
1464 exit_no_skb:
1465 	/* Start timer, if there is a remaining non-empty skb */
1466 	if (ctx->tx_curr_skb != NULL && n > 0)
1467 		cdc_ncm_tx_timeout_start(ctx);
1468 	return NULL;
1469 }
1470 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1471 
1472 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1473 {
1474 	/* start timer, if not already started */
1475 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1476 		hrtimer_start(&ctx->tx_timer,
1477 				ctx->timer_interval,
1478 				HRTIMER_MODE_REL);
1479 }
1480 
1481 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1482 {
1483 	struct cdc_ncm_ctx *ctx =
1484 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1485 
1486 	if (!atomic_read(&ctx->stop))
1487 		tasklet_schedule(&ctx->bh);
1488 	return HRTIMER_NORESTART;
1489 }
1490 
1491 static void cdc_ncm_txpath_bh(struct tasklet_struct *t)
1492 {
1493 	struct cdc_ncm_ctx *ctx = from_tasklet(ctx, t, bh);
1494 	struct usbnet *dev = ctx->dev;
1495 
1496 	spin_lock(&ctx->mtx);
1497 	if (ctx->tx_timer_pending != 0) {
1498 		ctx->tx_timer_pending--;
1499 		cdc_ncm_tx_timeout_start(ctx);
1500 		spin_unlock(&ctx->mtx);
1501 	} else if (dev->net != NULL) {
1502 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1503 		spin_unlock(&ctx->mtx);
1504 		netif_tx_lock_bh(dev->net);
1505 		usbnet_start_xmit(NULL, dev->net);
1506 		netif_tx_unlock_bh(dev->net);
1507 	} else {
1508 		spin_unlock(&ctx->mtx);
1509 	}
1510 }
1511 
1512 struct sk_buff *
1513 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1514 {
1515 	struct sk_buff *skb_out;
1516 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1517 
1518 	/*
1519 	 * The Ethernet API we are using does not support transmitting
1520 	 * multiple Ethernet frames in a single call. This driver will
1521 	 * accumulate multiple Ethernet frames and send out a larger
1522 	 * USB frame when the USB buffer is full or when a single jiffies
1523 	 * timeout happens.
1524 	 */
1525 	if (ctx == NULL)
1526 		goto error;
1527 
1528 	spin_lock_bh(&ctx->mtx);
1529 
1530 	if (ctx->is_ndp16)
1531 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1532 	else
1533 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1534 
1535 	spin_unlock_bh(&ctx->mtx);
1536 	return skb_out;
1537 
1538 error:
1539 	if (skb != NULL)
1540 		dev_kfree_skb_any(skb);
1541 
1542 	return NULL;
1543 }
1544 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1545 
1546 /* verify NTB header and return offset of first NDP, or negative error */
1547 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1548 {
1549 	struct usbnet *dev = netdev_priv(skb_in->dev);
1550 	struct usb_cdc_ncm_nth16 *nth16;
1551 	int len;
1552 	int ret = -EINVAL;
1553 
1554 	if (ctx == NULL)
1555 		goto error;
1556 
1557 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1558 					sizeof(struct usb_cdc_ncm_ndp16))) {
1559 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1560 		goto error;
1561 	}
1562 
1563 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1564 
1565 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1566 		netif_dbg(dev, rx_err, dev->net,
1567 			  "invalid NTH16 signature <%#010x>\n",
1568 			  le32_to_cpu(nth16->dwSignature));
1569 		goto error;
1570 	}
1571 
1572 	len = le16_to_cpu(nth16->wBlockLength);
1573 	if (len > ctx->rx_max) {
1574 		netif_dbg(dev, rx_err, dev->net,
1575 			  "unsupported NTB block length %u/%u\n", len,
1576 			  ctx->rx_max);
1577 		goto error;
1578 	}
1579 
1580 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1581 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1582 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1583 		netif_dbg(dev, rx_err, dev->net,
1584 			  "sequence number glitch prev=%d curr=%d\n",
1585 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1586 	}
1587 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1588 
1589 	ret = le16_to_cpu(nth16->wNdpIndex);
1590 error:
1591 	return ret;
1592 }
1593 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1594 
1595 int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1596 {
1597 	struct usbnet *dev = netdev_priv(skb_in->dev);
1598 	struct usb_cdc_ncm_nth32 *nth32;
1599 	int len;
1600 	int ret = -EINVAL;
1601 
1602 	if (ctx == NULL)
1603 		goto error;
1604 
1605 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1606 					sizeof(struct usb_cdc_ncm_ndp32))) {
1607 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1608 		goto error;
1609 	}
1610 
1611 	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1612 
1613 	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1614 		netif_dbg(dev, rx_err, dev->net,
1615 			  "invalid NTH32 signature <%#010x>\n",
1616 			  le32_to_cpu(nth32->dwSignature));
1617 		goto error;
1618 	}
1619 
1620 	len = le32_to_cpu(nth32->dwBlockLength);
1621 	if (len > ctx->rx_max) {
1622 		netif_dbg(dev, rx_err, dev->net,
1623 			  "unsupported NTB block length %u/%u\n", len,
1624 			  ctx->rx_max);
1625 		goto error;
1626 	}
1627 
1628 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1629 	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1630 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1631 		netif_dbg(dev, rx_err, dev->net,
1632 			  "sequence number glitch prev=%d curr=%d\n",
1633 			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1634 	}
1635 	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1636 
1637 	ret = le32_to_cpu(nth32->dwNdpIndex);
1638 error:
1639 	return ret;
1640 }
1641 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1642 
1643 /* verify NDP header and return number of datagrams, or negative error */
1644 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1645 {
1646 	struct usbnet *dev = netdev_priv(skb_in->dev);
1647 	struct usb_cdc_ncm_ndp16 *ndp16;
1648 	int ret = -EINVAL;
1649 
1650 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1651 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1652 			  ndpoffset);
1653 		goto error;
1654 	}
1655 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1656 
1657 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1658 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1659 			  le16_to_cpu(ndp16->wLength));
1660 		goto error;
1661 	}
1662 
1663 	ret = ((le16_to_cpu(ndp16->wLength) -
1664 					sizeof(struct usb_cdc_ncm_ndp16)) /
1665 					sizeof(struct usb_cdc_ncm_dpe16));
1666 	ret--; /* we process NDP entries except for the last one */
1667 
1668 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1669 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1670 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1671 		ret = -EINVAL;
1672 	}
1673 
1674 error:
1675 	return ret;
1676 }
1677 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1678 
1679 /* verify NDP header and return number of datagrams, or negative error */
1680 int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1681 {
1682 	struct usbnet *dev = netdev_priv(skb_in->dev);
1683 	struct usb_cdc_ncm_ndp32 *ndp32;
1684 	int ret = -EINVAL;
1685 
1686 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1687 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1688 			  ndpoffset);
1689 		goto error;
1690 	}
1691 	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1692 
1693 	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1694 		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1695 			  le16_to_cpu(ndp32->wLength));
1696 		goto error;
1697 	}
1698 
1699 	ret = ((le16_to_cpu(ndp32->wLength) -
1700 					sizeof(struct usb_cdc_ncm_ndp32)) /
1701 					sizeof(struct usb_cdc_ncm_dpe32));
1702 	ret--; /* we process NDP entries except for the last one */
1703 
1704 	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1705 	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1706 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1707 		ret = -EINVAL;
1708 	}
1709 
1710 error:
1711 	return ret;
1712 }
1713 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1714 
1715 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1716 {
1717 	struct sk_buff *skb;
1718 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1719 	unsigned int len;
1720 	int nframes;
1721 	int x;
1722 	unsigned int offset;
1723 	union {
1724 		struct usb_cdc_ncm_ndp16 *ndp16;
1725 		struct usb_cdc_ncm_ndp32 *ndp32;
1726 	} ndp;
1727 	union {
1728 		struct usb_cdc_ncm_dpe16 *dpe16;
1729 		struct usb_cdc_ncm_dpe32 *dpe32;
1730 	} dpe;
1731 
1732 	int ndpoffset;
1733 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1734 	u32 payload = 0;
1735 
1736 	if (ctx->is_ndp16)
1737 		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1738 	else
1739 		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1740 
1741 	if (ndpoffset < 0)
1742 		goto error;
1743 
1744 next_ndp:
1745 	if (ctx->is_ndp16) {
1746 		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1747 		if (nframes < 0)
1748 			goto error;
1749 
1750 		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1751 
1752 		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1753 			netif_dbg(dev, rx_err, dev->net,
1754 				  "invalid DPT16 signature <%#010x>\n",
1755 				  le32_to_cpu(ndp.ndp16->dwSignature));
1756 			goto err_ndp;
1757 		}
1758 		dpe.dpe16 = ndp.ndp16->dpe16;
1759 	} else {
1760 		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1761 		if (nframes < 0)
1762 			goto error;
1763 
1764 		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1765 
1766 		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1767 			netif_dbg(dev, rx_err, dev->net,
1768 				  "invalid DPT32 signature <%#010x>\n",
1769 				  le32_to_cpu(ndp.ndp32->dwSignature));
1770 			goto err_ndp;
1771 		}
1772 		dpe.dpe32 = ndp.ndp32->dpe32;
1773 	}
1774 
1775 	for (x = 0; x < nframes; x++) {
1776 		if (ctx->is_ndp16) {
1777 			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1778 			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1779 		} else {
1780 			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1781 			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1782 		}
1783 
1784 		/*
1785 		 * CDC NCM ch. 3.7
1786 		 * All entries after first NULL entry are to be ignored
1787 		 */
1788 		if ((offset == 0) || (len == 0)) {
1789 			if (!x)
1790 				goto err_ndp; /* empty NTB */
1791 			break;
1792 		}
1793 
1794 		/* sanity checking - watch out for integer wrap*/
1795 		if ((offset > skb_in->len) || (len > skb_in->len - offset) ||
1796 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1797 			netif_dbg(dev, rx_err, dev->net,
1798 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1799 				  x, offset, len, skb_in);
1800 			if (!x)
1801 				goto err_ndp;
1802 			break;
1803 
1804 		} else {
1805 			/* create a fresh copy to reduce truesize */
1806 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1807 			if (!skb)
1808 				goto error;
1809 			skb_put_data(skb, skb_in->data + offset, len);
1810 			usbnet_skb_return(dev, skb);
1811 			payload += len;	/* count payload bytes in this NTB */
1812 		}
1813 
1814 		if (ctx->is_ndp16)
1815 			dpe.dpe16++;
1816 		else
1817 			dpe.dpe32++;
1818 	}
1819 err_ndp:
1820 	/* are there more NDPs to process? */
1821 	if (ctx->is_ndp16)
1822 		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1823 	else
1824 		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1825 
1826 	if (ndpoffset && loopcount--)
1827 		goto next_ndp;
1828 
1829 	/* update stats */
1830 	ctx->rx_overhead += skb_in->len - payload;
1831 	ctx->rx_ntbs++;
1832 
1833 	return 1;
1834 error:
1835 	return 0;
1836 }
1837 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1838 
1839 static void
1840 cdc_ncm_speed_change(struct usbnet *dev,
1841 		     struct usb_cdc_speed_change *data)
1842 {
1843 	/* RTL8156 shipped before 2021 sends notification about every 32ms. */
1844 	dev->rx_speed = le32_to_cpu(data->DLBitRRate);
1845 	dev->tx_speed = le32_to_cpu(data->ULBitRate);
1846 }
1847 
1848 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1849 {
1850 	struct usb_cdc_notification *event;
1851 
1852 	if (urb->actual_length < sizeof(*event))
1853 		return;
1854 
1855 	/* test for split data in 8-byte chunks */
1856 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1857 		cdc_ncm_speed_change(dev,
1858 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1859 		return;
1860 	}
1861 
1862 	event = urb->transfer_buffer;
1863 
1864 	switch (event->bNotificationType) {
1865 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1866 		/*
1867 		 * According to the CDC NCM specification ch.7.1
1868 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1869 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1870 		 */
1871 		/* RTL8156 shipped before 2021 sends notification about
1872 		 * every 32ms. Don't forward notification if state is same.
1873 		 */
1874 		if (netif_carrier_ok(dev->net) != !!event->wValue)
1875 			usbnet_link_change(dev, !!event->wValue, 0);
1876 		break;
1877 
1878 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1879 		if (urb->actual_length < (sizeof(*event) +
1880 					sizeof(struct usb_cdc_speed_change)))
1881 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1882 		else
1883 			cdc_ncm_speed_change(dev,
1884 					     (struct usb_cdc_speed_change *)&event[1]);
1885 		break;
1886 
1887 	default:
1888 		dev_dbg(&dev->udev->dev,
1889 			"NCM: unexpected notification 0x%02x!\n",
1890 			event->bNotificationType);
1891 		break;
1892 	}
1893 }
1894 
1895 static const struct driver_info cdc_ncm_info = {
1896 	.description = "CDC NCM (NO ZLP)",
1897 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1898 			| FLAG_LINK_INTR | FLAG_ETHER,
1899 	.bind = cdc_ncm_bind,
1900 	.unbind = cdc_ncm_unbind,
1901 	.manage_power = usbnet_manage_power,
1902 	.status = cdc_ncm_status,
1903 	.rx_fixup = cdc_ncm_rx_fixup,
1904 	.tx_fixup = cdc_ncm_tx_fixup,
1905 	.set_rx_mode = usbnet_cdc_update_filter,
1906 };
1907 
1908 /* Same as cdc_ncm_info, but with FLAG_SEND_ZLP  */
1909 static const struct driver_info cdc_ncm_zlp_info = {
1910 	.description = "CDC NCM (SEND ZLP)",
1911 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1912 			| FLAG_LINK_INTR | FLAG_ETHER | FLAG_SEND_ZLP,
1913 	.bind = cdc_ncm_bind,
1914 	.unbind = cdc_ncm_unbind,
1915 	.manage_power = usbnet_manage_power,
1916 	.status = cdc_ncm_status,
1917 	.rx_fixup = cdc_ncm_rx_fixup,
1918 	.tx_fixup = cdc_ncm_tx_fixup,
1919 	.set_rx_mode = usbnet_cdc_update_filter,
1920 };
1921 
1922 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1923 static const struct driver_info wwan_info = {
1924 	.description = "Mobile Broadband Network Device",
1925 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1926 			| FLAG_LINK_INTR | FLAG_WWAN,
1927 	.bind = cdc_ncm_bind,
1928 	.unbind = cdc_ncm_unbind,
1929 	.manage_power = usbnet_manage_power,
1930 	.status = cdc_ncm_status,
1931 	.rx_fixup = cdc_ncm_rx_fixup,
1932 	.tx_fixup = cdc_ncm_tx_fixup,
1933 	.set_rx_mode = usbnet_cdc_update_filter,
1934 };
1935 
1936 /* Same as wwan_info, but with FLAG_NOARP  */
1937 static const struct driver_info wwan_noarp_info = {
1938 	.description = "Mobile Broadband Network Device (NO ARP)",
1939 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1940 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1941 	.bind = cdc_ncm_bind,
1942 	.unbind = cdc_ncm_unbind,
1943 	.manage_power = usbnet_manage_power,
1944 	.status = cdc_ncm_status,
1945 	.rx_fixup = cdc_ncm_rx_fixup,
1946 	.tx_fixup = cdc_ncm_tx_fixup,
1947 	.set_rx_mode = usbnet_cdc_update_filter,
1948 };
1949 
1950 static const struct usb_device_id cdc_devs[] = {
1951 	/* Ericsson MBM devices like F5521gw */
1952 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1953 		| USB_DEVICE_ID_MATCH_VENDOR,
1954 	  .idVendor = 0x0bdb,
1955 	  .bInterfaceClass = USB_CLASS_COMM,
1956 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1957 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1958 	  .driver_info = (unsigned long) &wwan_info,
1959 	},
1960 
1961 	/* Telit LE910 V2 */
1962 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1963 		USB_CLASS_COMM,
1964 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1965 	  .driver_info = (unsigned long)&wwan_noarp_info,
1966 	},
1967 
1968 	/* DW5812 LTE Verizon Mobile Broadband Card
1969 	 * Unlike DW5550 this device requires FLAG_NOARP
1970 	 */
1971 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1972 		USB_CLASS_COMM,
1973 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1974 	  .driver_info = (unsigned long)&wwan_noarp_info,
1975 	},
1976 
1977 	/* DW5813 LTE AT&T Mobile Broadband Card
1978 	 * Unlike DW5550 this device requires FLAG_NOARP
1979 	 */
1980 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1981 		USB_CLASS_COMM,
1982 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1983 	  .driver_info = (unsigned long)&wwan_noarp_info,
1984 	},
1985 
1986 	/* Dell branded MBM devices like DW5550 */
1987 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1988 		| USB_DEVICE_ID_MATCH_VENDOR,
1989 	  .idVendor = 0x413c,
1990 	  .bInterfaceClass = USB_CLASS_COMM,
1991 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1992 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1993 	  .driver_info = (unsigned long) &wwan_info,
1994 	},
1995 
1996 	/* Toshiba branded MBM devices */
1997 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1998 		| USB_DEVICE_ID_MATCH_VENDOR,
1999 	  .idVendor = 0x0930,
2000 	  .bInterfaceClass = USB_CLASS_COMM,
2001 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2002 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2003 	  .driver_info = (unsigned long) &wwan_info,
2004 	},
2005 
2006 	/* tag Huawei devices as wwan */
2007 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
2008 					USB_CLASS_COMM,
2009 					USB_CDC_SUBCLASS_NCM,
2010 					USB_CDC_PROTO_NONE),
2011 	  .driver_info = (unsigned long)&wwan_info,
2012 	},
2013 
2014 	/* Infineon(now Intel) HSPA Modem platform */
2015 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
2016 		USB_CLASS_COMM,
2017 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2018 	  .driver_info = (unsigned long)&wwan_noarp_info,
2019 	},
2020 
2021 	/* u-blox TOBY-L4 */
2022 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
2023 		USB_CLASS_COMM,
2024 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2025 	  .driver_info = (unsigned long)&wwan_info,
2026 	},
2027 
2028 	/* DisplayLink docking stations */
2029 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
2030 		| USB_DEVICE_ID_MATCH_VENDOR,
2031 	  .idVendor = 0x17e9,
2032 	  .bInterfaceClass = USB_CLASS_COMM,
2033 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2034 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2035 	  .driver_info = (unsigned long)&cdc_ncm_zlp_info,
2036 	},
2037 
2038 	/* Generic CDC-NCM devices */
2039 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2040 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2041 		.driver_info = (unsigned long)&cdc_ncm_info,
2042 	},
2043 	{
2044 	},
2045 };
2046 MODULE_DEVICE_TABLE(usb, cdc_devs);
2047 
2048 static struct usb_driver cdc_ncm_driver = {
2049 	.name = "cdc_ncm",
2050 	.id_table = cdc_devs,
2051 	.probe = usbnet_probe,
2052 	.disconnect = usbnet_disconnect,
2053 	.suspend = usbnet_suspend,
2054 	.resume = usbnet_resume,
2055 	.reset_resume =	usbnet_resume,
2056 	.supports_autosuspend = 1,
2057 	.disable_hub_initiated_lpm = 1,
2058 };
2059 
2060 module_usb_driver(cdc_ncm_driver);
2061 
2062 MODULE_AUTHOR("Hans Petter Selasky");
2063 MODULE_DESCRIPTION("USB CDC NCM host driver");
2064 MODULE_LICENSE("Dual BSD/GPL");
2065