xref: /openbmc/linux/drivers/net/usb/cdc_ncm.c (revision 1d05334d)
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(unsigned long param);
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,
146 	.set_link_ksettings      = usbnet_set_link_ksettings,
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_get_stats64     = usbnet_get_stats64,
796 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
797 	.ndo_set_mac_address = eth_mac_addr,
798 	.ndo_validate_addr   = eth_validate_addr,
799 };
800 
801 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
802 {
803 	struct cdc_ncm_ctx *ctx;
804 	struct usb_driver *driver;
805 	u8 *buf;
806 	int len;
807 	int temp;
808 	u8 iface_no;
809 	struct usb_cdc_parsed_header hdr;
810 
811 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
812 	if (!ctx)
813 		return -ENOMEM;
814 
815 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
816 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
817 	tasklet_init(&ctx->bh, cdc_ncm_txpath_bh, (unsigned long)dev);
818 	atomic_set(&ctx->stop, 0);
819 	spin_lock_init(&ctx->mtx);
820 
821 	/* store ctx pointer in device data field */
822 	dev->data[0] = (unsigned long)ctx;
823 
824 	/* only the control interface can be successfully probed */
825 	ctx->control = intf;
826 
827 	/* get some pointers */
828 	driver = driver_of(intf);
829 	buf = intf->cur_altsetting->extra;
830 	len = intf->cur_altsetting->extralen;
831 
832 	/* parse through descriptors associated with control interface */
833 	cdc_parse_cdc_header(&hdr, intf, buf, len);
834 
835 	if (hdr.usb_cdc_union_desc)
836 		ctx->data = usb_ifnum_to_if(dev->udev,
837 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
838 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
839 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
840 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
841 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
842 
843 	/* some buggy devices have an IAD but no CDC Union */
844 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
845 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
846 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
847 	}
848 
849 	/* check if we got everything */
850 	if (!ctx->data) {
851 		dev_dbg(&intf->dev, "CDC Union missing and no IAD found\n");
852 		goto error;
853 	}
854 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
855 		if (!ctx->mbim_desc) {
856 			dev_dbg(&intf->dev, "MBIM functional descriptor missing\n");
857 			goto error;
858 		}
859 	} else {
860 		if (!ctx->ether_desc || !ctx->func_desc) {
861 			dev_dbg(&intf->dev, "NCM or ECM functional descriptors missing\n");
862 			goto error;
863 		}
864 	}
865 
866 	/* claim data interface, if different from control */
867 	if (ctx->data != ctx->control) {
868 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
869 		if (temp) {
870 			dev_dbg(&intf->dev, "failed to claim data intf\n");
871 			goto error;
872 		}
873 	}
874 
875 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
876 
877 	/* Device-specific flags */
878 	ctx->drvflags = drvflags;
879 
880 	/* Reset data interface. Some devices will not reset properly
881 	 * unless they are configured first.  Toggle the altsetting to
882 	 * force a reset.
883 	 * Some other devices do not work properly with this procedure
884 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
885 	 */
886 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
887 		usb_set_interface(dev->udev, iface_no, data_altsetting);
888 
889 	temp = usb_set_interface(dev->udev, iface_no, 0);
890 	if (temp) {
891 		dev_dbg(&intf->dev, "set interface failed\n");
892 		goto error2;
893 	}
894 
895 	/* initialize basic device settings */
896 	if (cdc_ncm_init(dev))
897 		goto error2;
898 
899 	/* Some firmwares need a pause here or they will silently fail
900 	 * to set up the interface properly.  This value was decided
901 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
902 	 * firmware.
903 	 */
904 	usleep_range(10000, 20000);
905 
906 	/* configure data interface */
907 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
908 	if (temp) {
909 		dev_dbg(&intf->dev, "set interface failed\n");
910 		goto error2;
911 	}
912 
913 	cdc_ncm_find_endpoints(dev, ctx->data);
914 	cdc_ncm_find_endpoints(dev, ctx->control);
915 	if (!dev->in || !dev->out || !dev->status) {
916 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
917 		goto error2;
918 	}
919 
920 	usb_set_intfdata(ctx->data, dev);
921 	usb_set_intfdata(ctx->control, dev);
922 
923 	if (ctx->ether_desc) {
924 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
925 		if (temp) {
926 			dev_dbg(&intf->dev, "failed to get mac address\n");
927 			goto error2;
928 		}
929 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
930 	}
931 
932 	/* finish setting up the device specific data */
933 	cdc_ncm_setup(dev);
934 
935 	/* Allocate the delayed NDP if needed. */
936 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
937 		if (ctx->is_ndp16) {
938 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
939 			if (!ctx->delayed_ndp16)
940 				goto error2;
941 		} else {
942 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
943 			if (!ctx->delayed_ndp32)
944 				goto error2;
945 		}
946 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
947 	}
948 
949 	/* override ethtool_ops */
950 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
951 
952 	/* add our sysfs attrs */
953 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
954 
955 	/* must handle MTU changes */
956 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
957 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
958 
959 	return 0;
960 
961 error2:
962 	usb_set_intfdata(ctx->control, NULL);
963 	usb_set_intfdata(ctx->data, NULL);
964 	if (ctx->data != ctx->control)
965 		usb_driver_release_interface(driver, ctx->data);
966 error:
967 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
968 	dev->data[0] = 0;
969 	dev_info(&intf->dev, "bind() failure\n");
970 	return -ENODEV;
971 }
972 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
973 
974 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
975 {
976 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
977 	struct usb_driver *driver = driver_of(intf);
978 
979 	if (ctx == NULL)
980 		return;		/* no setup */
981 
982 	atomic_set(&ctx->stop, 1);
983 
984 	hrtimer_cancel(&ctx->tx_timer);
985 
986 	tasklet_kill(&ctx->bh);
987 
988 	/* handle devices with combined control and data interface */
989 	if (ctx->control == ctx->data)
990 		ctx->data = NULL;
991 
992 	/* disconnect master --> disconnect slave */
993 	if (intf == ctx->control && ctx->data) {
994 		usb_set_intfdata(ctx->data, NULL);
995 		usb_driver_release_interface(driver, ctx->data);
996 		ctx->data = NULL;
997 
998 	} else if (intf == ctx->data && ctx->control) {
999 		usb_set_intfdata(ctx->control, NULL);
1000 		usb_driver_release_interface(driver, ctx->control);
1001 		ctx->control = NULL;
1002 	}
1003 
1004 	usb_set_intfdata(intf, NULL);
1005 	cdc_ncm_free(ctx);
1006 }
1007 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1008 
1009 /* Return the number of the MBIM control interface altsetting iff it
1010  * is preferred and available,
1011  */
1012 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1013 {
1014 	struct usb_host_interface *alt;
1015 
1016 	/* The MBIM spec defines a NCM compatible default altsetting,
1017 	 * which we may have matched:
1018 	 *
1019 	 *  "Functions that implement both NCM 1.0 and MBIM (an
1020 	 *   “NCM/MBIM function”) according to this recommendation
1021 	 *   shall provide two alternate settings for the
1022 	 *   Communication Interface.  Alternate setting 0, and the
1023 	 *   associated class and endpoint descriptors, shall be
1024 	 *   constructed according to the rules given for the
1025 	 *   Communication Interface in section 5 of [USBNCM10].
1026 	 *   Alternate setting 1, and the associated class and
1027 	 *   endpoint descriptors, shall be constructed according to
1028 	 *   the rules given in section 6 (USB Device Model) of this
1029 	 *   specification."
1030 	 */
1031 	if (intf->num_altsetting < 2)
1032 		return intf->cur_altsetting->desc.bAlternateSetting;
1033 
1034 	if (prefer_mbim) {
1035 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1036 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1037 			return CDC_NCM_COMM_ALTSETTING_MBIM;
1038 	}
1039 	return CDC_NCM_COMM_ALTSETTING_NCM;
1040 }
1041 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1042 
1043 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1044 {
1045 	/* MBIM backwards compatible function? */
1046 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1047 		return -ENODEV;
1048 
1049 	/* The NCM data altsetting is fixed, so we hard-coded it.
1050 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1051 	 * placed NDP.
1052 	 */
1053 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1054 }
1055 
1056 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1057 {
1058 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1059 
1060 	if (skb->len + align > max)
1061 		align = max - skb->len;
1062 	if (align && skb_tailroom(skb) >= align)
1063 		skb_put_zero(skb, align);
1064 }
1065 
1066 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1067  * allocating a new one within skb
1068  */
1069 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1070 {
1071 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1072 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1073 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1074 
1075 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1076 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1077 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1078 	*/
1079 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1080 		if (ctx->delayed_ndp16->dwSignature == sign)
1081 			return ctx->delayed_ndp16;
1082 
1083 		/* We can only push a single NDP to the end. Return
1084 		 * NULL to send what we've already got and queue this
1085 		 * skb for later.
1086 		 */
1087 		else if (ctx->delayed_ndp16->dwSignature)
1088 			return NULL;
1089 	}
1090 
1091 	/* follow the chain of NDPs, looking for a match */
1092 	while (ndpoffset) {
1093 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1094 		if  (ndp16->dwSignature == sign)
1095 			return ndp16;
1096 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1097 	}
1098 
1099 	/* align new NDP */
1100 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1101 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1102 
1103 	/* verify that there is room for the NDP and the datagram (reserve) */
1104 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1105 		return NULL;
1106 
1107 	/* link to it */
1108 	if (ndp16)
1109 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1110 	else
1111 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1112 
1113 	/* push a new empty NDP */
1114 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1115 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1116 	else
1117 		ndp16 = ctx->delayed_ndp16;
1118 
1119 	ndp16->dwSignature = sign;
1120 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1121 	return ndp16;
1122 }
1123 
1124 static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1125 {
1126 	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1127 	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1128 	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1129 
1130 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1131 	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1132 	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1133 	 */
1134 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1135 		if (ctx->delayed_ndp32->dwSignature == sign)
1136 			return ctx->delayed_ndp32;
1137 
1138 		/* We can only push a single NDP to the end. Return
1139 		 * NULL to send what we've already got and queue this
1140 		 * skb for later.
1141 		 */
1142 		else if (ctx->delayed_ndp32->dwSignature)
1143 			return NULL;
1144 	}
1145 
1146 	/* follow the chain of NDPs, looking for a match */
1147 	while (ndpoffset) {
1148 		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1149 		if  (ndp32->dwSignature == sign)
1150 			return ndp32;
1151 		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1152 	}
1153 
1154 	/* align new NDP */
1155 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1156 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1157 
1158 	/* verify that there is room for the NDP and the datagram (reserve) */
1159 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1160 		return NULL;
1161 
1162 	/* link to it */
1163 	if (ndp32)
1164 		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1165 	else
1166 		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1167 
1168 	/* push a new empty NDP */
1169 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1170 		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1171 	else
1172 		ndp32 = ctx->delayed_ndp32;
1173 
1174 	ndp32->dwSignature = sign;
1175 	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1176 	return ndp32;
1177 }
1178 
1179 struct sk_buff *
1180 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1181 {
1182 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1183 	union {
1184 		struct usb_cdc_ncm_nth16 *nth16;
1185 		struct usb_cdc_ncm_nth32 *nth32;
1186 	} nth;
1187 	union {
1188 		struct usb_cdc_ncm_ndp16 *ndp16;
1189 		struct usb_cdc_ncm_ndp32 *ndp32;
1190 	} ndp;
1191 	struct sk_buff *skb_out;
1192 	u16 n = 0, index, ndplen;
1193 	u8 ready2send = 0;
1194 	u32 delayed_ndp_size;
1195 	size_t padding_count;
1196 
1197 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1198 	 * accordingly. Otherwise, we should check here.
1199 	 */
1200 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1201 		delayed_ndp_size = ALIGN(ctx->max_ndp_size, ctx->tx_ndp_modulus);
1202 	else
1203 		delayed_ndp_size = 0;
1204 
1205 	/* if there is a remaining skb, it gets priority */
1206 	if (skb != NULL) {
1207 		swap(skb, ctx->tx_rem_skb);
1208 		swap(sign, ctx->tx_rem_sign);
1209 	} else {
1210 		ready2send = 1;
1211 	}
1212 
1213 	/* check if we are resuming an OUT skb */
1214 	skb_out = ctx->tx_curr_skb;
1215 
1216 	/* allocate a new OUT skb */
1217 	if (!skb_out) {
1218 		if (ctx->tx_low_mem_val == 0) {
1219 			ctx->tx_curr_size = ctx->tx_max;
1220 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1221 			/* If the memory allocation fails we will wait longer
1222 			 * each time before attempting another full size
1223 			 * allocation again to not overload the system
1224 			 * further.
1225 			 */
1226 			if (skb_out == NULL) {
1227 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1228 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1229 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1230 			}
1231 		}
1232 		if (skb_out == NULL) {
1233 			/* See if a very small allocation is possible.
1234 			 * We will send this packet immediately and hope
1235 			 * that there is more memory available later.
1236 			 */
1237 			if (skb)
1238 				ctx->tx_curr_size = max(skb->len,
1239 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1240 			else
1241 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1242 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1243 
1244 			/* No allocation possible so we will abort */
1245 			if (skb_out == NULL) {
1246 				if (skb != NULL) {
1247 					dev_kfree_skb_any(skb);
1248 					dev->net->stats.tx_dropped++;
1249 				}
1250 				goto exit_no_skb;
1251 			}
1252 			ctx->tx_low_mem_val--;
1253 		}
1254 		if (ctx->is_ndp16) {
1255 			/* fill out the initial 16-bit NTB header */
1256 			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1257 			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1258 			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1259 			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1260 		} else {
1261 			/* fill out the initial 32-bit NTB header */
1262 			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1263 			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1264 			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1265 			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1266 		}
1267 
1268 		/* count total number of frames in this NTB */
1269 		ctx->tx_curr_frame_num = 0;
1270 
1271 		/* recent payload counter for this skb_out */
1272 		ctx->tx_curr_frame_payload = 0;
1273 	}
1274 
1275 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1276 		/* send any remaining skb first */
1277 		if (skb == NULL) {
1278 			skb = ctx->tx_rem_skb;
1279 			sign = ctx->tx_rem_sign;
1280 			ctx->tx_rem_skb = NULL;
1281 
1282 			/* check for end of skb */
1283 			if (skb == NULL)
1284 				break;
1285 		}
1286 
1287 		/* get the appropriate NDP for this skb */
1288 		if (ctx->is_ndp16)
1289 			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1290 		else
1291 			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1292 
1293 		/* align beginning of next frame */
1294 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1295 
1296 		/* check if we had enough room left for both NDP and frame */
1297 		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1298 		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1299 			if (n == 0) {
1300 				/* won't fit, MTU problem? */
1301 				dev_kfree_skb_any(skb);
1302 				skb = NULL;
1303 				dev->net->stats.tx_dropped++;
1304 			} else {
1305 				/* no room for skb - store for later */
1306 				if (ctx->tx_rem_skb != NULL) {
1307 					dev_kfree_skb_any(ctx->tx_rem_skb);
1308 					dev->net->stats.tx_dropped++;
1309 				}
1310 				ctx->tx_rem_skb = skb;
1311 				ctx->tx_rem_sign = sign;
1312 				skb = NULL;
1313 				ready2send = 1;
1314 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1315 			}
1316 			break;
1317 		}
1318 
1319 		/* calculate frame number withing this NDP */
1320 		if (ctx->is_ndp16) {
1321 			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1322 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1323 
1324 			/* OK, add this skb */
1325 			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1326 			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1327 			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1328 		} else {
1329 			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1330 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1331 
1332 			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1333 			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1334 			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1335 		}
1336 		skb_put_data(skb_out, skb->data, skb->len);
1337 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1338 		dev_kfree_skb_any(skb);
1339 		skb = NULL;
1340 
1341 		/* send now if this NDP is full */
1342 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1343 			ready2send = 1;
1344 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1345 			break;
1346 		}
1347 	}
1348 
1349 	/* free up any dangling skb */
1350 	if (skb != NULL) {
1351 		dev_kfree_skb_any(skb);
1352 		skb = NULL;
1353 		dev->net->stats.tx_dropped++;
1354 	}
1355 
1356 	ctx->tx_curr_frame_num = n;
1357 
1358 	if (n == 0) {
1359 		/* wait for more frames */
1360 		/* push variables */
1361 		ctx->tx_curr_skb = skb_out;
1362 		goto exit_no_skb;
1363 
1364 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1365 		/* wait for more frames */
1366 		/* push variables */
1367 		ctx->tx_curr_skb = skb_out;
1368 		/* set the pending count */
1369 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1370 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1371 		goto exit_no_skb;
1372 
1373 	} else {
1374 		if (n == ctx->tx_max_datagrams)
1375 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1376 		/* frame goes out */
1377 		/* variables will be reset at next call */
1378 	}
1379 
1380 	/* If requested, put NDP at end of frame. */
1381 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1382 		if (ctx->is_ndp16) {
1383 			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1384 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1385 			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1386 			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1387 
1388 			/* Zero out delayed NDP - signature checking will naturally fail. */
1389 			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1390 		} else {
1391 			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1392 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1393 			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1394 			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1395 
1396 			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1397 		}
1398 	}
1399 
1400 	/* If collected data size is less or equal ctx->min_tx_pkt
1401 	 * bytes, we send buffers as it is. If we get more data, it
1402 	 * would be more efficient for USB HS mobile device with DMA
1403 	 * engine to receive a full size NTB, than canceling DMA
1404 	 * transfer and receiving a short packet.
1405 	 *
1406 	 * This optimization support is pointless if we end up sending
1407 	 * a ZLP after full sized NTBs.
1408 	 */
1409 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1410 	    skb_out->len > ctx->min_tx_pkt) {
1411 		padding_count = ctx->tx_curr_size - skb_out->len;
1412 		skb_put_zero(skb_out, padding_count);
1413 	} else if (skb_out->len < ctx->tx_curr_size &&
1414 		   (skb_out->len % dev->maxpacket) == 0) {
1415 		skb_put_u8(skb_out, 0);	/* force short packet */
1416 	}
1417 
1418 	/* set final frame length */
1419 	if (ctx->is_ndp16) {
1420 		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1421 		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1422 	} else {
1423 		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1424 		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1425 	}
1426 
1427 	/* return skb */
1428 	ctx->tx_curr_skb = NULL;
1429 
1430 	/* keep private stats: framing overhead and number of NTBs */
1431 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1432 	ctx->tx_ntbs++;
1433 
1434 	/* usbnet will count all the framing overhead by default.
1435 	 * Adjust the stats so that the tx_bytes counter show real
1436 	 * payload data instead.
1437 	 */
1438 	usbnet_set_skb_tx_stats(skb_out, n,
1439 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1440 
1441 	return skb_out;
1442 
1443 exit_no_skb:
1444 	/* Start timer, if there is a remaining non-empty skb */
1445 	if (ctx->tx_curr_skb != NULL && n > 0)
1446 		cdc_ncm_tx_timeout_start(ctx);
1447 	return NULL;
1448 }
1449 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1450 
1451 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1452 {
1453 	/* start timer, if not already started */
1454 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1455 		hrtimer_start(&ctx->tx_timer,
1456 				ctx->timer_interval,
1457 				HRTIMER_MODE_REL);
1458 }
1459 
1460 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1461 {
1462 	struct cdc_ncm_ctx *ctx =
1463 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1464 
1465 	if (!atomic_read(&ctx->stop))
1466 		tasklet_schedule(&ctx->bh);
1467 	return HRTIMER_NORESTART;
1468 }
1469 
1470 static void cdc_ncm_txpath_bh(unsigned long param)
1471 {
1472 	struct usbnet *dev = (struct usbnet *)param;
1473 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1474 
1475 	spin_lock_bh(&ctx->mtx);
1476 	if (ctx->tx_timer_pending != 0) {
1477 		ctx->tx_timer_pending--;
1478 		cdc_ncm_tx_timeout_start(ctx);
1479 		spin_unlock_bh(&ctx->mtx);
1480 	} else if (dev->net != NULL) {
1481 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1482 		spin_unlock_bh(&ctx->mtx);
1483 		netif_tx_lock_bh(dev->net);
1484 		usbnet_start_xmit(NULL, dev->net);
1485 		netif_tx_unlock_bh(dev->net);
1486 	} else {
1487 		spin_unlock_bh(&ctx->mtx);
1488 	}
1489 }
1490 
1491 struct sk_buff *
1492 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1493 {
1494 	struct sk_buff *skb_out;
1495 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1496 
1497 	/*
1498 	 * The Ethernet API we are using does not support transmitting
1499 	 * multiple Ethernet frames in a single call. This driver will
1500 	 * accumulate multiple Ethernet frames and send out a larger
1501 	 * USB frame when the USB buffer is full or when a single jiffies
1502 	 * timeout happens.
1503 	 */
1504 	if (ctx == NULL)
1505 		goto error;
1506 
1507 	spin_lock_bh(&ctx->mtx);
1508 
1509 	if (ctx->is_ndp16)
1510 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1511 	else
1512 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1513 
1514 	spin_unlock_bh(&ctx->mtx);
1515 	return skb_out;
1516 
1517 error:
1518 	if (skb != NULL)
1519 		dev_kfree_skb_any(skb);
1520 
1521 	return NULL;
1522 }
1523 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1524 
1525 /* verify NTB header and return offset of first NDP, or negative error */
1526 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1527 {
1528 	struct usbnet *dev = netdev_priv(skb_in->dev);
1529 	struct usb_cdc_ncm_nth16 *nth16;
1530 	int len;
1531 	int ret = -EINVAL;
1532 
1533 	if (ctx == NULL)
1534 		goto error;
1535 
1536 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1537 					sizeof(struct usb_cdc_ncm_ndp16))) {
1538 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1539 		goto error;
1540 	}
1541 
1542 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1543 
1544 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1545 		netif_dbg(dev, rx_err, dev->net,
1546 			  "invalid NTH16 signature <%#010x>\n",
1547 			  le32_to_cpu(nth16->dwSignature));
1548 		goto error;
1549 	}
1550 
1551 	len = le16_to_cpu(nth16->wBlockLength);
1552 	if (len > ctx->rx_max) {
1553 		netif_dbg(dev, rx_err, dev->net,
1554 			  "unsupported NTB block length %u/%u\n", len,
1555 			  ctx->rx_max);
1556 		goto error;
1557 	}
1558 
1559 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1560 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1561 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1562 		netif_dbg(dev, rx_err, dev->net,
1563 			  "sequence number glitch prev=%d curr=%d\n",
1564 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1565 	}
1566 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1567 
1568 	ret = le16_to_cpu(nth16->wNdpIndex);
1569 error:
1570 	return ret;
1571 }
1572 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1573 
1574 int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1575 {
1576 	struct usbnet *dev = netdev_priv(skb_in->dev);
1577 	struct usb_cdc_ncm_nth32 *nth32;
1578 	int len;
1579 	int ret = -EINVAL;
1580 
1581 	if (ctx == NULL)
1582 		goto error;
1583 
1584 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1585 					sizeof(struct usb_cdc_ncm_ndp32))) {
1586 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1587 		goto error;
1588 	}
1589 
1590 	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1591 
1592 	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1593 		netif_dbg(dev, rx_err, dev->net,
1594 			  "invalid NTH32 signature <%#010x>\n",
1595 			  le32_to_cpu(nth32->dwSignature));
1596 		goto error;
1597 	}
1598 
1599 	len = le32_to_cpu(nth32->dwBlockLength);
1600 	if (len > ctx->rx_max) {
1601 		netif_dbg(dev, rx_err, dev->net,
1602 			  "unsupported NTB block length %u/%u\n", len,
1603 			  ctx->rx_max);
1604 		goto error;
1605 	}
1606 
1607 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1608 	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1609 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1610 		netif_dbg(dev, rx_err, dev->net,
1611 			  "sequence number glitch prev=%d curr=%d\n",
1612 			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1613 	}
1614 	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1615 
1616 	ret = le32_to_cpu(nth32->dwNdpIndex);
1617 error:
1618 	return ret;
1619 }
1620 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1621 
1622 /* verify NDP header and return number of datagrams, or negative error */
1623 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1624 {
1625 	struct usbnet *dev = netdev_priv(skb_in->dev);
1626 	struct usb_cdc_ncm_ndp16 *ndp16;
1627 	int ret = -EINVAL;
1628 
1629 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1630 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1631 			  ndpoffset);
1632 		goto error;
1633 	}
1634 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1635 
1636 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1637 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1638 			  le16_to_cpu(ndp16->wLength));
1639 		goto error;
1640 	}
1641 
1642 	ret = ((le16_to_cpu(ndp16->wLength) -
1643 					sizeof(struct usb_cdc_ncm_ndp16)) /
1644 					sizeof(struct usb_cdc_ncm_dpe16));
1645 	ret--; /* we process NDP entries except for the last one */
1646 
1647 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1648 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1649 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1650 		ret = -EINVAL;
1651 	}
1652 
1653 error:
1654 	return ret;
1655 }
1656 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1657 
1658 /* verify NDP header and return number of datagrams, or negative error */
1659 int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1660 {
1661 	struct usbnet *dev = netdev_priv(skb_in->dev);
1662 	struct usb_cdc_ncm_ndp32 *ndp32;
1663 	int ret = -EINVAL;
1664 
1665 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1666 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1667 			  ndpoffset);
1668 		goto error;
1669 	}
1670 	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1671 
1672 	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1673 		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1674 			  le16_to_cpu(ndp32->wLength));
1675 		goto error;
1676 	}
1677 
1678 	ret = ((le16_to_cpu(ndp32->wLength) -
1679 					sizeof(struct usb_cdc_ncm_ndp32)) /
1680 					sizeof(struct usb_cdc_ncm_dpe32));
1681 	ret--; /* we process NDP entries except for the last one */
1682 
1683 	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1684 	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1685 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1686 		ret = -EINVAL;
1687 	}
1688 
1689 error:
1690 	return ret;
1691 }
1692 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1693 
1694 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1695 {
1696 	struct sk_buff *skb;
1697 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1698 	int len;
1699 	int nframes;
1700 	int x;
1701 	int offset;
1702 	union {
1703 		struct usb_cdc_ncm_ndp16 *ndp16;
1704 		struct usb_cdc_ncm_ndp32 *ndp32;
1705 	} ndp;
1706 	union {
1707 		struct usb_cdc_ncm_dpe16 *dpe16;
1708 		struct usb_cdc_ncm_dpe32 *dpe32;
1709 	} dpe;
1710 
1711 	int ndpoffset;
1712 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1713 	u32 payload = 0;
1714 
1715 	if (ctx->is_ndp16)
1716 		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1717 	else
1718 		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1719 
1720 	if (ndpoffset < 0)
1721 		goto error;
1722 
1723 next_ndp:
1724 	if (ctx->is_ndp16) {
1725 		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1726 		if (nframes < 0)
1727 			goto error;
1728 
1729 		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1730 
1731 		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1732 			netif_dbg(dev, rx_err, dev->net,
1733 				  "invalid DPT16 signature <%#010x>\n",
1734 				  le32_to_cpu(ndp.ndp16->dwSignature));
1735 			goto err_ndp;
1736 		}
1737 		dpe.dpe16 = ndp.ndp16->dpe16;
1738 	} else {
1739 		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1740 		if (nframes < 0)
1741 			goto error;
1742 
1743 		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1744 
1745 		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1746 			netif_dbg(dev, rx_err, dev->net,
1747 				  "invalid DPT32 signature <%#010x>\n",
1748 				  le32_to_cpu(ndp.ndp32->dwSignature));
1749 			goto err_ndp;
1750 		}
1751 		dpe.dpe32 = ndp.ndp32->dpe32;
1752 	}
1753 
1754 	for (x = 0; x < nframes; x++) {
1755 		if (ctx->is_ndp16) {
1756 			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1757 			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1758 		} else {
1759 			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1760 			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1761 		}
1762 
1763 		/*
1764 		 * CDC NCM ch. 3.7
1765 		 * All entries after first NULL entry are to be ignored
1766 		 */
1767 		if ((offset == 0) || (len == 0)) {
1768 			if (!x)
1769 				goto err_ndp; /* empty NTB */
1770 			break;
1771 		}
1772 
1773 		/* sanity checking */
1774 		if (((offset + len) > skb_in->len) ||
1775 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1776 			netif_dbg(dev, rx_err, dev->net,
1777 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1778 				  x, offset, len, skb_in);
1779 			if (!x)
1780 				goto err_ndp;
1781 			break;
1782 
1783 		} else {
1784 			/* create a fresh copy to reduce truesize */
1785 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1786 			if (!skb)
1787 				goto error;
1788 			skb_put_data(skb, skb_in->data + offset, len);
1789 			usbnet_skb_return(dev, skb);
1790 			payload += len;	/* count payload bytes in this NTB */
1791 		}
1792 
1793 		if (ctx->is_ndp16)
1794 			dpe.dpe16++;
1795 		else
1796 			dpe.dpe32++;
1797 	}
1798 err_ndp:
1799 	/* are there more NDPs to process? */
1800 	if (ctx->is_ndp16)
1801 		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1802 	else
1803 		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1804 
1805 	if (ndpoffset && loopcount--)
1806 		goto next_ndp;
1807 
1808 	/* update stats */
1809 	ctx->rx_overhead += skb_in->len - payload;
1810 	ctx->rx_ntbs++;
1811 
1812 	return 1;
1813 error:
1814 	return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1817 
1818 static void
1819 cdc_ncm_speed_change(struct usbnet *dev,
1820 		     struct usb_cdc_speed_change *data)
1821 {
1822 	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1823 	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1824 
1825 	/*
1826 	 * Currently the USB-NET API does not support reporting the actual
1827 	 * device speed. Do print it instead.
1828 	 */
1829 	if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1830 		netif_info(dev, link, dev->net,
1831 			   "%u mbit/s downlink %u mbit/s uplink\n",
1832 			   (unsigned int)(rx_speed / 1000000U),
1833 			   (unsigned int)(tx_speed / 1000000U));
1834 	} else {
1835 		netif_info(dev, link, dev->net,
1836 			   "%u kbit/s downlink %u kbit/s uplink\n",
1837 			   (unsigned int)(rx_speed / 1000U),
1838 			   (unsigned int)(tx_speed / 1000U));
1839 	}
1840 }
1841 
1842 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1843 {
1844 	struct usb_cdc_notification *event;
1845 
1846 	if (urb->actual_length < sizeof(*event))
1847 		return;
1848 
1849 	/* test for split data in 8-byte chunks */
1850 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1851 		cdc_ncm_speed_change(dev,
1852 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1853 		return;
1854 	}
1855 
1856 	event = urb->transfer_buffer;
1857 
1858 	switch (event->bNotificationType) {
1859 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1860 		/*
1861 		 * According to the CDC NCM specification ch.7.1
1862 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1863 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1864 		 */
1865 		netif_info(dev, link, dev->net,
1866 			   "network connection: %sconnected\n",
1867 			   !!event->wValue ? "" : "dis");
1868 		usbnet_link_change(dev, !!event->wValue, 0);
1869 		break;
1870 
1871 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1872 		if (urb->actual_length < (sizeof(*event) +
1873 					sizeof(struct usb_cdc_speed_change)))
1874 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1875 		else
1876 			cdc_ncm_speed_change(dev,
1877 					     (struct usb_cdc_speed_change *)&event[1]);
1878 		break;
1879 
1880 	default:
1881 		dev_dbg(&dev->udev->dev,
1882 			"NCM: unexpected notification 0x%02x!\n",
1883 			event->bNotificationType);
1884 		break;
1885 	}
1886 }
1887 
1888 static const struct driver_info cdc_ncm_info = {
1889 	.description = "CDC NCM",
1890 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1891 			| FLAG_LINK_INTR,
1892 	.bind = cdc_ncm_bind,
1893 	.unbind = cdc_ncm_unbind,
1894 	.manage_power = usbnet_manage_power,
1895 	.status = cdc_ncm_status,
1896 	.rx_fixup = cdc_ncm_rx_fixup,
1897 	.tx_fixup = cdc_ncm_tx_fixup,
1898 };
1899 
1900 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1901 static const struct driver_info wwan_info = {
1902 	.description = "Mobile Broadband Network Device",
1903 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1904 			| FLAG_LINK_INTR | FLAG_WWAN,
1905 	.bind = cdc_ncm_bind,
1906 	.unbind = cdc_ncm_unbind,
1907 	.manage_power = usbnet_manage_power,
1908 	.status = cdc_ncm_status,
1909 	.rx_fixup = cdc_ncm_rx_fixup,
1910 	.tx_fixup = cdc_ncm_tx_fixup,
1911 };
1912 
1913 /* Same as wwan_info, but with FLAG_NOARP  */
1914 static const struct driver_info wwan_noarp_info = {
1915 	.description = "Mobile Broadband Network Device (NO ARP)",
1916 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1917 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1918 	.bind = cdc_ncm_bind,
1919 	.unbind = cdc_ncm_unbind,
1920 	.manage_power = usbnet_manage_power,
1921 	.status = cdc_ncm_status,
1922 	.rx_fixup = cdc_ncm_rx_fixup,
1923 	.tx_fixup = cdc_ncm_tx_fixup,
1924 };
1925 
1926 static const struct usb_device_id cdc_devs[] = {
1927 	/* Ericsson MBM devices like F5521gw */
1928 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1929 		| USB_DEVICE_ID_MATCH_VENDOR,
1930 	  .idVendor = 0x0bdb,
1931 	  .bInterfaceClass = USB_CLASS_COMM,
1932 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1933 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1934 	  .driver_info = (unsigned long) &wwan_info,
1935 	},
1936 
1937 	/* Telit LE910 V2 */
1938 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1939 		USB_CLASS_COMM,
1940 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1941 	  .driver_info = (unsigned long)&wwan_noarp_info,
1942 	},
1943 
1944 	/* DW5812 LTE Verizon Mobile Broadband Card
1945 	 * Unlike DW5550 this device requires FLAG_NOARP
1946 	 */
1947 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1948 		USB_CLASS_COMM,
1949 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1950 	  .driver_info = (unsigned long)&wwan_noarp_info,
1951 	},
1952 
1953 	/* DW5813 LTE AT&T Mobile Broadband Card
1954 	 * Unlike DW5550 this device requires FLAG_NOARP
1955 	 */
1956 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1957 		USB_CLASS_COMM,
1958 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1959 	  .driver_info = (unsigned long)&wwan_noarp_info,
1960 	},
1961 
1962 	/* Dell branded MBM devices like DW5550 */
1963 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1964 		| USB_DEVICE_ID_MATCH_VENDOR,
1965 	  .idVendor = 0x413c,
1966 	  .bInterfaceClass = USB_CLASS_COMM,
1967 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1968 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1969 	  .driver_info = (unsigned long) &wwan_info,
1970 	},
1971 
1972 	/* Toshiba branded MBM devices */
1973 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1974 		| USB_DEVICE_ID_MATCH_VENDOR,
1975 	  .idVendor = 0x0930,
1976 	  .bInterfaceClass = USB_CLASS_COMM,
1977 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1978 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1979 	  .driver_info = (unsigned long) &wwan_info,
1980 	},
1981 
1982 	/* tag Huawei devices as wwan */
1983 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
1984 					USB_CLASS_COMM,
1985 					USB_CDC_SUBCLASS_NCM,
1986 					USB_CDC_PROTO_NONE),
1987 	  .driver_info = (unsigned long)&wwan_info,
1988 	},
1989 
1990 	/* Infineon(now Intel) HSPA Modem platform */
1991 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
1992 		USB_CLASS_COMM,
1993 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1994 	  .driver_info = (unsigned long)&wwan_noarp_info,
1995 	},
1996 
1997 	/* u-blox TOBY-L4 */
1998 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
1999 		USB_CLASS_COMM,
2000 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2001 	  .driver_info = (unsigned long)&wwan_info,
2002 	},
2003 
2004 	/* Generic CDC-NCM devices */
2005 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2006 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2007 		.driver_info = (unsigned long)&cdc_ncm_info,
2008 	},
2009 	{
2010 	},
2011 };
2012 MODULE_DEVICE_TABLE(usb, cdc_devs);
2013 
2014 static struct usb_driver cdc_ncm_driver = {
2015 	.name = "cdc_ncm",
2016 	.id_table = cdc_devs,
2017 	.probe = usbnet_probe,
2018 	.disconnect = usbnet_disconnect,
2019 	.suspend = usbnet_suspend,
2020 	.resume = usbnet_resume,
2021 	.reset_resume =	usbnet_resume,
2022 	.supports_autosuspend = 1,
2023 	.disable_hub_initiated_lpm = 1,
2024 };
2025 
2026 module_usb_driver(cdc_ncm_driver);
2027 
2028 MODULE_AUTHOR("Hans Petter Selasky");
2029 MODULE_DESCRIPTION("USB CDC NCM host driver");
2030 MODULE_LICENSE("Dual BSD/GPL");
2031