xref: /linux/drivers/net/usb/cdc_ncm.c (revision 20dfee95936413708701eb151f419597fdd9d948)
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 	if (le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) == 0)
185 		max = CDC_NCM_NTB_MAX_SIZE_TX; /* dwNtbOutMaxSize not set */
186 	else
187 		max = clamp_t(u32, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize),
188 			      USB_CDC_NCM_NTB_MIN_OUT_SIZE,
189 			      CDC_NCM_NTB_MAX_SIZE_TX);
190 
191 	/* some devices set dwNtbOutMaxSize too low for the above default */
192 	min = min(min, max);
193 
194 	val = clamp_t(u32, new_tx, min, max);
195 	if (val != new_tx)
196 		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
197 
198 	return val;
199 }
200 
201 static ssize_t min_tx_pkt_show(struct device *d,
202 			       struct device_attribute *attr, char *buf)
203 {
204 	struct usbnet *dev = netdev_priv(to_net_dev(d));
205 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
206 
207 	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
208 }
209 
210 static ssize_t rx_max_show(struct device *d,
211 			   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->rx_max);
217 }
218 
219 static ssize_t tx_max_show(struct device *d,
220 			   struct device_attribute *attr, char *buf)
221 {
222 	struct usbnet *dev = netdev_priv(to_net_dev(d));
223 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
224 
225 	return sprintf(buf, "%u\n", ctx->tx_max);
226 }
227 
228 static ssize_t tx_timer_usecs_show(struct device *d,
229 				   struct device_attribute *attr, char *buf)
230 {
231 	struct usbnet *dev = netdev_priv(to_net_dev(d));
232 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
233 
234 	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
235 }
236 
237 static ssize_t min_tx_pkt_store(struct device *d,
238 				struct device_attribute *attr,
239 				const char *buf, size_t len)
240 {
241 	struct usbnet *dev = netdev_priv(to_net_dev(d));
242 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
243 	unsigned long val;
244 
245 	/* no need to restrict values - anything from 0 to infinity is OK */
246 	if (kstrtoul(buf, 0, &val))
247 		return -EINVAL;
248 
249 	ctx->min_tx_pkt = val;
250 	return len;
251 }
252 
253 static ssize_t rx_max_store(struct device *d,
254 			    struct device_attribute *attr,
255 			    const char *buf, size_t len)
256 {
257 	struct usbnet *dev = netdev_priv(to_net_dev(d));
258 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
259 	unsigned long val;
260 
261 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
262 		return -EINVAL;
263 
264 	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
265 	return len;
266 }
267 
268 static ssize_t tx_max_store(struct device *d,
269 			    struct device_attribute *attr,
270 			    const char *buf, size_t len)
271 {
272 	struct usbnet *dev = netdev_priv(to_net_dev(d));
273 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
274 	unsigned long val;
275 
276 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
277 		return -EINVAL;
278 
279 	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
280 	return len;
281 }
282 
283 static ssize_t tx_timer_usecs_store(struct device *d,
284 				    struct device_attribute *attr,
285 				    const char *buf, size_t len)
286 {
287 	struct usbnet *dev = netdev_priv(to_net_dev(d));
288 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
289 	ssize_t ret;
290 	unsigned long val;
291 
292 	ret = kstrtoul(buf, 0, &val);
293 	if (ret)
294 		return ret;
295 	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
296 		return -EINVAL;
297 
298 	spin_lock_bh(&ctx->mtx);
299 	ctx->timer_interval = val * NSEC_PER_USEC;
300 	if (!ctx->timer_interval)
301 		ctx->tx_timer_pending = 0;
302 	spin_unlock_bh(&ctx->mtx);
303 	return len;
304 }
305 
306 static DEVICE_ATTR_RW(min_tx_pkt);
307 static DEVICE_ATTR_RW(rx_max);
308 static DEVICE_ATTR_RW(tx_max);
309 static DEVICE_ATTR_RW(tx_timer_usecs);
310 
311 static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
312 {
313 	struct usbnet *dev = netdev_priv(to_net_dev(d));
314 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
315 
316 	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
317 }
318 
319 static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
320 {
321 	struct usbnet *dev = netdev_priv(to_net_dev(d));
322 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
323 	bool enable;
324 
325 	if (kstrtobool(buf, &enable))
326 		return -EINVAL;
327 
328 	/* no change? */
329 	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
330 		return len;
331 
332 	if (enable) {
333 		if (ctx->is_ndp16 && !ctx->delayed_ndp16) {
334 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
335 			if (!ctx->delayed_ndp16)
336 				return -ENOMEM;
337 		}
338 		if (!ctx->is_ndp16 && !ctx->delayed_ndp32) {
339 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
340 			if (!ctx->delayed_ndp32)
341 				return -ENOMEM;
342 		}
343 	}
344 
345 	/* flush pending data before changing flag */
346 	netif_tx_lock_bh(dev->net);
347 	usbnet_start_xmit(NULL, dev->net);
348 	spin_lock_bh(&ctx->mtx);
349 	if (enable)
350 		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
351 	else
352 		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
353 	spin_unlock_bh(&ctx->mtx);
354 	netif_tx_unlock_bh(dev->net);
355 
356 	return len;
357 }
358 static DEVICE_ATTR_RW(ndp_to_end);
359 
360 #define NCM_PARM_ATTR(name, format, tocpu)				\
361 static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
362 { \
363 	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
364 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
365 	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
366 } \
367 static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
368 
369 NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
370 NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
371 NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
372 NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
373 NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
374 NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
375 NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
376 NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
377 NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
378 NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
379 
380 static struct attribute *cdc_ncm_sysfs_attrs[] = {
381 	&dev_attr_min_tx_pkt.attr,
382 	&dev_attr_ndp_to_end.attr,
383 	&dev_attr_rx_max.attr,
384 	&dev_attr_tx_max.attr,
385 	&dev_attr_tx_timer_usecs.attr,
386 	&dev_attr_bmNtbFormatsSupported.attr,
387 	&dev_attr_dwNtbInMaxSize.attr,
388 	&dev_attr_wNdpInDivisor.attr,
389 	&dev_attr_wNdpInPayloadRemainder.attr,
390 	&dev_attr_wNdpInAlignment.attr,
391 	&dev_attr_dwNtbOutMaxSize.attr,
392 	&dev_attr_wNdpOutDivisor.attr,
393 	&dev_attr_wNdpOutPayloadRemainder.attr,
394 	&dev_attr_wNdpOutAlignment.attr,
395 	&dev_attr_wNtbOutMaxDatagrams.attr,
396 	NULL,
397 };
398 
399 static const struct attribute_group cdc_ncm_sysfs_attr_group = {
400 	.name = "cdc_ncm",
401 	.attrs = cdc_ncm_sysfs_attrs,
402 };
403 
404 /* handle rx_max and tx_max changes */
405 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
406 {
407 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
408 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
409 	u32 val;
410 
411 	val = cdc_ncm_check_rx_max(dev, new_rx);
412 
413 	/* inform device about NTB input size changes */
414 	if (val != ctx->rx_max) {
415 		__le32 dwNtbInMaxSize = cpu_to_le32(val);
416 
417 		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
418 
419 		/* tell device to use new size */
420 		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
421 				     USB_TYPE_CLASS | USB_DIR_OUT
422 				     | USB_RECIP_INTERFACE,
423 				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
424 			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
425 		else
426 			ctx->rx_max = val;
427 	}
428 
429 	/* usbnet use these values for sizing rx queues */
430 	if (dev->rx_urb_size != ctx->rx_max) {
431 		dev->rx_urb_size = ctx->rx_max;
432 		if (netif_running(dev->net))
433 			usbnet_unlink_rx_urbs(dev);
434 	}
435 
436 	val = cdc_ncm_check_tx_max(dev, new_tx);
437 	if (val != ctx->tx_max)
438 		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
439 
440 	/* Adding a pad byte here if necessary simplifies the handling
441 	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
442 	 * the real skb max size.
443 	 *
444 	 * We cannot use dev->maxpacket here because this is called from
445 	 * .bind which is called before usbnet sets up dev->maxpacket
446 	 */
447 	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
448 	    val % usb_maxpacket(dev->udev, dev->out) == 0)
449 		val++;
450 
451 	/* we might need to flush any pending tx buffers if running */
452 	if (netif_running(dev->net) && val > ctx->tx_max) {
453 		netif_tx_lock_bh(dev->net);
454 		usbnet_start_xmit(NULL, dev->net);
455 		/* make sure tx_curr_skb is reallocated if it was empty */
456 		if (ctx->tx_curr_skb) {
457 			dev_kfree_skb_any(ctx->tx_curr_skb);
458 			ctx->tx_curr_skb = NULL;
459 		}
460 		ctx->tx_max = val;
461 		netif_tx_unlock_bh(dev->net);
462 	} else {
463 		ctx->tx_max = val;
464 	}
465 
466 	dev->hard_mtu = ctx->tx_max;
467 
468 	/* max qlen depend on hard_mtu and rx_urb_size */
469 	usbnet_update_max_qlen(dev);
470 
471 	/* never pad more than 3 full USB packets per transfer */
472 	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out),
473 				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
474 }
475 
476 /* helpers for NCM and MBIM differences */
477 static u8 cdc_ncm_flags(struct usbnet *dev)
478 {
479 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
480 
481 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
482 		return ctx->mbim_desc->bmNetworkCapabilities;
483 	if (ctx->func_desc)
484 		return ctx->func_desc->bmNetworkCapabilities;
485 	return 0;
486 }
487 
488 static int cdc_ncm_eth_hlen(struct usbnet *dev)
489 {
490 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
491 		return 0;
492 	return ETH_HLEN;
493 }
494 
495 static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
496 {
497 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
498 		return CDC_MBIM_MIN_DATAGRAM_SIZE;
499 	return CDC_NCM_MIN_DATAGRAM_SIZE;
500 }
501 
502 static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
503 {
504 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
505 
506 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
507 		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
508 	if (ctx->ether_desc)
509 		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
510 	return CDC_NCM_MAX_DATAGRAM_SIZE;
511 }
512 
513 /* initial one-time device setup.  MUST be called with the data interface
514  * in altsetting 0
515  */
516 static int cdc_ncm_init(struct usbnet *dev)
517 {
518 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
519 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
520 	int err;
521 
522 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
523 			      USB_TYPE_CLASS | USB_DIR_IN
524 			      |USB_RECIP_INTERFACE,
525 			      0, iface_no, &ctx->ncm_parm,
526 			      sizeof(ctx->ncm_parm));
527 	if (err < 0) {
528 		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
529 		return err; /* GET_NTB_PARAMETERS is required */
530 	}
531 
532 	/* set CRC Mode */
533 	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
534 		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
535 		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
536 				       USB_TYPE_CLASS | USB_DIR_OUT
537 				       | USB_RECIP_INTERFACE,
538 				       USB_CDC_NCM_CRC_NOT_APPENDED,
539 				       iface_no, NULL, 0);
540 		if (err < 0)
541 			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
542 	}
543 
544 	/* use ndp16 by default */
545 	ctx->is_ndp16 = 1;
546 
547 	/* set NTB format, if both formats are supported.
548 	 *
549 	 * "The host shall only send this command while the NCM Data
550 	 *  Interface is in alternate setting 0."
551 	 */
552 	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
553 						USB_CDC_NCM_NTB32_SUPPORTED) {
554 		if (ctx->drvflags & CDC_NCM_FLAG_PREFER_NTB32) {
555 			ctx->is_ndp16 = 0;
556 			dev_dbg(&dev->intf->dev, "Setting NTB format to 32-bit\n");
557 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
558 					       USB_TYPE_CLASS | USB_DIR_OUT
559 					       | USB_RECIP_INTERFACE,
560 					       USB_CDC_NCM_NTB32_FORMAT,
561 					       iface_no, NULL, 0);
562 		} else {
563 			ctx->is_ndp16 = 1;
564 			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
565 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
566 					       USB_TYPE_CLASS | USB_DIR_OUT
567 					       | USB_RECIP_INTERFACE,
568 					       USB_CDC_NCM_NTB16_FORMAT,
569 					       iface_no, NULL, 0);
570 		}
571 		if (err < 0) {
572 			ctx->is_ndp16 = 1;
573 			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
574 		}
575 	}
576 
577 	/* set initial device values */
578 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
579 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
580 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
581 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
582 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
583 	/* devices prior to NCM Errata shall set this field to zero */
584 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
585 
586 	dev_dbg(&dev->intf->dev,
587 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
588 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
589 		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
590 
591 	/* max count of tx datagrams */
592 	if ((ctx->tx_max_datagrams == 0) ||
593 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
594 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
595 
596 	/* set up maximum NDP size */
597 	if (ctx->is_ndp16)
598 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
599 	else
600 		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp32) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe32);
601 
602 	/* initial coalescing timer interval */
603 	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
604 
605 	return 0;
606 }
607 
608 /* set a new max datagram size */
609 static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
610 {
611 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
612 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
613 	__le16 max_datagram_size;
614 	u16 mbim_mtu;
615 	int err;
616 
617 	/* set default based on descriptors */
618 	ctx->max_datagram_size = clamp_t(u32, new_size,
619 					 cdc_ncm_min_dgram_size(dev),
620 					 CDC_NCM_MAX_DATAGRAM_SIZE);
621 
622 	/* inform the device about the selected Max Datagram Size? */
623 	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
624 		goto out;
625 
626 	/* read current mtu value from device */
627 	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
628 			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
629 			      0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
630 	if (err != sizeof(max_datagram_size)) {
631 		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
632 		goto out;
633 	}
634 
635 	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
636 		goto out;
637 
638 	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
639 	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
640 			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
641 			       0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
642 	if (err < 0)
643 		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
644 
645 out:
646 	/* set MTU to max supported by the device if necessary */
647 	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
648 
649 	/* do not exceed operator preferred MTU */
650 	if (ctx->mbim_extended_desc) {
651 		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
652 		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
653 			dev->net->mtu = mbim_mtu;
654 	}
655 }
656 
657 static void cdc_ncm_fix_modulus(struct usbnet *dev)
658 {
659 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
660 	u32 val;
661 
662 	/*
663 	 * verify that the structure alignment is:
664 	 * - power of two
665 	 * - not greater than the maximum transmit length
666 	 * - not less than four bytes
667 	 */
668 	val = ctx->tx_ndp_modulus;
669 
670 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
671 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
672 		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
673 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
674 	}
675 
676 	/*
677 	 * verify that the payload alignment is:
678 	 * - power of two
679 	 * - not greater than the maximum transmit length
680 	 * - not less than four bytes
681 	 */
682 	val = ctx->tx_modulus;
683 
684 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
685 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
686 		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
687 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
688 	}
689 
690 	/* verify the payload remainder */
691 	if (ctx->tx_remainder >= ctx->tx_modulus) {
692 		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
693 		ctx->tx_remainder = 0;
694 	}
695 
696 	/* adjust TX-remainder according to NCM specification. */
697 	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
698 			     (ctx->tx_modulus - 1));
699 }
700 
701 static int cdc_ncm_setup(struct usbnet *dev)
702 {
703 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
704 	u32 def_rx, def_tx;
705 
706 	/* be conservative when selecting initial buffer size to
707 	 * increase the number of hosts this will work for
708 	 */
709 	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
710 		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
711 	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
712 		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
713 
714 	/* clamp rx_max and tx_max and inform device */
715 	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
716 
717 	/* sanitize the modulus and remainder values */
718 	cdc_ncm_fix_modulus(dev);
719 
720 	/* set max datagram size */
721 	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
722 	return 0;
723 }
724 
725 static void
726 cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
727 {
728 	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
729 	u8 ep;
730 
731 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
732 		e = intf->cur_altsetting->endpoint + ep;
733 
734 		/* ignore endpoints which cannot transfer data */
735 		if (!usb_endpoint_maxp(&e->desc))
736 			continue;
737 
738 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
739 		case USB_ENDPOINT_XFER_INT:
740 			if (usb_endpoint_dir_in(&e->desc)) {
741 				if (!dev->status)
742 					dev->status = e;
743 			}
744 			break;
745 
746 		case USB_ENDPOINT_XFER_BULK:
747 			if (usb_endpoint_dir_in(&e->desc)) {
748 				if (!in)
749 					in = e;
750 			} else {
751 				if (!out)
752 					out = e;
753 			}
754 			break;
755 
756 		default:
757 			break;
758 		}
759 	}
760 	if (in && !dev->in)
761 		dev->in = usb_rcvbulkpipe(dev->udev,
762 					  in->desc.bEndpointAddress &
763 					  USB_ENDPOINT_NUMBER_MASK);
764 	if (out && !dev->out)
765 		dev->out = usb_sndbulkpipe(dev->udev,
766 					   out->desc.bEndpointAddress &
767 					   USB_ENDPOINT_NUMBER_MASK);
768 }
769 
770 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
771 {
772 	if (ctx == NULL)
773 		return;
774 
775 	if (ctx->tx_rem_skb != NULL) {
776 		dev_kfree_skb_any(ctx->tx_rem_skb);
777 		ctx->tx_rem_skb = NULL;
778 	}
779 
780 	if (ctx->tx_curr_skb != NULL) {
781 		dev_kfree_skb_any(ctx->tx_curr_skb);
782 		ctx->tx_curr_skb = NULL;
783 	}
784 
785 	if (ctx->is_ndp16)
786 		kfree(ctx->delayed_ndp16);
787 	else
788 		kfree(ctx->delayed_ndp32);
789 
790 	kfree(ctx);
791 }
792 
793 /* we need to override the usbnet change_mtu ndo for two reasons:
794  *  - respect the negotiated maximum datagram size
795  *  - avoid unwanted changes to rx and tx buffers
796  */
797 int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
798 {
799 	struct usbnet *dev = netdev_priv(net);
800 
801 	WRITE_ONCE(net->mtu, new_mtu);
802 	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
803 
804 	return 0;
805 }
806 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
807 
808 static const struct net_device_ops cdc_ncm_netdev_ops = {
809 	.ndo_open	     = usbnet_open,
810 	.ndo_stop	     = usbnet_stop,
811 	.ndo_start_xmit	     = usbnet_start_xmit,
812 	.ndo_tx_timeout	     = usbnet_tx_timeout,
813 	.ndo_set_rx_mode     = usbnet_set_rx_mode,
814 	.ndo_get_stats64     = dev_get_tstats64,
815 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
816 	.ndo_set_mac_address = eth_mac_addr,
817 	.ndo_validate_addr   = eth_validate_addr,
818 };
819 
820 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
821 {
822 	struct cdc_ncm_ctx *ctx;
823 	struct usb_driver *driver;
824 	u8 *buf;
825 	int len;
826 	int temp;
827 	u8 iface_no;
828 	struct usb_cdc_parsed_header hdr;
829 
830 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
831 	if (!ctx)
832 		return -ENOMEM;
833 
834 	ctx->dev = dev;
835 
836 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
837 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
838 	tasklet_setup(&ctx->bh, cdc_ncm_txpath_bh);
839 	atomic_set(&ctx->stop, 0);
840 	spin_lock_init(&ctx->mtx);
841 
842 	/* store ctx pointer in device data field */
843 	dev->data[0] = (unsigned long)ctx;
844 
845 	/* only the control interface can be successfully probed */
846 	ctx->control = intf;
847 
848 	/* get some pointers */
849 	driver = driver_of(intf);
850 	buf = intf->cur_altsetting->extra;
851 	len = intf->cur_altsetting->extralen;
852 
853 	/* parse through descriptors associated with control interface */
854 	cdc_parse_cdc_header(&hdr, intf, buf, len);
855 
856 	if (hdr.usb_cdc_union_desc)
857 		ctx->data = usb_ifnum_to_if(dev->udev,
858 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
859 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
860 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
861 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
862 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
863 
864 	/* some buggy devices have an IAD but no CDC Union */
865 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
866 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
867 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
868 	}
869 
870 	/* check if we got everything */
871 	if (!ctx->data) {
872 		dev_err(&intf->dev, "CDC Union missing and no IAD found\n");
873 		goto error;
874 	}
875 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
876 		if (!ctx->mbim_desc) {
877 			dev_err(&intf->dev, "MBIM functional descriptor missing\n");
878 			goto error;
879 		}
880 	} else {
881 		if (!ctx->ether_desc || !ctx->func_desc) {
882 			dev_err(&intf->dev, "NCM or ECM functional descriptors missing\n");
883 			goto error;
884 		}
885 	}
886 
887 	/* claim data interface, if different from control */
888 	if (ctx->data != ctx->control) {
889 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
890 		if (temp) {
891 			dev_err(&intf->dev, "failed to claim data intf\n");
892 			goto error;
893 		}
894 	}
895 
896 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
897 
898 	/* Device-specific flags */
899 	ctx->drvflags = drvflags;
900 
901 	/* Reset data interface. Some devices will not reset properly
902 	 * unless they are configured first.  Toggle the altsetting to
903 	 * force a reset.
904 	 * Some other devices do not work properly with this procedure
905 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
906 	 */
907 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
908 		usb_set_interface(dev->udev, iface_no, data_altsetting);
909 
910 	temp = usb_set_interface(dev->udev, iface_no, 0);
911 	if (temp) {
912 		dev_dbg(&intf->dev, "set interface failed\n");
913 		goto error2;
914 	}
915 
916 	/* initialize basic device settings */
917 	if (cdc_ncm_init(dev))
918 		goto error2;
919 
920 	/* Some firmwares need a pause here or they will silently fail
921 	 * to set up the interface properly.  This value was decided
922 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
923 	 * firmware.
924 	 */
925 	usleep_range(10000, 20000);
926 
927 	/* configure data interface */
928 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
929 	if (temp) {
930 		dev_dbg(&intf->dev, "set interface failed\n");
931 		goto error2;
932 	}
933 
934 	cdc_ncm_find_endpoints(dev, ctx->data);
935 	cdc_ncm_find_endpoints(dev, ctx->control);
936 	if (!dev->in || !dev->out || !dev->status) {
937 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
938 		goto error2;
939 	}
940 
941 	usb_set_intfdata(ctx->control, dev);
942 
943 	if (ctx->ether_desc) {
944 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
945 		if (temp) {
946 			dev_err(&intf->dev, "failed to get mac address\n");
947 			goto error2;
948 		}
949 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
950 	}
951 
952 	/* finish setting up the device specific data */
953 	cdc_ncm_setup(dev);
954 
955 	/* Allocate the delayed NDP if needed. */
956 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
957 		if (ctx->is_ndp16) {
958 			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
959 			if (!ctx->delayed_ndp16)
960 				goto error2;
961 		} else {
962 			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
963 			if (!ctx->delayed_ndp32)
964 				goto error2;
965 		}
966 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
967 	}
968 
969 	/* override ethtool_ops */
970 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
971 
972 	/* add our sysfs attrs */
973 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
974 
975 	/* must handle MTU changes */
976 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
977 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
978 
979 	return 0;
980 
981 error2:
982 	usb_set_intfdata(ctx->control, NULL);
983 	usb_set_intfdata(ctx->data, NULL);
984 	if (ctx->data != ctx->control)
985 		usb_driver_release_interface(driver, ctx->data);
986 error:
987 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
988 	dev->data[0] = 0;
989 	dev_info(&intf->dev, "bind() failure\n");
990 	return -ENODEV;
991 }
992 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
993 
994 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
995 {
996 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
997 	struct usb_driver *driver = driver_of(intf);
998 
999 	if (ctx == NULL)
1000 		return;		/* no setup */
1001 
1002 	atomic_set(&ctx->stop, 1);
1003 
1004 	hrtimer_cancel(&ctx->tx_timer);
1005 
1006 	tasklet_kill(&ctx->bh);
1007 
1008 	/* handle devices with combined control and data interface */
1009 	if (ctx->control == ctx->data)
1010 		ctx->data = NULL;
1011 
1012 	/* disconnect master --> disconnect slave */
1013 	if (intf == ctx->control && ctx->data) {
1014 		usb_set_intfdata(ctx->data, NULL);
1015 		usb_driver_release_interface(driver, ctx->data);
1016 		ctx->data = NULL;
1017 
1018 	} else if (intf == ctx->data && ctx->control) {
1019 		usb_set_intfdata(ctx->control, NULL);
1020 		usb_driver_release_interface(driver, ctx->control);
1021 		ctx->control = NULL;
1022 	}
1023 
1024 	usb_set_intfdata(intf, NULL);
1025 	cdc_ncm_free(ctx);
1026 }
1027 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1028 
1029 /* Return the number of the MBIM control interface altsetting iff it
1030  * is preferred and available,
1031  */
1032 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1033 {
1034 	struct usb_host_interface *alt;
1035 
1036 	/* The MBIM spec defines a NCM compatible default altsetting,
1037 	 * which we may have matched:
1038 	 *
1039 	 *  "Functions that implement both NCM 1.0 and MBIM (an
1040 	 *   “NCM/MBIM function”) according to this recommendation
1041 	 *   shall provide two alternate settings for the
1042 	 *   Communication Interface.  Alternate setting 0, and the
1043 	 *   associated class and endpoint descriptors, shall be
1044 	 *   constructed according to the rules given for the
1045 	 *   Communication Interface in section 5 of [USBNCM10].
1046 	 *   Alternate setting 1, and the associated class and
1047 	 *   endpoint descriptors, shall be constructed according to
1048 	 *   the rules given in section 6 (USB Device Model) of this
1049 	 *   specification."
1050 	 */
1051 	if (intf->num_altsetting < 2)
1052 		return intf->cur_altsetting->desc.bAlternateSetting;
1053 
1054 	if (prefer_mbim) {
1055 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1056 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1057 			return CDC_NCM_COMM_ALTSETTING_MBIM;
1058 	}
1059 	return CDC_NCM_COMM_ALTSETTING_NCM;
1060 }
1061 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1062 
1063 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1064 {
1065 	/* MBIM backwards compatible function? */
1066 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1067 		return -ENODEV;
1068 
1069 	/* The NCM data altsetting is fixed, so we hard-coded it.
1070 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1071 	 * placed NDP.
1072 	 */
1073 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1074 }
1075 
1076 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1077 {
1078 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1079 
1080 	if (skb->len + align > max)
1081 		align = max - skb->len;
1082 	if (align && skb_tailroom(skb) >= align)
1083 		skb_put_zero(skb, align);
1084 }
1085 
1086 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1087  * allocating a new one within skb
1088  */
1089 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1090 {
1091 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1092 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1093 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1094 
1095 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1096 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1097 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1098 	*/
1099 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1100 		if (ctx->delayed_ndp16->dwSignature == sign)
1101 			return ctx->delayed_ndp16;
1102 
1103 		/* We can only push a single NDP to the end. Return
1104 		 * NULL to send what we've already got and queue this
1105 		 * skb for later.
1106 		 */
1107 		else if (ctx->delayed_ndp16->dwSignature)
1108 			return NULL;
1109 	}
1110 
1111 	/* follow the chain of NDPs, looking for a match */
1112 	while (ndpoffset) {
1113 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1114 		if  (ndp16->dwSignature == sign)
1115 			return ndp16;
1116 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1117 	}
1118 
1119 	/* align new NDP */
1120 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1121 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1122 
1123 	/* verify that there is room for the NDP and the datagram (reserve) */
1124 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1125 		return NULL;
1126 
1127 	/* link to it */
1128 	if (ndp16)
1129 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1130 	else
1131 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1132 
1133 	/* push a new empty NDP */
1134 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1135 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1136 	else
1137 		ndp16 = ctx->delayed_ndp16;
1138 
1139 	ndp16->dwSignature = sign;
1140 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1141 	return ndp16;
1142 }
1143 
1144 static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1145 {
1146 	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1147 	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1148 	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1149 
1150 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1151 	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1152 	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1153 	 */
1154 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1155 		if (ctx->delayed_ndp32->dwSignature == sign)
1156 			return ctx->delayed_ndp32;
1157 
1158 		/* We can only push a single NDP to the end. Return
1159 		 * NULL to send what we've already got and queue this
1160 		 * skb for later.
1161 		 */
1162 		else if (ctx->delayed_ndp32->dwSignature)
1163 			return NULL;
1164 	}
1165 
1166 	/* follow the chain of NDPs, looking for a match */
1167 	while (ndpoffset) {
1168 		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1169 		if  (ndp32->dwSignature == sign)
1170 			return ndp32;
1171 		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1172 	}
1173 
1174 	/* align new NDP */
1175 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1176 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1177 
1178 	/* verify that there is room for the NDP and the datagram (reserve) */
1179 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1180 		return NULL;
1181 
1182 	/* link to it */
1183 	if (ndp32)
1184 		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1185 	else
1186 		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1187 
1188 	/* push a new empty NDP */
1189 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1190 		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1191 	else
1192 		ndp32 = ctx->delayed_ndp32;
1193 
1194 	ndp32->dwSignature = sign;
1195 	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1196 	return ndp32;
1197 }
1198 
1199 struct sk_buff *
1200 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1201 {
1202 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1203 	union {
1204 		struct usb_cdc_ncm_nth16 *nth16;
1205 		struct usb_cdc_ncm_nth32 *nth32;
1206 	} nth;
1207 	union {
1208 		struct usb_cdc_ncm_ndp16 *ndp16;
1209 		struct usb_cdc_ncm_ndp32 *ndp32;
1210 	} ndp;
1211 	struct sk_buff *skb_out;
1212 	u16 n = 0, index, ndplen;
1213 	u8 ready2send = 0;
1214 	u32 delayed_ndp_size;
1215 	size_t padding_count;
1216 
1217 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1218 	 * accordingly. Otherwise, we should check here.
1219 	 */
1220 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1221 		delayed_ndp_size = ctx->max_ndp_size +
1222 			max_t(u32,
1223 			      ctx->tx_ndp_modulus,
1224 			      ctx->tx_modulus + ctx->tx_remainder) - 1;
1225 	else
1226 		delayed_ndp_size = 0;
1227 
1228 	/* if there is a remaining skb, it gets priority */
1229 	if (skb != NULL) {
1230 		swap(skb, ctx->tx_rem_skb);
1231 		swap(sign, ctx->tx_rem_sign);
1232 	} else {
1233 		ready2send = 1;
1234 	}
1235 
1236 	/* check if we are resuming an OUT skb */
1237 	skb_out = ctx->tx_curr_skb;
1238 
1239 	/* allocate a new OUT skb */
1240 	if (!skb_out) {
1241 		if (ctx->tx_low_mem_val == 0) {
1242 			ctx->tx_curr_size = ctx->tx_max;
1243 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1244 			/* If the memory allocation fails we will wait longer
1245 			 * each time before attempting another full size
1246 			 * allocation again to not overload the system
1247 			 * further.
1248 			 */
1249 			if (skb_out == NULL) {
1250 				/* If even the smallest allocation fails, abort. */
1251 				if (ctx->tx_curr_size == USB_CDC_NCM_NTB_MIN_OUT_SIZE)
1252 					goto alloc_failed;
1253 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1254 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1255 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1256 			}
1257 		}
1258 		if (skb_out == NULL) {
1259 			/* See if a very small allocation is possible.
1260 			 * We will send this packet immediately and hope
1261 			 * that there is more memory available later.
1262 			 */
1263 			if (skb)
1264 				ctx->tx_curr_size = max(skb->len,
1265 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1266 			else
1267 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1268 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1269 
1270 			/* No allocation possible so we will abort */
1271 			if (!skb_out)
1272 				goto alloc_failed;
1273 			ctx->tx_low_mem_val--;
1274 		}
1275 		if (ctx->is_ndp16) {
1276 			/* fill out the initial 16-bit NTB header */
1277 			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1278 			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1279 			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1280 			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1281 		} else {
1282 			/* fill out the initial 32-bit NTB header */
1283 			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1284 			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1285 			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1286 			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1287 		}
1288 
1289 		/* count total number of frames in this NTB */
1290 		ctx->tx_curr_frame_num = 0;
1291 
1292 		/* recent payload counter for this skb_out */
1293 		ctx->tx_curr_frame_payload = 0;
1294 	}
1295 
1296 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1297 		/* send any remaining skb first */
1298 		if (skb == NULL) {
1299 			skb = ctx->tx_rem_skb;
1300 			sign = ctx->tx_rem_sign;
1301 			ctx->tx_rem_skb = NULL;
1302 
1303 			/* check for end of skb */
1304 			if (skb == NULL)
1305 				break;
1306 		}
1307 
1308 		/* get the appropriate NDP for this skb */
1309 		if (ctx->is_ndp16)
1310 			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1311 		else
1312 			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1313 
1314 		/* align beginning of next frame */
1315 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1316 
1317 		/* check if we had enough room left for both NDP and frame */
1318 		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1319 		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1320 			if (n == 0) {
1321 				/* won't fit, MTU problem? */
1322 				dev_kfree_skb_any(skb);
1323 				skb = NULL;
1324 				dev->net->stats.tx_dropped++;
1325 			} else {
1326 				/* no room for skb - store for later */
1327 				if (ctx->tx_rem_skb != NULL) {
1328 					dev_kfree_skb_any(ctx->tx_rem_skb);
1329 					dev->net->stats.tx_dropped++;
1330 				}
1331 				ctx->tx_rem_skb = skb;
1332 				ctx->tx_rem_sign = sign;
1333 				skb = NULL;
1334 				ready2send = 1;
1335 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1336 			}
1337 			break;
1338 		}
1339 
1340 		/* calculate frame number within this NDP */
1341 		if (ctx->is_ndp16) {
1342 			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1343 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1344 
1345 			/* OK, add this skb */
1346 			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1347 			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1348 			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1349 		} else {
1350 			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1351 			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1352 
1353 			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1354 			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1355 			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1356 		}
1357 		skb_put_data(skb_out, skb->data, skb->len);
1358 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1359 		dev_kfree_skb_any(skb);
1360 		skb = NULL;
1361 
1362 		/* send now if this NDP is full */
1363 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1364 			ready2send = 1;
1365 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1366 			break;
1367 		}
1368 	}
1369 
1370 	/* free up any dangling skb */
1371 	if (skb != NULL) {
1372 		dev_kfree_skb_any(skb);
1373 		skb = NULL;
1374 		dev->net->stats.tx_dropped++;
1375 	}
1376 
1377 	ctx->tx_curr_frame_num = n;
1378 
1379 	if (n == 0) {
1380 		/* wait for more frames */
1381 		/* push variables */
1382 		ctx->tx_curr_skb = skb_out;
1383 		goto exit_no_skb;
1384 
1385 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1386 		/* wait for more frames */
1387 		/* push variables */
1388 		ctx->tx_curr_skb = skb_out;
1389 		/* set the pending count */
1390 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1391 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1392 		goto exit_no_skb;
1393 
1394 	} else {
1395 		if (n == ctx->tx_max_datagrams)
1396 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1397 		/* frame goes out */
1398 		/* variables will be reset at next call */
1399 	}
1400 
1401 	/* If requested, put NDP at end of frame. */
1402 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1403 		if (ctx->is_ndp16) {
1404 			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1405 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1406 			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1407 			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1408 
1409 			/* Zero out delayed NDP - signature checking will naturally fail. */
1410 			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1411 		} else {
1412 			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1413 			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1414 			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1415 			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1416 
1417 			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1418 		}
1419 	}
1420 
1421 	/* If collected data size is less or equal ctx->min_tx_pkt
1422 	 * bytes, we send buffers as it is. If we get more data, it
1423 	 * would be more efficient for USB HS mobile device with DMA
1424 	 * engine to receive a full size NTB, than canceling DMA
1425 	 * transfer and receiving a short packet.
1426 	 *
1427 	 * This optimization support is pointless if we end up sending
1428 	 * a ZLP after full sized NTBs.
1429 	 */
1430 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1431 	    skb_out->len > ctx->min_tx_pkt) {
1432 		padding_count = ctx->tx_curr_size - skb_out->len;
1433 		if (!WARN_ON(padding_count > ctx->tx_curr_size))
1434 			skb_put_zero(skb_out, padding_count);
1435 	} else if (skb_out->len < ctx->tx_curr_size &&
1436 		   (skb_out->len % dev->maxpacket) == 0) {
1437 		skb_put_u8(skb_out, 0);	/* force short packet */
1438 	}
1439 
1440 	/* set final frame length */
1441 	if (ctx->is_ndp16) {
1442 		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1443 		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1444 	} else {
1445 		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1446 		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1447 	}
1448 
1449 	/* return skb */
1450 	ctx->tx_curr_skb = NULL;
1451 
1452 	/* keep private stats: framing overhead and number of NTBs */
1453 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1454 	ctx->tx_ntbs++;
1455 
1456 	/* usbnet will count all the framing overhead by default.
1457 	 * Adjust the stats so that the tx_bytes counter show real
1458 	 * payload data instead.
1459 	 */
1460 	usbnet_set_skb_tx_stats(skb_out, n,
1461 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1462 
1463 	return skb_out;
1464 
1465 alloc_failed:
1466 	if (skb) {
1467 		dev_kfree_skb_any(skb);
1468 		dev->net->stats.tx_dropped++;
1469 	}
1470 exit_no_skb:
1471 	/* Start timer, if there is a remaining non-empty skb */
1472 	if (ctx->tx_curr_skb != NULL && n > 0)
1473 		cdc_ncm_tx_timeout_start(ctx);
1474 	return NULL;
1475 }
1476 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1477 
1478 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1479 {
1480 	/* start timer, if not already started */
1481 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1482 		hrtimer_start(&ctx->tx_timer,
1483 				ctx->timer_interval,
1484 				HRTIMER_MODE_REL);
1485 }
1486 
1487 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1488 {
1489 	struct cdc_ncm_ctx *ctx =
1490 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1491 
1492 	if (!atomic_read(&ctx->stop))
1493 		tasklet_schedule(&ctx->bh);
1494 	return HRTIMER_NORESTART;
1495 }
1496 
1497 static void cdc_ncm_txpath_bh(struct tasklet_struct *t)
1498 {
1499 	struct cdc_ncm_ctx *ctx = from_tasklet(ctx, t, bh);
1500 	struct usbnet *dev = ctx->dev;
1501 
1502 	spin_lock(&ctx->mtx);
1503 	if (ctx->tx_timer_pending != 0) {
1504 		ctx->tx_timer_pending--;
1505 		cdc_ncm_tx_timeout_start(ctx);
1506 		spin_unlock(&ctx->mtx);
1507 	} else if (dev->net != NULL) {
1508 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1509 		spin_unlock(&ctx->mtx);
1510 		netif_tx_lock_bh(dev->net);
1511 		usbnet_start_xmit(NULL, dev->net);
1512 		netif_tx_unlock_bh(dev->net);
1513 	} else {
1514 		spin_unlock(&ctx->mtx);
1515 	}
1516 }
1517 
1518 struct sk_buff *
1519 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1520 {
1521 	struct sk_buff *skb_out;
1522 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1523 
1524 	/*
1525 	 * The Ethernet API we are using does not support transmitting
1526 	 * multiple Ethernet frames in a single call. This driver will
1527 	 * accumulate multiple Ethernet frames and send out a larger
1528 	 * USB frame when the USB buffer is full or when a single jiffies
1529 	 * timeout happens.
1530 	 */
1531 	if (ctx == NULL)
1532 		goto error;
1533 
1534 	spin_lock_bh(&ctx->mtx);
1535 
1536 	if (ctx->is_ndp16)
1537 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1538 	else
1539 		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1540 
1541 	spin_unlock_bh(&ctx->mtx);
1542 	return skb_out;
1543 
1544 error:
1545 	if (skb != NULL)
1546 		dev_kfree_skb_any(skb);
1547 
1548 	return NULL;
1549 }
1550 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1551 
1552 /* verify NTB header and return offset of first NDP, or negative error */
1553 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1554 {
1555 	struct usbnet *dev = netdev_priv(skb_in->dev);
1556 	struct usb_cdc_ncm_nth16 *nth16;
1557 	int len;
1558 	int ret = -EINVAL;
1559 
1560 	if (ctx == NULL)
1561 		goto error;
1562 
1563 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1564 					sizeof(struct usb_cdc_ncm_ndp16))) {
1565 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1566 		goto error;
1567 	}
1568 
1569 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1570 
1571 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1572 		netif_dbg(dev, rx_err, dev->net,
1573 			  "invalid NTH16 signature <%#010x>\n",
1574 			  le32_to_cpu(nth16->dwSignature));
1575 		goto error;
1576 	}
1577 
1578 	len = le16_to_cpu(nth16->wBlockLength);
1579 	if (len > ctx->rx_max) {
1580 		netif_dbg(dev, rx_err, dev->net,
1581 			  "unsupported NTB block length %u/%u\n", len,
1582 			  ctx->rx_max);
1583 		goto error;
1584 	}
1585 
1586 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1587 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1588 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1589 		netif_dbg(dev, rx_err, dev->net,
1590 			  "sequence number glitch prev=%d curr=%d\n",
1591 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1592 	}
1593 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1594 
1595 	ret = le16_to_cpu(nth16->wNdpIndex);
1596 error:
1597 	return ret;
1598 }
1599 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1600 
1601 int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1602 {
1603 	struct usbnet *dev = netdev_priv(skb_in->dev);
1604 	struct usb_cdc_ncm_nth32 *nth32;
1605 	int len;
1606 	int ret = -EINVAL;
1607 
1608 	if (ctx == NULL)
1609 		goto error;
1610 
1611 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1612 					sizeof(struct usb_cdc_ncm_ndp32))) {
1613 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1614 		goto error;
1615 	}
1616 
1617 	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1618 
1619 	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1620 		netif_dbg(dev, rx_err, dev->net,
1621 			  "invalid NTH32 signature <%#010x>\n",
1622 			  le32_to_cpu(nth32->dwSignature));
1623 		goto error;
1624 	}
1625 
1626 	len = le32_to_cpu(nth32->dwBlockLength);
1627 	if (len > ctx->rx_max) {
1628 		netif_dbg(dev, rx_err, dev->net,
1629 			  "unsupported NTB block length %u/%u\n", len,
1630 			  ctx->rx_max);
1631 		goto error;
1632 	}
1633 
1634 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1635 	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1636 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1637 		netif_dbg(dev, rx_err, dev->net,
1638 			  "sequence number glitch prev=%d curr=%d\n",
1639 			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1640 	}
1641 	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1642 
1643 	ret = le32_to_cpu(nth32->dwNdpIndex);
1644 error:
1645 	return ret;
1646 }
1647 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1648 
1649 /* verify NDP header and return number of datagrams, or negative error */
1650 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1651 {
1652 	struct usbnet *dev = netdev_priv(skb_in->dev);
1653 	struct usb_cdc_ncm_ndp16 *ndp16;
1654 	int ret = -EINVAL;
1655 
1656 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1657 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1658 			  ndpoffset);
1659 		goto error;
1660 	}
1661 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1662 
1663 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1664 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1665 			  le16_to_cpu(ndp16->wLength));
1666 		goto error;
1667 	}
1668 
1669 	ret = ((le16_to_cpu(ndp16->wLength) -
1670 					sizeof(struct usb_cdc_ncm_ndp16)) /
1671 					sizeof(struct usb_cdc_ncm_dpe16));
1672 	ret--; /* we process NDP entries except for the last one */
1673 
1674 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1675 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1676 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1677 		ret = -EINVAL;
1678 	}
1679 
1680 error:
1681 	return ret;
1682 }
1683 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1684 
1685 /* verify NDP header and return number of datagrams, or negative error */
1686 int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1687 {
1688 	struct usbnet *dev = netdev_priv(skb_in->dev);
1689 	struct usb_cdc_ncm_ndp32 *ndp32;
1690 	int ret = -EINVAL;
1691 
1692 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1693 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1694 			  ndpoffset);
1695 		goto error;
1696 	}
1697 	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1698 
1699 	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1700 		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1701 			  le16_to_cpu(ndp32->wLength));
1702 		goto error;
1703 	}
1704 
1705 	ret = ((le16_to_cpu(ndp32->wLength) -
1706 					sizeof(struct usb_cdc_ncm_ndp32)) /
1707 					sizeof(struct usb_cdc_ncm_dpe32));
1708 	ret--; /* we process NDP entries except for the last one */
1709 
1710 	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1711 	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1712 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1713 		ret = -EINVAL;
1714 	}
1715 
1716 error:
1717 	return ret;
1718 }
1719 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1720 
1721 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1722 {
1723 	struct sk_buff *skb;
1724 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1725 	unsigned int len;
1726 	int nframes;
1727 	int x;
1728 	unsigned int offset;
1729 	union {
1730 		struct usb_cdc_ncm_ndp16 *ndp16;
1731 		struct usb_cdc_ncm_ndp32 *ndp32;
1732 	} ndp;
1733 	union {
1734 		struct usb_cdc_ncm_dpe16 *dpe16;
1735 		struct usb_cdc_ncm_dpe32 *dpe32;
1736 	} dpe;
1737 
1738 	int ndpoffset;
1739 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1740 	u32 payload = 0;
1741 
1742 	if (ctx->is_ndp16)
1743 		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1744 	else
1745 		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1746 
1747 	if (ndpoffset < 0)
1748 		goto error;
1749 
1750 next_ndp:
1751 	if (ctx->is_ndp16) {
1752 		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1753 		if (nframes < 0)
1754 			goto error;
1755 
1756 		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1757 
1758 		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1759 			netif_dbg(dev, rx_err, dev->net,
1760 				  "invalid DPT16 signature <%#010x>\n",
1761 				  le32_to_cpu(ndp.ndp16->dwSignature));
1762 			goto err_ndp;
1763 		}
1764 		dpe.dpe16 = ndp.ndp16->dpe16;
1765 	} else {
1766 		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1767 		if (nframes < 0)
1768 			goto error;
1769 
1770 		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1771 
1772 		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1773 			netif_dbg(dev, rx_err, dev->net,
1774 				  "invalid DPT32 signature <%#010x>\n",
1775 				  le32_to_cpu(ndp.ndp32->dwSignature));
1776 			goto err_ndp;
1777 		}
1778 		dpe.dpe32 = ndp.ndp32->dpe32;
1779 	}
1780 
1781 	for (x = 0; x < nframes; x++) {
1782 		if (ctx->is_ndp16) {
1783 			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1784 			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1785 		} else {
1786 			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1787 			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1788 		}
1789 
1790 		/*
1791 		 * CDC NCM ch. 3.7
1792 		 * All entries after first NULL entry are to be ignored
1793 		 */
1794 		if ((offset == 0) || (len == 0)) {
1795 			if (!x)
1796 				goto err_ndp; /* empty NTB */
1797 			break;
1798 		}
1799 
1800 		/* sanity checking - watch out for integer wrap*/
1801 		if ((offset > skb_in->len) || (len > skb_in->len - offset) ||
1802 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1803 			netif_dbg(dev, rx_err, dev->net,
1804 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1805 				  x, offset, len, skb_in);
1806 			if (!x)
1807 				goto err_ndp;
1808 			break;
1809 
1810 		} else {
1811 			/* create a fresh copy to reduce truesize */
1812 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1813 			if (!skb)
1814 				goto error;
1815 			skb_put_data(skb, skb_in->data + offset, len);
1816 			usbnet_skb_return(dev, skb);
1817 			payload += len;	/* count payload bytes in this NTB */
1818 		}
1819 
1820 		if (ctx->is_ndp16)
1821 			dpe.dpe16++;
1822 		else
1823 			dpe.dpe32++;
1824 	}
1825 err_ndp:
1826 	/* are there more NDPs to process? */
1827 	if (ctx->is_ndp16)
1828 		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1829 	else
1830 		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1831 
1832 	if (ndpoffset && loopcount--)
1833 		goto next_ndp;
1834 
1835 	/* update stats */
1836 	ctx->rx_overhead += skb_in->len - payload;
1837 	ctx->rx_ntbs++;
1838 
1839 	return 1;
1840 error:
1841 	return 0;
1842 }
1843 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1844 
1845 static void
1846 cdc_ncm_speed_change(struct usbnet *dev,
1847 		     struct usb_cdc_speed_change *data)
1848 {
1849 	/* RTL8156 shipped before 2021 sends notification about every 32ms. */
1850 	dev->rx_speed = le32_to_cpu(data->DLBitRRate);
1851 	dev->tx_speed = le32_to_cpu(data->ULBitRate);
1852 }
1853 
1854 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1855 {
1856 	struct usb_cdc_notification *event;
1857 
1858 	if (urb->actual_length < sizeof(*event))
1859 		return;
1860 
1861 	/* test for split data in 8-byte chunks */
1862 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1863 		cdc_ncm_speed_change(dev,
1864 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1865 		return;
1866 	}
1867 
1868 	event = urb->transfer_buffer;
1869 
1870 	switch (event->bNotificationType) {
1871 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1872 		/*
1873 		 * According to the CDC NCM specification ch.7.1
1874 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1875 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1876 		 */
1877 		/* RTL8156 shipped before 2021 sends notification about
1878 		 * every 32ms. Don't forward notification if state is same.
1879 		 */
1880 		if (netif_carrier_ok(dev->net) != !!event->wValue)
1881 			usbnet_link_change(dev, !!event->wValue, 0);
1882 		break;
1883 
1884 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1885 		if (urb->actual_length < (sizeof(*event) +
1886 					sizeof(struct usb_cdc_speed_change)))
1887 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1888 		else
1889 			cdc_ncm_speed_change(dev,
1890 					     (struct usb_cdc_speed_change *)&event[1]);
1891 		break;
1892 
1893 	default:
1894 		dev_dbg(&dev->udev->dev,
1895 			"NCM: unexpected notification 0x%02x!\n",
1896 			event->bNotificationType);
1897 		break;
1898 	}
1899 }
1900 
1901 static const struct driver_info cdc_ncm_info = {
1902 	.description = "CDC NCM (NO ZLP)",
1903 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1904 			| FLAG_LINK_INTR | FLAG_ETHER,
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 	.set_rx_mode = usbnet_cdc_update_filter,
1912 };
1913 
1914 /* Same as cdc_ncm_info, but with FLAG_SEND_ZLP  */
1915 static const struct driver_info cdc_ncm_zlp_info = {
1916 	.description = "CDC NCM (SEND ZLP)",
1917 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1918 			| FLAG_LINK_INTR | FLAG_ETHER | FLAG_SEND_ZLP,
1919 	.bind = cdc_ncm_bind,
1920 	.unbind = cdc_ncm_unbind,
1921 	.manage_power = usbnet_manage_power,
1922 	.status = cdc_ncm_status,
1923 	.rx_fixup = cdc_ncm_rx_fixup,
1924 	.tx_fixup = cdc_ncm_tx_fixup,
1925 	.set_rx_mode = usbnet_cdc_update_filter,
1926 };
1927 
1928 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1929 static const struct driver_info wwan_info = {
1930 	.description = "Mobile Broadband Network Device",
1931 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1932 			| FLAG_LINK_INTR | FLAG_WWAN,
1933 	.bind = cdc_ncm_bind,
1934 	.unbind = cdc_ncm_unbind,
1935 	.manage_power = usbnet_manage_power,
1936 	.status = cdc_ncm_status,
1937 	.rx_fixup = cdc_ncm_rx_fixup,
1938 	.tx_fixup = cdc_ncm_tx_fixup,
1939 	.set_rx_mode = usbnet_cdc_update_filter,
1940 };
1941 
1942 /* Same as wwan_info, but with FLAG_NOARP  */
1943 static const struct driver_info wwan_noarp_info = {
1944 	.description = "Mobile Broadband Network Device (NO ARP)",
1945 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1946 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1947 	.bind = cdc_ncm_bind,
1948 	.unbind = cdc_ncm_unbind,
1949 	.manage_power = usbnet_manage_power,
1950 	.status = cdc_ncm_status,
1951 	.rx_fixup = cdc_ncm_rx_fixup,
1952 	.tx_fixup = cdc_ncm_tx_fixup,
1953 	.set_rx_mode = usbnet_cdc_update_filter,
1954 };
1955 
1956 static const struct usb_device_id cdc_devs[] = {
1957 	/* Ericsson MBM devices like F5521gw */
1958 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1959 		| USB_DEVICE_ID_MATCH_VENDOR,
1960 	  .idVendor = 0x0bdb,
1961 	  .bInterfaceClass = USB_CLASS_COMM,
1962 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1963 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1964 	  .driver_info = (unsigned long) &wwan_info,
1965 	},
1966 
1967 	/* Telit LE910 V2 */
1968 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1969 		USB_CLASS_COMM,
1970 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1971 	  .driver_info = (unsigned long)&wwan_noarp_info,
1972 	},
1973 
1974 	/* DW5812 LTE Verizon Mobile Broadband Card
1975 	 * Unlike DW5550 this device requires FLAG_NOARP
1976 	 */
1977 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1978 		USB_CLASS_COMM,
1979 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1980 	  .driver_info = (unsigned long)&wwan_noarp_info,
1981 	},
1982 
1983 	/* DW5813 LTE AT&T Mobile Broadband Card
1984 	 * Unlike DW5550 this device requires FLAG_NOARP
1985 	 */
1986 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1987 		USB_CLASS_COMM,
1988 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1989 	  .driver_info = (unsigned long)&wwan_noarp_info,
1990 	},
1991 
1992 	/* Dell branded MBM devices like DW5550 */
1993 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1994 		| USB_DEVICE_ID_MATCH_VENDOR,
1995 	  .idVendor = 0x413c,
1996 	  .bInterfaceClass = USB_CLASS_COMM,
1997 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1998 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1999 	  .driver_info = (unsigned long) &wwan_info,
2000 	},
2001 
2002 	/* Toshiba branded MBM devices */
2003 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
2004 		| USB_DEVICE_ID_MATCH_VENDOR,
2005 	  .idVendor = 0x0930,
2006 	  .bInterfaceClass = USB_CLASS_COMM,
2007 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2008 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2009 	  .driver_info = (unsigned long) &wwan_info,
2010 	},
2011 
2012 	/* tag Huawei devices as wwan */
2013 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
2014 					USB_CLASS_COMM,
2015 					USB_CDC_SUBCLASS_NCM,
2016 					USB_CDC_PROTO_NONE),
2017 	  .driver_info = (unsigned long)&wwan_info,
2018 	},
2019 
2020 	/* Infineon(now Intel) HSPA Modem platform */
2021 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
2022 		USB_CLASS_COMM,
2023 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2024 	  .driver_info = (unsigned long)&wwan_noarp_info,
2025 	},
2026 
2027 	/* u-blox TOBY-L4 */
2028 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
2029 		USB_CLASS_COMM,
2030 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2031 	  .driver_info = (unsigned long)&wwan_info,
2032 	},
2033 
2034 	/* DisplayLink docking stations */
2035 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
2036 		| USB_DEVICE_ID_MATCH_VENDOR,
2037 	  .idVendor = 0x17e9,
2038 	  .bInterfaceClass = USB_CLASS_COMM,
2039 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2040 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2041 	  .driver_info = (unsigned long)&cdc_ncm_zlp_info,
2042 	},
2043 
2044 	/* Generic CDC-NCM devices */
2045 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2046 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2047 		.driver_info = (unsigned long)&cdc_ncm_info,
2048 	},
2049 	{
2050 	},
2051 };
2052 MODULE_DEVICE_TABLE(usb, cdc_devs);
2053 
2054 static struct usb_driver cdc_ncm_driver = {
2055 	.name = "cdc_ncm",
2056 	.id_table = cdc_devs,
2057 	.probe = usbnet_probe,
2058 	.disconnect = usbnet_disconnect,
2059 	.suspend = usbnet_suspend,
2060 	.resume = usbnet_resume,
2061 	.reset_resume =	usbnet_resume,
2062 	.supports_autosuspend = 1,
2063 	.disable_hub_initiated_lpm = 1,
2064 };
2065 
2066 module_usb_driver(cdc_ncm_driver);
2067 
2068 MODULE_AUTHOR("Hans Petter Selasky");
2069 MODULE_DESCRIPTION("USB CDC NCM host driver");
2070 MODULE_LICENSE("Dual BSD/GPL");
2071