xref: /openbmc/linux/drivers/net/usb/cdc_ncm.c (revision 4da722ca)
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, S_IRUGO | S_IWUSR);
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 	min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
179 	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
180 
181 	/* some devices set dwNtbOutMaxSize too low for the above default */
182 	min = min(min, max);
183 
184 	val = clamp_t(u32, new_tx, min, max);
185 	if (val != new_tx)
186 		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
187 
188 	return val;
189 }
190 
191 static ssize_t cdc_ncm_show_min_tx_pkt(struct device *d, struct device_attribute *attr, char *buf)
192 {
193 	struct usbnet *dev = netdev_priv(to_net_dev(d));
194 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
195 
196 	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
197 }
198 
199 static ssize_t cdc_ncm_show_rx_max(struct device *d, struct device_attribute *attr, char *buf)
200 {
201 	struct usbnet *dev = netdev_priv(to_net_dev(d));
202 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
203 
204 	return sprintf(buf, "%u\n", ctx->rx_max);
205 }
206 
207 static ssize_t cdc_ncm_show_tx_max(struct device *d, struct device_attribute *attr, char *buf)
208 {
209 	struct usbnet *dev = netdev_priv(to_net_dev(d));
210 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
211 
212 	return sprintf(buf, "%u\n", ctx->tx_max);
213 }
214 
215 static ssize_t cdc_ncm_show_tx_timer_usecs(struct device *d, struct device_attribute *attr, char *buf)
216 {
217 	struct usbnet *dev = netdev_priv(to_net_dev(d));
218 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
219 
220 	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
221 }
222 
223 static ssize_t cdc_ncm_store_min_tx_pkt(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
224 {
225 	struct usbnet *dev = netdev_priv(to_net_dev(d));
226 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
227 	unsigned long val;
228 
229 	/* no need to restrict values - anything from 0 to infinity is OK */
230 	if (kstrtoul(buf, 0, &val))
231 		return -EINVAL;
232 
233 	ctx->min_tx_pkt = val;
234 	return len;
235 }
236 
237 static ssize_t cdc_ncm_store_rx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
238 {
239 	struct usbnet *dev = netdev_priv(to_net_dev(d));
240 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
241 	unsigned long val;
242 
243 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
244 		return -EINVAL;
245 
246 	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
247 	return len;
248 }
249 
250 static ssize_t cdc_ncm_store_tx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
251 {
252 	struct usbnet *dev = netdev_priv(to_net_dev(d));
253 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
254 	unsigned long val;
255 
256 	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
257 		return -EINVAL;
258 
259 	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
260 	return len;
261 }
262 
263 static ssize_t cdc_ncm_store_tx_timer_usecs(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
264 {
265 	struct usbnet *dev = netdev_priv(to_net_dev(d));
266 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
267 	ssize_t ret;
268 	unsigned long val;
269 
270 	ret = kstrtoul(buf, 0, &val);
271 	if (ret)
272 		return ret;
273 	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
274 		return -EINVAL;
275 
276 	spin_lock_bh(&ctx->mtx);
277 	ctx->timer_interval = val * NSEC_PER_USEC;
278 	if (!ctx->timer_interval)
279 		ctx->tx_timer_pending = 0;
280 	spin_unlock_bh(&ctx->mtx);
281 	return len;
282 }
283 
284 static DEVICE_ATTR(min_tx_pkt, S_IRUGO | S_IWUSR, cdc_ncm_show_min_tx_pkt, cdc_ncm_store_min_tx_pkt);
285 static DEVICE_ATTR(rx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_rx_max, cdc_ncm_store_rx_max);
286 static DEVICE_ATTR(tx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_max, cdc_ncm_store_tx_max);
287 static DEVICE_ATTR(tx_timer_usecs, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_timer_usecs, cdc_ncm_store_tx_timer_usecs);
288 
289 static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
290 {
291 	struct usbnet *dev = netdev_priv(to_net_dev(d));
292 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
293 
294 	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
295 }
296 
297 static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
298 {
299 	struct usbnet *dev = netdev_priv(to_net_dev(d));
300 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
301 	bool enable;
302 
303 	if (strtobool(buf, &enable))
304 		return -EINVAL;
305 
306 	/* no change? */
307 	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
308 		return len;
309 
310 	if (enable && !ctx->delayed_ndp16) {
311 		ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
312 		if (!ctx->delayed_ndp16)
313 			return -ENOMEM;
314 	}
315 
316 	/* flush pending data before changing flag */
317 	netif_tx_lock_bh(dev->net);
318 	usbnet_start_xmit(NULL, dev->net);
319 	spin_lock_bh(&ctx->mtx);
320 	if (enable)
321 		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
322 	else
323 		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
324 	spin_unlock_bh(&ctx->mtx);
325 	netif_tx_unlock_bh(dev->net);
326 
327 	return len;
328 }
329 static DEVICE_ATTR_RW(ndp_to_end);
330 
331 #define NCM_PARM_ATTR(name, format, tocpu)				\
332 static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
333 { \
334 	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
335 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
336 	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
337 } \
338 static DEVICE_ATTR(name, S_IRUGO, cdc_ncm_show_##name, NULL)
339 
340 NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
341 NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
342 NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
343 NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
344 NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
345 NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
346 NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
347 NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
348 NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
349 NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
350 
351 static struct attribute *cdc_ncm_sysfs_attrs[] = {
352 	&dev_attr_min_tx_pkt.attr,
353 	&dev_attr_ndp_to_end.attr,
354 	&dev_attr_rx_max.attr,
355 	&dev_attr_tx_max.attr,
356 	&dev_attr_tx_timer_usecs.attr,
357 	&dev_attr_bmNtbFormatsSupported.attr,
358 	&dev_attr_dwNtbInMaxSize.attr,
359 	&dev_attr_wNdpInDivisor.attr,
360 	&dev_attr_wNdpInPayloadRemainder.attr,
361 	&dev_attr_wNdpInAlignment.attr,
362 	&dev_attr_dwNtbOutMaxSize.attr,
363 	&dev_attr_wNdpOutDivisor.attr,
364 	&dev_attr_wNdpOutPayloadRemainder.attr,
365 	&dev_attr_wNdpOutAlignment.attr,
366 	&dev_attr_wNtbOutMaxDatagrams.attr,
367 	NULL,
368 };
369 
370 static struct attribute_group cdc_ncm_sysfs_attr_group = {
371 	.name = "cdc_ncm",
372 	.attrs = cdc_ncm_sysfs_attrs,
373 };
374 
375 /* handle rx_max and tx_max changes */
376 static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
377 {
378 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
379 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
380 	u32 val;
381 
382 	val = cdc_ncm_check_rx_max(dev, new_rx);
383 
384 	/* inform device about NTB input size changes */
385 	if (val != ctx->rx_max) {
386 		__le32 dwNtbInMaxSize = cpu_to_le32(val);
387 
388 		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
389 
390 		/* tell device to use new size */
391 		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
392 				     USB_TYPE_CLASS | USB_DIR_OUT
393 				     | USB_RECIP_INTERFACE,
394 				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
395 			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
396 		else
397 			ctx->rx_max = val;
398 	}
399 
400 	/* usbnet use these values for sizing rx queues */
401 	if (dev->rx_urb_size != ctx->rx_max) {
402 		dev->rx_urb_size = ctx->rx_max;
403 		if (netif_running(dev->net))
404 			usbnet_unlink_rx_urbs(dev);
405 	}
406 
407 	val = cdc_ncm_check_tx_max(dev, new_tx);
408 	if (val != ctx->tx_max)
409 		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
410 
411 	/* Adding a pad byte here if necessary simplifies the handling
412 	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
413 	 * the real skb max size.
414 	 *
415 	 * We cannot use dev->maxpacket here because this is called from
416 	 * .bind which is called before usbnet sets up dev->maxpacket
417 	 */
418 	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
419 	    val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
420 		val++;
421 
422 	/* we might need to flush any pending tx buffers if running */
423 	if (netif_running(dev->net) && val > ctx->tx_max) {
424 		netif_tx_lock_bh(dev->net);
425 		usbnet_start_xmit(NULL, dev->net);
426 		/* make sure tx_curr_skb is reallocated if it was empty */
427 		if (ctx->tx_curr_skb) {
428 			dev_kfree_skb_any(ctx->tx_curr_skb);
429 			ctx->tx_curr_skb = NULL;
430 		}
431 		ctx->tx_max = val;
432 		netif_tx_unlock_bh(dev->net);
433 	} else {
434 		ctx->tx_max = val;
435 	}
436 
437 	dev->hard_mtu = ctx->tx_max;
438 
439 	/* max qlen depend on hard_mtu and rx_urb_size */
440 	usbnet_update_max_qlen(dev);
441 
442 	/* never pad more than 3 full USB packets per transfer */
443 	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out, 1),
444 				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
445 }
446 
447 /* helpers for NCM and MBIM differences */
448 static u8 cdc_ncm_flags(struct usbnet *dev)
449 {
450 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
451 
452 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
453 		return ctx->mbim_desc->bmNetworkCapabilities;
454 	if (ctx->func_desc)
455 		return ctx->func_desc->bmNetworkCapabilities;
456 	return 0;
457 }
458 
459 static int cdc_ncm_eth_hlen(struct usbnet *dev)
460 {
461 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
462 		return 0;
463 	return ETH_HLEN;
464 }
465 
466 static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
467 {
468 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
469 		return CDC_MBIM_MIN_DATAGRAM_SIZE;
470 	return CDC_NCM_MIN_DATAGRAM_SIZE;
471 }
472 
473 static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
474 {
475 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
476 
477 	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
478 		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
479 	if (ctx->ether_desc)
480 		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
481 	return CDC_NCM_MAX_DATAGRAM_SIZE;
482 }
483 
484 /* initial one-time device setup.  MUST be called with the data interface
485  * in altsetting 0
486  */
487 static int cdc_ncm_init(struct usbnet *dev)
488 {
489 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
490 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
491 	int err;
492 
493 	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
494 			      USB_TYPE_CLASS | USB_DIR_IN
495 			      |USB_RECIP_INTERFACE,
496 			      0, iface_no, &ctx->ncm_parm,
497 			      sizeof(ctx->ncm_parm));
498 	if (err < 0) {
499 		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
500 		return err; /* GET_NTB_PARAMETERS is required */
501 	}
502 
503 	/* set CRC Mode */
504 	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
505 		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
506 		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
507 				       USB_TYPE_CLASS | USB_DIR_OUT
508 				       | USB_RECIP_INTERFACE,
509 				       USB_CDC_NCM_CRC_NOT_APPENDED,
510 				       iface_no, NULL, 0);
511 		if (err < 0)
512 			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
513 	}
514 
515 	/* set NTB format, if both formats are supported.
516 	 *
517 	 * "The host shall only send this command while the NCM Data
518 	 *  Interface is in alternate setting 0."
519 	 */
520 	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
521 						USB_CDC_NCM_NTB32_SUPPORTED) {
522 		dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
523 		err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
524 				       USB_TYPE_CLASS | USB_DIR_OUT
525 				       | USB_RECIP_INTERFACE,
526 				       USB_CDC_NCM_NTB16_FORMAT,
527 				       iface_no, NULL, 0);
528 		if (err < 0)
529 			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
530 	}
531 
532 	/* set initial device values */
533 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
534 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
535 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
536 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
537 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
538 	/* devices prior to NCM Errata shall set this field to zero */
539 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
540 
541 	dev_dbg(&dev->intf->dev,
542 		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
543 		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
544 		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
545 
546 	/* max count of tx datagrams */
547 	if ((ctx->tx_max_datagrams == 0) ||
548 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
549 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
550 
551 	/* set up maximum NDP size */
552 	ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
553 
554 	/* initial coalescing timer interval */
555 	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
556 
557 	return 0;
558 }
559 
560 /* set a new max datagram size */
561 static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
562 {
563 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
564 	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
565 	__le16 max_datagram_size;
566 	u16 mbim_mtu;
567 	int err;
568 
569 	/* set default based on descriptors */
570 	ctx->max_datagram_size = clamp_t(u32, new_size,
571 					 cdc_ncm_min_dgram_size(dev),
572 					 CDC_NCM_MAX_DATAGRAM_SIZE);
573 
574 	/* inform the device about the selected Max Datagram Size? */
575 	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
576 		goto out;
577 
578 	/* read current mtu value from device */
579 	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
580 			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
581 			      0, iface_no, &max_datagram_size, 2);
582 	if (err < 0) {
583 		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
584 		goto out;
585 	}
586 
587 	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
588 		goto out;
589 
590 	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
591 	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
592 			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
593 			       0, iface_no, &max_datagram_size, 2);
594 	if (err < 0)
595 		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
596 
597 out:
598 	/* set MTU to max supported by the device if necessary */
599 	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
600 
601 	/* do not exceed operater preferred MTU */
602 	if (ctx->mbim_extended_desc) {
603 		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
604 		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
605 			dev->net->mtu = mbim_mtu;
606 	}
607 }
608 
609 static void cdc_ncm_fix_modulus(struct usbnet *dev)
610 {
611 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
612 	u32 val;
613 
614 	/*
615 	 * verify that the structure alignment is:
616 	 * - power of two
617 	 * - not greater than the maximum transmit length
618 	 * - not less than four bytes
619 	 */
620 	val = ctx->tx_ndp_modulus;
621 
622 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
623 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
624 		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
625 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
626 	}
627 
628 	/*
629 	 * verify that the payload alignment is:
630 	 * - power of two
631 	 * - not greater than the maximum transmit length
632 	 * - not less than four bytes
633 	 */
634 	val = ctx->tx_modulus;
635 
636 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
637 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
638 		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
639 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
640 	}
641 
642 	/* verify the payload remainder */
643 	if (ctx->tx_remainder >= ctx->tx_modulus) {
644 		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
645 		ctx->tx_remainder = 0;
646 	}
647 
648 	/* adjust TX-remainder according to NCM specification. */
649 	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
650 			     (ctx->tx_modulus - 1));
651 }
652 
653 static int cdc_ncm_setup(struct usbnet *dev)
654 {
655 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
656 	u32 def_rx, def_tx;
657 
658 	/* be conservative when selecting intial buffer size to
659 	 * increase the number of hosts this will work for
660 	 */
661 	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
662 		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
663 	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
664 		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
665 
666 	/* clamp rx_max and tx_max and inform device */
667 	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
668 
669 	/* sanitize the modulus and remainder values */
670 	cdc_ncm_fix_modulus(dev);
671 
672 	/* set max datagram size */
673 	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
674 	return 0;
675 }
676 
677 static void
678 cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
679 {
680 	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
681 	u8 ep;
682 
683 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
684 
685 		e = intf->cur_altsetting->endpoint + ep;
686 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
687 		case USB_ENDPOINT_XFER_INT:
688 			if (usb_endpoint_dir_in(&e->desc)) {
689 				if (!dev->status)
690 					dev->status = e;
691 			}
692 			break;
693 
694 		case USB_ENDPOINT_XFER_BULK:
695 			if (usb_endpoint_dir_in(&e->desc)) {
696 				if (!in)
697 					in = e;
698 			} else {
699 				if (!out)
700 					out = e;
701 			}
702 			break;
703 
704 		default:
705 			break;
706 		}
707 	}
708 	if (in && !dev->in)
709 		dev->in = usb_rcvbulkpipe(dev->udev,
710 					  in->desc.bEndpointAddress &
711 					  USB_ENDPOINT_NUMBER_MASK);
712 	if (out && !dev->out)
713 		dev->out = usb_sndbulkpipe(dev->udev,
714 					   out->desc.bEndpointAddress &
715 					   USB_ENDPOINT_NUMBER_MASK);
716 }
717 
718 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
719 {
720 	if (ctx == NULL)
721 		return;
722 
723 	if (ctx->tx_rem_skb != NULL) {
724 		dev_kfree_skb_any(ctx->tx_rem_skb);
725 		ctx->tx_rem_skb = NULL;
726 	}
727 
728 	if (ctx->tx_curr_skb != NULL) {
729 		dev_kfree_skb_any(ctx->tx_curr_skb);
730 		ctx->tx_curr_skb = NULL;
731 	}
732 
733 	kfree(ctx->delayed_ndp16);
734 
735 	kfree(ctx);
736 }
737 
738 /* we need to override the usbnet change_mtu ndo for two reasons:
739  *  - respect the negotiated maximum datagram size
740  *  - avoid unwanted changes to rx and tx buffers
741  */
742 int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
743 {
744 	struct usbnet *dev = netdev_priv(net);
745 
746 	net->mtu = new_mtu;
747 	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
748 
749 	return 0;
750 }
751 EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
752 
753 static const struct net_device_ops cdc_ncm_netdev_ops = {
754 	.ndo_open	     = usbnet_open,
755 	.ndo_stop	     = usbnet_stop,
756 	.ndo_start_xmit	     = usbnet_start_xmit,
757 	.ndo_tx_timeout	     = usbnet_tx_timeout,
758 	.ndo_get_stats64     = usbnet_get_stats64,
759 	.ndo_change_mtu	     = cdc_ncm_change_mtu,
760 	.ndo_set_mac_address = eth_mac_addr,
761 	.ndo_validate_addr   = eth_validate_addr,
762 };
763 
764 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
765 {
766 	struct cdc_ncm_ctx *ctx;
767 	struct usb_driver *driver;
768 	u8 *buf;
769 	int len;
770 	int temp;
771 	u8 iface_no;
772 	struct usb_cdc_parsed_header hdr;
773 
774 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
775 	if (!ctx)
776 		return -ENOMEM;
777 
778 	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
779 	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
780 	ctx->bh.data = (unsigned long)dev;
781 	ctx->bh.func = cdc_ncm_txpath_bh;
782 	atomic_set(&ctx->stop, 0);
783 	spin_lock_init(&ctx->mtx);
784 
785 	/* store ctx pointer in device data field */
786 	dev->data[0] = (unsigned long)ctx;
787 
788 	/* only the control interface can be successfully probed */
789 	ctx->control = intf;
790 
791 	/* get some pointers */
792 	driver = driver_of(intf);
793 	buf = intf->cur_altsetting->extra;
794 	len = intf->cur_altsetting->extralen;
795 
796 	/* parse through descriptors associated with control interface */
797 	cdc_parse_cdc_header(&hdr, intf, buf, len);
798 
799 	if (hdr.usb_cdc_union_desc)
800 		ctx->data = usb_ifnum_to_if(dev->udev,
801 					    hdr.usb_cdc_union_desc->bSlaveInterface0);
802 	ctx->ether_desc = hdr.usb_cdc_ether_desc;
803 	ctx->func_desc = hdr.usb_cdc_ncm_desc;
804 	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
805 	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
806 
807 	/* some buggy devices have an IAD but no CDC Union */
808 	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
809 		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
810 		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
811 	}
812 
813 	/* check if we got everything */
814 	if (!ctx->data) {
815 		dev_dbg(&intf->dev, "CDC Union missing and no IAD found\n");
816 		goto error;
817 	}
818 	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
819 		if (!ctx->mbim_desc) {
820 			dev_dbg(&intf->dev, "MBIM functional descriptor missing\n");
821 			goto error;
822 		}
823 	} else {
824 		if (!ctx->ether_desc || !ctx->func_desc) {
825 			dev_dbg(&intf->dev, "NCM or ECM functional descriptors missing\n");
826 			goto error;
827 		}
828 	}
829 
830 	/* claim data interface, if different from control */
831 	if (ctx->data != ctx->control) {
832 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
833 		if (temp) {
834 			dev_dbg(&intf->dev, "failed to claim data intf\n");
835 			goto error;
836 		}
837 	}
838 
839 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
840 
841 	/* Device-specific flags */
842 	ctx->drvflags = drvflags;
843 
844 	/* Reset data interface. Some devices will not reset properly
845 	 * unless they are configured first.  Toggle the altsetting to
846 	 * force a reset.
847 	 * Some other devices do not work properly with this procedure
848 	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
849 	 */
850 	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
851 		usb_set_interface(dev->udev, iface_no, data_altsetting);
852 
853 	temp = usb_set_interface(dev->udev, iface_no, 0);
854 	if (temp) {
855 		dev_dbg(&intf->dev, "set interface failed\n");
856 		goto error2;
857 	}
858 
859 	/* initialize basic device settings */
860 	if (cdc_ncm_init(dev))
861 		goto error2;
862 
863 	/* Some firmwares need a pause here or they will silently fail
864 	 * to set up the interface properly.  This value was decided
865 	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
866 	 * firmware.
867 	 */
868 	usleep_range(10000, 20000);
869 
870 	/* configure data interface */
871 	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
872 	if (temp) {
873 		dev_dbg(&intf->dev, "set interface failed\n");
874 		goto error2;
875 	}
876 
877 	cdc_ncm_find_endpoints(dev, ctx->data);
878 	cdc_ncm_find_endpoints(dev, ctx->control);
879 	if (!dev->in || !dev->out || !dev->status) {
880 		dev_dbg(&intf->dev, "failed to collect endpoints\n");
881 		goto error2;
882 	}
883 
884 	usb_set_intfdata(ctx->data, dev);
885 	usb_set_intfdata(ctx->control, dev);
886 
887 	if (ctx->ether_desc) {
888 		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
889 		if (temp) {
890 			dev_dbg(&intf->dev, "failed to get mac address\n");
891 			goto error2;
892 		}
893 		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
894 	}
895 
896 	/* finish setting up the device specific data */
897 	cdc_ncm_setup(dev);
898 
899 	/* Allocate the delayed NDP if needed. */
900 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
901 		ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
902 		if (!ctx->delayed_ndp16)
903 			goto error2;
904 		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
905 	}
906 
907 	/* override ethtool_ops */
908 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
909 
910 	/* add our sysfs attrs */
911 	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
912 
913 	/* must handle MTU changes */
914 	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
915 	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
916 
917 	return 0;
918 
919 error2:
920 	usb_set_intfdata(ctx->control, NULL);
921 	usb_set_intfdata(ctx->data, NULL);
922 	if (ctx->data != ctx->control)
923 		usb_driver_release_interface(driver, ctx->data);
924 error:
925 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
926 	dev->data[0] = 0;
927 	dev_info(&intf->dev, "bind() failure\n");
928 	return -ENODEV;
929 }
930 EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
931 
932 void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
933 {
934 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
935 	struct usb_driver *driver = driver_of(intf);
936 
937 	if (ctx == NULL)
938 		return;		/* no setup */
939 
940 	atomic_set(&ctx->stop, 1);
941 
942 	if (hrtimer_active(&ctx->tx_timer))
943 		hrtimer_cancel(&ctx->tx_timer);
944 
945 	tasklet_kill(&ctx->bh);
946 
947 	/* handle devices with combined control and data interface */
948 	if (ctx->control == ctx->data)
949 		ctx->data = NULL;
950 
951 	/* disconnect master --> disconnect slave */
952 	if (intf == ctx->control && ctx->data) {
953 		usb_set_intfdata(ctx->data, NULL);
954 		usb_driver_release_interface(driver, ctx->data);
955 		ctx->data = NULL;
956 
957 	} else if (intf == ctx->data && ctx->control) {
958 		usb_set_intfdata(ctx->control, NULL);
959 		usb_driver_release_interface(driver, ctx->control);
960 		ctx->control = NULL;
961 	}
962 
963 	usb_set_intfdata(intf, NULL);
964 	cdc_ncm_free(ctx);
965 }
966 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
967 
968 /* Return the number of the MBIM control interface altsetting iff it
969  * is preferred and available,
970  */
971 u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
972 {
973 	struct usb_host_interface *alt;
974 
975 	/* The MBIM spec defines a NCM compatible default altsetting,
976 	 * which we may have matched:
977 	 *
978 	 *  "Functions that implement both NCM 1.0 and MBIM (an
979 	 *   “NCM/MBIM function”) according to this recommendation
980 	 *   shall provide two alternate settings for the
981 	 *   Communication Interface.  Alternate setting 0, and the
982 	 *   associated class and endpoint descriptors, shall be
983 	 *   constructed according to the rules given for the
984 	 *   Communication Interface in section 5 of [USBNCM10].
985 	 *   Alternate setting 1, and the associated class and
986 	 *   endpoint descriptors, shall be constructed according to
987 	 *   the rules given in section 6 (USB Device Model) of this
988 	 *   specification."
989 	 */
990 	if (intf->num_altsetting < 2)
991 		return intf->cur_altsetting->desc.bAlternateSetting;
992 
993 	if (prefer_mbim) {
994 		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
995 		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
996 			return CDC_NCM_COMM_ALTSETTING_MBIM;
997 	}
998 	return CDC_NCM_COMM_ALTSETTING_NCM;
999 }
1000 EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1001 
1002 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1003 {
1004 	/* MBIM backwards compatible function? */
1005 	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1006 		return -ENODEV;
1007 
1008 	/* The NCM data altsetting is fixed, so we hard-coded it.
1009 	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1010 	 * placed NDP.
1011 	 */
1012 	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1013 }
1014 
1015 static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1016 {
1017 	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1018 
1019 	if (skb->len + align > max)
1020 		align = max - skb->len;
1021 	if (align && skb_tailroom(skb) >= align)
1022 		skb_put_zero(skb, align);
1023 }
1024 
1025 /* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1026  * allocating a new one within skb
1027  */
1028 static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1029 {
1030 	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1031 	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1032 	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1033 
1034 	/* If NDP should be moved to the end of the NCM package, we can't follow the
1035 	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1036 	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1037 	*/
1038 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1039 		if (ctx->delayed_ndp16->dwSignature == sign)
1040 			return ctx->delayed_ndp16;
1041 
1042 		/* We can only push a single NDP to the end. Return
1043 		 * NULL to send what we've already got and queue this
1044 		 * skb for later.
1045 		 */
1046 		else if (ctx->delayed_ndp16->dwSignature)
1047 			return NULL;
1048 	}
1049 
1050 	/* follow the chain of NDPs, looking for a match */
1051 	while (ndpoffset) {
1052 		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1053 		if  (ndp16->dwSignature == sign)
1054 			return ndp16;
1055 		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1056 	}
1057 
1058 	/* align new NDP */
1059 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1060 		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1061 
1062 	/* verify that there is room for the NDP and the datagram (reserve) */
1063 	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1064 		return NULL;
1065 
1066 	/* link to it */
1067 	if (ndp16)
1068 		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1069 	else
1070 		nth16->wNdpIndex = cpu_to_le16(skb->len);
1071 
1072 	/* push a new empty NDP */
1073 	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1074 		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1075 	else
1076 		ndp16 = ctx->delayed_ndp16;
1077 
1078 	ndp16->dwSignature = sign;
1079 	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1080 	return ndp16;
1081 }
1082 
1083 struct sk_buff *
1084 cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1085 {
1086 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1087 	struct usb_cdc_ncm_nth16 *nth16;
1088 	struct usb_cdc_ncm_ndp16 *ndp16;
1089 	struct sk_buff *skb_out;
1090 	u16 n = 0, index, ndplen;
1091 	u8 ready2send = 0;
1092 	u32 delayed_ndp_size;
1093 	size_t padding_count;
1094 
1095 	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1096 	 * accordingly. Otherwise, we should check here.
1097 	 */
1098 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1099 		delayed_ndp_size = ctx->max_ndp_size;
1100 	else
1101 		delayed_ndp_size = 0;
1102 
1103 	/* if there is a remaining skb, it gets priority */
1104 	if (skb != NULL) {
1105 		swap(skb, ctx->tx_rem_skb);
1106 		swap(sign, ctx->tx_rem_sign);
1107 	} else {
1108 		ready2send = 1;
1109 	}
1110 
1111 	/* check if we are resuming an OUT skb */
1112 	skb_out = ctx->tx_curr_skb;
1113 
1114 	/* allocate a new OUT skb */
1115 	if (!skb_out) {
1116 		if (ctx->tx_low_mem_val == 0) {
1117 			ctx->tx_curr_size = ctx->tx_max;
1118 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1119 			/* If the memory allocation fails we will wait longer
1120 			 * each time before attempting another full size
1121 			 * allocation again to not overload the system
1122 			 * further.
1123 			 */
1124 			if (skb_out == NULL) {
1125 				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1126 							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1127 				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1128 			}
1129 		}
1130 		if (skb_out == NULL) {
1131 			/* See if a very small allocation is possible.
1132 			 * We will send this packet immediately and hope
1133 			 * that there is more memory available later.
1134 			 */
1135 			if (skb)
1136 				ctx->tx_curr_size = max(skb->len,
1137 					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1138 			else
1139 				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1140 			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1141 
1142 			/* No allocation possible so we will abort */
1143 			if (skb_out == NULL) {
1144 				if (skb != NULL) {
1145 					dev_kfree_skb_any(skb);
1146 					dev->net->stats.tx_dropped++;
1147 				}
1148 				goto exit_no_skb;
1149 			}
1150 			ctx->tx_low_mem_val--;
1151 		}
1152 		/* fill out the initial 16-bit NTB header */
1153 		nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1154 		nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1155 		nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1156 		nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1157 
1158 		/* count total number of frames in this NTB */
1159 		ctx->tx_curr_frame_num = 0;
1160 
1161 		/* recent payload counter for this skb_out */
1162 		ctx->tx_curr_frame_payload = 0;
1163 	}
1164 
1165 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1166 		/* send any remaining skb first */
1167 		if (skb == NULL) {
1168 			skb = ctx->tx_rem_skb;
1169 			sign = ctx->tx_rem_sign;
1170 			ctx->tx_rem_skb = NULL;
1171 
1172 			/* check for end of skb */
1173 			if (skb == NULL)
1174 				break;
1175 		}
1176 
1177 		/* get the appropriate NDP for this skb */
1178 		ndp16 = cdc_ncm_ndp(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1179 
1180 		/* align beginning of next frame */
1181 		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1182 
1183 		/* check if we had enough room left for both NDP and frame */
1184 		if (!ndp16 || skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1185 			if (n == 0) {
1186 				/* won't fit, MTU problem? */
1187 				dev_kfree_skb_any(skb);
1188 				skb = NULL;
1189 				dev->net->stats.tx_dropped++;
1190 			} else {
1191 				/* no room for skb - store for later */
1192 				if (ctx->tx_rem_skb != NULL) {
1193 					dev_kfree_skb_any(ctx->tx_rem_skb);
1194 					dev->net->stats.tx_dropped++;
1195 				}
1196 				ctx->tx_rem_skb = skb;
1197 				ctx->tx_rem_sign = sign;
1198 				skb = NULL;
1199 				ready2send = 1;
1200 				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1201 			}
1202 			break;
1203 		}
1204 
1205 		/* calculate frame number withing this NDP */
1206 		ndplen = le16_to_cpu(ndp16->wLength);
1207 		index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1208 
1209 		/* OK, add this skb */
1210 		ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1211 		ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1212 		ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1213 		skb_put_data(skb_out, skb->data, skb->len);
1214 		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1215 		dev_kfree_skb_any(skb);
1216 		skb = NULL;
1217 
1218 		/* send now if this NDP is full */
1219 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1220 			ready2send = 1;
1221 			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1222 			break;
1223 		}
1224 	}
1225 
1226 	/* free up any dangling skb */
1227 	if (skb != NULL) {
1228 		dev_kfree_skb_any(skb);
1229 		skb = NULL;
1230 		dev->net->stats.tx_dropped++;
1231 	}
1232 
1233 	ctx->tx_curr_frame_num = n;
1234 
1235 	if (n == 0) {
1236 		/* wait for more frames */
1237 		/* push variables */
1238 		ctx->tx_curr_skb = skb_out;
1239 		goto exit_no_skb;
1240 
1241 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1242 		/* wait for more frames */
1243 		/* push variables */
1244 		ctx->tx_curr_skb = skb_out;
1245 		/* set the pending count */
1246 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1247 			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1248 		goto exit_no_skb;
1249 
1250 	} else {
1251 		if (n == ctx->tx_max_datagrams)
1252 			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1253 		/* frame goes out */
1254 		/* variables will be reset at next call */
1255 	}
1256 
1257 	/* If requested, put NDP at end of frame. */
1258 	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1259 		nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1260 		cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1261 		nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1262 		skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1263 
1264 		/* Zero out delayed NDP - signature checking will naturally fail. */
1265 		ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1266 	}
1267 
1268 	/* If collected data size is less or equal ctx->min_tx_pkt
1269 	 * bytes, we send buffers as it is. If we get more data, it
1270 	 * would be more efficient for USB HS mobile device with DMA
1271 	 * engine to receive a full size NTB, than canceling DMA
1272 	 * transfer and receiving a short packet.
1273 	 *
1274 	 * This optimization support is pointless if we end up sending
1275 	 * a ZLP after full sized NTBs.
1276 	 */
1277 	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1278 	    skb_out->len > ctx->min_tx_pkt) {
1279 		padding_count = ctx->tx_curr_size - skb_out->len;
1280 		skb_put_zero(skb_out, padding_count);
1281 	} else if (skb_out->len < ctx->tx_curr_size &&
1282 		   (skb_out->len % dev->maxpacket) == 0) {
1283 		skb_put_u8(skb_out, 0);	/* force short packet */
1284 	}
1285 
1286 	/* set final frame length */
1287 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1288 	nth16->wBlockLength = cpu_to_le16(skb_out->len);
1289 
1290 	/* return skb */
1291 	ctx->tx_curr_skb = NULL;
1292 
1293 	/* keep private stats: framing overhead and number of NTBs */
1294 	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1295 	ctx->tx_ntbs++;
1296 
1297 	/* usbnet will count all the framing overhead by default.
1298 	 * Adjust the stats so that the tx_bytes counter show real
1299 	 * payload data instead.
1300 	 */
1301 	usbnet_set_skb_tx_stats(skb_out, n,
1302 				(long)ctx->tx_curr_frame_payload - skb_out->len);
1303 
1304 	return skb_out;
1305 
1306 exit_no_skb:
1307 	/* Start timer, if there is a remaining non-empty skb */
1308 	if (ctx->tx_curr_skb != NULL && n > 0)
1309 		cdc_ncm_tx_timeout_start(ctx);
1310 	return NULL;
1311 }
1312 EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1313 
1314 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1315 {
1316 	/* start timer, if not already started */
1317 	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1318 		hrtimer_start(&ctx->tx_timer,
1319 				ctx->timer_interval,
1320 				HRTIMER_MODE_REL);
1321 }
1322 
1323 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1324 {
1325 	struct cdc_ncm_ctx *ctx =
1326 			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1327 
1328 	if (!atomic_read(&ctx->stop))
1329 		tasklet_schedule(&ctx->bh);
1330 	return HRTIMER_NORESTART;
1331 }
1332 
1333 static void cdc_ncm_txpath_bh(unsigned long param)
1334 {
1335 	struct usbnet *dev = (struct usbnet *)param;
1336 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1337 
1338 	spin_lock_bh(&ctx->mtx);
1339 	if (ctx->tx_timer_pending != 0) {
1340 		ctx->tx_timer_pending--;
1341 		cdc_ncm_tx_timeout_start(ctx);
1342 		spin_unlock_bh(&ctx->mtx);
1343 	} else if (dev->net != NULL) {
1344 		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1345 		spin_unlock_bh(&ctx->mtx);
1346 		netif_tx_lock_bh(dev->net);
1347 		usbnet_start_xmit(NULL, dev->net);
1348 		netif_tx_unlock_bh(dev->net);
1349 	} else {
1350 		spin_unlock_bh(&ctx->mtx);
1351 	}
1352 }
1353 
1354 struct sk_buff *
1355 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1356 {
1357 	struct sk_buff *skb_out;
1358 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1359 
1360 	/*
1361 	 * The Ethernet API we are using does not support transmitting
1362 	 * multiple Ethernet frames in a single call. This driver will
1363 	 * accumulate multiple Ethernet frames and send out a larger
1364 	 * USB frame when the USB buffer is full or when a single jiffies
1365 	 * timeout happens.
1366 	 */
1367 	if (ctx == NULL)
1368 		goto error;
1369 
1370 	spin_lock_bh(&ctx->mtx);
1371 	skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1372 	spin_unlock_bh(&ctx->mtx);
1373 	return skb_out;
1374 
1375 error:
1376 	if (skb != NULL)
1377 		dev_kfree_skb_any(skb);
1378 
1379 	return NULL;
1380 }
1381 EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1382 
1383 /* verify NTB header and return offset of first NDP, or negative error */
1384 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1385 {
1386 	struct usbnet *dev = netdev_priv(skb_in->dev);
1387 	struct usb_cdc_ncm_nth16 *nth16;
1388 	int len;
1389 	int ret = -EINVAL;
1390 
1391 	if (ctx == NULL)
1392 		goto error;
1393 
1394 	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1395 					sizeof(struct usb_cdc_ncm_ndp16))) {
1396 		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1397 		goto error;
1398 	}
1399 
1400 	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1401 
1402 	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1403 		netif_dbg(dev, rx_err, dev->net,
1404 			  "invalid NTH16 signature <%#010x>\n",
1405 			  le32_to_cpu(nth16->dwSignature));
1406 		goto error;
1407 	}
1408 
1409 	len = le16_to_cpu(nth16->wBlockLength);
1410 	if (len > ctx->rx_max) {
1411 		netif_dbg(dev, rx_err, dev->net,
1412 			  "unsupported NTB block length %u/%u\n", len,
1413 			  ctx->rx_max);
1414 		goto error;
1415 	}
1416 
1417 	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1418 	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1419 	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1420 		netif_dbg(dev, rx_err, dev->net,
1421 			  "sequence number glitch prev=%d curr=%d\n",
1422 			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1423 	}
1424 	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1425 
1426 	ret = le16_to_cpu(nth16->wNdpIndex);
1427 error:
1428 	return ret;
1429 }
1430 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1431 
1432 /* verify NDP header and return number of datagrams, or negative error */
1433 int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1434 {
1435 	struct usbnet *dev = netdev_priv(skb_in->dev);
1436 	struct usb_cdc_ncm_ndp16 *ndp16;
1437 	int ret = -EINVAL;
1438 
1439 	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1440 		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1441 			  ndpoffset);
1442 		goto error;
1443 	}
1444 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1445 
1446 	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1447 		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1448 			  le16_to_cpu(ndp16->wLength));
1449 		goto error;
1450 	}
1451 
1452 	ret = ((le16_to_cpu(ndp16->wLength) -
1453 					sizeof(struct usb_cdc_ncm_ndp16)) /
1454 					sizeof(struct usb_cdc_ncm_dpe16));
1455 	ret--; /* we process NDP entries except for the last one */
1456 
1457 	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1458 	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1459 		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1460 		ret = -EINVAL;
1461 	}
1462 
1463 error:
1464 	return ret;
1465 }
1466 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1467 
1468 int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1469 {
1470 	struct sk_buff *skb;
1471 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1472 	int len;
1473 	int nframes;
1474 	int x;
1475 	int offset;
1476 	struct usb_cdc_ncm_ndp16 *ndp16;
1477 	struct usb_cdc_ncm_dpe16 *dpe16;
1478 	int ndpoffset;
1479 	int loopcount = 50; /* arbitrary max preventing infinite loop */
1480 	u32 payload = 0;
1481 
1482 	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1483 	if (ndpoffset < 0)
1484 		goto error;
1485 
1486 next_ndp:
1487 	nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1488 	if (nframes < 0)
1489 		goto error;
1490 
1491 	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1492 
1493 	if (ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1494 		netif_dbg(dev, rx_err, dev->net,
1495 			  "invalid DPT16 signature <%#010x>\n",
1496 			  le32_to_cpu(ndp16->dwSignature));
1497 		goto err_ndp;
1498 	}
1499 	dpe16 = ndp16->dpe16;
1500 
1501 	for (x = 0; x < nframes; x++, dpe16++) {
1502 		offset = le16_to_cpu(dpe16->wDatagramIndex);
1503 		len = le16_to_cpu(dpe16->wDatagramLength);
1504 
1505 		/*
1506 		 * CDC NCM ch. 3.7
1507 		 * All entries after first NULL entry are to be ignored
1508 		 */
1509 		if ((offset == 0) || (len == 0)) {
1510 			if (!x)
1511 				goto err_ndp; /* empty NTB */
1512 			break;
1513 		}
1514 
1515 		/* sanity checking */
1516 		if (((offset + len) > skb_in->len) ||
1517 				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1518 			netif_dbg(dev, rx_err, dev->net,
1519 				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1520 				  x, offset, len, skb_in);
1521 			if (!x)
1522 				goto err_ndp;
1523 			break;
1524 
1525 		} else {
1526 			/* create a fresh copy to reduce truesize */
1527 			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1528 			if (!skb)
1529 				goto error;
1530 			skb_put_data(skb, skb_in->data + offset, len);
1531 			usbnet_skb_return(dev, skb);
1532 			payload += len;	/* count payload bytes in this NTB */
1533 		}
1534 	}
1535 err_ndp:
1536 	/* are there more NDPs to process? */
1537 	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1538 	if (ndpoffset && loopcount--)
1539 		goto next_ndp;
1540 
1541 	/* update stats */
1542 	ctx->rx_overhead += skb_in->len - payload;
1543 	ctx->rx_ntbs++;
1544 
1545 	return 1;
1546 error:
1547 	return 0;
1548 }
1549 EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1550 
1551 static void
1552 cdc_ncm_speed_change(struct usbnet *dev,
1553 		     struct usb_cdc_speed_change *data)
1554 {
1555 	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1556 	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1557 
1558 	/*
1559 	 * Currently the USB-NET API does not support reporting the actual
1560 	 * device speed. Do print it instead.
1561 	 */
1562 	if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1563 		netif_info(dev, link, dev->net,
1564 			   "%u mbit/s downlink %u mbit/s uplink\n",
1565 			   (unsigned int)(rx_speed / 1000000U),
1566 			   (unsigned int)(tx_speed / 1000000U));
1567 	} else {
1568 		netif_info(dev, link, dev->net,
1569 			   "%u kbit/s downlink %u kbit/s uplink\n",
1570 			   (unsigned int)(rx_speed / 1000U),
1571 			   (unsigned int)(tx_speed / 1000U));
1572 	}
1573 }
1574 
1575 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1576 {
1577 	struct cdc_ncm_ctx *ctx;
1578 	struct usb_cdc_notification *event;
1579 
1580 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1581 
1582 	if (urb->actual_length < sizeof(*event))
1583 		return;
1584 
1585 	/* test for split data in 8-byte chunks */
1586 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1587 		cdc_ncm_speed_change(dev,
1588 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1589 		return;
1590 	}
1591 
1592 	event = urb->transfer_buffer;
1593 
1594 	switch (event->bNotificationType) {
1595 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1596 		/*
1597 		 * According to the CDC NCM specification ch.7.1
1598 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1599 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1600 		 */
1601 		netif_info(dev, link, dev->net,
1602 			   "network connection: %sconnected\n",
1603 			   !!event->wValue ? "" : "dis");
1604 		usbnet_link_change(dev, !!event->wValue, 0);
1605 		break;
1606 
1607 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1608 		if (urb->actual_length < (sizeof(*event) +
1609 					sizeof(struct usb_cdc_speed_change)))
1610 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1611 		else
1612 			cdc_ncm_speed_change(dev,
1613 					     (struct usb_cdc_speed_change *)&event[1]);
1614 		break;
1615 
1616 	default:
1617 		dev_dbg(&dev->udev->dev,
1618 			"NCM: unexpected notification 0x%02x!\n",
1619 			event->bNotificationType);
1620 		break;
1621 	}
1622 }
1623 
1624 static const struct driver_info cdc_ncm_info = {
1625 	.description = "CDC NCM",
1626 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1627 			| FLAG_LINK_INTR,
1628 	.bind = cdc_ncm_bind,
1629 	.unbind = cdc_ncm_unbind,
1630 	.manage_power = usbnet_manage_power,
1631 	.status = cdc_ncm_status,
1632 	.rx_fixup = cdc_ncm_rx_fixup,
1633 	.tx_fixup = cdc_ncm_tx_fixup,
1634 };
1635 
1636 /* Same as cdc_ncm_info, but with FLAG_WWAN */
1637 static const struct driver_info wwan_info = {
1638 	.description = "Mobile Broadband Network Device",
1639 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1640 			| FLAG_LINK_INTR | FLAG_WWAN,
1641 	.bind = cdc_ncm_bind,
1642 	.unbind = cdc_ncm_unbind,
1643 	.manage_power = usbnet_manage_power,
1644 	.status = cdc_ncm_status,
1645 	.rx_fixup = cdc_ncm_rx_fixup,
1646 	.tx_fixup = cdc_ncm_tx_fixup,
1647 };
1648 
1649 /* Same as wwan_info, but with FLAG_NOARP  */
1650 static const struct driver_info wwan_noarp_info = {
1651 	.description = "Mobile Broadband Network Device (NO ARP)",
1652 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1653 			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1654 	.bind = cdc_ncm_bind,
1655 	.unbind = cdc_ncm_unbind,
1656 	.manage_power = usbnet_manage_power,
1657 	.status = cdc_ncm_status,
1658 	.rx_fixup = cdc_ncm_rx_fixup,
1659 	.tx_fixup = cdc_ncm_tx_fixup,
1660 };
1661 
1662 static const struct usb_device_id cdc_devs[] = {
1663 	/* Ericsson MBM devices like F5521gw */
1664 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1665 		| USB_DEVICE_ID_MATCH_VENDOR,
1666 	  .idVendor = 0x0bdb,
1667 	  .bInterfaceClass = USB_CLASS_COMM,
1668 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1669 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1670 	  .driver_info = (unsigned long) &wwan_info,
1671 	},
1672 
1673 	/* Telit LE910 V2 */
1674 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1675 		USB_CLASS_COMM,
1676 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1677 	  .driver_info = (unsigned long)&wwan_noarp_info,
1678 	},
1679 
1680 	/* DW5812 LTE Verizon Mobile Broadband Card
1681 	 * Unlike DW5550 this device requires FLAG_NOARP
1682 	 */
1683 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1684 		USB_CLASS_COMM,
1685 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1686 	  .driver_info = (unsigned long)&wwan_noarp_info,
1687 	},
1688 
1689 	/* DW5813 LTE AT&T Mobile Broadband Card
1690 	 * Unlike DW5550 this device requires FLAG_NOARP
1691 	 */
1692 	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1693 		USB_CLASS_COMM,
1694 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1695 	  .driver_info = (unsigned long)&wwan_noarp_info,
1696 	},
1697 
1698 	/* Dell branded MBM devices like DW5550 */
1699 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1700 		| USB_DEVICE_ID_MATCH_VENDOR,
1701 	  .idVendor = 0x413c,
1702 	  .bInterfaceClass = USB_CLASS_COMM,
1703 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1704 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1705 	  .driver_info = (unsigned long) &wwan_info,
1706 	},
1707 
1708 	/* Toshiba branded MBM devices */
1709 	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1710 		| USB_DEVICE_ID_MATCH_VENDOR,
1711 	  .idVendor = 0x0930,
1712 	  .bInterfaceClass = USB_CLASS_COMM,
1713 	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1714 	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1715 	  .driver_info = (unsigned long) &wwan_info,
1716 	},
1717 
1718 	/* tag Huawei devices as wwan */
1719 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
1720 					USB_CLASS_COMM,
1721 					USB_CDC_SUBCLASS_NCM,
1722 					USB_CDC_PROTO_NONE),
1723 	  .driver_info = (unsigned long)&wwan_info,
1724 	},
1725 
1726 	/* Infineon(now Intel) HSPA Modem platform */
1727 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
1728 		USB_CLASS_COMM,
1729 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1730 	  .driver_info = (unsigned long)&wwan_noarp_info,
1731 	},
1732 
1733 	/* Generic CDC-NCM devices */
1734 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
1735 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1736 		.driver_info = (unsigned long)&cdc_ncm_info,
1737 	},
1738 	{
1739 	},
1740 };
1741 MODULE_DEVICE_TABLE(usb, cdc_devs);
1742 
1743 static struct usb_driver cdc_ncm_driver = {
1744 	.name = "cdc_ncm",
1745 	.id_table = cdc_devs,
1746 	.probe = usbnet_probe,
1747 	.disconnect = usbnet_disconnect,
1748 	.suspend = usbnet_suspend,
1749 	.resume = usbnet_resume,
1750 	.reset_resume =	usbnet_resume,
1751 	.supports_autosuspend = 1,
1752 	.disable_hub_initiated_lpm = 1,
1753 };
1754 
1755 module_usb_driver(cdc_ncm_driver);
1756 
1757 MODULE_AUTHOR("Hans Petter Selasky");
1758 MODULE_DESCRIPTION("USB CDC NCM host driver");
1759 MODULE_LICENSE("Dual BSD/GPL");
1760