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)
  57static bool prefer_mbim = true;
  58#else
  59static bool prefer_mbim;
  60#endif
  61module_param(prefer_mbim, bool, 0644);
  62MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
  63
  64static void cdc_ncm_txpath_bh(unsigned long param);
  65static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
  66static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
  67static struct usb_driver cdc_ncm_driver;
  68
  69struct 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
  81static 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
  94static 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
 104static 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
 119static 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
 133static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
 134
 135static 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
 149static 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
 172static 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
 191static 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
 199static 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
 207static 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
 215static 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
 223static 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
 237static 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
 250static 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
 263static 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
 284static DEVICE_ATTR(min_tx_pkt, 0644, cdc_ncm_show_min_tx_pkt, cdc_ncm_store_min_tx_pkt);
 285static DEVICE_ATTR(rx_max, 0644, cdc_ncm_show_rx_max, cdc_ncm_store_rx_max);
 286static DEVICE_ATTR(tx_max, 0644, cdc_ncm_show_tx_max, cdc_ncm_store_tx_max);
 287static DEVICE_ATTR(tx_timer_usecs, 0644, cdc_ncm_show_tx_timer_usecs, cdc_ncm_store_tx_timer_usecs);
 288
 289static 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
 297static 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}
 329static DEVICE_ATTR_RW(ndp_to_end);
 330
 331#define NCM_PARM_ATTR(name, format, tocpu)				\
 332static 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} \
 338static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
 339
 340NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
 341NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
 342NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
 343NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
 344NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
 345NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
 346NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
 347NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
 348NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
 349NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
 350
 351static 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
 370static const 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 */
 376static 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 */
 448static 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
 459static 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
 466static 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
 473static 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 */
 487static 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 */
 561static 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
 597out:
 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
 609static 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
 653static 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
 677static void
 678cdc_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
 718static 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 */
 742int 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}
 751EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
 752
 753static 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
 764int 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	int err;
 772	u8 iface_no;
 773	struct usb_cdc_parsed_header hdr;
 774	__le16 curr_ntb_format;
 775
 776	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 777	if (!ctx)
 778		return -ENOMEM;
 779
 780	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 781	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
 782	ctx->bh.data = (unsigned long)dev;
 783	ctx->bh.func = cdc_ncm_txpath_bh;
 784	atomic_set(&ctx->stop, 0);
 785	spin_lock_init(&ctx->mtx);
 786
 787	/* store ctx pointer in device data field */
 788	dev->data[0] = (unsigned long)ctx;
 789
 790	/* only the control interface can be successfully probed */
 791	ctx->control = intf;
 792
 793	/* get some pointers */
 794	driver = driver_of(intf);
 795	buf = intf->cur_altsetting->extra;
 796	len = intf->cur_altsetting->extralen;
 797
 798	/* parse through descriptors associated with control interface */
 799	cdc_parse_cdc_header(&hdr, intf, buf, len);
 800
 801	if (hdr.usb_cdc_union_desc)
 802		ctx->data = usb_ifnum_to_if(dev->udev,
 803					    hdr.usb_cdc_union_desc->bSlaveInterface0);
 804	ctx->ether_desc = hdr.usb_cdc_ether_desc;
 805	ctx->func_desc = hdr.usb_cdc_ncm_desc;
 806	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
 807	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
 808
 809	/* some buggy devices have an IAD but no CDC Union */
 810	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
 811		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
 812		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
 813	}
 814
 815	/* check if we got everything */
 816	if (!ctx->data) {
 817		dev_dbg(&intf->dev, "CDC Union missing and no IAD found\n");
 818		goto error;
 819	}
 820	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
 821		if (!ctx->mbim_desc) {
 822			dev_dbg(&intf->dev, "MBIM functional descriptor missing\n");
 823			goto error;
 824		}
 825	} else {
 826		if (!ctx->ether_desc || !ctx->func_desc) {
 827			dev_dbg(&intf->dev, "NCM or ECM functional descriptors missing\n");
 828			goto error;
 829		}
 830	}
 831
 832	/* claim data interface, if different from control */
 833	if (ctx->data != ctx->control) {
 834		temp = usb_driver_claim_interface(driver, ctx->data, dev);
 835		if (temp) {
 836			dev_dbg(&intf->dev, "failed to claim data intf\n");
 837			goto error;
 838		}
 839	}
 840
 841	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
 842
 843	/* Device-specific flags */
 844	ctx->drvflags = drvflags;
 845
 846	/* Reset data interface. Some devices will not reset properly
 847	 * unless they are configured first.  Toggle the altsetting to
 848	 * force a reset.
 849	 * Some other devices do not work properly with this procedure
 850	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
 851	 */
 852	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
 853		usb_set_interface(dev->udev, iface_no, data_altsetting);
 854
 855	temp = usb_set_interface(dev->udev, iface_no, 0);
 856	if (temp) {
 857		dev_dbg(&intf->dev, "set interface failed\n");
 858		goto error2;
 859	}
 860
 861	/* initialize basic device settings */
 862	if (cdc_ncm_init(dev))
 863		goto error2;
 864
 865	/* Some firmwares need a pause here or they will silently fail
 866	 * to set up the interface properly.  This value was decided
 867	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
 868	 * firmware.
 869	 */
 870	usleep_range(10000, 20000);
 871
 872	/* configure data interface */
 873	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
 874	if (temp) {
 875		dev_dbg(&intf->dev, "set interface failed\n");
 876		goto error2;
 877	}
 878
 879	/*
 880	 * Some Huawei devices have been observed to come out of reset in NDP32 mode.
 881	 * Let's check if this is the case, and set the device to NDP16 mode again if
 882	 * needed.
 883	*/
 884	if (ctx->drvflags & CDC_NCM_FLAG_RESET_NTB16) {
 885		err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_FORMAT,
 886				      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
 887				      0, iface_no, &curr_ntb_format, 2);
 888		if (err < 0) {
 889			goto error2;
 890		}
 891
 892		if (curr_ntb_format == cpu_to_le16(USB_CDC_NCM_NTB32_FORMAT)) {
 893			dev_info(&intf->dev, "resetting NTB format to 16-bit");
 894			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
 895					       USB_TYPE_CLASS | USB_DIR_OUT
 896					       | USB_RECIP_INTERFACE,
 897					       USB_CDC_NCM_NTB16_FORMAT,
 898					       iface_no, NULL, 0);
 899
 900			if (err < 0)
 901				goto error2;
 902		}
 903	}
 904
 905	cdc_ncm_find_endpoints(dev, ctx->data);
 906	cdc_ncm_find_endpoints(dev, ctx->control);
 907	if (!dev->in || !dev->out || !dev->status) {
 908		dev_dbg(&intf->dev, "failed to collect endpoints\n");
 909		goto error2;
 910	}
 911
 912	usb_set_intfdata(ctx->data, dev);
 913	usb_set_intfdata(ctx->control, dev);
 914
 915	if (ctx->ether_desc) {
 916		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
 917		if (temp) {
 918			dev_dbg(&intf->dev, "failed to get mac address\n");
 919			goto error2;
 920		}
 921		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
 922	}
 923
 924	/* finish setting up the device specific data */
 925	cdc_ncm_setup(dev);
 926
 
 
 
 927	/* Allocate the delayed NDP if needed. */
 928	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
 929		ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
 930		if (!ctx->delayed_ndp16)
 931			goto error2;
 932		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
 933	}
 934
 935	/* override ethtool_ops */
 936	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
 937
 938	/* add our sysfs attrs */
 939	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
 940
 941	/* must handle MTU changes */
 942	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
 943	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
 944
 945	return 0;
 946
 947error2:
 948	usb_set_intfdata(ctx->control, NULL);
 949	usb_set_intfdata(ctx->data, NULL);
 950	if (ctx->data != ctx->control)
 951		usb_driver_release_interface(driver, ctx->data);
 952error:
 953	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
 954	dev->data[0] = 0;
 955	dev_info(&intf->dev, "bind() failure\n");
 956	return -ENODEV;
 957}
 958EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
 959
 960void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
 961{
 962	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 963	struct usb_driver *driver = driver_of(intf);
 964
 965	if (ctx == NULL)
 966		return;		/* no setup */
 967
 968	atomic_set(&ctx->stop, 1);
 969
 970	if (hrtimer_active(&ctx->tx_timer))
 971		hrtimer_cancel(&ctx->tx_timer);
 972
 973	tasklet_kill(&ctx->bh);
 974
 975	/* handle devices with combined control and data interface */
 976	if (ctx->control == ctx->data)
 977		ctx->data = NULL;
 978
 979	/* disconnect master --> disconnect slave */
 980	if (intf == ctx->control && ctx->data) {
 981		usb_set_intfdata(ctx->data, NULL);
 982		usb_driver_release_interface(driver, ctx->data);
 983		ctx->data = NULL;
 984
 985	} else if (intf == ctx->data && ctx->control) {
 986		usb_set_intfdata(ctx->control, NULL);
 987		usb_driver_release_interface(driver, ctx->control);
 988		ctx->control = NULL;
 989	}
 990
 991	usb_set_intfdata(intf, NULL);
 992	cdc_ncm_free(ctx);
 993}
 994EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
 995
 996/* Return the number of the MBIM control interface altsetting iff it
 997 * is preferred and available,
 998 */
 999u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1000{
1001	struct usb_host_interface *alt;
1002
1003	/* The MBIM spec defines a NCM compatible default altsetting,
1004	 * which we may have matched:
1005	 *
1006	 *  "Functions that implement both NCM 1.0 and MBIM (an
1007	 *   “NCM/MBIM function”) according to this recommendation
1008	 *   shall provide two alternate settings for the
1009	 *   Communication Interface.  Alternate setting 0, and the
1010	 *   associated class and endpoint descriptors, shall be
1011	 *   constructed according to the rules given for the
1012	 *   Communication Interface in section 5 of [USBNCM10].
1013	 *   Alternate setting 1, and the associated class and
1014	 *   endpoint descriptors, shall be constructed according to
1015	 *   the rules given in section 6 (USB Device Model) of this
1016	 *   specification."
1017	 */
1018	if (intf->num_altsetting < 2)
1019		return intf->cur_altsetting->desc.bAlternateSetting;
1020
1021	if (prefer_mbim) {
1022		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1023		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1024			return CDC_NCM_COMM_ALTSETTING_MBIM;
1025	}
1026	return CDC_NCM_COMM_ALTSETTING_NCM;
1027}
1028EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1029
1030static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1031{
1032	/* MBIM backwards compatible function? */
1033	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1034		return -ENODEV;
1035
1036	/* The NCM data altsetting is fixed, so we hard-coded it.
1037	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1038	 * placed NDP.
1039	 */
1040	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1041}
1042
1043static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1044{
1045	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1046
1047	if (skb->len + align > max)
1048		align = max - skb->len;
1049	if (align && skb_tailroom(skb) >= align)
1050		skb_put_zero(skb, align);
1051}
1052
1053/* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1054 * allocating a new one within skb
1055 */
1056static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1057{
1058	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1059	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1060	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1061
1062	/* If NDP should be moved to the end of the NCM package, we can't follow the
1063	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1064	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1065	*/
1066	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1067		if (ctx->delayed_ndp16->dwSignature == sign)
1068			return ctx->delayed_ndp16;
1069
1070		/* We can only push a single NDP to the end. Return
1071		 * NULL to send what we've already got and queue this
1072		 * skb for later.
1073		 */
1074		else if (ctx->delayed_ndp16->dwSignature)
1075			return NULL;
1076	}
1077
1078	/* follow the chain of NDPs, looking for a match */
1079	while (ndpoffset) {
1080		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1081		if  (ndp16->dwSignature == sign)
1082			return ndp16;
1083		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1084	}
1085
1086	/* align new NDP */
1087	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1088		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1089
1090	/* verify that there is room for the NDP and the datagram (reserve) */
1091	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1092		return NULL;
1093
1094	/* link to it */
1095	if (ndp16)
1096		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1097	else
1098		nth16->wNdpIndex = cpu_to_le16(skb->len);
1099
1100	/* push a new empty NDP */
1101	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1102		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1103	else
1104		ndp16 = ctx->delayed_ndp16;
1105
1106	ndp16->dwSignature = sign;
1107	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1108	return ndp16;
1109}
1110
1111struct sk_buff *
1112cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1113{
1114	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1115	struct usb_cdc_ncm_nth16 *nth16;
1116	struct usb_cdc_ncm_ndp16 *ndp16;
1117	struct sk_buff *skb_out;
1118	u16 n = 0, index, ndplen;
1119	u8 ready2send = 0;
1120	u32 delayed_ndp_size;
1121	size_t padding_count;
1122
1123	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1124	 * accordingly. Otherwise, we should check here.
1125	 */
1126	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1127		delayed_ndp_size = ctx->max_ndp_size;
1128	else
1129		delayed_ndp_size = 0;
1130
1131	/* if there is a remaining skb, it gets priority */
1132	if (skb != NULL) {
1133		swap(skb, ctx->tx_rem_skb);
1134		swap(sign, ctx->tx_rem_sign);
1135	} else {
1136		ready2send = 1;
1137	}
1138
1139	/* check if we are resuming an OUT skb */
1140	skb_out = ctx->tx_curr_skb;
1141
1142	/* allocate a new OUT skb */
1143	if (!skb_out) {
1144		if (ctx->tx_low_mem_val == 0) {
1145			ctx->tx_curr_size = ctx->tx_max;
1146			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1147			/* If the memory allocation fails we will wait longer
1148			 * each time before attempting another full size
1149			 * allocation again to not overload the system
1150			 * further.
1151			 */
1152			if (skb_out == NULL) {
1153				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1154							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1155				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1156			}
1157		}
1158		if (skb_out == NULL) {
1159			/* See if a very small allocation is possible.
1160			 * We will send this packet immediately and hope
1161			 * that there is more memory available later.
1162			 */
1163			if (skb)
1164				ctx->tx_curr_size = max(skb->len,
1165					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1166			else
1167				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1168			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1169
1170			/* No allocation possible so we will abort */
1171			if (skb_out == NULL) {
1172				if (skb != NULL) {
1173					dev_kfree_skb_any(skb);
1174					dev->net->stats.tx_dropped++;
1175				}
1176				goto exit_no_skb;
1177			}
1178			ctx->tx_low_mem_val--;
1179		}
1180		/* fill out the initial 16-bit NTB header */
1181		nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1182		nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1183		nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1184		nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1185
1186		/* count total number of frames in this NTB */
1187		ctx->tx_curr_frame_num = 0;
1188
1189		/* recent payload counter for this skb_out */
1190		ctx->tx_curr_frame_payload = 0;
1191	}
1192
1193	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1194		/* send any remaining skb first */
1195		if (skb == NULL) {
1196			skb = ctx->tx_rem_skb;
1197			sign = ctx->tx_rem_sign;
1198			ctx->tx_rem_skb = NULL;
1199
1200			/* check for end of skb */
1201			if (skb == NULL)
1202				break;
1203		}
1204
1205		/* get the appropriate NDP for this skb */
1206		ndp16 = cdc_ncm_ndp(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1207
1208		/* align beginning of next frame */
1209		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1210
1211		/* check if we had enough room left for both NDP and frame */
1212		if (!ndp16 || skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1213			if (n == 0) {
1214				/* won't fit, MTU problem? */
1215				dev_kfree_skb_any(skb);
1216				skb = NULL;
1217				dev->net->stats.tx_dropped++;
1218			} else {
1219				/* no room for skb - store for later */
1220				if (ctx->tx_rem_skb != NULL) {
1221					dev_kfree_skb_any(ctx->tx_rem_skb);
1222					dev->net->stats.tx_dropped++;
1223				}
1224				ctx->tx_rem_skb = skb;
1225				ctx->tx_rem_sign = sign;
1226				skb = NULL;
1227				ready2send = 1;
1228				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1229			}
1230			break;
1231		}
1232
1233		/* calculate frame number withing this NDP */
1234		ndplen = le16_to_cpu(ndp16->wLength);
1235		index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1236
1237		/* OK, add this skb */
1238		ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1239		ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1240		ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1241		skb_put_data(skb_out, skb->data, skb->len);
1242		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1243		dev_kfree_skb_any(skb);
1244		skb = NULL;
1245
1246		/* send now if this NDP is full */
1247		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1248			ready2send = 1;
1249			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1250			break;
1251		}
1252	}
1253
1254	/* free up any dangling skb */
1255	if (skb != NULL) {
1256		dev_kfree_skb_any(skb);
1257		skb = NULL;
1258		dev->net->stats.tx_dropped++;
1259	}
1260
1261	ctx->tx_curr_frame_num = n;
1262
1263	if (n == 0) {
1264		/* wait for more frames */
1265		/* push variables */
1266		ctx->tx_curr_skb = skb_out;
1267		goto exit_no_skb;
1268
1269	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1270		/* wait for more frames */
1271		/* push variables */
1272		ctx->tx_curr_skb = skb_out;
1273		/* set the pending count */
1274		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1275			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1276		goto exit_no_skb;
1277
1278	} else {
1279		if (n == ctx->tx_max_datagrams)
1280			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1281		/* frame goes out */
1282		/* variables will be reset at next call */
1283	}
1284
1285	/* If requested, put NDP at end of frame. */
1286	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1287		nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1288		cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1289		nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1290		skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1291
1292		/* Zero out delayed NDP - signature checking will naturally fail. */
1293		ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1294	}
1295
1296	/* If collected data size is less or equal ctx->min_tx_pkt
1297	 * bytes, we send buffers as it is. If we get more data, it
1298	 * would be more efficient for USB HS mobile device with DMA
1299	 * engine to receive a full size NTB, than canceling DMA
1300	 * transfer and receiving a short packet.
1301	 *
1302	 * This optimization support is pointless if we end up sending
1303	 * a ZLP after full sized NTBs.
1304	 */
1305	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1306	    skb_out->len > ctx->min_tx_pkt) {
1307		padding_count = ctx->tx_curr_size - skb_out->len;
1308		skb_put_zero(skb_out, padding_count);
1309	} else if (skb_out->len < ctx->tx_curr_size &&
1310		   (skb_out->len % dev->maxpacket) == 0) {
1311		skb_put_u8(skb_out, 0);	/* force short packet */
1312	}
1313
1314	/* set final frame length */
1315	nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1316	nth16->wBlockLength = cpu_to_le16(skb_out->len);
1317
1318	/* return skb */
1319	ctx->tx_curr_skb = NULL;
1320
1321	/* keep private stats: framing overhead and number of NTBs */
1322	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1323	ctx->tx_ntbs++;
1324
1325	/* usbnet will count all the framing overhead by default.
1326	 * Adjust the stats so that the tx_bytes counter show real
1327	 * payload data instead.
1328	 */
1329	usbnet_set_skb_tx_stats(skb_out, n,
1330				(long)ctx->tx_curr_frame_payload - skb_out->len);
1331
1332	return skb_out;
1333
1334exit_no_skb:
1335	/* Start timer, if there is a remaining non-empty skb */
1336	if (ctx->tx_curr_skb != NULL && n > 0)
1337		cdc_ncm_tx_timeout_start(ctx);
1338	return NULL;
1339}
1340EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1341
1342static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1343{
1344	/* start timer, if not already started */
1345	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1346		hrtimer_start(&ctx->tx_timer,
1347				ctx->timer_interval,
1348				HRTIMER_MODE_REL);
1349}
1350
1351static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1352{
1353	struct cdc_ncm_ctx *ctx =
1354			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1355
1356	if (!atomic_read(&ctx->stop))
1357		tasklet_schedule(&ctx->bh);
1358	return HRTIMER_NORESTART;
1359}
1360
1361static void cdc_ncm_txpath_bh(unsigned long param)
1362{
1363	struct usbnet *dev = (struct usbnet *)param;
1364	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1365
1366	spin_lock_bh(&ctx->mtx);
1367	if (ctx->tx_timer_pending != 0) {
1368		ctx->tx_timer_pending--;
1369		cdc_ncm_tx_timeout_start(ctx);
1370		spin_unlock_bh(&ctx->mtx);
1371	} else if (dev->net != NULL) {
1372		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1373		spin_unlock_bh(&ctx->mtx);
1374		netif_tx_lock_bh(dev->net);
1375		usbnet_start_xmit(NULL, dev->net);
1376		netif_tx_unlock_bh(dev->net);
1377	} else {
1378		spin_unlock_bh(&ctx->mtx);
1379	}
1380}
1381
1382struct sk_buff *
1383cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1384{
1385	struct sk_buff *skb_out;
1386	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1387
1388	/*
1389	 * The Ethernet API we are using does not support transmitting
1390	 * multiple Ethernet frames in a single call. This driver will
1391	 * accumulate multiple Ethernet frames and send out a larger
1392	 * USB frame when the USB buffer is full or when a single jiffies
1393	 * timeout happens.
1394	 */
1395	if (ctx == NULL)
1396		goto error;
1397
1398	spin_lock_bh(&ctx->mtx);
1399	skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1400	spin_unlock_bh(&ctx->mtx);
1401	return skb_out;
1402
1403error:
1404	if (skb != NULL)
1405		dev_kfree_skb_any(skb);
1406
1407	return NULL;
1408}
1409EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1410
1411/* verify NTB header and return offset of first NDP, or negative error */
1412int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1413{
1414	struct usbnet *dev = netdev_priv(skb_in->dev);
1415	struct usb_cdc_ncm_nth16 *nth16;
1416	int len;
1417	int ret = -EINVAL;
1418
1419	if (ctx == NULL)
1420		goto error;
1421
1422	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1423					sizeof(struct usb_cdc_ncm_ndp16))) {
1424		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1425		goto error;
1426	}
1427
1428	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1429
1430	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1431		netif_dbg(dev, rx_err, dev->net,
1432			  "invalid NTH16 signature <%#010x>\n",
1433			  le32_to_cpu(nth16->dwSignature));
1434		goto error;
1435	}
1436
1437	len = le16_to_cpu(nth16->wBlockLength);
1438	if (len > ctx->rx_max) {
1439		netif_dbg(dev, rx_err, dev->net,
1440			  "unsupported NTB block length %u/%u\n", len,
1441			  ctx->rx_max);
1442		goto error;
1443	}
1444
1445	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1446	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1447	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1448		netif_dbg(dev, rx_err, dev->net,
1449			  "sequence number glitch prev=%d curr=%d\n",
1450			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1451	}
1452	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1453
1454	ret = le16_to_cpu(nth16->wNdpIndex);
1455error:
1456	return ret;
1457}
1458EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1459
1460/* verify NDP header and return number of datagrams, or negative error */
1461int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1462{
1463	struct usbnet *dev = netdev_priv(skb_in->dev);
1464	struct usb_cdc_ncm_ndp16 *ndp16;
1465	int ret = -EINVAL;
1466
1467	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1468		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1469			  ndpoffset);
1470		goto error;
1471	}
1472	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1473
1474	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1475		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1476			  le16_to_cpu(ndp16->wLength));
1477		goto error;
1478	}
1479
1480	ret = ((le16_to_cpu(ndp16->wLength) -
1481					sizeof(struct usb_cdc_ncm_ndp16)) /
1482					sizeof(struct usb_cdc_ncm_dpe16));
1483	ret--; /* we process NDP entries except for the last one */
1484
1485	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1486	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1487		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1488		ret = -EINVAL;
1489	}
1490
1491error:
1492	return ret;
1493}
1494EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1495
1496int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1497{
1498	struct sk_buff *skb;
1499	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1500	int len;
1501	int nframes;
1502	int x;
1503	int offset;
1504	struct usb_cdc_ncm_ndp16 *ndp16;
1505	struct usb_cdc_ncm_dpe16 *dpe16;
1506	int ndpoffset;
1507	int loopcount = 50; /* arbitrary max preventing infinite loop */
1508	u32 payload = 0;
1509
1510	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1511	if (ndpoffset < 0)
1512		goto error;
1513
1514next_ndp:
1515	nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1516	if (nframes < 0)
1517		goto error;
1518
1519	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1520
1521	if (ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1522		netif_dbg(dev, rx_err, dev->net,
1523			  "invalid DPT16 signature <%#010x>\n",
1524			  le32_to_cpu(ndp16->dwSignature));
1525		goto err_ndp;
1526	}
1527	dpe16 = ndp16->dpe16;
1528
1529	for (x = 0; x < nframes; x++, dpe16++) {
1530		offset = le16_to_cpu(dpe16->wDatagramIndex);
1531		len = le16_to_cpu(dpe16->wDatagramLength);
1532
1533		/*
1534		 * CDC NCM ch. 3.7
1535		 * All entries after first NULL entry are to be ignored
1536		 */
1537		if ((offset == 0) || (len == 0)) {
1538			if (!x)
1539				goto err_ndp; /* empty NTB */
1540			break;
1541		}
1542
1543		/* sanity checking */
1544		if (((offset + len) > skb_in->len) ||
1545				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1546			netif_dbg(dev, rx_err, dev->net,
1547				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1548				  x, offset, len, skb_in);
1549			if (!x)
1550				goto err_ndp;
1551			break;
1552
1553		} else {
1554			/* create a fresh copy to reduce truesize */
1555			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1556			if (!skb)
1557				goto error;
1558			skb_put_data(skb, skb_in->data + offset, len);
1559			usbnet_skb_return(dev, skb);
1560			payload += len;	/* count payload bytes in this NTB */
1561		}
1562	}
1563err_ndp:
1564	/* are there more NDPs to process? */
1565	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1566	if (ndpoffset && loopcount--)
1567		goto next_ndp;
1568
1569	/* update stats */
1570	ctx->rx_overhead += skb_in->len - payload;
1571	ctx->rx_ntbs++;
1572
1573	return 1;
1574error:
1575	return 0;
1576}
1577EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1578
1579static void
1580cdc_ncm_speed_change(struct usbnet *dev,
1581		     struct usb_cdc_speed_change *data)
1582{
1583	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1584	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1585
1586	/*
1587	 * Currently the USB-NET API does not support reporting the actual
1588	 * device speed. Do print it instead.
1589	 */
1590	if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1591		netif_info(dev, link, dev->net,
1592			   "%u mbit/s downlink %u mbit/s uplink\n",
1593			   (unsigned int)(rx_speed / 1000000U),
1594			   (unsigned int)(tx_speed / 1000000U));
1595	} else {
1596		netif_info(dev, link, dev->net,
1597			   "%u kbit/s downlink %u kbit/s uplink\n",
1598			   (unsigned int)(rx_speed / 1000U),
1599			   (unsigned int)(tx_speed / 1000U));
1600	}
1601}
1602
1603static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1604{
1605	struct cdc_ncm_ctx *ctx;
1606	struct usb_cdc_notification *event;
1607
1608	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1609
1610	if (urb->actual_length < sizeof(*event))
1611		return;
1612
1613	/* test for split data in 8-byte chunks */
1614	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1615		cdc_ncm_speed_change(dev,
1616		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1617		return;
1618	}
1619
1620	event = urb->transfer_buffer;
1621
1622	switch (event->bNotificationType) {
1623	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1624		/*
1625		 * According to the CDC NCM specification ch.7.1
1626		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1627		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1628		 */
1629		netif_info(dev, link, dev->net,
1630			   "network connection: %sconnected\n",
1631			   !!event->wValue ? "" : "dis");
1632		usbnet_link_change(dev, !!event->wValue, 0);
1633		break;
1634
1635	case USB_CDC_NOTIFY_SPEED_CHANGE:
1636		if (urb->actual_length < (sizeof(*event) +
1637					sizeof(struct usb_cdc_speed_change)))
1638			set_bit(EVENT_STS_SPLIT, &dev->flags);
1639		else
1640			cdc_ncm_speed_change(dev,
1641					     (struct usb_cdc_speed_change *)&event[1]);
1642		break;
1643
1644	default:
1645		dev_dbg(&dev->udev->dev,
1646			"NCM: unexpected notification 0x%02x!\n",
1647			event->bNotificationType);
1648		break;
1649	}
1650}
1651
1652static const struct driver_info cdc_ncm_info = {
1653	.description = "CDC NCM",
1654	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1655			| FLAG_LINK_INTR,
1656	.bind = cdc_ncm_bind,
1657	.unbind = cdc_ncm_unbind,
1658	.manage_power = usbnet_manage_power,
1659	.status = cdc_ncm_status,
1660	.rx_fixup = cdc_ncm_rx_fixup,
1661	.tx_fixup = cdc_ncm_tx_fixup,
1662};
1663
1664/* Same as cdc_ncm_info, but with FLAG_WWAN */
1665static const struct driver_info wwan_info = {
1666	.description = "Mobile Broadband Network Device",
1667	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1668			| FLAG_LINK_INTR | FLAG_WWAN,
1669	.bind = cdc_ncm_bind,
1670	.unbind = cdc_ncm_unbind,
1671	.manage_power = usbnet_manage_power,
1672	.status = cdc_ncm_status,
1673	.rx_fixup = cdc_ncm_rx_fixup,
1674	.tx_fixup = cdc_ncm_tx_fixup,
1675};
1676
1677/* Same as wwan_info, but with FLAG_NOARP  */
1678static const struct driver_info wwan_noarp_info = {
1679	.description = "Mobile Broadband Network Device (NO ARP)",
1680	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1681			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1682	.bind = cdc_ncm_bind,
1683	.unbind = cdc_ncm_unbind,
1684	.manage_power = usbnet_manage_power,
1685	.status = cdc_ncm_status,
1686	.rx_fixup = cdc_ncm_rx_fixup,
1687	.tx_fixup = cdc_ncm_tx_fixup,
1688};
1689
1690static const struct usb_device_id cdc_devs[] = {
1691	/* Ericsson MBM devices like F5521gw */
1692	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1693		| USB_DEVICE_ID_MATCH_VENDOR,
1694	  .idVendor = 0x0bdb,
1695	  .bInterfaceClass = USB_CLASS_COMM,
1696	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1697	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1698	  .driver_info = (unsigned long) &wwan_info,
1699	},
1700
1701	/* Telit LE910 V2 */
1702	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1703		USB_CLASS_COMM,
1704		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1705	  .driver_info = (unsigned long)&wwan_noarp_info,
1706	},
1707
1708	/* DW5812 LTE Verizon Mobile Broadband Card
1709	 * Unlike DW5550 this device requires FLAG_NOARP
1710	 */
1711	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1712		USB_CLASS_COMM,
1713		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1714	  .driver_info = (unsigned long)&wwan_noarp_info,
1715	},
1716
1717	/* DW5813 LTE AT&T Mobile Broadband Card
1718	 * Unlike DW5550 this device requires FLAG_NOARP
1719	 */
1720	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1721		USB_CLASS_COMM,
1722		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1723	  .driver_info = (unsigned long)&wwan_noarp_info,
1724	},
1725
1726	/* Dell branded MBM devices like DW5550 */
1727	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1728		| USB_DEVICE_ID_MATCH_VENDOR,
1729	  .idVendor = 0x413c,
1730	  .bInterfaceClass = USB_CLASS_COMM,
1731	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1732	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1733	  .driver_info = (unsigned long) &wwan_info,
1734	},
1735
1736	/* Toshiba branded MBM devices */
1737	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1738		| USB_DEVICE_ID_MATCH_VENDOR,
1739	  .idVendor = 0x0930,
1740	  .bInterfaceClass = USB_CLASS_COMM,
1741	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1742	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1743	  .driver_info = (unsigned long) &wwan_info,
1744	},
1745
1746	/* tag Huawei devices as wwan */
1747	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
1748					USB_CLASS_COMM,
1749					USB_CDC_SUBCLASS_NCM,
1750					USB_CDC_PROTO_NONE),
1751	  .driver_info = (unsigned long)&wwan_info,
1752	},
1753
1754	/* Infineon(now Intel) HSPA Modem platform */
1755	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
1756		USB_CLASS_COMM,
1757		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1758	  .driver_info = (unsigned long)&wwan_noarp_info,
1759	},
1760
1761	/* u-blox TOBY-L4 */
1762	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
1763		USB_CLASS_COMM,
1764		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1765	  .driver_info = (unsigned long)&wwan_info,
1766	},
1767
1768	/* Generic CDC-NCM devices */
1769	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
1770		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1771		.driver_info = (unsigned long)&cdc_ncm_info,
1772	},
1773	{
1774	},
1775};
1776MODULE_DEVICE_TABLE(usb, cdc_devs);
1777
1778static struct usb_driver cdc_ncm_driver = {
1779	.name = "cdc_ncm",
1780	.id_table = cdc_devs,
1781	.probe = usbnet_probe,
1782	.disconnect = usbnet_disconnect,
1783	.suspend = usbnet_suspend,
1784	.resume = usbnet_resume,
1785	.reset_resume =	usbnet_resume,
1786	.supports_autosuspend = 1,
1787	.disable_hub_initiated_lpm = 1,
1788};
1789
1790module_usb_driver(cdc_ncm_driver);
1791
1792MODULE_AUTHOR("Hans Petter Selasky");
1793MODULE_DESCRIPTION("USB CDC NCM host driver");
1794MODULE_LICENSE("Dual BSD/GPL");