1/*
   2 * cdc_ncm.c
   3 *
   4 * Copyright (C) ST-Ericsson 2010-2012
   5 * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
   6 * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
   7 *
   8 * USB Host Driver for Network Control Model (NCM)
   9 * http://www.usb.org/developers/docs/devclass_docs/NCM10_012011.zip
  10 *
  11 * The NCM encoding, decoding and initialization logic
  12 * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
  13 *
  14 * This software is available to you under a choice of one of two
  15 * licenses. You may choose this file to be licensed under the terms
  16 * of the GNU General Public License (GPL) Version 2 or the 2-clause
  17 * BSD license listed below:
  18 *
  19 * Redistribution and use in source and binary forms, with or without
  20 * modification, are permitted provided that the following conditions
  21 * are met:
  22 * 1. Redistributions of source code must retain the above copyright
  23 *    notice, this list of conditions and the following disclaimer.
  24 * 2. Redistributions in binary form must reproduce the above copyright
  25 *    notice, this list of conditions and the following disclaimer in the
  26 *    documentation and/or other materials provided with the distribution.
  27 *
  28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38 * SUCH DAMAGE.
  39 */
  40
  41#include <linux/module.h>
  42#include <linux/netdevice.h>
  43#include <linux/ctype.h>
  44#include <linux/etherdevice.h>
  45#include <linux/ethtool.h>
  46#include <linux/kstrtox.h>
  47#include <linux/workqueue.h>
  48#include <linux/mii.h>
  49#include <linux/crc32.h>
  50#include <linux/usb.h>
  51#include <linux/hrtimer.h>
  52#include <linux/atomic.h>
  53#include <linux/usb/usbnet.h>
  54#include <linux/usb/cdc.h>
  55#include <linux/usb/cdc_ncm.h>
  56
  57#if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
  58static bool prefer_mbim = true;
  59#else
  60static bool prefer_mbim;
  61#endif
  62module_param(prefer_mbim, bool, 0644);
  63MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
  64
  65static void cdc_ncm_txpath_bh(struct tasklet_struct *t);
  66static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
  67static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
  68static struct usb_driver cdc_ncm_driver;
  69
  70struct cdc_ncm_stats {
  71	char stat_string[ETH_GSTRING_LEN];
  72	int sizeof_stat;
  73	int stat_offset;
  74};
  75
  76#define CDC_NCM_STAT(str, m) { \
  77		.stat_string = str, \
  78		.sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
  79		.stat_offset = offsetof(struct cdc_ncm_ctx, m) }
  80#define CDC_NCM_SIMPLE_STAT(m)	CDC_NCM_STAT(__stringify(m), m)
  81
  82static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
  83	CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
  84	CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
  85	CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
  86	CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
  87	CDC_NCM_SIMPLE_STAT(tx_overhead),
  88	CDC_NCM_SIMPLE_STAT(tx_ntbs),
  89	CDC_NCM_SIMPLE_STAT(rx_overhead),
  90	CDC_NCM_SIMPLE_STAT(rx_ntbs),
  91};
  92
  93#define CDC_NCM_LOW_MEM_MAX_CNT 10
  94
  95static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
  96{
  97	switch (sset) {
  98	case ETH_SS_STATS:
  99		return ARRAY_SIZE(cdc_ncm_gstrings_stats);
 100	default:
 101		return -EOPNOTSUPP;
 102	}
 103}
 104
 105static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
 106				    struct ethtool_stats __always_unused *stats,
 107				    u64 *data)
 108{
 109	struct usbnet *dev = netdev_priv(netdev);
 110	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 111	int i;
 112	char *p = NULL;
 113
 114	for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
 115		p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
 116		data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
 117	}
 118}
 119
 120static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
 121{
 122	u8 *p = data;
 123	int i;
 124
 125	switch (stringset) {
 126	case ETH_SS_STATS:
 127		for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
 128			memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
 129			p += ETH_GSTRING_LEN;
 130		}
 131	}
 132}
 133
 134static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
 135
 136static const struct ethtool_ops cdc_ncm_ethtool_ops = {
 137	.get_link		= usbnet_get_link,
 138	.nway_reset		= usbnet_nway_reset,
 139	.get_drvinfo		= usbnet_get_drvinfo,
 140	.get_msglevel		= usbnet_get_msglevel,
 141	.set_msglevel		= usbnet_set_msglevel,
 142	.get_ts_info		= ethtool_op_get_ts_info,
 143	.get_sset_count		= cdc_ncm_get_sset_count,
 144	.get_strings		= cdc_ncm_get_strings,
 145	.get_ethtool_stats	= cdc_ncm_get_ethtool_stats,
 146	.get_link_ksettings	= usbnet_get_link_ksettings_internal,
 147	.set_link_ksettings	= NULL,
 148};
 149
 150static u32 cdc_ncm_check_rx_max(struct usbnet *dev, u32 new_rx)
 151{
 152	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 153	u32 val, max, min;
 154
 155	/* clamp new_rx to sane values */
 156	min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
 157	max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
 158
 159	/* dwNtbInMaxSize spec violation? Use MIN size for both limits */
 160	if (max < min) {
 161		dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
 162			 le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
 163		max = min;
 164	}
 165
 166	val = clamp_t(u32, new_rx, min, max);
 167	if (val != new_rx)
 168		dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range\n", min, max);
 169
 170	return val;
 171}
 172
 173static u32 cdc_ncm_check_tx_max(struct usbnet *dev, u32 new_tx)
 174{
 175	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 176	u32 val, max, min;
 177
 178	/* clamp new_tx to sane values */
 179	if (ctx->is_ndp16)
 180		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
 181	else
 182		min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth32);
 183
 184	if (le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) == 0)
 185		max = CDC_NCM_NTB_MAX_SIZE_TX; /* dwNtbOutMaxSize not set */
 186	else
 187		max = clamp_t(u32, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize),
 188			      USB_CDC_NCM_NTB_MIN_OUT_SIZE,
 189			      CDC_NCM_NTB_MAX_SIZE_TX);
 190
 191	/* some devices set dwNtbOutMaxSize too low for the above default */
 192	min = min(min, max);
 193
 194	val = clamp_t(u32, new_tx, min, max);
 195	if (val != new_tx)
 196		dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
 197
 198	return val;
 199}
 200
 201static ssize_t min_tx_pkt_show(struct device *d,
 202			       struct device_attribute *attr, char *buf)
 203{
 204	struct usbnet *dev = netdev_priv(to_net_dev(d));
 205	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 206
 207	return sprintf(buf, "%u\n", ctx->min_tx_pkt);
 208}
 209
 210static ssize_t rx_max_show(struct device *d,
 211			   struct device_attribute *attr, char *buf)
 212{
 213	struct usbnet *dev = netdev_priv(to_net_dev(d));
 214	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 215
 216	return sprintf(buf, "%u\n", ctx->rx_max);
 217}
 218
 219static ssize_t tx_max_show(struct device *d,
 220			   struct device_attribute *attr, char *buf)
 221{
 222	struct usbnet *dev = netdev_priv(to_net_dev(d));
 223	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 224
 225	return sprintf(buf, "%u\n", ctx->tx_max);
 226}
 227
 228static ssize_t tx_timer_usecs_show(struct device *d,
 229				   struct device_attribute *attr, char *buf)
 230{
 231	struct usbnet *dev = netdev_priv(to_net_dev(d));
 232	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 233
 234	return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
 235}
 236
 237static ssize_t min_tx_pkt_store(struct device *d,
 238				struct device_attribute *attr,
 239				const char *buf, size_t len)
 240{
 241	struct usbnet *dev = netdev_priv(to_net_dev(d));
 242	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 243	unsigned long val;
 244
 245	/* no need to restrict values - anything from 0 to infinity is OK */
 246	if (kstrtoul(buf, 0, &val))
 247		return -EINVAL;
 248
 249	ctx->min_tx_pkt = val;
 250	return len;
 251}
 252
 253static ssize_t rx_max_store(struct device *d,
 254			    struct device_attribute *attr,
 255			    const char *buf, size_t len)
 256{
 257	struct usbnet *dev = netdev_priv(to_net_dev(d));
 258	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 259	unsigned long val;
 260
 261	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
 262		return -EINVAL;
 263
 264	cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
 265	return len;
 266}
 267
 268static ssize_t tx_max_store(struct device *d,
 269			    struct device_attribute *attr,
 270			    const char *buf, size_t len)
 271{
 272	struct usbnet *dev = netdev_priv(to_net_dev(d));
 273	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 274	unsigned long val;
 275
 276	if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
 277		return -EINVAL;
 278
 279	cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
 280	return len;
 281}
 282
 283static ssize_t tx_timer_usecs_store(struct device *d,
 284				    struct device_attribute *attr,
 285				    const char *buf, size_t len)
 286{
 287	struct usbnet *dev = netdev_priv(to_net_dev(d));
 288	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 289	ssize_t ret;
 290	unsigned long val;
 291
 292	ret = kstrtoul(buf, 0, &val);
 293	if (ret)
 294		return ret;
 295	if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
 296		return -EINVAL;
 297
 298	spin_lock_bh(&ctx->mtx);
 299	ctx->timer_interval = val * NSEC_PER_USEC;
 300	if (!ctx->timer_interval)
 301		ctx->tx_timer_pending = 0;
 302	spin_unlock_bh(&ctx->mtx);
 303	return len;
 304}
 305
 306static DEVICE_ATTR_RW(min_tx_pkt);
 307static DEVICE_ATTR_RW(rx_max);
 308static DEVICE_ATTR_RW(tx_max);
 309static DEVICE_ATTR_RW(tx_timer_usecs);
 310
 311static ssize_t ndp_to_end_show(struct device *d, struct device_attribute *attr, char *buf)
 312{
 313	struct usbnet *dev = netdev_priv(to_net_dev(d));
 314	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 315
 316	return sprintf(buf, "%c\n", ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END ? 'Y' : 'N');
 317}
 318
 319static ssize_t ndp_to_end_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
 320{
 321	struct usbnet *dev = netdev_priv(to_net_dev(d));
 322	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 323	bool enable;
 324
 325	if (kstrtobool(buf, &enable))
 326		return -EINVAL;
 327
 328	/* no change? */
 329	if (enable == (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
 330		return len;
 331
 332	if (enable) {
 333		if (ctx->is_ndp16 && !ctx->delayed_ndp16) {
 334			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
 335			if (!ctx->delayed_ndp16)
 336				return -ENOMEM;
 337		}
 338		if (!ctx->is_ndp16 && !ctx->delayed_ndp32) {
 339			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
 340			if (!ctx->delayed_ndp32)
 341				return -ENOMEM;
 342		}
 343	}
 344
 345	/* flush pending data before changing flag */
 346	netif_tx_lock_bh(dev->net);
 347	usbnet_start_xmit(NULL, dev->net);
 348	spin_lock_bh(&ctx->mtx);
 349	if (enable)
 350		ctx->drvflags |= CDC_NCM_FLAG_NDP_TO_END;
 351	else
 352		ctx->drvflags &= ~CDC_NCM_FLAG_NDP_TO_END;
 353	spin_unlock_bh(&ctx->mtx);
 354	netif_tx_unlock_bh(dev->net);
 355
 356	return len;
 357}
 358static DEVICE_ATTR_RW(ndp_to_end);
 359
 360#define NCM_PARM_ATTR(name, format, tocpu)				\
 361static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
 362{ \
 363	struct usbnet *dev = netdev_priv(to_net_dev(d)); \
 364	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
 365	return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));	\
 366} \
 367static DEVICE_ATTR(name, 0444, cdc_ncm_show_##name, NULL)
 368
 369NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
 370NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
 371NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
 372NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
 373NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
 374NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
 375NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
 376NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
 377NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
 378NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
 379
 380static struct attribute *cdc_ncm_sysfs_attrs[] = {
 381	&dev_attr_min_tx_pkt.attr,
 382	&dev_attr_ndp_to_end.attr,
 383	&dev_attr_rx_max.attr,
 384	&dev_attr_tx_max.attr,
 385	&dev_attr_tx_timer_usecs.attr,
 386	&dev_attr_bmNtbFormatsSupported.attr,
 387	&dev_attr_dwNtbInMaxSize.attr,
 388	&dev_attr_wNdpInDivisor.attr,
 389	&dev_attr_wNdpInPayloadRemainder.attr,
 390	&dev_attr_wNdpInAlignment.attr,
 391	&dev_attr_dwNtbOutMaxSize.attr,
 392	&dev_attr_wNdpOutDivisor.attr,
 393	&dev_attr_wNdpOutPayloadRemainder.attr,
 394	&dev_attr_wNdpOutAlignment.attr,
 395	&dev_attr_wNtbOutMaxDatagrams.attr,
 396	NULL,
 397};
 398
 399static const struct attribute_group cdc_ncm_sysfs_attr_group = {
 400	.name = "cdc_ncm",
 401	.attrs = cdc_ncm_sysfs_attrs,
 402};
 403
 404/* handle rx_max and tx_max changes */
 405static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
 406{
 407	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 408	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
 409	u32 val;
 410
 411	val = cdc_ncm_check_rx_max(dev, new_rx);
 412
 413	/* inform device about NTB input size changes */
 414	if (val != ctx->rx_max) {
 415		__le32 dwNtbInMaxSize = cpu_to_le32(val);
 416
 417		dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
 418
 419		/* tell device to use new size */
 420		if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
 421				     USB_TYPE_CLASS | USB_DIR_OUT
 422				     | USB_RECIP_INTERFACE,
 423				     0, iface_no, &dwNtbInMaxSize, 4) < 0)
 424			dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
 425		else
 426			ctx->rx_max = val;
 427	}
 428
 429	/* usbnet use these values for sizing rx queues */
 430	if (dev->rx_urb_size != ctx->rx_max) {
 431		dev->rx_urb_size = ctx->rx_max;
 432		if (netif_running(dev->net))
 433			usbnet_unlink_rx_urbs(dev);
 434	}
 435
 436	val = cdc_ncm_check_tx_max(dev, new_tx);
 437	if (val != ctx->tx_max)
 438		dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
 439
 440	/* Adding a pad byte here if necessary simplifies the handling
 441	 * in cdc_ncm_fill_tx_frame, making tx_max always represent
 442	 * the real skb max size.
 443	 *
 444	 * We cannot use dev->maxpacket here because this is called from
 445	 * .bind which is called before usbnet sets up dev->maxpacket
 446	 */
 447	if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
 448	    val % usb_maxpacket(dev->udev, dev->out) == 0)
 449		val++;
 450
 451	/* we might need to flush any pending tx buffers if running */
 452	if (netif_running(dev->net) && val > ctx->tx_max) {
 453		netif_tx_lock_bh(dev->net);
 454		usbnet_start_xmit(NULL, dev->net);
 455		/* make sure tx_curr_skb is reallocated if it was empty */
 456		if (ctx->tx_curr_skb) {
 457			dev_kfree_skb_any(ctx->tx_curr_skb);
 458			ctx->tx_curr_skb = NULL;
 459		}
 460		ctx->tx_max = val;
 461		netif_tx_unlock_bh(dev->net);
 462	} else {
 463		ctx->tx_max = val;
 464	}
 465
 466	dev->hard_mtu = ctx->tx_max;
 467
 468	/* max qlen depend on hard_mtu and rx_urb_size */
 469	usbnet_update_max_qlen(dev);
 470
 471	/* never pad more than 3 full USB packets per transfer */
 472	ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out),
 473				  CDC_NCM_MIN_TX_PKT, ctx->tx_max);
 474}
 475
 476/* helpers for NCM and MBIM differences */
 477static u8 cdc_ncm_flags(struct usbnet *dev)
 478{
 479	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 480
 481	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
 482		return ctx->mbim_desc->bmNetworkCapabilities;
 483	if (ctx->func_desc)
 484		return ctx->func_desc->bmNetworkCapabilities;
 485	return 0;
 486}
 487
 488static int cdc_ncm_eth_hlen(struct usbnet *dev)
 489{
 490	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
 491		return 0;
 492	return ETH_HLEN;
 493}
 494
 495static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
 496{
 497	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
 498		return CDC_MBIM_MIN_DATAGRAM_SIZE;
 499	return CDC_NCM_MIN_DATAGRAM_SIZE;
 500}
 501
 502static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
 503{
 504	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 505
 506	if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
 507		return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
 508	if (ctx->ether_desc)
 509		return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
 510	return CDC_NCM_MAX_DATAGRAM_SIZE;
 511}
 512
 513/* initial one-time device setup.  MUST be called with the data interface
 514 * in altsetting 0
 515 */
 516static int cdc_ncm_init(struct usbnet *dev)
 517{
 518	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 519	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
 520	int err;
 521
 522	err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
 523			      USB_TYPE_CLASS | USB_DIR_IN
 524			      |USB_RECIP_INTERFACE,
 525			      0, iface_no, &ctx->ncm_parm,
 526			      sizeof(ctx->ncm_parm));
 527	if (err < 0) {
 528		dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
 529		return err; /* GET_NTB_PARAMETERS is required */
 530	}
 531
 532	/* set CRC Mode */
 533	if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
 534		dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
 535		err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
 536				       USB_TYPE_CLASS | USB_DIR_OUT
 537				       | USB_RECIP_INTERFACE,
 538				       USB_CDC_NCM_CRC_NOT_APPENDED,
 539				       iface_no, NULL, 0);
 540		if (err < 0)
 541			dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
 542	}
 543
 544	/* use ndp16 by default */
 545	ctx->is_ndp16 = 1;
 546
 547	/* set NTB format, if both formats are supported.
 548	 *
 549	 * "The host shall only send this command while the NCM Data
 550	 *  Interface is in alternate setting 0."
 551	 */
 552	if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
 553						USB_CDC_NCM_NTB32_SUPPORTED) {
 554		if (ctx->drvflags & CDC_NCM_FLAG_PREFER_NTB32) {
 555			ctx->is_ndp16 = 0;
 556			dev_dbg(&dev->intf->dev, "Setting NTB format to 32-bit\n");
 557			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
 558					       USB_TYPE_CLASS | USB_DIR_OUT
 559					       | USB_RECIP_INTERFACE,
 560					       USB_CDC_NCM_NTB32_FORMAT,
 561					       iface_no, NULL, 0);
 562		} else {
 563			ctx->is_ndp16 = 1;
 564			dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
 565			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
 566					       USB_TYPE_CLASS | USB_DIR_OUT
 567					       | USB_RECIP_INTERFACE,
 568					       USB_CDC_NCM_NTB16_FORMAT,
 569					       iface_no, NULL, 0);
 570		}
 571		if (err < 0) {
 572			ctx->is_ndp16 = 1;
 573			dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
 574		}
 575	}
 576
 577	/* set initial device values */
 578	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
 579	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
 580	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
 581	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
 582	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
 583	/* devices prior to NCM Errata shall set this field to zero */
 584	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
 585
 586	dev_dbg(&dev->intf->dev,
 587		"dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
 588		ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
 589		ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
 590
 591	/* max count of tx datagrams */
 592	if ((ctx->tx_max_datagrams == 0) ||
 593			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
 594		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
 595
 596	/* set up maximum NDP size */
 597	if (ctx->is_ndp16)
 598		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
 599	else
 600		ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp32) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe32);
 601
 602	/* initial coalescing timer interval */
 603	ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
 604
 605	return 0;
 606}
 607
 608/* set a new max datagram size */
 609static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
 610{
 611	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 612	u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
 613	__le16 max_datagram_size;
 614	u16 mbim_mtu;
 615	int err;
 616
 617	/* set default based on descriptors */
 618	ctx->max_datagram_size = clamp_t(u32, new_size,
 619					 cdc_ncm_min_dgram_size(dev),
 620					 CDC_NCM_MAX_DATAGRAM_SIZE);
 621
 622	/* inform the device about the selected Max Datagram Size? */
 623	if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
 624		goto out;
 625
 626	/* read current mtu value from device */
 627	err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
 628			      USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
 629			      0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
 630	if (err != sizeof(max_datagram_size)) {
 631		dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
 632		goto out;
 633	}
 634
 635	if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
 636		goto out;
 637
 638	max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
 639	err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
 640			       USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
 641			       0, iface_no, &max_datagram_size, sizeof(max_datagram_size));
 642	if (err < 0)
 643		dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
 644
 645out:
 646	/* set MTU to max supported by the device if necessary */
 647	dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
 648
 649	/* do not exceed operator preferred MTU */
 650	if (ctx->mbim_extended_desc) {
 651		mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
 652		if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
 653			dev->net->mtu = mbim_mtu;
 654	}
 655}
 656
 657static void cdc_ncm_fix_modulus(struct usbnet *dev)
 658{
 659	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 660	u32 val;
 661
 662	/*
 663	 * verify that the structure alignment is:
 664	 * - power of two
 665	 * - not greater than the maximum transmit length
 666	 * - not less than four bytes
 667	 */
 668	val = ctx->tx_ndp_modulus;
 669
 670	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
 671	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
 672		dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
 673		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
 674	}
 675
 676	/*
 677	 * verify that the payload alignment is:
 678	 * - power of two
 679	 * - not greater than the maximum transmit length
 680	 * - not less than four bytes
 681	 */
 682	val = ctx->tx_modulus;
 683
 684	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
 685	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
 686		dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
 687		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
 688	}
 689
 690	/* verify the payload remainder */
 691	if (ctx->tx_remainder >= ctx->tx_modulus) {
 692		dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
 693		ctx->tx_remainder = 0;
 694	}
 695
 696	/* adjust TX-remainder according to NCM specification. */
 697	ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
 698			     (ctx->tx_modulus - 1));
 699}
 700
 701static int cdc_ncm_setup(struct usbnet *dev)
 702{
 703	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 704	u32 def_rx, def_tx;
 705
 706	/* be conservative when selecting initial buffer size to
 707	 * increase the number of hosts this will work for
 708	 */
 709	def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
 710		       le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
 711	def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
 712		       le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
 713
 714	/* clamp rx_max and tx_max and inform device */
 715	cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
 716
 717	/* sanitize the modulus and remainder values */
 718	cdc_ncm_fix_modulus(dev);
 719
 720	/* set max datagram size */
 721	cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
 722	return 0;
 723}
 724
 725static void
 726cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
 727{
 728	struct usb_host_endpoint *e, *in = NULL, *out = NULL;
 729	u8 ep;
 730
 731	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
 732		e = intf->cur_altsetting->endpoint + ep;
 733
 734		/* ignore endpoints which cannot transfer data */
 735		if (!usb_endpoint_maxp(&e->desc))
 736			continue;
 737
 738		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
 739		case USB_ENDPOINT_XFER_INT:
 740			if (usb_endpoint_dir_in(&e->desc)) {
 741				if (!dev->status)
 742					dev->status = e;
 743			}
 744			break;
 745
 746		case USB_ENDPOINT_XFER_BULK:
 747			if (usb_endpoint_dir_in(&e->desc)) {
 748				if (!in)
 749					in = e;
 750			} else {
 751				if (!out)
 752					out = e;
 753			}
 754			break;
 755
 756		default:
 757			break;
 758		}
 759	}
 760	if (in && !dev->in)
 761		dev->in = usb_rcvbulkpipe(dev->udev,
 762					  in->desc.bEndpointAddress &
 763					  USB_ENDPOINT_NUMBER_MASK);
 764	if (out && !dev->out)
 765		dev->out = usb_sndbulkpipe(dev->udev,
 766					   out->desc.bEndpointAddress &
 767					   USB_ENDPOINT_NUMBER_MASK);
 768}
 769
 770static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
 771{
 772	if (ctx == NULL)
 773		return;
 774
 775	if (ctx->tx_rem_skb != NULL) {
 776		dev_kfree_skb_any(ctx->tx_rem_skb);
 777		ctx->tx_rem_skb = NULL;
 778	}
 779
 780	if (ctx->tx_curr_skb != NULL) {
 781		dev_kfree_skb_any(ctx->tx_curr_skb);
 782		ctx->tx_curr_skb = NULL;
 783	}
 784
 785	if (ctx->is_ndp16)
 786		kfree(ctx->delayed_ndp16);
 787	else
 788		kfree(ctx->delayed_ndp32);
 789
 790	kfree(ctx);
 791}
 792
 793/* we need to override the usbnet change_mtu ndo for two reasons:
 794 *  - respect the negotiated maximum datagram size
 795 *  - avoid unwanted changes to rx and tx buffers
 796 */
 797int cdc_ncm_change_mtu(struct net_device *net, int new_mtu)
 798{
 799	struct usbnet *dev = netdev_priv(net);
 800
 801	net->mtu = new_mtu;
 802	cdc_ncm_set_dgram_size(dev, new_mtu + cdc_ncm_eth_hlen(dev));
 803
 804	return 0;
 805}
 806EXPORT_SYMBOL_GPL(cdc_ncm_change_mtu);
 807
 808static const struct net_device_ops cdc_ncm_netdev_ops = {
 809	.ndo_open	     = usbnet_open,
 810	.ndo_stop	     = usbnet_stop,
 811	.ndo_start_xmit	     = usbnet_start_xmit,
 812	.ndo_tx_timeout	     = usbnet_tx_timeout,
 813	.ndo_set_rx_mode     = usbnet_set_rx_mode,
 814	.ndo_get_stats64     = dev_get_tstats64,
 815	.ndo_change_mtu	     = cdc_ncm_change_mtu,
 816	.ndo_set_mac_address = eth_mac_addr,
 817	.ndo_validate_addr   = eth_validate_addr,
 818};
 819
 820int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
 821{
 822	struct cdc_ncm_ctx *ctx;
 823	struct usb_driver *driver;
 824	u8 *buf;
 825	int len;
 826	int temp;
 827	u8 iface_no;
 828	struct usb_cdc_parsed_header hdr;
 829
 830	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 831	if (!ctx)
 832		return -ENOMEM;
 833
 834	ctx->dev = dev;
 835
 836	hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 837	ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
 838	tasklet_setup(&ctx->bh, cdc_ncm_txpath_bh);
 839	atomic_set(&ctx->stop, 0);
 840	spin_lock_init(&ctx->mtx);
 841
 842	/* store ctx pointer in device data field */
 843	dev->data[0] = (unsigned long)ctx;
 844
 845	/* only the control interface can be successfully probed */
 846	ctx->control = intf;
 847
 848	/* get some pointers */
 849	driver = driver_of(intf);
 850	buf = intf->cur_altsetting->extra;
 851	len = intf->cur_altsetting->extralen;
 852
 853	/* parse through descriptors associated with control interface */
 854	cdc_parse_cdc_header(&hdr, intf, buf, len);
 855
 856	if (hdr.usb_cdc_union_desc)
 857		ctx->data = usb_ifnum_to_if(dev->udev,
 858					    hdr.usb_cdc_union_desc->bSlaveInterface0);
 859	ctx->ether_desc = hdr.usb_cdc_ether_desc;
 860	ctx->func_desc = hdr.usb_cdc_ncm_desc;
 861	ctx->mbim_desc = hdr.usb_cdc_mbim_desc;
 862	ctx->mbim_extended_desc = hdr.usb_cdc_mbim_extended_desc;
 863
 864	/* some buggy devices have an IAD but no CDC Union */
 865	if (!hdr.usb_cdc_union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
 866		ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
 867		dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
 868	}
 869
 870	/* check if we got everything */
 871	if (!ctx->data) {
 872		dev_err(&intf->dev, "CDC Union missing and no IAD found\n");
 873		goto error;
 874	}
 875	if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
 876		if (!ctx->mbim_desc) {
 877			dev_err(&intf->dev, "MBIM functional descriptor missing\n");
 878			goto error;
 879		}
 880	} else {
 881		if (!ctx->ether_desc || !ctx->func_desc) {
 882			dev_err(&intf->dev, "NCM or ECM functional descriptors missing\n");
 883			goto error;
 884		}
 885	}
 886
 887	/* claim data interface, if different from control */
 888	if (ctx->data != ctx->control) {
 889		temp = usb_driver_claim_interface(driver, ctx->data, dev);
 890		if (temp) {
 891			dev_err(&intf->dev, "failed to claim data intf\n");
 892			goto error;
 893		}
 894	}
 895
 896	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
 897
 898	/* Device-specific flags */
 899	ctx->drvflags = drvflags;
 900
 901	/* Reset data interface. Some devices will not reset properly
 902	 * unless they are configured first.  Toggle the altsetting to
 903	 * force a reset.
 904	 * Some other devices do not work properly with this procedure
 905	 * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
 906	 */
 907	if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
 908		usb_set_interface(dev->udev, iface_no, data_altsetting);
 909
 910	temp = usb_set_interface(dev->udev, iface_no, 0);
 911	if (temp) {
 912		dev_dbg(&intf->dev, "set interface failed\n");
 913		goto error2;
 914	}
 915
 916	/* initialize basic device settings */
 917	if (cdc_ncm_init(dev))
 918		goto error2;
 919
 920	/* Some firmwares need a pause here or they will silently fail
 921	 * to set up the interface properly.  This value was decided
 922	 * empirically on a Sierra Wireless MC7455 running 02.08.02.00
 923	 * firmware.
 924	 */
 925	usleep_range(10000, 20000);
 926
 927	/* configure data interface */
 928	temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
 929	if (temp) {
 930		dev_dbg(&intf->dev, "set interface failed\n");
 931		goto error2;
 932	}
 933
 934	cdc_ncm_find_endpoints(dev, ctx->data);
 935	cdc_ncm_find_endpoints(dev, ctx->control);
 936	if (!dev->in || !dev->out || !dev->status) {
 937		dev_dbg(&intf->dev, "failed to collect endpoints\n");
 938		goto error2;
 939	}
 940
 941	usb_set_intfdata(ctx->control, dev);
 942
 943	if (ctx->ether_desc) {
 944		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
 945		if (temp) {
 946			dev_err(&intf->dev, "failed to get mac address\n");
 947			goto error2;
 948		}
 949		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
 950	}
 951
 952	/* finish setting up the device specific data */
 953	cdc_ncm_setup(dev);
 954
 955	/* Allocate the delayed NDP if needed. */
 956	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
 957		if (ctx->is_ndp16) {
 958			ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
 959			if (!ctx->delayed_ndp16)
 960				goto error2;
 961		} else {
 962			ctx->delayed_ndp32 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
 963			if (!ctx->delayed_ndp32)
 964				goto error2;
 965		}
 966		dev_info(&intf->dev, "NDP will be placed at end of frame for this device.");
 967	}
 968
 969	/* override ethtool_ops */
 970	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
 971
 972	/* add our sysfs attrs */
 973	dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
 974
 975	/* must handle MTU changes */
 976	dev->net->netdev_ops = &cdc_ncm_netdev_ops;
 977	dev->net->max_mtu = cdc_ncm_max_dgram_size(dev) - cdc_ncm_eth_hlen(dev);
 978
 979	return 0;
 980
 981error2:
 982	usb_set_intfdata(ctx->control, NULL);
 983	usb_set_intfdata(ctx->data, NULL);
 984	if (ctx->data != ctx->control)
 985		usb_driver_release_interface(driver, ctx->data);
 986error:
 987	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
 988	dev->data[0] = 0;
 989	dev_info(&intf->dev, "bind() failure\n");
 990	return -ENODEV;
 991}
 992EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
 993
 994void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
 995{
 996	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
 997	struct usb_driver *driver = driver_of(intf);
 998
 999	if (ctx == NULL)
1000		return;		/* no setup */
1001
1002	atomic_set(&ctx->stop, 1);
1003
1004	hrtimer_cancel(&ctx->tx_timer);
1005
1006	tasklet_kill(&ctx->bh);
1007
1008	/* handle devices with combined control and data interface */
1009	if (ctx->control == ctx->data)
1010		ctx->data = NULL;
1011
1012	/* disconnect master --> disconnect slave */
1013	if (intf == ctx->control && ctx->data) {
1014		usb_set_intfdata(ctx->data, NULL);
1015		usb_driver_release_interface(driver, ctx->data);
1016		ctx->data = NULL;
1017
1018	} else if (intf == ctx->data && ctx->control) {
1019		usb_set_intfdata(ctx->control, NULL);
1020		usb_driver_release_interface(driver, ctx->control);
1021		ctx->control = NULL;
1022	}
1023
1024	usb_set_intfdata(intf, NULL);
1025	cdc_ncm_free(ctx);
1026}
1027EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
1028
1029/* Return the number of the MBIM control interface altsetting iff it
1030 * is preferred and available,
1031 */
1032u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
1033{
1034	struct usb_host_interface *alt;
1035
1036	/* The MBIM spec defines a NCM compatible default altsetting,
1037	 * which we may have matched:
1038	 *
1039	 *  "Functions that implement both NCM 1.0 and MBIM (an
1040	 *   “NCM/MBIM function”) according to this recommendation
1041	 *   shall provide two alternate settings for the
1042	 *   Communication Interface.  Alternate setting 0, and the
1043	 *   associated class and endpoint descriptors, shall be
1044	 *   constructed according to the rules given for the
1045	 *   Communication Interface in section 5 of [USBNCM10].
1046	 *   Alternate setting 1, and the associated class and
1047	 *   endpoint descriptors, shall be constructed according to
1048	 *   the rules given in section 6 (USB Device Model) of this
1049	 *   specification."
1050	 */
1051	if (intf->num_altsetting < 2)
1052		return intf->cur_altsetting->desc.bAlternateSetting;
1053
1054	if (prefer_mbim) {
1055		alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
1056		if (alt && cdc_ncm_comm_intf_is_mbim(alt))
1057			return CDC_NCM_COMM_ALTSETTING_MBIM;
1058	}
1059	return CDC_NCM_COMM_ALTSETTING_NCM;
1060}
1061EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
1062
1063static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
1064{
1065	/* MBIM backwards compatible function? */
1066	if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
1067		return -ENODEV;
1068
1069	/* The NCM data altsetting is fixed, so we hard-coded it.
1070	 * Additionally, generic NCM devices are assumed to accept arbitrarily
1071	 * placed NDP.
1072	 */
1073	return cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM, 0);
1074}
1075
1076static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
1077{
1078	size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
1079
1080	if (skb->len + align > max)
1081		align = max - skb->len;
1082	if (align && skb_tailroom(skb) >= align)
1083		skb_put_zero(skb, align);
1084}
1085
1086/* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
1087 * allocating a new one within skb
1088 */
1089static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1090{
1091	struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
1092	struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
1093	size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
1094
1095	/* If NDP should be moved to the end of the NCM package, we can't follow the
1096	* NTH16 header as we would normally do. NDP isn't written to the SKB yet, and
1097	* the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1098	*/
1099	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1100		if (ctx->delayed_ndp16->dwSignature == sign)
1101			return ctx->delayed_ndp16;
1102
1103		/* We can only push a single NDP to the end. Return
1104		 * NULL to send what we've already got and queue this
1105		 * skb for later.
1106		 */
1107		else if (ctx->delayed_ndp16->dwSignature)
1108			return NULL;
1109	}
1110
1111	/* follow the chain of NDPs, looking for a match */
1112	while (ndpoffset) {
1113		ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
1114		if  (ndp16->dwSignature == sign)
1115			return ndp16;
1116		ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1117	}
1118
1119	/* align new NDP */
1120	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1121		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1122
1123	/* verify that there is room for the NDP and the datagram (reserve) */
1124	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1125		return NULL;
1126
1127	/* link to it */
1128	if (ndp16)
1129		ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
1130	else
1131		nth16->wNdpIndex = cpu_to_le16(skb->len);
1132
1133	/* push a new empty NDP */
1134	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1135		ndp16 = skb_put_zero(skb, ctx->max_ndp_size);
1136	else
1137		ndp16 = ctx->delayed_ndp16;
1138
1139	ndp16->dwSignature = sign;
1140	ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
1141	return ndp16;
1142}
1143
1144static struct usb_cdc_ncm_ndp32 *cdc_ncm_ndp32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
1145{
1146	struct usb_cdc_ncm_ndp32 *ndp32 = NULL;
1147	struct usb_cdc_ncm_nth32 *nth32 = (void *)skb->data;
1148	size_t ndpoffset = le32_to_cpu(nth32->dwNdpIndex);
1149
1150	/* If NDP should be moved to the end of the NCM package, we can't follow the
1151	 * NTH32 header as we would normally do. NDP isn't written to the SKB yet, and
1152	 * the wNdpIndex field in the header is actually not consistent with reality. It will be later.
1153	 */
1154	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1155		if (ctx->delayed_ndp32->dwSignature == sign)
1156			return ctx->delayed_ndp32;
1157
1158		/* We can only push a single NDP to the end. Return
1159		 * NULL to send what we've already got and queue this
1160		 * skb for later.
1161		 */
1162		else if (ctx->delayed_ndp32->dwSignature)
1163			return NULL;
1164	}
1165
1166	/* follow the chain of NDPs, looking for a match */
1167	while (ndpoffset) {
1168		ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb->data + ndpoffset);
1169		if  (ndp32->dwSignature == sign)
1170			return ndp32;
1171		ndpoffset = le32_to_cpu(ndp32->dwNextNdpIndex);
1172	}
1173
1174	/* align new NDP */
1175	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1176		cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size);
1177
1178	/* verify that there is room for the NDP and the datagram (reserve) */
1179	if ((ctx->tx_curr_size - skb->len - reserve) < ctx->max_ndp_size)
1180		return NULL;
1181
1182	/* link to it */
1183	if (ndp32)
1184		ndp32->dwNextNdpIndex = cpu_to_le32(skb->len);
1185	else
1186		nth32->dwNdpIndex = cpu_to_le32(skb->len);
1187
1188	/* push a new empty NDP */
1189	if (!(ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END))
1190		ndp32 = skb_put_zero(skb, ctx->max_ndp_size);
1191	else
1192		ndp32 = ctx->delayed_ndp32;
1193
1194	ndp32->dwSignature = sign;
1195	ndp32->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp32) + sizeof(struct usb_cdc_ncm_dpe32));
1196	return ndp32;
1197}
1198
1199struct sk_buff *
1200cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
1201{
1202	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1203	union {
1204		struct usb_cdc_ncm_nth16 *nth16;
1205		struct usb_cdc_ncm_nth32 *nth32;
1206	} nth;
1207	union {
1208		struct usb_cdc_ncm_ndp16 *ndp16;
1209		struct usb_cdc_ncm_ndp32 *ndp32;
1210	} ndp;
1211	struct sk_buff *skb_out;
1212	u16 n = 0, index, ndplen;
1213	u8 ready2send = 0;
1214	u32 delayed_ndp_size;
1215	size_t padding_count;
1216
1217	/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
1218	 * accordingly. Otherwise, we should check here.
1219	 */
1220	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END)
1221		delayed_ndp_size = ctx->max_ndp_size +
1222			max_t(u32,
1223			      ctx->tx_ndp_modulus,
1224			      ctx->tx_modulus + ctx->tx_remainder) - 1;
1225	else
1226		delayed_ndp_size = 0;
1227
1228	/* if there is a remaining skb, it gets priority */
1229	if (skb != NULL) {
1230		swap(skb, ctx->tx_rem_skb);
1231		swap(sign, ctx->tx_rem_sign);
1232	} else {
1233		ready2send = 1;
1234	}
1235
1236	/* check if we are resuming an OUT skb */
1237	skb_out = ctx->tx_curr_skb;
1238
1239	/* allocate a new OUT skb */
1240	if (!skb_out) {
1241		if (ctx->tx_low_mem_val == 0) {
1242			ctx->tx_curr_size = ctx->tx_max;
1243			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1244			/* If the memory allocation fails we will wait longer
1245			 * each time before attempting another full size
1246			 * allocation again to not overload the system
1247			 * further.
1248			 */
1249			if (skb_out == NULL) {
1250				/* If even the smallest allocation fails, abort. */
1251				if (ctx->tx_curr_size == USB_CDC_NCM_NTB_MIN_OUT_SIZE)
1252					goto alloc_failed;
1253				ctx->tx_low_mem_max_cnt = min(ctx->tx_low_mem_max_cnt + 1,
1254							      (unsigned)CDC_NCM_LOW_MEM_MAX_CNT);
1255				ctx->tx_low_mem_val = ctx->tx_low_mem_max_cnt;
1256			}
1257		}
1258		if (skb_out == NULL) {
1259			/* See if a very small allocation is possible.
1260			 * We will send this packet immediately and hope
1261			 * that there is more memory available later.
1262			 */
1263			if (skb)
1264				ctx->tx_curr_size = max(skb->len,
1265					(u32)USB_CDC_NCM_NTB_MIN_OUT_SIZE);
1266			else
1267				ctx->tx_curr_size = USB_CDC_NCM_NTB_MIN_OUT_SIZE;
1268			skb_out = alloc_skb(ctx->tx_curr_size, GFP_ATOMIC);
1269
1270			/* No allocation possible so we will abort */
1271			if (!skb_out)
1272				goto alloc_failed;
 
 
 
 
 
1273			ctx->tx_low_mem_val--;
1274		}
1275		if (ctx->is_ndp16) {
1276			/* fill out the initial 16-bit NTB header */
1277			nth.nth16 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth16));
1278			nth.nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
1279			nth.nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
1280			nth.nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
1281		} else {
1282			/* fill out the initial 32-bit NTB header */
1283			nth.nth32 = skb_put_zero(skb_out, sizeof(struct usb_cdc_ncm_nth32));
1284			nth.nth32->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH32_SIGN);
1285			nth.nth32->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth32));
1286			nth.nth32->wSequence = cpu_to_le16(ctx->tx_seq++);
1287		}
1288
1289		/* count total number of frames in this NTB */
1290		ctx->tx_curr_frame_num = 0;
1291
1292		/* recent payload counter for this skb_out */
1293		ctx->tx_curr_frame_payload = 0;
1294	}
1295
1296	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
1297		/* send any remaining skb first */
1298		if (skb == NULL) {
1299			skb = ctx->tx_rem_skb;
1300			sign = ctx->tx_rem_sign;
1301			ctx->tx_rem_skb = NULL;
1302
1303			/* check for end of skb */
1304			if (skb == NULL)
1305				break;
1306		}
1307
1308		/* get the appropriate NDP for this skb */
1309		if (ctx->is_ndp16)
1310			ndp.ndp16 = cdc_ncm_ndp16(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1311		else
1312			ndp.ndp32 = cdc_ncm_ndp32(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
1313
1314		/* align beginning of next frame */
1315		cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_curr_size);
1316
1317		/* check if we had enough room left for both NDP and frame */
1318		if ((ctx->is_ndp16 && !ndp.ndp16) || (!ctx->is_ndp16 && !ndp.ndp32) ||
1319		    skb_out->len + skb->len + delayed_ndp_size > ctx->tx_curr_size) {
1320			if (n == 0) {
1321				/* won't fit, MTU problem? */
1322				dev_kfree_skb_any(skb);
1323				skb = NULL;
1324				dev->net->stats.tx_dropped++;
1325			} else {
1326				/* no room for skb - store for later */
1327				if (ctx->tx_rem_skb != NULL) {
1328					dev_kfree_skb_any(ctx->tx_rem_skb);
1329					dev->net->stats.tx_dropped++;
1330				}
1331				ctx->tx_rem_skb = skb;
1332				ctx->tx_rem_sign = sign;
1333				skb = NULL;
1334				ready2send = 1;
1335				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
1336			}
1337			break;
1338		}
1339
1340		/* calculate frame number within this NDP */
1341		if (ctx->is_ndp16) {
1342			ndplen = le16_to_cpu(ndp.ndp16->wLength);
1343			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
1344
1345			/* OK, add this skb */
1346			ndp.ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
1347			ndp.ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
1348			ndp.ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
1349		} else {
1350			ndplen = le16_to_cpu(ndp.ndp32->wLength);
1351			index = (ndplen - sizeof(struct usb_cdc_ncm_ndp32)) / sizeof(struct usb_cdc_ncm_dpe32) - 1;
1352
1353			ndp.ndp32->dpe32[index].dwDatagramLength = cpu_to_le32(skb->len);
1354			ndp.ndp32->dpe32[index].dwDatagramIndex = cpu_to_le32(skb_out->len);
1355			ndp.ndp32->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe32));
1356		}
1357		skb_put_data(skb_out, skb->data, skb->len);
1358		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
1359		dev_kfree_skb_any(skb);
1360		skb = NULL;
1361
1362		/* send now if this NDP is full */
1363		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
1364			ready2send = 1;
1365			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
1366			break;
1367		}
1368	}
1369
1370	/* free up any dangling skb */
1371	if (skb != NULL) {
1372		dev_kfree_skb_any(skb);
1373		skb = NULL;
1374		dev->net->stats.tx_dropped++;
1375	}
1376
1377	ctx->tx_curr_frame_num = n;
1378
1379	if (n == 0) {
1380		/* wait for more frames */
1381		/* push variables */
1382		ctx->tx_curr_skb = skb_out;
1383		goto exit_no_skb;
1384
1385	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
1386		/* wait for more frames */
1387		/* push variables */
1388		ctx->tx_curr_skb = skb_out;
1389		/* set the pending count */
1390		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
1391			ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
1392		goto exit_no_skb;
1393
1394	} else {
1395		if (n == ctx->tx_max_datagrams)
1396			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
1397		/* frame goes out */
1398		/* variables will be reset at next call */
1399	}
1400
1401	/* If requested, put NDP at end of frame. */
1402	if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
1403		if (ctx->is_ndp16) {
1404			nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1405			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1406			nth.nth16->wNdpIndex = cpu_to_le16(skb_out->len);
1407			skb_put_data(skb_out, ctx->delayed_ndp16, ctx->max_ndp_size);
1408
1409			/* Zero out delayed NDP - signature checking will naturally fail. */
1410			ndp.ndp16 = memset(ctx->delayed_ndp16, 0, ctx->max_ndp_size);
1411		} else {
1412			nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1413			cdc_ncm_align_tail(skb_out, ctx->tx_ndp_modulus, 0, ctx->tx_curr_size - ctx->max_ndp_size);
1414			nth.nth32->dwNdpIndex = cpu_to_le32(skb_out->len);
1415			skb_put_data(skb_out, ctx->delayed_ndp32, ctx->max_ndp_size);
1416
1417			ndp.ndp32 = memset(ctx->delayed_ndp32, 0, ctx->max_ndp_size);
1418		}
1419	}
1420
1421	/* If collected data size is less or equal ctx->min_tx_pkt
1422	 * bytes, we send buffers as it is. If we get more data, it
1423	 * would be more efficient for USB HS mobile device with DMA
1424	 * engine to receive a full size NTB, than canceling DMA
1425	 * transfer and receiving a short packet.
1426	 *
1427	 * This optimization support is pointless if we end up sending
1428	 * a ZLP after full sized NTBs.
1429	 */
1430	if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
1431	    skb_out->len > ctx->min_tx_pkt) {
1432		padding_count = ctx->tx_curr_size - skb_out->len;
1433		if (!WARN_ON(padding_count > ctx->tx_curr_size))
1434			skb_put_zero(skb_out, padding_count);
1435	} else if (skb_out->len < ctx->tx_curr_size &&
1436		   (skb_out->len % dev->maxpacket) == 0) {
1437		skb_put_u8(skb_out, 0);	/* force short packet */
1438	}
1439
1440	/* set final frame length */
1441	if (ctx->is_ndp16) {
1442		nth.nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
1443		nth.nth16->wBlockLength = cpu_to_le16(skb_out->len);
1444	} else {
1445		nth.nth32 = (struct usb_cdc_ncm_nth32 *)skb_out->data;
1446		nth.nth32->dwBlockLength = cpu_to_le32(skb_out->len);
1447	}
1448
1449	/* return skb */
1450	ctx->tx_curr_skb = NULL;
1451
1452	/* keep private stats: framing overhead and number of NTBs */
1453	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
1454	ctx->tx_ntbs++;
1455
1456	/* usbnet will count all the framing overhead by default.
1457	 * Adjust the stats so that the tx_bytes counter show real
1458	 * payload data instead.
1459	 */
1460	usbnet_set_skb_tx_stats(skb_out, n,
1461				(long)ctx->tx_curr_frame_payload - skb_out->len);
1462
1463	return skb_out;
1464
1465alloc_failed:
1466	if (skb) {
1467		dev_kfree_skb_any(skb);
1468		dev->net->stats.tx_dropped++;
1469	}
1470exit_no_skb:
1471	/* Start timer, if there is a remaining non-empty skb */
1472	if (ctx->tx_curr_skb != NULL && n > 0)
1473		cdc_ncm_tx_timeout_start(ctx);
1474	return NULL;
1475}
1476EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
1477
1478static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
1479{
1480	/* start timer, if not already started */
1481	if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
1482		hrtimer_start(&ctx->tx_timer,
1483				ctx->timer_interval,
1484				HRTIMER_MODE_REL);
1485}
1486
1487static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
1488{
1489	struct cdc_ncm_ctx *ctx =
1490			container_of(timer, struct cdc_ncm_ctx, tx_timer);
1491
1492	if (!atomic_read(&ctx->stop))
1493		tasklet_schedule(&ctx->bh);
1494	return HRTIMER_NORESTART;
1495}
1496
1497static void cdc_ncm_txpath_bh(struct tasklet_struct *t)
1498{
1499	struct cdc_ncm_ctx *ctx = from_tasklet(ctx, t, bh);
1500	struct usbnet *dev = ctx->dev;
1501
1502	spin_lock(&ctx->mtx);
1503	if (ctx->tx_timer_pending != 0) {
1504		ctx->tx_timer_pending--;
1505		cdc_ncm_tx_timeout_start(ctx);
1506		spin_unlock(&ctx->mtx);
1507	} else if (dev->net != NULL) {
1508		ctx->tx_reason_timeout++;	/* count reason for transmitting */
1509		spin_unlock(&ctx->mtx);
1510		netif_tx_lock_bh(dev->net);
1511		usbnet_start_xmit(NULL, dev->net);
1512		netif_tx_unlock_bh(dev->net);
1513	} else {
1514		spin_unlock(&ctx->mtx);
1515	}
1516}
1517
1518struct sk_buff *
1519cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
1520{
1521	struct sk_buff *skb_out;
1522	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1523
1524	/*
1525	 * The Ethernet API we are using does not support transmitting
1526	 * multiple Ethernet frames in a single call. This driver will
1527	 * accumulate multiple Ethernet frames and send out a larger
1528	 * USB frame when the USB buffer is full or when a single jiffies
1529	 * timeout happens.
1530	 */
1531	if (ctx == NULL)
1532		goto error;
1533
1534	spin_lock_bh(&ctx->mtx);
1535
1536	if (ctx->is_ndp16)
1537		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
1538	else
1539		skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN));
1540
1541	spin_unlock_bh(&ctx->mtx);
1542	return skb_out;
1543
1544error:
1545	if (skb != NULL)
1546		dev_kfree_skb_any(skb);
1547
1548	return NULL;
1549}
1550EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
1551
1552/* verify NTB header and return offset of first NDP, or negative error */
1553int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1554{
1555	struct usbnet *dev = netdev_priv(skb_in->dev);
1556	struct usb_cdc_ncm_nth16 *nth16;
1557	int len;
1558	int ret = -EINVAL;
1559
1560	if (ctx == NULL)
1561		goto error;
1562
1563	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
1564					sizeof(struct usb_cdc_ncm_ndp16))) {
1565		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1566		goto error;
1567	}
1568
1569	nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
1570
1571	if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
1572		netif_dbg(dev, rx_err, dev->net,
1573			  "invalid NTH16 signature <%#010x>\n",
1574			  le32_to_cpu(nth16->dwSignature));
1575		goto error;
1576	}
1577
1578	len = le16_to_cpu(nth16->wBlockLength);
1579	if (len > ctx->rx_max) {
1580		netif_dbg(dev, rx_err, dev->net,
1581			  "unsupported NTB block length %u/%u\n", len,
1582			  ctx->rx_max);
1583		goto error;
1584	}
1585
1586	if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
1587	    (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
1588	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
1589		netif_dbg(dev, rx_err, dev->net,
1590			  "sequence number glitch prev=%d curr=%d\n",
1591			  ctx->rx_seq, le16_to_cpu(nth16->wSequence));
1592	}
1593	ctx->rx_seq = le16_to_cpu(nth16->wSequence);
1594
1595	ret = le16_to_cpu(nth16->wNdpIndex);
1596error:
1597	return ret;
1598}
1599EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
1600
1601int cdc_ncm_rx_verify_nth32(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
1602{
1603	struct usbnet *dev = netdev_priv(skb_in->dev);
1604	struct usb_cdc_ncm_nth32 *nth32;
1605	int len;
1606	int ret = -EINVAL;
1607
1608	if (ctx == NULL)
1609		goto error;
1610
1611	if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth32) +
1612					sizeof(struct usb_cdc_ncm_ndp32))) {
1613		netif_dbg(dev, rx_err, dev->net, "frame too short\n");
1614		goto error;
1615	}
1616
1617	nth32 = (struct usb_cdc_ncm_nth32 *)skb_in->data;
1618
1619	if (nth32->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH32_SIGN)) {
1620		netif_dbg(dev, rx_err, dev->net,
1621			  "invalid NTH32 signature <%#010x>\n",
1622			  le32_to_cpu(nth32->dwSignature));
1623		goto error;
1624	}
1625
1626	len = le32_to_cpu(nth32->dwBlockLength);
1627	if (len > ctx->rx_max) {
1628		netif_dbg(dev, rx_err, dev->net,
1629			  "unsupported NTB block length %u/%u\n", len,
1630			  ctx->rx_max);
1631		goto error;
1632	}
1633
1634	if ((ctx->rx_seq + 1) != le16_to_cpu(nth32->wSequence) &&
1635	    (ctx->rx_seq || le16_to_cpu(nth32->wSequence)) &&
1636	    !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth32->wSequence))) {
1637		netif_dbg(dev, rx_err, dev->net,
1638			  "sequence number glitch prev=%d curr=%d\n",
1639			  ctx->rx_seq, le16_to_cpu(nth32->wSequence));
1640	}
1641	ctx->rx_seq = le16_to_cpu(nth32->wSequence);
1642
1643	ret = le32_to_cpu(nth32->dwNdpIndex);
1644error:
1645	return ret;
1646}
1647EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth32);
1648
1649/* verify NDP header and return number of datagrams, or negative error */
1650int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
1651{
1652	struct usbnet *dev = netdev_priv(skb_in->dev);
1653	struct usb_cdc_ncm_ndp16 *ndp16;
1654	int ret = -EINVAL;
1655
1656	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
1657		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1658			  ndpoffset);
1659		goto error;
1660	}
1661	ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1662
1663	if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
1664		netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
1665			  le16_to_cpu(ndp16->wLength));
1666		goto error;
1667	}
1668
1669	ret = ((le16_to_cpu(ndp16->wLength) -
1670					sizeof(struct usb_cdc_ncm_ndp16)) /
1671					sizeof(struct usb_cdc_ncm_dpe16));
1672	ret--; /* we process NDP entries except for the last one */
1673
1674	if ((sizeof(struct usb_cdc_ncm_ndp16) +
1675	     ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
1676		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1677		ret = -EINVAL;
1678	}
1679
1680error:
1681	return ret;
1682}
1683EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
1684
1685/* verify NDP header and return number of datagrams, or negative error */
1686int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset)
1687{
1688	struct usbnet *dev = netdev_priv(skb_in->dev);
1689	struct usb_cdc_ncm_ndp32 *ndp32;
1690	int ret = -EINVAL;
1691
1692	if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) {
1693		netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
1694			  ndpoffset);
1695		goto error;
1696	}
1697	ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1698
1699	if (le16_to_cpu(ndp32->wLength) < USB_CDC_NCM_NDP32_LENGTH_MIN) {
1700		netif_dbg(dev, rx_err, dev->net, "invalid DPT32 length <%u>\n",
1701			  le16_to_cpu(ndp32->wLength));
1702		goto error;
1703	}
1704
1705	ret = ((le16_to_cpu(ndp32->wLength) -
1706					sizeof(struct usb_cdc_ncm_ndp32)) /
1707					sizeof(struct usb_cdc_ncm_dpe32));
1708	ret--; /* we process NDP entries except for the last one */
1709
1710	if ((sizeof(struct usb_cdc_ncm_ndp32) +
1711	     ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) {
1712		netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
1713		ret = -EINVAL;
1714	}
1715
1716error:
1717	return ret;
1718}
1719EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp32);
1720
1721int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
1722{
1723	struct sk_buff *skb;
1724	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
1725	unsigned int len;
1726	int nframes;
1727	int x;
1728	unsigned int offset;
1729	union {
1730		struct usb_cdc_ncm_ndp16 *ndp16;
1731		struct usb_cdc_ncm_ndp32 *ndp32;
1732	} ndp;
1733	union {
1734		struct usb_cdc_ncm_dpe16 *dpe16;
1735		struct usb_cdc_ncm_dpe32 *dpe32;
1736	} dpe;
1737
1738	int ndpoffset;
1739	int loopcount = 50; /* arbitrary max preventing infinite loop */
1740	u32 payload = 0;
1741
1742	if (ctx->is_ndp16)
1743		ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1744	else
1745		ndpoffset = cdc_ncm_rx_verify_nth32(ctx, skb_in);
1746
1747	if (ndpoffset < 0)
1748		goto error;
1749
1750next_ndp:
1751	if (ctx->is_ndp16) {
1752		nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
1753		if (nframes < 0)
1754			goto error;
1755
1756		ndp.ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
1757
1758		if (ndp.ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
1759			netif_dbg(dev, rx_err, dev->net,
1760				  "invalid DPT16 signature <%#010x>\n",
1761				  le32_to_cpu(ndp.ndp16->dwSignature));
1762			goto err_ndp;
1763		}
1764		dpe.dpe16 = ndp.ndp16->dpe16;
1765	} else {
1766		nframes = cdc_ncm_rx_verify_ndp32(skb_in, ndpoffset);
1767		if (nframes < 0)
1768			goto error;
1769
1770		ndp.ndp32 = (struct usb_cdc_ncm_ndp32 *)(skb_in->data + ndpoffset);
1771
1772		if (ndp.ndp32->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP32_NOCRC_SIGN)) {
1773			netif_dbg(dev, rx_err, dev->net,
1774				  "invalid DPT32 signature <%#010x>\n",
1775				  le32_to_cpu(ndp.ndp32->dwSignature));
1776			goto err_ndp;
1777		}
1778		dpe.dpe32 = ndp.ndp32->dpe32;
1779	}
1780
1781	for (x = 0; x < nframes; x++) {
1782		if (ctx->is_ndp16) {
1783			offset = le16_to_cpu(dpe.dpe16->wDatagramIndex);
1784			len = le16_to_cpu(dpe.dpe16->wDatagramLength);
1785		} else {
1786			offset = le32_to_cpu(dpe.dpe32->dwDatagramIndex);
1787			len = le32_to_cpu(dpe.dpe32->dwDatagramLength);
1788		}
1789
1790		/*
1791		 * CDC NCM ch. 3.7
1792		 * All entries after first NULL entry are to be ignored
1793		 */
1794		if ((offset == 0) || (len == 0)) {
1795			if (!x)
1796				goto err_ndp; /* empty NTB */
1797			break;
1798		}
1799
1800		/* sanity checking - watch out for integer wrap*/
1801		if ((offset > skb_in->len) || (len > skb_in->len - offset) ||
1802				(len > ctx->rx_max) || (len < ETH_HLEN)) {
1803			netif_dbg(dev, rx_err, dev->net,
1804				  "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
1805				  x, offset, len, skb_in);
1806			if (!x)
1807				goto err_ndp;
1808			break;
1809
1810		} else {
1811			/* create a fresh copy to reduce truesize */
1812			skb = netdev_alloc_skb_ip_align(dev->net,  len);
1813			if (!skb)
1814				goto error;
1815			skb_put_data(skb, skb_in->data + offset, len);
1816			usbnet_skb_return(dev, skb);
1817			payload += len;	/* count payload bytes in this NTB */
1818		}
1819
1820		if (ctx->is_ndp16)
1821			dpe.dpe16++;
1822		else
1823			dpe.dpe32++;
1824	}
1825err_ndp:
1826	/* are there more NDPs to process? */
1827	if (ctx->is_ndp16)
1828		ndpoffset = le16_to_cpu(ndp.ndp16->wNextNdpIndex);
1829	else
1830		ndpoffset = le32_to_cpu(ndp.ndp32->dwNextNdpIndex);
1831
1832	if (ndpoffset && loopcount--)
1833		goto next_ndp;
1834
1835	/* update stats */
1836	ctx->rx_overhead += skb_in->len - payload;
1837	ctx->rx_ntbs++;
1838
1839	return 1;
1840error:
1841	return 0;
1842}
1843EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
1844
1845static void
1846cdc_ncm_speed_change(struct usbnet *dev,
1847		     struct usb_cdc_speed_change *data)
1848{
1849	/* RTL8156 shipped before 2021 sends notification about every 32ms. */
1850	dev->rx_speed = le32_to_cpu(data->DLBitRRate);
1851	dev->tx_speed = le32_to_cpu(data->ULBitRate);
1852}
1853
1854static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1855{
1856	struct usb_cdc_notification *event;
1857
1858	if (urb->actual_length < sizeof(*event))
1859		return;
1860
1861	/* test for split data in 8-byte chunks */
1862	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1863		cdc_ncm_speed_change(dev,
1864		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1865		return;
1866	}
1867
1868	event = urb->transfer_buffer;
1869
1870	switch (event->bNotificationType) {
1871	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1872		/*
1873		 * According to the CDC NCM specification ch.7.1
1874		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1875		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1876		 */
1877		/* RTL8156 shipped before 2021 sends notification about
1878		 * every 32ms. Don't forward notification if state is same.
1879		 */
1880		if (netif_carrier_ok(dev->net) != !!event->wValue)
1881			usbnet_link_change(dev, !!event->wValue, 0);
1882		break;
1883
1884	case USB_CDC_NOTIFY_SPEED_CHANGE:
1885		if (urb->actual_length < (sizeof(*event) +
1886					sizeof(struct usb_cdc_speed_change)))
1887			set_bit(EVENT_STS_SPLIT, &dev->flags);
1888		else
1889			cdc_ncm_speed_change(dev,
1890					     (struct usb_cdc_speed_change *)&event[1]);
1891		break;
1892
1893	default:
1894		dev_dbg(&dev->udev->dev,
1895			"NCM: unexpected notification 0x%02x!\n",
1896			event->bNotificationType);
1897		break;
1898	}
1899}
1900
1901static const struct driver_info cdc_ncm_info = {
1902	.description = "CDC NCM (NO ZLP)",
1903	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1904			| FLAG_LINK_INTR | FLAG_ETHER,
1905	.bind = cdc_ncm_bind,
1906	.unbind = cdc_ncm_unbind,
1907	.manage_power = usbnet_manage_power,
1908	.status = cdc_ncm_status,
1909	.rx_fixup = cdc_ncm_rx_fixup,
1910	.tx_fixup = cdc_ncm_tx_fixup,
1911	.set_rx_mode = usbnet_cdc_update_filter,
1912};
1913
1914/* Same as cdc_ncm_info, but with FLAG_SEND_ZLP  */
1915static const struct driver_info cdc_ncm_zlp_info = {
1916	.description = "CDC NCM (SEND ZLP)",
1917	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1918			| FLAG_LINK_INTR | FLAG_ETHER | FLAG_SEND_ZLP,
1919	.bind = cdc_ncm_bind,
1920	.unbind = cdc_ncm_unbind,
1921	.manage_power = usbnet_manage_power,
1922	.status = cdc_ncm_status,
1923	.rx_fixup = cdc_ncm_rx_fixup,
1924	.tx_fixup = cdc_ncm_tx_fixup,
1925	.set_rx_mode = usbnet_cdc_update_filter,
1926};
1927
1928/* Same as cdc_ncm_info, but with FLAG_WWAN */
1929static const struct driver_info wwan_info = {
1930	.description = "Mobile Broadband Network Device",
1931	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1932			| FLAG_LINK_INTR | FLAG_WWAN,
1933	.bind = cdc_ncm_bind,
1934	.unbind = cdc_ncm_unbind,
1935	.manage_power = usbnet_manage_power,
1936	.status = cdc_ncm_status,
1937	.rx_fixup = cdc_ncm_rx_fixup,
1938	.tx_fixup = cdc_ncm_tx_fixup,
1939	.set_rx_mode = usbnet_cdc_update_filter,
1940};
1941
1942/* Same as wwan_info, but with FLAG_NOARP  */
1943static const struct driver_info wwan_noarp_info = {
1944	.description = "Mobile Broadband Network Device (NO ARP)",
1945	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
1946			| FLAG_LINK_INTR | FLAG_WWAN | FLAG_NOARP,
1947	.bind = cdc_ncm_bind,
1948	.unbind = cdc_ncm_unbind,
1949	.manage_power = usbnet_manage_power,
1950	.status = cdc_ncm_status,
1951	.rx_fixup = cdc_ncm_rx_fixup,
1952	.tx_fixup = cdc_ncm_tx_fixup,
1953	.set_rx_mode = usbnet_cdc_update_filter,
1954};
1955
1956static const struct usb_device_id cdc_devs[] = {
1957	/* Ericsson MBM devices like F5521gw */
1958	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1959		| USB_DEVICE_ID_MATCH_VENDOR,
1960	  .idVendor = 0x0bdb,
1961	  .bInterfaceClass = USB_CLASS_COMM,
1962	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1963	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1964	  .driver_info = (unsigned long) &wwan_info,
1965	},
1966
1967	/* Telit LE910 V2 */
1968	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x0036,
1969		USB_CLASS_COMM,
1970		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1971	  .driver_info = (unsigned long)&wwan_noarp_info,
1972	},
1973
1974	/* DW5812 LTE Verizon Mobile Broadband Card
1975	 * Unlike DW5550 this device requires FLAG_NOARP
1976	 */
1977	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bb,
1978		USB_CLASS_COMM,
1979		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1980	  .driver_info = (unsigned long)&wwan_noarp_info,
1981	},
1982
1983	/* DW5813 LTE AT&T Mobile Broadband Card
1984	 * Unlike DW5550 this device requires FLAG_NOARP
1985	 */
1986	{ USB_DEVICE_AND_INTERFACE_INFO(0x413c, 0x81bc,
1987		USB_CLASS_COMM,
1988		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
1989	  .driver_info = (unsigned long)&wwan_noarp_info,
1990	},
1991
1992	/* Dell branded MBM devices like DW5550 */
1993	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
1994		| USB_DEVICE_ID_MATCH_VENDOR,
1995	  .idVendor = 0x413c,
1996	  .bInterfaceClass = USB_CLASS_COMM,
1997	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
1998	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
1999	  .driver_info = (unsigned long) &wwan_info,
2000	},
2001
2002	/* Toshiba branded MBM devices */
2003	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
2004		| USB_DEVICE_ID_MATCH_VENDOR,
2005	  .idVendor = 0x0930,
2006	  .bInterfaceClass = USB_CLASS_COMM,
2007	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2008	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2009	  .driver_info = (unsigned long) &wwan_info,
2010	},
2011
2012	/* tag Huawei devices as wwan */
2013	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
2014					USB_CLASS_COMM,
2015					USB_CDC_SUBCLASS_NCM,
2016					USB_CDC_PROTO_NONE),
2017	  .driver_info = (unsigned long)&wwan_info,
2018	},
2019
2020	/* Infineon(now Intel) HSPA Modem platform */
2021	{ USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
2022		USB_CLASS_COMM,
2023		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2024	  .driver_info = (unsigned long)&wwan_noarp_info,
2025	},
2026
2027	/* u-blox TOBY-L4 */
2028	{ USB_DEVICE_AND_INTERFACE_INFO(0x1546, 0x1010,
2029		USB_CLASS_COMM,
2030		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2031	  .driver_info = (unsigned long)&wwan_info,
2032	},
2033
2034	/* DisplayLink docking stations */
2035	{ .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
2036		| USB_DEVICE_ID_MATCH_VENDOR,
2037	  .idVendor = 0x17e9,
2038	  .bInterfaceClass = USB_CLASS_COMM,
2039	  .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
2040	  .bInterfaceProtocol = USB_CDC_PROTO_NONE,
2041	  .driver_info = (unsigned long)&cdc_ncm_zlp_info,
2042	},
2043
2044	/* Generic CDC-NCM devices */
2045	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
2046		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
2047		.driver_info = (unsigned long)&cdc_ncm_info,
2048	},
2049	{
2050	},
2051};
2052MODULE_DEVICE_TABLE(usb, cdc_devs);
2053
2054static struct usb_driver cdc_ncm_driver = {
2055	.name = "cdc_ncm",
2056	.id_table = cdc_devs,
2057	.probe = usbnet_probe,
2058	.disconnect = usbnet_disconnect,
2059	.suspend = usbnet_suspend,
2060	.resume = usbnet_resume,
2061	.reset_resume =	usbnet_resume,
2062	.supports_autosuspend = 1,
2063	.disable_hub_initiated_lpm = 1,
2064};
2065
2066module_usb_driver(cdc_ncm_driver);
2067
2068MODULE_AUTHOR("Hans Petter Selasky");
2069MODULE_DESCRIPTION("USB CDC NCM host driver");
2070MODULE_LICENSE("Dual BSD/GPL");