Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / usb / cdc_ncm.c
diff --git a/kernel/drivers/net/usb/cdc_ncm.c b/kernel/drivers/net/usb/cdc_ncm.c
new file mode 100644 (file)
index 0000000..8067b8f
--- /dev/null
@@ -0,0 +1,1616 @@
+/*
+ * cdc_ncm.c
+ *
+ * Copyright (C) ST-Ericsson 2010-2012
+ * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
+ * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
+ *
+ * USB Host Driver for Network Control Model (NCM)
+ * http://www.usb.org/developers/devclass_docs/NCM10.zip
+ *
+ * The NCM encoding, decoding and initialization logic
+ * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose this file to be licensed under the terms
+ * of the GNU General Public License (GPL) Version 2 or the 2-clause
+ * BSD license listed below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ctype.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/crc32.h>
+#include <linux/usb.h>
+#include <linux/hrtimer.h>
+#include <linux/atomic.h>
+#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/cdc_ncm.h>
+
+#if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
+static bool prefer_mbim = true;
+#else
+static bool prefer_mbim;
+#endif
+module_param(prefer_mbim, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
+
+static void cdc_ncm_txpath_bh(unsigned long param);
+static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
+static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
+static struct usb_driver cdc_ncm_driver;
+
+struct cdc_ncm_stats {
+       char stat_string[ETH_GSTRING_LEN];
+       int sizeof_stat;
+       int stat_offset;
+};
+
+#define CDC_NCM_STAT(str, m) { \
+               .stat_string = str, \
+               .sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
+               .stat_offset = offsetof(struct cdc_ncm_ctx, m) }
+#define CDC_NCM_SIMPLE_STAT(m) CDC_NCM_STAT(__stringify(m), m)
+
+static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
+       CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
+       CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
+       CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
+       CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
+       CDC_NCM_SIMPLE_STAT(tx_overhead),
+       CDC_NCM_SIMPLE_STAT(tx_ntbs),
+       CDC_NCM_SIMPLE_STAT(rx_overhead),
+       CDC_NCM_SIMPLE_STAT(rx_ntbs),
+};
+
+static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
+{
+       switch (sset) {
+       case ETH_SS_STATS:
+               return ARRAY_SIZE(cdc_ncm_gstrings_stats);
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
+                                   struct ethtool_stats __always_unused *stats,
+                                   u64 *data)
+{
+       struct usbnet *dev = netdev_priv(netdev);
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       int i;
+       char *p = NULL;
+
+       for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+               p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
+               data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
+       }
+}
+
+static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
+{
+       u8 *p = data;
+       int i;
+
+       switch (stringset) {
+       case ETH_SS_STATS:
+               for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+                       memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
+                       p += ETH_GSTRING_LEN;
+               }
+       }
+}
+
+static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx);
+
+static const struct ethtool_ops cdc_ncm_ethtool_ops = {
+       .get_settings      = usbnet_get_settings,
+       .set_settings      = usbnet_set_settings,
+       .get_link          = usbnet_get_link,
+       .nway_reset        = usbnet_nway_reset,
+       .get_drvinfo       = usbnet_get_drvinfo,
+       .get_msglevel      = usbnet_get_msglevel,
+       .set_msglevel      = usbnet_set_msglevel,
+       .get_ts_info       = ethtool_op_get_ts_info,
+       .get_sset_count    = cdc_ncm_get_sset_count,
+       .get_strings       = cdc_ncm_get_strings,
+       .get_ethtool_stats = cdc_ncm_get_ethtool_stats,
+};
+
+static u32 cdc_ncm_check_rx_max(struct usbnet *dev, u32 new_rx)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u32 val, max, min;
+
+       /* clamp new_rx to sane values */
+       min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
+       max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
+
+       /* dwNtbInMaxSize spec violation? Use MIN size for both limits */
+       if (max < min) {
+               dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
+                        le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
+               max = min;
+       }
+
+       val = clamp_t(u32, new_rx, min, max);
+       if (val != new_rx)
+               dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range\n", min, max);
+
+       return val;
+}
+
+static u32 cdc_ncm_check_tx_max(struct usbnet *dev, u32 new_tx)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u32 val, max, min;
+
+       /* clamp new_tx to sane values */
+       min = ctx->max_datagram_size + ctx->max_ndp_size + sizeof(struct usb_cdc_ncm_nth16);
+       max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
+
+       /* some devices set dwNtbOutMaxSize too low for the above default */
+       min = min(min, max);
+
+       val = clamp_t(u32, new_tx, min, max);
+       if (val != new_tx)
+               dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range\n", min, max);
+
+       return val;
+}
+
+static ssize_t cdc_ncm_show_min_tx_pkt(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       return sprintf(buf, "%u\n", ctx->min_tx_pkt);
+}
+
+static ssize_t cdc_ncm_show_rx_max(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       return sprintf(buf, "%u\n", ctx->rx_max);
+}
+
+static ssize_t cdc_ncm_show_tx_max(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       return sprintf(buf, "%u\n", ctx->tx_max);
+}
+
+static ssize_t cdc_ncm_show_tx_timer_usecs(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       return sprintf(buf, "%u\n", ctx->timer_interval / (u32)NSEC_PER_USEC);
+}
+
+static ssize_t cdc_ncm_store_min_tx_pkt(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       unsigned long val;
+
+       /* no need to restrict values - anything from 0 to infinity is OK */
+       if (kstrtoul(buf, 0, &val))
+               return -EINVAL;
+
+       ctx->min_tx_pkt = val;
+       return len;
+}
+
+static ssize_t cdc_ncm_store_rx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       unsigned long val;
+
+       if (kstrtoul(buf, 0, &val) || cdc_ncm_check_rx_max(dev, val) != val)
+               return -EINVAL;
+
+       cdc_ncm_update_rxtx_max(dev, val, ctx->tx_max);
+       return len;
+}
+
+static ssize_t cdc_ncm_store_tx_max(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       unsigned long val;
+
+       if (kstrtoul(buf, 0, &val) || cdc_ncm_check_tx_max(dev, val) != val)
+               return -EINVAL;
+
+       cdc_ncm_update_rxtx_max(dev, ctx->rx_max, val);
+       return len;
+}
+
+static ssize_t cdc_ncm_store_tx_timer_usecs(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       ssize_t ret;
+       unsigned long val;
+
+       ret = kstrtoul(buf, 0, &val);
+       if (ret)
+               return ret;
+       if (val && (val < CDC_NCM_TIMER_INTERVAL_MIN || val > CDC_NCM_TIMER_INTERVAL_MAX))
+               return -EINVAL;
+
+       spin_lock_bh(&ctx->mtx);
+       ctx->timer_interval = val * NSEC_PER_USEC;
+       if (!ctx->timer_interval)
+               ctx->tx_timer_pending = 0;
+       spin_unlock_bh(&ctx->mtx);
+       return len;
+}
+
+static DEVICE_ATTR(min_tx_pkt, S_IRUGO | S_IWUSR, cdc_ncm_show_min_tx_pkt, cdc_ncm_store_min_tx_pkt);
+static DEVICE_ATTR(rx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_rx_max, cdc_ncm_store_rx_max);
+static DEVICE_ATTR(tx_max, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_max, cdc_ncm_store_tx_max);
+static DEVICE_ATTR(tx_timer_usecs, S_IRUGO | S_IWUSR, cdc_ncm_show_tx_timer_usecs, cdc_ncm_store_tx_timer_usecs);
+
+#define NCM_PARM_ATTR(name, format, tocpu)                             \
+static ssize_t cdc_ncm_show_##name(struct device *d, struct device_attribute *attr, char *buf) \
+{ \
+       struct usbnet *dev = netdev_priv(to_net_dev(d)); \
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0]; \
+       return sprintf(buf, format "\n", tocpu(ctx->ncm_parm.name));    \
+} \
+static DEVICE_ATTR(name, S_IRUGO, cdc_ncm_show_##name, NULL)
+
+NCM_PARM_ATTR(bmNtbFormatsSupported, "0x%04x", le16_to_cpu);
+NCM_PARM_ATTR(dwNtbInMaxSize, "%u", le32_to_cpu);
+NCM_PARM_ATTR(wNdpInDivisor, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpInPayloadRemainder, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpInAlignment, "%u", le16_to_cpu);
+NCM_PARM_ATTR(dwNtbOutMaxSize, "%u", le32_to_cpu);
+NCM_PARM_ATTR(wNdpOutDivisor, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpOutPayloadRemainder, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNdpOutAlignment, "%u", le16_to_cpu);
+NCM_PARM_ATTR(wNtbOutMaxDatagrams, "%u", le16_to_cpu);
+
+static struct attribute *cdc_ncm_sysfs_attrs[] = {
+       &dev_attr_min_tx_pkt.attr,
+       &dev_attr_rx_max.attr,
+       &dev_attr_tx_max.attr,
+       &dev_attr_tx_timer_usecs.attr,
+       &dev_attr_bmNtbFormatsSupported.attr,
+       &dev_attr_dwNtbInMaxSize.attr,
+       &dev_attr_wNdpInDivisor.attr,
+       &dev_attr_wNdpInPayloadRemainder.attr,
+       &dev_attr_wNdpInAlignment.attr,
+       &dev_attr_dwNtbOutMaxSize.attr,
+       &dev_attr_wNdpOutDivisor.attr,
+       &dev_attr_wNdpOutPayloadRemainder.attr,
+       &dev_attr_wNdpOutAlignment.attr,
+       &dev_attr_wNtbOutMaxDatagrams.attr,
+       NULL,
+};
+
+static struct attribute_group cdc_ncm_sysfs_attr_group = {
+       .name = "cdc_ncm",
+       .attrs = cdc_ncm_sysfs_attrs,
+};
+
+/* handle rx_max and tx_max changes */
+static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+       u32 val;
+
+       val = cdc_ncm_check_rx_max(dev, new_rx);
+
+       /* inform device about NTB input size changes */
+       if (val != ctx->rx_max) {
+               __le32 dwNtbInMaxSize = cpu_to_le32(val);
+
+               dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
+
+               /* tell device to use new size */
+               if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
+                                    USB_TYPE_CLASS | USB_DIR_OUT
+                                    | USB_RECIP_INTERFACE,
+                                    0, iface_no, &dwNtbInMaxSize, 4) < 0)
+                       dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
+               else
+                       ctx->rx_max = val;
+       }
+
+       /* usbnet use these values for sizing rx queues */
+       if (dev->rx_urb_size != ctx->rx_max) {
+               dev->rx_urb_size = ctx->rx_max;
+               if (netif_running(dev->net))
+                       usbnet_unlink_rx_urbs(dev);
+       }
+
+       val = cdc_ncm_check_tx_max(dev, new_tx);
+       if (val != ctx->tx_max)
+               dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
+
+       /* Adding a pad byte here if necessary simplifies the handling
+        * in cdc_ncm_fill_tx_frame, making tx_max always represent
+        * the real skb max size.
+        *
+        * We cannot use dev->maxpacket here because this is called from
+        * .bind which is called before usbnet sets up dev->maxpacket
+        */
+       if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
+           val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
+               val++;
+
+       /* we might need to flush any pending tx buffers if running */
+       if (netif_running(dev->net) && val > ctx->tx_max) {
+               netif_tx_lock_bh(dev->net);
+               usbnet_start_xmit(NULL, dev->net);
+               /* make sure tx_curr_skb is reallocated if it was empty */
+               if (ctx->tx_curr_skb) {
+                       dev_kfree_skb_any(ctx->tx_curr_skb);
+                       ctx->tx_curr_skb = NULL;
+               }
+               ctx->tx_max = val;
+               netif_tx_unlock_bh(dev->net);
+       } else {
+               ctx->tx_max = val;
+       }
+
+       dev->hard_mtu = ctx->tx_max;
+
+       /* max qlen depend on hard_mtu and rx_urb_size */
+       usbnet_update_max_qlen(dev);
+
+       /* never pad more than 3 full USB packets per transfer */
+       ctx->min_tx_pkt = clamp_t(u16, ctx->tx_max - 3 * usb_maxpacket(dev->udev, dev->out, 1),
+                                 CDC_NCM_MIN_TX_PKT, ctx->tx_max);
+}
+
+/* helpers for NCM and MBIM differences */
+static u8 cdc_ncm_flags(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
+               return ctx->mbim_desc->bmNetworkCapabilities;
+       if (ctx->func_desc)
+               return ctx->func_desc->bmNetworkCapabilities;
+       return 0;
+}
+
+static int cdc_ncm_eth_hlen(struct usbnet *dev)
+{
+       if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
+               return 0;
+       return ETH_HLEN;
+}
+
+static u32 cdc_ncm_min_dgram_size(struct usbnet *dev)
+{
+       if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting))
+               return CDC_MBIM_MIN_DATAGRAM_SIZE;
+       return CDC_NCM_MIN_DATAGRAM_SIZE;
+}
+
+static u32 cdc_ncm_max_dgram_size(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       if (cdc_ncm_comm_intf_is_mbim(dev->intf->cur_altsetting) && ctx->mbim_desc)
+               return le16_to_cpu(ctx->mbim_desc->wMaxSegmentSize);
+       if (ctx->ether_desc)
+               return le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
+       return CDC_NCM_MAX_DATAGRAM_SIZE;
+}
+
+/* initial one-time device setup.  MUST be called with the data interface
+ * in altsetting 0
+ */
+static int cdc_ncm_init(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+       int err;
+
+       err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_PARAMETERS,
+                             USB_TYPE_CLASS | USB_DIR_IN
+                             |USB_RECIP_INTERFACE,
+                             0, iface_no, &ctx->ncm_parm,
+                             sizeof(ctx->ncm_parm));
+       if (err < 0) {
+               dev_err(&dev->intf->dev, "failed GET_NTB_PARAMETERS\n");
+               return err; /* GET_NTB_PARAMETERS is required */
+       }
+
+       /* set CRC Mode */
+       if (cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_CRC_MODE) {
+               dev_dbg(&dev->intf->dev, "Setting CRC mode off\n");
+               err = usbnet_write_cmd(dev, USB_CDC_SET_CRC_MODE,
+                                      USB_TYPE_CLASS | USB_DIR_OUT
+                                      | USB_RECIP_INTERFACE,
+                                      USB_CDC_NCM_CRC_NOT_APPENDED,
+                                      iface_no, NULL, 0);
+               if (err < 0)
+                       dev_err(&dev->intf->dev, "SET_CRC_MODE failed\n");
+       }
+
+       /* set NTB format, if both formats are supported.
+        *
+        * "The host shall only send this command while the NCM Data
+        *  Interface is in alternate setting 0."
+        */
+       if (le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported) &
+                                               USB_CDC_NCM_NTB32_SUPPORTED) {
+               dev_dbg(&dev->intf->dev, "Setting NTB format to 16-bit\n");
+               err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
+                                      USB_TYPE_CLASS | USB_DIR_OUT
+                                      | USB_RECIP_INTERFACE,
+                                      USB_CDC_NCM_NTB16_FORMAT,
+                                      iface_no, NULL, 0);
+               if (err < 0)
+                       dev_err(&dev->intf->dev, "SET_NTB_FORMAT failed\n");
+       }
+
+       /* set initial device values */
+       ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
+       ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
+       ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
+       ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
+       ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
+       /* devices prior to NCM Errata shall set this field to zero */
+       ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
+
+       dev_dbg(&dev->intf->dev,
+               "dwNtbInMaxSize=%u dwNtbOutMaxSize=%u wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
+               ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
+               ctx->tx_ndp_modulus, ctx->tx_max_datagrams, cdc_ncm_flags(dev));
+
+       /* max count of tx datagrams */
+       if ((ctx->tx_max_datagrams == 0) ||
+                       (ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
+               ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
+
+       /* set up maximum NDP size */
+       ctx->max_ndp_size = sizeof(struct usb_cdc_ncm_ndp16) + (ctx->tx_max_datagrams + 1) * sizeof(struct usb_cdc_ncm_dpe16);
+
+       /* initial coalescing timer interval */
+       ctx->timer_interval = CDC_NCM_TIMER_INTERVAL_USEC * NSEC_PER_USEC;
+
+       return 0;
+}
+
+/* set a new max datagram size */
+static void cdc_ncm_set_dgram_size(struct usbnet *dev, int new_size)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+       __le16 max_datagram_size;
+       u16 mbim_mtu;
+       int err;
+
+       /* set default based on descriptors */
+       ctx->max_datagram_size = clamp_t(u32, new_size,
+                                        cdc_ncm_min_dgram_size(dev),
+                                        CDC_NCM_MAX_DATAGRAM_SIZE);
+
+       /* inform the device about the selected Max Datagram Size? */
+       if (!(cdc_ncm_flags(dev) & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE))
+               goto out;
+
+       /* read current mtu value from device */
+       err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE,
+                             USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
+                             0, iface_no, &max_datagram_size, 2);
+       if (err < 0) {
+               dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n");
+               goto out;
+       }
+
+       if (le16_to_cpu(max_datagram_size) == ctx->max_datagram_size)
+               goto out;
+
+       max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
+       err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE,
+                              USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE,
+                              0, iface_no, &max_datagram_size, 2);
+       if (err < 0)
+               dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");
+
+out:
+       /* set MTU to max supported by the device if necessary */
+       dev->net->mtu = min_t(int, dev->net->mtu, ctx->max_datagram_size - cdc_ncm_eth_hlen(dev));
+
+       /* do not exceed operater preferred MTU */
+       if (ctx->mbim_extended_desc) {
+               mbim_mtu = le16_to_cpu(ctx->mbim_extended_desc->wMTU);
+               if (mbim_mtu != 0 && mbim_mtu < dev->net->mtu)
+                       dev->net->mtu = mbim_mtu;
+       }
+}
+
+static void cdc_ncm_fix_modulus(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u32 val;
+
+       /*
+        * verify that the structure alignment is:
+        * - power of two
+        * - not greater than the maximum transmit length
+        * - not less than four bytes
+        */
+       val = ctx->tx_ndp_modulus;
+
+       if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
+           (val != ((-val) & val)) || (val >= ctx->tx_max)) {
+               dev_dbg(&dev->intf->dev, "Using default alignment: 4 bytes\n");
+               ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
+       }
+
+       /*
+        * verify that the payload alignment is:
+        * - power of two
+        * - not greater than the maximum transmit length
+        * - not less than four bytes
+        */
+       val = ctx->tx_modulus;
+
+       if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
+           (val != ((-val) & val)) || (val >= ctx->tx_max)) {
+               dev_dbg(&dev->intf->dev, "Using default transmit modulus: 4 bytes\n");
+               ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
+       }
+
+       /* verify the payload remainder */
+       if (ctx->tx_remainder >= ctx->tx_modulus) {
+               dev_dbg(&dev->intf->dev, "Using default transmit remainder: 0 bytes\n");
+               ctx->tx_remainder = 0;
+       }
+
+       /* adjust TX-remainder according to NCM specification. */
+       ctx->tx_remainder = ((ctx->tx_remainder - cdc_ncm_eth_hlen(dev)) &
+                            (ctx->tx_modulus - 1));
+}
+
+static int cdc_ncm_setup(struct usbnet *dev)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u32 def_rx, def_tx;
+
+       /* be conservative when selecting intial buffer size to
+        * increase the number of hosts this will work for
+        */
+       def_rx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_RX,
+                      le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
+       def_tx = min_t(u32, CDC_NCM_NTB_DEF_SIZE_TX,
+                      le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
+
+       /* clamp rx_max and tx_max and inform device */
+       cdc_ncm_update_rxtx_max(dev, def_rx, def_tx);
+
+       /* sanitize the modulus and remainder values */
+       cdc_ncm_fix_modulus(dev);
+
+       /* set max datagram size */
+       cdc_ncm_set_dgram_size(dev, cdc_ncm_max_dgram_size(dev));
+       return 0;
+}
+
+static void
+cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf)
+{
+       struct usb_host_endpoint *e, *in = NULL, *out = NULL;
+       u8 ep;
+
+       for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
+
+               e = intf->cur_altsetting->endpoint + ep;
+               switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+               case USB_ENDPOINT_XFER_INT:
+                       if (usb_endpoint_dir_in(&e->desc)) {
+                               if (!dev->status)
+                                       dev->status = e;
+                       }
+                       break;
+
+               case USB_ENDPOINT_XFER_BULK:
+                       if (usb_endpoint_dir_in(&e->desc)) {
+                               if (!in)
+                                       in = e;
+                       } else {
+                               if (!out)
+                                       out = e;
+                       }
+                       break;
+
+               default:
+                       break;
+               }
+       }
+       if (in && !dev->in)
+               dev->in = usb_rcvbulkpipe(dev->udev,
+                                         in->desc.bEndpointAddress &
+                                         USB_ENDPOINT_NUMBER_MASK);
+       if (out && !dev->out)
+               dev->out = usb_sndbulkpipe(dev->udev,
+                                          out->desc.bEndpointAddress &
+                                          USB_ENDPOINT_NUMBER_MASK);
+}
+
+static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
+{
+       if (ctx == NULL)
+               return;
+
+       if (ctx->tx_rem_skb != NULL) {
+               dev_kfree_skb_any(ctx->tx_rem_skb);
+               ctx->tx_rem_skb = NULL;
+       }
+
+       if (ctx->tx_curr_skb != NULL) {
+               dev_kfree_skb_any(ctx->tx_curr_skb);
+               ctx->tx_curr_skb = NULL;
+       }
+
+       kfree(ctx);
+}
+
+int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting)
+{
+       const struct usb_cdc_union_desc *union_desc = NULL;
+       struct cdc_ncm_ctx *ctx;
+       struct usb_driver *driver;
+       u8 *buf;
+       int len;
+       int temp;
+       u8 iface_no;
+
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return -ENOMEM;
+
+       hrtimer_init(&ctx->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+       ctx->tx_timer.function = &cdc_ncm_tx_timer_cb;
+       ctx->bh.data = (unsigned long)dev;
+       ctx->bh.func = cdc_ncm_txpath_bh;
+       atomic_set(&ctx->stop, 0);
+       spin_lock_init(&ctx->mtx);
+
+       /* store ctx pointer in device data field */
+       dev->data[0] = (unsigned long)ctx;
+
+       /* only the control interface can be successfully probed */
+       ctx->control = intf;
+
+       /* get some pointers */
+       driver = driver_of(intf);
+       buf = intf->cur_altsetting->extra;
+       len = intf->cur_altsetting->extralen;
+
+       /* parse through descriptors associated with control interface */
+       while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
+
+               if (buf[1] != USB_DT_CS_INTERFACE)
+                       goto advance;
+
+               switch (buf[2]) {
+               case USB_CDC_UNION_TYPE:
+                       if (buf[0] < sizeof(*union_desc))
+                               break;
+
+                       union_desc = (const struct usb_cdc_union_desc *)buf;
+                       /* the master must be the interface we are probing */
+                       if (intf->cur_altsetting->desc.bInterfaceNumber !=
+                           union_desc->bMasterInterface0) {
+                               dev_dbg(&intf->dev, "bogus CDC Union\n");
+                               goto error;
+                       }
+                       ctx->data = usb_ifnum_to_if(dev->udev,
+                                                   union_desc->bSlaveInterface0);
+                       break;
+
+               case USB_CDC_ETHERNET_TYPE:
+                       if (buf[0] < sizeof(*(ctx->ether_desc)))
+                               break;
+
+                       ctx->ether_desc =
+                                       (const struct usb_cdc_ether_desc *)buf;
+                       break;
+
+               case USB_CDC_NCM_TYPE:
+                       if (buf[0] < sizeof(*(ctx->func_desc)))
+                               break;
+
+                       ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
+                       break;
+
+               case USB_CDC_MBIM_TYPE:
+                       if (buf[0] < sizeof(*(ctx->mbim_desc)))
+                               break;
+
+                       ctx->mbim_desc = (const struct usb_cdc_mbim_desc *)buf;
+                       break;
+
+               case USB_CDC_MBIM_EXTENDED_TYPE:
+                       if (buf[0] < sizeof(*(ctx->mbim_extended_desc)))
+                               break;
+
+                       ctx->mbim_extended_desc =
+                               (const struct usb_cdc_mbim_extended_desc *)buf;
+                       break;
+
+               default:
+                       break;
+               }
+advance:
+               /* advance to next descriptor */
+               temp = buf[0];
+               buf += temp;
+               len -= temp;
+       }
+
+       /* some buggy devices have an IAD but no CDC Union */
+       if (!union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) {
+               ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1);
+               dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n");
+       }
+
+       /* check if we got everything */
+       if (!ctx->data) {
+               dev_dbg(&intf->dev, "CDC Union missing and no IAD found\n");
+               goto error;
+       }
+       if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
+               if (!ctx->mbim_desc) {
+                       dev_dbg(&intf->dev, "MBIM functional descriptor missing\n");
+                       goto error;
+               }
+       } else {
+               if (!ctx->ether_desc || !ctx->func_desc) {
+                       dev_dbg(&intf->dev, "NCM or ECM functional descriptors missing\n");
+                       goto error;
+               }
+       }
+
+       /* claim data interface, if different from control */
+       if (ctx->data != ctx->control) {
+               temp = usb_driver_claim_interface(driver, ctx->data, dev);
+               if (temp) {
+                       dev_dbg(&intf->dev, "failed to claim data intf\n");
+                       goto error;
+               }
+       }
+
+       iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
+
+       /* reset data interface */
+       temp = usb_set_interface(dev->udev, iface_no, 0);
+       if (temp) {
+               dev_dbg(&intf->dev, "set interface failed\n");
+               goto error2;
+       }
+
+       /* initialize basic device settings */
+       if (cdc_ncm_init(dev))
+               goto error2;
+
+       /* configure data interface */
+       temp = usb_set_interface(dev->udev, iface_no, data_altsetting);
+       if (temp) {
+               dev_dbg(&intf->dev, "set interface failed\n");
+               goto error2;
+       }
+
+       cdc_ncm_find_endpoints(dev, ctx->data);
+       cdc_ncm_find_endpoints(dev, ctx->control);
+       if (!dev->in || !dev->out || !dev->status) {
+               dev_dbg(&intf->dev, "failed to collect endpoints\n");
+               goto error2;
+       }
+
+       usb_set_intfdata(ctx->data, dev);
+       usb_set_intfdata(ctx->control, dev);
+
+       if (ctx->ether_desc) {
+               temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
+               if (temp) {
+                       dev_dbg(&intf->dev, "failed to get mac address\n");
+                       goto error2;
+               }
+               dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
+       }
+
+       /* finish setting up the device specific data */
+       cdc_ncm_setup(dev);
+
+       /* override ethtool_ops */
+       dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
+
+       /* add our sysfs attrs */
+       dev->net->sysfs_groups[0] = &cdc_ncm_sysfs_attr_group;
+
+       return 0;
+
+error2:
+       usb_set_intfdata(ctx->control, NULL);
+       usb_set_intfdata(ctx->data, NULL);
+       if (ctx->data != ctx->control)
+               usb_driver_release_interface(driver, ctx->data);
+error:
+       cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
+       dev->data[0] = 0;
+       dev_info(&intf->dev, "bind() failure\n");
+       return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_bind_common);
+
+void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       struct usb_driver *driver = driver_of(intf);
+
+       if (ctx == NULL)
+               return;         /* no setup */
+
+       atomic_set(&ctx->stop, 1);
+
+       if (hrtimer_active(&ctx->tx_timer))
+               hrtimer_cancel(&ctx->tx_timer);
+
+       tasklet_kill(&ctx->bh);
+
+       /* handle devices with combined control and data interface */
+       if (ctx->control == ctx->data)
+               ctx->data = NULL;
+
+       /* disconnect master --> disconnect slave */
+       if (intf == ctx->control && ctx->data) {
+               usb_set_intfdata(ctx->data, NULL);
+               usb_driver_release_interface(driver, ctx->data);
+               ctx->data = NULL;
+
+       } else if (intf == ctx->data && ctx->control) {
+               usb_set_intfdata(ctx->control, NULL);
+               usb_driver_release_interface(driver, ctx->control);
+               ctx->control = NULL;
+       }
+
+       usb_set_intfdata(intf, NULL);
+       cdc_ncm_free(ctx);
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
+
+/* Return the number of the MBIM control interface altsetting iff it
+ * is preferred and available,
+ */
+u8 cdc_ncm_select_altsetting(struct usb_interface *intf)
+{
+       struct usb_host_interface *alt;
+
+       /* The MBIM spec defines a NCM compatible default altsetting,
+        * which we may have matched:
+        *
+        *  "Functions that implement both NCM 1.0 and MBIM (an
+        *   “NCM/MBIM function”) according to this recommendation
+        *   shall provide two alternate settings for the
+        *   Communication Interface.  Alternate setting 0, and the
+        *   associated class and endpoint descriptors, shall be
+        *   constructed according to the rules given for the
+        *   Communication Interface in section 5 of [USBNCM10].
+        *   Alternate setting 1, and the associated class and
+        *   endpoint descriptors, shall be constructed according to
+        *   the rules given in section 6 (USB Device Model) of this
+        *   specification."
+        */
+       if (intf->num_altsetting < 2)
+               return intf->cur_altsetting->desc.bAlternateSetting;
+
+       if (prefer_mbim) {
+               alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
+               if (alt && cdc_ncm_comm_intf_is_mbim(alt))
+                       return CDC_NCM_COMM_ALTSETTING_MBIM;
+       }
+       return CDC_NCM_COMM_ALTSETTING_NCM;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
+
+static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+       int ret;
+
+       /* MBIM backwards compatible function? */
+       if (cdc_ncm_select_altsetting(intf) != CDC_NCM_COMM_ALTSETTING_NCM)
+               return -ENODEV;
+
+       /* The NCM data altsetting is fixed */
+       ret = cdc_ncm_bind_common(dev, intf, CDC_NCM_DATA_ALTSETTING_NCM);
+
+       /*
+        * We should get an event when network connection is "connected" or
+        * "disconnected". Set network connection in "disconnected" state
+        * (carrier is OFF) during attach, so the IP network stack does not
+        * start IPv6 negotiation and more.
+        */
+       usbnet_link_change(dev, 0, 0);
+       return ret;
+}
+
+static void cdc_ncm_align_tail(struct sk_buff *skb, size_t modulus, size_t remainder, size_t max)
+{
+       size_t align = ALIGN(skb->len, modulus) - skb->len + remainder;
+
+       if (skb->len + align > max)
+               align = max - skb->len;
+       if (align && skb_tailroom(skb) >= align)
+               memset(skb_put(skb, align), 0, align);
+}
+
+/* return a pointer to a valid struct usb_cdc_ncm_ndp16 of type sign, possibly
+ * allocating a new one within skb
+ */
+static struct usb_cdc_ncm_ndp16 *cdc_ncm_ndp(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign, size_t reserve)
+{
+       struct usb_cdc_ncm_ndp16 *ndp16 = NULL;
+       struct usb_cdc_ncm_nth16 *nth16 = (void *)skb->data;
+       size_t ndpoffset = le16_to_cpu(nth16->wNdpIndex);
+
+       /* follow the chain of NDPs, looking for a match */
+       while (ndpoffset) {
+               ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb->data + ndpoffset);
+               if  (ndp16->dwSignature == sign)
+                       return ndp16;
+               ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
+       }
+
+       /* align new NDP */
+       cdc_ncm_align_tail(skb, ctx->tx_ndp_modulus, 0, ctx->tx_max);
+
+       /* verify that there is room for the NDP and the datagram (reserve) */
+       if ((ctx->tx_max - skb->len - reserve) < ctx->max_ndp_size)
+               return NULL;
+
+       /* link to it */
+       if (ndp16)
+               ndp16->wNextNdpIndex = cpu_to_le16(skb->len);
+       else
+               nth16->wNdpIndex = cpu_to_le16(skb->len);
+
+       /* push a new empty NDP */
+       ndp16 = (struct usb_cdc_ncm_ndp16 *)memset(skb_put(skb, ctx->max_ndp_size), 0, ctx->max_ndp_size);
+       ndp16->dwSignature = sign;
+       ndp16->wLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_ndp16) + sizeof(struct usb_cdc_ncm_dpe16));
+       return ndp16;
+}
+
+struct sk_buff *
+cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       struct usb_cdc_ncm_nth16 *nth16;
+       struct usb_cdc_ncm_ndp16 *ndp16;
+       struct sk_buff *skb_out;
+       u16 n = 0, index, ndplen;
+       u8 ready2send = 0;
+
+       /* if there is a remaining skb, it gets priority */
+       if (skb != NULL) {
+               swap(skb, ctx->tx_rem_skb);
+               swap(sign, ctx->tx_rem_sign);
+       } else {
+               ready2send = 1;
+       }
+
+       /* check if we are resuming an OUT skb */
+       skb_out = ctx->tx_curr_skb;
+
+       /* allocate a new OUT skb */
+       if (!skb_out) {
+               skb_out = alloc_skb(ctx->tx_max, GFP_ATOMIC);
+               if (skb_out == NULL) {
+                       if (skb != NULL) {
+                               dev_kfree_skb_any(skb);
+                               dev->net->stats.tx_dropped++;
+                       }
+                       goto exit_no_skb;
+               }
+               /* fill out the initial 16-bit NTB header */
+               nth16 = (struct usb_cdc_ncm_nth16 *)memset(skb_put(skb_out, sizeof(struct usb_cdc_ncm_nth16)), 0, sizeof(struct usb_cdc_ncm_nth16));
+               nth16->dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
+               nth16->wHeaderLength = cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16));
+               nth16->wSequence = cpu_to_le16(ctx->tx_seq++);
+
+               /* count total number of frames in this NTB */
+               ctx->tx_curr_frame_num = 0;
+
+               /* recent payload counter for this skb_out */
+               ctx->tx_curr_frame_payload = 0;
+       }
+
+       for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
+               /* send any remaining skb first */
+               if (skb == NULL) {
+                       skb = ctx->tx_rem_skb;
+                       sign = ctx->tx_rem_sign;
+                       ctx->tx_rem_skb = NULL;
+
+                       /* check for end of skb */
+                       if (skb == NULL)
+                               break;
+               }
+
+               /* get the appropriate NDP for this skb */
+               ndp16 = cdc_ncm_ndp(ctx, skb_out, sign, skb->len + ctx->tx_modulus + ctx->tx_remainder);
+
+               /* align beginning of next frame */
+               cdc_ncm_align_tail(skb_out,  ctx->tx_modulus, ctx->tx_remainder, ctx->tx_max);
+
+               /* check if we had enough room left for both NDP and frame */
+               if (!ndp16 || skb_out->len + skb->len > ctx->tx_max) {
+                       if (n == 0) {
+                               /* won't fit, MTU problem? */
+                               dev_kfree_skb_any(skb);
+                               skb = NULL;
+                               dev->net->stats.tx_dropped++;
+                       } else {
+                               /* no room for skb - store for later */
+                               if (ctx->tx_rem_skb != NULL) {
+                                       dev_kfree_skb_any(ctx->tx_rem_skb);
+                                       dev->net->stats.tx_dropped++;
+                               }
+                               ctx->tx_rem_skb = skb;
+                               ctx->tx_rem_sign = sign;
+                               skb = NULL;
+                               ready2send = 1;
+                               ctx->tx_reason_ntb_full++;      /* count reason for transmitting */
+                       }
+                       break;
+               }
+
+               /* calculate frame number withing this NDP */
+               ndplen = le16_to_cpu(ndp16->wLength);
+               index = (ndplen - sizeof(struct usb_cdc_ncm_ndp16)) / sizeof(struct usb_cdc_ncm_dpe16) - 1;
+
+               /* OK, add this skb */
+               ndp16->dpe16[index].wDatagramLength = cpu_to_le16(skb->len);
+               ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
+               ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
+               memcpy(skb_put(skb_out, skb->len), skb->data, skb->len);
+               ctx->tx_curr_frame_payload += skb->len; /* count real tx payload data */
+               dev_kfree_skb_any(skb);
+               skb = NULL;
+
+               /* send now if this NDP is full */
+               if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
+                       ready2send = 1;
+                       ctx->tx_reason_ndp_full++;      /* count reason for transmitting */
+                       break;
+               }
+       }
+
+       /* free up any dangling skb */
+       if (skb != NULL) {
+               dev_kfree_skb_any(skb);
+               skb = NULL;
+               dev->net->stats.tx_dropped++;
+       }
+
+       ctx->tx_curr_frame_num = n;
+
+       if (n == 0) {
+               /* wait for more frames */
+               /* push variables */
+               ctx->tx_curr_skb = skb_out;
+               goto exit_no_skb;
+
+       } else if ((n < ctx->tx_max_datagrams) && (ready2send == 0) && (ctx->timer_interval > 0)) {
+               /* wait for more frames */
+               /* push variables */
+               ctx->tx_curr_skb = skb_out;
+               /* set the pending count */
+               if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
+                       ctx->tx_timer_pending = CDC_NCM_TIMER_PENDING_CNT;
+               goto exit_no_skb;
+
+       } else {
+               if (n == ctx->tx_max_datagrams)
+                       ctx->tx_reason_max_datagram++;  /* count reason for transmitting */
+               /* frame goes out */
+               /* variables will be reset at next call */
+       }
+
+       /* If collected data size is less or equal ctx->min_tx_pkt
+        * bytes, we send buffers as it is. If we get more data, it
+        * would be more efficient for USB HS mobile device with DMA
+        * engine to receive a full size NTB, than canceling DMA
+        * transfer and receiving a short packet.
+        *
+        * This optimization support is pointless if we end up sending
+        * a ZLP after full sized NTBs.
+        */
+       if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
+           skb_out->len > ctx->min_tx_pkt)
+               memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0,
+                      ctx->tx_max - skb_out->len);
+       else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0)
+               *skb_put(skb_out, 1) = 0;       /* force short packet */
+
+       /* set final frame length */
+       nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
+       nth16->wBlockLength = cpu_to_le16(skb_out->len);
+
+       /* return skb */
+       ctx->tx_curr_skb = NULL;
+
+       /* keep private stats: framing overhead and number of NTBs */
+       ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
+       ctx->tx_ntbs++;
+
+       /* usbnet will count all the framing overhead by default.
+        * Adjust the stats so that the tx_bytes counter show real
+        * payload data instead.
+        */
+       usbnet_set_skb_tx_stats(skb_out, n,
+                               (long)ctx->tx_curr_frame_payload - skb_out->len);
+
+       return skb_out;
+
+exit_no_skb:
+       /* Start timer, if there is a remaining non-empty skb */
+       if (ctx->tx_curr_skb != NULL && n > 0)
+               cdc_ncm_tx_timeout_start(ctx);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_fill_tx_frame);
+
+static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
+{
+       /* start timer, if not already started */
+       if (!(hrtimer_active(&ctx->tx_timer) || atomic_read(&ctx->stop)))
+               hrtimer_start(&ctx->tx_timer,
+                               ktime_set(0, ctx->timer_interval),
+                               HRTIMER_MODE_REL);
+}
+
+static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *timer)
+{
+       struct cdc_ncm_ctx *ctx =
+                       container_of(timer, struct cdc_ncm_ctx, tx_timer);
+
+       if (!atomic_read(&ctx->stop))
+               tasklet_schedule(&ctx->bh);
+       return HRTIMER_NORESTART;
+}
+
+static void cdc_ncm_txpath_bh(unsigned long param)
+{
+       struct usbnet *dev = (struct usbnet *)param;
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       spin_lock_bh(&ctx->mtx);
+       if (ctx->tx_timer_pending != 0) {
+               ctx->tx_timer_pending--;
+               cdc_ncm_tx_timeout_start(ctx);
+               spin_unlock_bh(&ctx->mtx);
+       } else if (dev->net != NULL) {
+               ctx->tx_reason_timeout++;       /* count reason for transmitting */
+               spin_unlock_bh(&ctx->mtx);
+               netif_tx_lock_bh(dev->net);
+               usbnet_start_xmit(NULL, dev->net);
+               netif_tx_unlock_bh(dev->net);
+       } else {
+               spin_unlock_bh(&ctx->mtx);
+       }
+}
+
+struct sk_buff *
+cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+       struct sk_buff *skb_out;
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       /*
+        * The Ethernet API we are using does not support transmitting
+        * multiple Ethernet frames in a single call. This driver will
+        * accumulate multiple Ethernet frames and send out a larger
+        * USB frame when the USB buffer is full or when a single jiffies
+        * timeout happens.
+        */
+       if (ctx == NULL)
+               goto error;
+
+       spin_lock_bh(&ctx->mtx);
+       skb_out = cdc_ncm_fill_tx_frame(dev, skb, cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN));
+       spin_unlock_bh(&ctx->mtx);
+       return skb_out;
+
+error:
+       if (skb != NULL)
+               dev_kfree_skb_any(skb);
+
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
+
+/* verify NTB header and return offset of first NDP, or negative error */
+int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
+{
+       struct usbnet *dev = netdev_priv(skb_in->dev);
+       struct usb_cdc_ncm_nth16 *nth16;
+       int len;
+       int ret = -EINVAL;
+
+       if (ctx == NULL)
+               goto error;
+
+       if (skb_in->len < (sizeof(struct usb_cdc_ncm_nth16) +
+                                       sizeof(struct usb_cdc_ncm_ndp16))) {
+               netif_dbg(dev, rx_err, dev->net, "frame too short\n");
+               goto error;
+       }
+
+       nth16 = (struct usb_cdc_ncm_nth16 *)skb_in->data;
+
+       if (nth16->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) {
+               netif_dbg(dev, rx_err, dev->net,
+                         "invalid NTH16 signature <%#010x>\n",
+                         le32_to_cpu(nth16->dwSignature));
+               goto error;
+       }
+
+       len = le16_to_cpu(nth16->wBlockLength);
+       if (len > ctx->rx_max) {
+               netif_dbg(dev, rx_err, dev->net,
+                         "unsupported NTB block length %u/%u\n", len,
+                         ctx->rx_max);
+               goto error;
+       }
+
+       if ((ctx->rx_seq + 1) != le16_to_cpu(nth16->wSequence) &&
+           (ctx->rx_seq || le16_to_cpu(nth16->wSequence)) &&
+           !((ctx->rx_seq == 0xffff) && !le16_to_cpu(nth16->wSequence))) {
+               netif_dbg(dev, rx_err, dev->net,
+                         "sequence number glitch prev=%d curr=%d\n",
+                         ctx->rx_seq, le16_to_cpu(nth16->wSequence));
+       }
+       ctx->rx_seq = le16_to_cpu(nth16->wSequence);
+
+       ret = le16_to_cpu(nth16->wNdpIndex);
+error:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_nth16);
+
+/* verify NDP header and return number of datagrams, or negative error */
+int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset)
+{
+       struct usbnet *dev = netdev_priv(skb_in->dev);
+       struct usb_cdc_ncm_ndp16 *ndp16;
+       int ret = -EINVAL;
+
+       if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) {
+               netif_dbg(dev, rx_err, dev->net, "invalid NDP offset  <%u>\n",
+                         ndpoffset);
+               goto error;
+       }
+       ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
+
+       if (le16_to_cpu(ndp16->wLength) < USB_CDC_NCM_NDP16_LENGTH_MIN) {
+               netif_dbg(dev, rx_err, dev->net, "invalid DPT16 length <%u>\n",
+                         le16_to_cpu(ndp16->wLength));
+               goto error;
+       }
+
+       ret = ((le16_to_cpu(ndp16->wLength) -
+                                       sizeof(struct usb_cdc_ncm_ndp16)) /
+                                       sizeof(struct usb_cdc_ncm_dpe16));
+       ret--; /* we process NDP entries except for the last one */
+
+       if ((sizeof(struct usb_cdc_ncm_ndp16) +
+            ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) {
+               netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret);
+               ret = -EINVAL;
+       }
+
+error:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
+
+int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
+{
+       struct sk_buff *skb;
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       int len;
+       int nframes;
+       int x;
+       int offset;
+       struct usb_cdc_ncm_ndp16 *ndp16;
+       struct usb_cdc_ncm_dpe16 *dpe16;
+       int ndpoffset;
+       int loopcount = 50; /* arbitrary max preventing infinite loop */
+       u32 payload = 0;
+
+       ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
+       if (ndpoffset < 0)
+               goto error;
+
+next_ndp:
+       nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
+       if (nframes < 0)
+               goto error;
+
+       ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
+
+       if (ndp16->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) {
+               netif_dbg(dev, rx_err, dev->net,
+                         "invalid DPT16 signature <%#010x>\n",
+                         le32_to_cpu(ndp16->dwSignature));
+               goto err_ndp;
+       }
+       dpe16 = ndp16->dpe16;
+
+       for (x = 0; x < nframes; x++, dpe16++) {
+               offset = le16_to_cpu(dpe16->wDatagramIndex);
+               len = le16_to_cpu(dpe16->wDatagramLength);
+
+               /*
+                * CDC NCM ch. 3.7
+                * All entries after first NULL entry are to be ignored
+                */
+               if ((offset == 0) || (len == 0)) {
+                       if (!x)
+                               goto err_ndp; /* empty NTB */
+                       break;
+               }
+
+               /* sanity checking */
+               if (((offset + len) > skb_in->len) ||
+                               (len > ctx->rx_max) || (len < ETH_HLEN)) {
+                       netif_dbg(dev, rx_err, dev->net,
+                                 "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
+                                 x, offset, len, skb_in);
+                       if (!x)
+                               goto err_ndp;
+                       break;
+
+               } else {
+                       /* create a fresh copy to reduce truesize */
+                       skb = netdev_alloc_skb_ip_align(dev->net,  len);
+                       if (!skb)
+                               goto error;
+                       memcpy(skb_put(skb, len), skb_in->data + offset, len);
+                       usbnet_skb_return(dev, skb);
+                       payload += len; /* count payload bytes in this NTB */
+               }
+       }
+err_ndp:
+       /* are there more NDPs to process? */
+       ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
+       if (ndpoffset && loopcount--)
+               goto next_ndp;
+
+       /* update stats */
+       ctx->rx_overhead += skb_in->len - payload;
+       ctx->rx_ntbs++;
+
+       return 1;
+error:
+       return 0;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
+
+static void
+cdc_ncm_speed_change(struct usbnet *dev,
+                    struct usb_cdc_speed_change *data)
+{
+       uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
+       uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
+
+       /*
+        * Currently the USB-NET API does not support reporting the actual
+        * device speed. Do print it instead.
+        */
+       if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
+               netif_info(dev, link, dev->net,
+                          "%u mbit/s downlink %u mbit/s uplink\n",
+                          (unsigned int)(rx_speed / 1000000U),
+                          (unsigned int)(tx_speed / 1000000U));
+       } else {
+               netif_info(dev, link, dev->net,
+                          "%u kbit/s downlink %u kbit/s uplink\n",
+                          (unsigned int)(rx_speed / 1000U),
+                          (unsigned int)(tx_speed / 1000U));
+       }
+}
+
+static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
+{
+       struct cdc_ncm_ctx *ctx;
+       struct usb_cdc_notification *event;
+
+       ctx = (struct cdc_ncm_ctx *)dev->data[0];
+
+       if (urb->actual_length < sizeof(*event))
+               return;
+
+       /* test for split data in 8-byte chunks */
+       if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
+               cdc_ncm_speed_change(dev,
+                     (struct usb_cdc_speed_change *)urb->transfer_buffer);
+               return;
+       }
+
+       event = urb->transfer_buffer;
+
+       switch (event->bNotificationType) {
+       case USB_CDC_NOTIFY_NETWORK_CONNECTION:
+               /*
+                * According to the CDC NCM specification ch.7.1
+                * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
+                * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
+                */
+               netif_info(dev, link, dev->net,
+                          "network connection: %sconnected\n",
+                          !!event->wValue ? "" : "dis");
+               usbnet_link_change(dev, !!event->wValue, 0);
+               break;
+
+       case USB_CDC_NOTIFY_SPEED_CHANGE:
+               if (urb->actual_length < (sizeof(*event) +
+                                       sizeof(struct usb_cdc_speed_change)))
+                       set_bit(EVENT_STS_SPLIT, &dev->flags);
+               else
+                       cdc_ncm_speed_change(dev,
+                                            (struct usb_cdc_speed_change *)&event[1]);
+               break;
+
+       default:
+               dev_dbg(&dev->udev->dev,
+                       "NCM: unexpected notification 0x%02x!\n",
+                       event->bNotificationType);
+               break;
+       }
+}
+
+static const struct driver_info cdc_ncm_info = {
+       .description = "CDC NCM",
+       .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
+       .bind = cdc_ncm_bind,
+       .unbind = cdc_ncm_unbind,
+       .manage_power = usbnet_manage_power,
+       .status = cdc_ncm_status,
+       .rx_fixup = cdc_ncm_rx_fixup,
+       .tx_fixup = cdc_ncm_tx_fixup,
+};
+
+/* Same as cdc_ncm_info, but with FLAG_WWAN */
+static const struct driver_info wwan_info = {
+       .description = "Mobile Broadband Network Device",
+       .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
+                       | FLAG_WWAN,
+       .bind = cdc_ncm_bind,
+       .unbind = cdc_ncm_unbind,
+       .manage_power = usbnet_manage_power,
+       .status = cdc_ncm_status,
+       .rx_fixup = cdc_ncm_rx_fixup,
+       .tx_fixup = cdc_ncm_tx_fixup,
+};
+
+/* Same as wwan_info, but with FLAG_NOARP  */
+static const struct driver_info wwan_noarp_info = {
+       .description = "Mobile Broadband Network Device (NO ARP)",
+       .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET
+                       | FLAG_WWAN | FLAG_NOARP,
+       .bind = cdc_ncm_bind,
+       .unbind = cdc_ncm_unbind,
+       .manage_power = usbnet_manage_power,
+       .status = cdc_ncm_status,
+       .rx_fixup = cdc_ncm_rx_fixup,
+       .tx_fixup = cdc_ncm_tx_fixup,
+};
+
+static const struct usb_device_id cdc_devs[] = {
+       /* Ericsson MBM devices like F5521gw */
+       { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
+               | USB_DEVICE_ID_MATCH_VENDOR,
+         .idVendor = 0x0bdb,
+         .bInterfaceClass = USB_CLASS_COMM,
+         .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
+         .bInterfaceProtocol = USB_CDC_PROTO_NONE,
+         .driver_info = (unsigned long) &wwan_info,
+       },
+
+       /* Dell branded MBM devices like DW5550 */
+       { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
+               | USB_DEVICE_ID_MATCH_VENDOR,
+         .idVendor = 0x413c,
+         .bInterfaceClass = USB_CLASS_COMM,
+         .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
+         .bInterfaceProtocol = USB_CDC_PROTO_NONE,
+         .driver_info = (unsigned long) &wwan_info,
+       },
+
+       /* Toshiba branded MBM devices */
+       { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO
+               | USB_DEVICE_ID_MATCH_VENDOR,
+         .idVendor = 0x0930,
+         .bInterfaceClass = USB_CLASS_COMM,
+         .bInterfaceSubClass = USB_CDC_SUBCLASS_NCM,
+         .bInterfaceProtocol = USB_CDC_PROTO_NONE,
+         .driver_info = (unsigned long) &wwan_info,
+       },
+
+       /* tag Huawei devices as wwan */
+       { USB_VENDOR_AND_INTERFACE_INFO(0x12d1,
+                                       USB_CLASS_COMM,
+                                       USB_CDC_SUBCLASS_NCM,
+                                       USB_CDC_PROTO_NONE),
+         .driver_info = (unsigned long)&wwan_info,
+       },
+
+       /* Infineon(now Intel) HSPA Modem platform */
+       { USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
+               USB_CLASS_COMM,
+               USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
+         .driver_info = (unsigned long)&wwan_noarp_info,
+       },
+
+       /* Generic CDC-NCM devices */
+       { USB_INTERFACE_INFO(USB_CLASS_COMM,
+               USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
+               .driver_info = (unsigned long)&cdc_ncm_info,
+       },
+       {
+       },
+};
+MODULE_DEVICE_TABLE(usb, cdc_devs);
+
+static struct usb_driver cdc_ncm_driver = {
+       .name = "cdc_ncm",
+       .id_table = cdc_devs,
+       .probe = usbnet_probe,
+       .disconnect = usbnet_disconnect,
+       .suspend = usbnet_suspend,
+       .resume = usbnet_resume,
+       .reset_resume = usbnet_resume,
+       .supports_autosuspend = 1,
+       .disable_hub_initiated_lpm = 1,
+};
+
+module_usb_driver(cdc_ncm_driver);
+
+MODULE_AUTHOR("Hans Petter Selasky");
+MODULE_DESCRIPTION("USB CDC NCM host driver");
+MODULE_LICENSE("Dual BSD/GPL");