Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1711 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c
new file mode 100644
index 000000000..10b4612df
--- /dev/null
+++ b/drivers/usb/gadget/function/f_ncm.c
@@ -0,0 +1,1711 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_ncm.c -- USB CDC Network (NCM) link function driver
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
+ *
+ * The driver borrows from f_ecm.c which is:
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2008 Nokia Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+
+#include <linux/usb/cdc.h>
+
+#include "u_ether.h"
+#include "u_ether_configfs.h"
+#include "u_ncm.h"
+
+/*
+ * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
+ * NCM is intended to be used with high-speed network attachments.
+ *
+ * Note that NCM requires the use of "alternate settings" for its data
+ * interface.  This means that the set_alt() method has real work to do,
+ * and also means that a get_alt() method is required.
+ */
+
+/* to trigger crc/non-crc ndp signature */
+
+#define NCM_NDP_HDR_CRC_MASK	0x01000000
+#define NCM_NDP_HDR_CRC		0x01000000
+#define NCM_NDP_HDR_NOCRC	0x00000000
+
+enum ncm_notify_state {
+	NCM_NOTIFY_NONE,		/* don't notify */
+	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
+	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
+};
+
+struct f_ncm {
+	struct gether			port;
+	u8				ctrl_id, data_id;
+
+	char				ethaddr[14];
+
+	struct usb_ep			*notify;
+	struct usb_request		*notify_req;
+	u8				notify_state;
+	atomic_t			notify_count;
+	bool				is_open;
+
+	const struct ndp_parser_opts	*parser_opts;
+	bool				is_crc;
+	u32				ndp_sign;
+
+	/*
+	 * for notification, it is accessed from both
+	 * callback and ethernet open/close
+	 */
+	spinlock_t			lock;
+
+	struct net_device		*netdev;
+
+	/* For multi-frame NDP TX */
+	struct sk_buff			*skb_tx_data;
+	struct sk_buff			*skb_tx_ndp;
+	u16				ndp_dgram_count;
+	bool				timer_force_tx;
+	struct hrtimer			task_timer;
+	bool				timer_stopping;
+};
+
+static inline struct f_ncm *func_to_ncm(struct usb_function *f)
+{
+	return container_of(f, struct f_ncm, port.func);
+}
+
+/* peak (theoretical) bulk transfer rate in bits-per-second */
+static inline unsigned ncm_bitrate(struct usb_gadget *g)
+{
+	if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
+		return 4250000000U;
+	else if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
+		return 3750000000U;
+	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
+		return 13 * 512 * 8 * 1000 * 8;
+	else
+		return 19 *  64 * 1 * 1000 * 8;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * We cannot group frames so use just the minimal size which ok to put
+ * one max-size ethernet frame.
+ * If the host can group frames, allow it to do that, 16K is selected,
+ * because it's used by default by the current linux host driver
+ */
+#define NTB_DEFAULT_IN_SIZE	16384
+#define NTB_OUT_SIZE		16384
+
+/* Allocation for storing the NDP, 32 should suffice for a
+ * 16k packet. This allows a maximum of 32 * 507 Byte packets to
+ * be transmitted in a single 16kB skb, though when sending full size
+ * packets this limit will be plenty.
+ * Smaller packets are not likely to be trying to maximize the
+ * throughput and will be mstly sending smaller infrequent frames.
+ */
+#define TX_MAX_NUM_DPE		32
+
+/* Delay for the transmit to wait before sending an unfilled NTB frame. */
+#define TX_TIMEOUT_NSECS	300000
+
+#define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
+				 USB_CDC_NCM_NTB32_SUPPORTED)
+
+static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
+	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
+	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
+	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
+	.wNdpInDivisor = cpu_to_le16(4),
+	.wNdpInPayloadRemainder = cpu_to_le16(0),
+	.wNdpInAlignment = cpu_to_le16(4),
+
+	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
+	.wNdpOutDivisor = cpu_to_le16(4),
+	.wNdpOutPayloadRemainder = cpu_to_le16(0),
+	.wNdpOutAlignment = cpu_to_le16(4),
+};
+
+/*
+ * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
+ * packet, to simplify cancellation; and a big transfer interval, to
+ * waste less bandwidth.
+ */
+
+#define NCM_STATUS_INTERVAL_MS		32
+#define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
+
+static struct usb_interface_assoc_descriptor ncm_iad_desc = {
+	.bLength =		sizeof ncm_iad_desc,
+	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
+
+	/* .bFirstInterface =	DYNAMIC, */
+	.bInterfaceCount =	2,	/* control + data */
+	.bFunctionClass =	USB_CLASS_COMM,
+	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
+	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
+	/* .iFunction =		DYNAMIC */
+};
+
+/* interface descriptor: */
+
+static struct usb_interface_descriptor ncm_control_intf = {
+	.bLength =		sizeof ncm_control_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	/* .bInterfaceNumber = DYNAMIC */
+	.bNumEndpoints =	1,
+	.bInterfaceClass =	USB_CLASS_COMM,
+	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
+	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
+	/* .iInterface = DYNAMIC */
+};
+
+static struct usb_cdc_header_desc ncm_header_desc = {
+	.bLength =		sizeof ncm_header_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
+
+	.bcdCDC =		cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_union_desc ncm_union_desc = {
+	.bLength =		sizeof(ncm_union_desc),
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
+	/* .bMasterInterface0 =	DYNAMIC */
+	/* .bSlaveInterface0 =	DYNAMIC */
+};
+
+static struct usb_cdc_ether_desc ecm_desc = {
+	.bLength =		sizeof ecm_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
+
+	/* this descriptor actually adds value, surprise! */
+	/* .iMACAddress = DYNAMIC */
+	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
+	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
+	.wNumberMCFilters =	cpu_to_le16(0),
+	.bNumberPowerFilters =	0,
+};
+
+#define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
+
+static struct usb_cdc_ncm_desc ncm_desc = {
+	.bLength =		sizeof ncm_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
+
+	.bcdNcmVersion =	cpu_to_le16(0x0100),
+	/* can process SetEthernetPacketFilter */
+	.bmNetworkCapabilities = NCAPS,
+};
+
+/* the default data interface has no endpoints ... */
+
+static struct usb_interface_descriptor ncm_data_nop_intf = {
+	.bLength =		sizeof ncm_data_nop_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	.bInterfaceNumber =	1,
+	.bAlternateSetting =	0,
+	.bNumEndpoints =	0,
+	.bInterfaceClass =	USB_CLASS_CDC_DATA,
+	.bInterfaceSubClass =	0,
+	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
+	/* .iInterface = DYNAMIC */
+};
+
+/* ... but the "real" data interface has two bulk endpoints */
+
+static struct usb_interface_descriptor ncm_data_intf = {
+	.bLength =		sizeof ncm_data_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	.bInterfaceNumber =	1,
+	.bAlternateSetting =	1,
+	.bNumEndpoints =	2,
+	.bInterfaceClass =	USB_CLASS_CDC_DATA,
+	.bInterfaceSubClass =	0,
+	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
+	/* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
+	.bInterval =		NCM_STATUS_INTERVAL_MS,
+};
+
+static struct usb_endpoint_descriptor fs_ncm_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor fs_ncm_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *ncm_fs_function[] = {
+	(struct usb_descriptor_header *) &ncm_iad_desc,
+	/* CDC NCM control descriptors */
+	(struct usb_descriptor_header *) &ncm_control_intf,
+	(struct usb_descriptor_header *) &ncm_header_desc,
+	(struct usb_descriptor_header *) &ncm_union_desc,
+	(struct usb_descriptor_header *) &ecm_desc,
+	(struct usb_descriptor_header *) &ncm_desc,
+	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
+	/* data interface, altsettings 0 and 1 */
+	(struct usb_descriptor_header *) &ncm_data_nop_intf,
+	(struct usb_descriptor_header *) &ncm_data_intf,
+	(struct usb_descriptor_header *) &fs_ncm_in_desc,
+	(struct usb_descriptor_header *) &fs_ncm_out_desc,
+	NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
+	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
+};
+static struct usb_endpoint_descriptor hs_ncm_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_ncm_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *ncm_hs_function[] = {
+	(struct usb_descriptor_header *) &ncm_iad_desc,
+	/* CDC NCM control descriptors */
+	(struct usb_descriptor_header *) &ncm_control_intf,
+	(struct usb_descriptor_header *) &ncm_header_desc,
+	(struct usb_descriptor_header *) &ncm_union_desc,
+	(struct usb_descriptor_header *) &ecm_desc,
+	(struct usb_descriptor_header *) &ncm_desc,
+	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
+	/* data interface, altsettings 0 and 1 */
+	(struct usb_descriptor_header *) &ncm_data_nop_intf,
+	(struct usb_descriptor_header *) &ncm_data_intf,
+	(struct usb_descriptor_header *) &hs_ncm_in_desc,
+	(struct usb_descriptor_header *) &hs_ncm_out_desc,
+	NULL,
+};
+
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_INT,
+	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
+	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
+};
+
+static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
+	.bLength =		sizeof(ss_ncm_notify_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/* the following 3 values can be tweaked if necessary */
+	/* .bMaxBurst =		0, */
+	/* .bmAttributes =	0, */
+	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
+};
+
+static struct usb_endpoint_descriptor ss_ncm_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor ss_ncm_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
+	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/* the following 2 values can be tweaked if necessary */
+	/* .bMaxBurst =		0, */
+	/* .bmAttributes =	0, */
+};
+
+static struct usb_descriptor_header *ncm_ss_function[] = {
+	(struct usb_descriptor_header *) &ncm_iad_desc,
+	/* CDC NCM control descriptors */
+	(struct usb_descriptor_header *) &ncm_control_intf,
+	(struct usb_descriptor_header *) &ncm_header_desc,
+	(struct usb_descriptor_header *) &ncm_union_desc,
+	(struct usb_descriptor_header *) &ecm_desc,
+	(struct usb_descriptor_header *) &ncm_desc,
+	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
+	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
+	/* data interface, altsettings 0 and 1 */
+	(struct usb_descriptor_header *) &ncm_data_nop_intf,
+	(struct usb_descriptor_header *) &ncm_data_intf,
+	(struct usb_descriptor_header *) &ss_ncm_in_desc,
+	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
+	(struct usb_descriptor_header *) &ss_ncm_out_desc,
+	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
+	NULL,
+};
+
+/* string descriptors: */
+
+#define STRING_CTRL_IDX	0
+#define STRING_MAC_IDX	1
+#define STRING_DATA_IDX	2
+#define STRING_IAD_IDX	3
+
+static struct usb_string ncm_string_defs[] = {
+	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
+	[STRING_MAC_IDX].s = "",
+	[STRING_DATA_IDX].s = "CDC Network Data",
+	[STRING_IAD_IDX].s = "CDC NCM",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings ncm_string_table = {
+	.language =		0x0409,	/* en-us */
+	.strings =		ncm_string_defs,
+};
+
+static struct usb_gadget_strings *ncm_strings[] = {
+	&ncm_string_table,
+	NULL,
+};
+
+/*
+ * Here are options for NCM Datagram Pointer table (NDP) parser.
+ * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
+ * in NDP16 offsets and sizes fields are 1 16bit word wide,
+ * in NDP32 -- 2 16bit words wide. Also signatures are different.
+ * To make the parser code the same, put the differences in the structure,
+ * and switch pointers to the structures when the format is changed.
+ */
+
+struct ndp_parser_opts {
+	u32		nth_sign;
+	u32		ndp_sign;
+	unsigned	nth_size;
+	unsigned	ndp_size;
+	unsigned	dpe_size;
+	unsigned	ndplen_align;
+	/* sizes in u16 units */
+	unsigned	dgram_item_len; /* index or length */
+	unsigned	block_length;
+	unsigned	ndp_index;
+	unsigned	reserved1;
+	unsigned	reserved2;
+	unsigned	next_ndp_index;
+};
+
+#define INIT_NDP16_OPTS {					\
+		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
+		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
+		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
+		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
+		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
+		.ndplen_align = 4,				\
+		.dgram_item_len = 1,				\
+		.block_length = 1,				\
+		.ndp_index = 1,					\
+		.reserved1 = 0,					\
+		.reserved2 = 0,					\
+		.next_ndp_index = 1,				\
+	}
+
+
+#define INIT_NDP32_OPTS {					\
+		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
+		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
+		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
+		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
+		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
+		.ndplen_align = 8,				\
+		.dgram_item_len = 2,				\
+		.block_length = 2,				\
+		.ndp_index = 2,					\
+		.reserved1 = 1,					\
+		.reserved2 = 2,					\
+		.next_ndp_index = 2,				\
+	}
+
+static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
+static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
+
+static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
+{
+	switch (size) {
+	case 1:
+		put_unaligned_le16((u16)val, *p);
+		break;
+	case 2:
+		put_unaligned_le32((u32)val, *p);
+
+		break;
+	default:
+		BUG();
+	}
+
+	*p += size;
+}
+
+static inline unsigned get_ncm(__le16 **p, unsigned size)
+{
+	unsigned tmp;
+
+	switch (size) {
+	case 1:
+		tmp = get_unaligned_le16(*p);
+		break;
+	case 2:
+		tmp = get_unaligned_le32(*p);
+		break;
+	default:
+		BUG();
+	}
+
+	*p += size;
+	return tmp;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline void ncm_reset_values(struct f_ncm *ncm)
+{
+	ncm->parser_opts = &ndp16_opts;
+	ncm->is_crc = false;
+	ncm->port.cdc_filter = DEFAULT_FILTER;
+
+	/* doesn't make sense for ncm, fixed size used */
+	ncm->port.header_len = 0;
+
+	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
+	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
+}
+
+/*
+ * Context: ncm->lock held
+ */
+static void ncm_do_notify(struct f_ncm *ncm)
+{
+	struct usb_request		*req = ncm->notify_req;
+	struct usb_cdc_notification	*event;
+	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
+	__le32				*data;
+	int				status;
+
+	/* notification already in flight? */
+	if (atomic_read(&ncm->notify_count))
+		return;
+
+	event = req->buf;
+	switch (ncm->notify_state) {
+	case NCM_NOTIFY_NONE:
+		return;
+
+	case NCM_NOTIFY_CONNECT:
+		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
+		if (ncm->is_open)
+			event->wValue = cpu_to_le16(1);
+		else
+			event->wValue = cpu_to_le16(0);
+		event->wLength = 0;
+		req->length = sizeof *event;
+
+		DBG(cdev, "notify connect %s\n",
+				ncm->is_open ? "true" : "false");
+		ncm->notify_state = NCM_NOTIFY_NONE;
+		break;
+
+	case NCM_NOTIFY_SPEED:
+		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
+		event->wValue = cpu_to_le16(0);
+		event->wLength = cpu_to_le16(8);
+		req->length = NCM_STATUS_BYTECOUNT;
+
+		/* SPEED_CHANGE data is up/down speeds in bits/sec */
+		data = req->buf + sizeof *event;
+		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
+		data[1] = data[0];
+
+		DBG(cdev, "notify speed %u\n", ncm_bitrate(cdev->gadget));
+		ncm->notify_state = NCM_NOTIFY_CONNECT;
+		break;
+	}
+	event->bmRequestType = 0xA1;
+	event->wIndex = cpu_to_le16(ncm->ctrl_id);
+
+	atomic_inc(&ncm->notify_count);
+
+	/*
+	 * In double buffering if there is a space in FIFO,
+	 * completion callback can be called right after the call,
+	 * so unlocking
+	 */
+	spin_unlock(&ncm->lock);
+	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
+	spin_lock(&ncm->lock);
+	if (status < 0) {
+		atomic_dec(&ncm->notify_count);
+		DBG(cdev, "notify --> %d\n", status);
+	}
+}
+
+/*
+ * Context: ncm->lock held
+ */
+static void ncm_notify(struct f_ncm *ncm)
+{
+	/*
+	 * NOTE on most versions of Linux, host side cdc-ethernet
+	 * won't listen for notifications until its netdevice opens.
+	 * The first notification then sits in the FIFO for a long
+	 * time, and the second one is queued.
+	 *
+	 * If ncm_notify() is called before the second (CONNECT)
+	 * notification is sent, then it will reset to send the SPEED
+	 * notificaion again (and again, and again), but it's not a problem
+	 */
+	ncm->notify_state = NCM_NOTIFY_SPEED;
+	ncm_do_notify(ncm);
+}
+
+static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_ncm			*ncm = req->context;
+	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
+	struct usb_cdc_notification	*event = req->buf;
+
+	spin_lock(&ncm->lock);
+	switch (req->status) {
+	case 0:
+		VDBG(cdev, "Notification %02x sent\n",
+		     event->bNotificationType);
+		atomic_dec(&ncm->notify_count);
+		break;
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+		atomic_set(&ncm->notify_count, 0);
+		ncm->notify_state = NCM_NOTIFY_NONE;
+		break;
+	default:
+		DBG(cdev, "event %02x --> %d\n",
+			event->bNotificationType, req->status);
+		atomic_dec(&ncm->notify_count);
+		break;
+	}
+	ncm_do_notify(ncm);
+	spin_unlock(&ncm->lock);
+}
+
+static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	/* now for SET_NTB_INPUT_SIZE only */
+	unsigned		in_size;
+	struct usb_function	*f = req->context;
+	struct f_ncm		*ncm = func_to_ncm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	req->context = NULL;
+	if (req->status || req->actual != req->length) {
+		DBG(cdev, "Bad control-OUT transfer\n");
+		goto invalid;
+	}
+
+	in_size = get_unaligned_le32(req->buf);
+	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
+	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
+		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
+		goto invalid;
+	}
+
+	ncm->port.fixed_in_len = in_size;
+	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
+	return;
+
+invalid:
+	usb_ep_set_halt(ep);
+	return;
+}
+
+static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+	struct f_ncm		*ncm = func_to_ncm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	struct usb_request	*req = cdev->req;
+	int			value = -EOPNOTSUPP;
+	u16			w_index = le16_to_cpu(ctrl->wIndex);
+	u16			w_value = le16_to_cpu(ctrl->wValue);
+	u16			w_length = le16_to_cpu(ctrl->wLength);
+
+	/*
+	 * composite driver infrastructure handles everything except
+	 * CDC class messages; interface activation uses set_alt().
+	 */
+	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
+		/*
+		 * see 6.2.30: no data, wIndex = interface,
+		 * wValue = packet filter bitmap
+		 */
+		if (w_length != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		DBG(cdev, "packet filter %02x\n", w_value);
+		/*
+		 * REVISIT locking of cdc_filter.  This assumes the UDC
+		 * driver won't have a concurrent packet TX irq running on
+		 * another CPU; or that if it does, this write is atomic...
+		 */
+		ncm->port.cdc_filter = w_value;
+		value = 0;
+		break;
+	/*
+	 * and optionally:
+	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
+	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
+	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
+	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
+	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
+	 * case USB_CDC_GET_ETHERNET_STATISTIC:
+	 */
+
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_GET_NTB_PARAMETERS:
+
+		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		value = w_length > sizeof ntb_parameters ?
+			sizeof ntb_parameters : w_length;
+		memcpy(req->buf, &ntb_parameters, value);
+		VDBG(cdev, "Host asked NTB parameters\n");
+		break;
+
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_GET_NTB_INPUT_SIZE:
+
+		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
+		value = 4;
+		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
+		     ncm->port.fixed_in_len);
+		break;
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_SET_NTB_INPUT_SIZE:
+	{
+		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		req->complete = ncm_ep0out_complete;
+		req->length = w_length;
+		req->context = f;
+
+		value = req->length;
+		break;
+	}
+
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_GET_NTB_FORMAT:
+	{
+		uint16_t format;
+
+		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
+		put_unaligned_le16(format, req->buf);
+		value = 2;
+		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
+		break;
+	}
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_SET_NTB_FORMAT:
+	{
+		if (w_length != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		switch (w_value) {
+		case 0x0000:
+			ncm->parser_opts = &ndp16_opts;
+			DBG(cdev, "NCM16 selected\n");
+			break;
+		case 0x0001:
+			ncm->parser_opts = &ndp32_opts;
+			DBG(cdev, "NCM32 selected\n");
+			break;
+		default:
+			goto invalid;
+		}
+		value = 0;
+		break;
+	}
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_GET_CRC_MODE:
+	{
+		uint16_t is_crc;
+
+		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
+		put_unaligned_le16(is_crc, req->buf);
+		value = 2;
+		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
+		break;
+	}
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+		| USB_CDC_SET_CRC_MODE:
+	{
+		int ndp_hdr_crc = 0;
+
+		if (w_length != 0 || w_index != ncm->ctrl_id)
+			goto invalid;
+		switch (w_value) {
+		case 0x0000:
+			ncm->is_crc = false;
+			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
+			DBG(cdev, "non-CRC mode selected\n");
+			break;
+		case 0x0001:
+			ncm->is_crc = true;
+			ndp_hdr_crc = NCM_NDP_HDR_CRC;
+			DBG(cdev, "CRC mode selected\n");
+			break;
+		default:
+			goto invalid;
+		}
+		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
+		value = 0;
+		break;
+	}
+
+	/* and disabled in ncm descriptor: */
+	/* case USB_CDC_GET_NET_ADDRESS: */
+	/* case USB_CDC_SET_NET_ADDRESS: */
+	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
+	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
+
+	default:
+invalid:
+		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+	}
+
+	/* respond with data transfer or status phase? */
+	if (value >= 0) {
+		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
+			ctrl->bRequestType, ctrl->bRequest,
+			w_value, w_index, w_length);
+		req->zero = 0;
+		req->length = value;
+		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (value < 0)
+			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
+					ctrl->bRequestType, ctrl->bRequest,
+					value);
+	}
+
+	/* device either stalls (value < 0) or reports success */
+	return value;
+}
+
+
+static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_ncm		*ncm = func_to_ncm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	/* Control interface has only altsetting 0 */
+	if (intf == ncm->ctrl_id) {
+		if (alt != 0)
+			goto fail;
+
+		DBG(cdev, "reset ncm control %d\n", intf);
+		usb_ep_disable(ncm->notify);
+
+		if (!(ncm->notify->desc)) {
+			DBG(cdev, "init ncm ctrl %d\n", intf);
+			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
+				goto fail;
+		}
+		usb_ep_enable(ncm->notify);
+
+	/* Data interface has two altsettings, 0 and 1 */
+	} else if (intf == ncm->data_id) {
+		if (alt > 1)
+			goto fail;
+
+		if (ncm->port.in_ep->enabled) {
+			DBG(cdev, "reset ncm\n");
+			ncm->timer_stopping = true;
+			ncm->netdev = NULL;
+			gether_disconnect(&ncm->port);
+			ncm_reset_values(ncm);
+		}
+
+		/*
+		 * CDC Network only sends data in non-default altsettings.
+		 * Changing altsettings resets filters, statistics, etc.
+		 */
+		if (alt == 1) {
+			struct net_device	*net;
+
+			if (!ncm->port.in_ep->desc ||
+			    !ncm->port.out_ep->desc) {
+				DBG(cdev, "init ncm\n");
+				if (config_ep_by_speed(cdev->gadget, f,
+						       ncm->port.in_ep) ||
+				    config_ep_by_speed(cdev->gadget, f,
+						       ncm->port.out_ep)) {
+					ncm->port.in_ep->desc = NULL;
+					ncm->port.out_ep->desc = NULL;
+					goto fail;
+				}
+			}
+
+			/* TODO */
+			/* Enable zlps by default for NCM conformance;
+			 * override for musb_hdrc (avoids txdma ovhead)
+			 */
+			ncm->port.is_zlp_ok =
+				gadget_is_zlp_supported(cdev->gadget);
+			ncm->port.cdc_filter = DEFAULT_FILTER;
+			DBG(cdev, "activate ncm\n");
+			net = gether_connect(&ncm->port);
+			if (IS_ERR(net))
+				return PTR_ERR(net);
+			ncm->netdev = net;
+			ncm->timer_stopping = false;
+		}
+
+		spin_lock(&ncm->lock);
+		ncm_notify(ncm);
+		spin_unlock(&ncm->lock);
+	} else
+		goto fail;
+
+	return 0;
+fail:
+	return -EINVAL;
+}
+
+/*
+ * Because the data interface supports multiple altsettings,
+ * this NCM function *MUST* implement a get_alt() method.
+ */
+static int ncm_get_alt(struct usb_function *f, unsigned intf)
+{
+	struct f_ncm		*ncm = func_to_ncm(f);
+
+	if (intf == ncm->ctrl_id)
+		return 0;
+	return ncm->port.in_ep->enabled ? 1 : 0;
+}
+
+static struct sk_buff *package_for_tx(struct f_ncm *ncm)
+{
+	__le16		*ntb_iter;
+	struct sk_buff	*skb2 = NULL;
+	unsigned	ndp_pad;
+	unsigned	ndp_index;
+	unsigned	new_len;
+
+	const struct ndp_parser_opts *opts = ncm->parser_opts;
+	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
+	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
+
+	/* Stop the timer */
+	hrtimer_try_to_cancel(&ncm->task_timer);
+
+	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
+			ncm->skb_tx_data->len;
+	ndp_index = ncm->skb_tx_data->len + ndp_pad;
+	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
+
+	/* Set the final BlockLength and wNdpIndex */
+	ntb_iter = (void *) ncm->skb_tx_data->data;
+	/* Increment pointer to BlockLength */
+	ntb_iter += 2 + 1 + 1;
+	put_ncm(&ntb_iter, opts->block_length, new_len);
+	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
+
+	/* Set the final NDP wLength */
+	new_len = opts->ndp_size +
+			(ncm->ndp_dgram_count * dgram_idx_len);
+	ncm->ndp_dgram_count = 0;
+	/* Increment from start to wLength */
+	ntb_iter = (void *) ncm->skb_tx_ndp->data;
+	ntb_iter += 2;
+	put_unaligned_le16(new_len, ntb_iter);
+
+	/* Merge the skbs */
+	swap(skb2, ncm->skb_tx_data);
+	if (ncm->skb_tx_data) {
+		dev_consume_skb_any(ncm->skb_tx_data);
+		ncm->skb_tx_data = NULL;
+	}
+
+	/* Insert NDP alignment. */
+	skb_put_zero(skb2, ndp_pad);
+
+	/* Copy NTB across. */
+	skb_put_data(skb2, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
+	dev_consume_skb_any(ncm->skb_tx_ndp);
+	ncm->skb_tx_ndp = NULL;
+
+	/* Insert zero'd datagram. */
+	skb_put_zero(skb2, dgram_idx_len);
+
+	return skb2;
+}
+
+static struct sk_buff *ncm_wrap_ntb(struct gether *port,
+				    struct sk_buff *skb)
+{
+	struct f_ncm	*ncm = func_to_ncm(&port->func);
+	struct sk_buff	*skb2 = NULL;
+	int		ncb_len = 0;
+	__le16		*ntb_data;
+	__le16		*ntb_ndp;
+	int		dgram_pad;
+
+	unsigned	max_size = ncm->port.fixed_in_len;
+	const struct ndp_parser_opts *opts = ncm->parser_opts;
+	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
+	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
+	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
+	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
+
+	if (!skb && !ncm->skb_tx_data)
+		return NULL;
+
+	if (skb) {
+		/* Add the CRC if required up front */
+		if (ncm->is_crc) {
+			uint32_t	crc;
+			__le16		*crc_pos;
+
+			crc = ~crc32_le(~0,
+					skb->data,
+					skb->len);
+			crc_pos = skb_put(skb, sizeof(uint32_t));
+			put_unaligned_le32(crc, crc_pos);
+		}
+
+		/* If the new skb is too big for the current NCM NTB then
+		 * set the current stored skb to be sent now and clear it
+		 * ready for new data.
+		 * NOTE: Assume maximum align for speed of calculation.
+		 */
+		if (ncm->skb_tx_data
+		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
+		    || (ncm->skb_tx_data->len +
+		    div + rem + skb->len +
+		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
+		    > max_size)) {
+			skb2 = package_for_tx(ncm);
+			if (!skb2)
+				goto err;
+		}
+
+		if (!ncm->skb_tx_data) {
+			ncb_len = opts->nth_size;
+			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
+			ncb_len += dgram_pad;
+
+			/* Create a new skb for the NTH and datagrams. */
+			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
+			if (!ncm->skb_tx_data)
+				goto err;
+
+			ncm->skb_tx_data->dev = ncm->netdev;
+			ntb_data = skb_put_zero(ncm->skb_tx_data, ncb_len);
+			/* dwSignature */
+			put_unaligned_le32(opts->nth_sign, ntb_data);
+			ntb_data += 2;
+			/* wHeaderLength */
+			put_unaligned_le16(opts->nth_size, ntb_data++);
+
+			/* Allocate an skb for storing the NDP,
+			 * TX_MAX_NUM_DPE should easily suffice for a
+			 * 16k packet.
+			 */
+			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
+						    + opts->dpe_size
+						    * TX_MAX_NUM_DPE),
+						    GFP_ATOMIC);
+			if (!ncm->skb_tx_ndp)
+				goto err;
+
+			ncm->skb_tx_ndp->dev = ncm->netdev;
+			ntb_ndp = skb_put(ncm->skb_tx_ndp, opts->ndp_size);
+			memset(ntb_ndp, 0, ncb_len);
+			/* dwSignature */
+			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
+			ntb_ndp += 2;
+
+			/* There is always a zeroed entry */
+			ncm->ndp_dgram_count = 1;
+
+			/* Note: we skip opts->next_ndp_index */
+
+			/* Start the timer. */
+			hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
+				      HRTIMER_MODE_REL_SOFT);
+		}
+
+		/* Add the datagram position entries */
+		ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len);
+
+		ncb_len = ncm->skb_tx_data->len;
+		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
+		ncb_len += dgram_pad;
+
+		/* (d)wDatagramIndex */
+		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
+		/* (d)wDatagramLength */
+		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
+		ncm->ndp_dgram_count++;
+
+		/* Add the new data to the skb */
+		skb_put_zero(ncm->skb_tx_data, dgram_pad);
+		skb_put_data(ncm->skb_tx_data, skb->data, skb->len);
+		dev_consume_skb_any(skb);
+		skb = NULL;
+
+	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
+		/* If the tx was requested because of a timeout then send */
+		skb2 = package_for_tx(ncm);
+		if (!skb2)
+			goto err;
+	}
+
+	return skb2;
+
+err:
+	ncm->netdev->stats.tx_dropped++;
+
+	if (skb)
+		dev_kfree_skb_any(skb);
+	if (ncm->skb_tx_data)
+		dev_kfree_skb_any(ncm->skb_tx_data);
+	if (ncm->skb_tx_ndp)
+		dev_kfree_skb_any(ncm->skb_tx_ndp);
+
+	return NULL;
+}
+
+/*
+ * The transmit should only be run if no skb data has been sent
+ * for a certain duration.
+ */
+static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
+{
+	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
+
+	/* Only send if data is available. */
+	if (!ncm->timer_stopping && ncm->skb_tx_data) {
+		ncm->timer_force_tx = true;
+
+		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
+		 * XXX is not sane.  The gadget layer should be redesigned so
+		 * XXX that the dev->wrap() invocations to build SKBs is transparent
+		 * XXX and performed in some way outside of the ndo_start_xmit
+		 * XXX interface.
+		 */
+		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
+
+		ncm->timer_force_tx = false;
+	}
+	return HRTIMER_NORESTART;
+}
+
+static int ncm_unwrap_ntb(struct gether *port,
+			  struct sk_buff *skb,
+			  struct sk_buff_head *list)
+{
+	struct f_ncm	*ncm = func_to_ncm(&port->func);
+	__le16		*tmp = (void *) skb->data;
+	unsigned	index, index2;
+	int		ndp_index;
+	unsigned	dg_len, dg_len2;
+	unsigned	ndp_len;
+	unsigned	block_len;
+	struct sk_buff	*skb2;
+	int		ret = -EINVAL;
+	unsigned	ntb_max = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
+	unsigned	frame_max = le16_to_cpu(ecm_desc.wMaxSegmentSize);
+	const struct ndp_parser_opts *opts = ncm->parser_opts;
+	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
+	int		dgram_counter;
+
+	/* dwSignature */
+	if (get_unaligned_le32(tmp) != opts->nth_sign) {
+		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
+			skb->len);
+		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
+			       skb->data, 32, false);
+
+		goto err;
+	}
+	tmp += 2;
+	/* wHeaderLength */
+	if (get_unaligned_le16(tmp++) != opts->nth_size) {
+		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
+		goto err;
+	}
+	tmp++; /* skip wSequence */
+
+	block_len = get_ncm(&tmp, opts->block_length);
+	/* (d)wBlockLength */
+	if (block_len > ntb_max) {
+		INFO(port->func.config->cdev, "OUT size exceeded\n");
+		goto err;
+	}
+
+	ndp_index = get_ncm(&tmp, opts->ndp_index);
+
+	/* Run through all the NDP's in the NTB */
+	do {
+		/*
+		 * NCM 3.2
+		 * dwNdpIndex
+		 */
+		if (((ndp_index % 4) != 0) ||
+				(ndp_index < opts->nth_size) ||
+				(ndp_index > (block_len -
+					      opts->ndp_size))) {
+			INFO(port->func.config->cdev, "Bad index: %#X\n",
+			     ndp_index);
+			goto err;
+		}
+
+		/*
+		 * walk through NDP
+		 * dwSignature
+		 */
+		tmp = (void *)(skb->data + ndp_index);
+		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
+			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
+			goto err;
+		}
+		tmp += 2;
+
+		ndp_len = get_unaligned_le16(tmp++);
+		/*
+		 * NCM 3.3.1
+		 * wLength
+		 * entry is 2 items
+		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
+		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
+		 * Each entry is a dgram index and a dgram length.
+		 */
+		if ((ndp_len < opts->ndp_size
+				+ 2 * 2 * (opts->dgram_item_len * 2)) ||
+				(ndp_len % opts->ndplen_align != 0)) {
+			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
+			     ndp_len);
+			goto err;
+		}
+		tmp += opts->reserved1;
+		/* Check for another NDP (d)wNextNdpIndex */
+		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
+		tmp += opts->reserved2;
+
+		ndp_len -= opts->ndp_size;
+		index2 = get_ncm(&tmp, opts->dgram_item_len);
+		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
+		dgram_counter = 0;
+
+		do {
+			index = index2;
+			/* wDatagramIndex[0] */
+			if ((index < opts->nth_size) ||
+					(index > block_len - opts->dpe_size)) {
+				INFO(port->func.config->cdev,
+				     "Bad index: %#X\n", index);
+				goto err;
+			}
+
+			dg_len = dg_len2;
+			/*
+			 * wDatagramLength[0]
+			 * ethernet hdr + crc or larger than max frame size
+			 */
+			if ((dg_len < 14 + crc_len) ||
+					(dg_len > frame_max)) {
+				INFO(port->func.config->cdev,
+				     "Bad dgram length: %#X\n", dg_len);
+				goto err;
+			}
+			if (ncm->is_crc) {
+				uint32_t crc, crc2;
+
+				crc = get_unaligned_le32(skb->data +
+							 index + dg_len -
+							 crc_len);
+				crc2 = ~crc32_le(~0,
+						 skb->data + index,
+						 dg_len - crc_len);
+				if (crc != crc2) {
+					INFO(port->func.config->cdev,
+					     "Bad CRC\n");
+					goto err;
+				}
+			}
+
+			index2 = get_ncm(&tmp, opts->dgram_item_len);
+			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
+
+			/* wDatagramIndex[1] */
+			if (index2 > block_len - opts->dpe_size) {
+				INFO(port->func.config->cdev,
+				     "Bad index: %#X\n", index2);
+				goto err;
+			}
+
+			/*
+			 * Copy the data into a new skb.
+			 * This ensures the truesize is correct
+			 */
+			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
+							 dg_len - crc_len);
+			if (skb2 == NULL)
+				goto err;
+			skb_put_data(skb2, skb->data + index,
+				     dg_len - crc_len);
+
+			skb_queue_tail(list, skb2);
+
+			ndp_len -= 2 * (opts->dgram_item_len * 2);
+
+			dgram_counter++;
+			if (index2 == 0 || dg_len2 == 0)
+				break;
+		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
+	} while (ndp_index);
+
+	dev_consume_skb_any(skb);
+
+	VDBG(port->func.config->cdev,
+	     "Parsed NTB with %d frames\n", dgram_counter);
+	return 0;
+err:
+	skb_queue_purge(list);
+	dev_kfree_skb_any(skb);
+	return ret;
+}
+
+static void ncm_disable(struct usb_function *f)
+{
+	struct f_ncm		*ncm = func_to_ncm(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	DBG(cdev, "ncm deactivated\n");
+
+	if (ncm->port.in_ep->enabled) {
+		ncm->timer_stopping = true;
+		ncm->netdev = NULL;
+		gether_disconnect(&ncm->port);
+	}
+
+	if (ncm->notify->enabled) {
+		usb_ep_disable(ncm->notify);
+		ncm->notify->desc = NULL;
+	}
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Callbacks let us notify the host about connect/disconnect when the
+ * net device is opened or closed.
+ *
+ * For testing, note that link states on this side include both opened
+ * and closed variants of:
+ *
+ *   - disconnected/unconfigured
+ *   - configured but inactive (data alt 0)
+ *   - configured and active (data alt 1)
+ *
+ * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
+ * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
+ * imply the host is actually polling the notification endpoint, and
+ * likewise that "active" doesn't imply it's actually using the data
+ * endpoints for traffic.
+ */
+
+static void ncm_open(struct gether *geth)
+{
+	struct f_ncm		*ncm = func_to_ncm(&geth->func);
+
+	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
+
+	spin_lock(&ncm->lock);
+	ncm->is_open = true;
+	ncm_notify(ncm);
+	spin_unlock(&ncm->lock);
+}
+
+static void ncm_close(struct gether *geth)
+{
+	struct f_ncm		*ncm = func_to_ncm(&geth->func);
+
+	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
+
+	spin_lock(&ncm->lock);
+	ncm->is_open = false;
+	ncm_notify(ncm);
+	spin_unlock(&ncm->lock);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* ethernet function driver setup/binding */
+
+static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct f_ncm		*ncm = func_to_ncm(f);
+	struct usb_string	*us;
+	int			status;
+	struct usb_ep		*ep;
+	struct f_ncm_opts	*ncm_opts;
+
+	if (!can_support_ecm(cdev->gadget))
+		return -EINVAL;
+
+	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
+	/*
+	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
+	 * configurations are bound in sequence with list_for_each_entry,
+	 * in each configuration its functions are bound in sequence
+	 * with list_for_each_entry, so we assume no race condition
+	 * with regard to ncm_opts->bound access
+	 */
+	if (!ncm_opts->bound) {
+		mutex_lock(&ncm_opts->lock);
+		gether_set_gadget(ncm_opts->net, cdev->gadget);
+		status = gether_register_netdev(ncm_opts->net);
+		mutex_unlock(&ncm_opts->lock);
+		if (status)
+			return status;
+		ncm_opts->bound = true;
+	}
+	us = usb_gstrings_attach(cdev, ncm_strings,
+				 ARRAY_SIZE(ncm_string_defs));
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
+	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
+	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
+	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
+	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
+
+	/* allocate instance-specific interface IDs */
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	ncm->ctrl_id = status;
+	ncm_iad_desc.bFirstInterface = status;
+
+	ncm_control_intf.bInterfaceNumber = status;
+	ncm_union_desc.bMasterInterface0 = status;
+
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	ncm->data_id = status;
+
+	ncm_data_nop_intf.bInterfaceNumber = status;
+	ncm_data_intf.bInterfaceNumber = status;
+	ncm_union_desc.bSlaveInterface0 = status;
+
+	status = -ENODEV;
+
+	/* allocate instance-specific endpoints */
+	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
+	if (!ep)
+		goto fail;
+	ncm->port.in_ep = ep;
+
+	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
+	if (!ep)
+		goto fail;
+	ncm->port.out_ep = ep;
+
+	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
+	if (!ep)
+		goto fail;
+	ncm->notify = ep;
+
+	status = -ENOMEM;
+
+	/* allocate notification request and buffer */
+	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
+	if (!ncm->notify_req)
+		goto fail;
+	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
+	if (!ncm->notify_req->buf)
+		goto fail;
+	ncm->notify_req->context = ncm;
+	ncm->notify_req->complete = ncm_notify_complete;
+
+	/*
+	 * support all relevant hardware speeds... we expect that when
+	 * hardware is dual speed, all bulk-capable endpoints work at
+	 * both speeds
+	 */
+	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
+	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
+	hs_ncm_notify_desc.bEndpointAddress =
+		fs_ncm_notify_desc.bEndpointAddress;
+
+	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
+	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
+	ss_ncm_notify_desc.bEndpointAddress =
+		fs_ncm_notify_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
+			ncm_ss_function, ncm_ss_function);
+	if (status)
+		goto fail;
+
+	/*
+	 * NOTE:  all that is done without knowing or caring about
+	 * the network link ... which is unavailable to this code
+	 * until we're activated via set_alt().
+	 */
+
+	ncm->port.open = ncm_open;
+	ncm->port.close = ncm_close;
+
+	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	ncm->task_timer.function = ncm_tx_timeout;
+
+	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
+			gadget_is_superspeed(c->cdev->gadget) ? "super" :
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			ncm->port.in_ep->name, ncm->port.out_ep->name,
+			ncm->notify->name);
+	return 0;
+
+fail:
+	if (ncm->notify_req) {
+		kfree(ncm->notify_req->buf);
+		usb_ep_free_request(ncm->notify, ncm->notify_req);
+	}
+
+	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+	return status;
+}
+
+static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_ncm_opts,
+			    func_inst.group);
+}
+
+/* f_ncm_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(ncm);
+
+/* f_ncm_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
+
+/* f_ncm_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
+
+/* f_ncm_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
+
+/* f_ncm_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
+
+static struct configfs_attribute *ncm_attrs[] = {
+	&ncm_opts_attr_dev_addr,
+	&ncm_opts_attr_host_addr,
+	&ncm_opts_attr_qmult,
+	&ncm_opts_attr_ifname,
+	NULL,
+};
+
+static const struct config_item_type ncm_func_type = {
+	.ct_item_ops	= &ncm_item_ops,
+	.ct_attrs	= ncm_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void ncm_free_inst(struct usb_function_instance *f)
+{
+	struct f_ncm_opts *opts;
+
+	opts = container_of(f, struct f_ncm_opts, func_inst);
+	if (opts->bound)
+		gether_cleanup(netdev_priv(opts->net));
+	else
+		free_netdev(opts->net);
+	kfree(opts);
+}
+
+static struct usb_function_instance *ncm_alloc_inst(void)
+{
+	struct f_ncm_opts *opts;
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+	mutex_init(&opts->lock);
+	opts->func_inst.free_func_inst = ncm_free_inst;
+	opts->net = gether_setup_default();
+	if (IS_ERR(opts->net)) {
+		struct net_device *net = opts->net;
+		kfree(opts);
+		return ERR_CAST(net);
+	}
+
+	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
+
+	return &opts->func_inst;
+}
+
+static void ncm_free(struct usb_function *f)
+{
+	struct f_ncm *ncm;
+	struct f_ncm_opts *opts;
+
+	ncm = func_to_ncm(f);
+	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
+	kfree(ncm);
+	mutex_lock(&opts->lock);
+	opts->refcnt--;
+	mutex_unlock(&opts->lock);
+}
+
+static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct f_ncm *ncm = func_to_ncm(f);
+
+	DBG(c->cdev, "ncm unbind\n");
+
+	hrtimer_cancel(&ncm->task_timer);
+
+	ncm_string_defs[0].id = 0;
+	usb_free_all_descriptors(f);
+
+	if (atomic_read(&ncm->notify_count)) {
+		usb_ep_dequeue(ncm->notify, ncm->notify_req);
+		atomic_set(&ncm->notify_count, 0);
+	}
+
+	kfree(ncm->notify_req->buf);
+	usb_ep_free_request(ncm->notify, ncm->notify_req);
+}
+
+static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
+{
+	struct f_ncm		*ncm;
+	struct f_ncm_opts	*opts;
+	int status;
+
+	/* allocate and initialize one new instance */
+	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
+	if (!ncm)
+		return ERR_PTR(-ENOMEM);
+
+	opts = container_of(fi, struct f_ncm_opts, func_inst);
+	mutex_lock(&opts->lock);
+	opts->refcnt++;
+
+	/* export host's Ethernet address in CDC format */
+	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
+				      sizeof(ncm->ethaddr));
+	if (status < 12) { /* strlen("01234567890a") */
+		kfree(ncm);
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(-EINVAL);
+	}
+	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
+
+	spin_lock_init(&ncm->lock);
+	ncm_reset_values(ncm);
+	ncm->port.ioport = netdev_priv(opts->net);
+	mutex_unlock(&opts->lock);
+	ncm->port.is_fixed = true;
+	ncm->port.supports_multi_frame = true;
+
+	ncm->port.func.name = "cdc_network";
+	/* descriptors are per-instance copies */
+	ncm->port.func.bind = ncm_bind;
+	ncm->port.func.unbind = ncm_unbind;
+	ncm->port.func.set_alt = ncm_set_alt;
+	ncm->port.func.get_alt = ncm_get_alt;
+	ncm->port.func.setup = ncm_setup;
+	ncm->port.func.disable = ncm_disable;
+	ncm->port.func.free_func = ncm_free;
+
+	ncm->port.wrap = ncm_wrap_ntb;
+	ncm->port.unwrap = ncm_unwrap_ntb;
+
+	return &ncm->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yauheni Kaliuta");