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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * f_ncm.c -- USB CDC Network (NCM) link function driver
   4 *
   5 * Copyright (C) 2010 Nokia Corporation
   6 * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
   7 *
   8 * The driver borrows from f_ecm.c which is:
   9 *
  10 * Copyright (C) 2003-2005,2008 David Brownell
  11 * Copyright (C) 2008 Nokia Corporation
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/interrupt.h>
  16#include <linux/module.h>
  17#include <linux/device.h>
  18#include <linux/etherdevice.h>
  19#include <linux/crc32.h>
  20
  21#include <linux/usb/cdc.h>
  22
  23#include "u_ether.h"
  24#include "u_ether_configfs.h"
  25#include "u_ncm.h"
  26#include "configfs.h"
  27
  28/*
  29 * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
  30 * NCM is intended to be used with high-speed network attachments.
  31 *
  32 * Note that NCM requires the use of "alternate settings" for its data
  33 * interface.  This means that the set_alt() method has real work to do,
  34 * and also means that a get_alt() method is required.
  35 */
  36
  37/* to trigger crc/non-crc ndp signature */
  38
  39#define NCM_NDP_HDR_CRC		0x01000000
  40
  41enum ncm_notify_state {
  42	NCM_NOTIFY_NONE,		/* don't notify */
  43	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
  44	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
  45};
  46
  47struct f_ncm {
  48	struct gether			port;
  49	u8				ctrl_id, data_id;
  50
  51	char				ethaddr[14];
  52
  53	struct usb_ep			*notify;
  54	struct usb_request		*notify_req;
  55	u8				notify_state;
  56	atomic_t			notify_count;
  57	bool				is_open;
  58
  59	const struct ndp_parser_opts	*parser_opts;
  60	bool				is_crc;
  61	u32				ndp_sign;
  62
  63	/*
  64	 * for notification, it is accessed from both
  65	 * callback and ethernet open/close
  66	 */
  67	spinlock_t			lock;
  68
  69	struct net_device		*netdev;
  70
  71	/* For multi-frame NDP TX */
  72	struct sk_buff			*skb_tx_data;
  73	struct sk_buff			*skb_tx_ndp;
  74	u16				ndp_dgram_count;
  75	bool				timer_force_tx;
  76	struct hrtimer			task_timer;
  77	bool				timer_stopping;
  78};
  79
  80static inline struct f_ncm *func_to_ncm(struct usb_function *f)
  81{
  82	return container_of(f, struct f_ncm, port.func);
  83}
  84
  85/* peak (theoretical) bulk transfer rate in bits-per-second */
  86static inline unsigned ncm_bitrate(struct usb_gadget *g)
  87{
  88	if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
  89		return 4250000000U;
  90	else if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  91		return 3750000000U;
  92	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  93		return 13 * 512 * 8 * 1000 * 8;
  94	else
  95		return 19 *  64 * 1 * 1000 * 8;
  96}
  97
  98/*-------------------------------------------------------------------------*/
  99
 100/*
 101 * We cannot group frames so use just the minimal size which ok to put
 102 * one max-size ethernet frame.
 103 * If the host can group frames, allow it to do that, 16K is selected,
 104 * because it's used by default by the current linux host driver
 105 */
 106#define NTB_DEFAULT_IN_SIZE	16384
 107#define NTB_OUT_SIZE		16384
 108
 109/* Allocation for storing the NDP, 32 should suffice for a
 110 * 16k packet. This allows a maximum of 32 * 507 Byte packets to
 111 * be transmitted in a single 16kB skb, though when sending full size
 112 * packets this limit will be plenty.
 113 * Smaller packets are not likely to be trying to maximize the
 114 * throughput and will be mstly sending smaller infrequent frames.
 115 */
 116#define TX_MAX_NUM_DPE		32
 117
 118/* Delay for the transmit to wait before sending an unfilled NTB frame. */
 119#define TX_TIMEOUT_NSECS	300000
 120
 121#define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
 122				 USB_CDC_NCM_NTB32_SUPPORTED)
 123
 124static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
 125	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
 126	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
 127	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
 128	.wNdpInDivisor = cpu_to_le16(4),
 129	.wNdpInPayloadRemainder = cpu_to_le16(0),
 130	.wNdpInAlignment = cpu_to_le16(4),
 131
 132	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
 133	.wNdpOutDivisor = cpu_to_le16(4),
 134	.wNdpOutPayloadRemainder = cpu_to_le16(0),
 135	.wNdpOutAlignment = cpu_to_le16(4),
 136};
 137
 138/*
 139 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
 140 * packet, to simplify cancellation; and a big transfer interval, to
 141 * waste less bandwidth.
 142 */
 143
 144#define NCM_STATUS_INTERVAL_MS		32
 145#define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
 146
 147static struct usb_interface_assoc_descriptor ncm_iad_desc = {
 148	.bLength =		sizeof ncm_iad_desc,
 149	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
 150
 151	/* .bFirstInterface =	DYNAMIC, */
 152	.bInterfaceCount =	2,	/* control + data */
 153	.bFunctionClass =	USB_CLASS_COMM,
 154	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
 155	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
 156	/* .iFunction =		DYNAMIC */
 157};
 158
 159/* interface descriptor: */
 160
 161static struct usb_interface_descriptor ncm_control_intf = {
 162	.bLength =		sizeof ncm_control_intf,
 163	.bDescriptorType =	USB_DT_INTERFACE,
 164
 165	/* .bInterfaceNumber = DYNAMIC */
 166	.bNumEndpoints =	1,
 167	.bInterfaceClass =	USB_CLASS_COMM,
 168	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
 169	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
 170	/* .iInterface = DYNAMIC */
 171};
 172
 173static struct usb_cdc_header_desc ncm_header_desc = {
 174	.bLength =		sizeof ncm_header_desc,
 175	.bDescriptorType =	USB_DT_CS_INTERFACE,
 176	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 177
 178	.bcdCDC =		cpu_to_le16(0x0110),
 179};
 180
 181static struct usb_cdc_union_desc ncm_union_desc = {
 182	.bLength =		sizeof(ncm_union_desc),
 183	.bDescriptorType =	USB_DT_CS_INTERFACE,
 184	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
 185	/* .bMasterInterface0 =	DYNAMIC */
 186	/* .bSlaveInterface0 =	DYNAMIC */
 187};
 188
 189static struct usb_cdc_ether_desc ecm_desc = {
 190	.bLength =		sizeof ecm_desc,
 191	.bDescriptorType =	USB_DT_CS_INTERFACE,
 192	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
 193
 194	/* this descriptor actually adds value, surprise! */
 195	/* .iMACAddress = DYNAMIC */
 196	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
 197	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
 198	.wNumberMCFilters =	cpu_to_le16(0),
 199	.bNumberPowerFilters =	0,
 200};
 201
 202#define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
 203
 204static struct usb_cdc_ncm_desc ncm_desc = {
 205	.bLength =		sizeof ncm_desc,
 206	.bDescriptorType =	USB_DT_CS_INTERFACE,
 207	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
 208
 209	.bcdNcmVersion =	cpu_to_le16(0x0100),
 210	/* can process SetEthernetPacketFilter */
 211	.bmNetworkCapabilities = NCAPS,
 212};
 213
 214/* the default data interface has no endpoints ... */
 215
 216static struct usb_interface_descriptor ncm_data_nop_intf = {
 217	.bLength =		sizeof ncm_data_nop_intf,
 218	.bDescriptorType =	USB_DT_INTERFACE,
 219
 220	.bInterfaceNumber =	1,
 221	.bAlternateSetting =	0,
 222	.bNumEndpoints =	0,
 223	.bInterfaceClass =	USB_CLASS_CDC_DATA,
 224	.bInterfaceSubClass =	0,
 225	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
 226	/* .iInterface = DYNAMIC */
 227};
 228
 229/* ... but the "real" data interface has two bulk endpoints */
 230
 231static struct usb_interface_descriptor ncm_data_intf = {
 232	.bLength =		sizeof ncm_data_intf,
 233	.bDescriptorType =	USB_DT_INTERFACE,
 234
 235	.bInterfaceNumber =	1,
 236	.bAlternateSetting =	1,
 237	.bNumEndpoints =	2,
 238	.bInterfaceClass =	USB_CLASS_CDC_DATA,
 239	.bInterfaceSubClass =	0,
 240	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
 241	/* .iInterface = DYNAMIC */
 242};
 243
 244/* full speed support: */
 245
 246static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
 247	.bLength =		USB_DT_ENDPOINT_SIZE,
 248	.bDescriptorType =	USB_DT_ENDPOINT,
 249
 250	.bEndpointAddress =	USB_DIR_IN,
 251	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 252	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 253	.bInterval =		NCM_STATUS_INTERVAL_MS,
 254};
 255
 256static struct usb_endpoint_descriptor fs_ncm_in_desc = {
 257	.bLength =		USB_DT_ENDPOINT_SIZE,
 258	.bDescriptorType =	USB_DT_ENDPOINT,
 259
 260	.bEndpointAddress =	USB_DIR_IN,
 261	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 262};
 263
 264static struct usb_endpoint_descriptor fs_ncm_out_desc = {
 265	.bLength =		USB_DT_ENDPOINT_SIZE,
 266	.bDescriptorType =	USB_DT_ENDPOINT,
 267
 268	.bEndpointAddress =	USB_DIR_OUT,
 269	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 270};
 271
 272static struct usb_descriptor_header *ncm_fs_function[] = {
 273	(struct usb_descriptor_header *) &ncm_iad_desc,
 274	/* CDC NCM control descriptors */
 275	(struct usb_descriptor_header *) &ncm_control_intf,
 276	(struct usb_descriptor_header *) &ncm_header_desc,
 277	(struct usb_descriptor_header *) &ncm_union_desc,
 278	(struct usb_descriptor_header *) &ecm_desc,
 279	(struct usb_descriptor_header *) &ncm_desc,
 280	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
 281	/* data interface, altsettings 0 and 1 */
 282	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 283	(struct usb_descriptor_header *) &ncm_data_intf,
 284	(struct usb_descriptor_header *) &fs_ncm_in_desc,
 285	(struct usb_descriptor_header *) &fs_ncm_out_desc,
 286	NULL,
 287};
 288
 289/* high speed support: */
 290
 291static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
 292	.bLength =		USB_DT_ENDPOINT_SIZE,
 293	.bDescriptorType =	USB_DT_ENDPOINT,
 294
 295	.bEndpointAddress =	USB_DIR_IN,
 296	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 297	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 298	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
 299};
 300static struct usb_endpoint_descriptor hs_ncm_in_desc = {
 301	.bLength =		USB_DT_ENDPOINT_SIZE,
 302	.bDescriptorType =	USB_DT_ENDPOINT,
 303
 304	.bEndpointAddress =	USB_DIR_IN,
 305	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 306	.wMaxPacketSize =	cpu_to_le16(512),
 307};
 308
 309static struct usb_endpoint_descriptor hs_ncm_out_desc = {
 310	.bLength =		USB_DT_ENDPOINT_SIZE,
 311	.bDescriptorType =	USB_DT_ENDPOINT,
 312
 313	.bEndpointAddress =	USB_DIR_OUT,
 314	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 315	.wMaxPacketSize =	cpu_to_le16(512),
 316};
 317
 318static struct usb_descriptor_header *ncm_hs_function[] = {
 319	(struct usb_descriptor_header *) &ncm_iad_desc,
 320	/* CDC NCM control descriptors */
 321	(struct usb_descriptor_header *) &ncm_control_intf,
 322	(struct usb_descriptor_header *) &ncm_header_desc,
 323	(struct usb_descriptor_header *) &ncm_union_desc,
 324	(struct usb_descriptor_header *) &ecm_desc,
 325	(struct usb_descriptor_header *) &ncm_desc,
 326	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
 327	/* data interface, altsettings 0 and 1 */
 328	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 329	(struct usb_descriptor_header *) &ncm_data_intf,
 330	(struct usb_descriptor_header *) &hs_ncm_in_desc,
 331	(struct usb_descriptor_header *) &hs_ncm_out_desc,
 332	NULL,
 333};
 334
 335
 336/* super speed support: */
 337
 338static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
 339	.bLength =		USB_DT_ENDPOINT_SIZE,
 340	.bDescriptorType =	USB_DT_ENDPOINT,
 341
 342	.bEndpointAddress =	USB_DIR_IN,
 343	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 344	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 345	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
 346};
 347
 348static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
 349	.bLength =		sizeof(ss_ncm_notify_comp_desc),
 350	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 351
 352	/* the following 3 values can be tweaked if necessary */
 353	/* .bMaxBurst =		0, */
 354	/* .bmAttributes =	0, */
 355	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 356};
 357
 358static struct usb_endpoint_descriptor ss_ncm_in_desc = {
 359	.bLength =		USB_DT_ENDPOINT_SIZE,
 360	.bDescriptorType =	USB_DT_ENDPOINT,
 361
 362	.bEndpointAddress =	USB_DIR_IN,
 363	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 364	.wMaxPacketSize =	cpu_to_le16(1024),
 365};
 366
 367static struct usb_endpoint_descriptor ss_ncm_out_desc = {
 368	.bLength =		USB_DT_ENDPOINT_SIZE,
 369	.bDescriptorType =	USB_DT_ENDPOINT,
 370
 371	.bEndpointAddress =	USB_DIR_OUT,
 372	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 373	.wMaxPacketSize =	cpu_to_le16(1024),
 374};
 375
 376static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
 377	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
 378	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 379
 380	/* the following 2 values can be tweaked if necessary */
 381	.bMaxBurst =		15,
 382	/* .bmAttributes =	0, */
 383};
 384
 385static struct usb_descriptor_header *ncm_ss_function[] = {
 386	(struct usb_descriptor_header *) &ncm_iad_desc,
 387	/* CDC NCM control descriptors */
 388	(struct usb_descriptor_header *) &ncm_control_intf,
 389	(struct usb_descriptor_header *) &ncm_header_desc,
 390	(struct usb_descriptor_header *) &ncm_union_desc,
 391	(struct usb_descriptor_header *) &ecm_desc,
 392	(struct usb_descriptor_header *) &ncm_desc,
 393	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
 394	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
 395	/* data interface, altsettings 0 and 1 */
 396	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 397	(struct usb_descriptor_header *) &ncm_data_intf,
 398	(struct usb_descriptor_header *) &ss_ncm_in_desc,
 399	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
 400	(struct usb_descriptor_header *) &ss_ncm_out_desc,
 401	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
 402	NULL,
 403};
 404
 405/* string descriptors: */
 406
 407#define STRING_CTRL_IDX	0
 408#define STRING_MAC_IDX	1
 409#define STRING_DATA_IDX	2
 410#define STRING_IAD_IDX	3
 411
 412static struct usb_string ncm_string_defs[] = {
 413	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
 414	[STRING_MAC_IDX].s = "",
 415	[STRING_DATA_IDX].s = "CDC Network Data",
 416	[STRING_IAD_IDX].s = "CDC NCM",
 417	{  } /* end of list */
 418};
 419
 420static struct usb_gadget_strings ncm_string_table = {
 421	.language =		0x0409,	/* en-us */
 422	.strings =		ncm_string_defs,
 423};
 424
 425static struct usb_gadget_strings *ncm_strings[] = {
 426	&ncm_string_table,
 427	NULL,
 428};
 429
 430/*
 431 * Here are options for NCM Datagram Pointer table (NDP) parser.
 432 * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
 433 * in NDP16 offsets and sizes fields are 1 16bit word wide,
 434 * in NDP32 -- 2 16bit words wide. Also signatures are different.
 435 * To make the parser code the same, put the differences in the structure,
 436 * and switch pointers to the structures when the format is changed.
 437 */
 438
 439struct ndp_parser_opts {
 440	u32		nth_sign;
 441	u32		ndp_sign;
 442	unsigned	nth_size;
 443	unsigned	ndp_size;
 444	unsigned	dpe_size;
 445	unsigned	ndplen_align;
 446	/* sizes in u16 units */
 447	unsigned	dgram_item_len; /* index or length */
 448	unsigned	block_length;
 449	unsigned	ndp_index;
 450	unsigned	reserved1;
 451	unsigned	reserved2;
 452	unsigned	next_ndp_index;
 453};
 454
 455#define INIT_NDP16_OPTS {					\
 456		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
 457		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
 458		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
 459		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
 460		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
 461		.ndplen_align = 4,				\
 462		.dgram_item_len = 1,				\
 463		.block_length = 1,				\
 464		.ndp_index = 1,					\
 465		.reserved1 = 0,					\
 466		.reserved2 = 0,					\
 467		.next_ndp_index = 1,				\
 468	}
 469
 470
 471#define INIT_NDP32_OPTS {					\
 472		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
 473		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
 474		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
 475		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
 476		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
 477		.ndplen_align = 8,				\
 478		.dgram_item_len = 2,				\
 479		.block_length = 2,				\
 480		.ndp_index = 2,					\
 481		.reserved1 = 1,					\
 482		.reserved2 = 2,					\
 483		.next_ndp_index = 2,				\
 484	}
 485
 486static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
 487static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
 488
 489static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
 490{
 491	switch (size) {
 492	case 1:
 493		put_unaligned_le16((u16)val, *p);
 494		break;
 495	case 2:
 496		put_unaligned_le32((u32)val, *p);
 497
 498		break;
 499	default:
 500		BUG();
 501	}
 502
 503	*p += size;
 504}
 505
 506static inline unsigned get_ncm(__le16 **p, unsigned size)
 507{
 508	unsigned tmp;
 509
 510	switch (size) {
 511	case 1:
 512		tmp = get_unaligned_le16(*p);
 513		break;
 514	case 2:
 515		tmp = get_unaligned_le32(*p);
 516		break;
 517	default:
 518		BUG();
 519	}
 520
 521	*p += size;
 522	return tmp;
 523}
 524
 525/*-------------------------------------------------------------------------*/
 526
 527static inline void ncm_reset_values(struct f_ncm *ncm)
 528{
 529	ncm->parser_opts = &ndp16_opts;
 530	ncm->is_crc = false;
 531	ncm->ndp_sign = ncm->parser_opts->ndp_sign;
 532	ncm->port.cdc_filter = DEFAULT_FILTER;
 533
 534	/* doesn't make sense for ncm, fixed size used */
 535	ncm->port.header_len = 0;
 536
 537	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
 538	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
 539}
 540
 541/*
 542 * Context: ncm->lock held
 543 */
 544static void ncm_do_notify(struct f_ncm *ncm)
 545{
 546	struct usb_request		*req = ncm->notify_req;
 547	struct usb_cdc_notification	*event;
 548	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
 549	__le32				*data;
 550	int				status;
 551
 552	/* notification already in flight? */
 553	if (atomic_read(&ncm->notify_count))
 554		return;
 555
 556	event = req->buf;
 557	switch (ncm->notify_state) {
 558	case NCM_NOTIFY_NONE:
 559		return;
 560
 561	case NCM_NOTIFY_CONNECT:
 562		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 563		if (ncm->is_open)
 564			event->wValue = cpu_to_le16(1);
 565		else
 566			event->wValue = cpu_to_le16(0);
 567		event->wLength = 0;
 568		req->length = sizeof *event;
 569
 570		DBG(cdev, "notify connect %s\n",
 571				ncm->is_open ? "true" : "false");
 572		ncm->notify_state = NCM_NOTIFY_NONE;
 573		break;
 574
 575	case NCM_NOTIFY_SPEED:
 576		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 577		event->wValue = cpu_to_le16(0);
 578		event->wLength = cpu_to_le16(8);
 579		req->length = NCM_STATUS_BYTECOUNT;
 580
 581		/* SPEED_CHANGE data is up/down speeds in bits/sec */
 582		data = req->buf + sizeof *event;
 583		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
 584		data[1] = data[0];
 585
 586		DBG(cdev, "notify speed %u\n", ncm_bitrate(cdev->gadget));
 587		ncm->notify_state = NCM_NOTIFY_CONNECT;
 588		break;
 589	}
 590	event->bmRequestType = 0xA1;
 591	event->wIndex = cpu_to_le16(ncm->ctrl_id);
 592
 593	atomic_inc(&ncm->notify_count);
 594
 595	/*
 596	 * In double buffering if there is a space in FIFO,
 597	 * completion callback can be called right after the call,
 598	 * so unlocking
 599	 */
 600	spin_unlock(&ncm->lock);
 601	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
 602	spin_lock(&ncm->lock);
 603	if (status < 0) {
 604		atomic_dec(&ncm->notify_count);
 605		DBG(cdev, "notify --> %d\n", status);
 606	}
 607}
 608
 609/*
 610 * Context: ncm->lock held
 611 */
 612static void ncm_notify(struct f_ncm *ncm)
 613{
 614	/*
 615	 * NOTE on most versions of Linux, host side cdc-ethernet
 616	 * won't listen for notifications until its netdevice opens.
 617	 * The first notification then sits in the FIFO for a long
 618	 * time, and the second one is queued.
 619	 *
 620	 * If ncm_notify() is called before the second (CONNECT)
 621	 * notification is sent, then it will reset to send the SPEED
 622	 * notificaion again (and again, and again), but it's not a problem
 623	 */
 624	ncm->notify_state = NCM_NOTIFY_SPEED;
 625	ncm_do_notify(ncm);
 626}
 627
 628static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 629{
 630	struct f_ncm			*ncm = req->context;
 631	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
 632	struct usb_cdc_notification	*event = req->buf;
 633
 634	spin_lock(&ncm->lock);
 635	switch (req->status) {
 636	case 0:
 637		VDBG(cdev, "Notification %02x sent\n",
 638		     event->bNotificationType);
 639		atomic_dec(&ncm->notify_count);
 640		break;
 641	case -ECONNRESET:
 642	case -ESHUTDOWN:
 643		atomic_set(&ncm->notify_count, 0);
 644		ncm->notify_state = NCM_NOTIFY_NONE;
 645		break;
 646	default:
 647		DBG(cdev, "event %02x --> %d\n",
 648			event->bNotificationType, req->status);
 649		atomic_dec(&ncm->notify_count);
 650		break;
 651	}
 652	ncm_do_notify(ncm);
 653	spin_unlock(&ncm->lock);
 654}
 655
 656static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
 657{
 658	/* now for SET_NTB_INPUT_SIZE only */
 659	unsigned		in_size;
 660	struct usb_function	*f = req->context;
 661	struct f_ncm		*ncm = func_to_ncm(f);
 662	struct usb_composite_dev *cdev = f->config->cdev;
 663
 664	req->context = NULL;
 665	if (req->status || req->actual != req->length) {
 666		DBG(cdev, "Bad control-OUT transfer\n");
 667		goto invalid;
 668	}
 669
 670	in_size = get_unaligned_le32(req->buf);
 671	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
 672	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
 673		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
 674		goto invalid;
 675	}
 676
 677	ncm->port.fixed_in_len = in_size;
 678	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
 679	return;
 680
 681invalid:
 682	usb_ep_set_halt(ep);
 683	return;
 684}
 685
 686static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 687{
 688	struct f_ncm		*ncm = func_to_ncm(f);
 689	struct usb_composite_dev *cdev = f->config->cdev;
 690	struct usb_request	*req = cdev->req;
 691	int			value = -EOPNOTSUPP;
 692	u16			w_index = le16_to_cpu(ctrl->wIndex);
 693	u16			w_value = le16_to_cpu(ctrl->wValue);
 694	u16			w_length = le16_to_cpu(ctrl->wLength);
 695
 696	/*
 697	 * composite driver infrastructure handles everything except
 698	 * CDC class messages; interface activation uses set_alt().
 699	 */
 700	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 701	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 702			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
 703		/*
 704		 * see 6.2.30: no data, wIndex = interface,
 705		 * wValue = packet filter bitmap
 706		 */
 707		if (w_length != 0 || w_index != ncm->ctrl_id)
 708			goto invalid;
 709		DBG(cdev, "packet filter %02x\n", w_value);
 710		/*
 711		 * REVISIT locking of cdc_filter.  This assumes the UDC
 712		 * driver won't have a concurrent packet TX irq running on
 713		 * another CPU; or that if it does, this write is atomic...
 714		 */
 715		ncm->port.cdc_filter = w_value;
 716		value = 0;
 717		break;
 718	/*
 719	 * and optionally:
 720	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 721	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 722	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 723	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 724	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 725	 * case USB_CDC_GET_ETHERNET_STATISTIC:
 726	 */
 727
 728	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 729		| USB_CDC_GET_NTB_PARAMETERS:
 730
 731		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
 732			goto invalid;
 733		value = w_length > sizeof ntb_parameters ?
 734			sizeof ntb_parameters : w_length;
 735		memcpy(req->buf, &ntb_parameters, value);
 736		VDBG(cdev, "Host asked NTB parameters\n");
 737		break;
 738
 739	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 740		| USB_CDC_GET_NTB_INPUT_SIZE:
 741
 742		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
 743			goto invalid;
 744		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
 745		value = 4;
 746		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
 747		     ncm->port.fixed_in_len);
 748		break;
 749
 750	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 751		| USB_CDC_SET_NTB_INPUT_SIZE:
 752	{
 753		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
 754			goto invalid;
 755		req->complete = ncm_ep0out_complete;
 756		req->length = w_length;
 757		req->context = f;
 758
 759		value = req->length;
 760		break;
 761	}
 762
 763	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 764		| USB_CDC_GET_NTB_FORMAT:
 765	{
 766		uint16_t format;
 767
 768		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
 769			goto invalid;
 770		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
 771		put_unaligned_le16(format, req->buf);
 772		value = 2;
 773		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
 774		break;
 775	}
 776
 777	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 778		| USB_CDC_SET_NTB_FORMAT:
 779	{
 780		if (w_length != 0 || w_index != ncm->ctrl_id)
 781			goto invalid;
 782		switch (w_value) {
 783		case 0x0000:
 784			ncm->parser_opts = &ndp16_opts;
 785			DBG(cdev, "NCM16 selected\n");
 786			break;
 787		case 0x0001:
 788			ncm->parser_opts = &ndp32_opts;
 789			DBG(cdev, "NCM32 selected\n");
 790			break;
 791		default:
 792			goto invalid;
 793		}
 794		value = 0;
 795		break;
 796	}
 797	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 798		| USB_CDC_GET_CRC_MODE:
 799	{
 800		uint16_t is_crc;
 801
 802		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
 803			goto invalid;
 804		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
 805		put_unaligned_le16(is_crc, req->buf);
 806		value = 2;
 807		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
 808		break;
 809	}
 810
 811	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 812		| USB_CDC_SET_CRC_MODE:
 813	{
 814		if (w_length != 0 || w_index != ncm->ctrl_id)
 815			goto invalid;
 816		switch (w_value) {
 817		case 0x0000:
 818			ncm->is_crc = false;
 819			DBG(cdev, "non-CRC mode selected\n");
 820			break;
 821		case 0x0001:
 822			ncm->is_crc = true;
 823			DBG(cdev, "CRC mode selected\n");
 824			break;
 825		default:
 826			goto invalid;
 827		}
 828		value = 0;
 829		break;
 830	}
 831
 832	/* and disabled in ncm descriptor: */
 833	/* case USB_CDC_GET_NET_ADDRESS: */
 834	/* case USB_CDC_SET_NET_ADDRESS: */
 835	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
 836	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
 837
 838	default:
 839invalid:
 840		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 841			ctrl->bRequestType, ctrl->bRequest,
 842			w_value, w_index, w_length);
 843	}
 844	ncm->ndp_sign = ncm->parser_opts->ndp_sign |
 845		(ncm->is_crc ? NCM_NDP_HDR_CRC : 0);
 846
 847	/* respond with data transfer or status phase? */
 848	if (value >= 0) {
 849		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
 850			ctrl->bRequestType, ctrl->bRequest,
 851			w_value, w_index, w_length);
 852		req->zero = 0;
 853		req->length = value;
 854		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 855		if (value < 0)
 856			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
 857					ctrl->bRequestType, ctrl->bRequest,
 858					value);
 859	}
 860
 861	/* device either stalls (value < 0) or reports success */
 862	return value;
 863}
 864
 865
 866static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 867{
 868	struct f_ncm		*ncm = func_to_ncm(f);
 869	struct usb_composite_dev *cdev = f->config->cdev;
 870
 871	/* Control interface has only altsetting 0 */
 872	if (intf == ncm->ctrl_id) {
 873		if (alt != 0)
 874			goto fail;
 875
 876		DBG(cdev, "reset ncm control %d\n", intf);
 877		usb_ep_disable(ncm->notify);
 878
 879		if (!(ncm->notify->desc)) {
 880			DBG(cdev, "init ncm ctrl %d\n", intf);
 881			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
 882				goto fail;
 883		}
 884		usb_ep_enable(ncm->notify);
 885
 886	/* Data interface has two altsettings, 0 and 1 */
 887	} else if (intf == ncm->data_id) {
 888		if (alt > 1)
 889			goto fail;
 890
 891		if (ncm->port.in_ep->enabled) {
 892			DBG(cdev, "reset ncm\n");
 893			ncm->timer_stopping = true;
 894			ncm->netdev = NULL;
 895			gether_disconnect(&ncm->port);
 896			ncm_reset_values(ncm);
 897		}
 898
 899		/*
 900		 * CDC Network only sends data in non-default altsettings.
 901		 * Changing altsettings resets filters, statistics, etc.
 902		 */
 903		if (alt == 1) {
 904			struct net_device	*net;
 905
 906			if (!ncm->port.in_ep->desc ||
 907			    !ncm->port.out_ep->desc) {
 908				DBG(cdev, "init ncm\n");
 909				if (config_ep_by_speed(cdev->gadget, f,
 910						       ncm->port.in_ep) ||
 911				    config_ep_by_speed(cdev->gadget, f,
 912						       ncm->port.out_ep)) {
 913					ncm->port.in_ep->desc = NULL;
 914					ncm->port.out_ep->desc = NULL;
 915					goto fail;
 916				}
 917			}
 918
 919			/* TODO */
 920			/* Enable zlps by default for NCM conformance;
 921			 * override for musb_hdrc (avoids txdma ovhead)
 922			 */
 923			ncm->port.is_zlp_ok =
 924				gadget_is_zlp_supported(cdev->gadget);
 925			ncm->port.cdc_filter = DEFAULT_FILTER;
 926			DBG(cdev, "activate ncm\n");
 927			net = gether_connect(&ncm->port);
 928			if (IS_ERR(net))
 929				return PTR_ERR(net);
 930			ncm->netdev = net;
 931			ncm->timer_stopping = false;
 932		}
 933
 934		spin_lock(&ncm->lock);
 935		ncm_notify(ncm);
 936		spin_unlock(&ncm->lock);
 937	} else
 938		goto fail;
 939
 940	return 0;
 941fail:
 942	return -EINVAL;
 943}
 944
 945/*
 946 * Because the data interface supports multiple altsettings,
 947 * this NCM function *MUST* implement a get_alt() method.
 948 */
 949static int ncm_get_alt(struct usb_function *f, unsigned intf)
 950{
 951	struct f_ncm		*ncm = func_to_ncm(f);
 952
 953	if (intf == ncm->ctrl_id)
 954		return 0;
 955	return ncm->port.in_ep->enabled ? 1 : 0;
 956}
 957
 958static struct sk_buff *package_for_tx(struct f_ncm *ncm)
 959{
 960	__le16		*ntb_iter;
 961	struct sk_buff	*skb2 = NULL;
 962	unsigned	ndp_pad;
 963	unsigned	ndp_index;
 964	unsigned	new_len;
 965
 966	const struct ndp_parser_opts *opts = ncm->parser_opts;
 967	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
 968	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
 969
 970	/* Stop the timer */
 971	hrtimer_try_to_cancel(&ncm->task_timer);
 972
 973	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
 974			ncm->skb_tx_data->len;
 975	ndp_index = ncm->skb_tx_data->len + ndp_pad;
 976	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
 977
 978	/* Set the final BlockLength and wNdpIndex */
 979	ntb_iter = (void *) ncm->skb_tx_data->data;
 980	/* Increment pointer to BlockLength */
 981	ntb_iter += 2 + 1 + 1;
 982	put_ncm(&ntb_iter, opts->block_length, new_len);
 983	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
 984
 985	/* Set the final NDP wLength */
 986	new_len = opts->ndp_size +
 987			(ncm->ndp_dgram_count * dgram_idx_len);
 988	ncm->ndp_dgram_count = 0;
 989	/* Increment from start to wLength */
 990	ntb_iter = (void *) ncm->skb_tx_ndp->data;
 991	ntb_iter += 2;
 992	put_unaligned_le16(new_len, ntb_iter);
 993
 994	/* Merge the skbs */
 995	swap(skb2, ncm->skb_tx_data);
 996	if (ncm->skb_tx_data) {
 997		dev_consume_skb_any(ncm->skb_tx_data);
 998		ncm->skb_tx_data = NULL;
 999	}
1000
1001	/* Insert NDP alignment. */
1002	skb_put_zero(skb2, ndp_pad);
1003
1004	/* Copy NTB across. */
1005	skb_put_data(skb2, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1006	dev_consume_skb_any(ncm->skb_tx_ndp);
1007	ncm->skb_tx_ndp = NULL;
1008
1009	/* Insert zero'd datagram. */
1010	skb_put_zero(skb2, dgram_idx_len);
1011
1012	return skb2;
1013}
1014
1015static struct sk_buff *ncm_wrap_ntb(struct gether *port,
1016				    struct sk_buff *skb)
1017{
1018	struct f_ncm	*ncm = func_to_ncm(&port->func);
1019	struct sk_buff	*skb2 = NULL;
1020	int		ncb_len = 0;
1021	__le16		*ntb_data;
1022	__le16		*ntb_ndp;
1023	int		dgram_pad;
1024
1025	unsigned	max_size = ncm->port.fixed_in_len;
1026	const struct ndp_parser_opts *opts = ncm->parser_opts;
1027	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
1028	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
1029	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
1030	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
1031
1032	if (!skb && !ncm->skb_tx_data)
1033		return NULL;
1034
1035	if (skb) {
1036		/* Add the CRC if required up front */
1037		if (ncm->is_crc) {
1038			uint32_t	crc;
1039			__le16		*crc_pos;
1040
1041			crc = ~crc32_le(~0,
1042					skb->data,
1043					skb->len);
1044			crc_pos = skb_put(skb, sizeof(uint32_t));
1045			put_unaligned_le32(crc, crc_pos);
1046		}
1047
1048		/* If the new skb is too big for the current NCM NTB then
1049		 * set the current stored skb to be sent now and clear it
1050		 * ready for new data.
1051		 * NOTE: Assume maximum align for speed of calculation.
1052		 */
1053		if (ncm->skb_tx_data
1054		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
1055		    || (ncm->skb_tx_data->len +
1056		    div + rem + skb->len +
1057		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
1058		    > max_size)) {
1059			skb2 = package_for_tx(ncm);
1060			if (!skb2)
1061				goto err;
1062		}
1063
1064		if (!ncm->skb_tx_data) {
1065			ncb_len = opts->nth_size;
1066			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1067			ncb_len += dgram_pad;
1068
1069			/* Create a new skb for the NTH and datagrams. */
1070			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1071			if (!ncm->skb_tx_data)
1072				goto err;
1073
1074			ncm->skb_tx_data->dev = ncm->netdev;
1075			ntb_data = skb_put_zero(ncm->skb_tx_data, ncb_len);
1076			/* dwSignature */
1077			put_unaligned_le32(opts->nth_sign, ntb_data);
1078			ntb_data += 2;
1079			/* wHeaderLength */
1080			put_unaligned_le16(opts->nth_size, ntb_data++);
1081
1082			/* Allocate an skb for storing the NDP,
1083			 * TX_MAX_NUM_DPE should easily suffice for a
1084			 * 16k packet.
1085			 */
1086			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1087						    + opts->dpe_size
1088						    * TX_MAX_NUM_DPE),
1089						    GFP_ATOMIC);
1090			if (!ncm->skb_tx_ndp)
1091				goto err;
1092
1093			ncm->skb_tx_ndp->dev = ncm->netdev;
1094			ntb_ndp = skb_put(ncm->skb_tx_ndp, opts->ndp_size);
1095			memset(ntb_ndp, 0, ncb_len);
1096			/* dwSignature */
1097			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1098			ntb_ndp += 2;
1099
1100			/* There is always a zeroed entry */
1101			ncm->ndp_dgram_count = 1;
1102
1103			/* Note: we skip opts->next_ndp_index */
1104
1105			/* Start the timer. */
1106			hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
1107				      HRTIMER_MODE_REL_SOFT);
1108		}
1109
1110		/* Add the datagram position entries */
1111		ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len);
1112
1113		ncb_len = ncm->skb_tx_data->len;
1114		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1115		ncb_len += dgram_pad;
1116
1117		/* (d)wDatagramIndex */
1118		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1119		/* (d)wDatagramLength */
1120		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1121		ncm->ndp_dgram_count++;
1122
1123		/* Add the new data to the skb */
1124		skb_put_zero(ncm->skb_tx_data, dgram_pad);
1125		skb_put_data(ncm->skb_tx_data, skb->data, skb->len);
1126		dev_consume_skb_any(skb);
1127		skb = NULL;
1128
1129	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1130		/* If the tx was requested because of a timeout then send */
1131		skb2 = package_for_tx(ncm);
1132		if (!skb2)
1133			goto err;
1134	}
1135
1136	return skb2;
1137
1138err:
1139	ncm->netdev->stats.tx_dropped++;
1140
1141	if (skb)
1142		dev_kfree_skb_any(skb);
1143	if (ncm->skb_tx_data)
1144		dev_kfree_skb_any(ncm->skb_tx_data);
1145	if (ncm->skb_tx_ndp)
1146		dev_kfree_skb_any(ncm->skb_tx_ndp);
1147
1148	return NULL;
1149}
1150
1151/*
1152 * The transmit should only be run if no skb data has been sent
1153 * for a certain duration.
1154 */
1155static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1156{
1157	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1158
1159	/* Only send if data is available. */
1160	if (!ncm->timer_stopping && ncm->skb_tx_data) {
1161		ncm->timer_force_tx = true;
1162
1163		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1164		 * XXX is not sane.  The gadget layer should be redesigned so
1165		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1166		 * XXX and performed in some way outside of the ndo_start_xmit
1167		 * XXX interface.
1168		 */
1169		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1170
1171		ncm->timer_force_tx = false;
1172	}
1173	return HRTIMER_NORESTART;
1174}
1175
1176static int ncm_unwrap_ntb(struct gether *port,
1177			  struct sk_buff *skb,
1178			  struct sk_buff_head *list)
1179{
1180	struct f_ncm	*ncm = func_to_ncm(&port->func);
1181	__le16		*tmp = (void *) skb->data;
1182	unsigned	index, index2;
1183	int		ndp_index;
1184	unsigned	dg_len, dg_len2;
1185	unsigned	ndp_len;
1186	unsigned	block_len;
1187	struct sk_buff	*skb2;
1188	int		ret = -EINVAL;
1189	unsigned	ntb_max = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1190	unsigned	frame_max = le16_to_cpu(ecm_desc.wMaxSegmentSize);
1191	const struct ndp_parser_opts *opts = ncm->parser_opts;
1192	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1193	int		dgram_counter;
1194
1195	/* dwSignature */
1196	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1197		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1198			skb->len);
1199		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1200			       skb->data, 32, false);
1201
1202		goto err;
1203	}
1204	tmp += 2;
1205	/* wHeaderLength */
1206	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1207		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1208		goto err;
1209	}
1210	tmp++; /* skip wSequence */
1211
1212	block_len = get_ncm(&tmp, opts->block_length);
1213	/* (d)wBlockLength */
1214	if (block_len > ntb_max) {
1215		INFO(port->func.config->cdev, "OUT size exceeded\n");
1216		goto err;
1217	}
1218
1219	ndp_index = get_ncm(&tmp, opts->ndp_index);
1220
1221	/* Run through all the NDP's in the NTB */
1222	do {
1223		/*
1224		 * NCM 3.2
1225		 * dwNdpIndex
1226		 */
1227		if (((ndp_index % 4) != 0) ||
1228				(ndp_index < opts->nth_size) ||
1229				(ndp_index > (block_len -
1230					      opts->ndp_size))) {
1231			INFO(port->func.config->cdev, "Bad index: %#X\n",
1232			     ndp_index);
1233			goto err;
1234		}
1235
1236		/*
1237		 * walk through NDP
1238		 * dwSignature
1239		 */
1240		tmp = (void *)(skb->data + ndp_index);
1241		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1242			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1243			goto err;
1244		}
1245		tmp += 2;
1246
1247		ndp_len = get_unaligned_le16(tmp++);
1248		/*
1249		 * NCM 3.3.1
1250		 * wLength
1251		 * entry is 2 items
1252		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1253		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1254		 * Each entry is a dgram index and a dgram length.
1255		 */
1256		if ((ndp_len < opts->ndp_size
1257				+ 2 * 2 * (opts->dgram_item_len * 2)) ||
1258				(ndp_len % opts->ndplen_align != 0)) {
1259			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1260			     ndp_len);
1261			goto err;
1262		}
1263		tmp += opts->reserved1;
1264		/* Check for another NDP (d)wNextNdpIndex */
1265		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1266		tmp += opts->reserved2;
1267
1268		ndp_len -= opts->ndp_size;
1269		index2 = get_ncm(&tmp, opts->dgram_item_len);
1270		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1271		dgram_counter = 0;
1272
1273		do {
1274			index = index2;
1275			/* wDatagramIndex[0] */
1276			if ((index < opts->nth_size) ||
1277					(index > block_len - opts->dpe_size)) {
1278				INFO(port->func.config->cdev,
1279				     "Bad index: %#X\n", index);
1280				goto err;
1281			}
1282
1283			dg_len = dg_len2;
1284			/*
1285			 * wDatagramLength[0]
1286			 * ethernet hdr + crc or larger than max frame size
1287			 */
1288			if ((dg_len < 14 + crc_len) ||
1289					(dg_len > frame_max)) {
1290				INFO(port->func.config->cdev,
1291				     "Bad dgram length: %#X\n", dg_len);
1292				goto err;
1293			}
1294			if (ncm->is_crc) {
1295				uint32_t crc, crc2;
1296
1297				crc = get_unaligned_le32(skb->data +
1298							 index + dg_len -
1299							 crc_len);
1300				crc2 = ~crc32_le(~0,
1301						 skb->data + index,
1302						 dg_len - crc_len);
1303				if (crc != crc2) {
1304					INFO(port->func.config->cdev,
1305					     "Bad CRC\n");
1306					goto err;
1307				}
1308			}
1309
1310			index2 = get_ncm(&tmp, opts->dgram_item_len);
1311			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1312
1313			/* wDatagramIndex[1] */
1314			if (index2 > block_len - opts->dpe_size) {
1315				INFO(port->func.config->cdev,
1316				     "Bad index: %#X\n", index2);
1317				goto err;
1318			}
1319
1320			/*
1321			 * Copy the data into a new skb.
1322			 * This ensures the truesize is correct
1323			 */
1324			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1325							 dg_len - crc_len);
1326			if (skb2 == NULL)
1327				goto err;
1328			skb_put_data(skb2, skb->data + index,
1329				     dg_len - crc_len);
1330
1331			skb_queue_tail(list, skb2);
1332
1333			ndp_len -= 2 * (opts->dgram_item_len * 2);
1334
1335			dgram_counter++;
1336			if (index2 == 0 || dg_len2 == 0)
1337				break;
1338		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1339	} while (ndp_index);
1340
1341	dev_consume_skb_any(skb);
1342
1343	VDBG(port->func.config->cdev,
1344	     "Parsed NTB with %d frames\n", dgram_counter);
1345	return 0;
1346err:
1347	skb_queue_purge(list);
1348	dev_kfree_skb_any(skb);
1349	return ret;
1350}
1351
1352static void ncm_disable(struct usb_function *f)
1353{
1354	struct f_ncm		*ncm = func_to_ncm(f);
1355	struct usb_composite_dev *cdev = f->config->cdev;
1356
1357	DBG(cdev, "ncm deactivated\n");
1358
1359	if (ncm->port.in_ep->enabled) {
1360		ncm->timer_stopping = true;
1361		ncm->netdev = NULL;
1362		gether_disconnect(&ncm->port);
1363	}
1364
1365	if (ncm->notify->enabled) {
1366		usb_ep_disable(ncm->notify);
1367		ncm->notify->desc = NULL;
1368	}
1369}
1370
1371/*-------------------------------------------------------------------------*/
1372
1373/*
1374 * Callbacks let us notify the host about connect/disconnect when the
1375 * net device is opened or closed.
1376 *
1377 * For testing, note that link states on this side include both opened
1378 * and closed variants of:
1379 *
1380 *   - disconnected/unconfigured
1381 *   - configured but inactive (data alt 0)
1382 *   - configured and active (data alt 1)
1383 *
1384 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1385 * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1386 * imply the host is actually polling the notification endpoint, and
1387 * likewise that "active" doesn't imply it's actually using the data
1388 * endpoints for traffic.
1389 */
1390
1391static void ncm_open(struct gether *geth)
1392{
1393	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1394
1395	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1396
1397	spin_lock(&ncm->lock);
1398	ncm->is_open = true;
1399	ncm_notify(ncm);
1400	spin_unlock(&ncm->lock);
1401}
1402
1403static void ncm_close(struct gether *geth)
1404{
1405	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1406
1407	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1408
1409	spin_lock(&ncm->lock);
1410	ncm->is_open = false;
1411	ncm_notify(ncm);
1412	spin_unlock(&ncm->lock);
1413}
1414
1415/*-------------------------------------------------------------------------*/
1416
1417/* ethernet function driver setup/binding */
1418
1419static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1420{
1421	struct usb_composite_dev *cdev = c->cdev;
1422	struct f_ncm		*ncm = func_to_ncm(f);
1423	struct usb_string	*us;
1424	int			status;
1425	struct usb_ep		*ep;
1426	struct f_ncm_opts	*ncm_opts;
1427
1428	if (!can_support_ecm(cdev->gadget))
1429		return -EINVAL;
1430
1431	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1432
1433	if (cdev->use_os_string) {
1434		f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
1435					   GFP_KERNEL);
1436		if (!f->os_desc_table)
1437			return -ENOMEM;
1438		f->os_desc_n = 1;
1439		f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
1440	}
1441
1442	/*
1443	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1444	 * configurations are bound in sequence with list_for_each_entry,
1445	 * in each configuration its functions are bound in sequence
1446	 * with list_for_each_entry, so we assume no race condition
1447	 * with regard to ncm_opts->bound access
1448	 */
1449	if (!ncm_opts->bound) {
1450		mutex_lock(&ncm_opts->lock);
1451		gether_set_gadget(ncm_opts->net, cdev->gadget);
1452		status = gether_register_netdev(ncm_opts->net);
1453		mutex_unlock(&ncm_opts->lock);
1454		if (status)
1455			goto fail;
1456		ncm_opts->bound = true;
1457	}
1458	us = usb_gstrings_attach(cdev, ncm_strings,
1459				 ARRAY_SIZE(ncm_string_defs));
1460	if (IS_ERR(us)) {
1461		status = PTR_ERR(us);
1462		goto fail;
1463	}
1464	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1465	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1466	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1467	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1468	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1469
1470	/* allocate instance-specific interface IDs */
1471	status = usb_interface_id(c, f);
1472	if (status < 0)
1473		goto fail;
1474	ncm->ctrl_id = status;
1475	ncm_iad_desc.bFirstInterface = status;
1476
1477	ncm_control_intf.bInterfaceNumber = status;
1478	ncm_union_desc.bMasterInterface0 = status;
1479
1480	if (cdev->use_os_string)
1481		f->os_desc_table[0].if_id =
1482			ncm_iad_desc.bFirstInterface;
1483
1484	status = usb_interface_id(c, f);
1485	if (status < 0)
1486		goto fail;
1487	ncm->data_id = status;
1488
1489	ncm_data_nop_intf.bInterfaceNumber = status;
1490	ncm_data_intf.bInterfaceNumber = status;
1491	ncm_union_desc.bSlaveInterface0 = status;
1492
1493	status = -ENODEV;
1494
1495	/* allocate instance-specific endpoints */
1496	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1497	if (!ep)
1498		goto fail;
1499	ncm->port.in_ep = ep;
1500
1501	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1502	if (!ep)
1503		goto fail;
1504	ncm->port.out_ep = ep;
1505
1506	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1507	if (!ep)
1508		goto fail;
1509	ncm->notify = ep;
1510
1511	status = -ENOMEM;
1512
1513	/* allocate notification request and buffer */
1514	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1515	if (!ncm->notify_req)
1516		goto fail;
1517	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1518	if (!ncm->notify_req->buf)
1519		goto fail;
1520	ncm->notify_req->context = ncm;
1521	ncm->notify_req->complete = ncm_notify_complete;
1522
1523	/*
1524	 * support all relevant hardware speeds... we expect that when
1525	 * hardware is dual speed, all bulk-capable endpoints work at
1526	 * both speeds
1527	 */
1528	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1529	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1530	hs_ncm_notify_desc.bEndpointAddress =
1531		fs_ncm_notify_desc.bEndpointAddress;
1532
1533	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1534	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1535	ss_ncm_notify_desc.bEndpointAddress =
1536		fs_ncm_notify_desc.bEndpointAddress;
1537
1538	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1539			ncm_ss_function, ncm_ss_function);
1540	if (status)
1541		goto fail;
1542
1543	/*
1544	 * NOTE:  all that is done without knowing or caring about
1545	 * the network link ... which is unavailable to this code
1546	 * until we're activated via set_alt().
1547	 */
1548
1549	ncm->port.open = ncm_open;
1550	ncm->port.close = ncm_close;
1551
1552	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1553	ncm->task_timer.function = ncm_tx_timeout;
1554
1555	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1556			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1557			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1558			ncm->port.in_ep->name, ncm->port.out_ep->name,
1559			ncm->notify->name);
1560	return 0;
1561
1562fail:
1563	kfree(f->os_desc_table);
1564	f->os_desc_n = 0;
1565
1566	if (ncm->notify_req) {
1567		kfree(ncm->notify_req->buf);
1568		usb_ep_free_request(ncm->notify, ncm->notify_req);
1569	}
1570
1571	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1572
1573	return status;
1574}
1575
1576static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1577{
1578	return container_of(to_config_group(item), struct f_ncm_opts,
1579			    func_inst.group);
1580}
1581
1582/* f_ncm_item_ops */
1583USB_ETHERNET_CONFIGFS_ITEM(ncm);
1584
1585/* f_ncm_opts_dev_addr */
1586USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1587
1588/* f_ncm_opts_host_addr */
1589USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1590
1591/* f_ncm_opts_qmult */
1592USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1593
1594/* f_ncm_opts_ifname */
1595USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1596
1597static struct configfs_attribute *ncm_attrs[] = {
1598	&ncm_opts_attr_dev_addr,
1599	&ncm_opts_attr_host_addr,
1600	&ncm_opts_attr_qmult,
1601	&ncm_opts_attr_ifname,
1602	NULL,
1603};
1604
1605static const struct config_item_type ncm_func_type = {
1606	.ct_item_ops	= &ncm_item_ops,
1607	.ct_attrs	= ncm_attrs,
1608	.ct_owner	= THIS_MODULE,
1609};
1610
1611static void ncm_free_inst(struct usb_function_instance *f)
1612{
1613	struct f_ncm_opts *opts;
1614
1615	opts = container_of(f, struct f_ncm_opts, func_inst);
1616	if (opts->bound)
1617		gether_cleanup(netdev_priv(opts->net));
1618	else
1619		free_netdev(opts->net);
1620	kfree(opts->ncm_interf_group);
1621	kfree(opts);
1622}
1623
1624static struct usb_function_instance *ncm_alloc_inst(void)
1625{
1626	struct f_ncm_opts *opts;
1627	struct usb_os_desc *descs[1];
1628	char *names[1];
1629	struct config_group *ncm_interf_group;
1630
1631	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1632	if (!opts)
1633		return ERR_PTR(-ENOMEM);
1634	opts->ncm_os_desc.ext_compat_id = opts->ncm_ext_compat_id;
1635
1636	mutex_init(&opts->lock);
1637	opts->func_inst.free_func_inst = ncm_free_inst;
1638	opts->net = gether_setup_default();
1639	if (IS_ERR(opts->net)) {
1640		struct net_device *net = opts->net;
1641		kfree(opts);
1642		return ERR_CAST(net);
1643	}
1644	INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop);
1645
1646	descs[0] = &opts->ncm_os_desc;
1647	names[0] = "ncm";
1648
1649	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1650	ncm_interf_group =
1651		usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
1652					       names, THIS_MODULE);
1653	if (IS_ERR(ncm_interf_group)) {
1654		ncm_free_inst(&opts->func_inst);
1655		return ERR_CAST(ncm_interf_group);
1656	}
1657	opts->ncm_interf_group = ncm_interf_group;
1658
1659	return &opts->func_inst;
1660}
1661
1662static void ncm_free(struct usb_function *f)
1663{
1664	struct f_ncm *ncm;
1665	struct f_ncm_opts *opts;
1666
1667	ncm = func_to_ncm(f);
1668	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1669	kfree(ncm);
1670	mutex_lock(&opts->lock);
1671	opts->refcnt--;
1672	mutex_unlock(&opts->lock);
1673}
1674
1675static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1676{
1677	struct f_ncm *ncm = func_to_ncm(f);
1678
1679	DBG(c->cdev, "ncm unbind\n");
1680
1681	hrtimer_cancel(&ncm->task_timer);
1682
1683	kfree(f->os_desc_table);
1684	f->os_desc_n = 0;
1685
1686	ncm_string_defs[0].id = 0;
1687	usb_free_all_descriptors(f);
1688
1689	if (atomic_read(&ncm->notify_count)) {
1690		usb_ep_dequeue(ncm->notify, ncm->notify_req);
1691		atomic_set(&ncm->notify_count, 0);
1692	}
1693
1694	kfree(ncm->notify_req->buf);
1695	usb_ep_free_request(ncm->notify, ncm->notify_req);
1696}
1697
1698static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1699{
1700	struct f_ncm		*ncm;
1701	struct f_ncm_opts	*opts;
1702	int status;
1703
1704	/* allocate and initialize one new instance */
1705	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1706	if (!ncm)
1707		return ERR_PTR(-ENOMEM);
1708
1709	opts = container_of(fi, struct f_ncm_opts, func_inst);
1710	mutex_lock(&opts->lock);
1711	opts->refcnt++;
1712
1713	/* export host's Ethernet address in CDC format */
1714	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1715				      sizeof(ncm->ethaddr));
1716	if (status < 12) { /* strlen("01234567890a") */
1717		kfree(ncm);
1718		mutex_unlock(&opts->lock);
1719		return ERR_PTR(-EINVAL);
1720	}
1721	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1722
1723	spin_lock_init(&ncm->lock);
1724	ncm_reset_values(ncm);
1725	ncm->port.ioport = netdev_priv(opts->net);
1726	mutex_unlock(&opts->lock);
1727	ncm->port.is_fixed = true;
1728	ncm->port.supports_multi_frame = true;
1729
1730	ncm->port.func.name = "cdc_network";
1731	/* descriptors are per-instance copies */
1732	ncm->port.func.bind = ncm_bind;
1733	ncm->port.func.unbind = ncm_unbind;
1734	ncm->port.func.set_alt = ncm_set_alt;
1735	ncm->port.func.get_alt = ncm_get_alt;
1736	ncm->port.func.setup = ncm_setup;
1737	ncm->port.func.disable = ncm_disable;
1738	ncm->port.func.free_func = ncm_free;
1739
1740	ncm->port.wrap = ncm_wrap_ntb;
1741	ncm->port.unwrap = ncm_unwrap_ntb;
1742
1743	return &ncm->port.func;
1744}
1745
1746DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1747MODULE_LICENSE("GPL");
1748MODULE_AUTHOR("Yauheni Kaliuta");