1 /*
2  * f_ncm.c -- USB CDC Network (NCM) link function driver
3  *
4  * Copyright (C) 2010 Nokia Corporation
5  * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
6  *
7  * The driver borrows from f_ecm.c which is:
8  *
9  * Copyright (C) 2003-2005,2008 David Brownell
10  * Copyright (C) 2008 Nokia Corporation
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/interrupt.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/etherdevice.h>
23 #include <linux/crc32.h>
24 
25 #include <linux/usb/cdc.h>
26 
27 #include "u_ether.h"
28 #include "u_ether_configfs.h"
29 #include "u_ncm.h"
30 
31 /*
32  * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
33  * NCM is intended to be used with high-speed network attachments.
34  *
35  * Note that NCM requires the use of "alternate settings" for its data
36  * interface.  This means that the set_alt() method has real work to do,
37  * and also means that a get_alt() method is required.
38  */
39 
40 /* to trigger crc/non-crc ndp signature */
41 
42 #define NCM_NDP_HDR_CRC_MASK	0x01000000
43 #define NCM_NDP_HDR_CRC		0x01000000
44 #define NCM_NDP_HDR_NOCRC	0x00000000
45 
46 enum ncm_notify_state {
47 	NCM_NOTIFY_NONE,		/* don't notify */
48 	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
49 	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
50 };
51 
52 struct f_ncm {
53 	struct gether			port;
54 	u8				ctrl_id, data_id;
55 
56 	char				ethaddr[14];
57 
58 	struct usb_ep			*notify;
59 	struct usb_request		*notify_req;
60 	u8				notify_state;
61 	bool				is_open;
62 
63 	const struct ndp_parser_opts	*parser_opts;
64 	bool				is_crc;
65 	u32				ndp_sign;
66 
67 	/*
68 	 * for notification, it is accessed from both
69 	 * callback and ethernet open/close
70 	 */
71 	spinlock_t			lock;
72 
73 	struct net_device		*netdev;
74 
75 	/* For multi-frame NDP TX */
76 	struct sk_buff			*skb_tx_data;
77 	struct sk_buff			*skb_tx_ndp;
78 	u16				ndp_dgram_count;
79 	bool				timer_force_tx;
80 	struct tasklet_struct		tx_tasklet;
81 	struct hrtimer			task_timer;
82 
83 	bool				timer_stopping;
84 };
85 
86 static inline struct f_ncm *func_to_ncm(struct usb_function *f)
87 {
88 	return container_of(f, struct f_ncm, port.func);
89 }
90 
91 /* peak (theoretical) bulk transfer rate in bits-per-second */
92 static inline unsigned ncm_bitrate(struct usb_gadget *g)
93 {
94 	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
95 		return 13 * 1024 * 8 * 1000 * 8;
96 	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
97 		return 13 * 512 * 8 * 1000 * 8;
98 	else
99 		return 19 *  64 * 1 * 1000 * 8;
100 }
101 
102 /*-------------------------------------------------------------------------*/
103 
104 /*
105  * We cannot group frames so use just the minimal size which ok to put
106  * one max-size ethernet frame.
107  * If the host can group frames, allow it to do that, 16K is selected,
108  * because it's used by default by the current linux host driver
109  */
110 #define NTB_DEFAULT_IN_SIZE	16384
111 #define NTB_OUT_SIZE		16384
112 
113 /* Allocation for storing the NDP, 32 should suffice for a
114  * 16k packet. This allows a maximum of 32 * 507 Byte packets to
115  * be transmitted in a single 16kB skb, though when sending full size
116  * packets this limit will be plenty.
117  * Smaller packets are not likely to be trying to maximize the
118  * throughput and will be mstly sending smaller infrequent frames.
119  */
120 #define TX_MAX_NUM_DPE		32
121 
122 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
123 #define TX_TIMEOUT_NSECS	300000
124 
125 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
126 				 USB_CDC_NCM_NTB32_SUPPORTED)
127 
128 static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
129 	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
130 	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
131 	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
132 	.wNdpInDivisor = cpu_to_le16(4),
133 	.wNdpInPayloadRemainder = cpu_to_le16(0),
134 	.wNdpInAlignment = cpu_to_le16(4),
135 
136 	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
137 	.wNdpOutDivisor = cpu_to_le16(4),
138 	.wNdpOutPayloadRemainder = cpu_to_le16(0),
139 	.wNdpOutAlignment = cpu_to_le16(4),
140 };
141 
142 /*
143  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
144  * packet, to simplify cancellation; and a big transfer interval, to
145  * waste less bandwidth.
146  */
147 
148 #define NCM_STATUS_INTERVAL_MS		32
149 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
150 
151 static struct usb_interface_assoc_descriptor ncm_iad_desc = {
152 	.bLength =		sizeof ncm_iad_desc,
153 	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
154 
155 	/* .bFirstInterface =	DYNAMIC, */
156 	.bInterfaceCount =	2,	/* control + data */
157 	.bFunctionClass =	USB_CLASS_COMM,
158 	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
159 	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
160 	/* .iFunction =		DYNAMIC */
161 };
162 
163 /* interface descriptor: */
164 
165 static struct usb_interface_descriptor ncm_control_intf = {
166 	.bLength =		sizeof ncm_control_intf,
167 	.bDescriptorType =	USB_DT_INTERFACE,
168 
169 	/* .bInterfaceNumber = DYNAMIC */
170 	.bNumEndpoints =	1,
171 	.bInterfaceClass =	USB_CLASS_COMM,
172 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
173 	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
174 	/* .iInterface = DYNAMIC */
175 };
176 
177 static struct usb_cdc_header_desc ncm_header_desc = {
178 	.bLength =		sizeof ncm_header_desc,
179 	.bDescriptorType =	USB_DT_CS_INTERFACE,
180 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
181 
182 	.bcdCDC =		cpu_to_le16(0x0110),
183 };
184 
185 static struct usb_cdc_union_desc ncm_union_desc = {
186 	.bLength =		sizeof(ncm_union_desc),
187 	.bDescriptorType =	USB_DT_CS_INTERFACE,
188 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
189 	/* .bMasterInterface0 =	DYNAMIC */
190 	/* .bSlaveInterface0 =	DYNAMIC */
191 };
192 
193 static struct usb_cdc_ether_desc ecm_desc = {
194 	.bLength =		sizeof ecm_desc,
195 	.bDescriptorType =	USB_DT_CS_INTERFACE,
196 	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
197 
198 	/* this descriptor actually adds value, surprise! */
199 	/* .iMACAddress = DYNAMIC */
200 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
201 	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
202 	.wNumberMCFilters =	cpu_to_le16(0),
203 	.bNumberPowerFilters =	0,
204 };
205 
206 #define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
207 
208 static struct usb_cdc_ncm_desc ncm_desc = {
209 	.bLength =		sizeof ncm_desc,
210 	.bDescriptorType =	USB_DT_CS_INTERFACE,
211 	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
212 
213 	.bcdNcmVersion =	cpu_to_le16(0x0100),
214 	/* can process SetEthernetPacketFilter */
215 	.bmNetworkCapabilities = NCAPS,
216 };
217 
218 /* the default data interface has no endpoints ... */
219 
220 static struct usb_interface_descriptor ncm_data_nop_intf = {
221 	.bLength =		sizeof ncm_data_nop_intf,
222 	.bDescriptorType =	USB_DT_INTERFACE,
223 
224 	.bInterfaceNumber =	1,
225 	.bAlternateSetting =	0,
226 	.bNumEndpoints =	0,
227 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
228 	.bInterfaceSubClass =	0,
229 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
230 	/* .iInterface = DYNAMIC */
231 };
232 
233 /* ... but the "real" data interface has two bulk endpoints */
234 
235 static struct usb_interface_descriptor ncm_data_intf = {
236 	.bLength =		sizeof ncm_data_intf,
237 	.bDescriptorType =	USB_DT_INTERFACE,
238 
239 	.bInterfaceNumber =	1,
240 	.bAlternateSetting =	1,
241 	.bNumEndpoints =	2,
242 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
243 	.bInterfaceSubClass =	0,
244 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
245 	/* .iInterface = DYNAMIC */
246 };
247 
248 /* full speed support: */
249 
250 static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
251 	.bLength =		USB_DT_ENDPOINT_SIZE,
252 	.bDescriptorType =	USB_DT_ENDPOINT,
253 
254 	.bEndpointAddress =	USB_DIR_IN,
255 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
256 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
257 	.bInterval =		NCM_STATUS_INTERVAL_MS,
258 };
259 
260 static struct usb_endpoint_descriptor fs_ncm_in_desc = {
261 	.bLength =		USB_DT_ENDPOINT_SIZE,
262 	.bDescriptorType =	USB_DT_ENDPOINT,
263 
264 	.bEndpointAddress =	USB_DIR_IN,
265 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
266 };
267 
268 static struct usb_endpoint_descriptor fs_ncm_out_desc = {
269 	.bLength =		USB_DT_ENDPOINT_SIZE,
270 	.bDescriptorType =	USB_DT_ENDPOINT,
271 
272 	.bEndpointAddress =	USB_DIR_OUT,
273 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
274 };
275 
276 static struct usb_descriptor_header *ncm_fs_function[] = {
277 	(struct usb_descriptor_header *) &ncm_iad_desc,
278 	/* CDC NCM control descriptors */
279 	(struct usb_descriptor_header *) &ncm_control_intf,
280 	(struct usb_descriptor_header *) &ncm_header_desc,
281 	(struct usb_descriptor_header *) &ncm_union_desc,
282 	(struct usb_descriptor_header *) &ecm_desc,
283 	(struct usb_descriptor_header *) &ncm_desc,
284 	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
285 	/* data interface, altsettings 0 and 1 */
286 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
287 	(struct usb_descriptor_header *) &ncm_data_intf,
288 	(struct usb_descriptor_header *) &fs_ncm_in_desc,
289 	(struct usb_descriptor_header *) &fs_ncm_out_desc,
290 	NULL,
291 };
292 
293 /* high speed support: */
294 
295 static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
296 	.bLength =		USB_DT_ENDPOINT_SIZE,
297 	.bDescriptorType =	USB_DT_ENDPOINT,
298 
299 	.bEndpointAddress =	USB_DIR_IN,
300 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
301 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
302 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
303 };
304 static struct usb_endpoint_descriptor hs_ncm_in_desc = {
305 	.bLength =		USB_DT_ENDPOINT_SIZE,
306 	.bDescriptorType =	USB_DT_ENDPOINT,
307 
308 	.bEndpointAddress =	USB_DIR_IN,
309 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
310 	.wMaxPacketSize =	cpu_to_le16(512),
311 };
312 
313 static struct usb_endpoint_descriptor hs_ncm_out_desc = {
314 	.bLength =		USB_DT_ENDPOINT_SIZE,
315 	.bDescriptorType =	USB_DT_ENDPOINT,
316 
317 	.bEndpointAddress =	USB_DIR_OUT,
318 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
319 	.wMaxPacketSize =	cpu_to_le16(512),
320 };
321 
322 static struct usb_descriptor_header *ncm_hs_function[] = {
323 	(struct usb_descriptor_header *) &ncm_iad_desc,
324 	/* CDC NCM control descriptors */
325 	(struct usb_descriptor_header *) &ncm_control_intf,
326 	(struct usb_descriptor_header *) &ncm_header_desc,
327 	(struct usb_descriptor_header *) &ncm_union_desc,
328 	(struct usb_descriptor_header *) &ecm_desc,
329 	(struct usb_descriptor_header *) &ncm_desc,
330 	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
331 	/* data interface, altsettings 0 and 1 */
332 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
333 	(struct usb_descriptor_header *) &ncm_data_intf,
334 	(struct usb_descriptor_header *) &hs_ncm_in_desc,
335 	(struct usb_descriptor_header *) &hs_ncm_out_desc,
336 	NULL,
337 };
338 
339 
340 /* super speed support: */
341 
342 static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
343 	.bLength =		USB_DT_ENDPOINT_SIZE,
344 	.bDescriptorType =	USB_DT_ENDPOINT,
345 
346 	.bEndpointAddress =	USB_DIR_IN,
347 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
348 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
349 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
350 };
351 
352 static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
353 	.bLength =		sizeof(ss_ncm_notify_comp_desc),
354 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
355 
356 	/* the following 3 values can be tweaked if necessary */
357 	/* .bMaxBurst =		0, */
358 	/* .bmAttributes =	0, */
359 	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
360 };
361 
362 static struct usb_endpoint_descriptor ss_ncm_in_desc = {
363 	.bLength =		USB_DT_ENDPOINT_SIZE,
364 	.bDescriptorType =	USB_DT_ENDPOINT,
365 
366 	.bEndpointAddress =	USB_DIR_IN,
367 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
368 	.wMaxPacketSize =	cpu_to_le16(1024),
369 };
370 
371 static struct usb_endpoint_descriptor ss_ncm_out_desc = {
372 	.bLength =		USB_DT_ENDPOINT_SIZE,
373 	.bDescriptorType =	USB_DT_ENDPOINT,
374 
375 	.bEndpointAddress =	USB_DIR_OUT,
376 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
377 	.wMaxPacketSize =	cpu_to_le16(1024),
378 };
379 
380 static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
381 	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
382 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
383 
384 	/* the following 2 values can be tweaked if necessary */
385 	/* .bMaxBurst =		0, */
386 	/* .bmAttributes =	0, */
387 };
388 
389 static struct usb_descriptor_header *ncm_ss_function[] = {
390 	(struct usb_descriptor_header *) &ncm_iad_desc,
391 	/* CDC NCM control descriptors */
392 	(struct usb_descriptor_header *) &ncm_control_intf,
393 	(struct usb_descriptor_header *) &ncm_header_desc,
394 	(struct usb_descriptor_header *) &ncm_union_desc,
395 	(struct usb_descriptor_header *) &ecm_desc,
396 	(struct usb_descriptor_header *) &ncm_desc,
397 	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
398 	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
399 	/* data interface, altsettings 0 and 1 */
400 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
401 	(struct usb_descriptor_header *) &ncm_data_intf,
402 	(struct usb_descriptor_header *) &ss_ncm_in_desc,
403 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
404 	(struct usb_descriptor_header *) &ss_ncm_out_desc,
405 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
406 	NULL,
407 };
408 
409 /* string descriptors: */
410 
411 #define STRING_CTRL_IDX	0
412 #define STRING_MAC_IDX	1
413 #define STRING_DATA_IDX	2
414 #define STRING_IAD_IDX	3
415 
416 static struct usb_string ncm_string_defs[] = {
417 	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
418 	[STRING_MAC_IDX].s = "",
419 	[STRING_DATA_IDX].s = "CDC Network Data",
420 	[STRING_IAD_IDX].s = "CDC NCM",
421 	{  } /* end of list */
422 };
423 
424 static struct usb_gadget_strings ncm_string_table = {
425 	.language =		0x0409,	/* en-us */
426 	.strings =		ncm_string_defs,
427 };
428 
429 static struct usb_gadget_strings *ncm_strings[] = {
430 	&ncm_string_table,
431 	NULL,
432 };
433 
434 /*
435  * Here are options for NCM Datagram Pointer table (NDP) parser.
436  * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
437  * in NDP16 offsets and sizes fields are 1 16bit word wide,
438  * in NDP32 -- 2 16bit words wide. Also signatures are different.
439  * To make the parser code the same, put the differences in the structure,
440  * and switch pointers to the structures when the format is changed.
441  */
442 
443 struct ndp_parser_opts {
444 	u32		nth_sign;
445 	u32		ndp_sign;
446 	unsigned	nth_size;
447 	unsigned	ndp_size;
448 	unsigned	dpe_size;
449 	unsigned	ndplen_align;
450 	/* sizes in u16 units */
451 	unsigned	dgram_item_len; /* index or length */
452 	unsigned	block_length;
453 	unsigned	ndp_index;
454 	unsigned	reserved1;
455 	unsigned	reserved2;
456 	unsigned	next_ndp_index;
457 };
458 
459 #define INIT_NDP16_OPTS {					\
460 		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
461 		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
462 		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
463 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
464 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
465 		.ndplen_align = 4,				\
466 		.dgram_item_len = 1,				\
467 		.block_length = 1,				\
468 		.ndp_index = 1,					\
469 		.reserved1 = 0,					\
470 		.reserved2 = 0,					\
471 		.next_ndp_index = 1,				\
472 	}
473 
474 
475 #define INIT_NDP32_OPTS {					\
476 		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
477 		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
478 		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
479 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
480 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
481 		.ndplen_align = 8,				\
482 		.dgram_item_len = 2,				\
483 		.block_length = 2,				\
484 		.ndp_index = 2,					\
485 		.reserved1 = 1,					\
486 		.reserved2 = 2,					\
487 		.next_ndp_index = 2,				\
488 	}
489 
490 static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
491 static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
492 
493 static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
494 {
495 	switch (size) {
496 	case 1:
497 		put_unaligned_le16((u16)val, *p);
498 		break;
499 	case 2:
500 		put_unaligned_le32((u32)val, *p);
501 
502 		break;
503 	default:
504 		BUG();
505 	}
506 
507 	*p += size;
508 }
509 
510 static inline unsigned get_ncm(__le16 **p, unsigned size)
511 {
512 	unsigned tmp;
513 
514 	switch (size) {
515 	case 1:
516 		tmp = get_unaligned_le16(*p);
517 		break;
518 	case 2:
519 		tmp = get_unaligned_le32(*p);
520 		break;
521 	default:
522 		BUG();
523 	}
524 
525 	*p += size;
526 	return tmp;
527 }
528 
529 /*-------------------------------------------------------------------------*/
530 
531 static inline void ncm_reset_values(struct f_ncm *ncm)
532 {
533 	ncm->parser_opts = &ndp16_opts;
534 	ncm->is_crc = false;
535 	ncm->port.cdc_filter = DEFAULT_FILTER;
536 
537 	/* doesn't make sense for ncm, fixed size used */
538 	ncm->port.header_len = 0;
539 
540 	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
541 	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
542 }
543 
544 /*
545  * Context: ncm->lock held
546  */
547 static void ncm_do_notify(struct f_ncm *ncm)
548 {
549 	struct usb_request		*req = ncm->notify_req;
550 	struct usb_cdc_notification	*event;
551 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
552 	__le32				*data;
553 	int				status;
554 
555 	/* notification already in flight? */
556 	if (!req)
557 		return;
558 
559 	event = req->buf;
560 	switch (ncm->notify_state) {
561 	case NCM_NOTIFY_NONE:
562 		return;
563 
564 	case NCM_NOTIFY_CONNECT:
565 		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
566 		if (ncm->is_open)
567 			event->wValue = cpu_to_le16(1);
568 		else
569 			event->wValue = cpu_to_le16(0);
570 		event->wLength = 0;
571 		req->length = sizeof *event;
572 
573 		DBG(cdev, "notify connect %s\n",
574 				ncm->is_open ? "true" : "false");
575 		ncm->notify_state = NCM_NOTIFY_NONE;
576 		break;
577 
578 	case NCM_NOTIFY_SPEED:
579 		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
580 		event->wValue = cpu_to_le16(0);
581 		event->wLength = cpu_to_le16(8);
582 		req->length = NCM_STATUS_BYTECOUNT;
583 
584 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
585 		data = req->buf + sizeof *event;
586 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
587 		data[1] = data[0];
588 
589 		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
590 		ncm->notify_state = NCM_NOTIFY_CONNECT;
591 		break;
592 	}
593 	event->bmRequestType = 0xA1;
594 	event->wIndex = cpu_to_le16(ncm->ctrl_id);
595 
596 	ncm->notify_req = NULL;
597 	/*
598 	 * In double buffering if there is a space in FIFO,
599 	 * completion callback can be called right after the call,
600 	 * so unlocking
601 	 */
602 	spin_unlock(&ncm->lock);
603 	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
604 	spin_lock(&ncm->lock);
605 	if (status < 0) {
606 		ncm->notify_req = req;
607 		DBG(cdev, "notify --> %d\n", status);
608 	}
609 }
610 
611 /*
612  * Context: ncm->lock held
613  */
614 static void ncm_notify(struct f_ncm *ncm)
615 {
616 	/*
617 	 * NOTE on most versions of Linux, host side cdc-ethernet
618 	 * won't listen for notifications until its netdevice opens.
619 	 * The first notification then sits in the FIFO for a long
620 	 * time, and the second one is queued.
621 	 *
622 	 * If ncm_notify() is called before the second (CONNECT)
623 	 * notification is sent, then it will reset to send the SPEED
624 	 * notificaion again (and again, and again), but it's not a problem
625 	 */
626 	ncm->notify_state = NCM_NOTIFY_SPEED;
627 	ncm_do_notify(ncm);
628 }
629 
630 static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
631 {
632 	struct f_ncm			*ncm = req->context;
633 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
634 	struct usb_cdc_notification	*event = req->buf;
635 
636 	spin_lock(&ncm->lock);
637 	switch (req->status) {
638 	case 0:
639 		VDBG(cdev, "Notification %02x sent\n",
640 		     event->bNotificationType);
641 		break;
642 	case -ECONNRESET:
643 	case -ESHUTDOWN:
644 		ncm->notify_state = NCM_NOTIFY_NONE;
645 		break;
646 	default:
647 		DBG(cdev, "event %02x --> %d\n",
648 			event->bNotificationType, req->status);
649 		break;
650 	}
651 	ncm->notify_req = req;
652 	ncm_do_notify(ncm);
653 	spin_unlock(&ncm->lock);
654 }
655 
656 static 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 
681 invalid:
682 	usb_ep_set_halt(ep);
683 	return;
684 }
685 
686 static 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 		int ndp_hdr_crc = 0;
815 
816 		if (w_length != 0 || w_index != ncm->ctrl_id)
817 			goto invalid;
818 		switch (w_value) {
819 		case 0x0000:
820 			ncm->is_crc = false;
821 			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
822 			DBG(cdev, "non-CRC mode selected\n");
823 			break;
824 		case 0x0001:
825 			ncm->is_crc = true;
826 			ndp_hdr_crc = NCM_NDP_HDR_CRC;
827 			DBG(cdev, "CRC mode selected\n");
828 			break;
829 		default:
830 			goto invalid;
831 		}
832 		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
833 		value = 0;
834 		break;
835 	}
836 
837 	/* and disabled in ncm descriptor: */
838 	/* case USB_CDC_GET_NET_ADDRESS: */
839 	/* case USB_CDC_SET_NET_ADDRESS: */
840 	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
841 	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
842 
843 	default:
844 invalid:
845 		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
846 			ctrl->bRequestType, ctrl->bRequest,
847 			w_value, w_index, w_length);
848 	}
849 
850 	/* respond with data transfer or status phase? */
851 	if (value >= 0) {
852 		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
853 			ctrl->bRequestType, ctrl->bRequest,
854 			w_value, w_index, w_length);
855 		req->zero = 0;
856 		req->length = value;
857 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
858 		if (value < 0)
859 			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
860 					ctrl->bRequestType, ctrl->bRequest,
861 					value);
862 	}
863 
864 	/* device either stalls (value < 0) or reports success */
865 	return value;
866 }
867 
868 
869 static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
870 {
871 	struct f_ncm		*ncm = func_to_ncm(f);
872 	struct usb_composite_dev *cdev = f->config->cdev;
873 
874 	/* Control interface has only altsetting 0 */
875 	if (intf == ncm->ctrl_id) {
876 		if (alt != 0)
877 			goto fail;
878 
879 		DBG(cdev, "reset ncm control %d\n", intf);
880 		usb_ep_disable(ncm->notify);
881 
882 		if (!(ncm->notify->desc)) {
883 			DBG(cdev, "init ncm ctrl %d\n", intf);
884 			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
885 				goto fail;
886 		}
887 		usb_ep_enable(ncm->notify);
888 
889 	/* Data interface has two altsettings, 0 and 1 */
890 	} else if (intf == ncm->data_id) {
891 		if (alt > 1)
892 			goto fail;
893 
894 		if (ncm->port.in_ep->enabled) {
895 			DBG(cdev, "reset ncm\n");
896 			ncm->timer_stopping = true;
897 			ncm->netdev = NULL;
898 			gether_disconnect(&ncm->port);
899 			ncm_reset_values(ncm);
900 		}
901 
902 		/*
903 		 * CDC Network only sends data in non-default altsettings.
904 		 * Changing altsettings resets filters, statistics, etc.
905 		 */
906 		if (alt == 1) {
907 			struct net_device	*net;
908 
909 			if (!ncm->port.in_ep->desc ||
910 			    !ncm->port.out_ep->desc) {
911 				DBG(cdev, "init ncm\n");
912 				if (config_ep_by_speed(cdev->gadget, f,
913 						       ncm->port.in_ep) ||
914 				    config_ep_by_speed(cdev->gadget, f,
915 						       ncm->port.out_ep)) {
916 					ncm->port.in_ep->desc = NULL;
917 					ncm->port.out_ep->desc = NULL;
918 					goto fail;
919 				}
920 			}
921 
922 			/* TODO */
923 			/* Enable zlps by default for NCM conformance;
924 			 * override for musb_hdrc (avoids txdma ovhead)
925 			 */
926 			ncm->port.is_zlp_ok =
927 				gadget_is_zlp_supported(cdev->gadget);
928 			ncm->port.no_skb_reserve =
929 				gadget_avoids_skb_reserve(cdev->gadget);
930 			ncm->port.cdc_filter = DEFAULT_FILTER;
931 			DBG(cdev, "activate ncm\n");
932 			net = gether_connect(&ncm->port);
933 			if (IS_ERR(net))
934 				return PTR_ERR(net);
935 			ncm->netdev = net;
936 			ncm->timer_stopping = false;
937 		}
938 
939 		spin_lock(&ncm->lock);
940 		ncm_notify(ncm);
941 		spin_unlock(&ncm->lock);
942 	} else
943 		goto fail;
944 
945 	return 0;
946 fail:
947 	return -EINVAL;
948 }
949 
950 /*
951  * Because the data interface supports multiple altsettings,
952  * this NCM function *MUST* implement a get_alt() method.
953  */
954 static int ncm_get_alt(struct usb_function *f, unsigned intf)
955 {
956 	struct f_ncm		*ncm = func_to_ncm(f);
957 
958 	if (intf == ncm->ctrl_id)
959 		return 0;
960 	return ncm->port.in_ep->enabled ? 1 : 0;
961 }
962 
963 static struct sk_buff *package_for_tx(struct f_ncm *ncm)
964 {
965 	__le16		*ntb_iter;
966 	struct sk_buff	*skb2 = NULL;
967 	unsigned	ndp_pad;
968 	unsigned	ndp_index;
969 	unsigned	new_len;
970 
971 	const struct ndp_parser_opts *opts = ncm->parser_opts;
972 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
973 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
974 
975 	/* Stop the timer */
976 	hrtimer_try_to_cancel(&ncm->task_timer);
977 
978 	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
979 			ncm->skb_tx_data->len;
980 	ndp_index = ncm->skb_tx_data->len + ndp_pad;
981 	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
982 
983 	/* Set the final BlockLength and wNdpIndex */
984 	ntb_iter = (void *) ncm->skb_tx_data->data;
985 	/* Increment pointer to BlockLength */
986 	ntb_iter += 2 + 1 + 1;
987 	put_ncm(&ntb_iter, opts->block_length, new_len);
988 	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
989 
990 	/* Set the final NDP wLength */
991 	new_len = opts->ndp_size +
992 			(ncm->ndp_dgram_count * dgram_idx_len);
993 	ncm->ndp_dgram_count = 0;
994 	/* Increment from start to wLength */
995 	ntb_iter = (void *) ncm->skb_tx_ndp->data;
996 	ntb_iter += 2;
997 	put_unaligned_le16(new_len, ntb_iter);
998 
999 	/* Merge the skbs */
1000 	swap(skb2, ncm->skb_tx_data);
1001 	if (ncm->skb_tx_data) {
1002 		dev_consume_skb_any(ncm->skb_tx_data);
1003 		ncm->skb_tx_data = NULL;
1004 	}
1005 
1006 	/* Insert NDP alignment. */
1007 	skb_put_zero(skb2, ndp_pad);
1008 
1009 	/* Copy NTB across. */
1010 	skb_put_data(skb2, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1011 	dev_consume_skb_any(ncm->skb_tx_ndp);
1012 	ncm->skb_tx_ndp = NULL;
1013 
1014 	/* Insert zero'd datagram. */
1015 	skb_put_zero(skb2, dgram_idx_len);
1016 
1017 	return skb2;
1018 }
1019 
1020 static struct sk_buff *ncm_wrap_ntb(struct gether *port,
1021 				    struct sk_buff *skb)
1022 {
1023 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1024 	struct sk_buff	*skb2 = NULL;
1025 	int		ncb_len = 0;
1026 	__le16		*ntb_data;
1027 	__le16		*ntb_ndp;
1028 	int		dgram_pad;
1029 
1030 	unsigned	max_size = ncm->port.fixed_in_len;
1031 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1032 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
1033 	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
1034 	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
1035 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
1036 
1037 	if (!skb && !ncm->skb_tx_data)
1038 		return NULL;
1039 
1040 	if (skb) {
1041 		/* Add the CRC if required up front */
1042 		if (ncm->is_crc) {
1043 			uint32_t	crc;
1044 			__le16		*crc_pos;
1045 
1046 			crc = ~crc32_le(~0,
1047 					skb->data,
1048 					skb->len);
1049 			crc_pos = skb_put(skb, sizeof(uint32_t));
1050 			put_unaligned_le32(crc, crc_pos);
1051 		}
1052 
1053 		/* If the new skb is too big for the current NCM NTB then
1054 		 * set the current stored skb to be sent now and clear it
1055 		 * ready for new data.
1056 		 * NOTE: Assume maximum align for speed of calculation.
1057 		 */
1058 		if (ncm->skb_tx_data
1059 		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
1060 		    || (ncm->skb_tx_data->len +
1061 		    div + rem + skb->len +
1062 		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
1063 		    > max_size)) {
1064 			skb2 = package_for_tx(ncm);
1065 			if (!skb2)
1066 				goto err;
1067 		}
1068 
1069 		if (!ncm->skb_tx_data) {
1070 			ncb_len = opts->nth_size;
1071 			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1072 			ncb_len += dgram_pad;
1073 
1074 			/* Create a new skb for the NTH and datagrams. */
1075 			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1076 			if (!ncm->skb_tx_data)
1077 				goto err;
1078 
1079 			ncm->skb_tx_data->dev = ncm->netdev;
1080 			ntb_data = skb_put_zero(ncm->skb_tx_data, ncb_len);
1081 			/* dwSignature */
1082 			put_unaligned_le32(opts->nth_sign, ntb_data);
1083 			ntb_data += 2;
1084 			/* wHeaderLength */
1085 			put_unaligned_le16(opts->nth_size, ntb_data++);
1086 
1087 			/* Allocate an skb for storing the NDP,
1088 			 * TX_MAX_NUM_DPE should easily suffice for a
1089 			 * 16k packet.
1090 			 */
1091 			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1092 						    + opts->dpe_size
1093 						    * TX_MAX_NUM_DPE),
1094 						    GFP_ATOMIC);
1095 			if (!ncm->skb_tx_ndp)
1096 				goto err;
1097 
1098 			ncm->skb_tx_ndp->dev = ncm->netdev;
1099 			ntb_ndp = skb_put(ncm->skb_tx_ndp, opts->ndp_size);
1100 			memset(ntb_ndp, 0, ncb_len);
1101 			/* dwSignature */
1102 			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1103 			ntb_ndp += 2;
1104 
1105 			/* There is always a zeroed entry */
1106 			ncm->ndp_dgram_count = 1;
1107 
1108 			/* Note: we skip opts->next_ndp_index */
1109 		}
1110 
1111 		/* Delay the timer. */
1112 		hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
1113 			      HRTIMER_MODE_REL);
1114 
1115 		/* Add the datagram position entries */
1116 		ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len);
1117 
1118 		ncb_len = ncm->skb_tx_data->len;
1119 		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1120 		ncb_len += dgram_pad;
1121 
1122 		/* (d)wDatagramIndex */
1123 		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1124 		/* (d)wDatagramLength */
1125 		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1126 		ncm->ndp_dgram_count++;
1127 
1128 		/* Add the new data to the skb */
1129 		skb_put_zero(ncm->skb_tx_data, dgram_pad);
1130 		skb_put_data(ncm->skb_tx_data, skb->data, skb->len);
1131 		dev_consume_skb_any(skb);
1132 		skb = NULL;
1133 
1134 	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1135 		/* If the tx was requested because of a timeout then send */
1136 		skb2 = package_for_tx(ncm);
1137 		if (!skb2)
1138 			goto err;
1139 	}
1140 
1141 	return skb2;
1142 
1143 err:
1144 	ncm->netdev->stats.tx_dropped++;
1145 
1146 	if (skb)
1147 		dev_kfree_skb_any(skb);
1148 	if (ncm->skb_tx_data)
1149 		dev_kfree_skb_any(ncm->skb_tx_data);
1150 	if (ncm->skb_tx_ndp)
1151 		dev_kfree_skb_any(ncm->skb_tx_ndp);
1152 
1153 	return NULL;
1154 }
1155 
1156 /*
1157  * This transmits the NTB if there are frames waiting.
1158  */
1159 static void ncm_tx_tasklet(unsigned long data)
1160 {
1161 	struct f_ncm	*ncm = (void *)data;
1162 
1163 	if (ncm->timer_stopping)
1164 		return;
1165 
1166 	/* Only send if data is available. */
1167 	if (ncm->skb_tx_data) {
1168 		ncm->timer_force_tx = true;
1169 
1170 		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1171 		 * XXX is not sane.  The gadget layer should be redesigned so
1172 		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1173 		 * XXX and performed in some way outside of the ndo_start_xmit
1174 		 * XXX interface.
1175 		 */
1176 		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1177 
1178 		ncm->timer_force_tx = false;
1179 	}
1180 }
1181 
1182 /*
1183  * The transmit should only be run if no skb data has been sent
1184  * for a certain duration.
1185  */
1186 static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1187 {
1188 	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1189 	tasklet_schedule(&ncm->tx_tasklet);
1190 	return HRTIMER_NORESTART;
1191 }
1192 
1193 static int ncm_unwrap_ntb(struct gether *port,
1194 			  struct sk_buff *skb,
1195 			  struct sk_buff_head *list)
1196 {
1197 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1198 	__le16		*tmp = (void *) skb->data;
1199 	unsigned	index, index2;
1200 	int		ndp_index;
1201 	unsigned	dg_len, dg_len2;
1202 	unsigned	ndp_len;
1203 	struct sk_buff	*skb2;
1204 	int		ret = -EINVAL;
1205 	unsigned	max_size = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1206 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1207 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1208 	int		dgram_counter;
1209 
1210 	/* dwSignature */
1211 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1212 		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1213 			skb->len);
1214 		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1215 			       skb->data, 32, false);
1216 
1217 		goto err;
1218 	}
1219 	tmp += 2;
1220 	/* wHeaderLength */
1221 	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1222 		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1223 		goto err;
1224 	}
1225 	tmp++; /* skip wSequence */
1226 
1227 	/* (d)wBlockLength */
1228 	if (get_ncm(&tmp, opts->block_length) > max_size) {
1229 		INFO(port->func.config->cdev, "OUT size exceeded\n");
1230 		goto err;
1231 	}
1232 
1233 	ndp_index = get_ncm(&tmp, opts->ndp_index);
1234 
1235 	/* Run through all the NDP's in the NTB */
1236 	do {
1237 		/* NCM 3.2 */
1238 		if (((ndp_index % 4) != 0) &&
1239 				(ndp_index < opts->nth_size)) {
1240 			INFO(port->func.config->cdev, "Bad index: %#X\n",
1241 			     ndp_index);
1242 			goto err;
1243 		}
1244 
1245 		/* walk through NDP */
1246 		tmp = (void *)(skb->data + ndp_index);
1247 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1248 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1249 			goto err;
1250 		}
1251 		tmp += 2;
1252 
1253 		ndp_len = get_unaligned_le16(tmp++);
1254 		/*
1255 		 * NCM 3.3.1
1256 		 * entry is 2 items
1257 		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1258 		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1259 		 * Each entry is a dgram index and a dgram length.
1260 		 */
1261 		if ((ndp_len < opts->ndp_size
1262 				+ 2 * 2 * (opts->dgram_item_len * 2))
1263 				|| (ndp_len % opts->ndplen_align != 0)) {
1264 			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1265 			     ndp_len);
1266 			goto err;
1267 		}
1268 		tmp += opts->reserved1;
1269 		/* Check for another NDP (d)wNextNdpIndex */
1270 		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1271 		tmp += opts->reserved2;
1272 
1273 		ndp_len -= opts->ndp_size;
1274 		index2 = get_ncm(&tmp, opts->dgram_item_len);
1275 		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1276 		dgram_counter = 0;
1277 
1278 		do {
1279 			index = index2;
1280 			dg_len = dg_len2;
1281 			if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
1282 				INFO(port->func.config->cdev,
1283 				     "Bad dgram length: %#X\n", dg_len);
1284 				goto err;
1285 			}
1286 			if (ncm->is_crc) {
1287 				uint32_t crc, crc2;
1288 
1289 				crc = get_unaligned_le32(skb->data +
1290 							 index + dg_len -
1291 							 crc_len);
1292 				crc2 = ~crc32_le(~0,
1293 						 skb->data + index,
1294 						 dg_len - crc_len);
1295 				if (crc != crc2) {
1296 					INFO(port->func.config->cdev,
1297 					     "Bad CRC\n");
1298 					goto err;
1299 				}
1300 			}
1301 
1302 			index2 = get_ncm(&tmp, opts->dgram_item_len);
1303 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1304 
1305 			/*
1306 			 * Copy the data into a new skb.
1307 			 * This ensures the truesize is correct
1308 			 */
1309 			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1310 							 dg_len - crc_len);
1311 			if (skb2 == NULL)
1312 				goto err;
1313 			skb_put_data(skb2, skb->data + index,
1314 				     dg_len - crc_len);
1315 
1316 			skb_queue_tail(list, skb2);
1317 
1318 			ndp_len -= 2 * (opts->dgram_item_len * 2);
1319 
1320 			dgram_counter++;
1321 
1322 			if (index2 == 0 || dg_len2 == 0)
1323 				break;
1324 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1325 	} while (ndp_index);
1326 
1327 	dev_consume_skb_any(skb);
1328 
1329 	VDBG(port->func.config->cdev,
1330 	     "Parsed NTB with %d frames\n", dgram_counter);
1331 	return 0;
1332 err:
1333 	skb_queue_purge(list);
1334 	dev_kfree_skb_any(skb);
1335 	return ret;
1336 }
1337 
1338 static void ncm_disable(struct usb_function *f)
1339 {
1340 	struct f_ncm		*ncm = func_to_ncm(f);
1341 	struct usb_composite_dev *cdev = f->config->cdev;
1342 
1343 	DBG(cdev, "ncm deactivated\n");
1344 
1345 	if (ncm->port.in_ep->enabled) {
1346 		ncm->timer_stopping = true;
1347 		ncm->netdev = NULL;
1348 		gether_disconnect(&ncm->port);
1349 	}
1350 
1351 	if (ncm->notify->enabled) {
1352 		usb_ep_disable(ncm->notify);
1353 		ncm->notify->desc = NULL;
1354 	}
1355 }
1356 
1357 /*-------------------------------------------------------------------------*/
1358 
1359 /*
1360  * Callbacks let us notify the host about connect/disconnect when the
1361  * net device is opened or closed.
1362  *
1363  * For testing, note that link states on this side include both opened
1364  * and closed variants of:
1365  *
1366  *   - disconnected/unconfigured
1367  *   - configured but inactive (data alt 0)
1368  *   - configured and active (data alt 1)
1369  *
1370  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1371  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1372  * imply the host is actually polling the notification endpoint, and
1373  * likewise that "active" doesn't imply it's actually using the data
1374  * endpoints for traffic.
1375  */
1376 
1377 static void ncm_open(struct gether *geth)
1378 {
1379 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1380 
1381 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1382 
1383 	spin_lock(&ncm->lock);
1384 	ncm->is_open = true;
1385 	ncm_notify(ncm);
1386 	spin_unlock(&ncm->lock);
1387 }
1388 
1389 static void ncm_close(struct gether *geth)
1390 {
1391 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1392 
1393 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1394 
1395 	spin_lock(&ncm->lock);
1396 	ncm->is_open = false;
1397 	ncm_notify(ncm);
1398 	spin_unlock(&ncm->lock);
1399 }
1400 
1401 /*-------------------------------------------------------------------------*/
1402 
1403 /* ethernet function driver setup/binding */
1404 
1405 static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1406 {
1407 	struct usb_composite_dev *cdev = c->cdev;
1408 	struct f_ncm		*ncm = func_to_ncm(f);
1409 	struct usb_string	*us;
1410 	int			status;
1411 	struct usb_ep		*ep;
1412 	struct f_ncm_opts	*ncm_opts;
1413 
1414 	if (!can_support_ecm(cdev->gadget))
1415 		return -EINVAL;
1416 
1417 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1418 	/*
1419 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1420 	 * configurations are bound in sequence with list_for_each_entry,
1421 	 * in each configuration its functions are bound in sequence
1422 	 * with list_for_each_entry, so we assume no race condition
1423 	 * with regard to ncm_opts->bound access
1424 	 */
1425 	if (!ncm_opts->bound) {
1426 		mutex_lock(&ncm_opts->lock);
1427 		gether_set_gadget(ncm_opts->net, cdev->gadget);
1428 		status = gether_register_netdev(ncm_opts->net);
1429 		mutex_unlock(&ncm_opts->lock);
1430 		if (status)
1431 			return status;
1432 		ncm_opts->bound = true;
1433 	}
1434 	us = usb_gstrings_attach(cdev, ncm_strings,
1435 				 ARRAY_SIZE(ncm_string_defs));
1436 	if (IS_ERR(us))
1437 		return PTR_ERR(us);
1438 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1439 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1440 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1441 	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1442 	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1443 
1444 	/* allocate instance-specific interface IDs */
1445 	status = usb_interface_id(c, f);
1446 	if (status < 0)
1447 		goto fail;
1448 	ncm->ctrl_id = status;
1449 	ncm_iad_desc.bFirstInterface = status;
1450 
1451 	ncm_control_intf.bInterfaceNumber = status;
1452 	ncm_union_desc.bMasterInterface0 = status;
1453 
1454 	status = usb_interface_id(c, f);
1455 	if (status < 0)
1456 		goto fail;
1457 	ncm->data_id = status;
1458 
1459 	ncm_data_nop_intf.bInterfaceNumber = status;
1460 	ncm_data_intf.bInterfaceNumber = status;
1461 	ncm_union_desc.bSlaveInterface0 = status;
1462 
1463 	status = -ENODEV;
1464 
1465 	/* allocate instance-specific endpoints */
1466 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1467 	if (!ep)
1468 		goto fail;
1469 	ncm->port.in_ep = ep;
1470 
1471 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1472 	if (!ep)
1473 		goto fail;
1474 	ncm->port.out_ep = ep;
1475 
1476 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1477 	if (!ep)
1478 		goto fail;
1479 	ncm->notify = ep;
1480 
1481 	status = -ENOMEM;
1482 
1483 	/* allocate notification request and buffer */
1484 	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1485 	if (!ncm->notify_req)
1486 		goto fail;
1487 	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1488 	if (!ncm->notify_req->buf)
1489 		goto fail;
1490 	ncm->notify_req->context = ncm;
1491 	ncm->notify_req->complete = ncm_notify_complete;
1492 
1493 	/*
1494 	 * support all relevant hardware speeds... we expect that when
1495 	 * hardware is dual speed, all bulk-capable endpoints work at
1496 	 * both speeds
1497 	 */
1498 	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1499 	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1500 	hs_ncm_notify_desc.bEndpointAddress =
1501 		fs_ncm_notify_desc.bEndpointAddress;
1502 
1503 	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1504 	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1505 	ss_ncm_notify_desc.bEndpointAddress =
1506 		fs_ncm_notify_desc.bEndpointAddress;
1507 
1508 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1509 			ncm_ss_function, NULL);
1510 	if (status)
1511 		goto fail;
1512 
1513 	/*
1514 	 * NOTE:  all that is done without knowing or caring about
1515 	 * the network link ... which is unavailable to this code
1516 	 * until we're activated via set_alt().
1517 	 */
1518 
1519 	ncm->port.open = ncm_open;
1520 	ncm->port.close = ncm_close;
1521 
1522 	tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
1523 	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1524 	ncm->task_timer.function = ncm_tx_timeout;
1525 
1526 	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1527 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1528 			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1529 			ncm->port.in_ep->name, ncm->port.out_ep->name,
1530 			ncm->notify->name);
1531 	return 0;
1532 
1533 fail:
1534 	if (ncm->notify_req) {
1535 		kfree(ncm->notify_req->buf);
1536 		usb_ep_free_request(ncm->notify, ncm->notify_req);
1537 	}
1538 
1539 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1540 
1541 	return status;
1542 }
1543 
1544 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1545 {
1546 	return container_of(to_config_group(item), struct f_ncm_opts,
1547 			    func_inst.group);
1548 }
1549 
1550 /* f_ncm_item_ops */
1551 USB_ETHERNET_CONFIGFS_ITEM(ncm);
1552 
1553 /* f_ncm_opts_dev_addr */
1554 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1555 
1556 /* f_ncm_opts_host_addr */
1557 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1558 
1559 /* f_ncm_opts_qmult */
1560 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1561 
1562 /* f_ncm_opts_ifname */
1563 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1564 
1565 static struct configfs_attribute *ncm_attrs[] = {
1566 	&ncm_opts_attr_dev_addr,
1567 	&ncm_opts_attr_host_addr,
1568 	&ncm_opts_attr_qmult,
1569 	&ncm_opts_attr_ifname,
1570 	NULL,
1571 };
1572 
1573 static struct config_item_type ncm_func_type = {
1574 	.ct_item_ops	= &ncm_item_ops,
1575 	.ct_attrs	= ncm_attrs,
1576 	.ct_owner	= THIS_MODULE,
1577 };
1578 
1579 static void ncm_free_inst(struct usb_function_instance *f)
1580 {
1581 	struct f_ncm_opts *opts;
1582 
1583 	opts = container_of(f, struct f_ncm_opts, func_inst);
1584 	if (opts->bound)
1585 		gether_cleanup(netdev_priv(opts->net));
1586 	else
1587 		free_netdev(opts->net);
1588 	kfree(opts);
1589 }
1590 
1591 static struct usb_function_instance *ncm_alloc_inst(void)
1592 {
1593 	struct f_ncm_opts *opts;
1594 
1595 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1596 	if (!opts)
1597 		return ERR_PTR(-ENOMEM);
1598 	mutex_init(&opts->lock);
1599 	opts->func_inst.free_func_inst = ncm_free_inst;
1600 	opts->net = gether_setup_default();
1601 	if (IS_ERR(opts->net)) {
1602 		struct net_device *net = opts->net;
1603 		kfree(opts);
1604 		return ERR_CAST(net);
1605 	}
1606 
1607 	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1608 
1609 	return &opts->func_inst;
1610 }
1611 
1612 static void ncm_free(struct usb_function *f)
1613 {
1614 	struct f_ncm *ncm;
1615 	struct f_ncm_opts *opts;
1616 
1617 	ncm = func_to_ncm(f);
1618 	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1619 	kfree(ncm);
1620 	mutex_lock(&opts->lock);
1621 	opts->refcnt--;
1622 	mutex_unlock(&opts->lock);
1623 }
1624 
1625 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1626 {
1627 	struct f_ncm *ncm = func_to_ncm(f);
1628 
1629 	DBG(c->cdev, "ncm unbind\n");
1630 
1631 	hrtimer_cancel(&ncm->task_timer);
1632 	tasklet_kill(&ncm->tx_tasklet);
1633 
1634 	ncm_string_defs[0].id = 0;
1635 	usb_free_all_descriptors(f);
1636 
1637 	kfree(ncm->notify_req->buf);
1638 	usb_ep_free_request(ncm->notify, ncm->notify_req);
1639 }
1640 
1641 static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1642 {
1643 	struct f_ncm		*ncm;
1644 	struct f_ncm_opts	*opts;
1645 	int status;
1646 
1647 	/* allocate and initialize one new instance */
1648 	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1649 	if (!ncm)
1650 		return ERR_PTR(-ENOMEM);
1651 
1652 	opts = container_of(fi, struct f_ncm_opts, func_inst);
1653 	mutex_lock(&opts->lock);
1654 	opts->refcnt++;
1655 
1656 	/* export host's Ethernet address in CDC format */
1657 	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1658 				      sizeof(ncm->ethaddr));
1659 	if (status < 12) { /* strlen("01234567890a") */
1660 		kfree(ncm);
1661 		mutex_unlock(&opts->lock);
1662 		return ERR_PTR(-EINVAL);
1663 	}
1664 	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1665 
1666 	spin_lock_init(&ncm->lock);
1667 	ncm_reset_values(ncm);
1668 	ncm->port.ioport = netdev_priv(opts->net);
1669 	mutex_unlock(&opts->lock);
1670 	ncm->port.is_fixed = true;
1671 	ncm->port.supports_multi_frame = true;
1672 
1673 	ncm->port.func.name = "cdc_network";
1674 	/* descriptors are per-instance copies */
1675 	ncm->port.func.bind = ncm_bind;
1676 	ncm->port.func.unbind = ncm_unbind;
1677 	ncm->port.func.set_alt = ncm_set_alt;
1678 	ncm->port.func.get_alt = ncm_get_alt;
1679 	ncm->port.func.setup = ncm_setup;
1680 	ncm->port.func.disable = ncm_disable;
1681 	ncm->port.func.free_func = ncm_free;
1682 
1683 	ncm->port.wrap = ncm_wrap_ntb;
1684 	ncm->port.unwrap = ncm_unwrap_ntb;
1685 
1686 	return &ncm->port.func;
1687 }
1688 
1689 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1690 MODULE_LICENSE("GPL");
1691 MODULE_AUTHOR("Yauheni Kaliuta");
1692