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