xref: /linux/drivers/usb/gadget/function/f_ncm.c (revision db6d8d5fdf9537641c76ba7f32e02b4bcc600972)
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/module.h>
20 #include <linux/device.h>
21 #include <linux/etherdevice.h>
22 #include <linux/crc32.h>
23 
24 #include <linux/usb/cdc.h>
25 
26 #include "u_ether.h"
27 #include "u_ether_configfs.h"
28 #include "u_ncm.h"
29 
30 /*
31  * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
32  * NCM is intended to be used with high-speed network attachments.
33  *
34  * Note that NCM requires the use of "alternate settings" for its data
35  * interface.  This means that the set_alt() method has real work to do,
36  * and also means that a get_alt() method is required.
37  */
38 
39 /* to trigger crc/non-crc ndp signature */
40 
41 #define NCM_NDP_HDR_CRC_MASK	0x01000000
42 #define NCM_NDP_HDR_CRC		0x01000000
43 #define NCM_NDP_HDR_NOCRC	0x00000000
44 
45 enum ncm_notify_state {
46 	NCM_NOTIFY_NONE,		/* don't notify */
47 	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
48 	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
49 };
50 
51 struct f_ncm {
52 	struct gether			port;
53 	u8				ctrl_id, data_id;
54 
55 	char				ethaddr[14];
56 
57 	struct usb_ep			*notify;
58 	struct usb_request		*notify_req;
59 	u8				notify_state;
60 	bool				is_open;
61 
62 	const struct ndp_parser_opts	*parser_opts;
63 	bool				is_crc;
64 	u32				ndp_sign;
65 
66 	/*
67 	 * for notification, it is accessed from both
68 	 * callback and ethernet open/close
69 	 */
70 	spinlock_t			lock;
71 
72 	struct net_device		*netdev;
73 
74 	/* For multi-frame NDP TX */
75 	struct sk_buff			*skb_tx_data;
76 	struct sk_buff			*skb_tx_ndp;
77 	u16				ndp_dgram_count;
78 	bool				timer_force_tx;
79 	struct tasklet_struct		tx_tasklet;
80 	struct hrtimer			task_timer;
81 
82 	bool				timer_stopping;
83 };
84 
85 static inline struct f_ncm *func_to_ncm(struct usb_function *f)
86 {
87 	return container_of(f, struct f_ncm, port.func);
88 }
89 
90 /* peak (theoretical) bulk transfer rate in bits-per-second */
91 static inline unsigned ncm_bitrate(struct usb_gadget *g)
92 {
93 	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
94 		return 13 * 1024 * 8 * 1000 * 8;
95 	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
96 		return 13 * 512 * 8 * 1000 * 8;
97 	else
98 		return 19 *  64 * 1 * 1000 * 8;
99 }
100 
101 /*-------------------------------------------------------------------------*/
102 
103 /*
104  * We cannot group frames so use just the minimal size which ok to put
105  * one max-size ethernet frame.
106  * If the host can group frames, allow it to do that, 16K is selected,
107  * because it's used by default by the current linux host driver
108  */
109 #define NTB_DEFAULT_IN_SIZE	16384
110 #define NTB_OUT_SIZE		16384
111 
112 /* Allocation for storing the NDP, 32 should suffice for a
113  * 16k packet. This allows a maximum of 32 * 507 Byte packets to
114  * be transmitted in a single 16kB skb, though when sending full size
115  * packets this limit will be plenty.
116  * Smaller packets are not likely to be trying to maximize the
117  * throughput and will be mstly sending smaller infrequent frames.
118  */
119 #define TX_MAX_NUM_DPE		32
120 
121 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
122 #define TX_TIMEOUT_NSECS	300000
123 
124 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
125 				 USB_CDC_NCM_NTB32_SUPPORTED)
126 
127 static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
128 	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
129 	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
130 	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
131 	.wNdpInDivisor = cpu_to_le16(4),
132 	.wNdpInPayloadRemainder = cpu_to_le16(0),
133 	.wNdpInAlignment = cpu_to_le16(4),
134 
135 	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
136 	.wNdpOutDivisor = cpu_to_le16(4),
137 	.wNdpOutPayloadRemainder = cpu_to_le16(0),
138 	.wNdpOutAlignment = cpu_to_le16(4),
139 };
140 
141 /*
142  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
143  * packet, to simplify cancellation; and a big transfer interval, to
144  * waste less bandwidth.
145  */
146 
147 #define NCM_STATUS_INTERVAL_MS		32
148 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
149 
150 static struct usb_interface_assoc_descriptor ncm_iad_desc = {
151 	.bLength =		sizeof ncm_iad_desc,
152 	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
153 
154 	/* .bFirstInterface =	DYNAMIC, */
155 	.bInterfaceCount =	2,	/* control + data */
156 	.bFunctionClass =	USB_CLASS_COMM,
157 	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
158 	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
159 	/* .iFunction =		DYNAMIC */
160 };
161 
162 /* interface descriptor: */
163 
164 static struct usb_interface_descriptor ncm_control_intf = {
165 	.bLength =		sizeof ncm_control_intf,
166 	.bDescriptorType =	USB_DT_INTERFACE,
167 
168 	/* .bInterfaceNumber = DYNAMIC */
169 	.bNumEndpoints =	1,
170 	.bInterfaceClass =	USB_CLASS_COMM,
171 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
172 	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
173 	/* .iInterface = DYNAMIC */
174 };
175 
176 static struct usb_cdc_header_desc ncm_header_desc = {
177 	.bLength =		sizeof ncm_header_desc,
178 	.bDescriptorType =	USB_DT_CS_INTERFACE,
179 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
180 
181 	.bcdCDC =		cpu_to_le16(0x0110),
182 };
183 
184 static struct usb_cdc_union_desc ncm_union_desc = {
185 	.bLength =		sizeof(ncm_union_desc),
186 	.bDescriptorType =	USB_DT_CS_INTERFACE,
187 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
188 	/* .bMasterInterface0 =	DYNAMIC */
189 	/* .bSlaveInterface0 =	DYNAMIC */
190 };
191 
192 static struct usb_cdc_ether_desc ecm_desc = {
193 	.bLength =		sizeof ecm_desc,
194 	.bDescriptorType =	USB_DT_CS_INTERFACE,
195 	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
196 
197 	/* this descriptor actually adds value, surprise! */
198 	/* .iMACAddress = DYNAMIC */
199 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
200 	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
201 	.wNumberMCFilters =	cpu_to_le16(0),
202 	.bNumberPowerFilters =	0,
203 };
204 
205 #define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
206 
207 static struct usb_cdc_ncm_desc ncm_desc = {
208 	.bLength =		sizeof ncm_desc,
209 	.bDescriptorType =	USB_DT_CS_INTERFACE,
210 	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
211 
212 	.bcdNcmVersion =	cpu_to_le16(0x0100),
213 	/* can process SetEthernetPacketFilter */
214 	.bmNetworkCapabilities = NCAPS,
215 };
216 
217 /* the default data interface has no endpoints ... */
218 
219 static struct usb_interface_descriptor ncm_data_nop_intf = {
220 	.bLength =		sizeof ncm_data_nop_intf,
221 	.bDescriptorType =	USB_DT_INTERFACE,
222 
223 	.bInterfaceNumber =	1,
224 	.bAlternateSetting =	0,
225 	.bNumEndpoints =	0,
226 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
227 	.bInterfaceSubClass =	0,
228 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
229 	/* .iInterface = DYNAMIC */
230 };
231 
232 /* ... but the "real" data interface has two bulk endpoints */
233 
234 static struct usb_interface_descriptor ncm_data_intf = {
235 	.bLength =		sizeof ncm_data_intf,
236 	.bDescriptorType =	USB_DT_INTERFACE,
237 
238 	.bInterfaceNumber =	1,
239 	.bAlternateSetting =	1,
240 	.bNumEndpoints =	2,
241 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
242 	.bInterfaceSubClass =	0,
243 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
244 	/* .iInterface = DYNAMIC */
245 };
246 
247 /* full speed support: */
248 
249 static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
250 	.bLength =		USB_DT_ENDPOINT_SIZE,
251 	.bDescriptorType =	USB_DT_ENDPOINT,
252 
253 	.bEndpointAddress =	USB_DIR_IN,
254 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
255 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
256 	.bInterval =		NCM_STATUS_INTERVAL_MS,
257 };
258 
259 static struct usb_endpoint_descriptor fs_ncm_in_desc = {
260 	.bLength =		USB_DT_ENDPOINT_SIZE,
261 	.bDescriptorType =	USB_DT_ENDPOINT,
262 
263 	.bEndpointAddress =	USB_DIR_IN,
264 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
265 };
266 
267 static struct usb_endpoint_descriptor fs_ncm_out_desc = {
268 	.bLength =		USB_DT_ENDPOINT_SIZE,
269 	.bDescriptorType =	USB_DT_ENDPOINT,
270 
271 	.bEndpointAddress =	USB_DIR_OUT,
272 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
273 };
274 
275 static struct usb_descriptor_header *ncm_fs_function[] = {
276 	(struct usb_descriptor_header *) &ncm_iad_desc,
277 	/* CDC NCM control descriptors */
278 	(struct usb_descriptor_header *) &ncm_control_intf,
279 	(struct usb_descriptor_header *) &ncm_header_desc,
280 	(struct usb_descriptor_header *) &ncm_union_desc,
281 	(struct usb_descriptor_header *) &ecm_desc,
282 	(struct usb_descriptor_header *) &ncm_desc,
283 	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
284 	/* data interface, altsettings 0 and 1 */
285 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
286 	(struct usb_descriptor_header *) &ncm_data_intf,
287 	(struct usb_descriptor_header *) &fs_ncm_in_desc,
288 	(struct usb_descriptor_header *) &fs_ncm_out_desc,
289 	NULL,
290 };
291 
292 /* high speed support: */
293 
294 static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
295 	.bLength =		USB_DT_ENDPOINT_SIZE,
296 	.bDescriptorType =	USB_DT_ENDPOINT,
297 
298 	.bEndpointAddress =	USB_DIR_IN,
299 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
300 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
301 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
302 };
303 static struct usb_endpoint_descriptor hs_ncm_in_desc = {
304 	.bLength =		USB_DT_ENDPOINT_SIZE,
305 	.bDescriptorType =	USB_DT_ENDPOINT,
306 
307 	.bEndpointAddress =	USB_DIR_IN,
308 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
309 	.wMaxPacketSize =	cpu_to_le16(512),
310 };
311 
312 static struct usb_endpoint_descriptor hs_ncm_out_desc = {
313 	.bLength =		USB_DT_ENDPOINT_SIZE,
314 	.bDescriptorType =	USB_DT_ENDPOINT,
315 
316 	.bEndpointAddress =	USB_DIR_OUT,
317 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
318 	.wMaxPacketSize =	cpu_to_le16(512),
319 };
320 
321 static struct usb_descriptor_header *ncm_hs_function[] = {
322 	(struct usb_descriptor_header *) &ncm_iad_desc,
323 	/* CDC NCM control descriptors */
324 	(struct usb_descriptor_header *) &ncm_control_intf,
325 	(struct usb_descriptor_header *) &ncm_header_desc,
326 	(struct usb_descriptor_header *) &ncm_union_desc,
327 	(struct usb_descriptor_header *) &ecm_desc,
328 	(struct usb_descriptor_header *) &ncm_desc,
329 	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
330 	/* data interface, altsettings 0 and 1 */
331 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
332 	(struct usb_descriptor_header *) &ncm_data_intf,
333 	(struct usb_descriptor_header *) &hs_ncm_in_desc,
334 	(struct usb_descriptor_header *) &hs_ncm_out_desc,
335 	NULL,
336 };
337 
338 
339 /* super speed support: */
340 
341 static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
342 	.bLength =		USB_DT_ENDPOINT_SIZE,
343 	.bDescriptorType =	USB_DT_ENDPOINT,
344 
345 	.bEndpointAddress =	USB_DIR_IN,
346 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
347 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
348 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
349 };
350 
351 static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
352 	.bLength =		sizeof(ss_ncm_notify_comp_desc),
353 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
354 
355 	/* the following 3 values can be tweaked if necessary */
356 	/* .bMaxBurst =		0, */
357 	/* .bmAttributes =	0, */
358 	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
359 };
360 
361 static struct usb_endpoint_descriptor ss_ncm_in_desc = {
362 	.bLength =		USB_DT_ENDPOINT_SIZE,
363 	.bDescriptorType =	USB_DT_ENDPOINT,
364 
365 	.bEndpointAddress =	USB_DIR_IN,
366 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
367 	.wMaxPacketSize =	cpu_to_le16(1024),
368 };
369 
370 static struct usb_endpoint_descriptor ss_ncm_out_desc = {
371 	.bLength =		USB_DT_ENDPOINT_SIZE,
372 	.bDescriptorType =	USB_DT_ENDPOINT,
373 
374 	.bEndpointAddress =	USB_DIR_OUT,
375 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
376 	.wMaxPacketSize =	cpu_to_le16(1024),
377 };
378 
379 static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
380 	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
381 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
382 
383 	/* the following 2 values can be tweaked if necessary */
384 	/* .bMaxBurst =		0, */
385 	/* .bmAttributes =	0, */
386 };
387 
388 static struct usb_descriptor_header *ncm_ss_function[] = {
389 	(struct usb_descriptor_header *) &ncm_iad_desc,
390 	/* CDC NCM control descriptors */
391 	(struct usb_descriptor_header *) &ncm_control_intf,
392 	(struct usb_descriptor_header *) &ncm_header_desc,
393 	(struct usb_descriptor_header *) &ncm_union_desc,
394 	(struct usb_descriptor_header *) &ecm_desc,
395 	(struct usb_descriptor_header *) &ncm_desc,
396 	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
397 	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
398 	/* data interface, altsettings 0 and 1 */
399 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
400 	(struct usb_descriptor_header *) &ncm_data_intf,
401 	(struct usb_descriptor_header *) &ss_ncm_in_desc,
402 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
403 	(struct usb_descriptor_header *) &ss_ncm_out_desc,
404 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
405 	NULL,
406 };
407 
408 /* string descriptors: */
409 
410 #define STRING_CTRL_IDX	0
411 #define STRING_MAC_IDX	1
412 #define STRING_DATA_IDX	2
413 #define STRING_IAD_IDX	3
414 
415 static struct usb_string ncm_string_defs[] = {
416 	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
417 	[STRING_MAC_IDX].s = "",
418 	[STRING_DATA_IDX].s = "CDC Network Data",
419 	[STRING_IAD_IDX].s = "CDC NCM",
420 	{  } /* end of list */
421 };
422 
423 static struct usb_gadget_strings ncm_string_table = {
424 	.language =		0x0409,	/* en-us */
425 	.strings =		ncm_string_defs,
426 };
427 
428 static struct usb_gadget_strings *ncm_strings[] = {
429 	&ncm_string_table,
430 	NULL,
431 };
432 
433 /*
434  * Here are options for NCM Datagram Pointer table (NDP) parser.
435  * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
436  * in NDP16 offsets and sizes fields are 1 16bit word wide,
437  * in NDP32 -- 2 16bit words wide. Also signatures are different.
438  * To make the parser code the same, put the differences in the structure,
439  * and switch pointers to the structures when the format is changed.
440  */
441 
442 struct ndp_parser_opts {
443 	u32		nth_sign;
444 	u32		ndp_sign;
445 	unsigned	nth_size;
446 	unsigned	ndp_size;
447 	unsigned	dpe_size;
448 	unsigned	ndplen_align;
449 	/* sizes in u16 units */
450 	unsigned	dgram_item_len; /* index or length */
451 	unsigned	block_length;
452 	unsigned	ndp_index;
453 	unsigned	reserved1;
454 	unsigned	reserved2;
455 	unsigned	next_ndp_index;
456 };
457 
458 #define INIT_NDP16_OPTS {					\
459 		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
460 		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
461 		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
462 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
463 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
464 		.ndplen_align = 4,				\
465 		.dgram_item_len = 1,				\
466 		.block_length = 1,				\
467 		.ndp_index = 1,					\
468 		.reserved1 = 0,					\
469 		.reserved2 = 0,					\
470 		.next_ndp_index = 1,				\
471 	}
472 
473 
474 #define INIT_NDP32_OPTS {					\
475 		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
476 		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
477 		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
478 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
479 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
480 		.ndplen_align = 8,				\
481 		.dgram_item_len = 2,				\
482 		.block_length = 2,				\
483 		.ndp_index = 2,					\
484 		.reserved1 = 1,					\
485 		.reserved2 = 2,					\
486 		.next_ndp_index = 2,				\
487 	}
488 
489 static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
490 static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
491 
492 static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
493 {
494 	switch (size) {
495 	case 1:
496 		put_unaligned_le16((u16)val, *p);
497 		break;
498 	case 2:
499 		put_unaligned_le32((u32)val, *p);
500 
501 		break;
502 	default:
503 		BUG();
504 	}
505 
506 	*p += size;
507 }
508 
509 static inline unsigned get_ncm(__le16 **p, unsigned size)
510 {
511 	unsigned tmp;
512 
513 	switch (size) {
514 	case 1:
515 		tmp = get_unaligned_le16(*p);
516 		break;
517 	case 2:
518 		tmp = get_unaligned_le32(*p);
519 		break;
520 	default:
521 		BUG();
522 	}
523 
524 	*p += size;
525 	return tmp;
526 }
527 
528 /*-------------------------------------------------------------------------*/
529 
530 static inline void ncm_reset_values(struct f_ncm *ncm)
531 {
532 	ncm->parser_opts = &ndp16_opts;
533 	ncm->is_crc = false;
534 	ncm->port.cdc_filter = DEFAULT_FILTER;
535 
536 	/* doesn't make sense for ncm, fixed size used */
537 	ncm->port.header_len = 0;
538 
539 	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
540 	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
541 }
542 
543 /*
544  * Context: ncm->lock held
545  */
546 static void ncm_do_notify(struct f_ncm *ncm)
547 {
548 	struct usb_request		*req = ncm->notify_req;
549 	struct usb_cdc_notification	*event;
550 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
551 	__le32				*data;
552 	int				status;
553 
554 	/* notification already in flight? */
555 	if (!req)
556 		return;
557 
558 	event = req->buf;
559 	switch (ncm->notify_state) {
560 	case NCM_NOTIFY_NONE:
561 		return;
562 
563 	case NCM_NOTIFY_CONNECT:
564 		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
565 		if (ncm->is_open)
566 			event->wValue = cpu_to_le16(1);
567 		else
568 			event->wValue = cpu_to_le16(0);
569 		event->wLength = 0;
570 		req->length = sizeof *event;
571 
572 		DBG(cdev, "notify connect %s\n",
573 				ncm->is_open ? "true" : "false");
574 		ncm->notify_state = NCM_NOTIFY_NONE;
575 		break;
576 
577 	case NCM_NOTIFY_SPEED:
578 		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
579 		event->wValue = cpu_to_le16(0);
580 		event->wLength = cpu_to_le16(8);
581 		req->length = NCM_STATUS_BYTECOUNT;
582 
583 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
584 		data = req->buf + sizeof *event;
585 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
586 		data[1] = data[0];
587 
588 		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
589 		ncm->notify_state = NCM_NOTIFY_CONNECT;
590 		break;
591 	}
592 	event->bmRequestType = 0xA1;
593 	event->wIndex = cpu_to_le16(ncm->ctrl_id);
594 
595 	ncm->notify_req = NULL;
596 	/*
597 	 * In double buffering if there is a space in FIFO,
598 	 * completion callback can be called right after the call,
599 	 * so unlocking
600 	 */
601 	spin_unlock(&ncm->lock);
602 	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
603 	spin_lock(&ncm->lock);
604 	if (status < 0) {
605 		ncm->notify_req = req;
606 		DBG(cdev, "notify --> %d\n", status);
607 	}
608 }
609 
610 /*
611  * Context: ncm->lock held
612  */
613 static void ncm_notify(struct f_ncm *ncm)
614 {
615 	/*
616 	 * NOTE on most versions of Linux, host side cdc-ethernet
617 	 * won't listen for notifications until its netdevice opens.
618 	 * The first notification then sits in the FIFO for a long
619 	 * time, and the second one is queued.
620 	 *
621 	 * If ncm_notify() is called before the second (CONNECT)
622 	 * notification is sent, then it will reset to send the SPEED
623 	 * notificaion again (and again, and again), but it's not a problem
624 	 */
625 	ncm->notify_state = NCM_NOTIFY_SPEED;
626 	ncm_do_notify(ncm);
627 }
628 
629 static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
630 {
631 	struct f_ncm			*ncm = req->context;
632 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
633 	struct usb_cdc_notification	*event = req->buf;
634 
635 	spin_lock(&ncm->lock);
636 	switch (req->status) {
637 	case 0:
638 		VDBG(cdev, "Notification %02x sent\n",
639 		     event->bNotificationType);
640 		break;
641 	case -ECONNRESET:
642 	case -ESHUTDOWN:
643 		ncm->notify_state = NCM_NOTIFY_NONE;
644 		break;
645 	default:
646 		DBG(cdev, "event %02x --> %d\n",
647 			event->bNotificationType, req->status);
648 		break;
649 	}
650 	ncm->notify_req = req;
651 	ncm_do_notify(ncm);
652 	spin_unlock(&ncm->lock);
653 }
654 
655 static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
656 {
657 	/* now for SET_NTB_INPUT_SIZE only */
658 	unsigned		in_size;
659 	struct usb_function	*f = req->context;
660 	struct f_ncm		*ncm = func_to_ncm(f);
661 	struct usb_composite_dev *cdev = f->config->cdev;
662 
663 	req->context = NULL;
664 	if (req->status || req->actual != req->length) {
665 		DBG(cdev, "Bad control-OUT transfer\n");
666 		goto invalid;
667 	}
668 
669 	in_size = get_unaligned_le32(req->buf);
670 	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
671 	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
672 		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
673 		goto invalid;
674 	}
675 
676 	ncm->port.fixed_in_len = in_size;
677 	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
678 	return;
679 
680 invalid:
681 	usb_ep_set_halt(ep);
682 	return;
683 }
684 
685 static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
686 {
687 	struct f_ncm		*ncm = func_to_ncm(f);
688 	struct usb_composite_dev *cdev = f->config->cdev;
689 	struct usb_request	*req = cdev->req;
690 	int			value = -EOPNOTSUPP;
691 	u16			w_index = le16_to_cpu(ctrl->wIndex);
692 	u16			w_value = le16_to_cpu(ctrl->wValue);
693 	u16			w_length = le16_to_cpu(ctrl->wLength);
694 
695 	/*
696 	 * composite driver infrastructure handles everything except
697 	 * CDC class messages; interface activation uses set_alt().
698 	 */
699 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
700 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
701 			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
702 		/*
703 		 * see 6.2.30: no data, wIndex = interface,
704 		 * wValue = packet filter bitmap
705 		 */
706 		if (w_length != 0 || w_index != ncm->ctrl_id)
707 			goto invalid;
708 		DBG(cdev, "packet filter %02x\n", w_value);
709 		/*
710 		 * REVISIT locking of cdc_filter.  This assumes the UDC
711 		 * driver won't have a concurrent packet TX irq running on
712 		 * another CPU; or that if it does, this write is atomic...
713 		 */
714 		ncm->port.cdc_filter = w_value;
715 		value = 0;
716 		break;
717 	/*
718 	 * and optionally:
719 	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
720 	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
721 	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
722 	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
723 	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
724 	 * case USB_CDC_GET_ETHERNET_STATISTIC:
725 	 */
726 
727 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
728 		| USB_CDC_GET_NTB_PARAMETERS:
729 
730 		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
731 			goto invalid;
732 		value = w_length > sizeof ntb_parameters ?
733 			sizeof ntb_parameters : w_length;
734 		memcpy(req->buf, &ntb_parameters, value);
735 		VDBG(cdev, "Host asked NTB parameters\n");
736 		break;
737 
738 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
739 		| USB_CDC_GET_NTB_INPUT_SIZE:
740 
741 		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
742 			goto invalid;
743 		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
744 		value = 4;
745 		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
746 		     ncm->port.fixed_in_len);
747 		break;
748 
749 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
750 		| USB_CDC_SET_NTB_INPUT_SIZE:
751 	{
752 		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
753 			goto invalid;
754 		req->complete = ncm_ep0out_complete;
755 		req->length = w_length;
756 		req->context = f;
757 
758 		value = req->length;
759 		break;
760 	}
761 
762 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
763 		| USB_CDC_GET_NTB_FORMAT:
764 	{
765 		uint16_t format;
766 
767 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
768 			goto invalid;
769 		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
770 		put_unaligned_le16(format, req->buf);
771 		value = 2;
772 		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
773 		break;
774 	}
775 
776 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
777 		| USB_CDC_SET_NTB_FORMAT:
778 	{
779 		if (w_length != 0 || w_index != ncm->ctrl_id)
780 			goto invalid;
781 		switch (w_value) {
782 		case 0x0000:
783 			ncm->parser_opts = &ndp16_opts;
784 			DBG(cdev, "NCM16 selected\n");
785 			break;
786 		case 0x0001:
787 			ncm->parser_opts = &ndp32_opts;
788 			DBG(cdev, "NCM32 selected\n");
789 			break;
790 		default:
791 			goto invalid;
792 		}
793 		value = 0;
794 		break;
795 	}
796 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
797 		| USB_CDC_GET_CRC_MODE:
798 	{
799 		uint16_t is_crc;
800 
801 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
802 			goto invalid;
803 		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
804 		put_unaligned_le16(is_crc, req->buf);
805 		value = 2;
806 		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
807 		break;
808 	}
809 
810 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
811 		| USB_CDC_SET_CRC_MODE:
812 	{
813 		int ndp_hdr_crc = 0;
814 
815 		if (w_length != 0 || w_index != ncm->ctrl_id)
816 			goto invalid;
817 		switch (w_value) {
818 		case 0x0000:
819 			ncm->is_crc = false;
820 			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
821 			DBG(cdev, "non-CRC mode selected\n");
822 			break;
823 		case 0x0001:
824 			ncm->is_crc = true;
825 			ndp_hdr_crc = NCM_NDP_HDR_CRC;
826 			DBG(cdev, "CRC mode selected\n");
827 			break;
828 		default:
829 			goto invalid;
830 		}
831 		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
832 		value = 0;
833 		break;
834 	}
835 
836 	/* and disabled in ncm descriptor: */
837 	/* case USB_CDC_GET_NET_ADDRESS: */
838 	/* case USB_CDC_SET_NET_ADDRESS: */
839 	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
840 	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
841 
842 	default:
843 invalid:
844 		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
845 			ctrl->bRequestType, ctrl->bRequest,
846 			w_value, w_index, w_length);
847 	}
848 
849 	/* respond with data transfer or status phase? */
850 	if (value >= 0) {
851 		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
852 			ctrl->bRequestType, ctrl->bRequest,
853 			w_value, w_index, w_length);
854 		req->zero = 0;
855 		req->length = value;
856 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
857 		if (value < 0)
858 			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
859 					ctrl->bRequestType, ctrl->bRequest,
860 					value);
861 	}
862 
863 	/* device either stalls (value < 0) or reports success */
864 	return value;
865 }
866 
867 
868 static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
869 {
870 	struct f_ncm		*ncm = func_to_ncm(f);
871 	struct usb_composite_dev *cdev = f->config->cdev;
872 
873 	/* Control interface has only altsetting 0 */
874 	if (intf == ncm->ctrl_id) {
875 		if (alt != 0)
876 			goto fail;
877 
878 		DBG(cdev, "reset ncm control %d\n", intf);
879 		usb_ep_disable(ncm->notify);
880 
881 		if (!(ncm->notify->desc)) {
882 			DBG(cdev, "init ncm ctrl %d\n", intf);
883 			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
884 				goto fail;
885 		}
886 		usb_ep_enable(ncm->notify);
887 
888 	/* Data interface has two altsettings, 0 and 1 */
889 	} else if (intf == ncm->data_id) {
890 		if (alt > 1)
891 			goto fail;
892 
893 		if (ncm->port.in_ep->enabled) {
894 			DBG(cdev, "reset ncm\n");
895 			ncm->timer_stopping = true;
896 			ncm->netdev = NULL;
897 			gether_disconnect(&ncm->port);
898 			ncm_reset_values(ncm);
899 		}
900 
901 		/*
902 		 * CDC Network only sends data in non-default altsettings.
903 		 * Changing altsettings resets filters, statistics, etc.
904 		 */
905 		if (alt == 1) {
906 			struct net_device	*net;
907 
908 			if (!ncm->port.in_ep->desc ||
909 			    !ncm->port.out_ep->desc) {
910 				DBG(cdev, "init ncm\n");
911 				if (config_ep_by_speed(cdev->gadget, f,
912 						       ncm->port.in_ep) ||
913 				    config_ep_by_speed(cdev->gadget, f,
914 						       ncm->port.out_ep)) {
915 					ncm->port.in_ep->desc = NULL;
916 					ncm->port.out_ep->desc = NULL;
917 					goto fail;
918 				}
919 			}
920 
921 			/* TODO */
922 			/* Enable zlps by default for NCM conformance;
923 			 * override for musb_hdrc (avoids txdma ovhead)
924 			 */
925 			ncm->port.is_zlp_ok =
926 				gadget_is_zlp_supported(cdev->gadget);
927 			ncm->port.no_skb_reserve =
928 				gadget_avoids_skb_reserve(cdev->gadget);
929 			ncm->port.cdc_filter = DEFAULT_FILTER;
930 			DBG(cdev, "activate ncm\n");
931 			net = gether_connect(&ncm->port);
932 			if (IS_ERR(net))
933 				return PTR_ERR(net);
934 			ncm->netdev = net;
935 			ncm->timer_stopping = false;
936 		}
937 
938 		spin_lock(&ncm->lock);
939 		ncm_notify(ncm);
940 		spin_unlock(&ncm->lock);
941 	} else
942 		goto fail;
943 
944 	return 0;
945 fail:
946 	return -EINVAL;
947 }
948 
949 /*
950  * Because the data interface supports multiple altsettings,
951  * this NCM function *MUST* implement a get_alt() method.
952  */
953 static int ncm_get_alt(struct usb_function *f, unsigned intf)
954 {
955 	struct f_ncm		*ncm = func_to_ncm(f);
956 
957 	if (intf == ncm->ctrl_id)
958 		return 0;
959 	return ncm->port.in_ep->enabled ? 1 : 0;
960 }
961 
962 static struct sk_buff *package_for_tx(struct f_ncm *ncm)
963 {
964 	__le16		*ntb_iter;
965 	struct sk_buff	*skb2 = NULL;
966 	unsigned	ndp_pad;
967 	unsigned	ndp_index;
968 	unsigned	new_len;
969 
970 	const struct ndp_parser_opts *opts = ncm->parser_opts;
971 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
972 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
973 
974 	/* Stop the timer */
975 	hrtimer_try_to_cancel(&ncm->task_timer);
976 
977 	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
978 			ncm->skb_tx_data->len;
979 	ndp_index = ncm->skb_tx_data->len + ndp_pad;
980 	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
981 
982 	/* Set the final BlockLength and wNdpIndex */
983 	ntb_iter = (void *) ncm->skb_tx_data->data;
984 	/* Increment pointer to BlockLength */
985 	ntb_iter += 2 + 1 + 1;
986 	put_ncm(&ntb_iter, opts->block_length, new_len);
987 	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
988 
989 	/* Set the final NDP wLength */
990 	new_len = opts->ndp_size +
991 			(ncm->ndp_dgram_count * dgram_idx_len);
992 	ncm->ndp_dgram_count = 0;
993 	/* Increment from start to wLength */
994 	ntb_iter = (void *) ncm->skb_tx_ndp->data;
995 	ntb_iter += 2;
996 	put_unaligned_le16(new_len, ntb_iter);
997 
998 	/* Merge the skbs */
999 	swap(skb2, ncm->skb_tx_data);
1000 	if (ncm->skb_tx_data) {
1001 		dev_kfree_skb_any(ncm->skb_tx_data);
1002 		ncm->skb_tx_data = NULL;
1003 	}
1004 
1005 	/* Insert NDP alignment. */
1006 	ntb_iter = (void *) skb_put(skb2, ndp_pad);
1007 	memset(ntb_iter, 0, ndp_pad);
1008 
1009 	/* Copy NTB across. */
1010 	ntb_iter = (void *) skb_put(skb2, ncm->skb_tx_ndp->len);
1011 	memcpy(ntb_iter, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1012 	dev_kfree_skb_any(ncm->skb_tx_ndp);
1013 	ncm->skb_tx_ndp = NULL;
1014 
1015 	/* Insert zero'd datagram. */
1016 	ntb_iter = (void *) skb_put(skb2, dgram_idx_len);
1017 	memset(ntb_iter, 0, dgram_idx_len);
1018 
1019 	return skb2;
1020 }
1021 
1022 static struct sk_buff *ncm_wrap_ntb(struct gether *port,
1023 				    struct sk_buff *skb)
1024 {
1025 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1026 	struct sk_buff	*skb2 = NULL;
1027 	int		ncb_len = 0;
1028 	__le16		*ntb_data;
1029 	__le16		*ntb_ndp;
1030 	int		dgram_pad;
1031 
1032 	unsigned	max_size = ncm->port.fixed_in_len;
1033 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1034 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
1035 	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
1036 	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
1037 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
1038 
1039 	if (!skb && !ncm->skb_tx_data)
1040 		return NULL;
1041 
1042 	if (skb) {
1043 		/* Add the CRC if required up front */
1044 		if (ncm->is_crc) {
1045 			uint32_t	crc;
1046 			__le16		*crc_pos;
1047 
1048 			crc = ~crc32_le(~0,
1049 					skb->data,
1050 					skb->len);
1051 			crc_pos = (void *) skb_put(skb, sizeof(uint32_t));
1052 			put_unaligned_le32(crc, crc_pos);
1053 		}
1054 
1055 		/* If the new skb is too big for the current NCM NTB then
1056 		 * set the current stored skb to be sent now and clear it
1057 		 * ready for new data.
1058 		 * NOTE: Assume maximum align for speed of calculation.
1059 		 */
1060 		if (ncm->skb_tx_data
1061 		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
1062 		    || (ncm->skb_tx_data->len +
1063 		    div + rem + skb->len +
1064 		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
1065 		    > max_size)) {
1066 			skb2 = package_for_tx(ncm);
1067 			if (!skb2)
1068 				goto err;
1069 		}
1070 
1071 		if (!ncm->skb_tx_data) {
1072 			ncb_len = opts->nth_size;
1073 			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1074 			ncb_len += dgram_pad;
1075 
1076 			/* Create a new skb for the NTH and datagrams. */
1077 			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1078 			if (!ncm->skb_tx_data)
1079 				goto err;
1080 
1081 			ntb_data = (void *) skb_put(ncm->skb_tx_data, ncb_len);
1082 			memset(ntb_data, 0, ncb_len);
1083 			/* dwSignature */
1084 			put_unaligned_le32(opts->nth_sign, ntb_data);
1085 			ntb_data += 2;
1086 			/* wHeaderLength */
1087 			put_unaligned_le16(opts->nth_size, ntb_data++);
1088 
1089 			/* Allocate an skb for storing the NDP,
1090 			 * TX_MAX_NUM_DPE should easily suffice for a
1091 			 * 16k packet.
1092 			 */
1093 			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1094 						    + opts->dpe_size
1095 						    * TX_MAX_NUM_DPE),
1096 						    GFP_ATOMIC);
1097 			if (!ncm->skb_tx_ndp)
1098 				goto err;
1099 			ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp,
1100 						    opts->ndp_size);
1101 			memset(ntb_ndp, 0, ncb_len);
1102 			/* dwSignature */
1103 			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1104 			ntb_ndp += 2;
1105 
1106 			/* There is always a zeroed entry */
1107 			ncm->ndp_dgram_count = 1;
1108 
1109 			/* Note: we skip opts->next_ndp_index */
1110 		}
1111 
1112 		/* Delay the timer. */
1113 		hrtimer_start(&ncm->task_timer,
1114 			      ktime_set(0, TX_TIMEOUT_NSECS),
1115 			      HRTIMER_MODE_REL);
1116 
1117 		/* Add the datagram position entries */
1118 		ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp, dgram_idx_len);
1119 		memset(ntb_ndp, 0, dgram_idx_len);
1120 
1121 		ncb_len = ncm->skb_tx_data->len;
1122 		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1123 		ncb_len += dgram_pad;
1124 
1125 		/* (d)wDatagramIndex */
1126 		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1127 		/* (d)wDatagramLength */
1128 		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1129 		ncm->ndp_dgram_count++;
1130 
1131 		/* Add the new data to the skb */
1132 		ntb_data = (void *) skb_put(ncm->skb_tx_data, dgram_pad);
1133 		memset(ntb_data, 0, dgram_pad);
1134 		ntb_data = (void *) skb_put(ncm->skb_tx_data, skb->len);
1135 		memcpy(ntb_data, skb->data, skb->len);
1136 		dev_kfree_skb_any(skb);
1137 		skb = NULL;
1138 
1139 	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1140 		/* If the tx was requested because of a timeout then send */
1141 		skb2 = package_for_tx(ncm);
1142 		if (!skb2)
1143 			goto err;
1144 	}
1145 
1146 	return skb2;
1147 
1148 err:
1149 	ncm->netdev->stats.tx_dropped++;
1150 
1151 	if (skb)
1152 		dev_kfree_skb_any(skb);
1153 	if (ncm->skb_tx_data)
1154 		dev_kfree_skb_any(ncm->skb_tx_data);
1155 	if (ncm->skb_tx_ndp)
1156 		dev_kfree_skb_any(ncm->skb_tx_ndp);
1157 
1158 	return NULL;
1159 }
1160 
1161 /*
1162  * This transmits the NTB if there are frames waiting.
1163  */
1164 static void ncm_tx_tasklet(unsigned long data)
1165 {
1166 	struct f_ncm	*ncm = (void *)data;
1167 
1168 	if (ncm->timer_stopping)
1169 		return;
1170 
1171 	/* Only send if data is available. */
1172 	if (ncm->skb_tx_data) {
1173 		ncm->timer_force_tx = true;
1174 
1175 		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1176 		 * XXX is not sane.  The gadget layer should be redesigned so
1177 		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1178 		 * XXX and performed in some way outside of the ndo_start_xmit
1179 		 * XXX interface.
1180 		 */
1181 		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1182 
1183 		ncm->timer_force_tx = false;
1184 	}
1185 }
1186 
1187 /*
1188  * The transmit should only be run if no skb data has been sent
1189  * for a certain duration.
1190  */
1191 static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1192 {
1193 	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1194 	tasklet_schedule(&ncm->tx_tasklet);
1195 	return HRTIMER_NORESTART;
1196 }
1197 
1198 static int ncm_unwrap_ntb(struct gether *port,
1199 			  struct sk_buff *skb,
1200 			  struct sk_buff_head *list)
1201 {
1202 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1203 	__le16		*tmp = (void *) skb->data;
1204 	unsigned	index, index2;
1205 	int		ndp_index;
1206 	unsigned	dg_len, dg_len2;
1207 	unsigned	ndp_len;
1208 	struct sk_buff	*skb2;
1209 	int		ret = -EINVAL;
1210 	unsigned	max_size = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1211 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1212 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1213 	int		dgram_counter;
1214 
1215 	/* dwSignature */
1216 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1217 		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1218 			skb->len);
1219 		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1220 			       skb->data, 32, false);
1221 
1222 		goto err;
1223 	}
1224 	tmp += 2;
1225 	/* wHeaderLength */
1226 	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1227 		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1228 		goto err;
1229 	}
1230 	tmp++; /* skip wSequence */
1231 
1232 	/* (d)wBlockLength */
1233 	if (get_ncm(&tmp, opts->block_length) > max_size) {
1234 		INFO(port->func.config->cdev, "OUT size exceeded\n");
1235 		goto err;
1236 	}
1237 
1238 	ndp_index = get_ncm(&tmp, opts->ndp_index);
1239 
1240 	/* Run through all the NDP's in the NTB */
1241 	do {
1242 		/* NCM 3.2 */
1243 		if (((ndp_index % 4) != 0) &&
1244 				(ndp_index < opts->nth_size)) {
1245 			INFO(port->func.config->cdev, "Bad index: %#X\n",
1246 			     ndp_index);
1247 			goto err;
1248 		}
1249 
1250 		/* walk through NDP */
1251 		tmp = (void *)(skb->data + ndp_index);
1252 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1253 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1254 			goto err;
1255 		}
1256 		tmp += 2;
1257 
1258 		ndp_len = get_unaligned_le16(tmp++);
1259 		/*
1260 		 * NCM 3.3.1
1261 		 * entry is 2 items
1262 		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1263 		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1264 		 * Each entry is a dgram index and a dgram length.
1265 		 */
1266 		if ((ndp_len < opts->ndp_size
1267 				+ 2 * 2 * (opts->dgram_item_len * 2))
1268 				|| (ndp_len % opts->ndplen_align != 0)) {
1269 			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1270 			     ndp_len);
1271 			goto err;
1272 		}
1273 		tmp += opts->reserved1;
1274 		/* Check for another NDP (d)wNextNdpIndex */
1275 		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1276 		tmp += opts->reserved2;
1277 
1278 		ndp_len -= opts->ndp_size;
1279 		index2 = get_ncm(&tmp, opts->dgram_item_len);
1280 		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1281 		dgram_counter = 0;
1282 
1283 		do {
1284 			index = index2;
1285 			dg_len = dg_len2;
1286 			if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
1287 				INFO(port->func.config->cdev,
1288 				     "Bad dgram length: %#X\n", dg_len);
1289 				goto err;
1290 			}
1291 			if (ncm->is_crc) {
1292 				uint32_t crc, crc2;
1293 
1294 				crc = get_unaligned_le32(skb->data +
1295 							 index + dg_len -
1296 							 crc_len);
1297 				crc2 = ~crc32_le(~0,
1298 						 skb->data + index,
1299 						 dg_len - crc_len);
1300 				if (crc != crc2) {
1301 					INFO(port->func.config->cdev,
1302 					     "Bad CRC\n");
1303 					goto err;
1304 				}
1305 			}
1306 
1307 			index2 = get_ncm(&tmp, opts->dgram_item_len);
1308 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1309 
1310 			/*
1311 			 * Copy the data into a new skb.
1312 			 * This ensures the truesize is correct
1313 			 */
1314 			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1315 							 dg_len - crc_len);
1316 			if (skb2 == NULL)
1317 				goto err;
1318 			memcpy(skb_put(skb2, dg_len - crc_len),
1319 			       skb->data + index, dg_len - crc_len);
1320 
1321 			skb_queue_tail(list, skb2);
1322 
1323 			ndp_len -= 2 * (opts->dgram_item_len * 2);
1324 
1325 			dgram_counter++;
1326 
1327 			if (index2 == 0 || dg_len2 == 0)
1328 				break;
1329 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1330 	} while (ndp_index);
1331 
1332 	dev_kfree_skb_any(skb);
1333 
1334 	VDBG(port->func.config->cdev,
1335 	     "Parsed NTB with %d frames\n", dgram_counter);
1336 	return 0;
1337 err:
1338 	skb_queue_purge(list);
1339 	dev_kfree_skb_any(skb);
1340 	return ret;
1341 }
1342 
1343 static void ncm_disable(struct usb_function *f)
1344 {
1345 	struct f_ncm		*ncm = func_to_ncm(f);
1346 	struct usb_composite_dev *cdev = f->config->cdev;
1347 
1348 	DBG(cdev, "ncm deactivated\n");
1349 
1350 	if (ncm->port.in_ep->enabled) {
1351 		ncm->timer_stopping = true;
1352 		ncm->netdev = NULL;
1353 		gether_disconnect(&ncm->port);
1354 	}
1355 
1356 	if (ncm->notify->enabled) {
1357 		usb_ep_disable(ncm->notify);
1358 		ncm->notify->desc = NULL;
1359 	}
1360 }
1361 
1362 /*-------------------------------------------------------------------------*/
1363 
1364 /*
1365  * Callbacks let us notify the host about connect/disconnect when the
1366  * net device is opened or closed.
1367  *
1368  * For testing, note that link states on this side include both opened
1369  * and closed variants of:
1370  *
1371  *   - disconnected/unconfigured
1372  *   - configured but inactive (data alt 0)
1373  *   - configured and active (data alt 1)
1374  *
1375  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1376  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1377  * imply the host is actually polling the notification endpoint, and
1378  * likewise that "active" doesn't imply it's actually using the data
1379  * endpoints for traffic.
1380  */
1381 
1382 static void ncm_open(struct gether *geth)
1383 {
1384 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1385 
1386 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1387 
1388 	spin_lock(&ncm->lock);
1389 	ncm->is_open = true;
1390 	ncm_notify(ncm);
1391 	spin_unlock(&ncm->lock);
1392 }
1393 
1394 static void ncm_close(struct gether *geth)
1395 {
1396 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1397 
1398 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1399 
1400 	spin_lock(&ncm->lock);
1401 	ncm->is_open = false;
1402 	ncm_notify(ncm);
1403 	spin_unlock(&ncm->lock);
1404 }
1405 
1406 /*-------------------------------------------------------------------------*/
1407 
1408 /* ethernet function driver setup/binding */
1409 
1410 static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1411 {
1412 	struct usb_composite_dev *cdev = c->cdev;
1413 	struct f_ncm		*ncm = func_to_ncm(f);
1414 	struct usb_string	*us;
1415 	int			status;
1416 	struct usb_ep		*ep;
1417 	struct f_ncm_opts	*ncm_opts;
1418 
1419 	if (!can_support_ecm(cdev->gadget))
1420 		return -EINVAL;
1421 
1422 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1423 	/*
1424 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1425 	 * configurations are bound in sequence with list_for_each_entry,
1426 	 * in each configuration its functions are bound in sequence
1427 	 * with list_for_each_entry, so we assume no race condition
1428 	 * with regard to ncm_opts->bound access
1429 	 */
1430 	if (!ncm_opts->bound) {
1431 		mutex_lock(&ncm_opts->lock);
1432 		gether_set_gadget(ncm_opts->net, cdev->gadget);
1433 		status = gether_register_netdev(ncm_opts->net);
1434 		mutex_unlock(&ncm_opts->lock);
1435 		if (status)
1436 			return status;
1437 		ncm_opts->bound = true;
1438 	}
1439 	us = usb_gstrings_attach(cdev, ncm_strings,
1440 				 ARRAY_SIZE(ncm_string_defs));
1441 	if (IS_ERR(us))
1442 		return PTR_ERR(us);
1443 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1444 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1445 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1446 	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1447 	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1448 
1449 	/* allocate instance-specific interface IDs */
1450 	status = usb_interface_id(c, f);
1451 	if (status < 0)
1452 		goto fail;
1453 	ncm->ctrl_id = status;
1454 	ncm_iad_desc.bFirstInterface = status;
1455 
1456 	ncm_control_intf.bInterfaceNumber = status;
1457 	ncm_union_desc.bMasterInterface0 = status;
1458 
1459 	status = usb_interface_id(c, f);
1460 	if (status < 0)
1461 		goto fail;
1462 	ncm->data_id = status;
1463 
1464 	ncm_data_nop_intf.bInterfaceNumber = status;
1465 	ncm_data_intf.bInterfaceNumber = status;
1466 	ncm_union_desc.bSlaveInterface0 = status;
1467 
1468 	status = -ENODEV;
1469 
1470 	/* allocate instance-specific endpoints */
1471 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1472 	if (!ep)
1473 		goto fail;
1474 	ncm->port.in_ep = ep;
1475 
1476 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1477 	if (!ep)
1478 		goto fail;
1479 	ncm->port.out_ep = ep;
1480 
1481 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1482 	if (!ep)
1483 		goto fail;
1484 	ncm->notify = ep;
1485 
1486 	status = -ENOMEM;
1487 
1488 	/* allocate notification request and buffer */
1489 	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1490 	if (!ncm->notify_req)
1491 		goto fail;
1492 	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1493 	if (!ncm->notify_req->buf)
1494 		goto fail;
1495 	ncm->notify_req->context = ncm;
1496 	ncm->notify_req->complete = ncm_notify_complete;
1497 
1498 	/*
1499 	 * support all relevant hardware speeds... we expect that when
1500 	 * hardware is dual speed, all bulk-capable endpoints work at
1501 	 * both speeds
1502 	 */
1503 	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1504 	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1505 	hs_ncm_notify_desc.bEndpointAddress =
1506 		fs_ncm_notify_desc.bEndpointAddress;
1507 
1508 	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1509 	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1510 	ss_ncm_notify_desc.bEndpointAddress =
1511 		fs_ncm_notify_desc.bEndpointAddress;
1512 
1513 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1514 			ncm_ss_function, NULL);
1515 	if (status)
1516 		goto fail;
1517 
1518 	/*
1519 	 * NOTE:  all that is done without knowing or caring about
1520 	 * the network link ... which is unavailable to this code
1521 	 * until we're activated via set_alt().
1522 	 */
1523 
1524 	ncm->port.open = ncm_open;
1525 	ncm->port.close = ncm_close;
1526 
1527 	tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
1528 	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1529 	ncm->task_timer.function = ncm_tx_timeout;
1530 
1531 	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1532 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1533 			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1534 			ncm->port.in_ep->name, ncm->port.out_ep->name,
1535 			ncm->notify->name);
1536 	return 0;
1537 
1538 fail:
1539 	if (ncm->notify_req) {
1540 		kfree(ncm->notify_req->buf);
1541 		usb_ep_free_request(ncm->notify, ncm->notify_req);
1542 	}
1543 
1544 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1545 
1546 	return status;
1547 }
1548 
1549 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1550 {
1551 	return container_of(to_config_group(item), struct f_ncm_opts,
1552 			    func_inst.group);
1553 }
1554 
1555 /* f_ncm_item_ops */
1556 USB_ETHERNET_CONFIGFS_ITEM(ncm);
1557 
1558 /* f_ncm_opts_dev_addr */
1559 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1560 
1561 /* f_ncm_opts_host_addr */
1562 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1563 
1564 /* f_ncm_opts_qmult */
1565 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1566 
1567 /* f_ncm_opts_ifname */
1568 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1569 
1570 static struct configfs_attribute *ncm_attrs[] = {
1571 	&ncm_opts_attr_dev_addr,
1572 	&ncm_opts_attr_host_addr,
1573 	&ncm_opts_attr_qmult,
1574 	&ncm_opts_attr_ifname,
1575 	NULL,
1576 };
1577 
1578 static struct config_item_type ncm_func_type = {
1579 	.ct_item_ops	= &ncm_item_ops,
1580 	.ct_attrs	= ncm_attrs,
1581 	.ct_owner	= THIS_MODULE,
1582 };
1583 
1584 static void ncm_free_inst(struct usb_function_instance *f)
1585 {
1586 	struct f_ncm_opts *opts;
1587 
1588 	opts = container_of(f, struct f_ncm_opts, func_inst);
1589 	if (opts->bound)
1590 		gether_cleanup(netdev_priv(opts->net));
1591 	else
1592 		free_netdev(opts->net);
1593 	kfree(opts);
1594 }
1595 
1596 static struct usb_function_instance *ncm_alloc_inst(void)
1597 {
1598 	struct f_ncm_opts *opts;
1599 
1600 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1601 	if (!opts)
1602 		return ERR_PTR(-ENOMEM);
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 
1612 	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1613 
1614 	return &opts->func_inst;
1615 }
1616 
1617 static void ncm_free(struct usb_function *f)
1618 {
1619 	struct f_ncm *ncm;
1620 	struct f_ncm_opts *opts;
1621 
1622 	ncm = func_to_ncm(f);
1623 	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1624 	kfree(ncm);
1625 	mutex_lock(&opts->lock);
1626 	opts->refcnt--;
1627 	mutex_unlock(&opts->lock);
1628 }
1629 
1630 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1631 {
1632 	struct f_ncm *ncm = func_to_ncm(f);
1633 
1634 	DBG(c->cdev, "ncm unbind\n");
1635 
1636 	hrtimer_cancel(&ncm->task_timer);
1637 	tasklet_kill(&ncm->tx_tasklet);
1638 
1639 	ncm_string_defs[0].id = 0;
1640 	usb_free_all_descriptors(f);
1641 
1642 	kfree(ncm->notify_req->buf);
1643 	usb_ep_free_request(ncm->notify, ncm->notify_req);
1644 }
1645 
1646 static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1647 {
1648 	struct f_ncm		*ncm;
1649 	struct f_ncm_opts	*opts;
1650 	int status;
1651 
1652 	/* allocate and initialize one new instance */
1653 	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1654 	if (!ncm)
1655 		return ERR_PTR(-ENOMEM);
1656 
1657 	opts = container_of(fi, struct f_ncm_opts, func_inst);
1658 	mutex_lock(&opts->lock);
1659 	opts->refcnt++;
1660 
1661 	/* export host's Ethernet address in CDC format */
1662 	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1663 				      sizeof(ncm->ethaddr));
1664 	if (status < 12) { /* strlen("01234567890a") */
1665 		kfree(ncm);
1666 		mutex_unlock(&opts->lock);
1667 		return ERR_PTR(-EINVAL);
1668 	}
1669 	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1670 
1671 	spin_lock_init(&ncm->lock);
1672 	ncm_reset_values(ncm);
1673 	ncm->port.ioport = netdev_priv(opts->net);
1674 	mutex_unlock(&opts->lock);
1675 	ncm->port.is_fixed = true;
1676 	ncm->port.supports_multi_frame = true;
1677 
1678 	ncm->port.func.name = "cdc_network";
1679 	/* descriptors are per-instance copies */
1680 	ncm->port.func.bind = ncm_bind;
1681 	ncm->port.func.unbind = ncm_unbind;
1682 	ncm->port.func.set_alt = ncm_set_alt;
1683 	ncm->port.func.get_alt = ncm_get_alt;
1684 	ncm->port.func.setup = ncm_setup;
1685 	ncm->port.func.disable = ncm_disable;
1686 	ncm->port.func.free_func = ncm_free;
1687 
1688 	ncm->port.wrap = ncm_wrap_ntb;
1689 	ncm->port.unwrap = ncm_unwrap_ntb;
1690 
1691 	return &ncm->port.func;
1692 }
1693 
1694 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1695 MODULE_LICENSE("GPL");
1696 MODULE_AUTHOR("Yauheni Kaliuta");
1697