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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Networking over Thunderbolt cable using Apple ThunderboltIP protocol
4  *
5  * Copyright (C) 2017, Intel Corporation
6  * Authors: Amir Levy <amir.jer.levy@intel.com>
7  *          Michael Jamet <michael.jamet@intel.com>
8  *          Mika Westerberg <mika.westerberg@linux.intel.com>
9  */
10 
11 #include <linux/atomic.h>
12 #include <linux/highmem.h>
13 #include <linux/if_vlan.h>
14 #include <linux/jhash.h>
15 #include <linux/module.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/sizes.h>
19 #include <linux/thunderbolt.h>
20 #include <linux/uuid.h>
21 #include <linux/workqueue.h>
22 
23 #include <net/ip6_checksum.h>
24 
25 /* Protocol timeouts in ms */
26 #define TBNET_LOGIN_DELAY	4500
27 #define TBNET_LOGIN_TIMEOUT	500
28 #define TBNET_LOGOUT_TIMEOUT	100
29 
30 #define TBNET_RING_SIZE		256
31 #define TBNET_LOCAL_PATH	0xf
32 #define TBNET_LOGIN_RETRIES	60
33 #define TBNET_LOGOUT_RETRIES	5
34 #define TBNET_MATCH_FRAGS_ID	BIT(1)
35 #define TBNET_MAX_MTU		SZ_64K
36 #define TBNET_FRAME_SIZE	SZ_4K
37 #define TBNET_MAX_PAYLOAD_SIZE	\
38 	(TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))
39 /* Rx packets need to hold space for skb_shared_info */
40 #define TBNET_RX_MAX_SIZE	\
41 	(TBNET_FRAME_SIZE + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
42 #define TBNET_RX_PAGE_ORDER	get_order(TBNET_RX_MAX_SIZE)
43 #define TBNET_RX_PAGE_SIZE	(PAGE_SIZE << TBNET_RX_PAGE_ORDER)
44 
45 #define TBNET_L0_PORT_NUM(route) ((route) & GENMASK(5, 0))
46 
47 /**
48  * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame
49  * @frame_size: size of the data with the frame
50  * @frame_index: running index on the frames
51  * @frame_id: ID of the frame to match frames to specific packet
52  * @frame_count: how many frames assembles a full packet
53  *
54  * Each data frame passed to the high-speed DMA ring has this header. If
55  * the XDomain network directory announces that %TBNET_MATCH_FRAGS_ID is
56  * supported then @frame_id is filled, otherwise it stays %0.
57  */
58 struct thunderbolt_ip_frame_header {
59 	u32 frame_size;
60 	u16 frame_index;
61 	u16 frame_id;
62 	u32 frame_count;
63 };
64 
65 enum thunderbolt_ip_frame_pdf {
66 	TBIP_PDF_FRAME_START = 1,
67 	TBIP_PDF_FRAME_END,
68 };
69 
70 enum thunderbolt_ip_type {
71 	TBIP_LOGIN,
72 	TBIP_LOGIN_RESPONSE,
73 	TBIP_LOGOUT,
74 	TBIP_STATUS,
75 };
76 
77 struct thunderbolt_ip_header {
78 	u32 route_hi;
79 	u32 route_lo;
80 	u32 length_sn;
81 	uuid_t uuid;
82 	uuid_t initiator_uuid;
83 	uuid_t target_uuid;
84 	u32 type;
85 	u32 command_id;
86 };
87 
88 #define TBIP_HDR_LENGTH_MASK		GENMASK(5, 0)
89 #define TBIP_HDR_SN_MASK		GENMASK(28, 27)
90 #define TBIP_HDR_SN_SHIFT		27
91 
92 struct thunderbolt_ip_login {
93 	struct thunderbolt_ip_header hdr;
94 	u32 proto_version;
95 	u32 transmit_path;
96 	u32 reserved[4];
97 };
98 
99 #define TBIP_LOGIN_PROTO_VERSION	1
100 
101 struct thunderbolt_ip_login_response {
102 	struct thunderbolt_ip_header hdr;
103 	u32 status;
104 	u32 receiver_mac[2];
105 	u32 receiver_mac_len;
106 	u32 reserved[4];
107 };
108 
109 struct thunderbolt_ip_logout {
110 	struct thunderbolt_ip_header hdr;
111 };
112 
113 struct thunderbolt_ip_status {
114 	struct thunderbolt_ip_header hdr;
115 	u32 status;
116 };
117 
118 struct tbnet_stats {
119 	u64 tx_packets;
120 	u64 rx_packets;
121 	u64 tx_bytes;
122 	u64 rx_bytes;
123 	u64 rx_errors;
124 	u64 tx_errors;
125 	u64 rx_length_errors;
126 	u64 rx_over_errors;
127 	u64 rx_crc_errors;
128 	u64 rx_missed_errors;
129 };
130 
131 struct tbnet_frame {
132 	struct net_device *dev;
133 	struct page *page;
134 	struct ring_frame frame;
135 };
136 
137 struct tbnet_ring {
138 	struct tbnet_frame frames[TBNET_RING_SIZE];
139 	unsigned int cons;
140 	unsigned int prod;
141 	struct tb_ring *ring;
142 };
143 
144 /**
145  * struct tbnet - ThunderboltIP network driver private data
146  * @svc: XDomain service the driver is bound to
147  * @xd: XDomain the service blongs to
148  * @handler: ThunderboltIP configuration protocol handler
149  * @dev: Networking device
150  * @napi: NAPI structure for Rx polling
151  * @stats: Network statistics
152  * @skb: Network packet that is currently processed on Rx path
153  * @command_id: ID used for next configuration protocol packet
154  * @login_sent: ThunderboltIP login message successfully sent
155  * @login_received: ThunderboltIP login message received from the remote
156  *		    host
157  * @transmit_path: HopID the other end needs to use building the
158  *		   opposite side path.
159  * @connection_lock: Lock serializing access to @login_sent,
160  *		     @login_received and @transmit_path.
161  * @login_retries: Number of login retries currently done
162  * @login_work: Worker to send ThunderboltIP login packets
163  * @connected_work: Worker that finalizes the ThunderboltIP connection
164  *		    setup and enables DMA paths for high speed data
165  *		    transfers
166  * @disconnect_work: Worker that handles tearing down the ThunderboltIP
167  *		     connection
168  * @rx_hdr: Copy of the currently processed Rx frame. Used when a
169  *	    network packet consists of multiple Thunderbolt frames.
170  *	    In host byte order.
171  * @rx_ring: Software ring holding Rx frames
172  * @frame_id: Frame ID use for next Tx packet
173  *            (if %TBNET_MATCH_FRAGS_ID is supported in both ends)
174  * @tx_ring: Software ring holding Tx frames
175  */
176 struct tbnet {
177 	const struct tb_service *svc;
178 	struct tb_xdomain *xd;
179 	struct tb_protocol_handler handler;
180 	struct net_device *dev;
181 	struct napi_struct napi;
182 	struct tbnet_stats stats;
183 	struct sk_buff *skb;
184 	atomic_t command_id;
185 	bool login_sent;
186 	bool login_received;
187 	u32 transmit_path;
188 	struct mutex connection_lock;
189 	int login_retries;
190 	struct delayed_work login_work;
191 	struct work_struct connected_work;
192 	struct work_struct disconnect_work;
193 	struct thunderbolt_ip_frame_header rx_hdr;
194 	struct tbnet_ring rx_ring;
195 	atomic_t frame_id;
196 	struct tbnet_ring tx_ring;
197 };
198 
199 /* Network property directory UUID: c66189ca-1cce-4195-bdb8-49592e5f5a4f */
200 static const uuid_t tbnet_dir_uuid =
201 	UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
202 		  0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);
203 
204 /* ThunderboltIP protocol UUID: 798f589e-3616-8a47-97c6-5664a920c8dd */
205 static const uuid_t tbnet_svc_uuid =
206 	UUID_INIT(0x798f589e, 0x3616, 0x8a47,
207 		  0x97, 0xc6, 0x56, 0x64, 0xa9, 0x20, 0xc8, 0xdd);
208 
209 static struct tb_property_dir *tbnet_dir;
210 
tbnet_fill_header(struct thunderbolt_ip_header * hdr,u64 route,u8 sequence,const uuid_t * initiator_uuid,const uuid_t * target_uuid,enum thunderbolt_ip_type type,size_t size,u32 command_id)211 static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,
212 	u8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,
213 	enum thunderbolt_ip_type type, size_t size, u32 command_id)
214 {
215 	u32 length_sn;
216 
217 	/* Length does not include route_hi/lo and length_sn fields */
218 	length_sn = (size - 3 * 4) / 4;
219 	length_sn |= (sequence << TBIP_HDR_SN_SHIFT) & TBIP_HDR_SN_MASK;
220 
221 	hdr->route_hi = upper_32_bits(route);
222 	hdr->route_lo = lower_32_bits(route);
223 	hdr->length_sn = length_sn;
224 	uuid_copy(&hdr->uuid, &tbnet_svc_uuid);
225 	uuid_copy(&hdr->initiator_uuid, initiator_uuid);
226 	uuid_copy(&hdr->target_uuid, target_uuid);
227 	hdr->type = type;
228 	hdr->command_id = command_id;
229 }
230 
tbnet_login_response(struct tbnet * net,u64 route,u8 sequence,u32 command_id)231 static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,
232 				u32 command_id)
233 {
234 	struct thunderbolt_ip_login_response reply;
235 	struct tb_xdomain *xd = net->xd;
236 
237 	memset(&reply, 0, sizeof(reply));
238 	tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
239 			  xd->remote_uuid, TBIP_LOGIN_RESPONSE, sizeof(reply),
240 			  command_id);
241 	memcpy(reply.receiver_mac, net->dev->dev_addr, ETH_ALEN);
242 	reply.receiver_mac_len = ETH_ALEN;
243 
244 	return tb_xdomain_response(xd, &reply, sizeof(reply),
245 				   TB_CFG_PKG_XDOMAIN_RESP);
246 }
247 
tbnet_login_request(struct tbnet * net,u8 sequence)248 static int tbnet_login_request(struct tbnet *net, u8 sequence)
249 {
250 	struct thunderbolt_ip_login_response reply;
251 	struct thunderbolt_ip_login request;
252 	struct tb_xdomain *xd = net->xd;
253 
254 	memset(&request, 0, sizeof(request));
255 	tbnet_fill_header(&request.hdr, xd->route, sequence, xd->local_uuid,
256 			  xd->remote_uuid, TBIP_LOGIN, sizeof(request),
257 			  atomic_inc_return(&net->command_id));
258 
259 	request.proto_version = TBIP_LOGIN_PROTO_VERSION;
260 	request.transmit_path = TBNET_LOCAL_PATH;
261 
262 	return tb_xdomain_request(xd, &request, sizeof(request),
263 				  TB_CFG_PKG_XDOMAIN_RESP, &reply,
264 				  sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
265 				  TBNET_LOGIN_TIMEOUT);
266 }
267 
tbnet_logout_response(struct tbnet * net,u64 route,u8 sequence,u32 command_id)268 static int tbnet_logout_response(struct tbnet *net, u64 route, u8 sequence,
269 				 u32 command_id)
270 {
271 	struct thunderbolt_ip_status reply;
272 	struct tb_xdomain *xd = net->xd;
273 
274 	memset(&reply, 0, sizeof(reply));
275 	tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
276 			  xd->remote_uuid, TBIP_STATUS, sizeof(reply),
277 			  atomic_inc_return(&net->command_id));
278 	return tb_xdomain_response(xd, &reply, sizeof(reply),
279 				   TB_CFG_PKG_XDOMAIN_RESP);
280 }
281 
tbnet_logout_request(struct tbnet * net)282 static int tbnet_logout_request(struct tbnet *net)
283 {
284 	struct thunderbolt_ip_logout request;
285 	struct thunderbolt_ip_status reply;
286 	struct tb_xdomain *xd = net->xd;
287 
288 	memset(&request, 0, sizeof(request));
289 	tbnet_fill_header(&request.hdr, xd->route, 0, xd->local_uuid,
290 			  xd->remote_uuid, TBIP_LOGOUT, sizeof(request),
291 			  atomic_inc_return(&net->command_id));
292 
293 	return tb_xdomain_request(xd, &request, sizeof(request),
294 				  TB_CFG_PKG_XDOMAIN_RESP, &reply,
295 				  sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
296 				  TBNET_LOGOUT_TIMEOUT);
297 }
298 
start_login(struct tbnet * net)299 static void start_login(struct tbnet *net)
300 {
301 	mutex_lock(&net->connection_lock);
302 	net->login_sent = false;
303 	net->login_received = false;
304 	mutex_unlock(&net->connection_lock);
305 
306 	queue_delayed_work(system_long_wq, &net->login_work,
307 			   msecs_to_jiffies(1000));
308 }
309 
stop_login(struct tbnet * net)310 static void stop_login(struct tbnet *net)
311 {
312 	cancel_delayed_work_sync(&net->login_work);
313 	cancel_work_sync(&net->connected_work);
314 }
315 
tbnet_frame_size(const struct tbnet_frame * tf)316 static inline unsigned int tbnet_frame_size(const struct tbnet_frame *tf)
317 {
318 	return tf->frame.size ? : TBNET_FRAME_SIZE;
319 }
320 
tbnet_free_buffers(struct tbnet_ring * ring)321 static void tbnet_free_buffers(struct tbnet_ring *ring)
322 {
323 	unsigned int i;
324 
325 	for (i = 0; i < TBNET_RING_SIZE; i++) {
326 		struct device *dma_dev = tb_ring_dma_device(ring->ring);
327 		struct tbnet_frame *tf = &ring->frames[i];
328 		enum dma_data_direction dir;
329 		unsigned int order;
330 		size_t size;
331 
332 		if (!tf->page)
333 			continue;
334 
335 		if (ring->ring->is_tx) {
336 			dir = DMA_TO_DEVICE;
337 			order = 0;
338 			size = TBNET_FRAME_SIZE;
339 		} else {
340 			dir = DMA_FROM_DEVICE;
341 			order = TBNET_RX_PAGE_ORDER;
342 			size = TBNET_RX_PAGE_SIZE;
343 		}
344 
345 		if (tf->frame.buffer_phy)
346 			dma_unmap_page(dma_dev, tf->frame.buffer_phy, size,
347 				       dir);
348 
349 		__free_pages(tf->page, order);
350 		tf->page = NULL;
351 	}
352 
353 	ring->cons = 0;
354 	ring->prod = 0;
355 }
356 
tbnet_tear_down(struct tbnet * net,bool send_logout)357 static void tbnet_tear_down(struct tbnet *net, bool send_logout)
358 {
359 	netif_carrier_off(net->dev);
360 	netif_stop_queue(net->dev);
361 
362 	stop_login(net);
363 
364 	mutex_lock(&net->connection_lock);
365 
366 	if (net->login_sent && net->login_received) {
367 		int retries = TBNET_LOGOUT_RETRIES;
368 
369 		while (send_logout && retries-- > 0) {
370 			int ret = tbnet_logout_request(net);
371 			if (ret != -ETIMEDOUT)
372 				break;
373 		}
374 
375 		tb_ring_stop(net->rx_ring.ring);
376 		tb_ring_stop(net->tx_ring.ring);
377 		tbnet_free_buffers(&net->rx_ring);
378 		tbnet_free_buffers(&net->tx_ring);
379 
380 		if (tb_xdomain_disable_paths(net->xd))
381 			netdev_warn(net->dev, "failed to disable DMA paths\n");
382 	}
383 
384 	net->login_retries = 0;
385 	net->login_sent = false;
386 	net->login_received = false;
387 
388 	mutex_unlock(&net->connection_lock);
389 }
390 
tbnet_handle_packet(const void * buf,size_t size,void * data)391 static int tbnet_handle_packet(const void *buf, size_t size, void *data)
392 {
393 	const struct thunderbolt_ip_login *pkg = buf;
394 	struct tbnet *net = data;
395 	u32 command_id;
396 	int ret = 0;
397 	u32 sequence;
398 	u64 route;
399 
400 	/* Make sure the packet is for us */
401 	if (size < sizeof(struct thunderbolt_ip_header))
402 		return 0;
403 	if (!uuid_equal(&pkg->hdr.initiator_uuid, net->xd->remote_uuid))
404 		return 0;
405 	if (!uuid_equal(&pkg->hdr.target_uuid, net->xd->local_uuid))
406 		return 0;
407 
408 	route = ((u64)pkg->hdr.route_hi << 32) | pkg->hdr.route_lo;
409 	route &= ~BIT_ULL(63);
410 	if (route != net->xd->route)
411 		return 0;
412 
413 	sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
414 	sequence >>= TBIP_HDR_SN_SHIFT;
415 	command_id = pkg->hdr.command_id;
416 
417 	switch (pkg->hdr.type) {
418 	case TBIP_LOGIN:
419 		if (!netif_running(net->dev))
420 			break;
421 
422 		ret = tbnet_login_response(net, route, sequence,
423 					   pkg->hdr.command_id);
424 		if (!ret) {
425 			mutex_lock(&net->connection_lock);
426 			net->login_received = true;
427 			net->transmit_path = pkg->transmit_path;
428 
429 			/* If we reached the number of max retries or
430 			 * previous logout, schedule another round of
431 			 * login retries
432 			 */
433 			if (net->login_retries >= TBNET_LOGIN_RETRIES ||
434 			    !net->login_sent) {
435 				net->login_retries = 0;
436 				queue_delayed_work(system_long_wq,
437 						   &net->login_work, 0);
438 			}
439 			mutex_unlock(&net->connection_lock);
440 
441 			queue_work(system_long_wq, &net->connected_work);
442 		}
443 		break;
444 
445 	case TBIP_LOGOUT:
446 		ret = tbnet_logout_response(net, route, sequence, command_id);
447 		if (!ret)
448 			queue_work(system_long_wq, &net->disconnect_work);
449 		break;
450 
451 	default:
452 		return 0;
453 	}
454 
455 	if (ret)
456 		netdev_warn(net->dev, "failed to send ThunderboltIP response\n");
457 
458 	return 1;
459 }
460 
tbnet_available_buffers(const struct tbnet_ring * ring)461 static unsigned int tbnet_available_buffers(const struct tbnet_ring *ring)
462 {
463 	return ring->prod - ring->cons;
464 }
465 
tbnet_alloc_rx_buffers(struct tbnet * net,unsigned int nbuffers)466 static int tbnet_alloc_rx_buffers(struct tbnet *net, unsigned int nbuffers)
467 {
468 	struct tbnet_ring *ring = &net->rx_ring;
469 	int ret;
470 
471 	while (nbuffers--) {
472 		struct device *dma_dev = tb_ring_dma_device(ring->ring);
473 		unsigned int index = ring->prod & (TBNET_RING_SIZE - 1);
474 		struct tbnet_frame *tf = &ring->frames[index];
475 		dma_addr_t dma_addr;
476 
477 		if (tf->page)
478 			break;
479 
480 		/* Allocate page (order > 0) so that it can hold maximum
481 		 * ThunderboltIP frame (4kB) and the additional room for
482 		 * SKB shared info required by build_skb().
483 		 */
484 		tf->page = dev_alloc_pages(TBNET_RX_PAGE_ORDER);
485 		if (!tf->page) {
486 			ret = -ENOMEM;
487 			goto err_free;
488 		}
489 
490 		dma_addr = dma_map_page(dma_dev, tf->page, 0,
491 					TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
492 		if (dma_mapping_error(dma_dev, dma_addr)) {
493 			ret = -ENOMEM;
494 			goto err_free;
495 		}
496 
497 		tf->frame.buffer_phy = dma_addr;
498 		tf->dev = net->dev;
499 
500 		tb_ring_rx(ring->ring, &tf->frame);
501 
502 		ring->prod++;
503 	}
504 
505 	return 0;
506 
507 err_free:
508 	tbnet_free_buffers(ring);
509 	return ret;
510 }
511 
tbnet_get_tx_buffer(struct tbnet * net)512 static struct tbnet_frame *tbnet_get_tx_buffer(struct tbnet *net)
513 {
514 	struct tbnet_ring *ring = &net->tx_ring;
515 	struct device *dma_dev = tb_ring_dma_device(ring->ring);
516 	struct tbnet_frame *tf;
517 	unsigned int index;
518 
519 	if (!tbnet_available_buffers(ring))
520 		return NULL;
521 
522 	index = ring->cons++ & (TBNET_RING_SIZE - 1);
523 
524 	tf = &ring->frames[index];
525 	tf->frame.size = 0;
526 
527 	dma_sync_single_for_cpu(dma_dev, tf->frame.buffer_phy,
528 				tbnet_frame_size(tf), DMA_TO_DEVICE);
529 
530 	return tf;
531 }
532 
tbnet_tx_callback(struct tb_ring * ring,struct ring_frame * frame,bool canceled)533 static void tbnet_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
534 			      bool canceled)
535 {
536 	struct tbnet_frame *tf = container_of(frame, typeof(*tf), frame);
537 	struct tbnet *net = netdev_priv(tf->dev);
538 
539 	/* Return buffer to the ring */
540 	net->tx_ring.prod++;
541 
542 	if (tbnet_available_buffers(&net->tx_ring) >= TBNET_RING_SIZE / 2)
543 		netif_wake_queue(net->dev);
544 }
545 
tbnet_alloc_tx_buffers(struct tbnet * net)546 static int tbnet_alloc_tx_buffers(struct tbnet *net)
547 {
548 	struct tbnet_ring *ring = &net->tx_ring;
549 	struct device *dma_dev = tb_ring_dma_device(ring->ring);
550 	unsigned int i;
551 
552 	for (i = 0; i < TBNET_RING_SIZE; i++) {
553 		struct tbnet_frame *tf = &ring->frames[i];
554 		dma_addr_t dma_addr;
555 
556 		tf->page = alloc_page(GFP_KERNEL);
557 		if (!tf->page) {
558 			tbnet_free_buffers(ring);
559 			return -ENOMEM;
560 		}
561 
562 		dma_addr = dma_map_page(dma_dev, tf->page, 0, TBNET_FRAME_SIZE,
563 					DMA_TO_DEVICE);
564 		if (dma_mapping_error(dma_dev, dma_addr)) {
565 			__free_page(tf->page);
566 			tf->page = NULL;
567 			tbnet_free_buffers(ring);
568 			return -ENOMEM;
569 		}
570 
571 		tf->dev = net->dev;
572 		tf->frame.buffer_phy = dma_addr;
573 		tf->frame.callback = tbnet_tx_callback;
574 		tf->frame.sof = TBIP_PDF_FRAME_START;
575 		tf->frame.eof = TBIP_PDF_FRAME_END;
576 	}
577 
578 	ring->cons = 0;
579 	ring->prod = TBNET_RING_SIZE - 1;
580 
581 	return 0;
582 }
583 
tbnet_connected_work(struct work_struct * work)584 static void tbnet_connected_work(struct work_struct *work)
585 {
586 	struct tbnet *net = container_of(work, typeof(*net), connected_work);
587 	bool connected;
588 	int ret;
589 
590 	if (netif_carrier_ok(net->dev))
591 		return;
592 
593 	mutex_lock(&net->connection_lock);
594 	connected = net->login_sent && net->login_received;
595 	mutex_unlock(&net->connection_lock);
596 
597 	if (!connected)
598 		return;
599 
600 	/* Both logins successful so enable the high-speed DMA paths and
601 	 * start the network device queue.
602 	 */
603 	ret = tb_xdomain_enable_paths(net->xd, TBNET_LOCAL_PATH,
604 				      net->rx_ring.ring->hop,
605 				      net->transmit_path,
606 				      net->tx_ring.ring->hop);
607 	if (ret) {
608 		netdev_err(net->dev, "failed to enable DMA paths\n");
609 		return;
610 	}
611 
612 	tb_ring_start(net->tx_ring.ring);
613 	tb_ring_start(net->rx_ring.ring);
614 
615 	ret = tbnet_alloc_rx_buffers(net, TBNET_RING_SIZE);
616 	if (ret)
617 		goto err_stop_rings;
618 
619 	ret = tbnet_alloc_tx_buffers(net);
620 	if (ret)
621 		goto err_free_rx_buffers;
622 
623 	netif_carrier_on(net->dev);
624 	netif_start_queue(net->dev);
625 	return;
626 
627 err_free_rx_buffers:
628 	tbnet_free_buffers(&net->rx_ring);
629 err_stop_rings:
630 	tb_ring_stop(net->rx_ring.ring);
631 	tb_ring_stop(net->tx_ring.ring);
632 }
633 
tbnet_login_work(struct work_struct * work)634 static void tbnet_login_work(struct work_struct *work)
635 {
636 	struct tbnet *net = container_of(work, typeof(*net), login_work.work);
637 	unsigned long delay = msecs_to_jiffies(TBNET_LOGIN_DELAY);
638 	int ret;
639 
640 	if (netif_carrier_ok(net->dev))
641 		return;
642 
643 	ret = tbnet_login_request(net, net->login_retries % 4);
644 	if (ret) {
645 		if (net->login_retries++ < TBNET_LOGIN_RETRIES) {
646 			queue_delayed_work(system_long_wq, &net->login_work,
647 					   delay);
648 		} else {
649 			netdev_info(net->dev, "ThunderboltIP login timed out\n");
650 		}
651 	} else {
652 		net->login_retries = 0;
653 
654 		mutex_lock(&net->connection_lock);
655 		net->login_sent = true;
656 		mutex_unlock(&net->connection_lock);
657 
658 		queue_work(system_long_wq, &net->connected_work);
659 	}
660 }
661 
tbnet_disconnect_work(struct work_struct * work)662 static void tbnet_disconnect_work(struct work_struct *work)
663 {
664 	struct tbnet *net = container_of(work, typeof(*net), disconnect_work);
665 
666 	tbnet_tear_down(net, false);
667 }
668 
tbnet_check_frame(struct tbnet * net,const struct tbnet_frame * tf,const struct thunderbolt_ip_frame_header * hdr)669 static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,
670 			      const struct thunderbolt_ip_frame_header *hdr)
671 {
672 	u32 frame_id, frame_count, frame_size, frame_index;
673 	unsigned int size;
674 
675 	if (tf->frame.flags & RING_DESC_CRC_ERROR) {
676 		net->stats.rx_crc_errors++;
677 		return false;
678 	} else if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN) {
679 		net->stats.rx_over_errors++;
680 		return false;
681 	}
682 
683 	/* Should be greater than just header i.e. contains data */
684 	size = tbnet_frame_size(tf);
685 	if (size <= sizeof(*hdr)) {
686 		net->stats.rx_length_errors++;
687 		return false;
688 	}
689 
690 	frame_count = le32_to_cpu(hdr->frame_count);
691 	frame_size = le32_to_cpu(hdr->frame_size);
692 	frame_index = le16_to_cpu(hdr->frame_index);
693 	frame_id = le16_to_cpu(hdr->frame_id);
694 
695 	if ((frame_size > size - sizeof(*hdr)) || !frame_size) {
696 		net->stats.rx_length_errors++;
697 		return false;
698 	}
699 
700 	/* In case we're in the middle of packet, validate the frame
701 	 * header based on first fragment of the packet.
702 	 */
703 	if (net->skb && net->rx_hdr.frame_count) {
704 		/* Check the frame count fits the count field */
705 		if (frame_count != net->rx_hdr.frame_count) {
706 			net->stats.rx_length_errors++;
707 			return false;
708 		}
709 
710 		/* Check the frame identifiers are incremented correctly,
711 		 * and id is matching.
712 		 */
713 		if (frame_index != net->rx_hdr.frame_index + 1 ||
714 		    frame_id != net->rx_hdr.frame_id) {
715 			net->stats.rx_missed_errors++;
716 			return false;
717 		}
718 
719 		if (net->skb->len + frame_size > TBNET_MAX_MTU) {
720 			net->stats.rx_length_errors++;
721 			return false;
722 		}
723 
724 		return true;
725 	}
726 
727 	/* Start of packet, validate the frame header */
728 	if (frame_count == 0 || frame_count > TBNET_RING_SIZE / 4) {
729 		net->stats.rx_length_errors++;
730 		return false;
731 	}
732 	if (frame_index != 0) {
733 		net->stats.rx_missed_errors++;
734 		return false;
735 	}
736 
737 	return true;
738 }
739 
tbnet_poll(struct napi_struct * napi,int budget)740 static int tbnet_poll(struct napi_struct *napi, int budget)
741 {
742 	struct tbnet *net = container_of(napi, struct tbnet, napi);
743 	unsigned int cleaned_count = tbnet_available_buffers(&net->rx_ring);
744 	struct device *dma_dev = tb_ring_dma_device(net->rx_ring.ring);
745 	unsigned int rx_packets = 0;
746 
747 	while (rx_packets < budget) {
748 		const struct thunderbolt_ip_frame_header *hdr;
749 		unsigned int hdr_size = sizeof(*hdr);
750 		struct sk_buff *skb = NULL;
751 		struct ring_frame *frame;
752 		struct tbnet_frame *tf;
753 		struct page *page;
754 		bool last = true;
755 		u32 frame_size;
756 
757 		/* Return some buffers to hardware, one at a time is too
758 		 * slow so allocate MAX_SKB_FRAGS buffers at the same
759 		 * time.
760 		 */
761 		if (cleaned_count >= MAX_SKB_FRAGS) {
762 			tbnet_alloc_rx_buffers(net, cleaned_count);
763 			cleaned_count = 0;
764 		}
765 
766 		frame = tb_ring_poll(net->rx_ring.ring);
767 		if (!frame)
768 			break;
769 
770 		dma_unmap_page(dma_dev, frame->buffer_phy,
771 			       TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
772 
773 		tf = container_of(frame, typeof(*tf), frame);
774 
775 		page = tf->page;
776 		tf->page = NULL;
777 		net->rx_ring.cons++;
778 		cleaned_count++;
779 
780 		hdr = page_address(page);
781 		if (!tbnet_check_frame(net, tf, hdr)) {
782 			__free_pages(page, TBNET_RX_PAGE_ORDER);
783 			dev_kfree_skb_any(net->skb);
784 			net->skb = NULL;
785 			continue;
786 		}
787 
788 		frame_size = le32_to_cpu(hdr->frame_size);
789 
790 		skb = net->skb;
791 		if (!skb) {
792 			skb = build_skb(page_address(page),
793 					TBNET_RX_PAGE_SIZE);
794 			if (!skb) {
795 				__free_pages(page, TBNET_RX_PAGE_ORDER);
796 				net->stats.rx_errors++;
797 				break;
798 			}
799 
800 			skb_reserve(skb, hdr_size);
801 			skb_put(skb, frame_size);
802 
803 			net->skb = skb;
804 		} else {
805 			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
806 					page, hdr_size, frame_size,
807 					TBNET_RX_PAGE_SIZE - hdr_size);
808 		}
809 
810 		net->rx_hdr.frame_size = frame_size;
811 		net->rx_hdr.frame_count = le32_to_cpu(hdr->frame_count);
812 		net->rx_hdr.frame_index = le16_to_cpu(hdr->frame_index);
813 		net->rx_hdr.frame_id = le16_to_cpu(hdr->frame_id);
814 		last = net->rx_hdr.frame_index == net->rx_hdr.frame_count - 1;
815 
816 		rx_packets++;
817 		net->stats.rx_bytes += frame_size;
818 
819 		if (last) {
820 			skb->protocol = eth_type_trans(skb, net->dev);
821 			napi_gro_receive(&net->napi, skb);
822 			net->skb = NULL;
823 		}
824 	}
825 
826 	net->stats.rx_packets += rx_packets;
827 
828 	if (cleaned_count)
829 		tbnet_alloc_rx_buffers(net, cleaned_count);
830 
831 	if (rx_packets >= budget)
832 		return budget;
833 
834 	napi_complete_done(napi, rx_packets);
835 	/* Re-enable the ring interrupt */
836 	tb_ring_poll_complete(net->rx_ring.ring);
837 
838 	return rx_packets;
839 }
840 
tbnet_start_poll(void * data)841 static void tbnet_start_poll(void *data)
842 {
843 	struct tbnet *net = data;
844 
845 	napi_schedule(&net->napi);
846 }
847 
tbnet_open(struct net_device * dev)848 static int tbnet_open(struct net_device *dev)
849 {
850 	struct tbnet *net = netdev_priv(dev);
851 	struct tb_xdomain *xd = net->xd;
852 	u16 sof_mask, eof_mask;
853 	struct tb_ring *ring;
854 
855 	netif_carrier_off(dev);
856 
857 	ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE,
858 				RING_FLAG_FRAME);
859 	if (!ring) {
860 		netdev_err(dev, "failed to allocate Tx ring\n");
861 		return -ENOMEM;
862 	}
863 	net->tx_ring.ring = ring;
864 
865 	sof_mask = BIT(TBIP_PDF_FRAME_START);
866 	eof_mask = BIT(TBIP_PDF_FRAME_END);
867 
868 	ring = tb_ring_alloc_rx(xd->tb->nhi, -1, TBNET_RING_SIZE,
869 				RING_FLAG_FRAME, sof_mask, eof_mask,
870 				tbnet_start_poll, net);
871 	if (!ring) {
872 		netdev_err(dev, "failed to allocate Rx ring\n");
873 		tb_ring_free(net->tx_ring.ring);
874 		net->tx_ring.ring = NULL;
875 		return -ENOMEM;
876 	}
877 	net->rx_ring.ring = ring;
878 
879 	napi_enable(&net->napi);
880 	start_login(net);
881 
882 	return 0;
883 }
884 
tbnet_stop(struct net_device * dev)885 static int tbnet_stop(struct net_device *dev)
886 {
887 	struct tbnet *net = netdev_priv(dev);
888 
889 	napi_disable(&net->napi);
890 
891 	cancel_work_sync(&net->disconnect_work);
892 	tbnet_tear_down(net, true);
893 
894 	tb_ring_free(net->rx_ring.ring);
895 	net->rx_ring.ring = NULL;
896 	tb_ring_free(net->tx_ring.ring);
897 	net->tx_ring.ring = NULL;
898 
899 	return 0;
900 }
901 
tbnet_xmit_csum_and_map(struct tbnet * net,struct sk_buff * skb,struct tbnet_frame ** frames,u32 frame_count)902 static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
903 	struct tbnet_frame **frames, u32 frame_count)
904 {
905 	struct thunderbolt_ip_frame_header *hdr = page_address(frames[0]->page);
906 	struct device *dma_dev = tb_ring_dma_device(net->tx_ring.ring);
907 	__wsum wsum = htonl(skb->len - skb_transport_offset(skb));
908 	unsigned int i, len, offset = skb_transport_offset(skb);
909 	__be16 protocol = skb->protocol;
910 	void *data = skb->data;
911 	void *dest = hdr + 1;
912 	__sum16 *tucso;
913 
914 	if (skb->ip_summed != CHECKSUM_PARTIAL) {
915 		/* No need to calculate checksum so we just update the
916 		 * total frame count and sync the frames for DMA.
917 		 */
918 		for (i = 0; i < frame_count; i++) {
919 			hdr = page_address(frames[i]->page);
920 			hdr->frame_count = cpu_to_le32(frame_count);
921 			dma_sync_single_for_device(dma_dev,
922 				frames[i]->frame.buffer_phy,
923 				tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
924 		}
925 
926 		return true;
927 	}
928 
929 	if (protocol == htons(ETH_P_8021Q)) {
930 		struct vlan_hdr *vhdr, vh;
931 
932 		vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(vh), &vh);
933 		if (!vhdr)
934 			return false;
935 
936 		protocol = vhdr->h_vlan_encapsulated_proto;
937 	}
938 
939 	/* Data points on the beginning of packet.
940 	 * Check is the checksum absolute place in the packet.
941 	 * ipcso will update IP checksum.
942 	 * tucso will update TCP/UPD checksum.
943 	 */
944 	if (protocol == htons(ETH_P_IP)) {
945 		__sum16 *ipcso = dest + ((void *)&(ip_hdr(skb)->check) - data);
946 
947 		*ipcso = 0;
948 		*ipcso = ip_fast_csum(dest + skb_network_offset(skb),
949 				      ip_hdr(skb)->ihl);
950 
951 		if (ip_hdr(skb)->protocol == IPPROTO_TCP)
952 			tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
953 		else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
954 			tucso = dest + ((void *)&(udp_hdr(skb)->check) - data);
955 		else
956 			return false;
957 
958 		*tucso = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
959 					    ip_hdr(skb)->daddr, 0,
960 					    ip_hdr(skb)->protocol, 0);
961 	} else if (skb_is_gso(skb) && skb_is_gso_v6(skb)) {
962 		tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
963 		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
964 					  &ipv6_hdr(skb)->daddr, 0,
965 					  IPPROTO_TCP, 0);
966 	} else if (protocol == htons(ETH_P_IPV6)) {
967 		tucso = dest + skb_checksum_start_offset(skb) + skb->csum_offset;
968 		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
969 					  &ipv6_hdr(skb)->daddr, 0,
970 					  ipv6_hdr(skb)->nexthdr, 0);
971 	} else {
972 		return false;
973 	}
974 
975 	/* First frame was headers, rest of the frames contain data.
976 	 * Calculate checksum over each frame.
977 	 */
978 	for (i = 0; i < frame_count; i++) {
979 		hdr = page_address(frames[i]->page);
980 		dest = (void *)(hdr + 1) + offset;
981 		len = le32_to_cpu(hdr->frame_size) - offset;
982 		wsum = csum_partial(dest, len, wsum);
983 		hdr->frame_count = cpu_to_le32(frame_count);
984 
985 		offset = 0;
986 	}
987 
988 	*tucso = csum_fold(wsum);
989 
990 	/* Checksum is finally calculated and we don't touch the memory
991 	 * anymore, so DMA sync the frames now.
992 	 */
993 	for (i = 0; i < frame_count; i++) {
994 		dma_sync_single_for_device(dma_dev, frames[i]->frame.buffer_phy,
995 			tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
996 	}
997 
998 	return true;
999 }
1000 
tbnet_kmap_frag(struct sk_buff * skb,unsigned int frag_num,unsigned int * len)1001 static void *tbnet_kmap_frag(struct sk_buff *skb, unsigned int frag_num,
1002 			     unsigned int *len)
1003 {
1004 	const skb_frag_t *frag = &skb_shinfo(skb)->frags[frag_num];
1005 
1006 	*len = skb_frag_size(frag);
1007 	return kmap_atomic(skb_frag_page(frag)) + skb_frag_off(frag);
1008 }
1009 
tbnet_start_xmit(struct sk_buff * skb,struct net_device * dev)1010 static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
1011 				    struct net_device *dev)
1012 {
1013 	struct tbnet *net = netdev_priv(dev);
1014 	struct tbnet_frame *frames[MAX_SKB_FRAGS];
1015 	u16 frame_id = atomic_read(&net->frame_id);
1016 	struct thunderbolt_ip_frame_header *hdr;
1017 	unsigned int len = skb_headlen(skb);
1018 	unsigned int data_len = skb->len;
1019 	unsigned int nframes, i;
1020 	unsigned int frag = 0;
1021 	void *src = skb->data;
1022 	u32 frame_index = 0;
1023 	bool unmap = false;
1024 	void *dest;
1025 
1026 	nframes = DIV_ROUND_UP(data_len, TBNET_MAX_PAYLOAD_SIZE);
1027 	if (tbnet_available_buffers(&net->tx_ring) < nframes) {
1028 		netif_stop_queue(net->dev);
1029 		return NETDEV_TX_BUSY;
1030 	}
1031 
1032 	frames[frame_index] = tbnet_get_tx_buffer(net);
1033 	if (!frames[frame_index])
1034 		goto err_drop;
1035 
1036 	hdr = page_address(frames[frame_index]->page);
1037 	dest = hdr + 1;
1038 
1039 	/* If overall packet is bigger than the frame data size */
1040 	while (data_len > TBNET_MAX_PAYLOAD_SIZE) {
1041 		unsigned int size_left = TBNET_MAX_PAYLOAD_SIZE;
1042 
1043 		hdr->frame_size = cpu_to_le32(TBNET_MAX_PAYLOAD_SIZE);
1044 		hdr->frame_index = cpu_to_le16(frame_index);
1045 		hdr->frame_id = cpu_to_le16(frame_id);
1046 
1047 		do {
1048 			if (len > size_left) {
1049 				/* Copy data onto Tx buffer data with
1050 				 * full frame size then break and go to
1051 				 * next frame
1052 				 */
1053 				memcpy(dest, src, size_left);
1054 				len -= size_left;
1055 				dest += size_left;
1056 				src += size_left;
1057 				break;
1058 			}
1059 
1060 			memcpy(dest, src, len);
1061 			size_left -= len;
1062 			dest += len;
1063 
1064 			if (unmap) {
1065 				kunmap_atomic(src);
1066 				unmap = false;
1067 			}
1068 
1069 			/* Ensure all fragments have been processed */
1070 			if (frag < skb_shinfo(skb)->nr_frags) {
1071 				/* Map and then unmap quickly */
1072 				src = tbnet_kmap_frag(skb, frag++, &len);
1073 				unmap = true;
1074 			} else if (unlikely(size_left > 0)) {
1075 				goto err_drop;
1076 			}
1077 		} while (size_left > 0);
1078 
1079 		data_len -= TBNET_MAX_PAYLOAD_SIZE;
1080 		frame_index++;
1081 
1082 		frames[frame_index] = tbnet_get_tx_buffer(net);
1083 		if (!frames[frame_index])
1084 			goto err_drop;
1085 
1086 		hdr = page_address(frames[frame_index]->page);
1087 		dest = hdr + 1;
1088 	}
1089 
1090 	hdr->frame_size = cpu_to_le32(data_len);
1091 	hdr->frame_index = cpu_to_le16(frame_index);
1092 	hdr->frame_id = cpu_to_le16(frame_id);
1093 
1094 	frames[frame_index]->frame.size = data_len + sizeof(*hdr);
1095 
1096 	/* In case the remaining data_len is smaller than a frame */
1097 	while (len < data_len) {
1098 		memcpy(dest, src, len);
1099 		data_len -= len;
1100 		dest += len;
1101 
1102 		if (unmap) {
1103 			kunmap_atomic(src);
1104 			unmap = false;
1105 		}
1106 
1107 		if (frag < skb_shinfo(skb)->nr_frags) {
1108 			src = tbnet_kmap_frag(skb, frag++, &len);
1109 			unmap = true;
1110 		} else if (unlikely(data_len > 0)) {
1111 			goto err_drop;
1112 		}
1113 	}
1114 
1115 	memcpy(dest, src, data_len);
1116 
1117 	if (unmap)
1118 		kunmap_atomic(src);
1119 
1120 	if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1))
1121 		goto err_drop;
1122 
1123 	for (i = 0; i < frame_index + 1; i++)
1124 		tb_ring_tx(net->tx_ring.ring, &frames[i]->frame);
1125 
1126 	if (net->svc->prtcstns & TBNET_MATCH_FRAGS_ID)
1127 		atomic_inc(&net->frame_id);
1128 
1129 	net->stats.tx_packets++;
1130 	net->stats.tx_bytes += skb->len;
1131 
1132 	dev_consume_skb_any(skb);
1133 
1134 	return NETDEV_TX_OK;
1135 
1136 err_drop:
1137 	/* We can re-use the buffers */
1138 	net->tx_ring.cons -= frame_index;
1139 
1140 	dev_kfree_skb_any(skb);
1141 	net->stats.tx_errors++;
1142 
1143 	return NETDEV_TX_OK;
1144 }
1145 
tbnet_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * stats)1146 static void tbnet_get_stats64(struct net_device *dev,
1147 			      struct rtnl_link_stats64 *stats)
1148 {
1149 	struct tbnet *net = netdev_priv(dev);
1150 
1151 	stats->tx_packets = net->stats.tx_packets;
1152 	stats->rx_packets = net->stats.rx_packets;
1153 	stats->tx_bytes = net->stats.tx_bytes;
1154 	stats->rx_bytes = net->stats.rx_bytes;
1155 	stats->rx_errors = net->stats.rx_errors + net->stats.rx_length_errors +
1156 		net->stats.rx_over_errors + net->stats.rx_crc_errors +
1157 		net->stats.rx_missed_errors;
1158 	stats->tx_errors = net->stats.tx_errors;
1159 	stats->rx_length_errors = net->stats.rx_length_errors;
1160 	stats->rx_over_errors = net->stats.rx_over_errors;
1161 	stats->rx_crc_errors = net->stats.rx_crc_errors;
1162 	stats->rx_missed_errors = net->stats.rx_missed_errors;
1163 }
1164 
1165 static const struct net_device_ops tbnet_netdev_ops = {
1166 	.ndo_open = tbnet_open,
1167 	.ndo_stop = tbnet_stop,
1168 	.ndo_start_xmit = tbnet_start_xmit,
1169 	.ndo_get_stats64 = tbnet_get_stats64,
1170 };
1171 
tbnet_generate_mac(struct net_device * dev)1172 static void tbnet_generate_mac(struct net_device *dev)
1173 {
1174 	const struct tbnet *net = netdev_priv(dev);
1175 	const struct tb_xdomain *xd = net->xd;
1176 	u8 phy_port;
1177 	u32 hash;
1178 
1179 	phy_port = tb_phy_port_from_link(TBNET_L0_PORT_NUM(xd->route));
1180 
1181 	/* Unicast and locally administered MAC */
1182 	dev->dev_addr[0] = phy_port << 4 | 0x02;
1183 	hash = jhash2((u32 *)xd->local_uuid, 4, 0);
1184 	memcpy(dev->dev_addr + 1, &hash, sizeof(hash));
1185 	hash = jhash2((u32 *)xd->local_uuid, 4, hash);
1186 	dev->dev_addr[5] = hash & 0xff;
1187 }
1188 
tbnet_probe(struct tb_service * svc,const struct tb_service_id * id)1189 static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
1190 {
1191 	struct tb_xdomain *xd = tb_service_parent(svc);
1192 	struct net_device *dev;
1193 	struct tbnet *net;
1194 	int ret;
1195 
1196 	dev = alloc_etherdev(sizeof(*net));
1197 	if (!dev)
1198 		return -ENOMEM;
1199 
1200 	SET_NETDEV_DEV(dev, &svc->dev);
1201 
1202 	net = netdev_priv(dev);
1203 	INIT_DELAYED_WORK(&net->login_work, tbnet_login_work);
1204 	INIT_WORK(&net->connected_work, tbnet_connected_work);
1205 	INIT_WORK(&net->disconnect_work, tbnet_disconnect_work);
1206 	mutex_init(&net->connection_lock);
1207 	atomic_set(&net->command_id, 0);
1208 	atomic_set(&net->frame_id, 0);
1209 	net->svc = svc;
1210 	net->dev = dev;
1211 	net->xd = xd;
1212 
1213 	tbnet_generate_mac(dev);
1214 
1215 	strcpy(dev->name, "thunderbolt%d");
1216 	dev->netdev_ops = &tbnet_netdev_ops;
1217 
1218 	/* ThunderboltIP takes advantage of TSO packets but instead of
1219 	 * segmenting them we just split the packet into Thunderbolt
1220 	 * frames (maximum payload size of each frame is 4084 bytes) and
1221 	 * calculate checksum over the whole packet here.
1222 	 *
1223 	 * The receiving side does the opposite if the host OS supports
1224 	 * LRO, otherwise it needs to split the large packet into MTU
1225 	 * sized smaller packets.
1226 	 *
1227 	 * In order to receive large packets from the networking stack,
1228 	 * we need to announce support for most of the offloading
1229 	 * features here.
1230 	 */
1231 	dev->hw_features = NETIF_F_SG | NETIF_F_ALL_TSO | NETIF_F_GRO |
1232 			   NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
1233 	dev->features = dev->hw_features | NETIF_F_HIGHDMA;
1234 	dev->hard_header_len += sizeof(struct thunderbolt_ip_frame_header);
1235 
1236 	netif_napi_add(dev, &net->napi, tbnet_poll, NAPI_POLL_WEIGHT);
1237 
1238 	/* MTU range: 68 - 65522 */
1239 	dev->min_mtu = ETH_MIN_MTU;
1240 	dev->max_mtu = TBNET_MAX_MTU - ETH_HLEN;
1241 
1242 	net->handler.uuid = &tbnet_svc_uuid;
1243 	net->handler.callback = tbnet_handle_packet,
1244 	net->handler.data = net;
1245 	tb_register_protocol_handler(&net->handler);
1246 
1247 	tb_service_set_drvdata(svc, net);
1248 
1249 	ret = register_netdev(dev);
1250 	if (ret) {
1251 		tb_unregister_protocol_handler(&net->handler);
1252 		free_netdev(dev);
1253 		return ret;
1254 	}
1255 
1256 	return 0;
1257 }
1258 
tbnet_remove(struct tb_service * svc)1259 static void tbnet_remove(struct tb_service *svc)
1260 {
1261 	struct tbnet *net = tb_service_get_drvdata(svc);
1262 
1263 	unregister_netdev(net->dev);
1264 	tb_unregister_protocol_handler(&net->handler);
1265 	free_netdev(net->dev);
1266 }
1267 
tbnet_shutdown(struct tb_service * svc)1268 static void tbnet_shutdown(struct tb_service *svc)
1269 {
1270 	tbnet_tear_down(tb_service_get_drvdata(svc), true);
1271 }
1272 
tbnet_suspend(struct device * dev)1273 static int __maybe_unused tbnet_suspend(struct device *dev)
1274 {
1275 	struct tb_service *svc = tb_to_service(dev);
1276 	struct tbnet *net = tb_service_get_drvdata(svc);
1277 
1278 	stop_login(net);
1279 	if (netif_running(net->dev)) {
1280 		netif_device_detach(net->dev);
1281 		tbnet_tear_down(net, true);
1282 	}
1283 
1284 	tb_unregister_protocol_handler(&net->handler);
1285 	return 0;
1286 }
1287 
tbnet_resume(struct device * dev)1288 static int __maybe_unused tbnet_resume(struct device *dev)
1289 {
1290 	struct tb_service *svc = tb_to_service(dev);
1291 	struct tbnet *net = tb_service_get_drvdata(svc);
1292 
1293 	tb_register_protocol_handler(&net->handler);
1294 
1295 	netif_carrier_off(net->dev);
1296 	if (netif_running(net->dev)) {
1297 		netif_device_attach(net->dev);
1298 		start_login(net);
1299 	}
1300 
1301 	return 0;
1302 }
1303 
1304 static const struct dev_pm_ops tbnet_pm_ops = {
1305 	SET_SYSTEM_SLEEP_PM_OPS(tbnet_suspend, tbnet_resume)
1306 };
1307 
1308 static const struct tb_service_id tbnet_ids[] = {
1309 	{ TB_SERVICE("network", 1) },
1310 	{ },
1311 };
1312 MODULE_DEVICE_TABLE(tbsvc, tbnet_ids);
1313 
1314 static struct tb_service_driver tbnet_driver = {
1315 	.driver = {
1316 		.owner = THIS_MODULE,
1317 		.name = "thunderbolt-net",
1318 		.pm = &tbnet_pm_ops,
1319 	},
1320 	.probe = tbnet_probe,
1321 	.remove = tbnet_remove,
1322 	.shutdown = tbnet_shutdown,
1323 	.id_table = tbnet_ids,
1324 };
1325 
tbnet_init(void)1326 static int __init tbnet_init(void)
1327 {
1328 	int ret;
1329 
1330 	tbnet_dir = tb_property_create_dir(&tbnet_dir_uuid);
1331 	if (!tbnet_dir)
1332 		return -ENOMEM;
1333 
1334 	tb_property_add_immediate(tbnet_dir, "prtcid", 1);
1335 	tb_property_add_immediate(tbnet_dir, "prtcvers", 1);
1336 	tb_property_add_immediate(tbnet_dir, "prtcrevs", 1);
1337 	/* Currently only announce support for match frags ID (bit 1). Bit 0
1338 	 * is reserved for full E2E flow control which we do not support at
1339 	 * the moment.
1340 	 */
1341 	tb_property_add_immediate(tbnet_dir, "prtcstns",
1342 				  TBNET_MATCH_FRAGS_ID);
1343 
1344 	ret = tb_register_property_dir("network", tbnet_dir);
1345 	if (ret)
1346 		goto err_free_dir;
1347 
1348 	ret = tb_register_service_driver(&tbnet_driver);
1349 	if (ret)
1350 		goto err_unregister;
1351 
1352 	return 0;
1353 
1354 err_unregister:
1355 	tb_unregister_property_dir("network", tbnet_dir);
1356 err_free_dir:
1357 	tb_property_free_dir(tbnet_dir);
1358 
1359 	return ret;
1360 }
1361 module_init(tbnet_init);
1362 
tbnet_exit(void)1363 static void __exit tbnet_exit(void)
1364 {
1365 	tb_unregister_service_driver(&tbnet_driver);
1366 	tb_unregister_property_dir("network", tbnet_dir);
1367 	tb_property_free_dir(tbnet_dir);
1368 }
1369 module_exit(tbnet_exit);
1370 
1371 MODULE_AUTHOR("Amir Levy <amir.jer.levy@intel.com>");
1372 MODULE_AUTHOR("Michael Jamet <michael.jamet@intel.com>");
1373 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
1374 MODULE_DESCRIPTION("Thunderbolt network driver");
1375 MODULE_LICENSE("GPL v2");
1376