xref: /linux/drivers/thunderbolt/tunnel.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Thunderbolt driver - Tunneling support
4  *
5  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
6  * Copyright (C) 2019, Intel Corporation
7  */
8 
9 #include <linux/slab.h>
10 #include <linux/list.h>
11 
12 #include "tunnel.h"
13 #include "tb.h"
14 
15 /* PCIe adapters use always HopID of 8 for both directions */
16 #define TB_PCI_HOPID			8
17 
18 #define TB_PCI_PATH_DOWN		0
19 #define TB_PCI_PATH_UP			1
20 
21 /* DP adapters use HopID 8 for AUX and 9 for Video */
22 #define TB_DP_AUX_TX_HOPID		8
23 #define TB_DP_AUX_RX_HOPID		8
24 #define TB_DP_VIDEO_HOPID		9
25 
26 #define TB_DP_VIDEO_PATH_OUT		0
27 #define TB_DP_AUX_PATH_OUT		1
28 #define TB_DP_AUX_PATH_IN		2
29 
30 #define TB_DMA_PATH_OUT			0
31 #define TB_DMA_PATH_IN			1
32 
33 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA" };
34 
35 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
36 	do {                                                            \
37 		struct tb_tunnel *__tunnel = (tunnel);                  \
38 		level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
39 		      tb_route(__tunnel->src_port->sw),                 \
40 		      __tunnel->src_port->port,                         \
41 		      tb_route(__tunnel->dst_port->sw),                 \
42 		      __tunnel->dst_port->port,                         \
43 		      tb_tunnel_names[__tunnel->type],			\
44 		      ## arg);                                          \
45 	} while (0)
46 
47 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
48 	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
49 #define tb_tunnel_warn(tunnel, fmt, arg...) \
50 	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
51 #define tb_tunnel_info(tunnel, fmt, arg...) \
52 	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
53 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
54 	__TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
55 
56 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
57 					 enum tb_tunnel_type type)
58 {
59 	struct tb_tunnel *tunnel;
60 
61 	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
62 	if (!tunnel)
63 		return NULL;
64 
65 	tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
66 	if (!tunnel->paths) {
67 		tb_tunnel_free(tunnel);
68 		return NULL;
69 	}
70 
71 	INIT_LIST_HEAD(&tunnel->list);
72 	tunnel->tb = tb;
73 	tunnel->npaths = npaths;
74 	tunnel->type = type;
75 
76 	return tunnel;
77 }
78 
79 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
80 {
81 	int res;
82 
83 	res = tb_pci_port_enable(tunnel->src_port, activate);
84 	if (res)
85 		return res;
86 
87 	if (tb_port_is_pcie_up(tunnel->dst_port))
88 		return tb_pci_port_enable(tunnel->dst_port, activate);
89 
90 	return 0;
91 }
92 
93 static void tb_pci_init_path(struct tb_path *path)
94 {
95 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
96 	path->egress_shared_buffer = TB_PATH_NONE;
97 	path->ingress_fc_enable = TB_PATH_ALL;
98 	path->ingress_shared_buffer = TB_PATH_NONE;
99 	path->priority = 3;
100 	path->weight = 1;
101 	path->drop_packages = 0;
102 	path->nfc_credits = 0;
103 	path->hops[0].initial_credits = 7;
104 	path->hops[1].initial_credits = 16;
105 }
106 
107 /**
108  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
109  * @tb: Pointer to the domain structure
110  * @down: PCIe downstream adapter
111  *
112  * If @down adapter is active, follows the tunnel to the PCIe upstream
113  * adapter and back. Returns the discovered tunnel or %NULL if there was
114  * no tunnel.
115  */
116 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
117 {
118 	struct tb_tunnel *tunnel;
119 	struct tb_path *path;
120 
121 	if (!tb_pci_port_is_enabled(down))
122 		return NULL;
123 
124 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
125 	if (!tunnel)
126 		return NULL;
127 
128 	tunnel->activate = tb_pci_activate;
129 	tunnel->src_port = down;
130 
131 	/*
132 	 * Discover both paths even if they are not complete. We will
133 	 * clean them up by calling tb_tunnel_deactivate() below in that
134 	 * case.
135 	 */
136 	path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
137 				&tunnel->dst_port, "PCIe Up");
138 	if (!path) {
139 		/* Just disable the downstream port */
140 		tb_pci_port_enable(down, false);
141 		goto err_free;
142 	}
143 	tunnel->paths[TB_PCI_PATH_UP] = path;
144 	tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
145 
146 	path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
147 				"PCIe Down");
148 	if (!path)
149 		goto err_deactivate;
150 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
151 	tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
152 
153 	/* Validate that the tunnel is complete */
154 	if (!tb_port_is_pcie_up(tunnel->dst_port)) {
155 		tb_port_warn(tunnel->dst_port,
156 			     "path does not end on a PCIe adapter, cleaning up\n");
157 		goto err_deactivate;
158 	}
159 
160 	if (down != tunnel->src_port) {
161 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
162 		goto err_deactivate;
163 	}
164 
165 	if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
166 		tb_tunnel_warn(tunnel,
167 			       "tunnel is not fully activated, cleaning up\n");
168 		goto err_deactivate;
169 	}
170 
171 	tb_tunnel_dbg(tunnel, "discovered\n");
172 	return tunnel;
173 
174 err_deactivate:
175 	tb_tunnel_deactivate(tunnel);
176 err_free:
177 	tb_tunnel_free(tunnel);
178 
179 	return NULL;
180 }
181 
182 /**
183  * tb_tunnel_alloc_pci() - allocate a pci tunnel
184  * @tb: Pointer to the domain structure
185  * @up: PCIe upstream adapter port
186  * @down: PCIe downstream adapter port
187  *
188  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
189  * TB_TYPE_PCIE_DOWN.
190  *
191  * Return: Returns a tb_tunnel on success or NULL on failure.
192  */
193 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
194 				      struct tb_port *down)
195 {
196 	struct tb_tunnel *tunnel;
197 	struct tb_path *path;
198 
199 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
200 	if (!tunnel)
201 		return NULL;
202 
203 	tunnel->activate = tb_pci_activate;
204 	tunnel->src_port = down;
205 	tunnel->dst_port = up;
206 
207 	path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
208 			     "PCIe Down");
209 	if (!path) {
210 		tb_tunnel_free(tunnel);
211 		return NULL;
212 	}
213 	tb_pci_init_path(path);
214 	tunnel->paths[TB_PCI_PATH_UP] = path;
215 
216 	path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
217 			     "PCIe Up");
218 	if (!path) {
219 		tb_tunnel_free(tunnel);
220 		return NULL;
221 	}
222 	tb_pci_init_path(path);
223 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
224 
225 	return tunnel;
226 }
227 
228 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
229 {
230 	struct tb_port *out = tunnel->dst_port;
231 	struct tb_port *in = tunnel->src_port;
232 	u32 in_dp_cap, out_dp_cap;
233 	int ret;
234 
235 	/*
236 	 * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
237 	 * newer generation hardware.
238 	 */
239 	if (in->sw->generation < 2 || out->sw->generation < 2)
240 		return 0;
241 
242 	/* Read both DP_LOCAL_CAP registers */
243 	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
244 			   in->cap_adap + TB_DP_LOCAL_CAP, 1);
245 	if (ret)
246 		return ret;
247 
248 	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
249 			   out->cap_adap + TB_DP_LOCAL_CAP, 1);
250 	if (ret)
251 		return ret;
252 
253 	/* Write IN local caps to OUT remote caps */
254 	ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
255 			    out->cap_adap + TB_DP_REMOTE_CAP, 1);
256 	if (ret)
257 		return ret;
258 
259 	return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
260 			     in->cap_adap + TB_DP_REMOTE_CAP, 1);
261 }
262 
263 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
264 {
265 	int ret;
266 
267 	if (active) {
268 		struct tb_path **paths;
269 		int last;
270 
271 		paths = tunnel->paths;
272 		last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
273 
274 		tb_dp_port_set_hops(tunnel->src_port,
275 			paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
276 			paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
277 			paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
278 
279 		tb_dp_port_set_hops(tunnel->dst_port,
280 			paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
281 			paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
282 			paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
283 	} else {
284 		tb_dp_port_hpd_clear(tunnel->src_port);
285 		tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
286 		if (tb_port_is_dpout(tunnel->dst_port))
287 			tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
288 	}
289 
290 	ret = tb_dp_port_enable(tunnel->src_port, active);
291 	if (ret)
292 		return ret;
293 
294 	if (tb_port_is_dpout(tunnel->dst_port))
295 		return tb_dp_port_enable(tunnel->dst_port, active);
296 
297 	return 0;
298 }
299 
300 static void tb_dp_init_aux_path(struct tb_path *path)
301 {
302 	int i;
303 
304 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
305 	path->egress_shared_buffer = TB_PATH_NONE;
306 	path->ingress_fc_enable = TB_PATH_ALL;
307 	path->ingress_shared_buffer = TB_PATH_NONE;
308 	path->priority = 2;
309 	path->weight = 1;
310 
311 	for (i = 0; i < path->path_length; i++)
312 		path->hops[i].initial_credits = 1;
313 }
314 
315 static void tb_dp_init_video_path(struct tb_path *path, bool discover)
316 {
317 	u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
318 
319 	path->egress_fc_enable = TB_PATH_NONE;
320 	path->egress_shared_buffer = TB_PATH_NONE;
321 	path->ingress_fc_enable = TB_PATH_NONE;
322 	path->ingress_shared_buffer = TB_PATH_NONE;
323 	path->priority = 1;
324 	path->weight = 1;
325 
326 	if (discover) {
327 		path->nfc_credits = nfc_credits & TB_PORT_NFC_CREDITS_MASK;
328 	} else {
329 		u32 max_credits;
330 
331 		max_credits = (nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
332 			TB_PORT_MAX_CREDITS_SHIFT;
333 		/* Leave some credits for AUX path */
334 		path->nfc_credits = min(max_credits - 2, 12U);
335 	}
336 }
337 
338 /**
339  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
340  * @tb: Pointer to the domain structure
341  * @in: DP in adapter
342  *
343  * If @in adapter is active, follows the tunnel to the DP out adapter
344  * and back. Returns the discovered tunnel or %NULL if there was no
345  * tunnel.
346  *
347  * Return: DP tunnel or %NULL if no tunnel found.
348  */
349 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
350 {
351 	struct tb_tunnel *tunnel;
352 	struct tb_port *port;
353 	struct tb_path *path;
354 
355 	if (!tb_dp_port_is_enabled(in))
356 		return NULL;
357 
358 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
359 	if (!tunnel)
360 		return NULL;
361 
362 	tunnel->init = tb_dp_xchg_caps;
363 	tunnel->activate = tb_dp_activate;
364 	tunnel->src_port = in;
365 
366 	path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
367 				&tunnel->dst_port, "Video");
368 	if (!path) {
369 		/* Just disable the DP IN port */
370 		tb_dp_port_enable(in, false);
371 		goto err_free;
372 	}
373 	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
374 	tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
375 
376 	path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
377 	if (!path)
378 		goto err_deactivate;
379 	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
380 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
381 
382 	path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
383 				&port, "AUX RX");
384 	if (!path)
385 		goto err_deactivate;
386 	tunnel->paths[TB_DP_AUX_PATH_IN] = path;
387 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
388 
389 	/* Validate that the tunnel is complete */
390 	if (!tb_port_is_dpout(tunnel->dst_port)) {
391 		tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
392 		goto err_deactivate;
393 	}
394 
395 	if (!tb_dp_port_is_enabled(tunnel->dst_port))
396 		goto err_deactivate;
397 
398 	if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
399 		goto err_deactivate;
400 
401 	if (port != tunnel->src_port) {
402 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
403 		goto err_deactivate;
404 	}
405 
406 	tb_tunnel_dbg(tunnel, "discovered\n");
407 	return tunnel;
408 
409 err_deactivate:
410 	tb_tunnel_deactivate(tunnel);
411 err_free:
412 	tb_tunnel_free(tunnel);
413 
414 	return NULL;
415 }
416 
417 /**
418  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
419  * @tb: Pointer to the domain structure
420  * @in: DP in adapter port
421  * @out: DP out adapter port
422  *
423  * Allocates a tunnel between @in and @out that is capable of tunneling
424  * Display Port traffic.
425  *
426  * Return: Returns a tb_tunnel on success or NULL on failure.
427  */
428 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
429 				     struct tb_port *out)
430 {
431 	struct tb_tunnel *tunnel;
432 	struct tb_path **paths;
433 	struct tb_path *path;
434 
435 	if (WARN_ON(!in->cap_adap || !out->cap_adap))
436 		return NULL;
437 
438 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
439 	if (!tunnel)
440 		return NULL;
441 
442 	tunnel->init = tb_dp_xchg_caps;
443 	tunnel->activate = tb_dp_activate;
444 	tunnel->src_port = in;
445 	tunnel->dst_port = out;
446 
447 	paths = tunnel->paths;
448 
449 	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
450 			     1, "Video");
451 	if (!path)
452 		goto err_free;
453 	tb_dp_init_video_path(path, false);
454 	paths[TB_DP_VIDEO_PATH_OUT] = path;
455 
456 	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
457 			     TB_DP_AUX_TX_HOPID, 1, "AUX TX");
458 	if (!path)
459 		goto err_free;
460 	tb_dp_init_aux_path(path);
461 	paths[TB_DP_AUX_PATH_OUT] = path;
462 
463 	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
464 			     TB_DP_AUX_RX_HOPID, 1, "AUX RX");
465 	if (!path)
466 		goto err_free;
467 	tb_dp_init_aux_path(path);
468 	paths[TB_DP_AUX_PATH_IN] = path;
469 
470 	return tunnel;
471 
472 err_free:
473 	tb_tunnel_free(tunnel);
474 	return NULL;
475 }
476 
477 static u32 tb_dma_credits(struct tb_port *nhi)
478 {
479 	u32 max_credits;
480 
481 	max_credits = (nhi->config.nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
482 		TB_PORT_MAX_CREDITS_SHIFT;
483 	return min(max_credits, 13U);
484 }
485 
486 static int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
487 {
488 	struct tb_port *nhi = tunnel->src_port;
489 	u32 credits;
490 
491 	credits = active ? tb_dma_credits(nhi) : 0;
492 	return tb_port_set_initial_credits(nhi, credits);
493 }
494 
495 static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
496 			     unsigned int efc, u32 credits)
497 {
498 	int i;
499 
500 	path->egress_fc_enable = efc;
501 	path->ingress_fc_enable = TB_PATH_ALL;
502 	path->egress_shared_buffer = TB_PATH_NONE;
503 	path->ingress_shared_buffer = isb;
504 	path->priority = 5;
505 	path->weight = 1;
506 	path->clear_fc = true;
507 
508 	for (i = 0; i < path->path_length; i++)
509 		path->hops[i].initial_credits = credits;
510 }
511 
512 /**
513  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
514  * @tb: Pointer to the domain structure
515  * @nhi: Host controller port
516  * @dst: Destination null port which the other domain is connected to
517  * @transmit_ring: NHI ring number used to send packets towards the
518  *		   other domain
519  * @transmit_path: HopID used for transmitting packets
520  * @receive_ring: NHI ring number used to receive packets from the
521  *		  other domain
522  * @reveive_path: HopID used for receiving packets
523  *
524  * Return: Returns a tb_tunnel on success or NULL on failure.
525  */
526 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
527 				      struct tb_port *dst, int transmit_ring,
528 				      int transmit_path, int receive_ring,
529 				      int receive_path)
530 {
531 	struct tb_tunnel *tunnel;
532 	struct tb_path *path;
533 	u32 credits;
534 
535 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA);
536 	if (!tunnel)
537 		return NULL;
538 
539 	tunnel->activate = tb_dma_activate;
540 	tunnel->src_port = nhi;
541 	tunnel->dst_port = dst;
542 
543 	credits = tb_dma_credits(nhi);
544 
545 	path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, "DMA RX");
546 	if (!path) {
547 		tb_tunnel_free(tunnel);
548 		return NULL;
549 	}
550 	tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
551 			 credits);
552 	tunnel->paths[TB_DMA_PATH_IN] = path;
553 
554 	path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0, "DMA TX");
555 	if (!path) {
556 		tb_tunnel_free(tunnel);
557 		return NULL;
558 	}
559 	tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
560 	tunnel->paths[TB_DMA_PATH_OUT] = path;
561 
562 	return tunnel;
563 }
564 
565 /**
566  * tb_tunnel_free() - free a tunnel
567  * @tunnel: Tunnel to be freed
568  *
569  * Frees a tunnel. The tunnel does not need to be deactivated.
570  */
571 void tb_tunnel_free(struct tb_tunnel *tunnel)
572 {
573 	int i;
574 
575 	if (!tunnel)
576 		return;
577 
578 	for (i = 0; i < tunnel->npaths; i++) {
579 		if (tunnel->paths[i])
580 			tb_path_free(tunnel->paths[i]);
581 	}
582 
583 	kfree(tunnel->paths);
584 	kfree(tunnel);
585 }
586 
587 /**
588  * tb_tunnel_is_invalid - check whether an activated path is still valid
589  * @tunnel: Tunnel to check
590  */
591 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
592 {
593 	int i;
594 
595 	for (i = 0; i < tunnel->npaths; i++) {
596 		WARN_ON(!tunnel->paths[i]->activated);
597 		if (tb_path_is_invalid(tunnel->paths[i]))
598 			return true;
599 	}
600 
601 	return false;
602 }
603 
604 /**
605  * tb_tunnel_restart() - activate a tunnel after a hardware reset
606  * @tunnel: Tunnel to restart
607  *
608  * Return: 0 on success and negative errno in case if failure
609  */
610 int tb_tunnel_restart(struct tb_tunnel *tunnel)
611 {
612 	int res, i;
613 
614 	tb_tunnel_dbg(tunnel, "activating\n");
615 
616 	/*
617 	 * Make sure all paths are properly disabled before enabling
618 	 * them again.
619 	 */
620 	for (i = 0; i < tunnel->npaths; i++) {
621 		if (tunnel->paths[i]->activated) {
622 			tb_path_deactivate(tunnel->paths[i]);
623 			tunnel->paths[i]->activated = false;
624 		}
625 	}
626 
627 	if (tunnel->init) {
628 		res = tunnel->init(tunnel);
629 		if (res)
630 			return res;
631 	}
632 
633 	for (i = 0; i < tunnel->npaths; i++) {
634 		res = tb_path_activate(tunnel->paths[i]);
635 		if (res)
636 			goto err;
637 	}
638 
639 	if (tunnel->activate) {
640 		res = tunnel->activate(tunnel, true);
641 		if (res)
642 			goto err;
643 	}
644 
645 	return 0;
646 
647 err:
648 	tb_tunnel_warn(tunnel, "activation failed\n");
649 	tb_tunnel_deactivate(tunnel);
650 	return res;
651 }
652 
653 /**
654  * tb_tunnel_activate() - activate a tunnel
655  * @tunnel: Tunnel to activate
656  *
657  * Return: Returns 0 on success or an error code on failure.
658  */
659 int tb_tunnel_activate(struct tb_tunnel *tunnel)
660 {
661 	int i;
662 
663 	for (i = 0; i < tunnel->npaths; i++) {
664 		if (tunnel->paths[i]->activated) {
665 			tb_tunnel_WARN(tunnel,
666 				       "trying to activate an already activated tunnel\n");
667 			return -EINVAL;
668 		}
669 	}
670 
671 	return tb_tunnel_restart(tunnel);
672 }
673 
674 /**
675  * tb_tunnel_deactivate() - deactivate a tunnel
676  * @tunnel: Tunnel to deactivate
677  */
678 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
679 {
680 	int i;
681 
682 	tb_tunnel_dbg(tunnel, "deactivating\n");
683 
684 	if (tunnel->activate)
685 		tunnel->activate(tunnel, false);
686 
687 	for (i = 0; i < tunnel->npaths; i++) {
688 		if (tunnel->paths[i] && tunnel->paths[i]->activated)
689 			tb_path_deactivate(tunnel->paths[i]);
690 	}
691 }
692