xref: /linux/drivers/thunderbolt/switch.c (revision 56fb34d86e875dbb0d3e6a81c5d3d035db373031)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Thunderbolt driver - switch/port utility functions
4  *
5  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
6  * Copyright (C) 2018, Intel Corporation
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/idr.h>
11 #include <linux/nvmem-provider.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/sched/signal.h>
14 #include <linux/sizes.h>
15 #include <linux/slab.h>
16 #include <linux/vmalloc.h>
17 
18 #include "tb.h"
19 
20 /* Switch NVM support */
21 
22 #define NVM_DEVID		0x05
23 #define NVM_VERSION		0x08
24 #define NVM_CSS			0x10
25 #define NVM_FLASH_SIZE		0x45
26 
27 #define NVM_MIN_SIZE		SZ_32K
28 #define NVM_MAX_SIZE		SZ_512K
29 
30 static DEFINE_IDA(nvm_ida);
31 
32 struct nvm_auth_status {
33 	struct list_head list;
34 	uuid_t uuid;
35 	u32 status;
36 };
37 
38 /*
39  * Hold NVM authentication failure status per switch This information
40  * needs to stay around even when the switch gets power cycled so we
41  * keep it separately.
42  */
43 static LIST_HEAD(nvm_auth_status_cache);
44 static DEFINE_MUTEX(nvm_auth_status_lock);
45 
46 static struct nvm_auth_status *__nvm_get_auth_status(const struct tb_switch *sw)
47 {
48 	struct nvm_auth_status *st;
49 
50 	list_for_each_entry(st, &nvm_auth_status_cache, list) {
51 		if (uuid_equal(&st->uuid, sw->uuid))
52 			return st;
53 	}
54 
55 	return NULL;
56 }
57 
58 static void nvm_get_auth_status(const struct tb_switch *sw, u32 *status)
59 {
60 	struct nvm_auth_status *st;
61 
62 	mutex_lock(&nvm_auth_status_lock);
63 	st = __nvm_get_auth_status(sw);
64 	mutex_unlock(&nvm_auth_status_lock);
65 
66 	*status = st ? st->status : 0;
67 }
68 
69 static void nvm_set_auth_status(const struct tb_switch *sw, u32 status)
70 {
71 	struct nvm_auth_status *st;
72 
73 	if (WARN_ON(!sw->uuid))
74 		return;
75 
76 	mutex_lock(&nvm_auth_status_lock);
77 	st = __nvm_get_auth_status(sw);
78 
79 	if (!st) {
80 		st = kzalloc(sizeof(*st), GFP_KERNEL);
81 		if (!st)
82 			goto unlock;
83 
84 		memcpy(&st->uuid, sw->uuid, sizeof(st->uuid));
85 		INIT_LIST_HEAD(&st->list);
86 		list_add_tail(&st->list, &nvm_auth_status_cache);
87 	}
88 
89 	st->status = status;
90 unlock:
91 	mutex_unlock(&nvm_auth_status_lock);
92 }
93 
94 static void nvm_clear_auth_status(const struct tb_switch *sw)
95 {
96 	struct nvm_auth_status *st;
97 
98 	mutex_lock(&nvm_auth_status_lock);
99 	st = __nvm_get_auth_status(sw);
100 	if (st) {
101 		list_del(&st->list);
102 		kfree(st);
103 	}
104 	mutex_unlock(&nvm_auth_status_lock);
105 }
106 
107 static int nvm_validate_and_write(struct tb_switch *sw)
108 {
109 	unsigned int image_size, hdr_size;
110 	const u8 *buf = sw->nvm->buf;
111 	u16 ds_size;
112 	int ret;
113 
114 	if (!buf)
115 		return -EINVAL;
116 
117 	image_size = sw->nvm->buf_data_size;
118 	if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
119 		return -EINVAL;
120 
121 	/*
122 	 * FARB pointer must point inside the image and must at least
123 	 * contain parts of the digital section we will be reading here.
124 	 */
125 	hdr_size = (*(u32 *)buf) & 0xffffff;
126 	if (hdr_size + NVM_DEVID + 2 >= image_size)
127 		return -EINVAL;
128 
129 	/* Digital section start should be aligned to 4k page */
130 	if (!IS_ALIGNED(hdr_size, SZ_4K))
131 		return -EINVAL;
132 
133 	/*
134 	 * Read digital section size and check that it also fits inside
135 	 * the image.
136 	 */
137 	ds_size = *(u16 *)(buf + hdr_size);
138 	if (ds_size >= image_size)
139 		return -EINVAL;
140 
141 	if (!sw->safe_mode) {
142 		u16 device_id;
143 
144 		/*
145 		 * Make sure the device ID in the image matches the one
146 		 * we read from the switch config space.
147 		 */
148 		device_id = *(u16 *)(buf + hdr_size + NVM_DEVID);
149 		if (device_id != sw->config.device_id)
150 			return -EINVAL;
151 
152 		if (sw->generation < 3) {
153 			/* Write CSS headers first */
154 			ret = dma_port_flash_write(sw->dma_port,
155 				DMA_PORT_CSS_ADDRESS, buf + NVM_CSS,
156 				DMA_PORT_CSS_MAX_SIZE);
157 			if (ret)
158 				return ret;
159 		}
160 
161 		/* Skip headers in the image */
162 		buf += hdr_size;
163 		image_size -= hdr_size;
164 	}
165 
166 	return dma_port_flash_write(sw->dma_port, 0, buf, image_size);
167 }
168 
169 static int nvm_authenticate_host(struct tb_switch *sw)
170 {
171 	int ret;
172 
173 	/*
174 	 * Root switch NVM upgrade requires that we disconnect the
175 	 * existing paths first (in case it is not in safe mode
176 	 * already).
177 	 */
178 	if (!sw->safe_mode) {
179 		ret = tb_domain_disconnect_all_paths(sw->tb);
180 		if (ret)
181 			return ret;
182 		/*
183 		 * The host controller goes away pretty soon after this if
184 		 * everything goes well so getting timeout is expected.
185 		 */
186 		ret = dma_port_flash_update_auth(sw->dma_port);
187 		return ret == -ETIMEDOUT ? 0 : ret;
188 	}
189 
190 	/*
191 	 * From safe mode we can get out by just power cycling the
192 	 * switch.
193 	 */
194 	dma_port_power_cycle(sw->dma_port);
195 	return 0;
196 }
197 
198 static int nvm_authenticate_device(struct tb_switch *sw)
199 {
200 	int ret, retries = 10;
201 
202 	ret = dma_port_flash_update_auth(sw->dma_port);
203 	if (ret && ret != -ETIMEDOUT)
204 		return ret;
205 
206 	/*
207 	 * Poll here for the authentication status. It takes some time
208 	 * for the device to respond (we get timeout for a while). Once
209 	 * we get response the device needs to be power cycled in order
210 	 * to the new NVM to be taken into use.
211 	 */
212 	do {
213 		u32 status;
214 
215 		ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
216 		if (ret < 0 && ret != -ETIMEDOUT)
217 			return ret;
218 		if (ret > 0) {
219 			if (status) {
220 				tb_sw_warn(sw, "failed to authenticate NVM\n");
221 				nvm_set_auth_status(sw, status);
222 			}
223 
224 			tb_sw_info(sw, "power cycling the switch now\n");
225 			dma_port_power_cycle(sw->dma_port);
226 			return 0;
227 		}
228 
229 		msleep(500);
230 	} while (--retries);
231 
232 	return -ETIMEDOUT;
233 }
234 
235 static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
236 			      size_t bytes)
237 {
238 	struct tb_switch *sw = priv;
239 	int ret;
240 
241 	pm_runtime_get_sync(&sw->dev);
242 
243 	if (!mutex_trylock(&sw->tb->lock)) {
244 		ret = restart_syscall();
245 		goto out;
246 	}
247 
248 	ret = dma_port_flash_read(sw->dma_port, offset, val, bytes);
249 	mutex_unlock(&sw->tb->lock);
250 
251 out:
252 	pm_runtime_mark_last_busy(&sw->dev);
253 	pm_runtime_put_autosuspend(&sw->dev);
254 
255 	return ret;
256 }
257 
258 static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
259 			       size_t bytes)
260 {
261 	struct tb_switch *sw = priv;
262 	int ret = 0;
263 
264 	if (!mutex_trylock(&sw->tb->lock))
265 		return restart_syscall();
266 
267 	/*
268 	 * Since writing the NVM image might require some special steps,
269 	 * for example when CSS headers are written, we cache the image
270 	 * locally here and handle the special cases when the user asks
271 	 * us to authenticate the image.
272 	 */
273 	if (!sw->nvm->buf) {
274 		sw->nvm->buf = vmalloc(NVM_MAX_SIZE);
275 		if (!sw->nvm->buf) {
276 			ret = -ENOMEM;
277 			goto unlock;
278 		}
279 	}
280 
281 	sw->nvm->buf_data_size = offset + bytes;
282 	memcpy(sw->nvm->buf + offset, val, bytes);
283 
284 unlock:
285 	mutex_unlock(&sw->tb->lock);
286 
287 	return ret;
288 }
289 
290 static struct nvmem_device *register_nvmem(struct tb_switch *sw, int id,
291 					   size_t size, bool active)
292 {
293 	struct nvmem_config config;
294 
295 	memset(&config, 0, sizeof(config));
296 
297 	if (active) {
298 		config.name = "nvm_active";
299 		config.reg_read = tb_switch_nvm_read;
300 		config.read_only = true;
301 	} else {
302 		config.name = "nvm_non_active";
303 		config.reg_write = tb_switch_nvm_write;
304 		config.root_only = true;
305 	}
306 
307 	config.id = id;
308 	config.stride = 4;
309 	config.word_size = 4;
310 	config.size = size;
311 	config.dev = &sw->dev;
312 	config.owner = THIS_MODULE;
313 	config.priv = sw;
314 
315 	return nvmem_register(&config);
316 }
317 
318 static int tb_switch_nvm_add(struct tb_switch *sw)
319 {
320 	struct nvmem_device *nvm_dev;
321 	struct tb_switch_nvm *nvm;
322 	u32 val;
323 	int ret;
324 
325 	if (!sw->dma_port)
326 		return 0;
327 
328 	nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
329 	if (!nvm)
330 		return -ENOMEM;
331 
332 	nvm->id = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
333 
334 	/*
335 	 * If the switch is in safe-mode the only accessible portion of
336 	 * the NVM is the non-active one where userspace is expected to
337 	 * write new functional NVM.
338 	 */
339 	if (!sw->safe_mode) {
340 		u32 nvm_size, hdr_size;
341 
342 		ret = dma_port_flash_read(sw->dma_port, NVM_FLASH_SIZE, &val,
343 					  sizeof(val));
344 		if (ret)
345 			goto err_ida;
346 
347 		hdr_size = sw->generation < 3 ? SZ_8K : SZ_16K;
348 		nvm_size = (SZ_1M << (val & 7)) / 8;
349 		nvm_size = (nvm_size - hdr_size) / 2;
350 
351 		ret = dma_port_flash_read(sw->dma_port, NVM_VERSION, &val,
352 					  sizeof(val));
353 		if (ret)
354 			goto err_ida;
355 
356 		nvm->major = val >> 16;
357 		nvm->minor = val >> 8;
358 
359 		nvm_dev = register_nvmem(sw, nvm->id, nvm_size, true);
360 		if (IS_ERR(nvm_dev)) {
361 			ret = PTR_ERR(nvm_dev);
362 			goto err_ida;
363 		}
364 		nvm->active = nvm_dev;
365 	}
366 
367 	if (!sw->no_nvm_upgrade) {
368 		nvm_dev = register_nvmem(sw, nvm->id, NVM_MAX_SIZE, false);
369 		if (IS_ERR(nvm_dev)) {
370 			ret = PTR_ERR(nvm_dev);
371 			goto err_nvm_active;
372 		}
373 		nvm->non_active = nvm_dev;
374 	}
375 
376 	sw->nvm = nvm;
377 	return 0;
378 
379 err_nvm_active:
380 	if (nvm->active)
381 		nvmem_unregister(nvm->active);
382 err_ida:
383 	ida_simple_remove(&nvm_ida, nvm->id);
384 	kfree(nvm);
385 
386 	return ret;
387 }
388 
389 static void tb_switch_nvm_remove(struct tb_switch *sw)
390 {
391 	struct tb_switch_nvm *nvm;
392 
393 	nvm = sw->nvm;
394 	sw->nvm = NULL;
395 
396 	if (!nvm)
397 		return;
398 
399 	/* Remove authentication status in case the switch is unplugged */
400 	if (!nvm->authenticating)
401 		nvm_clear_auth_status(sw);
402 
403 	if (nvm->non_active)
404 		nvmem_unregister(nvm->non_active);
405 	if (nvm->active)
406 		nvmem_unregister(nvm->active);
407 	ida_simple_remove(&nvm_ida, nvm->id);
408 	vfree(nvm->buf);
409 	kfree(nvm);
410 }
411 
412 /* port utility functions */
413 
414 static const char *tb_port_type(struct tb_regs_port_header *port)
415 {
416 	switch (port->type >> 16) {
417 	case 0:
418 		switch ((u8) port->type) {
419 		case 0:
420 			return "Inactive";
421 		case 1:
422 			return "Port";
423 		case 2:
424 			return "NHI";
425 		default:
426 			return "unknown";
427 		}
428 	case 0x2:
429 		return "Ethernet";
430 	case 0x8:
431 		return "SATA";
432 	case 0xe:
433 		return "DP/HDMI";
434 	case 0x10:
435 		return "PCIe";
436 	case 0x20:
437 		return "USB";
438 	default:
439 		return "unknown";
440 	}
441 }
442 
443 static void tb_dump_port(struct tb *tb, struct tb_regs_port_header *port)
444 {
445 	tb_dbg(tb,
446 	       " Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
447 	       port->port_number, port->vendor_id, port->device_id,
448 	       port->revision, port->thunderbolt_version, tb_port_type(port),
449 	       port->type);
450 	tb_dbg(tb, "  Max hop id (in/out): %d/%d\n",
451 	       port->max_in_hop_id, port->max_out_hop_id);
452 	tb_dbg(tb, "  Max counters: %d\n", port->max_counters);
453 	tb_dbg(tb, "  NFC Credits: %#x\n", port->nfc_credits);
454 }
455 
456 /**
457  * tb_port_state() - get connectedness state of a port
458  *
459  * The port must have a TB_CAP_PHY (i.e. it should be a real port).
460  *
461  * Return: Returns an enum tb_port_state on success or an error code on failure.
462  */
463 static int tb_port_state(struct tb_port *port)
464 {
465 	struct tb_cap_phy phy;
466 	int res;
467 	if (port->cap_phy == 0) {
468 		tb_port_WARN(port, "does not have a PHY\n");
469 		return -EINVAL;
470 	}
471 	res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
472 	if (res)
473 		return res;
474 	return phy.state;
475 }
476 
477 /**
478  * tb_wait_for_port() - wait for a port to become ready
479  *
480  * Wait up to 1 second for a port to reach state TB_PORT_UP. If
481  * wait_if_unplugged is set then we also wait if the port is in state
482  * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
483  * switch resume). Otherwise we only wait if a device is registered but the link
484  * has not yet been established.
485  *
486  * Return: Returns an error code on failure. Returns 0 if the port is not
487  * connected or failed to reach state TB_PORT_UP within one second. Returns 1
488  * if the port is connected and in state TB_PORT_UP.
489  */
490 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
491 {
492 	int retries = 10;
493 	int state;
494 	if (!port->cap_phy) {
495 		tb_port_WARN(port, "does not have PHY\n");
496 		return -EINVAL;
497 	}
498 	if (tb_is_upstream_port(port)) {
499 		tb_port_WARN(port, "is the upstream port\n");
500 		return -EINVAL;
501 	}
502 
503 	while (retries--) {
504 		state = tb_port_state(port);
505 		if (state < 0)
506 			return state;
507 		if (state == TB_PORT_DISABLED) {
508 			tb_port_dbg(port, "is disabled (state: 0)\n");
509 			return 0;
510 		}
511 		if (state == TB_PORT_UNPLUGGED) {
512 			if (wait_if_unplugged) {
513 				/* used during resume */
514 				tb_port_dbg(port,
515 					    "is unplugged (state: 7), retrying...\n");
516 				msleep(100);
517 				continue;
518 			}
519 			tb_port_dbg(port, "is unplugged (state: 7)\n");
520 			return 0;
521 		}
522 		if (state == TB_PORT_UP) {
523 			tb_port_dbg(port, "is connected, link is up (state: 2)\n");
524 			return 1;
525 		}
526 
527 		/*
528 		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
529 		 * time.
530 		 */
531 		tb_port_dbg(port,
532 			    "is connected, link is not up (state: %d), retrying...\n",
533 			    state);
534 		msleep(100);
535 	}
536 	tb_port_warn(port,
537 		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
538 	return 0;
539 }
540 
541 /**
542  * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
543  *
544  * Change the number of NFC credits allocated to @port by @credits. To remove
545  * NFC credits pass a negative amount of credits.
546  *
547  * Return: Returns 0 on success or an error code on failure.
548  */
549 int tb_port_add_nfc_credits(struct tb_port *port, int credits)
550 {
551 	u32 nfc_credits;
552 
553 	if (credits == 0 || port->sw->is_unplugged)
554 		return 0;
555 
556 	nfc_credits = port->config.nfc_credits & TB_PORT_NFC_CREDITS_MASK;
557 	nfc_credits += credits;
558 
559 	tb_port_dbg(port, "adding %d NFC credits to %lu",
560 		    credits, port->config.nfc_credits & TB_PORT_NFC_CREDITS_MASK);
561 
562 	port->config.nfc_credits &= ~TB_PORT_NFC_CREDITS_MASK;
563 	port->config.nfc_credits |= nfc_credits;
564 
565 	return tb_port_write(port, &port->config.nfc_credits,
566 			     TB_CFG_PORT, 4, 1);
567 }
568 
569 /**
570  * tb_port_set_initial_credits() - Set initial port link credits allocated
571  * @port: Port to set the initial credits
572  * @credits: Number of credits to to allocate
573  *
574  * Set initial credits value to be used for ingress shared buffering.
575  */
576 int tb_port_set_initial_credits(struct tb_port *port, u32 credits)
577 {
578 	u32 data;
579 	int ret;
580 
581 	ret = tb_port_read(port, &data, TB_CFG_PORT, 5, 1);
582 	if (ret)
583 		return ret;
584 
585 	data &= ~TB_PORT_LCA_MASK;
586 	data |= (credits << TB_PORT_LCA_SHIFT) & TB_PORT_LCA_MASK;
587 
588 	return tb_port_write(port, &data, TB_CFG_PORT, 5, 1);
589 }
590 
591 /**
592  * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
593  *
594  * Return: Returns 0 on success or an error code on failure.
595  */
596 int tb_port_clear_counter(struct tb_port *port, int counter)
597 {
598 	u32 zero[3] = { 0, 0, 0 };
599 	tb_port_dbg(port, "clearing counter %d\n", counter);
600 	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
601 }
602 
603 /**
604  * tb_init_port() - initialize a port
605  *
606  * This is a helper method for tb_switch_alloc. Does not check or initialize
607  * any downstream switches.
608  *
609  * Return: Returns 0 on success or an error code on failure.
610  */
611 static int tb_init_port(struct tb_port *port)
612 {
613 	int res;
614 	int cap;
615 
616 	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
617 	if (res) {
618 		if (res == -ENODEV) {
619 			tb_dbg(port->sw->tb, " Port %d: not implemented\n",
620 			       port->port);
621 			return 0;
622 		}
623 		return res;
624 	}
625 
626 	/* Port 0 is the switch itself and has no PHY. */
627 	if (port->config.type == TB_TYPE_PORT && port->port != 0) {
628 		cap = tb_port_find_cap(port, TB_PORT_CAP_PHY);
629 
630 		if (cap > 0)
631 			port->cap_phy = cap;
632 		else
633 			tb_port_WARN(port, "non switch port without a PHY\n");
634 	} else if (port->port != 0) {
635 		cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
636 		if (cap > 0)
637 			port->cap_adap = cap;
638 	}
639 
640 	tb_dump_port(port->sw->tb, &port->config);
641 
642 	/* Control port does not need HopID allocation */
643 	if (port->port) {
644 		ida_init(&port->in_hopids);
645 		ida_init(&port->out_hopids);
646 	}
647 
648 	return 0;
649 
650 }
651 
652 static int tb_port_alloc_hopid(struct tb_port *port, bool in, int min_hopid,
653 			       int max_hopid)
654 {
655 	int port_max_hopid;
656 	struct ida *ida;
657 
658 	if (in) {
659 		port_max_hopid = port->config.max_in_hop_id;
660 		ida = &port->in_hopids;
661 	} else {
662 		port_max_hopid = port->config.max_out_hop_id;
663 		ida = &port->out_hopids;
664 	}
665 
666 	/* HopIDs 0-7 are reserved */
667 	if (min_hopid < TB_PATH_MIN_HOPID)
668 		min_hopid = TB_PATH_MIN_HOPID;
669 
670 	if (max_hopid < 0 || max_hopid > port_max_hopid)
671 		max_hopid = port_max_hopid;
672 
673 	return ida_simple_get(ida, min_hopid, max_hopid + 1, GFP_KERNEL);
674 }
675 
676 /**
677  * tb_port_alloc_in_hopid() - Allocate input HopID from port
678  * @port: Port to allocate HopID for
679  * @min_hopid: Minimum acceptable input HopID
680  * @max_hopid: Maximum acceptable input HopID
681  *
682  * Return: HopID between @min_hopid and @max_hopid or negative errno in
683  * case of error.
684  */
685 int tb_port_alloc_in_hopid(struct tb_port *port, int min_hopid, int max_hopid)
686 {
687 	return tb_port_alloc_hopid(port, true, min_hopid, max_hopid);
688 }
689 
690 /**
691  * tb_port_alloc_out_hopid() - Allocate output HopID from port
692  * @port: Port to allocate HopID for
693  * @min_hopid: Minimum acceptable output HopID
694  * @max_hopid: Maximum acceptable output HopID
695  *
696  * Return: HopID between @min_hopid and @max_hopid or negative errno in
697  * case of error.
698  */
699 int tb_port_alloc_out_hopid(struct tb_port *port, int min_hopid, int max_hopid)
700 {
701 	return tb_port_alloc_hopid(port, false, min_hopid, max_hopid);
702 }
703 
704 /**
705  * tb_port_release_in_hopid() - Release allocated input HopID from port
706  * @port: Port whose HopID to release
707  * @hopid: HopID to release
708  */
709 void tb_port_release_in_hopid(struct tb_port *port, int hopid)
710 {
711 	ida_simple_remove(&port->in_hopids, hopid);
712 }
713 
714 /**
715  * tb_port_release_out_hopid() - Release allocated output HopID from port
716  * @port: Port whose HopID to release
717  * @hopid: HopID to release
718  */
719 void tb_port_release_out_hopid(struct tb_port *port, int hopid)
720 {
721 	ida_simple_remove(&port->out_hopids, hopid);
722 }
723 
724 /**
725  * tb_next_port_on_path() - Return next port for given port on a path
726  * @start: Start port of the walk
727  * @end: End port of the walk
728  * @prev: Previous port (%NULL if this is the first)
729  *
730  * This function can be used to walk from one port to another if they
731  * are connected through zero or more switches. If the @prev is dual
732  * link port, the function follows that link and returns another end on
733  * that same link.
734  *
735  * If the @end port has been reached, return %NULL.
736  *
737  * Domain tb->lock must be held when this function is called.
738  */
739 struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
740 				     struct tb_port *prev)
741 {
742 	struct tb_port *next;
743 
744 	if (!prev)
745 		return start;
746 
747 	if (prev->sw == end->sw) {
748 		if (prev == end)
749 			return NULL;
750 		return end;
751 	}
752 
753 	if (start->sw->config.depth < end->sw->config.depth) {
754 		if (prev->remote &&
755 		    prev->remote->sw->config.depth > prev->sw->config.depth)
756 			next = prev->remote;
757 		else
758 			next = tb_port_at(tb_route(end->sw), prev->sw);
759 	} else {
760 		if (tb_is_upstream_port(prev)) {
761 			next = prev->remote;
762 		} else {
763 			next = tb_upstream_port(prev->sw);
764 			/*
765 			 * Keep the same link if prev and next are both
766 			 * dual link ports.
767 			 */
768 			if (next->dual_link_port &&
769 			    next->link_nr != prev->link_nr) {
770 				next = next->dual_link_port;
771 			}
772 		}
773 	}
774 
775 	return next;
776 }
777 
778 /**
779  * tb_port_is_enabled() - Is the adapter port enabled
780  * @port: Port to check
781  */
782 bool tb_port_is_enabled(struct tb_port *port)
783 {
784 	switch (port->config.type) {
785 	case TB_TYPE_PCIE_UP:
786 	case TB_TYPE_PCIE_DOWN:
787 		return tb_pci_port_is_enabled(port);
788 
789 	case TB_TYPE_DP_HDMI_IN:
790 	case TB_TYPE_DP_HDMI_OUT:
791 		return tb_dp_port_is_enabled(port);
792 
793 	default:
794 		return false;
795 	}
796 }
797 
798 /**
799  * tb_pci_port_is_enabled() - Is the PCIe adapter port enabled
800  * @port: PCIe port to check
801  */
802 bool tb_pci_port_is_enabled(struct tb_port *port)
803 {
804 	u32 data;
805 
806 	if (tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1))
807 		return false;
808 
809 	return !!(data & TB_PCI_EN);
810 }
811 
812 /**
813  * tb_pci_port_enable() - Enable PCIe adapter port
814  * @port: PCIe port to enable
815  * @enable: Enable/disable the PCIe adapter
816  */
817 int tb_pci_port_enable(struct tb_port *port, bool enable)
818 {
819 	u32 word = enable ? TB_PCI_EN : 0x0;
820 	if (!port->cap_adap)
821 		return -ENXIO;
822 	return tb_port_write(port, &word, TB_CFG_PORT, port->cap_adap, 1);
823 }
824 
825 /**
826  * tb_dp_port_hpd_is_active() - Is HPD already active
827  * @port: DP out port to check
828  *
829  * Checks if the DP OUT adapter port has HDP bit already set.
830  */
831 int tb_dp_port_hpd_is_active(struct tb_port *port)
832 {
833 	u32 data;
834 	int ret;
835 
836 	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap + 2, 1);
837 	if (ret)
838 		return ret;
839 
840 	return !!(data & TB_DP_HDP);
841 }
842 
843 /**
844  * tb_dp_port_hpd_clear() - Clear HPD from DP IN port
845  * @port: Port to clear HPD
846  *
847  * If the DP IN port has HDP set, this function can be used to clear it.
848  */
849 int tb_dp_port_hpd_clear(struct tb_port *port)
850 {
851 	u32 data;
852 	int ret;
853 
854 	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap + 3, 1);
855 	if (ret)
856 		return ret;
857 
858 	data |= TB_DP_HPDC;
859 	return tb_port_write(port, &data, TB_CFG_PORT, port->cap_adap + 3, 1);
860 }
861 
862 /**
863  * tb_dp_port_set_hops() - Set video/aux Hop IDs for DP port
864  * @port: DP IN/OUT port to set hops
865  * @video: Video Hop ID
866  * @aux_tx: AUX TX Hop ID
867  * @aux_rx: AUX RX Hop ID
868  *
869  * Programs specified Hop IDs for DP IN/OUT port.
870  */
871 int tb_dp_port_set_hops(struct tb_port *port, unsigned int video,
872 			unsigned int aux_tx, unsigned int aux_rx)
873 {
874 	u32 data[2];
875 	int ret;
876 
877 	ret = tb_port_read(port, data, TB_CFG_PORT, port->cap_adap,
878 			   ARRAY_SIZE(data));
879 	if (ret)
880 		return ret;
881 
882 	data[0] &= ~TB_DP_VIDEO_HOPID_MASK;
883 	data[1] &= ~(TB_DP_AUX_RX_HOPID_MASK | TB_DP_AUX_TX_HOPID_MASK);
884 
885 	data[0] |= (video << TB_DP_VIDEO_HOPID_SHIFT) & TB_DP_VIDEO_HOPID_MASK;
886 	data[1] |= aux_tx & TB_DP_AUX_TX_HOPID_MASK;
887 	data[1] |= (aux_rx << TB_DP_AUX_RX_HOPID_SHIFT) & TB_DP_AUX_RX_HOPID_MASK;
888 
889 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_adap,
890 			     ARRAY_SIZE(data));
891 }
892 
893 /**
894  * tb_dp_port_is_enabled() - Is DP adapter port enabled
895  * @port: DP adapter port to check
896  */
897 bool tb_dp_port_is_enabled(struct tb_port *port)
898 {
899 	u32 data;
900 
901 	if (tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1))
902 		return false;
903 
904 	return !!(data & (TB_DP_VIDEO_EN | TB_DP_AUX_EN));
905 }
906 
907 /**
908  * tb_dp_port_enable() - Enables/disables DP paths of a port
909  * @port: DP IN/OUT port
910  * @enable: Enable/disable DP path
911  *
912  * Once Hop IDs are programmed DP paths can be enabled or disabled by
913  * calling this function.
914  */
915 int tb_dp_port_enable(struct tb_port *port, bool enable)
916 {
917 	u32 data;
918 	int ret;
919 
920 	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1);
921 	if (ret)
922 		return ret;
923 
924 	if (enable)
925 		data |= TB_DP_VIDEO_EN | TB_DP_AUX_EN;
926 	else
927 		data &= ~(TB_DP_VIDEO_EN | TB_DP_AUX_EN);
928 
929 	return tb_port_write(port, &data, TB_CFG_PORT, port->cap_adap, 1);
930 }
931 
932 /* switch utility functions */
933 
934 static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
935 {
936 	tb_dbg(tb, " Switch: %x:%x (Revision: %d, TB Version: %d)\n",
937 	       sw->vendor_id, sw->device_id, sw->revision,
938 	       sw->thunderbolt_version);
939 	tb_dbg(tb, "  Max Port Number: %d\n", sw->max_port_number);
940 	tb_dbg(tb, "  Config:\n");
941 	tb_dbg(tb,
942 		"   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
943 	       sw->upstream_port_number, sw->depth,
944 	       (((u64) sw->route_hi) << 32) | sw->route_lo,
945 	       sw->enabled, sw->plug_events_delay);
946 	tb_dbg(tb, "   unknown1: %#x unknown4: %#x\n",
947 	       sw->__unknown1, sw->__unknown4);
948 }
949 
950 /**
951  * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
952  *
953  * Return: Returns 0 on success or an error code on failure.
954  */
955 int tb_switch_reset(struct tb *tb, u64 route)
956 {
957 	struct tb_cfg_result res;
958 	struct tb_regs_switch_header header = {
959 		header.route_hi = route >> 32,
960 		header.route_lo = route,
961 		header.enabled = true,
962 	};
963 	tb_dbg(tb, "resetting switch at %llx\n", route);
964 	res.err = tb_cfg_write(tb->ctl, ((u32 *) &header) + 2, route,
965 			0, 2, 2, 2);
966 	if (res.err)
967 		return res.err;
968 	res = tb_cfg_reset(tb->ctl, route, TB_CFG_DEFAULT_TIMEOUT);
969 	if (res.err > 0)
970 		return -EIO;
971 	return res.err;
972 }
973 
974 /**
975  * tb_plug_events_active() - enable/disable plug events on a switch
976  *
977  * Also configures a sane plug_events_delay of 255ms.
978  *
979  * Return: Returns 0 on success or an error code on failure.
980  */
981 static int tb_plug_events_active(struct tb_switch *sw, bool active)
982 {
983 	u32 data;
984 	int res;
985 
986 	if (!sw->config.enabled)
987 		return 0;
988 
989 	sw->config.plug_events_delay = 0xff;
990 	res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
991 	if (res)
992 		return res;
993 
994 	res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
995 	if (res)
996 		return res;
997 
998 	if (active) {
999 		data = data & 0xFFFFFF83;
1000 		switch (sw->config.device_id) {
1001 		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
1002 		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
1003 		case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
1004 			break;
1005 		default:
1006 			data |= 4;
1007 		}
1008 	} else {
1009 		data = data | 0x7c;
1010 	}
1011 	return tb_sw_write(sw, &data, TB_CFG_SWITCH,
1012 			   sw->cap_plug_events + 1, 1);
1013 }
1014 
1015 static ssize_t authorized_show(struct device *dev,
1016 			       struct device_attribute *attr,
1017 			       char *buf)
1018 {
1019 	struct tb_switch *sw = tb_to_switch(dev);
1020 
1021 	return sprintf(buf, "%u\n", sw->authorized);
1022 }
1023 
1024 static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
1025 {
1026 	int ret = -EINVAL;
1027 
1028 	if (!mutex_trylock(&sw->tb->lock))
1029 		return restart_syscall();
1030 
1031 	if (sw->authorized)
1032 		goto unlock;
1033 
1034 	/*
1035 	 * Make sure there is no PCIe rescan ongoing when a new PCIe
1036 	 * tunnel is created. Otherwise the PCIe rescan code might find
1037 	 * the new tunnel too early.
1038 	 */
1039 	pci_lock_rescan_remove();
1040 
1041 	switch (val) {
1042 	/* Approve switch */
1043 	case 1:
1044 		if (sw->key)
1045 			ret = tb_domain_approve_switch_key(sw->tb, sw);
1046 		else
1047 			ret = tb_domain_approve_switch(sw->tb, sw);
1048 		break;
1049 
1050 	/* Challenge switch */
1051 	case 2:
1052 		if (sw->key)
1053 			ret = tb_domain_challenge_switch_key(sw->tb, sw);
1054 		break;
1055 
1056 	default:
1057 		break;
1058 	}
1059 
1060 	pci_unlock_rescan_remove();
1061 
1062 	if (!ret) {
1063 		sw->authorized = val;
1064 		/* Notify status change to the userspace */
1065 		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);
1066 	}
1067 
1068 unlock:
1069 	mutex_unlock(&sw->tb->lock);
1070 	return ret;
1071 }
1072 
1073 static ssize_t authorized_store(struct device *dev,
1074 				struct device_attribute *attr,
1075 				const char *buf, size_t count)
1076 {
1077 	struct tb_switch *sw = tb_to_switch(dev);
1078 	unsigned int val;
1079 	ssize_t ret;
1080 
1081 	ret = kstrtouint(buf, 0, &val);
1082 	if (ret)
1083 		return ret;
1084 	if (val > 2)
1085 		return -EINVAL;
1086 
1087 	pm_runtime_get_sync(&sw->dev);
1088 	ret = tb_switch_set_authorized(sw, val);
1089 	pm_runtime_mark_last_busy(&sw->dev);
1090 	pm_runtime_put_autosuspend(&sw->dev);
1091 
1092 	return ret ? ret : count;
1093 }
1094 static DEVICE_ATTR_RW(authorized);
1095 
1096 static ssize_t boot_show(struct device *dev, struct device_attribute *attr,
1097 			 char *buf)
1098 {
1099 	struct tb_switch *sw = tb_to_switch(dev);
1100 
1101 	return sprintf(buf, "%u\n", sw->boot);
1102 }
1103 static DEVICE_ATTR_RO(boot);
1104 
1105 static ssize_t device_show(struct device *dev, struct device_attribute *attr,
1106 			   char *buf)
1107 {
1108 	struct tb_switch *sw = tb_to_switch(dev);
1109 
1110 	return sprintf(buf, "%#x\n", sw->device);
1111 }
1112 static DEVICE_ATTR_RO(device);
1113 
1114 static ssize_t
1115 device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
1116 {
1117 	struct tb_switch *sw = tb_to_switch(dev);
1118 
1119 	return sprintf(buf, "%s\n", sw->device_name ? sw->device_name : "");
1120 }
1121 static DEVICE_ATTR_RO(device_name);
1122 
1123 static ssize_t key_show(struct device *dev, struct device_attribute *attr,
1124 			char *buf)
1125 {
1126 	struct tb_switch *sw = tb_to_switch(dev);
1127 	ssize_t ret;
1128 
1129 	if (!mutex_trylock(&sw->tb->lock))
1130 		return restart_syscall();
1131 
1132 	if (sw->key)
1133 		ret = sprintf(buf, "%*phN\n", TB_SWITCH_KEY_SIZE, sw->key);
1134 	else
1135 		ret = sprintf(buf, "\n");
1136 
1137 	mutex_unlock(&sw->tb->lock);
1138 	return ret;
1139 }
1140 
1141 static ssize_t key_store(struct device *dev, struct device_attribute *attr,
1142 			 const char *buf, size_t count)
1143 {
1144 	struct tb_switch *sw = tb_to_switch(dev);
1145 	u8 key[TB_SWITCH_KEY_SIZE];
1146 	ssize_t ret = count;
1147 	bool clear = false;
1148 
1149 	if (!strcmp(buf, "\n"))
1150 		clear = true;
1151 	else if (hex2bin(key, buf, sizeof(key)))
1152 		return -EINVAL;
1153 
1154 	if (!mutex_trylock(&sw->tb->lock))
1155 		return restart_syscall();
1156 
1157 	if (sw->authorized) {
1158 		ret = -EBUSY;
1159 	} else {
1160 		kfree(sw->key);
1161 		if (clear) {
1162 			sw->key = NULL;
1163 		} else {
1164 			sw->key = kmemdup(key, sizeof(key), GFP_KERNEL);
1165 			if (!sw->key)
1166 				ret = -ENOMEM;
1167 		}
1168 	}
1169 
1170 	mutex_unlock(&sw->tb->lock);
1171 	return ret;
1172 }
1173 static DEVICE_ATTR(key, 0600, key_show, key_store);
1174 
1175 static void nvm_authenticate_start(struct tb_switch *sw)
1176 {
1177 	struct pci_dev *root_port;
1178 
1179 	/*
1180 	 * During host router NVM upgrade we should not allow root port to
1181 	 * go into D3cold because some root ports cannot trigger PME
1182 	 * itself. To be on the safe side keep the root port in D0 during
1183 	 * the whole upgrade process.
1184 	 */
1185 	root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev);
1186 	if (root_port)
1187 		pm_runtime_get_noresume(&root_port->dev);
1188 }
1189 
1190 static void nvm_authenticate_complete(struct tb_switch *sw)
1191 {
1192 	struct pci_dev *root_port;
1193 
1194 	root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev);
1195 	if (root_port)
1196 		pm_runtime_put(&root_port->dev);
1197 }
1198 
1199 static ssize_t nvm_authenticate_show(struct device *dev,
1200 	struct device_attribute *attr, char *buf)
1201 {
1202 	struct tb_switch *sw = tb_to_switch(dev);
1203 	u32 status;
1204 
1205 	nvm_get_auth_status(sw, &status);
1206 	return sprintf(buf, "%#x\n", status);
1207 }
1208 
1209 static ssize_t nvm_authenticate_store(struct device *dev,
1210 	struct device_attribute *attr, const char *buf, size_t count)
1211 {
1212 	struct tb_switch *sw = tb_to_switch(dev);
1213 	bool val;
1214 	int ret;
1215 
1216 	pm_runtime_get_sync(&sw->dev);
1217 
1218 	if (!mutex_trylock(&sw->tb->lock)) {
1219 		ret = restart_syscall();
1220 		goto exit_rpm;
1221 	}
1222 
1223 	/* If NVMem devices are not yet added */
1224 	if (!sw->nvm) {
1225 		ret = -EAGAIN;
1226 		goto exit_unlock;
1227 	}
1228 
1229 	ret = kstrtobool(buf, &val);
1230 	if (ret)
1231 		goto exit_unlock;
1232 
1233 	/* Always clear the authentication status */
1234 	nvm_clear_auth_status(sw);
1235 
1236 	if (val) {
1237 		if (!sw->nvm->buf) {
1238 			ret = -EINVAL;
1239 			goto exit_unlock;
1240 		}
1241 
1242 		ret = nvm_validate_and_write(sw);
1243 		if (ret)
1244 			goto exit_unlock;
1245 
1246 		sw->nvm->authenticating = true;
1247 
1248 		if (!tb_route(sw)) {
1249 			/*
1250 			 * Keep root port from suspending as long as the
1251 			 * NVM upgrade process is running.
1252 			 */
1253 			nvm_authenticate_start(sw);
1254 			ret = nvm_authenticate_host(sw);
1255 			if (ret)
1256 				nvm_authenticate_complete(sw);
1257 		} else {
1258 			ret = nvm_authenticate_device(sw);
1259 		}
1260 	}
1261 
1262 exit_unlock:
1263 	mutex_unlock(&sw->tb->lock);
1264 exit_rpm:
1265 	pm_runtime_mark_last_busy(&sw->dev);
1266 	pm_runtime_put_autosuspend(&sw->dev);
1267 
1268 	if (ret)
1269 		return ret;
1270 	return count;
1271 }
1272 static DEVICE_ATTR_RW(nvm_authenticate);
1273 
1274 static ssize_t nvm_version_show(struct device *dev,
1275 				struct device_attribute *attr, char *buf)
1276 {
1277 	struct tb_switch *sw = tb_to_switch(dev);
1278 	int ret;
1279 
1280 	if (!mutex_trylock(&sw->tb->lock))
1281 		return restart_syscall();
1282 
1283 	if (sw->safe_mode)
1284 		ret = -ENODATA;
1285 	else if (!sw->nvm)
1286 		ret = -EAGAIN;
1287 	else
1288 		ret = sprintf(buf, "%x.%x\n", sw->nvm->major, sw->nvm->minor);
1289 
1290 	mutex_unlock(&sw->tb->lock);
1291 
1292 	return ret;
1293 }
1294 static DEVICE_ATTR_RO(nvm_version);
1295 
1296 static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
1297 			   char *buf)
1298 {
1299 	struct tb_switch *sw = tb_to_switch(dev);
1300 
1301 	return sprintf(buf, "%#x\n", sw->vendor);
1302 }
1303 static DEVICE_ATTR_RO(vendor);
1304 
1305 static ssize_t
1306 vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
1307 {
1308 	struct tb_switch *sw = tb_to_switch(dev);
1309 
1310 	return sprintf(buf, "%s\n", sw->vendor_name ? sw->vendor_name : "");
1311 }
1312 static DEVICE_ATTR_RO(vendor_name);
1313 
1314 static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
1315 			      char *buf)
1316 {
1317 	struct tb_switch *sw = tb_to_switch(dev);
1318 
1319 	return sprintf(buf, "%pUb\n", sw->uuid);
1320 }
1321 static DEVICE_ATTR_RO(unique_id);
1322 
1323 static struct attribute *switch_attrs[] = {
1324 	&dev_attr_authorized.attr,
1325 	&dev_attr_boot.attr,
1326 	&dev_attr_device.attr,
1327 	&dev_attr_device_name.attr,
1328 	&dev_attr_key.attr,
1329 	&dev_attr_nvm_authenticate.attr,
1330 	&dev_attr_nvm_version.attr,
1331 	&dev_attr_vendor.attr,
1332 	&dev_attr_vendor_name.attr,
1333 	&dev_attr_unique_id.attr,
1334 	NULL,
1335 };
1336 
1337 static umode_t switch_attr_is_visible(struct kobject *kobj,
1338 				      struct attribute *attr, int n)
1339 {
1340 	struct device *dev = container_of(kobj, struct device, kobj);
1341 	struct tb_switch *sw = tb_to_switch(dev);
1342 
1343 	if (attr == &dev_attr_device.attr) {
1344 		if (!sw->device)
1345 			return 0;
1346 	} else if (attr == &dev_attr_device_name.attr) {
1347 		if (!sw->device_name)
1348 			return 0;
1349 	} else if (attr == &dev_attr_vendor.attr)  {
1350 		if (!sw->vendor)
1351 			return 0;
1352 	} else if (attr == &dev_attr_vendor_name.attr)  {
1353 		if (!sw->vendor_name)
1354 			return 0;
1355 	} else if (attr == &dev_attr_key.attr) {
1356 		if (tb_route(sw) &&
1357 		    sw->tb->security_level == TB_SECURITY_SECURE &&
1358 		    sw->security_level == TB_SECURITY_SECURE)
1359 			return attr->mode;
1360 		return 0;
1361 	} else if (attr == &dev_attr_nvm_authenticate.attr) {
1362 		if (sw->dma_port && !sw->no_nvm_upgrade)
1363 			return attr->mode;
1364 		return 0;
1365 	} else if (attr == &dev_attr_nvm_version.attr) {
1366 		if (sw->dma_port)
1367 			return attr->mode;
1368 		return 0;
1369 	} else if (attr == &dev_attr_boot.attr) {
1370 		if (tb_route(sw))
1371 			return attr->mode;
1372 		return 0;
1373 	}
1374 
1375 	return sw->safe_mode ? 0 : attr->mode;
1376 }
1377 
1378 static struct attribute_group switch_group = {
1379 	.is_visible = switch_attr_is_visible,
1380 	.attrs = switch_attrs,
1381 };
1382 
1383 static const struct attribute_group *switch_groups[] = {
1384 	&switch_group,
1385 	NULL,
1386 };
1387 
1388 static void tb_switch_release(struct device *dev)
1389 {
1390 	struct tb_switch *sw = tb_to_switch(dev);
1391 	int i;
1392 
1393 	dma_port_free(sw->dma_port);
1394 
1395 	for (i = 1; i <= sw->config.max_port_number; i++) {
1396 		if (!sw->ports[i].disabled) {
1397 			ida_destroy(&sw->ports[i].in_hopids);
1398 			ida_destroy(&sw->ports[i].out_hopids);
1399 		}
1400 	}
1401 
1402 	kfree(sw->uuid);
1403 	kfree(sw->device_name);
1404 	kfree(sw->vendor_name);
1405 	kfree(sw->ports);
1406 	kfree(sw->drom);
1407 	kfree(sw->key);
1408 	kfree(sw);
1409 }
1410 
1411 /*
1412  * Currently only need to provide the callbacks. Everything else is handled
1413  * in the connection manager.
1414  */
1415 static int __maybe_unused tb_switch_runtime_suspend(struct device *dev)
1416 {
1417 	struct tb_switch *sw = tb_to_switch(dev);
1418 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
1419 
1420 	if (cm_ops->runtime_suspend_switch)
1421 		return cm_ops->runtime_suspend_switch(sw);
1422 
1423 	return 0;
1424 }
1425 
1426 static int __maybe_unused tb_switch_runtime_resume(struct device *dev)
1427 {
1428 	struct tb_switch *sw = tb_to_switch(dev);
1429 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
1430 
1431 	if (cm_ops->runtime_resume_switch)
1432 		return cm_ops->runtime_resume_switch(sw);
1433 	return 0;
1434 }
1435 
1436 static const struct dev_pm_ops tb_switch_pm_ops = {
1437 	SET_RUNTIME_PM_OPS(tb_switch_runtime_suspend, tb_switch_runtime_resume,
1438 			   NULL)
1439 };
1440 
1441 struct device_type tb_switch_type = {
1442 	.name = "thunderbolt_device",
1443 	.release = tb_switch_release,
1444 	.pm = &tb_switch_pm_ops,
1445 };
1446 
1447 static int tb_switch_get_generation(struct tb_switch *sw)
1448 {
1449 	switch (sw->config.device_id) {
1450 	case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
1451 	case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
1452 	case PCI_DEVICE_ID_INTEL_LIGHT_PEAK:
1453 	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_2C:
1454 	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
1455 	case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
1456 	case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_2C_BRIDGE:
1457 	case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_4C_BRIDGE:
1458 		return 1;
1459 
1460 	case PCI_DEVICE_ID_INTEL_WIN_RIDGE_2C_BRIDGE:
1461 	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE:
1462 	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE:
1463 		return 2;
1464 
1465 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
1466 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_BRIDGE:
1467 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_BRIDGE:
1468 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
1469 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
1470 	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_BRIDGE:
1471 	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_BRIDGE:
1472 	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_DD_BRIDGE:
1473 	case PCI_DEVICE_ID_INTEL_ICL_NHI0:
1474 	case PCI_DEVICE_ID_INTEL_ICL_NHI1:
1475 		return 3;
1476 
1477 	default:
1478 		/*
1479 		 * For unknown switches assume generation to be 1 to be
1480 		 * on the safe side.
1481 		 */
1482 		tb_sw_warn(sw, "unsupported switch device id %#x\n",
1483 			   sw->config.device_id);
1484 		return 1;
1485 	}
1486 }
1487 
1488 /**
1489  * tb_switch_alloc() - allocate a switch
1490  * @tb: Pointer to the owning domain
1491  * @parent: Parent device for this switch
1492  * @route: Route string for this switch
1493  *
1494  * Allocates and initializes a switch. Will not upload configuration to
1495  * the switch. For that you need to call tb_switch_configure()
1496  * separately. The returned switch should be released by calling
1497  * tb_switch_put().
1498  *
1499  * Return: Pointer to the allocated switch or ERR_PTR() in case of
1500  * failure.
1501  */
1502 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
1503 				  u64 route)
1504 {
1505 	struct tb_switch *sw;
1506 	int upstream_port;
1507 	int i, ret, depth;
1508 
1509 	/* Make sure we do not exceed maximum topology limit */
1510 	depth = tb_route_length(route);
1511 	if (depth > TB_SWITCH_MAX_DEPTH)
1512 		return ERR_PTR(-EADDRNOTAVAIL);
1513 
1514 	upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
1515 	if (upstream_port < 0)
1516 		return ERR_PTR(upstream_port);
1517 
1518 	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
1519 	if (!sw)
1520 		return ERR_PTR(-ENOMEM);
1521 
1522 	sw->tb = tb;
1523 	ret = tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5);
1524 	if (ret)
1525 		goto err_free_sw_ports;
1526 
1527 	tb_dbg(tb, "current switch config:\n");
1528 	tb_dump_switch(tb, &sw->config);
1529 
1530 	/* configure switch */
1531 	sw->config.upstream_port_number = upstream_port;
1532 	sw->config.depth = depth;
1533 	sw->config.route_hi = upper_32_bits(route);
1534 	sw->config.route_lo = lower_32_bits(route);
1535 	sw->config.enabled = 0;
1536 
1537 	/* initialize ports */
1538 	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
1539 				GFP_KERNEL);
1540 	if (!sw->ports) {
1541 		ret = -ENOMEM;
1542 		goto err_free_sw_ports;
1543 	}
1544 
1545 	for (i = 0; i <= sw->config.max_port_number; i++) {
1546 		/* minimum setup for tb_find_cap and tb_drom_read to work */
1547 		sw->ports[i].sw = sw;
1548 		sw->ports[i].port = i;
1549 	}
1550 
1551 	sw->generation = tb_switch_get_generation(sw);
1552 
1553 	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
1554 	if (ret < 0) {
1555 		tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
1556 		goto err_free_sw_ports;
1557 	}
1558 	sw->cap_plug_events = ret;
1559 
1560 	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
1561 	if (ret > 0)
1562 		sw->cap_lc = ret;
1563 
1564 	/* Root switch is always authorized */
1565 	if (!route)
1566 		sw->authorized = true;
1567 
1568 	device_initialize(&sw->dev);
1569 	sw->dev.parent = parent;
1570 	sw->dev.bus = &tb_bus_type;
1571 	sw->dev.type = &tb_switch_type;
1572 	sw->dev.groups = switch_groups;
1573 	dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
1574 
1575 	return sw;
1576 
1577 err_free_sw_ports:
1578 	kfree(sw->ports);
1579 	kfree(sw);
1580 
1581 	return ERR_PTR(ret);
1582 }
1583 
1584 /**
1585  * tb_switch_alloc_safe_mode() - allocate a switch that is in safe mode
1586  * @tb: Pointer to the owning domain
1587  * @parent: Parent device for this switch
1588  * @route: Route string for this switch
1589  *
1590  * This creates a switch in safe mode. This means the switch pretty much
1591  * lacks all capabilities except DMA configuration port before it is
1592  * flashed with a valid NVM firmware.
1593  *
1594  * The returned switch must be released by calling tb_switch_put().
1595  *
1596  * Return: Pointer to the allocated switch or ERR_PTR() in case of failure
1597  */
1598 struct tb_switch *
1599 tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
1600 {
1601 	struct tb_switch *sw;
1602 
1603 	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
1604 	if (!sw)
1605 		return ERR_PTR(-ENOMEM);
1606 
1607 	sw->tb = tb;
1608 	sw->config.depth = tb_route_length(route);
1609 	sw->config.route_hi = upper_32_bits(route);
1610 	sw->config.route_lo = lower_32_bits(route);
1611 	sw->safe_mode = true;
1612 
1613 	device_initialize(&sw->dev);
1614 	sw->dev.parent = parent;
1615 	sw->dev.bus = &tb_bus_type;
1616 	sw->dev.type = &tb_switch_type;
1617 	sw->dev.groups = switch_groups;
1618 	dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
1619 
1620 	return sw;
1621 }
1622 
1623 /**
1624  * tb_switch_configure() - Uploads configuration to the switch
1625  * @sw: Switch to configure
1626  *
1627  * Call this function before the switch is added to the system. It will
1628  * upload configuration to the switch and makes it available for the
1629  * connection manager to use.
1630  *
1631  * Return: %0 in case of success and negative errno in case of failure
1632  */
1633 int tb_switch_configure(struct tb_switch *sw)
1634 {
1635 	struct tb *tb = sw->tb;
1636 	u64 route;
1637 	int ret;
1638 
1639 	route = tb_route(sw);
1640 	tb_dbg(tb, "initializing Switch at %#llx (depth: %d, up port: %d)\n",
1641 	       route, tb_route_length(route), sw->config.upstream_port_number);
1642 
1643 	if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
1644 		tb_sw_warn(sw, "unknown switch vendor id %#x\n",
1645 			   sw->config.vendor_id);
1646 
1647 	sw->config.enabled = 1;
1648 
1649 	/* upload configuration */
1650 	ret = tb_sw_write(sw, 1 + (u32 *)&sw->config, TB_CFG_SWITCH, 1, 3);
1651 	if (ret)
1652 		return ret;
1653 
1654 	ret = tb_lc_configure_link(sw);
1655 	if (ret)
1656 		return ret;
1657 
1658 	return tb_plug_events_active(sw, true);
1659 }
1660 
1661 static int tb_switch_set_uuid(struct tb_switch *sw)
1662 {
1663 	u32 uuid[4];
1664 	int ret;
1665 
1666 	if (sw->uuid)
1667 		return 0;
1668 
1669 	/*
1670 	 * The newer controllers include fused UUID as part of link
1671 	 * controller specific registers
1672 	 */
1673 	ret = tb_lc_read_uuid(sw, uuid);
1674 	if (ret) {
1675 		/*
1676 		 * ICM generates UUID based on UID and fills the upper
1677 		 * two words with ones. This is not strictly following
1678 		 * UUID format but we want to be compatible with it so
1679 		 * we do the same here.
1680 		 */
1681 		uuid[0] = sw->uid & 0xffffffff;
1682 		uuid[1] = (sw->uid >> 32) & 0xffffffff;
1683 		uuid[2] = 0xffffffff;
1684 		uuid[3] = 0xffffffff;
1685 	}
1686 
1687 	sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
1688 	if (!sw->uuid)
1689 		return -ENOMEM;
1690 	return 0;
1691 }
1692 
1693 static int tb_switch_add_dma_port(struct tb_switch *sw)
1694 {
1695 	u32 status;
1696 	int ret;
1697 
1698 	switch (sw->generation) {
1699 	case 3:
1700 		break;
1701 
1702 	case 2:
1703 		/* Only root switch can be upgraded */
1704 		if (tb_route(sw))
1705 			return 0;
1706 		break;
1707 
1708 	default:
1709 		/*
1710 		 * DMA port is the only thing available when the switch
1711 		 * is in safe mode.
1712 		 */
1713 		if (!sw->safe_mode)
1714 			return 0;
1715 		break;
1716 	}
1717 
1718 	/* Root switch DMA port requires running firmware */
1719 	if (!tb_route(sw) && sw->config.enabled)
1720 		return 0;
1721 
1722 	sw->dma_port = dma_port_alloc(sw);
1723 	if (!sw->dma_port)
1724 		return 0;
1725 
1726 	if (sw->no_nvm_upgrade)
1727 		return 0;
1728 
1729 	/*
1730 	 * Check status of the previous flash authentication. If there
1731 	 * is one we need to power cycle the switch in any case to make
1732 	 * it functional again.
1733 	 */
1734 	ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
1735 	if (ret <= 0)
1736 		return ret;
1737 
1738 	/* Now we can allow root port to suspend again */
1739 	if (!tb_route(sw))
1740 		nvm_authenticate_complete(sw);
1741 
1742 	if (status) {
1743 		tb_sw_info(sw, "switch flash authentication failed\n");
1744 		ret = tb_switch_set_uuid(sw);
1745 		if (ret)
1746 			return ret;
1747 		nvm_set_auth_status(sw, status);
1748 	}
1749 
1750 	tb_sw_info(sw, "power cycling the switch now\n");
1751 	dma_port_power_cycle(sw->dma_port);
1752 
1753 	/*
1754 	 * We return error here which causes the switch adding failure.
1755 	 * It should appear back after power cycle is complete.
1756 	 */
1757 	return -ESHUTDOWN;
1758 }
1759 
1760 /**
1761  * tb_switch_add() - Add a switch to the domain
1762  * @sw: Switch to add
1763  *
1764  * This is the last step in adding switch to the domain. It will read
1765  * identification information from DROM and initializes ports so that
1766  * they can be used to connect other switches. The switch will be
1767  * exposed to the userspace when this function successfully returns. To
1768  * remove and release the switch, call tb_switch_remove().
1769  *
1770  * Return: %0 in case of success and negative errno in case of failure
1771  */
1772 int tb_switch_add(struct tb_switch *sw)
1773 {
1774 	int i, ret;
1775 
1776 	/*
1777 	 * Initialize DMA control port now before we read DROM. Recent
1778 	 * host controllers have more complete DROM on NVM that includes
1779 	 * vendor and model identification strings which we then expose
1780 	 * to the userspace. NVM can be accessed through DMA
1781 	 * configuration based mailbox.
1782 	 */
1783 	ret = tb_switch_add_dma_port(sw);
1784 	if (ret)
1785 		return ret;
1786 
1787 	if (!sw->safe_mode) {
1788 		/* read drom */
1789 		ret = tb_drom_read(sw);
1790 		if (ret) {
1791 			tb_sw_warn(sw, "tb_eeprom_read_rom failed\n");
1792 			return ret;
1793 		}
1794 		tb_sw_dbg(sw, "uid: %#llx\n", sw->uid);
1795 
1796 		ret = tb_switch_set_uuid(sw);
1797 		if (ret)
1798 			return ret;
1799 
1800 		for (i = 0; i <= sw->config.max_port_number; i++) {
1801 			if (sw->ports[i].disabled) {
1802 				tb_port_dbg(&sw->ports[i], "disabled by eeprom\n");
1803 				continue;
1804 			}
1805 			ret = tb_init_port(&sw->ports[i]);
1806 			if (ret)
1807 				return ret;
1808 		}
1809 	}
1810 
1811 	ret = device_add(&sw->dev);
1812 	if (ret)
1813 		return ret;
1814 
1815 	if (tb_route(sw)) {
1816 		dev_info(&sw->dev, "new device found, vendor=%#x device=%#x\n",
1817 			 sw->vendor, sw->device);
1818 		if (sw->vendor_name && sw->device_name)
1819 			dev_info(&sw->dev, "%s %s\n", sw->vendor_name,
1820 				 sw->device_name);
1821 	}
1822 
1823 	ret = tb_switch_nvm_add(sw);
1824 	if (ret) {
1825 		device_del(&sw->dev);
1826 		return ret;
1827 	}
1828 
1829 	pm_runtime_set_active(&sw->dev);
1830 	if (sw->rpm) {
1831 		pm_runtime_set_autosuspend_delay(&sw->dev, TB_AUTOSUSPEND_DELAY);
1832 		pm_runtime_use_autosuspend(&sw->dev);
1833 		pm_runtime_mark_last_busy(&sw->dev);
1834 		pm_runtime_enable(&sw->dev);
1835 		pm_request_autosuspend(&sw->dev);
1836 	}
1837 
1838 	return 0;
1839 }
1840 
1841 /**
1842  * tb_switch_remove() - Remove and release a switch
1843  * @sw: Switch to remove
1844  *
1845  * This will remove the switch from the domain and release it after last
1846  * reference count drops to zero. If there are switches connected below
1847  * this switch, they will be removed as well.
1848  */
1849 void tb_switch_remove(struct tb_switch *sw)
1850 {
1851 	int i;
1852 
1853 	if (sw->rpm) {
1854 		pm_runtime_get_sync(&sw->dev);
1855 		pm_runtime_disable(&sw->dev);
1856 	}
1857 
1858 	/* port 0 is the switch itself and never has a remote */
1859 	for (i = 1; i <= sw->config.max_port_number; i++) {
1860 		if (tb_port_has_remote(&sw->ports[i])) {
1861 			tb_switch_remove(sw->ports[i].remote->sw);
1862 			sw->ports[i].remote = NULL;
1863 		} else if (sw->ports[i].xdomain) {
1864 			tb_xdomain_remove(sw->ports[i].xdomain);
1865 			sw->ports[i].xdomain = NULL;
1866 		}
1867 	}
1868 
1869 	if (!sw->is_unplugged)
1870 		tb_plug_events_active(sw, false);
1871 	tb_lc_unconfigure_link(sw);
1872 
1873 	tb_switch_nvm_remove(sw);
1874 
1875 	if (tb_route(sw))
1876 		dev_info(&sw->dev, "device disconnected\n");
1877 	device_unregister(&sw->dev);
1878 }
1879 
1880 /**
1881  * tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
1882  */
1883 void tb_sw_set_unplugged(struct tb_switch *sw)
1884 {
1885 	int i;
1886 	if (sw == sw->tb->root_switch) {
1887 		tb_sw_WARN(sw, "cannot unplug root switch\n");
1888 		return;
1889 	}
1890 	if (sw->is_unplugged) {
1891 		tb_sw_WARN(sw, "is_unplugged already set\n");
1892 		return;
1893 	}
1894 	sw->is_unplugged = true;
1895 	for (i = 0; i <= sw->config.max_port_number; i++) {
1896 		if (tb_port_has_remote(&sw->ports[i]))
1897 			tb_sw_set_unplugged(sw->ports[i].remote->sw);
1898 		else if (sw->ports[i].xdomain)
1899 			sw->ports[i].xdomain->is_unplugged = true;
1900 	}
1901 }
1902 
1903 int tb_switch_resume(struct tb_switch *sw)
1904 {
1905 	int i, err;
1906 	tb_sw_dbg(sw, "resuming switch\n");
1907 
1908 	/*
1909 	 * Check for UID of the connected switches except for root
1910 	 * switch which we assume cannot be removed.
1911 	 */
1912 	if (tb_route(sw)) {
1913 		u64 uid;
1914 
1915 		/*
1916 		 * Check first that we can still read the switch config
1917 		 * space. It may be that there is now another domain
1918 		 * connected.
1919 		 */
1920 		err = tb_cfg_get_upstream_port(sw->tb->ctl, tb_route(sw));
1921 		if (err < 0) {
1922 			tb_sw_info(sw, "switch not present anymore\n");
1923 			return err;
1924 		}
1925 
1926 		err = tb_drom_read_uid_only(sw, &uid);
1927 		if (err) {
1928 			tb_sw_warn(sw, "uid read failed\n");
1929 			return err;
1930 		}
1931 		if (sw->uid != uid) {
1932 			tb_sw_info(sw,
1933 				"changed while suspended (uid %#llx -> %#llx)\n",
1934 				sw->uid, uid);
1935 			return -ENODEV;
1936 		}
1937 	}
1938 
1939 	/* upload configuration */
1940 	err = tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3);
1941 	if (err)
1942 		return err;
1943 
1944 	err = tb_lc_configure_link(sw);
1945 	if (err)
1946 		return err;
1947 
1948 	err = tb_plug_events_active(sw, true);
1949 	if (err)
1950 		return err;
1951 
1952 	/* check for surviving downstream switches */
1953 	for (i = 1; i <= sw->config.max_port_number; i++) {
1954 		struct tb_port *port = &sw->ports[i];
1955 
1956 		if (!tb_port_has_remote(port) && !port->xdomain)
1957 			continue;
1958 
1959 		if (tb_wait_for_port(port, true) <= 0) {
1960 			tb_port_warn(port,
1961 				     "lost during suspend, disconnecting\n");
1962 			if (tb_port_has_remote(port))
1963 				tb_sw_set_unplugged(port->remote->sw);
1964 			else if (port->xdomain)
1965 				port->xdomain->is_unplugged = true;
1966 		} else if (tb_port_has_remote(port)) {
1967 			if (tb_switch_resume(port->remote->sw)) {
1968 				tb_port_warn(port,
1969 					     "lost during suspend, disconnecting\n");
1970 				tb_sw_set_unplugged(port->remote->sw);
1971 			}
1972 		}
1973 	}
1974 	return 0;
1975 }
1976 
1977 void tb_switch_suspend(struct tb_switch *sw)
1978 {
1979 	int i, err;
1980 	err = tb_plug_events_active(sw, false);
1981 	if (err)
1982 		return;
1983 
1984 	for (i = 1; i <= sw->config.max_port_number; i++) {
1985 		if (tb_port_has_remote(&sw->ports[i]))
1986 			tb_switch_suspend(sw->ports[i].remote->sw);
1987 	}
1988 
1989 	tb_lc_set_sleep(sw);
1990 }
1991 
1992 struct tb_sw_lookup {
1993 	struct tb *tb;
1994 	u8 link;
1995 	u8 depth;
1996 	const uuid_t *uuid;
1997 	u64 route;
1998 };
1999 
2000 static int tb_switch_match(struct device *dev, const void *data)
2001 {
2002 	struct tb_switch *sw = tb_to_switch(dev);
2003 	const struct tb_sw_lookup *lookup = data;
2004 
2005 	if (!sw)
2006 		return 0;
2007 	if (sw->tb != lookup->tb)
2008 		return 0;
2009 
2010 	if (lookup->uuid)
2011 		return !memcmp(sw->uuid, lookup->uuid, sizeof(*lookup->uuid));
2012 
2013 	if (lookup->route) {
2014 		return sw->config.route_lo == lower_32_bits(lookup->route) &&
2015 		       sw->config.route_hi == upper_32_bits(lookup->route);
2016 	}
2017 
2018 	/* Root switch is matched only by depth */
2019 	if (!lookup->depth)
2020 		return !sw->depth;
2021 
2022 	return sw->link == lookup->link && sw->depth == lookup->depth;
2023 }
2024 
2025 /**
2026  * tb_switch_find_by_link_depth() - Find switch by link and depth
2027  * @tb: Domain the switch belongs
2028  * @link: Link number the switch is connected
2029  * @depth: Depth of the switch in link
2030  *
2031  * Returned switch has reference count increased so the caller needs to
2032  * call tb_switch_put() when done with the switch.
2033  */
2034 struct tb_switch *tb_switch_find_by_link_depth(struct tb *tb, u8 link, u8 depth)
2035 {
2036 	struct tb_sw_lookup lookup;
2037 	struct device *dev;
2038 
2039 	memset(&lookup, 0, sizeof(lookup));
2040 	lookup.tb = tb;
2041 	lookup.link = link;
2042 	lookup.depth = depth;
2043 
2044 	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
2045 	if (dev)
2046 		return tb_to_switch(dev);
2047 
2048 	return NULL;
2049 }
2050 
2051 /**
2052  * tb_switch_find_by_uuid() - Find switch by UUID
2053  * @tb: Domain the switch belongs
2054  * @uuid: UUID to look for
2055  *
2056  * Returned switch has reference count increased so the caller needs to
2057  * call tb_switch_put() when done with the switch.
2058  */
2059 struct tb_switch *tb_switch_find_by_uuid(struct tb *tb, const uuid_t *uuid)
2060 {
2061 	struct tb_sw_lookup lookup;
2062 	struct device *dev;
2063 
2064 	memset(&lookup, 0, sizeof(lookup));
2065 	lookup.tb = tb;
2066 	lookup.uuid = uuid;
2067 
2068 	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
2069 	if (dev)
2070 		return tb_to_switch(dev);
2071 
2072 	return NULL;
2073 }
2074 
2075 /**
2076  * tb_switch_find_by_route() - Find switch by route string
2077  * @tb: Domain the switch belongs
2078  * @route: Route string to look for
2079  *
2080  * Returned switch has reference count increased so the caller needs to
2081  * call tb_switch_put() when done with the switch.
2082  */
2083 struct tb_switch *tb_switch_find_by_route(struct tb *tb, u64 route)
2084 {
2085 	struct tb_sw_lookup lookup;
2086 	struct device *dev;
2087 
2088 	if (!route)
2089 		return tb_switch_get(tb->root_switch);
2090 
2091 	memset(&lookup, 0, sizeof(lookup));
2092 	lookup.tb = tb;
2093 	lookup.route = route;
2094 
2095 	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
2096 	if (dev)
2097 		return tb_to_switch(dev);
2098 
2099 	return NULL;
2100 }
2101 
2102 void tb_switch_exit(void)
2103 {
2104 	ida_destroy(&nvm_ida);
2105 }
2106