summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/switch.c
blob: 2390f08b94da697e3190b8461ef28ce5552b397c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
/*
 * Thunderbolt Cactus Ridge driver - switch/port utility functions
 *
 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
 */

#include <linux/delay.h>
#include <linux/slab.h>

#include "tb.h"

/* port utility functions */

static const char *tb_port_type(struct tb_regs_port_header *port)
{
	switch (port->type >> 16) {
	case 0:
		switch ((u8) port->type) {
		case 0:
			return "Inactive";
		case 1:
			return "Port";
		case 2:
			return "NHI";
		default:
			return "unknown";
		}
	case 0x2:
		return "Ethernet";
	case 0x8:
		return "SATA";
	case 0xe:
		return "DP/HDMI";
	case 0x10:
		return "PCIe";
	case 0x20:
		return "USB";
	default:
		return "unknown";
	}
}

static void tb_dump_port(struct tb *tb, struct tb_regs_port_header *port)
{
	tb_info(tb,
		" Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
		port->port_number, port->vendor_id, port->device_id,
		port->revision, port->thunderbolt_version, tb_port_type(port),
		port->type);
	tb_info(tb, "  Max hop id (in/out): %d/%d\n",
		port->max_in_hop_id, port->max_out_hop_id);
	tb_info(tb, "  Max counters: %d\n", port->max_counters);
	tb_info(tb, "  NFC Credits: %#x\n", port->nfc_credits);
}

/**
 * tb_port_state() - get connectedness state of a port
 *
 * The port must have a TB_CAP_PHY (i.e. it should be a real port).
 *
 * Return: Returns an enum tb_port_state on success or an error code on failure.
 */
static int tb_port_state(struct tb_port *port)
{
	struct tb_cap_phy phy;
	int res;
	if (port->cap_phy == 0) {
		tb_port_WARN(port, "does not have a PHY\n");
		return -EINVAL;
	}
	res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
	if (res)
		return res;
	return phy.state;
}

/**
 * tb_wait_for_port() - wait for a port to become ready
 *
 * Wait up to 1 second for a port to reach state TB_PORT_UP. If
 * wait_if_unplugged is set then we also wait if the port is in state
 * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
 * switch resume). Otherwise we only wait if a device is registered but the link
 * has not yet been established.
 *
 * Return: Returns an error code on failure. Returns 0 if the port is not
 * connected or failed to reach state TB_PORT_UP within one second. Returns 1
 * if the port is connected and in state TB_PORT_UP.
 */
int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
{
	int retries = 10;
	int state;
	if (!port->cap_phy) {
		tb_port_WARN(port, "does not have PHY\n");
		return -EINVAL;
	}
	if (tb_is_upstream_port(port)) {
		tb_port_WARN(port, "is the upstream port\n");
		return -EINVAL;
	}

	while (retries--) {
		state = tb_port_state(port);
		if (state < 0)
			return state;
		if (state == TB_PORT_DISABLED) {
			tb_port_info(port, "is disabled (state: 0)\n");
			return 0;
		}
		if (state == TB_PORT_UNPLUGGED) {
			if (wait_if_unplugged) {
				/* used during resume */
				tb_port_info(port,
					     "is unplugged (state: 7), retrying...\n");
				msleep(100);
				continue;
			}
			tb_port_info(port, "is unplugged (state: 7)\n");
			return 0;
		}
		if (state == TB_PORT_UP) {
			tb_port_info(port,
				     "is connected, link is up (state: 2)\n");
			return 1;
		}

		/*
		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
		 * time.
		 */
		tb_port_info(port,
			     "is connected, link is not up (state: %d), retrying...\n",
			     state);
		msleep(100);
	}
	tb_port_warn(port,
		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
	return 0;
}

/**
 * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
 *
 * Change the number of NFC credits allocated to @port by @credits. To remove
 * NFC credits pass a negative amount of credits.
 *
 * Return: Returns 0 on success or an error code on failure.
 */
int tb_port_add_nfc_credits(struct tb_port *port, int credits)
{
	if (credits == 0)
		return 0;
	tb_port_info(port,
		     "adding %#x NFC credits (%#x -> %#x)",
		     credits,
		     port->config.nfc_credits,
		     port->config.nfc_credits + credits);
	port->config.nfc_credits += credits;
	return tb_port_write(port, &port->config.nfc_credits,
			     TB_CFG_PORT, 4, 1);
}

/**
 * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
 *
 * Return: Returns 0 on success or an error code on failure.
 */
int tb_port_clear_counter(struct tb_port *port, int counter)
{
	u32 zero[3] = { 0, 0, 0 };
	tb_port_info(port, "clearing counter %d\n", counter);
	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
}

/**
 * tb_init_port() - initialize a port
 *
 * This is a helper method for tb_switch_alloc. Does not check or initialize
 * any downstream switches.
 *
 * Return: Returns 0 on success or an error code on failure.
 */
static int tb_init_port(struct tb_port *port)
{
	int res;
	int cap;

	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
	if (res)
		return res;

	/* Port 0 is the switch itself and has no PHY. */
	if (port->config.type == TB_TYPE_PORT && port->port != 0) {
		cap = tb_port_find_cap(port, TB_PORT_CAP_PHY);

		if (cap > 0)
			port->cap_phy = cap;
		else
			tb_port_WARN(port, "non switch port without a PHY\n");
	}

	tb_dump_port(port->sw->tb, &port->config);

	/* TODO: Read dual link port, DP port and more from EEPROM. */
	return 0;

}

/* switch utility functions */

static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
{
	tb_info(tb,
		" Switch: %x:%x (Revision: %d, TB Version: %d)\n",
		sw->vendor_id, sw->device_id, sw->revision,
		sw->thunderbolt_version);
	tb_info(tb, "  Max Port Number: %d\n", sw->max_port_number);
	tb_info(tb, "  Config:\n");
	tb_info(tb,
		"   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
		sw->upstream_port_number, sw->depth,
		(((u64) sw->route_hi) << 32) | sw->route_lo,
		sw->enabled, sw->plug_events_delay);
	tb_info(tb,
		"   unknown1: %#x unknown4: %#x\n",
		sw->__unknown1, sw->__unknown4);
}

/**
 * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
 *
 * Return: Returns 0 on success or an error code on failure.
 */
int tb_switch_reset(struct tb *tb, u64 route)
{
	struct tb_cfg_result res;
	struct tb_regs_switch_header header = {
		header.route_hi = route >> 32,
		header.route_lo = route,
		header.enabled = true,
	};
	tb_info(tb, "resetting switch at %llx\n", route);
	res.err = tb_cfg_write(tb->ctl, ((u32 *) &header) + 2, route,
			0, 2, 2, 2);
	if (res.err)
		return res.err;
	res = tb_cfg_reset(tb->ctl, route, TB_CFG_DEFAULT_TIMEOUT);
	if (res.err > 0)
		return -EIO;
	return res.err;
}

struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
{
	u8 next_port = route; /*
			       * Routes use a stride of 8 bits,
			       * eventhough a port index has 6 bits at most.
			       * */
	if (route == 0)
		return sw;
	if (next_port > sw->config.max_port_number)
		return NULL;
	if (tb_is_upstream_port(&sw->ports[next_port]))
		return NULL;
	if (!sw->ports[next_port].remote)
		return NULL;
	return get_switch_at_route(sw->ports[next_port].remote->sw,
				   route >> TB_ROUTE_SHIFT);
}

/**
 * tb_plug_events_active() - enable/disable plug events on a switch
 *
 * Also configures a sane plug_events_delay of 255ms.
 *
 * Return: Returns 0 on success or an error code on failure.
 */
static int tb_plug_events_active(struct tb_switch *sw, bool active)
{
	u32 data;
	int res;

	if (!sw->config.enabled)
		return 0;

	sw->config.plug_events_delay = 0xff;
	res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
	if (res)
		return res;

	res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
	if (res)
		return res;

	if (active) {
		data = data & 0xFFFFFF83;
		switch (sw->config.device_id) {
		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
		case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
			break;
		default:
			data |= 4;
		}
	} else {
		data = data | 0x7c;
	}
	return tb_sw_write(sw, &data, TB_CFG_SWITCH,
			   sw->cap_plug_events + 1, 1);
}

static ssize_t device_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_switch *sw = tb_to_switch(dev);

	return sprintf(buf, "%#x\n", sw->device);
}
static DEVICE_ATTR_RO(device);

static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_switch *sw = tb_to_switch(dev);

	return sprintf(buf, "%#x\n", sw->vendor);
}
static DEVICE_ATTR_RO(vendor);

static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct tb_switch *sw = tb_to_switch(dev);

	return sprintf(buf, "%pUb\n", sw->uuid);
}
static DEVICE_ATTR_RO(unique_id);

static struct attribute *switch_attrs[] = {
	&dev_attr_device.attr,
	&dev_attr_vendor.attr,
	&dev_attr_unique_id.attr,
	NULL,
};

static struct attribute_group switch_group = {
	.attrs = switch_attrs,
};

static const struct attribute_group *switch_groups[] = {
	&switch_group,
	NULL,
};

static void tb_switch_release(struct device *dev)
{
	struct tb_switch *sw = tb_to_switch(dev);

	kfree(sw->uuid);
	kfree(sw->ports);
	kfree(sw->drom);
	kfree(sw);
}

struct device_type tb_switch_type = {
	.name = "thunderbolt_device",
	.release = tb_switch_release,
};

/**
 * tb_switch_alloc() - allocate a switch
 * @tb: Pointer to the owning domain
 * @parent: Parent device for this switch
 * @route: Route string for this switch
 *
 * Allocates and initializes a switch. Will not upload configuration to
 * the switch. For that you need to call tb_switch_configure()
 * separately. The returned switch should be released by calling
 * tb_switch_put().
 *
 * Return: Pointer to the allocated switch or %NULL in case of failure
 */
struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
				  u64 route)
{
	int i;
	int cap;
	struct tb_switch *sw;
	int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
	if (upstream_port < 0)
		return NULL;

	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
	if (!sw)
		return NULL;

	sw->tb = tb;
	if (tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5))
		goto err_free_sw_ports;

	tb_info(tb, "current switch config:\n");
	tb_dump_switch(tb, &sw->config);

	/* configure switch */
	sw->config.upstream_port_number = upstream_port;
	sw->config.depth = tb_route_length(route);
	sw->config.route_lo = route;
	sw->config.route_hi = route >> 32;
	sw->config.enabled = 0;

	/* initialize ports */
	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
				GFP_KERNEL);
	if (!sw->ports)
		goto err_free_sw_ports;

	for (i = 0; i <= sw->config.max_port_number; i++) {
		/* minimum setup for tb_find_cap and tb_drom_read to work */
		sw->ports[i].sw = sw;
		sw->ports[i].port = i;
	}

	cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
	if (cap < 0) {
		tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
		goto err_free_sw_ports;
	}
	sw->cap_plug_events = cap;

	device_initialize(&sw->dev);
	sw->dev.parent = parent;
	sw->dev.bus = &tb_bus_type;
	sw->dev.type = &tb_switch_type;
	sw->dev.groups = switch_groups;
	dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));

	return sw;

err_free_sw_ports:
	kfree(sw->ports);
	kfree(sw);

	return NULL;
}

/**
 * tb_switch_configure() - Uploads configuration to the switch
 * @sw: Switch to configure
 *
 * Call this function before the switch is added to the system. It will
 * upload configuration to the switch and makes it available for the
 * connection manager to use.
 *
 * Return: %0 in case of success and negative errno in case of failure
 */
int tb_switch_configure(struct tb_switch *sw)
{
	struct tb *tb = sw->tb;
	u64 route;
	int ret;

	route = tb_route(sw);
	tb_info(tb,
		"initializing Switch at %#llx (depth: %d, up port: %d)\n",
		route, tb_route_length(route), sw->config.upstream_port_number);

	if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
		tb_sw_warn(sw, "unknown switch vendor id %#x\n",
			   sw->config.vendor_id);

	if (sw->config.device_id != PCI_DEVICE_ID_INTEL_LIGHT_RIDGE &&
	    sw->config.device_id != PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C &&
	    sw->config.device_id != PCI_DEVICE_ID_INTEL_PORT_RIDGE &&
	    sw->config.device_id != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE &&
	    sw->config.device_id != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE)
		tb_sw_warn(sw, "unsupported switch device id %#x\n",
			   sw->config.device_id);

	sw->config.enabled = 1;

	/* upload configuration */
	ret = tb_sw_write(sw, 1 + (u32 *)&sw->config, TB_CFG_SWITCH, 1, 3);
	if (ret)
		return ret;

	return tb_plug_events_active(sw, true);
}

static void tb_switch_set_uuid(struct tb_switch *sw)
{
	u32 uuid[4];
	int cap;

	if (sw->uuid)
		return;

	/*
	 * The newer controllers include fused UUID as part of link
	 * controller specific registers
	 */
	cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
	if (cap > 0) {
		tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
	} else {
		/*
		 * ICM generates UUID based on UID and fills the upper
		 * two words with ones. This is not strictly following
		 * UUID format but we want to be compatible with it so
		 * we do the same here.
		 */
		uuid[0] = sw->uid & 0xffffffff;
		uuid[1] = (sw->uid >> 32) & 0xffffffff;
		uuid[2] = 0xffffffff;
		uuid[3] = 0xffffffff;
	}

	sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
}

/**
 * tb_switch_add() - Add a switch to the domain
 * @sw: Switch to add
 *
 * This is the last step in adding switch to the domain. It will read
 * identification information from DROM and initializes ports so that
 * they can be used to connect other switches. The switch will be
 * exposed to the userspace when this function successfully returns. To
 * remove and release the switch, call tb_switch_remove().
 *
 * Return: %0 in case of success and negative errno in case of failure
 */
int tb_switch_add(struct tb_switch *sw)
{
	int i, ret;

	/* read drom */
	ret = tb_drom_read(sw);
	if (ret) {
		tb_sw_warn(sw, "tb_eeprom_read_rom failed\n");
		return ret;
	}
	tb_sw_info(sw, "uid: %#llx\n", sw->uid);

	tb_switch_set_uuid(sw);

	for (i = 0; i <= sw->config.max_port_number; i++) {
		if (sw->ports[i].disabled) {
			tb_port_info(&sw->ports[i], "disabled by eeprom\n");
			continue;
		}
		ret = tb_init_port(&sw->ports[i]);
		if (ret)
			return ret;
	}

	return device_add(&sw->dev);
}

/**
 * tb_switch_remove() - Remove and release a switch
 * @sw: Switch to remove
 *
 * This will remove the switch from the domain and release it after last
 * reference count drops to zero. If there are switches connected below
 * this switch, they will be removed as well.
 */
void tb_switch_remove(struct tb_switch *sw)
{
	int i;

	/* port 0 is the switch itself and never has a remote */
	for (i = 1; i <= sw->config.max_port_number; i++) {
		if (tb_is_upstream_port(&sw->ports[i]))
			continue;
		if (sw->ports[i].remote)
			tb_switch_remove(sw->ports[i].remote->sw);
		sw->ports[i].remote = NULL;
	}

	if (!sw->is_unplugged)
		tb_plug_events_active(sw, false);

	device_unregister(&sw->dev);
}

/**
 * tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
 */
void tb_sw_set_unplugged(struct tb_switch *sw)
{
	int i;
	if (sw == sw->tb->root_switch) {
		tb_sw_WARN(sw, "cannot unplug root switch\n");
		return;
	}
	if (sw->is_unplugged) {
		tb_sw_WARN(sw, "is_unplugged already set\n");
		return;
	}
	sw->is_unplugged = true;
	for (i = 0; i <= sw->config.max_port_number; i++) {
		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
			tb_sw_set_unplugged(sw->ports[i].remote->sw);
	}
}

int tb_switch_resume(struct tb_switch *sw)
{
	int i, err;
	tb_sw_info(sw, "resuming switch\n");

	/*
	 * Check for UID of the connected switches except for root
	 * switch which we assume cannot be removed.
	 */
	if (tb_route(sw)) {
		u64 uid;

		err = tb_drom_read_uid_only(sw, &uid);
		if (err) {
			tb_sw_warn(sw, "uid read failed\n");
			return err;
		}
		if (sw->uid != uid) {
			tb_sw_info(sw,
				"changed while suspended (uid %#llx -> %#llx)\n",
				sw->uid, uid);
			return -ENODEV;
		}
	}

	/* upload configuration */
	err = tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3);
	if (err)
		return err;

	err = tb_plug_events_active(sw, true);
	if (err)
		return err;

	/* check for surviving downstream switches */
	for (i = 1; i <= sw->config.max_port_number; i++) {
		struct tb_port *port = &sw->ports[i];
		if (tb_is_upstream_port(port))
			continue;
		if (!port->remote)
			continue;
		if (tb_wait_for_port(port, true) <= 0
			|| tb_switch_resume(port->remote->sw)) {
			tb_port_warn(port,
				     "lost during suspend, disconnecting\n");
			tb_sw_set_unplugged(port->remote->sw);
		}
	}
	return 0;
}

void tb_switch_suspend(struct tb_switch *sw)
{
	int i, err;
	err = tb_plug_events_active(sw, false);
	if (err)
		return;

	for (i = 1; i <= sw->config.max_port_number; i++) {
		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
			tb_switch_suspend(sw->ports[i].remote->sw);
	}
	/*
	 * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
	 * effect?
	 */
}