summaryrefslogtreecommitdiff
path: root/drivers/thunderbolt/domain.c
blob: 9f2dcd48974d69d267a6987b957edda5667a1952 (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
/*
 * Thunderbolt bus support
 *
 * Copyright (C) 2017, Intel Corporation
 * Author:  Mika Westerberg <mika.westerberg@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <crypto/hash.h>

#include "tb.h"

static DEFINE_IDA(tb_domain_ida);

static const char * const tb_security_names[] = {
	[TB_SECURITY_NONE] = "none",
	[TB_SECURITY_USER] = "user",
	[TB_SECURITY_SECURE] = "secure",
	[TB_SECURITY_DPONLY] = "dponly",
};

static ssize_t security_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb *tb = container_of(dev, struct tb, dev);

	return sprintf(buf, "%s\n", tb_security_names[tb->security_level]);
}
static DEVICE_ATTR_RO(security);

static struct attribute *domain_attrs[] = {
	&dev_attr_security.attr,
	NULL,
};

static struct attribute_group domain_attr_group = {
	.attrs = domain_attrs,
};

static const struct attribute_group *domain_attr_groups[] = {
	&domain_attr_group,
	NULL,
};

struct bus_type tb_bus_type = {
	.name = "thunderbolt",
};

static void tb_domain_release(struct device *dev)
{
	struct tb *tb = container_of(dev, struct tb, dev);

	tb_ctl_free(tb->ctl);
	destroy_workqueue(tb->wq);
	ida_simple_remove(&tb_domain_ida, tb->index);
	mutex_destroy(&tb->lock);
	kfree(tb);
}

struct device_type tb_domain_type = {
	.name = "thunderbolt_domain",
	.release = tb_domain_release,
};

/**
 * tb_domain_alloc() - Allocate a domain
 * @nhi: Pointer to the host controller
 * @privsize: Size of the connection manager private data
 *
 * Allocates and initializes a new Thunderbolt domain. Connection
 * managers are expected to call this and then fill in @cm_ops
 * accordingly.
 *
 * Call tb_domain_put() to release the domain before it has been added
 * to the system.
 *
 * Return: allocated domain structure on %NULL in case of error
 */
struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize)
{
	struct tb *tb;

	/*
	 * Make sure the structure sizes map with that the hardware
	 * expects because bit-fields are being used.
	 */
	BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
	BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
	BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);

	tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL);
	if (!tb)
		return NULL;

	tb->nhi = nhi;
	mutex_init(&tb->lock);

	tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL);
	if (tb->index < 0)
		goto err_free;

	tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index);
	if (!tb->wq)
		goto err_remove_ida;

	tb->dev.parent = &nhi->pdev->dev;
	tb->dev.bus = &tb_bus_type;
	tb->dev.type = &tb_domain_type;
	tb->dev.groups = domain_attr_groups;
	dev_set_name(&tb->dev, "domain%d", tb->index);
	device_initialize(&tb->dev);

	return tb;

err_remove_ida:
	ida_simple_remove(&tb_domain_ida, tb->index);
err_free:
	kfree(tb);

	return NULL;
}

static void tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
			       const void *buf, size_t size)
{
	struct tb *tb = data;

	if (!tb->cm_ops->handle_event) {
		tb_warn(tb, "domain does not have event handler\n");
		return;
	}

	tb->cm_ops->handle_event(tb, type, buf, size);
}

/**
 * tb_domain_add() - Add domain to the system
 * @tb: Domain to add
 *
 * Starts the domain and adds it to the system. Hotplugging devices will
 * work after this has been returned successfully. In order to remove
 * and release the domain after this function has been called, call
 * tb_domain_remove().
 *
 * Return: %0 in case of success and negative errno in case of error
 */
int tb_domain_add(struct tb *tb)
{
	int ret;

	if (WARN_ON(!tb->cm_ops))
		return -EINVAL;

	mutex_lock(&tb->lock);

	tb->ctl = tb_ctl_alloc(tb->nhi, tb_domain_event_cb, tb);
	if (!tb->ctl) {
		ret = -ENOMEM;
		goto err_unlock;
	}

	/*
	 * tb_schedule_hotplug_handler may be called as soon as the config
	 * channel is started. Thats why we have to hold the lock here.
	 */
	tb_ctl_start(tb->ctl);

	if (tb->cm_ops->driver_ready) {
		ret = tb->cm_ops->driver_ready(tb);
		if (ret)
			goto err_ctl_stop;
	}

	ret = device_add(&tb->dev);
	if (ret)
		goto err_ctl_stop;

	/* Start the domain */
	if (tb->cm_ops->start) {
		ret = tb->cm_ops->start(tb);
		if (ret)
			goto err_domain_del;
	}

	/* This starts event processing */
	mutex_unlock(&tb->lock);

	return 0;

err_domain_del:
	device_del(&tb->dev);
err_ctl_stop:
	tb_ctl_stop(tb->ctl);
err_unlock:
	mutex_unlock(&tb->lock);

	return ret;
}

/**
 * tb_domain_remove() - Removes and releases a domain
 * @tb: Domain to remove
 *
 * Stops the domain, removes it from the system and releases all
 * resources once the last reference has been released.
 */
void tb_domain_remove(struct tb *tb)
{
	mutex_lock(&tb->lock);
	if (tb->cm_ops->stop)
		tb->cm_ops->stop(tb);
	/* Stop the domain control traffic */
	tb_ctl_stop(tb->ctl);
	mutex_unlock(&tb->lock);

	flush_workqueue(tb->wq);
	device_unregister(&tb->dev);
}

/**
 * tb_domain_suspend_noirq() - Suspend a domain
 * @tb: Domain to suspend
 *
 * Suspends all devices in the domain and stops the control channel.
 */
int tb_domain_suspend_noirq(struct tb *tb)
{
	int ret = 0;

	/*
	 * The control channel interrupt is left enabled during suspend
	 * and taking the lock here prevents any events happening before
	 * we actually have stopped the domain and the control channel.
	 */
	mutex_lock(&tb->lock);
	if (tb->cm_ops->suspend_noirq)
		ret = tb->cm_ops->suspend_noirq(tb);
	if (!ret)
		tb_ctl_stop(tb->ctl);
	mutex_unlock(&tb->lock);

	return ret;
}

/**
 * tb_domain_resume_noirq() - Resume a domain
 * @tb: Domain to resume
 *
 * Re-starts the control channel, and resumes all devices connected to
 * the domain.
 */
int tb_domain_resume_noirq(struct tb *tb)
{
	int ret = 0;

	mutex_lock(&tb->lock);
	tb_ctl_start(tb->ctl);
	if (tb->cm_ops->resume_noirq)
		ret = tb->cm_ops->resume_noirq(tb);
	mutex_unlock(&tb->lock);

	return ret;
}

int tb_domain_suspend(struct tb *tb)
{
	int ret;

	mutex_lock(&tb->lock);
	if (tb->cm_ops->suspend) {
		ret = tb->cm_ops->suspend(tb);
		if (ret) {
			mutex_unlock(&tb->lock);
			return ret;
		}
	}
	mutex_unlock(&tb->lock);
	return 0;
}

void tb_domain_complete(struct tb *tb)
{
	mutex_lock(&tb->lock);
	if (tb->cm_ops->complete)
		tb->cm_ops->complete(tb);
	mutex_unlock(&tb->lock);
}

/**
 * tb_domain_approve_switch() - Approve switch
 * @tb: Domain the switch belongs to
 * @sw: Switch to approve
 *
 * This will approve switch by connection manager specific means. In
 * case of success the connection manager will create tunnels for all
 * supported protocols.
 */
int tb_domain_approve_switch(struct tb *tb, struct tb_switch *sw)
{
	struct tb_switch *parent_sw;

	if (!tb->cm_ops->approve_switch)
		return -EPERM;

	/* The parent switch must be authorized before this one */
	parent_sw = tb_to_switch(sw->dev.parent);
	if (!parent_sw || !parent_sw->authorized)
		return -EINVAL;

	return tb->cm_ops->approve_switch(tb, sw);
}

/**
 * tb_domain_approve_switch_key() - Approve switch and add key
 * @tb: Domain the switch belongs to
 * @sw: Switch to approve
 *
 * For switches that support secure connect, this function first adds
 * key to the switch NVM using connection manager specific means. If
 * adding the key is successful, the switch is approved and connected.
 *
 * Return: %0 on success and negative errno in case of failure.
 */
int tb_domain_approve_switch_key(struct tb *tb, struct tb_switch *sw)
{
	struct tb_switch *parent_sw;
	int ret;

	if (!tb->cm_ops->approve_switch || !tb->cm_ops->add_switch_key)
		return -EPERM;

	/* The parent switch must be authorized before this one */
	parent_sw = tb_to_switch(sw->dev.parent);
	if (!parent_sw || !parent_sw->authorized)
		return -EINVAL;

	ret = tb->cm_ops->add_switch_key(tb, sw);
	if (ret)
		return ret;

	return tb->cm_ops->approve_switch(tb, sw);
}

/**
 * tb_domain_challenge_switch_key() - Challenge and approve switch
 * @tb: Domain the switch belongs to
 * @sw: Switch to approve
 *
 * For switches that support secure connect, this function generates
 * random challenge and sends it to the switch. The switch responds to
 * this and if the response matches our random challenge, the switch is
 * approved and connected.
 *
 * Return: %0 on success and negative errno in case of failure.
 */
int tb_domain_challenge_switch_key(struct tb *tb, struct tb_switch *sw)
{
	u8 challenge[TB_SWITCH_KEY_SIZE];
	u8 response[TB_SWITCH_KEY_SIZE];
	u8 hmac[TB_SWITCH_KEY_SIZE];
	struct tb_switch *parent_sw;
	struct crypto_shash *tfm;
	struct shash_desc *shash;
	int ret;

	if (!tb->cm_ops->approve_switch || !tb->cm_ops->challenge_switch_key)
		return -EPERM;

	/* The parent switch must be authorized before this one */
	parent_sw = tb_to_switch(sw->dev.parent);
	if (!parent_sw || !parent_sw->authorized)
		return -EINVAL;

	get_random_bytes(challenge, sizeof(challenge));
	ret = tb->cm_ops->challenge_switch_key(tb, sw, challenge, response);
	if (ret)
		return ret;

	tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
	if (IS_ERR(tfm))
		return PTR_ERR(tfm);

	ret = crypto_shash_setkey(tfm, sw->key, TB_SWITCH_KEY_SIZE);
	if (ret)
		goto err_free_tfm;

	shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
			GFP_KERNEL);
	if (!shash) {
		ret = -ENOMEM;
		goto err_free_tfm;
	}

	shash->tfm = tfm;
	shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	memset(hmac, 0, sizeof(hmac));
	ret = crypto_shash_digest(shash, challenge, sizeof(hmac), hmac);
	if (ret)
		goto err_free_shash;

	/* The returned HMAC must match the one we calculated */
	if (memcmp(response, hmac, sizeof(hmac))) {
		ret = -EKEYREJECTED;
		goto err_free_shash;
	}

	crypto_free_shash(tfm);
	kfree(shash);

	return tb->cm_ops->approve_switch(tb, sw);

err_free_shash:
	kfree(shash);
err_free_tfm:
	crypto_free_shash(tfm);

	return ret;
}

/**
 * tb_domain_disconnect_pcie_paths() - Disconnect all PCIe paths
 * @tb: Domain whose PCIe paths to disconnect
 *
 * This needs to be called in preparation for NVM upgrade of the host
 * controller. Makes sure all PCIe paths are disconnected.
 *
 * Return %0 on success and negative errno in case of error.
 */
int tb_domain_disconnect_pcie_paths(struct tb *tb)
{
	if (!tb->cm_ops->disconnect_pcie_paths)
		return -EPERM;

	return tb->cm_ops->disconnect_pcie_paths(tb);
}

int tb_domain_init(void)
{
	return bus_register(&tb_bus_type);
}

void tb_domain_exit(void)
{
	bus_unregister(&tb_bus_type);
	ida_destroy(&tb_domain_ida);
	tb_switch_exit();
}