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9d3cce0b MW |
1 | /* |
2 | * Thunderbolt bus support | |
3 | * | |
4 | * Copyright (C) 2017, Intel Corporation | |
5 | * Author: Mika Westerberg <mika.westerberg@linux.intel.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/device.h> | |
13 | #include <linux/idr.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/slab.h> | |
f67cf491 MW |
16 | #include <linux/random.h> |
17 | #include <crypto/hash.h> | |
9d3cce0b MW |
18 | |
19 | #include "tb.h" | |
20 | ||
21 | static DEFINE_IDA(tb_domain_ida); | |
22 | ||
f67cf491 MW |
23 | static const char * const tb_security_names[] = { |
24 | [TB_SECURITY_NONE] = "none", | |
25 | [TB_SECURITY_USER] = "user", | |
26 | [TB_SECURITY_SECURE] = "secure", | |
27 | [TB_SECURITY_DPONLY] = "dponly", | |
28 | }; | |
29 | ||
30 | static ssize_t security_show(struct device *dev, struct device_attribute *attr, | |
31 | char *buf) | |
32 | { | |
33 | struct tb *tb = container_of(dev, struct tb, dev); | |
34 | ||
35 | return sprintf(buf, "%s\n", tb_security_names[tb->security_level]); | |
36 | } | |
37 | static DEVICE_ATTR_RO(security); | |
38 | ||
39 | static struct attribute *domain_attrs[] = { | |
40 | &dev_attr_security.attr, | |
41 | NULL, | |
42 | }; | |
43 | ||
44 | static struct attribute_group domain_attr_group = { | |
45 | .attrs = domain_attrs, | |
46 | }; | |
47 | ||
48 | static const struct attribute_group *domain_attr_groups[] = { | |
49 | &domain_attr_group, | |
50 | NULL, | |
51 | }; | |
52 | ||
9d3cce0b MW |
53 | struct bus_type tb_bus_type = { |
54 | .name = "thunderbolt", | |
55 | }; | |
56 | ||
57 | static void tb_domain_release(struct device *dev) | |
58 | { | |
59 | struct tb *tb = container_of(dev, struct tb, dev); | |
60 | ||
61 | tb_ctl_free(tb->ctl); | |
62 | destroy_workqueue(tb->wq); | |
63 | ida_simple_remove(&tb_domain_ida, tb->index); | |
64 | mutex_destroy(&tb->lock); | |
65 | kfree(tb); | |
66 | } | |
67 | ||
68 | struct device_type tb_domain_type = { | |
69 | .name = "thunderbolt_domain", | |
70 | .release = tb_domain_release, | |
71 | }; | |
72 | ||
73 | /** | |
74 | * tb_domain_alloc() - Allocate a domain | |
75 | * @nhi: Pointer to the host controller | |
76 | * @privsize: Size of the connection manager private data | |
77 | * | |
78 | * Allocates and initializes a new Thunderbolt domain. Connection | |
79 | * managers are expected to call this and then fill in @cm_ops | |
80 | * accordingly. | |
81 | * | |
82 | * Call tb_domain_put() to release the domain before it has been added | |
83 | * to the system. | |
84 | * | |
85 | * Return: allocated domain structure on %NULL in case of error | |
86 | */ | |
87 | struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize) | |
88 | { | |
89 | struct tb *tb; | |
90 | ||
91 | /* | |
92 | * Make sure the structure sizes map with that the hardware | |
93 | * expects because bit-fields are being used. | |
94 | */ | |
95 | BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4); | |
96 | BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4); | |
97 | BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4); | |
98 | ||
99 | tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL); | |
100 | if (!tb) | |
101 | return NULL; | |
102 | ||
103 | tb->nhi = nhi; | |
104 | mutex_init(&tb->lock); | |
105 | ||
106 | tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL); | |
107 | if (tb->index < 0) | |
108 | goto err_free; | |
109 | ||
110 | tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index); | |
111 | if (!tb->wq) | |
112 | goto err_remove_ida; | |
113 | ||
114 | tb->dev.parent = &nhi->pdev->dev; | |
115 | tb->dev.bus = &tb_bus_type; | |
116 | tb->dev.type = &tb_domain_type; | |
f67cf491 | 117 | tb->dev.groups = domain_attr_groups; |
9d3cce0b MW |
118 | dev_set_name(&tb->dev, "domain%d", tb->index); |
119 | device_initialize(&tb->dev); | |
120 | ||
121 | return tb; | |
122 | ||
123 | err_remove_ida: | |
124 | ida_simple_remove(&tb_domain_ida, tb->index); | |
125 | err_free: | |
126 | kfree(tb); | |
127 | ||
128 | return NULL; | |
129 | } | |
130 | ||
81a54b5e MW |
131 | static void tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type, |
132 | const void *buf, size_t size) | |
133 | { | |
134 | struct tb *tb = data; | |
135 | ||
136 | if (!tb->cm_ops->handle_event) { | |
137 | tb_warn(tb, "domain does not have event handler\n"); | |
138 | return; | |
139 | } | |
140 | ||
141 | tb->cm_ops->handle_event(tb, type, buf, size); | |
142 | } | |
143 | ||
9d3cce0b MW |
144 | /** |
145 | * tb_domain_add() - Add domain to the system | |
146 | * @tb: Domain to add | |
147 | * | |
148 | * Starts the domain and adds it to the system. Hotplugging devices will | |
149 | * work after this has been returned successfully. In order to remove | |
150 | * and release the domain after this function has been called, call | |
151 | * tb_domain_remove(). | |
152 | * | |
153 | * Return: %0 in case of success and negative errno in case of error | |
154 | */ | |
155 | int tb_domain_add(struct tb *tb) | |
156 | { | |
157 | int ret; | |
158 | ||
159 | if (WARN_ON(!tb->cm_ops)) | |
160 | return -EINVAL; | |
161 | ||
162 | mutex_lock(&tb->lock); | |
163 | ||
81a54b5e | 164 | tb->ctl = tb_ctl_alloc(tb->nhi, tb_domain_event_cb, tb); |
9d3cce0b MW |
165 | if (!tb->ctl) { |
166 | ret = -ENOMEM; | |
167 | goto err_unlock; | |
168 | } | |
169 | ||
170 | /* | |
171 | * tb_schedule_hotplug_handler may be called as soon as the config | |
172 | * channel is started. Thats why we have to hold the lock here. | |
173 | */ | |
174 | tb_ctl_start(tb->ctl); | |
175 | ||
f67cf491 MW |
176 | if (tb->cm_ops->driver_ready) { |
177 | ret = tb->cm_ops->driver_ready(tb); | |
178 | if (ret) | |
179 | goto err_ctl_stop; | |
180 | } | |
181 | ||
9d3cce0b MW |
182 | ret = device_add(&tb->dev); |
183 | if (ret) | |
184 | goto err_ctl_stop; | |
185 | ||
186 | /* Start the domain */ | |
187 | if (tb->cm_ops->start) { | |
188 | ret = tb->cm_ops->start(tb); | |
189 | if (ret) | |
190 | goto err_domain_del; | |
191 | } | |
192 | ||
193 | /* This starts event processing */ | |
194 | mutex_unlock(&tb->lock); | |
195 | ||
196 | return 0; | |
197 | ||
198 | err_domain_del: | |
199 | device_del(&tb->dev); | |
200 | err_ctl_stop: | |
201 | tb_ctl_stop(tb->ctl); | |
202 | err_unlock: | |
203 | mutex_unlock(&tb->lock); | |
204 | ||
205 | return ret; | |
206 | } | |
207 | ||
208 | /** | |
209 | * tb_domain_remove() - Removes and releases a domain | |
210 | * @tb: Domain to remove | |
211 | * | |
212 | * Stops the domain, removes it from the system and releases all | |
213 | * resources once the last reference has been released. | |
214 | */ | |
215 | void tb_domain_remove(struct tb *tb) | |
216 | { | |
217 | mutex_lock(&tb->lock); | |
218 | if (tb->cm_ops->stop) | |
219 | tb->cm_ops->stop(tb); | |
220 | /* Stop the domain control traffic */ | |
221 | tb_ctl_stop(tb->ctl); | |
222 | mutex_unlock(&tb->lock); | |
223 | ||
224 | flush_workqueue(tb->wq); | |
225 | device_unregister(&tb->dev); | |
226 | } | |
227 | ||
228 | /** | |
229 | * tb_domain_suspend_noirq() - Suspend a domain | |
230 | * @tb: Domain to suspend | |
231 | * | |
232 | * Suspends all devices in the domain and stops the control channel. | |
233 | */ | |
234 | int tb_domain_suspend_noirq(struct tb *tb) | |
235 | { | |
236 | int ret = 0; | |
237 | ||
238 | /* | |
239 | * The control channel interrupt is left enabled during suspend | |
240 | * and taking the lock here prevents any events happening before | |
241 | * we actually have stopped the domain and the control channel. | |
242 | */ | |
243 | mutex_lock(&tb->lock); | |
244 | if (tb->cm_ops->suspend_noirq) | |
245 | ret = tb->cm_ops->suspend_noirq(tb); | |
246 | if (!ret) | |
247 | tb_ctl_stop(tb->ctl); | |
248 | mutex_unlock(&tb->lock); | |
249 | ||
250 | return ret; | |
251 | } | |
252 | ||
253 | /** | |
254 | * tb_domain_resume_noirq() - Resume a domain | |
255 | * @tb: Domain to resume | |
256 | * | |
257 | * Re-starts the control channel, and resumes all devices connected to | |
258 | * the domain. | |
259 | */ | |
260 | int tb_domain_resume_noirq(struct tb *tb) | |
261 | { | |
262 | int ret = 0; | |
263 | ||
264 | mutex_lock(&tb->lock); | |
265 | tb_ctl_start(tb->ctl); | |
266 | if (tb->cm_ops->resume_noirq) | |
267 | ret = tb->cm_ops->resume_noirq(tb); | |
268 | mutex_unlock(&tb->lock); | |
269 | ||
270 | return ret; | |
271 | } | |
272 | ||
f67cf491 MW |
273 | int tb_domain_suspend(struct tb *tb) |
274 | { | |
275 | int ret; | |
276 | ||
277 | mutex_lock(&tb->lock); | |
278 | if (tb->cm_ops->suspend) { | |
279 | ret = tb->cm_ops->suspend(tb); | |
280 | if (ret) { | |
281 | mutex_unlock(&tb->lock); | |
282 | return ret; | |
283 | } | |
284 | } | |
285 | mutex_unlock(&tb->lock); | |
286 | return 0; | |
287 | } | |
288 | ||
289 | void tb_domain_complete(struct tb *tb) | |
290 | { | |
291 | mutex_lock(&tb->lock); | |
292 | if (tb->cm_ops->complete) | |
293 | tb->cm_ops->complete(tb); | |
294 | mutex_unlock(&tb->lock); | |
295 | } | |
296 | ||
297 | /** | |
298 | * tb_domain_approve_switch() - Approve switch | |
299 | * @tb: Domain the switch belongs to | |
300 | * @sw: Switch to approve | |
301 | * | |
302 | * This will approve switch by connection manager specific means. In | |
303 | * case of success the connection manager will create tunnels for all | |
304 | * supported protocols. | |
305 | */ | |
306 | int tb_domain_approve_switch(struct tb *tb, struct tb_switch *sw) | |
307 | { | |
308 | struct tb_switch *parent_sw; | |
309 | ||
310 | if (!tb->cm_ops->approve_switch) | |
311 | return -EPERM; | |
312 | ||
313 | /* The parent switch must be authorized before this one */ | |
314 | parent_sw = tb_to_switch(sw->dev.parent); | |
315 | if (!parent_sw || !parent_sw->authorized) | |
316 | return -EINVAL; | |
317 | ||
318 | return tb->cm_ops->approve_switch(tb, sw); | |
319 | } | |
320 | ||
321 | /** | |
322 | * tb_domain_approve_switch_key() - Approve switch and add key | |
323 | * @tb: Domain the switch belongs to | |
324 | * @sw: Switch to approve | |
325 | * | |
326 | * For switches that support secure connect, this function first adds | |
327 | * key to the switch NVM using connection manager specific means. If | |
328 | * adding the key is successful, the switch is approved and connected. | |
329 | * | |
330 | * Return: %0 on success and negative errno in case of failure. | |
331 | */ | |
332 | int tb_domain_approve_switch_key(struct tb *tb, struct tb_switch *sw) | |
333 | { | |
334 | struct tb_switch *parent_sw; | |
335 | int ret; | |
336 | ||
337 | if (!tb->cm_ops->approve_switch || !tb->cm_ops->add_switch_key) | |
338 | return -EPERM; | |
339 | ||
340 | /* The parent switch must be authorized before this one */ | |
341 | parent_sw = tb_to_switch(sw->dev.parent); | |
342 | if (!parent_sw || !parent_sw->authorized) | |
343 | return -EINVAL; | |
344 | ||
345 | ret = tb->cm_ops->add_switch_key(tb, sw); | |
346 | if (ret) | |
347 | return ret; | |
348 | ||
349 | return tb->cm_ops->approve_switch(tb, sw); | |
350 | } | |
351 | ||
352 | /** | |
353 | * tb_domain_challenge_switch_key() - Challenge and approve switch | |
354 | * @tb: Domain the switch belongs to | |
355 | * @sw: Switch to approve | |
356 | * | |
357 | * For switches that support secure connect, this function generates | |
358 | * random challenge and sends it to the switch. The switch responds to | |
359 | * this and if the response matches our random challenge, the switch is | |
360 | * approved and connected. | |
361 | * | |
362 | * Return: %0 on success and negative errno in case of failure. | |
363 | */ | |
364 | int tb_domain_challenge_switch_key(struct tb *tb, struct tb_switch *sw) | |
365 | { | |
366 | u8 challenge[TB_SWITCH_KEY_SIZE]; | |
367 | u8 response[TB_SWITCH_KEY_SIZE]; | |
368 | u8 hmac[TB_SWITCH_KEY_SIZE]; | |
369 | struct tb_switch *parent_sw; | |
370 | struct crypto_shash *tfm; | |
371 | struct shash_desc *shash; | |
372 | int ret; | |
373 | ||
374 | if (!tb->cm_ops->approve_switch || !tb->cm_ops->challenge_switch_key) | |
375 | return -EPERM; | |
376 | ||
377 | /* The parent switch must be authorized before this one */ | |
378 | parent_sw = tb_to_switch(sw->dev.parent); | |
379 | if (!parent_sw || !parent_sw->authorized) | |
380 | return -EINVAL; | |
381 | ||
382 | get_random_bytes(challenge, sizeof(challenge)); | |
383 | ret = tb->cm_ops->challenge_switch_key(tb, sw, challenge, response); | |
384 | if (ret) | |
385 | return ret; | |
386 | ||
387 | tfm = crypto_alloc_shash("hmac(sha256)", 0, 0); | |
388 | if (IS_ERR(tfm)) | |
389 | return PTR_ERR(tfm); | |
390 | ||
391 | ret = crypto_shash_setkey(tfm, sw->key, TB_SWITCH_KEY_SIZE); | |
392 | if (ret) | |
393 | goto err_free_tfm; | |
394 | ||
395 | shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm), | |
396 | GFP_KERNEL); | |
397 | if (!shash) { | |
398 | ret = -ENOMEM; | |
399 | goto err_free_tfm; | |
400 | } | |
401 | ||
402 | shash->tfm = tfm; | |
403 | shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
404 | ||
405 | memset(hmac, 0, sizeof(hmac)); | |
406 | ret = crypto_shash_digest(shash, challenge, sizeof(hmac), hmac); | |
407 | if (ret) | |
408 | goto err_free_shash; | |
409 | ||
410 | /* The returned HMAC must match the one we calculated */ | |
411 | if (memcmp(response, hmac, sizeof(hmac))) { | |
412 | ret = -EKEYREJECTED; | |
413 | goto err_free_shash; | |
414 | } | |
415 | ||
416 | crypto_free_shash(tfm); | |
417 | kfree(shash); | |
418 | ||
419 | return tb->cm_ops->approve_switch(tb, sw); | |
420 | ||
421 | err_free_shash: | |
422 | kfree(shash); | |
423 | err_free_tfm: | |
424 | crypto_free_shash(tfm); | |
425 | ||
426 | return ret; | |
427 | } | |
428 | ||
e6b245cc MW |
429 | /** |
430 | * tb_domain_disconnect_pcie_paths() - Disconnect all PCIe paths | |
431 | * @tb: Domain whose PCIe paths to disconnect | |
432 | * | |
433 | * This needs to be called in preparation for NVM upgrade of the host | |
434 | * controller. Makes sure all PCIe paths are disconnected. | |
435 | * | |
436 | * Return %0 on success and negative errno in case of error. | |
437 | */ | |
438 | int tb_domain_disconnect_pcie_paths(struct tb *tb) | |
439 | { | |
440 | if (!tb->cm_ops->disconnect_pcie_paths) | |
441 | return -EPERM; | |
442 | ||
443 | return tb->cm_ops->disconnect_pcie_paths(tb); | |
444 | } | |
445 | ||
9d3cce0b MW |
446 | int tb_domain_init(void) |
447 | { | |
448 | return bus_register(&tb_bus_type); | |
449 | } | |
450 | ||
451 | void tb_domain_exit(void) | |
452 | { | |
453 | bus_unregister(&tb_bus_type); | |
454 | ida_destroy(&tb_domain_ida); | |
e6b245cc | 455 | tb_switch_exit(); |
9d3cce0b | 456 | } |