1 /*
2 * Copyright (C) 2004 IBM Corporation
3 * Copyright (C) 2014 Intel Corporation
4 *
5 * Authors:
6 * Leendert van Doorn <leendert@watson.ibm.com>
7 * Dave Safford <safford@watson.ibm.com>
8 * Reiner Sailer <sailer@watson.ibm.com>
9 * Kylene Hall <kjhall@us.ibm.com>
10 *
11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
12 *
13 * Device driver for TCG/TCPA TPM (trusted platform module).
14 * Specifications at www.trustedcomputinggroup.org
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation, version 2 of the
19 * License.
20 *
21 * Note, the TPM chip is not interrupt driven (only polling)
22 * and can have very long timeouts (minutes!). Hence the unusual
23 * calls to msleep.
24 *
25 */
26
27 #include <linux/poll.h>
28 #include <linux/slab.h>
29 #include <linux/mutex.h>
30 #include <linux/spinlock.h>
31 #include <linux/freezer.h>
32
33 #include "tpm.h"
34 #include "tpm_eventlog.h"
35
36 #define TPM_MAX_ORDINAL 243
37 #define TSC_MAX_ORDINAL 12
38 #define TPM_PROTECTED_COMMAND 0x00
39 #define TPM_CONNECTION_COMMAND 0x40
40
41 /*
42 * Bug workaround - some TPM's don't flush the most
43 * recently changed pcr on suspend, so force the flush
44 * with an extend to the selected _unused_ non-volatile pcr.
45 */
46 static int tpm_suspend_pcr;
47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
48 MODULE_PARM_DESC(suspend_pcr,
49 "PCR to use for dummy writes to faciltate flush on suspend.");
50
51 /*
52 * Array with one entry per ordinal defining the maximum amount
53 * of time the chip could take to return the result. The ordinal
54 * designation of short, medium or long is defined in a table in
55 * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
56 * values of the SHORT, MEDIUM, and LONG durations are retrieved
57 * from the chip during initialization with a call to tpm_get_timeouts.
58 */
59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
60 TPM_UNDEFINED, /* 0 */
61 TPM_UNDEFINED,
62 TPM_UNDEFINED,
63 TPM_UNDEFINED,
64 TPM_UNDEFINED,
65 TPM_UNDEFINED, /* 5 */
66 TPM_UNDEFINED,
67 TPM_UNDEFINED,
68 TPM_UNDEFINED,
69 TPM_UNDEFINED,
70 TPM_SHORT, /* 10 */
71 TPM_SHORT,
72 TPM_MEDIUM,
73 TPM_LONG,
74 TPM_LONG,
75 TPM_MEDIUM, /* 15 */
76 TPM_SHORT,
77 TPM_SHORT,
78 TPM_MEDIUM,
79 TPM_LONG,
80 TPM_SHORT, /* 20 */
81 TPM_SHORT,
82 TPM_MEDIUM,
83 TPM_MEDIUM,
84 TPM_MEDIUM,
85 TPM_SHORT, /* 25 */
86 TPM_SHORT,
87 TPM_MEDIUM,
88 TPM_SHORT,
89 TPM_SHORT,
90 TPM_MEDIUM, /* 30 */
91 TPM_LONG,
92 TPM_MEDIUM,
93 TPM_SHORT,
94 TPM_SHORT,
95 TPM_SHORT, /* 35 */
96 TPM_MEDIUM,
97 TPM_MEDIUM,
98 TPM_UNDEFINED,
99 TPM_UNDEFINED,
100 TPM_MEDIUM, /* 40 */
101 TPM_LONG,
102 TPM_MEDIUM,
103 TPM_SHORT,
104 TPM_SHORT,
105 TPM_SHORT, /* 45 */
106 TPM_SHORT,
107 TPM_SHORT,
108 TPM_SHORT,
109 TPM_LONG,
110 TPM_MEDIUM, /* 50 */
111 TPM_MEDIUM,
112 TPM_UNDEFINED,
113 TPM_UNDEFINED,
114 TPM_UNDEFINED,
115 TPM_UNDEFINED, /* 55 */
116 TPM_UNDEFINED,
117 TPM_UNDEFINED,
118 TPM_UNDEFINED,
119 TPM_UNDEFINED,
120 TPM_MEDIUM, /* 60 */
121 TPM_MEDIUM,
122 TPM_MEDIUM,
123 TPM_SHORT,
124 TPM_SHORT,
125 TPM_MEDIUM, /* 65 */
126 TPM_UNDEFINED,
127 TPM_UNDEFINED,
128 TPM_UNDEFINED,
129 TPM_UNDEFINED,
130 TPM_SHORT, /* 70 */
131 TPM_SHORT,
132 TPM_UNDEFINED,
133 TPM_UNDEFINED,
134 TPM_UNDEFINED,
135 TPM_UNDEFINED, /* 75 */
136 TPM_UNDEFINED,
137 TPM_UNDEFINED,
138 TPM_UNDEFINED,
139 TPM_UNDEFINED,
140 TPM_LONG, /* 80 */
141 TPM_UNDEFINED,
142 TPM_MEDIUM,
143 TPM_LONG,
144 TPM_SHORT,
145 TPM_UNDEFINED, /* 85 */
146 TPM_UNDEFINED,
147 TPM_UNDEFINED,
148 TPM_UNDEFINED,
149 TPM_UNDEFINED,
150 TPM_SHORT, /* 90 */
151 TPM_SHORT,
152 TPM_SHORT,
153 TPM_SHORT,
154 TPM_SHORT,
155 TPM_UNDEFINED, /* 95 */
156 TPM_UNDEFINED,
157 TPM_UNDEFINED,
158 TPM_UNDEFINED,
159 TPM_UNDEFINED,
160 TPM_MEDIUM, /* 100 */
161 TPM_SHORT,
162 TPM_SHORT,
163 TPM_UNDEFINED,
164 TPM_UNDEFINED,
165 TPM_UNDEFINED, /* 105 */
166 TPM_UNDEFINED,
167 TPM_UNDEFINED,
168 TPM_UNDEFINED,
169 TPM_UNDEFINED,
170 TPM_SHORT, /* 110 */
171 TPM_SHORT,
172 TPM_SHORT,
173 TPM_SHORT,
174 TPM_SHORT,
175 TPM_SHORT, /* 115 */
176 TPM_SHORT,
177 TPM_SHORT,
178 TPM_UNDEFINED,
179 TPM_UNDEFINED,
180 TPM_LONG, /* 120 */
181 TPM_LONG,
182 TPM_MEDIUM,
183 TPM_UNDEFINED,
184 TPM_SHORT,
185 TPM_SHORT, /* 125 */
186 TPM_SHORT,
187 TPM_LONG,
188 TPM_SHORT,
189 TPM_SHORT,
190 TPM_SHORT, /* 130 */
191 TPM_MEDIUM,
192 TPM_UNDEFINED,
193 TPM_SHORT,
194 TPM_MEDIUM,
195 TPM_UNDEFINED, /* 135 */
196 TPM_UNDEFINED,
197 TPM_UNDEFINED,
198 TPM_UNDEFINED,
199 TPM_UNDEFINED,
200 TPM_SHORT, /* 140 */
201 TPM_SHORT,
202 TPM_UNDEFINED,
203 TPM_UNDEFINED,
204 TPM_UNDEFINED,
205 TPM_UNDEFINED, /* 145 */
206 TPM_UNDEFINED,
207 TPM_UNDEFINED,
208 TPM_UNDEFINED,
209 TPM_UNDEFINED,
210 TPM_SHORT, /* 150 */
211 TPM_MEDIUM,
212 TPM_MEDIUM,
213 TPM_SHORT,
214 TPM_SHORT,
215 TPM_UNDEFINED, /* 155 */
216 TPM_UNDEFINED,
217 TPM_UNDEFINED,
218 TPM_UNDEFINED,
219 TPM_UNDEFINED,
220 TPM_SHORT, /* 160 */
221 TPM_SHORT,
222 TPM_SHORT,
223 TPM_SHORT,
224 TPM_UNDEFINED,
225 TPM_UNDEFINED, /* 165 */
226 TPM_UNDEFINED,
227 TPM_UNDEFINED,
228 TPM_UNDEFINED,
229 TPM_UNDEFINED,
230 TPM_LONG, /* 170 */
231 TPM_UNDEFINED,
232 TPM_UNDEFINED,
233 TPM_UNDEFINED,
234 TPM_UNDEFINED,
235 TPM_UNDEFINED, /* 175 */
236 TPM_UNDEFINED,
237 TPM_UNDEFINED,
238 TPM_UNDEFINED,
239 TPM_UNDEFINED,
240 TPM_MEDIUM, /* 180 */
241 TPM_SHORT,
242 TPM_MEDIUM,
243 TPM_MEDIUM,
244 TPM_MEDIUM,
245 TPM_MEDIUM, /* 185 */
246 TPM_SHORT,
247 TPM_UNDEFINED,
248 TPM_UNDEFINED,
249 TPM_UNDEFINED,
250 TPM_UNDEFINED, /* 190 */
251 TPM_UNDEFINED,
252 TPM_UNDEFINED,
253 TPM_UNDEFINED,
254 TPM_UNDEFINED,
255 TPM_UNDEFINED, /* 195 */
256 TPM_UNDEFINED,
257 TPM_UNDEFINED,
258 TPM_UNDEFINED,
259 TPM_UNDEFINED,
260 TPM_SHORT, /* 200 */
261 TPM_UNDEFINED,
262 TPM_UNDEFINED,
263 TPM_UNDEFINED,
264 TPM_SHORT,
265 TPM_SHORT, /* 205 */
266 TPM_SHORT,
267 TPM_SHORT,
268 TPM_SHORT,
269 TPM_SHORT,
270 TPM_MEDIUM, /* 210 */
271 TPM_UNDEFINED,
272 TPM_MEDIUM,
273 TPM_MEDIUM,
274 TPM_MEDIUM,
275 TPM_UNDEFINED, /* 215 */
276 TPM_MEDIUM,
277 TPM_UNDEFINED,
278 TPM_UNDEFINED,
279 TPM_SHORT,
280 TPM_SHORT, /* 220 */
281 TPM_SHORT,
282 TPM_SHORT,
283 TPM_SHORT,
284 TPM_SHORT,
285 TPM_UNDEFINED, /* 225 */
286 TPM_UNDEFINED,
287 TPM_UNDEFINED,
288 TPM_UNDEFINED,
289 TPM_UNDEFINED,
290 TPM_SHORT, /* 230 */
291 TPM_LONG,
292 TPM_MEDIUM,
293 TPM_UNDEFINED,
294 TPM_UNDEFINED,
295 TPM_UNDEFINED, /* 235 */
296 TPM_UNDEFINED,
297 TPM_UNDEFINED,
298 TPM_UNDEFINED,
299 TPM_UNDEFINED,
300 TPM_SHORT, /* 240 */
301 TPM_UNDEFINED,
302 TPM_MEDIUM,
303 };
304
305 /*
306 * Returns max number of jiffies to wait
307 */
tpm_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
309 u32 ordinal)
310 {
311 int duration_idx = TPM_UNDEFINED;
312 int duration = 0;
313
314 /*
315 * We only have a duration table for protected commands, where the upper
316 * 16 bits are 0. For the few other ordinals the fallback will be used.
317 */
318 if (ordinal < TPM_MAX_ORDINAL)
319 duration_idx = tpm_ordinal_duration[ordinal];
320
321 if (duration_idx != TPM_UNDEFINED)
322 duration = chip->duration[duration_idx];
323 if (duration <= 0)
324 return 2 * 60 * HZ;
325 else
326 return duration;
327 }
328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
329
330 /*
331 * Internal kernel interface to transmit TPM commands
332 */
tpm_transmit(struct tpm_chip * chip,const u8 * buf,size_t bufsiz,unsigned int flags)333 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
334 unsigned int flags)
335 {
336 ssize_t rc;
337 u32 count, ordinal;
338 unsigned long stop;
339
340 if (bufsiz < TPM_HEADER_SIZE)
341 return -EINVAL;
342
343 if (bufsiz > TPM_BUFSIZE)
344 bufsiz = TPM_BUFSIZE;
345
346 count = be32_to_cpu(*((__be32 *) (buf + 2)));
347 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
348 if (count == 0)
349 return -ENODATA;
350 if (count > bufsiz) {
351 dev_err(&chip->dev,
352 "invalid count value %x %zx\n", count, bufsiz);
353 return -E2BIG;
354 }
355
356 if (!(flags & TPM_TRANSMIT_UNLOCKED))
357 mutex_lock(&chip->tpm_mutex);
358
359 rc = chip->ops->send(chip, (u8 *) buf, count);
360 if (rc < 0) {
361 dev_err(&chip->dev,
362 "tpm_transmit: tpm_send: error %zd\n", rc);
363 goto out;
364 }
365
366 if (chip->flags & TPM_CHIP_FLAG_IRQ)
367 goto out_recv;
368
369 if (chip->flags & TPM_CHIP_FLAG_TPM2)
370 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
371 else
372 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
373 do {
374 u8 status = chip->ops->status(chip);
375 if ((status & chip->ops->req_complete_mask) ==
376 chip->ops->req_complete_val)
377 goto out_recv;
378
379 if (chip->ops->req_canceled(chip, status)) {
380 dev_err(&chip->dev, "Operation Canceled\n");
381 rc = -ECANCELED;
382 goto out;
383 }
384
385 msleep(TPM_TIMEOUT); /* CHECK */
386 rmb();
387 } while (time_before(jiffies, stop));
388
389 chip->ops->cancel(chip);
390 dev_err(&chip->dev, "Operation Timed out\n");
391 rc = -ETIME;
392 goto out;
393
394 out_recv:
395 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
396 if (rc < 0)
397 dev_err(&chip->dev,
398 "tpm_transmit: tpm_recv: error %zd\n", rc);
399 out:
400 if (!(flags & TPM_TRANSMIT_UNLOCKED))
401 mutex_unlock(&chip->tpm_mutex);
402 return rc;
403 }
404
405 #define TPM_DIGEST_SIZE 20
406 #define TPM_RET_CODE_IDX 6
407
tpm_transmit_cmd(struct tpm_chip * chip,const void * cmd,int len,unsigned int flags,const char * desc)408 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
409 int len, unsigned int flags, const char *desc)
410 {
411 const struct tpm_output_header *header;
412 int err;
413
414 len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
415 if (len < 0)
416 return len;
417 else if (len < TPM_HEADER_SIZE)
418 return -EFAULT;
419
420 header = cmd;
421
422 err = be32_to_cpu(header->return_code);
423 if (err != 0 && desc)
424 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
425 desc);
426
427 return err;
428 }
429
430 #define TPM_INTERNAL_RESULT_SIZE 200
431 #define TPM_ORD_GET_CAP cpu_to_be32(101)
432 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
433
434 static const struct tpm_input_header tpm_getcap_header = {
435 .tag = TPM_TAG_RQU_COMMAND,
436 .length = cpu_to_be32(22),
437 .ordinal = TPM_ORD_GET_CAP
438 };
439
tpm_getcap(struct tpm_chip * chip,__be32 subcap_id,cap_t * cap,const char * desc)440 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
441 const char *desc)
442 {
443 struct tpm_cmd_t tpm_cmd;
444 int rc;
445
446 tpm_cmd.header.in = tpm_getcap_header;
447 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
448 tpm_cmd.params.getcap_in.cap = subcap_id;
449 /*subcap field not necessary */
450 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
451 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
452 } else {
453 if (subcap_id == TPM_CAP_FLAG_PERM ||
454 subcap_id == TPM_CAP_FLAG_VOL)
455 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
456 else
457 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
458 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
459 tpm_cmd.params.getcap_in.subcap = subcap_id;
460 }
461 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
462 desc);
463 if (!rc)
464 *cap = tpm_cmd.params.getcap_out.cap;
465 return rc;
466 }
467 EXPORT_SYMBOL_GPL(tpm_getcap);
468
469 #define TPM_ORD_STARTUP cpu_to_be32(153)
470 #define TPM_ST_CLEAR cpu_to_be16(1)
471 #define TPM_ST_STATE cpu_to_be16(2)
472 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
473 static const struct tpm_input_header tpm_startup_header = {
474 .tag = TPM_TAG_RQU_COMMAND,
475 .length = cpu_to_be32(12),
476 .ordinal = TPM_ORD_STARTUP
477 };
478
tpm_startup(struct tpm_chip * chip,__be16 startup_type)479 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
480 {
481 struct tpm_cmd_t start_cmd;
482 start_cmd.header.in = tpm_startup_header;
483
484 start_cmd.params.startup_in.startup_type = startup_type;
485 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
486 "attempting to start the TPM");
487 }
488
tpm_get_timeouts(struct tpm_chip * chip)489 int tpm_get_timeouts(struct tpm_chip *chip)
490 {
491 struct tpm_cmd_t tpm_cmd;
492 unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
493 struct duration_t *duration_cap;
494 ssize_t rc;
495
496 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
497 /* Fixed timeouts for TPM2 */
498 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
499 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
500 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
501 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
502 chip->duration[TPM_SHORT] =
503 msecs_to_jiffies(TPM2_DURATION_SHORT);
504 chip->duration[TPM_MEDIUM] =
505 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
506 chip->duration[TPM_LONG] =
507 msecs_to_jiffies(TPM2_DURATION_LONG);
508 return 0;
509 }
510
511 tpm_cmd.header.in = tpm_getcap_header;
512 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
513 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
514 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
515 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
516 NULL);
517
518 if (rc == TPM_ERR_INVALID_POSTINIT) {
519 /* The TPM is not started, we are the first to talk to it.
520 Execute a startup command. */
521 dev_info(&chip->dev, "Issuing TPM_STARTUP");
522 if (tpm_startup(chip, TPM_ST_CLEAR))
523 return rc;
524
525 tpm_cmd.header.in = tpm_getcap_header;
526 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
527 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
528 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
529 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
530 0, NULL);
531 }
532 if (rc) {
533 dev_err(&chip->dev,
534 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
535 rc);
536 goto duration;
537 }
538
539 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
540 be32_to_cpu(tpm_cmd.header.out.length)
541 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
542 return -EINVAL;
543
544 timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
545 timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
546 timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
547 timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
548 timeout_chip[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
549 timeout_chip[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
550 timeout_chip[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
551 timeout_chip[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
552 memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
553
554 /*
555 * Provide ability for vendor overrides of timeout values in case
556 * of misreporting.
557 */
558 if (chip->ops->update_timeouts != NULL)
559 chip->timeout_adjusted =
560 chip->ops->update_timeouts(chip, timeout_eff);
561
562 if (!chip->timeout_adjusted) {
563 /* Restore default if chip reported 0 */
564 int i;
565
566 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
567 if (timeout_eff[i])
568 continue;
569
570 timeout_eff[i] = timeout_old[i];
571 chip->timeout_adjusted = true;
572 }
573
574 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
575 /* timeouts in msec rather usec */
576 for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
577 timeout_eff[i] *= 1000;
578 chip->timeout_adjusted = true;
579 }
580 }
581
582 /* Report adjusted timeouts */
583 if (chip->timeout_adjusted) {
584 dev_info(&chip->dev,
585 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
586 timeout_chip[0], timeout_eff[0],
587 timeout_chip[1], timeout_eff[1],
588 timeout_chip[2], timeout_eff[2],
589 timeout_chip[3], timeout_eff[3]);
590 }
591
592 chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
593 chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
594 chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
595 chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
596
597 duration:
598 tpm_cmd.header.in = tpm_getcap_header;
599 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
600 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
601 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
602
603 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
604 "attempting to determine the durations");
605 if (rc)
606 return rc;
607
608 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
609 be32_to_cpu(tpm_cmd.header.out.length)
610 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
611 return -EINVAL;
612
613 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
614 chip->duration[TPM_SHORT] =
615 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
616 chip->duration[TPM_MEDIUM] =
617 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
618 chip->duration[TPM_LONG] =
619 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
620
621 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
622 * value wrong and apparently reports msecs rather than usecs. So we
623 * fix up the resulting too-small TPM_SHORT value to make things work.
624 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
625 */
626 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
627 chip->duration[TPM_SHORT] = HZ;
628 chip->duration[TPM_MEDIUM] *= 1000;
629 chip->duration[TPM_LONG] *= 1000;
630 chip->duration_adjusted = true;
631 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
632 }
633 return 0;
634 }
635 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
636
637 #define TPM_ORD_CONTINUE_SELFTEST 83
638 #define CONTINUE_SELFTEST_RESULT_SIZE 10
639
640 static const struct tpm_input_header continue_selftest_header = {
641 .tag = TPM_TAG_RQU_COMMAND,
642 .length = cpu_to_be32(10),
643 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
644 };
645
646 /**
647 * tpm_continue_selftest -- run TPM's selftest
648 * @chip: TPM chip to use
649 *
650 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
651 * a TPM error code.
652 */
tpm_continue_selftest(struct tpm_chip * chip)653 static int tpm_continue_selftest(struct tpm_chip *chip)
654 {
655 int rc;
656 struct tpm_cmd_t cmd;
657
658 cmd.header.in = continue_selftest_header;
659 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
660 "continue selftest");
661 return rc;
662 }
663
664 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
665 #define READ_PCR_RESULT_SIZE 30
666 static const struct tpm_input_header pcrread_header = {
667 .tag = TPM_TAG_RQU_COMMAND,
668 .length = cpu_to_be32(14),
669 .ordinal = TPM_ORDINAL_PCRREAD
670 };
671
tpm_pcr_read_dev(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)672 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
673 {
674 int rc;
675 struct tpm_cmd_t cmd;
676
677 cmd.header.in = pcrread_header;
678 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
679 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
680 "attempting to read a pcr value");
681
682 if (rc == 0)
683 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
684 TPM_DIGEST_SIZE);
685 return rc;
686 }
687
688 /**
689 * tpm_is_tpm2 - is the chip a TPM2 chip?
690 * @chip_num: tpm idx # or ANY
691 *
692 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
693 * is a TPM2 chip.
694 */
tpm_is_tpm2(u32 chip_num)695 int tpm_is_tpm2(u32 chip_num)
696 {
697 struct tpm_chip *chip;
698 int rc;
699
700 chip = tpm_chip_find_get(chip_num);
701 if (chip == NULL)
702 return -ENODEV;
703
704 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
705
706 tpm_put_ops(chip);
707
708 return rc;
709 }
710 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
711
712 /**
713 * tpm_pcr_read - read a pcr value
714 * @chip_num: tpm idx # or ANY
715 * @pcr_idx: pcr idx to retrieve
716 * @res_buf: TPM_PCR value
717 * size of res_buf is 20 bytes (or NULL if you don't care)
718 *
719 * The TPM driver should be built-in, but for whatever reason it
720 * isn't, protect against the chip disappearing, by incrementing
721 * the module usage count.
722 */
tpm_pcr_read(u32 chip_num,int pcr_idx,u8 * res_buf)723 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
724 {
725 struct tpm_chip *chip;
726 int rc;
727
728 chip = tpm_chip_find_get(chip_num);
729 if (chip == NULL)
730 return -ENODEV;
731 if (chip->flags & TPM_CHIP_FLAG_TPM2)
732 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
733 else
734 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
735 tpm_put_ops(chip);
736 return rc;
737 }
738 EXPORT_SYMBOL_GPL(tpm_pcr_read);
739
740 /**
741 * tpm_pcr_extend - extend pcr value with hash
742 * @chip_num: tpm idx # or AN&
743 * @pcr_idx: pcr idx to extend
744 * @hash: hash value used to extend pcr value
745 *
746 * The TPM driver should be built-in, but for whatever reason it
747 * isn't, protect against the chip disappearing, by incrementing
748 * the module usage count.
749 */
750 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
751 #define EXTEND_PCR_RESULT_SIZE 34
752 static const struct tpm_input_header pcrextend_header = {
753 .tag = TPM_TAG_RQU_COMMAND,
754 .length = cpu_to_be32(34),
755 .ordinal = TPM_ORD_PCR_EXTEND
756 };
757
tpm_pcr_extend(u32 chip_num,int pcr_idx,const u8 * hash)758 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
759 {
760 struct tpm_cmd_t cmd;
761 int rc;
762 struct tpm_chip *chip;
763
764 chip = tpm_chip_find_get(chip_num);
765 if (chip == NULL)
766 return -ENODEV;
767
768 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
769 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
770 tpm_put_ops(chip);
771 return rc;
772 }
773
774 cmd.header.in = pcrextend_header;
775 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
776 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
777 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
778 "attempting extend a PCR value");
779
780 tpm_put_ops(chip);
781 return rc;
782 }
783 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
784
785 /**
786 * tpm_do_selftest - have the TPM continue its selftest and wait until it
787 * can receive further commands
788 * @chip: TPM chip to use
789 *
790 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
791 * a TPM error code.
792 */
tpm_do_selftest(struct tpm_chip * chip)793 int tpm_do_selftest(struct tpm_chip *chip)
794 {
795 int rc;
796 unsigned int loops;
797 unsigned int delay_msec = 100;
798 unsigned long duration;
799 u8 dummy[TPM_DIGEST_SIZE];
800
801 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
802
803 loops = jiffies_to_msecs(duration) / delay_msec;
804
805 rc = tpm_continue_selftest(chip);
806 /* This may fail if there was no TPM driver during a suspend/resume
807 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
808 */
809 if (rc)
810 return rc;
811
812 do {
813 /* Attempt to read a PCR value */
814 rc = tpm_pcr_read_dev(chip, 0, dummy);
815
816 /* Some buggy TPMs will not respond to tpm_tis_ready() for
817 * around 300ms while the self test is ongoing, keep trying
818 * until the self test duration expires. */
819 if (rc == -ETIME) {
820 dev_info(
821 &chip->dev, HW_ERR
822 "TPM command timed out during continue self test");
823 msleep(delay_msec);
824 continue;
825 }
826
827 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
828 dev_info(&chip->dev,
829 "TPM is disabled/deactivated (0x%X)\n", rc);
830 /* TPM is disabled and/or deactivated; driver can
831 * proceed and TPM does handle commands for
832 * suspend/resume correctly
833 */
834 return 0;
835 }
836 if (rc != TPM_WARN_DOING_SELFTEST)
837 return rc;
838 msleep(delay_msec);
839 } while (--loops > 0);
840
841 return rc;
842 }
843 EXPORT_SYMBOL_GPL(tpm_do_selftest);
844
845 /**
846 * tpm1_auto_startup - Perform the standard automatic TPM initialization
847 * sequence
848 * @chip: TPM chip to use
849 *
850 * Returns 0 on success, < 0 in case of fatal error.
851 */
tpm1_auto_startup(struct tpm_chip * chip)852 int tpm1_auto_startup(struct tpm_chip *chip)
853 {
854 int rc;
855
856 rc = tpm_get_timeouts(chip);
857 if (rc)
858 goto out;
859 rc = tpm_do_selftest(chip);
860 if (rc) {
861 dev_err(&chip->dev, "TPM self test failed\n");
862 goto out;
863 }
864
865 return rc;
866 out:
867 if (rc > 0)
868 rc = -ENODEV;
869 return rc;
870 }
871
tpm_send(u32 chip_num,void * cmd,size_t buflen)872 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
873 {
874 struct tpm_chip *chip;
875 int rc;
876
877 chip = tpm_chip_find_get(chip_num);
878 if (chip == NULL)
879 return -ENODEV;
880
881 rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
882
883 tpm_put_ops(chip);
884 return rc;
885 }
886 EXPORT_SYMBOL_GPL(tpm_send);
887
wait_for_tpm_stat_cond(struct tpm_chip * chip,u8 mask,bool check_cancel,bool * canceled)888 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
889 bool check_cancel, bool *canceled)
890 {
891 u8 status = chip->ops->status(chip);
892
893 *canceled = false;
894 if ((status & mask) == mask)
895 return true;
896 if (check_cancel && chip->ops->req_canceled(chip, status)) {
897 *canceled = true;
898 return true;
899 }
900 return false;
901 }
902
wait_for_tpm_stat(struct tpm_chip * chip,u8 mask,unsigned long timeout,wait_queue_head_t * queue,bool check_cancel)903 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
904 wait_queue_head_t *queue, bool check_cancel)
905 {
906 unsigned long stop;
907 long rc;
908 u8 status;
909 bool canceled = false;
910
911 /* check current status */
912 status = chip->ops->status(chip);
913 if ((status & mask) == mask)
914 return 0;
915
916 stop = jiffies + timeout;
917
918 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
919 again:
920 timeout = stop - jiffies;
921 if ((long)timeout <= 0)
922 return -ETIME;
923 rc = wait_event_interruptible_timeout(*queue,
924 wait_for_tpm_stat_cond(chip, mask, check_cancel,
925 &canceled),
926 timeout);
927 if (rc > 0) {
928 if (canceled)
929 return -ECANCELED;
930 return 0;
931 }
932 if (rc == -ERESTARTSYS && freezing(current)) {
933 clear_thread_flag(TIF_SIGPENDING);
934 goto again;
935 }
936 } else {
937 do {
938 msleep(TPM_TIMEOUT);
939 status = chip->ops->status(chip);
940 if ((status & mask) == mask)
941 return 0;
942 } while (time_before(jiffies, stop));
943 }
944 return -ETIME;
945 }
946 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
947
948 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
949 #define SAVESTATE_RESULT_SIZE 10
950
951 static const struct tpm_input_header savestate_header = {
952 .tag = TPM_TAG_RQU_COMMAND,
953 .length = cpu_to_be32(10),
954 .ordinal = TPM_ORD_SAVESTATE
955 };
956
957 /*
958 * We are about to suspend. Save the TPM state
959 * so that it can be restored.
960 */
tpm_pm_suspend(struct device * dev)961 int tpm_pm_suspend(struct device *dev)
962 {
963 struct tpm_chip *chip = dev_get_drvdata(dev);
964 struct tpm_cmd_t cmd;
965 int rc, try;
966
967 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
968
969 if (chip == NULL)
970 return -ENODEV;
971
972 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
973 tpm2_shutdown(chip, TPM2_SU_STATE);
974 return 0;
975 }
976
977 /* for buggy tpm, flush pcrs with extend to selected dummy */
978 if (tpm_suspend_pcr) {
979 cmd.header.in = pcrextend_header;
980 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
981 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
982 TPM_DIGEST_SIZE);
983 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
984 "extending dummy pcr before suspend");
985 }
986
987 /* now do the actual savestate */
988 for (try = 0; try < TPM_RETRY; try++) {
989 cmd.header.in = savestate_header;
990 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
991 NULL);
992
993 /*
994 * If the TPM indicates that it is too busy to respond to
995 * this command then retry before giving up. It can take
996 * several seconds for this TPM to be ready.
997 *
998 * This can happen if the TPM has already been sent the
999 * SaveState command before the driver has loaded. TCG 1.2
1000 * specification states that any communication after SaveState
1001 * may cause the TPM to invalidate previously saved state.
1002 */
1003 if (rc != TPM_WARN_RETRY)
1004 break;
1005 msleep(TPM_TIMEOUT_RETRY);
1006 }
1007
1008 if (rc)
1009 dev_err(&chip->dev,
1010 "Error (%d) sending savestate before suspend\n", rc);
1011 else if (try > 0)
1012 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1013 try * TPM_TIMEOUT_RETRY);
1014
1015 return rc;
1016 }
1017 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1018
1019 /*
1020 * Resume from a power safe. The BIOS already restored
1021 * the TPM state.
1022 */
tpm_pm_resume(struct device * dev)1023 int tpm_pm_resume(struct device *dev)
1024 {
1025 struct tpm_chip *chip = dev_get_drvdata(dev);
1026
1027 if (chip == NULL)
1028 return -ENODEV;
1029
1030 return 0;
1031 }
1032 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1033
1034 #define TPM_GETRANDOM_RESULT_SIZE 18
1035 static const struct tpm_input_header tpm_getrandom_header = {
1036 .tag = TPM_TAG_RQU_COMMAND,
1037 .length = cpu_to_be32(14),
1038 .ordinal = TPM_ORD_GET_RANDOM
1039 };
1040
1041 /**
1042 * tpm_get_random() - Get random bytes from the tpm's RNG
1043 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1044 * @out: destination buffer for the random bytes
1045 * @max: the max number of bytes to write to @out
1046 *
1047 * Returns < 0 on error and the number of bytes read on success
1048 */
tpm_get_random(u32 chip_num,u8 * out,size_t max)1049 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1050 {
1051 struct tpm_chip *chip;
1052 struct tpm_cmd_t tpm_cmd;
1053 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1054 int err, total = 0, retries = 5;
1055 u8 *dest = out;
1056
1057 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1058 return -EINVAL;
1059
1060 chip = tpm_chip_find_get(chip_num);
1061 if (chip == NULL)
1062 return -ENODEV;
1063
1064 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1065 err = tpm2_get_random(chip, out, max);
1066 tpm_put_ops(chip);
1067 return err;
1068 }
1069
1070 do {
1071 tpm_cmd.header.in = tpm_getrandom_header;
1072 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1073
1074 err = tpm_transmit_cmd(chip, &tpm_cmd,
1075 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1076 0, "attempting get random");
1077 if (err)
1078 break;
1079
1080 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1081 if (recd > num_bytes) {
1082 total = -EFAULT;
1083 break;
1084 }
1085
1086 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1087
1088 dest += recd;
1089 total += recd;
1090 num_bytes -= recd;
1091 } while (retries-- && total < max);
1092
1093 tpm_put_ops(chip);
1094 return total ? total : -EIO;
1095 }
1096 EXPORT_SYMBOL_GPL(tpm_get_random);
1097
1098 /**
1099 * tpm_seal_trusted() - seal a trusted key
1100 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1101 * @options: authentication values and other options
1102 * @payload: the key data in clear and encrypted form
1103 *
1104 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1105 * are supported.
1106 */
tpm_seal_trusted(u32 chip_num,struct trusted_key_payload * payload,struct trusted_key_options * options)1107 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1108 struct trusted_key_options *options)
1109 {
1110 struct tpm_chip *chip;
1111 int rc;
1112
1113 chip = tpm_chip_find_get(chip_num);
1114 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1115 return -ENODEV;
1116
1117 rc = tpm2_seal_trusted(chip, payload, options);
1118
1119 tpm_put_ops(chip);
1120 return rc;
1121 }
1122 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1123
1124 /**
1125 * tpm_unseal_trusted() - unseal a trusted key
1126 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1127 * @options: authentication values and other options
1128 * @payload: the key data in clear and encrypted form
1129 *
1130 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1131 * are supported.
1132 */
tpm_unseal_trusted(u32 chip_num,struct trusted_key_payload * payload,struct trusted_key_options * options)1133 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1134 struct trusted_key_options *options)
1135 {
1136 struct tpm_chip *chip;
1137 int rc;
1138
1139 chip = tpm_chip_find_get(chip_num);
1140 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1141 return -ENODEV;
1142
1143 rc = tpm2_unseal_trusted(chip, payload, options);
1144
1145 tpm_put_ops(chip);
1146
1147 return rc;
1148 }
1149 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1150
tpm_init(void)1151 static int __init tpm_init(void)
1152 {
1153 int rc;
1154
1155 tpm_class = class_create(THIS_MODULE, "tpm");
1156 if (IS_ERR(tpm_class)) {
1157 pr_err("couldn't create tpm class\n");
1158 return PTR_ERR(tpm_class);
1159 }
1160
1161 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1162 if (rc < 0) {
1163 pr_err("tpm: failed to allocate char dev region\n");
1164 class_destroy(tpm_class);
1165 return rc;
1166 }
1167
1168 return 0;
1169 }
1170
tpm_exit(void)1171 static void __exit tpm_exit(void)
1172 {
1173 idr_destroy(&dev_nums_idr);
1174 class_destroy(tpm_class);
1175 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1176 }
1177
1178 subsys_initcall(tpm_init);
1179 module_exit(tpm_exit);
1180
1181 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1182 MODULE_DESCRIPTION("TPM Driver");
1183 MODULE_VERSION("2.0");
1184 MODULE_LICENSE("GPL");
1185