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Merge remote-tracking branches 'asoc/topic/fsl-sai', 'asoc/topic/fsl-ssl', 'asoc...
[deliverable/linux.git] / drivers / char / tpm / tpm-interface.c
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 */
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->vendor.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 */
333 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
334 size_t bufsiz)
335 {
336 ssize_t rc;
337 u32 count, ordinal;
338 unsigned long stop;
339
340 if (bufsiz > TPM_BUFSIZE)
341 bufsiz = TPM_BUFSIZE;
342
343 count = be32_to_cpu(*((__be32 *) (buf + 2)));
344 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
345 if (count == 0)
346 return -ENODATA;
347 if (count > bufsiz) {
348 dev_err(chip->pdev,
349 "invalid count value %x %zx\n", count, bufsiz);
350 return -E2BIG;
351 }
352
353 mutex_lock(&chip->tpm_mutex);
354
355 rc = chip->ops->send(chip, (u8 *) buf, count);
356 if (rc < 0) {
357 dev_err(chip->pdev,
358 "tpm_transmit: tpm_send: error %zd\n", rc);
359 goto out;
360 }
361
362 if (chip->vendor.irq)
363 goto out_recv;
364
365 if (chip->flags & TPM_CHIP_FLAG_TPM2)
366 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
367 else
368 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
369 do {
370 u8 status = chip->ops->status(chip);
371 if ((status & chip->ops->req_complete_mask) ==
372 chip->ops->req_complete_val)
373 goto out_recv;
374
375 if (chip->ops->req_canceled(chip, status)) {
376 dev_err(chip->pdev, "Operation Canceled\n");
377 rc = -ECANCELED;
378 goto out;
379 }
380
381 msleep(TPM_TIMEOUT); /* CHECK */
382 rmb();
383 } while (time_before(jiffies, stop));
384
385 chip->ops->cancel(chip);
386 dev_err(chip->pdev, "Operation Timed out\n");
387 rc = -ETIME;
388 goto out;
389
390 out_recv:
391 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
392 if (rc < 0)
393 dev_err(chip->pdev,
394 "tpm_transmit: tpm_recv: error %zd\n", rc);
395 out:
396 mutex_unlock(&chip->tpm_mutex);
397 return rc;
398 }
399
400 #define TPM_DIGEST_SIZE 20
401 #define TPM_RET_CODE_IDX 6
402
403 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
404 int len, const char *desc)
405 {
406 struct tpm_output_header *header;
407 int err;
408
409 len = tpm_transmit(chip, (u8 *) cmd, len);
410 if (len < 0)
411 return len;
412 else if (len < TPM_HEADER_SIZE)
413 return -EFAULT;
414
415 header = cmd;
416
417 err = be32_to_cpu(header->return_code);
418 if (err != 0 && desc)
419 dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
420 desc);
421
422 return err;
423 }
424
425 #define TPM_INTERNAL_RESULT_SIZE 200
426 #define TPM_ORD_GET_CAP cpu_to_be32(101)
427 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
428
429 static const struct tpm_input_header tpm_getcap_header = {
430 .tag = TPM_TAG_RQU_COMMAND,
431 .length = cpu_to_be32(22),
432 .ordinal = TPM_ORD_GET_CAP
433 };
434
435 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
436 const char *desc)
437 {
438 struct tpm_cmd_t tpm_cmd;
439 int rc;
440 struct tpm_chip *chip = dev_get_drvdata(dev);
441
442 tpm_cmd.header.in = tpm_getcap_header;
443 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
444 tpm_cmd.params.getcap_in.cap = subcap_id;
445 /*subcap field not necessary */
446 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
447 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
448 } else {
449 if (subcap_id == TPM_CAP_FLAG_PERM ||
450 subcap_id == TPM_CAP_FLAG_VOL)
451 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
452 else
453 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
454 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
455 tpm_cmd.params.getcap_in.subcap = subcap_id;
456 }
457 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
458 if (!rc)
459 *cap = tpm_cmd.params.getcap_out.cap;
460 return rc;
461 }
462
463 void tpm_gen_interrupt(struct tpm_chip *chip)
464 {
465 struct tpm_cmd_t tpm_cmd;
466 ssize_t rc;
467
468 tpm_cmd.header.in = tpm_getcap_header;
469 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
470 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
471 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
472
473 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
474 "attempting to determine the timeouts");
475 }
476 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
477
478 #define TPM_ORD_STARTUP cpu_to_be32(153)
479 #define TPM_ST_CLEAR cpu_to_be16(1)
480 #define TPM_ST_STATE cpu_to_be16(2)
481 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
482 static const struct tpm_input_header tpm_startup_header = {
483 .tag = TPM_TAG_RQU_COMMAND,
484 .length = cpu_to_be32(12),
485 .ordinal = TPM_ORD_STARTUP
486 };
487
488 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
489 {
490 struct tpm_cmd_t start_cmd;
491 start_cmd.header.in = tpm_startup_header;
492
493 start_cmd.params.startup_in.startup_type = startup_type;
494 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
495 "attempting to start the TPM");
496 }
497
498 int tpm_get_timeouts(struct tpm_chip *chip)
499 {
500 struct tpm_cmd_t tpm_cmd;
501 unsigned long new_timeout[4];
502 unsigned long old_timeout[4];
503 struct duration_t *duration_cap;
504 ssize_t rc;
505
506 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
507 /* Fixed timeouts for TPM2 */
508 chip->vendor.timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
509 chip->vendor.timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
510 chip->vendor.timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
511 chip->vendor.timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
512 chip->vendor.duration[TPM_SHORT] =
513 msecs_to_jiffies(TPM2_DURATION_SHORT);
514 chip->vendor.duration[TPM_MEDIUM] =
515 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
516 chip->vendor.duration[TPM_LONG] =
517 msecs_to_jiffies(TPM2_DURATION_LONG);
518 return 0;
519 }
520
521 tpm_cmd.header.in = tpm_getcap_header;
522 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
523 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
524 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
525 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
526
527 if (rc == TPM_ERR_INVALID_POSTINIT) {
528 /* The TPM is not started, we are the first to talk to it.
529 Execute a startup command. */
530 dev_info(chip->pdev, "Issuing TPM_STARTUP");
531 if (tpm_startup(chip, TPM_ST_CLEAR))
532 return rc;
533
534 tpm_cmd.header.in = tpm_getcap_header;
535 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
536 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
537 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
538 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
539 NULL);
540 }
541 if (rc) {
542 dev_err(chip->pdev,
543 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
544 rc);
545 goto duration;
546 }
547
548 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
549 be32_to_cpu(tpm_cmd.header.out.length)
550 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
551 return -EINVAL;
552
553 old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
554 old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
555 old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
556 old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
557 memcpy(new_timeout, old_timeout, sizeof(new_timeout));
558
559 /*
560 * Provide ability for vendor overrides of timeout values in case
561 * of misreporting.
562 */
563 if (chip->ops->update_timeouts != NULL)
564 chip->vendor.timeout_adjusted =
565 chip->ops->update_timeouts(chip, new_timeout);
566
567 if (!chip->vendor.timeout_adjusted) {
568 /* Don't overwrite default if value is 0 */
569 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
570 int i;
571
572 /* timeouts in msec rather usec */
573 for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
574 new_timeout[i] *= 1000;
575 chip->vendor.timeout_adjusted = true;
576 }
577 }
578
579 /* Report adjusted timeouts */
580 if (chip->vendor.timeout_adjusted) {
581 dev_info(chip->pdev,
582 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
583 old_timeout[0], new_timeout[0],
584 old_timeout[1], new_timeout[1],
585 old_timeout[2], new_timeout[2],
586 old_timeout[3], new_timeout[3]);
587 }
588
589 chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
590 chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
591 chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
592 chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
593
594 duration:
595 tpm_cmd.header.in = tpm_getcap_header;
596 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
597 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
598 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
599
600 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
601 "attempting to determine the durations");
602 if (rc)
603 return rc;
604
605 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
606 be32_to_cpu(tpm_cmd.header.out.length)
607 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
608 return -EINVAL;
609
610 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
611 chip->vendor.duration[TPM_SHORT] =
612 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
613 chip->vendor.duration[TPM_MEDIUM] =
614 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
615 chip->vendor.duration[TPM_LONG] =
616 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
617
618 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
619 * value wrong and apparently reports msecs rather than usecs. So we
620 * fix up the resulting too-small TPM_SHORT value to make things work.
621 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
622 */
623 if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
624 chip->vendor.duration[TPM_SHORT] = HZ;
625 chip->vendor.duration[TPM_MEDIUM] *= 1000;
626 chip->vendor.duration[TPM_LONG] *= 1000;
627 chip->vendor.duration_adjusted = true;
628 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
629 }
630 return 0;
631 }
632 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
633
634 #define TPM_ORD_CONTINUE_SELFTEST 83
635 #define CONTINUE_SELFTEST_RESULT_SIZE 10
636
637 static struct tpm_input_header continue_selftest_header = {
638 .tag = TPM_TAG_RQU_COMMAND,
639 .length = cpu_to_be32(10),
640 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
641 };
642
643 /**
644 * tpm_continue_selftest -- run TPM's selftest
645 * @chip: TPM chip to use
646 *
647 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
648 * a TPM error code.
649 */
650 static int tpm_continue_selftest(struct tpm_chip *chip)
651 {
652 int rc;
653 struct tpm_cmd_t cmd;
654
655 cmd.header.in = continue_selftest_header;
656 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
657 "continue selftest");
658 return rc;
659 }
660
661 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
662 #define READ_PCR_RESULT_SIZE 30
663 static struct tpm_input_header pcrread_header = {
664 .tag = TPM_TAG_RQU_COMMAND,
665 .length = cpu_to_be32(14),
666 .ordinal = TPM_ORDINAL_PCRREAD
667 };
668
669 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
670 {
671 int rc;
672 struct tpm_cmd_t cmd;
673
674 cmd.header.in = pcrread_header;
675 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
676 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
677 "attempting to read a pcr value");
678
679 if (rc == 0)
680 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
681 TPM_DIGEST_SIZE);
682 return rc;
683 }
684
685 /**
686 * tpm_is_tpm2 - is the chip a TPM2 chip?
687 * @chip_num: tpm idx # or ANY
688 *
689 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
690 * is a TPM2 chip.
691 */
692 int tpm_is_tpm2(u32 chip_num)
693 {
694 struct tpm_chip *chip;
695 int rc;
696
697 chip = tpm_chip_find_get(chip_num);
698 if (chip == NULL)
699 return -ENODEV;
700
701 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
702
703 tpm_chip_put(chip);
704
705 return rc;
706 }
707 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
708
709 /**
710 * tpm_pcr_read - read a pcr value
711 * @chip_num: tpm idx # or ANY
712 * @pcr_idx: pcr idx to retrieve
713 * @res_buf: TPM_PCR value
714 * size of res_buf is 20 bytes (or NULL if you don't care)
715 *
716 * The TPM driver should be built-in, but for whatever reason it
717 * isn't, protect against the chip disappearing, by incrementing
718 * the module usage count.
719 */
720 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
721 {
722 struct tpm_chip *chip;
723 int rc;
724
725 chip = tpm_chip_find_get(chip_num);
726 if (chip == NULL)
727 return -ENODEV;
728 if (chip->flags & TPM_CHIP_FLAG_TPM2)
729 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
730 else
731 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
732 tpm_chip_put(chip);
733 return rc;
734 }
735 EXPORT_SYMBOL_GPL(tpm_pcr_read);
736
737 /**
738 * tpm_pcr_extend - extend pcr value with hash
739 * @chip_num: tpm idx # or AN&
740 * @pcr_idx: pcr idx to extend
741 * @hash: hash value used to extend pcr value
742 *
743 * The TPM driver should be built-in, but for whatever reason it
744 * isn't, protect against the chip disappearing, by incrementing
745 * the module usage count.
746 */
747 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
748 #define EXTEND_PCR_RESULT_SIZE 34
749 static struct tpm_input_header pcrextend_header = {
750 .tag = TPM_TAG_RQU_COMMAND,
751 .length = cpu_to_be32(34),
752 .ordinal = TPM_ORD_PCR_EXTEND
753 };
754
755 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
756 {
757 struct tpm_cmd_t cmd;
758 int rc;
759 struct tpm_chip *chip;
760
761 chip = tpm_chip_find_get(chip_num);
762 if (chip == NULL)
763 return -ENODEV;
764
765 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
766 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
767 tpm_chip_put(chip);
768 return rc;
769 }
770
771 cmd.header.in = pcrextend_header;
772 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
773 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
774 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
775 "attempting extend a PCR value");
776
777 tpm_chip_put(chip);
778 return rc;
779 }
780 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
781
782 /**
783 * tpm_do_selftest - have the TPM continue its selftest and wait until it
784 * can receive further commands
785 * @chip: TPM chip to use
786 *
787 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
788 * a TPM error code.
789 */
790 int tpm_do_selftest(struct tpm_chip *chip)
791 {
792 int rc;
793 unsigned int loops;
794 unsigned int delay_msec = 100;
795 unsigned long duration;
796 struct tpm_cmd_t cmd;
797
798 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
799
800 loops = jiffies_to_msecs(duration) / delay_msec;
801
802 rc = tpm_continue_selftest(chip);
803 /* This may fail if there was no TPM driver during a suspend/resume
804 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
805 */
806 if (rc)
807 return rc;
808
809 do {
810 /* Attempt to read a PCR value */
811 cmd.header.in = pcrread_header;
812 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
813 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
814 /* Some buggy TPMs will not respond to tpm_tis_ready() for
815 * around 300ms while the self test is ongoing, keep trying
816 * until the self test duration expires. */
817 if (rc == -ETIME) {
818 dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
819 msleep(delay_msec);
820 continue;
821 }
822
823 if (rc < TPM_HEADER_SIZE)
824 return -EFAULT;
825
826 rc = be32_to_cpu(cmd.header.out.return_code);
827 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
828 dev_info(chip->pdev,
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 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
846 {
847 struct tpm_chip *chip;
848 int rc;
849
850 chip = tpm_chip_find_get(chip_num);
851 if (chip == NULL)
852 return -ENODEV;
853
854 rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
855
856 tpm_chip_put(chip);
857 return rc;
858 }
859 EXPORT_SYMBOL_GPL(tpm_send);
860
861 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
862 bool check_cancel, bool *canceled)
863 {
864 u8 status = chip->ops->status(chip);
865
866 *canceled = false;
867 if ((status & mask) == mask)
868 return true;
869 if (check_cancel && chip->ops->req_canceled(chip, status)) {
870 *canceled = true;
871 return true;
872 }
873 return false;
874 }
875
876 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
877 wait_queue_head_t *queue, bool check_cancel)
878 {
879 unsigned long stop;
880 long rc;
881 u8 status;
882 bool canceled = false;
883
884 /* check current status */
885 status = chip->ops->status(chip);
886 if ((status & mask) == mask)
887 return 0;
888
889 stop = jiffies + timeout;
890
891 if (chip->vendor.irq) {
892 again:
893 timeout = stop - jiffies;
894 if ((long)timeout <= 0)
895 return -ETIME;
896 rc = wait_event_interruptible_timeout(*queue,
897 wait_for_tpm_stat_cond(chip, mask, check_cancel,
898 &canceled),
899 timeout);
900 if (rc > 0) {
901 if (canceled)
902 return -ECANCELED;
903 return 0;
904 }
905 if (rc == -ERESTARTSYS && freezing(current)) {
906 clear_thread_flag(TIF_SIGPENDING);
907 goto again;
908 }
909 } else {
910 do {
911 msleep(TPM_TIMEOUT);
912 status = chip->ops->status(chip);
913 if ((status & mask) == mask)
914 return 0;
915 } while (time_before(jiffies, stop));
916 }
917 return -ETIME;
918 }
919 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
920
921 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
922 #define SAVESTATE_RESULT_SIZE 10
923
924 static struct tpm_input_header savestate_header = {
925 .tag = TPM_TAG_RQU_COMMAND,
926 .length = cpu_to_be32(10),
927 .ordinal = TPM_ORD_SAVESTATE
928 };
929
930 /*
931 * We are about to suspend. Save the TPM state
932 * so that it can be restored.
933 */
934 int tpm_pm_suspend(struct device *dev)
935 {
936 struct tpm_chip *chip = dev_get_drvdata(dev);
937 struct tpm_cmd_t cmd;
938 int rc, try;
939
940 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
941
942 if (chip == NULL)
943 return -ENODEV;
944
945 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
946 tpm2_shutdown(chip, TPM2_SU_STATE);
947 return 0;
948 }
949
950 /* for buggy tpm, flush pcrs with extend to selected dummy */
951 if (tpm_suspend_pcr) {
952 cmd.header.in = pcrextend_header;
953 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
954 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
955 TPM_DIGEST_SIZE);
956 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
957 "extending dummy pcr before suspend");
958 }
959
960 /* now do the actual savestate */
961 for (try = 0; try < TPM_RETRY; try++) {
962 cmd.header.in = savestate_header;
963 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
964
965 /*
966 * If the TPM indicates that it is too busy to respond to
967 * this command then retry before giving up. It can take
968 * several seconds for this TPM to be ready.
969 *
970 * This can happen if the TPM has already been sent the
971 * SaveState command before the driver has loaded. TCG 1.2
972 * specification states that any communication after SaveState
973 * may cause the TPM to invalidate previously saved state.
974 */
975 if (rc != TPM_WARN_RETRY)
976 break;
977 msleep(TPM_TIMEOUT_RETRY);
978 }
979
980 if (rc)
981 dev_err(chip->pdev,
982 "Error (%d) sending savestate before suspend\n", rc);
983 else if (try > 0)
984 dev_warn(chip->pdev, "TPM savestate took %dms\n",
985 try * TPM_TIMEOUT_RETRY);
986
987 return rc;
988 }
989 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
990
991 /*
992 * Resume from a power safe. The BIOS already restored
993 * the TPM state.
994 */
995 int tpm_pm_resume(struct device *dev)
996 {
997 struct tpm_chip *chip = dev_get_drvdata(dev);
998
999 if (chip == NULL)
1000 return -ENODEV;
1001
1002 return 0;
1003 }
1004 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1005
1006 #define TPM_GETRANDOM_RESULT_SIZE 18
1007 static struct tpm_input_header tpm_getrandom_header = {
1008 .tag = TPM_TAG_RQU_COMMAND,
1009 .length = cpu_to_be32(14),
1010 .ordinal = TPM_ORD_GET_RANDOM
1011 };
1012
1013 /**
1014 * tpm_get_random() - Get random bytes from the tpm's RNG
1015 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1016 * @out: destination buffer for the random bytes
1017 * @max: the max number of bytes to write to @out
1018 *
1019 * Returns < 0 on error and the number of bytes read on success
1020 */
1021 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1022 {
1023 struct tpm_chip *chip;
1024 struct tpm_cmd_t tpm_cmd;
1025 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1026 int err, total = 0, retries = 5;
1027 u8 *dest = out;
1028
1029 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1030 return -EINVAL;
1031
1032 chip = tpm_chip_find_get(chip_num);
1033 if (chip == NULL)
1034 return -ENODEV;
1035
1036 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1037 err = tpm2_get_random(chip, out, max);
1038 tpm_chip_put(chip);
1039 return err;
1040 }
1041
1042 do {
1043 tpm_cmd.header.in = tpm_getrandom_header;
1044 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1045
1046 err = tpm_transmit_cmd(chip, &tpm_cmd,
1047 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1048 "attempting get random");
1049 if (err)
1050 break;
1051
1052 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1053 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1054
1055 dest += recd;
1056 total += recd;
1057 num_bytes -= recd;
1058 } while (retries-- && total < max);
1059
1060 tpm_chip_put(chip);
1061 return total ? total : -EIO;
1062 }
1063 EXPORT_SYMBOL_GPL(tpm_get_random);
1064
1065 /**
1066 * tpm_seal_trusted() - seal a trusted key
1067 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1068 * @options: authentication values and other options
1069 * @payload: the key data in clear and encrypted form
1070 *
1071 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1072 * are supported.
1073 */
1074 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1075 struct trusted_key_options *options)
1076 {
1077 struct tpm_chip *chip;
1078 int rc;
1079
1080 chip = tpm_chip_find_get(chip_num);
1081 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1082 return -ENODEV;
1083
1084 rc = tpm2_seal_trusted(chip, payload, options);
1085
1086 tpm_chip_put(chip);
1087 return rc;
1088 }
1089 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1090
1091 /**
1092 * tpm_unseal_trusted() - unseal a trusted key
1093 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1094 * @options: authentication values and other options
1095 * @payload: the key data in clear and encrypted form
1096 *
1097 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1098 * are supported.
1099 */
1100 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1101 struct trusted_key_options *options)
1102 {
1103 struct tpm_chip *chip;
1104 int rc;
1105
1106 chip = tpm_chip_find_get(chip_num);
1107 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1108 return -ENODEV;
1109
1110 rc = tpm2_unseal_trusted(chip, payload, options);
1111
1112 tpm_chip_put(chip);
1113 return rc;
1114 }
1115 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1116
1117 static int __init tpm_init(void)
1118 {
1119 int rc;
1120
1121 tpm_class = class_create(THIS_MODULE, "tpm");
1122 if (IS_ERR(tpm_class)) {
1123 pr_err("couldn't create tpm class\n");
1124 return PTR_ERR(tpm_class);
1125 }
1126
1127 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1128 if (rc < 0) {
1129 pr_err("tpm: failed to allocate char dev region\n");
1130 class_destroy(tpm_class);
1131 return rc;
1132 }
1133
1134 return 0;
1135 }
1136
1137 static void __exit tpm_exit(void)
1138 {
1139 class_destroy(tpm_class);
1140 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1141 }
1142
1143 subsys_initcall(tpm_init);
1144 module_exit(tpm_exit);
1145
1146 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1147 MODULE_DESCRIPTION("TPM Driver");
1148 MODULE_VERSION("2.0");
1149 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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