xref: /openbmc/linux/drivers/char/tpm/tpm_tis_core.c (revision 1372a51b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2005, 2006 IBM Corporation
4  * Copyright (C) 2014, 2015 Intel Corporation
5  *
6  * Authors:
7  * Leendert van Doorn <leendert@watson.ibm.com>
8  * Kylene Hall <kjhall@us.ibm.com>
9  *
10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11  *
12  * Device driver for TCG/TCPA TPM (trusted platform module).
13  * Specifications at www.trustedcomputinggroup.org
14  *
15  * This device driver implements the TPM interface as defined in
16  * the TCG TPM Interface Spec version 1.2, revision 1.0.
17  */
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/pnp.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/wait.h>
25 #include <linux/acpi.h>
26 #include <linux/freezer.h>
27 #include "tpm.h"
28 #include "tpm_tis_core.h"
29 
30 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
31 
32 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
33 					bool check_cancel, bool *canceled)
34 {
35 	u8 status = chip->ops->status(chip);
36 
37 	*canceled = false;
38 	if ((status & mask) == mask)
39 		return true;
40 	if (check_cancel && chip->ops->req_canceled(chip, status)) {
41 		*canceled = true;
42 		return true;
43 	}
44 	return false;
45 }
46 
47 static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
48 		unsigned long timeout, wait_queue_head_t *queue,
49 		bool check_cancel)
50 {
51 	unsigned long stop;
52 	long rc;
53 	u8 status;
54 	bool canceled = false;
55 
56 	/* check current status */
57 	status = chip->ops->status(chip);
58 	if ((status & mask) == mask)
59 		return 0;
60 
61 	stop = jiffies + timeout;
62 
63 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
64 again:
65 		timeout = stop - jiffies;
66 		if ((long)timeout <= 0)
67 			return -ETIME;
68 		rc = wait_event_interruptible_timeout(*queue,
69 			wait_for_tpm_stat_cond(chip, mask, check_cancel,
70 					       &canceled),
71 			timeout);
72 		if (rc > 0) {
73 			if (canceled)
74 				return -ECANCELED;
75 			return 0;
76 		}
77 		if (rc == -ERESTARTSYS && freezing(current)) {
78 			clear_thread_flag(TIF_SIGPENDING);
79 			goto again;
80 		}
81 	} else {
82 		do {
83 			usleep_range(TPM_TIMEOUT_USECS_MIN,
84 				     TPM_TIMEOUT_USECS_MAX);
85 			status = chip->ops->status(chip);
86 			if ((status & mask) == mask)
87 				return 0;
88 		} while (time_before(jiffies, stop));
89 	}
90 	return -ETIME;
91 }
92 
93 /* Before we attempt to access the TPM we must see that the valid bit is set.
94  * The specification says that this bit is 0 at reset and remains 0 until the
95  * 'TPM has gone through its self test and initialization and has established
96  * correct values in the other bits.'
97  */
98 static int wait_startup(struct tpm_chip *chip, int l)
99 {
100 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
101 	unsigned long stop = jiffies + chip->timeout_a;
102 
103 	do {
104 		int rc;
105 		u8 access;
106 
107 		rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
108 		if (rc < 0)
109 			return rc;
110 
111 		if (access & TPM_ACCESS_VALID)
112 			return 0;
113 		tpm_msleep(TPM_TIMEOUT);
114 	} while (time_before(jiffies, stop));
115 	return -1;
116 }
117 
118 static bool check_locality(struct tpm_chip *chip, int l)
119 {
120 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
121 	int rc;
122 	u8 access;
123 
124 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
125 	if (rc < 0)
126 		return false;
127 
128 	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
129 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
130 		priv->locality = l;
131 		return true;
132 	}
133 
134 	return false;
135 }
136 
137 static bool locality_inactive(struct tpm_chip *chip, int l)
138 {
139 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
140 	int rc;
141 	u8 access;
142 
143 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
144 	if (rc < 0)
145 		return false;
146 
147 	if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))
148 	    == TPM_ACCESS_VALID)
149 		return true;
150 
151 	return false;
152 }
153 
154 static int release_locality(struct tpm_chip *chip, int l)
155 {
156 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
157 	unsigned long stop, timeout;
158 	long rc;
159 
160 	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
161 
162 	stop = jiffies + chip->timeout_a;
163 
164 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
165 again:
166 		timeout = stop - jiffies;
167 		if ((long)timeout <= 0)
168 			return -1;
169 
170 		rc = wait_event_interruptible_timeout(priv->int_queue,
171 						      (locality_inactive(chip, l)),
172 						      timeout);
173 
174 		if (rc > 0)
175 			return 0;
176 
177 		if (rc == -ERESTARTSYS && freezing(current)) {
178 			clear_thread_flag(TIF_SIGPENDING);
179 			goto again;
180 		}
181 	} else {
182 		do {
183 			if (locality_inactive(chip, l))
184 				return 0;
185 			tpm_msleep(TPM_TIMEOUT);
186 		} while (time_before(jiffies, stop));
187 	}
188 	return -1;
189 }
190 
191 static int request_locality(struct tpm_chip *chip, int l)
192 {
193 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
194 	unsigned long stop, timeout;
195 	long rc;
196 
197 	if (check_locality(chip, l))
198 		return l;
199 
200 	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
201 	if (rc < 0)
202 		return rc;
203 
204 	stop = jiffies + chip->timeout_a;
205 
206 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
207 again:
208 		timeout = stop - jiffies;
209 		if ((long)timeout <= 0)
210 			return -1;
211 		rc = wait_event_interruptible_timeout(priv->int_queue,
212 						      (check_locality
213 						       (chip, l)),
214 						      timeout);
215 		if (rc > 0)
216 			return l;
217 		if (rc == -ERESTARTSYS && freezing(current)) {
218 			clear_thread_flag(TIF_SIGPENDING);
219 			goto again;
220 		}
221 	} else {
222 		/* wait for burstcount */
223 		do {
224 			if (check_locality(chip, l))
225 				return l;
226 			tpm_msleep(TPM_TIMEOUT);
227 		} while (time_before(jiffies, stop));
228 	}
229 	return -1;
230 }
231 
232 static u8 tpm_tis_status(struct tpm_chip *chip)
233 {
234 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
235 	int rc;
236 	u8 status;
237 
238 	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
239 	if (rc < 0)
240 		return 0;
241 
242 	return status;
243 }
244 
245 static void tpm_tis_ready(struct tpm_chip *chip)
246 {
247 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
248 
249 	/* this causes the current command to be aborted */
250 	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
251 }
252 
253 static int get_burstcount(struct tpm_chip *chip)
254 {
255 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
256 	unsigned long stop;
257 	int burstcnt, rc;
258 	u32 value;
259 
260 	/* wait for burstcount */
261 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
262 		stop = jiffies + chip->timeout_a;
263 	else
264 		stop = jiffies + chip->timeout_d;
265 	do {
266 		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
267 		if (rc < 0)
268 			return rc;
269 
270 		burstcnt = (value >> 8) & 0xFFFF;
271 		if (burstcnt)
272 			return burstcnt;
273 		usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX);
274 	} while (time_before(jiffies, stop));
275 	return -EBUSY;
276 }
277 
278 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
279 {
280 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
281 	int size = 0, burstcnt, rc;
282 
283 	while (size < count) {
284 		rc = wait_for_tpm_stat(chip,
285 				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
286 				 chip->timeout_c,
287 				 &priv->read_queue, true);
288 		if (rc < 0)
289 			return rc;
290 		burstcnt = get_burstcount(chip);
291 		if (burstcnt < 0) {
292 			dev_err(&chip->dev, "Unable to read burstcount\n");
293 			return burstcnt;
294 		}
295 		burstcnt = min_t(int, burstcnt, count - size);
296 
297 		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
298 					burstcnt, buf + size);
299 		if (rc < 0)
300 			return rc;
301 
302 		size += burstcnt;
303 	}
304 	return size;
305 }
306 
307 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
308 {
309 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
310 	int size = 0;
311 	int status;
312 	u32 expected;
313 
314 	if (count < TPM_HEADER_SIZE) {
315 		size = -EIO;
316 		goto out;
317 	}
318 
319 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
320 	/* read first 10 bytes, including tag, paramsize, and result */
321 	if (size < TPM_HEADER_SIZE) {
322 		dev_err(&chip->dev, "Unable to read header\n");
323 		goto out;
324 	}
325 
326 	expected = be32_to_cpu(*(__be32 *) (buf + 2));
327 	if (expected > count || expected < TPM_HEADER_SIZE) {
328 		size = -EIO;
329 		goto out;
330 	}
331 
332 	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
333 			  expected - TPM_HEADER_SIZE);
334 	if (size < expected) {
335 		dev_err(&chip->dev, "Unable to read remainder of result\n");
336 		size = -ETIME;
337 		goto out;
338 	}
339 
340 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
341 				&priv->int_queue, false) < 0) {
342 		size = -ETIME;
343 		goto out;
344 	}
345 	status = tpm_tis_status(chip);
346 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
347 		dev_err(&chip->dev, "Error left over data\n");
348 		size = -EIO;
349 		goto out;
350 	}
351 
352 out:
353 	tpm_tis_ready(chip);
354 	return size;
355 }
356 
357 /*
358  * If interrupts are used (signaled by an irq set in the vendor structure)
359  * tpm.c can skip polling for the data to be available as the interrupt is
360  * waited for here
361  */
362 static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
363 {
364 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
365 	int rc, status, burstcnt;
366 	size_t count = 0;
367 	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
368 
369 	status = tpm_tis_status(chip);
370 	if ((status & TPM_STS_COMMAND_READY) == 0) {
371 		tpm_tis_ready(chip);
372 		if (wait_for_tpm_stat
373 		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
374 		     &priv->int_queue, false) < 0) {
375 			rc = -ETIME;
376 			goto out_err;
377 		}
378 	}
379 
380 	while (count < len - 1) {
381 		burstcnt = get_burstcount(chip);
382 		if (burstcnt < 0) {
383 			dev_err(&chip->dev, "Unable to read burstcount\n");
384 			rc = burstcnt;
385 			goto out_err;
386 		}
387 		burstcnt = min_t(int, burstcnt, len - count - 1);
388 		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
389 					 burstcnt, buf + count);
390 		if (rc < 0)
391 			goto out_err;
392 
393 		count += burstcnt;
394 
395 		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
396 					&priv->int_queue, false) < 0) {
397 			rc = -ETIME;
398 			goto out_err;
399 		}
400 		status = tpm_tis_status(chip);
401 		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
402 			rc = -EIO;
403 			goto out_err;
404 		}
405 	}
406 
407 	/* write last byte */
408 	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
409 	if (rc < 0)
410 		goto out_err;
411 
412 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
413 				&priv->int_queue, false) < 0) {
414 		rc = -ETIME;
415 		goto out_err;
416 	}
417 	status = tpm_tis_status(chip);
418 	if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
419 		rc = -EIO;
420 		goto out_err;
421 	}
422 
423 	return 0;
424 
425 out_err:
426 	tpm_tis_ready(chip);
427 	return rc;
428 }
429 
430 static void disable_interrupts(struct tpm_chip *chip)
431 {
432 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
433 	u32 intmask;
434 	int rc;
435 
436 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
437 	if (rc < 0)
438 		intmask = 0;
439 
440 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
441 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
442 
443 	devm_free_irq(chip->dev.parent, priv->irq, chip);
444 	priv->irq = 0;
445 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
446 }
447 
448 /*
449  * If interrupts are used (signaled by an irq set in the vendor structure)
450  * tpm.c can skip polling for the data to be available as the interrupt is
451  * waited for here
452  */
453 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
454 {
455 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
456 	int rc;
457 	u32 ordinal;
458 	unsigned long dur;
459 
460 	rc = tpm_tis_send_data(chip, buf, len);
461 	if (rc < 0)
462 		return rc;
463 
464 	/* go and do it */
465 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
466 	if (rc < 0)
467 		goto out_err;
468 
469 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
470 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
471 
472 		dur = tpm_calc_ordinal_duration(chip, ordinal);
473 		if (wait_for_tpm_stat
474 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
475 		     &priv->read_queue, false) < 0) {
476 			rc = -ETIME;
477 			goto out_err;
478 		}
479 	}
480 	return 0;
481 out_err:
482 	tpm_tis_ready(chip);
483 	return rc;
484 }
485 
486 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
487 {
488 	int rc, irq;
489 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
490 
491 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
492 		return tpm_tis_send_main(chip, buf, len);
493 
494 	/* Verify receipt of the expected IRQ */
495 	irq = priv->irq;
496 	priv->irq = 0;
497 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
498 	rc = tpm_tis_send_main(chip, buf, len);
499 	priv->irq = irq;
500 	chip->flags |= TPM_CHIP_FLAG_IRQ;
501 	if (!priv->irq_tested)
502 		tpm_msleep(1);
503 	if (!priv->irq_tested)
504 		disable_interrupts(chip);
505 	priv->irq_tested = true;
506 	return rc;
507 }
508 
509 struct tis_vendor_durations_override {
510 	u32 did_vid;
511 	struct tpm1_version version;
512 	unsigned long durations[3];
513 };
514 
515 static const struct  tis_vendor_durations_override vendor_dur_overrides[] = {
516 	/* STMicroelectronics 0x104a */
517 	{ 0x0000104a,
518 	  { 1, 2, 8, 28 },
519 	  { (2 * 60 * HZ), (2 * 60 * HZ), (2 * 60 * HZ) } },
520 };
521 
522 static void tpm_tis_update_durations(struct tpm_chip *chip,
523 				     unsigned long *duration_cap)
524 {
525 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
526 	struct tpm1_version *version;
527 	u32 did_vid;
528 	int i, rc;
529 	cap_t cap;
530 
531 	chip->duration_adjusted = false;
532 
533 	if (chip->ops->clk_enable != NULL)
534 		chip->ops->clk_enable(chip, true);
535 
536 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
537 	if (rc < 0) {
538 		dev_warn(&chip->dev, "%s: failed to read did_vid. %d\n",
539 			 __func__, rc);
540 		goto out;
541 	}
542 
543 	/* Try to get a TPM version 1.2 or 1.1 TPM_CAP_VERSION_INFO */
544 	rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
545 			 "attempting to determine the 1.2 version",
546 			 sizeof(cap.version2));
547 	if (!rc) {
548 		version = &cap.version2.version;
549 	} else {
550 		rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
551 				 "attempting to determine the 1.1 version",
552 				 sizeof(cap.version1));
553 
554 		if (rc)
555 			goto out;
556 
557 		version = &cap.version1;
558 	}
559 
560 	for (i = 0; i != ARRAY_SIZE(vendor_dur_overrides); i++) {
561 		if (vendor_dur_overrides[i].did_vid != did_vid)
562 			continue;
563 
564 		if ((version->major ==
565 		     vendor_dur_overrides[i].version.major) &&
566 		    (version->minor ==
567 		     vendor_dur_overrides[i].version.minor) &&
568 		    (version->rev_major ==
569 		     vendor_dur_overrides[i].version.rev_major) &&
570 		    (version->rev_minor ==
571 		     vendor_dur_overrides[i].version.rev_minor)) {
572 
573 			memcpy(duration_cap,
574 			       vendor_dur_overrides[i].durations,
575 			       sizeof(vendor_dur_overrides[i].durations));
576 
577 			chip->duration_adjusted = true;
578 			goto out;
579 		}
580 	}
581 
582 out:
583 	if (chip->ops->clk_enable != NULL)
584 		chip->ops->clk_enable(chip, false);
585 }
586 
587 struct tis_vendor_timeout_override {
588 	u32 did_vid;
589 	unsigned long timeout_us[4];
590 };
591 
592 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
593 	/* Atmel 3204 */
594 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
595 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
596 };
597 
598 static void tpm_tis_update_timeouts(struct tpm_chip *chip,
599 				    unsigned long *timeout_cap)
600 {
601 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
602 	int i, rc;
603 	u32 did_vid;
604 
605 	chip->timeout_adjusted = false;
606 
607 	if (chip->ops->clk_enable != NULL)
608 		chip->ops->clk_enable(chip, true);
609 
610 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
611 	if (rc < 0) {
612 		dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
613 			 __func__, rc);
614 		goto out;
615 	}
616 
617 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
618 		if (vendor_timeout_overrides[i].did_vid != did_vid)
619 			continue;
620 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
621 		       sizeof(vendor_timeout_overrides[i].timeout_us));
622 		chip->timeout_adjusted = true;
623 	}
624 
625 out:
626 	if (chip->ops->clk_enable != NULL)
627 		chip->ops->clk_enable(chip, false);
628 
629 	return;
630 }
631 
632 /*
633  * Early probing for iTPM with STS_DATA_EXPECT flaw.
634  * Try sending command without itpm flag set and if that
635  * fails, repeat with itpm flag set.
636  */
637 static int probe_itpm(struct tpm_chip *chip)
638 {
639 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
640 	int rc = 0;
641 	static const u8 cmd_getticks[] = {
642 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
643 		0x00, 0x00, 0x00, 0xf1
644 	};
645 	size_t len = sizeof(cmd_getticks);
646 	u16 vendor;
647 
648 	if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
649 		return 0;
650 
651 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
652 	if (rc < 0)
653 		return rc;
654 
655 	/* probe only iTPMS */
656 	if (vendor != TPM_VID_INTEL)
657 		return 0;
658 
659 	if (request_locality(chip, 0) != 0)
660 		return -EBUSY;
661 
662 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
663 	if (rc == 0)
664 		goto out;
665 
666 	tpm_tis_ready(chip);
667 
668 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
669 
670 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
671 	if (rc == 0)
672 		dev_info(&chip->dev, "Detected an iTPM.\n");
673 	else {
674 		priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
675 		rc = -EFAULT;
676 	}
677 
678 out:
679 	tpm_tis_ready(chip);
680 	release_locality(chip, priv->locality);
681 
682 	return rc;
683 }
684 
685 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
686 {
687 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
688 
689 	switch (priv->manufacturer_id) {
690 	case TPM_VID_WINBOND:
691 		return ((status == TPM_STS_VALID) ||
692 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
693 	case TPM_VID_STM:
694 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
695 	default:
696 		return (status == TPM_STS_COMMAND_READY);
697 	}
698 }
699 
700 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
701 {
702 	struct tpm_chip *chip = dev_id;
703 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
704 	u32 interrupt;
705 	int i, rc;
706 
707 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
708 	if (rc < 0)
709 		return IRQ_NONE;
710 
711 	if (interrupt == 0)
712 		return IRQ_NONE;
713 
714 	priv->irq_tested = true;
715 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
716 		wake_up_interruptible(&priv->read_queue);
717 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
718 		for (i = 0; i < 5; i++)
719 			if (check_locality(chip, i))
720 				break;
721 	if (interrupt &
722 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
723 	     TPM_INTF_CMD_READY_INT))
724 		wake_up_interruptible(&priv->int_queue);
725 
726 	/* Clear interrupts handled with TPM_EOI */
727 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
728 	if (rc < 0)
729 		return IRQ_NONE;
730 
731 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
732 	return IRQ_HANDLED;
733 }
734 
735 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
736 {
737 	const char *desc = "attempting to generate an interrupt";
738 	u32 cap2;
739 	cap_t cap;
740 
741 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
742 		return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
743 	else
744 		return tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
745 				  0);
746 }
747 
748 /* Register the IRQ and issue a command that will cause an interrupt. If an
749  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
750  * everything and leave in polling mode. Returns 0 on success.
751  */
752 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
753 				    int flags, int irq)
754 {
755 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
756 	u8 original_int_vec;
757 	int rc;
758 	u32 int_status;
759 
760 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
761 			     dev_name(&chip->dev), chip) != 0) {
762 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
763 			 irq);
764 		return -1;
765 	}
766 	priv->irq = irq;
767 
768 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
769 			   &original_int_vec);
770 	if (rc < 0)
771 		return rc;
772 
773 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
774 	if (rc < 0)
775 		return rc;
776 
777 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
778 	if (rc < 0)
779 		return rc;
780 
781 	/* Clear all existing */
782 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
783 	if (rc < 0)
784 		return rc;
785 
786 	/* Turn on */
787 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
788 			     intmask | TPM_GLOBAL_INT_ENABLE);
789 	if (rc < 0)
790 		return rc;
791 
792 	priv->irq_tested = false;
793 
794 	/* Generate an interrupt by having the core call through to
795 	 * tpm_tis_send
796 	 */
797 	rc = tpm_tis_gen_interrupt(chip);
798 	if (rc < 0)
799 		return rc;
800 
801 	/* tpm_tis_send will either confirm the interrupt is working or it
802 	 * will call disable_irq which undoes all of the above.
803 	 */
804 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
805 		rc = tpm_tis_write8(priv, original_int_vec,
806 				TPM_INT_VECTOR(priv->locality));
807 		if (rc < 0)
808 			return rc;
809 
810 		return 1;
811 	}
812 
813 	return 0;
814 }
815 
816 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
817  * do not have ACPI/etc. We typically expect the interrupt to be declared if
818  * present.
819  */
820 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
821 {
822 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
823 	u8 original_int_vec;
824 	int i, rc;
825 
826 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
827 			   &original_int_vec);
828 	if (rc < 0)
829 		return;
830 
831 	if (!original_int_vec) {
832 		if (IS_ENABLED(CONFIG_X86))
833 			for (i = 3; i <= 15; i++)
834 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
835 							      i))
836 					return;
837 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
838 					     original_int_vec))
839 		return;
840 }
841 
842 void tpm_tis_remove(struct tpm_chip *chip)
843 {
844 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
845 	u32 reg = TPM_INT_ENABLE(priv->locality);
846 	u32 interrupt;
847 	int rc;
848 
849 	tpm_tis_clkrun_enable(chip, true);
850 
851 	rc = tpm_tis_read32(priv, reg, &interrupt);
852 	if (rc < 0)
853 		interrupt = 0;
854 
855 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
856 
857 	tpm_tis_clkrun_enable(chip, false);
858 
859 	if (priv->ilb_base_addr)
860 		iounmap(priv->ilb_base_addr);
861 }
862 EXPORT_SYMBOL_GPL(tpm_tis_remove);
863 
864 /**
865  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
866  *                           of a single TPM command
867  * @chip:	TPM chip to use
868  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
869  *		0 - Enable CLKRUN protocol
870  * Call this function directly in tpm_tis_remove() in error or driver removal
871  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
872  */
873 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
874 {
875 	struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
876 	u32 clkrun_val;
877 
878 	if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
879 	    !data->ilb_base_addr)
880 		return;
881 
882 	if (value) {
883 		data->clkrun_enabled++;
884 		if (data->clkrun_enabled > 1)
885 			return;
886 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
887 
888 		/* Disable LPC CLKRUN# */
889 		clkrun_val &= ~LPC_CLKRUN_EN;
890 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
891 
892 		/*
893 		 * Write any random value on port 0x80 which is on LPC, to make
894 		 * sure LPC clock is running before sending any TPM command.
895 		 */
896 		outb(0xCC, 0x80);
897 	} else {
898 		data->clkrun_enabled--;
899 		if (data->clkrun_enabled)
900 			return;
901 
902 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
903 
904 		/* Enable LPC CLKRUN# */
905 		clkrun_val |= LPC_CLKRUN_EN;
906 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
907 
908 		/*
909 		 * Write any random value on port 0x80 which is on LPC, to make
910 		 * sure LPC clock is running before sending any TPM command.
911 		 */
912 		outb(0xCC, 0x80);
913 	}
914 }
915 
916 static const struct tpm_class_ops tpm_tis = {
917 	.flags = TPM_OPS_AUTO_STARTUP,
918 	.status = tpm_tis_status,
919 	.recv = tpm_tis_recv,
920 	.send = tpm_tis_send,
921 	.cancel = tpm_tis_ready,
922 	.update_timeouts = tpm_tis_update_timeouts,
923 	.update_durations = tpm_tis_update_durations,
924 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
925 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
926 	.req_canceled = tpm_tis_req_canceled,
927 	.request_locality = request_locality,
928 	.relinquish_locality = release_locality,
929 	.clk_enable = tpm_tis_clkrun_enable,
930 };
931 
932 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
933 		      const struct tpm_tis_phy_ops *phy_ops,
934 		      acpi_handle acpi_dev_handle)
935 {
936 	u32 vendor;
937 	u32 intfcaps;
938 	u32 intmask;
939 	u32 clkrun_val;
940 	u8 rid;
941 	int rc, probe;
942 	struct tpm_chip *chip;
943 
944 	chip = tpmm_chip_alloc(dev, &tpm_tis);
945 	if (IS_ERR(chip))
946 		return PTR_ERR(chip);
947 
948 #ifdef CONFIG_ACPI
949 	chip->acpi_dev_handle = acpi_dev_handle;
950 #endif
951 
952 	chip->hwrng.quality = priv->rng_quality;
953 
954 	/* Maximum timeouts */
955 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
956 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
957 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
958 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
959 	priv->phy_ops = phy_ops;
960 	dev_set_drvdata(&chip->dev, priv);
961 
962 	if (is_bsw()) {
963 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
964 					ILB_REMAP_SIZE);
965 		if (!priv->ilb_base_addr)
966 			return -ENOMEM;
967 
968 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
969 		/* Check if CLKRUN# is already not enabled in the LPC bus */
970 		if (!(clkrun_val & LPC_CLKRUN_EN)) {
971 			iounmap(priv->ilb_base_addr);
972 			priv->ilb_base_addr = NULL;
973 		}
974 	}
975 
976 	if (chip->ops->clk_enable != NULL)
977 		chip->ops->clk_enable(chip, true);
978 
979 	if (wait_startup(chip, 0) != 0) {
980 		rc = -ENODEV;
981 		goto out_err;
982 	}
983 
984 	/* Take control of the TPM's interrupt hardware and shut it off */
985 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
986 	if (rc < 0)
987 		goto out_err;
988 
989 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
990 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
991 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
992 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
993 
994 	rc = tpm_chip_start(chip);
995 	if (rc)
996 		goto out_err;
997 	rc = tpm2_probe(chip);
998 	tpm_chip_stop(chip);
999 	if (rc)
1000 		goto out_err;
1001 
1002 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
1003 	if (rc < 0)
1004 		goto out_err;
1005 
1006 	priv->manufacturer_id = vendor;
1007 
1008 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
1009 	if (rc < 0)
1010 		goto out_err;
1011 
1012 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
1013 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
1014 		 vendor >> 16, rid);
1015 
1016 	probe = probe_itpm(chip);
1017 	if (probe < 0) {
1018 		rc = -ENODEV;
1019 		goto out_err;
1020 	}
1021 
1022 	/* Figure out the capabilities */
1023 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
1024 	if (rc < 0)
1025 		goto out_err;
1026 
1027 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
1028 		intfcaps);
1029 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
1030 		dev_dbg(dev, "\tBurst Count Static\n");
1031 	if (intfcaps & TPM_INTF_CMD_READY_INT)
1032 		dev_dbg(dev, "\tCommand Ready Int Support\n");
1033 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
1034 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
1035 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
1036 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
1037 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
1038 		dev_dbg(dev, "\tInterrupt Level Low\n");
1039 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
1040 		dev_dbg(dev, "\tInterrupt Level High\n");
1041 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
1042 		dev_dbg(dev, "\tLocality Change Int Support\n");
1043 	if (intfcaps & TPM_INTF_STS_VALID_INT)
1044 		dev_dbg(dev, "\tSts Valid Int Support\n");
1045 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
1046 		dev_dbg(dev, "\tData Avail Int Support\n");
1047 
1048 	/* INTERRUPT Setup */
1049 	init_waitqueue_head(&priv->read_queue);
1050 	init_waitqueue_head(&priv->int_queue);
1051 	if (irq != -1) {
1052 		/* Before doing irq testing issue a command to the TPM in polling mode
1053 		 * to make sure it works. May as well use that command to set the
1054 		 * proper timeouts for the driver.
1055 		 */
1056 		if (tpm_get_timeouts(chip)) {
1057 			dev_err(dev, "Could not get TPM timeouts and durations\n");
1058 			rc = -ENODEV;
1059 			goto out_err;
1060 		}
1061 
1062 		tpm_chip_start(chip);
1063 		chip->flags |= TPM_CHIP_FLAG_IRQ;
1064 		if (irq) {
1065 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
1066 						 irq);
1067 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
1068 				dev_err(&chip->dev, FW_BUG
1069 					"TPM interrupt not working, polling instead\n");
1070 		} else {
1071 			tpm_tis_probe_irq(chip, intmask);
1072 		}
1073 		tpm_chip_stop(chip);
1074 	}
1075 
1076 	rc = tpm_chip_register(chip);
1077 	if (rc)
1078 		goto out_err;
1079 
1080 	if (chip->ops->clk_enable != NULL)
1081 		chip->ops->clk_enable(chip, false);
1082 
1083 	return 0;
1084 out_err:
1085 	if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
1086 		chip->ops->clk_enable(chip, false);
1087 
1088 	tpm_tis_remove(chip);
1089 
1090 	return rc;
1091 }
1092 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
1093 
1094 #ifdef CONFIG_PM_SLEEP
1095 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
1096 {
1097 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
1098 	u32 intmask;
1099 	int rc;
1100 
1101 	if (chip->ops->clk_enable != NULL)
1102 		chip->ops->clk_enable(chip, true);
1103 
1104 	/* reenable interrupts that device may have lost or
1105 	 * BIOS/firmware may have disabled
1106 	 */
1107 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
1108 	if (rc < 0)
1109 		goto out;
1110 
1111 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
1112 	if (rc < 0)
1113 		goto out;
1114 
1115 	intmask |= TPM_INTF_CMD_READY_INT
1116 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
1117 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
1118 
1119 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1120 
1121 out:
1122 	if (chip->ops->clk_enable != NULL)
1123 		chip->ops->clk_enable(chip, false);
1124 
1125 	return;
1126 }
1127 
1128 int tpm_tis_resume(struct device *dev)
1129 {
1130 	struct tpm_chip *chip = dev_get_drvdata(dev);
1131 	int ret;
1132 
1133 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
1134 		tpm_tis_reenable_interrupts(chip);
1135 
1136 	ret = tpm_pm_resume(dev);
1137 	if (ret)
1138 		return ret;
1139 
1140 	/* TPM 1.2 requires self-test on resume. This function actually returns
1141 	 * an error code but for unknown reason it isn't handled.
1142 	 */
1143 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
1144 		tpm1_do_selftest(chip);
1145 
1146 	return 0;
1147 }
1148 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1149 #endif
1150 
1151 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1152 MODULE_DESCRIPTION("TPM Driver");
1153 MODULE_VERSION("2.0");
1154 MODULE_LICENSE("GPL");
1155