xref: /openbmc/linux/drivers/char/tpm/tpm_tis_core.c (revision 82df5b73)
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 	if (priv->irq == 0)
437 		return;
438 
439 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
440 	if (rc < 0)
441 		intmask = 0;
442 
443 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
444 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
445 
446 	devm_free_irq(chip->dev.parent, priv->irq, chip);
447 	priv->irq = 0;
448 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
449 }
450 
451 /*
452  * If interrupts are used (signaled by an irq set in the vendor structure)
453  * tpm.c can skip polling for the data to be available as the interrupt is
454  * waited for here
455  */
456 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
457 {
458 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
459 	int rc;
460 	u32 ordinal;
461 	unsigned long dur;
462 
463 	rc = tpm_tis_send_data(chip, buf, len);
464 	if (rc < 0)
465 		return rc;
466 
467 	/* go and do it */
468 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
469 	if (rc < 0)
470 		goto out_err;
471 
472 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
473 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
474 
475 		dur = tpm_calc_ordinal_duration(chip, ordinal);
476 		if (wait_for_tpm_stat
477 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
478 		     &priv->read_queue, false) < 0) {
479 			rc = -ETIME;
480 			goto out_err;
481 		}
482 	}
483 	return 0;
484 out_err:
485 	tpm_tis_ready(chip);
486 	return rc;
487 }
488 
489 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
490 {
491 	int rc, irq;
492 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
493 
494 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
495 		return tpm_tis_send_main(chip, buf, len);
496 
497 	/* Verify receipt of the expected IRQ */
498 	irq = priv->irq;
499 	priv->irq = 0;
500 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
501 	rc = tpm_tis_send_main(chip, buf, len);
502 	priv->irq = irq;
503 	chip->flags |= TPM_CHIP_FLAG_IRQ;
504 	if (!priv->irq_tested)
505 		tpm_msleep(1);
506 	if (!priv->irq_tested)
507 		disable_interrupts(chip);
508 	priv->irq_tested = true;
509 	return rc;
510 }
511 
512 struct tis_vendor_durations_override {
513 	u32 did_vid;
514 	struct tpm1_version version;
515 	unsigned long durations[3];
516 };
517 
518 static const struct  tis_vendor_durations_override vendor_dur_overrides[] = {
519 	/* STMicroelectronics 0x104a */
520 	{ 0x0000104a,
521 	  { 1, 2, 8, 28 },
522 	  { (2 * 60 * HZ), (2 * 60 * HZ), (2 * 60 * HZ) } },
523 };
524 
525 static void tpm_tis_update_durations(struct tpm_chip *chip,
526 				     unsigned long *duration_cap)
527 {
528 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
529 	struct tpm1_version *version;
530 	u32 did_vid;
531 	int i, rc;
532 	cap_t cap;
533 
534 	chip->duration_adjusted = false;
535 
536 	if (chip->ops->clk_enable != NULL)
537 		chip->ops->clk_enable(chip, true);
538 
539 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
540 	if (rc < 0) {
541 		dev_warn(&chip->dev, "%s: failed to read did_vid. %d\n",
542 			 __func__, rc);
543 		goto out;
544 	}
545 
546 	/* Try to get a TPM version 1.2 or 1.1 TPM_CAP_VERSION_INFO */
547 	rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
548 			 "attempting to determine the 1.2 version",
549 			 sizeof(cap.version2));
550 	if (!rc) {
551 		version = &cap.version2.version;
552 	} else {
553 		rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
554 				 "attempting to determine the 1.1 version",
555 				 sizeof(cap.version1));
556 
557 		if (rc)
558 			goto out;
559 
560 		version = &cap.version1;
561 	}
562 
563 	for (i = 0; i != ARRAY_SIZE(vendor_dur_overrides); i++) {
564 		if (vendor_dur_overrides[i].did_vid != did_vid)
565 			continue;
566 
567 		if ((version->major ==
568 		     vendor_dur_overrides[i].version.major) &&
569 		    (version->minor ==
570 		     vendor_dur_overrides[i].version.minor) &&
571 		    (version->rev_major ==
572 		     vendor_dur_overrides[i].version.rev_major) &&
573 		    (version->rev_minor ==
574 		     vendor_dur_overrides[i].version.rev_minor)) {
575 
576 			memcpy(duration_cap,
577 			       vendor_dur_overrides[i].durations,
578 			       sizeof(vendor_dur_overrides[i].durations));
579 
580 			chip->duration_adjusted = true;
581 			goto out;
582 		}
583 	}
584 
585 out:
586 	if (chip->ops->clk_enable != NULL)
587 		chip->ops->clk_enable(chip, false);
588 }
589 
590 struct tis_vendor_timeout_override {
591 	u32 did_vid;
592 	unsigned long timeout_us[4];
593 };
594 
595 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
596 	/* Atmel 3204 */
597 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
598 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
599 };
600 
601 static void tpm_tis_update_timeouts(struct tpm_chip *chip,
602 				    unsigned long *timeout_cap)
603 {
604 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
605 	int i, rc;
606 	u32 did_vid;
607 
608 	chip->timeout_adjusted = false;
609 
610 	if (chip->ops->clk_enable != NULL)
611 		chip->ops->clk_enable(chip, true);
612 
613 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
614 	if (rc < 0) {
615 		dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
616 			 __func__, rc);
617 		goto out;
618 	}
619 
620 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
621 		if (vendor_timeout_overrides[i].did_vid != did_vid)
622 			continue;
623 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
624 		       sizeof(vendor_timeout_overrides[i].timeout_us));
625 		chip->timeout_adjusted = true;
626 	}
627 
628 out:
629 	if (chip->ops->clk_enable != NULL)
630 		chip->ops->clk_enable(chip, false);
631 
632 	return;
633 }
634 
635 /*
636  * Early probing for iTPM with STS_DATA_EXPECT flaw.
637  * Try sending command without itpm flag set and if that
638  * fails, repeat with itpm flag set.
639  */
640 static int probe_itpm(struct tpm_chip *chip)
641 {
642 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
643 	int rc = 0;
644 	static const u8 cmd_getticks[] = {
645 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
646 		0x00, 0x00, 0x00, 0xf1
647 	};
648 	size_t len = sizeof(cmd_getticks);
649 	u16 vendor;
650 
651 	if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
652 		return 0;
653 
654 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
655 	if (rc < 0)
656 		return rc;
657 
658 	/* probe only iTPMS */
659 	if (vendor != TPM_VID_INTEL)
660 		return 0;
661 
662 	if (request_locality(chip, 0) != 0)
663 		return -EBUSY;
664 
665 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
666 	if (rc == 0)
667 		goto out;
668 
669 	tpm_tis_ready(chip);
670 
671 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
672 
673 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
674 	if (rc == 0)
675 		dev_info(&chip->dev, "Detected an iTPM.\n");
676 	else {
677 		priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
678 		rc = -EFAULT;
679 	}
680 
681 out:
682 	tpm_tis_ready(chip);
683 	release_locality(chip, priv->locality);
684 
685 	return rc;
686 }
687 
688 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
689 {
690 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
691 
692 	switch (priv->manufacturer_id) {
693 	case TPM_VID_WINBOND:
694 		return ((status == TPM_STS_VALID) ||
695 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
696 	case TPM_VID_STM:
697 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
698 	default:
699 		return (status == TPM_STS_COMMAND_READY);
700 	}
701 }
702 
703 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
704 {
705 	struct tpm_chip *chip = dev_id;
706 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
707 	u32 interrupt;
708 	int i, rc;
709 
710 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
711 	if (rc < 0)
712 		return IRQ_NONE;
713 
714 	if (interrupt == 0)
715 		return IRQ_NONE;
716 
717 	priv->irq_tested = true;
718 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
719 		wake_up_interruptible(&priv->read_queue);
720 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
721 		for (i = 0; i < 5; i++)
722 			if (check_locality(chip, i))
723 				break;
724 	if (interrupt &
725 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
726 	     TPM_INTF_CMD_READY_INT))
727 		wake_up_interruptible(&priv->int_queue);
728 
729 	/* Clear interrupts handled with TPM_EOI */
730 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
731 	if (rc < 0)
732 		return IRQ_NONE;
733 
734 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
735 	return IRQ_HANDLED;
736 }
737 
738 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
739 {
740 	const char *desc = "attempting to generate an interrupt";
741 	u32 cap2;
742 	cap_t cap;
743 
744 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
745 		return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
746 	else
747 		return tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
748 				  0);
749 }
750 
751 /* Register the IRQ and issue a command that will cause an interrupt. If an
752  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
753  * everything and leave in polling mode. Returns 0 on success.
754  */
755 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
756 				    int flags, int irq)
757 {
758 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
759 	u8 original_int_vec;
760 	int rc;
761 	u32 int_status;
762 
763 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
764 			     dev_name(&chip->dev), chip) != 0) {
765 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
766 			 irq);
767 		return -1;
768 	}
769 	priv->irq = irq;
770 
771 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
772 			   &original_int_vec);
773 	if (rc < 0)
774 		return rc;
775 
776 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
777 	if (rc < 0)
778 		return rc;
779 
780 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
781 	if (rc < 0)
782 		return rc;
783 
784 	/* Clear all existing */
785 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
786 	if (rc < 0)
787 		return rc;
788 
789 	/* Turn on */
790 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
791 			     intmask | TPM_GLOBAL_INT_ENABLE);
792 	if (rc < 0)
793 		return rc;
794 
795 	priv->irq_tested = false;
796 
797 	/* Generate an interrupt by having the core call through to
798 	 * tpm_tis_send
799 	 */
800 	rc = tpm_tis_gen_interrupt(chip);
801 	if (rc < 0)
802 		return rc;
803 
804 	/* tpm_tis_send will either confirm the interrupt is working or it
805 	 * will call disable_irq which undoes all of the above.
806 	 */
807 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
808 		rc = tpm_tis_write8(priv, original_int_vec,
809 				TPM_INT_VECTOR(priv->locality));
810 		if (rc < 0)
811 			return rc;
812 
813 		return 1;
814 	}
815 
816 	return 0;
817 }
818 
819 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
820  * do not have ACPI/etc. We typically expect the interrupt to be declared if
821  * present.
822  */
823 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
824 {
825 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
826 	u8 original_int_vec;
827 	int i, rc;
828 
829 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
830 			   &original_int_vec);
831 	if (rc < 0)
832 		return;
833 
834 	if (!original_int_vec) {
835 		if (IS_ENABLED(CONFIG_X86))
836 			for (i = 3; i <= 15; i++)
837 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
838 							      i))
839 					return;
840 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
841 					     original_int_vec))
842 		return;
843 }
844 
845 void tpm_tis_remove(struct tpm_chip *chip)
846 {
847 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
848 	u32 reg = TPM_INT_ENABLE(priv->locality);
849 	u32 interrupt;
850 	int rc;
851 
852 	tpm_tis_clkrun_enable(chip, true);
853 
854 	rc = tpm_tis_read32(priv, reg, &interrupt);
855 	if (rc < 0)
856 		interrupt = 0;
857 
858 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
859 
860 	tpm_tis_clkrun_enable(chip, false);
861 
862 	if (priv->ilb_base_addr)
863 		iounmap(priv->ilb_base_addr);
864 }
865 EXPORT_SYMBOL_GPL(tpm_tis_remove);
866 
867 /**
868  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
869  *                           of a single TPM command
870  * @chip:	TPM chip to use
871  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
872  *		0 - Enable CLKRUN protocol
873  * Call this function directly in tpm_tis_remove() in error or driver removal
874  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
875  */
876 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
877 {
878 	struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
879 	u32 clkrun_val;
880 
881 	if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
882 	    !data->ilb_base_addr)
883 		return;
884 
885 	if (value) {
886 		data->clkrun_enabled++;
887 		if (data->clkrun_enabled > 1)
888 			return;
889 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
890 
891 		/* Disable LPC CLKRUN# */
892 		clkrun_val &= ~LPC_CLKRUN_EN;
893 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
894 
895 		/*
896 		 * Write any random value on port 0x80 which is on LPC, to make
897 		 * sure LPC clock is running before sending any TPM command.
898 		 */
899 		outb(0xCC, 0x80);
900 	} else {
901 		data->clkrun_enabled--;
902 		if (data->clkrun_enabled)
903 			return;
904 
905 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
906 
907 		/* Enable LPC CLKRUN# */
908 		clkrun_val |= LPC_CLKRUN_EN;
909 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
910 
911 		/*
912 		 * Write any random value on port 0x80 which is on LPC, to make
913 		 * sure LPC clock is running before sending any TPM command.
914 		 */
915 		outb(0xCC, 0x80);
916 	}
917 }
918 
919 static const struct tpm_class_ops tpm_tis = {
920 	.flags = TPM_OPS_AUTO_STARTUP,
921 	.status = tpm_tis_status,
922 	.recv = tpm_tis_recv,
923 	.send = tpm_tis_send,
924 	.cancel = tpm_tis_ready,
925 	.update_timeouts = tpm_tis_update_timeouts,
926 	.update_durations = tpm_tis_update_durations,
927 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
928 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
929 	.req_canceled = tpm_tis_req_canceled,
930 	.request_locality = request_locality,
931 	.relinquish_locality = release_locality,
932 	.clk_enable = tpm_tis_clkrun_enable,
933 };
934 
935 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
936 		      const struct tpm_tis_phy_ops *phy_ops,
937 		      acpi_handle acpi_dev_handle)
938 {
939 	u32 vendor;
940 	u32 intfcaps;
941 	u32 intmask;
942 	u32 clkrun_val;
943 	u8 rid;
944 	int rc, probe;
945 	struct tpm_chip *chip;
946 
947 	chip = tpmm_chip_alloc(dev, &tpm_tis);
948 	if (IS_ERR(chip))
949 		return PTR_ERR(chip);
950 
951 #ifdef CONFIG_ACPI
952 	chip->acpi_dev_handle = acpi_dev_handle;
953 #endif
954 
955 	chip->hwrng.quality = priv->rng_quality;
956 
957 	/* Maximum timeouts */
958 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
959 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
960 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
961 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
962 	priv->phy_ops = phy_ops;
963 	dev_set_drvdata(&chip->dev, priv);
964 
965 	if (is_bsw()) {
966 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
967 					ILB_REMAP_SIZE);
968 		if (!priv->ilb_base_addr)
969 			return -ENOMEM;
970 
971 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
972 		/* Check if CLKRUN# is already not enabled in the LPC bus */
973 		if (!(clkrun_val & LPC_CLKRUN_EN)) {
974 			iounmap(priv->ilb_base_addr);
975 			priv->ilb_base_addr = NULL;
976 		}
977 	}
978 
979 	if (chip->ops->clk_enable != NULL)
980 		chip->ops->clk_enable(chip, true);
981 
982 	if (wait_startup(chip, 0) != 0) {
983 		rc = -ENODEV;
984 		goto out_err;
985 	}
986 
987 	/* Take control of the TPM's interrupt hardware and shut it off */
988 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
989 	if (rc < 0)
990 		goto out_err;
991 
992 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
993 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
994 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
995 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
996 
997 	rc = tpm_chip_start(chip);
998 	if (rc)
999 		goto out_err;
1000 	rc = tpm2_probe(chip);
1001 	tpm_chip_stop(chip);
1002 	if (rc)
1003 		goto out_err;
1004 
1005 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
1006 	if (rc < 0)
1007 		goto out_err;
1008 
1009 	priv->manufacturer_id = vendor;
1010 
1011 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
1012 	if (rc < 0)
1013 		goto out_err;
1014 
1015 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
1016 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
1017 		 vendor >> 16, rid);
1018 
1019 	probe = probe_itpm(chip);
1020 	if (probe < 0) {
1021 		rc = -ENODEV;
1022 		goto out_err;
1023 	}
1024 
1025 	/* Figure out the capabilities */
1026 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
1027 	if (rc < 0)
1028 		goto out_err;
1029 
1030 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
1031 		intfcaps);
1032 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
1033 		dev_dbg(dev, "\tBurst Count Static\n");
1034 	if (intfcaps & TPM_INTF_CMD_READY_INT)
1035 		dev_dbg(dev, "\tCommand Ready Int Support\n");
1036 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
1037 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
1038 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
1039 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
1040 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
1041 		dev_dbg(dev, "\tInterrupt Level Low\n");
1042 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
1043 		dev_dbg(dev, "\tInterrupt Level High\n");
1044 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
1045 		dev_dbg(dev, "\tLocality Change Int Support\n");
1046 	if (intfcaps & TPM_INTF_STS_VALID_INT)
1047 		dev_dbg(dev, "\tSts Valid Int Support\n");
1048 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
1049 		dev_dbg(dev, "\tData Avail Int Support\n");
1050 
1051 	/* INTERRUPT Setup */
1052 	init_waitqueue_head(&priv->read_queue);
1053 	init_waitqueue_head(&priv->int_queue);
1054 	if (irq != -1) {
1055 		/* Before doing irq testing issue a command to the TPM in polling mode
1056 		 * to make sure it works. May as well use that command to set the
1057 		 * proper timeouts for the driver.
1058 		 */
1059 		if (tpm_get_timeouts(chip)) {
1060 			dev_err(dev, "Could not get TPM timeouts and durations\n");
1061 			rc = -ENODEV;
1062 			goto out_err;
1063 		}
1064 
1065 		if (irq) {
1066 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
1067 						 irq);
1068 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
1069 				dev_err(&chip->dev, FW_BUG
1070 					"TPM interrupt not working, polling instead\n");
1071 
1072 				disable_interrupts(chip);
1073 			}
1074 		} else {
1075 			tpm_tis_probe_irq(chip, intmask);
1076 		}
1077 	}
1078 
1079 	rc = tpm_chip_register(chip);
1080 	if (rc)
1081 		goto out_err;
1082 
1083 	if (chip->ops->clk_enable != NULL)
1084 		chip->ops->clk_enable(chip, false);
1085 
1086 	return 0;
1087 out_err:
1088 	if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
1089 		chip->ops->clk_enable(chip, false);
1090 
1091 	tpm_tis_remove(chip);
1092 
1093 	return rc;
1094 }
1095 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
1096 
1097 #ifdef CONFIG_PM_SLEEP
1098 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
1099 {
1100 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
1101 	u32 intmask;
1102 	int rc;
1103 
1104 	if (chip->ops->clk_enable != NULL)
1105 		chip->ops->clk_enable(chip, true);
1106 
1107 	/* reenable interrupts that device may have lost or
1108 	 * BIOS/firmware may have disabled
1109 	 */
1110 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
1111 	if (rc < 0)
1112 		goto out;
1113 
1114 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
1115 	if (rc < 0)
1116 		goto out;
1117 
1118 	intmask |= TPM_INTF_CMD_READY_INT
1119 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
1120 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
1121 
1122 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1123 
1124 out:
1125 	if (chip->ops->clk_enable != NULL)
1126 		chip->ops->clk_enable(chip, false);
1127 
1128 	return;
1129 }
1130 
1131 int tpm_tis_resume(struct device *dev)
1132 {
1133 	struct tpm_chip *chip = dev_get_drvdata(dev);
1134 	int ret;
1135 
1136 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
1137 		tpm_tis_reenable_interrupts(chip);
1138 
1139 	ret = tpm_pm_resume(dev);
1140 	if (ret)
1141 		return ret;
1142 
1143 	/* TPM 1.2 requires self-test on resume. This function actually returns
1144 	 * an error code but for unknown reason it isn't handled.
1145 	 */
1146 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
1147 		tpm1_do_selftest(chip);
1148 
1149 	return 0;
1150 }
1151 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1152 #endif
1153 
1154 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1155 MODULE_DESCRIPTION("TPM Driver");
1156 MODULE_VERSION("2.0");
1157 MODULE_LICENSE("GPL");
1158