xref: /openbmc/linux/drivers/char/tpm/tpm_tis_core.c (revision 8931ddd8)
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 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
52 	unsigned long stop;
53 	long rc;
54 	u8 status;
55 	bool canceled = false;
56 
57 	/* check current status */
58 	status = chip->ops->status(chip);
59 	if ((status & mask) == mask)
60 		return 0;
61 
62 	stop = jiffies + timeout;
63 
64 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
65 again:
66 		timeout = stop - jiffies;
67 		if ((long)timeout <= 0)
68 			return -ETIME;
69 		rc = wait_event_interruptible_timeout(*queue,
70 			wait_for_tpm_stat_cond(chip, mask, check_cancel,
71 					       &canceled),
72 			timeout);
73 		if (rc > 0) {
74 			if (canceled)
75 				return -ECANCELED;
76 			return 0;
77 		}
78 		if (rc == -ERESTARTSYS && freezing(current)) {
79 			clear_thread_flag(TIF_SIGPENDING);
80 			goto again;
81 		}
82 	} else {
83 		do {
84 			usleep_range(priv->timeout_min,
85 				     priv->timeout_max);
86 			status = chip->ops->status(chip);
87 			if ((status & mask) == mask)
88 				return 0;
89 		} while (time_before(jiffies, stop));
90 	}
91 	return -ETIME;
92 }
93 
94 /* Before we attempt to access the TPM we must see that the valid bit is set.
95  * The specification says that this bit is 0 at reset and remains 0 until the
96  * 'TPM has gone through its self test and initialization and has established
97  * correct values in the other bits.'
98  */
99 static int wait_startup(struct tpm_chip *chip, int l)
100 {
101 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
102 	unsigned long stop = jiffies + chip->timeout_a;
103 
104 	do {
105 		int rc;
106 		u8 access;
107 
108 		rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
109 		if (rc < 0)
110 			return rc;
111 
112 		if (access & TPM_ACCESS_VALID)
113 			return 0;
114 		tpm_msleep(TPM_TIMEOUT);
115 	} while (time_before(jiffies, stop));
116 	return -1;
117 }
118 
119 static bool check_locality(struct tpm_chip *chip, int l)
120 {
121 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
122 	int rc;
123 	u8 access;
124 
125 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
126 	if (rc < 0)
127 		return false;
128 
129 	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID
130 		       | TPM_ACCESS_REQUEST_USE)) ==
131 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
132 		priv->locality = l;
133 		return true;
134 	}
135 
136 	return false;
137 }
138 
139 static int release_locality(struct tpm_chip *chip, int l)
140 {
141 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
142 
143 	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
144 
145 	return 0;
146 }
147 
148 static int request_locality(struct tpm_chip *chip, int l)
149 {
150 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
151 	unsigned long stop, timeout;
152 	long rc;
153 
154 	if (check_locality(chip, l))
155 		return l;
156 
157 	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
158 	if (rc < 0)
159 		return rc;
160 
161 	stop = jiffies + chip->timeout_a;
162 
163 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
164 again:
165 		timeout = stop - jiffies;
166 		if ((long)timeout <= 0)
167 			return -1;
168 		rc = wait_event_interruptible_timeout(priv->int_queue,
169 						      (check_locality
170 						       (chip, l)),
171 						      timeout);
172 		if (rc > 0)
173 			return l;
174 		if (rc == -ERESTARTSYS && freezing(current)) {
175 			clear_thread_flag(TIF_SIGPENDING);
176 			goto again;
177 		}
178 	} else {
179 		/* wait for burstcount */
180 		do {
181 			if (check_locality(chip, l))
182 				return l;
183 			tpm_msleep(TPM_TIMEOUT);
184 		} while (time_before(jiffies, stop));
185 	}
186 	return -1;
187 }
188 
189 static u8 tpm_tis_status(struct tpm_chip *chip)
190 {
191 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
192 	int rc;
193 	u8 status;
194 
195 	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
196 	if (rc < 0)
197 		return 0;
198 
199 	if (unlikely((status & TPM_STS_READ_ZERO) != 0)) {
200 		if  (!test_and_set_bit(TPM_TIS_INVALID_STATUS, &priv->flags)) {
201 			/*
202 			 * If this trips, the chances are the read is
203 			 * returning 0xff because the locality hasn't been
204 			 * acquired.  Usually because tpm_try_get_ops() hasn't
205 			 * been called before doing a TPM operation.
206 			 */
207 			dev_err(&chip->dev, "invalid TPM_STS.x 0x%02x, dumping stack for forensics\n",
208 				status);
209 
210 			/*
211 			 * Dump stack for forensics, as invalid TPM_STS.x could be
212 			 * potentially triggered by impaired tpm_try_get_ops() or
213 			 * tpm_find_get_ops().
214 			 */
215 			dump_stack();
216 		}
217 
218 		return 0;
219 	}
220 
221 	return status;
222 }
223 
224 static void tpm_tis_ready(struct tpm_chip *chip)
225 {
226 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
227 
228 	/* this causes the current command to be aborted */
229 	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
230 }
231 
232 static int get_burstcount(struct tpm_chip *chip)
233 {
234 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
235 	unsigned long stop;
236 	int burstcnt, rc;
237 	u32 value;
238 
239 	/* wait for burstcount */
240 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
241 		stop = jiffies + chip->timeout_a;
242 	else
243 		stop = jiffies + chip->timeout_d;
244 	do {
245 		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
246 		if (rc < 0)
247 			return rc;
248 
249 		burstcnt = (value >> 8) & 0xFFFF;
250 		if (burstcnt)
251 			return burstcnt;
252 		usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX);
253 	} while (time_before(jiffies, stop));
254 	return -EBUSY;
255 }
256 
257 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
258 {
259 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
260 	int size = 0, burstcnt, rc;
261 
262 	while (size < count) {
263 		rc = wait_for_tpm_stat(chip,
264 				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
265 				 chip->timeout_c,
266 				 &priv->read_queue, true);
267 		if (rc < 0)
268 			return rc;
269 		burstcnt = get_burstcount(chip);
270 		if (burstcnt < 0) {
271 			dev_err(&chip->dev, "Unable to read burstcount\n");
272 			return burstcnt;
273 		}
274 		burstcnt = min_t(int, burstcnt, count - size);
275 
276 		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
277 					burstcnt, buf + size);
278 		if (rc < 0)
279 			return rc;
280 
281 		size += burstcnt;
282 	}
283 	return size;
284 }
285 
286 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
287 {
288 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
289 	int size = 0;
290 	int status;
291 	u32 expected;
292 
293 	if (count < TPM_HEADER_SIZE) {
294 		size = -EIO;
295 		goto out;
296 	}
297 
298 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
299 	/* read first 10 bytes, including tag, paramsize, and result */
300 	if (size < TPM_HEADER_SIZE) {
301 		dev_err(&chip->dev, "Unable to read header\n");
302 		goto out;
303 	}
304 
305 	expected = be32_to_cpu(*(__be32 *) (buf + 2));
306 	if (expected > count || expected < TPM_HEADER_SIZE) {
307 		size = -EIO;
308 		goto out;
309 	}
310 
311 	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
312 			  expected - TPM_HEADER_SIZE);
313 	if (size < expected) {
314 		dev_err(&chip->dev, "Unable to read remainder of result\n");
315 		size = -ETIME;
316 		goto out;
317 	}
318 
319 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
320 				&priv->int_queue, false) < 0) {
321 		size = -ETIME;
322 		goto out;
323 	}
324 	status = tpm_tis_status(chip);
325 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
326 		dev_err(&chip->dev, "Error left over data\n");
327 		size = -EIO;
328 		goto out;
329 	}
330 
331 out:
332 	tpm_tis_ready(chip);
333 	return size;
334 }
335 
336 /*
337  * If interrupts are used (signaled by an irq set in the vendor structure)
338  * tpm.c can skip polling for the data to be available as the interrupt is
339  * waited for here
340  */
341 static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
342 {
343 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
344 	int rc, status, burstcnt;
345 	size_t count = 0;
346 	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
347 
348 	status = tpm_tis_status(chip);
349 	if ((status & TPM_STS_COMMAND_READY) == 0) {
350 		tpm_tis_ready(chip);
351 		if (wait_for_tpm_stat
352 		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
353 		     &priv->int_queue, false) < 0) {
354 			rc = -ETIME;
355 			goto out_err;
356 		}
357 	}
358 
359 	while (count < len - 1) {
360 		burstcnt = get_burstcount(chip);
361 		if (burstcnt < 0) {
362 			dev_err(&chip->dev, "Unable to read burstcount\n");
363 			rc = burstcnt;
364 			goto out_err;
365 		}
366 		burstcnt = min_t(int, burstcnt, len - count - 1);
367 		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
368 					 burstcnt, buf + count);
369 		if (rc < 0)
370 			goto out_err;
371 
372 		count += burstcnt;
373 
374 		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
375 					&priv->int_queue, false) < 0) {
376 			rc = -ETIME;
377 			goto out_err;
378 		}
379 		status = tpm_tis_status(chip);
380 		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
381 			rc = -EIO;
382 			goto out_err;
383 		}
384 	}
385 
386 	/* write last byte */
387 	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
388 	if (rc < 0)
389 		goto out_err;
390 
391 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
392 				&priv->int_queue, false) < 0) {
393 		rc = -ETIME;
394 		goto out_err;
395 	}
396 	status = tpm_tis_status(chip);
397 	if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
398 		rc = -EIO;
399 		goto out_err;
400 	}
401 
402 	return 0;
403 
404 out_err:
405 	tpm_tis_ready(chip);
406 	return rc;
407 }
408 
409 static void disable_interrupts(struct tpm_chip *chip)
410 {
411 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
412 	u32 intmask;
413 	int rc;
414 
415 	if (priv->irq == 0)
416 		return;
417 
418 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
419 	if (rc < 0)
420 		intmask = 0;
421 
422 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
423 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
424 
425 	devm_free_irq(chip->dev.parent, priv->irq, chip);
426 	priv->irq = 0;
427 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
428 }
429 
430 /*
431  * If interrupts are used (signaled by an irq set in the vendor structure)
432  * tpm.c can skip polling for the data to be available as the interrupt is
433  * waited for here
434  */
435 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
436 {
437 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
438 	int rc;
439 	u32 ordinal;
440 	unsigned long dur;
441 
442 	rc = tpm_tis_send_data(chip, buf, len);
443 	if (rc < 0)
444 		return rc;
445 
446 	/* go and do it */
447 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
448 	if (rc < 0)
449 		goto out_err;
450 
451 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
452 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
453 
454 		dur = tpm_calc_ordinal_duration(chip, ordinal);
455 		if (wait_for_tpm_stat
456 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
457 		     &priv->read_queue, false) < 0) {
458 			rc = -ETIME;
459 			goto out_err;
460 		}
461 	}
462 	return 0;
463 out_err:
464 	tpm_tis_ready(chip);
465 	return rc;
466 }
467 
468 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
469 {
470 	int rc, irq;
471 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
472 
473 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
474 		return tpm_tis_send_main(chip, buf, len);
475 
476 	/* Verify receipt of the expected IRQ */
477 	irq = priv->irq;
478 	priv->irq = 0;
479 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
480 	rc = tpm_tis_send_main(chip, buf, len);
481 	priv->irq = irq;
482 	chip->flags |= TPM_CHIP_FLAG_IRQ;
483 	if (!priv->irq_tested)
484 		tpm_msleep(1);
485 	if (!priv->irq_tested)
486 		disable_interrupts(chip);
487 	priv->irq_tested = true;
488 	return rc;
489 }
490 
491 struct tis_vendor_durations_override {
492 	u32 did_vid;
493 	struct tpm1_version version;
494 	unsigned long durations[3];
495 };
496 
497 static const struct  tis_vendor_durations_override vendor_dur_overrides[] = {
498 	/* STMicroelectronics 0x104a */
499 	{ 0x0000104a,
500 	  { 1, 2, 8, 28 },
501 	  { (2 * 60 * HZ), (2 * 60 * HZ), (2 * 60 * HZ) } },
502 };
503 
504 static void tpm_tis_update_durations(struct tpm_chip *chip,
505 				     unsigned long *duration_cap)
506 {
507 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
508 	struct tpm1_version *version;
509 	u32 did_vid;
510 	int i, rc;
511 	cap_t cap;
512 
513 	chip->duration_adjusted = false;
514 
515 	if (chip->ops->clk_enable != NULL)
516 		chip->ops->clk_enable(chip, true);
517 
518 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
519 	if (rc < 0) {
520 		dev_warn(&chip->dev, "%s: failed to read did_vid. %d\n",
521 			 __func__, rc);
522 		goto out;
523 	}
524 
525 	/* Try to get a TPM version 1.2 or 1.1 TPM_CAP_VERSION_INFO */
526 	rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
527 			 "attempting to determine the 1.2 version",
528 			 sizeof(cap.version2));
529 	if (!rc) {
530 		version = &cap.version2.version;
531 	} else {
532 		rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
533 				 "attempting to determine the 1.1 version",
534 				 sizeof(cap.version1));
535 
536 		if (rc)
537 			goto out;
538 
539 		version = &cap.version1;
540 	}
541 
542 	for (i = 0; i != ARRAY_SIZE(vendor_dur_overrides); i++) {
543 		if (vendor_dur_overrides[i].did_vid != did_vid)
544 			continue;
545 
546 		if ((version->major ==
547 		     vendor_dur_overrides[i].version.major) &&
548 		    (version->minor ==
549 		     vendor_dur_overrides[i].version.minor) &&
550 		    (version->rev_major ==
551 		     vendor_dur_overrides[i].version.rev_major) &&
552 		    (version->rev_minor ==
553 		     vendor_dur_overrides[i].version.rev_minor)) {
554 
555 			memcpy(duration_cap,
556 			       vendor_dur_overrides[i].durations,
557 			       sizeof(vendor_dur_overrides[i].durations));
558 
559 			chip->duration_adjusted = true;
560 			goto out;
561 		}
562 	}
563 
564 out:
565 	if (chip->ops->clk_enable != NULL)
566 		chip->ops->clk_enable(chip, false);
567 }
568 
569 struct tis_vendor_timeout_override {
570 	u32 did_vid;
571 	unsigned long timeout_us[4];
572 };
573 
574 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
575 	/* Atmel 3204 */
576 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
577 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
578 };
579 
580 static void tpm_tis_update_timeouts(struct tpm_chip *chip,
581 				    unsigned long *timeout_cap)
582 {
583 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
584 	int i, rc;
585 	u32 did_vid;
586 
587 	chip->timeout_adjusted = false;
588 
589 	if (chip->ops->clk_enable != NULL)
590 		chip->ops->clk_enable(chip, true);
591 
592 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
593 	if (rc < 0) {
594 		dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
595 			 __func__, rc);
596 		goto out;
597 	}
598 
599 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
600 		if (vendor_timeout_overrides[i].did_vid != did_vid)
601 			continue;
602 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
603 		       sizeof(vendor_timeout_overrides[i].timeout_us));
604 		chip->timeout_adjusted = true;
605 	}
606 
607 out:
608 	if (chip->ops->clk_enable != NULL)
609 		chip->ops->clk_enable(chip, false);
610 
611 	return;
612 }
613 
614 /*
615  * Early probing for iTPM with STS_DATA_EXPECT flaw.
616  * Try sending command without itpm flag set and if that
617  * fails, repeat with itpm flag set.
618  */
619 static int probe_itpm(struct tpm_chip *chip)
620 {
621 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
622 	int rc = 0;
623 	static const u8 cmd_getticks[] = {
624 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
625 		0x00, 0x00, 0x00, 0xf1
626 	};
627 	size_t len = sizeof(cmd_getticks);
628 	u16 vendor;
629 
630 	if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
631 		return 0;
632 
633 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
634 	if (rc < 0)
635 		return rc;
636 
637 	/* probe only iTPMS */
638 	if (vendor != TPM_VID_INTEL)
639 		return 0;
640 
641 	if (request_locality(chip, 0) != 0)
642 		return -EBUSY;
643 
644 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
645 	if (rc == 0)
646 		goto out;
647 
648 	tpm_tis_ready(chip);
649 
650 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
651 
652 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
653 	if (rc == 0)
654 		dev_info(&chip->dev, "Detected an iTPM.\n");
655 	else {
656 		priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
657 		rc = -EFAULT;
658 	}
659 
660 out:
661 	tpm_tis_ready(chip);
662 	release_locality(chip, priv->locality);
663 
664 	return rc;
665 }
666 
667 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
668 {
669 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
670 
671 	switch (priv->manufacturer_id) {
672 	case TPM_VID_WINBOND:
673 		return ((status == TPM_STS_VALID) ||
674 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
675 	case TPM_VID_STM:
676 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
677 	default:
678 		return (status == TPM_STS_COMMAND_READY);
679 	}
680 }
681 
682 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
683 {
684 	struct tpm_chip *chip = dev_id;
685 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
686 	u32 interrupt;
687 	int i, rc;
688 
689 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
690 	if (rc < 0)
691 		return IRQ_NONE;
692 
693 	if (interrupt == 0)
694 		return IRQ_NONE;
695 
696 	priv->irq_tested = true;
697 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
698 		wake_up_interruptible(&priv->read_queue);
699 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
700 		for (i = 0; i < 5; i++)
701 			if (check_locality(chip, i))
702 				break;
703 	if (interrupt &
704 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
705 	     TPM_INTF_CMD_READY_INT))
706 		wake_up_interruptible(&priv->int_queue);
707 
708 	/* Clear interrupts handled with TPM_EOI */
709 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
710 	if (rc < 0)
711 		return IRQ_NONE;
712 
713 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
714 	return IRQ_HANDLED;
715 }
716 
717 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
718 {
719 	const char *desc = "attempting to generate an interrupt";
720 	u32 cap2;
721 	cap_t cap;
722 	int ret;
723 
724 	ret = request_locality(chip, 0);
725 	if (ret < 0)
726 		return ret;
727 
728 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
729 		ret = tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
730 	else
731 		ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
732 
733 	release_locality(chip, 0);
734 
735 	return ret;
736 }
737 
738 /* Register the IRQ and issue a command that will cause an interrupt. If an
739  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
740  * everything and leave in polling mode. Returns 0 on success.
741  */
742 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
743 				    int flags, int irq)
744 {
745 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
746 	u8 original_int_vec;
747 	int rc;
748 	u32 int_status;
749 
750 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
751 			     dev_name(&chip->dev), chip) != 0) {
752 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
753 			 irq);
754 		return -1;
755 	}
756 	priv->irq = irq;
757 
758 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
759 			   &original_int_vec);
760 	if (rc < 0)
761 		return rc;
762 
763 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
764 	if (rc < 0)
765 		return rc;
766 
767 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
768 	if (rc < 0)
769 		return rc;
770 
771 	/* Clear all existing */
772 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
773 	if (rc < 0)
774 		return rc;
775 
776 	/* Turn on */
777 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
778 			     intmask | TPM_GLOBAL_INT_ENABLE);
779 	if (rc < 0)
780 		return rc;
781 
782 	priv->irq_tested = false;
783 
784 	/* Generate an interrupt by having the core call through to
785 	 * tpm_tis_send
786 	 */
787 	rc = tpm_tis_gen_interrupt(chip);
788 	if (rc < 0)
789 		return rc;
790 
791 	/* tpm_tis_send will either confirm the interrupt is working or it
792 	 * will call disable_irq which undoes all of the above.
793 	 */
794 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
795 		rc = tpm_tis_write8(priv, original_int_vec,
796 				TPM_INT_VECTOR(priv->locality));
797 		if (rc < 0)
798 			return rc;
799 
800 		return 1;
801 	}
802 
803 	return 0;
804 }
805 
806 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
807  * do not have ACPI/etc. We typically expect the interrupt to be declared if
808  * present.
809  */
810 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
811 {
812 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
813 	u8 original_int_vec;
814 	int i, rc;
815 
816 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
817 			   &original_int_vec);
818 	if (rc < 0)
819 		return;
820 
821 	if (!original_int_vec) {
822 		if (IS_ENABLED(CONFIG_X86))
823 			for (i = 3; i <= 15; i++)
824 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
825 							      i))
826 					return;
827 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
828 					     original_int_vec))
829 		return;
830 }
831 
832 void tpm_tis_remove(struct tpm_chip *chip)
833 {
834 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
835 	u32 reg = TPM_INT_ENABLE(priv->locality);
836 	u32 interrupt;
837 	int rc;
838 
839 	tpm_tis_clkrun_enable(chip, true);
840 
841 	rc = tpm_tis_read32(priv, reg, &interrupt);
842 	if (rc < 0)
843 		interrupt = 0;
844 
845 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
846 
847 	tpm_tis_clkrun_enable(chip, false);
848 
849 	if (priv->ilb_base_addr)
850 		iounmap(priv->ilb_base_addr);
851 }
852 EXPORT_SYMBOL_GPL(tpm_tis_remove);
853 
854 /**
855  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
856  *                           of a single TPM command
857  * @chip:	TPM chip to use
858  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
859  *		0 - Enable CLKRUN protocol
860  * Call this function directly in tpm_tis_remove() in error or driver removal
861  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
862  */
863 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
864 {
865 	struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
866 	u32 clkrun_val;
867 
868 	if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
869 	    !data->ilb_base_addr)
870 		return;
871 
872 	if (value) {
873 		data->clkrun_enabled++;
874 		if (data->clkrun_enabled > 1)
875 			return;
876 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
877 
878 		/* Disable LPC CLKRUN# */
879 		clkrun_val &= ~LPC_CLKRUN_EN;
880 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
881 
882 		/*
883 		 * Write any random value on port 0x80 which is on LPC, to make
884 		 * sure LPC clock is running before sending any TPM command.
885 		 */
886 		outb(0xCC, 0x80);
887 	} else {
888 		data->clkrun_enabled--;
889 		if (data->clkrun_enabled)
890 			return;
891 
892 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
893 
894 		/* Enable LPC CLKRUN# */
895 		clkrun_val |= LPC_CLKRUN_EN;
896 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
897 
898 		/*
899 		 * Write any random value on port 0x80 which is on LPC, to make
900 		 * sure LPC clock is running before sending any TPM command.
901 		 */
902 		outb(0xCC, 0x80);
903 	}
904 }
905 
906 static const struct tpm_class_ops tpm_tis = {
907 	.flags = TPM_OPS_AUTO_STARTUP,
908 	.status = tpm_tis_status,
909 	.recv = tpm_tis_recv,
910 	.send = tpm_tis_send,
911 	.cancel = tpm_tis_ready,
912 	.update_timeouts = tpm_tis_update_timeouts,
913 	.update_durations = tpm_tis_update_durations,
914 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
915 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
916 	.req_canceled = tpm_tis_req_canceled,
917 	.request_locality = request_locality,
918 	.relinquish_locality = release_locality,
919 	.clk_enable = tpm_tis_clkrun_enable,
920 };
921 
922 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
923 		      const struct tpm_tis_phy_ops *phy_ops,
924 		      acpi_handle acpi_dev_handle)
925 {
926 	u32 vendor;
927 	u32 intfcaps;
928 	u32 intmask;
929 	u32 clkrun_val;
930 	u8 rid;
931 	int rc, probe;
932 	struct tpm_chip *chip;
933 
934 	chip = tpmm_chip_alloc(dev, &tpm_tis);
935 	if (IS_ERR(chip))
936 		return PTR_ERR(chip);
937 
938 #ifdef CONFIG_ACPI
939 	chip->acpi_dev_handle = acpi_dev_handle;
940 #endif
941 
942 	chip->hwrng.quality = priv->rng_quality;
943 
944 	/* Maximum timeouts */
945 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
946 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
947 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
948 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
949 	priv->timeout_min = TPM_TIMEOUT_USECS_MIN;
950 	priv->timeout_max = TPM_TIMEOUT_USECS_MAX;
951 	priv->phy_ops = phy_ops;
952 
953 	dev_set_drvdata(&chip->dev, priv);
954 
955 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
956 	if (rc < 0)
957 		return rc;
958 
959 	priv->manufacturer_id = vendor;
960 
961 	if (priv->manufacturer_id == TPM_VID_ATML &&
962 		!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
963 		priv->timeout_min = TIS_TIMEOUT_MIN_ATML;
964 		priv->timeout_max = TIS_TIMEOUT_MAX_ATML;
965 	}
966 
967 	if (is_bsw()) {
968 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
969 					ILB_REMAP_SIZE);
970 		if (!priv->ilb_base_addr)
971 			return -ENOMEM;
972 
973 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
974 		/* Check if CLKRUN# is already not enabled in the LPC bus */
975 		if (!(clkrun_val & LPC_CLKRUN_EN)) {
976 			iounmap(priv->ilb_base_addr);
977 			priv->ilb_base_addr = NULL;
978 		}
979 	}
980 
981 	if (chip->ops->clk_enable != NULL)
982 		chip->ops->clk_enable(chip, true);
983 
984 	if (wait_startup(chip, 0) != 0) {
985 		rc = -ENODEV;
986 		goto out_err;
987 	}
988 
989 	/* Take control of the TPM's interrupt hardware and shut it off */
990 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
991 	if (rc < 0)
992 		goto out_err;
993 
994 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
995 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
996 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
997 
998 	rc = request_locality(chip, 0);
999 	if (rc < 0) {
1000 		rc = -ENODEV;
1001 		goto out_err;
1002 	}
1003 
1004 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1005 	release_locality(chip, 0);
1006 
1007 	rc = tpm_chip_start(chip);
1008 	if (rc)
1009 		goto out_err;
1010 	rc = tpm2_probe(chip);
1011 	tpm_chip_stop(chip);
1012 	if (rc)
1013 		goto out_err;
1014 
1015 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
1016 	if (rc < 0)
1017 		goto out_err;
1018 
1019 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
1020 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
1021 		 vendor >> 16, rid);
1022 
1023 	probe = probe_itpm(chip);
1024 	if (probe < 0) {
1025 		rc = -ENODEV;
1026 		goto out_err;
1027 	}
1028 
1029 	/* Figure out the capabilities */
1030 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
1031 	if (rc < 0)
1032 		goto out_err;
1033 
1034 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
1035 		intfcaps);
1036 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
1037 		dev_dbg(dev, "\tBurst Count Static\n");
1038 	if (intfcaps & TPM_INTF_CMD_READY_INT)
1039 		dev_dbg(dev, "\tCommand Ready Int Support\n");
1040 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
1041 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
1042 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
1043 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
1044 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
1045 		dev_dbg(dev, "\tInterrupt Level Low\n");
1046 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
1047 		dev_dbg(dev, "\tInterrupt Level High\n");
1048 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
1049 		dev_dbg(dev, "\tLocality Change Int Support\n");
1050 	if (intfcaps & TPM_INTF_STS_VALID_INT)
1051 		dev_dbg(dev, "\tSts Valid Int Support\n");
1052 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
1053 		dev_dbg(dev, "\tData Avail Int Support\n");
1054 
1055 	/* INTERRUPT Setup */
1056 	init_waitqueue_head(&priv->read_queue);
1057 	init_waitqueue_head(&priv->int_queue);
1058 	if (irq != -1) {
1059 		/*
1060 		 * Before doing irq testing issue a command to the TPM in polling mode
1061 		 * to make sure it works. May as well use that command to set the
1062 		 * proper timeouts for the driver.
1063 		 */
1064 
1065 		rc = request_locality(chip, 0);
1066 		if (rc < 0)
1067 			goto out_err;
1068 
1069 		rc = tpm_get_timeouts(chip);
1070 
1071 		release_locality(chip, 0);
1072 
1073 		if (rc) {
1074 			dev_err(dev, "Could not get TPM timeouts and durations\n");
1075 			rc = -ENODEV;
1076 			goto out_err;
1077 		}
1078 
1079 		if (irq) {
1080 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
1081 						 irq);
1082 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
1083 				dev_err(&chip->dev, FW_BUG
1084 					"TPM interrupt not working, polling instead\n");
1085 
1086 				disable_interrupts(chip);
1087 			}
1088 		} else {
1089 			tpm_tis_probe_irq(chip, intmask);
1090 		}
1091 	}
1092 
1093 	rc = tpm_chip_register(chip);
1094 	if (rc)
1095 		goto out_err;
1096 
1097 	if (chip->ops->clk_enable != NULL)
1098 		chip->ops->clk_enable(chip, false);
1099 
1100 	return 0;
1101 out_err:
1102 	if (chip->ops->clk_enable != NULL)
1103 		chip->ops->clk_enable(chip, false);
1104 
1105 	tpm_tis_remove(chip);
1106 
1107 	return rc;
1108 }
1109 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
1110 
1111 #ifdef CONFIG_PM_SLEEP
1112 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
1113 {
1114 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
1115 	u32 intmask;
1116 	int rc;
1117 
1118 	if (chip->ops->clk_enable != NULL)
1119 		chip->ops->clk_enable(chip, true);
1120 
1121 	/* reenable interrupts that device may have lost or
1122 	 * BIOS/firmware may have disabled
1123 	 */
1124 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
1125 	if (rc < 0)
1126 		goto out;
1127 
1128 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
1129 	if (rc < 0)
1130 		goto out;
1131 
1132 	intmask |= TPM_INTF_CMD_READY_INT
1133 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
1134 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
1135 
1136 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1137 
1138 out:
1139 	if (chip->ops->clk_enable != NULL)
1140 		chip->ops->clk_enable(chip, false);
1141 
1142 	return;
1143 }
1144 
1145 int tpm_tis_resume(struct device *dev)
1146 {
1147 	struct tpm_chip *chip = dev_get_drvdata(dev);
1148 	int ret;
1149 
1150 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
1151 		tpm_tis_reenable_interrupts(chip);
1152 
1153 	ret = tpm_pm_resume(dev);
1154 	if (ret)
1155 		return ret;
1156 
1157 	/*
1158 	 * TPM 1.2 requires self-test on resume. This function actually returns
1159 	 * an error code but for unknown reason it isn't handled.
1160 	 */
1161 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
1162 		ret = request_locality(chip, 0);
1163 		if (ret < 0)
1164 			return ret;
1165 
1166 		tpm1_do_selftest(chip);
1167 
1168 		release_locality(chip, 0);
1169 	}
1170 
1171 	return 0;
1172 }
1173 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1174 #endif
1175 
1176 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1177 MODULE_DESCRIPTION("TPM Driver");
1178 MODULE_VERSION("2.0");
1179 MODULE_LICENSE("GPL");
1180