xref: /openbmc/linux/drivers/char/tpm/tpm_tis_core.c (revision cfbb9be8)
1 /*
2  * Copyright (C) 2005, 2006 IBM Corporation
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Leendert van Doorn <leendert@watson.ibm.com>
7  * Kylene Hall <kjhall@us.ibm.com>
8  *
9  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
10  *
11  * Device driver for TCG/TCPA TPM (trusted platform module).
12  * Specifications at www.trustedcomputinggroup.org
13  *
14  * This device driver implements the TPM interface as defined in
15  * the TCG TPM Interface Spec version 1.2, revision 1.0.
16  *
17  * This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License as
19  * published by the Free Software Foundation, version 2 of the
20  * License.
21  */
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/pnp.h>
26 #include <linux/slab.h>
27 #include <linux/interrupt.h>
28 #include <linux/wait.h>
29 #include <linux/acpi.h>
30 #include <linux/freezer.h>
31 #include "tpm.h"
32 #include "tpm_tis_core.h"
33 
34 /* This is a polling delay to check for status and burstcount.
35  * As per ddwg input, expectation is that status check and burstcount
36  * check should return within few usecs.
37  */
38 #define TPM_POLL_SLEEP	1  /* msec */
39 
40 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
41 
42 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
43 					bool check_cancel, bool *canceled)
44 {
45 	u8 status = chip->ops->status(chip);
46 
47 	*canceled = false;
48 	if ((status & mask) == mask)
49 		return true;
50 	if (check_cancel && chip->ops->req_canceled(chip, status)) {
51 		*canceled = true;
52 		return true;
53 	}
54 	return false;
55 }
56 
57 static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
58 		unsigned long timeout, wait_queue_head_t *queue,
59 		bool check_cancel)
60 {
61 	unsigned long stop;
62 	long rc;
63 	u8 status;
64 	bool canceled = false;
65 
66 	/* check current status */
67 	status = chip->ops->status(chip);
68 	if ((status & mask) == mask)
69 		return 0;
70 
71 	stop = jiffies + timeout;
72 
73 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
74 again:
75 		timeout = stop - jiffies;
76 		if ((long)timeout <= 0)
77 			return -ETIME;
78 		rc = wait_event_interruptible_timeout(*queue,
79 			wait_for_tpm_stat_cond(chip, mask, check_cancel,
80 					       &canceled),
81 			timeout);
82 		if (rc > 0) {
83 			if (canceled)
84 				return -ECANCELED;
85 			return 0;
86 		}
87 		if (rc == -ERESTARTSYS && freezing(current)) {
88 			clear_thread_flag(TIF_SIGPENDING);
89 			goto again;
90 		}
91 	} else {
92 		do {
93 			tpm_msleep(TPM_POLL_SLEEP);
94 			status = chip->ops->status(chip);
95 			if ((status & mask) == mask)
96 				return 0;
97 		} while (time_before(jiffies, stop));
98 	}
99 	return -ETIME;
100 }
101 
102 /* Before we attempt to access the TPM we must see that the valid bit is set.
103  * The specification says that this bit is 0 at reset and remains 0 until the
104  * 'TPM has gone through its self test and initialization and has established
105  * correct values in the other bits.'
106  */
107 static int wait_startup(struct tpm_chip *chip, int l)
108 {
109 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
110 	unsigned long stop = jiffies + chip->timeout_a;
111 
112 	do {
113 		int rc;
114 		u8 access;
115 
116 		rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
117 		if (rc < 0)
118 			return rc;
119 
120 		if (access & TPM_ACCESS_VALID)
121 			return 0;
122 		tpm_msleep(TPM_TIMEOUT);
123 	} while (time_before(jiffies, stop));
124 	return -1;
125 }
126 
127 static bool check_locality(struct tpm_chip *chip, int l)
128 {
129 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
130 	int rc;
131 	u8 access;
132 
133 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
134 	if (rc < 0)
135 		return false;
136 
137 	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
138 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
139 		priv->locality = l;
140 		return true;
141 	}
142 
143 	return false;
144 }
145 
146 static void release_locality(struct tpm_chip *chip, int l)
147 {
148 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
149 
150 	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
151 }
152 
153 static int request_locality(struct tpm_chip *chip, int l)
154 {
155 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
156 	unsigned long stop, timeout;
157 	long rc;
158 
159 	if (check_locality(chip, l))
160 		return l;
161 
162 	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
163 	if (rc < 0)
164 		return rc;
165 
166 	stop = jiffies + chip->timeout_a;
167 
168 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
169 again:
170 		timeout = stop - jiffies;
171 		if ((long)timeout <= 0)
172 			return -1;
173 		rc = wait_event_interruptible_timeout(priv->int_queue,
174 						      (check_locality
175 						       (chip, l)),
176 						      timeout);
177 		if (rc > 0)
178 			return l;
179 		if (rc == -ERESTARTSYS && freezing(current)) {
180 			clear_thread_flag(TIF_SIGPENDING);
181 			goto again;
182 		}
183 	} else {
184 		/* wait for burstcount */
185 		do {
186 			if (check_locality(chip, l))
187 				return l;
188 			tpm_msleep(TPM_TIMEOUT);
189 		} while (time_before(jiffies, stop));
190 	}
191 	return -1;
192 }
193 
194 static u8 tpm_tis_status(struct tpm_chip *chip)
195 {
196 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
197 	int rc;
198 	u8 status;
199 
200 	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
201 	if (rc < 0)
202 		return 0;
203 
204 	return status;
205 }
206 
207 static void tpm_tis_ready(struct tpm_chip *chip)
208 {
209 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
210 
211 	/* this causes the current command to be aborted */
212 	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
213 }
214 
215 static int get_burstcount(struct tpm_chip *chip)
216 {
217 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
218 	unsigned long stop;
219 	int burstcnt, rc;
220 	u32 value;
221 
222 	/* wait for burstcount */
223 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
224 		stop = jiffies + chip->timeout_a;
225 	else
226 		stop = jiffies + chip->timeout_d;
227 	do {
228 		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
229 		if (rc < 0)
230 			return rc;
231 
232 		burstcnt = (value >> 8) & 0xFFFF;
233 		if (burstcnt)
234 			return burstcnt;
235 		tpm_msleep(TPM_POLL_SLEEP);
236 	} while (time_before(jiffies, stop));
237 	return -EBUSY;
238 }
239 
240 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
241 {
242 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
243 	int size = 0, burstcnt, rc;
244 
245 	while (size < count) {
246 		rc = wait_for_tpm_stat(chip,
247 				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
248 				 chip->timeout_c,
249 				 &priv->read_queue, true);
250 		if (rc < 0)
251 			return rc;
252 		burstcnt = get_burstcount(chip);
253 		if (burstcnt < 0) {
254 			dev_err(&chip->dev, "Unable to read burstcount\n");
255 			return burstcnt;
256 		}
257 		burstcnt = min_t(int, burstcnt, count - size);
258 
259 		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
260 					burstcnt, buf + size);
261 		if (rc < 0)
262 			return rc;
263 
264 		size += burstcnt;
265 	}
266 	return size;
267 }
268 
269 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
270 {
271 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
272 	int size = 0;
273 	int status;
274 	u32 expected;
275 
276 	if (count < TPM_HEADER_SIZE) {
277 		size = -EIO;
278 		goto out;
279 	}
280 
281 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
282 	/* read first 10 bytes, including tag, paramsize, and result */
283 	if (size < TPM_HEADER_SIZE) {
284 		dev_err(&chip->dev, "Unable to read header\n");
285 		goto out;
286 	}
287 
288 	expected = be32_to_cpu(*(__be32 *) (buf + 2));
289 	if (expected > count || expected < TPM_HEADER_SIZE) {
290 		size = -EIO;
291 		goto out;
292 	}
293 
294 	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
295 			  expected - TPM_HEADER_SIZE);
296 	if (size < expected) {
297 		dev_err(&chip->dev, "Unable to read remainder of result\n");
298 		size = -ETIME;
299 		goto out;
300 	}
301 
302 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
303 				&priv->int_queue, false) < 0) {
304 		size = -ETIME;
305 		goto out;
306 	}
307 	status = tpm_tis_status(chip);
308 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
309 		dev_err(&chip->dev, "Error left over data\n");
310 		size = -EIO;
311 		goto out;
312 	}
313 
314 out:
315 	tpm_tis_ready(chip);
316 	return size;
317 }
318 
319 /*
320  * If interrupts are used (signaled by an irq set in the vendor structure)
321  * tpm.c can skip polling for the data to be available as the interrupt is
322  * waited for here
323  */
324 static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
325 {
326 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
327 	int rc, status, burstcnt;
328 	size_t count = 0;
329 	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
330 
331 	status = tpm_tis_status(chip);
332 	if ((status & TPM_STS_COMMAND_READY) == 0) {
333 		tpm_tis_ready(chip);
334 		if (wait_for_tpm_stat
335 		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
336 		     &priv->int_queue, false) < 0) {
337 			rc = -ETIME;
338 			goto out_err;
339 		}
340 	}
341 
342 	while (count < len - 1) {
343 		burstcnt = get_burstcount(chip);
344 		if (burstcnt < 0) {
345 			dev_err(&chip->dev, "Unable to read burstcount\n");
346 			rc = burstcnt;
347 			goto out_err;
348 		}
349 		burstcnt = min_t(int, burstcnt, len - count - 1);
350 		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
351 					 burstcnt, buf + count);
352 		if (rc < 0)
353 			goto out_err;
354 
355 		count += burstcnt;
356 
357 		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
358 					&priv->int_queue, false) < 0) {
359 			rc = -ETIME;
360 			goto out_err;
361 		}
362 		status = tpm_tis_status(chip);
363 		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
364 			rc = -EIO;
365 			goto out_err;
366 		}
367 	}
368 
369 	/* write last byte */
370 	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
371 	if (rc < 0)
372 		goto out_err;
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 	return 0;
386 
387 out_err:
388 	tpm_tis_ready(chip);
389 	return rc;
390 }
391 
392 static void disable_interrupts(struct tpm_chip *chip)
393 {
394 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
395 	u32 intmask;
396 	int rc;
397 
398 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
399 	if (rc < 0)
400 		intmask = 0;
401 
402 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
403 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
404 
405 	devm_free_irq(chip->dev.parent, priv->irq, chip);
406 	priv->irq = 0;
407 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
408 }
409 
410 /*
411  * If interrupts are used (signaled by an irq set in the vendor structure)
412  * tpm.c can skip polling for the data to be available as the interrupt is
413  * waited for here
414  */
415 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
416 {
417 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
418 	int rc;
419 	u32 ordinal;
420 	unsigned long dur;
421 
422 	rc = tpm_tis_send_data(chip, buf, len);
423 	if (rc < 0)
424 		return rc;
425 
426 	/* go and do it */
427 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
428 	if (rc < 0)
429 		goto out_err;
430 
431 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
432 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
433 
434 		if (chip->flags & TPM_CHIP_FLAG_TPM2)
435 			dur = tpm2_calc_ordinal_duration(chip, ordinal);
436 		else
437 			dur = tpm_calc_ordinal_duration(chip, ordinal);
438 
439 		if (wait_for_tpm_stat
440 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
441 		     &priv->read_queue, false) < 0) {
442 			rc = -ETIME;
443 			goto out_err;
444 		}
445 	}
446 	return len;
447 out_err:
448 	tpm_tis_ready(chip);
449 	return rc;
450 }
451 
452 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
453 {
454 	int rc, irq;
455 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
456 
457 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
458 		return tpm_tis_send_main(chip, buf, len);
459 
460 	/* Verify receipt of the expected IRQ */
461 	irq = priv->irq;
462 	priv->irq = 0;
463 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
464 	rc = tpm_tis_send_main(chip, buf, len);
465 	priv->irq = irq;
466 	chip->flags |= TPM_CHIP_FLAG_IRQ;
467 	if (!priv->irq_tested)
468 		tpm_msleep(1);
469 	if (!priv->irq_tested)
470 		disable_interrupts(chip);
471 	priv->irq_tested = true;
472 	return rc;
473 }
474 
475 struct tis_vendor_timeout_override {
476 	u32 did_vid;
477 	unsigned long timeout_us[4];
478 };
479 
480 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
481 	/* Atmel 3204 */
482 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
483 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
484 };
485 
486 static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
487 				    unsigned long *timeout_cap)
488 {
489 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
490 	int i, rc;
491 	u32 did_vid;
492 
493 	if (chip->ops->clk_enable != NULL)
494 		chip->ops->clk_enable(chip, true);
495 
496 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
497 	if (rc < 0)
498 		goto out;
499 
500 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
501 		if (vendor_timeout_overrides[i].did_vid != did_vid)
502 			continue;
503 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
504 		       sizeof(vendor_timeout_overrides[i].timeout_us));
505 		rc = true;
506 	}
507 
508 	rc = false;
509 
510 out:
511 	if (chip->ops->clk_enable != NULL)
512 		chip->ops->clk_enable(chip, false);
513 
514 	return rc;
515 }
516 
517 /*
518  * Early probing for iTPM with STS_DATA_EXPECT flaw.
519  * Try sending command without itpm flag set and if that
520  * fails, repeat with itpm flag set.
521  */
522 static int probe_itpm(struct tpm_chip *chip)
523 {
524 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
525 	int rc = 0;
526 	static const u8 cmd_getticks[] = {
527 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
528 		0x00, 0x00, 0x00, 0xf1
529 	};
530 	size_t len = sizeof(cmd_getticks);
531 	u16 vendor;
532 
533 	if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
534 		return 0;
535 
536 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
537 	if (rc < 0)
538 		return rc;
539 
540 	/* probe only iTPMS */
541 	if (vendor != TPM_VID_INTEL)
542 		return 0;
543 
544 	if (request_locality(chip, 0) != 0)
545 		return -EBUSY;
546 
547 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
548 	if (rc == 0)
549 		goto out;
550 
551 	tpm_tis_ready(chip);
552 
553 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
554 
555 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
556 	if (rc == 0)
557 		dev_info(&chip->dev, "Detected an iTPM.\n");
558 	else {
559 		priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
560 		rc = -EFAULT;
561 	}
562 
563 out:
564 	tpm_tis_ready(chip);
565 	release_locality(chip, priv->locality);
566 
567 	return rc;
568 }
569 
570 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
571 {
572 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
573 
574 	switch (priv->manufacturer_id) {
575 	case TPM_VID_WINBOND:
576 		return ((status == TPM_STS_VALID) ||
577 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
578 	case TPM_VID_STM:
579 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
580 	default:
581 		return (status == TPM_STS_COMMAND_READY);
582 	}
583 }
584 
585 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
586 {
587 	struct tpm_chip *chip = dev_id;
588 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
589 	u32 interrupt;
590 	int i, rc;
591 
592 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
593 	if (rc < 0)
594 		return IRQ_NONE;
595 
596 	if (interrupt == 0)
597 		return IRQ_NONE;
598 
599 	priv->irq_tested = true;
600 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
601 		wake_up_interruptible(&priv->read_queue);
602 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
603 		for (i = 0; i < 5; i++)
604 			if (check_locality(chip, i))
605 				break;
606 	if (interrupt &
607 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
608 	     TPM_INTF_CMD_READY_INT))
609 		wake_up_interruptible(&priv->int_queue);
610 
611 	/* Clear interrupts handled with TPM_EOI */
612 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
613 	if (rc < 0)
614 		return IRQ_NONE;
615 
616 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
617 	return IRQ_HANDLED;
618 }
619 
620 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
621 {
622 	const char *desc = "attempting to generate an interrupt";
623 	u32 cap2;
624 	cap_t cap;
625 
626 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
627 		return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
628 	else
629 		return tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
630 				  0);
631 }
632 
633 /* Register the IRQ and issue a command that will cause an interrupt. If an
634  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
635  * everything and leave in polling mode. Returns 0 on success.
636  */
637 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
638 				    int flags, int irq)
639 {
640 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
641 	u8 original_int_vec;
642 	int rc;
643 	u32 int_status;
644 
645 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
646 			     dev_name(&chip->dev), chip) != 0) {
647 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
648 			 irq);
649 		return -1;
650 	}
651 	priv->irq = irq;
652 
653 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
654 			   &original_int_vec);
655 	if (rc < 0)
656 		return rc;
657 
658 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
659 	if (rc < 0)
660 		return rc;
661 
662 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
663 	if (rc < 0)
664 		return rc;
665 
666 	/* Clear all existing */
667 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
668 	if (rc < 0)
669 		return rc;
670 
671 	/* Turn on */
672 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
673 			     intmask | TPM_GLOBAL_INT_ENABLE);
674 	if (rc < 0)
675 		return rc;
676 
677 	priv->irq_tested = false;
678 
679 	/* Generate an interrupt by having the core call through to
680 	 * tpm_tis_send
681 	 */
682 	rc = tpm_tis_gen_interrupt(chip);
683 	if (rc < 0)
684 		return rc;
685 
686 	/* tpm_tis_send will either confirm the interrupt is working or it
687 	 * will call disable_irq which undoes all of the above.
688 	 */
689 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
690 		rc = tpm_tis_write8(priv, original_int_vec,
691 				TPM_INT_VECTOR(priv->locality));
692 		if (rc < 0)
693 			return rc;
694 
695 		return 1;
696 	}
697 
698 	return 0;
699 }
700 
701 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
702  * do not have ACPI/etc. We typically expect the interrupt to be declared if
703  * present.
704  */
705 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
706 {
707 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
708 	u8 original_int_vec;
709 	int i, rc;
710 
711 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
712 			   &original_int_vec);
713 	if (rc < 0)
714 		return;
715 
716 	if (!original_int_vec) {
717 		if (IS_ENABLED(CONFIG_X86))
718 			for (i = 3; i <= 15; i++)
719 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
720 							      i))
721 					return;
722 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
723 					     original_int_vec))
724 		return;
725 }
726 
727 void tpm_tis_remove(struct tpm_chip *chip)
728 {
729 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
730 	u32 reg = TPM_INT_ENABLE(priv->locality);
731 	u32 interrupt;
732 	int rc;
733 
734 	tpm_tis_clkrun_enable(chip, true);
735 
736 	rc = tpm_tis_read32(priv, reg, &interrupt);
737 	if (rc < 0)
738 		interrupt = 0;
739 
740 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
741 
742 	tpm_tis_clkrun_enable(chip, false);
743 
744 	if (priv->ilb_base_addr)
745 		iounmap(priv->ilb_base_addr);
746 }
747 EXPORT_SYMBOL_GPL(tpm_tis_remove);
748 
749 /**
750  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
751  *                           of a single TPM command
752  * @chip:	TPM chip to use
753  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
754  *		0 - Enable CLKRUN protocol
755  * Call this function directly in tpm_tis_remove() in error or driver removal
756  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
757  */
758 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
759 {
760 	struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
761 	u32 clkrun_val;
762 
763 	if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
764 	    !data->ilb_base_addr)
765 		return;
766 
767 	if (value) {
768 		data->clkrun_enabled++;
769 		if (data->clkrun_enabled > 1)
770 			return;
771 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
772 
773 		/* Disable LPC CLKRUN# */
774 		clkrun_val &= ~LPC_CLKRUN_EN;
775 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
776 
777 		/*
778 		 * Write any random value on port 0x80 which is on LPC, to make
779 		 * sure LPC clock is running before sending any TPM command.
780 		 */
781 		outb(0xCC, 0x80);
782 	} else {
783 		data->clkrun_enabled--;
784 		if (data->clkrun_enabled)
785 			return;
786 
787 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
788 
789 		/* Enable LPC CLKRUN# */
790 		clkrun_val |= LPC_CLKRUN_EN;
791 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
792 
793 		/*
794 		 * Write any random value on port 0x80 which is on LPC, to make
795 		 * sure LPC clock is running before sending any TPM command.
796 		 */
797 		outb(0xCC, 0x80);
798 	}
799 }
800 
801 static const struct tpm_class_ops tpm_tis = {
802 	.flags = TPM_OPS_AUTO_STARTUP,
803 	.status = tpm_tis_status,
804 	.recv = tpm_tis_recv,
805 	.send = tpm_tis_send,
806 	.cancel = tpm_tis_ready,
807 	.update_timeouts = tpm_tis_update_timeouts,
808 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
809 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
810 	.req_canceled = tpm_tis_req_canceled,
811 	.request_locality = request_locality,
812 	.relinquish_locality = release_locality,
813 	.clk_enable = tpm_tis_clkrun_enable,
814 };
815 
816 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
817 		      const struct tpm_tis_phy_ops *phy_ops,
818 		      acpi_handle acpi_dev_handle)
819 {
820 	u32 vendor;
821 	u32 intfcaps;
822 	u32 intmask;
823 	u32 clkrun_val;
824 	u8 rid;
825 	int rc, probe;
826 	struct tpm_chip *chip;
827 
828 	chip = tpmm_chip_alloc(dev, &tpm_tis);
829 	if (IS_ERR(chip))
830 		return PTR_ERR(chip);
831 
832 #ifdef CONFIG_ACPI
833 	chip->acpi_dev_handle = acpi_dev_handle;
834 #endif
835 
836 	/* Maximum timeouts */
837 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
838 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
839 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
840 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
841 	priv->phy_ops = phy_ops;
842 	dev_set_drvdata(&chip->dev, priv);
843 
844 	if (is_bsw()) {
845 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
846 					ILB_REMAP_SIZE);
847 		if (!priv->ilb_base_addr)
848 			return -ENOMEM;
849 
850 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
851 		/* Check if CLKRUN# is already not enabled in the LPC bus */
852 		if (!(clkrun_val & LPC_CLKRUN_EN)) {
853 			iounmap(priv->ilb_base_addr);
854 			priv->ilb_base_addr = NULL;
855 		}
856 	}
857 
858 	if (chip->ops->clk_enable != NULL)
859 		chip->ops->clk_enable(chip, true);
860 
861 	if (wait_startup(chip, 0) != 0) {
862 		rc = -ENODEV;
863 		goto out_err;
864 	}
865 
866 	/* Take control of the TPM's interrupt hardware and shut it off */
867 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
868 	if (rc < 0)
869 		goto out_err;
870 
871 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
872 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
873 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
874 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
875 
876 	rc = tpm2_probe(chip);
877 	if (rc)
878 		goto out_err;
879 
880 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
881 	if (rc < 0)
882 		goto out_err;
883 
884 	priv->manufacturer_id = vendor;
885 
886 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
887 	if (rc < 0)
888 		goto out_err;
889 
890 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
891 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
892 		 vendor >> 16, rid);
893 
894 	probe = probe_itpm(chip);
895 	if (probe < 0) {
896 		rc = -ENODEV;
897 		goto out_err;
898 	}
899 
900 	/* Figure out the capabilities */
901 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
902 	if (rc < 0)
903 		goto out_err;
904 
905 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
906 		intfcaps);
907 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
908 		dev_dbg(dev, "\tBurst Count Static\n");
909 	if (intfcaps & TPM_INTF_CMD_READY_INT)
910 		dev_dbg(dev, "\tCommand Ready Int Support\n");
911 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
912 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
913 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
914 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
915 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
916 		dev_dbg(dev, "\tInterrupt Level Low\n");
917 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
918 		dev_dbg(dev, "\tInterrupt Level High\n");
919 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
920 		dev_dbg(dev, "\tLocality Change Int Support\n");
921 	if (intfcaps & TPM_INTF_STS_VALID_INT)
922 		dev_dbg(dev, "\tSts Valid Int Support\n");
923 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
924 		dev_dbg(dev, "\tData Avail Int Support\n");
925 
926 	/* INTERRUPT Setup */
927 	init_waitqueue_head(&priv->read_queue);
928 	init_waitqueue_head(&priv->int_queue);
929 	if (irq != -1) {
930 		/* Before doing irq testing issue a command to the TPM in polling mode
931 		 * to make sure it works. May as well use that command to set the
932 		 * proper timeouts for the driver.
933 		 */
934 		if (tpm_get_timeouts(chip)) {
935 			dev_err(dev, "Could not get TPM timeouts and durations\n");
936 			rc = -ENODEV;
937 			goto out_err;
938 		}
939 
940 		if (irq) {
941 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
942 						 irq);
943 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
944 				dev_err(&chip->dev, FW_BUG
945 					"TPM interrupt not working, polling instead\n");
946 		} else {
947 			tpm_tis_probe_irq(chip, intmask);
948 		}
949 	}
950 
951 	rc = tpm_chip_register(chip);
952 	if (rc)
953 		goto out_err;
954 
955 	if (chip->ops->clk_enable != NULL)
956 		chip->ops->clk_enable(chip, false);
957 
958 	return 0;
959 out_err:
960 	if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
961 		chip->ops->clk_enable(chip, false);
962 
963 	tpm_tis_remove(chip);
964 
965 	return rc;
966 }
967 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
968 
969 #ifdef CONFIG_PM_SLEEP
970 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
971 {
972 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
973 	u32 intmask;
974 	int rc;
975 
976 	if (chip->ops->clk_enable != NULL)
977 		chip->ops->clk_enable(chip, true);
978 
979 	/* reenable interrupts that device may have lost or
980 	 * BIOS/firmware may have disabled
981 	 */
982 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
983 	if (rc < 0)
984 		goto out;
985 
986 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
987 	if (rc < 0)
988 		goto out;
989 
990 	intmask |= TPM_INTF_CMD_READY_INT
991 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
992 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
993 
994 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
995 
996 out:
997 	if (chip->ops->clk_enable != NULL)
998 		chip->ops->clk_enable(chip, false);
999 
1000 	return;
1001 }
1002 
1003 int tpm_tis_resume(struct device *dev)
1004 {
1005 	struct tpm_chip *chip = dev_get_drvdata(dev);
1006 	int ret;
1007 
1008 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
1009 		tpm_tis_reenable_interrupts(chip);
1010 
1011 	ret = tpm_pm_resume(dev);
1012 	if (ret)
1013 		return ret;
1014 
1015 	/* TPM 1.2 requires self-test on resume. This function actually returns
1016 	 * an error code but for unknown reason it isn't handled.
1017 	 */
1018 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
1019 		tpm_do_selftest(chip);
1020 
1021 	return 0;
1022 }
1023 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1024 #endif
1025 
1026 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1027 MODULE_DESCRIPTION("TPM Driver");
1028 MODULE_VERSION("2.0");
1029 MODULE_LICENSE("GPL");
1030