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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 
wait_for_tpm_stat_cond(struct tpm_chip * chip,u8 mask,bool check_cancel,bool * canceled)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 
wait_for_tpm_stat(struct tpm_chip * chip,u8 mask,unsigned long timeout,wait_queue_head_t * queue,bool check_cancel)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  */
wait_startup(struct tpm_chip * chip,int l)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 
check_locality(struct tpm_chip * chip,int l)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_REQUEST_USE)) ==
130 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
131 		priv->locality = l;
132 		return true;
133 	}
134 
135 	return false;
136 }
137 
release_locality(struct tpm_chip * chip,int l)138 static int release_locality(struct tpm_chip *chip, int l)
139 {
140 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
141 
142 	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
143 
144 	return 0;
145 }
146 
request_locality(struct tpm_chip * chip,int l)147 static int request_locality(struct tpm_chip *chip, int l)
148 {
149 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
150 	unsigned long stop, timeout;
151 	long rc;
152 
153 	if (check_locality(chip, l))
154 		return l;
155 
156 	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
157 	if (rc < 0)
158 		return rc;
159 
160 	stop = jiffies + chip->timeout_a;
161 
162 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
163 again:
164 		timeout = stop - jiffies;
165 		if ((long)timeout <= 0)
166 			return -1;
167 		rc = wait_event_interruptible_timeout(priv->int_queue,
168 						      (check_locality
169 						       (chip, l)),
170 						      timeout);
171 		if (rc > 0)
172 			return l;
173 		if (rc == -ERESTARTSYS && freezing(current)) {
174 			clear_thread_flag(TIF_SIGPENDING);
175 			goto again;
176 		}
177 	} else {
178 		/* wait for burstcount */
179 		do {
180 			if (check_locality(chip, l))
181 				return l;
182 			tpm_msleep(TPM_TIMEOUT);
183 		} while (time_before(jiffies, stop));
184 	}
185 	return -1;
186 }
187 
tpm_tis_status(struct tpm_chip * chip)188 static u8 tpm_tis_status(struct tpm_chip *chip)
189 {
190 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
191 	int rc;
192 	u8 status;
193 
194 	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
195 	if (rc < 0)
196 		return 0;
197 
198 	return status;
199 }
200 
tpm_tis_ready(struct tpm_chip * chip)201 static void tpm_tis_ready(struct tpm_chip *chip)
202 {
203 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
204 
205 	/* this causes the current command to be aborted */
206 	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
207 }
208 
get_burstcount(struct tpm_chip * chip)209 static int get_burstcount(struct tpm_chip *chip)
210 {
211 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
212 	unsigned long stop;
213 	int burstcnt, rc;
214 	u32 value;
215 
216 	/* wait for burstcount */
217 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
218 		stop = jiffies + chip->timeout_a;
219 	else
220 		stop = jiffies + chip->timeout_d;
221 	do {
222 		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
223 		if (rc < 0)
224 			return rc;
225 
226 		burstcnt = (value >> 8) & 0xFFFF;
227 		if (burstcnt)
228 			return burstcnt;
229 		usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX);
230 	} while (time_before(jiffies, stop));
231 	return -EBUSY;
232 }
233 
recv_data(struct tpm_chip * chip,u8 * buf,size_t count)234 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
235 {
236 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
237 	int size = 0, burstcnt, rc;
238 
239 	while (size < count) {
240 		rc = wait_for_tpm_stat(chip,
241 				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
242 				 chip->timeout_c,
243 				 &priv->read_queue, true);
244 		if (rc < 0)
245 			return rc;
246 		burstcnt = get_burstcount(chip);
247 		if (burstcnt < 0) {
248 			dev_err(&chip->dev, "Unable to read burstcount\n");
249 			return burstcnt;
250 		}
251 		burstcnt = min_t(int, burstcnt, count - size);
252 
253 		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
254 					burstcnt, buf + size);
255 		if (rc < 0)
256 			return rc;
257 
258 		size += burstcnt;
259 	}
260 	return size;
261 }
262 
tpm_tis_recv(struct tpm_chip * chip,u8 * buf,size_t count)263 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
264 {
265 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
266 	int size = 0;
267 	int status;
268 	u32 expected;
269 	int rc;
270 
271 	if (count < TPM_HEADER_SIZE) {
272 		size = -EIO;
273 		goto out;
274 	}
275 
276 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
277 	/* read first 10 bytes, including tag, paramsize, and result */
278 	if (size < TPM_HEADER_SIZE) {
279 		dev_err(&chip->dev, "Unable to read header\n");
280 		goto out;
281 	}
282 
283 	expected = be32_to_cpu(*(__be32 *) (buf + 2));
284 	if (expected > count || expected < TPM_HEADER_SIZE) {
285 		size = -EIO;
286 		goto out;
287 	}
288 
289 	rc = recv_data(chip, &buf[TPM_HEADER_SIZE],
290 		       expected - TPM_HEADER_SIZE);
291 	if (rc < 0) {
292 		size = rc;
293 		goto out;
294 	}
295 	size += rc;
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  */
tpm_tis_send_data(struct tpm_chip * chip,const u8 * buf,size_t len)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 
disable_interrupts(struct tpm_chip * chip)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 	if (priv->irq == 0)
399 		return;
400 
401 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
402 	if (rc < 0)
403 		intmask = 0;
404 
405 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
406 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
407 
408 	devm_free_irq(chip->dev.parent, priv->irq, chip);
409 	priv->irq = 0;
410 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
411 }
412 
413 /*
414  * If interrupts are used (signaled by an irq set in the vendor structure)
415  * tpm.c can skip polling for the data to be available as the interrupt is
416  * waited for here
417  */
tpm_tis_send_main(struct tpm_chip * chip,const u8 * buf,size_t len)418 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
419 {
420 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
421 	int rc;
422 	u32 ordinal;
423 	unsigned long dur;
424 	unsigned int try;
425 
426 	for (try = 0; try < TPM_RETRY; try++) {
427 		rc = tpm_tis_send_data(chip, buf, len);
428 		if (rc >= 0)
429 			/* Data transfer done successfully */
430 			break;
431 		else if (rc != -EIO)
432 			/* Data transfer failed, not recoverable */
433 			return rc;
434 	}
435 
436 	/* go and do it */
437 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
438 	if (rc < 0)
439 		goto out_err;
440 
441 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
442 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
443 
444 		dur = tpm_calc_ordinal_duration(chip, ordinal);
445 		if (wait_for_tpm_stat
446 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
447 		     &priv->read_queue, false) < 0) {
448 			rc = -ETIME;
449 			goto out_err;
450 		}
451 	}
452 	return 0;
453 out_err:
454 	tpm_tis_ready(chip);
455 	return rc;
456 }
457 
tpm_tis_send(struct tpm_chip * chip,u8 * buf,size_t len)458 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
459 {
460 	int rc, irq;
461 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
462 
463 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
464 		return tpm_tis_send_main(chip, buf, len);
465 
466 	/* Verify receipt of the expected IRQ */
467 	irq = priv->irq;
468 	priv->irq = 0;
469 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
470 	rc = tpm_tis_send_main(chip, buf, len);
471 	priv->irq = irq;
472 	chip->flags |= TPM_CHIP_FLAG_IRQ;
473 	if (!priv->irq_tested)
474 		tpm_msleep(1);
475 	if (!priv->irq_tested)
476 		disable_interrupts(chip);
477 	priv->irq_tested = true;
478 	return rc;
479 }
480 
481 struct tis_vendor_timeout_override {
482 	u32 did_vid;
483 	unsigned long timeout_us[4];
484 };
485 
486 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
487 	/* Atmel 3204 */
488 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
489 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
490 };
491 
tpm_tis_update_timeouts(struct tpm_chip * chip,unsigned long * timeout_cap)492 static void tpm_tis_update_timeouts(struct tpm_chip *chip,
493 				    unsigned long *timeout_cap)
494 {
495 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
496 	int i, rc;
497 	u32 did_vid;
498 
499 	chip->timeout_adjusted = false;
500 
501 	if (chip->ops->clk_enable != NULL)
502 		chip->ops->clk_enable(chip, true);
503 
504 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
505 	if (rc < 0) {
506 		dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
507 			 __func__, rc);
508 		goto out;
509 	}
510 
511 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
512 		if (vendor_timeout_overrides[i].did_vid != did_vid)
513 			continue;
514 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
515 		       sizeof(vendor_timeout_overrides[i].timeout_us));
516 		chip->timeout_adjusted = true;
517 	}
518 
519 out:
520 	if (chip->ops->clk_enable != NULL)
521 		chip->ops->clk_enable(chip, false);
522 
523 	return;
524 }
525 
526 /*
527  * Early probing for iTPM with STS_DATA_EXPECT flaw.
528  * Try sending command without itpm flag set and if that
529  * fails, repeat with itpm flag set.
530  */
probe_itpm(struct tpm_chip * chip)531 static int probe_itpm(struct tpm_chip *chip)
532 {
533 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
534 	int rc = 0;
535 	static const u8 cmd_getticks[] = {
536 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
537 		0x00, 0x00, 0x00, 0xf1
538 	};
539 	size_t len = sizeof(cmd_getticks);
540 	u16 vendor;
541 
542 	if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
543 		return 0;
544 
545 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
546 	if (rc < 0)
547 		return rc;
548 
549 	/* probe only iTPMS */
550 	if (vendor != TPM_VID_INTEL)
551 		return 0;
552 
553 	if (request_locality(chip, 0) != 0)
554 		return -EBUSY;
555 
556 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
557 	if (rc == 0)
558 		goto out;
559 
560 	tpm_tis_ready(chip);
561 
562 	priv->flags |= TPM_TIS_ITPM_WORKAROUND;
563 
564 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
565 	if (rc == 0)
566 		dev_info(&chip->dev, "Detected an iTPM.\n");
567 	else {
568 		priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
569 		rc = -EFAULT;
570 	}
571 
572 out:
573 	tpm_tis_ready(chip);
574 	release_locality(chip, priv->locality);
575 
576 	return rc;
577 }
578 
tpm_tis_req_canceled(struct tpm_chip * chip,u8 status)579 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
580 {
581 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
582 
583 	switch (priv->manufacturer_id) {
584 	case TPM_VID_WINBOND:
585 		return ((status == TPM_STS_VALID) ||
586 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
587 	case TPM_VID_STM:
588 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
589 	default:
590 		return (status == TPM_STS_COMMAND_READY);
591 	}
592 }
593 
tis_int_handler(int dummy,void * dev_id)594 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
595 {
596 	struct tpm_chip *chip = dev_id;
597 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
598 	u32 interrupt;
599 	int i, rc;
600 
601 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
602 	if (rc < 0)
603 		return IRQ_NONE;
604 
605 	if (interrupt == 0)
606 		return IRQ_NONE;
607 
608 	priv->irq_tested = true;
609 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
610 		wake_up_interruptible(&priv->read_queue);
611 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
612 		for (i = 0; i < 5; i++)
613 			if (check_locality(chip, i))
614 				break;
615 	if (interrupt &
616 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
617 	     TPM_INTF_CMD_READY_INT))
618 		wake_up_interruptible(&priv->int_queue);
619 
620 	/* Clear interrupts handled with TPM_EOI */
621 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
622 	if (rc < 0)
623 		return IRQ_NONE;
624 
625 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
626 	return IRQ_HANDLED;
627 }
628 
tpm_tis_gen_interrupt(struct tpm_chip * chip)629 static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
630 {
631 	const char *desc = "attempting to generate an interrupt";
632 	u32 cap2;
633 	cap_t cap;
634 	int ret;
635 
636 	ret = request_locality(chip, 0);
637 	if (ret < 0)
638 		return;
639 
640 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
641 		ret = tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
642 	else
643 		ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
644 
645 	release_locality(chip, 0);
646 }
647 
648 /* Register the IRQ and issue a command that will cause an interrupt. If an
649  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
650  * everything and leave in polling mode. Returns 0 on success.
651  */
tpm_tis_probe_irq_single(struct tpm_chip * chip,u32 intmask,int flags,int irq)652 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
653 				    int flags, int irq)
654 {
655 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
656 	u8 original_int_vec;
657 	int rc;
658 	u32 int_status;
659 
660 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
661 			     dev_name(&chip->dev), chip) != 0) {
662 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
663 			 irq);
664 		return -1;
665 	}
666 	priv->irq = irq;
667 
668 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
669 			   &original_int_vec);
670 	if (rc < 0)
671 		return rc;
672 
673 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
674 	if (rc < 0)
675 		goto restore_irqs;
676 
677 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
678 	if (rc < 0)
679 		goto restore_irqs;
680 
681 	/* Clear all existing */
682 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
683 	if (rc < 0)
684 		goto restore_irqs;
685 	/* Turn on */
686 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
687 			     intmask | TPM_GLOBAL_INT_ENABLE);
688 	if (rc < 0)
689 		goto restore_irqs;
690 
691 	priv->irq_tested = false;
692 
693 	/* Generate an interrupt by having the core call through to
694 	 * tpm_tis_send
695 	 */
696 	tpm_tis_gen_interrupt(chip);
697 
698 restore_irqs:
699 	/* tpm_tis_send will either confirm the interrupt is working or it
700 	 * will call disable_irq which undoes all of the above.
701 	 */
702 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
703 		tpm_tis_write8(priv, original_int_vec,
704 			       TPM_INT_VECTOR(priv->locality));
705 		return -1;
706 	}
707 
708 	return 0;
709 }
710 
711 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
712  * do not have ACPI/etc. We typically expect the interrupt to be declared if
713  * present.
714  */
tpm_tis_probe_irq(struct tpm_chip * chip,u32 intmask)715 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
716 {
717 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
718 	u8 original_int_vec;
719 	int i, rc;
720 
721 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
722 			   &original_int_vec);
723 	if (rc < 0)
724 		return;
725 
726 	if (!original_int_vec) {
727 		if (IS_ENABLED(CONFIG_X86))
728 			for (i = 3; i <= 15; i++)
729 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
730 							      i))
731 					return;
732 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
733 					     original_int_vec))
734 		return;
735 }
736 
tpm_tis_remove(struct tpm_chip * chip)737 void tpm_tis_remove(struct tpm_chip *chip)
738 {
739 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
740 	u32 reg = TPM_INT_ENABLE(priv->locality);
741 	u32 interrupt;
742 	int rc;
743 
744 	tpm_tis_clkrun_enable(chip, true);
745 
746 	rc = tpm_tis_read32(priv, reg, &interrupt);
747 	if (rc < 0)
748 		interrupt = 0;
749 
750 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
751 
752 	tpm_tis_clkrun_enable(chip, false);
753 
754 	if (priv->ilb_base_addr)
755 		iounmap(priv->ilb_base_addr);
756 }
757 EXPORT_SYMBOL_GPL(tpm_tis_remove);
758 
759 /**
760  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
761  *                           of a single TPM command
762  * @chip:	TPM chip to use
763  * @value:	1 - Disable CLKRUN protocol, so that clocks are free running
764  *		0 - Enable CLKRUN protocol
765  * Call this function directly in tpm_tis_remove() in error or driver removal
766  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
767  */
tpm_tis_clkrun_enable(struct tpm_chip * chip,bool value)768 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
769 {
770 	struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
771 	u32 clkrun_val;
772 
773 	if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
774 	    !data->ilb_base_addr)
775 		return;
776 
777 	if (value) {
778 		data->clkrun_enabled++;
779 		if (data->clkrun_enabled > 1)
780 			return;
781 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
782 
783 		/* Disable LPC CLKRUN# */
784 		clkrun_val &= ~LPC_CLKRUN_EN;
785 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
786 
787 		/*
788 		 * Write any random value on port 0x80 which is on LPC, to make
789 		 * sure LPC clock is running before sending any TPM command.
790 		 */
791 		outb(0xCC, 0x80);
792 	} else {
793 		data->clkrun_enabled--;
794 		if (data->clkrun_enabled)
795 			return;
796 
797 		clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
798 
799 		/* Enable LPC CLKRUN# */
800 		clkrun_val |= LPC_CLKRUN_EN;
801 		iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
802 
803 		/*
804 		 * Write any random value on port 0x80 which is on LPC, to make
805 		 * sure LPC clock is running before sending any TPM command.
806 		 */
807 		outb(0xCC, 0x80);
808 	}
809 }
810 
811 static const struct tpm_class_ops tpm_tis = {
812 	.flags = TPM_OPS_AUTO_STARTUP,
813 	.status = tpm_tis_status,
814 	.recv = tpm_tis_recv,
815 	.send = tpm_tis_send,
816 	.cancel = tpm_tis_ready,
817 	.update_timeouts = tpm_tis_update_timeouts,
818 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
819 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
820 	.req_canceled = tpm_tis_req_canceled,
821 	.request_locality = request_locality,
822 	.relinquish_locality = release_locality,
823 	.clk_enable = tpm_tis_clkrun_enable,
824 };
825 
tpm_tis_core_init(struct device * dev,struct tpm_tis_data * priv,int irq,const struct tpm_tis_phy_ops * phy_ops,acpi_handle acpi_dev_handle)826 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
827 		      const struct tpm_tis_phy_ops *phy_ops,
828 		      acpi_handle acpi_dev_handle)
829 {
830 	u32 vendor;
831 	u32 intfcaps;
832 	u32 intmask;
833 	u32 clkrun_val;
834 	u8 rid;
835 	int rc, probe;
836 	struct tpm_chip *chip;
837 
838 	chip = tpmm_chip_alloc(dev, &tpm_tis);
839 	if (IS_ERR(chip))
840 		return PTR_ERR(chip);
841 
842 #ifdef CONFIG_ACPI
843 	chip->acpi_dev_handle = acpi_dev_handle;
844 #endif
845 
846 	chip->hwrng.quality = priv->rng_quality;
847 
848 	/* Maximum timeouts */
849 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
850 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
851 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
852 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
853 	priv->phy_ops = phy_ops;
854 	dev_set_drvdata(&chip->dev, priv);
855 
856 	if (is_bsw()) {
857 		priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
858 					ILB_REMAP_SIZE);
859 		if (!priv->ilb_base_addr)
860 			return -ENOMEM;
861 
862 		clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
863 		/* Check if CLKRUN# is already not enabled in the LPC bus */
864 		if (!(clkrun_val & LPC_CLKRUN_EN)) {
865 			iounmap(priv->ilb_base_addr);
866 			priv->ilb_base_addr = NULL;
867 		}
868 	}
869 
870 	if (chip->ops->clk_enable != NULL)
871 		chip->ops->clk_enable(chip, true);
872 
873 	if (wait_startup(chip, 0) != 0) {
874 		rc = -ENODEV;
875 		goto out_err;
876 	}
877 
878 	/* Take control of the TPM's interrupt hardware and shut it off */
879 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
880 	if (rc < 0)
881 		goto out_err;
882 
883 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
884 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
885 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
886 
887 	rc = request_locality(chip, 0);
888 	if (rc < 0) {
889 		rc = -ENODEV;
890 		goto out_err;
891 	}
892 
893 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
894 	release_locality(chip, 0);
895 
896 	rc = tpm_chip_start(chip);
897 	if (rc)
898 		goto out_err;
899 	rc = tpm2_probe(chip);
900 	tpm_chip_stop(chip);
901 	if (rc)
902 		goto out_err;
903 
904 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
905 	if (rc < 0)
906 		goto out_err;
907 
908 	priv->manufacturer_id = vendor;
909 
910 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
911 	if (rc < 0)
912 		goto out_err;
913 
914 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
915 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
916 		 vendor >> 16, rid);
917 
918 	probe = probe_itpm(chip);
919 	if (probe < 0) {
920 		rc = -ENODEV;
921 		goto out_err;
922 	}
923 
924 	/* Figure out the capabilities */
925 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
926 	if (rc < 0)
927 		goto out_err;
928 
929 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
930 		intfcaps);
931 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
932 		dev_dbg(dev, "\tBurst Count Static\n");
933 	if (intfcaps & TPM_INTF_CMD_READY_INT)
934 		dev_dbg(dev, "\tCommand Ready Int Support\n");
935 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
936 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
937 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
938 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
939 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
940 		dev_dbg(dev, "\tInterrupt Level Low\n");
941 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
942 		dev_dbg(dev, "\tInterrupt Level High\n");
943 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
944 		dev_dbg(dev, "\tLocality Change Int Support\n");
945 	if (intfcaps & TPM_INTF_STS_VALID_INT)
946 		dev_dbg(dev, "\tSts Valid Int Support\n");
947 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
948 		dev_dbg(dev, "\tData Avail Int Support\n");
949 
950 	/* INTERRUPT Setup */
951 	init_waitqueue_head(&priv->read_queue);
952 	init_waitqueue_head(&priv->int_queue);
953 	if (irq != -1) {
954 		/*
955 		 * Before doing irq testing issue a command to the TPM in polling mode
956 		 * to make sure it works. May as well use that command to set the
957 		 * proper timeouts for the driver.
958 		 */
959 
960 		rc = request_locality(chip, 0);
961 		if (rc < 0)
962 			goto out_err;
963 
964 		rc = tpm_get_timeouts(chip);
965 
966 		release_locality(chip, 0);
967 
968 		if (rc) {
969 			dev_err(dev, "Could not get TPM timeouts and durations\n");
970 			rc = -ENODEV;
971 			goto out_err;
972 		}
973 
974 		if (irq) {
975 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
976 						 irq);
977 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
978 				dev_err(&chip->dev, FW_BUG
979 					"TPM interrupt not working, polling instead\n");
980 
981 				disable_interrupts(chip);
982 			}
983 		} else {
984 			tpm_tis_probe_irq(chip, intmask);
985 		}
986 	}
987 
988 	rc = tpm_chip_register(chip);
989 	if (rc)
990 		goto out_err;
991 
992 	if (chip->ops->clk_enable != NULL)
993 		chip->ops->clk_enable(chip, false);
994 
995 	return 0;
996 out_err:
997 	if (chip->ops->clk_enable != NULL)
998 		chip->ops->clk_enable(chip, false);
999 
1000 	tpm_tis_remove(chip);
1001 
1002 	return rc;
1003 }
1004 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
1005 
1006 #ifdef CONFIG_PM_SLEEP
tpm_tis_reenable_interrupts(struct tpm_chip * chip)1007 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
1008 {
1009 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
1010 	u32 intmask;
1011 	int rc;
1012 
1013 	if (chip->ops->clk_enable != NULL)
1014 		chip->ops->clk_enable(chip, true);
1015 
1016 	/* reenable interrupts that device may have lost or
1017 	 * BIOS/firmware may have disabled
1018 	 */
1019 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
1020 	if (rc < 0)
1021 		goto out;
1022 
1023 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
1024 	if (rc < 0)
1025 		goto out;
1026 
1027 	intmask |= TPM_INTF_CMD_READY_INT
1028 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
1029 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
1030 
1031 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1032 
1033 out:
1034 	if (chip->ops->clk_enable != NULL)
1035 		chip->ops->clk_enable(chip, false);
1036 
1037 	return;
1038 }
1039 
tpm_tis_resume(struct device * dev)1040 int tpm_tis_resume(struct device *dev)
1041 {
1042 	struct tpm_chip *chip = dev_get_drvdata(dev);
1043 	int ret;
1044 
1045 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
1046 		tpm_tis_reenable_interrupts(chip);
1047 
1048 	ret = tpm_pm_resume(dev);
1049 	if (ret)
1050 		return ret;
1051 
1052 	/*
1053 	 * TPM 1.2 requires self-test on resume. This function actually returns
1054 	 * an error code but for unknown reason it isn't handled.
1055 	 */
1056 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
1057 		ret = request_locality(chip, 0);
1058 		if (ret < 0)
1059 			return ret;
1060 
1061 		tpm1_do_selftest(chip);
1062 
1063 		release_locality(chip, 0);
1064 	}
1065 
1066 	return 0;
1067 }
1068 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1069 #endif
1070 
1071 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1072 MODULE_DESCRIPTION("TPM Driver");
1073 MODULE_VERSION("2.0");
1074 MODULE_LICENSE("GPL");
1075