xref: /openbmc/linux/drivers/char/tpm/tpm_ibmvtpm.c (revision 165f2d28)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012-2020 IBM Corporation
4  *
5  * Author: Ashley Lai <ashleydlai@gmail.com>
6  *
7  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
8  *
9  * Device driver for TCG/TCPA TPM (trusted platform module).
10  * Specifications at www.trustedcomputinggroup.org
11  */
12 
13 #include <linux/dma-mapping.h>
14 #include <linux/dmapool.h>
15 #include <linux/slab.h>
16 #include <asm/vio.h>
17 #include <asm/irq.h>
18 #include <linux/types.h>
19 #include <linux/list.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/wait.h>
23 #include <asm/prom.h>
24 
25 #include "tpm.h"
26 #include "tpm_ibmvtpm.h"
27 
28 static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
29 
30 static const struct vio_device_id tpm_ibmvtpm_device_table[] = {
31 	{ "IBM,vtpm", "IBM,vtpm"},
32 	{ "IBM,vtpm", "IBM,vtpm20"},
33 	{ "", "" }
34 };
35 MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);
36 
37 /**
38  * ibmvtpm_send_crq_word() - Send a CRQ request
39  * @vdev:	vio device struct
40  * @w1:		pre-constructed first word of tpm crq (second word is reserved)
41  *
42  * Return:
43  *	0 - Success
44  *	Non-zero - Failure
45  */
46 static int ibmvtpm_send_crq_word(struct vio_dev *vdev, u64 w1)
47 {
48 	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, 0);
49 }
50 
51 /**
52  * ibmvtpm_send_crq() - Send a CRQ request
53  *
54  * @vdev:	vio device struct
55  * @valid:	Valid field
56  * @msg:	Type field
57  * @len:	Length field
58  * @data:	Data field
59  *
60  * The ibmvtpm crq is defined as follows:
61  *
62  * Byte  |   0   |   1   |   2   |   3   |   4   |   5   |   6   |   7
63  * -----------------------------------------------------------------------
64  * Word0 | Valid | Type  |     Length    |              Data
65  * -----------------------------------------------------------------------
66  * Word1 |                Reserved
67  * -----------------------------------------------------------------------
68  *
69  * Which matches the following structure (on bigendian host):
70  *
71  * struct ibmvtpm_crq {
72  *         u8 valid;
73  *         u8 msg;
74  *         __be16 len;
75  *         __be32 data;
76  *         __be64 reserved;
77  * } __attribute__((packed, aligned(8)));
78  *
79  * However, the value is passed in a register so just compute the numeric value
80  * to load into the register avoiding byteswap altogether. Endian only affects
81  * memory loads and stores - registers are internally represented the same.
82  *
83  * Return:
84  *	0 (H_SUCCESS) - Success
85  *	Non-zero - Failure
86  */
87 static int ibmvtpm_send_crq(struct vio_dev *vdev,
88 		u8 valid, u8 msg, u16 len, u32 data)
89 {
90 	u64 w1 = ((u64)valid << 56) | ((u64)msg << 48) | ((u64)len << 32) |
91 		(u64)data;
92 	return ibmvtpm_send_crq_word(vdev, w1);
93 }
94 
95 /**
96  * tpm_ibmvtpm_recv - Receive data after send
97  *
98  * @chip:	tpm chip struct
99  * @buf:	buffer to read
100  * @count:	size of buffer
101  *
102  * Return:
103  *	Number of bytes read
104  */
105 static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
106 {
107 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
108 	u16 len;
109 	int sig;
110 
111 	if (!ibmvtpm->rtce_buf) {
112 		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
113 		return 0;
114 	}
115 
116 	sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
117 	if (sig)
118 		return -EINTR;
119 
120 	len = ibmvtpm->res_len;
121 
122 	if (count < len) {
123 		dev_err(ibmvtpm->dev,
124 			"Invalid size in recv: count=%zd, crq_size=%d\n",
125 			count, len);
126 		return -EIO;
127 	}
128 
129 	spin_lock(&ibmvtpm->rtce_lock);
130 	memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len);
131 	memset(ibmvtpm->rtce_buf, 0, len);
132 	ibmvtpm->res_len = 0;
133 	spin_unlock(&ibmvtpm->rtce_lock);
134 	return len;
135 }
136 
137 /**
138  * ibmvtpm_crq_send_init - Send a CRQ initialize message
139  * @ibmvtpm:	vtpm device struct
140  *
141  * Return:
142  *	0 on success.
143  *	Non-zero on failure.
144  */
145 static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
146 {
147 	int rc;
148 
149 	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
150 	if (rc != H_SUCCESS)
151 		dev_err(ibmvtpm->dev,
152 			"%s failed rc=%d\n", __func__, rc);
153 
154 	return rc;
155 }
156 
157 /**
158  * tpm_ibmvtpm_resume - Resume from suspend
159  *
160  * @dev:	device struct
161  *
162  * Return: Always 0.
163  */
164 static int tpm_ibmvtpm_resume(struct device *dev)
165 {
166 	struct tpm_chip *chip = dev_get_drvdata(dev);
167 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
168 	int rc = 0;
169 
170 	do {
171 		if (rc)
172 			msleep(100);
173 		rc = plpar_hcall_norets(H_ENABLE_CRQ,
174 					ibmvtpm->vdev->unit_address);
175 	} while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
176 
177 	if (rc) {
178 		dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
179 		return rc;
180 	}
181 
182 	rc = vio_enable_interrupts(ibmvtpm->vdev);
183 	if (rc) {
184 		dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
185 		return rc;
186 	}
187 
188 	rc = ibmvtpm_crq_send_init(ibmvtpm);
189 	if (rc)
190 		dev_err(dev, "Error send_init rc=%d\n", rc);
191 
192 	return rc;
193 }
194 
195 /**
196  * tpm_ibmvtpm_send() - Send a TPM command
197  * @chip:	tpm chip struct
198  * @buf:	buffer contains data to send
199  * @count:	size of buffer
200  *
201  * Return:
202  *   0 on success,
203  *   -errno on error
204  */
205 static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
206 {
207 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
208 	bool retry = true;
209 	int rc, sig;
210 
211 	if (!ibmvtpm->rtce_buf) {
212 		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
213 		return 0;
214 	}
215 
216 	if (count > ibmvtpm->rtce_size) {
217 		dev_err(ibmvtpm->dev,
218 			"Invalid size in send: count=%zd, rtce_size=%d\n",
219 			count, ibmvtpm->rtce_size);
220 		return -EIO;
221 	}
222 
223 	if (ibmvtpm->tpm_processing_cmd) {
224 		dev_info(ibmvtpm->dev,
225 		         "Need to wait for TPM to finish\n");
226 		/* wait for previous command to finish */
227 		sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
228 		if (sig)
229 			return -EINTR;
230 	}
231 
232 	spin_lock(&ibmvtpm->rtce_lock);
233 	ibmvtpm->res_len = 0;
234 	memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);
235 
236 	/*
237 	 * set the processing flag before the Hcall, since we may get the
238 	 * result (interrupt) before even being able to check rc.
239 	 */
240 	ibmvtpm->tpm_processing_cmd = true;
241 
242 again:
243 	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
244 			IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
245 			count, ibmvtpm->rtce_dma_handle);
246 	if (rc != H_SUCCESS) {
247 		/*
248 		 * H_CLOSED can be returned after LPM resume.  Call
249 		 * tpm_ibmvtpm_resume() to re-enable the CRQ then retry
250 		 * ibmvtpm_send_crq() once before failing.
251 		 */
252 		if (rc == H_CLOSED && retry) {
253 			tpm_ibmvtpm_resume(ibmvtpm->dev);
254 			retry = false;
255 			goto again;
256 		}
257 		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
258 		ibmvtpm->tpm_processing_cmd = false;
259 	}
260 
261 	spin_unlock(&ibmvtpm->rtce_lock);
262 	return 0;
263 }
264 
265 static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
266 {
267 	return;
268 }
269 
270 static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
271 {
272 	return 0;
273 }
274 
275 /**
276  * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size
277  *
278  * @ibmvtpm:	vtpm device struct
279  *
280  * Return:
281  *	0 on success.
282  *	Non-zero on failure.
283  */
284 static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
285 {
286 	int rc;
287 
288 	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
289 			IBMVTPM_VALID_CMD, VTPM_GET_RTCE_BUFFER_SIZE, 0, 0);
290 	if (rc != H_SUCCESS)
291 		dev_err(ibmvtpm->dev,
292 			"ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc);
293 
294 	return rc;
295 }
296 
297 /**
298  * ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version
299  *			   - Note that this is vtpm version and not tpm version
300  *
301  * @ibmvtpm:	vtpm device struct
302  *
303  * Return:
304  *	0 on success.
305  *	Non-zero on failure.
306  */
307 static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
308 {
309 	int rc;
310 
311 	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
312 			IBMVTPM_VALID_CMD, VTPM_GET_VERSION, 0, 0);
313 	if (rc != H_SUCCESS)
314 		dev_err(ibmvtpm->dev,
315 			"ibmvtpm_crq_get_version failed rc=%d\n", rc);
316 
317 	return rc;
318 }
319 
320 /**
321  * ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message
322  * @ibmvtpm:	vtpm device struct
323  *
324  * Return:
325  *	0 on success.
326  *	Non-zero on failure.
327  */
328 static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
329 {
330 	int rc;
331 
332 	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_COMP_CMD);
333 	if (rc != H_SUCCESS)
334 		dev_err(ibmvtpm->dev,
335 			"ibmvtpm_crq_send_init_complete failed rc=%d\n", rc);
336 
337 	return rc;
338 }
339 
340 /**
341  * tpm_ibmvtpm_remove - ibm vtpm remove entry point
342  * @vdev:	vio device struct
343  *
344  * Return: Always 0.
345  */
346 static int tpm_ibmvtpm_remove(struct vio_dev *vdev)
347 {
348 	struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
349 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
350 	int rc = 0;
351 
352 	tpm_chip_unregister(chip);
353 
354 	free_irq(vdev->irq, ibmvtpm);
355 
356 	do {
357 		if (rc)
358 			msleep(100);
359 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
360 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
361 
362 	dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
363 			 CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
364 	free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);
365 
366 	if (ibmvtpm->rtce_buf) {
367 		dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
368 				 ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
369 		kfree(ibmvtpm->rtce_buf);
370 	}
371 
372 	kfree(ibmvtpm);
373 	/* For tpm_ibmvtpm_get_desired_dma */
374 	dev_set_drvdata(&vdev->dev, NULL);
375 
376 	return 0;
377 }
378 
379 /**
380  * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver
381  * @vdev:	vio device struct
382  *
383  * Return:
384  *	Number of bytes the driver needs to DMA map.
385  */
386 static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev)
387 {
388 	struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
389 	struct ibmvtpm_dev *ibmvtpm;
390 
391 	/*
392 	 * ibmvtpm initializes at probe time, so the data we are
393 	 * asking for may not be set yet. Estimate that 4K required
394 	 * for TCE-mapped buffer in addition to CRQ.
395 	 */
396 	if (chip)
397 		ibmvtpm = dev_get_drvdata(&chip->dev);
398 	else
399 		return CRQ_RES_BUF_SIZE + PAGE_SIZE;
400 
401 	return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size;
402 }
403 
404 /**
405  * tpm_ibmvtpm_suspend - Suspend
406  * @dev:	device struct
407  *
408  * Return: Always 0.
409  */
410 static int tpm_ibmvtpm_suspend(struct device *dev)
411 {
412 	struct tpm_chip *chip = dev_get_drvdata(dev);
413 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
414 	int rc = 0;
415 
416 	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
417 			IBMVTPM_VALID_CMD, VTPM_PREPARE_TO_SUSPEND, 0, 0);
418 	if (rc != H_SUCCESS)
419 		dev_err(ibmvtpm->dev,
420 			"tpm_ibmvtpm_suspend failed rc=%d\n", rc);
421 
422 	return rc;
423 }
424 
425 /**
426  * ibmvtpm_reset_crq - Reset CRQ
427  *
428  * @ibmvtpm:	ibm vtpm struct
429  *
430  * Return:
431  *	0 on success.
432  *	Non-zero on failure.
433  */
434 static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
435 {
436 	int rc = 0;
437 
438 	do {
439 		if (rc)
440 			msleep(100);
441 		rc = plpar_hcall_norets(H_FREE_CRQ,
442 					ibmvtpm->vdev->unit_address);
443 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
444 
445 	memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE);
446 	ibmvtpm->crq_queue.index = 0;
447 
448 	return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address,
449 				  ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
450 }
451 
452 static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
453 {
454 	return (status == 0);
455 }
456 
457 static const struct tpm_class_ops tpm_ibmvtpm = {
458 	.recv = tpm_ibmvtpm_recv,
459 	.send = tpm_ibmvtpm_send,
460 	.cancel = tpm_ibmvtpm_cancel,
461 	.status = tpm_ibmvtpm_status,
462 	.req_complete_mask = 0,
463 	.req_complete_val = 0,
464 	.req_canceled = tpm_ibmvtpm_req_canceled,
465 };
466 
467 static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = {
468 	.suspend = tpm_ibmvtpm_suspend,
469 	.resume = tpm_ibmvtpm_resume,
470 };
471 
472 /**
473  * ibmvtpm_crq_get_next - Get next responded crq
474  *
475  * @ibmvtpm:	vtpm device struct
476  *
477  * Return: vtpm crq pointer or NULL.
478  */
479 static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
480 {
481 	struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue;
482 	struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index];
483 
484 	if (crq->valid & VTPM_MSG_RES) {
485 		if (++crq_q->index == crq_q->num_entry)
486 			crq_q->index = 0;
487 		smp_rmb();
488 	} else
489 		crq = NULL;
490 	return crq;
491 }
492 
493 /**
494  * ibmvtpm_crq_process - Process responded crq
495  *
496  * @crq:	crq to be processed
497  * @ibmvtpm:	vtpm device struct
498  *
499  */
500 static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
501 				struct ibmvtpm_dev *ibmvtpm)
502 {
503 	int rc = 0;
504 
505 	switch (crq->valid) {
506 	case VALID_INIT_CRQ:
507 		switch (crq->msg) {
508 		case INIT_CRQ_RES:
509 			dev_info(ibmvtpm->dev, "CRQ initialized\n");
510 			rc = ibmvtpm_crq_send_init_complete(ibmvtpm);
511 			if (rc)
512 				dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc);
513 			return;
514 		case INIT_CRQ_COMP_RES:
515 			dev_info(ibmvtpm->dev,
516 				 "CRQ initialization completed\n");
517 			return;
518 		default:
519 			dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
520 			return;
521 		}
522 	case IBMVTPM_VALID_CMD:
523 		switch (crq->msg) {
524 		case VTPM_GET_RTCE_BUFFER_SIZE_RES:
525 			if (be16_to_cpu(crq->len) <= 0) {
526 				dev_err(ibmvtpm->dev, "Invalid rtce size\n");
527 				return;
528 			}
529 			ibmvtpm->rtce_size = be16_to_cpu(crq->len);
530 			ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
531 						    GFP_ATOMIC);
532 			if (!ibmvtpm->rtce_buf) {
533 				dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
534 				return;
535 			}
536 
537 			ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
538 				ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
539 				DMA_BIDIRECTIONAL);
540 
541 			if (dma_mapping_error(ibmvtpm->dev,
542 					      ibmvtpm->rtce_dma_handle)) {
543 				kfree(ibmvtpm->rtce_buf);
544 				ibmvtpm->rtce_buf = NULL;
545 				dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
546 			}
547 
548 			return;
549 		case VTPM_GET_VERSION_RES:
550 			ibmvtpm->vtpm_version = be32_to_cpu(crq->data);
551 			return;
552 		case VTPM_TPM_COMMAND_RES:
553 			/* len of the data in rtce buffer */
554 			ibmvtpm->res_len = be16_to_cpu(crq->len);
555 			ibmvtpm->tpm_processing_cmd = false;
556 			wake_up_interruptible(&ibmvtpm->wq);
557 			return;
558 		default:
559 			return;
560 		}
561 	}
562 	return;
563 }
564 
565 /**
566  * ibmvtpm_interrupt -	Interrupt handler
567  *
568  * @irq:		irq number to handle
569  * @vtpm_instance:	vtpm that received interrupt
570  *
571  * Returns:
572  *	IRQ_HANDLED
573  **/
574 static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
575 {
576 	struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
577 	struct ibmvtpm_crq *crq;
578 
579 	/* while loop is needed for initial setup (get version and
580 	 * get rtce_size). There should be only one tpm request at any
581 	 * given time.
582 	 */
583 	while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
584 		ibmvtpm_crq_process(crq, ibmvtpm);
585 		wake_up_interruptible(&ibmvtpm->crq_queue.wq);
586 		crq->valid = 0;
587 		smp_wmb();
588 	}
589 
590 	return IRQ_HANDLED;
591 }
592 
593 /**
594  * tpm_ibmvtpm_probe - ibm vtpm initialize entry point
595  *
596  * @vio_dev:	vio device struct
597  * @id:		vio device id struct
598  *
599  * Return:
600  *	0 on success.
601  *	Non-zero on failure.
602  */
603 static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
604 				   const struct vio_device_id *id)
605 {
606 	struct ibmvtpm_dev *ibmvtpm;
607 	struct device *dev = &vio_dev->dev;
608 	struct ibmvtpm_crq_queue *crq_q;
609 	struct tpm_chip *chip;
610 	int rc = -ENOMEM, rc1;
611 
612 	chip = tpmm_chip_alloc(dev, &tpm_ibmvtpm);
613 	if (IS_ERR(chip))
614 		return PTR_ERR(chip);
615 
616 	ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
617 	if (!ibmvtpm) {
618 		dev_err(dev, "kzalloc for ibmvtpm failed\n");
619 		goto cleanup;
620 	}
621 
622 	ibmvtpm->dev = dev;
623 	ibmvtpm->vdev = vio_dev;
624 
625 	crq_q = &ibmvtpm->crq_queue;
626 	crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
627 	if (!crq_q->crq_addr) {
628 		dev_err(dev, "Unable to allocate memory for crq_addr\n");
629 		goto cleanup;
630 	}
631 
632 	crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
633 	init_waitqueue_head(&crq_q->wq);
634 	ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
635 						 CRQ_RES_BUF_SIZE,
636 						 DMA_BIDIRECTIONAL);
637 
638 	if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
639 		dev_err(dev, "dma mapping failed\n");
640 		goto cleanup;
641 	}
642 
643 	rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
644 				ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
645 	if (rc == H_RESOURCE)
646 		rc = ibmvtpm_reset_crq(ibmvtpm);
647 
648 	if (rc) {
649 		dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
650 		goto reg_crq_cleanup;
651 	}
652 
653 	rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
654 			 tpm_ibmvtpm_driver_name, ibmvtpm);
655 	if (rc) {
656 		dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq);
657 		goto init_irq_cleanup;
658 	}
659 
660 	rc = vio_enable_interrupts(vio_dev);
661 	if (rc) {
662 		dev_err(dev, "Error %d enabling interrupts\n", rc);
663 		goto init_irq_cleanup;
664 	}
665 
666 	init_waitqueue_head(&ibmvtpm->wq);
667 
668 	crq_q->index = 0;
669 
670 	dev_set_drvdata(&chip->dev, ibmvtpm);
671 
672 	spin_lock_init(&ibmvtpm->rtce_lock);
673 
674 	rc = ibmvtpm_crq_send_init(ibmvtpm);
675 	if (rc)
676 		goto init_irq_cleanup;
677 
678 	rc = ibmvtpm_crq_get_version(ibmvtpm);
679 	if (rc)
680 		goto init_irq_cleanup;
681 
682 	rc = ibmvtpm_crq_get_rtce_size(ibmvtpm);
683 	if (rc)
684 		goto init_irq_cleanup;
685 
686 	if (!strcmp(id->compat, "IBM,vtpm20")) {
687 		chip->flags |= TPM_CHIP_FLAG_TPM2;
688 		rc = tpm2_get_cc_attrs_tbl(chip);
689 		if (rc)
690 			goto init_irq_cleanup;
691 	}
692 
693 	if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
694 				ibmvtpm->rtce_buf != NULL,
695 				HZ)) {
696 		dev_err(dev, "CRQ response timed out\n");
697 		goto init_irq_cleanup;
698 	}
699 
700 	return tpm_chip_register(chip);
701 init_irq_cleanup:
702 	do {
703 		rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
704 	} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
705 reg_crq_cleanup:
706 	dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
707 			 DMA_BIDIRECTIONAL);
708 cleanup:
709 	if (ibmvtpm) {
710 		if (crq_q->crq_addr)
711 			free_page((unsigned long)crq_q->crq_addr);
712 		kfree(ibmvtpm);
713 	}
714 
715 	return rc;
716 }
717 
718 static struct vio_driver ibmvtpm_driver = {
719 	.id_table	 = tpm_ibmvtpm_device_table,
720 	.probe		 = tpm_ibmvtpm_probe,
721 	.remove		 = tpm_ibmvtpm_remove,
722 	.get_desired_dma = tpm_ibmvtpm_get_desired_dma,
723 	.name		 = tpm_ibmvtpm_driver_name,
724 	.pm		 = &tpm_ibmvtpm_pm_ops,
725 };
726 
727 /**
728  * ibmvtpm_module_init - Initialize ibm vtpm module.
729  *
730  *
731  * Return:
732  *	0 on success.
733  *	Non-zero on failure.
734  */
735 static int __init ibmvtpm_module_init(void)
736 {
737 	return vio_register_driver(&ibmvtpm_driver);
738 }
739 
740 /**
741  * ibmvtpm_module_exit - Tear down ibm vtpm module.
742  */
743 static void __exit ibmvtpm_module_exit(void)
744 {
745 	vio_unregister_driver(&ibmvtpm_driver);
746 }
747 
748 module_init(ibmvtpm_module_init);
749 module_exit(ibmvtpm_module_exit);
750 
751 MODULE_AUTHOR("adlai@us.ibm.com");
752 MODULE_DESCRIPTION("IBM vTPM Driver");
753 MODULE_VERSION("1.0");
754 MODULE_LICENSE("GPL");
755