xref: /linux/drivers/char/tpm/tpm_crb.c (revision e3966940559d52aa1800a008dcfeec218dd31f88)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Intel Corporation
4  *
5  * Authors:
6  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7  *
8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9  *
10  * This device driver implements the TPM interface as defined in
11  * the TCG CRB 2.0 TPM specification.
12  */
13 
14 #include <linux/acpi.h>
15 #include <linux/highmem.h>
16 #include <linux/rculist.h>
17 #include <linux/module.h>
18 #include <linux/pm_runtime.h>
19 #ifdef CONFIG_ARM64
20 #include <linux/arm-smccc.h>
21 #endif
22 #include "tpm_crb_ffa.h"
23 #include "tpm.h"
24 
25 #define ACPI_SIG_TPM2 "TPM2"
26 #define TPM_CRB_MAX_RESOURCES 3
27 
28 static const guid_t crb_acpi_start_guid =
29 	GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
30 		  0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4);
31 
32 enum crb_defaults {
33 	CRB_ACPI_START_REVISION_ID = 1,
34 	CRB_ACPI_START_INDEX = 1,
35 };
36 
37 enum crb_loc_ctrl {
38 	CRB_LOC_CTRL_REQUEST_ACCESS	= BIT(0),
39 	CRB_LOC_CTRL_RELINQUISH		= BIT(1),
40 };
41 
42 enum crb_loc_state {
43 	CRB_LOC_STATE_LOC_ASSIGNED	= BIT(1),
44 	CRB_LOC_STATE_TPM_REG_VALID_STS	= BIT(7),
45 };
46 
47 enum crb_ctrl_req {
48 	CRB_CTRL_REQ_CMD_READY	= BIT(0),
49 	CRB_CTRL_REQ_GO_IDLE	= BIT(1),
50 };
51 
52 enum crb_ctrl_sts {
53 	CRB_CTRL_STS_ERROR	= BIT(0),
54 	CRB_CTRL_STS_TPM_IDLE	= BIT(1),
55 };
56 
57 enum crb_start {
58 	CRB_START_INVOKE	= BIT(0),
59 };
60 
61 enum crb_cancel {
62 	CRB_CANCEL_INVOKE	= BIT(0),
63 };
64 
65 struct crb_regs_head {
66 	u32 loc_state;
67 	u32 reserved1;
68 	u32 loc_ctrl;
69 	u32 loc_sts;
70 	u8 reserved2[32];
71 	u64 intf_id;
72 	u64 ctrl_ext;
73 } __packed;
74 
75 struct crb_regs_tail {
76 	u32 ctrl_req;
77 	u32 ctrl_sts;
78 	u32 ctrl_cancel;
79 	u32 ctrl_start;
80 	u32 ctrl_int_enable;
81 	u32 ctrl_int_sts;
82 	u32 ctrl_cmd_size;
83 	u32 ctrl_cmd_pa_low;
84 	u32 ctrl_cmd_pa_high;
85 	u32 ctrl_rsp_size;
86 	u64 ctrl_rsp_pa;
87 } __packed;
88 
89 enum crb_status {
90 	CRB_DRV_STS_COMPLETE	= BIT(0),
91 };
92 
93 struct crb_priv {
94 	u32 sm;
95 	const char *hid;
96 	struct crb_regs_head __iomem *regs_h;
97 	struct crb_regs_tail __iomem *regs_t;
98 	u8 __iomem *cmd;
99 	u8 __iomem *rsp;
100 	u32 cmd_size;
101 	u32 smc_func_id;
102 	u32 __iomem *pluton_start_addr;
103 	u32 __iomem *pluton_reply_addr;
104 	u8 ffa_flags;
105 	u8 ffa_attributes;
106 };
107 
108 struct tpm2_crb_smc {
109 	u32 interrupt;
110 	u8 interrupt_flags;
111 	u8 op_flags;
112 	u16 reserved2;
113 	u32 smc_func_id;
114 };
115 
116 /* CRB over FFA start method parameters in TCG2 ACPI table */
117 struct tpm2_crb_ffa {
118 	u8 flags;
119 	u8 attributes;
120 	u16 partition_id;
121 	u8 reserved[8];
122 };
123 
124 struct tpm2_crb_pluton {
125 	u64 start_addr;
126 	u64 reply_addr;
127 };
128 
129 /*
130  * Returns true if the start method supports idle.
131  */
132 static inline bool tpm_crb_has_idle(u32 start_method)
133 {
134 	return !(start_method == ACPI_TPM2_START_METHOD ||
135 	       start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD ||
136 	       start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
137 }
138 
139 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
140 				unsigned long timeout)
141 {
142 	ktime_t start;
143 	ktime_t stop;
144 
145 	start = ktime_get();
146 	stop = ktime_add(start, ms_to_ktime(timeout));
147 
148 	do {
149 		if ((ioread32(reg) & mask) == value)
150 			return true;
151 
152 		usleep_range(50, 100);
153 	} while (ktime_before(ktime_get(), stop));
154 
155 	return ((ioread32(reg) & mask) == value);
156 }
157 
158 static int crb_try_pluton_doorbell(struct crb_priv *priv, bool wait_for_complete)
159 {
160 	if (priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
161 		return 0;
162 
163 	if (!crb_wait_for_reg_32(priv->pluton_reply_addr, ~0, 1, TPM2_TIMEOUT_C))
164 		return -ETIME;
165 
166 	iowrite32(1, priv->pluton_start_addr);
167 	if (wait_for_complete == false)
168 		return 0;
169 
170 	if (!crb_wait_for_reg_32(priv->pluton_start_addr,
171 				 0xffffffff, 0, 200))
172 		return -ETIME;
173 
174 	return 0;
175 }
176 
177 /**
178  * __crb_go_idle - request tpm crb device to go the idle state
179  *
180  * @dev:  crb device
181  * @priv: crb private data
182  *
183  * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
184  * The device should respond within TIMEOUT_C by clearing the bit.
185  * Anyhow, we do not wait here as a consequent CMD_READY request
186  * will be handled correctly even if idle was not completed.
187  *
188  * The function does nothing for devices with ACPI-start method
189  * or SMC-start method.
190  *
191  * Return: 0 always
192  */
193 static int __crb_go_idle(struct device *dev, struct crb_priv *priv, int loc)
194 {
195 	int rc;
196 
197 	if (!tpm_crb_has_idle(priv->sm))
198 		return 0;
199 
200 	iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
201 
202 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
203 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, loc);
204 		if (rc)
205 			return rc;
206 	}
207 
208 	rc = crb_try_pluton_doorbell(priv, true);
209 	if (rc)
210 		return rc;
211 
212 	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
213 				 CRB_CTRL_REQ_GO_IDLE/* mask */,
214 				 0, /* value */
215 				 TPM2_TIMEOUT_C)) {
216 		dev_warn(dev, "goIdle timed out\n");
217 		return -ETIME;
218 	}
219 
220 	return 0;
221 }
222 
223 static int crb_go_idle(struct tpm_chip *chip)
224 {
225 	struct device *dev = &chip->dev;
226 	struct crb_priv *priv = dev_get_drvdata(dev);
227 
228 	return __crb_go_idle(dev, priv, chip->locality);
229 }
230 
231 /**
232  * __crb_cmd_ready - request tpm crb device to enter ready state
233  *
234  * @dev:  crb device
235  * @priv: crb private data
236  *
237  * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
238  * and poll till the device acknowledge it by clearing the bit.
239  * The device should respond within TIMEOUT_C.
240  *
241  * The function does nothing for devices with ACPI-start method
242  * or SMC-start method.
243  *
244  * Return: 0 on success -ETIME on timeout;
245  */
246 static int __crb_cmd_ready(struct device *dev, struct crb_priv *priv, int loc)
247 {
248 	int rc;
249 
250 	if (!tpm_crb_has_idle(priv->sm))
251 		return 0;
252 
253 	iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
254 
255 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
256 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, loc);
257 		if (rc)
258 			return rc;
259 	}
260 
261 	rc = crb_try_pluton_doorbell(priv, true);
262 	if (rc)
263 		return rc;
264 
265 	if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
266 				 CRB_CTRL_REQ_CMD_READY /* mask */,
267 				 0, /* value */
268 				 TPM2_TIMEOUT_C)) {
269 		dev_warn(dev, "cmdReady timed out\n");
270 		return -ETIME;
271 	}
272 
273 	return 0;
274 }
275 
276 static int crb_cmd_ready(struct tpm_chip *chip)
277 {
278 	struct device *dev = &chip->dev;
279 	struct crb_priv *priv = dev_get_drvdata(dev);
280 
281 	return __crb_cmd_ready(dev, priv, chip->locality);
282 }
283 
284 static int __crb_request_locality(struct device *dev,
285 				  struct crb_priv *priv, int loc)
286 {
287 	u32 value = CRB_LOC_STATE_LOC_ASSIGNED | CRB_LOC_STATE_TPM_REG_VALID_STS;
288 	int rc;
289 
290 	if (!priv->regs_h)
291 		return 0;
292 
293 	iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
294 
295 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
296 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);
297 		if (rc)
298 			return rc;
299 	}
300 
301 	if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,
302 				 TPM2_TIMEOUT_C)) {
303 		dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
304 		return -ETIME;
305 	}
306 
307 	return 0;
308 }
309 
310 static int crb_request_locality(struct tpm_chip *chip, int loc)
311 {
312 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
313 
314 	return __crb_request_locality(&chip->dev, priv, loc);
315 }
316 
317 static int __crb_relinquish_locality(struct device *dev,
318 				     struct crb_priv *priv, int loc)
319 {
320 	u32 mask = CRB_LOC_STATE_LOC_ASSIGNED | CRB_LOC_STATE_TPM_REG_VALID_STS;
321 	u32 value = CRB_LOC_STATE_TPM_REG_VALID_STS;
322 	int rc;
323 
324 	if (!priv->regs_h)
325 		return 0;
326 
327 	iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
328 
329 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
330 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);
331 		if (rc)
332 			return rc;
333 	}
334 
335 	if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,
336 				 TPM2_TIMEOUT_C)) {
337 		dev_warn(dev, "TPM_LOC_STATE_x.Relinquish timed out\n");
338 		return -ETIME;
339 	}
340 
341 	return 0;
342 }
343 
344 static int crb_relinquish_locality(struct tpm_chip *chip, int loc)
345 {
346 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
347 
348 	return __crb_relinquish_locality(&chip->dev, priv, loc);
349 }
350 
351 static u8 crb_status(struct tpm_chip *chip)
352 {
353 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
354 	u8 sts = 0;
355 
356 	if ((ioread32(&priv->regs_t->ctrl_start) & CRB_START_INVOKE) !=
357 	    CRB_START_INVOKE)
358 		sts |= CRB_DRV_STS_COMPLETE;
359 
360 	return sts;
361 }
362 
363 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
364 {
365 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
366 	unsigned int expected;
367 
368 	/* A sanity check that the upper layer wants to get at least the header
369 	 * as that is the minimum size for any TPM response.
370 	 */
371 	if (count < TPM_HEADER_SIZE)
372 		return -EIO;
373 
374 	/* If this bit is set, according to the spec, the TPM is in
375 	 * unrecoverable condition.
376 	 */
377 	if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
378 		return -EIO;
379 
380 	/* Read the first 8 bytes in order to get the length of the response.
381 	 * We read exactly a quad word in order to make sure that the remaining
382 	 * reads will be aligned.
383 	 */
384 	memcpy_fromio(buf, priv->rsp, 8);
385 
386 	expected = be32_to_cpup((__be32 *)&buf[2]);
387 	if (expected > count || expected < TPM_HEADER_SIZE)
388 		return -EIO;
389 
390 	memcpy_fromio(&buf[8], &priv->rsp[8], expected - 8);
391 
392 	return expected;
393 }
394 
395 static int crb_do_acpi_start(struct tpm_chip *chip)
396 {
397 	union acpi_object *obj;
398 	int rc;
399 
400 	obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
401 				&crb_acpi_start_guid,
402 				CRB_ACPI_START_REVISION_ID,
403 				CRB_ACPI_START_INDEX,
404 				NULL);
405 	if (!obj)
406 		return -ENXIO;
407 	rc = obj->integer.value == 0 ? 0 : -ENXIO;
408 	ACPI_FREE(obj);
409 	return rc;
410 }
411 
412 #ifdef CONFIG_ARM64
413 /*
414  * This is a TPM Command Response Buffer start method that invokes a
415  * Secure Monitor Call to requrest the firmware to execute or cancel
416  * a TPM 2.0 command.
417  */
418 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
419 {
420 	struct arm_smccc_res res;
421 
422 	arm_smccc_smc(func_id, 0, 0, 0, 0, 0, 0, 0, &res);
423 	if (res.a0 != 0) {
424 		dev_err(dev,
425 			FW_BUG "tpm_crb_smc_start() returns res.a0 = 0x%lx\n",
426 			res.a0);
427 		return -EIO;
428 	}
429 
430 	return 0;
431 }
432 #else
433 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
434 {
435 	dev_err(dev, FW_BUG "tpm_crb: incorrect start method\n");
436 	return -EINVAL;
437 }
438 #endif
439 
440 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
441 {
442 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
443 	int rc = 0;
444 
445 	/* Zero the cancel register so that the next command will not get
446 	 * canceled.
447 	 */
448 	iowrite32(0, &priv->regs_t->ctrl_cancel);
449 
450 	if (len > priv->cmd_size) {
451 		dev_err(&chip->dev, "invalid command count value %zd %d\n",
452 			len, priv->cmd_size);
453 		return -E2BIG;
454 	}
455 
456 	/* Seems to be necessary for every command */
457 	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
458 		__crb_cmd_ready(&chip->dev, priv, chip->locality);
459 
460 	memcpy_toio(priv->cmd, buf, len);
461 
462 	/* Make sure that cmd is populated before issuing start. */
463 	wmb();
464 
465 	/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
466 	 * report only ACPI start but in practice seems to require both
467 	 * CRB start, hence invoking CRB start method if hid == MSFT0101.
468 	 */
469 	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||
470 	    priv->sm == ACPI_TPM2_MEMORY_MAPPED ||
471 	    !strcmp(priv->hid, "MSFT0101"))
472 		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
473 
474 	if (priv->sm == ACPI_TPM2_START_METHOD ||
475 	    priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
476 		rc = crb_do_acpi_start(chip);
477 
478 	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
479 		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
480 		rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
481 	}
482 
483 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
484 		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
485 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);
486 	}
487 
488 	if (rc)
489 		return rc;
490 
491 	return crb_try_pluton_doorbell(priv, false);
492 }
493 
494 static void crb_cancel(struct tpm_chip *chip)
495 {
496 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
497 	int rc;
498 
499 	iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
500 
501 	if ((priv->sm == ACPI_TPM2_START_METHOD ||
502 	     priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) &&
503 	     crb_do_acpi_start(chip))
504 		dev_err(&chip->dev, "ACPI Start failed\n");
505 
506 	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
507 		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);
508 		if (rc)
509 			dev_err(&chip->dev, "FF-A Start failed\n");
510 	}
511 }
512 
513 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
514 {
515 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
516 	u32 cancel = ioread32(&priv->regs_t->ctrl_cancel);
517 
518 	return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
519 }
520 
521 static const struct tpm_class_ops tpm_crb = {
522 	.flags = TPM_OPS_AUTO_STARTUP,
523 	.status = crb_status,
524 	.recv = crb_recv,
525 	.send = crb_send,
526 	.cancel = crb_cancel,
527 	.req_canceled = crb_req_canceled,
528 	.go_idle  = crb_go_idle,
529 	.cmd_ready = crb_cmd_ready,
530 	.request_locality = crb_request_locality,
531 	.relinquish_locality = crb_relinquish_locality,
532 	.req_complete_mask = CRB_DRV_STS_COMPLETE,
533 	.req_complete_val = CRB_DRV_STS_COMPLETE,
534 };
535 
536 static int crb_check_resource(struct acpi_resource *ares, void *data)
537 {
538 	struct resource *iores_array = data;
539 	struct resource_win win;
540 	struct resource *res = &(win.res);
541 	int i;
542 
543 	if (acpi_dev_resource_memory(ares, res) ||
544 	    acpi_dev_resource_address_space(ares, &win)) {
545 		for (i = 0; i < TPM_CRB_MAX_RESOURCES + 1; ++i) {
546 			if (resource_type(iores_array + i) != IORESOURCE_MEM) {
547 				iores_array[i] = *res;
548 				iores_array[i].name = NULL;
549 				break;
550 			}
551 		}
552 	}
553 
554 	return 1;
555 }
556 
557 static void __iomem *crb_map_res(struct device *dev, struct resource *iores,
558 				 void __iomem **iobase_ptr, u64 start, u32 size)
559 {
560 	struct resource new_res = {
561 		.start	= start,
562 		.end	= start + size - 1,
563 		.flags	= IORESOURCE_MEM,
564 	};
565 
566 	/* Detect a 64 bit address on a 32 bit system */
567 	if (start != new_res.start)
568 		return IOMEM_ERR_PTR(-EINVAL);
569 
570 	if (!iores)
571 		return devm_ioremap_resource(dev, &new_res);
572 
573 	if (!*iobase_ptr) {
574 		*iobase_ptr = devm_ioremap_resource(dev, iores);
575 		if (IS_ERR(*iobase_ptr))
576 			return *iobase_ptr;
577 	}
578 
579 	return *iobase_ptr + (new_res.start - iores->start);
580 }
581 
582 /*
583  * Work around broken BIOSs that return inconsistent values from the ACPI
584  * region vs the registers. Trust the ACPI region. Such broken systems
585  * probably cannot send large TPM commands since the buffer will be truncated.
586  */
587 static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res,
588 			      u64 start, u64 size)
589 {
590 	if (io_res->start > start || io_res->end < start)
591 		return size;
592 
593 	if (start + size - 1 <= io_res->end)
594 		return size;
595 
596 	dev_err(dev,
597 		FW_BUG "ACPI region does not cover the entire command/response buffer. %pr vs %llx %llx\n",
598 		io_res, start, size);
599 
600 	return io_res->end - start + 1;
601 }
602 
603 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
604 		      struct acpi_table_tpm2 *buf)
605 {
606 	struct list_head acpi_resource_list;
607 	struct resource iores_array[TPM_CRB_MAX_RESOURCES + 1] = { {0} };
608 	void __iomem *iobase_array[TPM_CRB_MAX_RESOURCES] = {NULL};
609 	struct device *dev = &device->dev;
610 	struct resource *iores;
611 	void __iomem **iobase_ptr;
612 	int i;
613 	u32 pa_high, pa_low;
614 	u64 cmd_pa;
615 	u32 cmd_size;
616 	__le64 __rsp_pa;
617 	u64 rsp_pa;
618 	u32 rsp_size;
619 	int ret;
620 
621 	/*
622 	 * Pluton sometimes does not define ACPI memory regions.
623 	 * Mapping is then done in crb_map_pluton
624 	 */
625 	if (priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
626 		INIT_LIST_HEAD(&acpi_resource_list);
627 		ret = acpi_dev_get_resources(device, &acpi_resource_list,
628 					     crb_check_resource, iores_array);
629 		if (ret < 0)
630 			return ret;
631 		acpi_dev_free_resource_list(&acpi_resource_list);
632 
633 		if (resource_type(iores_array) != IORESOURCE_MEM) {
634 			dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
635 			return -EINVAL;
636 		} else if (resource_type(iores_array + TPM_CRB_MAX_RESOURCES) ==
637 			   IORESOURCE_MEM) {
638 			dev_warn(dev, "TPM2 ACPI table defines too many memory resources\n");
639 			memset(iores_array + TPM_CRB_MAX_RESOURCES,
640 			       0, sizeof(*iores_array));
641 			iores_array[TPM_CRB_MAX_RESOURCES].flags = 0;
642 		}
643 	}
644 
645 	iores = NULL;
646 	iobase_ptr = NULL;
647 	for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
648 		if (buf->control_address >= iores_array[i].start &&
649 		    buf->control_address + sizeof(struct crb_regs_tail) - 1 <=
650 		    iores_array[i].end) {
651 			iores = iores_array + i;
652 			iobase_ptr = iobase_array + i;
653 			break;
654 		}
655 	}
656 
657 	priv->regs_t = crb_map_res(dev, iores, iobase_ptr, buf->control_address,
658 				   sizeof(struct crb_regs_tail));
659 
660 	if (IS_ERR(priv->regs_t))
661 		return PTR_ERR(priv->regs_t);
662 
663 	/* The ACPI IO region starts at the head area and continues to include
664 	 * the control area, as one nice sane region except for some older
665 	 * stuff that puts the control area outside the ACPI IO region.
666 	 */
667 	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||
668 	    priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA ||
669 	    priv->sm == ACPI_TPM2_MEMORY_MAPPED) {
670 		if (iores &&
671 		    buf->control_address == iores->start +
672 		    sizeof(*priv->regs_h))
673 			priv->regs_h = *iobase_ptr;
674 		else
675 			dev_warn(dev, FW_BUG "Bad ACPI memory layout");
676 	}
677 
678 	ret = __crb_request_locality(dev, priv, 0);
679 	if (ret)
680 		return ret;
681 
682 	/*
683 	 * PTT HW bug w/a: wake up the device to access
684 	 * possibly not retained registers.
685 	 */
686 	ret = __crb_cmd_ready(dev, priv, 0);
687 	if (ret)
688 		goto out_relinquish_locality;
689 
690 	pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high);
691 	pa_low  = ioread32(&priv->regs_t->ctrl_cmd_pa_low);
692 	cmd_pa = ((u64)pa_high << 32) | pa_low;
693 	cmd_size = ioread32(&priv->regs_t->ctrl_cmd_size);
694 
695 	iores = NULL;
696 	iobase_ptr = NULL;
697 	for (i = 0; iores_array[i].end; ++i) {
698 		if (cmd_pa >= iores_array[i].start &&
699 		    cmd_pa <= iores_array[i].end) {
700 			iores = iores_array + i;
701 			iobase_ptr = iobase_array + i;
702 			break;
703 		}
704 	}
705 
706 	if (iores)
707 		cmd_size = crb_fixup_cmd_size(dev, iores, cmd_pa, cmd_size);
708 
709 	dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
710 		pa_high, pa_low, cmd_size);
711 
712 	priv->cmd = crb_map_res(dev, iores, iobase_ptr,	cmd_pa, cmd_size);
713 	if (IS_ERR(priv->cmd)) {
714 		ret = PTR_ERR(priv->cmd);
715 		goto out;
716 	}
717 
718 	memcpy_fromio(&__rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8);
719 	rsp_pa = le64_to_cpu(__rsp_pa);
720 	rsp_size = ioread32(&priv->regs_t->ctrl_rsp_size);
721 
722 	iores = NULL;
723 	iobase_ptr = NULL;
724 	for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
725 		if (rsp_pa >= iores_array[i].start &&
726 		    rsp_pa <= iores_array[i].end) {
727 			iores = iores_array + i;
728 			iobase_ptr = iobase_array + i;
729 			break;
730 		}
731 	}
732 
733 	if (iores)
734 		rsp_size = crb_fixup_cmd_size(dev, iores, rsp_pa, rsp_size);
735 
736 	if (cmd_pa != rsp_pa) {
737 		priv->rsp = crb_map_res(dev, iores, iobase_ptr,
738 					rsp_pa, rsp_size);
739 		ret = PTR_ERR_OR_ZERO(priv->rsp);
740 		goto out;
741 	}
742 
743 	/* According to the PTP specification, overlapping command and response
744 	 * buffer sizes must be identical.
745 	 */
746 	if (cmd_size != rsp_size) {
747 		dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
748 		ret = -EINVAL;
749 		goto out;
750 	}
751 
752 	priv->rsp = priv->cmd;
753 
754 out:
755 	if (!ret)
756 		priv->cmd_size = cmd_size;
757 
758 	__crb_go_idle(dev, priv, 0);
759 
760 out_relinquish_locality:
761 
762 	__crb_relinquish_locality(dev, priv, 0);
763 
764 	return ret;
765 }
766 
767 static int crb_map_pluton(struct device *dev, struct crb_priv *priv,
768 	       struct acpi_table_tpm2 *buf, struct tpm2_crb_pluton *crb_pluton)
769 {
770 	priv->pluton_start_addr = crb_map_res(dev, NULL, NULL,
771 					      crb_pluton->start_addr, 4);
772 	if (IS_ERR(priv->pluton_start_addr))
773 		return PTR_ERR(priv->pluton_start_addr);
774 
775 	priv->pluton_reply_addr = crb_map_res(dev, NULL, NULL,
776 					      crb_pluton->reply_addr, 4);
777 	if (IS_ERR(priv->pluton_reply_addr))
778 		return PTR_ERR(priv->pluton_reply_addr);
779 
780 	return 0;
781 }
782 
783 static int crb_acpi_add(struct acpi_device *device)
784 {
785 	struct acpi_table_tpm2 *buf;
786 	struct crb_priv *priv;
787 	struct tpm_chip *chip;
788 	struct device *dev = &device->dev;
789 	struct tpm2_crb_smc *crb_smc;
790 	struct tpm2_crb_ffa *crb_ffa;
791 	struct tpm2_crb_pluton *crb_pluton;
792 	acpi_status status;
793 	u32 sm;
794 	int rc;
795 
796 	status = acpi_get_table(ACPI_SIG_TPM2, 1,
797 				(struct acpi_table_header **) &buf);
798 	if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
799 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
800 		return -EINVAL;
801 	}
802 
803 	/* Should the FIFO driver handle this? */
804 	sm = buf->start_method;
805 	if (sm == ACPI_TPM2_MEMORY_MAPPED) {
806 		rc = -ENODEV;
807 		goto out;
808 	}
809 
810 	priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
811 	if (!priv) {
812 		rc = -ENOMEM;
813 		goto out;
814 	}
815 
816 	if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
817 		if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
818 			dev_err(dev,
819 				FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
820 				buf->header.length,
821 				ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
822 			rc = -EINVAL;
823 			goto out;
824 		}
825 		crb_smc = ACPI_ADD_PTR(struct tpm2_crb_smc, buf, sizeof(*buf));
826 		priv->smc_func_id = crb_smc->smc_func_id;
827 	}
828 
829 	if (sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {
830 		if (buf->header.length < (sizeof(*buf) + sizeof(*crb_ffa))) {
831 			dev_err(dev,
832 				FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
833 				buf->header.length,
834 				ACPI_TPM2_CRB_WITH_ARM_FFA);
835 			rc = -EINVAL;
836 			goto out;
837 		}
838 		crb_ffa = ACPI_ADD_PTR(struct tpm2_crb_ffa, buf, sizeof(*buf));
839 		priv->ffa_flags = crb_ffa->flags;
840 		priv->ffa_attributes = crb_ffa->attributes;
841 		rc = tpm_crb_ffa_init();
842 		if (rc) {
843 			/* If FF-A driver is not available yet, request probe retry */
844 			if (rc == -ENOENT)
845 				rc = -EPROBE_DEFER;
846 			goto out;
847 		}
848 	}
849 
850 	if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
851 		if (buf->header.length < (sizeof(*buf) + sizeof(*crb_pluton))) {
852 			dev_err(dev,
853 				FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
854 				buf->header.length,
855 				ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON);
856 			rc = -EINVAL;
857 			goto out;
858 		}
859 		crb_pluton = ACPI_ADD_PTR(struct tpm2_crb_pluton, buf, sizeof(*buf));
860 		rc = crb_map_pluton(dev, priv, buf, crb_pluton);
861 		if (rc)
862 			goto out;
863 	}
864 
865 	priv->sm = sm;
866 	priv->hid = acpi_device_hid(device);
867 
868 	rc = crb_map_io(device, priv, buf);
869 	if (rc)
870 		goto out;
871 
872 	chip = tpmm_chip_alloc(dev, &tpm_crb);
873 	if (IS_ERR(chip)) {
874 		rc = PTR_ERR(chip);
875 		goto out;
876 	}
877 
878 	dev_set_drvdata(&chip->dev, priv);
879 	chip->acpi_dev_handle = device->handle;
880 	chip->flags = TPM_CHIP_FLAG_TPM2;
881 
882 	rc = tpm_chip_bootstrap(chip);
883 	if (rc)
884 		goto out;
885 
886 #ifdef CONFIG_X86
887 	/* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */
888 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
889 	    priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
890 		dev_info(dev, "Disabling hwrng\n");
891 		chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED;
892 	}
893 #endif /* CONFIG_X86 */
894 
895 	rc = tpm_chip_register(chip);
896 
897 out:
898 	acpi_put_table((struct acpi_table_header *)buf);
899 	return rc;
900 }
901 
902 static void crb_acpi_remove(struct acpi_device *device)
903 {
904 	struct device *dev = &device->dev;
905 	struct tpm_chip *chip = dev_get_drvdata(dev);
906 
907 	tpm_chip_unregister(chip);
908 }
909 
910 static const struct dev_pm_ops crb_pm = {
911 	SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
912 };
913 
914 static const struct acpi_device_id crb_device_ids[] = {
915 	{"MSFT0101", 0},
916 	{"", 0},
917 };
918 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
919 
920 static struct acpi_driver crb_acpi_driver = {
921 	.name = "tpm_crb",
922 	.ids = crb_device_ids,
923 	.ops = {
924 		.add = crb_acpi_add,
925 		.remove = crb_acpi_remove,
926 	},
927 	.drv = {
928 		.pm = &crb_pm,
929 	},
930 };
931 
932 module_acpi_driver(crb_acpi_driver);
933 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
934 MODULE_DESCRIPTION("TPM2 Driver");
935 MODULE_VERSION("0.1");
936 MODULE_LICENSE("GPL");
937