1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2014 Intel Corporation
6 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
8 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
10 * This device driver implements the TPM interface as defined in
11 * the TCG CRB 2.0 TPM specification.
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>
20 #include <linux/arm-smccc.h>
24 #define ACPI_SIG_TPM2 "TPM2"
25 #define TPM_CRB_MAX_RESOURCES 3
27 static const guid_t crb_acpi_start_guid =
28 GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
29 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4);
32 CRB_ACPI_START_REVISION_ID = 1,
33 CRB_ACPI_START_INDEX = 1,
37 CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0),
38 CRB_LOC_CTRL_RELINQUISH = BIT(1),
42 CRB_LOC_STATE_LOC_ASSIGNED = BIT(1),
43 CRB_LOC_STATE_TPM_REG_VALID_STS = BIT(7),
47 CRB_CTRL_REQ_CMD_READY = BIT(0),
48 CRB_CTRL_REQ_GO_IDLE = BIT(1),
52 CRB_CTRL_STS_ERROR = BIT(0),
53 CRB_CTRL_STS_TPM_IDLE = BIT(1),
57 CRB_START_INVOKE = BIT(0),
61 CRB_CANCEL_INVOKE = BIT(0),
64 struct crb_regs_head {
74 struct crb_regs_tail {
89 CRB_DRV_STS_COMPLETE = BIT(0),
95 struct crb_regs_head __iomem *regs_h;
96 struct crb_regs_tail __iomem *regs_t;
103 struct tpm2_crb_smc {
111 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
112 unsigned long timeout)
118 stop = ktime_add(start, ms_to_ktime(timeout));
121 if ((ioread32(reg) & mask) == value)
124 usleep_range(50, 100);
125 } while (ktime_before(ktime_get(), stop));
127 return ((ioread32(reg) & mask) == value);
131 * __crb_go_idle - request tpm crb device to go the idle state
134 * @priv: crb private data
136 * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
137 * The device should respond within TIMEOUT_C by clearing the bit.
138 * Anyhow, we do not wait here as a consequent CMD_READY request
139 * will be handled correctly even if idle was not completed.
141 * The function does nothing for devices with ACPI-start method
142 * or SMC-start method.
146 static int __crb_go_idle(struct device *dev, struct crb_priv *priv)
148 if ((priv->sm == ACPI_TPM2_START_METHOD) ||
149 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
150 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
153 iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
155 if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
156 CRB_CTRL_REQ_GO_IDLE/* mask */,
159 dev_warn(dev, "goIdle timed out\n");
166 static int crb_go_idle(struct tpm_chip *chip)
168 struct device *dev = &chip->dev;
169 struct crb_priv *priv = dev_get_drvdata(dev);
171 return __crb_go_idle(dev, priv);
175 * __crb_cmd_ready - request tpm crb device to enter ready state
178 * @priv: crb private data
180 * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
181 * and poll till the device acknowledge it by clearing the bit.
182 * The device should respond within TIMEOUT_C.
184 * The function does nothing for devices with ACPI-start method
185 * or SMC-start method.
187 * Return: 0 on success -ETIME on timeout;
189 static int __crb_cmd_ready(struct device *dev, struct crb_priv *priv)
191 if ((priv->sm == ACPI_TPM2_START_METHOD) ||
192 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
193 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
196 iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
197 if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
198 CRB_CTRL_REQ_CMD_READY /* mask */,
201 dev_warn(dev, "cmdReady timed out\n");
208 static int crb_cmd_ready(struct tpm_chip *chip)
210 struct device *dev = &chip->dev;
211 struct crb_priv *priv = dev_get_drvdata(dev);
213 return __crb_cmd_ready(dev, priv);
216 static int __crb_request_locality(struct device *dev,
217 struct crb_priv *priv, int loc)
219 u32 value = CRB_LOC_STATE_LOC_ASSIGNED |
220 CRB_LOC_STATE_TPM_REG_VALID_STS;
225 iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
226 if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,
228 dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
235 static int crb_request_locality(struct tpm_chip *chip, int loc)
237 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
239 return __crb_request_locality(&chip->dev, priv, loc);
242 static int __crb_relinquish_locality(struct device *dev,
243 struct crb_priv *priv, int loc)
245 u32 mask = CRB_LOC_STATE_LOC_ASSIGNED |
246 CRB_LOC_STATE_TPM_REG_VALID_STS;
247 u32 value = CRB_LOC_STATE_TPM_REG_VALID_STS;
252 iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
253 if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,
255 dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
262 static int crb_relinquish_locality(struct tpm_chip *chip, int loc)
264 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
266 return __crb_relinquish_locality(&chip->dev, priv, loc);
269 static u8 crb_status(struct tpm_chip *chip)
271 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
274 if ((ioread32(&priv->regs_t->ctrl_start) & CRB_START_INVOKE) !=
276 sts |= CRB_DRV_STS_COMPLETE;
281 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
283 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
284 unsigned int expected;
286 /* A sanity check that the upper layer wants to get at least the header
287 * as that is the minimum size for any TPM response.
289 if (count < TPM_HEADER_SIZE)
292 /* If this bit is set, according to the spec, the TPM is in
293 * unrecoverable condition.
295 if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
298 /* Read the first 8 bytes in order to get the length of the response.
299 * We read exactly a quad word in order to make sure that the remaining
300 * reads will be aligned.
302 memcpy_fromio(buf, priv->rsp, 8);
304 expected = be32_to_cpup((__be32 *)&buf[2]);
305 if (expected > count || expected < TPM_HEADER_SIZE)
308 memcpy_fromio(&buf[8], &priv->rsp[8], expected - 8);
313 static int crb_do_acpi_start(struct tpm_chip *chip)
315 union acpi_object *obj;
318 obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
319 &crb_acpi_start_guid,
320 CRB_ACPI_START_REVISION_ID,
321 CRB_ACPI_START_INDEX,
325 rc = obj->integer.value == 0 ? 0 : -ENXIO;
332 * This is a TPM Command Response Buffer start method that invokes a
333 * Secure Monitor Call to requrest the firmware to execute or cancel
336 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
338 struct arm_smccc_res res;
340 arm_smccc_smc(func_id, 0, 0, 0, 0, 0, 0, 0, &res);
343 FW_BUG "tpm_crb_smc_start() returns res.a0 = 0x%lx\n",
351 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
353 dev_err(dev, FW_BUG "tpm_crb: incorrect start method\n");
358 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
360 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
363 /* Zero the cancel register so that the next command will not get
366 iowrite32(0, &priv->regs_t->ctrl_cancel);
368 if (len > priv->cmd_size) {
369 dev_err(&chip->dev, "invalid command count value %zd %d\n",
370 len, priv->cmd_size);
374 memcpy_toio(priv->cmd, buf, len);
376 /* Make sure that cmd is populated before issuing start. */
379 /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
380 * report only ACPI start but in practice seems to require both
381 * CRB start, hence invoking CRB start method if hid == MSFT0101.
383 if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
384 (priv->sm == ACPI_TPM2_MEMORY_MAPPED) ||
385 (!strcmp(priv->hid, "MSFT0101")))
386 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
388 if ((priv->sm == ACPI_TPM2_START_METHOD) ||
389 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD))
390 rc = crb_do_acpi_start(chip);
392 if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
393 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
394 rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
400 static void crb_cancel(struct tpm_chip *chip)
402 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
404 iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
406 if (((priv->sm == ACPI_TPM2_START_METHOD) ||
407 (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)) &&
408 crb_do_acpi_start(chip))
409 dev_err(&chip->dev, "ACPI Start failed\n");
412 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
414 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
415 u32 cancel = ioread32(&priv->regs_t->ctrl_cancel);
417 return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
420 static const struct tpm_class_ops tpm_crb = {
421 .flags = TPM_OPS_AUTO_STARTUP,
422 .status = crb_status,
425 .cancel = crb_cancel,
426 .req_canceled = crb_req_canceled,
427 .go_idle = crb_go_idle,
428 .cmd_ready = crb_cmd_ready,
429 .request_locality = crb_request_locality,
430 .relinquish_locality = crb_relinquish_locality,
431 .req_complete_mask = CRB_DRV_STS_COMPLETE,
432 .req_complete_val = CRB_DRV_STS_COMPLETE,
435 static int crb_check_resource(struct acpi_resource *ares, void *data)
437 struct resource *iores_array = data;
438 struct resource_win win;
439 struct resource *res = &(win.res);
442 if (acpi_dev_resource_memory(ares, res) ||
443 acpi_dev_resource_address_space(ares, &win)) {
444 for (i = 0; i < TPM_CRB_MAX_RESOURCES + 1; ++i) {
445 if (resource_type(iores_array + i) != IORESOURCE_MEM) {
446 iores_array[i] = *res;
447 iores_array[i].name = NULL;
456 static void __iomem *crb_map_res(struct device *dev, struct resource *iores,
457 void __iomem **iobase_ptr, u64 start, u32 size)
459 struct resource new_res = {
461 .end = start + size - 1,
462 .flags = IORESOURCE_MEM,
465 /* Detect a 64 bit address on a 32 bit system */
466 if (start != new_res.start)
467 return (void __iomem *) ERR_PTR(-EINVAL);
470 return devm_ioremap_resource(dev, &new_res);
473 *iobase_ptr = devm_ioremap_resource(dev, iores);
474 if (IS_ERR(*iobase_ptr))
478 return *iobase_ptr + (new_res.start - iores->start);
482 * Work around broken BIOSs that return inconsistent values from the ACPI
483 * region vs the registers. Trust the ACPI region. Such broken systems
484 * probably cannot send large TPM commands since the buffer will be truncated.
486 static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res,
489 if (io_res->start > start || io_res->end < start)
492 if (start + size - 1 <= io_res->end)
496 FW_BUG "ACPI region does not cover the entire command/response buffer. %pr vs %llx %llx\n",
497 io_res, start, size);
499 return io_res->end - start + 1;
502 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
503 struct acpi_table_tpm2 *buf)
505 struct list_head acpi_resource_list;
506 struct resource iores_array[TPM_CRB_MAX_RESOURCES + 1] = { {0} };
507 void __iomem *iobase_array[TPM_CRB_MAX_RESOURCES] = {NULL};
508 struct device *dev = &device->dev;
509 struct resource *iores;
510 void __iomem **iobase_ptr;
520 INIT_LIST_HEAD(&acpi_resource_list);
521 ret = acpi_dev_get_resources(device, &acpi_resource_list,
522 crb_check_resource, iores_array);
525 acpi_dev_free_resource_list(&acpi_resource_list);
527 if (resource_type(iores_array) != IORESOURCE_MEM) {
528 dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
530 } else if (resource_type(iores_array + TPM_CRB_MAX_RESOURCES) ==
532 dev_warn(dev, "TPM2 ACPI table defines too many memory resources\n");
533 memset(iores_array + TPM_CRB_MAX_RESOURCES,
534 0, sizeof(*iores_array));
535 iores_array[TPM_CRB_MAX_RESOURCES].flags = 0;
540 for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
541 if (buf->control_address >= iores_array[i].start &&
542 buf->control_address + sizeof(struct crb_regs_tail) - 1 <=
543 iores_array[i].end) {
544 iores = iores_array + i;
545 iobase_ptr = iobase_array + i;
550 priv->regs_t = crb_map_res(dev, iores, iobase_ptr, buf->control_address,
551 sizeof(struct crb_regs_tail));
553 if (IS_ERR(priv->regs_t))
554 return PTR_ERR(priv->regs_t);
556 /* The ACPI IO region starts at the head area and continues to include
557 * the control area, as one nice sane region except for some older
558 * stuff that puts the control area outside the ACPI IO region.
560 if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
561 (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
563 buf->control_address == iores->start +
564 sizeof(*priv->regs_h))
565 priv->regs_h = *iobase_ptr;
567 dev_warn(dev, FW_BUG "Bad ACPI memory layout");
570 ret = __crb_request_locality(dev, priv, 0);
575 * PTT HW bug w/a: wake up the device to access
576 * possibly not retained registers.
578 ret = __crb_cmd_ready(dev, priv);
580 goto out_relinquish_locality;
582 pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high);
583 pa_low = ioread32(&priv->regs_t->ctrl_cmd_pa_low);
584 cmd_pa = ((u64)pa_high << 32) | pa_low;
585 cmd_size = ioread32(&priv->regs_t->ctrl_cmd_size);
589 for (i = 0; iores_array[i].end; ++i) {
590 if (cmd_pa >= iores_array[i].start &&
591 cmd_pa <= iores_array[i].end) {
592 iores = iores_array + i;
593 iobase_ptr = iobase_array + i;
599 cmd_size = crb_fixup_cmd_size(dev, iores, cmd_pa, cmd_size);
601 dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
602 pa_high, pa_low, cmd_size);
604 priv->cmd = crb_map_res(dev, iores, iobase_ptr, cmd_pa, cmd_size);
605 if (IS_ERR(priv->cmd)) {
606 ret = PTR_ERR(priv->cmd);
610 memcpy_fromio(&__rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8);
611 rsp_pa = le64_to_cpu(__rsp_pa);
612 rsp_size = ioread32(&priv->regs_t->ctrl_rsp_size);
616 for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
617 if (rsp_pa >= iores_array[i].start &&
618 rsp_pa <= iores_array[i].end) {
619 iores = iores_array + i;
620 iobase_ptr = iobase_array + i;
626 rsp_size = crb_fixup_cmd_size(dev, iores, rsp_pa, rsp_size);
628 if (cmd_pa != rsp_pa) {
629 priv->rsp = crb_map_res(dev, iores, iobase_ptr,
631 ret = PTR_ERR_OR_ZERO(priv->rsp);
635 /* According to the PTP specification, overlapping command and response
636 * buffer sizes must be identical.
638 if (cmd_size != rsp_size) {
639 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
644 priv->rsp = priv->cmd;
648 priv->cmd_size = cmd_size;
650 __crb_go_idle(dev, priv);
652 out_relinquish_locality:
654 __crb_relinquish_locality(dev, priv, 0);
659 static int crb_acpi_add(struct acpi_device *device)
661 struct acpi_table_tpm2 *buf;
662 struct crb_priv *priv;
663 struct tpm_chip *chip;
664 struct device *dev = &device->dev;
665 struct tpm2_crb_smc *crb_smc;
670 status = acpi_get_table(ACPI_SIG_TPM2, 1,
671 (struct acpi_table_header **) &buf);
672 if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
673 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
677 /* Should the FIFO driver handle this? */
678 sm = buf->start_method;
679 if (sm == ACPI_TPM2_MEMORY_MAPPED)
682 priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
686 if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
687 if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
689 FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
691 ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
694 crb_smc = ACPI_ADD_PTR(struct tpm2_crb_smc, buf, sizeof(*buf));
695 priv->smc_func_id = crb_smc->smc_func_id;
699 priv->hid = acpi_device_hid(device);
701 rc = crb_map_io(device, priv, buf);
705 chip = tpmm_chip_alloc(dev, &tpm_crb);
707 return PTR_ERR(chip);
709 dev_set_drvdata(&chip->dev, priv);
710 chip->acpi_dev_handle = device->handle;
711 chip->flags = TPM_CHIP_FLAG_TPM2;
713 return tpm_chip_register(chip);
716 static int crb_acpi_remove(struct acpi_device *device)
718 struct device *dev = &device->dev;
719 struct tpm_chip *chip = dev_get_drvdata(dev);
721 tpm_chip_unregister(chip);
726 static const struct dev_pm_ops crb_pm = {
727 SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
730 static const struct acpi_device_id crb_device_ids[] = {
734 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
736 static struct acpi_driver crb_acpi_driver = {
738 .ids = crb_device_ids,
741 .remove = crb_acpi_remove,
748 module_acpi_driver(crb_acpi_driver);
749 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
750 MODULE_DESCRIPTION("TPM2 Driver");
751 MODULE_VERSION("0.1");
752 MODULE_LICENSE("GPL");