Commit 9afb9eaa authored by Stuart Yoder's avatar Stuart Yoder Committed by Jarkko Sakkinen
Browse files

tpm_crb: Add support for the ARM FF-A start method 



The TCG ACPI spec v1.4 defines a start method for the TPMs implemented with
the ARM CRB over FF-A ABI.

Add support for the FF-A start method, and use interfaces provided by the
ffa_crb driver to interact with the FF-A based TPM.

[jarkko: Fine-tuned the commit message.]

Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarStuart Yoder <stuart.yoder@arm.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 6a457548

drivers/char/tpm/tpm_crb.c

+66 −5
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#ifdef CONFIG_ARM64

#include <linux/arm-smccc.h>

#endif

#include "tpm_crb_ffa.h"

#include "tpm.h"



#define ACPI_SIG_TPM2 "TPM2"
@@ -100,6 +101,8 @@ struct crb_priv { 
	u32 smc_func_id;

	u32 __iomem *pluton_start_addr;

	u32 __iomem *pluton_reply_addr;

	u8 ffa_flags;

	u8 ffa_attributes;

};



struct tpm2_crb_smc {
@@ -110,6 +113,14 @@ struct tpm2_crb_smc { 
	u32 smc_func_id;

};



/* CRB over FFA start method parameters in TCG2 ACPI table */

struct tpm2_crb_ffa {

	u8 flags;

	u8 attributes;

	u16 partition_id;

	u8 reserved[8];

};



struct tpm2_crb_pluton {

	u64 start_addr;

	u64 reply_addr;
@@ -122,7 +133,8 @@ static inline bool tpm_crb_has_idle(u32 start_method) 
{

	return !(start_method == ACPI_TPM2_START_METHOD ||

	       start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD ||

	       start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);

	       start_method == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC ||

	       start_method == ACPI_TPM2_CRB_WITH_ARM_FFA);

}



static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
@@ -261,13 +273,20 @@ static int crb_cmd_ready(struct tpm_chip *chip) 
static int __crb_request_locality(struct device *dev,

				  struct crb_priv *priv, int loc)

{

	u32 value = CRB_LOC_STATE_LOC_ASSIGNED |

		    CRB_LOC_STATE_TPM_REG_VALID_STS;

	u32 value = CRB_LOC_STATE_LOC_ASSIGNED | CRB_LOC_STATE_TPM_REG_VALID_STS;

	int rc;



	if (!priv->regs_h)

		return 0;



	iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);



	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {

		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);

		if (rc)

			return rc;

	}



	if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,

				 TPM2_TIMEOUT_C)) {

		dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
@@ -287,14 +306,21 @@ static int crb_request_locality(struct tpm_chip *chip, int loc) 
static int __crb_relinquish_locality(struct device *dev,

				     struct crb_priv *priv, int loc)

{

	u32 mask = CRB_LOC_STATE_LOC_ASSIGNED |

		   CRB_LOC_STATE_TPM_REG_VALID_STS;

	u32 mask = CRB_LOC_STATE_LOC_ASSIGNED | CRB_LOC_STATE_TPM_REG_VALID_STS;

	u32 value = CRB_LOC_STATE_TPM_REG_VALID_STS;

	int rc;



	if (!priv->regs_h)

		return 0;



	iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);



	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {

		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_LOCALITY_REQUEST, loc);

		if (rc)

			return rc;

	}



	if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,

				 TPM2_TIMEOUT_C)) {

		dev_warn(dev, "TPM_LOC_STATE_x.Relinquish timed out\n");
@@ -443,6 +469,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) 
		rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);

	}



	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {

		iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);

		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);

	}



	if (rc)

		return rc;
@@ -452,6 +483,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) 
static void crb_cancel(struct tpm_chip *chip)

{

	struct crb_priv *priv = dev_get_drvdata(&chip->dev);

	int rc;



	iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
@@ -459,6 +491,12 @@ static void crb_cancel(struct tpm_chip *chip) 
	     priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) &&

	     crb_do_acpi_start(chip))

		dev_err(&chip->dev, "ACPI Start failed\n");



	if (priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {

		rc = tpm_crb_ffa_start(CRB_FFA_START_TYPE_COMMAND, chip->locality);

		if (rc)

			dev_err(&chip->dev, "FF-A Start failed\n");

	}

}



static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
@@ -616,6 +654,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, 
	 * stuff that puts the control area outside the ACPI IO region.

	 */

	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER ||

	    priv->sm == ACPI_TPM2_CRB_WITH_ARM_FFA ||

	    priv->sm == ACPI_TPM2_MEMORY_MAPPED) {

		if (iores &&

		    buf->control_address == iores->start +
@@ -737,6 +776,7 @@ static int crb_acpi_add(struct acpi_device *device) 
	struct tpm_chip *chip;

	struct device *dev = &device->dev;

	struct tpm2_crb_smc *crb_smc;

	struct tpm2_crb_ffa *crb_ffa;

	struct tpm2_crb_pluton *crb_pluton;

	acpi_status status;

	u32 sm;
@@ -775,6 +815,27 @@ static int crb_acpi_add(struct acpi_device *device) 
		priv->smc_func_id = crb_smc->smc_func_id;

	}



	if (sm == ACPI_TPM2_CRB_WITH_ARM_FFA) {

		if (buf->header.length < (sizeof(*buf) + sizeof(*crb_ffa))) {

			dev_err(dev,

				FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",

				buf->header.length,

				ACPI_TPM2_CRB_WITH_ARM_FFA);

			rc = -EINVAL;

			goto out;

		}

		crb_ffa = ACPI_ADD_PTR(struct tpm2_crb_ffa, buf, sizeof(*buf));

		priv->ffa_flags = crb_ffa->flags;

		priv->ffa_attributes = crb_ffa->attributes;

		rc = tpm_crb_ffa_init();

		if (rc) {

			/* If FF-A driver is not available yet, request probe retry */

			if (rc == -ENOENT)

				rc = -EPROBE_DEFER;

			goto out;

		}

	}



	if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {

		if (buf->header.length < (sizeof(*buf) + sizeof(*crb_pluton))) {

			dev_err(dev,