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Commit c82a330c authored by Tomas Winkler's avatar Tomas Winkler Committed by Jarkko Sakkinen
Browse files

tpm: factor out tpm 1.x pm suspend flow into tpm1-cmd.c 



Factor out TPM 1.x suspend flow from tpm-interface.c into a new function
tpm1_pm_suspend() in tpm1-cmd.c

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent d4a31756

drivers/char/tpm/tpm-interface.c

+5 −50
Original line number Diff line number Diff line
@@ -585,15 +585,6 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) 
}

EXPORT_SYMBOL_GPL(tpm_send);



#define TPM_ORD_SAVESTATE 152

#define SAVESTATE_RESULT_SIZE 10



static const struct tpm_input_header savestate_header = {

	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),

	.length = cpu_to_be32(10),

	.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)

};



/*

 * We are about to suspend. Save the TPM state

 * so that it can be restored.
@@ -601,54 +592,18 @@ static const struct tpm_input_header savestate_header = { 
int tpm_pm_suspend(struct device *dev)

{

	struct tpm_chip *chip = dev_get_drvdata(dev);

	struct tpm_cmd_t cmd;

	int rc, try;



	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };

	int rc = 0;



	if (chip == NULL)

	if (!chip)

		return -ENODEV;



	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)

		return 0;



	if (chip->flags & TPM_CHIP_FLAG_TPM2) {

	if (chip->flags & TPM_CHIP_FLAG_TPM2)

		tpm2_shutdown(chip, TPM2_SU_STATE);

		return 0;

	}



	/* for buggy tpm, flush pcrs with extend to selected dummy */

	if (tpm_suspend_pcr)

		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,

				     "extending dummy pcr before suspend");



	/* now do the actual savestate */

	for (try = 0; try < TPM_RETRY; try++) {

		cmd.header.in = savestate_header;

		rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,

				      0, 0, NULL);



		/*

		 * If the TPM indicates that it is too busy to respond to

		 * this command then retry before giving up.  It can take

		 * several seconds for this TPM to be ready.

		 *

		 * This can happen if the TPM has already been sent the

		 * SaveState command before the driver has loaded.  TCG 1.2

		 * specification states that any communication after SaveState

		 * may cause the TPM to invalidate previously saved state.

		 */

		if (rc != TPM_WARN_RETRY)

			break;

		tpm_msleep(TPM_TIMEOUT_RETRY);

	}



	if (rc)

		dev_err(&chip->dev,

			"Error (%d) sending savestate before suspend\n", rc);

	else if (try > 0)

		dev_warn(&chip->dev, "TPM savestate took %dms\n",

			 try * TPM_TIMEOUT_RETRY);

	else

		rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);



	return rc;

}

drivers/char/tpm/tpm.h

+2 −0
Original line number Diff line number Diff line
@@ -542,6 +542,8 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space, 
			 const char *desc);

int tpm_startup(struct tpm_chip *chip);

int tpm_get_timeouts(struct tpm_chip *);



int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr);

int tpm1_auto_startup(struct tpm_chip *chip);

int tpm1_do_selftest(struct tpm_chip *chip);

int tpm1_get_timeouts(struct tpm_chip *chip);

drivers/char/tpm/tpm1-cmd.c

+61 −0
Original line number Diff line number Diff line
@@ -666,3 +666,64 @@ int tpm1_auto_startup(struct tpm_chip *chip) 
		rc = -ENODEV;

	return rc;

}



#define TPM_ORD_SAVESTATE 152

#define SAVESTATE_RESULT_SIZE 10

static const struct tpm_input_header savestate_header = {

	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),

	.length = cpu_to_be32(10),

	.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)

};



/**

 * tpm1_pm_suspend() - pm suspend handler

 * @chip: TPM chip to use.

 * @tpm_suspend_pcr: flush pcr for buggy TPM chips.

 *

 * The functions saves the TPM state to be restored on resume.

 *

 * Return:

 * * 0 on success,

 * * < 0 on error.

 */

int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr)

{

	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };

	struct tpm_cmd_t cmd;

	int rc, try;



	/* for buggy tpm, flush pcrs with extend to selected dummy */

	if (tpm_suspend_pcr)

		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,

				     "extending dummy pcr before suspend");



	/* now do the actual savestate */

	for (try = 0; try < TPM_RETRY; try++) {

		cmd.header.in = savestate_header;

		rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,

				      0, 0, NULL);



		/*

		 * If the TPM indicates that it is too busy to respond to

		 * this command then retry before giving up.  It can take

		 * several seconds for this TPM to be ready.

		 *

		 * This can happen if the TPM has already been sent the

		 * SaveState command before the driver has loaded.  TCG 1.2

		 * specification states that any communication after SaveState

		 * may cause the TPM to invalidate previously saved state.

		 */

		if (rc != TPM_WARN_RETRY)

			break;

		tpm_msleep(TPM_TIMEOUT_RETRY);

	}



	if (rc)

		dev_err(&chip->dev, "Error (%d) sending savestate before suspend\n",

			rc);

	else if (try > 0)

		dev_warn(&chip->dev, "TPM savestate took %dms\n",

			 try * TPM_TIMEOUT_RETRY);



	return rc;

}