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Commit 719b7d81 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

tpm: introduce tpm_chip_start() and tpm_chip_stop() 



Encapsulate power gating and locality functionality to tpm_chip_start()
and tpm_chip_stop() in order to clean up the branching mess in
tpm_transmit().

Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Tested-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: default avatarAlexander Steffen <Alexander.Steffen@infineon.com>
parent 2f257402

drivers/char/tpm/tpm-chip.c

+111 −0
Original line number Diff line number Diff line
@@ -37,6 +37,117 @@ struct class *tpm_class; 
struct class *tpmrm_class;

dev_t tpm_devt;



static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)

{

	int rc;



	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->request_locality)

		return 0;



	rc = chip->ops->request_locality(chip, 0);

	if (rc < 0)

		return rc;



	chip->locality = rc;

	return 0;

}



static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)

{

	int rc;



	if (flags & TPM_TRANSMIT_NESTED)

		return;



	if (!chip->ops->relinquish_locality)

		return;



	rc = chip->ops->relinquish_locality(chip, chip->locality);

	if (rc)

		dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);



	chip->locality = -1;

}



static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)

{

	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->cmd_ready)

		return 0;



	return chip->ops->cmd_ready(chip);

}



static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)

{

	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->go_idle)

		return 0;



	return chip->ops->go_idle(chip);

}



/**

 * tpm_chip_start() - power on the TPM

 * @chip:	a TPM chip to use

 * @flags:	TPM transmit flags

 *

 * Return:

 * * The response length	- OK

 * * -errno			- A system error

 */

int tpm_chip_start(struct tpm_chip *chip, unsigned int flags)

{

	int ret;



	if (chip->ops->clk_enable)

		chip->ops->clk_enable(chip, true);



	if (chip->locality == -1) {

		ret = tpm_request_locality(chip, flags);

		if (ret) {

			chip->ops->clk_enable(chip, false);

			return ret;

		}

	}



	ret = tpm_cmd_ready(chip, flags);

	if (ret) {

		tpm_relinquish_locality(chip, flags);

		if (chip->ops->clk_enable)

			chip->ops->clk_enable(chip, false);

		return ret;

	}



	return 0;

}

EXPORT_SYMBOL_GPL(tpm_chip_start);



/**

 * tpm_chip_stop() - power off the TPM

 * @chip:	a TPM chip to use

 * @flags:	TPM transmit flags

 *

 * Return:

 * * The response length	- OK

 * * -errno			- A system error

 */

void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags)

{

	tpm_go_idle(chip, flags);

	tpm_relinquish_locality(chip, flags);

	if (chip->ops->clk_enable)

		chip->ops->clk_enable(chip, false);

}

EXPORT_SYMBOL_GPL(tpm_chip_stop);



/**

 * tpm_try_get_ops() - Get a ref to the tpm_chip

 * @chip: Chip to ref

drivers/char/tpm/tpm-interface.c

+3 −81
Original line number Diff line number Diff line
@@ -62,64 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal) 
}

EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);



static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)

{

	int rc;



	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->request_locality)

		return 0;



	rc = chip->ops->request_locality(chip, 0);

	if (rc < 0)

		return rc;



	chip->locality = rc;



	return 0;

}



static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)

{

	int rc;



	if (flags & TPM_TRANSMIT_NESTED)

		return;



	if (!chip->ops->relinquish_locality)

		return;



	rc = chip->ops->relinquish_locality(chip, chip->locality);

	if (rc)

		dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);



	chip->locality = -1;

}



static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)

{

	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->cmd_ready)

		return 0;



	return chip->ops->cmd_ready(chip);

}



static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)

{

	if (flags & TPM_TRANSMIT_NESTED)

		return 0;



	if (!chip->ops->go_idle)

		return 0;



	return chip->ops->go_idle(chip);

}



static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz,

				unsigned int flags)

{
@@ -221,7 +163,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz, 
	/* space for header and handles */

	u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];

	unsigned int delay_msec = TPM2_DURATION_SHORT;

	bool has_locality = false;

	u32 rc = 0;

	ssize_t ret;

	const size_t save_size = min(sizeof(save), bufsiz);
@@ -236,32 +177,13 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz, 
	memcpy(save, buf, save_size);



	for (;;) {

		if (chip->ops->clk_enable != NULL)

			chip->ops->clk_enable(chip, true);



		if (chip->locality == -1) {

			ret = tpm_request_locality(chip, flags);

		ret = tpm_chip_start(chip, flags);

		if (ret)

				goto out_locality;

			has_locality = true;

		}



		ret = tpm_cmd_ready(chip, flags);

		if (ret)

			goto out_locality;

			return ret;



		ret = tpm_try_transmit(chip, buf, bufsiz, flags);



		/* This may fail but do not override ret. */

		tpm_go_idle(chip, flags);



out_locality:

		if (has_locality)

			tpm_relinquish_locality(chip, flags);



		if (chip->ops->clk_enable != NULL)

			chip->ops->clk_enable(chip, false);



		tpm_chip_stop(chip, flags);

		if (ret < 0)

			break;

		rc = be32_to_cpu(header->return_code);

drivers/char/tpm/tpm.h

+2 −0
Original line number Diff line number Diff line
@@ -523,6 +523,8 @@ static inline void tpm_msleep(unsigned int delay_msec) 
		     delay_msec * 1000);

};



int tpm_chip_start(struct tpm_chip *chip, unsigned int flags);

void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags);

struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);

__must_check int tpm_try_get_ops(struct tpm_chip *chip);

void tpm_put_ops(struct tpm_chip *chip);