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tpm: introduce tpm_chip_start() and tpm_chip_stop()

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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: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>
This commit is contained in:
Jarkko Sakkinen 2018-11-04 21:18:46 +02:00
parent 2f257402ee
commit 719b7d81f2
3 changed files with 116 additions and 81 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

111
drivers/char/tpm/tpm-chip.c
View File

@ -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

84
drivers/char/tpm/tpm-interface.c
View File

@ -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);
if (ret)
goto out_locality;
has_locality = true;
}
ret = tpm_cmd_ready(chip, flags);
ret = tpm_chip_start(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);

2
drivers/char/tpm/tpm.h
View File

@ -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);