On Thu, Dec 19, 2024 at 11:42:13AM -0800, Ross Philipson wrote:
> DRTM needs to be able to set the locality used by kernel. Provide
> a one-shot function tpm_chip_set_locality() for the purpose.
>
> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
> Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> ---
> drivers/char/tpm/tpm-chip.c | 33 ++++++++++++++++++++++++++++++++-
> drivers/char/tpm/tpm_tis_core.c | 2 ++
> include/linux/tpm.h | 4 ++++
> 3 files changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 7df7abaf3e52..ac200514c4d7 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -44,7 +44,7 @@ static int tpm_request_locality(struct tpm_chip *chip)
> if (!chip->ops->request_locality)
> return 0;
>
> - rc = chip->ops->request_locality(chip, 0);
> + rc = chip->ops->request_locality(chip, chip->kernel_locality);
> if (rc < 0)
> return rc;
>
> @@ -374,6 +374,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
> }
>
> chip->locality = -1;
> + chip->kernel_locality = 0;
> return chip;
>
> out:
> @@ -689,3 +690,33 @@ void tpm_chip_unregister(struct tpm_chip *chip)
> tpm_del_char_device(chip);
> }
> EXPORT_SYMBOL_GPL(tpm_chip_unregister);
> +
> +/**
> + * tpm_chip_set_locality() - Set the TPM locality kernel uses
> + * @chip: &tpm_chip instance
> + * @locality: new locality
> + *
> + * This a one-shot function. Returns zero or POSIX error on failure.
> + */
> +int tpm_chip_set_locality(struct tpm_chip *chip, u8 locality)
> +{
> + int ret;
> +
> + if (locality < 0 || locality >= TPM_MAX_LOCALITY)
> + return -EINVAL;
> +
> + ret = tpm_try_get_ops(chip);
> + if (ret)
> + return ret;
> +
> + if (!(chip->flags & TPM_CHIP_FLAG_SET_LOCALITY_ENABLED)) {
> + tpm_put_ops(chip);
> + return -EINVAL;
> + }
> +
> + chip->kernel_locality = locality;
> + chip->flags &= ~TPM_CHIP_FLAG_SET_LOCALITY_ENABLED;
> + tpm_put_ops(chip);
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tpm_chip_set_locality);
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index c86100ad743a..b85677eccc86 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -1114,6 +1114,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> if (IS_ERR(chip))
> return PTR_ERR(chip);
>
> + chip->flags |= TPM_CHIP_FLAG_SET_LOCALITY_ENABLED;
> +
> #ifdef CONFIG_ACPI
> chip->acpi_dev_handle = acpi_dev_handle;
> #endif
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index c5a4a2d7dd15..9f910d3bc2e4 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -207,6 +207,8 @@ struct tpm_chip {
>
> /* active locality */
> int locality;
> + /* the locality used by kernel */
> + u8 kernel_locality;
>
> #ifdef CONFIG_TCG_TPM2_HMAC
> /* details for communication security via sessions */
> @@ -354,6 +356,7 @@ enum tpm_chip_flags {
> TPM_CHIP_FLAG_SUSPENDED = BIT(8),
> TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9),
> TPM_CHIP_FLAG_DISABLE = BIT(10),
> + TPM_CHIP_FLAG_SET_LOCALITY_ENABLED = BIT(11),
> };
>
> #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
> @@ -447,6 +450,7 @@ static inline u32 tpm2_rc_value(u32 rc)
> extern int tpm_is_tpm2(struct tpm_chip *chip);
> extern __must_check int tpm_try_get_ops(struct tpm_chip *chip);
> extern void tpm_put_ops(struct tpm_chip *chip);
> +int tpm_chip_set_locality(struct tpm_chip *chip, u8 locality);
> extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
> size_t min_rsp_body_length, const char *desc);
> extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
> --
> 2.39.3
>
+1 for this.
BR, Jarkko
