On Thu Aug 3, 2023 at 4:50 AM EEST, Mario Limonciello wrote:
> As the behavior of whether a TPM is registered for hwrng can be controlled
> by command line, drop the kernel configuration option.
>
> Cc: Mateusz Schyboll <dragonn@xxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> drivers/char/tpm/Kconfig | 11 -----------
> drivers/char/tpm/tpm-chip.c | 6 +++---
> 2 files changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> index 927088b2c3d3f..69aaa730dc208 100644
> --- a/drivers/char/tpm/Kconfig
> +++ b/drivers/char/tpm/Kconfig
> @@ -27,17 +27,6 @@ menuconfig TCG_TPM
>
> if TCG_TPM
>
> -config HW_RANDOM_TPM
> - bool "TPM HW Random Number Generator support"
> - depends on TCG_TPM && HW_RANDOM && !(TCG_TPM=y && HW_RANDOM=m)
> - default y
> - help
> - This setting exposes the TPM's Random Number Generator as a hwrng
> - device. This allows the kernel to collect randomness from the TPM at
> - boot, and provides the TPM randomines in /dev/hwrng.
> -
> - If unsure, say Y.
> -
> config TCG_TIS_CORE
> tristate
> help
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 8fb42232bd7a5..0d69335743469 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -533,7 +533,7 @@ static int tpm_add_hwrng(struct tpm_chip *chip)
> if (!trust_tpm)
> chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED;
>
> - if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM) || tpm_is_firmware_upgrade(chip) ||
> + if (tpm_is_firmware_upgrade(chip) ||
> chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED)
> return 0;
>
> @@ -639,7 +639,7 @@ int tpm_chip_register(struct tpm_chip *chip)
> return 0;
>
> out_hwrng:
> - if (IS_ENABLED(CONFIG_HW_RANDOM_TPM) && !tpm_is_firmware_upgrade(chip) &&
> + if (!tpm_is_firmware_upgrade(chip) &&
> !(chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED))
> hwrng_unregister(&chip->hwrng);
> out_ppi:
> @@ -665,7 +665,7 @@ EXPORT_SYMBOL_GPL(tpm_chip_register);
> void tpm_chip_unregister(struct tpm_chip *chip)
> {
> tpm_del_legacy_sysfs(chip);
> - if (IS_ENABLED(CONFIG_HW_RANDOM_TPM) && !tpm_is_firmware_upgrade(chip) &&
> + if (!tpm_is_firmware_upgrade(chip) &&
> !(chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED))
> hwrng_unregister(&chip->hwrng);
> tpm_bios_log_teardown(chip);
> --
> 2.34.1
I don't understand this but please take it a way from patch set, which
should only contain critical fixes, which this definitely is not.
BR, Jarkko
