On Tue, 2020-10-13 at 03:28 +0300, Jarkko Sakkinen wrote: [...] > diff --git a/include/linux/tpm.h b/include/linux/tpm.h > index 8f4ff39f51e7..f0ebce14d2f8 100644 > --- a/include/linux/tpm.h > +++ b/include/linux/tpm.h > @@ -397,6 +397,10 @@ static inline u32 tpm2_rc_value(u32 rc) > #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE) > > 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); > +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, > struct tpm_digest *digest); > extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, > @@ -410,7 +414,18 @@ static inline int tpm_is_tpm2(struct tpm_chip > *chip) > { > return -ENODEV; > } > - > +static inline int tpm_try_get_ops(struct tpm_chip *chip) > +{ > + return -ENODEV; > +} > +static inline void tpm_put_ops(struct tpm_chip *chip) > +{ > +} > +static inline ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct > tpm_buf *buf, > + size_t min_rsp_body_length, > const char *desc) > +{ > + return -ENODEV; > +} > static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, I don't think we want this, do we? That's only for API access which should be available when the TPM isn't selected. Given that get/put are TPM critical operations, they should only appear when inside code where the TPM has already been selected. If they appear outside TPM selected code, I think we want the compile to fail, which is why we don't want these backup definitions. James