On Thu, Jun 25, 2020 at 05:46:44PM +0300, [email protected] wrote: > From: Amir Mizinski <[email protected]> > > When using I2C bus protocol, the TPM has the ability to report data > integrity on incoming or outgoing command parameter bytes. > According to the TCG specs, if this data validation functionality is > enabled via the TPM_DATA_CSUM_ENABLE register, the TPM will update the > TPM_DATA_CSUM register after reception of the last command byte and after > the last response byte has been read. > > Data integrity is checked if a "verify_data_integrity" handle is defined in > "tpm_tis_phy_ops". > > Co-developed-by: Christophe Ricard <[email protected]> > Signed-off-by: Christophe Ricard <[email protected]> > Signed-off-by: Amir Mizinski <[email protected]> > --- > drivers/char/tpm/tpm_tis_core.c | 14 ++++++++++++++ > drivers/char/tpm/tpm_tis_core.h | 2 ++ > 2 files changed, 16 insertions(+) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index e136467..347c020 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -347,6 +347,13 @@ static int __tpm_tis_recv(struct tpm_chip *chip, u8 > *buf, size_t count) > return size; > } > > + if (priv->phy_ops->verify_data_integrity) > + if (!priv->phy_ops->verify_data_integrity(priv, buf, > + size)) { > + size = -EIO; > + return size; > + } > + > return size; > } > > @@ -419,6 +426,13 @@ static int tpm_tis_send_data(struct tpm_chip *chip, > const u8 *buf, size_t len) > return rc; > } > > + if (priv->phy_ops->verify_data_integrity) { > + if (!priv->phy_ops->verify_data_integrity(priv, buf, len)) { > + rc = -EIO; > + return rc; > + } > + } > + > return 0; > } > > diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h > index 6cc6b76..cd97c01 100644 > --- a/drivers/char/tpm/tpm_tis_core.h > +++ b/drivers/char/tpm/tpm_tis_core.h > @@ -107,6 +107,8 @@ struct tpm_tis_phy_ops { > int (*read16)(struct tpm_tis_data *data, u32 addr, u16 *result); > int (*read32)(struct tpm_tis_data *data, u32 addr, u32 *result); > int (*write32)(struct tpm_tis_data *data, u32 addr, u32 src); > + bool (*verify_data_integrity)(struct tpm_tis_data *data, const u8 *buf, > + size_t len); > }; > > static inline int tpm_tis_read_bytes(struct tpm_tis_data *data, u32 addr, > -- > 2.7.4 >
As I've said before, I'm not too eager to add a new callback and nothing in the commit message rationalizes adding one. /Jarkko
