Add helper functions for the SCM calls required to support
hardware-wrapped inline storage encryption keys. These SCM calls manage
wrapped keys via Qualcomm's Hardware Key Manager (HWKM), which can only
be accessed from TrustZone.
QCOM_SCM_ES_GENERATE_ICE_KEY and QCOM_SCM_ES_IMPORT_ICE_KEY create a new
long-term wrapped key, with the former making the hardware generate the
key and the latter importing a raw key. QCOM_SCM_ES_PREPARE_ICE_KEY
converts the key to ephemerally-wrapped form so that it can be used for
inline storage encryption. These are planned to be wired up to new
ioctls via the blk-crypto framework; see the proposed documentation for
the hardware-wrapped keys feature for more information.
Similarly there's also QCOM_SCM_ES_DERIVE_SW_SECRET which derives a
"software secret" from an ephemerally-wrapped key and will be wired up
to the corresponding operation in the blk_crypto_profile.
These will all be used by the ICE driver in drivers/soc/qcom/ice.c.
[EB: merged related patches, fixed error handling, fixed naming, fixed
docs for size parameters, fixed qcom_scm_has_wrapped_key_support(),
improved comments, improved commit message.]
Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20241213041958.202565-9-ebiggers@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
1d45a1cd9f