crypto: qat - add anti-rollback support for GEN6 devices

crypto: qat - add anti-rollback support for GEN6 devices

Anti-Rollback (ARB) is a QAT GEN6 hardware feature that prevents loading
firmware with a Security Version Number (SVN) lower than an authorized
minimum. This protects against downgrade attacks by ensuring that only
firmware at or above a committed SVN can run on the acceleration device.

During firmware loading, the driver checks the SVN validation status via
a hardware CSR. If the check reports a failure, firmware authentication
is aborted. If it reports a retry status, the driver reissues the
authentication command up to a maximum number of retries.

Extend the firmware admin interface with two new messages,
ICP_QAT_FW_SVN_READ and ICP_QAT_FW_SVN_COMMIT, to query and commit the
SVN, respectively. Integrate the SVN check into the firmware
authentication path in qat_uclo.c so the driver can react to
anti-rollback status during device bring-up.

Expose SVN information to userspace via a new sysfs attribute group,
qat_svn, under the PCI device directory. The group provides read-only
attributes for the active, enforced minimum, and permanent minimum SVN
values, as well as a write-only commit attribute that allows a system
administrator to commit the currently active SVN as the new authorized
minimum.

This is based on earlier work by Ciunas Bennett.

Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>