Re: [PATCH v6 2/2] tee: optee: store OS revision for TEE core

[Sumit Garg via OP-TEE <op-tee@lists.trustedfirmware.org>]

On Fri, Jan 09, 2026 at 11:07:40PM +0800, Aristo Chen wrote:
> Hi Sumit
> 
> Sumit Garg <sumit.garg@kernel.org> 於 2026年1月9日週五 下午7:50寫道：
> >
> > On Thu, Jan 08, 2026 at 02:45:09PM +0800, Aristo Chen wrote:
> > > Collect OP-TEE OS revision from secure world for both SMC and FF-A
> > > ABIs, store it in the OP-TEE driver, and expose it through the
> > > generic get_tee_revision() callback.
> > >
> > > Signed-off-by: Aristo Chen <aristo.chen@canonical.com>
> > > ---
> > >  drivers/tee/optee/core.c          | 23 +++++++++++++
> > >  drivers/tee/optee/ffa_abi.c       | 57 ++++++++++++++++++++++++-------
> > >  drivers/tee/optee/optee_private.h | 19 +++++++++++
> > >  drivers/tee/optee/smc_abi.c       | 15 ++++++--
> > >  4 files changed, 99 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > > index 5b62139714ce..2d807bc748bc 100644
> > > --- a/drivers/tee/optee/core.c
> > > +++ b/drivers/tee/optee/core.c
> > > @@ -63,6 +63,29 @@ int optee_set_dma_mask(struct optee *optee, u_int pa_width)
> > >       return dma_coerce_mask_and_coherent(&optee->teedev->dev, mask);
> > >  }
> > >
> > > +int optee_get_revision(struct tee_device *teedev, char *buf, size_t len)
> > > +{
> > > +     struct optee *optee = tee_get_drvdata(teedev);
> > > +     u64 build_id;
> > > +
> > > +     if (!optee)
> > > +             return -ENODEV;
> > > +     if (!buf || !len)
> > > +             return -EINVAL;
> > > +
> > > +     build_id = optee->revision.os_build_id;
> > > +     if (build_id)
> > > +             scnprintf(buf, len, "%u.%u (%016llx)",
> > > +                       optee->revision.os_major,
> > > +                       optee->revision.os_minor,
> > > +                       (unsigned long long)build_id);
> > > +     else
> > > +             scnprintf(buf, len, "%u.%u", optee->revision.os_major,
> > > +                       optee->revision.os_minor);
> > > +
> > > +     return 0;
> > > +}
> > > +
> > >  static void optee_bus_scan(struct work_struct *work)
> > >  {
> > >       WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> > > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > > index bf8390789ecf..82dbed1c87e5 100644
> > > --- a/drivers/tee/optee/ffa_abi.c
> > > +++ b/drivers/tee/optee/ffa_abi.c
> > > @@ -775,6 +775,42 @@ static int optee_ffa_reclaim_protmem(struct optee *optee,
> > >   * with a matching configuration.
> > >   */
> > >
> > > +static bool optee_ffa_get_os_revision(struct ffa_device *ffa_dev,
> > > +                                     const struct ffa_ops *ops,
> > > +                                     struct optee_revision *revision,
> > > +                                     bool log)
> > > +{
> > > +     const struct ffa_msg_ops *msg_ops = ops->msg_ops;
> > > +     struct ffa_send_direct_data data = {
> > > +             .data0 = OPTEE_FFA_GET_OS_VERSION,
> > > +     };
> > > +     int rc;
> > > +
> > > +     msg_ops->mode_32bit_set(ffa_dev);
> > > +
> > > +     rc = msg_ops->sync_send_receive(ffa_dev, &data);
> > > +     if (rc) {
> > > +             pr_err("Unexpected error %d\n", rc);
> > > +             return false;
> > > +     }
> > > +
> > > +     if (revision) {
> > > +             revision->os_major = data.data0;
> > > +             revision->os_minor = data.data1;
> > > +             revision->os_build_id = data.data2;
> > > +     }
> > > +
> > > +     if (log) {
> > > +             if (data.data2)
> > > +                     pr_info("revision %lu.%lu (%08lx)",
> > > +                             data.data0, data.data1, data.data2);
> > > +             else
> > > +                     pr_info("revision %lu.%lu", data.data0, data.data1);
> > > +     }
> > > +
> > > +     return true;
> > > +}
> > > +
> > >  static bool optee_ffa_api_is_compatible(struct ffa_device *ffa_dev,
> > >                                       const struct ffa_ops *ops)
> > >  {
> > > @@ -798,19 +834,8 @@ static bool optee_ffa_api_is_compatible(struct ffa_device *ffa_dev,
> > >               return false;
> > >       }
> > >
> > > -     data = (struct ffa_send_direct_data){
> > > -             .data0 = OPTEE_FFA_GET_OS_VERSION,
> > > -     };
> > > -     rc = msg_ops->sync_send_receive(ffa_dev, &data);
> > > -     if (rc) {
> > > -             pr_err("Unexpected error %d\n", rc);
> > > +     if (!optee_ffa_get_os_revision(ffa_dev, ops, NULL, true))
> >
> > Why do you need to invoke optee_ffa_get_os_revision() here?
> 
> I’m calling optee_ffa_get_os_revision() here to avoid duplicating the
> GET_OS_VERSION call/printing logic. The original code in
> optee_ffa_api_is_compatible() already did the OS version query and
> printed it; after factoring it out, the helper keeps that behavior in one
> place. If we don’t call it there, we’d either lose the existing dmesg log
> or re‑implement the same OS‑version query/print block again, which I’m
> trying to avoid.
> 
> If you’d rather avoid the extra call at this stage, maybe we can always
> print the log in the optee_ffa_get_os_revision() and remove the call
> from optee_ffa_api_is_compatible() entirely.

Yeah move the print to optee_ffa_get_os_revision() and drop the extra
call.

-Sumit