Re: [PATCH v15 3/8] remoteproc: Introduce load_fw and release_fw optional operation

[Mathieu Poirier]

On Thu, 5 Dec 2024 at 11:22, Arnaud POULIQUEN
<arnaud.pouliquen@xxxxxxxxxxx> wrote:
>
> Hello Mathieu,
>
> Thanks for the review!
> I just need to clarify a point below before preparing the next revision.
>
> On 12/3/24 18:22, Mathieu Poirier wrote:
> > On Thu, Nov 28, 2024 at 09:42:10AM +0100, Arnaud Pouliquen wrote:
> >> This patch updates the rproc_ops structures to include two new optional
> >> operations.
> >>
> >> - The load_fw() op is responsible for loading the remote processor
> >> non-ELF firmware image before starting the boot sequence. This ops will
> >> be used, for instance, to call OP-TEE to  authenticate an load the firmware
> >> image before accessing to its resources (a.e the resource table)
> >>
> >> - The release_fw op is responsible for releasing the remote processor
> >> firmware image. For instance to clean memories.
> >> The ops is called in the following cases:
> >>  - An error occurs between the loading of the firmware image and the
> >>    start of the remote processor.
> >>  - after stopping the remote processor.
> >>
> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> >> ---
> >> Update vs version V13:
> >> - Rework the commit to introduce load_fw() op.
> >> - remove rproc_release_fw() call from  rproc_start() as called in
> >>   rproc_boot() and rproc_boot_recovery() in case of error.
> >> - create rproc_load_fw() and rproc_release_fw() internal functions.
> >> ---
> >>  drivers/remoteproc/remoteproc_core.c     | 16 +++++++++++++++-
> >>  drivers/remoteproc/remoteproc_internal.h | 14 ++++++++++++++
> >>  include/linux/remoteproc.h               |  6 ++++++
> >>  3 files changed, 35 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> >> index ace11ea17097..8df4b2c59bb6 100644
> >> --- a/drivers/remoteproc/remoteproc_core.c
> >> +++ b/drivers/remoteproc/remoteproc_core.c
> >> @@ -1488,6 +1488,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> >>      kfree(rproc->cached_table);
> >>      rproc->cached_table = NULL;
> >>      rproc->table_ptr = NULL;
> >> +    rproc_release_fw(rproc);
> >
> > This is not needed since rproc_release_fw() is called in rproc_boot().
> >
> >>  unprepare_rproc:
> >>      /* release HW resources if needed */
> >>      rproc_unprepare_device(rproc);
> >> @@ -1855,8 +1856,14 @@ static int rproc_boot_recovery(struct rproc *rproc)
> >>              return ret;
> >>      }
> >>
> >> +    ret = rproc_load_fw(rproc, firmware_p);
> >> +    if (ret)
> >> +            return ret;
> >> +
> >>      /* boot the remote processor up again */
> >>      ret = rproc_start(rproc, firmware_p);
> >> +    if (ret)
> >> +            rproc_release_fw(rproc);
> >>
> >>      release_firmware(firmware_p);
> >>
> >> @@ -1997,7 +2004,13 @@ int rproc_boot(struct rproc *rproc)
> >>                      goto downref_rproc;
> >>              }
> >>
> >> +            ret = rproc_load_fw(rproc, firmware_p);
> >> +            if (ret)
> >> +                    goto downref_rproc;
> >
> > In case of error the firmware is not released.
>
> I considered that if the load fails, the firmware is not loaded
> and therefore does not need to be released.
> In other words, in case of a load error in OP-TEE, OP-TEE should
> perform the cleanup to return to its initial state before the load.
>
> Do you see a use case where we should force the release in Linux?
> Otherwise, I would propose to implement this behavior later if needed.
>

I'm talking about release_firmware() - it is not called if
rproc_load_fw(), and it needs to.

> Thanks,
> Arnaud
>
> >
> >> +
> >>              ret = rproc_fw_boot(rproc, firmware_p);
> >> +            if (ret)
> >> +                    rproc_release_fw(rproc);
> >>
> >>              release_firmware(firmware_p);
> >>      }
> >> @@ -2071,6 +2084,7 @@ int rproc_shutdown(struct rproc *rproc)
> >>      kfree(rproc->cached_table);
> >>      rproc->cached_table = NULL;
> >>      rproc->table_ptr = NULL;
> >> +    rproc_release_fw(rproc);
> >
> > Please move this after rproc_disable_iommu().
> >
> >
> >>  out:
> >>      mutex_unlock(&rproc->lock);
> >>      return ret;
> >> @@ -2471,7 +2485,7 @@ static int rproc_alloc_ops(struct rproc *rproc, const struct rproc_ops *ops)
> >>      if (!rproc->ops->coredump)
> >>              rproc->ops->coredump = rproc_coredump;
> >>
> >> -    if (rproc->ops->load)
> >> +    if (rproc->ops->load || rproc->ops->load_fw)
> >>              return 0;
> >>
> >>      /* Default to ELF loader if no load function is specified */
> >> diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
> >> index 0cd09e67ac14..2104ca449178 100644
> >> --- a/drivers/remoteproc/remoteproc_internal.h
> >> +++ b/drivers/remoteproc/remoteproc_internal.h
> >> @@ -221,4 +221,18 @@ bool rproc_u64_fit_in_size_t(u64 val)
> >>      return (val <= (size_t) -1);
> >>  }
> >>
> >> +static inline void rproc_release_fw(struct rproc *rproc)
> >> +{
> >> +    if (rproc->ops->release_fw)
> >> +            rproc->ops->release_fw(rproc);
> >> +}
> >> +
> >> +static inline int rproc_load_fw(struct rproc *rproc, const struct firmware *fw)
> >> +{
> >> +    if (rproc->ops->load_fw)
> >> +            return rproc->ops->load_fw(rproc, fw);
> >> +
> >> +    return 0;
> >> +}
> >> +
> >>  #endif /* REMOTEPROC_INTERNAL_H */
> >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> >> index 2e0ddcb2d792..ba6fd560f7ba 100644
> >> --- a/include/linux/remoteproc.h
> >> +++ b/include/linux/remoteproc.h
> >> @@ -381,6 +381,10 @@ enum rsc_handling_status {
> >>   * @panic:  optional callback to react to system panic, core will delay
> >>   *          panic at least the returned number of milliseconds
> >>   * @coredump:         collect firmware dump after the subsystem is shutdown
> >> + * @load_fw:        optional function to load non-ELF firmware image to memory, where the remote
> >
> > Round this down to 80 characters please.  Here having a longer line doesn't
> > improve readability.
> >
> >> + *          processor expects to find it.
> >> + * @release_fw:     optional function to release the firmware image from memories.
> >> + *          This function is called after stopping the remote processor or in case of error
> >
> > Same.
> >
> > More comments tomorrow or later during the week.
> >
> > Thanks,
> > Mathieu
> >
> >>   */
> >>  struct rproc_ops {
> >>      int (*prepare)(struct rproc *rproc);
> >> @@ -403,6 +407,8 @@ struct rproc_ops {
> >>      u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
> >>      unsigned long (*panic)(struct rproc *rproc);
> >>      void (*coredump)(struct rproc *rproc);
> >> +    int (*load_fw)(struct rproc *rproc, const struct firmware *fw);
> >> +    void (*release_fw)(struct rproc *rproc);
> >>  };
> >>
> >>  /**
> >> --
> >> 2.25.1
> >>