Message-ID: <CANLsYkwPDFvJxgXrAV=92w+sT8tXB=-=K8Qs8eRVKm2C2v+0aA@mail.gmail.com>
Date: Wed, 20 Nov 2024 09:04:05 -0700
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: Arnaud POULIQUEN <arnaud.pouliquen@...s.st.com>
Cc: Bjorn Andersson <andersson@...nel.org>, Jens Wiklander <jens.wiklander@...aro.org>, 
	Rob Herring <robh+dt@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	linux-stm32@...md-mailman.stormreply.com, 
	linux-arm-kernel@...ts.infradead.org, linux-remoteproc@...r.kernel.org, 
	linux-kernel@...r.kernel.org, op-tee@...ts.trustedfirmware.org, 
	devicetree@...r.kernel.org
Subject: Re: [PATCH v13 4/7] remoteproc: Introduce release_fw optional operation

On Tue, 19 Nov 2024 at 13:38, Mathieu Poirier
<mathieu.poirier@...aro.org> wrote:
>
> On Tue, 19 Nov 2024 at 11:14, Arnaud POULIQUEN
> <arnaud.pouliquen@...s.st.com> wrote:
> >
> > Hello Mathieu,
> >
> > On 11/18/24 18:52, Mathieu Poirier wrote:
> > > On Mon, Nov 04, 2024 at 02:35:12PM +0100, Arnaud Pouliquen wrote:
> > >> This patch updates the rproc_ops struct to include an optional
> > >> release_fw function.
> > >>
> > >> The release_fw ops is responsible for releasing the remote processor
> > >> firmware image. The ops is called in the following cases:
> > >>
> > >>  - An error occurs in rproc_start() between the loading of the segments and
> > >>       the start of the remote processor.
> > >>  - after stopping the remote processor.
> > >>
> > >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@...s.st.com>
> > >> ---
> > >> Updates from version V11:
> > >> - fix typo in @release_fw comment
> > >> ---
> > >>  drivers/remoteproc/remoteproc_core.c | 5 +++++
> > >>  include/linux/remoteproc.h           | 3 +++
> > >>  2 files changed, 8 insertions(+)
> > >>
> > >> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > >> index 7694817f25d4..46863e1ca307 100644
> > >> --- a/drivers/remoteproc/remoteproc_core.c
> > >> +++ b/drivers/remoteproc/remoteproc_core.c
> > >> @@ -1258,6 +1258,9 @@ static int rproc_alloc_registered_carveouts(struct rproc *rproc)
> > >>
> > >>  static void rproc_release_fw(struct rproc *rproc)
> > >>  {
> > >> +    if (rproc->ops->release_fw)
> > >> +            rproc->ops->release_fw(rproc);
> > >> +
> > >>      /* Free the copy of the resource table */
> > >>      kfree(rproc->cached_table);
> > >>      rproc->cached_table = NULL;
> > >> @@ -1377,6 +1380,8 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> > >>  unprepare_subdevices:
> > >>      rproc_unprepare_subdevices(rproc);
> > >>  reset_table_ptr:
> > >> +    if (rproc->ops->release_fw)
> > >> +            rproc->ops->release_fw(rproc);
> > >>      rproc->table_ptr = rproc->cached_table;
> > >
> > > I suggest the following:
> > >
> > > 1) Create two new functions, i.e rproc_load_fw() and rproc_release_fw().  The
> > > only thing those would do is call rproc->ops->load_fw() and
> > > rproc->ops->release_fw(), if they are present.  When a TEE interface is
> > > available, ->load_fw() and ->release_fw() become rproc_tee_load_fw() and
> > > rproc_tee_release_fw().
> >
> >
> > I'm wondering if it should be ->preload_fw() instead of ->load_fw() ops, as the
> > ->load() op already exists.
> >
>
> I agree that ->load() and ->load_fw() will lead to confusion.  I would
> support ->preload_fw() but there is no obvious antonyme.
>
> Since we already have rproc_ops::prepare() and rproc_prepare_device()
> I suggest rproc_ops::prepare_fw() and rproc_prepare_fw().  The
> corollary would be rproc_ops::unprepare_fw() and rproc_unprepare_fm().
> That said, I'm open to other ideas should you be interested in finding
> other alternatives.
>

Actually...  A better approach might to rename rproc::load to
rproc::load_segments.  That way we can use rproc::load_fw() and
rproc_load_fw() without confusion.

> > >
> > > 2) Call rproc_load_fw() in rproc_boot(), just before rproc_fw_boot().  If the
> > > call to rproc_fw_boot() fails, call rproc_release_fw().
> > >
> > > 3) The same logic applies to rproc_boot_recovery(), i.e call rproc_load_fw()
> > > before rproc_start() and call rproc_release_fw() if rproc_start() fails.
> >
> >
> > I implemented this and I'm currently testing it.
> > Thise second part requires a few adjustments to work. The ->load() ops needs to
> > becomes optional to not be called if the "->preload_fw()" is used.
> >
> > For that, I propose to return 0 in rproc_load_segments if rproc->ops->load is
> > NULL and compensate by checking that at least "->preload_fw()" or ->load() is
> > non-null in rproc_alloc_ops.
> >
>
> I agree.
>
> > Thanks,
> > Arnaud
> >
> >
> > >
> > > 4) Take rproc_tee_load_fw() out of rproc_tee_parse_fw().  It will now be called
> > > in rproc_load_fw().
> > >
> > > 5) As stated above function rproc_release_fw() now calls rproc_tee_release_fw().
> > > The former is already called in rproc_shutdown() so we are good in that front.
> > >
> > > With the above the cached_table management within the core remains the same and
> > > we can get rid of patch 3.7.
> >
> > >
> > > Thanks,
> > > Mathieu
> > >
> > >>
> > >>      return ret;
> > >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > >> index 2e0ddcb2d792..08e0187a84d9 100644
> > >> --- a/include/linux/remoteproc.h
> > >> +++ b/include/linux/remoteproc.h
> > >> @@ -381,6 +381,8 @@ 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
> > >> + * @release_fw:     optional function to release the firmware image from ROM memories.
> > >> + *          This function is called after stopping the remote processor or in case of an error
> > >>   */
> > >>  struct rproc_ops {
> > >>      int (*prepare)(struct rproc *rproc);
> > >> @@ -403,6 +405,7 @@ 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);
> > >> +    void (*release_fw)(struct rproc *rproc);
> > >>  };
> > >>
> > >>  /**
> > >> --
> > >> 2.25.1
> > >>

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