Re: [PATCH v3 0/5] coresight: syscfg: Extend configfs for config load

[Mike Leach <mike.leach@linaro.org>]

HI Mathieu,

On Fri, 27 May 2022 at 17:32, Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
>
> On Thu, Apr 14, 2022 at 07:44:52AM +0100, Mike Leach wrote:
> > This set extends the configfs support to allow loading and unloading of
> > configurations as binary files via configfs.
> >
> > Additional attributes - load and unload are provided to in the
> > configurations group to implement the load functionality.
> >
> > Routines to generate binary configuration files are supplied in
> > ./tools/coresight.
> >
> > Example generator and reader applications are provided.
> >
> > Tools may be cross compiled or built for use on host system.
> >
> > Documentation is updated to describe feature usage.
>
> I think this patchset is looking quite good now.  The main issue for now is to
> know if we want to keep the capability to read and print configurations.  To me
> it doesn't provide much for the quirks it adds, i.e patch 3.
>

Given that the binary configuration files are very portable, I think
the reader is essential.
It is possible to install / use ETM4 configuration files on kernels /
systems separate from which they were built for (unlike configurations
in loadable modules which are bound to a kernel build).

It may be that a user of a file does not have the original source for
that file - which is fine as long as it can be passed through the
reader and evaluated by the user to assess suitability for the current
target.

> James and/or Leo will also have to do a review.  As such they should be added,
> along with Arnaldo, to the next revision.

OK

Thanks

Mike


>
> I am done reviewing this set.
>
> Thanks,
> Mathieu
>
> >
> > Changes since v2:
> > 1) Rebased & tested oo coresight/next - 5.18-rc2
> > 2) Moved coresight config generator and reader programs from samples to
> > tools/coresight. Docs updated to match. (suggested by Mathieu)
> > 3) userspace builds now use userspace headers from tools/...
> > 4) Other minor fixes from Mathieu's review.
> >
> > Changes since v1:
> > 1) Rebased to coresight/next - 5.16-rc1 with previous coresight config
> > set applied.
> > 2) Makefile.host fixed to default to all target.
> >
> > Mike Leach (5):
> >   coresight: configfs: Add in functionality for load via configfs
> >   coresight: configfs: Add in binary attributes to load files
> >   coresight: configfs: Modify config files to allow userspace use
> >   coresight: tools: Add config file write and reader tools
> >   Documentation: coresight: docs for config load via configfs
> >
> >  .../trace/coresight/coresight-config.rst      | 166 +++++-
> >  MAINTAINERS                                   |   2 +
> >  drivers/hwtracing/coresight/Makefile          |   2 +-
> >  .../coresight/coresight-config-file.c         | 475 ++++++++++++++++++
> >  .../coresight/coresight-config-file.h         | 126 +++++
> >  .../hwtracing/coresight/coresight-config.h    |  27 +
> >  .../coresight/coresight-syscfg-configfs.c     |  91 ++++
> >  .../hwtracing/coresight/coresight-syscfg.c    |  37 ++
> >  .../hwtracing/coresight/coresight-syscfg.h    |   2 +
> >  tools/coresight/Makefile                      |  51 ++
> >  tools/coresight/coresight-cfg-bufw.c          | 303 +++++++++++
> >  tools/coresight/coresight-cfg-bufw.h          |  26 +
> >  tools/coresight/coresight-cfg-example1.c      |  65 +++
> >  tools/coresight/coresight-cfg-examples.h      |  27 +
> >  tools/coresight/coresight-cfg-file-read.c     | 197 ++++++++
> >  tools/coresight/coresight-cfg-filegen.c       |  58 +++
> >  tools/include/uapi/coresight-config-uapi.h    |  76 +++
> >  17 files changed, 1724 insertions(+), 7 deletions(-)
> >  create mode 100644 drivers/hwtracing/coresight/coresight-config-file.c
> >  create mode 100644 drivers/hwtracing/coresight/coresight-config-file.h
> >  create mode 100644 tools/coresight/Makefile
> >  create mode 100644 tools/coresight/coresight-cfg-bufw.c
> >  create mode 100644 tools/coresight/coresight-cfg-bufw.h
> >  create mode 100644 tools/coresight/coresight-cfg-example1.c
> >  create mode 100644 tools/coresight/coresight-cfg-examples.h
> >  create mode 100644 tools/coresight/coresight-cfg-file-read.c
> >  create mode 100644 tools/coresight/coresight-cfg-filegen.c
> >  create mode 100644 tools/include/uapi/coresight-config-uapi.h
> >
> > --
> > 2.17.1
> >



--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK

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