Re: [PATCH v3 03/14] remoteproc: Add new operation and flags for synchronistation

Mathieu Poirier
2020-04-30T19:49:38Z

On Tue, Apr 28, 2020 at 06:38:41PM +0200, Arnaud POULIQUEN wrote:
>
>
> On 4/24/20 10:01 PM, Mathieu Poirier wrote:
> > Add a new sync_ops to support use cases where the remoteproc
> > core is synchronising with the remote processor. Exactly when to use
> > the synchronisation operations is directed by the flags in structure
> > rproc_sync_flags.
> >
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> > include/linux/remoteproc.h | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > index ac4082f12e8b..ceb3b2bba824 100644
> > --- a/include/linux/remoteproc.h
> > +++ b/include/linux/remoteproc.h
> > @@ -353,6 +353,23 @@ enum rsc_handling_status {
> > RSC_IGNORED = 1,
> > };
> >
> > +/**
> > + * struct rproc_sync_flags - platform specific flags indicating which
> > + * rproc_ops to use at specific times during
> > + * the rproc lifecycle.
> > + * @on_init: true if synchronising with the remote processor at
> > + * initialisation time
> > + * @after_stop: true if synchronising with the remote processor after it was
> > + * stopped from the cmmand line
> typo command
> > + * @after_crash: true if synchronising with the remote processor after
> > + * it has crashed
> > + */
> > +struct rproc_sync_flags {
> > + bool on_init;
> > + bool after_stop;
> > + bool after_crash;
> > +};
> > +
> how about a bit field instead (just a proposition)?
> Platform driver would set the sync flag and rproc_set_sync_flag could be a
> simple mask instead of a switch case.

I opted for a structure over bit fields because I thought it would be easier to
read/understand. Both approaches are valid and I have to particular preference
other than, in my own view, a structure is easier to understand.

I'll wait a little to see what other people think. If nobody objects the next
revision will have bit fields.

>
> Is it possible to split this patch in a different ways because difficult to understand as
> rproc_sync_flags seems not used before
> [PATCH v3 09/14] remoteproc: Deal with synchronisation when crashing

Certainly

>
> Thanks
> Arnaud
>
> > /**
> > * struct rproc_ops - platform-specific device handlers
> > * @start: power on the device and boot it
> > @@ -459,6 +476,9 @@ struct rproc_dump_segment {
> > * @firmware: name of firmware file to be loaded
> > * @priv: private data which belongs to the platform-specific rproc module
> > * @ops: platform-specific start/stop rproc handlers
> > + * @sync_ops: platform-specific start/stop rproc handlers when
> > + * synchronising with a remote processor.
> > + * @sync_flags: Determine the rproc_ops to choose in specific states.
> > * @dev: virtual device for refcounting and common remoteproc behavior
> > * @power: refcount of users who need this rproc powered up
> > * @state: state of the device
> > @@ -482,6 +502,7 @@ struct rproc_dump_segment {
> > * @table_sz: size of @cached_table
> > * @has_iommu: flag to indicate if remote processor is behind an MMU
> > * @auto_boot: flag to indicate if remote processor should be auto-started
> > + * @sync_with_rproc: true if currently synchronising with the rproc
> > * @dump_segments: list of segments in the firmware
> > * @nb_vdev: number of vdev currently handled by rproc
> > */
> > @@ -492,6 +513,8 @@ struct rproc {
> > const char *firmware;
> > void *priv;
> > struct rproc_ops *ops;
> > + struct rproc_ops *sync_ops;
> > + struct rproc_sync_flags sync_flags;
> > struct device dev;
> > atomic_t power;
> > unsigned int state;
> > @@ -515,6 +538,7 @@ struct rproc {
> > size_t table_sz;
> > bool has_iommu;
> > bool auto_boot;
> > + bool sync_with_rproc;
> > struct list_head dump_segments;
> > int nb_vdev;
> > u8 elf_class;
> >