Re: [PATCH v2 08/17] remoteproc: Allocate synchronisation state machine

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Fri, Mar 27, 2020 at 01:47:21PM +0000, Loic PALLARDY wrote:
> 
> 
> > -----Original Message-----
> > From: Mathieu Poirier <mathieu.poirier@linaro.org>
> > Sent: mardi 24 mars 2020 22:46
> > To: bjorn.andersson@linaro.org
> > Cc: ohad@wizery.com; Loic PALLARDY <loic.pallardy@st.com>; s-
> > anna@ti.com; peng.fan@nxp.com; Arnaud POULIQUEN
> > <arnaud.pouliquen@st.com>; Fabien DESSENNE
> > <fabien.dessenne@st.com>; linux-remoteproc@vger.kernel.org
> > Subject: [PATCH v2 08/17] remoteproc: Allocate synchronisation state
> > machine
> > 
> > This patch allocates a synchronisation state machine, either provided or
> > not by users, in order to enact the proper behavior requested by the
> > platform or specific scenarios.
> > 
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> >  drivers/remoteproc/remoteproc_core.c | 59
> > +++++++++++++++++++++++++++-
> >  1 file changed, 58 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/remoteproc/remoteproc_core.c
> > b/drivers/remoteproc/remoteproc_core.c
> > index 02dbb826aa29..1578a9c70422 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1955,6 +1955,7 @@ static void rproc_type_release(struct device *dev)
> >  	kfree(rproc->firmware);
> >  	kfree(rproc->ops);
> >  	kfree(rproc->sync_ops);
> > +	kfree(rproc->sync_states);
> >  	kfree(rproc);
> >  }
> > 
> > @@ -2035,6 +2036,59 @@ static int rproc_alloc_sync_ops(struct rproc *rproc,
> >  	return 0;
> >  }
> > 
> > +static int rproc_alloc_sync_states(struct rproc *rproc,
> > +				   const struct rproc_ops *boot_ops,
> > +				   const struct rproc_ops *sync_ops,
> > +				   struct rproc_sync_states *sync_states)
> > +{
> > +	struct rproc_sync_states *st;
> > +
> > +	/* At least one set of operation is needed */
> > +	if (!boot_ops && !sync_ops)
> > +		return -EINVAL;
> > +
> > +	/* We have a synchronisation state machine, no need to build one */
> > +	if (sync_states) {
> > +		st = kmemdup(sync_states, sizeof(*st), GFP_KERNEL);
> > +		if (!st)
> > +			return -ENOMEM;
> > +
> 
> I think a check between sync_states and boot_ops/sync_ops may be needed here
> even if it is platform driver responsibility to provide coherent configuration
> As soon as one of the sync_states is set at true, sync_ops must be provided
> As soon as one of the sync_states is set at false, boot_ops must be provided

That will help catch errors early - OK.

> 
> Regards,
> Loic
> 
> > +		/* Nothing else to do */
> > +		goto out;
> > +	}
> > +
> > +	/* Allocate synchronisation state machine */
> > +	st = kzalloc(sizeof(*st), GFP_KERNEL);
> > +	if (!st)
> > +		return -ENOMEM;
> > +
> > +	/*
> > +	 * We have a boot_ops and no sync_ops - build a state machine that
> > +	 * does _not_ synchronise with an MCU.
> > +	 */
> > +	if (boot_ops && !sync_ops) {
> > +		st->on_init = st->after_stop = st->after_crash = false;
> > +		goto out;
> > +	}
> > +
> > +	/*
> > +	 * We have a sync_ops and an no boot_ops - build a state machine
> > that
> > +	 * _only_ synchronises with an MCU.
> > +	 */
> > +	if (sync_ops && !boot_ops) {
> > +		st->on_init = st->after_stop = st->after_crash = true;
> > +		goto out;
> > +	}
> > +
> > +out:
> > +	rproc->sync_with_mcu = st->on_init;
> > +	/* And the synchronisation state machine to use */
> > +	rproc->sync_states = st;
> > +	/* Tell the core what to do when initialising */
> > +	rproc_set_mcu_sync_state(rproc, RPROC_SYNC_STATE_INIT);
> > +	return 0;
> > +}
> > +
> >  static int rproc_alloc_internals(struct rproc *rproc, const char *name,
> >  				 const struct rproc_ops *boot_ops,
> >  				 const struct rproc_ops *sync_ops,
> > @@ -2065,7 +2119,10 @@ static int rproc_alloc_internals(struct rproc *rproc,
> > const char *name,
> >  			return ret;
> >  	}
> > 
> > -	return 0;
> > +	/* Finally allocate the synchronisation state machine */
> > +	ret = rproc_alloc_sync_states(rproc, boot_ops, sync_ops,
> > sync_states);
> > +
> > +	return ret;
> >  }
> > 
> >  /**
> > --
> > 2.20.1
>