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

[Suman Anna <s-anna@ti.com>]

Hi Mathieu,

On 3/27/20 8:47 AM, 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
> 
> Regards,
> Loic
> 
>> +		/* Nothing else to do */
>> +		goto out;
>> +	}
>> +
>> +	/* Allocate synchronisation state machine */
>> +	st = kzalloc(sizeof(*st), GFP_KERNEL);

Hmm, do you really want to allocate these dynamically? You are
allocating/initializing these no matter what, and I see these as no
different from the likes of has_iommu or auto_boot. Why not just add the
struct as a regular member instead of a pointer?

>> +	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;

This is not needed because of the rproc_set_mcu_sync_state call below.

regards
Suman

>> +	/* 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
>