linux-kernel - Re: [PATCH v4 2/5] remoteproc: Add device-managed variants of rproc_alloc/rproc

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Message-ID: <20200120194500.GM1511@yoga>
Date:   Mon, 20 Jan 2020 11:45:00 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Fabien DESSENNE <fabien.dessenne@...com>
Cc:     Paul Cercueil <paul@...pouillou.net>,
        Ohad Ben-Cohen <ohad@...ery.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>, "od@...c.me" <od@...c.me>,
        "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 2/5] remoteproc: Add device-managed variants of
 rproc_alloc/rproc_add

On Thu 12 Dec 01:43 PST 2019, Fabien DESSENNE wrote:

> Hi Paul,
> 
> 
> Good initiative! See me remarks below.
> 

I concur!

> 
> On 10/12/2019 5:40 PM, Paul Cercueil wrote:
> > Add API functions devm_rproc_alloc() and devm_rproc_add(), which behave
> > like rproc_alloc() and rproc_add() respectively, but register their
> > respective cleanup function to be called on driver detach.
> >
> > Signed-off-by: Paul Cercueil <paul@...pouillou.net>
> > ---
> >
> > Notes:
> >      v3: New patch
> >      v4: No change
> >
> >   drivers/remoteproc/remoteproc_core.c | 67 ++++++++++++++++++++++++++++
> >   include/linux/remoteproc.h           |  5 +++
> >   2 files changed, 72 insertions(+)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index 307df98347ba..0a9fc7fdd1c3 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> 
> 
> Maybe these devm function shall be defined in a new remoteproc/devres.c 
> file. Although it seems to be a common usage I don't know if there is a 
> rule for that.
> 

Let's keep it in this same file, the devres.c would be tiny.

> 
> > @@ -1932,6 +1932,33 @@ int rproc_add(struct rproc *rproc)
> >   }
> >   EXPORT_SYMBOL(rproc_add);
> >   
> > +static void devm_rproc_remove(void *rproc)
> > +{
> > +	rproc_del(rproc);
> > +}
> > +
> > +/**
> > + * devm_rproc_add() - resource managed rproc_add()
> > + * @dev: the underlying device
> > + * @rproc: the remote processor handle to register
> > + *
> > + * This function performs like rproc_add() but the registered rproc device will
> > + * automatically be removed on driver detach.
> > + *
> > + * Returns 0 on success and an appropriate error code otherwise.
> > + */
> > +int devm_rproc_add(struct device *dev, struct rproc *rproc)
> > +{
> > +	int err;
> > +
> > +	err = rproc_add(rproc);
> > +	if (err)
> > +		return err;
> > +
> > +	return devm_add_action_or_reset(dev, devm_rproc_remove, rproc);
> > +}
> > +EXPORT_SYMBOL(devm_rproc_add);
> > +
> >   /**
> >    * rproc_type_release() - release a remote processor instance
> >    * @dev: the rproc's device
> > @@ -2149,6 +2176,46 @@ int rproc_del(struct rproc *rproc)
> >   }
> >   EXPORT_SYMBOL(rproc_del);
> >   
> > +static void devm_rproc_free(struct device *dev, void *res)
> > +{
> > +	rproc_free(*(struct rproc **)res);
> > +}
> > +
> > +/**
> > + * devm_rproc_alloc() - resource managed rproc_alloc()
> > + * @dev: the underlying device
> > + * @name: name of this remote processor
> > + * @ops: platform-specific handlers (mainly start/stop)
> > + * @firmware: name of firmware file to load, can be NULL
> > + * @len: length of private data needed by the rproc driver (in bytes)
> > + *
> > + * This function performs like rproc_alloc() but the acuired rproc device will
> 
> 
> typo: s/acuired/acquired
> 
> 
> > + * automatically be released on driver detach.
> > + *
> > + * On success the new rproc is returned, and on failure, NULL.
> > + */
> > +struct rproc *devm_rproc_alloc(struct device *dev, const char *name,
> > +			       const struct rproc_ops *ops,
> > +			       const char *firmware, int len)
> > +{
> > +	struct rproc **ptr, *rproc;
> > +
> > +	ptr = devres_alloc(devm_rproc_free, sizeof(*ptr), GFP_KERNEL);
> > +	if (!ptr)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	rproc = rproc_alloc(dev, name, ops, firmware, len);
> > +	if (rproc) {
> > +		*ptr = rproc;
> > +		devres_add(dev, ptr);
> > +	} else {
> > +		devres_free(ptr);
> > +	}
> > +
> > +	return rproc;
> 
> 
> Can't you use devm_add_action_or_reset() here too?
> 

The proposed function matches how everyone else is doing devm_*_alloc(),
so I would like to keep it as is.

Regards,
Bjorn

> 
> > +}
> > +EXPORT_SYMBOL(devm_rproc_alloc);
> > +
> >   /**
> >    * rproc_add_subdev() - add a subdevice to a remoteproc
> >    * @rproc: rproc handle to add the subdevice to
> > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > index 16ad66683ad0..5f201f0c86c3 100644
> > --- a/include/linux/remoteproc.h
> > +++ b/include/linux/remoteproc.h
> > @@ -595,6 +595,11 @@ int rproc_add(struct rproc *rproc);
> >   int rproc_del(struct rproc *rproc);
> >   void rproc_free(struct rproc *rproc);
> >   
> > +struct rproc *devm_rproc_alloc(struct device *dev, const char *name,
> > +			       const struct rproc_ops *ops,
> > +			       const char *firmware, int len);
> > +int devm_rproc_add(struct device *dev, struct rproc *rproc);
> > +
> >   void rproc_add_carveout(struct rproc *rproc, struct rproc_mem_entry *mem);
> >   
> >   struct rproc_mem_entry *
> 
> 
> BR
> 
> Fabien