linux-kernel - Re: [PATCH 2/4] remoteproc: Split firmware name allocation from rproc

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Date:   Mon, 13 Apr 2020 15:56:38 -0500
From:   Alex Elder <elder@...aro.org>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>,
        bjorn.andersson@...aro.org, ohad@...ery.com
Cc:     s-anna@...com, linux-remoteproc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] remoteproc: Split firmware name allocation from
 rproc_alloc()

On 4/13/20 2:33 PM, Mathieu Poirier wrote:
> Make the firmware name allocation a function on its own in order to
> introduce more flexibility to function rproc_alloc().
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>

I didn't look at the larger context (MCU series); I'm only looking
at this (and the others in this series) in isolation.  I like
that you're encapsulating this stuff into functions but doing so
doesn't really add any flexibility.

Two small suggestions for you to consider but they're truly
more about style so it's entirely up to you.  Outside of that
this looks straightforward to me, and the result of the series
is an improvement.

I'll let you comment on my suggestions before offering my
"reviewed-by" indication.

					-Alex

> ---
>  drivers/remoteproc/remoteproc_core.c | 66 ++++++++++++++++------------
>  1 file changed, 39 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 80056513ae71..4dee63f319ba 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1979,6 +1979,33 @@ static const struct device_type rproc_type = {
>  	.release	= rproc_type_release,
>  };
>  
> +static int rproc_alloc_firmware(struct rproc *rproc,
> +				const char *name, const char *firmware)
> +{
> +	char *p, *template = "rproc-%s-fw";
> +	int name_len;

Not a big deal (and maybe it's not consistent with other nearby
style) but template and name_len could be defined inside the
"if (!firmware)" block.

> +	if (!firmware) {
> +		/*
> +		 * If the caller didn't pass in a firmware name then
> +		 * construct a default name.
> +		 */
> +		name_len = strlen(name) + strlen(template) - 2 + 1;
> +		p = kmalloc(name_len, GFP_KERNEL);


I don't know if it would be an improvement, but you could
check for a null p value below for both cases.  I.e.:

		if (p)
			snprintf(p, ...);

(more below)

> +		if (!p)
> +			return -ENOMEM;
> +		snprintf(p, name_len, template, name);
> +	} else {
> +		p = kstrdup(firmware, GFP_KERNEL);
> +		if (!p)
> +			return -ENOMEM;
> +	}
> +

	if (!p)
		return -ENOMEM;
	
> +	rproc->firmware = p;
> +
> +	return 0;
> +}
> +
>  /**
>   * rproc_alloc() - allocate a remote processor handle
>   * @dev: the underlying device
> @@ -2007,42 +2034,21 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>  			  const char *firmware, int len)
>  {
>  	struct rproc *rproc;
> -	char *p, *template = "rproc-%s-fw";
> -	int name_len;
>  
>  	if (!dev || !name || !ops)
>  		return NULL;
>  
> -	if (!firmware) {
> -		/*
> -		 * If the caller didn't pass in a firmware name then
> -		 * construct a default name.
> -		 */
> -		name_len = strlen(name) + strlen(template) - 2 + 1;
> -		p = kmalloc(name_len, GFP_KERNEL);
> -		if (!p)
> -			return NULL;
> -		snprintf(p, name_len, template, name);
> -	} else {
> -		p = kstrdup(firmware, GFP_KERNEL);
> -		if (!p)
> -			return NULL;
> -	}
> -
>  	rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL);
> -	if (!rproc) {
> -		kfree(p);
> +	if (!rproc)
>  		return NULL;
> -	}
> +
> +	if (rproc_alloc_firmware(rproc, name, firmware))
> +		goto free_rproc;
>  
>  	rproc->ops = kmemdup(ops, sizeof(*ops), GFP_KERNEL);
> -	if (!rproc->ops) {
> -		kfree(p);
> -		kfree(rproc);
> -		return NULL;
> -	}
> +	if (!rproc->ops)
> +		goto free_firmware;
>  
> -	rproc->firmware = p;
>  	rproc->name = name;
>  	rproc->priv = &rproc[1];
>  	rproc->auto_boot = true;
> @@ -2091,6 +2097,12 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>  	rproc->state = RPROC_OFFLINE;
>  
>  	return rproc;
> +
> +free_firmware:
> +	kfree(rproc->firmware);
> +free_rproc:
> +	kfree(rproc);
> +	return NULL;
>  }
>  EXPORT_SYMBOL(rproc_alloc);
>  
>