Re: [PATCH v2 2/3] coresight: refactor with function of_coresight_get_cpu

[Mathieu Poirier]

On Tue, Feb 28, 2017 at 11:06:59PM +0800, Leo Yan wrote:
> This is refactor to add function of_coresight_get_cpu(), so it's used to
> retrieve CPU id for coresight component. Finally can use it as a common
> function for multiple places.
> 
> Suggested-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> ---
>  drivers/hwtracing/coresight/of_coresight.c | 35 ++++++++++++++++++++----------
>  include/linux/coresight.h                  |  2 ++
>  2 files changed, 25 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
> index 629e031..2e7bbe2 100644
> --- a/drivers/hwtracing/coresight/of_coresight.c
> +++ b/drivers/hwtracing/coresight/of_coresight.c
> @@ -101,14 +101,34 @@ static int of_coresight_alloc_memory(struct device *dev,
>  	return 0;
>  }
>  
> +int of_coresight_get_cpu(struct device_node *node)
> +{
> +	int cpu;
> +	struct device_node *dn;
> +
> +	dn = of_parse_phandle(node, "cpu", 0);
> +
> +	/* Affinity defaults to CPU0 */
> +	if (!dn)
> +		return 0;
> +
> +	for_each_possible_cpu(cpu) {
> +		if (dn == of_get_cpu_node(cpu, NULL))
> +			break;
> +	}
> +	of_node_put(dn);

In the case where no CPU nodes are found this function will return the number
of the last CPU that was probed instead of '0'.

> +
> +	return cpu;
> +}
> +EXPORT_SYMBOL_GPL(of_coresight_get_cpu);

Any reason you exported this - the fact that is it declared in corsight.h should
be enough.

Thanks,
Mathieu

> +
>  struct coresight_platform_data *of_get_coresight_platform_data(
>  				struct device *dev, struct device_node *node)
>  {
> -	int i = 0, ret = 0, cpu;
> +	int i = 0, ret = 0;
>  	struct coresight_platform_data *pdata;
>  	struct of_endpoint endpoint, rendpoint;
>  	struct device *rdev;
> -	struct device_node *dn;
>  	struct device_node *ep = NULL;
>  	struct device_node *rparent = NULL;
>  	struct device_node *rport = NULL;
> @@ -175,16 +195,7 @@ struct coresight_platform_data *of_get_coresight_platform_data(
>  		} while (ep);
>  	}
>  
> -	/* Affinity defaults to CPU0 */
> -	pdata->cpu = 0;
> -	dn = of_parse_phandle(node, "cpu", 0);
> -	for (cpu = 0; dn && cpu < nr_cpu_ids; cpu++) {
> -		if (dn == of_get_cpu_node(cpu, NULL)) {
> -			pdata->cpu = cpu;
> -			break;
> -		}
> -	}
> -	of_node_put(dn);
> +	pdata->cpu = of_coresight_get_cpu(node);
>  
>  	return pdata;
>  }
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index 2a5982c..6709561 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -263,11 +263,13 @@ static inline int coresight_timeout(void __iomem *addr, u32 offset,
>  #endif
>  
>  #ifdef CONFIG_OF
> +extern int of_coresight_get_cpu(struct device_node *node);
>  extern struct coresight_platform_data *of_get_coresight_platform_data(
>  				struct device *dev, struct device_node *node);
>  #else
>  static inline struct coresight_platform_data *of_get_coresight_platform_data(
>  	struct device *dev, struct device_node *node) { return NULL; }
> +static int of_coresight_get_cpu(struct device_node *node) { return 0; }
>  #endif
>  
>  #ifdef CONFIG_PID_NS
> -- 
> 2.7.4
>