Subject: Re: [PATCH v5 20/27] cxl/region: factor out interleave ways setup

From: Zhi Wang <[email-masked]>
Date: Tue, 19 Nov 2024 22:20:50 +0200

On Mon, 18 Nov 2024 16:44:27 +0000
<[email-masked]> wrote:

LGTM. Reviewed-by: Zhi Wang <[email-masked]>

> From: Alejandro Lucero <[email-masked]>
> 
> In preparation for kernel driven region creation, factor out a common
> helper from the user-sysfs region setup for interleave ways.
> 
> Signed-off-by: Alejandro Lucero <[email-masked]>
> Co-developed-by: Dan Williams <[email-masked]>
> ---
>  drivers/cxl/core/region.c | 46
> +++++++++++++++++++++++---------------- 1 file changed, 27
> insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 8e2dbd15cfc0..04f82adb763f 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -464,22 +464,14 @@ static ssize_t interleave_ways_show(struct
> device *dev, 
>  static const struct attribute_group
> *get_cxl_region_target_group(void); 
> -static ssize_t interleave_ways_store(struct device *dev,
> -				     struct device_attribute *attr,
> -				     const char *buf, size_t len)
> +static int set_interleave_ways(struct cxl_region *cxlr, int val)
>  {
> -	struct cxl_root_decoder *cxlrd =
> to_cxl_root_decoder(dev->parent);
> +	struct cxl_root_decoder *cxlrd =
> to_cxl_root_decoder(cxlr->dev.parent); struct cxl_decoder *cxld =
> &cxlrd->cxlsd.cxld;
> -	struct cxl_region *cxlr = to_cxl_region(dev);
>  	struct cxl_region_params *p = &cxlr->params;
> -	unsigned int val, save;
> -	int rc;
> +	int save, rc;
>  	u8 iw;
>  
> -	rc = kstrtouint(buf, 0, &val);
> -	if (rc)
> -		return rc;
> -
>  	rc = ways_to_eiw(val, &iw);
>  	if (rc)
>  		return rc;
> @@ -494,20 +486,36 @@ static ssize_t interleave_ways_store(struct
> device *dev, return -EINVAL;
>  	}
>  
> -	rc = down_write_killable(&cxl_region_rwsem);
> -	if (rc)
> -		return rc;
> -	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
> -		rc = -EBUSY;
> -		goto out;
> -	}
> +	lockdep_assert_held_write(&cxl_region_rwsem);
> +	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
> +		return -EBUSY;
>  
>  	save = p->interleave_ways;
>  	p->interleave_ways = val;
>  	rc = sysfs_update_group(&cxlr->dev.kobj,
> get_cxl_region_target_group()); if (rc)
>  		p->interleave_ways = save;
> -out:
> +
> +	return rc;
> +}
> +
> +static ssize_t interleave_ways_store(struct device *dev,
> +				     struct device_attribute *attr,
> +				     const char *buf, size_t len)
> +{
> +	struct cxl_region *cxlr = to_cxl_region(dev);
> +	unsigned int val;
> +	int rc;
> +
> +	rc = kstrtouint(buf, 0, &val);
> +	if (rc)
> +		return rc;
> +
> +	rc = down_write_killable(&cxl_region_rwsem);
> +	if (rc)
> +		return rc;
> +
> +	rc = set_interleave_ways(cxlr, val);
>  	up_write(&cxl_region_rwsem);
>  	if (rc)
>  		return rc;