Re: [PATCH 12/19] cxl/region: Factor out interleave ways setup

[Dave Jiang <dave.jiang@intel.com>]

On 6/4/23 16:32, Dan Williams wrote:
> In preparation for kernel driven region creation, factor out a common
> helper from the user-sysfs region setup for interleave_ways.
>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>   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 bd3c3d4b2683..821c2d90154f 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -338,22 +338,14 @@ 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;
> @@ -368,21 +360,37 @@ 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;
>   	return len;
>