Re: [PATCH 1/4 v3] cxl/core: Change match_*_by_range() calling convention

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

On 3/14/25 4:36 AM, Fabio M. De Francesco wrote:
> Replace struct range parameter with struct cxl_endpoint_decoder of
> which range is a member in the match_*_by_range() functions.
> 
> This is in preparation for expanding these helpers to perform arch
> specific region matching that requires a cxl_endpoint_decoder.
> 
> No functional changes.
> 
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/cxl/core/region.c | 26 ++++++++++++++++----------
>  1 file changed, 16 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index b3260d433ec7..97122d645cc1 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1758,24 +1758,27 @@ static struct cxl_port *next_port(struct cxl_port *port)
>  static int match_switch_decoder_by_range(struct device *dev,
>  					 const void *data)
>  {
> +	const struct cxl_endpoint_decoder *cxled = data;
>  	struct cxl_switch_decoder *cxlsd;
> -	const struct range *r1, *r2 = data;
> -
> +	const struct range *r1, *r2;
>  
>  	if (!is_switch_decoder(dev))
>  		return 0;
>  
>  	cxlsd = to_cxl_switch_decoder(dev);
>  	r1 = &cxlsd->cxld.hpa_range;
> +	r2 = &cxled->cxld.hpa_range;
>  
>  	if (is_root_decoder(dev))
>  		return range_contains(r1, r2);
>  	return (r1->start == r2->start && r1->end == r2->end);
>  }
>  
> -static int find_pos_and_ways(struct cxl_port *port, struct range *range,
> +static int find_pos_and_ways(struct cxl_port *port,
> +			     struct cxl_endpoint_decoder *cxled,
>  			     int *pos, int *ways)
>  {
> +	struct range *range = &cxled->cxld.hpa_range;
>  	struct cxl_switch_decoder *cxlsd;
>  	struct cxl_port *parent;
>  	struct device *dev;
> @@ -1785,7 +1788,7 @@ static int find_pos_and_ways(struct cxl_port *port, struct range *range,
>  	if (!parent)
>  		return rc;
>  
> -	dev = device_find_child(&parent->dev, range,
> +	dev = device_find_child(&parent->dev, cxled,
>  				match_switch_decoder_by_range);
>  	if (!dev) {
>  		dev_err(port->uport_dev,
> @@ -1865,7 +1868,7 @@ static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
>  		if (is_cxl_root(iter))
>  			break;
>  
> -		rc = find_pos_and_ways(iter, range, &parent_pos, &parent_ways);
> +		rc = find_pos_and_ways(iter, cxled, &parent_pos, &parent_ways);
>  		if (rc)
>  			return rc;
>  
> @@ -3199,22 +3202,26 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
>  static int match_root_decoder_by_range(struct device *dev,
>  				       const void *data)
>  {
> -	const struct range *r1, *r2 = data;
> +	const struct cxl_endpoint_decoder *cxled = data;
>  	struct cxl_root_decoder *cxlrd;
> +	const struct range *r1, *r2;
>  
>  	if (!is_root_decoder(dev))
>  		return 0;
>  
>  	cxlrd = to_cxl_root_decoder(dev);
>  	r1 = &cxlrd->cxlsd.cxld.hpa_range;
> +	r2 = &cxled->cxld.hpa_range;
> +
>  	return range_contains(r1, r2);
>  }
>  
>  static int match_region_by_range(struct device *dev, const void *data)
>  {
> +	const struct cxl_endpoint_decoder *cxled = data;
> +	const struct range *r = &cxled->cxld.hpa_range;
>  	struct cxl_region_params *p;
>  	struct cxl_region *cxlr;
> -	const struct range *r = data;
>  
>  	if (!is_cxl_region(dev))
>  		return 0;
> @@ -3382,7 +3389,6 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
>  int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
>  {
>  	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
> -	struct range *hpa = &cxled->cxld.hpa_range;
>  	struct cxl_decoder *cxld = &cxled->cxld;
>  	struct device *cxlrd_dev, *region_dev;
>  	struct cxl_root_decoder *cxlrd;
> @@ -3391,7 +3397,7 @@ int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
>  	bool attach = false;
>  	int rc;
>  
> -	cxlrd_dev = device_find_child(&root->dev, &cxld->hpa_range,
> +	cxlrd_dev = device_find_child(&root->dev, cxled,
>  				      match_root_decoder_by_range);
>  	if (!cxlrd_dev) {
>  		dev_err(cxlmd->dev.parent,
> @@ -3408,7 +3414,7 @@ int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
>  	 * one does the construction and the others add to that.
>  	 */
>  	mutex_lock(&cxlrd->range_lock);
> -	region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, hpa,
> +	region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, cxled,
>  				       match_region_by_range);
>  	if (!region_dev) {
>  		cxlr = construct_region(cxlrd, cxled);