Re: [PATCH 1/3] cxl/region: Prepare the decoder match range helper for reuse

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Thu,  5 Oct 2023 17:43:11 -0700
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> match_decoder_by_range() and decoder_match_range() both determine
> if an HPA range matches a decoder. The first does it for root
> decoders and the second one operates on switch decoders.
> 
> Tidy these up with clear naming and make the switch helper more
> like the root decoder helper in style and functionality. Make it
> take the actual range, rather than an endpoint decoder from which
> it extracts the range.
> 
> Aside from aethetics and maintainability, this is in preparation
> for reuse.
> 
> Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery")
> Reported-by: Dmytro Adamenko <dmytro.adamenko@intel.com>
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/cxl/core/region.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 6d63b8798c29..64206fc4d99b 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1487,16 +1487,19 @@ static struct cxl_port *next_port(struct cxl_port *port)
>  	return port->parent_dport->port;
>  }
>  
> -static int decoder_match_range(struct device *dev, void *data)
> +static int match_switch_decoder_by_range(struct device *dev, void *data)
>  {
> -	struct cxl_endpoint_decoder *cxled = data;
> +	struct range *r1, *r2 = data;
>  	struct cxl_switch_decoder *cxlsd;
>  
>  	if (!is_switch_decoder(dev))
>  		return 0;
>  
>  	cxlsd = to_cxl_switch_decoder(dev);
> -	return range_contains(&cxlsd->cxld.hpa_range, &cxled->cxld.hpa_range);
> +	r1 = &cxlsd->cxld.hpa_range;
> +	return range_contains(r1, r2);
> +}
> +
>  }
>  
>  static void find_positions(const struct cxl_switch_decoder *cxlsd,
> @@ -1565,7 +1568,8 @@ static int cmp_decode_pos(const void *a, const void *b)
>  		goto err;
>  	}
>  
> -	dev = device_find_child(&port->dev, cxled_a, decoder_match_range);
> +	dev = device_find_child(&port->dev, &cxled_a->cxld.hpa_range,
> +				match_switch_decoder_by_range);
>  	if (!dev) {
>  		struct range *range = &cxled_a->cxld.hpa_range;
>  
> @@ -2696,7 +2700,7 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
>  	return rc;
>  }
>  
> -static int match_decoder_by_range(struct device *dev, void *data)
> +static int match_root_decoder_by_range(struct device *dev, void *data)
>  {
>  	struct range *r1, *r2 = data;
>  	struct cxl_root_decoder *cxlrd;
> @@ -2827,7 +2831,7 @@ int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
>  	int rc;
>  
>  	cxlrd_dev = device_find_child(&root->dev, &cxld->hpa_range,
> -				      match_decoder_by_range);
> +				      match_root_decoder_by_range);
>  	if (!cxlrd_dev) {
>  		dev_err(cxlmd->dev.parent,
>  			"%s:%s no CXL window for range %#llx:%#llx\n",