linux-kernel - Re: [PATCH v4 04/14] cxl/region: Add @hpa_range argument to function cxl_calc_interleave

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <df23145b-b088-4131-ba23-6f63a4c49de0@intel.com>
Date: Mon, 3 Nov 2025 14:52:01 -0700
From: Dave Jiang <dave.jiang@...el.com>
To: Robert Richter <rrichter@....com>,
 Alison Schofield <alison.schofield@...el.com>,
 Vishal Verma <vishal.l.verma@...el.com>, Ira Weiny <ira.weiny@...el.com>,
 Dan Williams <dan.j.williams@...el.com>,
 Jonathan Cameron <Jonathan.Cameron@...wei.com>,
 Davidlohr Bueso <dave@...olabs.net>
Cc: linux-cxl@...r.kernel.org, linux-kernel@...r.kernel.org,
 Gregory Price <gourry@...rry.net>,
 "Fabio M. De Francesco" <fabio.m.de.francesco@...ux.intel.com>,
 Terry Bowman <terry.bowman@....com>, Joshua Hahn <joshua.hahnjy@...il.com>
Subject: Re: [PATCH v4 04/14] cxl/region: Add @hpa_range argument to function
 cxl_calc_interleave_pos()



On 11/3/25 11:47 AM, Robert Richter wrote:
> cxl_calc_interleave_pos() uses the endpoint decoder's HPA range to
> determine its interleaving position. This requires the endpoint
> decoders to be an SPA, which is not the case for systems that need
> address translation.
> 
> Add a separate @hpa_range argument to function
> cxl_calc_interleave_pos() to specify the address range. Now it is
> possible to pass the SPA translated address range of an endpoint
> decoder to function cxl_calc_interleave_pos().
> 
> Refactor only, no functional changes.
> 
> Patch is a prerequisite to implement address translation.
> 
> Reviewed-by: Gregory Price <gourry@...rry.net>
> Signed-off-by: Robert Richter <rrichter@....com>

Reviewed-by: Dave Jiang <dave.jiang@...el.com>> ---
>  drivers/cxl/core/region.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index bb889c891cf7..d3557d9d5b0f 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1845,11 +1845,11 @@ static int find_pos_and_ways(struct cxl_port *port, struct range *range,
>   * Return: position >= 0 on success
>   *	   -ENXIO on failure
>   */
> -static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
> +static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled,
> +				   struct range *hpa_range)
>  {
>  	struct cxl_port *iter, *port = cxled_to_port(cxled);
>  	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
> -	struct range *range = &cxled->cxld.hpa_range;
>  	int parent_ways = 0, parent_pos = 0, pos = 0;
>  	int rc;
>  
> @@ -1887,7 +1887,8 @@ 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, hpa_range, &parent_pos,
> +				       &parent_ways);
>  		if (rc)
>  			return rc;
>  
> @@ -1897,7 +1898,7 @@ static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
>  	dev_dbg(&cxlmd->dev,
>  		"decoder:%s parent:%s port:%s range:%#llx-%#llx pos:%d\n",
>  		dev_name(&cxled->cxld.dev), dev_name(cxlmd->dev.parent),
> -		dev_name(&port->dev), range->start, range->end, pos);
> +		dev_name(&port->dev), hpa_range->start, hpa_range->end, pos);
>  
>  	return pos;
>  }
> @@ -1910,7 +1911,7 @@ static int cxl_region_sort_targets(struct cxl_region *cxlr)
>  	for (i = 0; i < p->nr_targets; i++) {
>  		struct cxl_endpoint_decoder *cxled = p->targets[i];
>  
> -		cxled->pos = cxl_calc_interleave_pos(cxled);
> +		cxled->pos = cxl_calc_interleave_pos(cxled, &cxlr->hpa_range);
>  		/*
>  		 * Record that sorting failed, but still continue to calc
>  		 * cxled->pos so that follow-on code paths can reliably
> @@ -2094,7 +2095,7 @@ static int cxl_region_attach(struct cxl_region *cxlr,
>  		struct cxl_endpoint_decoder *cxled = p->targets[i];
>  		int test_pos;
>  
> -		test_pos = cxl_calc_interleave_pos(cxled);
> +		test_pos = cxl_calc_interleave_pos(cxled, &cxlr->hpa_range);
>  		dev_dbg(&cxled->cxld.dev,
>  			"Test cxl_calc_interleave_pos(): %s test_pos:%d cxled->pos:%d\n",
>  			(test_pos == cxled->pos) ? "success" : "fail",