Re: [PATCH v1 24/29] cxl/region: Use endpoint's SPA range to check a region

[Alison Schofield]

On Tue, Jan 07, 2025 at 03:10:10PM +0100, Robert Richter wrote:
> Endpoints or switches requiring address translation might not be aware
> of the system's interleaving configuration. Then, the configured
> endpoint's address range might not match the expected range. In
> contrast, the SPA range of an endpoint is calculated applying platform
> specific address translation. That range is correct and can be used to
> check a region range.
> 
> Adjust the region range check and use the endpoint's SPA range to
> check it.
> 
> Signed-off-by: Robert Richter <rrichter@xxxxxxx>
> ---
>  drivers/cxl/core/region.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index c3322bae05b9..1dae7d36d37c 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1516,22 +1516,26 @@ static int cxl_port_setup_targets(struct cxl_port *port,
>  	if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
>  		if (cxld->interleave_ways != iw ||
>  		    cxld->interleave_granularity != ig ||
> -		    cxld->hpa_range.start != p->res->start ||
> -		    cxld->hpa_range.end != p->res->end ||
> +		    cxled->spa_range.start != p->res->start ||
> +		    cxled->spa_range.end != p->res->end ||
>  		    ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
>  			dev_err(&cxlr->dev,
>  				"%s:%s %s expected iw: %d ig: %d %pr\n",
>  				dev_name(port->uport_dev), dev_name(&port->dev),
>  				__func__, iw, ig, p->res);
>  			dev_err(&cxlr->dev,
> -				"%s:%s %s got iw: %d ig: %d state: %s %#llx:%#llx\n",
> +				"%s:%s %s got iw: %d ig: %d state: %s %#llx-%#llx:%#llx-%#llx(%s):%#llx-%#llx(%s)\n",
>  				dev_name(port->uport_dev), dev_name(&port->dev),
>  				__func__, cxld->interleave_ways,
>  				cxld->interleave_granularity,
>  				(cxld->flags & CXL_DECODER_F_ENABLE) ?
>  					"enabled" :
>  					"disabled",
> -				cxld->hpa_range.start, cxld->hpa_range.end);
> +				p->res->start, p->res->end,
> +				cxled->spa_range.start, cxled->spa_range.end,
> +				dev_name(&cxled->cxld.dev),
> +				cxld->hpa_range.start, cxld->hpa_range.end,
> +				dev_name(&cxld->dev));
>  			return -ENXIO;
>  		}
>  	} else {
> @@ -2051,13 +2055,12 @@ static int cxl_region_attach(struct cxl_region *cxlr,
>  		return -ENXIO;
>  	}
>  
> -	if (resource_size(cxled->dpa_res) * p->interleave_ways !=
> -	    resource_size(p->res)) {
> +	if (range_len(&cxled->spa_range) != resource_size(p->res)) {
>  		dev_dbg(&cxlr->dev,
> -			"%s:%s: decoder-size-%#llx * ways-%d != region-size-%#llx\n",
> +			"%s:%s: SPA size mismatch: %#llx-%#llx:%#llx-%#llx\n",

The cxled->spa_range is only set in the auto region path, yet this
path is taken by both auto and user created regions. User created regions
die here.


>  			dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
> -			(u64)resource_size(cxled->dpa_res), p->interleave_ways,
> -			(u64)resource_size(p->res));
> +			p->res->start, p->res->end,
> +			cxled->spa_range.start, cxled->spa_range.end);
>  		return -EINVAL;
>  	}
>  
> -- 
> 2.39.5
>