[PATCH v2 11/15] cxl/region: Use the endpoint's SPA range to check a region

Robert Richter posted 15 patches 10 months ago
[PATCH v2 11/15] cxl/region: Use the endpoint's SPA range to check a region
Posted by Robert Richter 10 months ago
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@amd.com>
---
 drivers/cxl/core/region.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 3afcc9ca06ae..2ca24565757a 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1531,22 +1531,26 @@ 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 {
-- 
2.39.5
Re: [PATCH v2 11/15] cxl/region: Use the endpoint's SPA range to check a region
Posted by Gregory Price 8 months, 2 weeks ago
On Tue, Feb 18, 2025 at 02:23:52PM +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@amd.com>

Like other patches, I think this can probably just be folded into patch
5 under the comment that cxled->spa_range == cxled->cxld.hpa_range for
all systems that do not implement a translation mechanism.

~Gregory
Re: [PATCH v2 11/15] cxl/region: Use the endpoint's SPA range to check a region
Posted by Gregory Price 10 months ago
On Tue, Feb 18, 2025 at 02:23:52PM +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@amd.com>

Explanation could be a little clearer, something like:

Endpoint and switch decoders may have an HPA range that differs from
the memory region's SPA range.  Utilize the device's calculated
spa_range instead of its hpa_range to validate the region mapping.


The interleave comments don't seem particularly relevant here unless i'm
missing something.

The content of the patch looks good.

Reviewed-by: Gregory Price <gourry@gourry.net>

> ---
>  drivers/cxl/core/region.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 3afcc9ca06ae..2ca24565757a 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1531,22 +1531,26 @@ 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 {
> -- 
> 2.39.5
>