[PATCH v4 04/14] cxl/region: Add @hpa_range argument to function cxl_calc_interleave_pos()

Robert Richter
2025-11-03T18:49:07Z

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@gourry.net>
Signed-off-by: Robert Richter <rrichter@amd.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",
--
2.47.3