[PATCH 1/4 v4] cxl/core: Change match_*_by_range() signatures

From: Fabio M. De Francesco
Date: Thu Jul 24 2025 - 10:27:43 EST


Replace struct range parameter with struct cxl_endpoint_decoder of
which range is a member in the match_*_by_range() functions and rename
them according to their semantics.

This is in preparation for expanding these helpers to perform arch
specific Root Decoders and Region matchings with
cxl_endpoint_decoder(s).

Cc: Alison Schofield <alison.schofield@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco@xxxxxxxxxxxxxxx>
---
drivers/cxl/core/region.c | 60 +++++++++++++++++++++------------------
1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 6e5e1460068d..f607e7f97184 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1759,27 +1759,29 @@ static int cmp_interleave_pos(const void *a, const void *b)
return cxled_a->pos - cxled_b->pos;
}

-static int match_switch_decoder_by_range(struct device *dev,
- const void *data)
+static int match_switch_and_ep_decoders(struct device *dev, const void *data)
{
+ const struct cxl_endpoint_decoder *cxled = data;
struct cxl_switch_decoder *cxlsd;
- const struct range *r1, *r2 = data;
-
+ const struct range *r1, *r2;

if (!is_switch_decoder(dev))
return 0;

cxlsd = to_cxl_switch_decoder(dev);
r1 = &cxlsd->cxld.hpa_range;
+ r2 = &cxled->cxld.hpa_range;

if (is_root_decoder(dev))
return range_contains(r1, r2);
return (r1->start == r2->start && r1->end == r2->end);
}

-static int find_pos_and_ways(struct cxl_port *port, struct range *range,
- int *pos, int *ways)
+static int find_pos_and_ways(struct cxl_port *port,
+ struct cxl_endpoint_decoder *cxled, int *pos,
+ int *ways)
{
+ struct range *range = &cxled->cxld.hpa_range;
struct cxl_switch_decoder *cxlsd;
struct cxl_port *parent;
struct device *dev;
@@ -1789,8 +1791,8 @@ static int find_pos_and_ways(struct cxl_port *port, struct range *range,
if (!parent)
return rc;

- dev = device_find_child(&parent->dev, range,
- match_switch_decoder_by_range);
+ dev = device_find_child(&parent->dev, cxled,
+ match_switch_and_ep_decoders);
if (!dev) {
dev_err(port->uport_dev,
"failed to find decoder mapping %#llx-%#llx\n",
@@ -1876,7 +1878,7 @@ 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, cxled, &parent_pos, &parent_ways);
if (rc)
return rc;

@@ -3215,24 +3217,28 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
return rc;
}

-static int match_decoder_by_range(struct device *dev, const void *data)
+static int match_root_and_ep_decoders(struct device *dev, const void *data)
{
- const struct range *r1, *r2 = data;
- struct cxl_decoder *cxld;
+ const struct cxl_endpoint_decoder *cxled = data;
+ const struct range *r1, *r2;
+ struct cxl_root_decoder *cxlrd;

- if (!is_switch_decoder(dev))
+ if (!is_root_decoder(dev))
return 0;

- cxld = to_cxl_decoder(dev);
- r1 = &cxld->hpa_range;
+ cxlrd = to_cxl_root_decoder(dev);
+ r1 = &cxlrd->cxlsd.cxld.hpa_range;
+ r2 = &cxled->cxld.hpa_range;
+
return range_contains(r1, r2);
}

static struct cxl_decoder *
-cxl_port_find_switch_decoder(struct cxl_port *port, struct range *hpa)
+cxl_port_find_root_decoder(struct cxl_port *port,
+ struct cxl_endpoint_decoder *cxled)
{
- struct device *cxld_dev = device_find_child(&port->dev, hpa,
- match_decoder_by_range);
+ struct device *cxld_dev = device_find_child(&port->dev, cxled,
+ match_root_and_ep_decoders);

return cxld_dev ? to_cxl_decoder(cxld_dev) : NULL;
}
@@ -3244,9 +3250,8 @@ cxl_find_root_decoder(struct cxl_endpoint_decoder *cxled)
struct cxl_port *port = cxled_to_port(cxled);
struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
struct cxl_decoder *root, *cxld = &cxled->cxld;
- struct range *hpa = &cxld->hpa_range;

- root = cxl_port_find_switch_decoder(&cxl_root->port, hpa);
+ root = cxl_port_find_root_decoder(&cxl_root->port, cxled);
if (!root) {
dev_err(cxlmd->dev.parent,
"%s:%s no CXL window for range %#llx:%#llx\n",
@@ -3258,11 +3263,12 @@ cxl_find_root_decoder(struct cxl_endpoint_decoder *cxled)
return to_cxl_root_decoder(&root->dev);
}

-static int match_region_by_range(struct device *dev, const void *data)
+static int match_region_and_ep_decoder(struct device *dev, const void *data)
{
+ const struct cxl_endpoint_decoder *cxled = data;
+ const struct range *r = &cxled->cxld.hpa_range;
struct cxl_region_params *p;
struct cxl_region *cxlr;
- const struct range *r = data;

if (!is_cxl_region(dev))
return 0;
@@ -3425,12 +3431,13 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
}

static struct cxl_region *
-cxl_find_region_by_range(struct cxl_root_decoder *cxlrd, struct range *hpa)
+cxl_find_region_by_range(struct cxl_root_decoder *cxlrd,
+ struct cxl_endpoint_decoder *cxled)
{
struct device *region_dev;

- region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, hpa,
- match_region_by_range);
+ region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, cxled,
+ match_region_and_ep_decoder);
if (!region_dev)
return NULL;

@@ -3439,7 +3446,6 @@ cxl_find_region_by_range(struct cxl_root_decoder *cxlrd, struct range *hpa)

int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
{
- struct range *hpa = &cxled->cxld.hpa_range;
struct cxl_region_params *p;
bool attach = false;
int rc;
@@ -3455,7 +3461,7 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
*/
mutex_lock(&cxlrd->range_lock);
struct cxl_region *cxlr __free(put_cxl_region) =
- cxl_find_region_by_range(cxlrd, hpa);
+ cxl_find_region_by_range(cxlrd, cxled);
if (!cxlr)
cxlr = construct_region(cxlrd, cxled);
mutex_unlock(&cxlrd->range_lock);
--
2.50.1