[PATCH v3 08/18] cxl/region: Move find_cxl_root() to cxl_add_to_region()

Robert Richter
2025-02-11T09:54:49Z

When adding an endpoint to a region, the root port is determined
first. Move this directly into cxl_add_to_region(). This is in
preparation of the initialization of endpoints that iterates the port
hierarchy from the endpoint up to the root port.

As a side-effect the root argument is removed from the argument lists
of cxl_add_to_region() and related functions. Now, the endpoint is the
only parameter to add a region. This simplifies the function
interface.

Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Gregory Price <gourry@gourry.net>
---
drivers/cxl/core/region.c | 6 ++++--
drivers/cxl/cxl.h | 6 ++----
drivers/cxl/port.c | 15 +++------------
3 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index b8201c2faa87..0e38bcb43be6 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3312,9 +3312,11 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
return ERR_PTR(rc);
}

-int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
+int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
{
struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+ struct cxl_port *port = cxled_to_port(cxled);
+ struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
struct range *hpa = &cxled->cxld.hpa_range;
struct cxl_decoder *cxld = &cxled->cxld;
struct device *cxlrd_dev, *region_dev;
@@ -3324,7 +3326,7 @@ int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
bool attach = false;
int rc;

- cxlrd_dev = device_find_child(&root->dev, &cxld->hpa_range,
+ cxlrd_dev = device_find_child(&cxl_root->port.dev, &cxld->hpa_range,
match_root_decoder_by_range);
if (!cxlrd_dev) {
dev_err(cxlmd->dev.parent,
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 0d7aff8b97b3..85dfc8df0a80 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -854,8 +854,7 @@ struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port);
#ifdef CONFIG_CXL_REGION
bool is_cxl_pmem_region(struct device *dev);
struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
-int cxl_add_to_region(struct cxl_port *root,
- struct cxl_endpoint_decoder *cxled);
+int cxl_add_to_region(struct cxl_endpoint_decoder *cxled);
struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
#else
static inline bool is_cxl_pmem_region(struct device *dev)
@@ -866,8 +865,7 @@ static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
{
return NULL;
}
-static inline int cxl_add_to_region(struct cxl_port *root,
- struct cxl_endpoint_decoder *cxled)
+static inline int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
{
return 0;
}
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index d2bfd1ff5492..74587a403e3d 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -30,7 +30,7 @@ static void schedule_detach(void *cxlmd)
schedule_cxl_memdev_detach(cxlmd);
}

-static int discover_region(struct device *dev, void *root)
+static int discover_region(struct device *dev, void *unused)
{
struct cxl_endpoint_decoder *cxled;
int rc;
@@ -49,7 +49,7 @@ static int discover_region(struct device *dev, void *root)
* Region enumeration is opportunistic, if this add-event fails,
* continue to the next endpoint decoder.
*/
- rc = cxl_add_to_region(root, cxled);
+ rc = cxl_add_to_region(cxled);
if (rc)
dev_dbg(dev, "failed to add to region: %#llx-%#llx\n",
cxled->cxld.hpa_range.start, cxled->cxld.hpa_range.end);
@@ -95,7 +95,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
struct cxl_hdm *cxlhdm;
- struct cxl_port *root;
int rc;

rc = cxl_dvsec_rr_decode(cxlds, &info);
@@ -126,19 +125,11 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
if (rc)
return rc;

- /*
- * This can't fail in practice as CXL root exit unregisters all
- * descendant ports and that in turn synchronizes with cxl_port_probe()
- */
- struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
-
- root = &cxl_root->port;
-
/*
* Now that all endpoint decoders are successfully enumerated, try to
* assemble regions from committed decoders
*/
- device_for_each_child(&port->dev, root, discover_region);
+ device_for_each_child(&port->dev, NULL, discover_region);

return 0;
}
--
2.39.5