[PATCH v3 05/18] cxl: Introduce parent_port_of() helper

Robert Richter
2025-02-11T09:54:37Z

Often a parent port must be determined. Introduce the parent_port_of()
helper function for this.

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/port.c | 15 +++++++++------
drivers/cxl/core/region.c | 11 ++---------
drivers/cxl/cxl.h | 1 +
3 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index f9501a16b390..d19930c009ce 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -606,17 +606,20 @@ struct cxl_port *to_cxl_port(const struct device *dev)
}
EXPORT_SYMBOL_NS_GPL(to_cxl_port, "CXL");

+struct cxl_port *parent_port_of(struct cxl_port *port)
+{
+ if (!port || !port->parent_dport)
+ return NULL;
+ return port->parent_dport->port;
+}
+EXPORT_SYMBOL_NS_GPL(parent_port_of, "CXL");
+
static void unregister_port(void *_port)
{
struct cxl_port *port = _port;
- struct cxl_port *parent;
+ struct cxl_port *parent = parent_port_of(port);
struct device *lock_dev;

- if (is_cxl_root(port))
- parent = NULL;
- else
- parent = to_cxl_port(port->dev.parent);
-
/*
* CXL root port's and the first level of ports are unregistered
* under the platform firmware device lock, all other ports are
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 5d252dfae138..54afdb0fa61c 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1734,13 +1734,6 @@ static int cmp_interleave_pos(const void *a, const void *b)
return cxled_a->pos - cxled_b->pos;
}

-static struct cxl_port *next_port(struct cxl_port *port)
-{
- if (!port->parent_dport)
- return NULL;
- return port->parent_dport->port;
-}
-
static int match_switch_decoder_by_range(struct device *dev,
const void *data)
{
@@ -1767,7 +1760,7 @@ static int find_pos_and_ways(struct cxl_port *port, struct range *range,
struct device *dev;
int rc = -ENXIO;

- parent = next_port(port);
+ parent = parent_port_of(port);
if (!parent)
return rc;

@@ -1847,7 +1840,7 @@ static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
*/

/* Iterate from endpoint to root_port refining the position */
- for (iter = port; iter; iter = next_port(iter)) {
+ for (iter = port; iter; iter = parent_port_of(iter)) {
if (is_cxl_root(iter))
break;

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 6baec4ba9141..0d7aff8b97b3 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -721,6 +721,7 @@ static inline bool is_cxl_root(struct cxl_port *port)
int cxl_num_decoders_committed(struct cxl_port *port);
bool is_cxl_port(const struct device *dev);
struct cxl_port *to_cxl_port(const struct device *dev);
+struct cxl_port *parent_port_of(struct cxl_port *port);
void cxl_port_commit_reap(struct cxl_decoder *cxld);
struct pci_bus;
int devm_cxl_register_pci_bus(struct device *host, struct device *uport_dev,
--
2.39.5