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

Dave Jiang
2025-02-20T16:12:27Z

On 2/11/25 2:53 AM, Robert Richter wrote:
> 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>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
> 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,