From: Dan Williams <dan.j.williams@intel.com>

In support of generic CXL protocol error handling across various 'struct
cxl_port' types, update find_cxl_port_by_uport() to retrieve endpoint CXL
port companions from endpoint PCIe device instances.

The end result is that upstream switch ports and endpoint ports can share
error handling and eventually delete the misplaced cxl_error_handlers from
the cxl_pci class driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Terry Bowman <terry.bowman@amd.com>

---

Changes in v13->v14:
- New patch
---
 drivers/cxl/core/port.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 3f730511f11d..a535e57360e0 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1561,10 +1561,20 @@ static int match_port_by_uport(struct device *dev, const void *data)
 		return 0;
 
 	port = to_cxl_port(dev);
+	/* Endpoint ports are hosted by memdevs */
+	if (is_cxl_memdev(port->uport_dev))
+		return uport_dev == port->uport_dev->parent;
 	return uport_dev == port->uport_dev;
 }
 
-/*
+/**
+ * find_cxl_port_by_uport - Find a CXL port device companion
+ * @uport_dev: Device that acts as a switch or endpoint in the CXL hierarchy
+ *
+ * In the case of endpoint ports recall that port->uport_dev points to a 'struct
+ * cxl_memdev' device. So, the @uport_dev argument is the parent device of the
+ * 'struct cxl_memdev' in that case.
+ *
  * Function takes a device reference on the port device. Caller should do a
  * put_device() when done.
  */
-- 
2.34.1

On Wed, 14 Jan 2026 12:20:50 -0600
Terry Bowman <terry.bowman@amd.com> wrote:

> From: Dan Williams <dan.j.williams@intel.com>
> 
> In support of generic CXL protocol error handling across various 'struct
> cxl_port' types, update find_cxl_port_by_uport() to retrieve endpoint CXL
> port companions from endpoint PCIe device instances.
> 
> The end result is that upstream switch ports and endpoint ports can share
> error handling and eventually delete the misplaced cxl_error_handlers from
> the cxl_pci class driver.

Should mention that you are converting to kernel-doc.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Reviewed-by: Terry Bowman <terry.bowman@amd.com>
> 

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

On 1/14/26 11:20 AM, Terry Bowman wrote:
> From: Dan Williams <dan.j.williams@intel.com>
> 
> In support of generic CXL protocol error handling across various 'struct
> cxl_port' types, update find_cxl_port_by_uport() to retrieve endpoint CXL
> port companions from endpoint PCIe device instances.
> 
> The end result is that upstream switch ports and endpoint ports can share
> error handling and eventually delete the misplaced cxl_error_handlers from
> the cxl_pci class driver.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Reviewed-by: Terry Bowman <terry.bowman@amd.com>

missing sign off

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

> 
> ---
> 
> Changes in v13->v14:
> - New patch
> ---
>  drivers/cxl/core/port.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 3f730511f11d..a535e57360e0 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -1561,10 +1561,20 @@ static int match_port_by_uport(struct device *dev, const void *data)
>  		return 0;
>  
>  	port = to_cxl_port(dev);
> +	/* Endpoint ports are hosted by memdevs */
> +	if (is_cxl_memdev(port->uport_dev))
> +		return uport_dev == port->uport_dev->parent;
>  	return uport_dev == port->uport_dev;
>  }
>  
> -/*
> +/**
> + * find_cxl_port_by_uport - Find a CXL port device companion
> + * @uport_dev: Device that acts as a switch or endpoint in the CXL hierarchy
> + *
> + * In the case of endpoint ports recall that port->uport_dev points to a 'struct
> + * cxl_memdev' device. So, the @uport_dev argument is the parent device of the
> + * 'struct cxl_memdev' in that case.
> + *
>   * Function takes a device reference on the port device. Caller should do a
>   * put_device() when done.
>   */