Re: [PATCH 9/9] cxl/port: Unify endpoint and switch port lookup

[Dave Jiang <dave.jiang@intel.com>]

On 1/21/26 8:33 PM, Dan Williams wrote:
> 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.
> 
> Reviewed-by: Terry Bowman <terry.bowman@amd.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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


> ---
>  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 436d9f8f65cb..446a97d48423 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -1591,10 +1591,20 @@ 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.
>   */