RE: [PATCH v4 05/11] cxl: Split out combine_coordinates() for common shared usage

[Dan Williams <dan.j.williams@intel.com>]

Dave Jiang wrote:
> Refactor the common code of combining coordinates in order to reduce code.
> Create a new function cxl_cooordinates_combine() it combine two 'struct
> access_coordinate'.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/cxl/core/cdat.c |   32 +++++++++++++++++++++++---------
>  drivers/cxl/core/port.c |   18 ++----------------
>  drivers/cxl/cxl.h       |    4 ++++
>  3 files changed, 29 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
> index cd84d87f597a..4d542627d02d 100644
> --- a/drivers/cxl/core/cdat.c
> +++ b/drivers/cxl/core/cdat.c
> @@ -183,15 +183,7 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port,
>  	xa_for_each(dsmas_xa, index, dent) {
>  		int qos_class;
>  
> -		dent->coord.read_latency = dent->coord.read_latency +
> -					   c.read_latency;
> -		dent->coord.write_latency = dent->coord.write_latency +
> -					    c.write_latency;
> -		dent->coord.read_bandwidth = min_t(int, c.read_bandwidth,
> -						   dent->coord.read_bandwidth);
> -		dent->coord.write_bandwidth = min_t(int, c.write_bandwidth,
> -						    dent->coord.write_bandwidth);
> -
> +		cxl_coordinates_combine(&dent->coord, &dent->coord, &c);
>  		dent->entries = 1;
>  		rc = cxl_root->ops->qos_class(root_port, &dent->coord, 1, &qos_class);
>  		if (rc != 1)
> @@ -514,4 +506,26 @@ void cxl_switch_parse_cdat(struct cxl_port *port)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_switch_parse_cdat, CXL);
>  
> +/**
> + * cxl_coordinates_combine - Combine the two input coordinates into the first
> + *
> + * @c1: first coordinate, to be written to
> + * @c2: second coordinate
> + */
> +void cxl_coordinates_combine(struct access_coordinate *out,
> +			     struct access_coordinate *c1,
> +			     struct access_coordinate *c2)
> +{
> +		if (c2->write_bandwidth)
> +			out->write_bandwidth = min(c1->write_bandwidth,
> +						   c2->write_bandwidth);
> +		out->write_latency = c1->write_latency + c2->write_latency;
> +
> +		if (c2->read_bandwidth)
> +			out->read_bandwidth = min(c1->read_bandwidth,
> +						  c2->read_bandwidth);
> +		out->read_latency = c1->read_latency + c2->read_latency;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_coordinates_combine, CXL);

There is no need for EXPORT_SYMBOL() when the definition and the only
caller exist within the same compilation unit, cxl_core.o.

However, given there is nothing "CXL" about this function it likely wants
to move out of cxl_core.o if another caller ever arrives.