Commit 6ef83c4e authored Mar 08, 2024 by Dave Jiang Committed by Dan Williams Mar 12, 2024

cxl: Move QoS class to be calculated from the nearest CPU

Retrieve the qos_class (QTG ID) using the access coordinates from the
nearest CPU rather than the nearst initiator that may not be a CPU.
This may be the more appropriate number that applications care about.

For most cases, access0 and access1 have the same values.

Link: https://lore.kernel.org/linux-cxl/20240112113023.00006c50@Huawei.com/

Suggested-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20240308220055.2172956-8-dave.jiang@intel.com

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 863027d4

drivers/cxl/core/cdat.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -198,12 +198,12 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port,
		* coordinates in order to allow calculation of access class
		* 0 and 1 for region later.
		*/
		cxl_coordinates_combine(&coord[ACCESS_COORDINATE_LOCAL],
		&coord[ACCESS_COORDINATE_LOCAL],
		cxl_coordinates_combine(&coord[ACCESS_COORDINATE_CPU],
		&coord[ACCESS_COORDINATE_CPU],
		&dent->coord);
		dent->entries = 1;
		rc = cxl_root->ops->qos_class(cxl_root,
		&coord[ACCESS_COORDINATE_LOCAL],
		&coord[ACCESS_COORDINATE_CPU],
		1, &qos_class);
		if (rc != 1)
		continue;