cxl: Split out combine_coordinates() for common shared usage

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'.

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/20240308220055.2172956-6-dave.jiang@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/cdat.c

@@ -185,15 +185,7 @@ 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(cxl_root, &dent->coord, 1,
 					      &qos_class);
@@ -484,4 +476,26 @@ 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
+ *
+ * @out: Output coordinate of c1 and c2 combined
+ * @c1: input coordinates
+ * @c2: input coordinates
+ */
+void cxl_coordinates_combine(struct access_coordinate *out,
+			     struct access_coordinate *c1,
+			     struct access_coordinate *c2)
+{
+		if (c1->write_bandwidth && c2->write_bandwidth)
+			out->write_bandwidth = min(c1->write_bandwidth,
+						   c2->write_bandwidth);
+		out->write_latency = c1->write_latency + c2->write_latency;
+
+		if (c1->read_bandwidth && c2->read_bandwidth)
+			out->read_bandwidth = min(c1->read_bandwidth,
+						  c2->read_bandwidth);
+		out->read_latency = c1->read_latency + c2->read_latency;
+}
+
 MODULE_IMPORT_NS(CXL);

drivers/cxl/core/port.c

@@ -2096,20 +2096,6 @@ bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd)
 }
 EXPORT_SYMBOL_NS_GPL(schedule_cxl_memdev_detach, CXL);
 
-static void combine_coordinates(struct access_coordinate *c1,
-				struct access_coordinate *c2)
-{
-		if (c2->write_bandwidth)
-			c1->write_bandwidth = min(c1->write_bandwidth,
-						  c2->write_bandwidth);
-		c1->write_latency += c2->write_latency;
-
-		if (c2->read_bandwidth)
-			c1->read_bandwidth = min(c1->read_bandwidth,
-						 c2->read_bandwidth);
-		c1->read_latency += c2->read_latency;
-}
-
 /**
  * cxl_endpoint_get_perf_coordinates - Retrieve performance numbers stored in dports
  *				   of CXL path
@@ -2143,7 +2129,7 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
 	 * nothing to gather.
 	 */
 	while (iter && !is_cxl_root(to_cxl_port(iter->dev.parent))) {
-		combine_coordinates(&c, &dport->sw_coord);
+		cxl_coordinates_combine(&c, &c, &dport->sw_coord);
 		c.write_latency += dport->link_latency;
 		c.read_latency += dport->link_latency;
 
@@ -2152,7 +2138,7 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
 	}
 
 	/* Augment with the generic port (host bridge) perf data */
-	combine_coordinates(&c, &dport->hb_coord[ACCESS_COORDINATE_LOCAL]);
+	cxl_coordinates_combine(&c, &c, &dport->hb_coord[ACCESS_COORDINATE_LOCAL]);
 
 	/* Get the calculated PCI paths bandwidth */
 	pdev = to_pci_dev(port->uport_dev->parent);

drivers/cxl/cxl.h

@@ -882,6 +882,10 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
 
 void cxl_memdev_update_perf(struct cxl_memdev *cxlmd);
 
+void cxl_coordinates_combine(struct access_coordinate *out,
+			     struct access_coordinate *c1,
+			     struct access_coordinate *c2);
+
 /*
  * Unit test builds overrides this to __weak, find the 'strong' version
  * of these symbols in tools/testing/cxl/.