cxl: Change sslbis handler to only handle single dport

While cxl_switch_parse_cdat() is harmless to be run multiple times, it is
not efficient in the current scheme where one dport is being updated at
a time by the memdev probe path. Change the input parameter to the
specific dport being updated to pick up the SSLBIS information for just
that dport.

Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: davejiang

drivers/cxl/core/cdat.c

@@ -440,8 +440,8 @@ static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
 	} *tbl = (struct acpi_cdat_sslbis_table *)header;
 	int size = sizeof(header->cdat) + sizeof(tbl->sslbis_header);
 	struct acpi_cdat_sslbis *sslbis;
-	struct cxl_port *port = arg;
-	struct device *dev = &port->dev;
+	struct cxl_dport *dport = arg;
+	struct device *dev = &dport->port->dev;
 	int remain, entries, i;
 	u16 len;
 
@@ -467,8 +467,6 @@ static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
 		u16 y = le16_to_cpu((__force __le16)tbl->entries[i].porty_id);
 		__le64 le_base;
 		__le16 le_val;
-		struct cxl_dport *dport;
-		unsigned long index;
 		u16 dsp_id;
 		u64 val;
 
@@ -499,28 +497,27 @@ static int cdat_sslbis_handler(union acpi_subtable_headers *header, void *arg,
 		val = cdat_normalize(le16_to_cpu(le_val), le64_to_cpu(le_base),
 				     sslbis->data_type);
 
-		xa_for_each(&port->dports, index, dport) {
-			if (dsp_id == ACPI_CDAT_SSLBIS_ANY_PORT ||
-			    dsp_id == dport->port_id) {
-				cxl_access_coordinate_set(dport->coord,
-							  sslbis->data_type,
-							  val);
-			}
+		if (dsp_id == ACPI_CDAT_SSLBIS_ANY_PORT ||
+		    dsp_id == dport->port_id) {
+			cxl_access_coordinate_set(dport->coord,
+						  sslbis->data_type, val);
+			return 0;
 		}
 	}
 
 	return 0;
 }
 
-void cxl_switch_parse_cdat(struct cxl_port *port)
+void cxl_switch_parse_cdat(struct cxl_dport *dport)
 {
+	struct cxl_port *port = dport->port;
 	int rc;
 
 	if (!port->cdat.table)
 		return;
 
 	rc = cdat_table_parse(ACPI_CDAT_TYPE_SSLBIS, cdat_sslbis_handler,
-			      port, port->cdat.table, port->cdat.length);
+			      dport, port->cdat.table, port->cdat.length);
 	rc = cdat_table_parse_output(rc);
 	if (rc)
 		dev_dbg(&port->dev, "Failed to parse SSLBIS: %d\n", rc);

drivers/cxl/core/port.c

@@ -1607,7 +1607,7 @@ static struct cxl_dport *cxl_port_add_dport(struct cxl_port *port,
 	if (IS_ERR(new_dport))
 		return new_dport;
 
-	cxl_switch_parse_cdat(port);
+	cxl_switch_parse_cdat(new_dport);
 
 	if (ida_is_empty(&port->decoder_ida)) {
 		rc = devm_cxl_switch_port_decoders_setup(port);

drivers/cxl/cxl.h

@@ -892,7 +892,7 @@ static inline u64 cxl_port_get_spa_cache_alias(struct cxl_port *endpoint,
 #endif
 
 void cxl_endpoint_parse_cdat(struct cxl_port *port);
-void cxl_switch_parse_cdat(struct cxl_port *port);
+void cxl_switch_parse_cdat(struct cxl_dport *dport);
 
 int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
 				      struct access_coordinate *coord);