Hi Shaopeng,

On 09/09/2025 08:03, Shaopeng Tan (Fujitsu) wrote:

quoted

Probing MPAM is convoluted. MSCs that are integrated with a CPU may only be
accessible from those CPUs, and they may not be online.
Touching the hardware early is pointless as MPAM can't be used until the
system-wide common values for num_partid and num_pmg have been
discovered.

Start with driver probe/remove and mapping the MSC.

quoted

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
new file mode 100644 index 000000000000..a0d9a699a6e7
--- /dev/null
+++ b/drivers/resctrl/mpam_devices.c

@@ -0,0 +1,336 @@

quoted

+static int mpam_dt_parse_resources(struct mpam_msc *msc, void *ignored)
+{
+	int err, num_ris = 0;
+	const u32 *ris_idx_p;
+	struct device_node *iter, *np;
+
+	np = msc->pdev->dev.of_node;
+	for_each_child_of_node(np, iter) {
+		ris_idx_p = of_get_property(iter, "reg", NULL);
+		if (ris_idx_p) {
+			num_ris++;
+			err = mpam_dt_parse_resource(msc, iter, *ris_idx_p);
+			if (err) {
+				of_node_put(iter);
+				return err;
+			}
+		}
+	}
+
+	if (!num_ris)
+		mpam_dt_parse_resource(msc, np, 0);

err = mpam_dt_parse_resource(msc, np, 0);

Oops! Thanks for catching that,


James