Hi Ben,

On 24/07/2025 12:02, Ben Horgan wrote:

On 11/07/2025 19:36, James Morse 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/platform/arm64/mpam/mpam_devices.c b/drivers/platform/arm64/mpam/

mpam_devices.c
new file mode 100644
index 000000000000..5b886ba54ba8

--- /dev/null
+++ b/drivers/platform/arm64/mpam/mpam_devices.c

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

quoted

+static int mpam_dt_count_msc(void)
+{
+    int count = 0;
+    struct device_node *np;
+
+    for_each_compatible_node(np, NULL, "arm,mpam-msc")

This will count even 'status = "disabled"' nodes. Add a check for that.

if (of_device_is_available(np))> +        count++;

Good spot, fixed - thanks.


Thanks,

James

quoted

+
+    return count;
+}