Hi Jonathan,

On 1/6/26 14:58, Jonathan Cameron wrote:

On Fri, 19 Dec 2025 18:11:41 +0000
Ben Horgan [off-list ref] wrote:

quoted

From: James Morse <james.morse@arm.com>

Now that MPAM links against resctrl, call resctrl_init() to register the
filesystem and setup resctrl's structures.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>

Just minor suggestions inline.  I'm not sure the for loop macros
are worth doing but that particular pair of loops feel awfully familiar
at this point, so maybe. 

Either way..

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
 

quoted

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 059148c38a38..bbb12b5dfd8c 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c

quoted

@@ -1840,11 +1861,70 @@ int mpam_resctrl_setup(void)
 		pr_warn("Number of PMG is not a power of 2! resctrl may misbehave");
 	}
 
-	/* TODO: call resctrl_init() */
+	err = resctrl_init();
+	if (!err)
+		WRITE_ONCE(resctrl_enabled, true);

Trivial but I'd prefer the error path out of line.

	if (err)
		return err;

	WRITE_ONCE(resctrl_enabled, true);
	
	return 0;

Ok, updated.

quoted

 
 	return err;
 }

quoted

+
+/*
+ * The driver is detaching an MSC from this class, if resctrl was using it,
+ * pull on resctrl_exit().
+ */
+void mpam_resctrl_teardown_class(struct mpam_class *class)
+{
+	int i;
+	struct mpam_resctrl_res *res;
+	struct mpam_resctrl_mon *mon;
+
+	might_sleep();
+
+	for (i = 0; i < RDT_NUM_RESOURCES; i++) {

There are enough iterators over these that I wonder
if it is worth some macros.
 
	for_each_mpam_resctrl_control(res) {
	}
and
	for_each_mpam_resctrl_counter(mon) {
	}

The index is often needed too so I changed to helpers that include it too:
for_each_mpam_resctrl_control(res, rid) and
for_each_mpam_resctrl_mon(mon, eventid).

quoted

+		res = &mpam_resctrl_controls[i];
+		if (res->class == class) {
+			res->class = NULL;
+			break;
+		}
+	}
+	for (i = 0; i < QOS_NUM_EVENTS; i++) {
+		mon = &mpam_resctrl_counters[i];
+		if (mon->class == class) {
+			mon->class = NULL;
+
+			mpam_resctrl_teardown_mon(mon, class);
+
+			break;
+		}
+	}
+}
+
 static int __init __cacheinfo_ready(void)
 {
 	cacheinfo_ready = true;

Thanks,

Ben