[RFC PATCH v1 4/4] arm_mpam: resctrl: Add resctrl_arch_cntr_read() & resctrl_arch_reset_cntr()

Ben Horgan ben.horgan at arm.com
Wed Feb 25 12:54:36 PST 2026


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

When used in ABMC mode, resctrl uses a different set of helpers to read and
reset the counters.

Add these.

Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>
Signed-off-by: James Morse <james.morse at arm.com>
Signed-off-by: Ben Horgan <ben.horgan at arm.com>
---
 drivers/resctrl/mpam_resctrl.c | 56 ++++++++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 13 deletions(-)

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 18528210ba46..6c2542cfb0df 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -137,19 +137,6 @@ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_l3_mon_domai
 {
 }
 
-void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
-			     u32 closid, u32 rmid, int cntr_id,
-			     enum resctrl_event_id eventid)
-{
-}
-
-int resctrl_arch_cntr_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
-			   u32 unused, u32 rmid, int cntr_id,
-			   enum resctrl_event_id eventid, u64 *val)
-{
-	return -EOPNOTSUPP;
-}
-
 bool resctrl_arch_mbm_cntr_assign_enabled(struct rdt_resource *r)
 {
 	if (r != &mpam_resctrl_controls[RDT_RESOURCE_L3].resctrl_res)
@@ -544,6 +531,28 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr,
 				 closid, rmid, val);
 }
 
+/* MBWU counters when in ABMC mode */
+int resctrl_arch_cntr_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+			   u32 closid, u32 rmid, int mon_idx,
+			   enum resctrl_event_id eventid, u64 *val)
+{
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
+	if (eventid == QOS_L3_OCCUP_EVENT_ID || !mon->class)
+		return -EINVAL;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	return read_mon_cdp_safe(mon, mon_comp, mpam_feat_msmon_mbwu, mon_idx,
+				 closid, rmid, val);
+}
+
 static void __reset_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
 			int mon_idx,
 			enum resctrl_conf_type cdp_type, u32 closid, u32 rmid)
@@ -600,6 +609,27 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_l3_mon_domain *d
 	reset_mon_cdp_safe(mon, mon_comp, USE_PRE_ALLOCATED, closid, rmid);
 }
 
+/* Reset an assigned counter */
+void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+			     u32 closid, u32 rmid, int cntr_id,
+			     enum resctrl_event_id eventid)
+{
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+
+	if (!mpam_is_enabled())
+		return;
+
+	if (eventid == QOS_L3_OCCUP_EVENT_ID || !mon->class)
+		return;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	reset_mon_cdp_safe(mon, mon_comp, USE_PRE_ALLOCATED, closid, rmid);
+}
+
 /*
  * The rmid realloc threshold should be for the smallest cache exposed to
  * resctrl.
-- 
2.43.0




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