[PATCH v5 3/5] arm_mpam: resctrl: Add resctrl_arch_config_cntr() for ABMC use

From: Ben Horgan

Date: Tue Jul 07 2026 - 12:31:27 EST


From: James Morse <james.morse@xxxxxxx>

ABMC, mbm_event mode, has a helper resctrl_arch_config_cntr() for changing
the mapping between 'cntr_id' and a CLOSID/RMID pair.

Add the helper.

For MPAM this is done by updating the mon->mbwu_idx_to_mon[] array, and as
usual CDP means it needs doing in three different ways.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Ben Horgan <ben.horgan@xxxxxxx>
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Tested-by: Fenghua Yu <fenghuay@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghuay@xxxxxxxxxx>
---
Changes since new rfc:
Mention mbm_event mode in commit message

Changes since v3:
Warning bound (Sashiko)

Changes since v4:
resctrl_arch_reset_rmid() -> reset_arch_reset_cntr()
---
drivers/resctrl/mpam_resctrl.c | 48 +++++++++++++++++++++++++++++-----
1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 91b589b110a2..29a8cf8092e0 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -125,12 +125,6 @@ void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d
{
}

-void resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
- enum resctrl_event_id evtid, u32 rmid, u32 closid,
- u32 cntr_id, bool assign)
-{
-}
-
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)
@@ -1082,6 +1076,48 @@ static void mpam_resctrl_pick_counters(void)
}
}

+static void __config_cntr(struct mpam_resctrl_mon *mon, u32 cntr_id,
+ enum resctrl_conf_type cdp_type, u32 closid, u32 rmid,
+ bool assign)
+{
+ /* Same CDP index remap as closid; maps cntr_id to assigned_counters[]. */
+ u32 mbwu_idx, mon_idx = resctrl_get_config_index(cntr_id, cdp_type);
+
+ closid = resctrl_get_config_index(closid, cdp_type);
+ mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+ if (assign)
+ mon->mbwu_idx_to_mon[mbwu_idx] = mon->assigned_counters[mon_idx];
+ else
+ mon->mbwu_idx_to_mon[mbwu_idx] = -1;
+}
+
+void resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+ enum resctrl_event_id evtid, u32 rmid, u32 closid,
+ u32 cntr_id, bool assign)
+{
+ struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[evtid];
+
+ if (evtid != QOS_L3_MBM_TOTAL_EVENT_ID) {
+ pr_debug("unexpected event id\n");
+ return;
+ }
+
+ if (!mon->mbwu_idx_to_mon || !mon->assigned_counters) {
+ pr_debug("monitor arrays not allocated\n");
+ return;
+ }
+
+ if (cdp_enabled) {
+ __config_cntr(mon, cntr_id, CDP_CODE, closid, rmid, assign);
+ __config_cntr(mon, cntr_id, CDP_DATA, closid, rmid, assign);
+ } else {
+ __config_cntr(mon, cntr_id, CDP_NONE, closid, rmid, assign);
+ }
+
+ resctrl_arch_reset_cntr(r, d, closid, rmid, cntr_id, QOS_L3_MBM_TOTAL_EVENT_ID);
+}
+
static int mpam_resctrl_control_init(struct mpam_resctrl_res *res)
{
struct mpam_class *class = res->class;
--
2.43.0