@@ -354,6 +354,165 @@ void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
 	resctrl_arch_mon_ctx_free_no_wait(evtid, mon_idx);
 }
 
+static int
+__read_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+	   enum mpam_device_features mon_type,
+	   int mon_idx,
+	   enum resctrl_conf_type cdp_type, u32 closid, u32 rmid, u64 *val)
+{
+	struct mon_cfg cfg;
+
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
+	/* Shift closid to account for CDP */
+	closid = resctrl_get_config_index(closid, cdp_type);
+
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+		if (mon_idx == -1) {
+			if (mpam_resctrl_abmc_enabled()) {
+				/* Report Unassigned */
+				return -ENOENT;
+			}
+			/* Report Unavailable */
+			return -EINVAL;
+		}
+	}
+
+	if (irqs_disabled()) {
+		/* Check if we can access this domain without an IPI */
+		return -EIO;
+	}
+
+	cfg = (struct mon_cfg) {
+		.mon = mon_idx,
+		.match_pmg = true,
+		.partid = closid,
+		.pmg = rmid,
+	};
+
+	return mpam_msmon_read(mon_comp, &cfg, mon_type, val);
+}
+
+static int read_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			     enum mpam_device_features mon_type,
+			     int mon_idx, u32 closid, u32 rmid, u64 *val)
+{
+	if (cdp_enabled) {
+		u64 code_val = 0, data_val = 0;
+		int err;
+
+		err = __read_mon(mon, mon_comp, mon_type, mon_idx,
+				 CDP_CODE, closid, rmid, &code_val);
+		if (err)
+			return err;
+
+		err = __read_mon(mon, mon_comp, mon_type, mon_idx,
+				 CDP_DATA, closid, rmid, &data_val);
+		if (err)
+			return err;
+
+		*val += code_val + data_val;
+		return 0;
+	}
+
+	return __read_mon(mon, mon_comp, mon_type, mon_idx,
+			  CDP_NONE, closid, rmid, val);
+}
+
+/* MBWU when not in ABMC mode, and CSU counters. */
+int resctrl_arch_rmid_read(struct rdt_resource	*r, struct rdt_mon_domain *d,
+			   u32 closid, u32 rmid, enum resctrl_event_id eventid,
+			   u64 *val, void *arch_mon_ctx)
+{
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+	u32 mon_idx = *(u32 *)arch_mon_ctx;
+	enum mpam_device_features mon_type;
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+
+	resctrl_arch_rmid_read_context_check();
+
+	if (eventid >= QOS_NUM_EVENTS || !mon->class)
+		return -EINVAL;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	switch (eventid) {
+	case QOS_L3_OCCUP_EVENT_ID:
+		mon_type = mpam_feat_msmon_csu;
+		break;
+	case QOS_L3_MBM_LOCAL_EVENT_ID:
+	case QOS_L3_MBM_TOTAL_EVENT_ID:
+		mon_type = mpam_feat_msmon_mbwu;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return read_mon_cdp_safe(mon, mon_comp, mon_type, 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)
+{
+	struct mon_cfg cfg = { };
+
+	if (!mpam_is_enabled())
+		return;
+
+	/* Shift closid to account for CDP */
+	closid = resctrl_get_config_index(closid, cdp_type);
+
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+	}
+
+	if (mon_idx == -1)
+		return;
+	cfg.mon = mon_idx;
+	mpam_msmon_reset_mbwu(mon_comp, &cfg);
+}
+
+static void reset_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			       int mon_idx, u32 closid, u32 rmid)
+{
+	if (cdp_enabled) {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_CODE, closid, rmid);
+		__reset_mon(mon, mon_comp, mon_idx, CDP_DATA, closid, rmid);
+	} else {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_NONE, closid, rmid);
+	}
+}
+
+/* Called via IPI. Call with read_cpus_lock() held. */
+void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d,
+			     u32 closid, u32 rmid, enum resctrl_event_id eventid)
+{
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+
+	if (!mpam_is_enabled())
+		return;
+
+	/* Only MBWU counters are relevant, and for supported event types. */
+	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);
+}
+
 static bool cache_has_usable_cpor(struct mpam_class *class)
 {
 	struct mpam_props *cprops = &class->props;

@@ -67,6 +67,11 @@ struct rdt_resource;
 void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, enum resctrl_event_id evtid);
 void resctrl_arch_mon_ctx_free(struct rdt_resource *r, enum resctrl_event_id evtid, void *ctx);
 
+static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
+{
+	return val;
+}
+
 /**
  * mpam_register_requestor() - Register a requestor with the MPAM driver
  * @partid_max:		The maximum PARTID value the requestor can generate.