1 files changed, 46 insertions, 16 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 9c38ddcfe150..8502385e389f 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3026,7 +3026,8 @@ static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
 }
 
 static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
-			     struct rdt_resource *r, struct rdtgroup *prgrp)
+			     struct rdt_resource *r, struct rdtgroup *prgrp,
+			     bool do_sum)
 {
 	struct rmid_read rr = {0};
 	union mon_data_bits priv;
@@ -3037,14 +3038,15 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
 		return -EPERM;
 
 	priv.u.rid = r->rid;
-	priv.u.domid = d->hdr.id;
+	priv.u.domid = do_sum ? d->ci->id : d->hdr.id;
+	priv.u.sum = do_sum;
 	list_for_each_entry(mevt, &r->evt_list, list) {
 		priv.u.evtid = mevt->evtid;
 		ret = mon_addfile(kn, mevt->name, priv.priv);
 		if (ret)
 			return ret;
 
-		if (is_mbm_event(mevt->evtid))
+		if (!do_sum && is_mbm_event(mevt->evtid))
 			mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);
 	}
 
@@ -3055,23 +3057,51 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
 				struct rdt_mon_domain *d,
 				struct rdt_resource *r, struct rdtgroup *prgrp)
 {
-	struct kernfs_node *kn;
+	struct kernfs_node *kn, *ckn;
 	char name[32];
-	int ret;
+	bool snc_mode;
+	int ret = 0;
 
-	sprintf(name, "mon_%s_%02d", r->name, d->hdr.id);
-	/* create the directory */
-	kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
-	if (IS_ERR(kn))
-		return PTR_ERR(kn);
+	lockdep_assert_held(&rdtgroup_mutex);
 
-	ret = rdtgroup_kn_set_ugid(kn);
-	if (ret)
-		goto out_destroy;
+	snc_mode = r->mon_scope == RESCTRL_L3_NODE;
+	sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
+	kn = kernfs_find_and_get(parent_kn, name);
+	if (kn) {
+		/*
+		 * rdtgroup_mutex will prevent this directory from being
+		 * removed. No need to keep this hold.
+		 */
+		kernfs_put(kn);
+	} else {
+		kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+		if (IS_ERR(kn))
+			return PTR_ERR(kn);
 
-	ret = mon_add_all_files(kn, d, r, prgrp);
-	if (ret)
-		goto out_destroy;
+		ret = rdtgroup_kn_set_ugid(kn);
+		if (ret)
+			goto out_destroy;
+		ret = mon_add_all_files(kn, d, r, prgrp, snc_mode);
+		if (ret)
+			goto out_destroy;
+	}
+
+	if (snc_mode) {
+		sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id);
+		ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp);
+		if (IS_ERR(ckn)) {
+			ret = -EINVAL;
+			goto out_destroy;
+		}
+
+		ret = rdtgroup_kn_set_ugid(ckn);
+		if (ret)
+			goto out_destroy;
+
+		ret = mon_add_all_files(ckn, d, r, prgrp, false);
+		if (ret)
+			goto out_destroy;
+	}
 
 	kernfs_activate(kn);
 	return 0;