[PATCH 06/10] x86/resctrl: Update mkdir_mondata_subdir() for Sub-NUMA domains

[Tony Luck]

When Sub-NUMA domain mode is enabled all the monitoring happens
at the SUBL3 resource level. Changes are required to populate the
"mon_data" directories in the resctrl file system.

When making the first SUBL3 directory code must first create the
parent mon_L3_XX directory and fill it with files for each of
the monitoring functions. Subsequent SUBL3 creation requests will
simply use the directory that was created by the first request.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/internal.h | 12 +++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 74 ++++++++++++++++++--------
 2 files changed, 65 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 21d81f51838f..7f05502454c5 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -456,6 +456,18 @@ static inline struct rdt_hw_resource *resctrl_to_arch_res(struct rdt_resource *r
 	return container_of(r, struct rdt_hw_resource, r_resctrl);
 }
 
+static inline struct rdt_domain *get_parent_domain(struct rdt_resource *r,
+						   struct rdt_domain *d)
+{
+	struct  rdt_domain *pd;
+
+	list_for_each_entry(pd, &r->parent->domains, list)
+		if (pd->id == d->parent)
+			return pd;
+
+	return NULL;
+}
+
 int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
 	      struct rdt_domain *d);
 int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index f2af58a791a4..22effd8dc207 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3026,31 +3026,16 @@ static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
 	}
 }
 
-static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
-				struct rdt_domain *d,
-				struct rdt_resource *r, struct rdtgroup *prgrp)
+static int mon_add_all_files(struct kernfs_node *kn, struct rdt_domain *d,
+			     struct rdt_resource *r, struct rdtgroup *prgrp)
 {
 	union mon_data_bits priv;
-	struct kernfs_node *kn;
 	struct mon_evt *mevt;
 	struct rmid_read rr;
-	char name[32];
 	int ret;
 
-	sprintf(name, "mon_%s_%02d", r->name, d->id);
-	/* create the directory */
-	kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
-	if (IS_ERR(kn))
-		return PTR_ERR(kn);
-
-	ret = rdtgroup_kn_set_ugid(kn);
-	if (ret)
-		goto out_destroy;
-
-	if (WARN_ON(list_empty(&r->evt_list))) {
-		ret = -EPERM;
-		goto out_destroy;
-	}
+	if (WARN_ON(list_empty(&r->evt_list)))
+		return -EPERM;
 
 	priv.u.rid = r->rid;
 	priv.u.domid = d->id;
@@ -3058,11 +3043,58 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
 		priv.u.evtid = mevt->evtid;
 		ret = mon_addfile(kn, mevt->name, priv.priv);
 		if (ret)
-			goto out_destroy;
+			return ret;
 
 		if (is_mbm_event(mevt->evtid))
 			mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);
 	}
+
+	return 0;
+}
+
+static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
+				struct rdt_domain *d,
+				struct rdt_resource *r, struct rdtgroup *prgrp)
+{
+	struct kernfs_node *kn = parent_kn, *ckn;
+	struct rdt_domain *pd;
+	char name[32];
+	int ret;
+
+	if (r->parent) {
+		pd = get_parent_domain(r, d);
+		if (!pd)
+			return 0;
+		sprintf(name, "mon_%s_%02d", r->parent->name, pd->id);
+		kn = kernfs_find_and_get_ns(parent_kn, name, NULL);
+		if (kn) {
+			parent_kn = kn;
+			goto subdir;
+		}
+		kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+		if (IS_ERR(kn))
+			return PTR_ERR(kn);
+		ret = rdtgroup_kn_set_ugid(kn);
+		if (ret)
+			goto out_destroy;
+		ret = mon_add_all_files(kn, d, r, prgrp);
+		if (ret)
+			goto out_destroy;
+	}
+subdir:
+	sprintf(name, "mon_%s_%02d", r->name, d->id);
+	/* create the directory */
+	ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp);
+	if (IS_ERR(ckn))
+		goto out_destroy;
+
+	ret = rdtgroup_kn_set_ugid(ckn);
+	if (ret)
+		goto out_destroy;
+
+	ret = mon_add_all_files(ckn, d, r, prgrp);
+	if (ret)
+		goto out_destroy;
 	kernfs_activate(kn);
 	return 0;
 
@@ -3078,8 +3110,8 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
 static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
 					   struct rdt_domain *d)
 {
-	struct kernfs_node *parent_kn;
 	struct rdtgroup *prgrp, *crgrp;
+	struct kernfs_node *parent_kn;
 	struct list_head *head;
 
 	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
-- 
2.44.0