[PATCH v14 30/32] fs/resctrl: Hide the BMEC related files when mbm_event mode is enabled

[Babu Moger]

BMEC (Bandwidth Monitoring Event Configuration) and mbm_event mode do not
work simultaneously.

When mbm_event mode is enabled, hide BMEC-related files to avoid confusion
and update the mon_features display accordingly.

The files /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config and
/sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config will not be visible
when mbm_event mode is enabled.

Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v14: Updated the changelog for change in mbm_assign_modes.
     Added check in rdt_mon_features_show to hide bmec related feature.

v13: New patch to hide BMEC related files.
---
 fs/resctrl/rdtgroup.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 92bb8f3adfae..8c67e0897f25 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -1164,7 +1164,8 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
 		if (mevt->rid != r->rid || !mevt->enabled)
 			continue;
 		seq_printf(seq, "%s\n", mevt->name);
-		if (mevt->configurable)
+		if (mevt->configurable &&
+		    !resctrl_arch_mbm_cntr_assign_enabled(r))
 			seq_printf(seq, "%s_config\n", mevt->name);
 	}
 
@@ -1813,6 +1814,38 @@ static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
 	return ret ?: nbytes;
 }
 
+/**
+ * resctrl_bmec_files_show() — Controls the visibility of BMEC-related resctrl
+ * files. When @show is true, the files are displayed; when false, the files
+ * are hidden.
+ */
+static void resctrl_bmec_files_show(struct rdt_resource *r, bool show)
+{
+	struct kernfs_node *kn_config, *l3_mon_kn;
+	char name[32];
+
+	sprintf(name, "%s_MON", r->name);
+	l3_mon_kn = kernfs_find_and_get(kn_info, name);
+	if (!l3_mon_kn)
+		return;
+
+	kn_config = kernfs_find_and_get(l3_mon_kn, "mbm_total_bytes_config");
+	if (kn_config) {
+		kernfs_get(kn_config);
+		kernfs_show(kn_config, show);
+		kernfs_put(kn_config);
+	}
+
+	kn_config = kernfs_find_and_get(l3_mon_kn, "mbm_local_bytes_config");
+	if (kn_config) {
+		kernfs_get(kn_config);
+		kernfs_show(kn_config, show);
+		kernfs_put(kn_config);
+	}
+
+	kernfs_put(l3_mon_kn);
+}
+
 static int resctrl_mbm_assign_mode_show(struct kernfs_open_file *of,
 					struct seq_file *s, void *v)
 {
@@ -2808,6 +2841,13 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
 			ret = resctrl_mkdir_counter_configs(r, name);
 			if (ret)
 				goto out_destroy;
+
+			/*
+			 * Hide BMEC related files if mbm_event mode
+			 * is enabled.
+			 */
+			if (resctrl_arch_mbm_cntr_assign_enabled(r))
+				resctrl_bmec_files_show(r, false);
 		}
 	}
 
-- 
2.34.1