arm_mpam: propagate MSC access errors in mpam_reset_class_locked()

The mpam_reset_ris() function can return an error, propagate this up
through mpam_reset_component_locked() to mpam_reset_class_locked(),
which is exported. The external caller is a void function, so cannot
really handle the error at the moment, but at least we report everything
on the MPAM interface side.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>

2 files changed, 19 insertions, 7 deletions

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index c0f51d41e7fe..31f4826ab399 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -3040,7 +3040,7 @@ static void mpam_enable_once(void)
 	       mpam_partid_max + 1, mpam_pmg_max + 1);
 }
 
-static void mpam_reset_component_locked(struct mpam_component *comp)
+static int mpam_reset_component_locked(struct mpam_component *comp)
 {
 	struct mpam_vmsc *vmsc;
 
@@ -3054,26 +3054,38 @@ static void mpam_reset_component_locked(struct mpam_component *comp)
 				 srcu_read_lock_held(&mpam_srcu)) {
 		struct mpam_msc *msc = vmsc->msc;
 		struct mpam_msc_ris *ris;
+		int ret;
 
 		list_for_each_entry_srcu(ris, &vmsc->ris, vmsc_list,
 					 srcu_read_lock_held(&mpam_srcu)) {
-			if (!ris->in_reset_state)
-				mpam_touch_msc(msc, mpam_reset_ris, ris);
+			if (!ris->in_reset_state) {
+				ret = mpam_touch_msc(msc, mpam_reset_ris, ris);
+				if (ret)
+					return ret;
+			}
 			ris->in_reset_state = true;
 		}
 	}
+
+	return 0;
 }
 
-void mpam_reset_class_locked(struct mpam_class *class)
+int mpam_reset_class_locked(struct mpam_class *class)
 {
 	struct mpam_component *comp;
+	int ret;
 
 	lockdep_assert_cpus_held();
 
 	guard(srcu)(&mpam_srcu);
 	list_for_each_entry_srcu(comp, &class->components, class_list,
-				 srcu_read_lock_held(&mpam_srcu))
-		mpam_reset_component_locked(comp);
+				 srcu_read_lock_held(&mpam_srcu)) {
+		ret = mpam_reset_component_locked(comp);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static void mpam_reset_class(struct mpam_class *class)
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
index 68a6cf2b9cc7..09f8168fb4d2 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -465,7 +465,7 @@ void mpam_enable(struct work_struct *work);
 void mpam_disable(struct work_struct *work);
 
 /* Reset all the RIS in a class under cpus_read_lock() */
-void mpam_reset_class_locked(struct mpam_class *class);
+int mpam_reset_class_locked(struct mpam_class *class);
 
 int mpam_apply_config(struct mpam_component *comp, u16 partid,
 		      struct mpam_config *cfg);