1 files changed, 63 insertions, 0 deletions

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 846bd42c7ed1..2ab2819aee65 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 }
 
 /**
+ * pm_qos_flags_remove_req - Remove device PM QoS flags request.
+ * @pqf: Device PM QoS flags set to remove the request from.
+ * @req: Request to remove from the set.
+ */
+static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
+                                    struct pm_qos_flags_request *req)
+{
+        s32 val = 0;
+
+        list_del(&req->node);
+        list_for_each_entry(req, &pqf->list, node)
+                val |= req->flags;
+
+        pqf->effective_flags = val;
+}
+
+/**
+ * pm_qos_update_flags - Update a set of PM QoS flags.
+ * @pqf: Set of flags to update.
+ * @req: Request to add to the set, to modify, or to remove from the set.
+ * @action: Action to take on the set.
+ * @val: Value of the request to add or modify.
+ *
+ * Update the given set of PM QoS flags and call notifiers if the aggregate
+ * value has changed.  Returns 1 if the aggregate constraint value has changed,
+ * 0 otherwise.
+ */
+bool pm_qos_update_flags(struct pm_qos_flags *pqf,
+                         struct pm_qos_flags_request *req,
+                         enum pm_qos_req_action action, s32 val)
+{
+        unsigned long irqflags;
+        s32 prev_value, curr_value;
+
+        spin_lock_irqsave(&pm_qos_lock, irqflags);
+
+        prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+        switch (action) {
+        case PM_QOS_REMOVE_REQ:
+                pm_qos_flags_remove_req(pqf, req);
+                break;
+        case PM_QOS_UPDATE_REQ:
+                pm_qos_flags_remove_req(pqf, req);
+        case PM_QOS_ADD_REQ:
+                req->flags = val;
+                INIT_LIST_HEAD(&req->node);
+                list_add_tail(&req->node, &pqf->list);
+                pqf->effective_flags |= val;
+                break;
+        default:
+                /* no action */
+                ;
+        }
+
+        curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
+
+        spin_unlock_irqrestore(&pm_qos_lock, irqflags);
+
+        return prev_value != curr_value;
+}
+
+/**
  * pm_qos_request - returns current system wide qos expectation
  * @pm_qos_class: identification of which qos value is requested
  *