2 files changed, 46 insertions, 0 deletions

diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 1c12afd113d6..b090d55d5eb8 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -64,6 +64,16 @@ typedef long	psched_tdiff_t;
 #define PSCHED_IS_PASTPERFECT(t)        ((t) == 0)
 #define PSCHED_AUDIT_TDIFF(t)
 
+struct qdisc_watchdog {
+        struct hrtimer  timer;
+        struct Qdisc    *qdisc;
+};
+
+extern void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
+extern void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
+                                    psched_time_t expires);
+extern void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
+
 extern struct Qdisc_ops pfifo_qdisc_ops;
 extern struct Qdisc_ops bfifo_qdisc_ops;
 
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index d71bf79eb80b..6bc395cb235b 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -34,6 +34,7 @@
 #include <linux/kmod.h>
 #include <linux/list.h>
 #include <linux/bitops.h>
+#include <linux/hrtimer.h>
 
 #include <net/sock.h>
 #include <net/pkt_sched.h>
@@ -291,6 +292,41 @@ void qdisc_put_rtab(struct qdisc_rate_table *tab)
         }
 }
 
+static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
+{
+        struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
+                                                 timer);
+
+        wd->qdisc->flags &= ~TCQ_F_THROTTLED;
+        netif_schedule(wd->qdisc->dev);
+        return HRTIMER_NORESTART;
+}
+
+void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc)
+{
+        hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+        wd->timer.function = qdisc_watchdog;
+        wd->qdisc = qdisc;
+}
+EXPORT_SYMBOL(qdisc_watchdog_init);
+
+void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
+{
+        ktime_t time;
+
+        wd->qdisc->flags |= TCQ_F_THROTTLED;
+        time = ktime_set(0, 0);
+        time = ktime_add_ns(time, PSCHED_US2NS(expires));
+        hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
+}
+EXPORT_SYMBOL(qdisc_watchdog_schedule);
+
+void qdisc_watchdog_cancel(struct qdisc_watchdog *wd)
+{
+        hrtimer_cancel(&wd->timer);
+        wd->qdisc->flags &= ~TCQ_F_THROTTLED;
+}
+EXPORT_SYMBOL(qdisc_watchdog_cancel);
 
 /* Allocate an unique handle from space managed by kernel */