2 files changed, 35 insertions, 0 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index c9ec9400ee5b..cc07d2777bbe 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -327,6 +327,7 @@ extern ktime_t ktime_get(void);
 extern ktime_t ktime_get_real(void);
 extern ktime_t ktime_get_boottime(void);
 extern ktime_t ktime_get_monotonic_offset(void);
+extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot);
 
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 1c038dac71a2..269b1fe5f2ae 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1271,6 +1271,40 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
         } while (read_seqretry(&timekeeper.lock, seq));
 }
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+/**
+ * ktime_get_update_offsets - hrtimer helper
+ * @offs_real:  pointer to storage for monotonic -> realtime offset
+ * @offs_boot:  pointer to storage for monotonic -> boottime offset
+ *
+ * Returns current monotonic time and updates the offsets
+ * Called from hrtimer_interupt() or retrigger_next_event()
+ */
+ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
+{
+        ktime_t now;
+        unsigned int seq;
+        u64 secs, nsecs;
+
+        do {
+                seq = read_seqbegin(&timekeeper.lock);
+
+                secs = timekeeper.xtime.tv_sec;
+                nsecs = timekeeper.xtime.tv_nsec;
+                nsecs += timekeeping_get_ns();
+                /* If arch requires, add in gettimeoffset() */
+                nsecs += arch_gettimeoffset();
+
+                *offs_real = timekeeper.offs_real;
+                *offs_boot = timekeeper.offs_boot;
+        } while (read_seqretry(&timekeeper.lock, seq));
+
+        now = ktime_add_ns(ktime_set(secs, 0), nsecs);
+        now = ktime_sub(now, *offs_real);
+        return now;
+}
+#endif
+
 /**
  * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
  */