+#ifdef CONFIG_DEBUG_TIMEKEEPING
+static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
+{
+
+ cycle_t max_cycles = tk->tkr.clock->max_cycles;
+ const char *name = tk->tkr.clock->name;
+
+ if (offset > max_cycles) {
+ printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n",
+ offset, name, max_cycles);
+ printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n");
+ } else {
+ if (offset > (max_cycles >> 1)) {
+ printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the the '%s' clock's 50%% safety margin (%lld)\n",
+ offset, name, max_cycles >> 1);
+ printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n");
+ }
+ }
+}
+
+static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
+{
+ cycle_t cycle_now, delta;
+
+ /* read clocksource */
+ cycle_now = tkr->read(tkr->clock);
+
+ /* calculate the delta since the last update_wall_time */
+ delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
+
+ /* Cap delta value to the max_cycles values to avoid mult overflows */
+ if (unlikely(delta > tkr->clock->max_cycles))
+ delta = tkr->clock->max_cycles;
+
+ return delta;
+}
+#else
+static inline void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
+{
+}
+static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
+{
+ cycle_t cycle_now, delta;
+
+ /* read clocksource */
+ cycle_now = tkr->read(tkr->clock);
+
+ /* calculate the delta since the last update_wall_time */
+ delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
+
+ return delta;
+}
+#endif
+