2 files changed, 115 insertions, 5 deletions

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 55449909f114..489642b08d64 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -94,6 +94,57 @@ u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt)
 }
 EXPORT_SYMBOL_GPL(clockevent_delta2ns);
 
+static int __clockevents_set_mode(struct clock_event_device *dev,
+                                  enum clock_event_mode mode)
+{
+        /* Transition with legacy set_mode() callback */
+        if (dev->set_mode) {
+                /* Legacy callback doesn't support new modes */
+                if (mode > CLOCK_EVT_MODE_RESUME)
+                        return -ENOSYS;
+                dev->set_mode(mode, dev);
+                return 0;
+        }
+
+        if (dev->features & CLOCK_EVT_FEAT_DUMMY)
+                return 0;
+
+        /* Transition with new mode-specific callbacks */
+        switch (mode) {
+        case CLOCK_EVT_MODE_UNUSED:
+                /*
+                 * This is an internal state, which is guaranteed to go from
+                 * SHUTDOWN to UNUSED. No driver interaction required.
+                 */
+                return 0;
+
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                return dev->set_mode_shutdown(dev);
+
+        case CLOCK_EVT_MODE_PERIODIC:
+                /* Core internal bug */
+                if (!(dev->features & CLOCK_EVT_FEAT_PERIODIC))
+                        return -ENOSYS;
+                return dev->set_mode_periodic(dev);
+
+        case CLOCK_EVT_MODE_ONESHOT:
+                /* Core internal bug */
+                if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
+                        return -ENOSYS;
+                return dev->set_mode_oneshot(dev);
+
+        case CLOCK_EVT_MODE_RESUME:
+                /* Optional callback */
+                if (dev->set_mode_resume)
+                        return dev->set_mode_resume(dev);
+                else
+                        return 0;
+
+        default:
+                return -ENOSYS;
+        }
+}
+
 /**
  * clockevents_set_mode - set the operating mode of a clock event device
  * @dev:        device to modify
@@ -105,7 +156,9 @@ void clockevents_set_mode(struct clock_event_device *dev,
                                  enum clock_event_mode mode)
 {
         if (dev->mode != mode) {
-                dev->set_mode(mode, dev);
+                if (__clockevents_set_mode(dev, mode))
+                        return;
+
                 dev->mode = mode;
 
                 /*
@@ -373,6 +426,35 @@ int clockevents_unbind_device(struct clock_event_device *ced, int cpu)
 }
 EXPORT_SYMBOL_GPL(clockevents_unbind);
 
+/* Sanity check of mode transition callbacks */
+static int clockevents_sanity_check(struct clock_event_device *dev)
+{
+        /* Legacy set_mode() callback */
+        if (dev->set_mode) {
+                /* We shouldn't be supporting new modes now */
+                WARN_ON(dev->set_mode_periodic || dev->set_mode_oneshot ||
+                        dev->set_mode_shutdown || dev->set_mode_resume);
+                return 0;
+        }
+
+        if (dev->features & CLOCK_EVT_FEAT_DUMMY)
+                return 0;
+
+        /* New mode-specific callbacks */
+        if (!dev->set_mode_shutdown)
+                return -EINVAL;
+
+        if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
+            !dev->set_mode_periodic)
+                return -EINVAL;
+
+        if ((dev->features & CLOCK_EVT_FEAT_ONESHOT) &&
+            !dev->set_mode_oneshot)
+                return -EINVAL;
+
+        return 0;
+}
+
 /**
  * clockevents_register_device - register a clock event device
  * @dev:        device to register
@@ -382,6 +464,8 @@ void clockevents_register_device(struct clock_event_device *dev)
         unsigned long flags;
 
         BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+        BUG_ON(clockevents_sanity_check(dev));
+
         if (!dev->cpumask) {
                 WARN_ON(num_possible_cpus() > 1);
                 dev->cpumask = cpumask_of(smp_processor_id());
@@ -449,7 +533,7 @@ int __clockevents_update_freq(struct clock_event_device *dev, u32 freq)
                 return clockevents_program_event(dev, dev->next_event, false);
 
         if (dev->mode == CLOCK_EVT_MODE_PERIODIC)
-                dev->set_mode(CLOCK_EVT_MODE_PERIODIC, dev);
+                return __clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
 
         return 0;
 }
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 61ed862cdd37..2cfd19485824 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -228,9 +228,35 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
         print_name_offset(m, dev->set_next_event);
         SEQ_printf(m, "\n");
 
-        SEQ_printf(m, " set_mode:       ");
-        print_name_offset(m, dev->set_mode);
-        SEQ_printf(m, "\n");
+        if (dev->set_mode) {
+                SEQ_printf(m, " set_mode:       ");
+                print_name_offset(m, dev->set_mode);
+                SEQ_printf(m, "\n");
+        } else {
+                if (dev->set_mode_shutdown) {
+                        SEQ_printf(m, " shutdown: ");
+                        print_name_offset(m, dev->set_mode_shutdown);
+                        SEQ_printf(m, "\n");
+                }
+
+                if (dev->set_mode_periodic) {
+                        SEQ_printf(m, " periodic: ");
+                        print_name_offset(m, dev->set_mode_periodic);
+                        SEQ_printf(m, "\n");
+                }
+
+                if (dev->set_mode_oneshot) {
+                        SEQ_printf(m, " oneshot:  ");
+                        print_name_offset(m, dev->set_mode_oneshot);
+                        SEQ_printf(m, "\n");
+                }
+
+                if (dev->set_mode_resume) {
+                        SEQ_printf(m, " resume:   ");
+                        print_name_offset(m, dev->set_mode_resume);
+                        SEQ_printf(m, "\n");
+                }
+        }
 
         SEQ_printf(m, " event_handler:  ");
         print_name_offset(m, dev->event_handler);