clockevents: Handle tick device's resume separately

Upcoming patch will redefine possible states of a clockevent
device. The RESUME mode is a special case only for tick's
clockevent devices. In future it can be replaced by ->resume()
callback already available for clockevent devices.

Lets handle it separately so that clockevents_set_mode() only
handles states valid across all devices. This also renames
set_mode_resume() to tick_resume() to make it more explicit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: linaro-kernel@lists.linaro.org
Cc: linaro-networking@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/c1b0112410870f49e7bf06958e1483eac6c15e20.1425037853.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 28 insertions, 15 deletions

diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 59af26b54d15..a41749543d48 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -87,7 +87,7 @@ enum clock_event_mode {
  * @set_mode_periodic:  switch mode to periodic, if !set_mode
  * @set_mode_oneshot:   switch mode to oneshot, if !set_mode
  * @set_mode_shutdown:  switch mode to shutdown, if !set_mode
- * @set_mode_resume:    resume clkevt device, if !set_mode
+ * @tick_resume:        resume clkevt device, if !set_mode
  * @broadcast:          function to broadcast events
  * @min_delta_ticks:    minimum delta value in ticks stored for reconfiguration
  * @max_delta_ticks:    maximum delta value in ticks stored for reconfiguration
@@ -125,7 +125,7 @@ struct clock_event_device {
         int                     (*set_mode_periodic)(struct clock_event_device *);
         int                     (*set_mode_oneshot)(struct clock_event_device *);
         int                     (*set_mode_shutdown)(struct clock_event_device *);
-        int                     (*set_mode_resume)(struct clock_event_device *);
+        int                     (*tick_resume)(struct clock_event_device *);
 
         void                    (*broadcast)(const struct cpumask *mask);
         void                    (*suspend)(struct clock_event_device *);
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 489642b08d64..1b0ea63de69c 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -100,7 +100,7 @@ static int __clockevents_set_mode(struct clock_event_device *dev,
         /* Transition with legacy set_mode() callback */
         if (dev->set_mode) {
                 /* Legacy callback doesn't support new modes */
-                if (mode > CLOCK_EVT_MODE_RESUME)
+                if (mode > CLOCK_EVT_MODE_ONESHOT)
                         return -ENOSYS;
                 dev->set_mode(mode, dev);
                 return 0;
@@ -133,13 +133,6 @@ static int __clockevents_set_mode(struct clock_event_device *dev,
                         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;
         }
@@ -184,6 +177,25 @@ void clockevents_shutdown(struct clock_event_device *dev)
         dev->next_event.tv64 = KTIME_MAX;
 }
 
+/**
+ * clockevents_tick_resume -    Resume the tick device before using it again
+ * @dev:                        device to resume
+ */
+int clockevents_tick_resume(struct clock_event_device *dev)
+{
+        int ret = 0;
+
+        if (dev->set_mode)
+                dev->set_mode(CLOCK_EVT_MODE_RESUME, dev);
+        else if (dev->tick_resume)
+                ret = dev->tick_resume(dev);
+
+        if (likely(!ret))
+                dev->mode = CLOCK_EVT_MODE_RESUME;
+
+        return ret;
+}
+
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST
 
 /* Limit min_delta to a jiffie */
@@ -433,7 +445,7 @@ static int clockevents_sanity_check(struct clock_event_device *dev)
         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);
+                        dev->set_mode_shutdown || dev->tick_resume);
                 return 0;
         }
 
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 066f0ec05e48..542d5bb5c13d 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -464,7 +464,7 @@ int tick_resume_broadcast(void)
         bc = tick_broadcast_device.evtdev;
 
         if (bc) {
-                clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME);
+                clockevents_tick_resume(bc);
 
                 switch (tick_broadcast_device.mode) {
                 case TICKDEV_MODE_PERIODIC:
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index f7c515595b42..5c50664c21d7 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -384,7 +384,7 @@ void tick_resume(void)
         struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
         int broadcast = tick_resume_broadcast();
 
-        clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
+        clockevents_tick_resume(td->evtdev);
 
         if (!broadcast) {
                 if (td->mode == TICKDEV_MODE_PERIODIC)
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 366aeb4f2c66..98700e4a2000 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -32,6 +32,7 @@ extern bool tick_check_replacement(struct clock_event_device *curdev,
 extern void tick_install_replacement(struct clock_event_device *dev);
 
 extern void clockevents_shutdown(struct clock_event_device *dev);
+extern int clockevents_tick_resume(struct clock_event_device *dev);
 
 extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
 
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 2cfd19485824..2b3e9393034d 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -251,9 +251,9 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
                         SEQ_printf(m, "\n");
                 }
 
-                if (dev->set_mode_resume) {
+                if (dev->tick_resume) {
                         SEQ_printf(m, " resume:   ");
-                        print_name_offset(m, dev->set_mode_resume);
+                        print_name_offset(m, dev->tick_resume);
                         SEQ_printf(m, "\n");
                 }
         }