diff options
Diffstat (limited to 'kernel/time/clockevents.c')
| -rw-r--r-- | kernel/time/clockevents.c | 88 |
1 files changed, 86 insertions, 2 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; } |