From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/drivers/cpuidle/cpuidle.c | 57 ++++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 14 deletions(-) (limited to 'kernel/drivers/cpuidle/cpuidle.c') diff --git a/kernel/drivers/cpuidle/cpuidle.c b/kernel/drivers/cpuidle/cpuidle.c index 61c417b9e..17a6dc0e2 100644 --- a/kernel/drivers/cpuidle/cpuidle.c +++ b/kernel/drivers/cpuidle/cpuidle.c @@ -65,7 +65,7 @@ int cpuidle_play_dead(void) return -ENODEV; /* Find lowest-power state that supports long-term idle */ - for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--) + for (i = drv->state_count - 1; i >= 0; i--) if (drv->states[i].enter_dead) return drv->states[i].enter_dead(dev, i); @@ -73,16 +73,21 @@ int cpuidle_play_dead(void) } static int find_deepest_state(struct cpuidle_driver *drv, - struct cpuidle_device *dev, bool freeze) + struct cpuidle_device *dev, + unsigned int max_latency, + unsigned int forbidden_flags, + bool freeze) { unsigned int latency_req = 0; - int i, ret = freeze ? -1 : CPUIDLE_DRIVER_STATE_START - 1; + int i, ret = -ENXIO; - for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { + for (i = 0; i < drv->state_count; i++) { struct cpuidle_state *s = &drv->states[i]; struct cpuidle_state_usage *su = &dev->states_usage[i]; if (s->disabled || su->disable || s->exit_latency <= latency_req + || s->exit_latency > max_latency + || (s->flags & forbidden_flags) || (freeze && !s->enter_freeze)) continue; @@ -92,6 +97,7 @@ static int find_deepest_state(struct cpuidle_driver *drv, return ret; } +#ifdef CONFIG_SUSPEND /** * cpuidle_find_deepest_state - Find the deepest available idle state. * @drv: cpuidle driver for the given CPU. @@ -100,26 +106,33 @@ static int find_deepest_state(struct cpuidle_driver *drv, int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) { - return find_deepest_state(drv, dev, false); + return find_deepest_state(drv, dev, UINT_MAX, 0, false); } static void enter_freeze_proper(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { - tick_freeze(); + /* + * trace_suspend_resume() called by tick_freeze() for the last CPU + * executing it contains RCU usage regarded as invalid in the idle + * context, so tell RCU about that. + */ + RCU_NONIDLE(tick_freeze()); /* * The state used here cannot be a "coupled" one, because the "coupled" * cpuidle mechanism enables interrupts and doing that with timekeeping * suspended is generally unsafe. */ + stop_critical_timings(); drv->states[index].enter_freeze(dev, drv, index); WARN_ON(!irqs_disabled()); /* * timekeeping_resume() that will be called by tick_unfreeze() for the - * last CPU executing it calls functions containing RCU read-side + * first CPU executing it calls functions containing RCU read-side * critical sections, so tell RCU about that. */ RCU_NONIDLE(tick_unfreeze()); + start_critical_timings(); } /** @@ -139,18 +152,19 @@ int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) * that interrupts won't be enabled when it exits and allows the tick to * be frozen safely. */ - index = find_deepest_state(drv, dev, true); + index = find_deepest_state(drv, dev, UINT_MAX, 0, true); if (index >= 0) enter_freeze_proper(drv, dev, index); return index; } +#endif /* CONFIG_SUSPEND */ /** * cpuidle_enter_state - enter the state and update stats * @dev: cpuidle device for this cpu * @drv: cpuidle driver for this cpu - * @next_state: index into drv->states of the state to enter + * @index: index into the states table in @drv of the state to enter */ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) @@ -167,17 +181,32 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, * local timer will be shut down. If a local timer is used from another * CPU as a broadcast timer, this call may fail if it is not available. */ - if (broadcast && tick_broadcast_enter()) - return -EBUSY; + if (broadcast && tick_broadcast_enter()) { + index = find_deepest_state(drv, dev, target_state->exit_latency, + CPUIDLE_FLAG_TIMER_STOP, false); + if (index < 0) { + default_idle_call(); + return -EBUSY; + } + target_state = &drv->states[index]; + } + + /* Take note of the planned idle state. */ + sched_idle_set_state(target_state); trace_cpu_idle_rcuidle(index, dev->cpu); time_start = ktime_get(); + stop_critical_timings(); entered_state = target_state->enter(dev, drv, index); + start_critical_timings(); time_end = ktime_get(); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); + /* The cpu is no longer idle or about to enter idle. */ + sched_idle_set_state(NULL); + if (broadcast) { if (WARN_ON_ONCE(!irqs_disabled())) local_irq_disable(); @@ -185,7 +214,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, tick_broadcast_exit(); } - if (!cpuidle_state_is_coupled(dev, drv, entered_state)) + if (!cpuidle_state_is_coupled(drv, entered_state)) local_irq_enable(); diff = ktime_to_us(ktime_sub(time_end, time_start)); @@ -234,7 +263,7 @@ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { - if (cpuidle_state_is_coupled(dev, drv, index)) + if (cpuidle_state_is_coupled(drv, index)) return cpuidle_enter_state_coupled(dev, drv, index); return cpuidle_enter_state(dev, drv, index); } @@ -249,7 +278,7 @@ int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, */ void cpuidle_reflect(struct cpuidle_device *dev, int index) { - if (cpuidle_curr_governor->reflect) + if (cpuidle_curr_governor->reflect && index >= 0) cpuidle_curr_governor->reflect(dev, index); } -- cgit 1.2.3-korg