Merge "Revert "hrtimer: reprogram remote CPU's timer hardware"" (13d47110) · Commits · e / devices / android_kernel_xiaomi_markw

kernel/time/hrtimer.c

+40 −38

Original line number	Diff line number	Diff line
		@@ -49,7 +49,6 @@
		#include <linux/sched/deadline.h>
		#include <linux/timer.h>
		#include <linux/freezer.h>
		#include <linux/irq_work.h>

		#include <asm/uaccess.h>

		@@ -168,6 +167,29 @@ struct hrtimer_clock_base lock_hrtimer_base(const struct hrtimer timer,
		}
		}

		/*
		* With HIGHRES=y we do not migrate the timer when it is expiring
		* before the next event on the target cpu because we cannot reprogram
		* the target cpu hardware and we would cause it to fire late.
		*
		* Called with cpu_base->lock of target cpu held.
		*/
		static int
		hrtimer_check_target(struct hrtimer timer, struct hrtimer_clock_base new_base)
		{
		#ifdef CONFIG_HIGH_RES_TIMERS
		ktime_t expires;

		if (!new_base->cpu_base->hres_active)
		return 0;

		expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
		return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
		#else
		return 0;
		#endif
		}

		/*
		* Switch the timer base to the current CPU when possible.
		*/
		@@ -177,9 +199,11 @@ switch_hrtimer_base(struct hrtimer timer, struct hrtimer_clock_base base,
		{
		struct hrtimer_clock_base *new_base;
		struct hrtimer_cpu_base *new_cpu_base;
		int this_cpu = smp_processor_id();
		int cpu = get_nohz_timer_target(pinned);
		int basenum = base->index;

		again:
		new_cpu_base = &per_cpu(hrtimer_bases, cpu);
		new_base = &new_cpu_base->clock_base[basenum];

		@@ -200,7 +224,20 @@ switch_hrtimer_base(struct hrtimer timer, struct hrtimer_clock_base base,
		timer->base = NULL;
		raw_spin_unlock(&base->cpu_base->lock);
		raw_spin_lock(&new_base->cpu_base->lock);

		if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
		cpu = this_cpu;
		raw_spin_unlock(&new_base->cpu_base->lock);
		raw_spin_lock(&base->cpu_base->lock);
		timer->base = base;
		goto again;
		}
		timer->base = new_base;
		} else {
		if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
		cpu = this_cpu;
		goto again;
		}
		}
		return new_base;
		}
		@@ -620,20 +657,6 @@ static void retrigger_next_event(void *arg)
		raw_spin_unlock(&base->lock);
		}

		#ifdef CONFIG_SMP
		static void raise_hrtimer_softirq(struct irq_work *arg)
		{
		if (!hrtimer_hres_active())
		return;

		raise_softirq(HRTIMER_SOFTIRQ);
		}

		static DEFINE_PER_CPU(struct irq_work, hrtimer_kick_work) = {
		.func = raise_hrtimer_softirq,
		};
		#endif

		/*
		* Switch to high resolution mode
		*/
		@@ -698,22 +721,6 @@ static inline void retrigger_next_event(void *arg) { }

		#endif /* CONFIG_HIGH_RES_TIMERS */

		#ifdef CONFIG_SMP

		static void kick_remote_cpu(int cpu)
		{
		get_cpu();
		if (cpu_online(cpu))
		irq_work_queue_on(&per_cpu(hrtimer_kick_work, cpu), cpu);
		put_cpu();
		}

		#else

		static inline void kick_remote_cpu(int cpu) { }

		#endif

		/*
		* Clock realtime was set
		*
		@@ -932,7 +939,7 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
		{
		struct hrtimer_clock_base base, new_base;
		unsigned long flags;
		int ret, leftmost, kick = 0, cpu;
		int ret, leftmost;

		base = lock_hrtimer_base(timer, &flags);

		@@ -979,6 +986,7 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
		* Only allow reprogramming if the new base is on this CPU.
		* (it might still be on another CPU if the timer was pending)
		*
		* XXX send_remote_softirq() ?
		*/
		if (wakeup) {
		/*
		@@ -992,16 +1000,10 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
		} else {
		__raise_softirq_irqoff(HRTIMER_SOFTIRQ);
		}
		} else {
		cpu = new_base->cpu_base->cpu;
		kick = (leftmost && (cpu != smp_processor_id()));
		}

		unlock_hrtimer_base(timer, &flags);

		if (kick)
		kick_remote_cpu(cpu);

		return ret;
		}
		EXPORT_SYMBOL_GPL(__hrtimer_start_range_ns);