From 1b7839559b3f1c7a09ff94904788a732063ce2de Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Wed, 26 Feb 2014 05:38:01 +0530 Subject: [PATCH] powerpc: Split timer_interrupt() into timer handling and interrupt handling routines Split timer_interrupt(), which is the local timer interrupt handler on ppc into routines called during regular interrupt handling and __timer_interrupt(), which takes care of running local timers and collecting time related stats. This will enable callers interested only in running expired local timers to directly call into __timer_interupt(). One of the use cases of this is the tick broadcast IPI handling in which the sleeping CPUs need to handle the local timers that have expired. Signed-off-by: Preeti U Murthy Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/time.c | 83 +++++++++++++++++++++----------------- 1 file changed, 47 insertions(+), 36 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 3ff97dbb35be..df2989b0d4c0 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -478,47 +478,13 @@ void arch_irq_work_raise(void) #endif /* CONFIG_IRQ_WORK */ -/* - * timer_interrupt - gets called when the decrementer overflows, - * with interrupts disabled. - */ -void timer_interrupt(struct pt_regs * regs) +void __timer_interrupt(void) { - struct pt_regs *old_regs; + struct pt_regs *regs = get_irq_regs(); u64 *next_tb = &__get_cpu_var(decrementers_next_tb); struct clock_event_device *evt = &__get_cpu_var(decrementers); u64 now; - /* Ensure a positive value is written to the decrementer, or else - * some CPUs will continue to take decrementer exceptions. - */ - set_dec(DECREMENTER_MAX); - - /* Some implementations of hotplug will get timer interrupts while - * offline, just ignore these and we also need to set - * decrementers_next_tb as MAX to make sure __check_irq_replay - * don't replay timer interrupt when return, otherwise we'll trap - * here infinitely :( - */ - if (!cpu_online(smp_processor_id())) { - *next_tb = ~(u64)0; - return; - } - - /* Conditionally hard-enable interrupts now that the DEC has been - * bumped to its maximum value - */ - may_hard_irq_enable(); - - -#if defined(CONFIG_PPC32) && defined(CONFIG_PMAC) - if (atomic_read(&ppc_n_lost_interrupts) != 0) - do_IRQ(regs); -#endif - - old_regs = set_irq_regs(regs); - irq_enter(); - trace_timer_interrupt_entry(regs); if (test_irq_work_pending()) { @@ -551,7 +517,48 @@ void timer_interrupt(struct pt_regs * regs) #endif trace_timer_interrupt_exit(regs); +} +/* + * timer_interrupt - gets called when the decrementer overflows, + * with interrupts disabled. + */ +void timer_interrupt(struct pt_regs * regs) +{ + struct pt_regs *old_regs; + u64 *next_tb = &__get_cpu_var(decrementers_next_tb); + + /* Ensure a positive value is written to the decrementer, or else + * some CPUs will continue to take decrementer exceptions. + */ + set_dec(DECREMENTER_MAX); + + /* Some implementations of hotplug will get timer interrupts while + * offline, just ignore these and we also need to set + * decrementers_next_tb as MAX to make sure __check_irq_replay + * don't replay timer interrupt when return, otherwise we'll trap + * here infinitely :( + */ + if (!cpu_online(smp_processor_id())) { + *next_tb = ~(u64)0; + return; + } + + /* Conditionally hard-enable interrupts now that the DEC has been + * bumped to its maximum value + */ + may_hard_irq_enable(); + + +#if defined(CONFIG_PPC32) && defined(CONFIG_PMAC) + if (atomic_read(&ppc_n_lost_interrupts) != 0) + do_IRQ(regs); +#endif + + old_regs = set_irq_regs(regs); + irq_enter(); + + __timer_interrupt(); irq_exit(); set_irq_regs(old_regs); } @@ -828,6 +835,10 @@ static void decrementer_set_mode(enum clock_event_mode mode, /* Interrupt handler for the timer broadcast IPI */ void tick_broadcast_ipi_handler(void) { + u64 *next_tb = &__get_cpu_var(decrementers_next_tb); + + *next_tb = get_tb_or_rtc(); + __timer_interrupt(); } static void register_decrementer_clockevent(int cpu)