diff options
Diffstat (limited to 'arch/mips/kernel/time.c')
| -rw-r--r-- | arch/mips/kernel/time.c | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c index 751b4a18b133..7def1ff3da94 100644 --- a/arch/mips/kernel/time.c +++ b/arch/mips/kernel/time.c @@ -199,6 +199,30 @@ int (*perf_irq)(void) = null_perf_irq; EXPORT_SYMBOL(null_perf_irq); EXPORT_SYMBOL(perf_irq); +/* + * Performance counter IRQ or -1 if shared with timer + */ +int mipsxx_perfcount_irq; +EXPORT_SYMBOL(mipsxx_perfcount_irq); + +/* + * Possibly handle a performance counter interrupt. + * Return true if the timer interrupt should not be checked + */ +static inline int handle_perf_irq (int r2) +{ + /* + * The performance counter overflow interrupt may be shared with the + * timer interrupt (mipsxx_perfcount_irq < 0). If it is and a + * performance counter has overflowed (perf_irq() == IRQ_HANDLED) + * and we can't reliably determine if a counter interrupt has also + * happened (!r2) then don't check for a timer interrupt. + */ + return (mipsxx_perfcount_irq < 0) && + perf_irq() == IRQ_HANDLED && + !r2; +} + asmlinkage void ll_timer_interrupt(int irq) { int r2 = cpu_has_mips_r2; @@ -206,19 +230,13 @@ asmlinkage void ll_timer_interrupt(int irq) irq_enter(); kstat_this_cpu.irqs[irq]++; - /* - * Suckage alert: - * Before R2 of the architecture there was no way to see if a - * performance counter interrupt was pending, so we have to run the - * performance counter interrupt handler anyway. - */ - if (!r2 || (read_c0_cause() & (1 << 26))) - if (perf_irq()) - goto out; + if (handle_perf_irq(r2)) + goto out; - /* we keep interrupt disabled all the time */ - if (!r2 || (read_c0_cause() & (1 << 30))) - timer_interrupt(irq, NULL); + if (r2 && ((read_c0_cause() & (1 << 30)) == 0)) + goto out; + + timer_interrupt(irq, NULL); out: irq_exit(); @@ -258,7 +276,7 @@ unsigned int mips_hpt_frequency; static struct irqaction timer_irqaction = { .handler = timer_interrupt, - .flags = IRQF_DISABLED, + .flags = IRQF_DISABLED | IRQF_PERCPU, .name = "timer", }; |