diff options
| -rw-r--r-- | arch/powerpc/include/asm/hw_irq.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 46 | ||||
| -rw-r--r-- | arch/powerpc/platforms/cell/pervasive.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/processor_idle.c | 17 |
4 files changed, 64 insertions, 12 deletions
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h index 6627a3e1b13..09e6d5951bb 100644 --- a/arch/powerpc/include/asm/hw_irq.h +++ b/arch/powerpc/include/asm/hw_irq.h @@ -124,6 +124,8 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs) return !regs->softe; } +extern bool prep_irq_for_idle(void); + #else /* CONFIG_PPC64 */ #define SET_MSR_EE(x) mtmsr(x) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 64eec59193f..d6946e10a25 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -286,6 +286,52 @@ void notrace restore_interrupts(void) __hard_irq_enable(); } +/* + * This is a helper to use when about to go into idle low-power + * when the latter has the side effect of re-enabling interrupts + * (such as calling H_CEDE under pHyp). + * + * You call this function with interrupts soft-disabled (this is + * already the case when ppc_md.power_save is called). The function + * will return whether to enter power save or just return. + * + * In the former case, it will have notified lockdep of interrupts + * being re-enabled and generally sanitized the lazy irq state, + * and in the latter case it will leave with interrupts hard + * disabled and marked as such, so the local_irq_enable() call + * in cpu_idle() will properly re-enable everything. + */ +bool prep_irq_for_idle(void) +{ + /* + * First we need to hard disable to ensure no interrupt + * occurs before we effectively enter the low power state + */ + hard_irq_disable(); + + /* + * If anything happened while we were soft-disabled, + * we return now and do not enter the low power state. + */ + if (lazy_irq_pending()) + return false; + + /* Tell lockdep we are about to re-enable */ + trace_hardirqs_on(); + + /* + * Mark interrupts as soft-enabled and clear the + * PACA_IRQ_HARD_DIS from the pending mask since we + * are about to hard enable as well as a side effect + * of entering the low power state. + */ + local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; + local_paca->soft_enabled = 1; + + /* Tell the caller to enter the low power state */ + return true; +} + #endif /* CONFIG_PPC64 */ int arch_show_interrupts(struct seq_file *p, int prec) diff --git a/arch/powerpc/platforms/cell/pervasive.c b/arch/powerpc/platforms/cell/pervasive.c index efdacc82957..d17e98bc0c1 100644 --- a/arch/powerpc/platforms/cell/pervasive.c +++ b/arch/powerpc/platforms/cell/pervasive.c @@ -42,11 +42,9 @@ static void cbe_power_save(void) { unsigned long ctrl, thread_switch_control; - /* - * We need to hard disable interrupts, the local_irq_enable() done by - * our caller upon return will hard re-enable. - */ - hard_irq_disable(); + /* Ensure our interrupt state is properly tracked */ + if (!prep_irq_for_idle()) + return; ctrl = mfspr(SPRN_CTRLF); @@ -81,6 +79,9 @@ static void cbe_power_save(void) */ ctrl &= ~(CTRL_RUNLATCH | CTRL_TE); mtspr(SPRN_CTRLT, ctrl); + + /* Re-enable interrupts in MSR */ + __hard_irq_enable(); } static int cbe_system_reset_exception(struct pt_regs *regs) diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c index e61483e8e96..c71be66bd5d 100644 --- a/arch/powerpc/platforms/pseries/processor_idle.c +++ b/arch/powerpc/platforms/pseries/processor_idle.c @@ -99,15 +99,18 @@ out: static void check_and_cede_processor(void) { /* - * Interrupts are soft-disabled at this point, - * but not hard disabled. So an interrupt might have - * occurred before entering NAP, and would be potentially - * lost (edge events, decrementer events, etc...) unless - * we first hard disable then check. + * Ensure our interrupt state is properly tracked, + * also checks if no interrupt has occurred while we + * were soft-disabled */ - hard_irq_disable(); - if (!lazy_irq_pending()) + if (prep_irq_for_idle()) { cede_processor(); +#ifdef CONFIG_TRACE_IRQFLAGS + /* Ensure that H_CEDE returns with IRQs on */ + if (WARN_ON(!(mfmsr() & MSR_EE))) + __hard_irq_enable(); +#endif + } } static int dedicated_cede_loop(struct cpuidle_device *dev, |