On Mon, 1 Aug 2016 00:36:28 +0530
Madhavan Srinivasan <ma...@linux.vnet.ibm.com> wrote:
> Code to replay the Performance Monitoring Interrupts(PMI).
> In the masked_interrupt handler, for PMIs we reset the MSR[EE]
> and return. This is due the fact that PMIs are level triggered.
> In the __check_irq_replay(), we enabled the MSR[EE] which will
> fire the interrupt for us.
>
> Patch also adds a new arch_local_irq_disable_var() variant. New
> variant takes an input value to write to the paca->soft_enabled.
> This will be used in following patch to implement the tri-state
> value for soft-enabled.
>
> Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/hw_irq.h | 14 ++++++++++++++
> arch/powerpc/kernel/irq.c | 9 ++++++++-
> 2 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/hw_irq.h
> b/arch/powerpc/include/asm/hw_irq.h
> index a7b86edc94bf..9f235d25b9f8 100644
> --- a/arch/powerpc/include/asm/hw_irq.h
> +++ b/arch/powerpc/include/asm/hw_irq.h
> @@ -84,6 +84,20 @@ static inline unsigned long arch_local_irq_disable(void)
> return flags;
> }
>
> +static inline unsigned long soft_irq_set_level(int value)
> +{
> + unsigned long flags, zero;
> +
> + asm volatile(
> + "li %1,%3; lbz %0,%2(13); stb %1,%2(13)"
> + : "=r" (flags), "=&r" (zero)
> + : "i" (offsetof(struct paca_struct, soft_enabled)),\
> + "i" (value)
> + : "memory");
> +
> + return flags;
> +}
> +
> extern void arch_local_irq_restore(unsigned long);
>
> static inline void arch_local_irq_enable(void)
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index 857e1e8188e5..9d70e51db8bc 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -158,9 +158,16 @@ notrace unsigned int __check_irq_replay(void)
> if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow())
> return 0x900;
>
> + /*
> + * In masked_handler() for PMI, we disable MSR[EE] and return.
> + * When replaying it, just enabling the MSR[EE] will do
> + * trick, since the PMI are "level" triggered.
> + */
> + local_paca->irq_happened &= ~PACA_IRQ_PMI;
> +
> /* Finally check if an external interrupt happened */
> local_paca->irq_happened &= ~PACA_IRQ_EE;
> - if (happened & PACA_IRQ_EE)
> + if ((happened & PACA_IRQ_EE) || (happened & PACA_IRQ_PMI))
> return 0x500;
This will replay hardware_interrupt_common in the case we got a PMI
interrupt but no EE.
Should we just follow the normal pattern here, return 0xf00 for PMI,
and replay the same as the other cases?
Thanks,
Nick
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