[RFC PATCH 09/12] powerpc: move NMI entry/exit code into wrapper

[Christophe Leroy]

On 9/5/20 5:43 PM, Nicholas Piggin wrote:
> This moves the common NMI entry and exit code into the interrupt handler
> wrappers.
> 
> This changes the behaviour of soft-NMI (watchdog) and HMI interrupts, and
> also MCE interrupts on 64e, by adding missing parts of the NMI entry to
> them.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>   arch/powerpc/include/asm/interrupt.h | 26 +++++++++++++++++++
>   arch/powerpc/kernel/mce.c            | 12 ---------
>   arch/powerpc/kernel/traps.c          | 38 +++++-----------------------
>   arch/powerpc/kernel/watchdog.c       | 10 +++-----
>   4 files changed, 37 insertions(+), 49 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
> index 83fe1d64cf23..69eb8a432984 100644
> --- a/arch/powerpc/include/asm/interrupt.h
> +++ b/arch/powerpc/include/asm/interrupt.h
> @@ -31,6 +31,27 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs)
>   }
>   #endif /* CONFIG_PPC_BOOK3S_64 */
>   
> +struct interrupt_nmi_state {
> +#ifdef CONFIG_PPC64
> +	u8 ftrace_enabled;
> +#endif
> +};
> +
> +static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
> +{
> +	this_cpu_set_ftrace_enabled(0);
> +
> +	nmi_enter();
> +}
> +
> +static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state)
> +{
> +	nmi_exit();
> +
> +	this_cpu_set_ftrace_enabled(state->ftrace_enabled);

PPC32 build:

In file included from arch/powerpc/kernel/irq.c:57:0:
./arch/powerpc/include/asm/interrupt.h: In function 
‘interrupt_nmi_exit_prepare’:
./arch/powerpc/include/asm/interrupt.h:96:35: error: ‘struct 
interrupt_nmi_state’ has no member named ‘ftrace_enabled’
   this_cpu_set_ftrace_enabled(state->ftrace_enabled);
                                    ^

> +}
> +
> +
>   /**
>    * DECLARE_INTERRUPT_HANDLER_RAW - Declare raw interrupt handler function
>    * @func:	Function name of the entry point
> @@ -177,10 +198,15 @@ static __always_inline long ___##func(struct pt_regs *regs);		\
>   									\
>   __visible noinstr long func(struct pt_regs *regs)			\
>   {									\
> +	struct interrupt_nmi_state state;				\
>   	long ret;							\
>   									\
> +	interrupt_nmi_enter_prepare(regs, &state);			\
> +									\
>   	ret = ___##func (regs);						\
>   									\
> +	interrupt_nmi_exit_prepare(regs, &state);			\
> +									\
>   	return ret;							\
>   }									\
>   									\

Christophe