Re: [PATCH v5 05/22] powerpc/irq: Add helper to set regs->softe

Nicholas Piggin
2021-02-09T01:13:21Z

Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
> regs->softe doesn't exist on PPC32.
>
> Add irq_soft_mask_regs_set_state() helper to set regs->softe.
> This helper will void on PPC32.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/include/asm/hw_irq.h | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
> index 614957f74cee..ed0c3b049dfd 100644
> --- a/arch/powerpc/include/asm/hw_irq.h
> +++ b/arch/powerpc/include/asm/hw_irq.h
> @@ -38,6 +38,8 @@
> #define PACA_IRQ_MUST_HARD_MASK (PACA_IRQ_EE)
> #endif
>
> +#endif /* CONFIG_PPC64 */
> +
> /*
> * flags for paca->irq_soft_mask
> */
> @@ -46,8 +48,6 @@
> #define IRQS_PMI_DISABLED 2
> #define IRQS_ALL_DISABLED (IRQS_DISABLED | IRQS_PMI_DISABLED)
>
> -#endif /* CONFIG_PPC64 */
> -
> #ifndef __ASSEMBLY__
>
> #ifdef CONFIG_PPC64
> @@ -287,6 +287,10 @@ extern void irq_set_pending_from_srr1(unsigned long srr1);
>
> extern void force_external_irq_replay(void);
>
> +static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
> +{
> + regs->softe = val;
> +}
> #else /* CONFIG_PPC64 */
>
> static inline unsigned long arch_local_save_flags(void)
> @@ -355,6 +359,9 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
>
> static inline void may_hard_irq_enable(void) { }
>
> +static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
> +{
> +}
> #endif /* CONFIG_PPC64 */
>
> #define ARCH_IRQ_INIT_FLAGS IRQ_NOREQUEST

What I don't like about this where you use it is it kind of pollutes
the ppc32 path with this function which is not valid to use.

I would prefer if you had this purely so it could compile with:

if (IS_ENABLED(CONFIG_PPC64)))
irq_soft_mask_regs_set_state(regs, blah);

And then you could make the ppc32 cause a link error if it did not
get eliminated at compile time (e.g., call an undefined function).

You could do the same with the kuap_ functions to change some ifdefs
to IS_ENABLED.

That's just my preference but if you prefer this way I guess that's
okay.

Thanks,
Nick