Re: [PATCH v6 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT

[Kuppuswamy, Sathyanarayanan]

On 9/3/21 11:22 AM, Borislav Petkov wrote:
> On Fri, Sep 03, 2021 at 10:28:02AM -0700, Kuppuswamy Sathyanarayanan wrote:
> > diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
> > index c5ce9845c999..ddc77c95adc6 100644
> > --- a/arch/x86/include/asm/irqflags.h
> > +++ b/arch/x86/include/asm/irqflags.h
> > @@ -59,27 +59,8 @@ static inline __cpuidle void native_halt(void)
> >   
> >   #endif
> >   
> > -#ifdef CONFIG_PARAVIRT_XXL
> > -#include <asm/paravirt.h>
> > -#else
> > +#ifndef CONFIG_PARAVIRT
> >   #ifndef __ASSEMBLY__
> > -#include <linux/types.h>
> > -
> > -static __always_inline unsigned long arch_local_save_flags(void)
> > -{
> > -	return native_save_fl();
> > -}
> > -
> > -static __always_inline void arch_local_irq_disable(void)
> > -{
> > -	native_irq_disable();
> > -}
> > -
> > -static __always_inline void arch_local_irq_enable(void)
> > -{
> > -	native_irq_enable();
> > -}
> > -
> >   /*
> >    * Used in the idle loop; sti takes one instruction cycle
> >    * to complete:
> > @@ -97,6 +78,33 @@ static inline __cpuidle void halt(void)
> >   {
> >   	native_halt();
> >   }
> > +#endif /* __ASSEMBLY__ */
> > +#endif /* CONFIG_PARAVIRT */
> > +
> > +#ifdef CONFIG_PARAVIRT
> > +#ifndef __ASSEMBLY__
> > +#include <asm/paravirt.h>
> > +#endif /* __ASSEMBLY__ */
> > +#endif /* CONFIG_PARAVIRT */
>
> I think the way we write those is like this:
>
> #ifdef CONFIG_PARAVIRT
>
> # ifndef __ASSEMBLY__
> # include <asm/paravirt.h>
> # endif
>
> #else /* ! CONFIG_PARAVIRT */
>
> # ifndef __ASSEMBLY__
> /*
>   * Used in the idle loop; sti takes one instruction cycle
>   * to complete:
>   */
> static inline __cpuidle void arch_safe_halt(void)
> {
> 	native_safe_halt();
> }
>
> /*
>   * Used when interrupts are already enabled or to
>   * shutdown the processor:
>   */
> static inline __cpuidle void halt(void)
> {
> 	native_halt();
> }
> # endif /* __ASSEMBLY__ */
>
> #endif /* CONFIG_PARAVIRT */

Yes, I can combine the #ifdef as you have mentioned. I can fix this
in next version.

> Note the empty space after the '#' of the inner ifdef to show that it is
> an inner one.

Is this new convention? #ifdefs used in this file does not follow this
format.

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer