Re: [PATCH v8 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kuppuswamy Sathyanarayanan  <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
	David Hildenbrand <david@redhat.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Juergen Gross <jgross@suse.com>, Deep Shah <sdeep@vmware.com>,
	VMware Inc <pv-drivers@vmware.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Peter H Anvin <hpa@zytor.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT
Date: Tue, 5 Oct 2021 13:13:18 -0700	[thread overview]
Message-ID: <20211005201318.j3qg3swnovo7a3ot@treble> (raw)
In-Reply-To: <20211005025205.1784480-2-sathyanarayanan.kuppuswamy@linux.intel.com>

On Mon, Oct 04, 2021 at 07:51:55PM -0700, Kuppuswamy Sathyanarayanan wrote:
> diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
> index c5ce9845c999..2a2ebf9af43e 100644
> --- a/arch/x86/include/asm/irqflags.h
> +++ b/arch/x86/include/asm/irqflags.h
> @@ -59,27 +59,15 @@ static inline __cpuidle void native_halt(void)
>  
>  #endif
>  
> -#ifdef CONFIG_PARAVIRT_XXL
> -#include <asm/paravirt.h>
> -#else
> -#ifndef __ASSEMBLY__
> -#include <linux/types.h>
> +#ifdef CONFIG_PARAVIRT
>  
> -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();
> -}
> +# ifndef __ASSEMBLY__
> +# include <asm/paravirt.h>
> +# endif /* __ASSEMBLY__ */
>  
> -static __always_inline void arch_local_irq_enable(void)
> -{
> -	native_irq_enable();
> -}
> +#else /* ! CONFIG_PARAVIRT */
>  
> +# ifndef __ASSEMBLY__
>  /*
>   * Used in the idle loop; sti takes one instruction cycle
>   * to complete:
> @@ -97,6 +85,28 @@ static inline __cpuidle void halt(void)
>  {
>  	native_halt();
>  }
> +# endif /* __ASSEMBLY__ */
> +
> +#endif /* CONFIG_PARAVIRT */
> +
> +#ifndef CONFIG_PARAVIRT_XXL
> +#ifndef __ASSEMBLY__

There are a lot of '__ASSEMBLY__' #ifdefs which make this macro maze
extra hard to follow.  Folding in something like this would help a lot:

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 2a2ebf9af43e..afecf7fa20d0 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -57,17 +57,12 @@ static inline __cpuidle void native_halt(void)
 	asm volatile("hlt": : :"memory");
 }
 
-#endif
-
 #ifdef CONFIG_PARAVIRT
 
-# ifndef __ASSEMBLY__
 # include <asm/paravirt.h>
-# endif /* __ASSEMBLY__ */
 
 #else /* ! CONFIG_PARAVIRT */
 
-# ifndef __ASSEMBLY__
 /*
  * Used in the idle loop; sti takes one instruction cycle
  * to complete:
@@ -85,9 +80,9 @@ static inline __cpuidle void halt(void)
 {
 	native_halt();
 }
-# endif /* __ASSEMBLY__ */
 
 #endif /* CONFIG_PARAVIRT */
+#endif /* __ASSEMBLY__ */
 
 #ifndef CONFIG_PARAVIRT_XXL
 #ifndef __ASSEMBLY__

