linux-kernel - Re: [PATCH v5 06/22] powerpc/irq: Rework helpers that manipulate MSR[EE/RI]

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Date:   Tue, 09 Feb 2021 11:14:24 +1000
From:   Nicholas Piggin <npiggin@...il.com>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Michael Ellerman <mpe@...erman.id.au>, msuchanek@...e.de,
        Paul Mackerras <paulus@...ba.org>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH v5 06/22] powerpc/irq: Rework helpers that manipulate
 MSR[EE/RI]

Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
> In preparation of porting PPC32 to C syscall entry/exit,
> rewrite the following helpers as static inline functions and
> add support for PPC32 in them:
> 	__hard_irq_enable()
> 	__hard_irq_disable()
> 	__hard_EE_RI_disable()
> 	__hard_RI_enable()
> 
> Then use them in PPC32 version of arch_local_irq_disable()
> and arch_local_irq_enable() to avoid code duplication.
> 

Reviewed-by: Nicholas Piggin <npiggin@...il.com>

> Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
> ---
>  arch/powerpc/include/asm/hw_irq.h | 75 +++++++++++++++++++++----------
>  arch/powerpc/include/asm/reg.h    |  1 +
>  2 files changed, 52 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
> index ed0c3b049dfd..4739f61e632c 100644
> --- a/arch/powerpc/include/asm/hw_irq.h
> +++ b/arch/powerpc/include/asm/hw_irq.h
> @@ -50,6 +50,55 @@
>  
>  #ifndef __ASSEMBLY__
>  
> +static inline void __hard_irq_enable(void)
> +{
> +	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
> +		wrtee(MSR_EE);
> +	else if (IS_ENABLED(CONFIG_PPC_8xx))
> +		wrtspr(SPRN_EIE);
> +	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
> +		__mtmsrd(MSR_EE | MSR_RI, 1);
> +	else
> +		mtmsr(mfmsr() | MSR_EE);
> +}
> +
> +static inline void __hard_irq_disable(void)
> +{
> +	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
> +		wrtee(0);
> +	else if (IS_ENABLED(CONFIG_PPC_8xx))
> +		wrtspr(SPRN_EID);
> +	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
> +		__mtmsrd(MSR_RI, 1);
> +	else
> +		mtmsr(mfmsr() & ~MSR_EE);
> +}
> +
> +static inline void __hard_EE_RI_disable(void)
> +{
> +	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
> +		wrtee(0);
> +	else if (IS_ENABLED(CONFIG_PPC_8xx))
> +		wrtspr(SPRN_NRI);
> +	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
> +		__mtmsrd(0, 1);
> +	else
> +		mtmsr(mfmsr() & ~(MSR_EE | MSR_RI));
> +}
> +
> +static inline void __hard_RI_enable(void)
> +{
> +	if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
> +		return;
> +
> +	if (IS_ENABLED(CONFIG_PPC_8xx))
> +		wrtspr(SPRN_EID);
> +	else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
> +		__mtmsrd(MSR_RI, 1);
> +	else
> +		mtmsr(mfmsr() | MSR_RI);
> +}
> +
>  #ifdef CONFIG_PPC64
>  #include <asm/paca.h>
>  
> @@ -212,18 +261,6 @@ static inline bool arch_irqs_disabled(void)
>  
>  #endif /* CONFIG_PPC_BOOK3S */
>  
> -#ifdef CONFIG_PPC_BOOK3E
> -#define __hard_irq_enable()	wrtee(MSR_EE)
> -#define __hard_irq_disable()	wrtee(0)
> -#define __hard_EE_RI_disable()	wrtee(0)
> -#define __hard_RI_enable()	do { } while (0)
> -#else
> -#define __hard_irq_enable()	__mtmsrd(MSR_EE|MSR_RI, 1)
> -#define __hard_irq_disable()	__mtmsrd(MSR_RI, 1)
> -#define __hard_EE_RI_disable()	__mtmsrd(0, 1)
> -#define __hard_RI_enable()	__mtmsrd(MSR_RI, 1)
> -#endif
> -
>  #define hard_irq_disable()	do {					\
>  	unsigned long flags;						\
>  	__hard_irq_disable();						\
> @@ -322,22 +359,12 @@ static inline unsigned long arch_local_irq_save(void)
>  
>  static inline void arch_local_irq_disable(void)
>  {
> -	if (IS_ENABLED(CONFIG_BOOKE))
> -		wrtee(0);
> -	else if (IS_ENABLED(CONFIG_PPC_8xx))
> -		wrtspr(SPRN_EID);
> -	else
> -		mtmsr(mfmsr() & ~MSR_EE);
> +	__hard_irq_disable();
>  }
>  
>  static inline void arch_local_irq_enable(void)
>  {
> -	if (IS_ENABLED(CONFIG_BOOKE))
> -		wrtee(MSR_EE);
> -	else if (IS_ENABLED(CONFIG_PPC_8xx))
> -		wrtspr(SPRN_EIE);
> -	else
> -		mtmsr(mfmsr() | MSR_EE);
> +	__hard_irq_enable();
>  }
>  
>  static inline bool arch_irqs_disabled_flags(unsigned long flags)
> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
> index c5a3e856191c..bc4305ba00d0 100644
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -1375,6 +1375,7 @@
>  #define mtmsr(v)	asm volatile("mtmsr %0" : \
>  				     : "r" ((unsigned long)(v)) \
>  				     : "memory")
> +#define __mtmsrd(v, l)	BUILD_BUG()
>  #define __MTMSR		"mtmsr"
>  #endif
>  
> -- 
> 2.25.0
> 
>