Re: [PATCH v4 4/9] powerpc/mm/book3s64: Fix possible build error

From: Michael Ellerman <mpe@ellerman.id.au>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linuxppc-dev@lists.ozlabs.org, kaleshsingh@google.com,
	npiggin@gmail.com, joel@joelfernandes.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: Re: [PATCH v4 4/9] powerpc/mm/book3s64: Fix possible build error
Date: Tue, 20 Apr 2021 13:43:33 +1000	[thread overview]
Message-ID: <87k0oxd3iy.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <20210414085915.301189-5-aneesh.kumar@linux.ibm.com>

"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
> Update _tlbiel_pid() such that we can avoid build errors like below when
> using this function in other places.
>
> arch/powerpc/mm/book3s64/radix_tlb.c: In function ‘__radix__flush_tlb_range_psize’:
> arch/powerpc/mm/book3s64/radix_tlb.c:114:2: warning: ‘asm’ operand 3 probably does not match constraints
>   114 |  asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
>       |  ^~~
> arch/powerpc/mm/book3s64/radix_tlb.c:114:2: error: impossible constraint in ‘asm’
> make[4]: *** [scripts/Makefile.build:271: arch/powerpc/mm/book3s64/radix_tlb.o] Error 1
> m
>
> With this fix, we can also drop the __always_inline in __radix_flush_tlb_range_psize
> which was added by commit e12d6d7d46a6 ("powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline")
>
> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  arch/powerpc/mm/book3s64/radix_tlb.c | 26 +++++++++++++++++---------
>  1 file changed, 17 insertions(+), 9 deletions(-)

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheers

> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 409e61210789..817a02ef6032 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -291,22 +291,30 @@ static inline void fixup_tlbie_lpid(unsigned long lpid)
>  /*
>   * We use 128 set in radix mode and 256 set in hpt mode.
>   */
> -static __always_inline void _tlbiel_pid(unsigned long pid, unsigned long ric)
> +static inline void _tlbiel_pid(unsigned long pid, unsigned long ric)
>  {
>  	int set;
>  
>  	asm volatile("ptesync": : :"memory");
>  
> -	/*
> -	 * Flush the first set of the TLB, and if we're doing a RIC_FLUSH_ALL,
> -	 * also flush the entire Page Walk Cache.
> -	 */
> -	__tlbiel_pid(pid, 0, ric);
> +	switch (ric) {
> +	case RIC_FLUSH_PWC:
>  
> -	/* For PWC, only one flush is needed */
> -	if (ric == RIC_FLUSH_PWC) {
> +		/* For PWC, only one flush is needed */
> +		__tlbiel_pid(pid, 0, RIC_FLUSH_PWC);
>  		ppc_after_tlbiel_barrier();
>  		return;
> +	case RIC_FLUSH_TLB:
> +		__tlbiel_pid(pid, 0, RIC_FLUSH_TLB);
> +		break;
> +	case RIC_FLUSH_ALL:
> +	default:
> +		/*
> +		 * Flush the first set of the TLB, and if
> +		 * we're doing a RIC_FLUSH_ALL, also flush
> +		 * the entire Page Walk Cache.
> +		 */
> +		__tlbiel_pid(pid, 0, RIC_FLUSH_ALL);
>  	}
>  
>  	if (!cpu_has_feature(CPU_FTR_ARCH_31)) {
> @@ -1176,7 +1184,7 @@ void radix__tlb_flush(struct mmu_gather *tlb)
>  	}
>  }
>  
> -static __always_inline void __radix__flush_tlb_range_psize(struct mm_struct *mm,
> +static void __radix__flush_tlb_range_psize(struct mm_struct *mm,
>  				unsigned long start, unsigned long end,
>  				int psize, bool also_pwc)
>  {
> -- 
> 2.30.2