Subject: Re: [PATCH v3 6/9] KVM: PPC: Ultravisor: Restrict flush of the partition tlb cache

From: Murilo Opsfelder Araújo <[email-masked]>
Date: Thu, 06 Jun 2019 16:39:04 -0300

Claudio Carvalho <[email-masked]> writes:

> From: Ram Pai <[email-masked]>
>
> Ultravisor is responsible for flushing the tlb cache, since it manages
> the PATE entries. Hence skip tlb flush, if the ultravisor firmware is
> available.
>
> Signed-off-by: Ram Pai <[email-masked]>
> Signed-off-by: Claudio Carvalho <[email-masked]>
> ---
>  arch/powerpc/mm/book3s64/pgtable.c | 33 +++++++++++++++++-------------
>  1 file changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> index 40a9fc8b139f..1eeb5fe87023 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -224,6 +224,23 @@ void __init mmu_partition_table_init(void)
>  	powernv_set_nmmu_ptcr(ptcr);
>  }
>
> +static void flush_partition(unsigned int lpid, unsigned long dw0)
> +{
> +	if (dw0 & PATB_HR) {
> +		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 1) : :
> +			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> +		asm volatile(PPC_TLBIE_5(%0, %1, 2, 1, 1) : :
> +			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> +		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
> +	} else {
> +		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 0) : :
> +			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> +		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
> +	}
> +	/* do we need fixup here ?*/
> +	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
> +}
> +

checkpatch.pl seems to complain:

ERROR: need consistent spacing around '%' (ctx:WxV)
#125: FILE: arch/powerpc/mm/book3s64/pgtable.c:230:
+               asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 1) : :
                                             ^

ERROR: need consistent spacing around '%' (ctx:WxV)
#127: FILE: arch/powerpc/mm/book3s64/pgtable.c:232:
+               asm volatile(PPC_TLBIE_5(%0, %1, 2, 1, 1) : :
                                             ^

ERROR: need consistent spacing around '%' (ctx:WxV)
#131: FILE: arch/powerpc/mm/book3s64/pgtable.c:236:
+               asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 0) : :
                                             ^

>  static void __mmu_partition_table_set_entry(unsigned int lpid,
>  					    unsigned long dw0,
>  					    unsigned long dw1)
> @@ -238,20 +255,8 @@ static void __mmu_partition_table_set_entry(unsigned int lpid,
>  	 * The type of flush (hash or radix) depends on what the previous
>  	 * use of this partition ID was, not the new use.
>  	 */
> -	asm volatile("ptesync" : : : "memory");
> -	if (old & PATB_HR) {
> -		asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
> -			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> -		asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
> -			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> -		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
> -	} else {
> -		asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
> -			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
> -		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
> -	}
> -	/* do we need fixup here ?*/
> -	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
> +	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
> +		flush_partition(lpid, old);
>  }
>
>  void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
> --
> 2.20.1