Re: [powerpc v6 1/3] Setup AMOR in HV mode

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Balbir Singh <bsingharora@gmail.com> writes:

> AMOR should be setup in HV mode, we set it up once
> and let the generic kernel handle IAMR. This patch is
> used to enable storage keys in a following patch as
> defined in ISA 3. We don't setup AMOR in DD1, since we
> can't setup IAMR in DD1 (bits have to be 0). If we setup
> AMOR some other code could potentially try to set IAMR
> (guest kernel for example).
>
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
> ---
>  arch/powerpc/mm/pgtable-radix.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
> index ed7bddc..7aa104d 100644
> --- a/arch/powerpc/mm/pgtable-radix.c
> +++ b/arch/powerpc/mm/pgtable-radix.c
> @@ -320,6 +320,27 @@ static void update_hid_for_radix(void)
>  		cpu_relax();
>  }
>  
> +/*
> + * In HV mode, we init AMOR so that the hypervisor
> + * and guest can setup IMAR, enable key 0 and set
> + * it to 1
> + * AMOR = 1100....00 (Mask for key 0 is 11)
> + */
> +static void radix_init_amor(void)
> +{
> +	unsigned long amor_mask = 0xc000000000000000;
> +	unsigned long amor;

I guess michael mentioned this in another email, why two variables ?

> +
> +	/*
> +	 * The amor bits are unused in DD1
> +	 */
> +	if (cpu_has_feature(CPU_FTR_POWER9_DD1))
> +		return;
> +
> +	amor = amor_mask;
> +	mtspr(SPRN_AMOR, amor);
> +}
> +
>  void __init radix__early_init_mmu(void)
>  {
>  	unsigned long lpcr;
> @@ -376,6 +397,7 @@ void __init radix__early_init_mmu(void)
>  		lpcr = mfspr(SPRN_LPCR);
>  		mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
>  		radix_init_partition_table();
> +		radix_init_amor();
>  	}
>  
>  	radix_init_pgtable();
> @@ -393,6 +415,7 @@ void radix__early_init_mmu_secondary(void)
>  
>  		mtspr(SPRN_PTCR,
>  		      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
> +		radix_init_amor();
>  	}
>  }
>  
> -- 
> 2.5.5