Re: [PATCH 2/5] hw/ppc/pnv_xscom: PBA bar mask values are incorrect with homer/occ sizes

[Cédric Le Goater]

On 19/11/2019 18:50, Balamuruhan S wrote:
> homer/occ sizes are calculated in skiboot with `(mask | 0xfffff) + 1`,
> and from xscom access should return correct mask values instead of actual
> sizes.
> 
> Signed-off-by: Cédric Le Goater <address@hidden>
> Signed-off-by: Balamuruhan S <address@hidden>
> ---
>  hw/ppc/pnv_xscom.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ppc/pnv_xscom.c b/hw/ppc/pnv_xscom.c
> index f01d788a65..cdd5fa356e 100644
> --- a/hw/ppc/pnv_xscom.c
> +++ b/hw/ppc/pnv_xscom.c
> @@ -46,6 +46,10 @@
>  #define P9_PBA_BARMASK0                 0x5012b04
>  #define P9_PBA_BARMASK2                 0x5012b06
>  
> +/* Mask to calculate Homer/Occ size */
> +#define HOMER_SIZE_MASK                 0x0000000000300000ull
> +#define OCC_SIZE_MASK                   0x0000000000700000ull
> +

Can't we deduce these values from the size ? 

>  static void xscom_complete(CPUState *cs, uint64_t hmer_bits)
>  {
>      /*
> @@ -90,9 +94,8 @@ static uint64_t xscom_read_default(PnvChip *chip, uint32_t 
> pcba)
>          return PNV_HOMER_BASE(chip);
>  
>      case P9_PBA_BARMASK0: /* P9 homer region size */
> -        return PNV9_HOMER_SIZE;
>      case P8_PBA_BARMASK0: /* P8 homer region size */
> -        return PNV_HOMER_SIZE;
> +        return HOMER_SIZE_MASK;

I would prefer to move all the HOMER accesses in a XSCOM region
under the PnvHomer model than expanding the default handlers. 
You will need a different set of handlers for P8 and P9 and a 
different mapping address also. 

Could you do that please ? 
  
>      case P9_PBA_BAR2: /* P9 occ common area */
>          return PNV9_OCC_COMMON_AREA(chip);
> @@ -100,9 +103,8 @@ static uint64_t xscom_read_default(PnvChip *chip, 
> uint32_t pcba)
>          return PNV_OCC_COMMON_AREA(chip);
>  
>      case P9_PBA_BARMASK2: /* P9 occ common area size */
> -        return PNV9_OCC_COMMON_AREA_SIZE;
>      case P8_PBA_BARMASK2: /* P8 occ common area size */

Shouldn't that be PBA_*3 under P8 ? 

C. 

> -        return PNV_OCC_COMMON_AREA_SIZE;
> +        return OCC_SIZE_MASK;
>  
>      case 0x1010c00:     /* PIBAM FIR */
>      case 0x1010c03:     /* PIBAM FIR MASK */
>