[Skiboot] [PATCH v2] phb4: Enable PHB MMIO-0/1 Bars only when mmio window exists

[Oliver]

Reviewed-by: Oliver O'Halloran <oohall at gmail.com>

On Thu, Aug 23, 2018 at 8:07 PM, Vaibhav Jain <vaibhav at linux.ibm.com> wrote:
> Presently phb4_probe_stack() will always enable PHB MMIO0/1 windows
> even if they doesn't exist in phy_map. Hence we do some minor shuffling
> in the phb4_probe_stack() so that MMIO-0/1 Bars are only enabled if
> there corresponding MMIO window exists in the phy_map. In case phy_map
> for an mmio window is '0' we set the corresponding BAR register to
> '0'.
>
> Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>
> ---
> Change-log
>
> v2      -> Re-factored the patch to make sure bar registers are set to
>         '0' if the corresponding mmio window doesn't exist. [Oliver]
> ---
>  hw/phb4.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/hw/phb4.c b/hw/phb4.c
> index d1245dce..2ecd80e7 100644
> --- a/hw/phb4.c
> +++ b/hw/phb4.c
> @@ -5537,7 +5537,7 @@ static void phb4_probe_stack(struct dt_node *stk_node, uint32_t pec_index,
>         uint32_t pci_stack, nest_stack, etu_base, gcid, phb_num, stk_index;
>         uint64_t val, phb_bar = 0, irq_bar = 0, bar_en;
>         uint64_t mmio0_bar = 0, mmio0_bmask, mmio0_sz;
> -       uint64_t mmio1_bar, mmio1_bmask, mmio1_sz;
> +       uint64_t mmio1_bar = 0, mmio1_bmask, mmio1_sz;
>         uint64_t reg[4];
>         void *foo;
>         uint64_t mmio_win[4];
> @@ -5587,7 +5587,6 @@ static void phb4_probe_stack(struct dt_node *stk_node, uint32_t pec_index,
>         mmio1_bmask =  (~(mmio1_sz - 1)) & 0x00FFFFFFFFFFFFFFULL;
>         xscom_write(gcid, nest_stack + XPEC_NEST_STK_MMIO_BAR1, mmio1_bar << 8);
>         xscom_write(gcid, nest_stack + XPEC_NEST_STK_MMIO_BAR1_MASK, mmio1_bmask << 8);
> -       bar_en |= XPEC_NEST_STK_BAR_EN_MMIO0 | XPEC_NEST_STK_BAR_EN_MMIO1;
>
>         /* Build MMIO windows list */
>         mmio_win_sz = 0;
> --
> 2.17.1
>