Re: [PATCH for-7.2 v3 07/11] ppc/pnv: add PHB4 helpers for user created pnv-phb

[Cédric Le Goater]

On 8/10/22 12:05, Daniel Henrique Barboza wrote:
> The PHB4 backend relies on a link with the corresponding PEC element.
> This is trivial to do during machine_init() time for default devices,
> but not so much for user created ones.
>
> pnv_phb4_get_pec() is a small variation of the function that was
> reverted by commit 9c10d86fee "ppc/pnv: Remove user-created PHB{3,4,5}
> devices". We'll use it to determine the appropriate PEC for a given user
> created pnv-phb that uses a PHB4 backend.
>
> This is done during realize() time, in pnv_phb_user_device_init().
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>   hw/pci-host/pnv_phb.c | 40 ++++++++++++++++++++++++++++++++++++++--
>   1 file changed, 38 insertions(+), 2 deletions(-)
>
> diff --git a/hw/pci-host/pnv_phb.c b/hw/pci-host/pnv_phb.c
> index 887b25d49e..f9516fdc4a 100644
> --- a/hw/pci-host/pnv_phb.c
> +++ b/hw/pci-host/pnv_phb.c
> @@ -50,6 +50,34 @@ static void pnv_parent_bus_fixup(DeviceState *parent, 
> DeviceState *child)
>       }
>   }
>   
> +static PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB4 *phb,
> +                                         Error **errp)
> +{
> +    Pnv9Chip *chip9 = PNV9_CHIP(chip);
> +    int chip_id = phb->chip_id;
> +    int index = phb->phb_id;
> +    int i, j;
> +
> +    for (i = 0; i < chip->num_pecs; i++) {
> +        /*
> +         * For each PEC, check the amount of phbs it supports
> +         * and see if the given phb4 index matches an index.
> +         */
> +        PnvPhb4PecState *pec = &chip9->pecs[i];
> +
> +        for (j = 0; j < pec->num_phbs; j++) {
> +            if (index == pnv_phb4_pec_get_phb_id(pec, j)) {
> +                return pec;
> +            }
> +        }
> +    }
> +    error_setg(errp,
> +               "pnv-phb4 chip-id %d index %d didn't match any existing PEC",
> +               chip_id, index);
> +
> +    return NULL;
> +}
> +
>   /*
>    * Attach a root port device.
>    *
> @@ -100,8 +128,16 @@ static void pnv_phb_user_device_init(PnvPHB *phb)
>   
>           parent = OBJECT(chip);
>       } else {
> -        /* phb4 support will be added later */
> -        return;
> +        Error *local_err = NULL;
> +
> +        phb->pec = pnv_phb4_get_pec(chip, PNV_PHB4(phb->backend), &local_err);
> +
> +        if (local_err) {
> +            error_propagate(&error_fatal, local_err);

That's weird. pnv_phb_user_device_init() should have an errp parameter I think.

C.

> +            return;
> +        }
> +
> +        parent = OBJECT(phb->pec);
>       }
>   
>       /*