Re: [PATCH 08/10] vpci/arm: Allow updating BAR's header for non-ECAM bridges

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Nov 09, 2020 at 02:50:29PM +0200, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> 
> Non-ECAM host bridges in hwdom go directly to PCI config space,
> not through vpci (they use their specific method for accessing PCI
> configuration, e.g. dedicated registers etc.). Thus hwdom's vpci BARs are
> never updated via vPCI MMIO handlers, so implement a dedicated method
> for a PCI host bridge, so it has a chance to update the initial state of
> the device BARs.
> 
> Note, we rely on the fact that control/hardware domain will not update
> physical BAR locations for the given devices.

This is quite ugly.

I'm looking at the commit that implements the hook for R-Car and I'm
having trouble seeing how that's different from the way we would
normally read the BAR addresses.

I think this should likely be paired with the actual implementation of
a hook, or else it's hard to tell whether it really needed or not.

Thanks, Roger.