Re: [Xen-devel] [PATCH v2 14/15] xen/arm: Add vgic support for GIC v3

[Vijay Kilari <vijay.kilari@xxxxxxxxx>]

On Thu, Apr 10, 2014 at 3:53 PM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> On Fri, 2014-04-04 at 17:26 +0530, vijay.kilari@xxxxxxxxx wrote:
>> From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
>>
>> Add vgic driver support for GIC v3 version.
>
> There is an awful lot of code duplication with the v2 stuff here,
> especially with the distributor, but even the redistrubotr stuff looks
> like it could share common implementation with the v2 distro for at
> least some functionality.
>
> I think we should investigate a sinlge driver here, or at least
> refactoring anything which is common into a library of helper functions
> which both can use.

Yes, only distributor code is common which is just 2 functions i.e
read & write functions.
But the whole complexity is v2 gic & vgic driver is it runs with byte
offset that is the reason
why in gic_v2_defs all the register addresses definitions are divided by 4.
So this make it quite difficult to make common code.

With GICv2 HW constraint, I could not take it up. May be we can take
this as separate task.

>> +    case GICR_SETLPIR:
> I think you should either register two mmio handlers or maybe just
> handle this all at once in a single callback.
>
   There is only one address rdistributore base and size extracted from dt.
So we register one handle for this entire region and this single callback will
take access either GICR or SGI's GICR region.

> I didn't see any system register handling, I suppose that is all handled
> by the hardware GICV stuff?
   For all system register accesses in Dom's, HW treats are virtual access.
The memory mapped GICD & GICR registers are virtualized by VGIC
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel