On 9 February 2016 at 11:30, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > > On 09/02/16 09:14, Tsahee Zidenberg wrote: > > > > > > On 9 February 2016 at 11:09, Marc Zyngier <marc.zyngier@xxxxxxx > > <mailto:marc.zyngier@xxxxxxx>> wrote: > > > > On 09/02/16 09:01, Antoine Tenart wrote: > > > On Tue, Feb 09, 2016 at 09:56:33AM +0100, Antoine Tenart wrote: > > >> Hi Marc, > > >> > > >> On Mon, Feb 08, 2016 at 03:29:33PM +0000, Marc Zyngier wrote: > > >>> On 08/02/16 09:11, Antoine Tenart wrote: > > >>> > > >>>> + gic: gic@f0100000 { > > >>>> + compatible = "arm,gic-v3"; > > >>>> + reg = <0x0 0xf0200000 0x0 0x10000>, /* GIC Dist */ > > >>>> + <0x0 0xf0280000 0x0 0x200000>, /* GICR */ > > >>>> + <0x0 0xf0100000 0x0 0x2000>; /* GICC */ > > >>>> + interrupt-controller; > > >>>> + #interrupt-cells = <3>; > > >>>> + }; > > >>> > > >>> Something is wrong here. Either you are missing GICH and GICV (assuming > > >>> you have legacy support), or you have an extra GICC region (which > > >>> doesn't make sense on its own). > > >> > > >> I'll add the missing regions. > > > > > > Hmm, in fact the GICC region shouldn't be there. I'll make some tests > > > and remove it. > > > > If you have a GICv3 with legacy support, you will probably have GICC, > > GICH and GICV. Linux itself will only use GICD and GICR, but it needs at > > least GICV to be able to virtualize GICv2 guests. And GICV is not > > allowed to exist without GICC and GICH, so I really recommend that you > > keep GICC around. > > > > > > We use the GIC without legacy support (we disable it in early boot > > stages), so I think removing the GICC region is the better solution. > > Disabling legacy support doesn't mean that: > - the HW isn't present > - the associated regions are not useful > By "disabling lecgacy support in early boot" I don't just mean that ARE bit will be set, but it will actually be RAO/WI. There will be no way for SW to enable it and use these registers (which, sadly, means that there will be no way to enable gicv2 virtualization). If you insist - I will dig up the supposed location of GICV and GICH - yet it will be both untested and entirely unusable. We will add an entry for the maintenance interrupt, as it really can be used by future configurations. > Here, we describe the HW, not the usage you make of it. > > And unless you think that having working virtualization is completely > useless, I strongly suggest that you properly document the HW in the > device tree. > > Thanks, > > M. > -- > Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
