From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/3] arm64: dts: add the Alpine v2 EVP
Date: Tue, 9 Feb 2016 09:30:29 +0000 [thread overview]
Message-ID: <56B9B1B5.5070106@arm.com> (raw)
In-Reply-To: <CABM=7knaepbyy4nw_GczVM7E_t6py7gG0ERs8ru_AYoVXvAQ+A@mail.gmail.com>
On 09/02/16 09:14, Tsahee Zidenberg wrote:
>
>
> On 9 February 2016 at 11:09, Marc Zyngier <marc.zyngier@arm•com
> <mailto:marc.zyngier@arm•com>> 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 at 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
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...
next prev parent reply other threads:[~2016-02-09 9:30 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-08 9:11 [PATCH 0/3] arm64: introduce the Alpine support Antoine Tenart
2016-02-08 9:11 ` [PATCH 1/3] arm64: add Alpine SoC family Antoine Tenart
2016-02-08 9:11 ` [PATCH 2/3] arm64: dts: add the Alpine v2 EVP Antoine Tenart
2016-02-08 10:51 ` Mark Rutland
2016-02-08 11:00 ` Antoine Tenart
2016-02-08 12:20 ` Arnd Bergmann
2016-02-09 10:18 ` Antoine Tenart
2016-02-08 15:29 ` Marc Zyngier
2016-02-09 8:56 ` Antoine Tenart
2016-02-09 9:01 ` Antoine Tenart
2016-02-09 9:09 ` Marc Zyngier
[not found] ` <CABM=7knaepbyy4nw_GczVM7E_t6py7gG0ERs8ru_AYoVXvAQ+A@mail.gmail.com>
2016-02-09 9:30 ` Marc Zyngier [this message]
2016-02-09 10:13 ` Tsahee Zidenberg
2016-02-09 10:42 ` Marc Zyngier
2016-02-09 11:48 ` Marc Zyngier
2016-02-09 13:54 ` Tsahee Zidenberg
2016-02-08 9:11 ` [PATCH 3/3] arm64: defconfig: enable the Alpine family Antoine Tenart
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