RE: [PATCH] arm64: dts: exynos: correct GIC CPU interfaces address range on Exynos7

Alim Akhtar
2021-08-05T09:59:52Z

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Sent: 05 August 2021 15:15
> To: Alim Akhtar <alim.akhtar@samsung.com>; 'Rob Herring'
> <robh+dt@kernel.org>; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: 'Chanwoo Choi' <cw00.choi@samsung.com>; 'Pankaj Dubey'
> <pankaj.dubey@samsung.com>; 'Sam Protsenko'
> <semen.protsenko@linaro.org>; 'Marc Zyngier' <maz@kernel.org>
> Subject: Re: [PATCH] arm64: dts: exynos: correct GIC CPU interfaces address
> range on Exynos7
>
> On 05/08/2021 11:43, Krzysztof Kozlowski wrote:
> > On 05/08/2021 11:26, Alim Akhtar wrote:
> >> Hi Krzysztof,
> >>
> >>> -----Original Message-----
> >>> From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> >>> Sent: 05 August 2021 13:07
> >>> To: Rob Herring <robh+dt@kernel.org>; devicetree@vger.kernel.org;
> >>> linux- arm-kernel@lists.infradead.org;
> >>> linux-samsung-soc@vger.kernel.org; linux- kernel@vger.kernel.org
> >>> Cc: Alim Akhtar <alim.akhtar@samsung.com>; Chanwoo Choi
> >>> <cw00.choi@samsung.com>; Pankaj Dubey
> <pankaj.dubey@samsung.com>;
> >>> Sam Protsenko <semen.protsenko@linaro.org>; Marc Zyngier
> >>> <maz@kernel.org>
> >>> Subject: Re: [PATCH] arm64: dts: exynos: correct GIC CPU interfaces
> >>> address range on Exynos7
> >>>
> >>> On 05/08/2021 09:21, Krzysztof Kozlowski wrote:
> >>>> The GIC-400 CPU interfaces address range is defined as
> >>>> 0x2000-0x3FFF (by ARM).
> >>>>
> >>>
> >> Looking at DDI0471B_gic400_r0p1_trm.pdf, CPU interface range is
> >> 0x0000 ~ 0x10000
> >>
> >>> I underestimated the issue - this is actually bug as there is a
> >>> GICC_DIR register at offset 0x1000. Therefore:
> >>>
> >> Looking at the exynos7 and exynos5433 UMs looks like GICC_DIR is at
> >> offset 0x2100 (from 0x1100_0000 GIC base) It is possible for you to cross
> check once?
> >>
> >
> > That's a mistake in Exynos manual. GICC_DIR is at 0x1000:
>
> 0x1000 from CPU base offset, so 0x3000 from GIC base.
>
> > https://developer.arm.com/documentation/ddi0471/b/programmers-
> model/cp
> > u-interface-register-summary
> >
> > We have discussion here:
> > https://lore.kernel.org/linux-samsung-soc/0277c701-cc25-cdc5-d3b9-cf2c
> >
> c2ba4de5@canonical.com/T/#m1ced9a28bed27f5cf74e281fb68efe1b57d5609
> e
Thanks for pointing to this discussion, I missed this.
Agreed.
Feel Free to add
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

> >
> > Range of 0x10000 is definitely wrong as it overlaps with two other
> > ranges.
>
>
> Best regards,
> Krzysztof