[PATCH] ARM: tegra: select required CPU and L2 errata options

Marc Dietrich
2012-01-05T22:03:41Z

On Thursday 05 January 2012 10:40:48 Doug Anderson wrote:
> I can't comment on the L2 stuff (haven't looked there), but just going
> by Cortex-A9 revisions (T25 has roughly r1p1 and T30 has r2p7), I've
> got this table:
>
> Errata T25 (A9 ~r1p1) T30 (A9 r2p7) Applies to
> ARM_ERRATA_364296 pre A8
> ARM_ERRATA_411920 pre A8
> ARM_ERRATA_430973 A8
> ARM_ERRATA_458693 A8
> ARM_ERRATA_460075 A8
> ARM_ERRATA_720789 yes A9 (prior to r2p0)
> ARM_ERRATA_742230 yes A9 (r1p0..r2p2)
> ARM_ERRATA_742231 A9 (r2p0..r2p2)
> ARM_ERRATA_743622 A9 (r2p0..r2p2)
> ARM_ERRATA_751472 yes yes A9 (prior to r3p0)
> ARM_ERRATA_754322 yes A9 (r2p*, r3p*)
> ARM_ERRATA_754327 yes A9 (prior to r2p0)
> ARM_ERRATA_764369 yes yes A9 MPCore (all revs)
>
> ...so that means we should also be adding in 720789 (T2x), 751472
> (T2x, T30), 754322 (T30), 754327 (T2x), 764369 (T2x, T30).

AFAIK, 720789 (TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty
ASID) is fixed in userspace (or gcc) nowadays (at least in Ubuntu) so I think
this can be neglected.

Marc

> Certainly appreciate anyone checking my work and definitely appreciate
> input from nVidia.
>
> -Doug
>
> ---
>
> On Thu, Jan 5, 2012 at 8:30 AM, Marc Dietrich <marvin24@gmx.de> wrote:
> > Hi,
> >
> > Am Mittwoch, 4. Januar 2012, 15:29:12 schrieb Olof Johansson:
> > > Only one of the L2 erratas are needed on T30, but T20/25
> > > needs a few more.
> >
> > can we have a word from someone from NVIDIA about which Tegra
> > versions/revisions need which erratum applied?
> >
> > Currently the kernel has selections for the following errata (on ARM):
> >
> > T2x T30
> > ERRATA_430973
> > Stale prediction on replaced interworking branch ERRATA_458693
> > Processor deadlock when a false hazard is created
> > ERRATA_460075 Data written to the L2 cache can be
> > overwritten with stale data x
> > ERRATA_742230 DMB operation may be faulty
> > ERRATA_742231 Incorrect hazard handling in the SCU
> > may lead to data corruption PL310_ERRATA_588369 Clean & Invalidate
> > maintenance operations do not invalidate clean lines ERRATA_720789
> > TLBIASIDIS and TLBIMVAIS operations can broadcast a
> > faulty ASID PL310_ERRATA_727915 Background Clean & Invalidate by
> > Way operation can cause data corruption ERRATA_743622
> > Faulty hazard checking in the Store Buffer may lead to data corruption
> > ERRATA_751472 Interrupted ICIALLUIS may prevent
> > completion of broadcasted operation x
> > PL310_ERRATA_753970 cache sync operation may be faulty
> > ERRATA_754322 possible faulty MMU translations
> > following an ASID switch ERRATA_754327 no automatic
> > Store Buffer drain ERRATA_764369 Data cache line
> > maintenance operation by MVA may not succeed x x
> > PL310_ERRATA_769419 no automatic Store Buffer drain
> >
> > With Olofs patch, the following errata are enabled by tegra_defconfig:
> >
> > 742230(T2x), 753970(T2x), 769419(T2x + T30)
> >
> > I have the feeling that at least 764369 also needs to be enabled. From
> > the description: ... affecting Cortex-A9 MPCore with two or more
> > processors (all current revisions). I wonder if this includes multi
> > *cores*.
> >
> > The TRM is not very detailed about this topic. Having this info will
> > likely remove some headache for non OEM custumers.
> >
> > Marc
> >
> > > Signed-off-by: Olof Johansson <olof@lixom.net>
> > > ---
> > > arch/arm/mach-tegra/Kconfig | 4 ++++
> > > 1 files changed, 4 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/arm/mach-tegra/Kconfig
> > > b/arch/arm/mach-tegra/Kconfig
> > > index 373652d..a2c76ee 100644
> > > --- a/arch/arm/mach-tegra/Kconfig
> > > +++ b/arch/arm/mach-tegra/Kconfig
> > > @@ -10,6 +10,9 @@ config ARCH_TEGRA_2x_SOC
> > > select USB_ARCH_HAS_EHCI if USB_SUPPORT
> > > select USB_ULPI if USB_SUPPORT
> > > select USB_ULPI_VIEWPORT if USB_SUPPORT
> > > + select ARM_ERRATA_742230
> > > + select PL310_ERRATA_753970 if CACHE_PL310
> > > + select PL310_ERRATA_769419 if CACHE_L2X0
> > > help
> > > Support for NVIDIA Tegra AP20 and T20 processors, based on
> > > the
> > > ARM CortexA9MP CPU and the ARM PL310 L2 cache controller
> > > @@ -23,6 +26,7 @@ config ARCH_TEGRA_3x_SOC
> > > select USB_ULPI if USB_SUPPORT
> > > select USB_ULPI_VIEWPORT if USB_SUPPORT
> > > select USE_OF
> > > + select PL310_ERRATA_769419 if CACHE_L2X0
> > > help
> > > Support for NVIDIA Tegra T30 processor family, based on the
> > > ARM CortexA9MP CPU and the ARM PL310 L2 cache controller