[PATCH v2] arm64: cpu_errata: Add Kryo to Falkor 1003 errata

On 12/12, Will Deacon wrote:

Hi Stephen,

On Wed, Nov 29, 2017 at 03:03:53PM -0800, Stephen Boyd wrote:

quoted

The Kryo CPUs are also affected by the Falkor 1003 errata, so
we need to do the same workaround on Kryo CPUs. The MIDR is
slightly more complicated here, where the PART number is not
always the same when looking at all the bits from 15 to 4. Drop
the lower 8 bits and just look at the top 4 to see if it's '2'
and then consider those as Kryo CPUs. This covers all the
combinations without having to list them all out.

Introduce a new hardware cap bit for the combination of hardware
PAN support and this errata so that we can disable support for
software PAN at runtime if this errata is present and the CPU
doesn't support HW PAN. This happens on some Kryo CPUs where the
HW PAN feature isn't supported but we can't prevent software PAN
from being selected in the configuration. Previously, Falkor CPUs
were all known to have HW PAN support, so we didn't need to worry
about this case.

Fixes: 38fd94b0275c ("arm64: Work around Falkor erratum 1003")
Signed-off-by: Stephen Boyd <redacted>
---

Can you respin this on top of for-next/core please? The PAN bits should
be much simpler with the KPTI code.

No problem. I'll send it out in a couple hours.

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