[PATCH] ARM: Fix errata 751472 handling on Cortex-A9 r1p*

[Tony Lindgren]

* Jon Hunter <jon-hunter at ti.com> [121114 11:09]:
> 
> On 11/14/2012 12:53 PM, Tony Lindgren wrote:
> > Looks like enabling CONFIG_ARM_ERRATA_751472 causes omap4 blaze
> > to not boot when enabled. The ARM core on it is an earlier r1p2:
> > 
> > CPU: ARMv7 Processor [411fc092] revision 2 (ARMv7), cr=10c53c7d
> > 
> > Unfortunately I don't have the details of errata 751472, but I'm
> > guessing we need to disable it for r1p*.
> 
> I checked the CA9MP errata document and this erratum impacts all
> r0/r1/r2 CPUs. I am wondering if the problem is because the workaround
> requires you to set a bit in the Diagnostic Control register and the
> read-modify-write sequence provided in the workaround is for secure
> mode. Not sure if there is a non-secure workaround available :-(

So it seems :( And I guess we still don't have a generic way to
check if the core has secure mode or not, and what registers are
accessible in secure mode.

Regards,

Tony