Re: [PATCH ppc-next] powerpc/fsl-booke: don't load early TLB at once

On Sat, Sep 22, 2018 at 12:45:16AM -0500, Scott Wood wrote:

I don't suppose you're running a relocatable kernel at a non-zero

# CONFIG_RELOCATABLE is not set

address, and/or are running in an environment that sets
HID0[EN_L2MMU_MHD] (neither standard U-boot nor Linux sets this bit,

It's u-boot v2018.09-rc3;  bit "33" / 30 isn't even defined as a
constant, much less touched anywhere.  HID0 in u-boot seems to be
0x80000080 aka EMCP | EN_MAS7_UPDATE.

though they probably should)?  On 32-bit, we're already running in an AS1
trampoline when loadcam_multi() is called, but loadcam_multi() sets up
its own.  This happens to not be catastrophic in standard scenarios, but
it does add a duplicate TLB entry, and we return to AS0 sooner than
expected.  I think your patch, plus ifdefs to make the change 32-bit
only, is the appropriate fix.

I'll resend it with ifdefs inserted.  Meanwhile, still trying the
default config as mentioned in my previous mail.

I also got an earlier udbg for e500 working (and happened to decide to
test it with a relocatable kernel); I'll send that out once I've cleaned
it up (or sooner with the extra TLB dumping included if the above doesn't
explain why you're hitting this bug).

Thanks & Cheers,


-David