[Skiboot] [PATCH RFC 0/2] Some changes in phb4

Guilherme G. Piccoli gpiccoli at linux.vnet.ibm.com
Tue Oct 3 09:22:59 AEDT 2017

These 2 patches are complementary: first patch is (or should be) just a
code refactor, while the 2nd makes use of the first in order to perform
more reliable resets on PHB4.

The reasoning behind this: suddenly kdump stopped working in wspoon when
we have GPUs. While debug is ongoing, we have no offical workaround for
this. Russell found that by disabling OCC, it seems to work, but the
investigation is ongoing and it might affect other tests...

Now, allowing the PHB initialization to use ASB "bus" access works as good
workaround, enabling kdump on wspoon even with the issue of all PHB seems
fenced on kdump kernel load. Also, it seems to have no big issue...

This is RFC since it might have some cons I'm not seeing (probably has!),
but patch 1 could be considered anyway since it standardizes the code.

Any feedback is appreciated.


Guilherme G. Piccoli (2):
  phb4: Use read/write primitives when accessing PHB registers
  phb4: Use ASB for read/writes to PHB registers on resets

 hw/phb4.c | 425 ++++++++++++++++++++++++++++++++------------------------------
 1 file changed, 216 insertions(+), 209 deletions(-)


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