When DEBUG_WEDGE is defined, expose the last committed and next in the
reorder buffer PC and corresponding instruction via DMI registers, since
even when the core is wedged and we can't read GPRs etc we can still
interact with the debug module itself. Hopefully this proves useful for
debugging wedges.
Previously we were relying on the beat count registers being exactly the
right number of bits such that we'd overflow from 7 back to 0 after the
final flit. This change aligns the LLC adapter with the MMIO adapter,
which already does things in a safer way. We can also just look at rlast
for read respones rather than a full 3-bit comparison (the MMIO adapter
also makes this micro-optimisation).
If DRAM latency is too high and the cache is performing frequent writes,
it would be possible to overflow this counter, which means we don't rate
limit, the cache could erroneously believe it's safe to do I/O
accesses/cache refills/page table walks, and the cache would block due
to the guard on decr when it finally gets enough write responses back.
We should block the incr method to automatically stall the cache until
it receives a new write response.
alignment of the original data.
Also eliminate the call to the reimplementation of the AMO functions.
(One call was already converted to use the common function, and I've now
converted the other.)
It's honestly unknown how much of this works, but it's more likely to
work than what was previously implemented, I think, given that the
previou implementation was based on some basic misconceptions concerning
data alignment.
This incorporates the fix made to Piccolo and Flute to not trap on
C.FLWSP/C.FLDSP when rd == 0; unlike the compressed stack pointer
relative integer loads/stores, these are legal, since f0 is a real FPR
rather than a constant zero.
This incorporates the fix made to Piccolo and Flute to not trap on
C.FLWSP/C.FLDSP when rd == 0; unlike the compressed stack pointer
relative integer loads/stores, these are legal, since f0 is a real FPR
rather than a constant zero.
