The TL port can easily starve the processor, even at only 20% utilization,
because of a bad interaction with the pipeline. Giving the processor
static priority is OK in practice, since <50% of instructions are loads
and stores in typical workloads. Even if it executes 100% loads and stores,
it must eventually encounter an I$ miss, taken branch, or exception, so
even malicious code can't permanently starve the TL port.
* Make dts generation reusable across tile subclasses
* First attempt to standardize tile IO nodes and connect methods
* hartid => hartId when talking about scala Ints
HasTiles now deals with only extremely general tile IOs.
Some RocketTiles specific behavior moved into RocketCoreplex.
BaseTile now has optional LocalInterruptNode.
Putting the common DTS nodes into a shared object makes them get
emitted only one time. Plus it's better style.
timebase-frequency should really have been in the cpu nodes in the
first place according to the spec anyway. I was foolishly trying to
save bytes. However, now we really want it there in case it differs.
...instead of on the master side of the system bus.
People inheriting from HasTileMasterPort might need to add
`masterNode := tileBus.node` to their Tile child class.
- Put correctness responsibility on Frontend, not IBuf, for improved
separation of concerns. Frontend must detect case that the BTB
predicts a taken branch in the middle of an instruction.
- Pass BTB information down pipeline unconditionally, fixing case that
screws up the branch history when the BTB misses and the instruction
is misaligned.
- Remove jumpInFrontend option; it's now unconditional.
- Default to one-bit counters in the BHT. For tiny BHTs like these, it's
more resource efficient to have a larger index space than to have
hysteresis.
Require and/or force vaddrBits to be bigger than paddrBits so there's
room to zero-extend a physical address by 1 bit, so that when the virtual
address is sign-extended, the sign is zero.
FlipRendering { implicit p => ... } now changes the render direction of edges.
diplomatic NodeImps can specify a default render flip using the new 'render' method.
Schuyler Eldridge
Henry Cook
Andrew Waterman
Andrew Waterman
Wesley W. Terpstra
Megan Wachs
Henry Styles