Andrew Waterman
7bcf28c585
Define fetchBytes in HasCoreParams, not Frontend
...
It is more generally useful.
2017-10-03 17:34:18 -07:00
Wesley W. Terpstra
60614055e3
diplomacy: eliminate some wasted IdentityNodes using cross-module refs
2017-09-25 12:06:27 -07:00
Wesley W. Terpstra
b9a2e4c243
diplomacy: API beautification
2017-09-22 15:01:42 -07:00
Wesley W. Terpstra
9217baf9d4
diplomacy: change API to auto-create node bundles => cross-module refs
2017-09-22 15:01:39 -07:00
Andrew Waterman
034ea722f4
Report I$ errors
2017-09-20 00:05:07 -07:00
Henry Cook
9c0bfbd500
tile: remove global Field ResetVectorBits
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Reset vector width is determined by systemBus.busView.
Also move some defs from HasCoreParameters to HasTileParameters.
2017-09-08 14:50:59 -07:00
Wesley W. Terpstra
1365c5f90c
diplomacy: implement DisableMonitors scope
2017-09-07 16:03:35 -07:00
Andrew Waterman
74d309c18e
Make I vs. D a static property of TLB, not an input pin
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The microarchitecture doesn't really support unified TLBs, so don't fake it.
2017-08-08 11:54:47 -07:00
Andrew Waterman
658e36f98b
Reduce fanout on frontend io.cpu.req.valid signal
2017-08-06 17:38:51 -07:00
Andrew Waterman
4bfbe75d74
Avoid pipeline replays when fetch queue is full
2017-08-04 16:59:21 -07:00
Andrew Waterman
a45997d03f
Separate I$ parity error from miss signal
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Handle parity errors with a pipeline flush rather than a faster
frontend replay, reducing a critical path.
2017-08-04 16:59:21 -07:00
Andrew Waterman
f483bab4aa
Fix I$ miss perfctr
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The old version was counting prefetches, too.
2017-08-03 00:52:12 -07:00
Andrew Waterman
1be1433f04
Merge pull request #918 from freechipsproject/icache-prefetch
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Icache prefetch
2017-08-02 21:22:20 -07:00
Andrew Waterman
2537d0d54e
Optionally prefetch next I$ line into L2$ on miss
2017-08-02 17:10:56 -07:00
Andrew Waterman
9464c6db40
Mitigate(?) frontend critical path
2017-08-01 18:51:17 -07:00
Andrew Waterman
735701382f
Mitigate some I$ response valid critical paths
2017-08-01 18:51:17 -07:00
Andrew Waterman
d811692c3b
Mitigate I$->D$->I$ critical path
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This seemingly irrelevant change shaves several gate delays off the I$
tl.a.valid path.
2017-07-31 01:43:04 -07:00
Andrew Waterman
acca0fccf5
Fix BTB not being refilled on some indirect jumps
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We are overloading the BTB-hit signal to mean that any part of the frontend
changed the control-flow, not just the BTB. That's the right thing to do for
most of the control logic, but it means the BTB sometimes won't get refilled
when we'd like it to. This commit makes the frontend use an invalid BTB entry
number when it, rather than the BTB, changes the control flow. Since the
entry number is invalid, the BTB will treat it as a miss and refill itself.
This is kind of a hack, but a more palatable fix requires reworking the RVC
IBuf, which I don't have time for right now.
2017-07-26 02:13:43 -07:00
Andrew Waterman
15878d4691
Perform some control-flow transfers within the Frontend
2017-07-25 15:19:16 -07:00
Henry Cook
4c595d175c
Refactor package hierarchy and remove legacy bus protocol implementations ( #845 )
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* Refactors package hierarchy.
Additionally:
- Removes legacy ground tests and configs
- Removes legacy bus protocol implementations
- Removes NTiles
- Adds devices package
- Adds more functions to util package
2017-07-07 10:48:16 -07:00
Andrew Waterman
438abc76d2
Handle TL errors in L1 I$
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Cache the error bit in the tag array; report precisely on access.
2017-07-06 01:02:11 -07:00
Wesley W. Terpstra
fbcd6f0eb2
Revert "rocket: link itim to its cpu"
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This reverts commit 48390ed604e12dbcb1b119cb2d4eb1c645ea8f7e.
2017-06-28 23:10:57 -07:00
Henry Cook
6e5a4c687f
diplomacy: a type of connect that always disables monitors ( #828 )
2017-06-28 21:48:10 -07:00
Wesley W. Terpstra
48390ed604
rocket: link itim to its cpu
2017-06-28 15:06:19 -07:00
Andrew Waterman
3e04a99f61
Refactor frontend exception passing
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Bundle them, and leverage regularity, so that if we have to add more
exceptions in the future, we don't need to change so much code.
2017-06-28 02:09:18 -07:00
Andrew Waterman
25f585f2a9
Remove unused signal from TLB interface
2017-06-28 02:09:18 -07:00
Andrew Waterman
d5f80df0ae
Allow speculative I$ refill to cacheable regions
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Backpedaling on 27b143013fccf27cd289f72f1588cca9086a457e. Shaving
four cycles off of I$ miss penalty is obviously worth the HW cost.
2017-06-28 02:09:18 -07:00
Colin Schmidt
675f183dd2
refactor ICache to be reusable by other frontends ( #808 )
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* refactor ICache to be reusable by other frontends
specifically one that would like to change the fetch width and number of
bytes in an instruction
2017-06-20 08:21:01 -07:00
Andrew Waterman
8552c77972
Fix I$ reset regression FU-357
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Can't rely on s2 TLB response, so mask using s2_valid.
2017-06-09 00:48:24 -07:00
Andrew Waterman
27b143013f
Improve ITLB QoR
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- No need to check cacheability
- Remove a gate delay from PMP path
2017-06-02 20:45:50 -07:00
Andrew Waterman
dbc5e7c494
Add TLB miss performance counters ( #762 )
2017-05-23 12:52:25 -07:00
Henry Cook
a19fc2549e
tile: add tileBus xbar
2017-05-16 16:12:01 -07:00
Andrew Waterman
fa6ecdf813
Fix RVC/uncacheable instruction memory performance bug
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9c1d12696552c70313c0c0ba22fef49287187d88 was an incomplete fix, so
sometimes we were requesting pipeline replays when they weren't
necessary.
2017-05-03 17:52:06 -07:00
Andrew Waterman
4efcb5a139
Increase frontend decoupling ( #722 )
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Reduce pathological RVC stalls
2017-05-03 07:54:46 -07:00
Henry Cook
e99fa057ac
cleanup scratchpad nodes
2017-04-27 14:02:05 -07:00
Andrew Waterman
e23ee274f6
Size hartid field with NTiles, not XLen
2017-04-26 20:11:43 -07:00
Andrew Waterman
418879a47f
Add Instruction Tightly Integrated Memory
2017-04-26 19:35:35 -07:00
Wesley W. Terpstra
9c1d126965
Allow speculative fetch to uncacheable memory if it hits in I$ ( #700 )
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@aswaterman it's in
2017-04-24 19:12:37 -07:00
Andrew Waterman
f2d4cb8152
Update RAS speculatively from fetch stage
2017-04-24 02:01:15 -07:00
Andrew Waterman
bf861293d9
Add ShiftQueue; use it
2017-04-24 02:01:15 -07:00
Andrew Waterman
d24d8ff84b
Don't stall the frontend, making it easier to add more features later
2017-04-24 02:01:15 -07:00
Andrew Waterman
061a0adceb
Fetch smaller parcels from the I$
2017-04-24 02:01:15 -07:00
Andrew Waterman
410e9cf736
I$ bugfix, to be reworked
2017-03-31 12:17:41 -07:00
Andrew Waterman
069858a20c
rocket: separate page faults from physical memory access exceptions
2017-03-27 16:37:09 -07:00
Andrew Waterman
723352c3e2
Mitigate some more PMP critical paths
2017-03-24 16:39:52 -07:00
Andrew Waterman
487b8db5ef
Address some PMP critical paths
2017-03-24 16:39:52 -07:00
Andrew Waterman
f0796f0509
Pass correct access size information to PMP checker
2017-03-24 16:39:52 -07:00
Andrew Waterman
cf168e419b
Support SFENCE.VMA rs1 argument
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This one's a little invasive. To flush a specific entry from the TLB, you
need to reuse its CAM port. Since the TLB lookup can be on the critical
path, we wish to avoid muxing in another address.
This is simple on the data side, where the datapath already carries rs1 to
the TLB (it's the same path as the AMO address calculation). It's trickier
for the I$, where the TLB lookup address comes from the fetch stage PC.
The trick is to temporarily redirect the PC to rs1, then redirect the PC
again to the instruction after SFENCE.VMA.
2017-03-24 16:39:52 -07:00
Andrew Waterman
1fea0460ba
Support superpage entries in TLB
2017-03-13 14:50:06 -07:00
Henry Cook
dbc8f4b30b
last => done
2017-03-10 15:58:38 -08:00