Ross Thompson
cd58a388e4
fixed issues with dc shell not liking modules with parameters without default values.
2021-10-18 17:24:15 -05:00
Ross Thompson
221dbe92b2
Fixed the amo on dcache miss cpu stall issue.
2021-09-17 22:15:03 -05:00
Ross Thompson
e16c27225b
Finished adding the d cache flush. Required ensuring the write data, address, and size are
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correct when transmitting to AHBLite interface.
2021-09-17 13:03:04 -05:00
Ross Thompson
0b1e59d075
Updated Dcache to fully support flush. This appears to work.
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Updated PCNextF so it points to the correct PC after icache invalidate.
Build root crashes with PCW mismatch and invalid register writes.
2021-09-17 10:25:21 -05:00
Ross Thompson
615fd41e7b
Added states and all control and data path logic to support d cache flush. This is currently untested; however the existing regresss test passes.
2021-09-16 18:32:29 -05:00
Ross Thompson
348187ea70
Added counters to walk through d cache flush.
2021-09-16 17:12:51 -05:00
Ross Thompson
d901f60a6d
Added flush controls to cachway.
2021-09-16 16:56:48 -05:00
Ross Thompson
cae350abb7
Added invalidate to icache.
2021-09-16 16:15:54 -05:00
Ross Thompson
5744796431
Fixed dcache to prevent latches in FPGA synthesized design.
2021-09-11 12:03:48 -05:00
Ross Thompson
6f4542f063
Third attempt at fixing the write enables for the icache cacheway.
2021-09-09 15:08:10 -05:00
Ross Thompson
6965bde95c
Merge branch 'main' of github.com:davidharrishmc/riscv-wally into main
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Refixed some bit width issues in the icache.
2021-09-09 12:44:02 -05:00
Ross Thompson
1d370ca71f
fixed some lint bugs.
2021-09-09 12:38:57 -05:00
David Harris
12bd351edf
Lint cleaning, riscv-arch-test testing
2021-09-09 11:05:12 -04:00
Ross Thompson
49e75d579c
Set associate icache working, but way 0 is never written.
2021-09-07 12:46:16 -05:00
Ross Thompson
05455f8392
Changed name of memory in icache.
2021-09-06 20:54:52 -05:00
Ross Thompson
2968623f9a
Partial multiway set associative icache.
2021-08-30 10:49:24 -05:00
Ross Thompson
6a9fa2fae3
Fixed bugs I introduced to the icache.
2021-08-27 15:00:40 -05:00
Ross Thompson
d433db3048
Renamed PCMux (icache) to SelAdr to match dcache.
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Removed unused cache files.
2021-08-27 11:14:10 -05:00
Ross Thompson
96cbd8e785
Modified icache to no longer need StallF in the PCMux logic. Instead this is handled in the icachefsm.
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One downside is it increases the icache complexity. However it also fixes an untested bug. If a region
was uncacheable it would have been possible for the request to be made multiple times. Now that is
not possible. Additionally spills were oscillating between the spill hit states without this change.
The impact was 'benign' as the final spilled instruction always had the correct upper 16 bits.
2021-08-27 11:03:36 -05:00
Ross Thompson
4ace7fe946
Renamed ICacheCntrl to icachefsm.
2021-08-26 15:57:17 -05:00
Ross Thompson
d6ff89b7e6
Swapped out the icachemem for cacheway. cacheway is modified to optionally support dirty bits.
2021-08-26 15:43:02 -05:00
Ross Thompson
aea7afead6
Finished moving data path logic from the ICacheCntrl.sv to icache.sv.
2021-08-26 13:06:24 -05:00
Ross Thompson
86fc632790
Moved data path logic from icacheCntrl to icache.
2021-08-26 10:58:19 -05:00
Ross Thompson
fd28c4f556
Removed unused logic in icache.
2021-08-26 10:49:54 -05:00
Ross Thompson
e4bbd3bbc7
Converted the icache type from logic to state type.
2021-08-26 10:41:42 -05:00
Ross Thompson
596bc138bc
Forgot to include a few files in the last few commits.
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Also reorganized the dcache by read cpu path, write cpu path, and bus interface path.
Changed i/o names on subwordread to match signals in dcache.
2021-08-25 22:30:05 -05:00
Ross Thompson
0530047f53
Moved dcache fsm to separate module.
2021-08-25 21:37:10 -05:00
Ross Thompson
d23b860c96
Moved LRU and storage for the LRU into a single module. Also found a subtle bug with the update address used to write the cache's memory.
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This was correct for the LRU but incorrect for the data, tag, valid, and dirty storage.
2021-08-25 21:09:42 -05:00
Ross Thompson
c5e2443298
Replaced dcache generate ORing with or_rows.
2021-08-25 13:46:36 -05:00
Ross Thompson
e5336f4ee1
Rename of DCacheMem to cacheway.
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simplified dcache names.
2021-08-25 13:33:15 -05:00
Ross Thompson
e9a1dc90f6
Removed generate around the dcache memories.
2021-08-25 13:27:26 -05:00
Ross Thompson
2ccf479354
Moved more logic inside the dcache memory.
2021-08-25 13:17:07 -05:00
Ross Thompson
35e57a7c61
partial dcache reorg.
2021-08-25 12:42:05 -05:00
David Harris
3fa55a01f4
simplified or_rows generation and renamed oneHotDecoder to onehotdecoder
2021-08-25 06:46:41 -04:00
Ross Thompson
91b51c698e
Minor changes to dcache.
2021-08-17 15:22:10 -05:00
Ross Thompson
6a6d5e9b15
Added documentation about how the dcache and ptw interact.
2021-08-12 18:05:36 -05:00
Ross Thompson
565c01709d
Removed unused states from dcache fsm.
2021-08-11 17:06:09 -05:00
Ross Thompson
4b25fed6d8
Simplified Dcache by sharing the read data mux with the victim selection mux.
2021-08-11 16:55:55 -05:00
Ross Thompson
67c1028862
Dcache and LSU clean up.
2021-08-10 13:36:21 -05:00
Ross Thompson
cce0571925
Fixed another bug with the atomic instrucitons implemention in the dcache.
2021-08-08 22:50:31 -05:00
Ross Thompson
d3be04b7de
Fixed another bug with AMO. If the CPU stalled as an AMO was finishing, the write to the
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cache's SRAM would occur. Then in the next cycle the SRAM would be reread while stalled
providing the new update dated rather than the correct older value.
2021-08-08 11:42:10 -05:00
Ross Thompson
fc7016eea6
Fixed the AMO dcache bug. The subword write needs to occur before the AMO logic.
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Fixed logic for trace update in the M and W stages. The M stage should not update if there
is an instruction fault.
2021-08-08 00:28:18 -05:00
Ross Thompson
7b9e53fbe5
Removed 1 cycle delay on store miss.
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Changed some logic to partially support atomics.
2021-07-30 14:00:51 -05:00
Ross Thompson
915d8136e5
Fixed bug which caused stores to take an extra clock cycle.
2021-07-26 12:22:53 -05:00
Ross Thompson
60177b92a6
Added additional interlock for itlb miss -> instrPageFault with concurrent memory operation.
2021-07-25 23:14:28 -05:00
Ross Thompson
3e916da36e
Removed the hardware page table walker fault state from the icache so that the icache will only unstall CPU for 1 cycle.
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In the dcache we added a register to save the load read data in the event an itlb miss occurs concurrently with
the load in the memory stage. Under this situation we need to record the load ReadDataM into a temporary register,
SavedReadDataM. At this time the CPU is stall; however the walker is going to change the address in the dcache
which destroys this data. When leaving the PTW_READY state via a walker instruction fault or ITLB write we select
this SavedReadDataM so that the CPU can capture it.
2021-07-22 19:42:19 -05:00
Ross Thompson
551e3491af
Moved the ReadDataW register into the datapath.
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The StallW from the hazard unit controls this.
Previously it was in the dcache and controlled by both the HPTW and hazard unit.
This caused an issue when the CPU expected the data to stay constant while
stalled, but the HPTW was causing the data to be modified.
2021-07-22 14:52:03 -05:00
Ross Thompson
9c90b4bdf7
Fixed bug with the itlb fault not dcache ptw ready state to ready state.
2021-07-22 14:04:56 -05:00
Ross Thompson
b4029a2848
Cleaned up icache and dcache.
2021-07-22 11:06:44 -05:00
Ross Thompson
25a8920a69
Tested all numbers of ways for dcache 1, 2, 4, and 8.
2021-07-22 10:38:07 -05:00
Ross Thompson
313bc5255c
Improved address bus names and usages in the walker, dcache, and tlbs.
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Merge branch 'walkerEnhance' into main
2021-07-21 14:55:09 -05:00
Ross Thompson
310b454fa1
Added comment about better muxing.
2021-07-21 14:40:14 -05:00
Ross Thompson
5860f147d4
4 way set associative is now working.
2021-07-21 14:01:14 -05:00
Ross Thompson
e0990535e1
Fixed remaining bugs in 2 way set associative dcache.
2021-07-21 10:35:23 -05:00
Ross Thompson
3f780f012a
Finally fixed bug with the set associative design. The issue was not in the LRU but instead in the way selection mux.
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Also forgot to include cacheLRU.sv file.
2021-07-20 23:17:42 -05:00
Ross Thompson
14e949d6e3
Partially working 2 way set associative d cache.
2021-07-20 17:51:42 -05:00
Ross Thompson
00081ebc68
Replaced FinalReadDataM with ReadDataM in dcache.
2021-07-20 13:27:29 -05:00
David Harris
e1a1a8395e
Parameterized I$/D$ configurations and added sanity check assertions in testbench
2021-07-20 08:57:13 -04:00
Ross Thompson
365485bd8b
Added performance counters for dcache access and dcache miss.
2021-07-19 22:12:20 -05:00
Ross Thompson
bf3ca50a9a
Furture simplification of the dcache ReadDataW update.
2021-07-19 12:46:31 -05:00
Ross Thompson
b61dad4b83
Fixed a complex bug in the dcache, where back to back loads would lose data on the load before a stall occurred. The solution was to modify the logic for SelAdrM in the dcache so that a stall would cause the SRAM to reread the address in the Memory stage rather than Execution stage. This also required updating the ReadDataWEn control so it is always enabled on ~StallW.
2021-07-19 12:32:16 -05:00
Ross Thompson
4d53b9002f
Broken.
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Possible change to walker, dcache, tlb addressing.
Improves the naming of address signals.
But has a problem when the walker finishes the dcache does not get the correct
address on the cycle the DTLB is updated. This leads to incorrect index
selection in the dcache.
2021-07-19 10:33:27 -05:00
bbracker
67eb1f5c6b
change sram1rw to have a small delay so that we don't have signals changing on clock edges
2021-07-19 11:30:07 -04:00
Ross Thompson
009c5314b4
Fixed LRSC in 64bit version. 32bit version is broken.
2021-07-17 20:58:49 -05:00
Ross Thompson
1aac97030a
Before returning to the ready state the dcache must set SelAdr = 0 on the cycle before.
2021-07-17 18:26:29 -05:00
Ross Thompson
0b3dc288ec
Made furture progress in the mmu tests.
2021-07-16 15:56:06 -05:00
Ross Thompson
6521d2b468
Also changed the shadow ram's dcache copy widths.
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Merge branch 'dcache' into main
2021-07-16 14:21:09 -05:00
Ross Thompson
46bce70e42
Fixed walker fault interaction with dcache.
2021-07-16 12:22:13 -05:00
Ross Thompson
e0f719d513
Updated the ptw, lsuarb and dcache to hopefully solve the interlock issues.
2021-07-16 11:12:57 -05:00
Kip Macsai-Goren
abd5b1c02d
Still broken, midway through fixing understanding of how ptw and datacache interact in time especially wrt adrE, adrM, faults, and tlb interaction.
2021-07-15 18:30:29 -04:00
Ross Thompson
b9902b0560
Fixed how the dcache and page table walker stall cpu so that once a tlb miss occurs the CPU is always stalled until the walk is complete, the tlb updated, and the dcache fetched and hits.
2021-07-15 11:00:42 -05:00
Ross Thompson
8610ef204c
Renamed DCacheStall to LSUStall in hart and hazard.
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Added missing logic in lsu.
2021-07-15 10:16:16 -05:00
Ross Thompson
704f4f724e
dcache STATE_CPU_BUSY needs to assert CommittedM. This is required to ensure a completed memory operation is not bound to an interrupt. ie. MEPC should not be PCM when committed.
2021-07-14 23:08:07 -05:00
Ross Thompson
ba1e1ec231
Finally have the ptw correctly walking through the dcache to update the itlb.
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Still not working fully.
2021-07-14 22:26:07 -05:00
Ross Thompson
c79650b508
Added d cache StallW checks for any time the cache wants to go to STATE_READY.
2021-07-14 17:25:50 -05:00
Ross Thompson
2c946a282f
Fixed d cache not honoring StallW for uncache writes and reads.
2021-07-14 17:23:28 -05:00
Ross Thompson
adce800041
Fixed a bug where the dcache did not update the read data if the CPU was stalled, but the memory not stalled.
2021-07-14 15:47:38 -05:00
Ross Thompson
f4295ff097
Separated interruptM into PendingInterruptM and InterruptM. The d cache now takes in both exceptions and PendingInterrupts.
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This solves the committedM issue.
2021-07-14 15:00:33 -05:00
Ross Thompson
9b756d6a94
Implemented uncached reads.
2021-07-13 23:03:09 -05:00
Ross Thompson
e8bf502bc2
Added CommitedM to data cache output.
2021-07-13 22:43:42 -05:00
Ross Thompson
3e57c899a2
Partially working changes to support uncached memory access. Not sure what CommitedM is.
2021-07-13 17:24:59 -05:00
Ross Thompson
baa2b5d15f
Fixed interaction between icache stall and dcache. On hit dcache needs to enter a cpu busy state when the cpu is stalled.
2021-07-13 14:51:42 -05:00
Ross Thompson
3c1a717399
Fixed the fetch buffer accidental overwrite on eviction.
2021-07-13 14:21:29 -05:00
Ross Thompson
32f27cfecf
Dcache AHB address generation was wrong. Needed to zero the offset.
2021-07-13 14:19:04 -05:00
Ross Thompson
afc1bc9c38
Moved StoreStall into the hazard unit instead of in the d cache.
2021-07-13 13:20:50 -05:00
Ross Thompson
47e16f5629
Fixed back to back store issue.
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Note there is a bug in the lsuarb which needs to arbitrate a few execution stage signals.
2021-07-13 12:46:20 -05:00
Ross Thompson
224e3b2991
Fixed subword write. subword read should not feed into subword write.
2021-07-13 11:21:44 -05:00
Ross Thompson
49f6eec579
Team work on solving the dcache data inconsistency problem.
2021-07-12 23:46:32 -05:00
Ross Thompson
1cc258ade1
Progress towards the test bench flush.
2021-07-12 14:22:13 -05:00
Ross Thompson
f26d635614
Fixed the spurious AHB requests to address 0. Somehow by not having a default
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(else) in the fsm branch selection for STATE_READY in the d cache it was
possible to take an invalid branch through the fsm.
2021-07-10 22:34:47 -05:00
Ross Thompson
fed7042fd9
Loads are working.
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There is a bug when the icache stalls 1 cycle before the d cache.
2021-07-10 22:15:44 -05:00
Ross Thompson
60ed023734
Actually writes the correct data now on stores.
2021-07-10 17:48:47 -05:00
Ross Thompson
efe37ea079
Write miss with eviction works.
2021-07-10 15:17:40 -05:00
Ross Thompson
d65c01bc29
Write Hits and Write Misses without eviction are working correctly! The next
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step is to add eviction of dirty lines.
2021-07-10 10:56:25 -05:00
Ross Thompson
b1ceeb40df
Loads in modelsim, but the first store double does not function correctly. The write address is wrong so the cache is updated using the wrong address.
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I think this is do to the cycle latency of stores. We probably need extra muxes to select between MemPAdrM and MemPAdrW depending on if the write is a
full cache block or a word write from the CPU.
2021-07-09 17:14:54 -05:00
Ross Thompson
4c0cee1c19
Design loads in modelsim, but trap is an X.
2021-07-09 15:37:16 -05:00
Ross Thompson
ec80cc1820
Lint passes, but I only hope to have loads working. Stores, lr/sc, atomic, are not fully implemented.
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Also faults and the dcache ptw interlock are not implemented.
2021-07-09 15:16:38 -05:00
Ross Thompson
93aa39ca31
completed read miss branch through dcache fsm.
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The challenge now is to connect to ahb and lsu.
2021-07-08 17:53:08 -05:00
Ross Thompson
910ddb83ae
This d cache fsm is getting complex.
2021-07-08 15:26:16 -05:00
Ross Thompson
1fe06bc670
Partial implementation of the data cache. Missing the fsm.
2021-07-07 17:52:16 -05:00