Ross Thompson
7139279e50
Moved more logic inside the dcache memory.
2021-08-25 13:17:07 -05:00
Ross Thompson
a99b5f648b
partial dcache reorg.
2021-08-25 12:42:05 -05:00
David Harris
cf1e458ccf
simplified or_rows generation and renamed oneHotDecoder to onehotdecoder
2021-08-25 06:46:41 -04:00
Ross Thompson
d3417e309b
Minor changes to dcache.
2021-08-17 15:22:10 -05:00
Ross Thompson
272425c41f
Added documentation about how the dcache and ptw interact.
2021-08-12 18:05:36 -05:00
Ross Thompson
4dfe326761
Removed unused states from dcache fsm.
2021-08-11 17:06:09 -05:00
Ross Thompson
d0afa397ba
Simplified Dcache by sharing the read data mux with the victim selection mux.
2021-08-11 16:55:55 -05:00
Ross Thompson
05a32508eb
Dcache and LSU clean up.
2021-08-10 13:36:21 -05:00
Ross Thompson
467e24c05c
Fixed another bug with the atomic instrucitons implemention in the dcache.
2021-08-08 22:50:31 -05:00
Ross Thompson
20a04d8cee
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
25533bdc49
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
89a7b38f79
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
c60a1fed69
Fixed bug which caused stores to take an extra clock cycle.
2021-07-26 12:22:53 -05:00
Ross Thompson
0291d987da
Added additional interlock for itlb miss -> instrPageFault with concurrent memory operation.
2021-07-25 23:14:28 -05:00
Ross Thompson
32ec457e09
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
007812dbdc
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
936e034be9
Fixed bug with the itlb fault not dcache ptw ready state to ready state.
2021-07-22 14:04:56 -05:00
Ross Thompson
42fe5ceee3
Cleaned up icache and dcache.
2021-07-22 11:06:44 -05:00
Ross Thompson
e907d57340
Tested all numbers of ways for dcache 1, 2, 4, and 8.
2021-07-22 10:38:07 -05:00
Ross Thompson
511c36fb1b
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
abe57e3fd0
Added comment about better muxing.
2021-07-21 14:40:14 -05:00
Ross Thompson
3d79dc51bb
4 way set associative is now working.
2021-07-21 14:01:14 -05:00
Ross Thompson
39fc9278ba
Fixed remaining bugs in 2 way set associative dcache.
2021-07-21 10:35:23 -05:00
Ross Thompson
ba3aed8760
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
8d0a552b5b
Partially working 2 way set associative d cache.
2021-07-20 17:51:42 -05:00
Ross Thompson
bb5b5e71b1
Replaced FinalReadDataM with ReadDataM in dcache.
2021-07-20 13:27:29 -05:00
David Harris
c117356432
Parameterized I$/D$ configurations and added sanity check assertions in testbench
2021-07-20 08:57:13 -04:00
Ross Thompson
ae2371f2ce
Added performance counters for dcache access and dcache miss.
2021-07-19 22:12:20 -05:00
Ross Thompson
5edd513f8c
Furture simplification of the dcache ReadDataW update.
2021-07-19 12:46:31 -05:00
Ross Thompson
2ee97efb9c
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
6ccbdc372d
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
986b7a8252
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
d0ed6e250a
Fixed LRSC in 64bit version. 32bit version is broken.
2021-07-17 20:58:49 -05:00
Ross Thompson
053e9593af
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
e9649eb1f5
Made furture progress in the mmu tests.
2021-07-16 15:56:06 -05:00
Ross Thompson
abce241f68
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
d3715acf2d
Fixed walker fault interaction with dcache.
2021-07-16 12:22:13 -05:00
Ross Thompson
5ca7dc619c
Updated the ptw, lsuarb and dcache to hopefully solve the interlock issues.
2021-07-16 11:12:57 -05:00
Kip Macsai-Goren
ba5bb12e26
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
c39a228266
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
c954fb510b
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
f234875779
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
6163629204
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
d41c9d5ad9
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
d3a1a2c90a
Fixed d cache not honoring StallW for uncache writes and reads.
2021-07-14 17:23:28 -05:00
Ross Thompson
1d7aa27316
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
e17de4eb11
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
ef598d0e79
Implemented uncached reads.
2021-07-13 23:03:09 -05:00
Ross Thompson
b6e5670bc3
Added CommitedM to data cache output.
2021-07-13 22:43:42 -05:00
Ross Thompson
278bbfbe3c
Partially working changes to support uncached memory access. Not sure what CommitedM is.
2021-07-13 17:24:59 -05:00
