David Harris
24bb3f4baf
Added more pipeline stage suffixes to divider
2021-10-02 22:54:01 -04:00
Ross Thompson
99d675b872
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
d4398c23fb
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
eb7b5f1d63
Added invalidate to icache.
2021-09-16 16:15:54 -05:00
Ross Thompson
5bc90ef32f
Slight modification to wave file.
2021-09-08 10:40:46 -05:00
Ross Thompson
00f50184d8
Changed name of memory in icache.
2021-09-06 20:54:52 -05:00
Ross Thompson
5c2deab4e4
Partial multiway set associative icache.
2021-08-30 10:49:24 -05:00
Ross Thompson
de9e234ffa
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
cbb47956cb
Swapped out the icachemem for cacheway. cacheway is modified to optionally support dirty bits.
2021-08-26 15:43:02 -05:00
Ross Thompson
642efbb563
Converted the icache type from logic to state type.
2021-08-26 10:41:42 -05:00
Ross Thompson
d2b3b7345e
Moved dcache fsm to separate module.
2021-08-25 21:37:10 -05:00
Ross Thompson
7be0a73db1
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
c48556836b
Removed generate around the dcache memories.
2021-08-25 13:27:26 -05:00
Ross Thompson
4f3f26c5cb
Switched ExceptionM to dcache to be just exceptions.
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Added test bench logic to hold forces until the W stage is unstalled.
2021-08-13 15:53:50 -05:00
Ross Thompson
cd8a66353c
Patched up changes for wally-pipelined.do and wally-buildroot.do to support moved common testbench files.
2021-07-30 14:24:50 -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
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
39fc9278ba
Fixed remaining bugs in 2 way set associative dcache.
2021-07-21 10:35:23 -05:00
Ross Thompson
8d0a552b5b
Partially working 2 way set associative d cache.
2021-07-20 17:51:42 -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
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
bebc7cc5e3
Updated wave file.
2021-07-16 12:34:37 -05:00
Ross Thompson
d3715acf2d
Fixed walker fault interaction with dcache.
2021-07-16 12:22:13 -05:00
Ross Thompson
96aa106852
Found bug in the PMA such that invalid addresses were sent to the tim. Once addressing this issue the sv48 test fails early with a pma access fault.
2021-07-15 11:56:35 -05:00
Ross Thompson
5fb5ac3d5a
Updated wave file.
2021-07-15 11:04:49 -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
d3a1a2c90a
Fixed d cache not honoring StallW for uncache writes and reads.
2021-07-14 17:23:28 -05:00
Ross Thompson
771c7ff130
Routed CommittedM and PendingInterruptM through the lsu arb.
2021-07-14 16:18:09 -05:00
Ross Thompson
ef598d0e79
Implemented uncached reads.
2021-07-13 23:03:09 -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
Ross Thompson
b780e471b4
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
51249a0e04
Fixed the fetch buffer accidental overwrite on eviction.
2021-07-13 14:21:29 -05:00
Ross Thompson
2034a6584f
Dcache AHB address generation was wrong. Needed to zero the offset.
2021-07-13 14:19:04 -05:00
Ross Thompson
ee09fa5f58
Moved StoreStall into the hazard unit instead of in the d cache.
2021-07-13 13:20:50 -05:00
Ross Thompson
17dc488010
Got the shadow ram cache flush working.
2021-07-13 10:03:47 -05:00
Ross Thompson
9fe6190763
Team work on solving the dcache data inconsistency problem.
2021-07-12 23:46:32 -05:00
Ross Thompson
8ca8b9075d
Progress towards the test bench flush.
2021-07-12 14:22:13 -05:00
Ross Thompson
a82c4c99c2
Actually writes the correct data now on stores.
2021-07-10 17:48:47 -05:00
Ross Thompson
71a23626d5
Fixed bug in the LSU pagetable walker interlock.
2021-07-06 10:41:36 -05:00
Ross Thompson
f2c4df0a5b
Removed the TranslationVAdrQ as it is not necessary.
2021-07-04 16:49:34 -05:00
Ross Thompson
8ae0a5bd7d
relocated lsuarb and pagetable walker inside the lsu. Does not pass busybear or buildroot, but passes rv32ic and rv64ic.
2021-07-04 13:49:38 -05:00
Ross Thompson
3dae02818c
OMG. It's working!
2021-07-01 17:37:53 -05:00
Ross Thompson
c3eaa3169e
Fixed the wrong virtual address write into the dtlb.
2021-07-01 16:55:16 -05:00
Ross Thompson
9d9415ea67
Got some stores working in virtual memory.
2021-07-01 12:49:09 -05:00
Ross Thompson
4530e43df6
The icache ptw interlock is actually correct now. There needed to be a 1 cycle delay.
2021-06-30 17:02:36 -05:00
Ross Thompson
07a0b66fdf
Major rewrite of ptw to remove combo loop.
2021-06-30 16:25:03 -05:00
