Commit Graph

127 Commits

Author SHA1 Message Date
Ross Thompson
150a73d6cf Set associate icache working, but way 0 is never written. 2021-09-07 12:46:16 -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
4b0344898b Fixed bugs I introduced to the icache. 2021-08-27 15:00:40 -05:00
Ross Thompson
2dff72d9e9 Renamed PCMux (icache) to SelAdr to match dcache.
Removed unused cache files.
2021-08-27 11:14:10 -05:00
Ross Thompson
de9e234ffa Modified icache to no longer need StallF in the PCMux logic. Instead this is handled in the icachefsm.
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
62d91e9ea1 Renamed ICacheCntrl to icachefsm. 2021-08-26 15:57:17 -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
b230d4daec Finished moving data path logic from the ICacheCntrl.sv to icache.sv. 2021-08-26 13:06:24 -05:00
Ross Thompson
b3849d8abb Moved data path logic from icacheCntrl to icache. 2021-08-26 10:58:19 -05:00
Ross Thompson
c83f0a2e99 Removed unused logic in icache. 2021-08-26 10:49:54 -05:00
Ross Thompson
642efbb563 Converted the icache type from logic to state type. 2021-08-26 10:41:42 -05:00
Ross Thompson
939ff663a5 Forgot to include a few files in the last few commits.
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
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.
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
b5eba44417 Replaced dcache generate ORing with or_rows. 2021-08-25 13:46:36 -05:00
Ross Thompson
83cc0266b2 Rename of DCacheMem to cacheway.
simplified dcache names.
2021-08-25 13:33:15 -05:00
Ross Thompson
c48556836b Removed generate around the dcache memories. 2021-08-25 13:27:26 -05:00
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
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.
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.
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.
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.
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.
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.
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.
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