Commit Graph

64 Commits

Author SHA1 Message Date
Ross Thompson
60ed023734 Actually writes the correct data now on stores. 2021-07-10 17:48:47 -05:00
Ross Thompson
6e7e318396 Fixed bug in the LSU pagetable walker interlock. 2021-07-06 10:41:36 -05:00
Ross Thompson
a252416535 Removed the TranslationVAdrQ as it is not necessary. 2021-07-04 16:49:34 -05:00
Ross Thompson
5b70eb86b0 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
61027f650c OMG. It's working! 2021-07-01 17:37:53 -05:00
Ross Thompson
2dc349ea6f Fixed the wrong virtual address write into the dtlb. 2021-07-01 16:55:16 -05:00
Ross Thompson
88a18496cf Got some stores working in virtual memory. 2021-07-01 12:49:09 -05:00
Ross Thompson
002c32d2ad 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
9ec624702d Major rewrite of ptw to remove combo loop. 2021-06-30 16:25:03 -05:00
Ross Thompson
b2d8ba6742 The icache now correctly interlocks with the PTW on TLB miss. 2021-06-30 11:24:26 -05:00
Ross Thompson
dd84f2958e Page table walker now walks the table.
Added interlock so the icache stalls.
Page table walker not walking correctly, goes to fault state.
2021-06-29 22:33:57 -05:00
Ross Thompson
bc9c944ba0 Don't use this branch walker still broken. 2021-06-28 17:26:11 -05:00
Ross Thompson
d80ebab941 AMO and LR/SC instructions now working correctly.
Page table walking is not working.
2021-06-25 15:42:07 -05:00
Ross Thompson
b4a788c341 Working through a combo loop. 2021-06-25 14:49:27 -05:00
Ross Thompson
d6c19e73f4 Regression test runs further. The LSU state machine which fakes the Dcache had a few bugs. MemAccessM needed to be squashed on bus faults. 2021-06-25 11:05:17 -05:00
Ross Thompson
6bab454b17 Works until pma checker breaks the simulation by reading HADDR rather than data physical address. 2021-06-24 14:42:59 -05:00
Ross Thompson
7406e33b61 Continued I-Cache cleanup.
Removed strange mux on InstrRawD along with
the select logic.
2021-06-04 15:14:05 -05:00
Ross Thompson
191f7e61fd Moved I-Cache offset selection mux to icache.sv (top level).
When we switch to set associative this is will be more efficient.
2021-06-04 13:49:33 -05:00
Ross Thompson
fdef8df76b Reorganized the icache names. 2021-06-04 12:53:42 -05:00
Ross Thompson
7f38056879 fixed subtle typo in icache fsm. Was messing up hit spill hit.
I believe the mibench qsort benchmark runs after this icache fix.
2021-05-03 16:55:36 -05:00
Ross Thompson
19a93345b5 Reduced icache to 1 port memory. 2021-05-03 14:47:49 -05:00
Ross Thompson
a54c231489 Eliminated extra register and fixed ports to icache.
Still need to support physical tag check and write in icache memory.
Still need to reduce to 1 port SRAM in icache.
I would like to refactor the icache code.
2021-05-03 12:04:54 -05:00
Ross Thompson
c7b97d0339 Added back in function name to wave.do 2021-05-03 09:04:48 -05:00
Ross Thompson
72363f5c66 Added the ability to exclude branch predictor. 2021-04-26 14:27:42 -05:00
Ross Thompson
6e803b724e Merge branch 'tests' into icache-almost-working 2021-04-25 21:25:36 -05:00
Ross Thompson
27ef10df07 almost working icache. 2021-04-23 16:47:23 -05:00
Ross Thompson
020fb65adf Fixed icache for 32 bit.
Merge branch 'cache' into main
2021-04-22 16:45:29 -05:00
Ross Thompson
c42399bdb5 Yes. The hack to not repeat the d memory operation fixed this issue. 2021-04-22 15:22:56 -05:00
Ross Thompson
d8ab7a5de2 Partially working icache.
The current issue is a StallF is required to halt the icache from getting an updated PCF. However
if the dmemory is the reason for a stall it is possible for the icache stall to hold the d memory request continuously causing d memory to repeatedly read from memory.  This keeps StallF high and
the icache FSM is never allowed to complete.
2021-04-22 10:20:36 -05:00
Ross Thompson
7b3735fc25 Fixed for the instruction spills. 2021-04-21 16:47:05 -05:00
Ross Thompson
532c8771ba major progress.
It's running the icache is imperas tests now.
Compressed does not work yet.
2021-04-21 08:39:54 -05:00
Ross Thompson
f3093ac612 Why was the linter messed up?
There are a number of combo loops which need fixing outside the icache.  They may be fixed in main.
We get to instruction address 50 now!
2021-04-20 22:06:12 -05:00
Ross Thompson
99424fb983 Progress on icache. Fixed some issues aligning the PC with instruction. Still broken. 2021-04-20 21:19:53 -05:00
Ross Thompson
251ece20fe Broken icache. Design is done. Time to debug. 2021-04-20 19:55:49 -05:00
Ross Thompson
e73e16e57a Created special test for driving the instruction spill error.
The extact problem occurs when a 4 byte instruction startles two cache blocks (or without a cache two ahbi words) and the code jumps to a cache block other than the next cache block. Consider the following sample of code.

0000000000000080 <test_spill>:
  80:	42a9                	li	t0,10
  82:	0001                	nop
  84:	0001                	nop
  86:	0001                	nop
  88:	02bd                	addi	t0,t0,15
  8a:	00628e33          	add	t3,t0,t1
  8e:	01ce8963          	beq	t4,t3,a0 <match>

0000000000000092 <failure>:
  92:	557d                	li	a0,-1
  94:	8082                	ret
  96:	00000013          	nop
  9a:	00000013          	nop
  9e:	0001                	nop

00000000000000a0 <match>:
  a0:	1ffd                	addi	t6,t6,-1
  a2:	fc0f9fe3          	bnez	t6,80 <test_spill>
  a6:	4501                	li	a0,0
  a8:	8082                	ret

Instructions 0x88, 0x8a and 0x8e are read incorrectly.  However once the branch predictor begins to correctly predict the beq at 0x8e the instrution at 0xa0 is loaded incorrectly as the 2 upper bytes of 0x8e and the two bytes of 0x92.  This amalgamation causes c.addi at 0xa0 to do something else and the loop never terminates.

The button of wavefile wave.do shows the exact problem in the 'icache'.
2021-04-08 15:05:08 -05:00
Ross Thompson
4322694f7a Switch to use RV64IC for the benchmarks.
Still not working correctly with the icache.

instr
addr   correct   got
2021-04-07 19:12:43 -05:00
Ross Thompson
c91436d3b7 Merge branch 'icache_bp_bug' into tests
Not sure this merge is right.
2021-04-06 21:46:40 -05:00
Ross Thompson
bff2d61a1f Steps to getting branch predictor benchmarks running. 2021-04-06 21:20:51 -05:00
Ross Thompson
d21006d048 Partial fix to the integer divide stall issue. 2021-04-02 15:32:15 -05:00
Ross Thompson
a64a37d702 Merge of main with the new icache and the branch predictor. I believe there is a bug in the icache with unaligned memory access. The second part of the access is incorrectly relying on the PCF being the address of the next two bytes of the instruction. However this is not always the case as the branch predictor can get the wrong target address. The icache needs to generate the +2 address internally. 2021-03-30 23:18:20 -05:00
ushakya22
6b9ae41302 Merge branch 'main' of https://github.com/davidharrishmc/riscv-wally into main 2021-03-30 15:25:07 -04:00
ShreyaSanghai
139c2076a1 Removed PCW and InstrW from ifu 2021-03-26 01:53:19 +05:30
Ross Thompson
a99c0502e5 Fixed bugs with the csr interacting with StallW. StallW is required to pervent updating a csr. Now have a working branch predictor and performance counters to track the number of commited branches and mispredictions. 2021-03-24 15:56:55 -05:00
Ross Thompson
11109e5a88 Updated the function radix to have a new name FunctionName and it now pervents false transisions from the current function name when the PCD is flushed. 2021-03-24 13:03:43 -05:00
Ross Thompson
1c6e37120e Fixed RAS errors. Still some room for improvement with the BTB and RAS. 2021-03-23 23:00:44 -05:00
Ross Thompson
84ad1353e4 Fixed a bunch of bugs with the RAS. 2021-03-23 21:49:16 -05:00
Ross Thompson
49348d734b fixed issue with BTB's valid bit not updating. There is still a problem is valid not ocurring in the correct clock cycle. 2021-03-23 20:06:45 -05:00
Ross Thompson
95dbc5f1fa fixed a whole bunch of bugs with the branch predictor. Still an issue with how PCNextF is not updated because the CPU is stalled. 2021-03-23 16:53:48 -05:00
Ross Thompson
174557ae89 Simulation definitely shows the branch predictor counters and branch predictor don't work. :( 2021-03-23 14:04:58 -05:00
Shreya Sanghai
bbe0957df5 Merge branch 'gshare' into main
Conflicts:
	wally-pipelined/regression/wave.do
2021-03-18 17:25:48 -04:00