Luke Wren
8ef9d77be8
Add 'everything but MHARTID' option to config_inst, to allow its reuse in multicore instantiations.
...
Use this to fix the multicore tb not instantiating cores with all parameters correct (e.g. U_MODE)
2022-06-25 13:11:40 +01:00
Luke Wren
31efd07042
Fix incorrect tracking of predictedness of fetch data phase. Fixes performance regression in RV32IMC CoreMark (now runs faster, as it should.)
2022-06-25 11:32:56 +01:00
Luke Wren
979e80be99
Attempt to fix fetch mismatch caused by jumping halfway into a 32-bit
...
instruction that precedes a taken branch.
The bookkeeping in the frontend has been tightened up so that the entire
branch instruction, and nothing but the branch instruction, is marked as a
taken branch. This required some extra state, e.g. remembering the size of
the taken branch instruction, but saved an incrementer on the BTB source
address value.
2022-06-24 19:58:21 +01:00
Luke Wren
d9389fb23e
Fix a half-valid valid address phase being left behind when taking a new path with the jump going straight to the bus. If left in place, this causes the next-next fetch to be marked as half valid, corrupting fetch data.
2022-06-16 01:42:28 +01:00
Luke Wren
f8aad6d2f3
Fix some bugs, too tired to list them, look at the diff
2022-06-15 04:05:31 +01:00
Luke Wren
0766ec6f8a
First pass at adding branch prediction
2022-06-15 02:05:46 +01:00
Luke Wren
3703b1fc4c
Allow use of cir_flush_behind in frontend_match formal tb
2022-06-13 20:36:15 +01:00
Luke Wren
e68d8a6cd6
Fix two frontend bugs: possibility for fetch to be blocked at CIR whilst also not going to FIFO (fixed by making those signals the complement of each other) and typo in the shift value for shifting into a CIR with 32 bits of contents, which is only reachable via a CIR-locked branch to an unaligned address.
2022-06-13 01:23:32 +01:00
Luke Wren
26d54d0023
Re-rewrite frontend to track the halfword-validity of in-flight transfers, and clean up the old cir_lock mechanism to be a modified flush
2022-06-12 21:01:39 +01:00
Luke Wren
e3da922f8b
Revert previous frontend changes. Seemed promising but is a dead end for area.
...
The original frontend design can probably be tweaked to support predictions.
2022-06-12 16:25:42 +01:00
Luke Wren
940b7e4009
Actually still need 7 halfwords for full throughput in the case of sequential word-sized halfword-aligned instructions
2022-06-12 16:21:56 +01:00
Luke Wren
8458dff083
Fix bus errors not being applied in frontend
2022-06-12 05:28:21 +01:00
Luke Wren
23b4dbe7f3
Redesign fetch queue: 2x32 + 3x16 -> 6x16.
...
Should make it easier to support finer-grained flushing,
and handle predicted branches cleanly.
2022-06-12 02:44:08 +01:00
Luke Wren
d5a202e4a5
Add standalone frontend formal tb
2022-06-11 20:14:24 +01:00
Luke Wren
3b5879da66
Small code cleanup in frontend. The address phase alignment state no longer needs to be tracked, since we just generate word accesses always, for simplicity.
2022-06-11 14:27:59 +01:00
Luke Wren
de9b51b787
Remove default zeroing of fetch address when no fetch is asserted -- this puts LUTs on a critical path and arguably causes more toggling than asserting the sequentially next address by default.
2022-06-11 14:26:40 +01:00
Luke Wren
11596a5bd7
Remove unused/untested RISC-V timer implementation
2022-06-09 00:12:26 +01:00
Luke Wren
ea2b8888a4
Update copyright years
2022-06-09 00:12:01 +01:00
Luke Wren
ae2784d0ea
PMP config: separate granularity config from hardwired region config. Give correct read value for G > 1.
2022-06-03 17:09:43 +01:00
Luke Wren
e0a9fb7312
Add option to hardwire PMP regions, or reduce their granularity
2022-06-03 01:19:03 +01:00
Luke Wren
66965ac073
Fix inverted sc return code (argh) and lr/sc tests which also assumed the sc code was inverted
2022-05-28 15:36:21 +01:00
Luke Wren
81aec325bb
ecall from U-mode has a different mcause value than ecall from M-mode
2022-05-28 12:07:29 +01:00
Luke Wren
f2876eb51f
Fix bad mepc reported after branching to a branch in a no-X address range
2022-05-27 22:47:04 +01:00
Luke Wren
0e462574b2
Move declaration of x_exec_pmp_fail to before its first use
2022-05-27 15:04:43 +01:00
Luke Wren
156fbcd019
Update behaviour of mstatus.mpp and mprv on mret to match priv-1.12 spec
2022-05-26 00:42:50 +01:00
Luke Wren
a17b941e38
Add U bit to misa, and fix some broken debug tests (no hazard3 bugs)
2022-05-25 23:46:23 +01:00
Luke Wren
0efcf53fe5
Fix X PMP fail not suppressing load/store address phase.
...
Fix PMP-failed load/store still passing on a data phase tag to stage 3.
Fix WFI still pausing the core after a PMP X fail.
2022-05-25 16:18:03 +01:00
Luke Wren
e2b9a3b2f9
Fix two PMP-related bugs:
...
1. Generating PMP load/store exceptions when the instruction is not a load/store
2. Passing a PMP exec permission exception into M whilst the frontend is still
starved, causing early taking of the exception and a bad mepc value.
2022-05-25 13:23:44 +01:00
Luke Wren
51750eb81d
Add mstatus.tw to control U-mode WFI, and prevent mret execution in U-mode.
2022-05-24 21:12:44 +01:00
Luke Wren
c93228d13e
Integrate PMP, and fix a couple of PMP bugs
2022-05-24 19:57:45 +01:00
Luke Wren
4878a752d6
Plumb privilege state through to the bus ports
2022-05-24 18:24:34 +01:00
Luke Wren
f033cde874
Add test for readability of CSRs in U mode. Fix readback value of mstatus.mpp
2022-05-24 17:30:24 +01:00
Luke Wren
0199f48087
Add read-only counter CSRs to readability/writability tests, and fix cycleh being unreadable when U mode is not implemented
2022-05-24 16:44:03 +01:00
Luke Wren
d62861159f
First pass at U-mode CSR support. Bizarrely causes CXXRTL tb to not write to stdout when invoked by subprocess.run from Python.
2022-05-24 16:17:54 +01:00
Luke Wren
2df1179994
Wire privilege through from core to bus masters. Tied off inside core.
2022-05-24 14:05:26 +01:00
Luke Wren
c0b5d73cbd
Typo in for loop, surprised Yosys accepted this
2022-05-23 18:15:36 +01:00
Luke Wren
5466c8131e
Sketch in PMP implementation
2022-05-23 18:06:23 +01:00
Luke Wren
06647b78c6
Fix IALIGN fault to trap on the control flow instruction instead of its target
2022-05-23 16:25:43 +01:00
Luke Wren
da244f54c3
Remove unused FAKE_DUALPORT option from regfile
2022-05-23 16:22:01 +01:00
Luke Wren
f849517202
Split CSR addresses into separate header file
2022-05-23 15:54:37 +01:00
Luke Wren
5f4127948d
Add a parameter to control register file reset, instead of the weird ifdef tree
2022-05-23 13:29:44 +01:00
Luke Wren
df0fd536eb
Fix IRQ priority to match the priv spec
2022-05-23 12:56:37 +01:00
Luke Wren
96a9ee18e1
Add IALIGN exception to non-RVC implementations
2022-05-23 12:47:48 +01:00
Luke Wren
c4e81922da
Don't store bit 1 of mepc on non-RVC implementations
2022-05-23 12:27:07 +01:00
Luke Wren
210dbeae64
Correct the name and operation of the brev8 (formerly rev.b) instruction
2022-05-20 15:28:18 +01:00
Luke Wren
a2582976fc
Fix opcodes for zip/unzip, which are wrong in the bitmanip copy of the Zbkb spec, but correct in the crypto copy of that spec
2022-05-20 15:15:37 +01:00
Luke Wren
43e0b1d16a
Implement Zbkb (untested)
2022-05-06 17:36:25 +01:00
Luke Wren
2c8f3974d0
Correctly implement fence.i as branch-to-next. Make Zifencei optional. Tighten up decode on fence and fence.i.
2022-04-09 13:49:16 +01:00
Luke Wren
35651f52a7
Stronger property for correct predecode
2022-04-05 08:18:00 +01:00
Luke Wren
20cf408632
Add fine (as well as coarse) register predecode, so that predecoded regnum can be used in bypass zeroing.
2022-04-04 20:16:19 +01:00