Commit Graph

145 Commits

Author SHA1 Message Date
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
Luke Wren 357efac66e Don't decode unnecessary bits in register predecode logic 2022-04-04 18:22:09 +01:00
Luke Wren be80bd4c18 Radical opinion, we should have good performance by default, not bad 2022-04-02 17:53:22 +01:00
Luke Wren 7dc5046505 Perf option for dedicated branch comparator 2022-04-02 11:40:47 +01:00
Luke Wren 3c61fae9ef Remove the halfword fetch thing, was only really useful on RISCBoy 2022-04-02 10:54:16 +01:00
Luke Wren 7b8fe43c1c Fix bad timing of predecoded regnum register update (thanks BMC) 2022-04-02 10:11:55 +01:00
Luke Wren b80b09afe5 Typo -- fully encode all 128 possible IRQs 2022-03-15 09:01:55 +00:00
Luke Wren b0b8703ea4 Support up to 128 IRQs 2022-03-13 09:27:43 +00:00
Luke Wren 887c93dbf0 Reuse predecoded regnums for bypass mux (though can't be used for zeroing unfortunately) 2022-03-02 18:35:16 +00:00
Luke Wren 96c69d0bb0 Cut in->out paths on debug halt/resume request
Should be harmless, because in practice these should always be driven from a register
in the DM, but still better to cut the path
2022-03-01 21:14:49 +00:00
Luke Wren 8fbffbe133 Assign full width of fifo_valid in non-reset clause (cosmetic fix) 2022-02-24 12:00:27 +00:00
Luke Wren 9ed99d8695 Use define to guard X-checks, instead of hot comments 2022-02-24 10:35:16 +00:00
Luke Wren bf15b6c49f Fix forward reference to net 2022-01-18 23:02:39 +00:00
Luke Wren 0a369efc06 Add single-port bus compliance. Fix adapter not re-arbitrating following an ERROR response, causing a squashed younger load-store to remain presented to the bus. 2021-12-18 15:41:05 +00:00
Luke Wren 1b0e205f87 Fix bad AMO asserts. Fix hwdata instability during stalled AMO write dphase, which meant AMOs were fundamentally broken following yesterday's datapath origami 2021-12-18 14:51:46 +00:00
Luke Wren 6b8d4913ee Remove unnecessary mux of mw_result -> m_result 2021-12-18 01:34:25 +00:00
Luke Wren 79fec3a2f5 Overload mw_result register for capturing AMO read data. Save some LCs. 2021-12-18 01:24:26 +00:00
Luke Wren 28b53ef7b5 Delete the AMO ALU. Save around 80 LCs vs original implementation, maybe enables some more savings. 2021-12-18 00:35:13 +00:00
Luke Wren 7485269ddf Use the branch target adder for load/store addresses. Preparing for AMO ALU deletion 2021-12-17 22:36:40 +00:00
Luke Wren a35739baf1 Fix AMO failing to loop on global monitor write fail 2021-12-17 17:04:22 +00:00
Luke Wren b0d28447ab New license headers: DWTFPL -> Apache 2.0 2021-12-13 23:23:40 +00:00
Luke Wren f1cda26bcc Oops, try a little harder this time to ensure local monitor is cleared by sc.w errors _always_, even if lined up with trap entry stalls etc 2021-12-12 23:32:01 +00:00
Luke Wren 25b44d04cf Add more properties wrt AMO. Fix awful bugs in interaction between AMOs and prior lr/sc, prior load/store exception, or IRQ which is asserted then deasserted. Fix sc with HRESP=1 HEXOKAY=1 not clearing the local monitor (not a bug, but unfriendly). 2021-12-12 23:24:25 +00:00
Luke Wren 88fea7acfa Fix lockup on misaligned AMO. Add tests for misaligned/faulting AMOs. 2021-12-12 18:28:23 +00:00
Luke Wren 8a003dbbed Make mcycle/minstret inhibited by default 2021-12-12 13:55:33 +00:00
Luke Wren 2bbc3637a2 Simplify CSR update logic. Showed promise in block synth but no difference to example soc. Still cleaner RTL. 2021-12-12 00:38:30 +00:00
Luke Wren 9460b3cd04 Add load/store and lr/sc bus fault tests. Fix lr.w not clearing local monitor when HRESP=1 HEXOKAY=1. 2021-12-11 15:52:34 +00:00
Luke Wren 3d2c912b4f Add test script to make it easier to add software testcases 2021-12-09 22:25:18 +00:00
Luke Wren 7d2fa6a049 Fix width warnings in A instruction decode, add don't-care to bus rdata picking logic 2021-12-09 06:26:31 +00:00
Luke Wren 116e34df49 Fix commented out frontend properties which relied on non-constant past reset values 2021-12-07 20:24:29 +00:00
Luke Wren 449348f459 Fix bug where an IRQ can fire during load/store dphase, followed by dphase bus exception.
Result was that the exception would sample the IRQ vector PC rather than the load/store instruction PC.
Fix by fencing off on in-flight dphases before asserting the IRQ. This adds a cycle of jitter
to IRQs, but is required for correct operation without adding a full exception-gathering pipeline.
2021-12-07 19:24:53 +00:00
Luke Wren 6ef3503ef5 Add A bit to MISA, update docs 2021-12-07 05:10:20 +00:00
Luke Wren 93be227d8a Add (currently failing) trap entry property. Fails when an IRQ arrives during a load/store data phase which subsequently excepts. 2021-12-06 20:12:23 +00:00
Luke Wren ed22d502fd Fix bus stall getting stuck high when a bus fault exception isn't immediately accepted by the frontend 2021-12-06 19:28:21 +00:00
Luke Wren 50d3d5d3b3 Maintain AMO IRQ holdoff when transitioning from data phase to error phase, to prevent error possibly being flushed 2021-12-06 19:27:20 +00:00
Luke Wren 29c5c8ca7f Fix AMO stall falling through when write data phase should proceed to error phase 2021-12-06 18:28:56 +00:00
Luke Wren 8bfc089660 Slightly more strict holdoff of IRQs on AMO 2021-12-06 18:13:43 +00:00
Luke Wren 0b3629564c Don't apply shifter assertions to rotates 2021-12-06 18:12:23 +00:00
Luke Wren 4c532240f8 Hold off IRQ when AMO is past the point of no return 2021-12-06 07:45:13 +00:00
Luke Wren 260491405a Fix atomic instructions not asserting decode error when A extension is disabled 2021-12-06 07:28:50 +00:00
Luke Wren cc38f46848 Fix AMO wdata valid left high when entering trap at just the right time 2021-12-06 07:28:50 +00:00
Luke Wren 12c79c0b41 Fix feature-flag for Zbs instructions in decoder 2021-12-05 02:05:35 +00:00
Luke Wren 9b9120960d Fix missing RAW stall on sc.w succes result. Closing laptop again. 2021-12-05 01:05:01 +00:00
Luke Wren df658d86ff First plausibly working AMOs. Add AMOs to instruction timings list 2021-12-04 23:44:22 +00:00
Luke Wren 5c098866f2 Sketch in AMO support 2021-12-04 20:46:39 +00:00