Commit Graph

126 Commits

Author SHA1 Message Date
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
Luke Wren 34e57f0b14 Sketch in an AMO ALU 2021-12-04 18:52:41 +00:00
Luke Wren a8933c332d Fix illegal issue of pipelined exclusives on the bus, and document correct timings 2021-12-04 18:23:01 +00:00
Luke Wren 5e17bb805e Add basic support for lr/sc instructions from the A extension 2021-12-04 15:02:31 +00:00
Luke Wren 607147f280 Rewrite byte pick/sign-extend logic, preparing to handle more memops 2021-12-04 12:08:54 +00:00
Luke Wren a988adfec8 Add RISC-V opcodes and memory operation codes for atomics 2021-12-04 11:16:24 +00:00
Luke Wren 52ba930638 Remove useless midcr.eivect feature. Make mlei left-shift its value by 2. 2021-12-04 01:17:57 +00:00
Luke Wren dfb07822ee Remove UART DTM 2021-12-02 02:08:16 +00:00
Luke Wren be6b2f3f76 Fix up DTMs to use byte addressing 2021-12-02 02:05:23 +00:00
Luke Wren 1ebccb7cce Switch DM to use byte addresses on APB, not word addresses 2021-12-02 01:47:30 +00:00
Luke Wren c5e85dea4c Add mconfigptr CSR 2021-12-01 03:25:56 +00:00
Luke Wren c8afb4ac33 Add option for fast high-half multiplies 2021-11-29 18:48:02 +00:00
Luke Wren 94a3d43f27 Add Hazard3's registered marchid value to hdl and docs 2021-11-28 19:53:49 +00:00
Luke Wren 1aa9dbcddd Fix comment typo in APB clock crossing 2021-11-28 17:40:57 +00:00
Luke Wren e7466ae4be Move DM data0 CSR into the M-custom space, and document this 2021-11-28 15:52:52 +00:00
Luke Wren 76172cdade Start filling out CSR documentation. Change misa to report X=1 because of nonstandard IRQ CSRs. 2021-11-28 06:33:35 +00:00
Luke Wren 800b21d2f5 Remove event feedback path (not logical path) in priority encoder 2021-11-28 02:19:01 +00:00
Luke Wren 14a4f1a281 Add bitmanip reference vectors and test scripts. Fix bug in bclr implementation 2021-11-27 17:19:41 +00:00
Luke Wren 5d093487b7 Update README 2021-11-26 23:33:46 +00:00
Luke Wren 1bb7e33b69 Fix alignment of heap_ptr in init.S. Small ALU cleanup 2021-11-26 02:59:50 +00:00