Commit Graph

99 Commits

Author SHA1 Message Date
Luke Wren 97bf2d06f6 Hold off first instruction fetch until pwrup_ack is first seen high 2022-11-05 14:58:47 +00:00
Luke Wren 1953773ca5 Don't gate exception into D-mode CSR write, as a valid CSR instruction
writing to a valid CSR in D-mode is guaranteed not to raise any exception
(particularly the external data0 CSR is of interest)
2022-10-10 22:15:56 +01:00
Luke Wren f771a1294d Alias DPC to the real program counter, small savings overall 2022-10-10 00:28:42 +01:00
Luke Wren 954bae5cf1 Implement block/unblock instructions, and fix questionable partial masking of sleep signals on exceptions. Add simple test for self-block/unblock with loopback in tb. 2022-08-29 14:52:01 +01:00
Luke Wren 2ae2463b97 First stab at adding wake/sleep state machine 2022-08-28 19:50:04 +01:00
Luke Wren bf38d93d33 Remove references to AHB-Lite, describe buses as (a subset of) AHB5 2022-08-28 14:15:20 +01:00
Luke Wren 49c2edeff8 Avoid reserved keyword 2022-08-22 10:26:20 +01:00
Luke Wren ba775563d5 Fix suspicious gating of jump request 2022-08-22 09:10:12 +01:00
Luke Wren 6e3799eed0 First attempt at hacking in triggers, at least seems to have not broken other exception logic. Not yet tested. 2022-08-22 08:47:03 +01:00
Luke Wren d299a3ca4e More width tweaks 2022-08-20 16:11:58 +01:00
Luke Wren 5819f8eb7e Remove wrong/useless mxr logic in PMP 2022-08-08 18:45:37 +01:00
Luke Wren 15cb21ae43 First pass at implementing the new IRQ controls. Works well enough that the old tests pass :) 2022-08-07 20:51:12 +01:00
Luke Wren 185194973f Add a custom instruction (bextm/bextmi: 1 to 8-bit version of bext/bexti from Zbs) for fooling around with toolchains 2022-08-06 23:02:08 +01:00
Luke Wren b7d9defcf2 Add MUL_FASTER option to retire fast mul to stage 2 instead of stage 3 2022-07-05 03:37:19 +01:00
Luke Wren d5cd3e0681 Add SBA patch-through to 1-core wrapper.
Add SBA properties to bus compliance checks.
Hook up SBA in dual-core single-port debug tb.
2022-07-03 15:17:44 +01:00
Luke Wren edfe7f601e Clear local monitor on non-debug trap entry/exit 2022-06-26 21:55:51 +01:00
Luke Wren fb15894731 Hopefully fix case where we jump to the address immediately after a
halfword-sized word-aligned predicted-taken branch, and an
address-phase hold causes the jump target to go to the fetch address
counter, causing a spurious BTB match on the branch.
2022-06-26 15:28:08 +01:00
Luke Wren 5193dfe477 Add separate define HAZARD3_ASSERTIONS for enabling internal assertions,
and enable it only on the bus compliance model checks. Trying to make
the solver's life easier in instruction_fetch_match.
2022-06-25 20:08:40 +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 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 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 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 ea2b8888a4 Update copyright years 2022-06-09 00:12:01 +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 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 2df1179994 Wire privilege through from core to bus masters. Tied off inside core. 2022-05-24 14:05:26 +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 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 96a9ee18e1 Add IALIGN exception to non-RVC implementations 2022-05-23 12:47:48 +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 7dc5046505 Perf option for dedicated branch comparator 2022-04-02 11:40:47 +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 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 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