From 49f620605cd0e78b8ec8ab67488c7e60ad673a23 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Wed, 15 Dec 2021 12:39:24 +0000 Subject: [PATCH] get fetch_failed working with no MMU --- src/soc/simple/issuer.py | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/src/soc/simple/issuer.py b/src/soc/simple/issuer.py index d7f23c7f..5763e37a 100644 --- a/src/soc/simple/issuer.py +++ b/src/soc/simple/issuer.py @@ -711,14 +711,14 @@ class TestIssuerInternal(Elaboratable): if hasattr(core, "icache"): fetch_failed = core.icache.i_out.fetch_failed flush_needed = True + # set to fault in decoder + # update (highest priority) instruction fault + rising_fetch_failed = rising_edge(m, fetch_failed) + with m.If(rising_fetch_failed): + sync += pdecode2.instr_fault.eq(1) else: fetch_failed = Const(0, 1) flush_needed = False - # set to fault in decoder - # update (highest priority) instruction fault - rising_fetch_failed = rising_edge(m, fetch_failed) - with m.If(rising_fetch_failed): - sync += pdecode2.instr_fault.eq(1) with m.FSM(name="issue_fsm"): @@ -909,15 +909,16 @@ class TestIssuerInternal(Elaboratable): with m.If(exc_happened): mmu = core.fus.get_exc("mmu0") ldst = core.fus.get_exc("ldst0") - with m.If(fetch_failed): - # instruction fetch: exception is from MMU - # reset instr_fault (highest priority) - sync += pdecode2.ldst_exc.eq(mmu) - sync += pdecode2.instr_fault.eq(0) - if flush_needed: - # request the icache to stop asserting "failed" - comb += core.icache.flush_in.eq(1) - with m.Else(): + if mmu is not None: + with m.If(fetch_failed): + # instruction fetch: exception is from MMU + # reset instr_fault (highest priority) + sync += pdecode2.ldst_exc.eq(mmu) + sync += pdecode2.instr_fault.eq(0) + if flush_needed: + # request icache to stop asserting "failed" + comb += core.icache.flush_in.eq(1) + with m.If(~fetch_failed): # otherwise assume it was a LDST exception sync += pdecode2.ldst_exc.eq(ldst) -- 2.30.2