From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 14 Jan 2022 01:28:17 +0000 (+0000)
Subject: Revert "dcache 2nd stage (r1) should only indicate not-busy"
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=eeeb9345465393b032a2ffe86dc49e241cfb38e1;p=soc.git

Revert "dcache 2nd stage (r1) should only indicate not-busy"

This reverts commit a03aefb1e8ae7d6110a328b57f1336890ebee469.
---

diff --git a/src/soc/experiment/dcache.py b/src/soc/experiment/dcache.py
index e8e0f077..374297ba 100644
--- a/src/soc/experiment/dcache.py
+++ b/src/soc/experiment/dcache.py
@@ -1550,6 +1550,7 @@ class DCache(Elaboratable):
                               ((r1.dcbz & r1.req.dcbz) |
                                (~r1.dcbz & (r1.req.op == Op.OP_LOAD_MISS))) &
                                 (r1.store_row == get_row(req.real_addr))):
+                        sync += r1.full.eq(0)
                         sync += r1.slow_valid.eq(1)
                         with m.If(r1.mmu_req):
                             sync += r1.mmu_done.eq(1)
@@ -1570,8 +1571,6 @@ class DCache(Elaboratable):
                         comb += cv.bit_select(r1.store_way, 1).eq(1)
                         sync += cache_tags[r1.store_index].valid.eq(cv)
 
-                        # return to idle and indicate r1 stage no longer busy
-                        sync += r1.full.eq(0)
                         sync += r1.state.eq(State.IDLE)
                         sync += Display("cache valid set %x "
                                         "idx %d way %d",
@@ -1614,6 +1613,7 @@ class DCache(Elaboratable):
 
                         with m.If(req.op == Op.OP_STORE_HIT):
                             sync += r1.write_bram.eq(1)
+                        sync += r1.full.eq(0)
                         sync += r1.slow_valid.eq(1)
 
                         # Store requests never come from the MMU
@@ -1629,12 +1629,9 @@ class DCache(Elaboratable):
                                 bus.ack, bus.ack, st_stbs_done, adjust_acks)
                 with m.If(bus.ack):
                     with m.If(st_stbs_done & (adjust_acks == 1)):
-                        # all done, r1 no longer busy, return to idle
-                        sync += r1.full.eq(0)
                         sync += r1.state.eq(State.IDLE)
                         sync += r1.wb.cyc.eq(0)
                         sync += r1.wb.stb.eq(0)
-                    # decrement the number of acks expected
                     sync += r1.dec_acks.eq(1)
 
             with m.Case(State.NC_LOAD_WAIT_ACK):