Yoichi Yuasa wrote:
Some mtc0_tlbw_hazard() were broken by "[MIPS] Cleanup hazard handling" patch.
Please apply this patch.
8009018c: 40066000 mfc0 a2,$12
80090190: 34c1001f ori at,a2,0x1f
80090194: 3821001f xori at,at,0x1f
80090198: 40816000 mtc0 at,$12
8009019c: 00000040 ssnop
800901a0: 00000040 ssnop
800901a4: 00000040 ssnop
Hm, why there are ssnop's here...
ssnop is a part of dvpe().
Yep, this is irq_disable_hazard, looking sane.
800901a8: 40075000 mfc0 a3,$10
800901ac: 40801000 mtc0 zero,$2
800901b0: 40801800 mtc0 zero,$3
800901b4: 40043000 mfc0 a0,$6
800901b8: 3c028035 lui v0,0x8035
800901bc: 8c457ac0 lw a1,31424(v0)
800901c0: 0085182a slt v1,a0,a1
800901c4: 1060000b beqz v1,800901f4 <local_flush_tlb_all+0x68>
800901c8: 00044340 sll t0,a0,0xd
800901cc: 3c098000 lui t1,0x8000
800901d0: 01091821 addu v1,t0,t1
800901d4: 40835000 mtc0 v1,$10
800901d8: 10000002 b 800901e4 <local_flush_tlb_all+0x58> <--
800901dc: 40840000 mtc0 a0,$0
800901e0: 42000002 tlbwi
Signed-off-by: Yoichi Yuasa <firstname.lastname@example.org>
diff -pruN -X mips/Documentation/dontdiff mips-orig/include/asm-mips/hazards.h
--- mips-orig/include/asm-mips/hazards.h 2006-09-21 18:21:11.793973750
+++ mips/include/asm-mips/hazards.h 2006-09-21 18:55:07.569201750 +0900
@@ -138,7 +138,7 @@ ASMMACRO(back_to_back_c0_hazard,
This is under #elif defined(CONFIG_CPU_SB1), right?
* Mostly like R4000 for historic reasons
- b . + 8
+ nop; nop; nop; nop; nop; nop
... and nop's there? This looks inconsistent.
previous mtc0_tlbw_hazard() for C used nop.
"b . + 8" is trick for R4000/R4400, see comment in old hazard.h .
I fail to see what was changed WRT SB1 CPUs by the suspected patch. Though
wait... the previous version was inconsistent, using the different barrier
definitions for C and assembly (nops in the former, and branch in the latter).
But since the assembly version was not really used, it couldn't break
Anyway, shouldn't ssnop's be used for SB1 instead? CPU has quad-issue
pipeline, hasn't it?