Hi Sergei,
On Thu, 21 Sep 2006 20:22:02 +0400
Sergei Shtylyov <sshtylyov@dev.rtsoft.ru> wrote:
> Hello.
>
> Yoichi Yuasa wrote:
>
> > Some mtc0_tlbw_hazard() were broken by "[MIPS] Cleanup hazard handling"
> > patch.
> > Please apply this patch.
>
> > tlb-r4k.o disassemble:
>
> > 8009018c <local_flush_tlb_all>:
> > 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().
> > 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>
> > <-- mtc0_tlbw_hazard()
> > 800901dc: 40840000 mtc0 a0,$0
> > 800901e0: 42000002 tlbwi
> >
> > Yoichi
> >
> > Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
> >
> > diff -pruN -X mips/Documentation/dontdiff
> > mips-orig/include/asm-mips/hazards.h mips/include/asm-mips/hazards.h
> > --- mips-orig/include/asm-mips/hazards.h 2006-09-21 18:21:11.793973750
> > +0900
> > +++ mips/include/asm-mips/hazards.h 2006-09-21 18:55:07.569201750 +0900
> > @@ -138,7 +138,7 @@ ASMMACRO(back_to_back_c0_hazard,
> > * Mostly like R4000 for historic reasons
> > */
> > ASMMACRO(mtc0_tlbw_hazard,
> > - 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 .
Yoichi
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