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().
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> <-- mtc0_tlbw_hazard() 800901dc: 40840000 mtc0 a0,$0 800901e0: 42000002 tlbwi
Yoichi
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@xxxxxxxxxxxxxx> 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,
This is under #elif defined(CONFIG_CPU_SB1), right?
* 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 .
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 anything... :-/
Anyway, shouldn't ssnop's be used for SB1 instead? CPU has quad-issue pipeline, hasn't it?
Yoichi
WBR, Sergei
