Re: [PATCH] Synthesize TLB refill handler at runtime

[Thiemo Seufer <ica2_ts@csv.ica.uni-stuttgart.de>]

Maciej W. Rozycki wrote:
> On Mon, 22 Nov 2004, Manish Lachwani wrote:
> 
> > However, the crash still occurs. I dont think your patch was intended to 
> > fix the problem that I see below (resulting in crash).
> 
>  Certainly, it wasn't, but it couldn't have hurt, either.
> 
> > Data bus error, epc == 801f83b8, ra == 80323f04
> 
>  The reason are cp0 hazards, likely leading to an incorrect mapping.  Try
> the following patch; already applied to the mainline as obviously correct.
[snip]
> @@ -799,12 +800,12 @@ static __init void build_tlb_write_rando
>       default:
>               /*
>                * Others are assumed to have one cycle mtc0 hazard,
> -              * and one cycle tlbwr hazard.
> +              * and one cycle tlbwr hazard or to understand ehb.
>                * XXX: This might be overly general.
>                */
> -             i_nop(p);
> +             i_ehb(p);
>               i_tlbwr(p);
> -             i_nop(p);
> +             i_ehb(p);
>               break;

Does r24k really need both delays? If not, it should get its own case.
Probably it should be separated even if it is identical, the code above
is nothing but a guess based on preexisting code.


Thiemo