PPC440 tlbwe

[BALATON Zoltan]

Hello,

I have a question about tlbwe emulation in TCG for PPC440. This seems to 
be implemented in mmu_helper.c::helper_440_tlbwe which calls tlb_flush a 
lot flushing all TLB entries. This causes a big performance hit with 
sam460ex running AmigaOS which seems to do tlbwe on every task or context 
switch so it runs much slower than on other machines with a G4 CPU 
(pegasos2 and amigaone we also emulate) that use hardware TLB which does 
not have such problem in TCG. Even the embedded TLB emulation has 3 
versions for 40x, 440 and BookE 2.06 (I think that's e500) and at least 
the booke206 version uses flush_page instead of flushing everything. I 
don't know much about this so is there somebody with better understanding 
of this who can have a look at it and see if it can be optimised to 
resolve this problem or give some advice?

Thanks,
BALATON Zoltan