On 01/23/2012 11:33 AM, Alexander Graf wrote:
> On 01/23/2012 06:32 PM, Scott Wood wrote:
>> On 01/20/2012 10:15 PM, Alexander Graf wrote:
>>> @@ -4273,6 +4274,16 @@ void helper_booke206_tlbwe(void)
>>> tlb->mas1&= ~MAS1_IPROT;
>>> }
>>>
>>> + /* check that we support the targeted size */
>>> + size_tlb = (tlb->mas1& MAS1_TSIZE_MASK)>> MAS1_TSIZE_SHIFT;
>>> + size_ps = booke206_tlbnps(env, tlbn);
>>> + if ((tlb->mas1& MAS1_VALID)&& (tlbncfg& TLBnCFG_AVAIL)&&
>>> + !(size_ps& (1<< size_tlb))) {
>>> + helper_raise_exception_err(POWERPC_EXCP_PROGRAM,
>>> + POWERPC_EXCP_INVAL |
>>> + POWERPC_EXCP_INVAL_INVAL);
>>> + }
>>> +
>>> if (booke206_tlb_to_page_size(env, tlb) == TARGET_PAGE_SIZE) {
>>> tlb_flush_page(env, tlb->mas2& MAS2_EPN_MASK);
>>> } else {
>> For tlb0 on e500 and derivatives, tsize is explicitly documented as
>> ignored. Software may rely on this.
>
> Yup, that's why there's the check for TLBnCG_AVAIL, which indicates that
> a TLB has dynamic page size capabilities, which TLB0 does not have.
Silly me, thinking "avail" meant "this TLB is available" instead of
looking up the actual meaning. :-P
Where do we check whether the TLB exists at all?
-Scott
