Re: [Qemu-ppc] [Qemu-devel] [PATCH] booke_206_tlbwe: Discard invalid bits in MAS2

[Fabien Chouteau]

On 05/20/2012 12:18 PM, Alexander Graf wrote:
> 
> 
> On 20.05.2012, at 12:15, Alexander Graf <address@hidden> wrote:
> 
>>
>>
>> On 09.05.2012, at 15:28, Fabien Chouteau <address@hidden> wrote:
>>
>>> The size of EPN field in MAS2 depends on page size. This patch adds a
>>> mask to discard invalid bits in EPN field.
>>>
>>> Definition of EPN field from e500v2 RM:
>>> EPN Effective page number: Depending on page size, only the bits
>>> associated with a page boundary are valid. Bits that represent offsets
>>> within a page are ignored and should be cleared.
>>>
>>> There is a similar (but more complicated) definition in PowerISA V2.06.
>>>
>>> Signed-off-by: Fabien Chouteau <address@hidden>
>>> ---
>>> target-ppc/op_helper.c |   10 ++++++++--
>>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
>>> index 4ef2332..6bc64ad 100644
>>> --- a/target-ppc/op_helper.c
>>> +++ b/target-ppc/op_helper.c
>>> @@ -4227,6 +4227,8 @@ void helper_booke206_tlbwe(void)
>>>    uint32_t tlbncfg, tlbn;
>>>    ppcmas_tlb_t *tlb;
>>>    uint32_t size_tlb, size_ps;
>>> +    target_ulong mask;
>>> +
>>>
>>>    switch (env->spr[SPR_BOOKE_MAS0] & MAS0_WQ_MASK) {
>>>    case MAS0_WQ_ALWAYS:
>>> @@ -4289,8 +4291,12 @@ void helper_booke206_tlbwe(void)
>>>        tlb->mas1 |= (tlbncfg & TLBnCFG_MINSIZE) >> 12;
>>>    }
>>>
>>> -    /* XXX needs to change when supporting 64-bit e500 */
>>> -    tlb->mas2 = env->spr[SPR_BOOKE_MAS2] & 0xffffffff;
>>> +    /* Make a mask from TLB size to discard invalid bits in EPN field */
>>> +    mask = ~(booke206_tlb_to_page_size(env, tlb)
>>
>> This breaks execution of -cpu with qemu-system-ppc64, no?
> 
> -cpu e500 I mean of course :).
> 

Maybe but I don't see why...

-- 
Fabien Chouteau