Re: [Qemu-devel] [PATCH] target-mips: apply CP0.PageMask before writing into TLB entry

[Yongbok Kim]

On 02/08/2017 19:56, Philippe Mathieu-Daudé wrote:
> Hi Leon,
> 
> On 08/02/2017 10:58 AM, Yongbok Kim wrote:
>> From: Leon Alrae <address@hidden>
>>
>> PFN0 and PFN1 have to be masked out with PageMask_Mask.
>>
>> Signed-off-by: Leon Alrae <address@hidden>
>> Reviewed-by: Yongbok Kim <address@hidden>
>> [Yongbok Kim:
>>    Added commit message]
>> Signed-off-by: Yongbok Kim <address@hidden>
>> ---
>>   target/mips/op_helper.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
>> index 526f8e4..320f2b0 100644
>> --- a/target/mips/op_helper.c
>> +++ b/target/mips/op_helper.c
>> @@ -2008,6 +2008,7 @@ static inline uint64_t
>> get_tlb_pfn_from_entrylo(uint64_t entrylo)
>>   static void r4k_fill_tlb(CPUMIPSState *env, int idx)
>>   {
>>       r4k_tlb_t *tlb;
>> +    uint64_t mask = env->CP0_PageMask >> (TARGET_PAGE_BITS + 1);
>>         /* XXX: detect conflicting TLBs and raise a MCHECK exception when
>> needed */
>>       tlb = &env->tlb->mmu.r4k.tlb[idx];
>> @@ -2028,13 +2029,13 @@ static void r4k_fill_tlb(CPUMIPSState *env, int idx)
>>       tlb->C0 = (env->CP0_EntryLo0 >> 3) & 0x7;
>>       tlb->XI0 = (env->CP0_EntryLo0 >> CP0EnLo_XI) & 1;
>>       tlb->RI0 = (env->CP0_EntryLo0 >> CP0EnLo_RI) & 1;
>> -    tlb->PFN[0] = get_tlb_pfn_from_entrylo(env->CP0_EntryLo0) << 12;
>> +    tlb->PFN[0] = (get_tlb_pfn_from_entrylo(env->CP0_EntryLo0) & ~mask)
>> << 12;
>>       tlb->V1 = (env->CP0_EntryLo1 & 2) != 0;
>>       tlb->D1 = (env->CP0_EntryLo1 & 4) != 0;
>>       tlb->C1 = (env->CP0_EntryLo1 >> 3) & 0x7;
>>       tlb->XI1 = (env->CP0_EntryLo1 >> CP0EnLo_XI) & 1;
>>       tlb->RI1 = (env->CP0_EntryLo1 >> CP0EnLo_RI) & 1;
>> -    tlb->PFN[1] = get_tlb_pfn_from_entrylo(env->CP0_EntryLo1) << 12;
>> +    tlb->PFN[1] = (get_tlb_pfn_from_entrylo(env->CP0_EntryLo1) & ~mask)
>> << 12;
>>   }
>>     void r4k_helper_tlbinv(CPUMIPSState *env)
>>
> 
> What about refactoring get_tlb_pfn_from_entrylo(uint64_t entrylo) ->
> r4k_get_tlb_pfn_from_entrylo(uint64_t entrylo, uint64_t pagemask) to
> directly masked pfn?
> 
> Regards,
> 
> Phil.

Hi Phil,

Leon left Imagination a year ago and this patch is one of his remainders.
I agree to refactor the inline function but it is paired with other inline
function get_entrylo_pfn_from_tlb(). I will send another patch for both of
them but it should be after 2.10.

Regards,
Yongbok