[PATCH 1/3] drm/radeon: stop poisoning the GART TLB

[Christian König]

Am 04.06.2014 15:46, schrieb Alex Deucher:
> On Wed, Jun 4, 2014 at 9:29 AM, Christian König <deathsimple at vodafone.de> wrote:
>> From: Christian König <christian.koenig at amd.com>
>>
>> When we set the valid bit on invalid GART entries they are
>> loaded into the TLB when an adjacent entry is loaded. This
>> poisons the TLB with invalid entries which are sometimes
>> not correctly removed on TLB flush.
>>
>> For stable inclusion the patch probably needs to be modified a bit.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Cc: stable at vger.kernel.org
> Series is:
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>
> stable cc on patch 2 or 3 as well?  I suppose we'd need to modify the
> patches anyway so that they would apply on older kernels anyway.

No, the second patch is just an improvement of removing unnecessary 
checks and I think using the CPDMA on stable kernels is maybe still a 
good idea.

Christian

>
> Alex
>
>> ---
>>   drivers/gpu/drm/radeon/rs600.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
>> index 0a8be63..e0465b2 100644
>> --- a/drivers/gpu/drm/radeon/rs600.c
>> +++ b/drivers/gpu/drm/radeon/rs600.c
>> @@ -634,7 +634,10 @@ int rs600_gart_set_page(struct radeon_device *rdev, int i, uint64_t addr)
>>                  return -EINVAL;
>>          }
>>          addr = addr & 0xFFFFFFFFFFFFF000ULL;
>> -       addr |= R600_PTE_GART;
>> +       if (addr == rdev->dummy_page.addr)
>> +               addr |= R600_PTE_SYSTEM | R600_PTE_SNOOPED;
>> +       else
>> +               addr |= R600_PTE_GART;
>>          writeq(addr, ptr + (i * 8));
>>          return 0;
>>   }
>> --
>> 1.9.1
>>