[PATCH] drm/radeon/kms: forbid big bo allocation (fdo 31708) v2

[Jerome Glisse]

2010/11/22 Michel Dänzer <michel at daenzer.net>:
> On Fre, 2010-11-19 at 16:34 -0500, jglisse at redhat.com wrote:
>> From: Jerome Glisse <jglisse at redhat.com>
>>
>> Forbid allocating buffer bigger than visible VRAM or GTT, also
>> properly set lpfn field.
>>
>> v2 - use max macro
>>    - silence warning
>>
>> Signed-off-by: Jerome Glisse <jglisse at redhat.com>
>> ---
>>  drivers/gpu/drm/radeon/radeon_object.c |   34 ++++++++++++++++++++++++++-----
>>  1 files changed, 28 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
>> index 1d06774..c2fa64c 100644
>> --- a/drivers/gpu/drm/radeon/radeon_object.c
>> +++ b/drivers/gpu/drm/radeon/radeon_object.c
>> @@ -69,18 +69,28 @@ void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain)
>>       u32 c = 0;
>>
>>       rbo->placement.fpfn = 0;
>> -     rbo->placement.lpfn = rbo->rdev->mc.active_vram_size >> PAGE_SHIFT;
>> +     rbo->placement.lpfn = 0;
>>       rbo->placement.placement = rbo->placements;
>>       rbo->placement.busy_placement = rbo->placements;
>> -     if (domain & RADEON_GEM_DOMAIN_VRAM)
>> +     if (domain & RADEON_GEM_DOMAIN_VRAM) {
>> +             rbo->placement.lpfn = max((unsigned)rbo->placement.lpfn, (unsigned)rbo->rdev->mc.active_vram_size >> PAGE_SHIFT);
>>               rbo->placements[c++] = TTM_PL_FLAG_WC | TTM_PL_FLAG_UNCACHED |
>>                                       TTM_PL_FLAG_VRAM;
>> -     if (domain & RADEON_GEM_DOMAIN_GTT)
>> +     }
>> +     if (domain & RADEON_GEM_DOMAIN_GTT) {
>> +             rbo->placement.lpfn = max((unsigned)rbo->placement.lpfn, (unsigned)rbo->rdev->mc.gtt_size >> PAGE_SHIFT);
>>               rbo->placements[c++] = TTM_PL_MASK_CACHING | TTM_PL_FLAG_TT;
>> -     if (domain & RADEON_GEM_DOMAIN_CPU)
>> +     }
>> +     if (domain & RADEON_GEM_DOMAIN_CPU) {
>> +             /* 4G limit for CPU domain */
>> +             rbo->placement.lpfn = max(rbo->placement.lpfn, 0xFFFFFFFF >> PAGE_SHIFT);
>>               rbo->placements[c++] = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM;
>> -     if (!c)
>> +     }
>> +     if (!c) {
>> +             /* 4G limit for CPU domain */
>> +             rbo->placement.lpfn = max(rbo->placement.lpfn, 0xFFFFFFFF >> PAGE_SHIFT);
>>               rbo->placements[c++] = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM;
>> +     }
>
> I don't think taxing the maximum is the right thing to do: If domain is
> (RADEON_GEM_DOMAIN_VRAM | RADEON_GEM_DOMAIN_GTT) and VRAM doesn't happen
> to be the same size as GTT, lpfn will end up larger than one of them.
>
> AFAICT radeon_ttm_placement_from_domain() should just set lpfn to 0
> (i.e. unrestricted), the callers that need it to be non-0 already set it
> afterwards.
>
> Out of curiosity, where does the 4G limit come from?
>
>