On 11/22/2010 06:07 PM, Jerome Glisse wrote:
> 2010/11/22 Michel D?nzer<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?
>>
>>
>>
> > From my hat, but iirc ttm limit things to 1G anyway (vm size for
> mapping object in drm file and iirc we will report error if we can't
> find a mapping for userspace object). I guess at one point we should
> start thinking about what we want to do on that front.
>
That limit is taken from *my* hat. Nothing prevents us to increase that
limit to whatever.
/Thomas
> Doing a v3.
>
> Cheers,
> Jerome
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