[PATCH 1/6] drm/amdgpu: add support for BO_VAs without BO

[Christian König]

Am 30.01.2017 um 15:43 schrieb Nicolai Hähnle:
> On 30.01.2017 13:57, Christian König wrote:
>> From: Christian König <christian.koenig at amd.com>
>>
>> For PRT support we need mappings which aren't backed by any memory.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 20 ++++++++++++++------
>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> index 8e6030d..87eae9b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -1117,7 +1117,7 @@ int amdgpu_vm_bo_update(struct amdgpu_device 
>> *adev,
>>      struct fence *exclusive;
>>      int r;
>>
>> -    if (clear) {
>> +    if (clear || !bo_va->bo) {
>>          mem = NULL;
>>          nodes = NULL;
>>          exclusive = NULL;
>> @@ -1134,9 +1134,15 @@ int amdgpu_vm_bo_update(struct amdgpu_device 
>> *adev,
>>          exclusive = reservation_object_get_excl(bo_va->bo->tbo.resv);
>>      }
>>
>> -    flags = amdgpu_ttm_tt_pte_flags(adev, bo_va->bo->tbo.ttm, mem);
>> -    gtt_flags = (amdgpu_ttm_is_bound(bo_va->bo->tbo.ttm) &&
>> -        adev == amdgpu_ttm_adev(bo_va->bo->tbo.bdev)) ? flags : 0;
>> +    if (bo_va->bo) {
>> +        flags = amdgpu_ttm_tt_pte_flags(adev, bo_va->bo->tbo.ttm, mem);
>> +        gtt_flags = (amdgpu_ttm_is_bound(bo_va->bo->tbo.ttm) &&
>> +            adev == amdgpu_ttm_adev(bo_va->bo->tbo.bdev)) ?
>> +            flags : 0;
>> +    } else {
>> +        flags = 0x0;
>> +        gtt_flags = ~0x0;
>> +    }
>>
>>      spin_lock(&vm->status_lock);
>>      if (!list_empty(&bo_va->vm_status))
>> @@ -1271,7 +1277,8 @@ struct amdgpu_bo_va *amdgpu_vm_bo_add(struct 
>> amdgpu_device *adev,
>>      INIT_LIST_HEAD(&bo_va->invalids);
>>      INIT_LIST_HEAD(&bo_va->vm_status);
>>
>> -    list_add_tail(&bo_va->bo_list, &bo->va);
>> +    if (bo)
>> +        list_add_tail(&bo_va->bo_list, &bo->va);
>>
>>      return bo_va;
>>  }
>> @@ -1309,7 +1316,8 @@ int amdgpu_vm_bo_map(struct amdgpu_device *adev,
>>
>>      /* make sure object fit at this offset */
>>      eaddr = saddr + size - 1;
>> -    if ((saddr >= eaddr) || (offset + size > 
>> amdgpu_bo_size(bo_va->bo)))
>> +    if (bo_va->bo && (saddr >= eaddr ||
>> +              (offset + size > amdgpu_bo_size(bo_va->bo))))
>>          return -EINVAL;
>
> At least the saddr >= eaddr check should probably apply apply.

Oh, yes of course.

>
> Come to think of it, what if offset + size wraps around?

Well that is exactly what the saddr >= eaddr check is good for :)

Christian.

> There should probably be an explicit check for that.
>
> Cheers,
> Nicolai
>
>>
>>      last_pfn = eaddr / AMDGPU_GPU_PAGE_SIZE;
>>
>