[PATCH] drm/amdgpu: Initialise drm_gem_object_funcs for imported BOs

Andrey Grodzovsky Andrey.Grodzovsky at amd.com
Tue Dec 8 19:11:41 UTC 2020


On 12/8/20 2:01 PM, Christian König wrote:
> Am 08.12.20 um 19:52 schrieb Andrey Grodzovsky:
>>
>> On 12/8/20 1:47 PM, Christian König wrote:
>>> Am 08.12.20 um 19:44 schrieb Andrey Grodzovsky:
>>>>
>>>> On 12/8/20 1:29 PM, Christian König wrote:
>>>>> Am 08.12.20 um 19:26 schrieb Andrey Grodzovsky:
>>>>>>
>>>>>> On 12/8/20 12:36 PM, Christian König wrote:
>>>>>>> Am 08.12.20 um 18:10 schrieb Andrey Grodzovsky:
>>>>>>>> For BOs imported from outside of amdgpu, setting of 
>>>>>>>> amdgpu_gem_object_funcs
>>>>>>>> was missing in amdgpu_dma_buf_create_obj. Fix by refactoring BO creation
>>>>>>>> and amdgpu_gem_object_funcs setting into single function called
>>>>>>>> from both code paths.
>>>>>>>
>>>>>>> Can you outline why we can't use amdgpu_gem_object_create() directly?
>>>>>>>
>>>>>>> I mean we have a bit of extra error handling in there and we need to 
>>>>>>> grab the resv lock and set the domains after creation, but that 
>>>>>>> shouldn't matter and I don't see why that should not work.
>>>>>>
>>>>>>
>>>>>> On top of what you mentioned you also have bp.domain/bp.preferred_domain 
>>>>>> being set differently so you need to add another
>>>>>> argument to amdgpu_gem_object_create to reflect this difference which 
>>>>>> clutters even more the already cluttered argument list.
>>>>>
>>>>> That should be outside of the call to amdgpu_gem_object_create(), similar 
>>>>> to how it is outside of the amdgpu_bo_create currently.
>>>>
>>>>
>>>> So you agree we have to add another argument to amdgpu_gem_object_create 
>>>> (e.g. u32 preferred_domain) which will be 0 for amdgpu_dma_buf_create_obj
>>>> and equal to initial_domain for all the code path currently calling 
>>>> amdgpu_gem_object_create ?
>>>
>>> No, I just don't see the need for that. We need to overwrite the preferred 
>>> domain after the function call anyway.
>>>
>>> DMA-buf imports are created with the initial domain CPU and then get that 
>>> overwritten to GTT after creation.
>>>
>>>>
>>>>
>>>>>
>>>>>> Regarding the extra error handling - you have the 'retry' dance in 
>>>>>> amdgpu_gem_object_create which jumps back to the middle of amdgpu_bo_param
>>>>>> initialization but you don't have it in amdgpu_dma_buf_create_obj which 
>>>>>> also complicates the reuse of amdgpu_gem_object_create as is.
>>>>>
>>>>> Regarding the extra error handling, that kicks in only when 
>>>>> AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED is specified as flags or 
>>>>> AMDGPU_GEM_DOMAIN_VRAM as initial domain. Neither is the case here.
>>>>
>>>>
>>>> Yes, still, it makes me a bit uncomfortable relying on internal 
>>>> implementation details of an API function I call to do the thing I expect.
>>>
>>> Yeah, ok that is a rather good argument.
>>>
>>> Christian.
>>
>>
>> So should I just keep it as is or you think it's still would be more 
>> beneficial to unify them the way you propose ?
>
> Maybe we should move the error handling into amdgpu_gem_create_ioctl() anyway.
>
> We don't really want that handling in the userptr stuff and for the call from 
> amdgpufb_create_pinned_object() that is actually a bug!
>
> E.g. for the fb emulation we can't fall back from VRAM to GTT like in the 
> create ioctl.


What about amdgpu_mode_dumb_create, seems like there GTT domain is also relevant 
and so the error handling would be needed there too.

Andrey


>
> Christian.
>
>>
>> Andrey
>>
>>
>>>
>>>>
>>>> Andrey
>>>>
>>>>
>>>>>
>>>>> Christian.
>>>>>
>>>>>>
>>>>>> Andrey
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Christian.
>>>>>>>
>>>>>>>>
>>>>>>>> This fixes null ptr regression casued by commit
>>>>>>>> d693def drm: Remove obsolete GEM and PRIME callbacks from struct 
>>>>>>>> drm_driver
>>>>>>>>
>>>>>>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>>>>>>>> ---
>>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 13 ++++++-------
>>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c     | 22 +++++++++++++++++-----
>>>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gem.h     |  5 +++++
>>>>>>>>   3 files changed, 28 insertions(+), 12 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c 
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>>>>>> index e5919ef..da4d0ab 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>>>>>> @@ -405,6 +405,7 @@ struct dma_buf *amdgpu_gem_prime_export(struct 
>>>>>>>> drm_gem_object *gobj,
>>>>>>>>       return buf;
>>>>>>>>   }
>>>>>>>>   +
>>>>>>>>   /**
>>>>>>>>    * amdgpu_dma_buf_create_obj - create BO for DMA-buf import
>>>>>>>>    *
>>>>>>>> @@ -424,7 +425,7 @@ amdgpu_dma_buf_create_obj(struct drm_device *dev, 
>>>>>>>> struct dma_buf *dma_buf)
>>>>>>>>       struct amdgpu_device *adev = drm_to_adev(dev);
>>>>>>>>       struct amdgpu_bo *bo;
>>>>>>>>       struct amdgpu_bo_param bp;
>>>>>>>> -    int ret;
>>>>>>>> +    struct drm_gem_object *obj;
>>>>>>>>         memset(&bp, 0, sizeof(bp));
>>>>>>>>       bp.size = dma_buf->size;
>>>>>>>> @@ -434,21 +435,19 @@ amdgpu_dma_buf_create_obj(struct drm_device *dev, 
>>>>>>>> struct dma_buf *dma_buf)
>>>>>>>>       bp.type = ttm_bo_type_sg;
>>>>>>>>       bp.resv = resv;
>>>>>>>>       dma_resv_lock(resv, NULL);
>>>>>>>> -    ret = amdgpu_bo_create(adev, &bp, &bo);
>>>>>>>> -    if (ret)
>>>>>>>> +    obj = amdgpu_gem_object_create_raw(adev, &bp);
>>>>>>>> +    if (IS_ERR(obj))
>>>>>>>>           goto error;
>>>>>>>>   +    bo = gem_to_amdgpu_bo(obj);
>>>>>>>>       bo->allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
>>>>>>>>       bo->preferred_domains = AMDGPU_GEM_DOMAIN_GTT;
>>>>>>>>       if (dma_buf->ops != &amdgpu_dmabuf_ops)
>>>>>>>>           bo->prime_shared_count = 1;
>>>>>>>>   -    dma_resv_unlock(resv);
>>>>>>>> -    return &bo->tbo.base;
>>>>>>>> -
>>>>>>>>   error:
>>>>>>>>       dma_resv_unlock(resv);
>>>>>>>> -    return ERR_PTR(ret);
>>>>>>>> +    return obj;
>>>>>>>>   }
>>>>>>>>     /**
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c 
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>>>>> index c9f94fb..5f22ce6 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>>>>> @@ -52,13 +52,26 @@ static void amdgpu_gem_object_free(struct 
>>>>>>>> drm_gem_object *gobj)
>>>>>>>>       }
>>>>>>>>   }
>>>>>>>>   +struct drm_gem_object *amdgpu_gem_object_create_raw(struct 
>>>>>>>> amdgpu_device *adev,
>>>>>>>> +                            struct amdgpu_bo_param *bp)
>>>>>>>> +{
>>>>>>>> +    struct amdgpu_bo *bo;
>>>>>>>> +    int r;
>>>>>>>> +
>>>>>>>> +    r = amdgpu_bo_create(adev, bp, &bo);
>>>>>>>> +    if (r)
>>>>>>>> +        return ERR_PTR(r);
>>>>>>>> +
>>>>>>>> +    bo->tbo.base.funcs = &amdgpu_gem_object_funcs;
>>>>>>>> +    return &bo->tbo.base;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>>   int amdgpu_gem_object_create(struct amdgpu_device *adev, unsigned 
>>>>>>>> long size,
>>>>>>>>                    int alignment, u32 initial_domain,
>>>>>>>>                    u64 flags, enum ttm_bo_type type,
>>>>>>>>                    struct dma_resv *resv,
>>>>>>>>                    struct drm_gem_object **obj)
>>>>>>>>   {
>>>>>>>> -    struct amdgpu_bo *bo;
>>>>>>>>       struct amdgpu_bo_param bp;
>>>>>>>>       int r;
>>>>>>>>   @@ -73,8 +86,9 @@ int amdgpu_gem_object_create(struct amdgpu_device 
>>>>>>>> *adev, unsigned long size,
>>>>>>>>   retry:
>>>>>>>>       bp.flags = flags;
>>>>>>>>       bp.domain = initial_domain;
>>>>>>>> -    r = amdgpu_bo_create(adev, &bp, &bo);
>>>>>>>> -    if (r) {
>>>>>>>> +    *obj = amdgpu_gem_object_create_raw(adev, &bp);
>>>>>>>> +    if (IS_ERR(*obj)) {
>>>>>>>> +        r = PTR_ERR(*obj);
>>>>>>>>           if (r != -ERESTARTSYS) {
>>>>>>>>               if (flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) {
>>>>>>>>                   flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
>>>>>>>> @@ -90,8 +104,6 @@ int amdgpu_gem_object_create(struct amdgpu_device 
>>>>>>>> *adev, unsigned long size,
>>>>>>>>           }
>>>>>>>>           return r;
>>>>>>>>       }
>>>>>>>> -    *obj = &bo->tbo.base;
>>>>>>>> -    (*obj)->funcs = &amdgpu_gem_object_funcs;
>>>>>>>>         return 0;
>>>>>>>>   }
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.h 
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.h
>>>>>>>> index 637bf51..a6b90d3 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.h
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.h
>>>>>>>> @@ -38,12 +38,17 @@ unsigned long amdgpu_gem_timeout(uint64_t timeout_ns);
>>>>>>>>   /*
>>>>>>>>    * GEM objects.
>>>>>>>>    */
>>>>>>>> +
>>>>>>>> +struct amdgpu_bo_param;
>>>>>>>> +
>>>>>>>>   void amdgpu_gem_force_release(struct amdgpu_device *adev);
>>>>>>>>   int amdgpu_gem_object_create(struct amdgpu_device *adev, unsigned 
>>>>>>>> long size,
>>>>>>>>                    int alignment, u32 initial_domain,
>>>>>>>>                    u64 flags, enum ttm_bo_type type,
>>>>>>>>                    struct dma_resv *resv,
>>>>>>>>                    struct drm_gem_object **obj);
>>>>>>>> +struct drm_gem_object *amdgpu_gem_object_create_raw(struct 
>>>>>>>> amdgpu_device *adev,
>>>>>>>> +                            struct amdgpu_bo_param *bp);
>>>>>>>>     int amdgpu_mode_dumb_create(struct drm_file *file_priv,
>>>>>>>>                   struct drm_device *dev,
>>>>>>>
>>>>>
>>>
>


More information about the amd-gfx mailing list