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

[Christian König]

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.

> 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.

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,
>>