[PATCH] drm/amdgpu: Initialise drm_gem_object_funcs for imported BOs
Andrey Grodzovsky
Andrey.Grodzovsky at amd.com
Tue Dec 8 18:44:42 UTC 2020
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 ?
>
>> 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.
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,
>>>
>
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