Re: [PATCH v5 5/6] drm/amdgpu: Add helper to alloc GART entries

[Philip Yang <yangp@amd.com>]

On 2025-12-15 10:14, Christian König wrote:
> On 12/10/25 00:43, Philip Yang wrote:
>> Add helper amdgpu_gtt_mgr_alloc/free_entries, export the configurable drm_mm
>> allocator parameters to caller.
>>
>> Signed-off-by: Philip Yang <Philip.Yang@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 27 +++++++++++++++++++++
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h     |  7 ++++++
>>   2 files changed, 34 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> index 895c1e4c6747..d21c7187e4aa 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
>> @@ -321,3 +321,30 @@ void amdgpu_gtt_mgr_fini(struct amdgpu_device *adev)
>>   	ttm_resource_manager_cleanup(man);
>>   	ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_TT, NULL);
>>   }
>> +
>> +int amdgpu_gtt_mgr_alloc_entries(struct amdgpu_gtt_mgr *mgr,
>> +				 struct drm_mm_node *node,
>> +				 u64 num_pages, u64 alignment,
>> +				 unsigned long color,
>> +				 enum drm_mm_insert_mode mode)
> The color is unused as far as I remember and the insert mode should be hardcoded, at least I don't see a good reason to expose that.
>
> Any specific reason that was added here?
The color parameter removed in next version, Eric pointed out same 
issue, the new alloc color is hardcoded inside alloc_entries.

Thanks,
Philip
>
> Regards,
> Christian.
>
>> +{
>> +	struct amdgpu_device *adev = container_of(mgr, typeof(*adev), mman.gtt_mgr);
>> +	int r;
>> +
>> +	spin_lock(&mgr->lock);
>> +	r = drm_mm_insert_node_in_range(&mgr->mm, node, num_pages,
>> +					alignment, color, 0,
>> +					adev->gmc.gart_size >> PAGE_SHIFT,
>> +					mode);
>> +	spin_unlock(&mgr->lock);
>> +	return r;
>> +}
>> +
>> +void amdgpu_gtt_mgr_free_entries(struct amdgpu_gtt_mgr *mgr,
>> +				 struct drm_mm_node *mm_node)
>> +{
>> +	spin_lock(&mgr->lock);
>> +	if (drm_mm_node_allocated(mm_node))
>> +		drm_mm_remove_node(mm_node);
>> +	spin_unlock(&mgr->lock);
>> +}
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> index 72488124aa59..28511e66d364 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -141,6 +141,13 @@ void amdgpu_vram_mgr_fini(struct amdgpu_device *adev);
>>   bool amdgpu_gtt_mgr_has_gart_addr(struct ttm_resource *mem);
>>   void amdgpu_gtt_mgr_recover(struct amdgpu_gtt_mgr *mgr);
>>   
>> +int amdgpu_gtt_mgr_alloc_entries(struct amdgpu_gtt_mgr *mgr,
>> +				 struct drm_mm_node *node,
>> +				 u64 num_pages, u64 alignment,
>> +				 unsigned long color,
>> +				 enum drm_mm_insert_mode mode);
>> +void amdgpu_gtt_mgr_free_entries(struct amdgpu_gtt_mgr *mgr,
>> +				 struct drm_mm_node *mm_node);
>>   uint64_t amdgpu_preempt_mgr_usage(struct ttm_resource_manager *man);
>>   
>>   u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo);