[PATCH v2 07/12] get absolute offset from doorbell index

[Christian König]

Am 12.04.23 um 18:25 schrieb Shashank Sharma:
> This patch adds a helper function which converts a doorbell's
> relative index in a BO to an absolute doorbell offset in the
> doorbell BAR.
>
> V2: No space between the variable name doc (Luben)
>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Christian Koenig <christian.koenig at amd.com>
> Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>

Acked-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h  |  3 +++
>   .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  | 21 +++++++++++++++++++
>   2 files changed, 24 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> index fbbff12a14cd..b110e002bad2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
> @@ -317,6 +317,9 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v);
>   int amdgpu_doorbell_init(struct amdgpu_device *adev);
>   void amdgpu_doorbell_fini(struct amdgpu_device *adev);
>   int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev);
> +uint32_t amdgpu_doorbell_index_on_bar(struct amdgpu_device *adev,
> +				       struct amdgpu_bo *db_bo,
> +				       uint32_t doorbell_index);
>   
>   #define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
>   #define WDOORBELL32(index, v) amdgpu_mm_wdoorbell(adev, (index), (v))
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
> index 8be2dfa8fa74..a99cd56e8bf4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
> @@ -108,6 +108,27 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
>   		DRM_ERROR("writing beyond doorbell aperture: 0x%08x!\n", index);
>   }
>   
> +/**
> + * amdgpu_doorbell_index_on_bar - Find doorbell's absolute offset in BAR
> + *
> + * @adev: amdgpu_device pointer
> + * @db_bo: doorbell object's bo
> + * @db_index: doorbell relative index in this doorbell object
> + *
> + * returns doorbell's absolute index in BAR
> + */
> +uint32_t amdgpu_doorbell_index_on_bar(struct amdgpu_device *adev,
> +				       struct amdgpu_bo *db_bo,
> +				       uint32_t doorbell_index)
> +{
> +	int db_bo_offset;
> +
> +	db_bo_offset = amdgpu_bo_gpu_offset_no_check(db_bo);
> +
> +	/* doorbell index is 32 bit but doorbell's size is 64-bit, so *2 */
> +	return db_bo_offset / sizeof(u32) + doorbell_index * 2;
> +}
> +
>   /**
>    * amdgpu_doorbell_create_kernel_doorbells - Create kernel doorbells for graphics
>    *