Re: [PATCH v4 09/10] drm/amdgpu: generate doorbell index for userqueue

["Christian König" <christian.koenig@amd.com>]

Am 24.04.23 um 19:38 schrieb Shashank Sharma:
> The userspace sends us the doorbell object and the doobell index
> to be used for the usermode queue, but the FW expects the absolute
> doorbell index on the PCI BAR in the MQD. This patch adds a function
> to convert this relative doorbell index to the absolute doorbell index.
>
> This patch is dependent on the doorbell manager series being reviewed
> here: https://patchwork.freedesktop.org/series/115802/
>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian Koenig <christian.koenig@amd.com>
> Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 33 +++++++++++++++++++
>   1 file changed, 33 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> index 385cd51b6c96..fbc9cb5c24ad 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> @@ -44,6 +44,30 @@ amdgpu_userqueue_find(struct amdgpu_userq_mgr *uq_mgr, int qid)
>   	return idr_find(&uq_mgr->userq_idr, qid);
>   }
>   
> +static uint64_t
> +amdgpu_userqueue_get_doorbell_index(struct amdgpu_userq_mgr *uq_mgr,
> +				    struct amdgpu_usermode_queue *queue,
> +				    struct drm_file *filp,
> +				    uint32_t doorbell_index)
> +{
> +	struct drm_gem_object *gobj;
> +	struct amdgpu_bo *db_bo;
> +	uint64_t index;
> +
> +	gobj = drm_gem_object_lookup(filp, queue->doorbell_handle);
> +	if (gobj == NULL) {
> +		DRM_ERROR("Can't find GEM object for doorbell\n");
> +		return -EINVAL;
> +	}
> +
> +	db_bo = amdgpu_bo_ref(gem_to_amdgpu_bo(gobj));

That looks like we are leaking the object reference here.

Christian.

> +	drm_gem_object_put(gobj);
> +
> +	index = amdgpu_doorbell_index_on_bar(uq_mgr->adev, db_bo, doorbell_index);
> +	DRM_DEBUG_DRIVER("[Usermode queues] doorbell index=%lld\n", index);
> +	return index;
> +}
> +
>   static int
>   amdgpu_userqueue_map_gtt_bo_to_gart(struct amdgpu_device *adev, struct amdgpu_bo *bo)
>   {
> @@ -133,6 +157,7 @@ static int amdgpu_userqueue_create_gfx(struct drm_file *filp, union drm_amdgpu_u
>   	struct amdgpu_fpriv *fpriv = filp->driver_priv;
>   	struct amdgpu_userq_mgr *uq_mgr = &fpriv->userq_mgr;
>   	struct drm_amdgpu_userq_mqd_gfx *mqd_in = &args->in.mqd.gfx;
> +	uint64_t index;
>   	int r;
>   
>   	/* Do we support usermode queues on this GFX IP ? */
> @@ -154,6 +179,14 @@ static int amdgpu_userqueue_create_gfx(struct drm_file *filp, union drm_amdgpu_u
>   	queue->userq_prop.hqd_base_gpu_addr = mqd_in->queue_va;
>   
>   	queue->doorbell_handle = mqd_in->doorbell_handle;
> +	index = amdgpu_userqueue_get_doorbell_index(uq_mgr, queue, filp, mqd_in->doorbell_offset);
> +	if (index == (uint64_t)-EINVAL) {
> +		DRM_ERROR("Invalid doorbell object\n");
> +		r = -EINVAL;
> +		goto free_queue;
> +	}
> +
> +	queue->userq_prop.doorbell_index = index;
>   	queue->queue_type = AMDGPU_HW_IP_GFX;
>   	queue->flags = mqd_in->flags;
>   	queue->vm = &fpriv->vm;