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

[Shashank Sharma <shashank.sharma@amd.com>]

On 25/04/2023 14:38, Christian König wrote:
> 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.
>
That's correct, I will fix it.

- Shashank

> 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;
>