On Thu, Apr 30, 2026 at 12:29 PM Jesse Zhang <[email protected]> wrote:
>
> From: "Jesse.zhang" <[email protected]>
>
> Pair the userspace aggregated-doorbell ring (added by the
> AMDGPU_INFO_DOORBELL / AMDGPU_GEM_GLOBAL_AGGREGATED_DOORBELL ABI in
> the previous patches) with a kernel-side
> MES_MISC_OP_NOTIFY_WORK_ON_UNMAPPED_QUEUE in amdgpu_userq_signal_ioctl
> for SDMA UMQs.
>
> Signed-off-by: Jesse Zhang <[email protected]>
How will this work if the user doesn't use this IOCTL? protected
fences are optional. An application can create a user queue and never
use a protected fence. Why don't KFD SDMA queues need this special
treatment?
Alex
> ---
> .../gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 29 +++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> index a58342c2ac44..50e275b51c9e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> @@ -598,6 +598,35 @@ int amdgpu_userq_signal_ioctl(struct drm_device *dev,
> void *data,
> /* drop the reference acquired in fence creation function */
> dma_fence_put(fence);
>
> + /*
> + * SDMA UMQ wake: SDMA has no CP_UNMAPPED_DOORBELL HW intercept, so
> + * once MES gangs the queue out (after the first IB's PROTECTED_FENCE
> + * idles the queue), per-queue doorbell rings hit a mapped-out HW
> + * slot and are silently dropped — FENCE IRQ never fires.
> + *
> + * Userspace rings the priority's MES aggregated doorbell directly
> + * via the agdb_bo mmap (see AMDGPU_INFO_DOORBELL +
> + * AMDGPU_GEM_GLOBAL_AGGREGATED_DOORBELL). That alone, however, is
> + * not enough on current MES12 firmware — MES will not scan the
> + * priority's queue list unless its hasReadyQueues flag is set.
> + * NOTIFY_WORK_ON_UNMAPPED_QUEUE flips that flag, so MES then
> + * processes the doorbell ring and re-MAP_QUEUEs the SDMA UMQ.
> + *
> + * This is a kernel-side companion to the userspace agg doorbell
> + * ring; remove once firmware learns to wake on bare aggregated
> + * doorbell.
> + */
> + if (queue && queue->queue_type == AMDGPU_HW_IP_DMA &&
> + adev->enable_mes && adev->mes.funcs->misc_op) {
> + struct mes_misc_op_input op = { 0 };
> +
> + op.op = MES_MISC_OP_NOTIFY_WORK_ON_UNMAPPED_QUEUE;
> + op.notify_work.priority_level =
> AMDGPU_MES_PRIORITY_LEVEL_NORMAL;
> + amdgpu_mes_lock(&adev->mes);
> + (void)adev->mes.funcs->misc_op(&adev->mes, &op);
> + amdgpu_mes_unlock(&adev->mes);
> + }
> +
> exec_fini:
> drm_exec_fini(&exec);
> put_gobj_write:
> --
> 2.49.0
>
