drm/amdkfd: set CP_HQD_PQ_CONTROL.SCOPE to SYSTEM for GFX 12.1

On GFX 12.1, ring buffers may be mapped with a non-coherently
cached memory type. In that case the queue fetch can observe stale
packets, since the packet producers (CPU or other GPUs) do not keep the
device-side cache coherent.

Set CP_HQD_PQ_CONTROL.SCOPE=3 (SYSTEM) so the queue fetches use
system scope and pick up the latest packets. Apply this to compute queue
MQDs and to MES-managed queues.

Without this, the queue can consume stale packets for long periods,
causing severe slowdowns and, in the worst case, application hangs.

Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Joseph Greathouse <joseph.greathouse@amd.com>
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions