drm/amdgpu: Emit cleaner shader at end of IB submission

This commit introduces the emission of a cleaner shader at the end of
the IB submission process. This is achieved by adding a new function
pointer, `emit_cleaner_shader`, to the `amdgpu_ring_funcs` structure. If
the `emit_cleaner_shader` function is set in the ring functions, it is
called during the VM flush process.

The cleaner shader is only emitted if the `enable_cleaner_shader` flag
is set in the `amdgpu_device` structure. This allows the cleaner shader
emission to be controlled on a per-device basis.

By emitting a cleaner shader at the end of the IB submission, we can
ensure that the VM state is properly cleaned up after each submission.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h

@@ -236,6 +236,7 @@ struct amdgpu_ring_funcs {
 	void (*patch_ce)(struct amdgpu_ring *ring, unsigned offset);
 	void (*patch_de)(struct amdgpu_ring *ring, unsigned offset);
 	int (*reset)(struct amdgpu_ring *ring, unsigned int vmid);
+	void (*emit_cleaner_shader)(struct amdgpu_ring *ring);
 };
 
 struct amdgpu_ring {

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -681,6 +681,10 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
 	pasid_mapping_needed &= adev->gmc.gmc_funcs->emit_pasid_mapping &&
 		ring->funcs->emit_wreg;
 
+	if (adev->gfx.enable_cleaner_shader &&
+	    ring->funcs->emit_cleaner_shader)
+		ring->funcs->emit_cleaner_shader(ring);
+
 	if (!vm_flush_needed && !gds_switch_needed && !need_pipe_sync)
 		return 0;
 
@@ -742,6 +746,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
 		amdgpu_ring_emit_switch_buffer(ring);
 		amdgpu_ring_emit_switch_buffer(ring);
 	}
+
 	amdgpu_ring_ib_end(ring);
 	return 0;
 }