drm/amd/display: Enable HostVM based on rIOMMU active

[ Upstream commit 97fa4dfa66fdd52ad3d0c9fadeaaa1e87605bac7 ]

[Why]
There is underflow and flickering occuring. The
underflow stops when hostvm is forced to active.
According to policy, hostvm should be enabled if riommu
is active, but this is not taken into account when
deciding whether to enable hostvm.

[What]
For DCN314, set hostvm to true if riommu is active.

Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Gabe Teeger <gabe.teeger@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
index 4f91e64754239c537c04b78d48534ef15670d370..bf77e56c3f3ef058ae57ae5683405c3921f88eb9 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c
@@ -310,6 +310,10 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c
                                pipe->plane_state->src_rect.width < pipe->plane_state->dst_rect.width))
                        upscaled = true;
 
+               /* Apply HostVM policy - either based on hypervisor globally enabled, or rIOMMU active */
+               if (dc->debug.dml_hostvm_override == DML_HOSTVM_NO_OVERRIDE)
+                       pipes[i].pipe.src.hostvm = dc->vm_pa_config.is_hvm_enabled || dc->res_pool->hubbub->riommu_active;
+
                /*
                 * Immediate flip can be set dynamically after enabling the plane.
                 * We need to require support for immediate flip or underflow can be