drm/amdgpu: force to use legacy inv in mmhub

MMHUB v4.1.0 only support fixed cache mode, so
only use legacy invalidation accordingly.

Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Frank Min <Frank.Min@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 9192c76)

Author: Likun Gao

drivers/gpu/drm/amd/amdgpu/mmhub_v4_1_0.c

@@ -80,7 +80,8 @@ static uint32_t mmhub_v4_1_0_get_invalidate_req(unsigned int vmid,
 	/* invalidate using legacy mode on vmid*/
 	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ,
 			    PER_VMID_INVALIDATE_REQ, 1 << vmid);
-	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ, FLUSH_TYPE, flush_type);
+	/* Only use legacy inv on mmhub side */
+	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ, FLUSH_TYPE, 0);
 	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ, INVALIDATE_L2_PTES, 1);
 	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ, INVALIDATE_L2_PDE0, 1);
 	req = REG_SET_FIELD(req, MMVM_INVALIDATE_ENG0_REQ, INVALIDATE_L2_PDE1, 1);