drm/amdgpu: Init MMVM_CONTEXTS_DISABLE in gmc11 golden setting under SRIOV

[Why]
If disable the mmhub vm contexts(set MMVM_CONTEXTS_DISABLE to 0xffff),
driver loading failed on vf due to fence fallback timer expired on all rings.
FLR cannot reset MMVM_CONTEXTS_DISABLE.
So this vf can not be recovered anymore unless trigger a whole gpu reset.

[How]
Under SRIOV, init MMVM_CONTEXTS_DISABLE in gmc11 golden register setting.
Signed-off-by: Yifan Zha <Yifan.Zha@amd.com>
Reviewed-by: Horace Chen <Horace.Chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -104,6 +104,8 @@ struct amdgpu_vmhub {
 	uint32_t	vm_cntx_cntl_vm_fault;
 	uint32_t	vm_l2_bank_select_reserved_cid2;
 
+	uint32_t	vm_contexts_disable;
+
 	const struct amdgpu_vmhub_funcs *vmhub_funcs;
 };
 

drivers/gpu/drm/amd/amdgpu/gmc_v11_0.c

@@ -862,6 +862,12 @@ static int gmc_v11_0_sw_fini(void *handle)
 
 static void gmc_v11_0_init_golden_registers(struct amdgpu_device *adev)
 {
+	if (amdgpu_sriov_vf(adev)) {
+		struct amdgpu_vmhub *hub = &adev->vmhub[AMDGPU_MMHUB_0];
+
+		WREG32(hub->vm_contexts_disable, 0);
+		return;
+	}
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/mmhub_v3_0.c

@@ -517,6 +517,9 @@ static void mmhub_v3_0_init(struct amdgpu_device *adev)
 	hub->vm_l2_bank_select_reserved_cid2 =
 		SOC15_REG_OFFSET(MMHUB, 0, regMMVM_L2_BANK_SELECT_RESERVED_CID2);
 
+	hub->vm_contexts_disable =
+		SOC15_REG_OFFSET(MMHUB, 0, regMMVM_CONTEXTS_DISABLE);
+
 	hub->vmhub_funcs = &mmhub_v3_0_vmhub_funcs;
 }