drm/amdgpu: Use physical translation mode to access page table

On A+A platform, CPU write page directory and page table in cached
mode. So it is necessary for page table walker to snoop CPU cache.
This setting is necessary for page walker to snoop page directory
and page table data out of CPU cache.
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Acked-by: Christian Konig <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c

@@ -173,8 +173,13 @@ static void gfxhub_v1_0_init_cache_regs(struct amdgpu_device *adev)
 	WREG32_SOC15_RLC(GC, 0, mmVM_L2_CNTL3, tmp);
 
 	tmp = mmVM_L2_CNTL4_DEFAULT;
+	if (adev->gmc.xgmi.connected_to_cpu) {
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PDE_REQUEST_PHYSICAL, 1);
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PTE_REQUEST_PHYSICAL, 1);
+	} else {
 		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PDE_REQUEST_PHYSICAL, 0);
 		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PTE_REQUEST_PHYSICAL, 0);
+	}
 	WREG32_SOC15_RLC(GC, 0, mmVM_L2_CNTL4, tmp);
 }
 

drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c

@@ -178,8 +178,17 @@ static void mmhub_v1_7_init_cache_regs(struct amdgpu_device *adev)
 	WREG32_SOC15(MMHUB, 0, regVM_L2_CNTL3, tmp);
 
 	tmp = regVM_L2_CNTL4_DEFAULT;
-	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PDE_REQUEST_PHYSICAL, 0);
-	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PTE_REQUEST_PHYSICAL, 0);
+	if (adev->gmc.xgmi.connected_to_cpu) {
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4,
+				    VMC_TAP_PDE_REQUEST_PHYSICAL, 1);
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4,
+				    VMC_TAP_PTE_REQUEST_PHYSICAL, 1);
+	} else {
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4,
+				    VMC_TAP_PDE_REQUEST_PHYSICAL, 0);
+		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4,
+				    VMC_TAP_PTE_REQUEST_PHYSICAL, 0);
+	}
 	WREG32_SOC15(MMHUB, 0, regVM_L2_CNTL4, tmp);
 }