drm/amd: the data retured from PRT is expected to be 0

The dummy page for returning from PRT resides inside system memory,
need set system flag bit in VM_L2_CNTL.

Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 4 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_0.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_0.c
index 231c77aed01b..b7de60a15623 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v2_0.c
@@ -135,7 +135,8 @@ static void gfxhub_v2_0_init_cache_regs(struct amdgpu_device *adev)
         tmp = RREG32_SOC15(GC, 0, mmGCVM_L2_CNTL);
         tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL, ENABLE_L2_CACHE, 1);
         tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL, ENABLE_L2_FRAGMENT_PROCESSING, 0);
-
+        tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL,
+                            ENABLE_DEFAULT_PAGE_OUT_TO_SYSTEM_MEMORY, 1);
         /* XXX for emulation, Refer to closed source code.*/
         tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL,
                             L2_PDE0_CACHE_TAG_GENERATION_MODE, 0);
diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
index f65b9c827970..37a1a318ae63 100644
--- a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
@@ -121,6 +121,8 @@ static void mmhub_v2_0_init_cache_regs(struct amdgpu_device *adev)
         tmp = RREG32_SOC15(MMHUB, 0, mmMMVM_L2_CNTL);
         tmp = REG_SET_FIELD(tmp, MMVM_L2_CNTL, ENABLE_L2_CACHE, 1);
         tmp = REG_SET_FIELD(tmp, MMVM_L2_CNTL, ENABLE_L2_FRAGMENT_PROCESSING, 0);
+        tmp = REG_SET_FIELD(tmp, MMVM_L2_CNTL,
+                            ENABLE_DEFAULT_PAGE_OUT_TO_SYSTEM_MEMORY, 1);
         /* XXX for emulation, Refer to closed source code.*/
         tmp = REG_SET_FIELD(tmp, MMVM_L2_CNTL, L2_PDE0_CACHE_TAG_GENERATION_MODE,
                             0);