drm/amdgpu: pin the csb buffer on hw init v2

Without this pin, the csb buffer will be filled with inconsistent
data after S3 resume. And that will causes gfx hang on gfxoff
exit since this csb will be executed then.

v2: fit amdgpu_bo_pin change(take one less argument)
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -943,6 +943,7 @@ static int gfx_v9_0_rlc_init(struct amdgpu_device *adev)
 		dst_ptr = adev->gfx.rlc.cs_ptr;
 		gfx_v9_0_get_csb_buffer(adev, dst_ptr);
 		amdgpu_bo_kunmap(adev->gfx.rlc.clear_state_obj);
+		amdgpu_bo_unpin(adev->gfx.rlc.clear_state_obj);
 		amdgpu_bo_unreserve(adev->gfx.rlc.clear_state_obj);
 	}
 
@@ -971,6 +972,39 @@ static int gfx_v9_0_rlc_init(struct amdgpu_device *adev)
 	return 0;
 }
 
+static int gfx_v9_0_csb_vram_pin(struct amdgpu_device *adev)
+{
+	int r;
+
+	r = amdgpu_bo_reserve(adev->gfx.rlc.clear_state_obj, false);
+	if (unlikely(r != 0))
+		return r;
+
+	r = amdgpu_bo_pin(adev->gfx.rlc.clear_state_obj,
+			AMDGPU_GEM_DOMAIN_VRAM);
+	if (!r)
+		adev->gfx.rlc.clear_state_gpu_addr =
+			amdgpu_bo_gpu_offset(adev->gfx.rlc.clear_state_obj);
+
+	amdgpu_bo_unreserve(adev->gfx.rlc.clear_state_obj);
+
+	return r;
+}
+
+static void gfx_v9_0_csb_vram_unpin(struct amdgpu_device *adev)
+{
+	int r;
+
+	if (!adev->gfx.rlc.clear_state_obj)
+		return;
+
+	r = amdgpu_bo_reserve(adev->gfx.rlc.clear_state_obj, true);
+	if (likely(r == 0)) {
+		amdgpu_bo_unpin(adev->gfx.rlc.clear_state_obj);
+		amdgpu_bo_unreserve(adev->gfx.rlc.clear_state_obj);
+	}
+}
+
 static void gfx_v9_0_mec_fini(struct amdgpu_device *adev)
 {
 	amdgpu_bo_free_kernel(&adev->gfx.mec.hpd_eop_obj, NULL, NULL);
@@ -3116,6 +3150,10 @@ static int gfx_v9_0_hw_init(void *handle)
 
 	gfx_v9_0_gpu_init(adev);
 
+	r = gfx_v9_0_csb_vram_pin(adev);
+	if (r)
+		return r;
+
 	r = gfx_v9_0_rlc_resume(adev);
 	if (r)
 		return r;
@@ -3224,6 +3262,8 @@ static int gfx_v9_0_hw_fini(void *handle)
 	gfx_v9_0_cp_enable(adev, false);
 	gfx_v9_0_rlc_stop(adev);
 
+	gfx_v9_0_csb_vram_unpin(adev);
+
 	return 0;
 }