drm/amd/display: enable seamless boot for DCN301

[Why]
DCN301 is capable of running seamless boot
if keep_stolen_vga_memory is not set.

[How]
Add a helper to check whether an ASIC can support
seamless boot and set it based on base driver flags.

Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Zhan Liu <Zhan.Liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -1454,6 +1454,12 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 
 	init_data.flags.power_down_display_on_boot = true;
 
+	if (check_seamless_boot_capability(adev)) {
+		init_data.flags.power_down_display_on_boot = false;
+		init_data.flags.allow_seamless_boot_optimization = true;
+		DRM_INFO("Seamless boot condition check passed\n");
+	}
+
 	INIT_LIST_HEAD(&adev->dm.da_list);
 	/* Display Core create. */
 	adev->dm.dc = dc_create(&init_data);
@@ -11616,3 +11622,24 @@ int amdgpu_dm_process_dmub_aux_transfer_sync(bool is_cmd_aux, struct dc_context
 			ctx, DMUB_ASYNC_TO_SYNC_ACCESS_SUCCESS,
 			(uint32_t *)operation_result);
 }
+
+/*
+ * Check whether seamless boot is supported.
+ *
+ * So far we only support seamless boot on CHIP_VANGOGH.
+ * If everything goes well, we may consider expanding
+ * seamless boot to other ASICs.
+ */
+bool check_seamless_boot_capability(struct amdgpu_device *adev)
+{
+	switch (adev->asic_type) {
+	case CHIP_VANGOGH:
+		if (!adev->mman.keep_stolen_vga_memory)
+			return true;
+		break;
+	default:
+		break;
+	}
+
+	return false;
+}

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -731,4 +731,7 @@ extern const struct drm_encoder_helper_funcs amdgpu_dm_encoder_helper_funcs;
 int amdgpu_dm_process_dmub_aux_transfer_sync(bool is_cmd_aux,
 					struct dc_context *ctx, unsigned int link_index,
 					void *payload, void *operation_result);
+
+bool check_seamless_boot_capability(struct amdgpu_device *adev);
+
 #endif /* __AMDGPU_DM_H__ */

drivers/gpu/drm/amd/display/dc/core/dc_resource.c

@@ -2078,7 +2078,6 @@ static void mark_seamless_boot_stream(
 {
 	struct dc_bios *dcb = dc->ctx->dc_bios;
 
-	/* TODO: Check Linux */
 	if (dc->config.allow_seamless_boot_optimization &&
 			!dcb->funcs->is_accelerated_mode(dcb)) {
 		if (dc_validate_seamless_boot_timing(dc, stream->sink, &stream->timing))

drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c

@@ -686,7 +686,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.disable_clock_gate = true,
 	.disable_pplib_clock_request = true,
 	.disable_pplib_wm_range = true,
-	.pipe_split_policy = MPC_SPLIT_AVOID_MULT_DISP,
+	.pipe_split_policy = MPC_SPLIT_AVOID,
 	.force_single_disp_pipe_split = false,
 	.disable_dcc = DCC_ENABLE,
 	.vsr_support = true,