drm/amd/display: Hande writeback request from userspace

[WHAT]
Handle writeback requests and fill in the required information for DWB
programming and setup.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -416,6 +416,9 @@ struct amdgpu_crtc {
 
 	int otg_inst;
 	struct drm_pending_vblank_event *event;
+
+	bool wb_pending;
+	struct drm_writeback_connector *wb_conn;
 };
 
 struct amdgpu_encoder_atom_dig {

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

@@ -578,6 +578,7 @@ static void dm_crtc_high_irq(void *interrupt_params)
 {
 	struct common_irq_params *irq_params = interrupt_params;
 	struct amdgpu_device *adev = irq_params->adev;
+	struct drm_writeback_job *job;
 	struct amdgpu_crtc *acrtc;
 	unsigned long flags;
 	int vrr_active;
@@ -586,6 +587,21 @@ static void dm_crtc_high_irq(void *interrupt_params)
 	if (!acrtc)
 		return;
 
+	if (acrtc->wb_pending) {
+		if (acrtc->wb_conn) {
+			spin_lock_irqsave(&acrtc->wb_conn->job_lock, flags);
+			job = list_first_entry_or_null(&acrtc->wb_conn->job_queue,
+						       struct drm_writeback_job,
+						       list_entry);
+			spin_unlock_irqrestore(&acrtc->wb_conn->job_lock, flags);
+
+			if (job)
+				drm_writeback_signal_completion(acrtc->wb_conn, 0);
+		} else
+			DRM_ERROR("%s: no amdgpu_crtc wb_conn\n", __func__);
+		acrtc->wb_pending = false;
+	}
+
 	vrr_active = amdgpu_dm_crtc_vrr_active_irq(acrtc);
 
 	drm_dbg_vbl(adev_to_drm(adev),
@@ -8639,6 +8655,12 @@ static void amdgpu_dm_crtc_copy_transient_flags(struct drm_crtc_state *crtc_stat
 	stream_state->mode_changed = drm_atomic_crtc_needs_modeset(crtc_state);
 }
 
+static void dm_clear_writeback(struct amdgpu_display_manager *dm,
+			      struct dm_crtc_state *crtc_state)
+{
+	dc_stream_remove_writeback(dm->dc, crtc_state->stream, 0);
+}
+
 static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 					struct dc_state *dc_state)
 {
@@ -8648,9 +8670,34 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
 	struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state;
+	struct drm_connector_state *old_con_state;
+	struct drm_connector *connector;
 	bool mode_set_reset_required = false;
 	u32 i;
 
+	/* Disable writeback */
+	for_each_old_connector_in_state(state, connector, old_con_state, i) {
+		struct dm_connector_state *dm_old_con_state;
+		struct amdgpu_crtc *acrtc;
+
+		if (connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
+			continue;
+
+		old_crtc_state = NULL;
+
+		dm_old_con_state = to_dm_connector_state(old_con_state);
+		if (!dm_old_con_state->base.crtc)
+			continue;
+
+		acrtc = to_amdgpu_crtc(dm_old_con_state->base.crtc);
+		if (acrtc)
+			old_crtc_state = drm_atomic_get_old_crtc_state(state, &acrtc->base);
+
+		dm_old_crtc_state = to_dm_crtc_state(old_crtc_state);
+
+		dm_clear_writeback(dm, dm_old_crtc_state);
+	}
+
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
 				      new_crtc_state, i) {
 		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc);
@@ -8787,6 +8834,97 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	}
 }
 
+static void dm_set_writeback(struct amdgpu_display_manager *dm,
+			      struct dm_crtc_state *crtc_state,
+			      struct drm_connector *connector,
+			      struct drm_connector_state *new_con_state)
+{
+	struct drm_writeback_connector *wb_conn = drm_connector_to_writeback(connector);
+	struct amdgpu_crtc *acrtc;
+	struct dc_writeback_info *wb_info;
+	struct pipe_ctx *pipe = NULL;
+	struct amdgpu_framebuffer *afb;
+	int i = 0;
+
+	wb_info = kzalloc(sizeof(*wb_info), GFP_KERNEL);
+	if (!wb_info) {
+		DRM_ERROR("Failed to allocate wb_info\n");
+		return;
+	}
+
+	acrtc = to_amdgpu_crtc(wb_conn->encoder.crtc);
+	if (!acrtc) {
+		DRM_ERROR("no amdgpu_crtc found\n");
+		return;
+	}
+
+	afb = to_amdgpu_framebuffer(new_con_state->writeback_job->fb);
+	if (!afb) {
+		DRM_ERROR("No amdgpu_framebuffer found\n");
+		return;
+	}
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		if (dm->dc->current_state->res_ctx.pipe_ctx[i].stream == crtc_state->stream) {
+			pipe = &dm->dc->current_state->res_ctx.pipe_ctx[i];
+			break;
+		}
+	}
+
+	/* fill in wb_info */
+	wb_info->wb_enabled = true;
+
+	wb_info->dwb_pipe_inst = 0;
+	wb_info->dwb_params.dwbscl_black_color = 0;
+	wb_info->dwb_params.hdr_mult = 0x1F000;
+	wb_info->dwb_params.csc_params.gamut_adjust_type = CM_GAMUT_ADJUST_TYPE_BYPASS;
+	wb_info->dwb_params.csc_params.gamut_coef_format = CM_GAMUT_REMAP_COEF_FORMAT_S2_13;
+	wb_info->dwb_params.output_depth = DWB_OUTPUT_PIXEL_DEPTH_10BPC;
+	wb_info->dwb_params.cnv_params.cnv_out_bpc = DWB_CNV_OUT_BPC_10BPC;
+
+	/* width & height from crtc */
+	wb_info->dwb_params.cnv_params.src_width = acrtc->base.mode.crtc_hdisplay;
+	wb_info->dwb_params.cnv_params.src_height = acrtc->base.mode.crtc_vdisplay;
+	wb_info->dwb_params.dest_width = acrtc->base.mode.crtc_hdisplay;
+	wb_info->dwb_params.dest_height = acrtc->base.mode.crtc_vdisplay;
+
+	wb_info->dwb_params.cnv_params.crop_en = false;
+	wb_info->dwb_params.stereo_params.stereo_enabled = false;
+
+	wb_info->dwb_params.cnv_params.out_max_pix_val = 0x3ff;	// 10 bits
+	wb_info->dwb_params.cnv_params.out_min_pix_val = 0;
+	wb_info->dwb_params.cnv_params.fc_out_format = DWB_OUT_FORMAT_32BPP_ARGB;
+	wb_info->dwb_params.cnv_params.out_denorm_mode = DWB_OUT_DENORM_BYPASS;
+
+	wb_info->dwb_params.out_format = dwb_scaler_mode_bypass444;
+
+	wb_info->dwb_params.capture_rate = dwb_capture_rate_0;
+
+	wb_info->dwb_params.scaler_taps.h_taps = 4;
+	wb_info->dwb_params.scaler_taps.v_taps = 4;
+	wb_info->dwb_params.scaler_taps.h_taps_c = 2;
+	wb_info->dwb_params.scaler_taps.v_taps_c = 2;
+	wb_info->dwb_params.subsample_position = DWB_INTERSTITIAL_SUBSAMPLING;
+
+	wb_info->mcif_buf_params.luma_pitch = afb->base.pitches[0];
+	wb_info->mcif_buf_params.chroma_pitch = afb->base.pitches[1];
+
+	for (i = 0; i < DWB_MCIF_BUF_COUNT; i++) {
+		wb_info->mcif_buf_params.luma_address[i] = afb->address;
+		wb_info->mcif_buf_params.chroma_address[i] = 0;
+	}
+
+	wb_info->mcif_buf_params.p_vmid = 1;
+	wb_info->mcif_warmup_params.p_vmid = 1;
+	wb_info->writeback_source_plane = pipe->plane_state;
+
+	dc_stream_add_writeback(dm->dc, crtc_state->stream, wb_info);
+
+	acrtc->wb_pending = true;
+	acrtc->wb_conn = wb_conn;
+	drm_writeback_queue_job(wb_conn, new_con_state);
+}
+
 /**
  * amdgpu_dm_atomic_commit_tail() - AMDgpu DM's commit tail implementation.
  * @state: The atomic state to commit
@@ -9119,6 +9257,27 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 			amdgpu_dm_commit_planes(state, dev, dm, crtc, wait_for_vblank);
 	}
 
+	/* Enable writeback */
+	for_each_new_connector_in_state(state, connector, new_con_state, i) {
+		struct dm_connector_state *dm_new_con_state = to_dm_connector_state(new_con_state);
+		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc);
+
+		if (connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
+			continue;
+
+		if (!new_con_state->writeback_job)
+			continue;
+
+		new_crtc_state = NULL;
+
+		if (acrtc)
+			new_crtc_state = drm_atomic_get_new_crtc_state(state, &acrtc->base);
+
+		dm_new_crtc_state = to_dm_crtc_state(new_crtc_state);
+
+		dm_set_writeback(dm, dm_new_crtc_state, connector, new_con_state);
+	}
+
 	/* Update audio instances for each connector. */
 	amdgpu_dm_commit_audio(dev, state);