drm/amd/display: Add hblank borrowing support

[WHY]
Some DSC timing failed at bandwidth validation due to hactive
can't be evenly divided on each ODM segment.

[HOW]
Borrow from hblank to increase hactive to support these timing.

Cc: Mario Limonciello <[e-mail]>
Cc: Alex Deucher <[e-mail]>
Cc: [e-mail]
Reviewed-by: Wenjing Liu <[e-mail]>
Signed-off-by: Chris Park <[e-mail]>
Signed-off-by: Alex Hung <[e-mail]>
Tested-by: Daniel Wheeler <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 	count = resource_get_odm_slice_count(otg_master);
 	h_active = timing->h_addressable +
 			timing->h_border_left +
-			timing->h_border_right;
+			timing->h_border_right +
+			otg_master->hblank_borrow;
 	width = h_active / count;
 
 	if (otg_master->stream_res.tg)
···
 }
 
 /**
+ * decide_hblank_borrow - Decides the horizontal blanking borrow value for a given pipe context.
+ * @pipe_ctx: Pointer to the pipe context structure.
+ *
+ * This function calculates the horizontal blanking borrow value for a given pipe context based on the
+ * display stream compression (DSC) configuration. If the horizontal active pixels (hactive) are less
+ * than the total width of the DSC slices, it sets the hblank_borrow value to the difference. If the
+ * total horizontal timing minus the hblank_borrow value is less than 32, it resets the hblank_borrow
+ * value to 0.
+ */
+static void decide_hblank_borrow(struct pipe_ctx *pipe_ctx)
+{
+	uint32_t hactive;
+	uint32_t ceil_slice_width;
+	struct dc_stream_state *stream = NULL;
+
+	if (!pipe_ctx)
+		return;
+
+	stream = pipe_ctx->stream;
+
+	if (stream->timing.flags.DSC) {
+		hactive = stream->timing.h_addressable + stream->timing.h_border_left + stream->timing.h_border_right;
+
+		/* Assume if determined slices does not divide Hactive evenly, Hborrow is needed for padding*/
+		if (hactive % stream->timing.dsc_cfg.num_slices_h != 0) {
+			ceil_slice_width = (hactive / stream->timing.dsc_cfg.num_slices_h) + 1;
+			pipe_ctx->hblank_borrow = ceil_slice_width * stream->timing.dsc_cfg.num_slices_h - hactive;
+
+			if (stream->timing.h_total - hactive - pipe_ctx->hblank_borrow < 32)
+				pipe_ctx->hblank_borrow = 0;
+		}
+	}
+}
+
+/**
  * dc_validate_global_state() - Determine if hardware can support a given state
  *
  * @dc: dc struct for this driver
···
 
 			if (pipe_ctx->stream != stream)
 				continue;
+
+			/* Decide whether hblank borrow is needed and save it in pipe_ctx */
+			if (dc->debug.enable_hblank_borrow)
+				decide_hblank_borrow(pipe_ctx);
 
 			if (dc->res_pool->funcs->patch_unknown_plane_state &&
 					pipe_ctx->plane_state &&

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

···
 	unsigned int scale_to_sharpness_policy;
 	bool skip_full_updated_if_possible;
 	unsigned int enable_oled_edp_power_up_opt;
+	bool enable_hblank_borrow;
 };
 
 

drivers/gpu/drm/amd/display/dc/dc_spl_translate.c

···
 	spl_in->odm_slice_index = resource_get_odm_slice_index(pipe_ctx);
 	// Make spl input basic out info output_size width point to stream h active
 	spl_in->basic_out.output_size.width =
-		stream->timing.h_addressable + stream->timing.h_border_left + stream->timing.h_border_right;
+		stream->timing.h_addressable + stream->timing.h_border_left + stream->timing.h_border_right + pipe_ctx->hblank_borrow;
 	// Make spl input basic out info output_size height point to v active
 	spl_in->basic_out.output_size.height =
 		stream->timing.v_addressable + stream->timing.v_border_bottom + stream->timing.v_border_top;

drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.c

···
 	timing->vblank_nom = timing->v_total - timing->v_active;
 }
 
+/**
+ * adjust_dml21_hblank_timing_config_from_pipe_ctx - Adjusts the horizontal blanking timing configuration
+ *                                                   based on the pipe context.
+ * @timing: Pointer to the dml2_timing_cfg structure to be adjusted.
+ * @pipe: Pointer to the pipe_ctx structure containing the horizontal blanking borrow value.
+ *
+ * This function modifies the horizontal active and blank end timings by adding and subtracting
+ * the horizontal blanking borrow value from the pipe context, respectively.
+ */
+static void adjust_dml21_hblank_timing_config_from_pipe_ctx(struct dml2_timing_cfg *timing, struct pipe_ctx *pipe)
+{
+	timing->h_active += pipe->hblank_borrow;
+	timing->h_blank_end -= pipe->hblank_borrow;
+}
+
 static void populate_dml21_output_config_from_stream_state(struct dml2_link_output_cfg *output,
 		struct dc_stream_state *stream, const struct pipe_ctx *pipe)
 {
···
 			temp_pipe->plane_state = pipe->plane_state;
 			temp_pipe->plane_res.scl_data.taps = pipe->plane_res.scl_data.taps;
 			temp_pipe->stream_res = pipe->stream_res;
+			temp_pipe->hblank_borrow = pipe->hblank_borrow;
 			dml_ctx->config.callbacks.build_scaling_params(temp_pipe);
 			break;
 		}
···
 
 		ASSERT(disp_cfg_stream_location >= 0 && disp_cfg_stream_location <= __DML2_WRAPPER_MAX_STREAMS_PLANES__);
 		populate_dml21_timing_config_from_stream_state(&dml_dispcfg->stream_descriptors[disp_cfg_stream_location].timing, context->streams[stream_index], dml_ctx);
+		adjust_dml21_hblank_timing_config_from_pipe_ctx(&dml_dispcfg->stream_descriptors[disp_cfg_stream_location].timing, &context->res_ctx.pipe_ctx[stream_index]);
 		populate_dml21_output_config_from_stream_state(&dml_dispcfg->stream_descriptors[disp_cfg_stream_location].output, context->streams[stream_index], &context->res_ctx.pipe_ctx[stream_index]);
 		populate_dml21_stream_overrides_from_stream_state(&dml_dispcfg->stream_descriptors[disp_cfg_stream_location], context->streams[stream_index]);
 
···
 	struct dc_crtc_timing *timing = &pipe_ctx->stream->timing;
 	union dml2_global_sync_programming *global_sync = &stream_programming->global_sync;
 
-	hactive = timing->h_addressable + timing->h_border_left + timing->h_border_right;
+	hactive = timing->h_addressable + timing->h_border_left + timing->h_border_right + pipe_ctx->hblank_borrow;
 	vactive = timing->v_addressable + timing->v_border_bottom + timing->v_border_top;
 	hblank_start = pipe_ctx->stream->timing.h_total - pipe_ctx->stream->timing.h_front_porch;
 	vblank_start = pipe_ctx->stream->timing.v_total - pipe_ctx->stream->timing.v_front_porch;
 
-	hblank_end = hblank_start - timing->h_addressable - timing->h_border_left - timing->h_border_right;
+	hblank_end = hblank_start - timing->h_addressable - timing->h_border_left - timing->h_border_right - pipe_ctx->hblank_borrow;
 	vblank_end = vblank_start - timing->v_addressable - timing->v_border_top - timing->v_border_bottom;
 
 	if (dml_ctx->config.svp_pstate.callbacks.get_pipe_subvp_type(context, pipe_ctx) == SUBVP_PHANTOM) {

drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c

···
 		}
 
 		/* Enable DSC hw block */
-		dsc_cfg.pic_width = (stream->timing.h_addressable + stream->timing.h_border_left + stream->timing.h_border_right) / opp_cnt;
+		dsc_cfg.pic_width = (stream->timing.h_addressable + pipe_ctx->hblank_borrow +
+				stream->timing.h_border_left + stream->timing.h_border_right) / opp_cnt;
 		dsc_cfg.pic_height = stream->timing.v_addressable + stream->timing.v_border_top + stream->timing.v_border_bottom;
 		dsc_cfg.pixel_encoding = stream->timing.pixel_encoding;
 		dsc_cfg.color_depth = stream->timing.display_color_depth;

drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c

···
 	int opp_cnt = 1;
 	int opp_inst[MAX_PIPES] = {0};
 	struct pipe_ctx *opp_heads[MAX_PIPES] = {0};
+	struct dc_crtc_timing patched_crtc_timing = stream->timing;
 	bool manual_mode;
 	unsigned int tmds_div = PIXEL_RATE_DIV_NA;
 	unsigned int unused_div = PIXEL_RATE_DIV_NA;
···
 	if (dc->hwseq->funcs.PLAT_58856_wa && (!dc_is_dp_signal(stream->signal)))
 		dc->hwseq->funcs.PLAT_58856_wa(context, pipe_ctx);
 
+	/* if we are borrowing from hblank, h_addressable needs to be adjusted */
+	if (dc->debug.enable_hblank_borrow)
+		patched_crtc_timing.h_addressable = patched_crtc_timing.h_addressable + pipe_ctx->hblank_borrow;
+
 	pipe_ctx->stream_res.tg->funcs->program_timing(
 			pipe_ctx->stream_res.tg,
-			&stream->timing,
+			&patched_crtc_timing,
 			pipe_ctx->pipe_dlg_param.vready_offset,
 			pipe_ctx->pipe_dlg_param.vstartup_start,
 			pipe_ctx->pipe_dlg_param.vupdate_offset,

drivers/gpu/drm/amd/display/dc/inc/core_types.h

···
 	/* subvp_index: only valid if the pipe is a SUBVP_MAIN*/
 	uint8_t subvp_index;
 	struct pixel_rate_divider pixel_rate_divider;
+	/* pixels borrowed from hblank to hactive */
+	uint8_t hblank_borrow;
 };
 
 /* Data used for dynamic link encoder assignment.

drivers/gpu/drm/amd/display/dc/link/link_dpms.c

···
 		enum optc_dsc_mode optc_dsc_mode;
 
 		/* Enable DSC hw block */
-		dsc_cfg.pic_width = (stream->timing.h_addressable + stream->timing.h_border_left + stream->timing.h_border_right) / opp_cnt;
+		dsc_cfg.pic_width = (stream->timing.h_addressable + pipe_ctx->hblank_borrow +
+				stream->timing.h_border_left + stream->timing.h_border_right) / opp_cnt;
 		dsc_cfg.pic_height = stream->timing.v_addressable + stream->timing.v_border_top + stream->timing.v_border_bottom;
 		dsc_cfg.pixel_encoding = stream->timing.pixel_encoding;
 		dsc_cfg.color_depth = stream->timing.display_color_depth;

drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c

···
 		free_pipe->plane_res.xfm = pool->transforms[free_pipe_idx];
 		free_pipe->plane_res.dpp = pool->dpps[free_pipe_idx];
 		free_pipe->plane_res.mpcc_inst = pool->dpps[free_pipe_idx]->inst;
+		free_pipe->hblank_borrow = otg_master->hblank_borrow;
 		if (free_pipe->stream->timing.flags.DSC == 1) {
 			dcn20_acquire_dsc(free_pipe->stream->ctx->dc,
 					&new_ctx->res_ctx,