drm/amd/display: abstract encoder related hwseq across different types

[why]
Current we have hundreds of if/else or switch statement to check
encoder type in dc_link level. The reason is because depending
on the type of encoder dc_link needs to perform similar programming
task but with different encoder interfaces. The story is to abstract
these interfaces so dc_link can just perform the programming task
without knowing the detail of which encoder it's dealing with.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -3433,6 +3433,8 @@ static enum dc_status dc_link_update_sst_payload(struct pipe_ctx *pipe_ctx,
 	struct hpo_dp_stream_encoder *hpo_dp_stream_encoder = pipe_ctx->stream_res.hpo_dp_stream_enc;
 	struct link_mst_stream_allocation_table proposed_table = {0};
 	struct fixed31_32 avg_time_slots_per_mtp;
+	const struct dc_link_settings empty_link_settings = {0};
+	const struct dc_link_hwss *link_hwss = dc_link_hwss_get(link, &pipe_ctx->link_res);
 	DC_LOGGER_INIT(link->ctx->logger);
 
 	/* slot X.Y for SST payload deallocate */
@@ -3441,10 +3443,11 @@ static enum dc_status dc_link_update_sst_payload(struct pipe_ctx *pipe_ctx,
 
 		dc_log_vcp_x_y(link, avg_time_slots_per_mtp);
 
-		hpo_dp_link_encoder->funcs->set_throttled_vcp_size(
+		link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-				hpo_dp_link_encoder,
+		if (link_hwss->set_hblank_min_symbol_width)
-				hpo_dp_stream_encoder->inst,
+			link_hwss->set_hblank_min_symbol_width(pipe_ctx,
-				avg_time_slots_per_mtp);
+					&empty_link_settings,
+					avg_time_slots_per_mtp);
 	}
 
 	/* calculate VC payload and update branch with new payload allocation table*/
@@ -3488,10 +3491,11 @@ static enum dc_status dc_link_update_sst_payload(struct pipe_ctx *pipe_ctx,
 
 		dc_log_vcp_x_y(link, avg_time_slots_per_mtp);
 
-		hpo_dp_link_encoder->funcs->set_throttled_vcp_size(
+		link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-				hpo_dp_link_encoder,
+		if (link_hwss->set_hblank_min_symbol_width)
-				hpo_dp_stream_encoder->inst,
+			link_hwss->set_hblank_min_symbol_width(pipe_ctx,
-				avg_time_slots_per_mtp);
+					&link->cur_link_settings,
+					avg_time_slots_per_mtp);
 	}
 
 	/* Always return DC_OK.
@@ -3508,15 +3512,14 @@ enum dc_status dc_link_allocate_mst_payload(struct pipe_ctx *pipe_ctx)
 	struct dc_stream_state *stream = pipe_ctx->stream;
 	struct dc_link *link = stream->link;
 	struct link_encoder *link_encoder = NULL;
-	struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
 	struct hpo_dp_link_encoder *hpo_dp_link_encoder = pipe_ctx->link_res.hpo_dp_link_enc;
-	struct hpo_dp_stream_encoder *hpo_dp_stream_encoder = pipe_ctx->stream_res.hpo_dp_stream_enc;
 	struct dp_mst_stream_allocation_table proposed_table = {0};
 	struct fixed31_32 avg_time_slots_per_mtp;
 	struct fixed31_32 pbn;
 	struct fixed31_32 pbn_per_slot;
 	int i;
 	enum act_return_status ret;
+	const struct dc_link_hwss *link_hwss = dc_link_hwss_get(link, &pipe_ctx->link_res);
 	DC_LOGGER_INIT(link->ctx->logger);
 
 	/* Link encoder may have been dynamically assigned to non-physical display endpoint. */
@@ -3622,22 +3625,13 @@ enum dc_status dc_link_allocate_mst_payload(struct pipe_ctx *pipe_ctx)
 	pbn = get_pbn_from_timing(pipe_ctx);
 	avg_time_slots_per_mtp = dc_fixpt_div(pbn, pbn_per_slot);
 
-	switch (dp_get_link_encoding_format(&link->cur_link_settings)) {
+	dc_log_vcp_x_y(link, avg_time_slots_per_mtp);
-	case DP_8b_10b_ENCODING:
+
-		stream_encoder->funcs->set_throttled_vcp_size(
+	link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-			stream_encoder,
+	if (link_hwss->set_hblank_min_symbol_width)
-			avg_time_slots_per_mtp);
+		link_hwss->set_hblank_min_symbol_width(pipe_ctx,
-		break;
+				&link->cur_link_settings,
-	case DP_128b_132b_ENCODING:
-		hpo_dp_link_encoder->funcs->set_throttled_vcp_size(
-				hpo_dp_link_encoder,
-				hpo_dp_stream_encoder->inst,
 				avg_time_slots_per_mtp);
-		break;
-	case DP_UNKNOWN_ENCODING:
-		DC_LOG_ERROR("Failure: unknown encoding format\n");
-		return DC_ERROR_UNEXPECTED;
-	}
 
 	return DC_OK;
 
@@ -3651,10 +3645,10 @@ enum dc_status dc_link_reduce_mst_payload(struct pipe_ctx *pipe_ctx, uint32_t bw
 	struct fixed31_32 pbn;
 	struct fixed31_32 pbn_per_slot;
 	struct link_encoder *link_encoder = link->link_enc;
-	struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
 	struct dp_mst_stream_allocation_table proposed_table = {0};
 	uint8_t i;
 	enum act_return_status ret;
+	const struct dc_link_hwss *link_hwss = dc_link_hwss_get(link, &pipe_ctx->link_res);
 	DC_LOGGER_INIT(link->ctx->logger);
 
 	/* decrease throttled vcp size */
@@ -3662,8 +3656,10 @@ enum dc_status dc_link_reduce_mst_payload(struct pipe_ctx *pipe_ctx, uint32_t bw
 	pbn = get_pbn_from_bw_in_kbps(bw_in_kbps);
 	avg_time_slots_per_mtp = dc_fixpt_div(pbn, pbn_per_slot);
 
-	stream_encoder->funcs->set_throttled_vcp_size(
+	link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-				stream_encoder,
+	if (link_hwss->set_hblank_min_symbol_width)
+		link_hwss->set_hblank_min_symbol_width(pipe_ctx,
+				&link->cur_link_settings,
 				avg_time_slots_per_mtp);
 
 	/* send ALLOCATE_PAYLOAD sideband message with updated pbn */
@@ -3731,10 +3727,10 @@ enum dc_status dc_link_increase_mst_payload(struct pipe_ctx *pipe_ctx, uint32_t
 	struct fixed31_32 pbn;
 	struct fixed31_32 pbn_per_slot;
 	struct link_encoder *link_encoder = link->link_enc;
-	struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
 	struct dp_mst_stream_allocation_table proposed_table = {0};
 	uint8_t i;
 	enum act_return_status ret;
+	const struct dc_link_hwss *link_hwss = dc_link_hwss_get(link, &pipe_ctx->link_res);
 	DC_LOGGER_INIT(link->ctx->logger);
 
 	/* notify immediate branch device table update */
@@ -3793,8 +3789,10 @@ enum dc_status dc_link_increase_mst_payload(struct pipe_ctx *pipe_ctx, uint32_t
 	pbn_per_slot = get_pbn_per_slot(stream);
 	avg_time_slots_per_mtp = dc_fixpt_div(pbn, pbn_per_slot);
 
-	stream_encoder->funcs->set_throttled_vcp_size(
+	link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-				stream_encoder,
+	if (link_hwss->set_hblank_min_symbol_width)
+		link_hwss->set_hblank_min_symbol_width(pipe_ctx,
+				&link->cur_link_settings,
 				avg_time_slots_per_mtp);
 
 	return DC_OK;
@@ -3805,13 +3803,13 @@ static enum dc_status deallocate_mst_payload(struct pipe_ctx *pipe_ctx)
 	struct dc_stream_state *stream = pipe_ctx->stream;
 	struct dc_link *link = stream->link;
 	struct link_encoder *link_encoder = NULL;
-	struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
 	struct hpo_dp_link_encoder *hpo_dp_link_encoder = pipe_ctx->link_res.hpo_dp_link_enc;
-	struct hpo_dp_stream_encoder *hpo_dp_stream_encoder = pipe_ctx->stream_res.hpo_dp_stream_enc;
 	struct dp_mst_stream_allocation_table proposed_table = {0};
 	struct fixed31_32 avg_time_slots_per_mtp = dc_fixpt_from_int(0);
 	int i;
 	bool mst_mode = (link->type == dc_connection_mst_branch);
+	const struct dc_link_hwss *link_hwss = dc_link_hwss_get(link, &pipe_ctx->link_res);
+	const struct dc_link_settings empty_link_settings = {0};
 	DC_LOGGER_INIT(link->ctx->logger);
 
 	/* Link encoder may have been dynamically assigned to non-physical display endpoint. */
@@ -3829,22 +3827,11 @@ static enum dc_status deallocate_mst_payload(struct pipe_ctx *pipe_ctx)
 	 */
 
 	/* slot X.Y */
-	switch (dp_get_link_encoding_format(&link->cur_link_settings)) {
+	link_hwss->set_throttled_vcp_size(pipe_ctx, avg_time_slots_per_mtp);
-	case DP_8b_10b_ENCODING:
+	if (link_hwss->set_hblank_min_symbol_width)
-		stream_encoder->funcs->set_throttled_vcp_size(
+		link_hwss->set_hblank_min_symbol_width(pipe_ctx,
-			stream_encoder,
+				&empty_link_settings,
-			avg_time_slots_per_mtp);
-		break;
-	case DP_128b_132b_ENCODING:
-		hpo_dp_link_encoder->funcs->set_throttled_vcp_size(
-				hpo_dp_link_encoder,
-				hpo_dp_stream_encoder->inst,
 				avg_time_slots_per_mtp);
-		break;
-	case DP_UNKNOWN_ENCODING:
-		DC_LOG_ERROR("Failure: unknown encoding format\n");
-		return DC_ERROR_UNEXPECTED;
-	}
 
 	/* TODO: which component is responsible for remove payload table? */
 	if (mst_mode) {

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

@@ -844,4 +844,89 @@ void setup_dp_hpo_stream(struct pipe_ctx *pipe_ctx, bool enable)
 	}
 }
 
+/******************************* dio_link_hwss ********************************/
+static void set_dio_throttled_vcp_size(struct pipe_ctx *pipe_ctx,
+		struct fixed31_32 throttled_vcp_size)
+{
+	struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
+
+	stream_encoder->funcs->set_throttled_vcp_size(
+				stream_encoder,
+				throttled_vcp_size);
+}
+
+/***************************** hpo_dp_link_hwss *******************************/
+static void set_dp_hpo_throttled_vcp_size(struct pipe_ctx *pipe_ctx,
+		struct fixed31_32 throttled_vcp_size)
+{
+	struct hpo_dp_stream_encoder *hpo_dp_stream_encoder = pipe_ctx->stream_res.hpo_dp_stream_enc;
+	struct hpo_dp_link_encoder *hpo_dp_link_encoder = pipe_ctx->link_res.hpo_dp_link_enc;
+
+	hpo_dp_link_encoder->funcs->set_throttled_vcp_size(hpo_dp_link_encoder,
+			hpo_dp_stream_encoder->inst,
+			throttled_vcp_size);
+}
+
+static void set_dp_hpo_hblank_min_symbol_width(struct pipe_ctx *pipe_ctx,
+		const struct dc_link_settings *link_settings,
+		struct fixed31_32 throttled_vcp_size)
+{
+	struct hpo_dp_stream_encoder *hpo_dp_stream_encoder = pipe_ctx->stream_res.hpo_dp_stream_enc;
+	struct dc_crtc_timing *timing = &pipe_ctx->stream->timing;
+	struct fixed31_32 h_blank_in_ms, time_slot_in_ms, mtp_cnt_per_h_blank;
+	uint32_t link_bw_in_kbps = dc_link_bandwidth_kbps(pipe_ctx->stream->link, link_settings);
+	uint16_t hblank_min_symbol_width = 0;
+
+	if (link_bw_in_kbps > 0) {
+		h_blank_in_ms = dc_fixpt_div(dc_fixpt_from_int(timing->h_total-timing->h_addressable),
+				dc_fixpt_from_fraction(timing->pix_clk_100hz, 10));
+		time_slot_in_ms = dc_fixpt_from_fraction(32 * 4, link_bw_in_kbps);
+		mtp_cnt_per_h_blank = dc_fixpt_div(h_blank_in_ms, dc_fixpt_mul_int(time_slot_in_ms, 64));
+		hblank_min_symbol_width = dc_fixpt_floor(
+				dc_fixpt_mul(mtp_cnt_per_h_blank, throttled_vcp_size));
+	}
+
+	hpo_dp_stream_encoder->funcs->set_hblank_min_symbol_width(hpo_dp_stream_encoder,
+			hblank_min_symbol_width);
+}
+
+static const struct dc_link_hwss hpo_dp_link_hwss = {
+	.set_throttled_vcp_size = set_dp_hpo_throttled_vcp_size,
+
+	/* function pointers below this point require check for NULL
+	 * *********************************************************************
+	 */
+	.set_hblank_min_symbol_width = set_dp_hpo_hblank_min_symbol_width,
+};
+
+static const struct dc_link_hwss dio_link_hwss = {
+	.set_throttled_vcp_size = set_dio_throttled_vcp_size,
+};
+
+const struct dc_link_hwss *dc_link_hwss_get(const struct dc_link *link,
+		const struct link_resource *link_res)
+{
+	if (link_res->hpo_dp_link_enc)
+		/* TODO: some assumes that if decided link settings is 128b/132b
+		 * channel coding format hpo_dp_link_enc should be used.
+		 * Others believe that if hpo_dp_link_enc is available in link
+		 * resource then hpo_dp_link_enc must be used. This bound between
+		 * hpo_dp_link_enc != NULL and decided link settings is loosely coupled
+		 * with a premise that both hpo_dp_link_enc pointer and decided link
+		 * settings are determined based on single policy function like
+		 * "decide_link_settings" from upper layer. This "convention"
+		 * cannot be maintained and enforced at current level.
+		 * Therefore a refactor is due so we can enforce a strong bound
+		 * between those two parameters at this level.
+		 *
+		 * To put it simple, we want to make enforcement at low level so that
+		 * we will not return link hwss if caller plans to do 8b/10b
+		 * with an hpo encoder. Or we can return a very dummy one that doesn't
+		 * do work for all functions
+		 */
+		return &hpo_dp_link_hwss;
+	else
+		return &dio_link_hwss;
+}
+
 #undef DC_LOGGER

drivers/gpu/drm/amd/display/dc/inc/hw/stream_encoder.h

@@ -327,6 +327,10 @@ struct hpo_dp_stream_encoder_funcs {
 	void (*read_state)(
 			struct hpo_dp_stream_encoder *enc,
 			struct hpo_dp_stream_encoder_state *state);
+
+	void (*set_hblank_min_symbol_width)(
+			struct hpo_dp_stream_encoder *enc,
+			uint16_t width);
 };
 
 #endif /* STREAM_ENCODER_H_ */

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

@@ -72,4 +72,23 @@ void dp_retrain_link_dp_test(struct dc_link *link,
 		struct dc_link_settings *link_setting,
 		bool skip_video_pattern);
 
+struct dc_link;
+struct link_resource;
+struct fixed31_32;
+struct pipe_ctx;
+
+struct dc_link_hwss {
+	void (*set_throttled_vcp_size)(struct pipe_ctx *pipe_ctx,
+			struct fixed31_32 throttled_vcp_size);
+
+	/* function pointers below this point require check for NULL
+	 * *********************************************************************
+	 */
+	void (*set_hblank_min_symbol_width)(struct pipe_ctx *pipe_ctx,
+			const struct dc_link_settings *link_settings,
+			struct fixed31_32 throttled_vcp_size);
+};
+
+const struct dc_link_hwss *dc_link_hwss_get(const struct dc_link *link, const struct link_resource *link_res);
+
 #endif /* __DC_LINK_HWSS_H__ */