drm/amd/display: implement pipe type definition and adding accessors

[why]
There is a lack of encapsulation of pipe connection representation in pipe context.
This has caused many challenging bugs and coding errors with repeated
logic to identify the same pipe type.

[how]
Formally define pipe types and provide getters to identify a pipe type and
find a pipe based on specific requirements. Update existing logic in non dcn
specific files and dcn32 and future versions to use the new accessors.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 207 insertions, 13 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/inc/resource.h b/drivers/gpu/drm/amd/display/dc/inc/resource.h
index 8dabbbc2a7b9..e546b9c506c1 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/resource.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/resource.h
@@ -37,7 +37,6 @@
 #define IS_PIPE_SYNCD_VALID(pipe) ((((pipe)->pipe_idx_syncd) & 0x80)?1:0)
 #define GET_PIPE_SYNCD_FROM_PIPE(pipe) ((pipe)->pipe_idx_syncd & 0x7F)
 #define SET_PIPE_SYNCD_TO_PIPE(pipe, pipe_syncd) ((pipe)->pipe_idx_syncd = (0x80 | pipe_syncd))
-#define FREE_PIPE_INDEX_NOT_FOUND -1
 
 enum dce_version resource_parse_asic_id(
 		struct hw_asic_id asic_id);
@@ -143,10 +142,6 @@ struct clock_source *dc_resource_find_first_free_pll(
 		struct resource_context *res_ctx,
 		const struct resource_pool *pool);
 
-struct pipe_ctx *resource_get_head_pipe_for_stream(
-		struct resource_context *res_ctx,
-		struct dc_stream_state *stream);
-
 bool resource_attach_surfaces_to_context(
 		struct dc_plane_state *const *plane_state,
 		int surface_count,
@@ -154,29 +149,232 @@ bool resource_attach_surfaces_to_context(
 		struct dc_state *context,
 		const struct resource_pool *pool);
 
-struct pipe_ctx *find_free_secondary_pipe_legacy(
-		struct resource_context *res_ctx,
-		const struct resource_pool *pool,
-		const struct pipe_ctx *primary_pipe);
+#define FREE_PIPE_INDEX_NOT_FOUND -1
 
+/*
+ * pipe types are identified based on MUXes in DCN front end that are capable
+ * of taking input from one DCN pipeline to another DCN pipeline. The name is
+ * in a form of XXXX_YYYY, where XXXX is the DCN front end hardware block the
+ * pipeline ends with and YYYY is the rendering role that the pipe is in.
+ *
+ * For instance OTG_MASTER is a pipe ending with OTG hardware block in its
+ * pipeline and it is in a role of a master pipe for timing generation.
+ *
+ * For quick reference a diagram of each pipe type's areas of responsibility
+ * for outputting timings on the screen is shown below:
+ *
+ *       Timing Active for Stream 0
+ *        __________________________________________________
+ *       |OTG master 0 (OPP head 0)|OPP head 2 (DPP pipe 2) |
+ *       |             (DPP pipe 0)|                        |
+ *       | Top Plane 0             |                        |
+ *       |           ______________|____                    |
+ *       |          |DPP pipe 1    |DPP |                   |
+ *       |          |              |pipe|                   |
+ *       |          |  Bottom      |3   |                   |
+ *       |          |  Plane 1     |    |                   |
+ *       |          |              |    |                   |
+ *       |          |______________|____|                   |
+ *       |                         |                        |
+ *       |                         |                        |
+ *       | ODM slice 0             | ODM slice 1            |
+ *       |_________________________|________________________|
+ *
+ *       Timing Active for Stream 1
+ *        __________________________________________________
+ *       |OTG master 4 (OPP head 4)                         |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |               Blank Pixel Data                   |
+ *       |              (generated by DPG4)                 |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |                                                  |
+ *       |__________________________________________________|
+ *
+ *       Inter-pipe Relation
+ *        __________________________________________________
+ *       |PIPE IDX|   DPP PIPES   | OPP HEADS | OTG MASTER  |
+ *       |        |  plane 0      | slice 0   |             |
+ *       |   0    | -------------MPC---------ODM----------- |
+ *       |        |  plane 1    | |         | |             |
+ *       |   1    | ------------- |         | |             |
+ *       |        |  plane 0      | slice 1 | |             |
+ *       |   2    | -------------MPC--------- |             |
+ *       |        |  plane 1    | |           |             |
+ *       |   3    | ------------- |           |             |
+ *       |        |               | blank     |             |
+ *       |   4    |               | ----------------------- |
+ *       |        |               |           |             |
+ *       |   5    |  (FREE)       |           |             |
+ *       |________|_______________|___________|_____________|
+ */
+enum pipe_type {
+	/* free pipe - free pipe is an uninitialized pipe without a stream
+	 * associated with it. It is a free DCN pipe resource. It can be
+	 * acquired as any type of pipe.
+	 */
+	FREE_PIPE,
+
+	/* OTG master pipe - the master pipe of its OPP head pipes with a
+	 * functional OTG. It merges all its OPP head pipes pixel data in ODM
+	 * block and output to backend DIG. OTG master pipe is responsible for
+	 * generating entire crtc timing to backend DIG. An OTG master pipe may
+	 * or may not have a plane. If it has a plane it blends it as the left
+	 * most MPC slice of the top most layer. If it doesn't have a plane it
+	 * can output pixel data from its OPP head pipes' test pattern
+	 * generators (DPG) such as solid black pixel data to blank the screen.
+	 */
+	OTG_MASTER,
+
+	/* OPP head pipe - the head pipe of an MPC blending tree with a
+	 * functional OPP outputting to an OTG. OPP head pipe is responsible for
+	 * processing output pixels in its own ODM slice. It may or may not have
+	 * a plane. If it has a plane it blends it as the top most layer within
+	 * its own ODM slice. If it doesn't have a plane it can output pixel
+	 * data from its DPG such as solid black pixel data to blank the pixel
+	 * data in its own ODM slice. OTG master pipe is also an OPP head pipe
+	 * but with more responsibility.
+	 */
+	OPP_HEAD,
+
+	/* DPP pipe - the pipe with a functional DPP outputting to an OPP head
+	 * pipe's MPC. DPP pipe is responsible for processing pixel data from
+	 * its own MPC slice of a plane. It must be connected to an OPP head
+	 * pipe and it must have a plane associated with it.
+	 */
+	DPP_PIPE,
+};
+
+/*
+ * Determine if the input pipe ctx is of a pipe type.
+ * return - true if pipe ctx is of the input type.
+ */
+bool resource_is_pipe_type(const struct pipe_ctx *pipe_ctx, enum pipe_type type);
+
+/*
+ * Determine if the input pipe ctx is used for rendering a plane with MPCC
+ * combine. MPCC combine is a hardware feature to combine multiple DPP pipes
+ * into a single plane. It is typically used for bypassing pipe bandwidth
+ * limitation for rendering a very large plane or saving power by reducing UCLK
+ * and DPPCLK speeds.
+ *
+ * For instance in the Inter-pipe Relation diagram shown below, both PIPE 0 and
+ * 1 are for MPCC combine for plane 0
+ *
+ *       Inter-pipe Relation
+ *        __________________________________________________
+ *       |PIPE IDX|   DPP PIPES   | OPP HEADS | OTG MASTER  |
+ *       |        |  plane 0      |           |             |
+ *       |   0    | -------------MPC----------------------- |
+ *       |        |  plane 0    | |           |             |
+ *       |   1    | ------------- |           |             |
+ *       |________|_______________|___________|_____________|
+ *
+ * return - true if pipe ctx is used for mpcc combine.
+ */
+bool resource_is_for_mpcc_combine(const struct pipe_ctx *pipe_ctx);
+
+/*
+ * Look for a free pipe in new resource context that is used as a secondary DPP
+ * pipe in MPC blending tree associated with input OPP head pipe.
+ *
+ * return - FREE_PIPE_INDEX_NOT_FOUND if free pipe is not found, otherwise
+ * pipe idx of the free pipe
+ */
 int resource_find_free_pipe_used_in_cur_mpc_blending_tree(
 		const struct resource_context *cur_res_ctx,
 		struct resource_context *new_res_ctx,
 		const struct pipe_ctx *cur_opp_head);
 
+/*
+ * Look for a free pipe in new resource context that is not used in current
+ * resource context.
+ *
+ * return - FREE_PIPE_INDEX_NOT_FOUND if free pipe is not found, otherwise
+ * pipe idx of the free pipe
+ */
 int recource_find_free_pipe_not_used_in_cur_res_ctx(
 		const struct resource_context *cur_res_ctx,
 		struct resource_context *new_res_ctx,
 		const struct resource_pool *pool);
 
+/*
+ * Look for a free pipe in new resource context that is used as a secondary DPP
+ * pipe in any MPCC combine in current resource context.
+ * return - FREE_PIPE_INDEX_NOT_FOUND if free pipe is not found, otherwise
+ * pipe idx of the free pipe
+ */
 int resource_find_free_pipe_used_as_cur_sec_dpp_in_mpcc_combine(
 		const struct resource_context *cur_res_ctx,
 		struct resource_context *new_res_ctx,
 		const struct resource_pool *pool);
 
+/*
+ * Look for any free pipe in new resource context.
+ * return - FREE_PIPE_INDEX_NOT_FOUND if free pipe is not found, otherwise
+ * pipe idx of the free pipe
+ */
 int resource_find_any_free_pipe(struct resource_context *new_res_ctx,
 		const struct resource_pool *pool);
 
+/*
+ * Legacy find free secondary pipe logic deprecated for newer DCNs as it doesn't
+ * find the most optimal free pipe to prevent from time consuming hardware state
+ * transitions.
+ */
+struct pipe_ctx *resource_find_free_secondary_pipe_legacy(
+		struct resource_context *res_ctx,
+		const struct resource_pool *pool,
+		const struct pipe_ctx *primary_pipe);
+
+/*
+ * Get number of MPC "cuts" of the plane associated with the pipe. MPC slice
+ * count is equal to MPC splits + 1. For example if a plane is cut 3 times, it
+ * will have 4 pieces of slice.
+ * return - 0 if pipe is not used for a plane with MPCC combine. otherwise
+ * the number of MPC "cuts" for the plane.
+ */
+int resource_get_num_mpc_splits(const struct pipe_ctx *pipe);
+
+/*
+ * Get number of ODM "cuts" of the timing associated with the pipe. ODM slice
+ * count is equal to ODM splits + 1. For example if a timing is cut 3 times, it
+ * will have 4 pieces of slice.
+ * return - 0 if pipe is not used for ODM combine. otherwise
+ * the number of ODM "cuts" for the timing.
+ */
+int resource_get_num_odm_splits(const struct pipe_ctx *pipe);
+
+/*
+ * Get the OTG master pipe in resource context associated with the stream.
+ * return - NULL if not found. Otherwise the OTG master pipe associated with the
+ * stream.
+ */
+struct pipe_ctx *resource_get_otg_master_for_stream(
+		struct resource_context *res_ctx,
+		struct dc_stream_state *stream);
+
+/*
+ * Get the OTG master pipe for the input pipe context.
+ * return - the OTG master pipe for the input pipe
+ * context.
+ */
+struct pipe_ctx *resource_get_otg_master(const struct pipe_ctx *pipe_ctx);
+
+/*
+ * Get the OPP head pipe for the input pipe context.
+ * return - the OPP head pipe for the input pipe
+ * context.
+ */
+struct pipe_ctx *resource_get_opp_head(const struct pipe_ctx *pipe_ctx);
+
+
 bool resource_validate_attach_surfaces(
 		const struct dc_validation_set set[],
 		int set_count,
@@ -212,10 +410,6 @@ unsigned int resource_pixel_format_to_bpp(enum surface_pixel_format format);
 void get_audio_check(struct audio_info *aud_modes,
 	struct audio_check *aud_chk);
 
-int get_num_mpc_splits(struct pipe_ctx *pipe);
-
-int get_num_odm_splits(struct pipe_ctx *pipe);
-
 bool get_temp_dp_link_res(struct dc_link *link,
 		struct link_resource *link_res,
 		struct dc_link_settings *link_settings);