[PATCH 29/74] drm/amd/display: Read accelerated mode through a query builder

[Wayne Lin <Wayne.Lin@amd.com>]

From: Tony Cheng <tony.cheng@amd.com>

[Why]
DC2 read the VBIOS accelerated-mode bit with a direct BIOS call. The
core layer must not access hardware.

[How]
Add a query builder that emits one accelerated-mode read into an output
target. The core layer builds and executes it in place before it accepts
a commit or an update.

Cc: Jun Lei <jun.lei@amd.com>
Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
---
 .../amd/display/dc/bls_builder/bls_builder.h  |  2 +
 .../dc/bls_builder/dcn401_init_builder.c      | 32 +++++++++++
 .../gpu/drm/amd/display/dc/core2/dc_core2.c   | 53 +++++++++++++------
 3 files changed, 72 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/bls_builder/bls_builder.h b/drivers/gpu/drm/amd/display/dc/bls_builder/bls_builder.h
index 954adc590ed4..9a3907bf950a 100644
--- a/drivers/gpu/drm/amd/display/dc/bls_builder/bls_builder.h
+++ b/drivers/gpu/drm/amd/display/dc/bls_builder/bls_builder.h
@@ -26,6 +26,7 @@ enum bls_builder_name {
 	DCN_DECL_INITIALIZATION_LEGACY,
 	DCN_DECL_NON_SEAMLESS_COMMIT,
 	DCN_DECL_SEAMLESS_UPDATE,
+	DCN_DECL_QUERY_ACCELERATED_MODE,
 	BLS_BUILDER_NAME_COUNT,
 };
 
@@ -51,6 +52,7 @@ struct bls_builder_output_targets {
 	union {
 		struct bls_builder_output_init *DCN_DECL_INITIALIZATION;
 		struct bls_builder_legacy_hw_init_info *DCN_DECL_INITIALIZATION_LEGACY;
+		bool *DCN_DECL_QUERY_ACCELERATED_MODE;
 	};
 };
 
diff --git a/drivers/gpu/drm/amd/display/dc/bls_builder/dcn401_init_builder.c b/drivers/gpu/drm/amd/display/dc/bls_builder/dcn401_init_builder.c
index 75fd4be3690a..1dc502c0839c 100644
--- a/drivers/gpu/drm/amd/display/dc/bls_builder/dcn401_init_builder.c
+++ b/drivers/gpu/drm/amd/display/dc/bls_builder/dcn401_init_builder.c
@@ -386,6 +386,31 @@ static enum bls_builder_result dcn401_build_initialization(
 	return BLS_BUILD_ERROR_UNSUPPORTED_STATE_UPDATE;
 }
 
+/* Reads the VBIOS accelerated-mode bit into the caller's out-target. */
+static enum bls_builder_result dcn401_build_accelerated_mode_query(
+		struct bls_builder_declarative_params *params)
+{
+	union block_sequence_params bls_params = {0};
+	struct block_sequence_state sequence;
+	struct dc_bios *dcb;
+
+	if (!params || !params->dc || !params->dc->ctx || !params->out_targets ||
+			!params->out_targets->DCN_DECL_QUERY_ACCELERATED_MODE)
+		return BLS_BUILD_ERROR_RESOURCE_MAPPING;
+	dcb = params->dc->ctx->dc_bios;
+	if (!dcb || !dcb->funcs || !dcb->funcs->is_accelerated_mode)
+		return BLS_BUILD_ERROR_RESOURCE_MAPPING;
+
+	sequence.steps = params->head_sequence;
+	sequence.num_steps = &params->head_num_steps;
+	bls_params.bios_is_accelerated_mode_params.dcb = dcb;
+	bls_params.bios_is_accelerated_mode_params.out_accelerated_mode =
+			params->out_targets->DCN_DECL_QUERY_ACCELERATED_MODE;
+	if (!bls_append(&sequence, BIOS_IS_ACCELERATED_MODE, &bls_params))
+		return BLS_BUILD_ERROR_RESOURCE_MAPPING;
+	return BLS_BUILD_SUCCESS;
+}
+
 const struct bls_builder *dcn401_bls_builder_create(
 		enum bls_builder_name name)
 {
@@ -401,6 +426,11 @@ const struct bls_builder *dcn401_bls_builder_create(
 		.check_capability = dcn401_dc1_initialization_check_capability,
 		.build.declarative = dcn401_build_dc1_initialization,
 	};
+	static const struct bls_builder accelerated_mode_query_builder = {
+		.name = DCN_DECL_QUERY_ACCELERATED_MODE,
+		.kind = BLS_BUILDER_DECLARATIVE,
+		.build.declarative = dcn401_build_accelerated_mode_query,
+	};
 
 	switch (name) {
 	case DCN_DECL_INITIALIZATION:
@@ -411,6 +441,8 @@ const struct bls_builder *dcn401_bls_builder_create(
 		return dcn401_non_seamless_commit_builder();
 	case DCN_DECL_SEAMLESS_UPDATE:
 		return dcn401_seamless_update_builder();
+	case DCN_DECL_QUERY_ACCELERATED_MODE:
+		return &accelerated_mode_query_builder;
 	default:
 		return NULL;
 	}
diff --git a/drivers/gpu/drm/amd/display/dc/core2/dc_core2.c b/drivers/gpu/drm/amd/display/dc/core2/dc_core2.c
index 052f29df1797..295d2d8b277e 100644
--- a/drivers/gpu/drm/amd/display/dc/core2/dc_core2.c
+++ b/drivers/gpu/drm/amd/display/dc/core2/dc_core2.c
@@ -53,20 +53,6 @@ void core2_destruct(struct dc *dc)
 	(void)dc;
 }
 
-/*
- * The VBIOS scratch read legacy_commit_state_hw makes
- * before it enables accelerated mode. The commit has no accelerated-mode
- * entries, so it runs only after init has left VBIOS mode. Remove when a
- * BLC exposes the accelerated-mode bit.
- */
-static bool core2_is_accelerated_mode(struct dc *dc)
-{
-	struct dc_bios *dcb = dc->ctx->dc_bios;
-
-	return dcb && dcb->funcs && dcb->funcs->is_accelerated_mode &&
-			dcb->funcs->is_accelerated_mode(dcb);
-}
-
 static struct pipe_ctx *core2_otg_master(struct dc_state *state)
 {
 	unsigned int i;
@@ -105,6 +91,43 @@ static bool core2_run_commit_sequence(struct dc *dc,
 			result == DC2_BLS_EXEC_CONTINUED_ON_ERROR;
 }
 
+/*
+ * legacy_commit_state_hw reads this bit before it enables accelerated
+ * mode. The commit and the update have no accelerated-mode entries, so
+ * they run only after init has left VBIOS mode.
+ */
+static bool core2_query_accelerated_mode(struct dc *dc)
+{
+	const struct bls_builder *builder =
+			TO_DC2(dc)->builders[DCN_DECL_QUERY_ACCELERATED_MODE];
+	const struct workaround_manager *wam = dc2_workaround_manager_get();
+	struct bls_builder_output_targets out_targets = {0};
+	struct bls_builder_declarative_params *params;
+	bool accelerated_mode = false;
+
+	if (!builder || builder->kind != BLS_BUILDER_DECLARATIVE ||
+			!builder->build.declarative || !wam)
+		return false;
+
+	/* 256 block-sequence entries; keep them off the kernel stack. */
+	params = kvzalloc(sizeof(*params), GFP_KERNEL);
+	if (!params)
+		return false;
+	params->dc = dc;
+	params->current_state = dc->current_state;
+	out_targets.DCN_DECL_QUERY_ACCELERATED_MODE = &accelerated_mode;
+	params->out_targets = &out_targets;
+
+	if (builder->build.declarative(params) != BLS_BUILD_SUCCESS ||
+			params->tail_num_steps ||
+			!core2_run_commit_sequence(dc, builder, wam,
+			params->head_sequence, &params->head_num_steps))
+		accelerated_mode = false;
+
+	kvfree(params);
+	return accelerated_mode;
+}
+
 /*
  * dcn401_prepare_bandwidth's optimized_required writes. The Executor ORs
  * in the watermark and arbiter results.
@@ -196,7 +219,7 @@ static bool core2_builder_supports(struct dc *dc, enum bls_builder_name name,
 			builder->build.declarative &&
 			dc2_workaround_manager_get() &&
 			builder->check_capability(&check) &&
-			core2_is_accelerated_mode(dc);
+			core2_query_accelerated_mode(dc);
 }
 
 /* Never falls back to legacy_commit_state_hw: DC2 must not call DC1. */
-- 
2.43.0