[PATCH 4/4] drm/i915: Implement vblank synchronized MBUS join changes

[Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>]

Currently we can't change MBUS join status without doing a modeset,
because we are lacking mechanism to synchronize those with vblank.
However then this means that we can't do a fastset, if there is a need
to change MBUS join state. Fix that by implementing such change.
We already call correspondent check and update at pre_plane dbuf update,
so the only thing left is to have a non-modeset version of that.
If active pipes stay the same then fastset is possible and only MBUS
join state/ddb allocation updates would be committed.

v2: - Removed redundant parentheses(Ville Syrjälä)
    - Constified new_crtc_state in intel_mbus_joined_pipe(Ville Syrjälä)
    - Removed pipe_select variable(Ville Syrjälä)

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |   6 +-
 drivers/gpu/drm/i915/display/skl_watermark.c | 119 +++++++++++++++----
 drivers/gpu/drm/i915/display/skl_watermark.h |   2 +
 3 files changed, 101 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index b88f214e111ae..d5351f6fa2eb4 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6895,6 +6895,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
 		intel_pre_update_crtc(state, crtc);
 	}
 
+	intel_dbuf_mbus_pre_ddb_update(state);
+
 	while (update_pipes) {
 		for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
 						    new_crtc_state, i) {
@@ -6925,6 +6927,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
 		}
 	}
 
+	intel_dbuf_mbus_post_ddb_update(state);
+
 	update_pipes = modeset_pipes;
 
 	/*
@@ -7169,9 +7173,7 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	}
 
 	intel_encoders_update_prepare(state);
-
 	intel_dbuf_pre_plane_update(state);
-	intel_mbus_dbox_update(state);
 
 	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
 		if (new_crtc_state->do_async_flip)
diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
index 7eb78e0c8c8e3..7f2b4dc2a27d4 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.c
+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
@@ -4,6 +4,7 @@
  */
 
 #include <drm/drm_blend.h>
+#include <drm/drm_print.h>
 
 #include "i915_drv.h"
 #include "i915_fixed.h"
@@ -2636,13 +2637,6 @@ skl_compute_ddb(struct intel_atomic_state *state)
 		if (ret)
 			return ret;
 
-		if (old_dbuf_state->joined_mbus != new_dbuf_state->joined_mbus) {
-			/* TODO: Implement vblank synchronized MBUS joining changes */
-			ret = intel_modeset_all_pipes_late(state, "MBUS joining change");
-			if (ret)
-				return ret;
-		}
-
 		drm_dbg_kms(&i915->drm,
 			    "Enabled dbuf slices 0x%x -> 0x%x (total dbuf slices 0x%x), mbus joined? %s->%s\n",
 			    old_dbuf_state->enabled_slices,
@@ -3594,11 +3588,32 @@ static void intel_dbuf_mdclk_min_tracker_update(struct intel_atomic_state *state
 					    new_dbuf_state->joined_mbus);
 }
 
+static enum pipe intel_mbus_joined_pipe(struct intel_atomic_state *state,
+				        const struct intel_dbuf_state *dbuf_state)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	enum pipe sync_pipe = ffs(dbuf_state->active_pipes) - 1;
+	const struct intel_crtc_state *new_crtc_state;
+	struct intel_crtc *crtc;
+
+	drm_WARN_ON(&i915->drm, !dbuf_state->joined_mbus);
+	drm_WARN_ON(&i915->drm, !is_power_of_2(dbuf_state->active_pipes));
+
+	crtc = intel_crtc_for_pipe(i915, sync_pipe);
+	new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
+
+	if (new_crtc_state && !intel_crtc_needs_modeset(new_crtc_state))
+		return sync_pipe;
+	else
+		return INVALID_PIPE;
+}
+
 /*
  * Configure MBUS_CTL and all DBUF_CTL_S of each slice to join_mbus state before
  * update the request state of all DBUS slices.
  */
-static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state)
+static void intel_dbuf_mbus_ctl_update(struct intel_atomic_state *state,
+				       enum pipe sync_pipe)
 {
 	struct drm_i915_private *i915 = to_i915(state->base.dev);
 	u32 mbus_ctl;
@@ -3612,12 +3627,21 @@ static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state)
 	 * TODO: Implement vblank synchronized MBUS joining changes.
 	 * Must be properly coordinated with dbuf reprogramming.
 	 */
-	if (new_dbuf_state->joined_mbus)
-		mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN |
-			MBUS_JOIN_PIPE_SELECT_NONE;
-	else
-		mbus_ctl = MBUS_HASHING_MODE_2x2 |
-			MBUS_JOIN_PIPE_SELECT_NONE;
+	if (new_dbuf_state->joined_mbus) {
+		if (sync_pipe != INVALID_PIPE)
+			mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN |
+				   MBUS_JOIN_PIPE_SELECT(sync_pipe);
+		else
+			mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN |
+				   MBUS_JOIN_PIPE_SELECT_NONE;
+	} else {
+		if (sync_pipe != INVALID_PIPE)
+			mbus_ctl = MBUS_HASHING_MODE_2x2 |
+				   MBUS_JOIN_PIPE_SELECT(sync_pipe);
+		else
+			mbus_ctl = MBUS_HASHING_MODE_2x2 |
+				   MBUS_JOIN_PIPE_SELECT_NONE;
+	}
 
 	intel_de_rmw(i915, MBUS_CTL,
 		     MBUS_HASHING_MODE_MASK | MBUS_JOIN |
@@ -3632,6 +3656,42 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
 	const struct intel_dbuf_state *old_dbuf_state =
 		intel_atomic_get_old_dbuf_state(state);
 
+	if (!new_dbuf_state ||
+	    new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices)
+		return;
+
+	WARN_ON(!new_dbuf_state->base.changed);
+
+	gen9_dbuf_slices_update(i915,
+				old_dbuf_state->enabled_slices |
+				new_dbuf_state->enabled_slices);
+}
+
+void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	const struct intel_dbuf_state *new_dbuf_state =
+		intel_atomic_get_new_dbuf_state(state);
+	const struct intel_dbuf_state *old_dbuf_state =
+		intel_atomic_get_old_dbuf_state(state);
+
+	if (!new_dbuf_state ||
+	    new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices)
+		return;
+
+	WARN_ON(!new_dbuf_state->base.changed);
+
+	gen9_dbuf_slices_update(i915,
+				new_dbuf_state->enabled_slices);
+}
+
+void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state)
+{
+	const struct intel_dbuf_state *new_dbuf_state =
+		intel_atomic_get_new_dbuf_state(state);
+	const struct intel_dbuf_state *old_dbuf_state =
+		intel_atomic_get_old_dbuf_state(state);
+
 	if (!new_dbuf_state ||
 	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
 	     new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
@@ -3640,16 +3700,15 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
 	WARN_ON(!new_dbuf_state->base.changed);
 
 	if (!old_dbuf_state->joined_mbus && new_dbuf_state->joined_mbus) {
-		intel_dbuf_mbus_join_update(state);
+		enum pipe sync_pipe = intel_mbus_joined_pipe(state, new_dbuf_state);
+
+		intel_dbuf_mbus_ctl_update(state, sync_pipe);
+		intel_mbus_dbox_update(state);
 		intel_dbuf_mdclk_min_tracker_update(state);
 	}
-
-	gen9_dbuf_slices_update(i915,
-				old_dbuf_state->enabled_slices |
-				new_dbuf_state->enabled_slices);
 }
 
-void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
+void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *i915 = to_i915(state->base.dev);
 	const struct intel_dbuf_state *new_dbuf_state =
@@ -3657,6 +3716,12 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
 	const struct intel_dbuf_state *old_dbuf_state =
 		intel_atomic_get_old_dbuf_state(state);
 
+	if (new_dbuf_state && old_dbuf_state &&
+	    new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus) {
+		intel_dbuf_mdclk_min_tracker_update(state);
+		intel_mbus_dbox_update(state);
+	}
+
 	if (!new_dbuf_state ||
 	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
 	     new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
@@ -3665,12 +3730,18 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
 	WARN_ON(!new_dbuf_state->base.changed);
 
 	if (old_dbuf_state->joined_mbus && !new_dbuf_state->joined_mbus) {
-		intel_dbuf_mbus_join_update(state);
+		enum pipe sync_pipe = intel_mbus_joined_pipe(state, old_dbuf_state);
+
 		intel_dbuf_mdclk_min_tracker_update(state);
-	}
+		intel_mbus_dbox_update(state);
+		intel_dbuf_mbus_ctl_update(state, sync_pipe);
 
-	gen9_dbuf_slices_update(i915,
-				new_dbuf_state->enabled_slices);
+		if (sync_pipe != INVALID_PIPE) {
+			struct intel_crtc *crtc = intel_crtc_for_pipe(i915, sync_pipe);
+
+			intel_crtc_wait_for_next_vblank(crtc);
+		}
+	}
 }
 
 static bool xelpdp_is_only_pipe_per_dbuf_bank(enum pipe pipe, u8 active_pipes)
diff --git a/drivers/gpu/drm/i915/display/skl_watermark.h b/drivers/gpu/drm/i915/display/skl_watermark.h
index 3a90741cab06a..f6d38b41e3a6c 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.h
+++ b/drivers/gpu/drm/i915/display/skl_watermark.h
@@ -77,6 +77,8 @@ int intel_dbuf_state_set_mdclk_cdclk_ratio(struct intel_atomic_state *state, u8
 void intel_dbuf_pre_plane_update(struct intel_atomic_state *state);
 void intel_dbuf_post_plane_update(struct intel_atomic_state *state);
 void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio, bool joined_mbus);
+void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state);
+void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state);
 void intel_mbus_dbox_update(struct intel_atomic_state *state);
 
 #endif /* __SKL_WATERMARK_H__ */
-- 
2.37.3