drm/i915/gen9: Drop re-allocation of DDB at atomic commit (v2)

Now that we're properly pre-allocating the DDB during the atomic check
phase and we trust that the allocation is appropriate, let's actually
use the allocation computed and not duplicate that work during the
commit phase.

v2:
 - Significant rebasing now that we can use cached data rates and
   minimum block allocations to avoid grabbing additional plane states.
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463061971-19638-11-git-send-email-matthew.d.roper@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -13600,6 +13600,7 @@ static int intel_atomic_commit(struct drm_device *dev,
 	drm_atomic_helper_swap_state(dev, state);
 	dev_priv->wm.config = intel_state->wm_config;
 	dev_priv->wm.distrust_bios_wm = false;
+	dev_priv->wm.skl_results.ddb = intel_state->ddb;
 	intel_shared_dpll_commit(state);
 
 	if (intel_state->modeset) {
@@ -13717,19 +13718,6 @@ static int intel_atomic_commit(struct drm_device *dev,
 		intel_modeset_verify_crtc(crtc, old_crtc_state, crtc->state);
 	}
 
-	/*
-	 * Temporary sanity check: make sure our pre-computed DDB matches the
-	 * one we actually wind up programming.
-	 *
-	 * Not a great place to put this, but the easiest place we have access
-	 * to both the pre-computed and final DDB's; we'll be removing this
-	 * check in the next patch anyway.
-	 */
-	WARN(IS_GEN9(dev) &&
-	     memcmp(&intel_state->ddb, &dev_priv->wm.skl_results.ddb,
-		    sizeof(intel_state->ddb)),
-	     "Pre-computed DDB does not match final DDB!\n");
-
 	if (intel_state->modeset)
 		intel_display_power_put(dev_priv, POWER_DOMAIN_MODESET);
 

drivers/gpu/drm/i915/intel_pm.c

@@ -2849,7 +2849,6 @@ skl_wm_plane_id(const struct intel_plane *plane)
 static void
 skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
 				   const struct intel_crtc_state *cstate,
-				   struct intel_wm_config *config,
 				   struct skl_ddb_entry *alloc, /* out */
 				   int *num_active /* out */)
 {
@@ -2857,24 +2856,22 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
 	struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_crtc *for_crtc = cstate->base.crtc;
-	struct drm_crtc *crtc;
 	unsigned int pipe_size, ddb_size;
 	int nth_active_pipe;
 	int pipe = to_intel_crtc(for_crtc)->pipe;
 
-	if (intel_state && intel_state->active_pipe_changes)
-		*num_active = hweight32(intel_state->active_crtcs);
-	else if (intel_state)
-		*num_active = hweight32(dev_priv->active_crtcs);
-	else
-		*num_active = config->num_pipes_active;
-
-	if (!cstate->base.active) {
+	if (WARN_ON(!state) || !cstate->base.active) {
 		alloc->start = 0;
 		alloc->end = 0;
+		*num_active = hweight32(dev_priv->active_crtcs);
 		return;
 	}
 
+	if (intel_state->active_pipe_changes)
+		*num_active = hweight32(intel_state->active_crtcs);
+	else
+		*num_active = hweight32(dev_priv->active_crtcs);
+
 	if (IS_BROXTON(dev))
 		ddb_size = BXT_DDB_SIZE;
 	else
@@ -2882,16 +2879,6 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
 
 	ddb_size -= 4; /* 4 blocks for bypass path allocation */
 
-	/*
-	 * FIXME: At the moment we may be called on either in-flight or fully
-	 * committed cstate's.  Once we fully move DDB allocation in the check
-	 * phase, we'll only be called on in-flight states and the 'else'
-	 * branch here will go away.
-	 *
-	 * The 'else' branch is slightly racy here, but it was racy to begin
-	 * with; since it's going away soon, no effort is made to address that.
-	 */
-	if (state) {
 	/*
 	 * If the state doesn't change the active CRTC's, then there's
 	 * no need to recalculate; the existing pipe allocation limits
@@ -2910,23 +2897,6 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
 	pipe_size = ddb_size / hweight32(intel_state->active_crtcs);
 	alloc->start = nth_active_pipe * ddb_size / *num_active;
 	alloc->end = alloc->start + pipe_size;
-	} else {
-		nth_active_pipe = 0;
-		for_each_crtc(dev, crtc) {
-			if (!to_intel_crtc(crtc)->active)
-				continue;
-
-			if (crtc == for_crtc)
-				break;
-
-			nth_active_pipe++;
-		}
-
-		pipe_size = ddb_size / config->num_pipes_active;
-		alloc->start = nth_active_pipe * ddb_size /
-			config->num_pipes_active;
-		alloc->end = alloc->start + pipe_size;
-	}
 }
 
 static unsigned int skl_cursor_allocation(int num_active)
@@ -3025,32 +2995,20 @@ skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate)
 	struct drm_crtc *crtc = cstate->crtc;
 	struct drm_device *dev = crtc->dev;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	const struct drm_plane *plane;
 	const struct intel_plane *intel_plane;
+	struct drm_plane_state *pstate;
 	unsigned int rate, total_data_rate = 0;
 	int id;
-
-	/* Calculate and cache data rate for each plane */
-	/*
-	 * FIXME: At the moment this function can be called on either an
-	 * in-flight or a committed state object.  If it's in-flight then we
-	 * only want to re-calculate the plane data rate for planes that are
-	 * part of the transaction (i.e., we don't want to grab any additional
-	 * plane states if we don't have to).  If we're operating on committed
-	 * state, we'll just go ahead and recalculate the plane data rate for
-	 * all planes.
-	 *
-	 * Once we finish moving our DDB allocation to the atomic check phase,
-	 * we'll only be calling this function on in-flight state objects, so
-	 * the 'else' branch here will go away.
-	 */
-	if (state) {
-		struct drm_plane *plane;
-		struct drm_plane_state *pstate;
 	int i;
 
+	if (WARN_ON(!state))
+		return 0;
+
+	/* Calculate and cache data rate for each plane */
 	for_each_plane_in_state(state, plane, pstate, i) {
+		id = skl_wm_plane_id(to_intel_plane(plane));
 		intel_plane = to_intel_plane(plane);
-			id = skl_wm_plane_id(intel_plane);
 
 		if (intel_plane->pipe != intel_crtc->pipe)
 			continue;
@@ -3065,23 +3023,6 @@ skl_get_total_relative_data_rate(struct intel_crtc_state *intel_cstate)
 						    pstate, 1);
 		intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
 	}
-	} else {
-		for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
-			const struct drm_plane_state *pstate =
-				intel_plane->base.state;
-			int id = skl_wm_plane_id(intel_plane);
-
-			/* packed/uv */
-			rate = skl_plane_relative_data_rate(intel_cstate,
-							    pstate, 0);
-			intel_cstate->wm.skl.plane_data_rate[id] = rate;
-
-			/* y-plane */
-			rate = skl_plane_relative_data_rate(intel_cstate,
-							    pstate, 1);
-			intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
-		}
-	}
 
 	/* Calculate CRTC's total data rate from cached values */
 	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
@@ -3104,8 +3045,6 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 	struct drm_atomic_state *state = cstate->base.state;
 	struct drm_crtc *crtc = cstate->base.crtc;
 	struct drm_device *dev = crtc->dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	struct intel_wm_config *config = &dev_priv->wm.config;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	struct intel_plane *intel_plane;
 	struct drm_plane *plane;
@@ -3119,6 +3058,9 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 	int num_active;
 	int id, i;
 
+	if (WARN_ON(!state))
+		return 0;
+
 	if (!cstate->base.active) {
 		ddb->pipe[pipe].start = ddb->pipe[pipe].end = 0;
 		memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
@@ -3126,8 +3068,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 		return 0;
 	}
 
-	skl_ddb_get_pipe_allocation_limits(dev, cstate, config, alloc,
-					   &num_active);
+	skl_ddb_get_pipe_allocation_limits(dev, cstate, alloc, &num_active);
 	alloc_size = skl_ddb_entry_size(alloc);
 	if (alloc_size == 0) {
 		memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
@@ -3139,14 +3080,8 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 	ddb->plane[pipe][PLANE_CURSOR].end = alloc->end;
 
 	alloc_size -= cursor_blocks;
-	alloc->end -= cursor_blocks;
 
 	/* 1. Allocate the mininum required blocks for each active plane */
-	/*
-	 * TODO: Remove support for already-committed state once we
-	 * only allocate DDB on in-flight states.
-	 */
-	if (state) {
 	for_each_plane_in_state(state, plane, pstate, i) {
 		intel_plane = to_intel_plane(plane);
 		id = skl_wm_plane_id(intel_plane);
@@ -3171,22 +3106,6 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 		else
 			y_minimum[id] = 0;
 	}
-	} else {
-		for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
-			struct drm_plane *plane = &intel_plane->base;
-			struct drm_framebuffer *fb = plane->state->fb;
-			int id = skl_wm_plane_id(intel_plane);
-
-			if (!to_intel_plane_state(plane->state)->visible)
-				continue;
-
-			if (plane->type == DRM_PLANE_TYPE_CURSOR)
-				continue;
-
-			minimum[id] = 8;
-			y_minimum[id] = (fb->pixel_format == DRM_FORMAT_NV12) ? 8 : 0;
-		}
-	}
 
 	for (i = 0; i < PLANE_CURSOR; i++) {
 		alloc_size -= minimum[i];
@@ -3736,7 +3655,6 @@ static bool skl_update_pipe_wm(struct drm_crtc *crtc,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
 
-	WARN_ON(skl_allocate_pipe_ddb(cstate, ddb) != 0);
 	skl_build_pipe_wm(cstate, ddb, pipe_wm);
 
 	if (!memcmp(&intel_crtc->wm.active.skl, pipe_wm, sizeof(*pipe_wm)))
@@ -3800,16 +3718,6 @@ static void skl_clear_wm(struct skl_wm_values *watermarks, enum pipe pipe)
 	memset(watermarks->plane_trans[pipe],
 	       0, sizeof(uint32_t) * I915_MAX_PLANES);
 	watermarks->plane_trans[pipe][PLANE_CURSOR] = 0;
-
-	/* Clear ddb entries for pipe */
-	memset(&watermarks->ddb.pipe[pipe], 0, sizeof(struct skl_ddb_entry));
-	memset(&watermarks->ddb.plane[pipe], 0,
-	       sizeof(struct skl_ddb_entry) * I915_MAX_PLANES);
-	memset(&watermarks->ddb.y_plane[pipe], 0,
-	       sizeof(struct skl_ddb_entry) * I915_MAX_PLANES);
-	memset(&watermarks->ddb.plane[pipe][PLANE_CURSOR], 0,
-	       sizeof(struct skl_ddb_entry));
-
 }
 
 static int