drm/i915: Add an atomic evasion step to watermark programming, v4.

Allow the driver to write watermarks during atomic evasion.
This will make it possible to write the watermarks in a cleaner
way on gen9+.

intel_atomic_state is not used here yet, but will be used when
we program all watermarks as a separate step during evasion.

This also writes linetime all the time, while before it was only
done during plane updates. This looks like this could be a bugfix,
but I'm not sure what it affects.

Changes since v1:
- Add comment about atomic evasion to commit message.
- Unwrap I915_WRITE call. (Lyude)
Changes since v2:
- Rename atomic_evade_watermarks to atomic_update_watermarks. (Ville)
- Add line wraps where appropriate, fix grammar in commit message. (Matt)
Changes since v3:
- Actually fix commit message. (Matt)
- Line wrap calls to watermark update functions. (Matt)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478609742-13603-2-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -474,6 +474,7 @@ struct sdvo_device_mapping {
 
 struct intel_connector;
 struct intel_encoder;
+struct intel_atomic_state;
 struct intel_crtc_state;
 struct intel_initial_plane_config;
 struct intel_crtc;
@@ -487,8 +488,12 @@ struct drm_i915_display_funcs {
 	int (*compute_intermediate_wm)(struct drm_device *dev,
 				       struct intel_crtc *intel_crtc,
 				       struct intel_crtc_state *newstate);
-	void (*initial_watermarks)(struct intel_crtc_state *cstate);
-	void (*optimize_watermarks)(struct intel_crtc_state *cstate);
+	void (*initial_watermarks)(struct intel_atomic_state *state,
+				   struct intel_crtc_state *cstate);
+	void (*atomic_update_watermarks)(struct intel_atomic_state *state,
+					 struct intel_crtc_state *cstate);
+	void (*optimize_watermarks)(struct intel_atomic_state *state,
+				    struct intel_crtc_state *cstate);
 	int (*compute_global_watermarks)(struct drm_atomic_state *state);
 	void (*update_wm)(struct intel_crtc *crtc);
 	int (*modeset_calc_cdclk)(struct drm_atomic_state *state);

drivers/gpu/drm/i915/intel_display.c

@@ -5111,6 +5111,8 @@ static void intel_pre_plane_update(struct intel_crtc_state *old_crtc_state)
 	struct drm_plane_state *old_pri_state =
 		drm_atomic_get_existing_plane_state(old_state, primary);
 	bool modeset = needs_modeset(&pipe_config->base);
+	struct intel_atomic_state *old_intel_state =
+		to_intel_atomic_state(old_state);
 
 	if (old_pri_state) {
 		struct intel_plane_state *primary_state =
@@ -5178,7 +5180,8 @@ static void intel_pre_plane_update(struct intel_crtc_state *old_crtc_state)
 	 * us to.
 	 */
 	if (dev_priv->display.initial_watermarks != NULL)
-		dev_priv->display.initial_watermarks(pipe_config);
+		dev_priv->display.initial_watermarks(old_intel_state,
+						     pipe_config);
 	else if (pipe_config->update_wm_pre)
 		intel_update_watermarks(crtc);
 }
@@ -5334,6 +5337,8 @@ static void ironlake_crtc_enable(struct intel_crtc_state *pipe_config,
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
+	struct intel_atomic_state *old_intel_state =
+		to_intel_atomic_state(old_state);
 
 	if (WARN_ON(intel_crtc->active))
 		return;
@@ -5392,7 +5397,7 @@ static void ironlake_crtc_enable(struct intel_crtc_state *pipe_config,
 	intel_color_load_luts(&pipe_config->base);
 
 	if (dev_priv->display.initial_watermarks != NULL)
-		dev_priv->display.initial_watermarks(intel_crtc->config);
+		dev_priv->display.initial_watermarks(old_intel_state, intel_crtc->config);
 	intel_enable_pipe(intel_crtc);
 
 	if (intel_crtc->config->has_pch_encoder)
@@ -5428,6 +5433,8 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe, hsw_workaround_pipe;
 	enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
+	struct intel_atomic_state *old_intel_state =
+		to_intel_atomic_state(old_state);
 
 	if (WARN_ON(intel_crtc->active))
 		return;
@@ -5498,7 +5505,8 @@ static void haswell_crtc_enable(struct intel_crtc_state *pipe_config,
 		intel_ddi_enable_transcoder_func(crtc);
 
 	if (dev_priv->display.initial_watermarks != NULL)
-		dev_priv->display.initial_watermarks(pipe_config);
+		dev_priv->display.initial_watermarks(old_intel_state,
+						     pipe_config);
 	else
 		intel_update_watermarks(intel_crtc);
 
@@ -14484,7 +14492,8 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 		intel_cstate = to_intel_crtc_state(crtc->state);
 
 		if (dev_priv->display.optimize_watermarks)
-			dev_priv->display.optimize_watermarks(intel_cstate);
+			dev_priv->display.optimize_watermarks(intel_state,
+							      intel_cstate);
 	}
 
 	for_each_crtc_in_state(state, crtc, old_crtc_state, i) {
@@ -14927,10 +14936,11 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	struct intel_crtc_state *intel_cstate =
 		to_intel_crtc_state(crtc->state);
-	struct intel_crtc_state *old_intel_state =
+	struct intel_crtc_state *old_intel_cstate =
 		to_intel_crtc_state(old_crtc_state);
+	struct intel_atomic_state *old_intel_state =
+		to_intel_atomic_state(old_crtc_state->state);
 	bool modeset = needs_modeset(crtc->state);
-	enum pipe pipe = intel_crtc->pipe;
 
 	/* Perform vblank evasion around commit operation */
 	intel_pipe_update_start(intel_crtc);
@@ -14943,14 +14953,14 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
 		intel_color_load_luts(crtc->state);
 	}
 
-	if (intel_cstate->update_pipe) {
-		intel_update_pipe_config(intel_crtc, old_intel_state);
-	} else if (INTEL_GEN(dev_priv) >= 9) {
+	if (intel_cstate->update_pipe)
+		intel_update_pipe_config(intel_crtc, old_intel_cstate);
+	else if (INTEL_GEN(dev_priv) >= 9)
 		skl_detach_scalers(intel_crtc);
 
-		I915_WRITE(PIPE_WM_LINETIME(pipe),
-			   intel_cstate->wm.skl.optimal.linetime);
-	}
+	if (dev_priv->display.atomic_update_watermarks)
+		dev_priv->display.atomic_update_watermarks(old_intel_state,
+							   intel_cstate);
 }
 
 static void intel_finish_crtc_commit(struct drm_crtc *crtc,
@@ -16373,6 +16383,7 @@ static void sanitize_watermarks(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_atomic_state *state;
+	struct intel_atomic_state *intel_state;
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *cstate;
 	struct drm_modeset_acquire_ctx ctx;
@@ -16401,12 +16412,14 @@ retry:
 	if (WARN_ON(IS_ERR(state)))
 		goto fail;
 
+	intel_state = to_intel_atomic_state(state);
+
 	/*
 	 * Hardware readout is the only time we don't want to calculate
 	 * intermediate watermarks (since we don't trust the current
 	 * watermarks).
 	 */
-	to_intel_atomic_state(state)->skip_intermediate_wm = true;
+	intel_state->skip_intermediate_wm = true;
 
 	ret = intel_atomic_check(dev, state);
 	if (ret) {
@@ -16430,7 +16443,7 @@ retry:
 		struct intel_crtc_state *cs = to_intel_crtc_state(cstate);
 
 		cs->wm.need_postvbl_update = true;
-		dev_priv->display.optimize_watermarks(cs);
+		dev_priv->display.optimize_watermarks(intel_state, cs);
 	}
 
 put_state:

drivers/gpu/drm/i915/intel_pm.c

@@ -4196,6 +4196,17 @@ skl_compute_wm(struct drm_atomic_state *state)
 	return 0;
 }
 
+static void skl_atomic_update_crtc_wm(struct intel_atomic_state *state,
+				      struct intel_crtc_state *cstate)
+{
+	struct intel_crtc *crtc = to_intel_crtc(cstate->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct skl_pipe_wm *pipe_wm = &cstate->wm.skl.optimal;
+	enum pipe pipe = crtc->pipe;
+
+	I915_WRITE(PIPE_WM_LINETIME(pipe), pipe_wm->linetime);
+}
+
 static void skl_update_wm(struct intel_crtc *intel_crtc)
 {
 	struct drm_device *dev = intel_crtc->base.dev;
@@ -4286,7 +4297,8 @@ static void ilk_program_watermarks(struct drm_i915_private *dev_priv)
 	ilk_write_wm_values(dev_priv, &results);
 }
 
-static void ilk_initial_watermarks(struct intel_crtc_state *cstate)
+static void ilk_initial_watermarks(struct intel_atomic_state *state,
+				   struct intel_crtc_state *cstate)
 {
 	struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
 	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
@@ -4297,7 +4309,8 @@ static void ilk_initial_watermarks(struct intel_crtc_state *cstate)
 	mutex_unlock(&dev_priv->wm.wm_mutex);
 }
 
-static void ilk_optimize_watermarks(struct intel_crtc_state *cstate)
+static void ilk_optimize_watermarks(struct intel_atomic_state *state,
+				    struct intel_crtc_state *cstate)
 {
 	struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
 	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
@@ -7694,6 +7707,7 @@ void intel_init_pm(struct drm_i915_private *dev_priv)
 	if (INTEL_GEN(dev_priv) >= 9) {
 		skl_setup_wm_latency(dev_priv);
 		dev_priv->display.update_wm = skl_update_wm;
+		dev_priv->display.atomic_update_watermarks = skl_atomic_update_crtc_wm;
 		dev_priv->display.compute_global_watermarks = skl_compute_wm;
 	} else if (HAS_PCH_SPLIT(dev_priv)) {
 		ilk_setup_wm_latency(dev_priv);