drm/i915: Add enable/disable flip done and flip done handler

Add enable/disable flip done functions and the flip done handler
function which handles the flip done interrupt.

Enable the flip done interrupt in IER.

Enable flip done function is called before writing the
surface address register as the write to this register triggers
the flip done interrupt

Flip done handler is used to send the page flip event as soon as the
surface address is written as per the requirement of async flips.
The interrupt is disabled after the event is sent.

v2: -Change function name from icl_* to skl_* (Paulo)
    -Move flip handler to this patch (Paulo)
    -Remove vblank_put() (Paulo)
    -Enable flip done interrupt for gen9+ only (Paulo)
    -Enable flip done interrupt in power_well_post_enable hook (Paulo)
    -Removed the event check in flip done handler to handle async
     flips without pageflip events.

v3: -Move skl_disable_flip_done out of interrupt handler (Paulo)
    -Make the pending vblank event NULL in the beginning of
     flip_done_handler to remove sporadic WARN_ON that is seen.

v4: -Calculate timestamps using flip done time stamp and current
     timestamp for async flips (Ville)

v5: -Fix the sparse warning by making the function 'g4x_get_flip_counter'
     static.(Reported-by: kernel test robot <lkp@intel.com>)
    -Fix the typo in commit message.

v6: -Revert back to old time stamping code.
    -Remove the break while calling skl_enable_flip_done. (Paulo)

v7: -Rebased.

v8: -Rebased.

v9: -Use struct drm_i915_private *i915 in new code. (Ville)
    -Use intel_crtc instead of drm_crtc. (Ville)
    -Do not mix the flip done and vblank hooks. (Ville)

v10: -Rebased.
Signed-off-by: Karthik B S <karthik.b.s@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200921110210.21182-2-karthik.b.s@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -15613,6 +15613,11 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 
 	intel_dbuf_pre_plane_update(state);
 
+	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
+		if (new_crtc_state->uapi.async_flip)
+			skl_enable_flip_done(crtc);
+	}
+
 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
 	dev_priv->display.commit_modeset_enables(state);
 
@@ -15634,6 +15639,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	drm_atomic_helper_wait_for_flip_done(dev, &state->base);
 
 	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
+		if (new_crtc_state->uapi.async_flip)
+			skl_disable_flip_done(crtc);
+
 		if (new_crtc_state->hw.active &&
 		    !needs_modeset(new_crtc_state) &&
 		    !new_crtc_state->preload_luts &&

drivers/gpu/drm/i915/i915_irq.c

@@ -1245,6 +1245,23 @@ display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
 			     u32 crc4) {}
 #endif
 
+static void flip_done_handler(struct drm_i915_private *i915,
+			      enum pipe pipe)
+{
+	struct intel_crtc *crtc = intel_get_crtc_for_pipe(i915, pipe);
+	struct drm_crtc_state *crtc_state = crtc->base.state;
+	struct drm_pending_vblank_event *e = crtc_state->event;
+	struct drm_device *dev = &i915->drm;
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dev->event_lock, irqflags);
+
+	crtc_state->event = NULL;
+
+	drm_crtc_send_vblank_event(&crtc->base, e);
+
+	spin_unlock_irqrestore(&dev->event_lock, irqflags);
+}
 
 static void hsw_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
 				     enum pipe pipe)
@@ -2329,6 +2346,9 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 		if (iir & GEN8_PIPE_VBLANK)
 			intel_handle_vblank(dev_priv, pipe);
 
+		if (iir & GEN9_PIPE_PLANE1_FLIP_DONE)
+			flip_done_handler(dev_priv, pipe);
+
 		if (iir & GEN8_PIPE_CDCLK_CRC_DONE)
 			hsw_pipe_crc_irq_handler(dev_priv, pipe);
 
@@ -2650,6 +2670,19 @@ int bdw_enable_vblank(struct drm_crtc *crtc)
 	return 0;
 }
 
+void skl_enable_flip_done(struct intel_crtc *crtc)
+{
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&i915->irq_lock, irqflags);
+
+	bdw_enable_pipe_irq(i915, pipe, GEN9_PIPE_PLANE1_FLIP_DONE);
+
+	spin_unlock_irqrestore(&i915->irq_lock, irqflags);
+}
+
 /* Called from drm generic code, passed 'crtc' which
  * we use as a pipe index
  */
@@ -2710,6 +2743,19 @@ void bdw_disable_vblank(struct drm_crtc *crtc)
 	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
 }
 
+void skl_disable_flip_done(struct intel_crtc *crtc)
+{
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	enum pipe pipe = crtc->pipe;
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&i915->irq_lock, irqflags);
+
+	bdw_disable_pipe_irq(i915, pipe, GEN9_PIPE_PLANE1_FLIP_DONE);
+
+	spin_unlock_irqrestore(&i915->irq_lock, irqflags);
+}
+
 static void ibx_irq_reset(struct drm_i915_private *dev_priv)
 {
 	struct intel_uncore *uncore = &dev_priv->uncore;
@@ -2920,6 +2966,9 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv,
 	u32 extra_ier = GEN8_PIPE_VBLANK | GEN8_PIPE_FIFO_UNDERRUN;
 	enum pipe pipe;
 
+	if (INTEL_GEN(dev_priv) >= 9)
+		extra_ier |= GEN9_PIPE_PLANE1_FLIP_DONE;
+
 	spin_lock_irq(&dev_priv->irq_lock);
 
 	if (!intel_irqs_enabled(dev_priv)) {
@@ -3403,6 +3452,9 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 	de_pipe_enables = de_pipe_masked | GEN8_PIPE_VBLANK |
 					   GEN8_PIPE_FIFO_UNDERRUN;
 
+	if (INTEL_GEN(dev_priv) >= 9)
+		de_pipe_enables |= GEN9_PIPE_PLANE1_FLIP_DONE;
+
 	de_port_enables = de_port_masked;
 	if (IS_GEN9_LP(dev_priv))
 		de_port_enables |= BXT_DE_PORT_HOTPLUG_MASK;

drivers/gpu/drm/i915/i915_irq.h

@@ -118,6 +118,9 @@ void i965_disable_vblank(struct drm_crtc *crtc);
 void ilk_disable_vblank(struct drm_crtc *crtc);
 void bdw_disable_vblank(struct drm_crtc *crtc);
 
+void skl_enable_flip_done(struct intel_crtc *crtc);
+void skl_disable_flip_done(struct intel_crtc *crtc);
+
 void gen2_irq_reset(struct intel_uncore *uncore);
 void gen3_irq_reset(struct intel_uncore *uncore, i915_reg_t imr,
 		    i915_reg_t iir, i915_reg_t ier);