drm/i915: Rip out legacy page_flip completion/irq handling

All these races and things are now solved through the vblank evasion
trick, plus event handling is done using normal vblank even processing
and drm_crtc_arm_vblank_event. We can get rid of all this complexity.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170720175754.30751-5-daniel.vetter@ffwll.ch

drivers/gpu/drm/i915/i915_irq.c

@@ -1708,18 +1708,6 @@ static void gen9_guc_irq_handler(struct drm_i915_private *dev_priv, u32 gt_iir)
 	}
 }
 
-static bool intel_pipe_handle_vblank(struct drm_i915_private *dev_priv,
-				     enum pipe pipe)
-{
-	bool ret;
-
-	ret = drm_handle_vblank(&dev_priv->drm, pipe);
-	if (ret)
-		intel_finish_page_flip_mmio(dev_priv, pipe);
-
-	return ret;
-}
-
 static void valleyview_pipestat_irq_ack(struct drm_i915_private *dev_priv,
 					u32 iir, u32 pipe_stats[I915_MAX_PIPES])
 {
@@ -1784,12 +1772,8 @@ static void valleyview_pipestat_irq_handler(struct drm_i915_private *dev_priv,
 	enum pipe pipe;
 
 	for_each_pipe(dev_priv, pipe) {
-		if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS &&
-		    intel_pipe_handle_vblank(dev_priv, pipe))
-			intel_check_page_flip(dev_priv, pipe);
-
-		if (pipe_stats[pipe] & PLANE_FLIP_DONE_INT_STATUS_VLV)
-			intel_finish_page_flip_cs(dev_priv, pipe);
+		if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS)
+			drm_handle_vblank(&dev_priv->drm, pipe);
 
 		if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
 			i9xx_pipe_crc_irq_handler(dev_priv, pipe);
@@ -2241,19 +2225,14 @@ static void ilk_display_irq_handler(struct drm_i915_private *dev_priv,
 		DRM_ERROR("Poison interrupt\n");
 
 	for_each_pipe(dev_priv, pipe) {
-		if (de_iir & DE_PIPE_VBLANK(pipe) &&
-		    intel_pipe_handle_vblank(dev_priv, pipe))
-			intel_check_page_flip(dev_priv, pipe);
+		if (de_iir & DE_PIPE_VBLANK(pipe))
+			drm_handle_vblank(&dev_priv->drm, pipe);
 
 		if (de_iir & DE_PIPE_FIFO_UNDERRUN(pipe))
 			intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
 
 		if (de_iir & DE_PIPE_CRC_DONE(pipe))
 			i9xx_pipe_crc_irq_handler(dev_priv, pipe);
-
-		/* plane/pipes map 1:1 on ilk+ */
-		if (de_iir & DE_PLANE_FLIP_DONE(pipe))
-			intel_finish_page_flip_cs(dev_priv, pipe);
 	}
 
 	/* check event from PCH */
@@ -2292,13 +2271,8 @@ static void ivb_display_irq_handler(struct drm_i915_private *dev_priv,
 		intel_opregion_asle_intr(dev_priv);
 
 	for_each_pipe(dev_priv, pipe) {
-		if (de_iir & (DE_PIPE_VBLANK_IVB(pipe)) &&
-		    intel_pipe_handle_vblank(dev_priv, pipe))
-			intel_check_page_flip(dev_priv, pipe);
-
-		/* plane/pipes map 1:1 on ilk+ */
-		if (de_iir & DE_PLANE_FLIP_DONE_IVB(pipe))
-			intel_finish_page_flip_cs(dev_priv, pipe);
+		if (de_iir & (DE_PIPE_VBLANK_IVB(pipe)))
+			drm_handle_vblank(&dev_priv->drm, pipe);
 	}
 
 	/* check event from PCH */
@@ -2479,7 +2453,7 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 	}
 
 	for_each_pipe(dev_priv, pipe) {
-		u32 flip_done, fault_errors;
+		u32 fault_errors;
 
 		if (!(master_ctl & GEN8_DE_PIPE_IRQ(pipe)))
 			continue;
@@ -2493,18 +2467,8 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
 		ret = IRQ_HANDLED;
 		I915_WRITE(GEN8_DE_PIPE_IIR(pipe), iir);
 
-		if (iir & GEN8_PIPE_VBLANK &&
-		    intel_pipe_handle_vblank(dev_priv, pipe))
-			intel_check_page_flip(dev_priv, pipe);
-
-		flip_done = iir;
-		if (INTEL_GEN(dev_priv) >= 9)
-			flip_done &= GEN9_PIPE_PLANE1_FLIP_DONE;
-		else
-			flip_done &= GEN8_PIPE_PRIMARY_FLIP_DONE;
-
-		if (flip_done)
-			intel_finish_page_flip_cs(dev_priv, pipe);
+		if (iir & GEN8_PIPE_VBLANK)
+			drm_handle_vblank(&dev_priv->drm, pipe);
 
 		if (iir & GEN8_PIPE_CDCLK_CRC_DONE)
 			hsw_pipe_crc_irq_handler(dev_priv, pipe);
@@ -3675,34 +3639,6 @@ static int i8xx_irq_postinstall(struct drm_device *dev)
 /*
  * Returns true when a page flip has completed.
  */
-static bool i8xx_handle_vblank(struct drm_i915_private *dev_priv,
-			       int plane, int pipe, u32 iir)
-{
-	u16 flip_pending = DISPLAY_PLANE_FLIP_PENDING(plane);
-
-	if (!intel_pipe_handle_vblank(dev_priv, pipe))
-		return false;
-
-	if ((iir & flip_pending) == 0)
-		goto check_page_flip;
-
-	/* We detect FlipDone by looking for the change in PendingFlip from '1'
-	 * to '0' on the following vblank, i.e. IIR has the Pendingflip
-	 * asserted following the MI_DISPLAY_FLIP, but ISR is deasserted, hence
-	 * the flip is completed (no longer pending). Since this doesn't raise
-	 * an interrupt per se, we watch for the change at vblank.
-	 */
-	if (I915_READ16(ISR) & flip_pending)
-		goto check_page_flip;
-
-	intel_finish_page_flip_cs(dev_priv, pipe);
-	return true;
-
-check_page_flip:
-	intel_check_page_flip(dev_priv, pipe);
-	return false;
-}
-
 static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 {
 	struct drm_device *dev = arg;
@@ -3710,9 +3646,6 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 	u16 iir, new_iir;
 	u32 pipe_stats[2];
 	int pipe;
-	u16 flip_mask =
-		I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
-		I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
 	irqreturn_t ret;
 
 	if (!intel_irqs_enabled(dev_priv))
@@ -3726,7 +3659,7 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 	if (iir == 0)
 		goto out;
 
-	while (iir & ~flip_mask) {
+	while (iir) {
 		/* Can't rely on pipestat interrupt bit in iir as it might
 		 * have been cleared after the pipestat interrupt was received.
 		 * It doesn't set the bit in iir again, but it still produces
@@ -3748,7 +3681,7 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 		}
 		spin_unlock(&dev_priv->irq_lock);
 
-		I915_WRITE16(IIR, iir & ~flip_mask);
+		I915_WRITE16(IIR, iir);
 		new_iir = I915_READ16(IIR); /* Flush posted writes */
 
 		if (iir & I915_USER_INTERRUPT)
@@ -3759,9 +3692,8 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 			if (HAS_FBC(dev_priv))
 				plane = !plane;
 
-			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS &&
-			    i8xx_handle_vblank(dev_priv, plane, pipe, iir))
-				flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(plane);
+			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS)
+				drm_handle_vblank(&dev_priv->drm, pipe);
 
 			if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
 				i9xx_pipe_crc_irq_handler(dev_priv, pipe);
@@ -3861,45 +3793,11 @@ static int i915_irq_postinstall(struct drm_device *dev)
 	return 0;
 }
 
-/*
- * Returns true when a page flip has completed.
- */
-static bool i915_handle_vblank(struct drm_i915_private *dev_priv,
-			       int plane, int pipe, u32 iir)
-{
-	u32 flip_pending = DISPLAY_PLANE_FLIP_PENDING(plane);
-
-	if (!intel_pipe_handle_vblank(dev_priv, pipe))
-		return false;
-
-	if ((iir & flip_pending) == 0)
-		goto check_page_flip;
-
-	/* We detect FlipDone by looking for the change in PendingFlip from '1'
-	 * to '0' on the following vblank, i.e. IIR has the Pendingflip
-	 * asserted following the MI_DISPLAY_FLIP, but ISR is deasserted, hence
-	 * the flip is completed (no longer pending). Since this doesn't raise
-	 * an interrupt per se, we watch for the change at vblank.
-	 */
-	if (I915_READ(ISR) & flip_pending)
-		goto check_page_flip;
-
-	intel_finish_page_flip_cs(dev_priv, pipe);
-	return true;
-
-check_page_flip:
-	intel_check_page_flip(dev_priv, pipe);
-	return false;
-}
-
 static irqreturn_t i915_irq_handler(int irq, void *arg)
 {
 	struct drm_device *dev = arg;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	u32 iir, new_iir, pipe_stats[I915_MAX_PIPES];
-	u32 flip_mask =
-		I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
-		I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
 	int pipe, ret = IRQ_NONE;
 
 	if (!intel_irqs_enabled(dev_priv))
@@ -3910,7 +3808,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
 
 	iir = I915_READ(IIR);
 	do {
-		bool irq_received = (iir & ~flip_mask) != 0;
+		bool irq_received = (iir) != 0;
 		bool blc_event = false;
 
 		/* Can't rely on pipestat interrupt bit in iir as it might
@@ -3945,7 +3843,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
 				i9xx_hpd_irq_handler(dev_priv, hotplug_status);
 		}
 
-		I915_WRITE(IIR, iir & ~flip_mask);
+		I915_WRITE(IIR, iir);
 		new_iir = I915_READ(IIR); /* Flush posted writes */
 
 		if (iir & I915_USER_INTERRUPT)
@@ -3956,9 +3854,8 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
 			if (HAS_FBC(dev_priv))
 				plane = !plane;
 
-			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS &&
-			    i915_handle_vblank(dev_priv, plane, pipe, iir))
-				flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(plane);
+			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS)
+				drm_handle_vblank(&dev_priv->drm, pipe);
 
 			if (pipe_stats[pipe] & PIPE_LEGACY_BLC_EVENT_STATUS)
 				blc_event = true;
@@ -3991,7 +3888,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
 		 */
 		ret = IRQ_HANDLED;
 		iir = new_iir;
-	} while (iir & ~flip_mask);
+	} while (iir);
 
 	enable_rpm_wakeref_asserts(dev_priv);
 
@@ -4126,9 +4023,6 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
 	u32 iir, new_iir;
 	u32 pipe_stats[I915_MAX_PIPES];
 	int ret = IRQ_NONE, pipe;
-	u32 flip_mask =
-		I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
-		I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
 
 	if (!intel_irqs_enabled(dev_priv))
 		return IRQ_NONE;
@@ -4139,7 +4033,7 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
 	iir = I915_READ(IIR);
 
 	for (;;) {
-		bool irq_received = (iir & ~flip_mask) != 0;
+		bool irq_received = (iir) != 0;
 		bool blc_event = false;
 
 		/* Can't rely on pipestat interrupt bit in iir as it might
@@ -4177,7 +4071,7 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
 				i9xx_hpd_irq_handler(dev_priv, hotplug_status);
 		}
 
-		I915_WRITE(IIR, iir & ~flip_mask);
+		I915_WRITE(IIR, iir);
 		new_iir = I915_READ(IIR); /* Flush posted writes */
 
 		if (iir & I915_USER_INTERRUPT)
@@ -4186,9 +4080,8 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
 			notify_ring(dev_priv->engine[VCS]);
 
 		for_each_pipe(dev_priv, pipe) {
-			if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS &&
-			    i915_handle_vblank(dev_priv, pipe, pipe, iir))
-				flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(pipe);
+			if (pipe_stats[pipe] & PIPE_START_VBLANK_INTERRUPT_STATUS)
+				drm_handle_vblank(&dev_priv->drm, pipe);
 
 			if (pipe_stats[pipe] & PIPE_LEGACY_BLC_EVENT_STATUS)
 				blc_event = true;

drivers/gpu/drm/i915/intel_display.c

@@ -3405,14 +3405,6 @@ static void skylake_disable_primary_plane(struct intel_plane *primary,
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
-static void intel_complete_page_flips(struct drm_i915_private *dev_priv)
-{
-	struct intel_crtc *crtc;
-
-	for_each_intel_crtc(&dev_priv->drm, crtc)
-		intel_finish_page_flip_cs(dev_priv, crtc->pipe);
-}
-
 static int
 __intel_display_resume(struct drm_device *dev,
 		       struct drm_atomic_state *state,
@@ -3521,13 +3513,6 @@ void intel_finish_reset(struct drm_i915_private *dev_priv)
 	if (!state)
 		goto unlock;
 
-	/*
-	 * Flips in the rings will be nuked by the reset,
-	 * so complete all pending flips so that user space
-	 * will get its events and not get stuck.
-	 */
-	intel_complete_page_flips(dev_priv);
-
 	dev_priv->modeset_restore_state = NULL;
 
 	/* reset doesn't touch the display */
@@ -10121,140 +10106,6 @@ static void intel_crtc_destroy(struct drm_crtc *crtc)
 	kfree(intel_crtc);
 }
 
-/* Is 'a' after or equal to 'b'? */
-static bool g4x_flip_count_after_eq(u32 a, u32 b)
-{
-	return !((a - b) & 0x80000000);
-}
-
-static bool __pageflip_finished_cs(struct intel_crtc *crtc,
-				   struct intel_flip_work *work)
-{
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
-
-	if (abort_flip_on_reset(crtc))
-		return true;
-
-	/*
-	 * The relevant registers doen't exist on pre-ctg.
-	 * As the flip done interrupt doesn't trigger for mmio
-	 * flips on gmch platforms, a flip count check isn't
-	 * really needed there. But since ctg has the registers,
-	 * include it in the check anyway.
-	 */
-	if (INTEL_GEN(dev_priv) < 5 && !IS_G4X(dev_priv))
-		return true;
-
-	/*
-	 * BDW signals flip done immediately if the plane
-	 * is disabled, even if the plane enable is already
-	 * armed to occur at the next vblank :(
-	 */
-
-	/*
-	 * A DSPSURFLIVE check isn't enough in case the mmio and CS flips
-	 * used the same base address. In that case the mmio flip might
-	 * have completed, but the CS hasn't even executed the flip yet.
-	 *
-	 * A flip count check isn't enough as the CS might have updated
-	 * the base address just after start of vblank, but before we
-	 * managed to process the interrupt. This means we'd complete the
-	 * CS flip too soon.
-	 *
-	 * Combining both checks should get us a good enough result. It may
-	 * still happen that the CS flip has been executed, but has not
-	 * yet actually completed. But in case the base address is the same
-	 * anyway, we don't really care.
-	 */
-	return (I915_READ(DSPSURFLIVE(crtc->plane)) & ~0xfff) ==
-		crtc->flip_work->gtt_offset &&
-		g4x_flip_count_after_eq(I915_READ(PIPE_FLIPCOUNT_G4X(crtc->pipe)),
-				    crtc->flip_work->flip_count);
-}
-
-static bool
-__pageflip_finished_mmio(struct intel_crtc *crtc,
-			       struct intel_flip_work *work)
-{
-	/*
-	 * MMIO work completes when vblank is different from
-	 * flip_queued_vblank.
-	 *
-	 * Reset counter value doesn't matter, this is handled by
-	 * i915_wait_request finishing early, so no need to handle
-	 * reset here.
-	 */
-	return intel_crtc_get_vblank_counter(crtc) != work->flip_queued_vblank;
-}
-
-
-static bool pageflip_finished(struct intel_crtc *crtc,
-			      struct intel_flip_work *work)
-{
-	if (!atomic_read(&work->pending))
-		return false;
-
-	smp_rmb();
-
-	if (is_mmio_work(work))
-		return __pageflip_finished_mmio(crtc, work);
-	else
-		return __pageflip_finished_cs(crtc, work);
-}
-
-void intel_finish_page_flip_cs(struct drm_i915_private *dev_priv, int pipe)
-{
-	struct drm_device *dev = &dev_priv->drm;
-	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
-	struct intel_flip_work *work;
-	unsigned long flags;
-
-	/* Ignore early vblank irqs */
-	if (!crtc)
-		return;
-
-	/*
-	 * This is called both by irq handlers and the reset code (to complete
-	 * lost pageflips) so needs the full irqsave spinlocks.
-	 */
-	spin_lock_irqsave(&dev->event_lock, flags);
-	work = crtc->flip_work;
-
-	if (work != NULL &&
-	    !is_mmio_work(work) &&
-	    pageflip_finished(crtc, work))
-		page_flip_completed(crtc);
-
-	spin_unlock_irqrestore(&dev->event_lock, flags);
-}
-
-void intel_finish_page_flip_mmio(struct drm_i915_private *dev_priv, int pipe)
-{
-	struct drm_device *dev = &dev_priv->drm;
-	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
-	struct intel_flip_work *work;
-	unsigned long flags;
-
-	/* Ignore early vblank irqs */
-	if (!crtc)
-		return;
-
-	/*
-	 * This is called both by irq handlers and the reset code (to complete
-	 * lost pageflips) so needs the full irqsave spinlocks.
-	 */
-	spin_lock_irqsave(&dev->event_lock, flags);
-	work = crtc->flip_work;
-
-	if (work != NULL &&
-	    is_mmio_work(work) &&
-	    pageflip_finished(crtc, work))
-		page_flip_completed(crtc);
-
-	spin_unlock_irqrestore(&dev->event_lock, flags);
-}
-
 static inline void intel_mark_page_flip_active(struct intel_crtc *crtc,
 					       struct intel_flip_work *work)
 {
@@ -10265,72 +10116,6 @@ static inline void intel_mark_page_flip_active(struct intel_crtc *crtc,
 	atomic_set(&work->pending, 1);
 }
 
-static bool __pageflip_stall_check_cs(struct drm_i915_private *dev_priv,
-				      struct intel_crtc *intel_crtc,
-				      struct intel_flip_work *work)
-{
-	u32 addr, vblank;
-
-	if (!atomic_read(&work->pending))
-		return false;
-
-	smp_rmb();
-
-	vblank = intel_crtc_get_vblank_counter(intel_crtc);
-	if (work->flip_ready_vblank == 0) {
-		if (work->flip_queued_req &&
-		    !i915_gem_request_completed(work->flip_queued_req))
-			return false;
-
-		work->flip_ready_vblank = vblank;
-	}
-
-	if (vblank - work->flip_ready_vblank < 3)
-		return false;
-
-	/* Potential stall - if we see that the flip has happened,
-	 * assume a missed interrupt. */
-	if (INTEL_GEN(dev_priv) >= 4)
-		addr = I915_HI_DISPBASE(I915_READ(DSPSURF(intel_crtc->plane)));
-	else
-		addr = I915_READ(DSPADDR(intel_crtc->plane));
-
-	/* There is a potential issue here with a false positive after a flip
-	 * to the same address. We could address this by checking for a
-	 * non-incrementing frame counter.
-	 */
-	return addr == work->gtt_offset;
-}
-
-void intel_check_page_flip(struct drm_i915_private *dev_priv, int pipe)
-{
-	struct drm_device *dev = &dev_priv->drm;
-	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
-	struct intel_flip_work *work;
-
-	WARN_ON(!in_interrupt());
-
-	if (crtc == NULL)
-		return;
-
-	spin_lock(&dev->event_lock);
-	work = crtc->flip_work;
-
-	if (work != NULL && !is_mmio_work(work) &&
-	    __pageflip_stall_check_cs(dev_priv, crtc, work)) {
-		WARN_ONCE(1,
-			  "Kicking stuck page flip: queued at %d, now %d\n",
-			work->flip_queued_vblank, intel_crtc_get_vblank_counter(crtc));
-		page_flip_completed(crtc);
-		work = NULL;
-	}
-
-	if (work != NULL && !is_mmio_work(work) &&
-	    intel_crtc_get_vblank_counter(crtc) - work->flip_queued_vblank > 1)
-		intel_queue_rps_boost_for_request(work->flip_queued_req);
-	spin_unlock(&dev->event_lock);
-}
-
 /**
  * intel_wm_need_update - Check whether watermarks need updating
  * @plane: drm plane

drivers/gpu/drm/i915/intel_drv.h

@@ -1408,9 +1408,6 @@ void intel_unpin_fb_vma(struct i915_vma *vma);
 struct drm_framebuffer *
 intel_framebuffer_create(struct drm_i915_gem_object *obj,
 			 struct drm_mode_fb_cmd2 *mode_cmd);
-void intel_finish_page_flip_cs(struct drm_i915_private *dev_priv, int pipe);
-void intel_finish_page_flip_mmio(struct drm_i915_private *dev_priv, int pipe);
-void intel_check_page_flip(struct drm_i915_private *dev_priv, int pipe);
 int intel_prepare_plane_fb(struct drm_plane *plane,
 			   struct drm_plane_state *new_state);
 void intel_cleanup_plane_fb(struct drm_plane *plane,