drm/vbl rework: rework how the drm deals with vblank.

Other Authors: Michel Dänzer <michel@tungstengraphics.com>
mga: Ian Romanick <idr@us.ibm.com>
via: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>

This re-works the DRM internals to provide a better interface for drivers
to expose vblank on multiple crtcs.

It also includes work done by Michel on making i915 triple buffering and pageflipping work properly.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/char/drm/radeon_irq.c b/drivers/char/drm/radeon_irq.c
index 009af38..507d6b7 100644
--- a/drivers/char/drm/radeon_irq.c
+++ b/drivers/char/drm/radeon_irq.c
@@ -35,12 +35,61 @@
 #include "radeon_drm.h"
 #include "radeon_drv.h"
 
-static __inline__ u32 radeon_acknowledge_irqs(drm_radeon_private_t * dev_priv,
-					      u32 mask)
+static void radeon_irq_set_state(struct drm_device *dev, u32 mask, int state)
 {
-	u32 irqs = RADEON_READ(RADEON_GEN_INT_STATUS) & mask;
+	drm_radeon_private_t *dev_priv = dev->dev_private;
+
+	if (state)
+		dev_priv->irq_enable_reg |= mask;
+	else
+		dev_priv->irq_enable_reg &= ~mask;
+
+	RADEON_WRITE(RADEON_GEN_INT_CNTL, dev_priv->irq_enable_reg);
+}
+
+int radeon_enable_vblank(struct drm_device *dev, int crtc)
+{
+	switch (crtc) {
+	case 0:
+		radeon_irq_set_state(dev, RADEON_CRTC_VBLANK_MASK, 1);
+		break;
+	case 1:
+		radeon_irq_set_state(dev, RADEON_CRTC2_VBLANK_MASK, 1);
+		break;
+	default:
+		DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
+			  crtc);
+		return EINVAL;
+	}
+
+	return 0;
+}
+
+void radeon_disable_vblank(struct drm_device *dev, int crtc)
+{
+	switch (crtc) {
+	case 0:
+		radeon_irq_set_state(dev, RADEON_CRTC_VBLANK_MASK, 0);
+		break;
+	case 1:
+		radeon_irq_set_state(dev, RADEON_CRTC2_VBLANK_MASK, 0);
+		break;
+	default:
+		DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
+			  crtc);
+		break;
+	}
+}
+
+static __inline__ u32 radeon_acknowledge_irqs(drm_radeon_private_t * dev_priv)
+{
+	u32 irqs = RADEON_READ(RADEON_GEN_INT_STATUS) &
+		(RADEON_SW_INT_TEST | RADEON_CRTC_VBLANK_STAT |
+		 RADEON_CRTC2_VBLANK_STAT);
+
 	if (irqs)
 		RADEON_WRITE(RADEON_GEN_INT_STATUS, irqs);
+
 	return irqs;
 }
 
@@ -72,39 +121,21 @@
 	/* Only consider the bits we're interested in - others could be used
 	 * outside the DRM
 	 */
-	stat = radeon_acknowledge_irqs(dev_priv, (RADEON_SW_INT_TEST_ACK |
-						  RADEON_CRTC_VBLANK_STAT |
-						  RADEON_CRTC2_VBLANK_STAT));
+	stat = radeon_acknowledge_irqs(dev_priv);
 	if (!stat)
 		return IRQ_NONE;
 
 	stat &= dev_priv->irq_enable_reg;
 
 	/* SW interrupt */
-	if (stat & RADEON_SW_INT_TEST) {
+	if (stat & RADEON_SW_INT_TEST)
 		DRM_WAKEUP(&dev_priv->swi_queue);
-	}
 
 	/* VBLANK interrupt */
-	if (stat & (RADEON_CRTC_VBLANK_STAT|RADEON_CRTC2_VBLANK_STAT)) {
-		int vblank_crtc = dev_priv->vblank_crtc;
-
-		if ((vblank_crtc &
-		     (DRM_RADEON_VBLANK_CRTC1 | DRM_RADEON_VBLANK_CRTC2)) ==
-		    (DRM_RADEON_VBLANK_CRTC1 | DRM_RADEON_VBLANK_CRTC2)) {
-			if (stat & RADEON_CRTC_VBLANK_STAT)
-				atomic_inc(&dev->vbl_received);
-			if (stat & RADEON_CRTC2_VBLANK_STAT)
-				atomic_inc(&dev->vbl_received2);
-		} else if (((stat & RADEON_CRTC_VBLANK_STAT) &&
-			   (vblank_crtc & DRM_RADEON_VBLANK_CRTC1)) ||
-			   ((stat & RADEON_CRTC2_VBLANK_STAT) &&
-			    (vblank_crtc & DRM_RADEON_VBLANK_CRTC2)))
-			atomic_inc(&dev->vbl_received);
-
-		DRM_WAKEUP(&dev->vbl_queue);
-		drm_vbl_send_signals(dev);
-	}
+	if (stat & RADEON_CRTC_VBLANK_STAT)
+		drm_handle_vblank(dev, 0);
+	if (stat & RADEON_CRTC2_VBLANK_STAT)
+		drm_handle_vblank(dev, 1);
 
 	return IRQ_HANDLED;
 }
@@ -144,54 +175,27 @@
 	return ret;
 }
 
-static int radeon_driver_vblank_do_wait(struct drm_device * dev,
-					unsigned int *sequence, int crtc)
+u32 radeon_get_vblank_counter(struct drm_device *dev, int crtc)
 {
-	drm_radeon_private_t *dev_priv =
-	    (drm_radeon_private_t *) dev->dev_private;
-	unsigned int cur_vblank;
-	int ret = 0;
-	int ack = 0;
-	atomic_t *counter;
+	drm_radeon_private_t *dev_priv = dev->dev_private;
+	u32 crtc_cnt_reg, crtc_status_reg;
+
 	if (!dev_priv) {
 		DRM_ERROR("called with no initialization\n");
 		return -EINVAL;
 	}
 
-	if (crtc == DRM_RADEON_VBLANK_CRTC1) {
-		counter = &dev->vbl_received;
-		ack |= RADEON_CRTC_VBLANK_STAT;
-	} else if (crtc == DRM_RADEON_VBLANK_CRTC2) {
-		counter = &dev->vbl_received2;
-		ack |= RADEON_CRTC2_VBLANK_STAT;
-	} else
+	if (crtc == 0) {
+		crtc_cnt_reg = RADEON_CRTC_CRNT_FRAME;
+		crtc_status_reg = RADEON_CRTC_STATUS;
+	} else if (crtc == 1) {
+		crtc_cnt_reg = RADEON_CRTC2_CRNT_FRAME;
+		crtc_status_reg = RADEON_CRTC2_STATUS;
+	} else {
 		return -EINVAL;
+	}
 
-	radeon_acknowledge_irqs(dev_priv, ack);
-
-	dev_priv->stats.boxes |= RADEON_BOX_WAIT_IDLE;
-
-	/* Assume that the user has missed the current sequence number
-	 * by about a day rather than she wants to wait for years
-	 * using vertical blanks...
-	 */
-	DRM_WAIT_ON(ret, dev->vbl_queue, 3 * DRM_HZ,
-		    (((cur_vblank = atomic_read(counter))
-		      - *sequence) <= (1 << 23)));
-
-	*sequence = cur_vblank;
-
-	return ret;
-}
-
-int radeon_driver_vblank_wait(struct drm_device *dev, unsigned int *sequence)
-{
-	return radeon_driver_vblank_do_wait(dev, sequence, DRM_RADEON_VBLANK_CRTC1);
-}
-
-int radeon_driver_vblank_wait2(struct drm_device *dev, unsigned int *sequence)
-{
-	return radeon_driver_vblank_do_wait(dev, sequence, DRM_RADEON_VBLANK_CRTC2);
+	return RADEON_READ(crtc_cnt_reg) + (RADEON_READ(crtc_status_reg) & 1);
 }
 
 /* Needs the lock as it touches the ring.
@@ -234,21 +238,6 @@
 	return radeon_wait_irq(dev, irqwait->irq_seq);
 }
 
-static void radeon_enable_interrupt(struct drm_device *dev)
-{
-	drm_radeon_private_t *dev_priv = (drm_radeon_private_t *) dev->dev_private;
-
-	dev_priv->irq_enable_reg = RADEON_SW_INT_ENABLE;
-	if (dev_priv->vblank_crtc & DRM_RADEON_VBLANK_CRTC1)
-		dev_priv->irq_enable_reg |= RADEON_CRTC_VBLANK_MASK;
-
-	if (dev_priv->vblank_crtc & DRM_RADEON_VBLANK_CRTC2)
-		dev_priv->irq_enable_reg |= RADEON_CRTC2_VBLANK_MASK;
-
-	RADEON_WRITE(RADEON_GEN_INT_CNTL, dev_priv->irq_enable_reg);
-	dev_priv->irq_enabled = 1;
-}
-
 /* drm_dma.h hooks
 */
 void radeon_driver_irq_preinstall(struct drm_device * dev)
@@ -260,20 +249,27 @@
 	RADEON_WRITE(RADEON_GEN_INT_CNTL, 0);
 
 	/* Clear bits if they're already high */
-	radeon_acknowledge_irqs(dev_priv, (RADEON_SW_INT_TEST_ACK |
-					   RADEON_CRTC_VBLANK_STAT |
-					   RADEON_CRTC2_VBLANK_STAT));
+	radeon_acknowledge_irqs(dev_priv);
 }
 
-void radeon_driver_irq_postinstall(struct drm_device * dev)
+int radeon_driver_irq_postinstall(struct drm_device * dev)
 {
 	drm_radeon_private_t *dev_priv =
 	    (drm_radeon_private_t *) dev->dev_private;
+	int ret;
 
 	atomic_set(&dev_priv->swi_emitted, 0);
 	DRM_INIT_WAITQUEUE(&dev_priv->swi_queue);
 
-	radeon_enable_interrupt(dev);
+	ret = drm_vblank_init(dev, 2);
+	if (ret)
+		return ret;
+
+	dev->max_vblank_count = 0x001fffff;
+
+	radeon_irq_set_state(dev, RADEON_SW_INT_ENABLE, 1);
+
+	return 0;
 }
 
 void radeon_driver_irq_uninstall(struct drm_device * dev)
@@ -315,6 +311,5 @@
 		return -EINVAL;
 	}
 	dev_priv->vblank_crtc = (unsigned int)value;
-	radeon_enable_interrupt(dev);
 	return 0;
 }