drm/i915: ring irq cleanups

- gen6 put/get only need one argument
    rflags and gflags are always the same (see above explanation)
- remove a couple redundantly defined IRQs
- reordered some lines to make things go in descending order

Every ring has its own interrupts, enables, masks, and status bits that
are fed into the main interrupt enable/mask/status registers. At one
point in time it seemed like a good idea to make our functions support
the notion that each interrupt may have a different bit position in the
corresponding register (blitter parser error may be bit n in IMR, but
bit m in blitter IMR). It turned out though that the HW designers did us
a solid on Gen6+ and this unfortunate situation has been avoided. This
allows our interrupt code to be cleaned up a bit.

I jammed this into one commit because there should be no functional
change with this commit, and staging it into multiple commits was
unnecessarily artificial IMO.

CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet:
- fixed up merged conflict with vlv changes.
- added GEN6 to GT blitter bit, we only use it on gen6+.
- added a comment to both ring irq bits and GT irq bits that on gen6+
  these alias.
- added comment that GT_BSD_USER_INTERRUPT is ilk-only.
- I've got confused a bit that we still use GT_USER_INTERRUPT on ivb
  for the render ring - but this goes back to ilk where we have only
  gt interrupt bits and so we be equally confusing if changed.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -462,7 +462,7 @@ static irqreturn_t valleyview_irq_handler(DRM_IRQ_ARGS)
 			notify_ring(dev, &dev_priv->ring[RCS]);
 		if (gt_iir & GT_GEN6_BSD_USER_INTERRUPT)
 			notify_ring(dev, &dev_priv->ring[VCS]);
-		if (gt_iir & GT_BLT_USER_INTERRUPT)
+		if (gt_iir & GT_GEN6_BLT_USER_INTERRUPT)
 			notify_ring(dev, &dev_priv->ring[BCS]);
 
 		if (gt_iir & (GT_GEN6_BLT_CS_ERROR_INTERRUPT |
@@ -620,9 +620,9 @@ static irqreturn_t ivybridge_irq_handler(DRM_IRQ_ARGS)
 
 	if (gt_iir & (GT_USER_INTERRUPT | GT_PIPE_NOTIFY))
 		notify_ring(dev, &dev_priv->ring[RCS]);
-	if (gt_iir & GT_GEN6_BSD_USER_INTERRUPT)
+	if (gt_iir & GEN6_BSD_USER_INTERRUPT)
 		notify_ring(dev, &dev_priv->ring[VCS]);
-	if (gt_iir & GT_BLT_USER_INTERRUPT)
+	if (gt_iir & GEN6_BLITTER_USER_INTERRUPT)
 		notify_ring(dev, &dev_priv->ring[BCS]);
 
 	if (de_iir & DE_GSE_IVB)
@@ -688,7 +688,7 @@ static irqreturn_t ironlake_irq_handler(DRM_IRQ_ARGS)
 	atomic_inc(&dev_priv->irq_received);
 
 	if (IS_GEN6(dev))
-		bsd_usr_interrupt = GT_GEN6_BSD_USER_INTERRUPT;
+		bsd_usr_interrupt = GEN6_BSD_USER_INTERRUPT;
 
 	/* disable master interrupt before clearing iir  */
 	de_ier = I915_READ(DEIER);
@@ -722,7 +722,7 @@ static irqreturn_t ironlake_irq_handler(DRM_IRQ_ARGS)
 		notify_ring(dev, &dev_priv->ring[RCS]);
 	if (gt_iir & bsd_usr_interrupt)
 		notify_ring(dev, &dev_priv->ring[VCS]);
-	if (gt_iir & GT_BLT_USER_INTERRUPT)
+	if (gt_iir & GEN6_BLITTER_USER_INTERRUPT)
 		notify_ring(dev, &dev_priv->ring[BCS]);
 
 	if (de_iir & DE_GSE)
@@ -2081,8 +2081,8 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
 	if (IS_GEN6(dev))
 		render_irqs =
 			GT_USER_INTERRUPT |
-			GT_GEN6_BSD_USER_INTERRUPT |
-			GT_BLT_USER_INTERRUPT;
+			GEN6_BSD_USER_INTERRUPT |
+			GEN6_BLITTER_USER_INTERRUPT;
 	else
 		render_irqs =
 			GT_USER_INTERRUPT |
@@ -2154,8 +2154,8 @@ static int ivybridge_irq_postinstall(struct drm_device *dev)
 	I915_WRITE(GTIIR, I915_READ(GTIIR));
 	I915_WRITE(GTIMR, dev_priv->gt_irq_mask);
 
-	render_irqs = GT_USER_INTERRUPT | GT_GEN6_BSD_USER_INTERRUPT |
-		GT_BLT_USER_INTERRUPT;
+	render_irqs = GT_USER_INTERRUPT | GEN6_BSD_USER_INTERRUPT |
+		GEN6_BLITTER_USER_INTERRUPT;
 	I915_WRITE(GTIER, render_irqs);
 	POSTING_READ(GTIER);
 
@@ -2218,7 +2218,7 @@ static int valleyview_irq_postinstall(struct drm_device *dev)
 
 	render_irqs = GT_GEN6_BLT_FLUSHDW_NOTIFY_INTERRUPT |
 		GT_GEN6_BLT_CS_ERROR_INTERRUPT |
-		GT_BLT_USER_INTERRUPT |
+		GT_GEN6_BLT_USER_INTERRUPT |
 		GT_GEN6_BSD_USER_INTERRUPT |
 		GT_GEN6_BSD_CS_ERROR_INTERRUPT |
 		GT_GEN7_L3_PARITY_ERROR_INTERRUPT |

drivers/gpu/drm/i915/i915_reg.h

@@ -643,7 +643,9 @@
 #define CACHE_MODE_1		0x7004 /* IVB+ */
 #define   PIXEL_SUBSPAN_COLLECT_OPT_DISABLE (1<<6)
 
-/* GEN6 interrupt control */
+/* GEN6 interrupt control
+ * Note that the per-ring interrupt bits do alias with the global interrupt bits
+ * in GTIMR. */
 #define GEN6_RENDER_HWSTAM	0x2098
 #define GEN6_RENDER_IMR		0x20a8
 #define   GEN6_RENDER_CONTEXT_SWITCH_INTERRUPT		(1 << 8)
@@ -3203,13 +3205,15 @@
 #define DEIIR   0x44008
 #define DEIER   0x4400c
 
-/* GT interrupt */
+/* GT interrupt.
+ * Note that for gen6+ the ring-specific interrupt bits do alias with the
+ * corresponding bits in the per-ring interrupt control registers. */
 #define GT_GEN6_BLT_FLUSHDW_NOTIFY_INTERRUPT	(1 << 26)
 #define GT_GEN6_BLT_CS_ERROR_INTERRUPT		(1 << 25)
-#define GT_BLT_USER_INTERRUPT			(1 << 22)
+#define GT_GEN6_BLT_USER_INTERRUPT		(1 << 22)
 #define GT_GEN6_BSD_CS_ERROR_INTERRUPT		(1 << 15)
 #define GT_GEN6_BSD_USER_INTERRUPT		(1 << 12)
-#define GT_BSD_USER_INTERRUPT			(1 << 5)
+#define GT_BSD_USER_INTERRUPT			(1 << 5) /* ilk only */
 #define GT_GEN7_L3_PARITY_ERROR_INTERRUPT	(1 << 5)
 #define GT_PIPE_NOTIFY				(1 << 4)
 #define GT_RENDER_CS_ERROR_INTERRUPT		(1 << 3)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -788,7 +788,7 @@ ring_add_request(struct intel_ring_buffer *ring,
 }
 
 static bool
-gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
+gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 mask)
 {
 	struct drm_device *dev = ring->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
@@ -803,26 +803,26 @@ gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
 
 	spin_lock(&ring->irq_lock);
 	if (ring->irq_refcount++ == 0) {
-		ring->irq_mask &= ~rflag;
+		ring->irq_mask &= ~mask;
 		I915_WRITE_IMR(ring, ring->irq_mask);
-		ironlake_enable_irq(dev_priv, gflag);
+		ironlake_enable_irq(dev_priv, mask);
 	}
 	spin_unlock(&ring->irq_lock);
 
 	return true;
 }
 
 static void
-gen6_ring_put_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
+gen6_ring_put_irq(struct intel_ring_buffer *ring, u32 mask)
 {
 	struct drm_device *dev = ring->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 
 	spin_lock(&ring->irq_lock);
 	if (--ring->irq_refcount == 0) {
-		ring->irq_mask |= rflag;
+		ring->irq_mask |= mask;
 		I915_WRITE_IMR(ring, ring->irq_mask);
-		ironlake_disable_irq(dev_priv, gflag);
+		ironlake_disable_irq(dev_priv, mask);
 	}
 	spin_unlock(&ring->irq_lock);
 
@@ -1376,33 +1376,25 @@ gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
 static bool
 gen6_render_ring_get_irq(struct intel_ring_buffer *ring)
 {
-	return gen6_ring_get_irq(ring,
-				 GT_USER_INTERRUPT,
-				 GEN6_RENDER_USER_INTERRUPT);
+	return gen6_ring_get_irq(ring, GT_USER_INTERRUPT);
 }
 
 static void
 gen6_render_ring_put_irq(struct intel_ring_buffer *ring)
 {
-	return gen6_ring_put_irq(ring,
-				 GT_USER_INTERRUPT,
-				 GEN6_RENDER_USER_INTERRUPT);
+	return gen6_ring_put_irq(ring, GT_USER_INTERRUPT);
 }
 
 static bool
 gen6_bsd_ring_get_irq(struct intel_ring_buffer *ring)
 {
-	return gen6_ring_get_irq(ring,
-				 GT_GEN6_BSD_USER_INTERRUPT,
-				 GEN6_BSD_USER_INTERRUPT);
+	return gen6_ring_get_irq(ring, GEN6_BSD_USER_INTERRUPT);
 }
 
 static void
 gen6_bsd_ring_put_irq(struct intel_ring_buffer *ring)
 {
-	return gen6_ring_put_irq(ring,
-				 GT_GEN6_BSD_USER_INTERRUPT,
-				 GEN6_BSD_USER_INTERRUPT);
+	return gen6_ring_put_irq(ring, GEN6_BSD_USER_INTERRUPT);
 }
 
 /* ring buffer for Video Codec for Gen6+ */
@@ -1431,17 +1423,13 @@ static const struct intel_ring_buffer gen6_bsd_ring = {
 static bool
 blt_ring_get_irq(struct intel_ring_buffer *ring)
 {
-	return gen6_ring_get_irq(ring,
-				 GT_BLT_USER_INTERRUPT,
-				 GEN6_BLITTER_USER_INTERRUPT);
+	return gen6_ring_get_irq(ring, GEN6_BLITTER_USER_INTERRUPT);
 }
 
 static void
 blt_ring_put_irq(struct intel_ring_buffer *ring)
 {
-	gen6_ring_put_irq(ring,
-			  GT_BLT_USER_INTERRUPT,
-			  GEN6_BLITTER_USER_INTERRUPT);
+	gen6_ring_put_irq(ring, GEN6_BLITTER_USER_INTERRUPT);
 }
 
 static int blt_ring_flush(struct intel_ring_buffer *ring,