drm/i915: Rearrange code to only have a single method for waiting upon the ring

Replace the wait for the ring to be clear with the more common wait for
the ring to be idle. The principle advantage is one less exported
intel_ring_wait function, and the removal of a hardcoded value.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -592,10 +592,8 @@ static int i915_dispatch_flip(struct drm_device * dev)
 
 static int i915_quiescent(struct drm_device *dev)
 {
-	struct intel_ring_buffer *ring = LP_RING(dev->dev_private);
-
 	i915_kernel_lost_context(dev);
-	return intel_wait_ring_idle(ring);
+	return intel_ring_idle(LP_RING(dev->dev_private));
 }
 
 static int i915_flush_ioctl(struct drm_device *dev, void *data,

drivers/gpu/drm/i915/i915_gem.c

@@ -2480,29 +2480,6 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 	return 0;
 }
 
-static int i915_ring_idle(struct intel_ring_buffer *ring)
-{
-	u32 seqno;
-	int ret;
-
-	/* We need to add any requests required to flush the objects and ring */
-	if (ring->outstanding_lazy_request) {
-		ret = i915_add_request(ring, NULL, NULL);
-		if (ret)
-			return ret;
-	}
-
-	/* Wait upon the last request to be completed */
-	if (list_empty(&ring->request_list))
-		return 0;
-
-	seqno = list_entry(ring->request_list.prev,
-			   struct drm_i915_gem_request,
-			   list)->seqno;
-
-	return i915_wait_seqno(ring, seqno);
-}
-
 int i915_gpu_idle(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
@@ -2515,7 +2492,7 @@ int i915_gpu_idle(struct drm_device *dev)
 		if (ret)
 			return ret;
 
-		ret = i915_ring_idle(ring);
+		ret = intel_ring_idle(ring);
 		if (ret)
 			return ret;
 	}

drivers/gpu/drm/i915/intel_pm.c

@@ -2653,6 +2653,7 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_ring_buffer *ring = &dev_priv->ring[RCS];
+	bool was_interruptible;
 	int ret;
 
 	/* rc6 disabled by default due to repeated reports of hanging during
@@ -2667,6 +2668,9 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	if (ret)
 		return;
 
+	was_interruptible = dev_priv->mm.interruptible;
+	dev_priv->mm.interruptible = false;
+
 	/*
 	 * GPU can automatically power down the render unit if given a page
 	 * to save state.
@@ -2674,6 +2678,7 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	ret = intel_ring_begin(ring, 6);
 	if (ret) {
 		ironlake_teardown_rc6(dev);
+		dev_priv->mm.interruptible = was_interruptible;
 		return;
 	}
 
@@ -2694,7 +2699,8 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	 * does an implicit flush, combined with MI_FLUSH above, it should be
 	 * safe to assume that renderctx is valid
 	 */
-	ret = intel_wait_ring_idle(ring);
+	ret = intel_ring_idle(ring);
+	dev_priv->mm.interruptible = was_interruptible;
 	if (ret) {
 		DRM_ERROR("failed to enable ironlake power power savings\n");
 		ironlake_teardown_rc6(dev);

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1175,7 +1175,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 
 	/* Disable the ring buffer. The ring must be idle at this point */
 	dev_priv = ring->dev->dev_private;
-	ret = intel_wait_ring_idle(ring);
+	ret = intel_ring_idle(ring);
 	if (ret)
 		DRM_ERROR("failed to quiesce %s whilst cleaning up: %d\n",
 			  ring->name, ret);
@@ -1194,28 +1194,6 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 	cleanup_status_page(ring);
 }
 
-static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
-{
-	uint32_t __iomem *virt;
-	int rem = ring->size - ring->tail;
-
-	if (ring->space < rem) {
-		int ret = intel_wait_ring_buffer(ring, rem);
-		if (ret)
-			return ret;
-	}
-
-	virt = ring->virtual_start + ring->tail;
-	rem /= 4;
-	while (rem--)
-		iowrite32(MI_NOOP, virt++);
-
-	ring->tail = 0;
-	ring->space = ring_space(ring);
-
-	return 0;
-}
-
 static int intel_ring_wait_seqno(struct intel_ring_buffer *ring, u32 seqno)
 {
 	int ret;
@@ -1284,7 +1262,7 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
 	return 0;
 }
 
-int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n)
+static int ring_wait_for_space(struct intel_ring_buffer *ring, int n)
 {
 	struct drm_device *dev = ring->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1327,6 +1305,51 @@ int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n)
 	return -EBUSY;
 }
 
+static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
+{
+	uint32_t __iomem *virt;
+	int rem = ring->size - ring->tail;
+
+	if (ring->space < rem) {
+		int ret = ring_wait_for_space(ring, rem);
+		if (ret)
+			return ret;
+	}
+
+	virt = ring->virtual_start + ring->tail;
+	rem /= 4;
+	while (rem--)
+		iowrite32(MI_NOOP, virt++);
+
+	ring->tail = 0;
+	ring->space = ring_space(ring);
+
+	return 0;
+}
+
+int intel_ring_idle(struct intel_ring_buffer *ring)
+{
+	u32 seqno;
+	int ret;
+
+	/* We need to add any requests required to flush the objects and ring */
+	if (ring->outstanding_lazy_request) {
+		ret = i915_add_request(ring, NULL, NULL);
+		if (ret)
+			return ret;
+	}
+
+	/* Wait upon the last request to be completed */
+	if (list_empty(&ring->request_list))
+		return 0;
+
+	seqno = list_entry(ring->request_list.prev,
+			   struct drm_i915_gem_request,
+			   list)->seqno;
+
+	return i915_wait_seqno(ring, seqno);
+}
+
 static int
 intel_ring_alloc_seqno(struct intel_ring_buffer *ring)
 {
@@ -1359,7 +1382,7 @@ int intel_ring_begin(struct intel_ring_buffer *ring,
 	}
 
 	if (unlikely(ring->space < n)) {
-		ret = intel_wait_ring_buffer(ring, n);
+		ret = ring_wait_for_space(ring, n);
 		if (unlikely(ret))
 			return ret;
 	}

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -187,22 +187,15 @@ intel_read_status_page(struct intel_ring_buffer *ring,
 
 void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring);
 
-int __must_check intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n);
-static inline int intel_wait_ring_idle(struct intel_ring_buffer *ring)
-{
-	return intel_wait_ring_buffer(ring, ring->size - 8);
-}
-
 int __must_check intel_ring_begin(struct intel_ring_buffer *ring, int n);
-
 static inline void intel_ring_emit(struct intel_ring_buffer *ring,
 				   u32 data)
 {
 	iowrite32(data, ring->virtual_start + ring->tail);
 	ring->tail += 4;
 }
-
 void intel_ring_advance(struct intel_ring_buffer *ring);
+int __must_check intel_ring_idle(struct intel_ring_buffer *ring);
 
 int intel_ring_flush_all_caches(struct intel_ring_buffer *ring);
 int intel_ring_invalidate_all_caches(struct intel_ring_buffer *ring);