[PATCH 07/14] drm/i915: Preferentially allocate mappable GTT space to uncached bo

[Chris Wilson <chris@chris-wilson.co.uk>]

Both to reduce GTT wastage due to intermingling colouring and to
reduce the number of cached bo allocated in the mappable aperture.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c         |   13 +++++++++----
 drivers/gpu/drm/i915/intel_ringbuffer.c |   13 +++++++++----
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ec07f33..86d549b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2898,6 +2898,7 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_mm_node *free_space;
 	u32 size, fence_size, fence_alignment, unfenced_alignment;
+	unsigned search;
 	bool mappable, fenceable;
 	int ret;
 
@@ -2937,16 +2938,20 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 
 	i915_gem_object_pin_pages(obj);
 
+	search = 0;
+	if (obj->cache_level != I915_CACHE_NONE && !map_and_fenceable)
+		search |= DRM_MM_SEARCH_BELOW;
+
  search_free:
 	if (map_and_fenceable)
 		free_space = drm_mm_search_free_in_range_color(&dev_priv->mm.gtt_space,
 							       size, alignment, obj->cache_level,
 							       0, dev_priv->mm.gtt_mappable_end,
-							       false);
+							       search);
 	else
 		free_space = drm_mm_search_free_color(&dev_priv->mm.gtt_space,
 						      size, alignment, obj->cache_level,
-						      false);
+						      search);
 
 	if (free_space != NULL) {
 		if (map_and_fenceable)
@@ -2954,12 +2959,12 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 				drm_mm_get_block_range_generic(free_space,
 							       size, alignment, obj->cache_level,
 							       0, dev_priv->mm.gtt_mappable_end,
-							       0);
+							       search);
 		else
 			free_space =
 				drm_mm_get_block_generic(free_space,
 							 size, alignment, obj->cache_level,
-							 0);
+							 search);
 	}
 	if (free_space == NULL) {
 		ret = i915_gem_evict_something(dev, size, alignment,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 36e1e13a..c06d528 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -458,10 +458,13 @@ init_pipe_control(struct intel_ring_buffer *ring)
 
 	i915_gem_object_set_cache_level(obj, I915_CACHE_LLC);
 
-	ret = i915_gem_object_pin(obj, 4096, true, false);
+	ret = i915_gem_object_pin(obj, 4096, false, false);
 	if (ret)
 		goto err_unref;
 
+	if (!obj->has_global_gtt_mapping)
+		i915_gem_gtt_bind_object(obj, obj->cache_level);
+
 	pc->gtt_offset = obj->gtt_offset;
 	pc->cpu_page =  kmap(sg_page(obj->pages->sgl));
 	if (pc->cpu_page == NULL)
@@ -1036,10 +1039,12 @@ static int init_status_page(struct intel_ring_buffer *ring)
 
 	i915_gem_object_set_cache_level(obj, I915_CACHE_LLC);
 
-	ret = i915_gem_object_pin(obj, 4096, true, false);
-	if (ret != 0) {
+	ret = i915_gem_object_pin(obj, 4096, false, false);
+	if (ret != 0)
 		goto err_unref;
-	}
+
+	if (!obj->has_global_gtt_mapping)
+		i915_gem_gtt_bind_object(obj, obj->cache_level);
 
 	ring->status_page.gfx_addr = obj->gtt_offset;
 	ring->status_page.page_addr = kmap(sg_page(obj->pages->sgl));
-- 
1.7.10.4