drm/i915: Not all mappable regions require GTT fence regions
Combining map_and_fenceable revealed a bug in
i915_gem_object_gtt_size() in that it always computed the appropriate
fence size for the object regardless of tiling state which caused us to
over-allocate linear buffers when binding to the GTT.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d196895..8e3f1de 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -41,9 +41,6 @@
uint32_t flush_rings;
};
-static uint32_t i915_gem_get_gtt_alignment(struct drm_i915_gem_object *obj);
-static uint32_t i915_gem_get_gtt_size(struct drm_i915_gem_object *obj);
-
static int i915_gem_object_flush_gpu_write_domain(struct drm_i915_gem_object *obj,
bool pipelined);
static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj);
@@ -1443,6 +1440,28 @@
list->map = NULL;
}
+static uint32_t
+i915_gem_get_gtt_size(struct drm_i915_gem_object *obj)
+{
+ struct drm_device *dev = obj->base.dev;
+ uint32_t size;
+
+ if (INTEL_INFO(dev)->gen >= 4 ||
+ obj->tiling_mode == I915_TILING_NONE)
+ return obj->base.size;
+
+ /* Previous chips need a power-of-two fence region when tiling */
+ if (INTEL_INFO(dev)->gen == 3)
+ size = 1024*1024;
+ else
+ size = 512*1024;
+
+ while (size < obj->base.size)
+ size <<= 1;
+
+ return size;
+}
+
/**
* i915_gem_get_gtt_alignment - return required GTT alignment for an object
* @obj: object to check
@@ -1505,34 +1524,6 @@
return tile_height * obj->stride * 2;
}
-static uint32_t
-i915_gem_get_gtt_size(struct drm_i915_gem_object *obj)
-{
- struct drm_device *dev = obj->base.dev;
- uint32_t size;
-
- /*
- * Minimum alignment is 4k (GTT page size), but might be greater
- * if a fence register is needed for the object.
- */
- if (INTEL_INFO(dev)->gen >= 4)
- return obj->base.size;
-
- /*
- * Previous chips need to be aligned to the size of the smallest
- * fence register that can contain the object.
- */
- if (INTEL_INFO(dev)->gen == 3)
- size = 1024*1024;
- else
- size = 512*1024;
-
- while (size < obj->base.size)
- size <<= 1;
-
- return size;
-}
-
/**
* i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
* @dev: DRM device