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Commit ed2f3452 authored by Chris Wilson's avatar Chris Wilson Committed by Daniel Vetter
Browse files

drm/i915: Avoid clearing preallocated regions from the GTT 



As yet we do not do any preallocation (chicken-and-egg problem), but we
may like to preserve anything already allocated by the BIOS or grub and
reuse for own purposes after initialising the driver.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: default avatarBen Widawsky <ben@bwidawsk.net>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent e12a2d53

drivers/gpu/drm/i915/i915_drv.h

+2 −0
Original line number Diff line number Diff line
@@ -935,6 +935,8 @@ enum i915_cache_level { 
	I915_CACHE_LLC_MLC, /* gen6+, in docs at least! */

};



#define I915_GTT_RESERVED ((struct drm_mm_node *)0x1)



struct drm_i915_gem_object_ops {

	/* Interface between the GEM object and its backing storage.

	 * get_pages() is called once prior to the use of the associated set

drivers/gpu/drm/i915/i915_gem_gtt.c

+29 −3
Original line number Diff line number Diff line
@@ -531,20 +531,46 @@ void i915_gem_init_global_gtt(struct drm_device *dev, 
			      unsigned long end)

{

	drm_i915_private_t *dev_priv = dev->dev_private;

	struct drm_mm_node *entry;

	struct drm_i915_gem_object *obj;

	unsigned long hole_start, hole_end;



	/* Substract the guard page ... */

	/* Subtract the guard page ... */

	drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);

	if (!HAS_LLC(dev))

		dev_priv->mm.gtt_space.color_adjust = i915_gtt_color_adjust;



	/* Mark any preallocated objects as occupied */

	list_for_each_entry(obj, &dev_priv->mm.bound_list, gtt_list) {

		DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",

			      obj->gtt_offset, obj->base.size);



		BUG_ON(obj->gtt_space != I915_GTT_RESERVED);

		obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,

						     obj->gtt_offset,

						     obj->base.size,

						     false);

		obj->has_global_gtt_mapping = 1;

	}



	dev_priv->mm.gtt_start = start;

	dev_priv->mm.gtt_mappable_end = mappable_end;

	dev_priv->mm.gtt_end = end;

	dev_priv->mm.gtt_total = end - start;

	dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start;



	/* ... but ensure that we clear the entire range. */

	i915_ggtt_clear_range(dev, start / PAGE_SIZE, (end-start) / PAGE_SIZE);

	/* Clear any non-preallocated blocks */

	drm_mm_for_each_hole(entry, &dev_priv->mm.gtt_space,

			     hole_start, hole_end) {

		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",

			      hole_start, hole_end);

		i915_ggtt_clear_range(dev,

				      hole_start / PAGE_SIZE,

				      (hole_end-hole_start) / PAGE_SIZE);

	}



	/* And finally clear the reserved guard page */

	i915_ggtt_clear_range(dev, end / PAGE_SIZE - 1, 1);

}



static int setup_scratch_page(struct drm_device *dev)