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Commit a61007a8 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Fix partial GGTT faulting 



We want to always use the partial VMA as a fallback for a failure to
bind the object into the GGTT. This extends the support partial objects
in the GGTT to cover everything, not just objects too large.

v2: Call the partial view, view not partial.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-23-chris@chris-wilson.co.uk
parent 03af84fe

drivers/gpu/drm/i915/i915_gem.c

+30 −31
Original line number Diff line number Diff line
@@ -1702,7 +1702,6 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) 
	struct drm_device *dev = obj->base.dev;

	struct drm_i915_private *dev_priv = to_i915(dev);

	struct i915_ggtt *ggtt = &dev_priv->ggtt;

	struct i915_ggtt_view view = i915_ggtt_view_normal;

	bool write = !!(vmf->flags & FAULT_FLAG_WRITE);

	struct i915_vma *vma;

	pgoff_t page_offset;
@@ -1736,11 +1735,14 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) 
		goto err_unlock;

	}



	/* Use a partial view if the object is bigger than the aperture. */

	if (obj->base.size >= ggtt->mappable_end &&

	    !i915_gem_object_is_tiled(obj)) {

	/* Now pin it into the GTT as needed */

	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,

				       PIN_MAPPABLE | PIN_NONBLOCK);

	if (IS_ERR(vma)) {

		struct i915_ggtt_view view;

		unsigned int chunk_size;



		/* Use a partial view if it is bigger than available space */

		chunk_size = MIN_CHUNK_PAGES;

		if (i915_gem_object_is_tiled(obj))

			chunk_size = max(chunk_size, tile_row_pages(obj));
@@ -1749,14 +1751,12 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) 
		view.type = I915_GGTT_VIEW_PARTIAL;

		view.params.partial.offset = rounddown(page_offset, chunk_size);

		view.params.partial.size =

			min_t(unsigned int,

			      chunk_size,

			min_t(unsigned int, chunk_size,

			      (area->vm_end - area->vm_start) / PAGE_SIZE -

			      view.params.partial.offset);

	}



	/* Now pin it into the GTT if needed */

		vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, PIN_MAPPABLE);

	}

	if (IS_ERR(vma)) {

		ret = PTR_ERR(vma);

		goto err_unlock;
@@ -1774,26 +1774,7 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) 
	pfn = ggtt->mappable_base + i915_ggtt_offset(vma);

	pfn >>= PAGE_SHIFT;



	if (unlikely(view.type == I915_GGTT_VIEW_PARTIAL)) {

		/* Overriding existing pages in partial view does not cause

		 * us any trouble as TLBs are still valid because the fault

		 * is due to userspace losing part of the mapping or never

		 * having accessed it before (at this partials' range).

		 */

		unsigned long base = area->vm_start +

				     (view.params.partial.offset << PAGE_SHIFT);

		unsigned int i;



		for (i = 0; i < view.params.partial.size; i++) {

			ret = vm_insert_pfn(area,

					    base + i * PAGE_SIZE,

					    pfn + i);

			if (ret)

				break;

		}



		obj->fault_mappable = true;

	} else {

	if (vma->ggtt_view.type == I915_GGTT_VIEW_NORMAL) {

		if (!obj->fault_mappable) {

			unsigned long size =

				min_t(unsigned long,
@@ -1809,13 +1790,31 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf) 
				if (ret)

					break;

			}



			obj->fault_mappable = true;

		} else

			ret = vm_insert_pfn(area,

					    (unsigned long)vmf->virtual_address,

					    pfn + page_offset);

	} else {

		/* Overriding existing pages in partial view does not cause

		 * us any trouble as TLBs are still valid because the fault

		 * is due to userspace losing part of the mapping or never

		 * having accessed it before (at this partials' range).

		 */

		const struct i915_ggtt_view *view = &vma->ggtt_view;

		unsigned long base = area->vm_start +

			(view->params.partial.offset << PAGE_SHIFT);

		unsigned int i;



		for (i = 0; i < view->params.partial.size; i++) {

			ret = vm_insert_pfn(area,

					    base + i * PAGE_SIZE,

					    pfn + i);

			if (ret)

				break;

		}

	}



	obj->fault_mappable = true;

err_unpin:

	__i915_vma_unpin(vma);

err_unlock: