[PATCH 35/66] drm/i915: Exercise filling the top/bottom portions of the ppgtt

[Chris Wilson]

Allocate objects with varying number of pages (which should hopefully
consist of a mixture of contiguous page chunks and so coalesced sg
lists) and check that the sg walkers in insert_pages cope.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 174 ++++++++++++++++++++++++++
 1 file changed, 174 insertions(+)

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 2559600c4755..98c23a585ed3 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -22,7 +22,11 @@
  *
  */
 
+#include <linux/prime_numbers.h>
+
 #include "i915_selftest.h"
+#include "mock_drm.h"
+#include "huge_gem_object.h"
 
 static int igt_ppgtt_alloc(void *arg)
 {
@@ -87,10 +91,180 @@ static int igt_ppgtt_alloc(void *arg)
 	return err;
 }
 
+static void close_object_list(struct list_head *objects,
+			      struct i915_address_space *vm)
+{
+	struct drm_i915_gem_object *obj, *on;
+
+	list_for_each_entry_safe(obj, on, objects, batch_pool_link) {
+		struct i915_vma *vma;
+
+		vma = i915_vma_instance(obj, vm, NULL);
+		if (!IS_ERR(vma))
+			i915_vma_close(vma);
+
+		list_del(&obj->batch_pool_link);
+		i915_gem_object_put(obj);
+	}
+}
+
+static int fill_hole(struct drm_i915_private *i915,
+		     struct i915_address_space *vm,
+		     u64 hole_start, u64 hole_end,
+		     unsigned long end_time)
+{
+	const u64 hole_size = hole_end - hole_start;
+	struct drm_i915_gem_object *obj;
+	const unsigned long max_pages =
+		min_t(u64, 1 << 20, hole_size/2 >> PAGE_SHIFT);
+	unsigned long npages, prime;
+	struct i915_vma *vma;
+	LIST_HEAD(objects);
+	int err;
+
+	for_each_prime_number_from(prime, 2, 13) {
+		for (npages = 1; npages <= max_pages; npages *= prime) {
+			const u64 full_size = npages << PAGE_SHIFT;
+			const struct {
+				u64 base;
+				s64 step;
+				const char *name;
+			} phases[] = {
+				{
+					(hole_end - full_size) | PIN_OFFSET_FIXED | PIN_USER,
+					-full_size,
+					"top-down",
+				},
+				{
+					hole_start | PIN_OFFSET_FIXED | PIN_USER,
+					full_size,
+					"bottom-up",
+				},
+				{ }
+			}, *p;
+
+			GEM_BUG_ON(!full_size);
+			obj = huge_gem_object(i915, PAGE_SIZE, full_size);
+			if (IS_ERR(obj))
+				break;
+
+			list_add(&obj->batch_pool_link, &objects);
+
+			/* Align differing sized objects against the edges, and
+			 * check we don't walk off into the void when binding
+			 * them into the GTT.
+			 */
+			for (p = phases; p->name; p++) {
+				u64 flags;
+
+				flags = p->base;
+				list_for_each_entry(obj, &objects, batch_pool_link) {
+					vma = i915_vma_instance(obj, vm, NULL);
+					if (IS_ERR(vma))
+						continue;
+
+					err = i915_vma_pin(vma, 0, 0, flags);
+					if (err) {
+						pr_err("Fill %s pin failed with err=%d on size=%lu pages (prime=%lu), flags=%llx\n", p->name, err, npages, prime, flags);
+						goto err;
+					}
+
+					i915_vma_unpin(vma);
+
+					flags += p->step;
+					if (flags < hole_start ||
+					    flags > hole_end)
+						break;
+				}
+
+				flags = p->base;
+				list_for_each_entry(obj, &objects, batch_pool_link) {
+					vma = i915_vma_instance(obj, vm, NULL);
+					if (IS_ERR(vma))
+						continue;
+
+					if (!drm_mm_node_allocated(&vma->node) ||
+					    i915_vma_misplaced(vma, 0, 0, flags)) {
+						pr_err("Fill %s moved vma.node=%llx + %llx, expected offset %llx\n",
+						       p->name, vma->node.start, vma->node.size,
+						       flags & PAGE_MASK);
+						err = -EINVAL;
+						goto err;
+					}
+
+					err = i915_vma_unbind(vma);
+					if (err) {
+						pr_err("Fill %s unbind of vma.node=%llx + %llx failed with err=%d\n",
+						       p->name, vma->node.start, vma->node.size,
+						       err);
+						goto err;
+					}
+
+					flags += p->step;
+					if (flags < hole_start ||
+					    flags > hole_end)
+						break;
+				}
+			}
+
+			if (igt_timeout(end_time, "Fill timed out (npages=%lu, prime=%lu)\n",
+					npages, prime)) {
+				err = -EINTR;
+				goto err;
+			}
+		}
+
+		close_object_list(&objects, vm);
+	}
+
+	return 0;
+
+err:
+	close_object_list(&objects, vm);
+	return err;
+}
+
+static int igt_ppgtt_fill(void *arg)
+{
+	struct drm_i915_private *dev_priv = arg;
+	struct drm_file *file;
+	struct i915_hw_ppgtt *ppgtt;
+	IGT_TIMEOUT(end_time);
+	int err;
+
+	/* Try binding many VMA working outwards from either edge */
+
+	if (!USES_FULL_PPGTT(dev_priv))
+		return 0;
+
+	file = mock_file(dev_priv);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	ppgtt = i915_ppgtt_create(dev_priv, file->driver_priv, "mock");
+	if (IS_ERR(ppgtt)) {
+		err = PTR_ERR(ppgtt);
+		goto out_unlock;
+	}
+	GEM_BUG_ON(offset_in_page(ppgtt->base.total));
+
+	err = fill_hole(dev_priv, &ppgtt->base, 0, ppgtt->base.total, end_time);
+
+	i915_ppgtt_close(&ppgtt->base);
+	i915_ppgtt_put(ppgtt);
+out_unlock:
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+
+	mock_file_free(dev_priv, file);
+	return err;
+}
+
 int i915_gem_gtt_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
 		SUBTEST(igt_ppgtt_alloc),
+		SUBTEST(igt_ppgtt_fill),
 	};
 
 	return i915_subtests(tests, i915);
-- 
2.11.0